Biomedical subjects
G Victor
Publications and source records attributed to G Victor.
The phantom Jew: from spoiled identity to genocide.
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Activity of the combination of nelfinavir and saquinavir against human immunodeficiency virus after failure of prior protease inhibitor therapy.
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Effect of antiretroviral therapy and viral load on the perceived risk of HIV transmission and the need for safer sexual practices.
BACKGROUND: Dramatic reductions in plasma HIV RNA levels are possible with current antiretroviral regimens; the effect of potent therapies and "undetectable" viral load on the perceived risk of HIV transmission and need for safer practices remains unknown. METHODS: A questionnaire was developed to examine perceptions of HIV transmission risk and need for safer practices with unprotected anal, vaginal, and oral sex and intravenous drug use with needle sharing for HIV-discordant couples in which the HIV-infected partner was receiving no therapy, was receiving reverse transcriptase inhibitor therapy, and protease inhibitor (PI)-based therapy with viral load "undetectable". This was applied anonymously to 147 unselected HIV-infected individuals attending a university-based HIV clinic. RESULTS: Almost all respondents believed that all sexual activities except oral sex were "very risky" and that safer practices were "extremely important" for those not receiving antiretroviral agents. Significantly fewer considered that anal or vaginal sex was "very risky" for those receiving PI therapy (90.9% and 86.0%, respectively), and fewer thought that safer practices for anal or vaginal sex were "very important" for those receiving PI therapy (93.0% and 91.6%, respectively). In total, 20.4% thought the risk of HIV transmission for at least one activity was reduced for those receiving PI therapy, and 19.0% believed that the need for safer practices was reduced by PI therapy. CONCLUSION: A small but significant proportion of HIV-infected people perceive the need for safer practices to be reduced during antiretroviral therapy, particularly those containing PIs. Even if the risk is truly reduced, the importance of safer practices should be conveyed consistently and terms such as "undetectable" to describe HIV RNA responses should be avoided.
Causes of death of HIV-infected persons in Ottawa, Ontario, 1984-1995.
BACKGROUND: Acquired immunodeficiency syndrome (AIDS) has become a leading cause of death of young men in the United States. With the introduction of prophylaxes and antiretrovirals for opportunistic infection, there have been significant changes in the clinical history of human immunodeficiency virus (HIV) infection. OBJECTIVE: To determine the cause of death of the patients followed up by our clinic from 1984 to 1995. METHODS: A critical chart review was performed on the records of all patients affiliated with the Ottawa General Hospital HIV/AIDS Clinic, Ottawa, Ontario, who died between 1984 and July 15, 1995. Data regarding the cause of death, last CD4 T-lymphocyte cell count before death, medication use at time of death, and location and year of death were collected. Data were analyzed for 1984 through 1988, 1989 through 1991, and 1992 through 1995, corresponding to the evolution of HIV-related medical care. RESULTS: The median CD4 T-lymphocyte cell count at death had declined. Pneumocystis carinii pneumonia has decreased significantly as cause of death (28.6%-3.8%, P < .001). No other specific attributable terminal illness has decreased in frequency during 11 years. The wasting illnesses, particularly HIV wasting syndrome (3.6%-13.7%, P = .04), and untreatable illnesses have increased in frequency as causes of death. Patients are increasingly likely to die at home (0%-25%, P < .001) and less likely to die in hospital (54%-35%, P < .001). CONCLUSIONS: The HIV-infected persons are dying with more advanced HIV immunosuppression. Advances in P carinii pneumonia prophylaxis and treatment have had a dramatic effect on the cause of death of HIV-infected persons. Improved prophylaxis and treatment for non-P carinii pneumonia opportunistic infections and malignancies and HIV wasting syndrome are required.
Selective association of phospholipids as a clue for the passive flip-flop diffusion through bilayer lipid membranes.
We showed that the investigation of the selective association of phospholipids might contribute to the insight of the flip-flop diffusion processes. The process of selective association was studied quantitatively by testing the association probabilities for both parallel and anti-parallel orientations of the polar headgroups. The model of double chain binary mixture confirms a high capacity of phospholipids for self-association in parallel configuration of the electric dipole moments whether the cross-sectional area of the polar headgroups are in an usual range of 25-55 A2. It is demonstrated that the aggregation of a class of phospholipids from a binary mixture is strongly dependent on the dipole-dipole interaction between the same phospholipids and is modulated by the magnitude of the electric dipole moment of the other phospholipids from that binary mixture. There are a great number of mechanisms involved in the transbilayer movement of phospholipids. We referred here only to the passive transport of lipids from one monolayer to the other. The flip-flop mechanisms raised in this paper are the breakdown of bilayer due to the increase of the packing density and the inversion of the coupled phospholipids from the opposite monolayers of the same bilayer. Thus, the pair formation promoting a drop in occupied volume decreases the packing pressure in the respective monolayer and consequently triggers a flip-flop into the other direction since the packing pressure in the other monolayer has not dropped. According to the present model for the binary mixtures of double-chain lipids, the rate of the flip-flop diffusion decreased by increasing the number of the methylene groups added to the acyl chain. This dependence may be perturbed whether the phospholipids possesses a very high cross-section area of the polar headgroups (a > 55 A2). We think that the selective association of phospholipids is neither exclusively, nor only involved in promoting the transbilayer diffusion of phospholipids. Most probably, the selective association determines some phospholipid domains that attract certain particular proteins so that it can modulate the protein activity.
Risk factors for acquiring ampicillin-resistant enterococci and clinical outcomes at a Canadian tertiary-care hospital.
The number of ampicillin-resistant enterococci (ARE) was noted to be increased at our teaching hospital. To determine the risk factors for acquiring this organism and to compare clinical outcomes, over a 5-month period 38 patients infected or colonized with ARE were compared with 76 patients, infected or colonized with ampicillin-susceptible enterococci (ASE). Risk factors included nosocomial acquisition, duration of hospitalization, admission to a medical service, prior antimicrobial therapy, and combination therapy for at least 7 days. The mortality rate of patients infected or colonized with ARE was higher than that of patients infected or colonized with ASE (34 versus 14%; P = 0.03), but most deaths did not appear to be related to enterococcal infection. Over a 2-year period, 16 patients with ARE bacteremia were also compared with 23 patients with ASE bacteremia. The risk factors associated with ARE bacteremia also included nosocomial acquisition, duration of hospitalization, and prior antimicrobial therapy. The mortality of patients with ARE bacteremia was also higher than that of patients with ASE bacteremia (81 versus 30%; P = 0.003), with most deaths being due to the underlying disease or a complication of it. Typing of ARE isolates by pulsed-field gel electrophoresis showed that two genotypes predominated in our institution. A prolonged hospital stay, exposure to multiple antimicrobial agents, and perhaps nosocomial transmission are important factors in acquiring ARE. The presence of ARE may also be a marker for poor outcome.
Internal radiation therapy for hepatocellular carcinoma. Results of a French multicenter phase II trial of transarterial injection of iodine 131-labeled Lipiodol.
Preliminary Phase I trials have shown iodine 131 (131I)-Lipiodol (ethiodized oil; Laboratoires Guerbet, Aulnaysous-Bois, France) to be well tolerated and most likely effective in the treatment of hepatocellular carcinoma (HCC). In this multicenter Phase II trial, the authors tested the feasibility and reproducibility of this treatment in other medical institutions and evaluated its efficacy in 50 patients with unresectable Stage I or II HCC, by the classification of Okuda et al. The authors studied 47 men and 3 women (63.9 +/- 7.1 years old) with Stage I (n = 18) or II (n = 32) HCC, by the classification of Okuda et al., which was verified by histologic findings (n = 25), cytologic findings (n = 11), or association of a tumor with alpha-fetoprotein serum values greater than 500 micrograms/l (n = 14). This multicenter trial (1) confirmed that the 131I-Lipiodol treatment is well tolerated; (2) showed that there is a high reproducibility of results with respect to other institutions and an objective tumor response in 40% of the cases; and (3) indicated the necessity of performing a randomized controlled study.
Emergence and nosocomial transmission of ampicillin-resistant enterococci.
Between 1986 and 1988, the incidence of ampicillin-resistant enterococci increased sevenfold at a university-affiliated hospital. Forty-three patients acquired nosocomial infections with ampicillin-resistant enterococci, most of which were also resistant to mezlocillin, piperacillin, and imipenem. An analysis of plasmid and chromosomal DNAs of isolates revealed that the increase was due to an epidemic of 19 nosocomial infections that yielded closely related strains of Enterococcus faecium and to a significant increase in the incidence of nonepidemic, largely unrelated strains of ampicillin-resistant enterococci. The nonepidemic strains were identified as E. faecium, E. raffinosus, E. durans, and E. gallinarum. A logistic regression analysis revealed that patients with nonepidemic resistant strains were 16 times more likely than controls to have received preceding therapy with imipenem. In our institution, the increase in the incidence of ampicillin-resistant enterococci appears to be due to the selection of various strains of resistant enterococci by the use of imipenem and to the nosocomial transmission of E. faecium and E. raffinosus.
Calculation of the optimal surface area for amphiphile molecules using the hard core method.
In this work, we have calculated the optimal surface area per amphiphile molecule using a two-dimensional gas of electric dipoles interacting with hard The optimal surface area can be evaluated according to a formula (in the two-body approximation) or as a root of an equation (in the three-body approximation). If the equation has more than one positive root, which is greater than the hard core area, then a polydisperse dimensional distribution of supramolecular aggregates is possible.
Association probabilities between the single chain amphiphiles into a binary mixture in planar monolayers.
In this work, we have calculated the probabilities of selfassociation of single chain amphiphile molecules for 36 binary mixtures of molecules having an even number of carbon atoms (from 8 to 24 carbon atoms). The association probabilities depend on the dipole moment of head groups, the length of chains and the mole fraction of the mixture of both types of amphiphile. These calculations are useful for the quantitative and qualitative explanation of the cluster formation on the surface of the mono- or bilayers.
Pyomyositis in a patient with the acquired immunodeficiency syndrome.
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'U' and 'I' can do a lot for healthy living.
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Cerebral blood flow studied by Xenon-133 inhalation technique in parkinsonism: loss of hyperfrontal pattern.
Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of 133Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid 133Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the "hyperfrontal distribution" in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.
Effects of a dopaminergic agonist (piribedil) on cerebral blood flow in man.
In baboons, the intravenous administration of piribedil, a dopaminergic agonist, was associated with marked dose dependent increases in CBF and cerebral oxygen consumption. We have studied the effects of piribedil on CBF in 20 normal, human volunteers of comparable ages. Ten received 0.1 mg/kg piribedil intravenously for 30 min; the other ten received 0.2 mg/kg. In the first group, CBF did not vary significantly, in the second group, there was a mean increase in CBF of 21.8% (p less than or equal to 0.005). In man, as in animals, piribedil provokes an increase of CBF.
Letter: Sybil: grande hystérie or folie à deux?
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Liver biopsy in hepatomegaly. Analysis of 525 cases of hepatomogaly.
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Clinical trial with alpha-methyldopa ('Aldomet') in hypertension.
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