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Biomedical subjects

R Brown

Publications and source records attributed to R Brown.

At least 811 records · Page 45Linked to original sources
PubMed1975

Studies on the synthesis and subcellular distribution of dopamine in the rat adrenal medulla.

Rats received intravenous injections of 3H-tyrosine and were killed at various time intervals thereafter. 3H-dopamine (DA) in the adrenals reached a maximum within 1.5 min after the administration of 3h=tyrosine. From the 15th min it disappeared with an apparent half life of 90 min. 3H-Adrenaline (A) plus 3H-noradrenaline(NA) increased much more slowly and reached a plateau 120-240 min after the injection. The approximate synthesis rate of adrenal A plus NA, calculated from the specific activity curves, ranged from 0.3 to 2.2 nmoles/h per kg b.w. The highest value was noted the first few minutes, the lowest 1-2 hrs after the administration of 3H-tyrosine. In some experiments subcellular fractionation of the adrenals was performed. In untreated animals the amount of DA and A plus NA recovered from the supernatant fraction was about 10 and 8 per cent, respectively, of the total amount recovered from the supernatant and particulate fractions. In the adrenals of animals receiving 3H-tyrosine 3.75 or 60 min beforehand these figures were significantly elevated whereas the DA and A plus NA of the particulate fraction did not deviate significantly from control values. The specific activities of 3H-DA were the same in the supernatant and particulate fractions within 3.75 min after the injection of 3H-tyrosine.

Adrenal Medulla↗
PubMed1975

A defined medium for the growth of Clostridium tetani and other anaerobes of clinical interest.

The growth of six strains of Clostridium tetani was assessed in a chemically supplemented commercially available defined medium. All strains grew reliably even after 12 serial passages, and two strains produced demonstrable toxic activity after passage. Consistent growth of the test strains could also be obtained on a solid version of this medium ("CA109-S" medium), and the strains could be serially passaged on this medium. Preliminary evidence is presented that the medium supports the surface growth of some other test anaerobes. Such a defined solid medium might prove of value in further studies on the surface growth of C. tetani and of other anaerobes of clinical interest.

Anaerobiosis↗
PubMed1975

Dynamic/static brain scintigraphy: an effective screening test for subdural hematoma.

Dynamic perfusion scintigraphy of the brain was coupled with the delayed static scan in 5,853 studies as a screening test for neurological disease. Of approximately 1,000 patients referred for investigation for possible subdural hematoma (SDH), 23 proved to have SDH at surgery. Their scintigraphic abnormalities were analyzed and classified. When neither study indicates abnormality, angiography is not required, as SDH is unlikely. When the scintigraphic appearance is characteristic of SDH, angiography or surgical exploration is mandatory, since SDH is probably present. When the scintigraphic findings are consistent with but not typical of SDH, the study remains useful as a screening procedure, but the decision to proceed with angiography is based primarily on the neurological course.

Adolescent↗
PubMed1975

Pneumatoceles as a complication of chemical pneumonia after hydrocarbon ingestion.

Of 338 children with hydrocarbon ingestion, 134 (40 percent) had pneumonia. Pneumonia was most common after kerosene, furniture polish and lighter fluid ingestion. The pneumonia was most severe, however, with furniture polish. Pneumatoceles occurred in 14 children, most commonly with charcoal lighter fluid ingestion. Pneumatoceles generally appeared late, after the consolidation had cleared. Pneumatoceles were often large, septate and irregular, and sometimes contained fluid levels.

Acetone↗
PubMed1975

Double outlet right ventricle with l-malposition and uncommitted ventricular septal defect.

A case is described which exhibited Double Outlet Right Ventricle (DORV) with l-malposition of the aorta in association with a ventricular septal defect of the noncommitted, atrioventricular canal variety. When the ventriculoarterial relationship of DORV is encountered, it is more usual to find the aorta to the right of the pulmonary artery. Review of the literature shows that examples of DORV and l-malposition have been described with subaortic, subpulmonary and doubly committed defects, but we are unaware of any previous example reported with a noncommitted defect. These findings indicate that DORV with l-malposition should be anticipated in association with the same accompanying defects as those described in DORV with d-malposition, and emphasize the necessity for adopting a segmental approach to nomenclature. They also have morphogenetic significance, suggesting that DORV with l-malposition is closely linked with the anomalies for anatomically corrected malposition and concordant (complete) l-transposition. The present case exhibited an electrocardiographic superior axis, which is probably related to the presence of the atrioventricular canal deformity. The coexistence of hypoplasia of the aortic isthmus is speculatively related to the presence of conal and valvar factors, which can be considered to have reduced aortic blood flow.

Adult↗
PubMed1974

The recovery of anaerobic bacteria from swabs.

When a standard sample of simulated exudate containing known numbers of anaerobic bacteria was taken up on a swab and plated on solid medium, the number of colonies subsequently cultured represented a very small proportion of the original sample. Evidence is produced that the apparent loss is not primarily attributable to inactivation on the swab but rather to retention of organisms on the swab. This was demonstrable with Clostridium welchii and with Bacteroides species that have hitherto been regarded as relatively oxygen-sensitive.When stock strains of Bacteroides species were held for some hours on swabs, some progressive loss of viability was demonstrable. A measure of protection was afforded when these organisms were held aerobically on blood agar medium, but a very exacting anaerobe and some wild strains of faecal anaerobes showed gradual inactivation under these conditions.These findings may have important implications in relation to currently employed bacteriological sampling procedures with swabs in clinical practice.

Aerobiosis↗