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Biomedical subjects

G Williams

Publications and source records attributed to G Williams.

At least 451 records · Page 25Linked to original sources
PubMed1991

Do doctors and patients agree? Views of the outcome of transurethral resection of the prostate.

In an attempt to establish the extent to which patients and doctors agree on the outcome of health care, the pre- and postoperative states of health of 388 men undergoing transurethral resection of the prostate for benign disease were studied. Generally, high levels of concordance (greater than 70%) were obtained. The strongest agreement was for clearly defined events, such as episodes of acute retention (95%); the weakest agreement occurred over the most subjective symptoms, prognostic expectations, and ambiguous terms (around 60%). The level of agreement was not associated with any characteristics of the patient, surgeon, or treatment.

Cystoscopy↗
PubMed1991

Serum and urinary levels of beta human chorionic gonadotrophin in patients with transitional cell carcinoma.

Serum and early morning urine specimens were obtained from 62 patients. The levels of beta human chorionic gonadotrophin (BhCG) in both serum and urine were estimated simultaneously in all cases. At the time of estimation 43 patients had transitional cell carcinoma of the bladder, one had transitional cell carcinoma of the renal pelvis and three had carcinoma in situ (two of whom also had overt carcinoma). Raised serum and urinary levels were found in only three patients, all of whom had poorly differentiated or metastatic transitional cell carcinoma of the bladder. This observation is in accordance with previous studies. In one of these patients, who underwent transurethral resection of her bladder tumour, the urinary levels returned to within normal limits post resection. An additional three patients had elevations of serum BhCG. Two of these three patients had poorly differentiated transitional cell carcinoma present at the time of estimation and one had no sign of recurrence. Using immunoperoxidase staining a retrospective study was undertaken to stain all available sections belonging to patients studied to observe whether BhCG was being produced by the respective tumours. Twelve well differentiated, nine moderately well differentiated and seven poorly differentiated specimens were available. In no case was evidence of BhCG production demonstrated in these tumours despite its presence being demonstrable in positive controls. We confirm the production of BhCG associated with bladder tumours, a feature correlated with poorer differentiation. Studies employing larger patient numbers are necessary to clarify the role of this tumor marker in patients with well differentiated bladder tumours.

Carcinoma, Transitional Cell↗
PubMed1991

Hypothalamic regulatory peptides in obese and lean Zucker rats.

1. Hypothalamic concentrations of nine peptides with experimental effects on energy balance were compared in obese (fa/fa) and lean (Fa/?) male Zucker rats. To determine whether any peptide differences between obese and lean rats might be due to the overweight condition per se, separate groups of obese rats were food-restricted to reduce their body weight to lean values. 2. Concentrations of neuromedin B, a bombesin-like peptide, in the central hypothalamus were significantly higher in obese than in lean rats. This difference was not affected in food-restricted obese rats. 3. Hypothalamic levels of neuropeptide Y, an extremely potent central appetite stimulant, were similar in lean and freely fed obese rats but central hypothalamic levels of neuropeptide Y rose significantly in food-restricted obese rats. 4. These findings suggest that disturbances in hypothalamic neuromedin B concentrations may be involved in the obesity syndrome of the fa/fa Zucker rat. Increased central hypothalamic levels of neuropeptide Y in food-restricted rats suggest that this peptide may help to defend body weight by stimulating eating after weight loss.

Animals↗
PubMed1991

Ureteric obstruction in renal transplants: the role of percutaneous balloon dilatation.

With widespread use of balloon dilatation catheters outside the vascular system, percutaneous balloon dilatation has become an accepted alternative to surgery. Seventeen patients who developed ureteric stenosis following renal transplantation underwent 21 transrenal angioplastic balloon dilatations. Fifteen patients had lower ureteric strictures (2-22 mm long), and two had multiple strictures. The time interval between transplantation and obstruction ranged from 11 to 1370 days (median 71, mean 228.9 days). Nine patients were treated successfully (53%) with no stricture recurrence during the follow-up period, which ranged from 3 to 44 months (median 16, mean 17.8 months). In eight of nine patients in this group, the stricture impression on the inflation balloon was eliminated, and this appears to correlate best with a successful outcome. The eight patients who failed balloon dilatation and restenosed, did so within 7-42 days in seven patients; one patient had late stricturing at 238 days. Serious complications occurred in only one patient, who developed an A-V fistula not amenable to correction and necessitating transplant nephrectomy.

Adult↗
PubMed1991

Anti-platelet monoclonal antibody P256 in the diagnosis of renal transplant rejection.

Platelets labeled in vitro with In-111 have a recognized place in the diagnosis of renal transplant rejection. Following their introduction for imaging thrombi, radio-labeled anti-platelet antibodies may also have a role in the diagnosis of transplant rejection. Four of 11 patients with recently donated transplants had biopsy-proven acute rejection episodes close to the time of administration of In-111 P256 Fab' fragment, which recognizes the IIb-IIIa fibrinogen receptor on primate platelets. The transplant-to-background count rate at 3 and 24 hours after these injections were 2.2 (SE 0.14) and 2.3 (0.23), respectively, almost identical to the ratios, 2.0 (0.1) and 2.2 (0.11), recorded at the corresponding times after 19 injections of P256 Fab' that were remote in timing from rejection episodes. P256 Fab' may have value in the detection of postoperative venous thrombosis, but it has no value for the detection of transplant rejection.

Adult↗
PubMed1991

The effect of apnea on brain compliance and intracranial pressure.

The effect of 2 minutes of apnea during endotracheal intubation on intracranial pressure (ICP), compliance, and cerebral blood volume (CBV) was studied in 19 adult dogs during normo-, hypo-, and hypercapnia. The compliance was measured from the cisterna magna in response to an intrathecal bolus injection (pressure-volume index). CBV was monitored by radiolabeled red blood cell activity. These measurements were made before and after 2 minutes of apnea. At normocapnia (pCO2 of 35-40 mm Hg), a period of apnea resulted in an increase in ICP from 9.6 to 26.3 mm Hg, a decrease in compliance from 0.051 to 0.020 ml/mm Hg (60%), and an increase in CBV of 0.26 ml (9.6%). When the animals were hypocapnic (pCO2 of 24-28 mm Hg), ICP increased from 12.8 to 19.6 mm Hg, compliance fell from 0.041 to 0.029 ml/mm Hg(29%), and CBV increased 0.07 ml (3.1%). Hypercapnia (pCO2 of 50-58 mm Hg) before apnea resulted in an increase in ICP from 21.5 to 47.1 mm Hg, a decrease in compliance from 0.032 to 0.015 ml/mm Hg (52%), and an increase in CBV of 0.41 ml (13.4%). These results suggest that hyperventilation (hypocapnia) before intubation limits the adverse decrease in brain compliance and increase in ICP by reducing changes in cerebral blood volume.

Animals↗
PubMed1991

Cardiovascular effects of a chlorpheniramine/paracetamol combination in hypertensive patients who were sensitive to the pressor effect of pseudoephedrine.

Twelve hypertensive patients who were classified as pseudoephedrine-sensitive in a preliminary trial were selected for further investigation with single doses of pseudoephedrine 60 mg, a combination of chlorpheniramine 4 mg with paracetamol 650 mg and placebo. A double-blind, randomised, crossover study design was followed. Treatment with pseudoephedrine produced significant effects on all the four variables measured (systolic, diastolic and mean arterial blood pressure, and heart rate). Effects of the chlorpheniramine/paracetamol combination were found to be not significantly different from placebo. It was concluded that the combination may be useful as a medication for 'colds' in hypertensive patients, since it does not induce cardiovascular effects such as those observed with pseudoephedrine.

Acetaminophen↗
PubMed1991

Parental problems influencing the academic achievement of medical students: a prospective study.

The 227 students offered places in the 1988 medical student intake at the University of Queensland were surveyed regarding their demographic characteristics. This was correlated with the students' subsequent performance and persistence during the first year of the medical course. Coming from a lower socioeconomic background and having family problems were both associated with either a decreased academic performance or an increased attrition rate. The results are discussed, relevant literature is reviewed and suggestions for further research are made.

Education, Medical, Undergraduate↗
PubMed1991

Dilatation of the prostatic urethra with 35 mm balloon.

A series of 54 men, 25 with acute urinary retention and 29 with cytometrically proven bladder outflow obstruction (BOO), underwent dilatation of the prostatic urethra using a 35 mm fixed diameter, low compliance balloon. In 42 patients this was performed under cystoscopic guidance and in 12 patients under fluoroscopic control. Three months following dilatation, 13/27 patients (48%) with BOO who returned for review were rendered unobstructed and 19/27 (70%) were symptomatically improved. By 6 months only 3 remained unobstructed but 15 remained symptomatically improved. Nine months after dilatation 14 patients retained symptomatic improvement but only 2 remained unobstructed. Of the 25 patients treated for acute retention only 6 voided spontaneously, 1 of these relapsing into retention at 2 months and another at 4 months. No patient was rendered unobstructed but 2 patients (who declined prostatectomy) noted an improvement in their obstructive symptoms at both 3 and 6 months. No patient developed retrograde ejaculation following dilatation. Balloon dilatation to 35 mm has no role in acute urinary retention but may have a role in younger men with BOO who wish to avoid prostatectomy and the risk of retrograde ejaculation. In these patients careful follow-up is required.

Aged↗
PubMed1991

Ureteroureterostomy and pyeloureterostomy without native nephrectomy in renal transplantation.

A series of 23 patients, receiving full immunosuppression following renal transplantation, underwent a uretero- or pyelo-ureterostomy with ligation of the native ureter and no nephrectomy. In 5 patients this was carried out at the time of transplantation because of a short donor ureter and in 18 patients, at a median of 47 days after transplantation, following ureteric complications. With a median follow-up of 22 months, no complications have been seen in relation to the native kidney. Ureteroureterostomy was successful in all but 3 patients. A ureteroureterostomy without native nephrectomy is a safe and effective treatment for the management of ureteric complications following renal transplantation.

Anastomosis, Surgical↗
PubMed1991

The nutritional contribution to bovine spongiform encephalopathy.

Evidence that changes in feeding style alter the membrane fatty acid composition of ruminant tissue is presented here by comparing zoo giraffe with the same species from their natural habitat. The membrane changes seen are similar to those used experimentally to make animals susceptible to basic brain protein and encephalomalacia. Similar membrane responses have been noted in cattle. Use of animal protein and increased nitrogen in cattle feeds would lead to a relative deficiency of essential fatty acids in the cell membranes and hence reduced membrane stability. By analogy with crazy chick disease (nutritional encephalomalacia) and experimental encephalomyelitis in rats, the possibility that the changes in animals feeds would have depleted cattle tissue membranes and made them susceptible to BSE is discussed. The assumption being made is that the principle of a requirement of essential fatty acids for neural integrity and immune system function would apply to cattle as well as to other species.

Animal Feed↗
PubMed1991

Peer-mediated procedures to induce swallowing and food acceptance in young children.

Two studies demonstrated a functional relationship between a peer modeling procedure and the treatment of feeding disorders with 2 young children. In the first experiment, the use of a peer model treatment package was shown to induce swallowing in a child with dysphagia who had never swallowed food or liquid. In the second experiment, a child who consistently declined food was induced to increase food acceptance as a function of the same peer modeling package. In the latter experiment, a peer-mediated procedure, consisting of rotated opportunities to consume food with a peer, was found to increase consumption more than did modeling alone. The first experiment used a multiple baseline design across solids and liquids, and the second used a multiple treatment design. The results of both experiments are discussed as new and nonaversive treatments for feeding disorders of young children who are imitative.

Behavior Therapy↗
PubMed1991

Altered neuropeptide Y concentrations in specific hypothalamic regions of obese (fa/fa) Zucker rats. Possible relationship to obesity and neuroendocrine disturbances.

Neuropeptide Y (NPY) concentrations were measured by radioimmunoassay in eight microdissected hypothalamic regions of obese (fa/fa) and lean (Fa/?) Zucker rats. Freely fed obese rats showed significant (40-100%) increases in NPY concentrations in several regions, notably the paraventricular, ventromedial, and dorsomedial nuclei and the arcuate nucleus/median eminence, compared with lean rats. Hypothalamic NPY concentrations were not affected in either obese or lean rats by food restriction, which caused 25% weight loss over 3 wk. Refeeding to initial weight significantly increased NPY levels in the ventromedial and dorsomedial nuclei in lean rats but did not significantly alter NPY concentrations in any hypothalamic region in obese rats. These observations indicate fundamental differences in the regulation of hypothalamic NPY between obese and lean Zucker rats. NPY injected into the paraventricular nucleus and other regions causes hyperphagia, obesity, and increased secretion of insulin, glucagon, ACTH, and corticosterone. These behavioral and neuroendocrine abnormalities all occur in the obese Zucker syndrome and may be due to increased NPY-ergic activity in the hypothalamus.

Adrenocorticotropic Hormone↗