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Biomedical subjects

P O'Brien

Publications and source records attributed to P O'Brien.

At least 217 records · Page 12Linked to original sources
PubMed1980

Role of acid-base status in the response of the isolated amphibian gastric mucosa to back diffusion of H+.

The effect of a period of induced back diffusion of H+ on the isolated amphibian gastric mucosa was studied under various conditions. Under standard conditions (HCO3--buffered nutrient solution; 95% O2-5% CO2), passage of an electrical current of 500 microA/cm2 for 15 min from a secretory fluid of pH 2.10 across the mucosal resulted in a decrease of the transmucosal potential difference (PD) of 10.9 +/- 1.9 mV, a decrease of resistance (R) of 48 +/- 26 ogema cm2 and a decrease of short circuit current (Isc) of 18 +/- 7 microA/cm2. Flux of the neutral molecule, erythritol from secretory (S) to nutrient (N) fluid increased by 66% and the active transport of Cl- N lead to S decreased from 2.9 to 1.9 microeq/cm2/hr. With removal of HCO3- from the nutrient fluid and with inhibition of carbonic anhydrase activity the period of back diffusion induced significantly greater change in the electrical measurements than occurred when under standard conditions. This increased effect of back diffusion of H+ was not changed by change of the nutrient fluid pH from 7.20 to either 6.6 or 8.2. Increase of the HCO3- concentration of the nutrient fluid to 35 mM or decrease of the CO2 content of the aerating gas to 1% were associated with significantly less change of the electrical measurements than occurred with standard conditions. These studies support the proposal that the the neutralizing reaction HCO3- + H+ leads to CO2 + H2O plays a central role in the gastric mucosal handling of backing diffusing H+ and suggests that the capacity and poise of the HCO3-/CO2 buffer system is an important determinant of the ability of the mucosa to tolerate luminal acidity.

Acid-Base Equilibrium↗
PubMed1979

Alcoholics Anonymous, alcoholism counseling, and social work treatment.

The authors suggest that the misunderstanding by many social workers of the particular values of Alcoholics Anonymous and the skills of alcoholism counselors can involve alcoholic patients themselves in the stress of reconciling different approaches to treatment. They call upon all who treat alcoholics to build mutual trust and cooperation on two assumptions basic to all forms of treatment-that alcoholism is a disease and abstinence is essential to recovery.

Alcoholics Anonymous↗
PubMed1979

Diabetes insipidus following obstetric shock.

The first known case of obstetric shock followed by diabetes insipidus without anterior pituitary deficiency is presented. A patient developed extreme thirst and polyuria after massive bleeding and prolonged shock due to placenta previa percreta with bladder invasion. Evaluation confirmed diabetes insipidus sensitive to vasopressin administration. Anterior pituitary deficiency could not be identified, either acutely or 6 months later.

Adult↗
PubMed1979

Qualitative analysis of proteinuria associated with bladder cancer.

In the present investigation molecular components associated with the urines from bladder cancer patients and normal individuals are identified. Polyacrylamide gels of urines from bladder cancer, bladder papilloma, and normal individual exhibit clear differences in banding patterns. Urine from bladder cancer patients shows gels with increased quantities of low (less than 100,000) and increased and additional high (less than 100,000) molecular weight proteins when compared to gels with urine from papilloma and normal individuals. In order to localize and identify proteins in the urine from bladder cancer, papilloma, and normal individuals, proteins were separately fractionated on Sephadex G-200 columns and each elution fraction was reacted on Ouchterlony gel diffusion against various specific antisera. The qualitative analysis of proteins in urine from bladder cancer patients is discussed in relation to their molecular weight distribution in the Sephadex G-200 profiles and their possible role in tumor host relationships.

Albuminuria↗
PubMed1978

Cellular adaptations of the ventilatory muscles to a chronic increased respiratory load.

It is not known whether cellular adaptations of the ventilatory muscles are induced by increased respiratory loads. A chronic respiratory load was produced in rats by tracheal banding. Five weeks after the imposition of this increased load, biochemical and histochemical analyses were performed on the diaphragm and intercostal muscles. The oxidative capacity, as indicated by succinate dehydrogenase (SDH) activity, increased 38% in the diaphragm. The capacity for beta-oxidation fatty acids, as indicated by 3-hydroxy-acyl-CoA dehydrogenase (HADH) activity, increased 29%. The glycolytic capacity, as indicated by phosphofructokinase (PFK) activity, did not change. Similar enzymatic adaptations were observed in the intercostal muscles. The proportion of slow-twitch muscle fibers, as indicated by the myofibrillar adenosine triphosphatase (ATPase) stain, increased in the diaphragm, but not in the intercostal muscles. Thus, these ventilatory muscles responded with an increase in their oxidative capacity, and the diaphragm reponded with an increase in the proportion of muscle fibers having the myofibriller ATPase staining characteristic of slow-twich fibers. We conclude that cellular adaptations are induced in the ventilatory muscles by chronic increased respiratory loads.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1978

The pineal gland does not control rod outer segment shedding and phagocytosis in the rat retina and pigment epithelium.

Diurnal patterns of retinal outer segment shedding and phagocytosis by the pigment epithelium were examined in pinealectomized, superior-cervical-ganglionectomized, and sham-operated rats. Phagocytosis was quantitatively similar in all groups. Sharp increases in the number of large phagosomes were observed soon after lights were turned on in the tree sets of animals. Pinealectomized animals kept in constant darkness over a 24 hr period also exhibited normal shedding patterns. Our results suggest that the pineal does not exert a major influence on the daily rhythms of shedding and phagocytosis observed in the retina-pigment epithelium unit.

Animals↗
PubMed1977

Secretory state of gastric mucosa and resistance to injury by exogenous acid.

The capacity of the stomach to resist the effects of highly acid solutions was assessed by comparing the effects of such solutions on spontaneously secreting, stimulated, and inhibited gastric mucosae of rabbits in vivo and frogs in vitro. Exposure of unstimulated resting mucosa to HC1, 120 mM, for 60 minutes produced superficial erosions in all rabbits, whereas such lesions were observed in only one of ten animals stimulated with histamine. Metiamide obviated the protective effect of histamine against ulcerations even though it did not reduce H+ secretion to zero. Exposure of inhibited isolated frog fundic mucosa to HC1 resulted in significant deterioration of electrical parameters, suggesting impairment of active transport processes and increased tissue permeability. These data are consistent with the hypothesis that actively secreting gastric mucosae from two species resist injury to exogenous acid more effectively than do resting or inhibited tissues, perhaps in part as a result of a greater alkaline tide.

Animals↗
PubMed1977

Use of heterogenous and monospecific antisera for the diagnosis of bladder cancer.

A rabbit antibody to antigens present in urine from bladder cancer patients was prepared and used in conjunction with various monospecific antisera to detect urine components related to bladder cancer. All urine samples were centrifuged routinely, dialyzed and concentrated 10 times before assay by gel diffusion versus the various antisera. Urine was considered positive when it showed reactivity with 2 or more antibodies. This method of analysis resulted in the diagnosis of 64% of the bladder papillomas and 77% of the bladder cancers tested, compared to only a 7% falsely positive rate with normal urine. These data support the potential usefulness of an antiserum panel in the immunological diagnosis of bladder cancer in the general population and in high risk individuals.

Animals↗
PubMed1977

Distribution of carbonic anhydrase within the gastric mucosa.

Bullfrog fundic mucosa was separated into fractions containing predominantly surface epithelial cells, mucous neck cells, and and oxyntic cells, respectively, and the carbonic anhydrase concentration of each fraction and of antral mucosa was measured. There were no significant differences between the enzyme concentrations of these fractions. The mean level was 12.4 units of activity per milligram of protein. The cellular localization of carbonic anhydrase in the gastric fundic and antral mucosa of the bullfrog, rat, rabbit, and dog was studied using a specific histochemical technique. The enzyme was shown to be present in both parietal and nonparietal epithelium of all species and to characterize a specific cell type in the dog antrum. The widespread distribution of high levels of carbonic anhydrase activity in both acid secreting and nonsecreting cells of the gastric mucosa suggests a possible role for the enzyme beyond one solely relating to acid secretion.

Animals↗
PubMed1975

Alpha1-antitrypsin phenotypes in sex chromosome mosaicism.

We report the alpha1-antitrypsin phenotypes of 21 patients with sex chromosome mosaicism and their parents. The proportion of heterozygotes in the group of parents is significantly greater (p less than 0.01) than that proportion in both control groups. The maternal or paternal contribution to the statistical significance of this observation cannot be distinguished in our small sample of families.

Adolescent↗