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H Benjamin

Publications and source records attributed to H Benjamin.

At least 19 recordsLinked to original sources
PubMed2005

Complications and mortality following stoma formation.

INTRODUCTION: As stoma formation is thought to be declining, we performed a study to evaluate the rate of stoma formation and the impact on stoma complication rates, together with risk factors for complications. PATIENTS AND METHODS: Stoma incidence, individual complications and mortality rates were retrieved from a stoma nurse database of 345 stomas created over an 8-year period. RESULTS: Stoma formation increased over the study period, although the incidence of complications declined. Stoma complications were more frequently seen in emergency surgery. A significant association between stoma complications and mortality was identified. CONCLUSIONS: Age of patient, urgency of surgery and diagnosis were associated with high levels of morbidity and mortality. Stomas are often formed in frail patients unsuitable for anastomosis formation, which may explain the high mortality in ostomy patients.

Adolescent↗
PubMed1998

IHF modulation of Tn10 transposition: sensory transduction of supercoiling status via a proposed protein/DNA molecular spring.

Architectural protein IHF modulates Tn10 transposition in vitro. IHF stimulates transposon excision. Also, separately, IHF forces transposon end/target DNA interactions into a constrained pathway, "channeling," that yields only unknotted intratransposon inversion circles. Negative supercoiling influences both effects, differently. We infer that IHF is an architectural catalyst: it promotes initial transpososome assembly and is then ejected from the transpososome. IHF then rebinds, altering transpososome conformation to promote channeling. We also infer that the developing transpososome is a molecular spring: DNA provides basic elasticity; a conformational change in transposase provides force; and IHF and/or supercoiling provide conformational inputs. In vivo, IHF is a sensory transducer of chromosomal supercoiling status: with supercoiling absent, IHF is "supercoiling relief factor"; with supercoiling present, stimulation and channeling comprise a homeostatic pair such that modest changes in chromosome condition strongly influence transpositional outcome.

Bacterial Proteins↗
PubMed1996

Fusion of the EWS gene to CHN, a member of the steroid/thyroid receptor gene superfamily, in a human myxoid chondrosarcoma.

The specific chromosomal translocation t(9;22)(q22-31;q11-12) has been observed in the myxoid variant of human chondrosarcoma. In agreement with this observation we report that the EWS gene located at chromosome band 22q12 becomes fused to CHN, a member of the steroid/thyroid receptor gene superfamily located at 9q22-31, in a skeletal myxoid chondrosarcoma. CHN appears to be the human homologue of the rat gene NOR1, which was recently identified as a sequence overexpressed in rat brain cells undergoing apoptosis. Our results also indicate that the chimaeric EWS-CHN gene encodes a EWS-CHN fusion protein in which the C-terminal RNA-binding domain of EWS is replaced by the entire CHN protein, comprising a long N-terminal domain, a central DNA binding domain and a C-terminal ligand-binding/dimerisation domain.

Amino Acid Sequence↗
PubMed1996

Permissive residues within the minimal epitopes of neutralizing monoclonal antibodies to the V3 loop of HIV-1.

Neutralizing monoclonal antibodies (mAb) specific for the third variable (V3) domain of gp120, the HIV-1 surface envelope protein, are mainly isolate specific. We have studied the composition and the permissivity of the minimal epitopes interacting with two of these, the 110-A and 19.26.4 mAb, which are strictly LAI isolate specific. Screening a hexapeptide phage library displayed on the surface of filamentous phage with the 110-A mAb has allowed selection of 49 phage sequences, permitting the definition of a consensus sequence. Based on this sequence, substituted synthetic peptides were prepared and used in binding assays. Our results show that both mAb interact with the same narrow region (316-320) of the V3 domain. The minimal epitope of the 110-A mAb was identified as a five amino acid sequence, Hy x R G p, where Hy represents any non-aromatic hydrophobic amino acid. By contrast, the minimal epitope of the 19.26.4 mAb was identified as x Q Pos G P, where Pos is any positively charged amino acid. Core residues of the epitope, critical for the binding to the mAb (written in uppercase letters), were set apart from permissive amino acid positions that tolerate substitutions (written in lowercase letters). Interestingly, the identified core residues Q2/317 (19.26.4 mAb) and R3/318 (110-A mAb) do not tolerate substitution and correspond to the QR insertion in the V3 domain, characteristic of the LAI isolate as compared to other isolates. This result may explain the strict isolate specificity of most anti-V3 LAI mAb. The two epitopes have totally different patterns of permissivity; thus, the effect of substitutions will differ depending on the mAb involved in the interaction. This suggests that the diversity of the antibody response is high enough to delay the emergence of HIV-1 variants resistant to neutralization by V3-specific antibodies.

Amino Acid Sequence↗
PubMed1995

Fusion of the EWS gene to a DNA segment from 9q22-31 in a human myxoid chondrosarcoma.

Southern blot analyses revealed a rearrangement of the EWS gene in a skeletal human myxoid chondrosarcoma. Interphase fluorescence in situ hybridization (FISH) studies, using cosmid clones F7 and G9 that flank the EWS locus on 22q12, confirmed the presence of this EWS gene abnormality. Cloning the rearranged EWS DNA fragment and mapping by FISH demonstrated that the EWS gene is joined to DNA sequences localised in 9q22-31. These findings are consistent with previous cytogenetic reports of a recurrent t(9;22)(q22-31;q11-12) in the myxoid variant of chondrosarcoma and reveal involvement of the EWS gene in a fourth type of human sarcoma.

Adult↗
PubMed1992

Inhibition of benzo[a]pyrene-induced mouse forestomach neoplasia by a principal flavor component of Japanese-style fermented soy sauce.

A refined diet supplemented with Japanese-style fermented soy sauce (shoyu) inhibits benzo[a]pyrene-induced forestomach neoplasia in mice (Cancer Res., 51:2940-2942, 1991). In the present study, soy sauce was extracted with ethyl acetate. The soluble fraction contained flavor/aroma compounds and antioxidants, whereas amino-carbonyl compounds that impart color were concentrated in the ethyl acetate insoluble fraction. Both fractions inhibited benzo[a]pyrene-induced forestomach neoplasia in a protocol in which the test material was fed following exposure to the carcinogen. A principal flavor/aroma component of soy sauce, 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone, was fed to mice following benzo[a]pyrene administration and found to inhibit the subsequent development of forestomach neoplasia. 4-Hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone was effective when fed at 4 mg/kg body weight/day, indicating that it is a potent anticarcinogen.

Animals↗
PubMed1991

Inhibition of benzo(a)pyrene-induced mouse forestomach neoplasia by dietary soy sauce.

We show that Japanese-style fermented soy sauce (shoyu) contains anticarcinogenic activity. Female ICR mice were fed a semipurified diet containing soy sauce (0-30%). Two weeks later a regimen consisting of 4 doses of benzo(a)pyrene (1 dose/week p.o. for 4 weeks) was begun to initiate forestomach neoplasia. Twenty-three weeks after the first intubation the animals were sacrificed, and forestomach neoplasms were counted and histologically confirmed. Soy sauce produced a significant dose-dependent reduction in forestomach neoplasms, which appeared to be maximal when soy sauce constituted 20% of the diet. Exposure to nitrite (0-500 ppm through drinking water) neither enhanced nor diminished the anticarcinogenic effect of the dietary soy sauce. Soy sauce was found to contain antioxidant activity which may be related to the observed anticarcinogenic effect. Contrary to expectations, mouse forestomach ornithine decarboxylase activity was induced by soy sauce. This appeared to be due at least in part to the relatively high sodium chloride content of soy sauce.

Animals↗
PubMed1991

Formation and action of anticarcinogenic fatty acids.

Conjugated dienoic derivatives of linoleic acid (referred to by the acronym CLA) constitute a newly recognized class of anticarcinogenic fatty acids. Of the eight major CLA isomers, the cis-9, trans-11 isomer alone is incorporated into phospholipid and may be the most biologically relevant isomer. CLA exhibits potent antioxidant activity; evidence is presented indicating that CLA acts both as an in vitro and in vivo antioxidant. The formation of CLA in foods, and its possible biological significance in cell membranes, is discussed.

Animals↗
PubMed1988

Reduction of benzo[a]pyrene-induced forestomach neoplasms in mice given nitrite and dietary soy sauce.

This study was conducted to determine the effects of nitrite (0.05% in drinking-water) and soy sauce (20% in a refined diet) on the initiation and promotion of benzo[a]pyrene-induced forestomach neoplasia in ICR mice. In two experiments nitrite and soy sauce together significantly reduced the number of neoplasms per animal. Soy sauce (without nitrite) produced a smaller apparent (non-significant) reduction whereas nitrite (without soy sauce) had no effect. Evidence suggested that soy sauce might contain factors that reduce calorie absorption or utilization, but this observation was independent of the inclusion of nitrite in the drinking-water and therefore could not by itself explain the significant reduction in neoplasms in mice given soy sauce plus nitrite. Protection appeared to primarily involve the tumour promotion stage.

Animals↗
PubMed1986

Modulation of carcinogenesis by dietary factors.

The purpose of this report is to present recent data on two modulating factors of carcinogenesis that are found in Western-type diets: a beef-derived mutagenesis modulator that has been shown to inhibit the initiation of epidermal carcinogenesis in mice, and the possible role of net energy rather than dietary fat per se in the enhancement of rat mammary carcinogenesis.

Animals↗
PubMed1978

Mode of action of theophylline on sodium efflux in barnacle muscle fibers.

The response of the Na efflux in unpoisoned barnacle fibers to 10 mM theophylline is biphasic; i.e., inhibition is followed by stimulation. The stimulatory response is unaffected by ouabain. Fibers pretreated with ouabain show no transitory inhibition when 10 mM theophylline is applied, but show prompt stimulation the magnitude of which is comparable to that observed with unpoisoned fibers. The same holds true for lower concentrations of theophylline. Prior injection of 500 mM EGTA completely abolishes the biphasic action of 10 mM theophylline. External application of 10 mM theophylline following removal of external Ca2+ fails to bring about a biphasic effect. Ca2+ restoration, however, results in a moderate rise in the Na efflux. External application of 10 mM theophylline stimulates the Na efflux into Ca2+-free artificial seawater (ASW) when the test fibers are pretreated with ouabain. Injection of the protein inhibitor of Walsh leads to reduced stimulation by 10 mM theophylline of the Na efflux in unpoisoned fibers. Injection of the protein inhibitor of Corbin into unpoisoned fibers leads to reduced stimulation by 10 mM theophylline. Injection of cAMP into ouabain-poisoned fibers, following internal application of Corbin's inhibitor and external application of 10 mM theophylline, fails to cause a marked rise in the ouabain-insensitive Na efflux. Injection of Corbin's inhibitor into ouabain-poisoned fibers, following the onset of peak stimulation by 10 mM theophylline, fails to reduce the Na efflux. Fibers injected with 1 mM and 100 mM EGTA and exposed to 10 mM theophylline show a marked reduction in the response of the ouabain-insensitive Na efflux to injected cAMP when the concentration of theophylline is 10 mM. A poor response to injected cAMP is also seen in fibers bathed in Ca-free ASW containing 10 mM theophylline. Theophylline (10 mM) fails to cause an enhanced stimulation of the ouabain-insensitive Na efflux into Ca-free 3 mM-HEPES ASW or 10 mM-Ca2+ -3mM-HEPES ASW following the addition of protons to the bathing medium. An enhanced response is similarly not observed with injected cAMP following the addition of theophylline to the bathing medium. Injection of 8-fluorotheophylline, 3-isobutyl-1-methylxanthine and doxantrazole leads to a marked reduction in the response of the ouabain-insensitive Na efflux to injected cAMP. Contraction always takes place upon injecting these substances. These results are in keeping with the theory that theophylline acts chiefly by reducing myoplasmic pCa(pCa=-log10[Ca2+]), and that a reduced pCa leads to stimulation of the ouabain-insensitive Na efflux as the result of activation of the cGMP-dependent protein kinase system by newly formed cGMP.

Animals↗
PubMed1976

A new technique for hemipelvectomy.

A new technique for hemipelvectomy has been developed in which a large anterior well vascularized flap is used. The preservation of an anterior flap is essential if the posterior flap cannot be preserved because of tumor involvement. The vascularized anterior flap may be superior to the posterior flap because of less dermal necrosis. Use of the anterior flap may increase the ease of hemipelvectomy and reduce blood loss at operation.

Adult↗
PubMed1973

Transsexualism.

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Gonadal Steroid Hormones↗