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Biomedical subjects

J Marsh

Publications and source records attributed to J Marsh.

At least 127 records · Page 7Linked to original sources
PubMed1984

Nonspecificity of elevated angiotensin-converting enzyme activity in bronchoalveolar lavage fluid from high permeability lung edema states.

Elevated levels of angiotensin-converting enzyme activity (ACE) in bronchoalveolar lavage fluid (BAL) have been used as a specific marker for pulmonary endothelial cell injury associated with high permeability lung edema. Alternatively, however, BAL-ACE elevations might reflect a nonspecific leak of plasma proteins into bronchoalveolar spaces. To investigate the cause of BAL-ACE elevations in high permeability lung injury states, we measured ACE and protein concentrations in BAL from isolated perfused rabbit lungs injured with oleic acid or hyperoxia. Although BAL-ACE was elevated, we found no increase in the BAL-ACE:protein ratio over values from control preparations, despite the presence of marked nonhydrostatic lung edema. We conclude that, in the experimental setting of nonhydrostatic lung edema, BAL-ACE elevations are no more helpful in identifying acute lung injury than are elevated BAL-protein levels.

Animals↗
PubMed1983

Diagnostic criteria and natural history of catheter-associated urinary tract infections after prostatectomy.

Bacteriuria occurred postoperatively in 28 of 122 patients who had sterile urine before transurethral prostatectomy without antibiotic prophylaxis. Prospective monitoring of catheter bacteriuria indicated that a bacterial count of 10(3) colony-forming-units (cfu/ml progressed to significant infection except when the bacterium in the urine was Staphylococcus epidermidis. Bacteraemia developed in 4 bacteriuric patients, including 2 in whom the bacteria in the urine and blood were mixed. Catheter removal without antibiotic therapy resulted in spontaneous resolution of Staph epidermidis bacteriuria in 9 patients but infection persisted in 5 of 6 patients with other bacteria in the urine. This study indicates that a bacterial count of 10(3) cfu/ml in catheter urine is associated with pathological sequelae and that catheter removal does not result in resolution of bacteriuria caused by pathogenic bacteria.

Bacteria↗
PubMed1983

The R-factors of multiple antibiotic resistant faecal coliforms isolated from a domestic dog.

The antibiotic resistant faecal flora of a domestic dog suffering from an acute enteric infection was examined. The flora exhibited overall resistance to a wide variety of antibiotics. However, following restoration of the animal to normal health, overall resistance to ampicillin (Ap), tetracycline (Tc), chloramphenicol (Cm) and streptomycin Sm was lost, although low numbers of bacteria resistant to these four antimicrobial agents could still be isolated up to one year later. A total of 11 strains were purified for further study. All 11 were positively identified as Escherichia coli and shown to be resistant to various combinations of the above antibiotics, and additionally to kanamycin (Km). Each strain harboured from one to five plasmids, although only four proved capable of transferring antibiotic resistance to Escherichia coli K-12. One of the strains was found to harbour two conjugal plasmids pNJ101 (60 Md) and pNJ102 (133 Md) which coded for resistance to Cm, Tc, Ap and Cm, Tc, Km respectively. A third plasmid pNJ103 (29 Md) remains cryptic. The possession of the two plasmids pNJ101 and pNJ102 appears to be an unstable situation as variants arose harbouring one or other of the plasmids.

Animals↗
PubMed1983

Abnormalities in the plasma concentrations of thyroxine, tri-iodothyronine and growth hormone in sex-linked dwarf and autosomal dwarf White Leghorn domestic fowl (Gallus domesticus).

Plasma concentrations of GH were high in young birds (2-12 weeks old) and low in older birds (15 and 18 weeks old) in the control Cornell K strain of White Leghorn fowl. There was little variation in the plasma concentrations of tri-iodothyronine (T3) and thyroxine (T4) with age in this strain. Similar patterns of plasma hormone concentrations with age were observed in autosomal recessive dwarf chickens. However, the plasma concentrations of T3 and T4 tended to be depressed while that of GH was raised. There was little age-related change in the plasma concentrations of GH, T3 and T4 in sex-linked recessive dwarf chickens. Throughout growth and maturation the plasma concentrations of T3 in the sex-linked dwarf birds were less 40% of those observed in the control strain. Plasma concentrations of T4 tended to be raised relative to the control in the sex-linked dwarf at each age examined. The plasma concentration of GH was raised only in older (12, 15 and 18 weeks old) sex-linked dwarfs. Liver T4-5' monodeiodinase activity was slightly depressed in autosomal dwarf chickens and very low in the sex-linked dwarf fowl. Neither autosomal nor sex-linked dwarfism appears to be due to hypopituitarism. It is probable that the depressed liver 5' monodeiodinase activity and the concomitant low plasma concentrations of T3 are a causative factor in the reduced growth and stature of the sex-linked dwarf chicken.

Animals↗
PubMed1982

Ventilation and carotid chemoreceptor discharge during venous CO2 loading via the gut.

A simple method of loading CO2 into the venous blood of anaesthetized or decerebrate cats is described. Heated humidified gas of high CO2 content is passed retrogradely through the gut. This increases CO2 elimination from the lungs by 1.8 to 3.6 fold, minute ventilation by 1.5 to 2.7 fold and cardiac output by 1.1 to 1.6 fold. This method of venous CO2 loading allows the recording of afferent nerve impulses. We show that it has little effect on the mean discharge frequency of carotid body chemoreceptors when end-tidal gases are held constant, but that it enhances greatly the amplitude of the respiratory oscillation of their discharge.

Animals↗
PubMed1982

The reflex respiratory effects on cats of breathing through a tube.

1. In anaesthetized cats, breathing air through an external dead space (a tube, 20-40 ml.) stimulated ventilation in excess of that expected from the end-tidal gases. 2. The stimulatory effect remained after bilateral vagotomy. 3. The stimulatory effect was reduced or abolished after bilateral section of the carotid sinus nerves. 4. The stimulatory effect was abolished by bilateral section of both the vagi and the sinus nerves. 5. Recording from chemoreceptor afferents in the sinus nerve showed that, although the tube increased mean discharge frequency, this increase was insufficient to account for the stimulation of ventilation observed. 6. Some feature of chemoreceptor discharge other than its mean level, possibly related to its wave form, may explain the effect.

Animals↗
PubMed1982

Examination of insulin formulations using quasi-elastic light scattering.

A selection of neutral insulin formulations from commercially available vials was examined by quasi-elastic light scattering. In preliminary investigation, significant differences in the particulate nature of insulins from different manufacturers were apparent. Some preparations contained only small diameter species believed to be insulin hexamer while others showed evidence of larger aggregates and microcrystals. Addition of small amounts of bicarbonate had no detectable effect on the small species but dissolves the microcrystals. Speculation on further and more quantitative use of this new technique for analysis of insulin solutions is reported.

Animals↗
PubMed1981

The quality of life after cardiac surgery.

A follow-up study to assess the quality of life after cardiac surgery was begun in 1973. The results, for a total of 383 patients followed up for a maximum of 44 months after surgery, showed an overall improvement in all aspects of life for most patients.

Activities of Daily Living↗
PubMed1980

Processing mechanisms in the biosynthesis of proteins.

Limited proteolysis is a widely occurring mechanism in protein biosynthesis. Protein precursors can be classified according to their functions, localization within cell compartments, and enzymic cleavage mechanisms. The presecretory proteins represent an important class of very rapidly turning over precursors which play an early role in the sequestration of secretory products and whose cleavage appears to be intimately associated with structures formed at the ribosome-membrane junction during protein synthesis. A model is proposed which predicts that the prepeptide forms a beta-pleated sheet structure with other components of the membrane which results in the transfer of a loop of peptide across the microsomal membrane. Proinsulin is representative of the general class of proproteins that are processed post-translationally within their secretory cells either during the formation and maturation of secretory granules (peptides hormones and neurotransmitters, serum albumins) or during the assembly of macromolecular structures (virus capsules, membrane-associated enzyme complexes). The former group are cleaved by Golgi-associated proteases having tryptic and carboxypeptidase B-like specificity. Some precursors are secreted as such and processed extracellularly either in the circulation or at special sites (procollagens, zymogens, provenoms, vitellogenins).

Amino Acid Sequence↗
PubMed1980

Protease and antiprotease responses in lung and peripheral blood in experimental canine pneumococcal pneumonia.

We studied the effects of pulmonary infection with type III pneumococcus in dogs on the degree of granulocyte elastase-like esterase activity and on the degree of antiproteases in peripheral blood and lung lavage fluid. In 9 infected dogs the peripheral blood granulocyte esterase activity increased from a preinfection level of 361.3 +/- 51 units/10(8) leukocytes to 593.8 +/- 80 units/10(8) leukocytes (mean +/- SE) 24 h after pneumonia had been induced (p less than .02). Parallel changes were measured in granulocytes obtained from bronchial lavage fluid. The antitrypsin activity and esterase inhibitory activity of peripheral blood increased by 15% after infection was induced. The esterase inhibitory activity of lung lavage fluid increased from a preinfection level of 776 +/- 160 units/mg of lavage protein to 1,390 +/- 200 units/mg of lavage protein (p less than .05). These findings indicate that whereas both circulating and lung lavage granulocytes contain increased concentrations of proteolytic activity during infection, serum antiproteases and, to a larger extent, lung antiproteases, also are increased.

Animals↗
PubMed1980

Disability, health status, and utilization of health services.

Change in the patterns of utilization of services is an important indicator of the influence of policies and programs concerning health care. This paper focuses on these patterns as revealed in a survey of a probability sample of the U.S. adult population conducted in 1972. The analysis sought to assess the influence of a number of health dimensions, as well as economic and sociodemographic characteristics, on utilization. Coverage through insurance or other payment plants constituted one of the independent factors in the analysis. The dimensions of health included indicators of disabilities in work and independent living, limitations in physical and emotional performance, and the existence and severity of pathology and impairment. A discriminant analysis was employed to assess the relative importance of these variables in their influence upon the utilization of services. Finally, the paper presents information about unmet needs for care.

Activities of Daily Living↗
PubMed1978

Swimming speed distributions of bull spermatozoa as determined by quasi-elastic light scattering.

88 semen samples from 39 bulls have been investigated by the quasi-elastic light scattering technique. Normal, defective, and dead cells each yielded characteristic autocorrelation functions. The form of these functions indicates that the swimming speed distribution of normal cells is a gamma distribution with two degrees of freedom while that for defective or circular swimmers is a gamma distribution with one degree of freedom. The resulting analysis of the experimental autocorrelation functions yields the fraction of the sample that is normal, the fraction that is defective, and the average speed of each group. The average helical swimming speed of normal cells was found to be 384 micron/s, while the average trajectory speed of the circular swimmers was found to be 103 micron/s. The overall quality of the semen samples as determined by light scattering is compared to quality determination on the same samples by technicians from the artificial insemination industry.

Animals↗