Measuring the effects of race differentials in mortality upon surviving family members

A model is developed to use marital history data from the U.S. Current Population Survey and mortality statistics from the federal registration system to estimate color differences in (a) the risk of widowhood among women in the working ages and (by the cumulative duration of widowhood. Color differentials in mortality among married males are thereby translated into person-years of dependent survivorship among women, in anticipation of our later estimating average and cumulative lifetime income losses for the survivors. Initial results of this model, dealing with the demographic aspects of survivorship, are presented.     

An epidemiologic summary of the AIDS/HIV epidemic in Minnesota

Health care is seeing a revival of customer service, driven by cost pressure, competition, and a nagging conscience to do the right thing. In some markets, health systems no longer compete on prices. They're already cut to the bone. Service is how they aim to set themselves apart.     

Socioeconomic and spatial differentials in mortality and means of committing suicide in New South Wales, Australia, 1985-91

Analysis of suicide mortality in New South Wales, Australia is undertaken with reference to marital status and occupational status between 1986-89/90 and with reference to the principal means of committing suicide. Not currently married male manual workers were particularly at risk although marital status variations were significant with both genders and at different ages. Between 1985-91 male suicide mortality rates were significantly higher in inland non-metropolitan regions, especially among younger men, and were higher in inner areas of metropolitan Sydney. While there were no significant variations by marital status in the means of committing suicide there were variations between genders, and there were regional and social class variations in the use of guns with males. The use of guns was a factor in the elevated suicide mortality levels among inland rural youth and men, and among farmers and transport workers while the use of poisons was also significant with these occupational groups. The use of poisons was greater among persons committing suicide in the areas of elevated mortality in inner Sydney and the use of guns much lower.     

Estimation of AIDS morbidity and mortality in Spain

BACKGROUND: To obtain corrected estimates of the cumulative incidence and mortality, as well as prevalence of AIDS in Spain on June 1992. METHODS: The number of cases in the National Register of AIDS by December 1992 was adjusted for reporting delays to estimate the cumulative incidence by June 1992. The prevalence and mortality in this date were obtained using this figure and the probabilities of survival after diagnosis from the AIDS Register of Madrid. This methodology was used for Spain as all, and for each Autonomous Community. RESULTS: The estimated cumulative incidence of AIDS in Spain by June 1992 was 16,486 cases, 13.4% greater than that reported by the same date. The prevalent cases were 6,351 (95% CI, 5,996-6,708) and the remaining 10,135 (61.5%) would have died. This number of deaths is 69.6% greater than the reported figure. There were considerable differences among Autonomous Communities. Some of them exhibited rates more than six times greater than others. CONCLUSIONS: The adjusted estimations provide a view of the actual situation more accurate than the raw figures from the register. These great differences should be taken into account for appropriate allocation of health care resources.     

The impact of AIDS in the global mortality in Catalonia, 1981-1993

OBJECTIVES: To compare the evolution of the principal causes of death in Catalonia, Spain and to assess the impact of AIDS as a contributing factor to the increase of mortality in young people in Catalonia. METHODS: Data from the mortality register of Department of Health in Catalonia has been used. We have compared the principal causes of death in Catalonia for the global population and for the group of 20 to 39 year olds. We have calculated the potential years of life lost (PYLL) between the ages of 13 to 65. RESULTS: Since the first case of AIDS in 1981, AIDS has been the cause of death with the most important increase for the global population in Catalonia. AIDS is the sixth cause of death and the first cause of PYLL. For the young population in Catalonia (aged 20-39) AIDS became, in 1993, the first cause of death. From 1992 to 1993 the PYLL due to AIDS increased 5% in men and 51% in women. CONCLUSIONS: The present situation has led AIDS being the first cause of death among young population. The collaboration between mortality registers and AIDS registers is absolutely essential to assess more accurately the impact of AIDS on the mortality of population.     

Molecular theory of lipid-protein interaction and the Lalpha-HII transition

We present a molecular-level theory for lipid-protein interaction and apply it to the study of lipid-mediated interactions between proteins and the protein-induced transition from the planar bilayer (Lalpha) to the inverse-hexagonal (HII) phase. The proteins are treated as rigid, membrane-spanning, hydrophobic inclusions of different size and shape, e.g., "cylinder-like," "barrel-like," or "vase-like." We assume strong hydrophobic coupling between the protein and its neighbor lipids. This means that, if necessary, the flexible lipid chains surrounding the protein will stretch, compress, and/or tilt to bridge the hydrophobic thickness mismatch between the protein and the unperturbed bilayer. The system free energy is expressed as an integral over local molecular contributions, the latter accounting for interheadgroup repulsion, hydrocarbon-water surface energy, and chain stretching-tilting effects. We show that the molecular interaction constants are intimately related to familiar elastic (continuum) characteristics of the membrane, such as the bending rigidity and spontaneous curvature, as well as to the less familiar tilt modulus. The equilibrium configuration of the membrane is determined by minimizing the free energy functional, subject to boundary conditions dictated by the size, shape, and spatial distribution of inclusions. A similar procedure is used to calculate the free energy and structure of peptide-free and peptide-rich hexagonal phases. Two degrees of freedom are involved in the variational minimization procedure: the local length and local tilt angle of the lipid chains. The inclusion of chain tilt is particularly important for studying noncylindrical (for instance, barrel-like) inclusions and analyzing the structure of the HII lipid phase; e.g., we find that chain tilt relaxation implies strong faceting of the lipid monolayers in the hexagonal phase. Consistent with experiment, we find that only short peptides (large negative mismatch) can induce the Lalpha --> HII transition. At the transition, a peptide-poor Lalpha phase coexists with a peptide-rich HII phase.     

Tuberculosis mortality in England and Wales during 1982-1992: its association with poverty, ethnicity and AIDS

A linear DNA with partial sequence redundancy can be recircularized in cells by either nonhomologous end joining (NEJ) or by homologous recombination (HR). We have studied the relative contributions of these processes in zygotes or early embryos of species that serve as model organisms for developmental genetics. Thus, we have microinjected a linearized plasmid substrate into zygotes of zebrafish (Danio rerio) or into the posterior end of Drosophila melanogaster early embryos before pole cell formation. Similar to the situation observed previously in Xenopus zygotes/early embryos, we detected a large preponderance of DNA-end joining over homologous recombination. A comparison of end-joined junctions revealed that from the three species tested, zebrafish introduced the least number of sequence distortions upon DNA-end joining, while Drosophila produced the largest deletions (average 14 bp) with occasional nucleotide patch insertions, reminiscent of the N nucleotides at V(D)J junctions in mammalian immune receptor genes. Double-strand gap repair by homologous sequences ('homologous recombination') involving a bimolecular reaction was readily detectable in both zebrafish and Drosophila. This involved specifically designed recombination substrates consisting of a mutagenized linear plasmid and DNA fragments carrying the wild-type sequence. Our results show that the basic machinery for homologous recombination is present at early developmental stages of these two genetic model organisms. However, it seems that for any experimental exploitation, such as targeted gene disruption, one would have to inhibit or bypass the overwhelming DNA-end joining activity.     

Elasticity theory of the B-DNA to S-DNA transition

We propose in this note a simple model--the two-state Worm Like Chain--to describe the elasticity of the recently discovered stress-induced transformation from B-DNA to S-DNA. The model reduces for low tractions to the well-known Worm Like chain theory, which is used to describe the elastic properties of B-DNA, while in the limit of high chain-bending moduli it reduces to the two-state Ising model proposed by Cluzel et al. for the B-S transition [Cluzel, P., A. Lebrun, C. Heller, R. Lavery, J-L. Viovy, D. Chatenay, and F. Caron. 1996. DNA: an extensible molecule. Science. 271:792-794]. Our model can be treated analytically to produce an explicit form of the force-extension relationship which agrees reasonably with the observations. We use the model to show that conformational fluctuations of the chain play a role also for the B to S transformation.     

Deep venous thrombosis: epidemiologic, diagnostic and therapeutic aspects

Deep vein thrombosis (DVT) has a high social and economic cost disease being its prevalence in the general population elevated and producing possibly fatal (pulmonary embolism) or disabling (post-thrombotic syndrome) complications. Thus, it appears of great importance to know the epidemiological and clinical characteristics of DVT in order to perform the best diagnosis, therapy and prophylaxis. The study population is composed by 146 patients (84 males and 62 females, mean age 60.9 +/- 15.3 years, range 19.92 years), arrived in our Vascular Echography Laboratory with the clinical suspect of DVT confirmed by means of echo color Doppler. The most frequent clinical signs were skin hyperthermia in 118 patients (80.8%) and edema in 116 patients (79.5%), while the most common symptom was pain, 89 patients (61.0%). Eleven patients (7.5%) were asymptomatic. The echo criteria utilized were direct thrombus visualization, vessel diameter higher than the contralateral, reduced or absent vessel wall ability to be compressed, reduced or absent color Doppler venous flow, lack or reduction of respiratory flow modulation, visualization of collateral circulation. DVT was located in 131 patients (89.7%) in inferior limbs (proximal in 122 patients, isolated distal in 9 patients), in 14 patients (9.6%) in superior limbs and in 3 patients (2.1%) in the internal jugular vein. In 130 patients a risk factor or a predisposing condition was identified: secondary DVT; in 16 patients the DVT was considered idiopathic. The most frequent risk factors were: previous surgery 28.1%, immobilization 19.9% trauma 17.1%, tumors 9.6%. A hypercoagulation was detected in 4 patients: antithrombin III deficit in 2, post-splenectomy thrombocytosis in 1 and antiphospholipid antibodies syndrome in the last one. The Pisa territory epidemiologic data showed a male 0.51 and female 0.38/1000 subject/year DVT incidence, with significantly higher values in older than 45-54 males and 55-64 females. One hundred and thirty one patients were treated with 5-11 day heparin infusion and thereafter with warfarin at least for 6 months, 1 year or indefinitely depending on thromboembolic risk. Six patients with distal DVT and 9 patients with hemorrhagic risk were treated with subcutaneous calcic or low weight heparin. In 1 patient with a mobile thrombus judged as at very high risk of embolization, a caval filter was positioned. Anticoagulant therapy complications were: 2 minor bleedings, 1 alopecia, 1 thrombocytopenia. Two patients died for neoplastic complications. Fifty-seven patients completed a 6-month follow-up and were submitted to a control each study that evidenced: total recanalization in 15 (26.3%), partial recanalization in 25 (43.9%) and no recanalization in 17 patients (29.8%). In 6 patients there was a DVT relapse and in 9 pulmonary embolization: almost all these patients were in the partial recanalization group.     

Lipoprotein oxidation, antioxidants and cardiovascular risk: epidemiologic evidence

This review summarizes the scientific evidence for a possible role of antioxidants in the prevention of coronary heart disease (CHD). Dietary antioxidants include vitamin E, vitamin C and beta-carotene, whereas selenium is an integral part of the antioxidant enzyme glutathione peroxidase. Experimental studies suggest that the oxidation of low-density lipoproteins (LDL) in the vessel wall plays an important role in the development of atherosclerotic lesions. The resistance of LDL to oxidation is increased by antioxidant supplementation, at least in vitro. Epidemiological studies have not demonstrated unequivocally that a high intake of antioxidants leads to a decreased risk of CHD. Studies on dietary intake and serum levels of antioxidants do point in the direction of a preventive effect of antioxidants, whereas the results of intervention studies are less conclusive. Beta-carotene supplementation is not associated with any decrease in CHD; high doses of vitamin E may be beneficial, but results from large trials are to be awaited. General preventive measures based on antioxidant supplementation are not yet justifiable.     

Toxic-shock syndrome: epidemiologic features, recurrence, risk factors, and prevention

Surveillance for toxic-shock syndrome (TSS) in Wisconsin detected 38 cases with onsets from September 1975 through June 1980. Thirty-seven of the cases occurred after January 1, 1979; 37 of the patients were women, 35 cases occurred during menses; 38 patients were white; and one patient died. Cervical or vaginal cultures were obtained before antibiotic therapy in 23 patients, and 17 cultures were positive for Staphylococcus aureus. Ten patients had at least one recurrent episode during subsequent menstrual periods. The recurrence rate was lower in patients who had been treated with beta-lactamase-resistant antibiotics. Thirty-five patients were matched for age and menstruation to 105 controls: 34 of 35 cases (versus 80 of 105 controls) used tampons during every menstrual period (P < 0.01); nine of 35 cases (versus 64 of 105 controls) practiced contraception (P < 0.001). In Wisconsin the minimum incidence of TSS as defined by clinical criteria is 6.2 cases per 100,000 menstruating women per year. The rate of TSS among menstruating women younger than 30 years was 2.4 to 3.3 times the rate among those who were 30 or older.