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Biomedical subjects

J Mayer

Publications and source records attributed to J Mayer.

At least 199 records · Page 11Linked to original sources
PubMed1993

An analysis of ischemic stroke in an urban southern California population. The University of California, San Diego, Stroke Data Bank.

BACKGROUND: Stroke databanks may provide important information regarding regional and temporal variations in the causes of stroke. METHODS: Five hundred consecutive patients presenting to the University of California, San Diego, stroke services with acute ischemic stroke were evaluated prospectively. A specific cause of stroke was assigned in each case according to predetermined diagnostic criteria. RESULTS: Relative incidences of ischemic stroke causes were as follows: lacunar, 27%; unknown cause, 23%; cardioembolic, 22%; large-vessel atherothrombotic/embolic, 18%; and miscellaneous, 10%. CONCLUSIONS: These relatively high rates of lacunar stroke and stroke of unknown cause are similar to those from other recent surveys and may reflect an important shift in the pathophysiologic mechanisms that underlie ischemic stroke.

Adolescent↗
PubMed1993

"Prion dementia".

Explore the source record for details and available documents.

Dementia↗
PubMed1993

Comparison of three different forms of HLA-DR4Dw4 proteins.

The biochemical behavior and peptide binding properties of a soluble form of the human class II DR4Dw4 molecule (PI-DR4Dw4) were compared to DR4Dw4 molecules containing the transmembrane and cytoplasmic domains that were purified both from B and transfected chinese hamster ovary cells. Recombinant and B cell-derived DR4Dw4 molecules bound monoclonal anti-DR4Dw4 antibodies with different affinities and varied in their stability in the presence of sodium dodecyl sulfate. The three forms of DR4Dw4 bound peptides with a similar apparent affinity constant, but soluble class II molecules bound up to ten times more peptide than DR4Dw4 containing a transmembrane region. Peptide binding kinetics for soluble DR4Dw4 molecules were 10-20 times faster than for the other two forms of DR4Dw4 molecules. Finally, soluble PI-DR4Dw4/peptide complexes were shown to stimulate T cell proliferation.

Amino Acid Sequence↗
PubMed1993

Subcloning of HIV-2 nef genes in E. coli and immunological reactivity of expressed fusion proteins.

The nef gene located in the 3' region of the HIV-2 genome encodes an N-terminally myristylated protein of 27-35 kD, likely to be involved in the regulation of viral transcription. The nef genes of HIV-2 isolates GH-1, ROD, ST, BEN, and D194.17 were inserted into E. coli pEX vectors and expression of Nef beta-galactosidase fusion proteins was detected in stained gels. All fusion proteins specifically reacted with a rabbit serum raised against bacterially expressed Nef from HIV-2D194.17. Sera from monkeys inoculated with HIV-2BEN or SIVMAC251 recognized the Nef proteins of only certain HIV-2 isolates. No cross-reactivity of these sera with HIV-1 Nef and of a rabbit anti-HIV-1-Nef serum with the described HIV-2 Nef fusion proteins was observed.

Animals↗
PubMed1993

Gamma interferon-induced nitric oxide production reduces Chlamydia trachomatis infectivity in McCoy cells.

McCoy cells, murine-derived cells commonly used for propagation of chlamydiae, were found to be efficient producers of nitric oxide (NO) when primed with murine gamma interferon (IFN-gamma) and then exposed to the second signals provided by Escherichia coli lipopolysaccharide, human interleukin-1 alpha, murine tumor necrosis factor alpha, or Chlamydia trachomatis type H. Murine recombinant IFN-gamma over a range of 0 to 50 U/ml inhibited infectivity of C. trachomatis type H in a dose-dependent fashion in McCoy cells while simultaneously inducing NO production. Quantitation of infectious chlamydia progeny remaining in McCoy cells 48 or 72 h postinfection revealed that IFN-gamma-primed McCoy cells reduced chlamydial inclusion-forming units (expressed as units per milliliter) by 4 log10 units at higher IFN-gamma concentrations (50 U/ml) compared with control values. The magnitude of this antichlamydial effect was directly related to increased synthesis of NO, the production of which was IFN-gamma dose dependent. The antichlamydial effects of IFN-gamma were blocked in a dose-dependent manner by the addition of N-guanidino-monomethyl L-arginine (MLA), an inhibitor of nitric oxide synthesis. These results suggest that although IFN-gamma priming of McCoy cells is required for antichlamydial activity, nitric oxide is a necessary effector molecule involved in the mechanism(s) of IFN-gamma-induced inhibition of chlamydial proliferation in this murine cell line. The ability to block the potent antichlamydial effects of IFN-gamma by inhibition of a specific enzyme, nitric oxide synthase, may give insights into mechanisms by which IFN-gamma and perhaps other cytokines are able to control proliferation of chlamydiae and other intracellular pathogens.

Animals↗
PubMed1993

[Current perspectives in molecular virology].

For reproduction viruses depend on the metabolism of higher organisms that use a variety of different antiviral mechanisms for defense. Insights into virus-host cell interactions and in the strategies viruses employ to produce progeny virions were possible by sophisticated methods of modern virology. Knowing about the molecular mechanisms during infection and replication we have been able to counteract viral attacks on the molecular level by rationally designed vaccines. On the other hand these viruses can be used as molecular vector tools for treatment of e.g. genetically determined diseases. On the basis of new molecular-biological methods the sensitivity of detection of infectious agents and diagnosis of diseases could be drastically improved.

Gene Expression Regulation, Viral↗
PubMed1993

[Experience with sulodexide (Vessel Due F) in diabetics with ischemic disease of the lower extremities].

A total of nine patients with diabetes type I and II and with claudications due to macro- and microangiopathies of the lower extremities took sulodexide (Vessel Due F) by the i.m. route for a period of 20 days and then as capsules for 90 days. In all a favourable therapeutic effect was recorded, in particular as regards delay of claudications. The authors recorded lower blood sugar values, lower levels of cholesterol, triglycerides, fibrinogen and plasma viscosity. In the authors' view sulodexide is an important advance in the treatment of diabetics with claudications.

Arteriosclerosis↗
PubMed1993

[Mechanisms of erythrocyte sedimentation. Do we know more today than Robin Fahraeus?].

The authors analyze in detail all substantial factors which influence the red cell sedimentation. They express this one a function of time, hematocrit, hemoglobin concentration, concentration of some plasma proteins, citrate density and viscosity. These values serve to describe the plasma and red cell density, plasma viscosity, red cell aggregation and to express the influence of the hematocrit on the red cell sedimentation. The authors try to quantify all influences in order to differentiate important factors from less important ones. Finally they demonstrate on several case-histories the necessity of a rational analytical attitude to values of the red cell sedimentation rate.

Blood Sedimentation↗
PubMed1993

[The effect of selective decontamination on malignant hematologic diseases treated with aggressive chemotherapy].

The authors analyzed the course of 100 cycles of chemotherapy administered on account of haematological oncological disease: 66 cycles with administration of selective decontamination and 34 without its administration. Based on an analysis of the gut flora they provided evidence of the necessity of concurrent administration of originally separately administered antibiotics and of the necessity to replace nystatin by amphotericin B. They found a significant reduction of the incidence of infectious complications, the number of days with a body temperature above 38 and reduced consumption of antibiotics. The authors found a different composition of the agents causing infectious complications--a reduction of the ratio of Gram-negative agents and an increase of Gram-positive agents and fungi and also in increased percentage of fever of unknown origin. By analysis of the sensitivity of the detected microbes to antibiotics the authors assessed changes in the resistance caused by administration of selective decontamination and assessed the order of assumed effectiveness of the tested antibiotics.

Adult↗
PubMed1993

[Hemoglobin SD disease].

A 7 year old Kurdish girl presented with a cerebral infarction and a resulting hemiparesis following a blood transfusion. Examination of the blood film suggested sickle cell anaemia. However a simultaneously carried out haemoglobin electrophoresis showed haemoglobin S and haemoglobin D. The diagnosis of haemoglobin SD disease was thereby established. This kind of haemoglobin disorder usually shows a mild clinical manifestation. According to our knowledge such serious cases have not been published before. With this disease the main emphasis is on the prevention of recurrent cerebral infarctions bay a long-term transfusion programme whereas the effects of the cerebral infarction are treated in the usual way.

Anemia, Sickle Cell↗
PubMed1993

[Long-term registration of arterial blood pressure in sleep with noninvasive methods].

Sleep related breathing disorders and essential hypertension are highly interrelated. Many different studies proved a casual relationship between the two disorders (1,2). In a clinical sleep laboratory diagnostics of hypertension has to be non-invasive. There are two completely different methodologies to record blood pressure noninvasively. Continuous methods using fingerphotoplethysmography can record apnea related cyclical variations of blood pressure beat to beat. Unfortunately the absolute value of the pressure readings is sensitive to the position of the finger sensor. Noncontinuous methods using arm cuff inflation preserve appropriate blood pressure values but these are only spot measures during the night. To make use of these it is necessary to record other sleep and respiration related signals in parallel. Both methods were applied in our sleep laboratory and results are presented.

Blood Pressure↗