HICNet Medical News Digest Wed, 15 Jun 1994 Volume 07 : Issue 26 Today's Topics: [MMWR 10 June 94] Risky Driving Behaviors Among Teenagers [MMWR] Birth Outcomes Following Zidovudine Use in Pregnant Women [MMWR] Multidrug-Resistant Tuberculosis in a Hospital [MMWR] Atlanta Conference on Human Health and the Environment Boning Up: New Ways to Prevent Fractures in Older Americans Vaccine Slows Gum Disease An Unexpected Window on High Blood Pressure Institute of Tropical Medicine Epidemiological Bulletin +------------------------------------------------+ ! ! ! Health Info-Com Network ! ! Medical Newsletter ! +------------------------------------------------+ Editor: David Dodell, D.M.D. 10250 North 92nd Street, Suite 210, Scottsdale, Arizona 85258-4599 USA Telephone +1 (602) 860-1121 FAX +1 (602) 451-1165 Internet: mednews@stat.com Bitnet: ATW1H@ASUACAD Compilation Copyright 1994 by David Dodell, D.M.D. All rights Reserved. License is hereby granted to republish on electronic media for which no fees are charged, so long as the text of this copyright notice and license are attached intact to any and all republished portion or portions. The Health Info-Com Network Newsletter is distributed biweekly. Articles on a medical nature are welcomed. If you have an article, please contact the editor for information on how to submit it. If you are interested in joining the automated distribution system, please contact the editor. Associate Editors: E. Loren Buhle, Jr. Ph.D. Dept. of Radiation Oncology, Univ of Pennsylvania Tom Whalen, M.D., Robert Wood Johnson Medical School at Camden Douglas B. Hanson, Ph.D., Forsyth Dental Center, Boston, MA Lawrence Lee Miller, B.S. Biological Sciences, UCI Dr K C Lun, National University Hospital, Singapore W. Scott Erdley, MS, RN, SUNY@UB School of Nursing Jack E. Cross, B.S Health Care Admin, 882 Medical Trng Grp, USAF Albert Shar, Ph.D. CIO, Associate Prof, Univ of Penn School of Medicine Martin I. Herman, M.D., LeBonheur Children's Medical Center, Memphis TN Stephen Cristol, M.D., Dept of Ophthalmology, Emory Univ, Atlanta, GA Subscription Requests = mednews@stat.com anonymous ftp = vm1.nodak.edu; directory HICNEWS FAX Delivery = Contact Editor for information ---------------------------------------------------------------------- Date: Wed, 15 Jun 94 06:42:02 MST From: mednews (HICNet Medical News) To: hicnews Subject: [MMWR 10 June 94] Risky Driving Behaviors Among Teenagers Message-ID: Risky Driving Behaviors Among Teenagers -- Gwinnett County, Georgia, 1993 In the United States in 1991, approximately 6000 persons aged 16-20 years died from motor-vehicle crashes (MVCs)--twice as many as from any other cause of death among persons in this age group (1). During 1991, approximately 3000 crashes in Gwinnett County, Georgia (1990 population: 352,910) (26% of all crashes in Gwinnett County), involved at least one teenage driver (Gwinnett County Department of Transportation, unpublished data, 1992). Risky driving behaviors are among the risk factors for teenage MVC death and injury (2). To better characterize these risk factors, the Georgia Department of Human Resources, the Gwinnett County Board of Health, the community-based Gwinnett County Teen Traffic Tragedies Task Force, and CDC conducted a case-control study of MVCs among teenage drivers in Gwinnett County during 1993. This report summarizes the results of that study. To be eligible for the study, a person must have been aged 16- 19 years, a licensed driver, and enrolled in a Gwinnett County public high school. Case-students (n=64) had been involved as drivers in injury-producing MVCs during January-March 1993 according to Police Accident Reports filed with the Gwinnett County Department of Transportation. Control-students (n=227) were randomly selected from enrollment files of Gwinnett County public high schools; these students had never been involved in a police-reported crash, were aged 16-19 years, and were licensed drivers. Participants completed a written questionnaire in which they specified how often they had engaged in 11 potentially risky driving behaviors during the 3 months preceding the survey (Table 1). Questions were adapted from a survey on risky driving behavior (3). Possible responses were "never," "one to two times," "three to five times," and "six or more times." The chi-square test was used to assist in assessing associations between behaviors and risk for MVCs. Three behaviors that appeared to be associated with MVCs and two additional behaviors thought to be potentially life-threatening were analyzed further by stratifying by sex. For seven of the 11 risky behaviors, at least 50% of both cases and controls reported engaging in the behaviors at least once during the 3 months preceding the survey. For example, at least once during the 3 months preceding the survey, 63% of all respondents reported tailgating, 80% reported driving 20 miles per hour (mph) over the speed limit, and 91% reported entering an intersection when the light was about to turn red. Twenty-six percent of all students surveyed reported passing in a no-passing zone, and 21% reported passing two to three cars at once on a two-lane road. When cases and controls were compared, three behaviors appeared to be associated with risk for MVCs: driving 20 mph over the speed limit (p=0.06), passing a car in a no-passing zone (p=0.06), and taking risks while driving in traffic because it makes driving more fun (p=0.07). For these behaviors, differences were greatest for those who reported engaging in the behaviors six or more times during the 3 months preceding the survey (Table 1). At this level, 28 (44%) cases and 65 (29%) controls reported driving 20 mph over the speed limit; five (8%) cases and nine (4%) controls reported passing a car in a no-passing zone; and 12 (19%) cases and 18 (8%) controls reported taking some risks while driving in traffic because it makes driving more fun. Compared with male controls and all females, male cases were more likely to drive 20 mph over the speed limit (p=0.02), pass a car in a no-passing zone (p=0.05), take driving risks for fun (p=0.04), and pass two to three cars at once on a two-lane road (p=0.09) (Table 2). Reported by: Gwinnett County Teen Traffic Tragedies Task Force; JC Crutcher, MD, Gwinnett County Board of Health; G Black, P Campbell, Gwinnett County Dept of Transportation, Lawrenceville; JD Smith, K Toomey, MD, State Epidemiologist, Georgia Dept of Human Resources. Div of Unintentional Injury Prevention, Div of Acute Care and Rehabilitation Research and Disability Prevention, Office of Statistics, Programming, and Graphics, National Center for Injury Prevention and Control, CDC. Editorial Note: Young drivers account disproportionately for MVCs worldwide (4), reflecting, in part, the combination of immaturity and lack of driving experience (5). Adolescent drivers are more likely than adult drivers to report speeding, running red lights, making illegal turns, not wearing safety belts, riding with an intoxicated driver, and driving after using drugs or alcohol (6). In the Gwinnett County study, most students--regardless of whether they were cases or controls--reported engaging in risky driving behaviors. Parents should recognize that driving is a complex task that can take several years to master and can assist in reducing the risk for MVCs among adolescent drivers by 1) providing young drivers a longer period of supervised driving in low-risk settings (e.g., with supervision, during daylight, and in safe environments) in addition to traditional driver's education courses, 2) serving as role models by practicing good driving behaviors and always obeying traffic laws, and 3) requiring all family members to be properly restrained each time they ride in a motor vehicle. The findings in this report are subject to at least five limitations. First, because respondents were students who were licensed drivers enrolled in public schools, the study did not include students in private schools, youth not enrolled in school, and drivers with learners' permits. Second, because the study assessed only MVCs that occurred during January-March 1993, the effects of seasonal trends could not be analyzed. Third, the study did not include MVCs that resulted only in property damage or were not reported to the police. Fourth, other potential risk factors (e.g., alcohol use) were not analyzed in this report, although they were included in the study. Finally, the analysis of findings in this case-control study was influenced by the high prevalences of risky behaviors among members of both the case and control groups. Graduated driver licensing is one strategy for promoting safe driving behaviors and reducing the incidence and severity of MVCs among young drivers. This method allows new drivers to accumulate driving experience in low-risk settings and gradually lifts restrictions until an unrestricted license is earned (7). In addition, because up to 24 months may be required to obtain an unrestricted license, drivers are older and more mature when they become fully licensed. Driving restrictions may include prohibiting unsupervised nighttime driving, requiring zero or near-zero blood alcohol concentration, requiring all occupants to be properly restrained, and limiting the number of passengers and the distances and types of roads traveled. The threshold for corrective action (e.g., a lengthened restriction period) may be lower for restricted drivers than for unrestricted drivers. Graduated licensing systems have been instituted in Australia, New Zealand, and Ontario, Canada. Although this system has not been implemented in the United States, the National Highway Traffic Safety Administration is providing funds to states to evaluate the impact of various elements of the graduated licensing system. The Gwinnett County Teen Traffic Tragedies Task Force is planning to use findings from this study to assist in developing and targeting specific intervention strategies for reducing MVC injuries and deaths among young drivers. References 1. National Highway Traffic Safety Administration. Fatal Accident Reporting System, 1991: a review of information on fatal traffic crashes in the United States. Washington, DC: US Department of Transportation, National Highway Traffic Safety Administration, 1992. 2. Insurance Institute for Highway Safety. Teenage drivers: questions and answers. Arlington, Virginia: Insurance Institute for Highway Safety, 1993. 3. Donovan JE, Jessor R. Young adult driving questionnaire. Boulder, Colorado: University of Colorado Institute of Behavioral Science, 1992. 4. Evans L. Traffic safety and the driver. New York: Van Nostrand Reinhold, 1991. 5. Mayhew DR, Simpson HM. New to the road: young drivers and novice drivers: similar problems and solutions? Ottawa: Traffic Injury Research Foundation of Canada, 1991. 6. Hingson R, Howland J. Promoting safety in adolescents. In: Millstein SG, Petersen AC, Nightingale EO, eds. Promoting the health of adolescents: new directions for the twenty-first century. New York: Oxford University Press, 1993. 7. Insurance Institute for Highway Safety. Slower graduation to full licensing means fewer teenage deaths. In: Status report. Arlington, Virginia: Insurance Institute for Highway Safety 1994;29(4):1-3. ------------------------------ Date: Wed, 15 Jun 94 06:43:06 MST From: mednews (HICNet Medical News) To: hicnews Subject: [MMWR] Birth Outcomes Following Zidovudine Use in Pregnant Women Message-ID: Birth Outcomes Following Zidovudine Therapy in Pregnant Women Approximately 100,000 childbearing-aged women in the United States are infected with human immunodeficiency virus (HIV), and an estimated 7000 infants are born to HIV-positive mothers each year (1). In the United States, the rate of perinatal transmission of HIV among mothers who do not receive antiretroviral therapy is 15%- 30% (2). Results from a recent multicenter randomized double-blind clinical trial suggest that treatment of HIV-positive mothers and their infants with zidovudine (ZDV) may substantially reduce the risk for perinatal HIV transmission (3). However, any potential risk for adverse outcomes associated with use of antiretrovirals during pregnancy should be considered. This report summarizes data from the Antiretroviral Pregnancy Registry regarding use of ZDV and the occurrence of structural birth defects reported for pregnancies registered during January 1989-December 1993. In January 1989, the Zidovudine in Pregnancy Registry was established by the Wellcome Foundation, in conjunction with CDC, and has been managed by the Burroughs Wellcome Co. (Research Triangle Park, North Carolina),* the manufacturer of ZDV. In January 1993, the Zidovudine in Pregnancy Registry was expanded to include zalcitabine and became the Antiretroviral Pregnancy Registry. Although ZDV is not yet approved for use during pregnancy, physicians and other health professionals have provided to the registry reports of women who received antiretroviral therapy during pregnancy. The purpose of the worldwide registry is to measure the incidence of infants with structural defects among prospectively registered cases (i.e., those registered predelivery) and to monitor potential patterns of defects by collecting data on outcomes of pregnancies registered retrospectively (i.e., cases reported post-delivery). A prenatal exposure to ZDV is defined as inadvertent or intentional use of oral or intravenous ZDV at any time during pregnancy. The registry follows CDC guidelines for definitions of major birth defects (4). Physicians provide information regarding pregnancy dates, lowest CD4+ T-cell count, CDC classification of HIV disease, dosage, length of therapy, and trimester of exposure to antiretroviral drugs. At the expected delivery date, a follow-up form is sent to the physician to ascertain the pregnancy outcome and occurrence of concurrent illnesses. From 1989 through 1993, 198 prenatal exposures to ZDV were reported prospectively. As of December 31, 1993, 30 women were still awaiting delivery. Of the other 168 women, 47 (28%) were lost to follow-up--39 (83%) because the initial reporting physician did not respond to inquiries after the date of expected delivery. Reports are considered lost to follow-up only after efforts to obtain information have been made by sending at least three monthly letters and making one telephone call after the expected delivery date or if the reporting physician can no longer locate the patient. Of the 121 prospectively registered women, four delivered infants with structural birth defects. ZDV therapy in 54 pregnancies occurred during the first trimester: among these 54 women, one infant was born with a birth defect (agenesis of the right kidney), and 45 infants were born without defects; eight pregnancies were terminated by induced abortions. Among 47 women who received ZDV therapy during the second trimester, three infants were born with birth defects (pectus excavatum, atrial septal defect, and fetal alcohol syndrome), and 44 infants were born without defects. No birth defects occurred among infants born to the 20 women who received ZDV therapy during the third trimester. Indications for ZDV treatment of the 121 women included asymptomatic HIV infection with low CD4+ count (97), treatment for acquired immunodeficiency syndrome (AIDS) (nine), symptomatic HIV infection (six), and prophylaxis following needlestick injury (six); indications were unknown for three women. Of the pregnancies registered retrospectively, four infants were born with defects following third trimester ZDV therapy (extra digits; asymptomatic ventricular septal defect; left hydronephrosis and ureteral pelvic junction obstruction; and two-vessel cord, hypoplastic left heart and mitral atresia). Reported by: A White, PhD, E Andrews, PhD, R Eldridge, M Dickerson, H Tilson, MD, International Div of Surveillance, Epidemiology, and Economics Research; M Elkins, Infectious Diseases, Burroughs Wellcome Co, Research Triangle Park, North Carolina. W Dai, MD, Div of Drug Safety, Hoffmann-LaRoche, Inc, Nutley, New Jersey. B Hurn, MD, Clinical and Safety Surveillance Svc, Wellcome Research Laboratories, Beckenham, England. ER Alexander, Seattle-King County Health Dept, Seattle. H Fox, Dept of Obstetrics and Gynecology, Columbia Presbyterian Medical Center, New York. P Garcia, MD, Prentice Hospital, Chicago. A Rogers, Pediatric, Adolescent, and Maternal AIDS Br, Center for Research for Mothers and Children, National Institute of Child Health and Human Development, National Institutes of Health. Div of Sexually Transmitted Diseases and HIV Prevention, National Center for Prevention Svcs; Div of HIV/AIDS; National Center for Infectious Diseases; Div of Birth Defects and Developmental Disabilities, National Center for Environmental Health, CDC. Editorial Note: Based on findings in the registry, the observed proportion of birth defects among infants of women who received ZDV therapy during the first trimester of pregnancy (when the fetus is most sensitive to teratogens [5]) was 2% (1 of 46). This does not differ from the expected proportion in the general population (3%) (4). Neither the prospective nor retrospective reports indicated a consistent pattern of defects. In addition, cases of birth defects from the AIDS Clinical Trial Group 076 clinical trial (3) do not suggest an increase or unusual pattern of birth defects. Public Health Service agencies are evaluating possible recommendations for use of ZDV to reduce the risk for perinatal transmission of HIV. The findings in this report are preliminary, and the sample size was limited. Other potential limitations of this and other registries include differential reporting of pregnancy outcomes, losses to follow-up, and underreporting. In general, cases lost to follow-up are more common for observational registries than for cases obtained from registries using active ascertainment methods. Retrospective reports may include cases with more unusual or severe features and may be less representative of the population. Because the number of HIV-positive women who use ZDV during pregnancy may increase, the registry must be sustained to monitor for possible teratogenicity among infants of women receiving ZDV or other antiretroviral therapy during pregnancy. Physicians who provide care for women treated with ZDV or zalcitabine can register patients by calling the registry, (800) 722-9292, extension 8465, in the United States or by calling (919) 315-8465 for registrations from countries outside the United States. Copies of the semiannual registry report are available to health professionals by calling these numbers or by writing to the Antiretroviral Pregnancy Registry, P.O. Box 12700, Research Triangle Park, NC 27709. References 1. CDC. National HIV serosurveillance summary: results through 1992. Vol 3. Atlanta: US Department of Health and Human Services, Public Health Service, CDC, 1994. 2. CDC. 1993 Sexually transmitted diseases treatment guidelines. MMWR 1993;42(no. RR-14). 3. CDC. Zidovudine for the prevention of HIV transmission from mother to infant. MMWR 1994;43:285-7. 4. CDC. Congenital malformations surveillance report, January 1982- December 1985. Atlanta: US Department of Health and Human Services, Public Health Service, CDC, 1988. 5. Tuchmann-Duplessis H. Drug effects on the fetus. New York: Adis Press, 1977. *Use of trade names and commercial sources is for identification only and does not imply endorsement by the Public Health Service or the U.S. Department of Health and Human Services. ------------------------------ Date: Wed, 15 Jun 94 06:44:03 MST From: mednews (HICNet Medical News) To: hicnews Subject: [MMWR] Multidrug-Resistant Tuberculosis in a Hospital Message-ID: <5ZRyNc3w165w@stat.com> Multidrug-Resistant Tuberculosis in a Hospital -- Jersey City, New Jersey, 1990-1992 Since 1986 (the first full year following implementation of the revised tuberculosis [TB] surveillance case definition), the reported rate of TB per 100,000 persons in New Jersey increased from 9.5 cases to 12.6 cases in 1992 (1). Of the 984 cases reported to CDC from New Jersey in 1992, 108 (11.0%) were reported from Jersey City (1990 population: 230,300)--the city ranked second in number of TB cases reported (1) and fourth in rate of TB (46.9 per 100,000) in the state. In addition, in 1992, the rate of multidrug-resistant TB (MDR-TB) (i.e., Mycobacterium tuberculosis isolates resistant to at least isoniazid [INH] and rifampin [RIF]) among TB patients in New Jersey was 5%; the rate in Jersey City was 13% (1,2). To characterize the epidemiologic features of persons with drug-resistant TB, the New Jersey Department of Health and the Infectious Diseases Division of the Jersey City Medical Center conducted a study among patients treated at that hospital during 1990-1992. This report presents the findings of the study and compares the hospital's rates of drug-resistant TB with previously reported rates, rates for other cities in New Jersey, and rates for the state. The hospital serves a predominantly inner-city population and treats more than 40% of TB patients in Jersey City. Information about hospital inpatients with TB was abstracted from mycobacteriology log books and TB reporting forms. Mycobacterial species identification and drug-susceptibility testing were performed at the New Jersey Public Health Laboratory (NJPHL) or a commercial laboratory. The DNA probe method was used for species identification (3). Drug susceptibility was determined by the radiometric method for NJPHL and the conventional plate method for the commercial laboratory (4). Data were analyzed for all 146 patients with culture-positive M. tuberculosis during 1990-1992. Of the 142 patients for whom TB reporting forms were available, 131 (92%) had had drug-susceptibility tests performed for anti-TB drugs. Patients ranged in age from 11 to 79 years (mean: 40 years); 95 (73%) patients were male. A total of 36 (28%) patients had extrapulmonary TB. Although no serologic survey for human immunodeficiency virus (HIV) infection was performed, matching of state TB records with state HIV/acquired immunodeficiency syndrome records indicated that at least 58 (44%) TB patients had concurrent HIV infection. Of the 131 patients for whom drug-susceptibility testing had been performed, 32 (24%) had M. tuberculosis isolates resistant to at least one drug, and 21 (16%) had MDR-TB (Table 1). Of the six patients with a prior history of TB, four (67%) had MDR-TB, compared with 17 (14%) of the 125 patients with no prior history of TB (relative risk [RR]=4.9). Of the 97 patients known to have been born in the United States, 23 (24%) had TB resistant to at least one anti-TB drug, and 12 (12%) had MDR-TB; in comparison, of the 22 known foreign-born patients, four (18%) had MDR-TB (RR=0.7). Of the 18 foreign-born patients for whom information was available, seven had resided in the United States for 5 or fewer years before diagnosis of TB. Of those seven, two (29%) had MDR-TB, compared with two (18%) of the 11 persons who had resided in the United States more than 5 years (RR=1.6). Among these 131 patients, drug resistance was not associated with sex, age, race, or known HIV infection; because these cases were not associated with clustering in time or location in the hospital, nosocomial transmission of M. tuberculosis was unlikely. Reported by: A Lin-Greenberg, MD, Jersey City Medical Center, Jersey City; A Cortes, Tuberculosis Control Program, New Jersey Dept of Health. Div of Tuberculosis Elimination, National Center for Prevention Svcs; Div of Field Epidemiology, Epidemiology Program Office, CDC. Editorial Note: The findings in this report indicate that the rate of MDR-TB in New Jersey varied widely: the rate among patients treated at the hospital described in this report during 1990-1992 was similar to that for Jersey City in 1992 but substantially higher than that reported for the state and for other New Jersey cities (2). For example, in Newark in 1992, the rate of MDR-TB was nearly one third (5%) of that reported for the Jersey City hospital, and although the number of isolates tested was small, no cases of MDR-TB were reported from Trenton or Camden--urban areas with demographic and socioeconomic compositions similar to Jersey City's (2). In addition, the rate of primary INH resistance among patients at the hospital in Jersey City was higher during 1990-1992 (21%) than during 1984-1986 (15%), while the rates of presumptive primary MDR-TB during 1990-1992 and 1984-1986 were similar (14% and 13%, respectively) (5). The higher rate of MDR-TB among patients in the hospital in Jersey City than in Newark and for the state of New Jersey may reflect a greater prevalence of nonadherence to treatment and/or exposure to persons with drug-resistant TB--known risk factors for drug resistance (6). Jersey City is located near New York City, in which 19% of patients with TB in 1991 had MDR-TB (7) and outbreaks of MDR-TB have occurred recently (8). In addition, the five counties in New Jersey that reported more than one case of MDR-TB in 1992 are located closest to New York City (2). The findings in this report also are consistent with previous reports indicating an association between MDR-TB and prior history of TB (6). The pattern of anti-TB drug resistance in Jersey City and other communities in New Jersey illustrates the substantial geographic variations in this problem, even within a small state. Knowledge of local resistance patterns is critical for determining optimal treatment regimens before drug-susceptibility test results are available. As a result of this study, use of directly observed therapy was instituted in hospitals throughout Jersey City. In areas with rates of INH resistance of 4% or more, anti-TB treatment should be initiated with four drugs (INH, RIF, pyrazinamide, plus either ethambutol or streptomycin), and directly observed therapy should be used (9). Institutions experiencing outbreaks or high rates of MDR-TB may need to begin five- or six-drug regimens as initial therapy. These regimens should include the four-drug regimen and at least three drugs to which the suspected MDR strain may be susceptible (9). References 1. Bureau of Tuberculosis Control, New Jersey Department of Health. Annual report, 1992. Trenton, New Jersey: New Jersey Department of Health, Bureau of Tuberculosis Control, 1993. 2. Bureau of Tuberculosis Control, New Jersey Department of Health. Multiple drug-resistant tuberculosis in New Jersey. Trenton, New Jersey: New Jersey Department of Health, Bureau of Tuberculosis Control, 1992. 3. Body BA, Warren NG, Spicer A, Henderson D, Chery M. Use of Gen-Probe and Bactec for rapid isolation and identification of mycobacteria: correlation of probe results with growth index. Am J Clin Pathol 1990;93:415-20. 4. Heiferts L. Qualitative and quantitative drug susceptibility tests in mycobacteriology. Am Rev Respir Dis 1988;137:1217-21. 5. Lin-Greenberg A, Deltieure M. Primary resistance to anti-tuberculosis drugs in a New Jersey hospital. New Jersey Medicine 1987;84:427-8. 6. Barnes PF. The influence of epidemiologic factors on drug resistance rates in tuberculosis. Am Rev Respir Dis 1987;136:325-8. 7. Frieden TR, Sterling T, Pablos-Mendez A, Kilburn JO, Cauthen GM, Dooley SW. The emergence of drug-resistant tuberculosis in New York City. N Engl J Med 1993;328:521-6. 8. CDC. Nosocomial transmission of multidrug-resistant tuberculosis among HIV-infected persons--Florida and New York, 1988-1991. MMWR 1991;40:585-91. 9. CDC. Initial therapy for tuberculosis in the era of multidrug resistance: recommendations of the Advisory Council for the Elimination of Tuberculosis. MMWR 1993;42(no. RR-7). ------------------------------ Date: Wed, 15 Jun 94 06:44:54 MST From: mednews (HICNet Medical News) To: hicnews Subject: [MMWR] Atlanta Conference on Human Health and the Environment Message-ID: Atlanta Conference on Human Health and the Environment The Agency for Toxic Substances and Disease Registry and CDC are cosponsors of the Atlanta Conference on Human Health and the Environment in Atlanta on June 24-26, 1994. The conference will present information about environmental degradation and the effects of global changes to the environment on human health; workshops will focus on clinical and community aspects of specific environmental hazards. The conference is targeted toward physicians, scientists, other health-care workers, journalists, and environmentalists. Participants can earn Continuing Medical Education credits. Registration information is available from Physicians for Social Responsibility/Atlanta, P.O. Box 95190, Executive Park, Atlanta, GA 30347; telephone (404) 315-7443; fax (404) 315-7413. ------------------------------ Date: Wed, 15 Jun 94 06:46:18 MST From: mednews (HICNet Medical News) To: hicnews Subject: Boning Up: New Ways to Prevent Fractures in Older Americans Message-ID: Boning Up: New Ways to Prevent Fractures in Older Americans by Ole Henriksen, PhD NCRR Reporter, May/June 1994 As we age, our bones age too. Because they are thinner and more brittle, they are far too easily broken in a fall. Often they heal slowly and painfully if they heal at all. The kind of fall that matters little to someone younger can bring independent living to an abrupt halt. In some cases, bones fracture spontaneously because they are unable to carry out their normal weightsupporting role. Through studies that approach this problem from very different perspectives, two independent teams of NCRR-supported investigators have arrived at results that could help prevent bone fractures among older Americans. The first team of investigators, based at the General Clinical Research Center (GCRC) at the University of Texas Southwestern Medical Center at Dallas, has shown that an experimental treatment with sodium fluoride, the chemical that is added to drinking water, can stimulate mineral buildup and prevent new fractures in osteoporotic bones of the spinal column. Osteoporosis-the hollowing out of bones caused by reduced mineral content-affects more than 25 million Americans, including one of every three postmenopausal women. At the beginning of the study, which included 110 postmenopausal osteoporotic patients, the average mineral content of the women's lower-back vertebrae was approximately 30 percent below that of a 30-year-old normal woman, and they all had spinal compression fractures. According to Dr. Charles Y. C. Pak, GCRC principal investigator and Distinguished Chair in Mineral Metabolism at the Southwestern Medical Center, painful spontaneous fractures often develop in the lower part of the spine in osteoporotic women. "The strength of the bone is not sufficient to sustain the weight-bearing function of the skeleton, so the spine becomes compressed and fractures develop," he explains. Fractures of the spine can cause back pain and deformity; damage to several vertebrae in the upper spine results in "dowager's hump." Investigators conducting the ongoing trial randomized the 110 patients into two groups. One group (54 patients) receives slowrelease sodium fluoride tablets two times daily in repeated 14-month cycles (12 months treatment, 2 months withdrawal). The other group (56 patients) receives a placebo preparation on the same schedule. All patients receive calcium citrate tablets twice daily continuously as an optimally absorbable calcium supplement. Once a year the researchers determine how many spontaneous vertebral fractures the patients have developed and measure the mineral content of vertebrae and other bones. To date, 48 of the patients taking sodium fluoride have completed more than one cycle (mean of 2.5 cycles) of treatment. Eleven patients withdrew from the study prior to completing a full treatment cycle. Interim analysis of the trial data in the remaining 99 patients shows that the treatment caused a continued 4-6 percent increase per cycle in vertebral bone mineral density in the fluoride-treated group, but did not result in any significant change in the placebo group. The fluoride-treated group developed substantially fewer spontaneous spinal fractures (10 new fractures) than did the placebo group (26 new fractures). Researchers did not observe any significant side effects among treated patients, in contrast to earlier studies that have linked high levels of sodium fluoride intake with many side effects, including severe diarrhea, gastrointestinal bleeding, microfractures, and an increased rate of nonspinal fractures. Studies by other researchers have also previously reported that sodium fluoride administration promotes buildup of abnormal bone structure, but Dr. Pak and his colleagues use lower doses of a different type of sodium fluoride. "We use a slow-release preparation. Sodium fluoride leaks out of numerous tiny holes in the wax matrix tablets we use," he says. The slow release prevents high concentrations of fluoride in the stomach and blood. If the concentration of sodium fluoride delivered to bone were high - as it was in other studies - and the amount of available calcium were low, the newly formed bone could be defective, Dr. Pak notes. "Sodium fluoride should not be given without adequate calcium. It could produce collagen, the bone matrix, but that would fail to mineralize, resulting in defective bone formation," he says. In addition, in contrast to the damaging effects on cortical bone seen by researchers in other studies, interim results in the current trial indicate "absolutely no change in cortical bone density and quality says Dr. Pak. "Our findings show that this approach can greatly reduce new fractures, and they support the hypothesis we have had since the beginning of this work. That is, given in proper amounts with adequate calcium, fluoride is a means to form normal bone." The Texas researchers plan to follow the patients through four cycles of treatment. The investigators have also initiated a similar study on a group of women who have lower than normal bone density but no compression fractures. They hope that the earlier treatment may prevent development of fractures. In the second investigation, a team of researchers has evaluated the mechanics of falls and suggested preventive methods to reduce the risk of hip fracture, the most devastating fall injury. Hip fracture, which affects more than 250,000 Americans each year, is the second leading cause of nursing home placement in the United States and exacts an estimated $8.7 billion annual cost to society. Dr. Susan L. Greenspan and her colleagues at Beth Israel Hospital in Boston studied 149 ambulatory men and women who had fallen (126 women and 23 men aged 65 years or older). By falling, 72 patients broke their hips. These "case" patients were compared to 77 "control" patients who fell but did not break their hips. By examining how people fell, the investigators found that a fall to the side carried a significant risk of hip fracture. In contrast, there was no increased risk of hip fracture associated with forward, backward, or straight-down falls, in which the individual collapses vertically to the floor. It has been estimated that only about 5 percent of all falls by the elderly result in hip fracture. According to Dr. Greenspan, who is director of the Osteoporosis Prevention and Treatment Center at Beth Israel Hospital and assistant professor of medicine at Harvard Medical School, "The relatively low incidence of hip fracture in elderly fallers probably has a lot to do with factors other than osteoporosis. How people fall, where they land, and what they fall on-these factors all play a role. Many elderly persons may be able to break the fall or twist and turn the body to lessen the impact." Not surprisingly, the mineral content, or bone mineral density (BMD), of hip bones was also an independent risk factor in predicting hip fracture and had a significance similar to that of fall mechanics in determining the risk of fracture among the study patients. The nondominant role of BMD in predicting the risk of hip fracture may seem very surprising. But Dr. Greenspan emphasizes that, since the mean age of her study group was 83, the majority of women were likely to have had a BMD below the fracture threshold, the mineral density at which a bone easily breaks. Other factors, as a result, dominate in this statistical comparison between very similar people. "Osteoporosis is still very important, but our study shows that in addition to maintaining bone mass we need to focus on alternative methods to prevent hip fracture," she says. People who broke their hips in a fall were generally taller and weighed slightly less than those who did not break their hips. From the weights and heights of the study participants, the investigators calculated the body mass index, BMI (kg/m2). Both women and men with hip fractures had significantly lower body mass indexes than those who did not break their hips. The Boston investigators suggest that current approaches to prevent hip fracture should be modified. Today most efforts aim to retard bone loss rather than increase bone mass. In individuals older than 70 years the bone mineral density is already below a critical risk level for fracture, but the rate of bone loss has slowed. For these individuals preventive strategies could also focus on multidisciplinary measures that are unrelated to bone mass. For example, education about environmental hazards such as throw rugs, loose electrical cords, poorly lit stairs, and high-heeled shoes might prevent many accidents. Dr. Greenspan says that elderly people should also be encouraged to exercise their muscles to increase their strength in general and the strength of their thigh muscles in particular. In addition, their medication should be reviewed in order to eliminate drugs that affect balance or cause dizziness. Such medications can aggravate preexisting balance limitations that are common among the elderly and spring from many causes. "I think that many independent factors - such as cardiovascular, neuromuscular, and pharmacological problems - get compounded and lead to poor balance," says Dr. Greenspan. Additional Reading 1. Pak, C. Y. C., Sakhaee, K., Piziak, V., et al., Randomized controlled trial of slow-release sodium fluoride in the management of postmenopausal osteoporosis. Annals of Internal Medicine 120:625432,1994. 2. Greenspan, S. L., Myers, E. R., Maitland, L. A., et al., Fall severity and bone mineral density as risk factors for hip fracture in ambulatory elderly. JAMA 271:128-133, 1994. ------------------------------ Date: Wed, 15 Jun 94 06:48:01 MST From: mednews (HICNet Medical News) To: hicnews Subject: Vaccine Slows Gum Disease Message-ID: Vaccine Slows Gum Disease by Maureen Curran NCRR Reporter, May/June 1994 Researchers at the University of Washington have shown for the first time that immunization can slow the progression of periodontal disease in monkeys. The study conducted at NCRR's Regional Primate Research Center in Seattle, Washington, and supported by the National Institute of Dental Research, indicates that one day it may be possible to develop a human vaccine to prevent periodontitis, the major cause of tooth loss among older Americans. "We know enough already to say that a human periodontitis vaccine seems feasible, but it may be a decade before we see full fledged clinical trials of such a vaccine," says Dr. Roy C. Page, director of the Research Center in Oral Biology at the University of Washington School of Dentistry, Seattle. Periodontitis is a common infectious disease in which the tissues and bones surrounding and supporting the teeth are destroyed by invading bacteria. Treatment to restore tooth support can be costly and time- consuming. One of the primary culprits in periodontal disease is the gram- negative bacterium , Porphyromonas gingivalis. The University of Washington researchers, working with scientists at the University of Texas in San Antonio and the Bristol Myers Squibb Pharmaceutical Research Institute in Seattle, have developed a vaccine containing killed P. gingivalis. The vaccine was tested in long-tailed macaque monkeys (Macacafascicularis). Twenty monkeys were enrolled in the study. They had pre-existing P. gingivalis infection. Ten randomly chosen monkeys received the vaccine and 10 received placebo inoculations at the start of the study and again at 3, 6, and 16 weeks. At the time of the final injection, the investigators wrapped silk thread beneath the gum line of eight teeth in each of the monkeys to induce bacterial buildup and periodontal disease. Examination of the animals' gums at intervals after the silk thread was placed showed that the amount of P. gingivalis and gum inflammation increased significantly in both groups of animals, indicating that the vaccine was not effective in clearing P. gingivalis from the gum tissue. However, dental X rays and bone density measurements taken 30 and 36 weeks after the inoculations showed that the nonvaccinated monkeys had lost twice as much tooth-supporting bone as had the vaccinated animals. Although the vaccine elicited relatively large amounts of antibody against P. gingivalis, the antibody response did not appear to be long-lasting. Antibody titers peaked after the third injection (at week 6), decreasing by 50 percent by week 12. The titer increased again following the fourth injection (at week 16), but dropped by more than half by week 36. In spite of the dissipating antibody response, vaccination protected the monkeys against a challenge with the bacteria. In a test conducted at week 36, Dr. Page and his colleagues applied live P. gingivalis bacteria directly to the gum lines of six monkeys-three vaccinated and three nonvaccinated animals. Eight weeks later, the vaccinated animals appeared to be completely resistant to this bacterial onslaught, while the control animals showed rapid and dramatic bone loss. " It appears that immunization may in fact block bacterially induced bone loss," says Dr. Page. "Over the next 5 years we're going to study why the vaccine works, how it works, and whether we will be able to produce a vaccine that effectively reduces the level of bacteria in the gum tissue." ------------------------------ Date: Wed, 15 Jun 94 06:49:26 MST From: mednews (HICNet Medical News) To: hicnews Subject: An Unexpected Window on High Blood Pressure Message-ID: <49RyNc7w165w@stat.com> An Unexpected Window on High Blood Pressure NCRR Reporter; May/June 1994 Nobody realized it at the time, but when Gloria Brown checked into the renal transplantation unit at the University of Alabama at Birmingham (UAB) Medical Center, she was setting in motion a clinical study that would involve nearly 100 members of her extended family. In the end her case would help to uncover the origins of a rare inherited ailment, trigger a spate of discoveries, and spur new lines of research related to the causes of high blood pressure, which affects more than 60 million Americans. At first glance Ms. Brown's case did not seem terribly unusual. Each year UAB provides new kidneys to more than 250 patients, and Ms. Brown was one of the many whose renal failure could not be fully explained. But looking at her medical records, an astute postdoctoral fellow noted that this patient also had a rare inherited disorder known as Liddle syndrome, which leads to severe hypertension. In fact, more than three decades ago, while under the care of Dr. Grant W. Liddle at Vanderbilt University's General Clinical Research Center (GCRC), Ms. Brown was the first person ever to be diagnosed with this syndrome. The fellow, Dr. Mauricio Botero-Velez, consulted with Dr. David G. Warnock, professor of medicine and director of the division of nephrology at UAB, and Dr. John J. Curtis, medical director of UAB's kidney transplant program and principal investigator of the university's GCRC. The researchers realized that they were presented with a rare opportunity to probe the origins of high blood pressure. Liddle syndrome, when undiagnosed or untreated, leads to soaring hypertension and sometimes to premature death from stroke or heart failure. Five of Ms. Brown's relatives had died in this way at an early age. When Dr. Liddle first evaluated Gloria Brown and 22 members of her family back in the 1960's, he discovered that their ailment mimicked a disorder known as primary aldosteronism. Liddle syndrome, in fact, is sometimes called pseudoaldosteronism. Both conditions are marked by high blood pressure that worsens dramatically when salt is consumed, but the biological origins of these disorders are very different. Aldosteronism results from overly vigorous adrenal glands that produce excess aldosterone, the hormone that causes kidneys to retain sodium and water. With Liddle syndrome aldosterone is barely detectable in the blood, yet the kidneys behave as though they were constantly bathed in the hormone. Because the kidneys retain sodium and water, blood volume expands and blood pressure soars. Dr. Liddle speculated that the kidneys themselves, and not an imbalance of the hormones that act on the kidneys, must be the culprit behind Liddle syndrome. But over the next 30 years no one was able to determine with certainty whether he was correct. By a stroke of serendipity the Alabama researchers were able to put Dr. Liddle's hypothesis to the test. "The patient was at UAB to get a new kidney, and we realized that the operation would quite possibly reverse the manifestations of the disease," says Dr. Warnock. And indeed that is what happened. Ms. Brown received her new kidney without complication in November 1989. Once the organ was in place and functioning, the clinical indicators of Liddle syndrome--including severe hypertension and suppressed aldosterone secretion--dissipated. "We were able to confirm Grant Liddle's speculations from 30 years ago," says Dr. Curtis. "He believed that the defect lies within the kidney itself, and with the kidney transplant it became fairly obvious that he was right." Confirming Grant Liddle's hypothesis may at first seem esoteric, but it will likely have important implications for understanding more common forms of hypertension, says Dr. Curtis. Despite the prevalence of hypertension, clinicians can identify its cause in fewer than 10 percent of cases. The remaining 90 percent are categorized as "essential hypertension." Dr. Curtis speculates that many cases of essential hypertension are attributable to malfunctions in the kidneys themselves, as in Liddle syndrome. "This rare disease may turn out to be not so rare in terms of its underlying mechanisms. If Liddle syndrome helps us to understand how the kidney tubules handle salt, it might help us to advance knowledge about essential hypertension in general," says Dr. Curtis. From a clinical standpoint, scrutinizing the microscopic tubules and their salt-regulating activities deep within the kidneys can be problematic. But UAB researchers believe Liddle syndrome has led them to a simple cellular model for how the kidneys manage salt. Dr. Warnock and Dr. James K. Bubien, assistant professor of medicine at UAB, discovered that the white blood cells of Liddle syndrome patients have irregular sodium channels that seem to be permanently open, allowing sodium to continually pass into and out of the cells. This finding complements an earlier study, conducted in the 1970's, which reported that sodium movement was also exceptionally high in the red blood cells of Liddle syndrome patients. Because similar types of sodium channels are found in the kidney's tubules, the blood cells may serve as an accessible window on sodium transport in the kidneys. Along another avenue of inquiry, UAB scientists hope to pinpoint the gene that causes Liddle syndrome. The researchers have tracked down nearly 100 of Gloria Brown's relatives--both living and dead, related by blood or marriage--and produced a five-generation family tree. By far the largest known kindred with Liddle syndrome, Ms. Brown's extended family is an ideal target for genetic analysis, says Dr. Warnock. The family tree confirms that Liddle syndrome is inherited in an autosomal dominant fashion, which means that about half of the children of affected parents inherit a predisposition to the disease. "This family is so large--and with so many members affected or unaffected with Liddle syndrome--that we are quite optimistic that we will be successful in finding the gene," says Dr. Warnock. "If we are able to isolate, define, and identify the gene, we will then know one of the major players that regulates the renal absorption of salt." The scientists already have ruled out several candidate genes such as those that produce the aldosterone receptor and some components of the cellular sodium channel. Gloria Brown's story has essentially come full circle in a GCRC setting, notes Dr. Curtis. She was originally treated at Vanderbilt's GCRC, which was founded in 1960 and is one of the oldest GCRC's in the country. There she was diagnosed as having an atypical form of hypertension. But now, at UAB's GCRC, her condition has been cured, and studies of her and her family are opening up novel opportunities for understanding more common causes of high blood pressure. "It's very interesting that she ended up at two different GCRC's at two different times, and each time made a major contribution to our understanding of hypertension in general," says Dr. Curtis. "The fact that GCRC's have been in existence for a long time allowed us to follow through on a study Grant Liddle began 30 years ago. This patient's story illustrates the value of GCRC's and the in-depth, thoughtful workups patients receive in these settings." Additional Reading 1. Warnock DG, Bubien JK. Cellular physiology of Liddle's syndrome. Hospital Practice, in press. 2. Botero-Velez M, Curtis JJ, Warnock DG. Brief report: Liddle's syndrome revisited--A disorder of sodium reabsorption in the distal tubule. N Engl J Med 330:178-81 1994. ------------------------------ Date: Wed, 15 Jun 94 06:51:06 MST From: mednews (HICNet Medical News) To: hicnews Subject: Institute of Tropical Medicine Epidemiological Bulletin Message-ID: IPK - EPIDEMIOLOGICAL BULLETIN Vol 4e / No.17 Date: 04/30/94 Institute of Tropical Medicine Pedro Kouri National Epidemiology Office Ministry of Public Health ------------------------------------------------------------ Cuba. Cases and Cumulative of selected notifiable diseases. Week ending 04/30/94. ------------------------------------------------------------ DISEASES IN THIS WEEK CUMULATIVE 1992 1993 1992 1993 ------------------------------------------------------------ TYPHOID FEVER 1 1 9 15 SHIGELLOSIS 1 11 85 66 AMEBIAN D. 7 4 1486 121 TUBERCULOSIS 18 18 231 278 HANSEN DISEASE 11 9 69 63 PERTUSSIS * * 4 * SCARLET FEVER 10 9 160 128 MENINGOCOCCAL M.(1) * * 26 22 MENINGOCCEMIES(1) * 2 5 7 TETANUS * 1 * 1 VIRAL M. 48 95 789 1372 BACTERIAL M. 9 15 366 426 VARICELLA 2099 1910 24743 21143 MEASLES * * * * RUBELLA * * * * VIRAL HEPATITIS 364 340 5752 5201 MUMPS * * * * MALARIA 1 * 3 1 LEPTOSPIROSIS 19 19 158 304 SYPHILIS 166 226 3127 3668 GONORRHEA 393 566 6693 8277 ACUMINATA COND. 47 47 719 617 ------------------------------------------------------------ Source: 1993, MND (Written Report) EIG-IPK. 1994, MND (Phone Report) EIG-IPK. (1) DIS * Means 0 reported case. ------------------------------------------------------------ This bulletin was prepared with the 69% of provinces-days- information. The offered indexes are provisionals and were taken from the daily report of the Direct Information System (DIS) remitted by Provincial Centers of Hygiene and Epidemiology, from the weekly phone report of Mandatory Notifiable Diseases (MND) remitted by National Statistics Division of the Ministry of Public Health, and from the Reference Laboratories of the Institute of Tropical Medicine Pedro Kouri. ------------------------------------------------------------ This is the weekly IPK-Epidemiological Bulletin emitted via Electronic Mail. The numbering plan agree with the IPK-Epidemiological Bulletin edited by Institute of Tropical Medicine Pedro Kouri and it is an abbreviated version. Lic. Andres M. Alonso ipk-b@infomed.cu IPK - EPIDEMIOLOGICAL BULLETIN Vol 4e / No.18 Date: 05/07/94 Institute of Tropical Medicine Pedro Kouri National Epidemiology Office Ministry of Public Health ------------------------------------------------------------ Cuba. Cases and Cumulative of selected notifiable diseases. Week ending 05/07/94. ------------------------------------------------------------ DISEASES IN THIS WEEK CUMULATIVE 1993 1994 1993 1994 ------------------------------------------------------------ TYPHOID FEVER * * 9 15 SHIGELLOSIS 1 * 86 66 AMEBIAN D. 7 * 1493 121 TUBERCULOSIS 14 15 245 293 HANSEN DISEASE 6 5 75 68 PERTUSSIS * * 4 * SCARLET FEVER 7 4 167 132 MENINGOCOCCAL M.(1) 1 2 27 24 MENINGOCCEMIES(1) * 1 5 8 TETANUS * * * 1 VIRAL M. 30 148 819 1520 BACTERIAL M. 11 20 377 446 VARICELLA 1775 1509 26518 22652 MEASLES * * * * RUBELLA * * * * VIRAL HEPATITIS 260 321 6012 5522 MUMPS * * * * MALARIA * * 3 1 LEPTOSPIROSIS 5 21 163 325 SYPHILIS 220 181 3347 3849 GONORRHEA 334 492 7027 8769 ACUMINATA COND. 43 29 762 646 ------------------------------------------------------------ Source: 1993, MND (Written Report) EIG-IPK. 1994, MND (Phone Report) EIG-IPK. (1) DIS * Means 0 reported case. Notified Outbreaks. Week 05/05/94 - 05/11/94. ------------------------------------------------------------ DISEASES OUTBREAKS CASES PROVINCES ------------------------------------------------------------ F.T.D. 1 187 CAMAGUEY ------------------------------------------------------------ VIRAL HEP. 3 18 PROV. HABANA 1/6 VILLA CLARA 1/4 CIEGO DE AVILA 1/8 ------------------------------------------------------------ Source: DIS. ------------------------------------------------------------ This bulletin was prepared with the 68% of provinces-days- information. The offered indexes are provisionals and were taken from the daily report of the Direct Information System (DIS) remitted by Provincial Centers of Hygiene and Epidemiology, from the weekly phone report of Mandatory Notifiable Diseases (MND) remitted by National Statistics Division of the Ministry of Public Health, and from the Reference Laboratories of the Institute of Tropical Medicine Pedro Kouri. ------------------------------------------------------------ This is the weekly IPK-Epidemiological Bulletin emitted via Electronic Mail. The numbering plan agree with the IPK-Epidemiological Bulletin edited by Institute of Tropical Medicine Pedro Kouri and it is an abbreviated version. Lic. Andres M. Alonso ipk-b@infomed.cu ------------------------------ End of HICNet Medical News Digest V07 Issue #26 *********************************************** --- Editor, HICNet Medical Newsletter Internet: david@stat.com FAX: +1 (602) 451-1165 Bitnet : ATW1H@ASUACAD