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Biomedical subjects

C Williams

Publications and source records attributed to C Williams.

At least 289 records · Page 16Linked to original sources
PubMed1996

Immune function is more compromised after closed bone fracture and hemorrhagic shock than hemorrhage alone.

OBJECTIVE: To determine whether closed bone fracture in conjunction with hemorrhagic shock compromises immune functions more severely than hemorrhagic shock alone. DESIGN: In a randomized, controlled trial, closed bone fracture of the right lower leg and/or hemorrhagic shock (mean +/- SEM arterial blood pressure, 35 +/- 5 mm Hg for 90 minutes) were induced in male C3H/HeN mice (weight, 25 g). Animals subjected to hemorrhage were resuscitated with the shed blood and lactated Ringer solution. At 72 hours after the experiment, all animals were killed to obtain whole blood, splenocytes, and splenic and peritoneal macrophages. Macrophage interleukin-1 and splenocyte interleukin-2 and interleukin-3 release were determined by bioassay, and splenocyte proliferation was measured by tritiated thymidine incorporation. RESULTS: Closed bone fracture alone did not affect immune functions 72 hours after the trauma. Hemorrhagic shock, however, induced a significant depression of splenocyte and macrophage functions. Bone fracture followed by hemorrhagic shock further depressed splenocyte proliferation and splenocyte interleukin-2 and interleukin-3 release as well as interleukin-1 release. CONCLUSION: Since bone injury coupled with hemorrhagic shock produces more severe depression of immune functions than hemorrhage alone, bone injury appears to play a contributory role in further depressing immune functions in trauma patients who experience major blood loss.

Animals↗
PubMed1996

Anthropometric determination of thigh volumes and thigh forces following acute training of increasing intensity in adult men.

The purpose of the present study was to investigate the influence of submaximal training of increasing intensity on the rate of fatigue and on the anthropometry of the quadriceps muscle. A group of 24 middle-aged male subjects trained three times a week for 12 weeks at incremental exercise intensities which elicited 66%-83% of the maximal heart rate reserve; 11 male subjects acted as controls. A purpose-built, isometric chair with an adjustable force transducer ensured a standard posture for each subject during a 20 s maximal voluntary contraction (MVC). The muscle plus bone mass of the thigh was calculated from a previously validated anthropometric method reinforced by measurements derived from water displacement and ultrasonics. Training-induced submaximal relationships were assessed by means of two ergometer tests of progressive intensity. Following training, the subjects' blood lactate concentrations had decreased from 5.5 (SD 1.7) to 3.9 (SD 1.4) mmol.1(-1) (P < 0.01) at the final exercise intensities. They increased thigh volumes from 10.7 (SD 1.7) to 11.0 (SD 1.7) 1 (P < 0.05) and thigh forces in 47.5% (P < 0.05) of the measurements. Heart rates and rates of perceived exertion were reduced (P < 0.01) following training; for the controls, all the above parameters remained constant. These results would seem to indicate that a submaximal type of training could enable a group of middle-aged men to increase the isometric forces of the thigh muscles by almost 50% when completing a MVC test following training. This suggests that this is a more suitable, safer form of maintaining and increasing maximal thigh forces for this, and older, age groups than specific isometric training alone.

Adult↗
PubMed1996

Information technology in diabetes care 'Diabeta': 23 years of development and use of a computer-based record for diabetes care.

In this article we have stressed that a diabetes care information system should be useful to, usable and actually used by carers at the point of patient contact. Information resulting from such encounters should, at no extra cost, furnish the needs of communication, audit, research and management. Diabeta is a clinical record system for supporting the management of patients with diabetes. It has grown 'organically' within an academic clinical unit over a period of 23 years. It is used for each and every encounter with the clinicians in our diabetes team and as such, contains an immense amount of objective clinical experience. This experience can be interrogated very easily by computer-naive clinicians using a remarkable interactive program ('Datascan') which contains statistical procedures 'embedded' in the APL computer code, eliminating the need to 'export' the data into a statistical package. The latest PC-based version is incredibly fast and this immense amount of clinical experience can be carried around on a notebook PC and be available for exploration at any time. This makes 'evidence-based medicine' available in a remarkably flexible way since it shares the accumulated objective experience of literally 'dozens' of clinicians over a period which now extends to 23 years. It adds a completely new dimension to the term 'clinical experience' and is unattainable with manual records. It would be naive to assume that such systems are easy to design, build or implement, or that the initial capital outlay required will be small although costs are falling continuously. Medicine is a highly complex activity, the essential basis of which is human interaction. Introduction of a technology into this interaction requires sensitivity to the wishes and requirements of individuals, and protection of their exchanges from third parties. The potential of computers in diabetes care is so great that these issues must be addressed through continuing research, development, evaluation and funding of new systems. This must be led by the medical profession not the computer industry.

Ambulatory Care↗
PubMed1996

Induction of clusterin in the immature brain following a hypoxic-ischemic injury.

A unilateral hypoxic-ischemic (HI) insult in the 21 day old rat has been used to assess the role of clusterin in nerve cell death. Both clusterin mRNA and protein levels were measured at various time points after moderate (15 min) and severe (60 min) HI insult using in situ hybridisation and immunocytochemistry respectively. The severe HI insult lead primarily to necrotic neuronal death and showed very little if any clusterin mRNA and protein induction on the ligated side of the brain. However, following the moderate HI insult there was a dramatic time-dependent accumulation of clusterin protein in neurons of the CA1-CA2 pyramidal cell layers in the hippocampus and cortical layers 3-5, regions undergoing delayed neuronal death. Clusterin mRNA expression, in contrast to neuronal protein accumulation, appeared to be glial in origin (probably astrocytes) with increases in mRNA in and around the hippocampal fissure and only a weak signal over the CA1-CA2 pyramidal cell layer. These results support the hypothesis that the clusterin protein is synthesised in the astrocytes, secreted and then taken up by dying neurons. Clusterin immunoreactivity and in situ DNA end-labelling performed on the same sections revealed that clusterin was accumulating in neurons destined to die by programmed cell death. However the relative time-courses of DNA fragmentation and clusterin immunoreactivity suggest that clusterin production was a result of the selective delayed neuronal death rather than being involved in the biochemical cascade of events that cause it.

Animals↗
PubMed1996

Purification and characterization of a novel human 15 kd cholesterol crystallization inhibitor protein in bile.

Crystallization-inhibiting proteins can explain longer nucleation times associated with bile from gallstone-free subjects as compared with bile from patients with cholesterol gallstones. We partially characterized and examined the crystallization inhibitory potency of a newly purified 15 kd human biliary protein. Gallbladder bile was passed through an anti-apolipoprotein A-I (apo A-I) immunoaffinity column to extract lipid-associated proteins. The bound fraction was separated by 30 kd ultrafiltration. Sodium dodecyl sulfate-polyacrylamide gel electrophesis (SDS-PAGE) was performed under nonreducing and reducing conditions. Cholesterol crystallization activity was tested in a photometric cholesterol crystal growth assay. Isoelectric focusing was performed by using a standard gel. The purified 15 kd protein was subjected to N-terminal amino acid sequencing. Although the whole apo A-I-bound fraction contained a variety of proteins and lipids, its 30 kd filtrate yielded a nearly pure 15 kd protein with only minor contamination from apo A-1. Amino acid sequencing showed that the protein was unique. Enzymatic deglycosylation revealed no evidence for glycosylation. At a protein concentration of 10 micrograms/ml, crystallization time was delayed as compared with control and apo A-I, and final crystal mass was reduced to 75% of control. Its isoelectric point was 6.1 without isoforms. Under nonreducing conditions, the protein formed a 30 kd dimer and a 60 kd tetramer. We conclude that this protein is a novel potent biliary crystallization inhibitor protein.

Amino Acid Sequence↗
PubMed1996

Moderate dieting causes 5-HT2C receptor supersensitivity.

Dieting is a widespread behaviour in developed countries, which in predisposed individuals can lead to the development of clinical eating disorders such as bulimia nervosa and anorexia nervosa. We studied the effect of moderate dieting in healthy women on the prolactin response to the serotonin (5-HT) receptor agonist, m-chlorophenylpiperazine (mCPP), a measure of the sensitivity of post-synaptic 5-HT2C receptors. Dieting significantly increased the prolactin response to mCPP and lowered plasma concentrations of the 5-HT precursor, tryptophan. We propose that dieting in women is associated with the development of functional supersensitivity of 5-HT2C receptors, probably in response to lowered levels of brain 5-HT. Alterations in brain 5-HT neurotransmission could play a part in dieting-induced dysregulation of eating and the development of clinical eating disorders in predisposed individuals.

Adult↗
PubMed1996

Effect of water ingestion on endurance capacity during prolonged running.

This study examined the influence of water ingestion on endurance capacity during submaximal treadmill running. Four men and four women with a mean (+/-S.E.) age of 21.4 +/- 0.7 years, height of 169 +/- 2 cm, body mass of 63.1 +/- 2.9 kg and VO2 max of 51.1 +/- 1.8 ml kg-1 min-1, performed two randomly assigned treadmill runs at 70% VO2 max to exhaustion. No fluid was ingested during one trial (NF-trial), whereas a single water bolus of 3.0 ml kg-1 body mass was ingested immediately pre-exercise and serial feedings of 2.0 ml kg-1 body mass were ingested every 15 min during exercise in a fluid replacement trial (FR-trial). Run time for the NF-trial was 77.7 +/- 7.7 min, compared to 103 +/- 12.4 min for the FR-trial (P < 0.01). Body mass (corrected for water ingestion) decreased by 2.0 +/- 0.2% in the NF-trial and 2.7 +/- 0.2% in the FR-trial (P < 0.01), while plasma volume decreased by 1.1 +/- 1.1% and 3.5 +/- 1.1% in the two trials respectively (N.S.). However, these apparent differences in circulatory volume were not associated with differences in rectal temperature. Respiratory exchange ratios indicated increased carbohydrate metabolism (73% vs 64% of total energy expenditure) and suppressed fat metabolism after 75 min of exercise in the NF-trial compared with the FR-trial (NF-trial, 0.90 +/- 0.01; FR-trial, 0.86 +/- 0.03; P < 0.01). Blood glucose concentrations were similar in both trials, while blood lactate concentrations were higher in the NF-trial at the end of exercise (4.83 +/- 0.34 vs 4.18 +/- 0.38 mM; P < 0.05). In summary, water ingestion during prolonged running improved endurance capacity.

Adult↗
PubMed1996

Influence of carbohydrate supplementation early in exercise on endurance running capacity.

The aim of this study is to examine the effect of carbohydrate (CHO) ingestion during the first hour of treadmill running on endurance capacity. Eleven male subjects ran at 70% VO2max to exhaustion on three occasions one week apart. On two occasions two CHO-electrolyte solutions (a 5.5% (E) and a 6.9% (L) were ingested for the first hour of exercise; water was ingested until exhaustion. On the third occasion water (W) was ingested throughout the run. The order testing was randomly assigned. Exhaustion times for the W, E, and L trials were 109.6 +/- 9.6 min, 124.5 +/- 8.4 min, and 121.4 +/- 9.4 min, respectively. There was no difference between the two CHO trials, but time to exhaustion was longer only for the E trial (P < 0.05), compared with the W trial. Nevertheless the average performance times for the combined results of the two CHO trials were longer than the water trial. Carbohydrate ingestion resulted in higher blood glucose concentration (P < 0.01) at 20 min in the E trail only and lower (P < 0.05) serum growth hormone and plasma FFA and glycerol concentrations at 60 min but not at exhaustion in both E and L trials compared with the W trial. Blood lactate, plasma ammonia, electrolytes, catecholamines, and serum insulin and cortisol concentrations were not different in the three trials. In conclusion, CHO ingestion during the first hour of exercise improves endurance capacity go a greater extent compared with water alone.

Adult↗
PubMed1996

Post-traumatic stress reactions in children: gender differences in the incidence of trauma reactions at two years and examination of factors influencing adjustment.

Although a number of studies have noted gender differences in post-traumatic reactions, little has been written about the phenomena. This study examines the post-traumatic reactions among 25 predominantly adolescent children, from a rural community college, two years after a non-fatal school coach accident in the Austrian Alps. For the group as a whole psychological adjustment is good, but gender differences are noted with poorer adjustment for girls. Hospitalization was associated with worse outcome for both boys and girls. The gender differences noted are considered in the light of coping strategies chosen by the children.

Accidents, Traffic↗