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Biomedical subjects

J Gilbert

Publications and source records attributed to J Gilbert.

At least 217 records · Page 12Linked to original sources
PubMed1984

Continuous flow apneic ventilation.

A study was designed to evaluate the adequacy of gas exchange during continuous flow apneic ventilation (CFAV) in dogs. Seventeen dogs (average weight 22.9 kg) were divided into three experimental groups. Group I (n = 7) was anesthetized, paralyzed and ventilated with air using intermittent positive pressure ventilation (IPPV) through a tracheal tube. The tube was removed and each main stem bronchus was cannulated with a 2.5 mm i.d., 4 mm o.d. polyethylene catheter using a fiberoptic bronchoscope. The tracheal tube was replaced to hold the catheters in place. Heated, humidified air was continuously delivered equally to each catheter. Total flows ranged from 8 to 28 l/min (0.4-1.4 l X kg-1 X min-1). Airway pressure (Paw) in the trachea did not exceed 2 mmHg (0.27 kPa). Adequate gas exchange in terms of arterial oxygen and arterial carbon dioxide tension (Pao2 and Paco2) was found after 30 min at flows greater than 16 l X min-1. Group II (n = 7) was managed similarly to the first group, insufflating endobronchial air using the optimal flow of 1.0 l X kg-1 X min-1 obtained from Group I. CFAV continued for 5 h in all animals. Blood gas samples and measurements of systemic blood pressure, heart rate (HR), pulmonary artery blood pressure, pulmonary artery wedge pressure, cardiac output (Qt), and temperature were taken every 30 min. Group III (n = 3) was anesthetized similarly to the other groups. Pulmonary gas distribution was evaluated in relation to catheter placement using Xe133. Results showed significant differences between Pao2 values during CFAV and IPPV; however, all animals were adequately oxygenated.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1983

Deliberate metallic paint inhalation and cultural marginality: paint sniffing among acculturating central California youth.

Deliberate metallic paint inhalation, paint sniffing, has recently become the focus of community concern in central California, as numbers of recalcitrant young abusers have entered the overloaded Mental Health and Juvenile Justice systems. This study, based on an extension of psychological, sociological and anthropological explanations of inhalant abuse, describes the adolescent paint sniffer and proposes that a combination of interacting factors both differentiates him/her from other-drug abusing youth, and predisposes him/her to inhalant use. The experimental hypothesis was tested by a stepwise discriminant analysis performed on 50 subjects, equally divided into two groups, paint and other-drug. Six variables, in combination, were found to significantly differentiate the groups, and the derived function accounted for 56% of the between group differences. The following conclusions can be drawn from this investigation. Firstly, the adolescent paint sniffer is demonstrably and meaningfully different as discriminated by a combination of personal, familial and sociocultural variables. Secondly, these identified factors have predisposed the sniffer to abuse, and cannot be considered simply the consequence of said abuse. Finally, it can be concluded that the paint sniffer is a youth disengaged from the symbols and traditions of his/her culture of origin and concomitantly rejected by the majority culture. Inhalant intoxication provides a "cheap" and effective escape from his/her isolation. Recommendations for prevention, early intervention and treatment are addressed.

Acculturation↗
PubMed1983

Inhibition of prostaglandin synthetase by di- and triphenylethylene derivatives: a structure-activity study.

The syntheses of new di- and triphenylethylene derivatives are described along with their X-ray analysis and NMR study, which have helped to establish their conformation. Screening of over 50 derivatives for inhibition of prostaglandin synthetase (PGS) activity in bovine seminal vesicle microsomes has revealed that many of the triphenylethylene derivatives are potent inhibitors of PGS. Several even show marked activity at the extremely low concentration (IC50) of about 4 X 10(-8) M, which is two orders of magnitude lower than the active concentration of the majority of known nonsteroidal antiinflammatory agents (IC50 approximately equal to 10(-6) M). Unlike the latter, these compounds are not carboxylic acids. Furthermore, in contrast to biphenyl, diphenylmethane, or unsymmetrical, alpha, alpha'-diphenylethylene PGS inhibitors, the presence of a beta-phenyl ring was an essential requirement for high potency. The best inhibitors possessed a cyanide group (acids, amides, and amines were poor inhibitors), methoxy in preference to hydroxy groups on the alpha-phenyl rings, and a halogen (F or Cl) in a para position on the beta-phenyl ring. These data provide additional insight into the nature of the PGS binding site.

Animals↗
PubMed1982

The action of aldosterone and ouabain on cation concentrations in incubated renal slices.

Studies have been made on the effects of aldosterone and ouabain on Na+ and K+ concentrations in incubated rat kidney slices. The results indicate that, control slices gained Na+ over the first 10 min of incubation and subsequently extruded it, with increase in incubation time. In the presence of aldosterone, the same pattern was observed as with control slices, but tissue Na+ concentrations were significantly higher at all times. In the presence of ouabain, slices accumulated Na+ continuously, but in the presence of both drugs, tissue Na+ concentrations were not as high as with ouabain alone. Both aldosterone and ouabain increased the loss of cell K+ whereas control slices reaccumulated their intracellular K+ concentration, with increase in incubation time. The results suggest that aldosterone may have an actual mechanism of action in the renal tubule: either by activating two Na+, K+ pumps located on the luminal and serosal membranes, respectively, or by enhancing luminal membrane permeability, and at the same time stimulating Na+, K+-ATPase on the serosal membrane.

Aldosterone↗
PubMed1982

[Factor analysis of the structure-activity relationship of di- and triphenylethylenes in 2 biochemical tests].

This paper deals with the study of biochemical activity, by means of correspondence analysis, of about fifty original molecules of di- and triphenylethylene structures. The pharmacological experiments were made on glutamate deshydrogenase and prostaglandine synthetase. A typology of several molecular groups is established and the effects of various substituents are specified.

Animals↗
PubMed1981

Predicting cardiac morbidity based on risk factors and coronary angiographic findings.

A cohort of 189 men was followed up for 1 year after performance of coronary angiography and determination of risk factors to ascertain which risk factors or clinical and laboratory findings could aid in predicting the patients who would have a substantial cardiac morbid event. Data on clinical signs and symptoms, psychosocial assessments, angiographic findings and presence of standard risk factors for coronary artery disease were collected in each case. Twenty-five percent of the men experienced a substantial cardiac morbid event (hospitalization, myocardial infarction, resuscitation or death). With or without inclusion of the patients who underwent surgery, discriminant analysis equations were successful in predicting morbidity on the basis of risk factor data. For the whole sample such analysis was significant at p < 0.00005 and accurately predicting the fate of 78 percent of the subjects. With exclusion of the surgically treated patients, the discriminant analysis accurately predicted future morbidity 83 percent of the time (p < 0.0001). The following risk factors for increased morbidity were common to both analyses: severity of angina, history of myocardial infarction, family history of heart disease, fatigue and absence of type A behavior.

Adolescent↗
PubMed1981

Experimental observations on the effects of leg lengthening by the Wagner Method.

A proximal tibial epiphysiodesis was successfully performed on the right hind legs of 23 young lambs, producing an average shortening of 12% of the total length of the tibia. A lengthener was attached to stainless steel pins which were then tapped into the shortened tibia prior to osteotomy. In 16 of the 23 animals it was possible to lengthen the shortened bone at a rate of 0.5 mm twice daily until the discrepancy was corrected. The gait was normal in most of the animals, all had full knee motion with no thigh atrophy, and 16 had limited hock (ankle) joint motion. Lengthening of the tibia by more than 11% consistently produced muscle changes in the leg and cartilage damage in the hock (ankle) joint. Any malalignment of the tibial fragments during lengthening intensified these changes.

Animals↗
PubMed1980

Gas chromatographic determination of vinylidene chloride monomer in packaging films and in foods.

Headspace electron-capture-gas chromatographic methods are described for the quantification of vinylidene chloride monomer in poly(vinylidene chloride) containing films and in film-packaged foodstuffs. Quantification of vinylidene chloride was possible at levels down to 0.001 mg/m2 in the films and 0.005 ppm in the foodstuffs. The results of a small survey of the amounts of this compound in packaging films and foodstuffs purchased from retail outlets are reported.

Chromatography, Gas↗
PubMed1979

Controlled clinical trial of prophylactic human-leukocyte interferon in renal transplantation. Effects on cytomegalovirus and herpes simplex virus infections.

A double-blind, placebo-controlled trial of interferon prophylaxis against viral infections was conducted in renal-transplant recipients receiving standard immunosuprressive therapy with or without antithymocyte globulin. Interferon was administered for six weeks, beginning on the day of transplantation. Cytomegalovirus excretion began earlier and viremia was more frequent in placebo-treated than in interferon-treated patients. Cytomegalovirus viremia correlated with clinical syndromes was more frequent in recipients of antithymocyte globulin. In contrast, neither interferon nor antithymocyte globulin altered excretion of herpes simplex virus. Reversible leukopenia and thrombocytopenia occurred in seven interferon recipients. Patient and graft survival were comparable in interferon and placebo groups. There preliminary results suggest that a six-week course of prophylactic interferon delays shedding of cytomegalovirus and decreases the incidence of viremia after transplantation. In contrast, antithymocyte globulin appears to increase the severity of infection from cytomegalovirus among these patients.

Adult↗