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Biomedical subjects

N O'Connor

Publications and source records attributed to N O'Connor.

At least 73 records · Page 4Linked to original sources
PubMed1981

Viscosity differences between various guar gums.

Guar gum from four industrial sources was investigated. The viscosity of two preparations of hydrated guar gum in the form of powdered flour and one granulate flour was measured at 22 degrees and 32 degrees C and pH 1.0 and pH 4.0. Viscosity measurements on wax-coated guar granules proved impossible but visual assessment indicated an extremely low viscosity in all conditions. These findings were compared with the ability of the equivalent of 5 g guar gum of the various preparations to modify the absorption of a 50 g liquid glucose load. The mean post-prandial blood glucose curve was not significantly different from the control situation after the incorporation of each preparation. Despite the granulate flour attaining a considerably lower viscosity than the powdered flour they were equally effective in significantly reducing the mean post-prandial insulin curve (area under the curve (0-180 min) reduced by 46 and 50% respectively). The wax-coated granules which achieved minimal viscosity caused significantly less reduction of post-prandial insulin levels (area under the curve reduced by 37%). The viscosity of guar gum upon hydration is of importance in assessing the efficacy of a preparation in clinical use.

Adult↗
PubMed1980

Pilot study on the value of a beta-blocking drug in initial helicopter training.

The effect on performance of a standard dose of a beta-blocking drug was examined in a controlled test situation closely approximating actual flying training conditions and involving helicopter flying skills. Pindolol or a placebo was administered 90 min before a test flight and the flying and hovering performance of five students was assessed by qualified flying instructors. No significant difference was found between assigned performance ratings of test drug flights and placebo flights. It could not be concluded that a beta-blocking drug would improve the hovering performance of ab initio helicopter trainee pilots.

Adrenergic beta-Antagonists↗
PubMed1980

Carbon monoxide poisoning in fire victims: a reappraisal of prognosis.

In victims of carbon monoxide (CO) poisoning, metabolic acidosis has been considered a clinical finding of ominous prognostic importance. In previous studies, such patients either died or suffered serious neurologic sequelae, resulting in the recommendation by some authors that these patients require more complicated therapy, including hyperbaric oxygen and hypothermia. This report documents the full neurologic recovery of three patients with severe metabolic acidosis and CO poisoning. Our experience indicates that acidosis may not be as important a prognostic factor as previously thought, and that randomized prospective trials are needed in such patients before more complicated therapy becomes accepted medical practice.

Acidosis↗
PubMed1979

Fc receptors for IgA on human B, and human non-B, non-T lymphocytes.

Recently, receptors for IgA were demonstrated on subpopulations of human T lymphocytes. In this report, TNP-modified ox erythrocytes coated with the IgA myeloma MOPC-315 were used to detect IgA receptor-bearing lymphocytes within the human non T cell lymphocyte population. A mean of 5.3% (range 2.9 to 12.4%) of E-rosette negative human lymphocytes bound IgA-coated indicator cells. Blocking studies with soluble IgA, IgG, and IgM demonstrated that the IgA receptors on the non-T cell populations were separate and distinct from the Fc-receptors for IgG and IgM. Fractionation of the non-T lymphocytes on anti-human (Fab)2 columns into sIg+ and sIg- populations or by rosetting with EAC to provide CRL+ and CRL- populations demonstrated that Fc-IgA receptors were present on a subpopulation of sIg+, CRL+ lymphocytes, and also on sIg- (non-T, non-B) lymphocytes.

Animals↗
PubMed1978

Lung water changes after thermal burns. An observational study.

Pulmonary extravascular water has been measured as lung thermal volume (LTV) in a group of nine burned patients. Transducer-detectable indicators were used to permit frequent repetition and quick results. Concurrent recordings were made of cardiac output, pulmonary capillary wedge pressure and the usual hemodynamic variables. Moderate elevation of LTV was seen in all, reaching a maximum value before peripheral edema formation was complete. Left heart filling pressures were low as plasma albumin concentration. Clinical pulmonary edema occurred in one patient treated mostly with crystalloid solution. In several, a secondary peak coincided with edema mobilization.

Adult↗
PubMed1976

Turnover of erythrocyte protoporphyrin, with special reference to bovine porphyria and iron deficiency anemia.

Available data from human subjects suggests that most of the pools of free protoporphyrin in circulating erythrocytes have T 1/2 values which range from less than 1 hour to approximately 2 weeks. An exception was observed in 2 cows with erythropoietic ("congenital") porphyria. During the several months which followed the simultaneous injection of 14C- and 3H-labelled glycine and ALA, changes in the specific activities of both free- and hemoglobin-protoporphyrin were similar. Since erythropoietic porphyria in the bovine differs from that in the human mainly in the elevated values of free erythrocyte protoporphyrin in the former, it is suggested that this prolonged T 1/2 (equal approximately to the red cell life span) may account for the elevated values seen in the bovine. Variable ratios of red cell/fecal protoporphyrin concentrations reported in other diseases are also believed to be due largely to T 1/2 differences in porphyrin pools. Recorded fluorescence and excitation spectra of blood showed the single fluorescence band of "free" porphyrin in bloods of normal and porphyric cows and of patients with erythropoietic porphyria, protoporphyria, and sideroblastic anemia. The 2 band zinc complex spectrum was found, as expected, in blood of subjects with Pb poisoning and Fe deficiency anemia. T 1/2 values of 1 to 2 weeks were calculated for red cell protoporphyrin from previously published data of patients with Fe deficiency anemia who were treated effectively with iron.

Aminolevulinic Acid↗
PubMed1975

The recall of digits by normal, deaf and autistic children.

Normal, autistic and deaf children were tested for their immediate memory of visually presented digits. The digits were exposed either with or without a left to right spatial display arrangement, and had to be recalled forewards as well as backwards. Normal and deaf children tended to be sensitive to both display conditions and recall requirements whereas autistic children were mainly affected by direction of recall. Serial position effects in the normal and deaf groups were more dependent on order of retrieval than on input order.

Autistic Disorder↗
PubMed1975

Uptake and supply of purine compounds by the liver.

We have analyzed for purine compounds entering and leaving the liver in lightly anesthetized rabbits and rats and for the export of utilizable purine from liver perfused with oxypurine. The in vivo results indicate that roughly 80% of hypoxanthine, xanthine, and urate is removed in a single passage of blood through liver. Conversely, the adenosine concentration of hepatic venous blood is increased 10-fold over portal or arterial levels. When the liver is isolated and perfused with hypoxanthine there is significant release of adenosine, whether measured quantitatively by microbiological assay or qualitatively by analysis of the radioactive purines released from liver that has been prelabeled with [14C]hypoxanthine. These results provide direct evidence for the clearance of hydroxylated purines and the release of utilizable adenine derivatives by liver.

Adenosine↗