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Biomedical subjects

R Weiss

Publications and source records attributed to R Weiss.

At least 199 records · Page 11Linked to original sources

Comparison of survival. Chemotherapeutically treated and untreated older patient with acute myeloid leukemia.

Survival of older patients with acute nonlymphocytic leukemia treated with chemotherapy was compared with those given only supportive care. The treated group was younger and had better survival. The benefits which measure in months must be balanced against socioeconomic cost, toxicity of therapy, patient wishes, and evolving information about the standards of management in the older leukemia patient.

Acute Disease↗

Lower dose diuretic therapy in the treatment of patients with mild to moderate hypertension.

Indapamide (Lozol), an indoline antihypertensive drug with diuretic and vasodilating activities, was evaluated in 195 patients with mild to moderate essential hypertension (sitting DBP between 95 and 110 mmHg) in a multicentre, randomised, double-blind, parallel-group design trial. A four week single-blind placebo wash-out period was followed by an eight week double-blind period. Patients were randomised to indapamide 1.25 mg/day or to placebo. The primary efficacy endpoint was the mean change in sitting DBP from baseline to week 8. Ninety patients in the placebo group (93%) and 82 patients (84%) in the indapamide group completed the eight weeks of double-blind therapy. Indapamide produced a mean (SE) decrease in sitting DBP of 7.4 (0.63) mmHg (from 100.1 to 92.8 mmHg) compared with a decrease of 3.6 (0.75) mmHg (from 99.6 to 95.8 mmHg) produced by placebo (p < 0.0001). Indapamide and placebo also produced mean decreases in standing DBP of 6.8 (0.75) and 2.8 (0.77) mmHg, respectively (p = 0.0002), in sitting SBP of 11.1 (1.18) and 3.2 (1.35) mmHg, respectively (p = 0.0001) and in standing SBP of 11.4 (1.29) and 4.0 (1.43) mmHg, respectively (P = 0.0002). Reduction in BP of > or = 10 mmHg or to a DBP of < or = 90 mmHg was more frequent (P = 0.0005) among indapamide (46.6%) compared with placebo (23.7%) treated patients. During the eight week double-blind treatment period, incidence rates for all adverse experiences and for drug-related adverse experiences were similar between the two treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

A rapid screening method to detect nonsense and frameshift mutations: identification of disease-causing APC alleles.

A functional screen for nonsense and frameshift mutations has been devised that allows genes of interest to be scanned in segments. This assay is based on the cloning of these segments in-frame with a colorimetric marker gene (lacZ) followed by screening for the level of functional activity from the marker polypeptide (beta-galactosidase). Individuals at risk for any one of a number of genetic diseases, in particular familial adenomatous polyposis coli (APC), can be quickly screened for chain-terminating mutations introduced by stops and frameshifts. At present, scanning of the APC gene for mutation requires significant effort because it is a large gene and most APC mutations are unique. Therefore, this assay offers a powerful option for the diagnosis of this and other genetic diseases, as well as great potential for the development of a similar rapid screen to detect APC mutations in colorectal adenomas and carcinomas.

Alleles↗

Inhibition of endosome fusion by phospholipase A2 (PLA2) inhibitors points to a role for PLA2 in endocytosis.

Fusion of intracellular membrane-bound compartments is a common step in the transport of macromolecules along the endocytic and secretory pathways. A large number of factors active in the fusion process or its regulation have been identified; however, the actual sequence of events leading to membrane fusion is still unknown. In this study, we have assessed a possible role for PLA2 in endosome fusion by using an in vitro reconstitution assay and by examining endocytosis in intact cells. Several PLA2 inhibitors blocked endosome fusion in a broken-cell preparation. Inhibition was reversed by addition of arachidonic acid. At the electron microscope level, endosome clusters were observed even in the presence of inhibitors; however, actual fusion between endosomes was largely reduced. Fusion frequency increased upon the addition of arachidonic acid. A membrane-permeable PLA2 inhibitor blocked mixing of ligands internalized sequentially but did not affect internalization. The results indicate that vesicle fusion along the endocytic pathway requires a PLA2 activity. The effect of this activity would be, at least in part, mediated by arachidonic acid release.

Animals↗

Is CD4 sufficient for HIV entry? Cell surface molecules involved in HIV infection.

HIV-1, HIV-2 and SIV each bind to CD4 as the first step in virus entry. However, alternative receptors may also be used. HIV-1 binds to glycolipids with terminal galactosylceramide residues on neural cells; opsonized virus binds to Fc receptors; HIV-2 can infect certain CD4-negative cells. Further receptors may also play a role in CD4-mediated infection, including cell adhesion molecules and possibly cell surface proteinases. After binding to CD4, immunodeficiency viruses require secondary molecules to effect fusion between the virus envelope and the cell membrane; these accessory requirements differ between HIV-1, HIV-2 and SIV.

Animals↗

Line scanning system for direct digital chemiluminescence imaging of DNA sequencing blots.

A cryogenically cooled charge-coupled device (CCD) camera equipped with an area CCD array is used in a line scanning system for low-light-level imaging of chemiluminescent DNA sequencing blots. Operating the CCD camera in time-delayed integration (TDI) mode results in continuous data acquisition independent of the length of the CCD array. Scanning is possible with a resolution of 1.4 line pairs/mm at the 50% level of the modulation transfer function. High-sensitivity, low-light-level scanning of chemiluminescent direct-transfer electrophoresis (DTE) DNA sequencing blots is shown. The detection of DNA fragments on the blot involves DNA-DNA hybridization with oligonucleotide-alkaline phosphatase conjugate and 1,2-dioxetane-based chemiluminescence. The width of the scan allows the recording of up to four sequencing reactions (16 lanes) on one scan. The scan speed of 52 cm/h used for the sequencing blots corresponds to a data acquisition rate of 384 pixels/s. The chemiluminescence detection limit on the scanned images is 3.9 x 10(-18) mol of plasmid DNA. A conditional median filter is described to remove spikes caused by cosmic ray events from the CCD images.

Alkaline Phosphatase↗

Scientific results from the Cosmic Background Explorer (COBE).

The National Aeronautics and Space Administration (NASA) has flown the COBE satellite to observe the Big Bang and the subsequent formation of galaxies and large-scale structure. Data from the Far-Infrared Absolute Spectrophotometer (FIRAS) show that the spectrum of the cosmic microwave background is that of a black body of temperature T = 2.73 +/- 0.06 K, with no deviation from a black-body spectrum greater than 0.25% of the peak brightness. The data from the Differential Microwave Radiometers (DMR) show statistically significant cosmic microwave background anisotropy, consistent with a scale-invariant primordial density fluctuation spectrum. Measurements from the Diffuse Infrared Background Experiment (DIRBE) provide new conservative upper limits to the cosmic infrared background. Extensive modeling of solar system and galactic infrared foregrounds is required for further improvement in the cosmic infrared background limits.

Journal Article↗

[Primary care consultation rates among the middle aged and elderly].

The consultation rate among family physicians has been widely discussed in the literature, but very few studies have been done in Israel. We analyzed the pattern of visits to the family physician of 1,860 patients aged 40 years and older in 3 urban clinics, 2 kibbutzim and 1 rural clinic with a total population of 6,700. The consultation rate rose steadily with age. It was 3.4 per year at age 40-49, and 5.6 at ages 70 and over, with a mean annual rate of 4.6. 77% of the screened population consulted the physician in 1 year and 91.4% in 3 years. Only 9.6% did not visit their physicians in the 3 years. About two-thirds visited the physician 1-4 times a year, and only 2% visited more than 15 times. In urban practices women attended more often than men but there was no significant sex difference in the rural practices. As a result of the greater visit rates of the elderly, they consumed a larger share of medical services. The mean consultation rate in this survey is similar to that in England and in other Western countries. However, it is relatively low in comparison to other studies in Israel. This may be due to the different practice setting and the use of a different sampling frame.

Adult↗

Transcomplementation of VIF- HIV-1 mutants in CEM cells suggests that VIF affects late steps of the viral life cycle.

The vif gene of HIV-1 has previously been claimed to be essential for the ability of cell-free virus preparations to infect cells. Here we report that the CEM T-cell-line, stably transfected with and expressing vif, supports the replication of vif- HIV-1 viruses to the same extent as wild-type HIV1. Cell entry and early replication stages are the same for vif- and vif+ HIV-1 passaged in CEM, as measured both by a PCR-based cell entry assay and by fusogenic potential. These findings indicate that vif does not affect viral infectivity on CEM cells, but seems to act at a later stage of virus replication/maturation. We also show that the VIF proteins of two different HIV-1 strains can transcomplement different vif- HIV-1 mutants.

Cell Line↗

Effects of interleukin-1 and interleukin-6 on metallothionein and amyloid precursor protein expression in human neuroblastoma cells. Evidence that interleukin-6 possibly acts via a receptor different from the 80-kDa interleukin-6 receptor.

Since immunohistochemical studies indicated the presence of interleukin-6 in the cortices of patients with Alzheimer's disease, we were interested in the eventual biological effects of this cytokine on neuronal cells. We found that interleukin-6 and interleukin-1 induced metallothionein expression in a human neuronal (SH-SY5Y neuroblastoma) cell line. In contrast to metallothionein, amyloid precursor protein expression was unaffected by both cytokines. When searching in the same cell line for the expression of the classical 80-kDa interleukin-6 binding protein, which is part of the dimeric interleukin-6 receptor, we were unable to detect the respective mRNA. Our findings either indicate that the interleukin-6 receptor in these cells is expressed in extremely low levels or that interleukin-6 may act upon neuronal cells via a different, yet unknown neuronal receptor.

Amyloid beta-Protein Precursor↗

Enzootic Mycobacterium avium infection in captive Parma wallabies (Macropus parma) with unusual spinal cord manifestations.

Pathological, microbiological and clinical findings in Parma wallabies (Macropus parma) with an enzootic infection caused by Mycobacterium avium are described. Disorders of locomotion resulted from granulomatous myelitis, meningitis and radiculitis in the lumbosacral spinal cord. Lesions found in a number of internal organs suggested protracted systemic infection due to an alimentary or airborne infection with Mycobacterium avium. This organism was isolated and identified by methods that included microbiological examinations, based on microscopy, culture, in-vitro tests, animal inoculation, polymerase chain reaction and cycle sequencing.

Animals↗

Interscalene block for shoulder arthroscopy: comparison with general anesthesia.

Arthroscopic shoulder surgery can be performed under regional or general anesthesia. The objective of this study was to demonstrate that regional anesthesia has several benefits over general anesthesia for this type of surgery, particularly in the ambulatory patient. Forty patients received general anesthesia and 63 an interscalene block. The regional block was found to be safe and effective, with a high degree of patient acceptance. It provided excellent intraoperative analgesia and muscle relaxation. Postoperatively, regional anesthesia resulted in fewer side effects, fewer hospital admissions, and a shorter hospital stay than did general anesthesia.

Adolescent↗

Characteristics of registered clinic patients who have not visited their family physician for 3 years.

The objective of this study was to obtain and critically evaluate data on the health characteristics and the need for medical assistance in patients aged 40 years and over, from six urban and rural medical practices in northern Israel, who have not consulted their family physician for at least 3 years. A health questionnaire was completed by means of telephone calls and personal contacts, regarding 139 non-visitors (out of 1847 patients aged 40 and over). The health characteristics and prevalence of medical and social problems were compared to regular clinic attenders. Questionnaires of 101 non-attenders were completed for a response rate of 73% (101/139). The non-attendance rate was 7.5% (139/1847) and there was a low rate of morbidity. The majority (81%) were 40-59 years old and only 16% had had previous illnesses. Only 10% took medications regularly, most of them medical personnel. Twenty-eight of the non-attenders were employees of the regional health care system. Most of these individuals coped with chronic illnesses by consulting the regional hospital's outpatient clinics. Non-attenders could be characterized as less prone to health problems. Most of them seemed remarkably fit and were not suffering unduly as a result of their lack of medical attention.

Adult↗

The nephritogenic immune response.

An emerging viewpoint states that localization of antibodies, T cells, and macrophages within the kidney occurs through specific receptor-mediated interactions to initiate nephritis. The initial events involve loss of tolerance with activation of autoreactive B cells, autoreactive T cells, or both. Many pathogenic autoantibodies form immune deposits either by binding directly to renal antigens or by complexing with endogenous antigens with affinity for renal antigens. Autoreactive T-cell infiltration requires both the presence of specific antigens and costimulatory factors expressed by cells capable of antigen presentation. It is particularly noteworthy that some of the antigen targets of the nephritogenic immune response involve either cell surface molecules or matrix components with functional properties, raising the possibility that ligation of these components could serve to modulate the local inflammatory response. Furthermore, specific perturbations within endogenous cells, resulting directly from these interactions, probably influence subsequent inflammatory-fibrogenic events. In this review, we focus on recent work relating to the loss of tolerance leading to the emergence of autoreactive B and T lymphocytes; specific autoantibody and T-cell interactions within the kidney; and the active participation of endogenous cells in the initiation of the nephritogenic response.

Animals↗