PubMed Health⌕ Search

Biomedical subjects

R M Baker

Publications and source records attributed to R M Baker.

At least 55 records · Page 3Linked to original sources
PubMed1979

Variations in the response of sheep to experimental magnesium deficiency.

Hypomagnesaemia was induced in adult sheep by changing their diet from chaff given orally to a milk diet, low in Mg, infused via the abomasum. All sheep given the milk diet developed hypomagnesaemia and four out of 19 developed nervous convulsions similar to the natural disease grass tetany. Analysis of the sequential changes in plasma Ca, P and Mg revealed a striking positive correlation between Ca and Mg and hypocalcaemia thus appeared to be a general response to Mg deficiency. Many sheep appeared to adapt to the deficiency since after a period of about 11 days the decline in plasma Mg (and Ca) was either alleviated or reversed. However the four sheep which developed convulsions all showed a rapid and substantial decline in plasma Mg associated with a decline in plasma Ca.

Animals↗
PubMed1978

Dominance of colchicine resistance in hybrid CHO cells.

Intraspecific hybrids of colchicine-sensitive with colchicine-resistant (CHR) Chinese hamster ovary cells were constructed, using six different colchicine-resistant clones from two independent series. In each instance, colchicine resistance was expressed in an incompletely dominant manner. Some hybrid clones were examined further for the expression of the pleiotropic CHR phenotype and for the cell surface P glycoprotein. These features of the colchicine-resistant phenotype were also expressed coordinately.

Animals↗
PubMed1978

Exploring the doctor-patient relationship: a sociocultural pilot study in a family practice residency.

Family physicians' growing attention to the nature of their patients' live should include the social and cultural factors that influence patient health and illness behavior. Patient visits to a family practice residency program were found to be influenced by the patients' beliefs about symptoms and the beliefs of their significant others, and symptom interference with valued activities. Data from physician-patient encounters suggest that physician attention to such sociocultural information as occupation and family structure may have positively influenced rapport. Results from this pilot study confirm the feasibility of observational research by physician-behavioral scientist teams in a primary care setting.

Adult↗
PubMed1977

(Na, K)ATPase activity in membrane preparations of ouabain-resistant HeLa cells.

Membrane preparations from two independent ouabain-resistant HeLa cell clones, HI-B1 and HI-C1, each appear to contain two species of (Na,K)ATPase. Two-thirds of the total (Na,K)ATPase in each mutant is indistinguishable from the enzyme in preparations of wild type cells with respect to ouabain binding, ouabain inhibition of (Na,K)ATPase activity, and dependence of ATP hydrolysis on Na, Mg, K, and ATP concentration. The remaining (Na,K)ATPase activity in the mutants is up to 1000 and 10 000 times, respectively, more resistant to ouabain than wild type enzyme. Resistance results from a lower affinity of the mutant enzymes for the inhibitor. The presence of Na, K, or Mg has little or no effect on the degree of resistance expressed by the mutant enzymes, although the resistance of the wild type enzyme varies 400-fold in the presence of different ligands. Incubation with 5 X 10(-8) M ouabain abolishes the activity of the wild type enzyme without affecting the activity of the resistant enzymes. Using this procedure we compared the parameters of ATP hydrolysis via the resistant and wild type enzymes. Ouabain-resistant (Na,K)ATPase of HI-C1 has an apparent K0.5 for potassium 3-4 times higher than that of either wild type enzyme or the resistant enzyme of HI-B1.

Adenosine Triphosphatases↗
PubMed1977

Reduced synthesis of [14C]mannosyl oligosaccharide-lipid by membranes prepared from concanavalin A-resistant Chinese hamster ovary cells.

We compared the synthesis of mannosyl oligosaccharide-lipid by membranes of wild type and concanavalin A-resistant Chinese hamster ovary cells during incubations with GDP-[14C]mannose and UDP-N-acetylglucosamine. The membranes prepared from exponentially growing mutant cells incorporated 10- to 70-fold less [14C]mannose into oligosaccharide-lipid than did membranes of wild type cells. The lectin-resistant cells are temperature-sensitive for growth. Using temperature-resistant revertants, we showed that the reduction in labeled oligosaccharide-lipid correlated with resistance to concanavalin A rather than with the temperature-sensitive phenotype. Tunicamycin, a specific inhibitor of oligosaccharide-lipid synthesis, reduced the synthesis of the oligosaccharide-lipid by membranes of wild type cells but did not affect the residual synthesis measured in membranes of the mutant cells. As the mutant cells were grown to high density, there was a marked increase in the synthesis of oligosaccharide-lipid by the membranes.

Anti-Bacterial Agents↗
PubMed1977

Classification and coding of psychosocial problems in family medicine.

Disease and problem classification systems for primary care have recognized that psychosocial problems are integrally related to more traditional medical problems which patients present to physicians. These classification systems remain inadequate for the description of primary care problems, especially as several disciplines interrelate in primary care, such as medicine, nursing, and social work. This paper presents a classification and coding system of psychosocial problems gleaned from a number of existing coding systems. The purpose of presenting it here is to contribute to a dialogue which will result in the establishment of a common psychosocial language for all health professionals. By so doing, progress in research, education, patient care, and administration in the psychosocial area will be facilitated.

Family Practice↗
PubMed1975

Water drinking induced in sheep by angiotensin--a physiological or pharmacological effect?

The effect of val5-angiotensin II amide on water drinking in sheep was studied against a background of comprehensive data on arterial blood and cerebrospinal fluid angiotensin II levels in sheep under a variety of physiological conditions. Physiological range of blood angiotensin II concentration is 1-100 ng/100 ml. Intravenous infusion of angiotensin II within the physiological range did not increase water drinking. Intracarotid infusion of angiotensin II, or injection into third ventricle or hypothalamus, consistently caused immediate drinking of large amounts of water. Dosages necessary for effect were in the supraphysiological range. Quantitative examination of data in sheep and other species suggests that a physiological role for angiotensin II in thirst is not proved.

Angiotensin II↗