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Biomedical subjects

G Lewis

Publications and source records attributed to G Lewis.

At least 235 records · Page 13Linked to original sources
PubMed1989

Bile acid synthesis by cultured rabbit hepatocytes: stimulation by three lipoprotein fractions.

Bile acid and cholesterol synthesis were measured in monolayer cultures of rabbit hepatocytes maintained in a defined culture medium. In the absence of lipoproteins, bile acid synthesis and secretion were correlated with cholesterol synthesis and were increased 245% by mevalonolactone (10 mM) and inhibited 45% by lovastatin (50 micrograms/ml) over 24 h. When included in the culture medium, normal rabbit plasma low-density and high-density lipoproteins increased bile acid synthesis and secretion by up to 140% of values obtained without lipoproteins in hepatocytes from normal or cholestyramine-fed rabbits. Three cholesterol-rich lipoprotein fractions (beta-very low density, low density and high density) also were isolated from rabbits fed 1% cholesterol for 14 days. When added to rabbit hepatocyte cultures, each fraction markedly increased hepatocellular cholesterol content, stimulated bile acid synthesis and secretion in a dose-dependent manner, and inhibited cholesterol synthesis from radioactive acetate. These data indicate that three different lipoprotein fractions can provide cholesterol for uptake and subsequent breakdown to bile acids by cultured rabbit hepatocytes.

Animals↗
PubMed1989

Laser-assisted thermal angioplasty in human peripheral artery occlusions: mechanism of recanalization.

Recanalization of completely occluded superficial femoral or popliteal arteries was attempted in 18 patients with use of an Argon laser-mediated thermal probe. The length of the occluded segments varied between 0.5 and 26.0 cm, but 67% of the occlusions were greater than 9 cm long. The initial success rate was 67%. Arterial perforation occurred in six patients but was not associated with major complications. To study the mechanism of the laser-mediated thermal probe, thermal recanalization was performed on 11 human arterial segments in vitro obtained after amputation, and mechanical recanalization was performed in vitro in 10 human peripheral arteries with use of a guide wire and catheter technique. An additional four arteries were studied with the laser probe as a non-heated mechanical device. Both the mechanical and thermal devices appear to follow a similar pathway through a complete obstruction. These studies suggest that the thermal probe burns through soft fibrous tissue but is mechanically deflected away from hard fibrocalcific plaque. The probe then advances along the plane between the intimal plaque and the media for a variable length before perforating through the adventitia. These observations suggest that the major mechanism of thermal probe recanalization may be a mechanical process. It appears that thermal probe devices do not inherently seek the true lumen of an occluded artery and that better guidance systems need to be developed.

Aged↗
PubMed1989

Clinical judgement and the standardized interview in psychiatry.

There has been little discussion of the advantages and disadvantages of allowing a psychiatrist to make clinical judgements about the presence or absence of symptoms in administering currently used standardized psychiatric interviews. This paper reports an examination of the value of clinical judgements in defining cases of minor psychiatric disorder, by studying existing data in which the Clinical Interview Schedule (CIS) was used. This comparison can be made because the first section of the CIS is largely self-report while interviewers are also instructed to use clinical judgement in the second section to decide on ratings. The results indicate that in the context of identifying minor psychiatric disorder the ratings requiring clinical judgement add little information to those based on self-report, may be less reliable and may lead to the biased assessment of anxiety and depression.

Anxiety↗
PubMed1988

The development of a computerized assessment for minor psychiatric disorder.

This paper describes the development, validation and use of a computerized assessment for minor psychiatric disorder based on the Clinical Interview Schedule (CIS; Goldberg et al. 1970). There was good agreement between the computerized assessment and the CIS administered by psychiatrists, both in assessing overall severity and in defining 'cases' of psychiatric disorder. Individual symptoms elicited by the computer and the CIS were compared, and the levels of agreement found were similar to those from inter-observer studies of standardized interviews. Subjects from a variety of non-psychiatric settings regarded the assessment as acceptable, accurate and easy to use. It is concluded that this computerized assessment of neurotic symptoms is valid and reliable. It eliminates observer bias, it is an efficient use of research resources and it may have clinical applications in primary care.

Adolescent↗
PubMed1988

Enhanced susceptibility of gram-negative bacteria to phagocytic killing by human polymorphonuclear leucocytes after brief exposure to aztreonam.

Brief exposure of Escherichia coli, Serratia marcescens, Klebsiella pneumoniae and Salmonella typhimurium to supra-inhibitory concentrations of aztreonam enhanced their susceptibility to phagocytic killing by human polymorphonuclear leucocytes. The effect was independent of the continuous presence of the antibiotic and required the presence of serum opsonins. Phagocytic killing of Pseudomonas aeruginosa was enhanced by prior exposure to subminimal inhibitory concentrations, and killing, relative to control bacteria, was not increased with increasing concentrations of aztreonam above minimal inhibitory concentrations. The degree of sensitization, and the range of bacteria susceptible to antibiotic modulation varied between antibiotics. Under the conditions of these experiments, gentamicin sensitized pseudomonas, but failed to sensitize E. coli, while cefotaxime failed to sensitize serratia, and varied in it's activity against E. coli and pseudomonas. Enhanced killing of aztreonam-pretreated bacteria was associated with an increase in uptake by leucocytes. Aztreonam exposure decreased the liability of the bacteria to hydrophilic interactions in an aqueous two-phase partitioning system. These observations indicate that exposure of Gram-negative bacteria to aztreonam enhances phagocytic killing through modification of cell surface structures. This may be mediated through an increase in surface hydrophobicity which enhances bacterial association with leucocyte membranes with subsequent phagocytosis and intracellular killing.

Aztreonam↗
PubMed1988

Personality disorder: the patients psychiatrists dislike.

A sample of psychiatrists was asked to read a case vignette and indicate likely management and attitudes to the patient on a number of semantic-differential scales. Patients given a previous diagnosis of personality disorder (PD) were seen as more difficult and less deserving of care compared with control subjects who were not. The PD cases were regarded as manipulative, attention-seeking, annoying, and in control of their suicidal urges and debts. PD therefore appears to be an enduring pejorative judgement rather than a clinical diagnosis. It is proposed that the concept be abandoned.

Adjustment Disorders↗
PubMed1988

Cardiac arrest associated with halothane anesthesia in a patient receiving theophylline.

A case of a 10-year-old asthmatic patient who had cardiac arrest during induction for elective ear surgery is presented. The patient's serum theophylline level was 21.6 micrograms/mL one hour after surgery. It is likely that, since other factors that can contribute to cardiac arrest during the perioperative period were not present, the combined use of aminophylline and halothane was responsible.

Anesthesia↗
PubMed1987

Femoral nerve block with bupivacaine 0.25 per cent for postoperative analgesia after open knee surgery.

An assessment was made, in a randomised double-blind fashion, of the pain relief afforded by femoral nerve block (FNB) performed at the end of ligament reconstruction of the knee, using 0.25 per cent bupivacaine in ten patients, and normal saline in ten patients. All patients commenced "continuous passive motion" (CPM) of the operated knee after arrival in the Recovery Room. The postoperative analgesic requirement, both for intravenous fentanyl in the Recovery Room, and intramuscular and oral analgesia on the ward, was then studied. The time interval between FNB and first dose of analgesia was significantly longer in the bupivacaine group than in the control group. The bupivacaine group also required significantly less intravenous fentanyl in the Recovery Room. On the ward, there was no difference between the two groups in the total dose of intramuscular meperidine given in the first 12 hours postoperatively. We conclude that femoral nerve block is a useful adjunct in pain management after ligament reconstruction of the knee, especially in the early postoperative period, but does not decrease the total intramuscular dose of analgesia in the first 12 postoperative hours.

Bupivacaine↗
PubMed1987

Increasing productivity and decreasing costs: the value of RNs.

Are increased nursing personnel or increased levels of preparation of nursing personnel major factors contributing to the sky-rocketing costs of hospital care over the past two decades? The authors discuss a comparison of staffing patterns and staffing costs at a large midwestern medical center and suggest that there is little basis for this belief.

Budgets↗
PubMed1987

Recurrent pancreatitis caused by a calcified ascaris in the duct of Wirsung.

A case report of recurrent pancreatitis in a 20-yr-old woman due to an impacted calcified Ascaris remnant within the duct of Wirsung is presented. Endoscopic retrograde cholangiography identified a filling defect in the proximal main pancreatic duct. Transampullary endoscopic retrieval failed to extract the calculus and operative intervention was required to remove the calcified worm remnant.

Adult↗
PubMed1986

Inpatient participation in treatment planning: a preliminary report.

This study investigated the effect of patient participation in treatment planning conferences (TPCs) upon length of hospitalization and upon the frequency of military soldiers being returned to duty. Patients with major affective disorders and schizophrenic disorders showed an 8.2% decrease in hospital stay whereas patients with minor affective disorders, personality disorders, substance abuse, and adjustment disorders showed a 98.8% increase. Additionally, the percentage of active duty soldiers with a major depressive episode who were returned to duty increased significantly when they participated in their TPC.

Adult↗