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Biomedical subjects

N Cohen

Publications and source records attributed to N Cohen.

At least 253 records · Page 14Linked to original sources
PubMed1987

Barium appendicitis: fact or fancy? Report of a case and review of the literature.

Whether barium retained in the appendix can be a cause of acute appendicitis is debatable. We describe a 40-year-old man who developed nonspecific right abdominal pain 7 weeks after a barium enema, which proved to be normal. On abdominal film a distended appendix containing barium was seen, and at laparotomy acute appendicitis was present. Thus far, 26 cases of "barium appendicitis" have been reported. On the basis of the relevant literature and the cases collected, it is appropriate to draw the following conclusions: 1) With present knowledge it is not possible to state whether retained barium plays any etiologic role in the development of subsequent uncomplicated acute appendicitis. 2) If a later appendicitis does supervene, it carries a high risk of being complicated; barium seems to be responsible for the complication. 3) The longer the interval between the barium study and the subsequent appearance of acute appendicitis, the higher will be the risk of complications.

Acute Disease↗
PubMed1987

A factor with interleukin-1-like activity is produced by peritoneal cells from the frog, Xenopus laevis.

Thymocytes from juevenile Xenopus laevis did not proliferate in response to commercial preparations of lipopolysaccharide (LPS), responded poorly when cultured with the T-cell mitogen, phytohaemagglutinin-P (PHA), and were not co-stimulated by PHA plus LPS. However, supernatants (SNs) from LPS-treated cultures of adult Xenopus macrophage-enriched resident peritoneal cells (PCs) enhanced the proliferative responses of thymocytes to a submitogenic dose of PHA. These SNs were incapable of supporting long-term growth of thymic lymphoblast cell lines, and thus could be distinguished from T-cell growth factor (TCGF)-rich SNs, which were essential for propagating these cells. The co-stimulatory activity was present in 0-24-hr SNs; after 48 hr, SN activity declined. No functional cross-reactivity of mammalian and Xenopus interleukin-1 (IL-1)-rich SNs was detected. These data are consistent with the proposition that a macrophage-derived factor, functionally homologous with mammalian IL-1, can enhance a T-cell proliferative response in an amphibian.

Animals↗
PubMed1986

Polymorphism of the HLA DR1 haplotype in the Israeli population investigated at the serological, cellular, and genomic levels.

In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-Dw"LVA", which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dw1. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8,Bw65,BfS,DR1,DQw1,DPw4. No specificity could be assigned to HLA-Dw"LVA" using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with Dw"LVA" and a panel of DR1/Dw1 HTCs. HLA-Dw"LVA" showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population Dw"LVA" is the main lymphocyte-defined determinant associated with the serologically defined DR1 specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of Dw"LVA"-positive carriers were also Bw65 carriers, indicating that Bw65,DR1, Dw"LVA" may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and Dw"LVA". In addition, we describe a cluster of FRLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.

DNA Restriction Enzymes↗
PubMed1986

A study of the HLA-D region in patients with classic Kaposi's sarcoma.

The HLA-D region in nine Sardinian patients with classic Kaposi's sarcoma was studied with two restriction enzymes, Eco RI and Eco RV, and two cDNA probes, DR beta and DQ beta. A total of 41 polymorphic restriction fragments were identified. One, an 11.5 kb Eco RV DQ beta fragment, was present in three of the patients but in none of the controls; a second, an 8.0 kb Eco RV DR beta fragment, was present in six patients and all the controls. No single fragment was identified which was significantly over or under-represented in either group.

Alleles↗
PubMed1986

HLA-DR2-associated Dw subtypes correlate with RFLP clusters: most DR2 IDDM patients belong to one of these clusters.

Two variants of the serologically defined HLA-DR2 specificity have been reported: DR2 long and DR2 short. Distinct HLA-DR2-associated Dw subtypes have been described at the cellular level. In the Israeli population, DR2 individuals may be grouped into three clusters: DR2/Dw2, DR2/Dw12, and DR2/Dw"AZH". A new approach for the study of the polymorphism of HLA class II genes is to investigate restriction endonuclease fragments obtained from genomic DNA with specific class II cDNA probes. Previous analysis of DQ beta restriction endonuclease fragments subdivided the DR2 haplotypes into two subsets: a DQR1-positive subset and a DQR2.6-positive subset. These two subsets behave in the population as alleles that split HLA DQw1. In the present study, we have analyzed class II DQ alpha, DQ beta, and DR beta restriction fragment length polymorphism (RFLP) in HLA-DR2/Dw-typed healthy, unrelated Israeli individuals, as well as in 11 French HLA-DR2 insulin-dependent diabetes mellitus (IDDM) patients and 11 French DR-matched controls. Three DQ beta allelic clusters (DQR2.6, DQR1, and DQR12) were observed among the DR2 haplotypes and clearly correlated with Dw2, Dw"AZH", and Dw12, respectively. The vast majority of the DR2 IDDM patients (9 out of 11) fit into the DQR1 cluster which correlates with Dw"AZH", while only two patients (2 out of 11) belong to the DQR2.6 cluster (Dw2-like). In contrast, among 11 DR-matched healthy controls, 9 belonged to the DQR2.6 cluster and only 2 belonged to the DQR1 cluster. These studies establish the correlation between the DR2-associated Dw subtypes with specific RFLPs, and indicate that the frequency of the DQR1 subset which correlates with Dw"AZH" is increased in DR2 IDDM patients.

DNA Restriction Enzymes↗
PubMed1986

Obesity and hypertension. Demonstration of a "floor effect".

Weight loss has a role in the treatment of essential hypertension. With the use of a medically supervised protein-sparing supplemented fast and a behavioral program, the changes in blood pressure as a result of weight loss in 135 obese hypertensive subjects were examined. Subjects' weight, blood pressure, and antihypertensive medication intake were recorded at baseline, at conclusion of supplemented fast, and at follow-up. Significant weight loss accompanied by decrements in blood pressure occurred in all subjects. Reductions in the number of antihypertensive medications also occurred. Although the correlations between changes in weight and blood pressure were significant, their moderate size suggests the amount of weight loss accounted for a relatively small part of the blood pressure reduction. Given the large weight losses in the majority of subjects, there appears to be a degree of weight loss beyond which further decrements in blood pressure will not occur ("floor effect"). Maintenance of blood pressure reductions at realimentation/follow-up suggests that weight loss, and not the supplemented fast, results in decreased blood pressure and medication level.

Adult↗
PubMed1986

Comparative pathway analysis of radiocesium in the Hudson River Estuary: environmental measurements and regulatory dose assessment models.

This work summarizes the measurements and associated environmental dosimetry of reactor-released 137Cs and 134Cs and weapons-produced 137Cs in samples of water, shoreline sediment and fish collected from 1971 to 1980 in the Hudson River Estuary. Trends observed in annual mean concentrations and the resultant dose implications for man from each source are discussed. The human exposure pathways examined are: fish consumption, water consumption, swimming and recreational use of the shoreline. Based on environmental measurements, a maximum, adult, whole-body, 50-y committed effective dose equivalent (CEDE) of 0.79 mu Sv (79 mu rem) is estimated from fish consumption in 1971, the year of maximum reactor discharge of the radiocesiums. For comparison, during the period 1974-79, mean estimates (+/- 1 SD) of the CEDE based on environmental measurements and attributed to other pathways are as follows: consumption of indigenous fish species caught downstream of the reactor outfall, 0.05 +/- 0.02 mu Sv (5 +/- 2 mu rem); consumption of fresh water sampled upstream of the reactors, 0.02 +/- 0.03 mu Sv (2 +/- 3 mu rem); and swimming, 10(-4) +/- 10(-4) mu Sv (0.01 +/- 0.01 mu rem). In addition, external, whole-body exposure resulting from recreational use of the shoreline 1.6 km downstream of the reactors is estimated to be 1.2 X 10(-8) C kg-1 (46 +/- 11 mu R yr-1). The above dose estimates are based on consumption factors of 3.9 and 803 kg y-1 (fish and water, respectively) and on usage factors of 50 and 140 h y-1 (swimming and shoreline recreation, respectively). Differences in dose estimates obtained from these long-term environmental measurements and from assessment models currently recommended for use by the U.S. Nuclear Regulatory Commission (NRC) are discussed.

Adult↗
PubMed1986

Primary pulmonary Hodgkin's disease with air bronchogram.

A 30-year-old woman presented with a large pulmonary mass and air bronchogram. Hodgkin's disease of the nodular sclerosing type was diagnosed. Survival was short despite aggressive treatment. Primary pulmonary Hodgkin's disease is extremely rare. This is the first reported case of its presentation with an air bronchogram.

Adult↗
PubMed1986

Induction of suppressor cells in normal lymphocytes by uremic serum.

Sera of patients on chronic hemodialysis induced suppressor cell activity (SCA) in normal peripheral blood mononuclear cells, which significantly impaired blastogenic response to PHA. This SCA is statistically not different from Con A induced SCA. Both SCAs are however additive. Speculations concerning the modes of action of this induced SCA are discussed.

Adult↗
PubMed1986

Inhibition of lactogenic activities of ovine prolactin and human growth hormone (hGH) by a novel form of a modified recombinant hGH.

A recombinant analog of human GH (hGH) lacking 13 amino acids at the amino-terminus (Met14hGH) inhibited the hGH- or ovine PRL (oPRL)-stimulated proliferation of Nb2 lymphoma cells and bovine PRL-stimulated fat synthesis and alpha-lactalbumin secretion in explants from bovine lactating mammary gland. The inhibition was competitive in nature, and in Nb2 cells could be abolished by an excess of hGH or oPRL. Inhibition of oPRL-stimulated proliferation of Nb2 cells by Met14hGH could also be specifically abolished by anti-hGH monoclonal antibodies. Met14hGH had no growth-stimulating activity in Nb2 cells and was not cytotoxic. It also did not affect glucose uptake by the mammary gland explants. Met14hGH competed with [125I]hGH for binding to intact Nb2 cells, IM-9 lymphocytes, solubilized microsomal fraction from lactating bovine mammary gland, and microsomal fraction from the liver of female virgin rats, but its affinity for those receptors was 2 orders of magnitude lower than the affinity of hGH. Since Met14hGH used in most experiments contained about 25% impurities and degradation products, a small amount of it was further purified by immunoaffinity chromatography. Two purified fractions, one consisting of a single 20K protein and the other accompanied by a small amount of 25K protein, were obtained. Both fractions exhibited increased inhibition of hGH- or oPRL-stimulated proliferation of Nb2 cells, thus indicating that the inhibitory activity results from the intact Met14hGH molecule. To the best of our knowledge, this is the first report describing the inhibition of lactogenic hormone activities by a modified hGH.

Animals↗
PubMed1986

An esoteric occupational hazard for lead poisoning.

A case of life threatening lead poisoning was diagnosed clinically in a Jewish scribe and verified by appropriate laboratory studies. The special ink used by the scribe was found to contain lead in appreciable amounts. Eleven more asymptomatic subjects, both scribes and manufacturers of the ink, were studied and five were found to have subclinical lead overload. Handling or production of this ink is a potential hazard for lead intoxication.

Adult↗
PubMed1986

Long-lasting enhancement of the delayed-type hypersensitivity response to heterologous erythrocytes in mice after a single injection of cyclophosphamide.

Previous reports have indicated that cyclophosphamide (CY) treatment can enhance delayed-type hypersensitivity (DTH) reactions by abrogating suppressor T cell functions. Such findings have suggested that cells in the suppressor lineage may be particularly sensitive to this alkylating agent. The experiments reported here demonstrate that a single injection of CY before sensitization can induce a long-lasting state of enhanced DTH responsiveness to sheep red blood cells (SRBC) in mice. This enhancement required concurrent antigenic stimulation and appeared to be antigen-specific. Additionally, CY treatment of sensitized mice before the first antigenic challenge for DTH resulted in suppressed responses to that challenge, followed by enhanced DTH to subsequent challenge with the same antigen. The suppressed response was achieved with a lower dose of CY than the subsequent enhancement and also required concurrent antigenic stimulation. These results indicate that the effects of CY on both effector and suppressor mechanisms are critically dependent upon antigenic stimulation, and suggest that apparent suppressor sensitivity to CY may be a function of differential ability to recover from CY treatment in a context of antigenic stimulation.

Animals↗