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Biomedical subjects

J Bamforth

Publications and source records attributed to J Bamforth.

18 recordsLinked to original sources
PubMed2006

Development of chronic tests for endocrine active chemicals. Part 1. An extended fish early-life stage test for oestrogenic active chemicals in the fathead minnow (Pimephales promelas).

An extended early-life stage test (based on OECD test guideline 210) was developed to allow the evaluation of a weak environmental oestrogen, 4-tert-pentyphenol (4TPP), on sexual differentiation and gonadal development. Fathead minnow (Pimephales promelas) embryos were exposed to three concentrations of 4TPP (56, 180 and 560 microg l(-1)) in a flow-through system, at 25+/-1 degrees C, for <107 days post-hatch (dph). In addition, some embryos were exposed to 180 microg 4TPPl(-1) until 30 or 60 dph, after which they were exposed to dilution water only until 107 dph. At 30, 60 and 107 dph fish were evaluated for growth and gonadal development (via histology), and at 107 dph fish were also evaluated for secondary sexual characteristics (SSC), gonadosomatic index (GSI) and plasma vitellogenin (VTG). There were no effects of 4TPP on hatching success or survival, however, there was a delay in the time taken for embryos to hatch (560 microg 4TPPl(-1)). No treatment-related effects were observed on fish growth, with the exception of at 107 dph when the condition factor in female fish was reduced in all 4TPP continuous exposure treatments. Plasma VTG was only elevated in female fish exposed to 180 microg 4TPPl(-1) and inhibition of gonadal growth (GSI) occurred only in females exposed to 560 microg 4TPPl(-1). Histological examination of the gonads revealed delays and disruption in male sexual differentiation and development (180 microg 4TPPl(-1)) and no testicular tissue was observed in any fish exposed to 560 microg 4TPPl(-1). Mixed gonads (predominately testes with a scattering of primary oocytes) were present in fish exposed to all doses of 180 microg 4TPPl(-1) at 107 dph. Feminisation of the reproductive ducts (formation of an ovarian like cavity) occurred in the testis of all males exposed to 180 microg l(-1), regardless of length of 4TPP exposure. Results indicate that the period of 30-60 dph appears to be the sensitive window for disruption of formation of the reproductive duct and this effect is not reversible when the fish are transferred to dilution water. The data also show that this integrative test is suitable for the detection of a weak environmental oestrogen and comparisons of these results with that of a fish full life-cycle, in medaka, indicate that this test could be a suitable surrogate for a fish full life-cycle.

Animals↗
PubMed2005

High-resolution sequence-based DPA1 typing identified two novel DPA1 alleles, DPA1*010303 and DPA1*0303, from a Kenyan population.

We report here two novel DPA1 alleles, DPA1*010303 and DPA1*0303, identified from a Kenyan population during sequence-based HLA-DPA1 typing. Molecular cloning and sequencing of multiple clones confirmed that one of the new DPA1 alleles is identical to DPA1*010301 at exon 2, except for a single nucleotide substitution (ACG ACC) at codon 15. The new allele has been named by the WHO Nomenclature Committee as DPA1*010303. The second novel DPA1 allele is identical to DPA1*0301, except for a single nucleotide difference (GAA GAC) at codon 28 that changed the amino acid from Glu to Asp. The new allele has been named by the WHO Nomenclature Committee as DPA1*0303. Identification of the two novel DPA1 alleles reflects the genetic diversity of this East African population.

Base Sequence↗
PubMed1986

Value of a simple biochemical ratio in distinguishing upper and lower sites of gastrointestinal haemorrhage.

59 cases of overt gastrointestinal haemorrhage were reviewed in which the source of bleeding was not initially evident but was identified by later investigation. The admission plasma urea to creatinine concentration ratio proved highly accurate in distinguishing upper and lower gastrointestinal sources of haemorrhage. Regardless of blood volume lost, 33 of 38 patients with upper gastrointestinal haemorrhage (87%) had a ratio of 100 or more, and 20 of 21 patients with lower gastrointestinal haemorrhage (95%) had a ratio of less than 100, an overall accuracy of 90%. Elevation of the ratio was not related to clinical evidence of hypovolaemia. This simple ratio may be valuable in determining the sequence of investigations in patients with an unidentified source of gastrointestinal haemorrhage.

Acute Disease↗
PubMed1986

Clinical importance of Campylobacter pyloridis and associated serum IgG and IgA antibody responses in patients undergoing upper gastrointestinal endoscopy.

Campylobacter pyloridis was isolated from 77% of 220 (35%) unselected adults undergoing gastroscopy. Isolation was significantly associated with histological gastritis (p less than 0.0001), duodenal ulcer (p less than 0.0001), and to a much lesser extent, with gastric ulcer (p less than 0.05). The relation between the isolation of C pyloridis and peptic ulcer seemed to be independent of coexisting gastritis. In those with no endoscopic or histological evidence of disease there was no relation between isolation and increasing age. Antibody responses to a whole cell sonicate of a strain of C pyloridis were measured by means of an enzyme linked immunosorbent assay (ELISA). Increased IgA (p less than 0.0001) and IgG (p less than 0.0001) antibody titres were found in patients with C pyloridis. Peptic ulceration or gastritis were present in 78% and 100% of patients with a high concentration of IgG and IgA, respectively, but in only 9% and 18% of those with low titres. These results provide further evidence for a possible pathogenic role of these organisms in gastric disease and suggest that immunological markers of their presence might be useful non-invasive indicators of disease.

Adult↗
PubMed1984

Reducing overnight secretion of acid to heal duodenal ulcers. Comparison of standard divided dose of ranitidine with a single dose administered at night.

This study was undertaken to assess the clinical usefulness of a single nighttime dose of ranitidine in the short-term healing of duodenal ulcer. One hundred and nine patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine, either 150 mg twice daily or 300 mg as a single nighttime dose for four weeks, in a prospective double-blind, double-placebo trial. Of the 102 patients who completed the study, 48 of 57 (84 percent) healed endoscopically on ranitidine 150 mg twice daily, and 43 of 45 (96 percent) healed on 300 mg at nighttime (Mantel-Haenszel test without continuity correction: X2 = 2.9, p = 0.09). One patient treated with ranitidine 150 mg twice daily had a transient episode of cholestatic hepatitis that did not necessitate stopping the drug; in this patient the ulcer healed after 28 days of treatment. There were no other unwanted effects in either group and no significant abnormal biochemical or hematologic changes. This study shows that ranitidine 300 mg given as one nighttime dose is as safe as 150 mg twice daily, and equally as effective. Three hundred milligrams at night appear to confer protection against the adverse effect of smoking in ulcer healing.

Adolescent↗
PubMed1984

Ranitidine 150 mg twice daily vs 300 mg nightly in treatment of duodenal ulcers.

102 patients with endoscopically proven duodenal ulcers were randomly allocated to treatment with ranitidine either 150 mg twice a day or 300 mg every evening for 4 weeks in a prospective double-blind study. The two groups were similar. 48/57 (84%) healed on ranitidine 150 mg twice daily and 43/45 (96%) healed on 300 mg every evening (p = 0.9)--that is, ranitidine 300 mg as a single night time dose is as effective as 150 mg twice daily. The results also indicate the importance of overnight gastric acidity in the pathogenesis of duodenal ulcers.

Adolescent↗
PubMed1983

Upper gastrointestinal endoscopy in systemic vasculitis presenting as an acute abdomen.

Three cases of upper gastrointestinal vasculitis presenting as acute abdominal emergencies highlight an uncommon but often fatal presentation of systemic vasculitis. Although abdominal symptoms are common in such diseases, there may be a doubt during assessment of the patient as to whether the gastrointestinal tract is the prime target organ. Radiology is often negative during the acute illness. Endoscopy was important in documenting early and more advanced bleeding lesions of polyarteritis nodosa (PAN) and Henoch-Schoenlein disease, both conditions in which upper gastrointestinal lesions are rare. The gastric and duodenal vasculitic lesions demonstrated by endoscopy in such a clinical setting were confirmed histologically. Endoscopic assessment and early aggressive medical therapy contributed significantly towards the overall successful outcome. Gastroduodenoscopy has not been used either routinely or as an emergency investigation for the assessment of patients with vasculitis who present with acute abdominal pain. Involvement of the stomach and duodenum by vasculitis is therefore poorly appreciated, but remains a serious complication of vasculitic disease when the gastrointestinal tract is the prime target organ, and the information gained by endoscopy in a difficult clinical situation might alter the overall outcome of the disease.

Abdomen, Acute↗
PubMed1981

A double-blind controlled trial of the effect of sodium cromoglycate in preventing relapse in ulcerative colitis.

A double-blind controlled trial of the effect of sodium cromoglycate (SCG) in preventing relapse in ulcerative colitis has been completed in 100 subjects. In patients already taking sulphasalazine, SCG did not prove to be of any additional benefit. However, in patients not on any other maintenance therapy, the relapse rate was 40% for SCG as compared with 75% for placebo. A large study of the effect of SCG in patients intolerant of sulphasalazine is indicated.

Adult↗
PubMed1974

Clinical evaluation of the 14C fat absorption test.

The absorption of (14)C-labelled glyceryl tripalmitate was tested in 62 patients by determining the maximum specific activity of CO(2) in the breath after an oral dose. A significant correlation with faecal fat excretion was found. The absorption of (14)C labelled palmitic acid was tested subsequently in 54 patients. In cases of pancreatic steatorrhoea, normal absorption of palmitic acid with impaired absorption of glyceryl tripalmitate was found, whereas in most patients with coeliac disease the absorption of both substances was depressed to the same extent.

Blind Loop Syndrome↗