Search PubMed⌕ Search

Biomedical subjects

C Hall

Publications and source records attributed to C Hall.

At least 271 records · Page 15Linked to original sources
PubMed1990

The cost of day surgery.

Recently there has been an expansion of day surgery in Britain. However, it is difficult to prove that surgical treatment on a day case basis actually saves money. This paper discusses the development of a new costing strategy which suggests that costs could be reduced by a planned programme of day surgery. These results have obvious significance for the National Health Service.

Ambulatory Surgical Procedures↗
PubMed1990

Human recombinant interleukin-2 provokes acute pulmonary vascular endothelial injury in rabbits.

Human recombinant interleukin-2 (rIL-2), with or without lymphokine-activated killer cells, has been shown to mediate tumor regressions in animals and in humans. A well-recognized adverse effect of rIL-2 is the development of a generalized vascular leak syndrome that involves the pulmonary microvasculature. We present a rabbit model for the study of rIL-2 pulmonary toxicity that closely reflects the human situation. Rabbits were treated with rIL-2 (Cetus) by two dose/schedule schemata. Separate control groups received rIL-2 excipient (Cetus) or 5% dextrose in water (D5W). In a short-term model, animals were treated with 10(6) Cetus units of rIL-2 in five bolus injections of 200,000 Cetus units each. In a long-term model, rabbits were treated with 3 (x) 10(6) Cetus units/kg of rIL-2 daily in three divided doses every 8 h for 9-11 doses (a schedule analogous to one used in human trials). Following treatment, animals were killed and examined for evidence of pulmonary toxicity. Among the treatment and control groups, there was no evidence of pulmonary leukostasis as determined by mean alveolar septal wall granulocytes per high power field or mean lung myeloperoxidase activity per gram of tissue. While there were no differences among the three treatment groups with regard to pulmonary edema formation (wet/dry weights), there was a tendency toward statistically significant differences between the rIL-2 and control groups. Pulmonary vascular permeability was assessed using i.v.-administered [125I]rabbit serum albumin (RSA) and expressed as mean bronchoalveolar lavage fluid/plasma [125I]RSA ratios. The rIL-2-treated animals had significantly increased pulmonary extravasation of [125I]RSA compared to controls, but there were no differences between the excipient- and D5W-treated controls. Lungs from rIL-2-treated (but not controls) animals displayed marked ultrastructural changes by electron microscopy in the arteriolar segment to include intracellular and subcellular blebs throughout the arteriole with separation of endothelial cells from basement membrane, interstitial edema, endothelial adhesion, and transmigration of lymphocytes into interstitium. Immunoperoxidase stains using an antirabbit T-cell monoclonal antibody demonstrated significant T-cell infiltration into the pulmonary interstitium of rIL-2-treated animals compared to controls. The long-term treatment model described appears to be highly suited for studies of rIL-2-induced pulmonary toxicity.

Animals↗
PubMed1990

Human recombinant interleukin-2 provokes infiltration of lymphocytes into myocardium and liver in rabbits.

Treatment with human recombinant interleukin-2 (rIL-2) is associated with multiple organ dysfunctions, including hepatic and cardiac toxicities. We present a rabbit model that may be highly suited to investigations of these organ toxicities. Rabbits were treated with rIL-2 at a dose of 3 x 10(6) Cetus units/kg/day in divided doses every 8 h for 9-11 doses. Control animals received either excipient or 5% dextrose in water. Treatment with rIL-2 resulted in hepatic and myocardial infiltration by lymphocytes and mononuclear cells. Monoclonal antibody-staining techniques revealed a high percentage of T lymphocytes. It remains to be shown whether these infiltrates are responsible for the respective organ toxicities or represent merely an epiphenomenon of rIL-2 treatment.

Animals↗
PubMed1990

Alcohol use as a situational influence on young women's pregnancy risk-taking behaviors.

Recent studies have found that many young women just beginning their sexual lives use alcohol prior to intercourse. A large number appear to drink heavily enough prior to sex to compromise their ability to use contraceptives. The question emerges whether there is a relationship between drinking before intercourse, the nonuse of birth control methods, and unplanned pregnancies. The present research describes 43 instances of intercourse which resulted in unplanned pregnancies in 14- to 21-year-olds. Variables examined included alcohol use prior to sex, amount of alcohol consumed, the use of other drugs, the planning of intercourse, respondents' stated reasons for nonuse of contraceptives, and other general demographic data.

Adolescent↗
PubMed1989

T-cell antigen receptor (TCR)-alpha/beta heterodimer formation is a prerequisite for association of CD3-zeta 2 into functionally competent TCR.CD3 complexes.

In order to study the relationship between assembly, surface expression, and signal transduction of the alpha/beta T-cell antigen receptor-CD3 complex (TCR.CD3), a series of T-cell mutants with a partial block in assembly of the complex was generated. By chemical mutagenesis, we produced somatic cell variants of the human T-leukemia cell line, HPB-ALL, which expressed low amounts of TCR.CD3 complexes on their surface. RNA and protein analyses demonstrated that most variants synthesized normal amounts of the individual members of the complex, i.e. TCR-alpha, TCR-beta, CD3-gamma, -delta, -epsilon, and -zeta. In these variants, less than 10% of the TCR.CD3 complexes inside the cell contained the CD3-zeta 2 homodimer due to an intrinsic deficiency in the formation of the TCR-alpha/beta heterodimer. The low level of assembly of CD3-zeta 2 into the TCR.CD3 complex and an additional decrease in the rate of export of the TCR.CD3 complex from the endoplasmic reticulum explained the low level of expression of alpha/beta receptors on the surface of these mutants. Only cells with the complete set of subunits of the TCR.CD3 complex on their surface were capable of transducing CD3-mediated signals. The results presented in this paper indicate that TCR-alpha/beta heterodimer formation is an obligatory requirement for assemblage of CD3-zeta 2 into a functionally competent TCR.CD3 complex.

Antigens, CD↗
PubMed1989

Stabilization of detergent-solubilized Ca2+-ATPase by poly(ethylene glycol).

The (Ca2+ + Mg2+)-ATPase from sarcoplasmic reticulum (SR) has been solubilized with 1-alkanoyl propanediol-3-phosphorylcholines with chainlengths ranging between 8 and 12 C atoms. A marked dependence of the ATPase activity upon the chainlength was found, indicating that alkyl chainlengths with 12 C atoms are necessary for retention of activity. Addition of poly(ethylene glycol) to the eluting buffers used for gel filtration of the ATPase-detergent micelles was found to increase the activity and the long-term stability significantly. In the presence of Ca2+, the elution volume indicated an ATPase dimer, whereas in the absence of Ca2+ the elution volume indicated a monomeric solution. The purity of the preparations after gel filtration was improved by subsequent chromatography with a hydroxyapatite column.

Animals↗
PubMed1989

The effects of calcium, temperature and phospholamban phosphorylation on the dynamics of the calcium-stimulated ATPase of canine cardiac sarcoplasmic reticulum.

Highly purified sarcoplasmic reticulum (SR) has been prepared from dog hearts and has been incubated with the triplet probe erythrosinyl isothiocyanate to specifically label the Ca2+-stimulated ATPase (Ca2+-ATPase) of the SR. The rotational mobility of the Ca2+-ATPase has been studied in this erythrosin-labelled SR using time-resolved phosphorescence polarization. Qualitatively, the mobility of the cardiac Ca2+-ATPase resembles that of skeletal muscle SR Ca2+-ATPase. Addition of Ca2+ to SR affects the mobility of the Ca2+-ATPase in a way consistent with a segment of the ATPase altering its orientation relative to the plane of the membrane. Phosphorylation of phospholamban in cardiac SR by the purified catalytic subunit of cAMP-dependent protein kinase, which is known to increase the activity of the Ca2+-ATPase by deinhibition, also alters measured anisotropy. The changes observed are not compatible with dissociation of the Ca2+-ATPase from phospholamban after the latter is phosphorylated. The data are more consistent with phospholamban associating with the Ca2+-ATPase following phosphorylation, or more complex models in which only the hydrophilic domain of phospholamban binds with and dissociates from the Ca2+-ATPase.

Animals↗
PubMed1989

Nitrite and nitrate levels in ileostomy effluent: effect of dietary change.

1. Nitrite and nitrate levels were measured in samples from ileostomy bags or stomal samples of thirty-one ileostomists (twenty-two ulcerative colitis, nine Crohn's disease), 14-16 h after ingestion of a conventional meal or a meal containing a high content of nitrite and nitrate. 2. Ileostomy samples were decolourized with barium chloride, sodium sulphate and charcoal. Nitrite was determined spectrophotometrically by the Griess reaction and nitrate determined as nitrite after reduction with nitrate reductase (EC 1.7.99.4) in the presence of sodium formate. The mean percentage recovery from twenty-six spiked samples was 101.9 (SE 3.5)% for nitrite and 82.9 (SE 3.3)% for nitrate. 3. Ileostomy bag samples were obtained in twenty-nine cases of which ten had measurable nitrite (median 0, range 0-20.7 nmol/g) on a conventional meal compared with twenty-three cases (median 7.2, range 0-31.1 nmol/g) on the test meal (P less than 0.01). Nitrate levels were measurable in sixteen (median 6.7, range 0-48.2 nmol/g) after a conventional meal compared with twenty-one (median 20.5, range 0-53.2 nmol/g) after the test meal (P less than 0.01). 4. Stomal fresh-catch samples were obtained in twenty-four cases: combined nitrate and nitrite was higher in eighteen, lower in four and unchanged in two subjects after the test meal (P less than 0.05). 5. The type of foodstuff ingested can significantly alter measurable levels of nitrite-nitrate in the distal ileum and is one factor determining nitrite-nitrate input into the proximal colon.

Diet↗
PubMed1989

A randomized trial to compare amoxycillin/clavulanate with metronidazole plus gentamicin in prophylaxis in elective colorectal surgery.

A randomized controlled trial was designed to compare antibiotic prophylaxis with a standard combination of agents, metronidazole and gentamicin, with a single preparation, amoxycillin/clavulanate in 400 patients undergoing elective colorectal surgery. There were 41 patients who were excluded or withdrawn (wrong dose, inappropriate operation, established sepsis or concurrent disease). Abdominal wound sepsis occurred in 14% of the assessable patients in the amoxycillin/clavulanate group and in 15% of the metronidazole plus gentamicin group. Perineal sepsis occurred in 27% of the amoxycillin/clavulanate group with a perineal wound compared with 18% in the metronidazole plus gentamicin group. Intra-abdominal abscess occurred in 8% of those who received amoxycillin/clavulanate compared with 6% of those given metronidazole plus gentamicin. Only two patients in each group developed septicaemia. Postoperative diarrhoea occurred in 11 patients receiving amoxycillin/clavulanate compared with four given metronidazole plus gentamicin. Clostridium difficile was not isolated from the stool cultures in any of these cases. Thirteen of the 164 abdominal or perineal wounds were infected by 15 strains of Bacteroides spp. in the group receiving amoxycillin/clavulanate compared with only three of the 165 wounds in those given metronidazole plus gentamicin. (P less than 0.01). There was no other significant difference in the pattern of isolates between the groups.

Adolescent↗
PubMed1989

The effect of arterial PCO2-variations on ocular and cerebral blood flow in the newborn piglet.

The response of ocular and cerebral blood flow to different arterial PCO2 levels was studied in ventilated paralyzed newborn piglets with the radionuclide-labeled microsphere method. The retina and the choroid have different blood flow responses to variations in arterial PCO2 levels. Retinal blood flow (ml/g/min) was increased during hypercarbia, from 0.26 +/- 0.03 at baseline to 0.51 +/- 0.07 (PaCO2 8.7 +/- 0.2 kPa) and 0.62 +/- 0.07 (PaCO2 11.0 +/- 0.2 kPa). However, no significant change was found in choroidal blood flow during hypercarbia. Cerebral blood flow was more responsive to PaCO2 than retinal blood flow, increasing from 0.71 +/- 0.03 at baseline to 2.25 +/- 0.25 (PaCO2 8.7 +/- 0.2) and 1.77 +/- 0.13 (PaCO2 11.0 +/- 0.2). Hypocarbia did not influence either retinal or choroidal blood flow.

Animals↗
PubMed1989

Going in circles.

Explore the source record for details and available documents.

Hospital Bed Capacity, 500 and over↗