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Biomedical subjects

M Egger

Publications and source records attributed to M Egger.

At least 145 records · Page 8Linked to original sources
PubMed1994

The Swiss HIV Cohort Study: rationale, organization and selected baseline characteristics.

OBJECTIVES: This paper describes the rationale and design features of the Swiss HIV Cohort Study (SHCS) and the baseline characteristics of participants enrolled up to March 31st 1993. The objectives include epidemiological, clinical and laboratory research. DESIGN: The SHCS is a prospective cohort study of HIV infected adolescents and adults seen at the outpatient clinics of the Swiss University Hospitals in Basle, Berne, Geneva, Lausanne and Zurich and the Cantonal Hospital St. Gall. The multicentre collaboration was initiated in September 1988 by the Swiss Federal Office of Public Health. Data collected prior to this date by several participating centers using a similar protocol were included, the earliest records dating back to 1982. Follow-up visits are scheduled every 6 months. ENROLLMENT: As of March 31st 1993, 6253 participants (M: 4580, F: 1675) were included with a total of 16015 person-years of follow-up (mean 2.6 years). HIV transmission categories were 46% intravenous drug users (IDU), 32% men who had sex with men (MSM), 18% heterosexual contacts (HET) and 4% other. The proportion of MSM among male participants decreased from 62% in 1985 to 40% in 1987, to remain stable thereafter. The proportion of IDU among males was around 40% throughout, whereas in females, there was a pronounced decline from 90% IDU in 1985 to 50% in 1992. Conversely, there was a striking increase in registrations of women presumably infected by HET, from 8% in 1985 to 50% in 1992. Among men, the proportion classified as HET increased from 2% to 15%. It is estimated, that a large proportion of all Swiss AIDS patients (70%) and HIV infected individuals (32%-47%) are enrolled in the Swiss HIV Cohort Study. Losses to follow-up, however, are common. CONCLUSIONS: The SHCS serves multiple purposes as a research project, as infrastructure for multidisciplinary research and as a tool to improve patient care. Several international and national trials, post-marketing surveillances and expanded access protocols were or still are based upon its infrastructure. The large number of female participants and of participants AIDS-free at entry, make the database especially valuable.

Adolescent↗
PubMed1994

Thyroid cancer in Belarus post-Chernobyl: improved detection or increased incidence?

There is debate on whether the reported increase in the number of cases of childhood thyroid cancer in Belarus is real and attributable to radiation released following the Chernobyl nuclear accident, or rather an artefact due to incorrect histological diagnosis, more complete case reporting and mass screening of children after the accident. We have scrutinised the histological slides of 120 (75%) of the 160 cases reported among children aged up to 15 years to the Belarus tumour registry from 1986 to 1992 and examined time trends and geographical patterns in incidence and tumour characteristics. Incidence based on reported cases increased from 0.041 per 100,000 in 1986 to 2.548 in 1992. Carcinoma was confirmed in 94% of reviewed tumours. Except for one medullary carcinoma all histologies were of the papillary type. Most of the tumours had spread beyond the organ capsule and measured over 10 mm in diameter. There was a weak and statistically non-significant trend (p = 0.19) towards smaller tumours in the later years. The proportion of cases with lymphnode or distant metastasis remained unchanged. Incidence based on histologically confirmed cases was highest adjacent and to the west and north of Chernobyl, matching best estimates of iodine-131 contamination. Our data thus strongly suggest that the observed increase is real but more data are needed in order to assess the impact of mass screening and to clarify the possible association with radiation released at Chernobyl in 1986.

Adolescent↗
PubMed1994

Survival in HIV infection: do sex and category of transmission matter? Swiss HIV Cohort Study.

OBJECTIVE: To examine survival differences in HIV-infected individuals between the sexes and the categories of transmission. PATIENTS AND SETTING: Subjects assumed to have been infected by injecting drug use, by male homosexual contact or by heterosexual contact and enrolled in the Swiss HIV Cohort Study, a national multicentre cohort study of adult HIV-infected patients. METHODS: Kaplan-Meier lifetable and Cox regression analyses were performed (time 0 = date of study entry) and survivors were censored at their last follow-up visit. RESULTS: A total of 4428 patients (mean duration of follow-up, 2.1 years) were considered. At entry, men were older and had lower CD4+ counts than women (P < 0.0001). Homosexual men were the oldest group with the lowest CD4+ counts and the most advanced disease at study entry (P < 0.0001). Crude hazard ratios indicated a 28% lower mortality from all causes in women compared with men (P < 0.0001) and, among men but not in women, a 28 and 32% higher mortality in homosexuals and heterosexuals compared with injecting drug users (IDU) (P = 0.0002 and P = 0.008, respectively). After adjusting for differences at entry, the mortality difference between the sexes disappeared (P = 0.5) and differences across transmission categories were reversed. Mortality in homosexual men was an estimated 13% (P = 0.057) lower than in male IDU; mortality was 22% lower in heterosexual women than in female IDU (P = 0.098). In stratified analysis the increased risk in IDU was confined to subjects with CD4+ cell counts > 500 x 10(6)/l cells at study entry. CONCLUSIONS: These results indicate a uniform mortality risk across the sexes but indicate an increased risk in IDU without CD4+ cell depletion at entry, the latter probably attributable to causes not related to progression of HIV infection. This study underscores the importance of adjusting for prognostic factors when comparing survival between different patient groups.

Adult↗
PubMed1993

Childhood anemia in Africa: to transfuse or not transfuse?

Blood transfusions are an important route for HIV transmission in Africa. To explore whether transfusions are necessary in the case management of childhood anemia, a randomized trial was performed in Ifakara, Tanzania, a holoendemic malaria region. 116 children were randomized to receive either treatment for malaria and hookworm alone or, in addition, a transfusion of whole blood which had been tested negative for antibodies against the human immunodeficiency virus. Mean packed cell volume (PCV) at admission was 14.0% in the transfusion and 14.4% in the no transfusion group. Children were followed up for 8 weeks with measurements of PCV at 2 days, 4 weeks and 8 weeks after study entry. PCV was similar in both groups after 4 and 8 weeks (22.9% in the transfusion and 23.6% in the no transfusion group). There was a trend towards more hospital admissions and deaths in the no transfusion group; however, 95% confidence intervals included both a beneficial and an adverse effect of blood transfusions. The costs and benefits of transfusion for childhood anemia in countries with a high HIV prevalence need to be considered carefully before a rational treatment policy can be adopted. For that purpose, a larger randomized trial is urgently needed.

Anemia↗
PubMed1993

AIDS in Nicaragua: epidemiological, political, and sociocultural perspectives.

The AIDS epidemic in Nicaragua is several years behind that in the United States and neighboring countries of Central and South America. A combination of events, including the isolation caused by the war of the U.S.-backed Contra army against the Sandinista government, the complete economic embargo imposed on Nicaragua by the United States in 1985, self-sufficiency for blood products, and a low rate of recreational injectable-drug use, have contributed to this situation. Since the Sandinistas were defeated in the general election of 1990, people have returned to Nicaragua from areas where HIV is more prevalent, such as Honduras and the United States. It is probable that many HIV-infected persons have now entered the country. Because of the high rates of sexually transmitted diseases and cultural factors such as "machismo," HIV is likely to spread rapidly by heterosexual transmission, unless effective, culturally appropriate education and sexually transmitted disease prevention programs are implemented now.

Acquired Immunodeficiency Syndrome↗
PubMed1993

HIV/AIDS-related knowledge, attitudes, and practices among Managuan secondary school students.

In 1990, the AIDS-related knowledge, attitudes, and practices of fifth year (final year) students at four Managuan high schools were assessed. This was done by means of a self-administered questionnaire completed by 451 students (155 males, 296 females) whose mean age was 18 years. Eighty-six percent of the subjects knew AIDS was transmitted sexually, but the percentages aware of other transmission pathways and effective preventive measures were much lower. Use of condoms was cited as a preventive measure by 41% of the students, but by significantly more male respondents than female respondents (55% of the males versus 33% of the females, p = 0.0001). Sixty-four percent of all the survey subjects (90% of the males, 50% of the females) reported experiencing sexual intercourse. Sixty percent of the respondents were "very much" worried about AIDS, but only 23% considered themselves at risk of contracting the disease. Among the sexually active students, 29% of the respondents (38% of the males but only 7% of the females, p = 0.001) indicated a change in sexual behavior because of AIDS. Reported behavior change was strongly associated with concern about AIDS, but the association between reported behavior change and perception of personal risk was weak. Overall, the survey indicated that knowledge about transmission and prevention of AIDS among Managuan high school students was insufficient, especially among females, indicating a need for health education including interventions specifically targeted at female youth.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Post-challenge glucose concentration, impaired glucose tolerance, diabetes, and cancer mortality in men.

The possibility that diabetes is associated with an elevated risk of cancer mortality has been discussed for many years. Recently, Levine et al. (Am J Epidemiol, 1990; 131:254-62) approached this issue by relating post-load plasma glucose concentration to cancer mortality. For men, there appeared to be a positive association between post-load glucose and mortality from cancer for all sites combined and for some specific sites. However, that analysis was based on only 298 cancer deaths among 11,521 men followed for 12 years. The current authors explored this issue in a cohort of 18,274 male civil servants, among whom there were 1,282 cancer deaths over 18-20 years of follow-up. There was no association between post-load glucose and cancer mortality, except for pancreatic cancer. A role for asymptomatic hyperglycemia in the etiology of cancer is not supported by the results of the present study.

Adult↗
PubMed1992

Hip fractures and fluoridation in Utah's elderly population.

OBJECTIVE: To test the effect of water fluoridated to 1 ppm on the incidence of hip fractures in the elderly. DESIGN: Ecological cohort. SETTING: The incidence of femoral neck fractures in patients 65 years of age or older was compared in three communities in Utah, one with and two without water fluoridated to 1 ppm. PATIENTS: All patients with hip fractures who were 65 years of age and older over a 7-year period in the three communities, excluding (1) those with revisions of hip fractures, (2) those in whom the hip fracture was anything but a first diagnosis, (3) those in whom metastatic disease was present, or (4) those in whom the fracture was a second fracture (n = 246). OUTCOME MEASURE: Rate of hospital discharge for hip fracture. RESULTS: The relative risk for hip fracture for women in the fluoridated area was 1.27 (95% confidence interval [CI] = 1.08 to 1.46) and for men was 1.41 (95% CI = 1.00 to 1.81) relative to the nonfluoridated areas. CONCLUSIONS: We found a small but significant increase in the risk of hip fracture in both men and women exposed to artificial fluoridation at 1 ppm, suggesting that low levels of fluoride may increase the risk of hip fracture in the elderly.

Aged↗
PubMed1992

Synthetic lipid-anchored receptors based on the binding site of a monoclonal antibody.

Highly specific ligand receptor interactions generally characterize molecular recognition at cell surfaces and other biological systems. In this study we simulate a membrane receptor by fusing a monoclonal antibody fragment to a phospholipid. A sulfhydryl group in the hinge region of a monoclonal antibody fragment, was covalently linked to derivatives of phosphatidylethanolamines and phosphatidylserine via three different hydrophilic spacer arms. We investigated and characterized these lipid-anchored Fab-fragments which we have named 'Fab-lipids' in liposomal and monolayer systems. Methods for the monomolecular assembling of such films at the air/water interface and techniques used for their manipulation are outlined. We describe two possibilities for building a monomolecular receptor layer, consisting of two-dimensional pattern of oriented Fab-fragments with their artificial hydrophobic anchor embedded in a lipid matrix. In the first method a monomolecular film at the air/water interface was allowed to form from a vesicular suspension and driven into a phase separation, resulting in protein rich domains embedded in a protein depleted phase. This film was transferred onto a solid support in such a way that the established pattern was preserved. Alternatively, a recognition pattern was formed by directly cross-linking the Fab-fragments to preformed planar membranes composed of the reactive spacer-lipids and an inert matrix lipid. Specificity as well as contrast of the binding activity of the receptor layers were qualified using micro-fluorimetry.

2,4-Dinitrophenol↗