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Biomedical subjects

J Ziegler

Publications and source records attributed to J Ziegler.

At least 91 records · Page 5Linked to original sources

KSHV antibodies among Americans, Italians and Ugandans with and without Kaposi's sarcoma.

A major controversy regarding Kaposi's sarcoma-associated herpesvirus (KSHV or HHV8) is whether or not it is a ubiquitous infection of humans. Immunoassays based on KSHV- and Epstein-Barr virus (EBV)-coinfected cell lines show that most US AIDS-KS patients have specific antibodies to KSHV-related antigens. We have developed a sensitive indirect immunofluorescence assay (IFA) based on an EBV-negative, KSHV-infected cell line, BCP-1. When we used this IFA assay, KSHV-related antibodies were found in 71-88% of serum samples from US, Italian and Ugandan AIDS-KS patients, as well as all serum samples examined from HIV-seronegative KS patients. Although none of the US blood donors examined were KSHV seropositive by IFA, intermediate and high seroprevalence rates were found in Italian and Ugandan control populations. Antibody kinetics showed that more than half of the AIDS-KS patients who were examined IgG-seroconverted before KS development, and antibody levels did not decline after seroconversion. For these patients, seropositivity rates increased linearly with time, suggesting that the rate of infection was constant and that the risk of developing KS once infected with KSHV is not highly dependent on the duration of infection. These data strongly suggest that KSHV is not ubiquitous in most populations and that the virus may be under strict immunologic control in healthy KSHV-infected persons.

AIDS-Related Opportunistic Infections↗

Intraoperative jugular desaturation during surgery for traumatic intracranial hematomas.

Traumatic intracranial hematomas which are present on hospital admission or which develop during the hospital course are associated with a worse neurological outcome than diffuse injuries. The purpose of this study was to monitor jugular venous oxygen saturation (Sjvo2) during surgery for evacuation of traumatic intracranial mass lesions, to determine the incidence and the causes of jugular venous desaturation, and to assess the usefulness of Sjvo2 monitoring in this setting. Twenty-five severely head injured patients were monitored during 27 surgical procedures. At the start of the surgical procedure, the median Sjvo2 was 47% (range 25%-89%). Seventeen (63%) of the patients had a Sjvo2 less than 50%. Five patients had extremely low Sjvo2 values (< or = 30%). Upon evacuation of the intracranial hematoma, there was a significant (P < 0.001) increase in the median Sjvo2 to 65% (range 50%-88%). Intracranial hypertension was the primary cause of the low Sjvo2, as confirmed by the response to surgical evacuation. Hypotension (mean arterial pressure < 80 mm Hg) was a contributing factor in seven of the cases of jugular desaturation. The definitive treatment of a traumatic intracranial hematoma is surgical evacuation. However, during the period prior to evacuation of the hematoma, jugular venous desaturation was common, suggesting that monitoring Sjvo2 might provide useful information about the adequacy of cerebral perfusion.

Adult↗

Bronchial asthma and air pollution at workplaces.

OBJECTIVES: This case-referent study was performed to investigate the possibility of nonspecific air pollution at workplaces increasing the risk of bronchial asthma for formerly healthy adults. METHODS: Seventy-nine cases of asthma, diagnosed at a lung clinic, among persons aged 20-65 years were compared with 304 referents drawn randomly from the population of the catchment area. Questionnaire information was obtained regarding occupation, exposure to suspect allergens, place of residence, smoking habits, and atopy. The subjects' occupations were categorized into four air pollution classes based on how the referents reported air pollution in their respective occupations. RESULTS: Three years or more of work in air-polluted occupations resulted in an odds ratio of 3.0 (OR) (95% confidence interval 1.5-6.1) in a comparison with work in occupations with slight or no air pollution. Stratification of the material for smoking habits or atopy did not alter the results. Nor did the exclusion of specific exposures to asthmatogenic agents such as ioscyanates, stainless steel welding, or aluminum salts change the effects of the nonspecific air pollution at workplaces. Smoking per se was associated with an almost doubled risk for asthma (OR 1.9, 95% confidence interval 1.1-3.4). CONCLUSION: The results of this study support an association between occupational exposure to nonspecific air pollution and the development of bronchial asthma.

Adult↗

An HIV-1 infected long-term non-progressor (LTNP): molecular analysis of HIV-1 strains in the vpr and nef genes.

We describe a long-term non-progressive injecting drug user (IDU) who was infected with human immunodeficiency virus type-1 (HIV-1) in 1984, and has survived with stable CD4+ T-cell counts (> 800/microliters blood) without any acquired immune deficiency syndrome (AIDS) related illness. With a goal to investigate the molecular nature of HIV-1 strains infecting this patient, we amplified the nef and vpr genes directly from the fresh uncultured peripheral blood mononuclear cells (PBMCs), and carried out co-culture studies. Sequence analysis of the nef gene (from 1994 samples) showed no deletions (as has been previously reported) expected for a 7 base pair duplication at the C-terminus which prematurely terminated the nef reading frame, whereas even after repeated attempts the nef gene could not be amplified from the 1992 PBMC samples. In contrast, the vpr gene (from 1992 and 1994 samples) revealed two distinct quasispecies with no apparent defects. We observed five amino acid substitutions, between residues 83-90, at the C-terminus which has been recently implicated in G2 cell cycle arrest as an early step to HIV-1 infection. In the light of recent evidence on the role of nef gene defects/attenuations in long-term survival of HIV-1 infected patients, it may be that the nef gene defect created by gene duplication, which eliminated the cysteine-206 crucial in disulfide bond formation, may play a role in chronic HIV-1 infection in this patient. These data further suggest that deletions in the nef gene may not be the only reason for long-term non-progression of HIV-1 infection in some individuals, but the gene defects like duplication and subtle mutations in the functional motifs of both nef and vpr genes may confer similar protection in HIV-1 infected patients surviving for longer periods of time with stable CD4 counts.

Acquired Immunodeficiency Syndrome↗

Medical similes in religious discourse: the case of Giovanni di San Gimignano OP (ca. 1260-ca. 1333).

By the beginning of the fourteenth century, medicine had acquired a cultural role in addition to its traditional function as a therapeutic art. Medical subject matter infiltrated the religious discourse via the new thirteenth-century encyclopedic literature. Preachers came to employ in their moral analogies a wider range of medical topics, using sophisticated medical examples and citations attributed to recognized medical authorities. These developments coincided with the growing prestige of medicine as an academic discipline.

Christianity↗

An epidemiologic study of bronchial asthma and smoking.

The role of smoking and air pollution in bronchial asthma in otherwise healthy adults is still unclear. We compared 79 cases of asthma, diagnosed between ages 20 and 65 years, with 304 randomly drawn population controls of similar age from the same catchment area as the cases. The comparison involved questionnaire information on smoking habits, occupational exposures, dwelling conditions, various suspect allergenic exposures, and atopy. Those who had smoked for 3 years or more, present or past, were at increased risk for bronchial asthma (odds ratio = 1.9; 95% confidence interval = 1.1-3.3). Adjustment by multiple logistic regression for age and gender as well as atopy and air pollution at work did not change the relative risk estimate. Exposure to environmental tobacco smoke, or passive smoking, at work involved a slightly greater risk.

Adult↗

Visual search for singleton feature targets within and across feature dimensions.

Three experiments investigated visual search for singleton feature targets. The critical dimension on which the target differed from the nontargets was either known in advance or unknown--that is, the critical difference varied either within a dimension or across dimensions. Previous work (Treisman, 1988) had shown that, while the search reaction time (RT) functions were flat in both conditions, there was an intercept cost for the cross-dimension condition. Experiment 1 examined whether this cost would disappear when responses could be based on the detection of any (target-nontarget) difference in the display (by requiring a "heterogeneity/homogeneity" decision). The cost remained. This argues that pop-out requires (or involves) knowledge of the particular dimension in which an odd-one-out target differs from the nontargets; furthermore, that knowledge is acquired through the elimination of dimensions not containing a target. In Experiment 2, the subjects had to eliminate (or ignore) one potential source of difference in order to give a positive response (displays could contain a "noncritical" difference requiring a negative response). The result was a comparatively large cost in the within-dimension (positive) condition. This can be taken to indicate that pop-out as such does not make available information as to the particular feature value in which the target differs from the nontargets. Experiment 3 examined whether search priorities can be biased in accordance with advance knowledge of the likely source of difference. The subjects were found to have a high degree of top-down control over what particular dimension to assign priority of checking to. The implication of the results for models of visual search and selection are discussed.

Adult↗