Search PubMed⌕ Search

Biomedical subjects

B Evans

Publications and source records attributed to B Evans.

At least 73 records · Page 4Linked to original sources
PubMed1995

Autocrine/paracrine induction of tissue inhibitor of metalloproteinase-1 in Chinese hamster ovary cells by oncostatin M.

Chinese hamster ovary (CHO) cells expressing recombinant human oncostatin M (rOM) were found to secrete high levels of a 28-kDa protein. Sequence analysis of the protein suggested that it was hamster tissue inhibitor of metalloproteinase-1 (TIMP-1). In this study, we show that induction of TIMP-1 mRNA and protein by CHO cells is due to rOM action in an autocrine/paracrine mode. TIMP-1 expression in rOM-producing CHO cells increased concomitantly with methotrexate-induced rOM amplification. TIMP-1 upregulation was not caused by either transfection of nonspecific DNA nor was it a direct effect of treatment of the cells with methotrexate. These results suggest that oncostatin M is a potent inducer of TIMP-1 and that its receptor-mediated expression is conserved across species.

Animals↗
PubMed1995

Changes in the characteristics of clients admitted to an Australian therapeutic community, "The Buttery", 1980-92.

Data are presented on the characteristics of clients admitted to an Australian therapeutic community, The Buttery, between 1980 and 1992. The typical client was a 28-year-old male with a primary opioid drug problem complicated by polydrug use, particularly of alcohol and stimulants. Prior treatment experience was common, with one in three having been enrolled in methadone maintenance treatment. The average age of clients increased by about 7 months per year, and there was an increase in the prevalence of alcohol, stimulant and polydrug problems over the period of study. There was also an increase in the exposure of clients to methadone maintenance treatment prior to admission to the Buttery. Overall, the characteristics of patients in this drug-free treatment programme were strikingly similar to those observed among patients in methadone maintenance treatment over the same period.

Journal Article↗
PubMed1995

Australasian multicentre phase II study of paclitaxel (Taxol) in relapsed ovarian cancer.

BACKGROUND: Until recently there has been no effective therapy for patients with relapsed ovarian carcinoma following standard platinum based chemotherapy. Paclitaxel has recently been approved for clinical use in this malignancy. AIMS: To evaluate the objective response rate and toxicity of paclitaxel in patients with relapsed ovarian cancer. METHODS: Paclitaxel was given on an outpatient basis as a three hour infusion every 21 days for a maximum of ten cycles to 72 patients with advanced ovarian cancer previously treated with at least one platinum containing regimen. The starting dose was either 175 mg/m2 (patients with one or two prior chemotherapy regimens) or 135 mg/m2 (three previous regimens). Premedication was given because of the documented risk of hypersensitivity reactions to paclitaxel. RESULTS: The overall response rate was 22% (95% confidence interval [CI] 13% to 34%) in the 72 patients enrolled in the study: four patients had a complete response. Three patients (4%) ceased treatment due to hypersensitivity reactions. Other significant (WHO grade 3 or 4) toxicities included neutropenia (51%), myalgia (14%), neurological (3%), alopecia (93%) and nausea and vomiting (3%). The estimated median survival of all patients was 9.8 months (95% CI: 9.1-13.0 months) with 44% alive at one year (standard error [SE] 7%). CONCLUSIONS: This study confirms that paclitaxel given as a three hour infusion has significant activity and acceptable toxicity in advanced ovarian carcinoma previously treated with platinum regimens.

Adolescent↗
PubMed1995

Laparoscopic surgery for inflammatory bowel disease.

In the setting of inflammatory bowel disease (IBD), laparoscopic approaches have been avoided because of the often fragile intestinal tissue, thickened mesentery, malnutrition, immunosuppression, and the presence of dense adhesions. In this article, we report 10 successfully managed laparoscopic cases in IBD patients (five with ulcerative colitis, five with Crohn's Disease). Patients with ulcerative colitis underwent total abdominal colectomies, mucosal proctectomies, J-pouch construction, and diverting ileostomies. Procedures in patients with Crohn's disease included ileocecectomy (3), sigmoid colectomy with takedown of a transverse colonic fistula (1), and stricturoplasty (1). One of the 10 cases was converted to an open technique for technical reasons. Six of the 10 patients were on high dose corticosteroids for disease control. Hospital stay ranged from 6-13 days, with a median of 7 days. The morbidity rate was 20 per cent, and included one case of mild postoperative pancreatitis in a Crohn's disease patient and one delayed peri-ileostomy fistula in an ulcerative colitis patient. There was no mortality. Based on these results, we conclude that laparoscopic intestinal surgery is both feasible and safe in selected patients with inflammatory bowel disease. Use of laparoscopic techniques in these patients may reduce hospital stay, lessen adhesion formation, and improve cosmetic results in this generally young group of patients.

Adolescent↗
PubMed1995

Cold urticaria, raised IgE and HIV infection.

We present a patient with cold urticaria as an unusual and late cutaneous manifestation of acquired immunodeficiency syndrome. The severe CD4 cell depletion and markedly elevated serum IgE levels in our patient provide some insights into certain aspects of immune regulatory mechanisms.

Adult↗
PubMed1993

Non-radiological technique for three-dimensional imaging of endoscopes.

A novel system is described which images in three dimensions, the total configuration of a colonoscope without the use of conventional radiological techniques. A low intensity magnetic field is used in conjunction with a miniature inductive sensor. The system intrinsically safe and it is potentially inexpensive and capable of being used in a normal hospital environment. Clinical trials are described in which the system is validated in terms of its suitability for the application. Magnetic and conventional X-ray images obtained ex vivo with the endoscope held in various configurations and comparisons in the patients confirm the practical applicability of the new system.

Colonoscopes↗
PubMed1993

The sheep erythropoietin gene: molecular cloning and effect of hemorrhage on plasma erythropoietin and renal/liver messenger RNA in adult sheep.

Erythropoietin (Epo) production was studied in adult sheep. Nine ewes, body weight (BW) 39 +/- 1.3 kg, were hemorrhaged a volume of blood equivalent to 1.6% BW, and sampled at 0, 2, 4, 6, 24 h. Oxygen content (O2 CT) decreased by 2.7 +/- 0.6 ml/dl at 2 h. Plasma immunoreactive (IR) Epo was only significantly increased at 24 h, from 18.5 +/- 3.5 to 40 +/- 10.7 mU/ml (mean +/- SEM). A further 5 ewes were bled extensively (2793 +/- 82 ml) over 54 h, and killed for Epo mRNA determination. The O2 CT decreased from 12.3 +/- 1.6 to 4.1 +/- 0.6 ml/dl, and plasma Epo increased from 15 +/- 4 to 1675 +/- 287 mU/ml. The sequence of ovine Epo cDNA was derived from the kidney RNA of a severely bled sheep using reverse transcription/polymerase chain reaction (RT/PCR), and from an ovine Epo genomic clone. The cDNA encodes a peptide of 194 amino acids, including a 27 amino acid signal peptide. The deduced amino acid sequence of sheep Epo shows 82%, 78% and 80% homology with mature Epos of human, mouse and monkey, respectively. The gene structure resembles closely those of human and mouse, with 5 exons and 4 introns. The expression of the ovine Epo gene in tissues from normal and hemorrhaged sheep was analysed by a competitive RT/PCR method. Epo mRNA was difficult to detect in liver from normal sheep, but was detectable at 0.01-0.04 amol/microgram total RNA in kidney from normal sheep. In the kidneys of severely bled sheep, the Epo mRNA levels (per micrograms total RNA) increased 400-1500-fold compared to that of normal kidneys, and were approximately 60-fold greater than those in the livers of the hemorrhaged sheep.

Amino Acid Sequence↗
PubMed1993

Suppression of non-esterified fatty acids and triacylglycerol in experimental animals by the adenosine analogue GR79236.

1. This is the first description of the metabolic activity of a novel adenosine A1-receptor agonist, GR79236. GR79236 inhibited catecholamine-induced lipolysis in human, rat and dog isolated adipocytes. 2. Oral administration of GR79236 (0.1-10 mg/kg) to fed rats induced minimal changes in the plasma concentration of non-esterified fatty acids and in the blood concentrations of glucose and lactate. 3. Intravenous infusion of GR79236 to fasted pithed rats, or oral administration of GR79236 to fasted conscious rats and dogs, produced time- and dose-dependent decreases in the plasma non-esterified fatty acid concentration. In the fasted rats, doses of GR79236 that lowered plasma levels of non-esterified fatty acids also produced hypotriglyceridaemia and anti-ketotic effects. 4. Only in the pithed rats were acute effects on the plasma glucose and lactate concentrations observed. Hypoglycaemia and hyperlactataemia occurred over the dose range studied (1 x 10(-11)-1 x 10(-8) mol min-1 kg-1). 5. This profile of activity suggests that compounds such as GR79236 might be agents which can be used to define the role of excessive lipolysis in experimental (and human) pathophysiology.

Adenosine↗
PubMed1993

Functional characterization of three adenosine receptor types.

1. The purpose of the present study was to classify adenosine receptors into A1 and A2 subtypes in a wide range of isolated tissues and cell types (rat adipocytes and atria, guinea-pig ileum and atria (A1); guinea-pig aorta, dog coronary artery and human platelets and neutrophils (A2)) using the R- and S-diastereoisomers of N-phenylisopropyladenosine (PIA), N-cyclopentyladenosine (CPA), the novel compound, N-[(1S,trans)-2-hydroxycyclopentyl]adenosine (GR79236), N-[(2-methylphenyl)methyl]adenosine (metrifudil), 2-(phenylamino)adenosine (CV1808), and 2[[2-[4-(2-carboxyethyl)phenyl]ethyl]amino]-N- ethylcarboxamidoadenosine (CGS21680); N-ethylcarboxamidoadenosine (NECA) was used as a standard. 2. Results obtained in all tissue preparations previously reported to contain A1-receptors could be described by a single rank order of agonist potency: CPA > or = GR79236, R-PIA > or = NECA >> S-PAI > or = metrifudil > or = CV1808, CGS21680. 3. In contrast, two distinct rank orders of agonist potency were observed in preparations previously reported to contain A2-receptors. In dog coronary artery, human neutrophils and platelets the rank order of potency was: CV1808, CGS21680 > or = NECA > R-PIA > or = metrifudil > or = CPA > GR79236 S-PIA. However, in guinea-pig aorta the rank order was: NECA > metrifudil > R-PIA, CPA > CV1808, GR79236 > or = S-PIA, CGS21680. 4. The results of this study are consistent with the existence of three types of adenosine receptor: A1-and two subtypes of A2-receptor. The receptor present in dog coronary artery, human platelets and neutrophils, probably corresponds to the A2a subtype, whilst that present in the guinea-pig aorta may be of the A2b subtype.

Adenosine↗
PubMed1993

Fibrin deposition in SLE glomerulonephritis.

Coagulation and fibrinolytic processes are involved in the pathogenesis of some forms of glomerulonephritis. In human renal disease extensive fibrin deposition is mainly associated with severe diseases such as rapidly progressive glomerulonephritis. Staining methods for fibrin have problems and many immunohistochemical methods do not distinguish fibrinogen from fibrin and its degradation products, which result from coagulation. The presence of cross-linked fibrin in the glomerulus indicates that coagulation has occurred, but the presence of fibrinogen may be a result of non-specific protein permeation. A monoclonal antibody (DD3B6) has been used to demonstrate cross-linked fibrin in 30 renal biopsies in systemic lupus erythematosus. The biopsies were also stained with an 'antifibrinogen' and an antiplatelet antibody. The severity of renal disease in each biopsy was graded by both the World Health Organization (WHO) classification and Austin's Activity and Chronicity Indices. Three of the renal biopsies were shown to stain with DD3B6 and five stained with antiplatelet antibody. Twenty-seven contained fibrinogen and there was no evidence of intraglomerular coagulation in these biopsies. The biopsies containing cross-linked fibrin were all in WHO group IVc. The severity of disease measured by Austin's Activity Index was no greater in these biopsies than in other biopsies in WHO Group IVc in which cross-linked fibrin was not detected. The presence of cross-linked fibrin may be associated with intraglomerular coagulation and more severe disease.

Antigens, Human Platelet↗
PubMed1993

The effects of SDRNFLRFamide and TNRNFLRFamide on the motor patterns of the stomatogastric ganglion of the crab Cancer borealis.

TNRNFLRFamide was isolated and sequenced from the stomatogastric nervous system of the crab Cancer borealis by reverse-phase high performance liquid chromatography followed by automated Edman degradation. An SDRNFLRFamide-like peptide that exactly co-migrated with SDRNFLRFamide was also observed. The effects of TNRNFLRFamide and SDRNFLRFamide on the gastric and pyloric rhythms of the stomatogastric nervous system of the crab Cancer borealis were studied. Both peptides activated pyloric rhythms in quiescent preparations in a dose-dependent manner with a threshold between 10(-11) and 10(-10) mol l-1. Both peptides increased the pyloric rhythm frequency of preparations showing moderate activity levels and had relatively little effect on preparations that showed strong pyloric rhythms prior to peptide application. Both peptides evoked gastric mill activity in preparations without existing gastric rhythms. The activation of the gastric rhythm is associated with activation of oscillatory properties in the dorsal gastric neurone. The induction of gastric rhythms by these peptides was accompanied by switches from pyloric-timed activity to gastric-timed activity by several stomatogastric ganglion neurones. Application of these peptides provides direct experimental control of circuit modification in the stomatogastric nervous system.

Amino Acid Sequence↗
PubMed1992

Bending-incompetent variants of Flp recombinase mediate strand transfer in half-site recombinations: role of DNA bending in recombination.

One key feature of the interaction of Flp recombinase with its target site (FRT) is the large bend introduced in the substrate as a result of protein binding. The extent of bending was found to depend on the phasing and spacing of the Flp monomers occupying the two Flp-binding elements (FBE) bordering the strand-exchange region (spacer) of the substrate. The relative mobilities of the Flp complexes formed by the two permuted substrate fragments, containing the FRT site near the end or in the middle, corresponded to a DNA bend of approx. 140 degrees when each of the two FBEs flanking the spacer was occupied by a protein monomer. The estimated bend angle was the same when the reference DNA fragment with the FRT site at the end was substituted by one with the site in the middle, but containing a 4-bp insertion within the spacer. We used a combination of wild-type Flp and Flp variants that were competent or incompetent in DNA bending, together with full, or half FRT sites, to ask whether bending is a conformational requirement for catalysis, namely cleavage and exchange of strands. We obtained the following results: in full-site (FRT) vs. full-site recombinations or in full-site vs. half-site (half FRT) recombinations, there was a large difference in the reactivity between Flp and a bending-incompetent Flp variant. This difference virtually disappeared when reactions were done with half-FRT sites. We conclude that bending is not a prerequisite for catalysis, but represents the manner in which the substrate accommodates the Flp protomer-protomer interactions that are pertinent to catalysis.

Base Sequence↗