Biomedical subjects

A O'Shea

Publications and source records attributed to A O'Shea.

12 recordsLinked to original sources

PubMed2001

Icodextrin as salvage therapy in peritoneal dialysis patients with refractory fluid overload.

BACKGROUND: Icodextrin is a high molecular weight, starch-derived glucose polymer, which is capable of inducing sustained ultrafiltration over prolonged (12-16 hour) peritoneal dialysis (PD) dwells. The aim of this study was to evaluate the ability of icodextrin to alleviate refractory, symptomatic fluid overload and prolong technique survival in PD patients. METHODS: A prospective, open-label, pre-test/post-test study was conducted in 17 PD patients (8 females/9 males, mean age 56.8 +/- 2.9 years) who were on the verge of being transferred to haemodialysis because of symptomatic fluid retention that was refractory to fluid restriction, loop diuretic therapy, hypertonic glucose exchanges and dwell time optimisation. One icodextrin exchange (2.5 L 7.5%, 12-hour dwell) was substituted for a long-dwell glucose exchange each day. RESULTS: Icodextrin significantly increased peritoneal ultrafiltration (885 +/- 210 ml to 1454 +/- 215 ml, p < 0.05) and reduced mean arterial pressure (106 +/- 4 to 96 +/- 4 mmHg, p < 0.05), but did not affect weight, plasma albumin concentration, haemoglobin levels or dialysate:plasma creatinine ratio. Diabetic patients (n = 12) also experienced improved glycaemic control (haemoglobin Alc decreased from 8.9 +/- 0.7% to 7.9 +/- 0.7%, p < 0.05). Overall PD technique survival was prolonged by a mean of 11.6 months (95% CI 6.0-17.3 months). On multivariate Cox proportional hazards analysis, extension of technique survival by icodextrin was only significantly predicted by baseline net daily peritoneal ultrafiltration (adjusted HR 2.52, 95% CI 1.13-5.62, p < 0.05). CONCLUSIONS: Icodextrin significantly improved peritoneal ultrafiltration and extended technique survival in PD patients with symptomatic fluid overload, especially those who had substantially impaired peritoneal ultrafiltration.

Dialysis Solutions↗

PubMed2000

Target similarity effects: support for the parallel distributed processing assumptions.

Recent research has begun to provide support for the assumptions that memories are stored as a composite and are accessed in parallel (Tehan & Humphreys, 1998). New predictions derived from these assumptions and from the Chappell and Humphreys (1994) implementation of these assumptions were tested. In three experiments, subjects studied relatively short lists of words. Some of the lists contained two similar targets (thief and theft) or two dissimilar targets (thief and steal) associated with the same cue (robbery). As predicted, target similarity affected performance in cued recall but not free association. Contrary to predictions, two spaced presentations of a target did not improve performance in free association. Two additional experiments confirmed and extended this finding. Several alternative explanations for the target similarity effect, which incorporate assumptions about separate representations and sequential search, are rejected. The importance of the finding that, in at least one implicit memory paradigm, repetition does not improve performance is also discussed.

Association↗

PubMed1999

Management of bilateral flexural deformity of the metacarpophalangeal joints in three alpaca crias.

Three neonatal alpacas were treated for MCP flexural deformities. Two crias responded well to conservative therapy using splints made from fibreglass cast material. One cria with severe deformity failed to respond to conservative treatment but recovered satisfactorily after transection of the suspensory ligament in both legs. It seems that mild cases of flexural deformity of the MCP joint in alpaca crias respond well to conservative therapy but that surgical correction may be required in more severe cases. Sequential transection of the structures limiting extension of the MCP joint may result in fewer complications than previously reported techniques.

Animals↗

PubMed1990

Mapping of an assembled epitope of human follicle-stimulating hormone-beta utilizing monoclonal antibodies, synthetic peptides, and hormone-receptor inhibition.

Monoclonal antibodies (mabs) to human (h) FSH were utilized to probe epitopes of the beta-subunit of hFSH (hFSH beta). These mabs had an average approximate affinity constant (Ka) of 10(8) M-1 for hFSH beta and 10(7) M-1 for heterodimeric hFSH. Hormone specificity of mabs for hFSH beta was demonstrated by a lack of cross-reactivity with hCG alpha, FSH alpha, or LH alpha. Epitope specificity of each mab was initially assessed by determining whether solid phase mab could bind to [125I]hFSH already bound to mabs in liquid phase. In addition, it was determined whether [125I]mab could bind to hFSH already bound to solid-phase mabs. Both epitope cross-matching protocols indicated that all mabs bound to the same epitopes on hFSH beta. Next, synthetic peptides corresponding to the sequence of hFSH beta were used in an enzyme-linked immunosorbent assay to map this epitope. All mabs bound to peptides 7-19, 1-20, 33-53 and 66-85 but did not bind or bound weakly to peptides 81-100, 95-103, and 103-110. Titration experiments were performed using different concentrations of peptide (0.3-41 nmol) and one mab 3G3 (500 ng-25 ng) in the enzyme-linked immunosorbent assay. The product of the lowest mass of both peptide and antibody which gave a positive result was used to rank the peptides for their binding with mab 3G3. Peptides were ranked in the following descending order of potency: 33-53, 49-67, 66-85 much greater than 16-36, 1-20, 95-103, 52-65, 81-100, and 103-110. Ability of the mabs to inhibit binding of [125I]hFSH to bovine testis membrane receptor (Rec) was also studied. When [125I]hFSH was preincubated with increments of each mab for 2 h at 25 C before adding Rec with further incubation for 16 h, all mabs inhibited [125I]hFSH binding to Rec. The data suggest that most of the hFSH beta molecule has a conformation enabling all antibody recognizable regions to be in close proximity to each other. The present study provides evidence for an assembled epitope comprising in part, amino acids 33-53, which has been previously shown to be involved in receptor binding. Peptide sequences 49-67 and 66-85 are neighboring sequences in this assembled epitope which contains the determinants for receptor binding.

Amino Acid Sequence↗

PubMed1983

Ranitidine and placebo in the treatment of reflux oesophagitis. A double-blind randomized trial.

A study was carried out to assess the effectiveness of ranitidine in the short-term treatment of reflux oesophagitis. In a double-blind randomized trial of 37 outpatients with symptomatic, endoscopically proven, moderate or severe reflux oesophagitis, 18 patients received ranitidine (150 mg twice a day) and 19 patients received identical-looking placebo tablets for a period of six weeks. Clinical, laboratory, and endoscopic assessments were made initially, and at the end of six weeks. Two patients withdrew during the trial. Endoscopic evidence of improvement was found in 15 of 17 ranitidine-treated and in five of 18 placebo-treated patients. This difference was significant (P less than 0.01). Antacid consumption was significantly lower in the ranitidine-treated group (P less than 0.01). Improvement in histological findings, and the relief of retrosternal pain, regurgitation, dysphagia, and epigastric pain did not achieve levels of statistical significance. No adverse clinical or laboratory changes occurred in patients in either group. It is concluded that, as judged by endoscopic evidence, ranitidine is an effective drug for the short-term treatment of reflux oesophagitis.

Clinical Trials as Topic↗

PubMed1979

Hormone replacement therapy in the menopause: a suitable animal model.

Female CBA mice, aged 11 months, were treated cyclically with oral ethynyl oestradiol or oestrone sulphate for 3 months. The ovaries of all animals appeared to be atrophied. Target tissues throughout the genital tract showed a response to both oestrogens. Electron microscopy of both the endometrium and the urothelium demonstrated morphological changes characteristic of increased cellular metabolic activity in the treated mice. Endometrial hyperplasia developed in both treatment groups but more pronounced epithelial changes occurred with oestrone sulphate. This hyperplasia was accompanied by a doubling in the number of uterine cytoplasmic oestrogen receptors. A 50% fall in serum levels of luteinizing hormone in the treated mice revealed that the hypothalamic-pituitary system was still intact. Both oestrogens improved skeletal balance by changes in cortical-endosteal bone remodelling. The results suggest that the CBA strain of mouse is a suitable model for the study of the human climacteric and its response to hormone replacement therapy.

Animals↗

PubMed1975

Functional and post-oral contraceptive amenorrhoea: response to luteinizing hormone releasing hormone (LH-RH).

Basal levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) in serum and their response to the luteinizing hormone releasing hormone (LH-RH) were measured in a group of patients with functional amenorrhoea. The results in this group were compared to those obtained in a second group of patients with secondary amenorrhoea which had followed cessation of a combined oral contraceptive. No difference either in the basal levels or in the response to LH-RH could be found. These data indicate that there is no detectable difference in pituitary gonadotrophin status between the two groups and that the two types of amenorrhoea have ghe same aetiological background.

Amenorrhea↗

PubMed1975