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Biomedical subjects

I Hirsch

Publications and source records attributed to I Hirsch.

At least 73 records · Page 4Linked to original sources
PubMed1988

Absence of cytomegalovirus, Epstein-Barr virus, and papillomavirus DNA from adenoma and adenocarcinoma of the colon.

Biopsy specimens from 13 patients with adenocarcinoma of the colon and from 10 patients with endoscopic polypectomies for colon adenoma were examined for the presence of the DNA of cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human papillomavirus (HPV) types 2, 6, 16 and 18. The specific activities of viral DNA probes obtained by nick--translation ranged from 10(7) to 10(8) cpm/micrograms DNA. By Southern blot hybridization with an estimated sensitivity of 10 pg virus DNA which corresponded to 0.05 virus genome equivalents per cell we failed to detect any virus DNA in the biopsy material tested.

Adenocarcinoma↗
PubMed1988

Mitral valve prolapse (Barlow's syndrome) and retinal emboli.

Mitral valve prolapse (M.V.P.) is a noninflammatory degeneration of the mitral valve leaflets which results in a billowing of the redundant valve tissue toward the left atrium during the systolic phase. Mitral valve prolapse can be diagnosed by echocardiography or by auscultation where a characteristic mid-systolic click and late systolic murmur can be heard. Ophthalmic complications of MVP include chronic external progressive ophthalmoplegia and an association with keratoconus. In this case we present a case of a young woman who presented with sudden recurrent decrease in vision secondary to retinal arterioli emboli associated with the mitral valve prolapse syndrome.

Adult↗
PubMed1987

Electron microscopy of binding of Epstein-Barr virus (EBV) nuclear antigen (EBNA-1) to EBV DNA.

Specific binding sites for Epstein-Barr virus (EBV) nuclear antigen (EBNA-1), isolated and semipurified from EBV-transformed nonproductive Raji cells, were visualized on the molecule of EBV DNA by electron microscopy and mapped. Two measures had to be applied to counteract the limited purity of the EBNA-1 preparation: (i) EBV DNA/EBNA-1 complexes were specifically enlarged by binding with anti-EBNA-1 (IR-3) IgG antibody. (ii) DNA-binding proteins that did not react with the anti-EBNA-1 antibody were eluted from EBV DNA with 1.5 M NaCl, taking advantage of the resistance of DNA/EBNA-1/anti-EBNA-1 antibody complexes to the high-salt treatment. EBNA-1 bound at the highest relative frequency (greater than 30%) to the EBV DNA map positions of 8.8 +/- 0.3, 10.3 +/- 0.5, and 46.6 +/- 1.2 kb. It bound with a lower but still statistically significant frequency (16%) to the map positions of 64.5 +/- 1.0, 89.7 +/- 1.6, 129.6 +/- 1.1 kb.

Antigens, Viral↗
PubMed1987

Transfection of human lymphocytes with cloned Epstein-Barr virus (EBV) DNA.

Human primary cord-blood lymphocytes were transfected, using the DEAE-dextran technique, with a set of seven largely overlapping clones jointly covering the whole M-ABA Epstein-Barr virus (EBV) genome. Three fragments, cosmids cMB-14 and cM301-99 and plasmid pM966-20, were able to stimulate transient cellular DNA synthesis, blastic transformation, and clumps formation, as well as to prolong the life span from a maximum of 2 weeks in control cultures to up to 6 weeks. The fragments stimulating DNA synthesis also expressed this property in mutual combinations or when combined with cosmid cMSal-A or cM302-21. Their use with any other fragments in cotransfection did not result in further DNA synthesis stimulation. Cosmids cM302-23 and cMSal-B suppressed this effect. Cosmid cM301-99 but not cM302-23 induced transient EBNA-1 formation in about 1% of lymphocytes. Lymphocytes transfected with single fragments or their combinations failed to grow into immortalized cell lines. The results suggest that transient expression of viral functions at levels achievable by transfection is not sufficient for cell immortalization.

Cell Transformation, Viral↗
PubMed1987

[Detection of Epstein-Barr virus nucleic acid sequences in non-Hodgkin's lymphoma].

Tumor tissue specimens of 25 patients with various entities of Non-Hodgkin's lymphomas were examined for the presence of Epstein-Barr virus (EBV) nucleic acids and EBV nuclear antigens (EBNA) by in situ hybridization and anticomplement immunofluorescence. In tumor cells of five patients EBV nucleic acid and EBNA were demonstrated. The histopathologic examinations revealed in these cases one Burkitt's lymphoma, two centroblastic lymphomas and each one lymphoplasmocytic and lymphocytic lymphoma.

Adolescent↗
PubMed1986

In vitro fertilization in couples with male factor infertility.

The data from 83 consecutive in vitro fertilization-embryo transfer cycles were examined with emphasis on the presence of subfertile male parameters, including abnormal sperm density, motility, morphologic features, or an abnormal result in the sperm penetration assay (zona-free hamster ova penetration). There were 25 cycles (21 couples) in which there was a solitary or coexistent abnormal male factor. The presence of a male factor was associated with a lower fertilization rate and fewer embryos transferred. Statistically important reductions in the fertilization rate occurred with reduced sperm density and abnormal motility, but not with abnormal morphologic features. The parameter that was most significantly associated with human ova fertilizability was the ability to exceed two penetrations per egg in the sperm penetration assay.

Animals↗
PubMed1986

Effect of long term treatment with metoprolol and sotalol on ventricular repolarisation measured by use of transoesophageal atrial pacing.

The effects of long term (4 weeks) treatment with oral metoprolol (100 mg twice daily) and sotalol (160 mg twice daily) on ventricular repolarisation time were compared in a double blind crossover study in 20 patients post-infarction. For QT interval studies transoesophageal atrial pacing was performed at a cycle length of 800 ms. Sotalol prolonged the QT interval by 5-7% compared with metoprolol. The prolongation reflects a change in the repolarisation time because there was no change in the QS interval. Measurements of heart rate at rest and during bicycle exercise indicated that metoprolol and sotalol in the doses selected were equipotent as beta blockers. Transoesophageal atrial pacing is a simple non-invasive method with few and mild side effects that is well suited to drug studies.

Aged↗
PubMed1986

Recurrent tears following successful retinal detachment surgery.

In 17 cases of recurrent retinal tears occurring after successful retinal detachment surgery, the new tears developed on or near the treated primary tear in seven cases and away from the treated tear in ten cases. It took an average of 25.6 months for the second tears to develop, and almost all of the recurrent tears were the same distance from the limbus as the primary tear. The benefit of the 360 degree encircling band and the relationship of the thermal injury to production of a second tear is discussed.

Adult↗
PubMed1986

New issues in agricultural spraying in Israel.

Food and fiber production on relatively small, irrigated plots with high-yielding potential makes the agricultural aircraft a vital tool in Israel's modern agriculture. Extensive preventive measures are carried out to minimize chemical drift and to dispose of chemical wastes. The Civil Aviation Authority is concerned with both pilot fatigue and exposure to toxic chemicals and thus the legal limits of flight time and the medical monitoring methods are enforced. With the introduction of new pesticides, such as the pyrethroids, new medical monitoring methods must be developed. The tables show amounts and kinds of chemicals used on cotton since 1978 and the percentages of various insecticides used on cotton in 1979, 1981, and 1984. Since pyrethroids are of low, short-term mammalian toxicity, can we continue to apply them in increasing amounts without monitoring exposure? Past experience has taught us to treat any pesticide with caution. A method for monitoring exposure to pyrethroids should be introduced.

Aerospace Medicine↗
PubMed1985

Bactericidal activity of phenoxymethylpenicillin in an in-vitro model simulating tissue kinetics.

The antibacterial efficacy of phenoxymethylpenicillin (Pen-V-K) against strains of Staphylococcus aureus was assessed in an in-vitro kinetic model. Simulation was based on human serum levels and tissue water curves obtained after a single oral dose of 392.2 mg of the drug. Differences in bacterial elimination kinetics were noted depending upon the type of curve (serum or tissue water) being simulated.

Humans↗
PubMed1985

Effects of lidocaine, procainamide, metoprolol, digoxin and atropine on the conduction of premature ventricular beats in man.

The acute electrophysiologic effects of clinical doses of procainamide, lidocaine, metoprolol, digoxin and atropine upon the conduction of ventricular premature beats, were studied in 48 healthy volunteers. The conduction time of the first premature beat, induced 1 ms after the ventricular effective refractory period (VERP) was longer than that of the basic paced beats in 41 of the 48 subjects (85%); in 31 (65%) the delay was greater than 5 ms, indicating subnormal conduction. Digoxin decreased the delay so that it became insignificant, while, after procainamide, the delay increased significantly. The other agents did not significantly affect the subnormal conduction. The mean conduction times of premature beats, induced 30-50 ms after the VERP, were shorter than the basic conduction time in 43 of the 48 subjects (90%), and in 25 (52%) the decrease was greater than 5 ms, showing supernormal conduction. Lidocaine abolished the supernormal conduction. The other agents did not significantly alter the supernormal conduction. In the healthy heart, sub- and supernormal conduction of premature beats seem to be common phenomena, and seem, with few exceptions, to be largely unaffected by clinical doses of procainamide, lidocaine, metoprolol, digoxin and atropine.

Action Potentials↗
PubMed1985

Immunoprecipitation of Epstein-Barr virus (EBV)-specific proteins by prelymphomatous and normal baboon sera containing antibodies reactive with EBV early antigen.

Carbon (14C)-amino acid mixture-labelled antigen extracted from 12-0-tetradecanoyl-phorbol-13-acetate (TPA) and sodium n-butyrate-induced P3HR-1 cells was immunoprecipitated with sera from normal, prelymphomatous and lymphomatous baboons, as well as with sera from human controls. Most of the Epstein-Barr virus (EBV)-specific proteins that were precipitated by human sera were also precipitated by baboon sera. A major difference between prelymphomatous and normal control baboon sera was that 5 out of 6 the former and none of the latter immuno-precipitated an EBV-early antigen-specific protein with Mr 31,000.

Animals↗
PubMed1985

Viral DNA sequences in human cytomegalovirus transformed hamster cell line at low passage levels.

The characteristics of a human cytomegalovirus (HCMV) transformed syrian hamster cell line (87-TRH-5) were examined. The cytomegalovirus DNA (HCMV-DNA) labelled in vitro by nick translation was used as a probe to detect viral DNA sequences in the 87-TRH-5 line. Cytomegalovirus specified DNA sequences were detected in cells examined up to passage 58, but were undetectable at higher passage levels. Six clones were derived from the 28th passage of 87-TRH-5 cells and examined for HCMV-DNA sequences. Various amounts of HCMV-DNA were found. A tumour induced by passage 28 cells contained no detectable HCMV-DNA sequences.

Animals↗