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Biomedical subjects

W C McCormick

Publications and source records attributed to W C McCormick.

At least 91 records · Page 5Linked to original sources
PubMed1979

pH regulation in barnacle muscle fibers: dependence on intracellular and extracellular pH.

Intracellular pH (pHi) regulation was studied in acid-loaded barnacle muscle fibers by monitoring recovery of pHi with a pH-sensitive microelectrode. By multiplying the rate of pHi recovery by total intracellular buffering power, the acid extrusion rate was obtained. The acid extrusion rate was greatest at low values of pHi, and declined toward zero as pHi approached normal levels. It increased as the extracellular pH (pHo) was raised either by increasing external [HCO3] ([HCO3]o) at constant PCO2 or by decreasing PCO2 at constant [HCO3]o, but more so in the former case than in the latter. These observations suggest that pHo per se is an important determinant of the acid extrusion rate, but that raising [HCO3]o by itself also stimulates acid extrusion. This would be expected if acid extrusion involves the inward movement of HCO3. When fibers were exposed to HCO3-containing solutions at very low or very high pHo, pHi drifted downward or upward, respectively; thbe drifts were inhibited by 4-acetamido-4' isothiocyanostilbene-2,2' disulfonic acid (SITS). Our results are discussed in terms of possible mechanisms of acid extrusion.

Animals↗
PubMed1975

Ensiled diet containing processed municipal garbage and sorghum forage for heifers.

Diets of similar proximate analysis formulated with a base of sorghum forage and primarily supplemented with equivalent dry matter of 18.4% of aerobically digested municipal garbage (garbage diet) or 17.5% of cottonseed hulls (control diet) were ensiled for 52 days and then individually and group fed to 16 dairy heifers for 56 and 35 days. Apparent digestibility of dry matter, crude protein, ether extract, crude fiber, and nitrogen-free extract in garbage and control diets averaged 54.2 and 47.4, 50.0 and 41.3, 62.0 and 65.1, 53.1 and 42.3, and 61.8 and 54.5% as determined by chromium oxide technique. Potential advantages from digestibility of the garbage diet appeared to be nullified by a 12% depression of dry matter intake and a consequent deterioration of feed efficiency. Dry matter intakes of garbage and control diets during the 56-day comparison were 1.98 and 2.25% of body weight and daily gains of .42 and .57 kg required 13.9 and 11.8 kg dry matter per kilogram of gain. Over the 91 days of combined comparison feeding, the .62 kg of average daily gain from control diet was 32% above the .47 kg from the garbage diet.

Animal Feed↗
PubMed1975

Bile acid metabolism in cirrhosis. IV. Characterization of the abnormality in deoxycholic acid metabolism.

Several recent studies have demonstrated that patients with cirrhosis frequently lack deoxycholic acid in bile and plasma. In order to explain this observation, comparative experiments on the colonic absorption of deoxycholic acid and on the colonic conversion of cholic to deoxycholic acid were carried out in the cirrhotic patients with normal and very low percentages of deoxycholic acid. Deoxycholic or cholic acid (100 mg) plus 5 muc of each [14C] bile acid were administered by enema to 8 patients with and 5 without liver disease. Deoxycholic acid produced a significant increase in the percentage of biliary deoxycholic acid in patients with cirrhosis. However, the rate of appearance of 14C-deoxycholic acid in patients with cirrhosis was slower than in normal control subjects. Distribution of the 14C activity among the bile acids indicated that rehydroxylation of deoxycholic to cholic acid did not occur. The distribution of 14C activity in biliary bile acids after the rectal administration of [14C]cholic acid showed that patients with severe cirrhosis converted [14C]cholic to [14C]deoxycholic acid at a much slower rate than did cirrhotic patients with normal percentages of biliary deoxycholic acid. Feeding of cholic acid (450 mg per day) for 3 days to 4 cirrhotic patients resulted in a 2-fold increase in the percentage of biliary cholic acid, but only a small increase in the percentage of deoxycholic acid. In a separate group of 9 cirrhotic patients, fecal bile acid analysis indicated that cirrhotic patients had a significantly lower percentage of deoxycholic acid than 12 patients without liver disease; there was no significant difference in fecal lithocholic acid. The data suggest that alteration of bacterial flora and/or altered conditions for bacterial 7alpha-dehydroxylase enzyme activity in the colon could account for the virtual absence of biliary deoxycholic acid in severely cirrhotic patients.

Adult↗
PubMed1973

Cholic acid synthesis as an index of the severity of liver disease in man.

Bile acid pool size and kinetics were determined in 17 patients with cirrhosis and 11 patients without liver disease and correlated with the severity of liver disease as determined by the usual clinical and laboratory criteria. In order to assess the severity of liver disease, a grading system was devised which assigned numerical values to various clinical signs and laboratory results. The total clinical score and the patients were divided into two groups of advanced (7-18 points) or mild (1-6 points) cirrhosis. The clinical rating was then correlated with the various aspects of bile acid metabolism. Cholic acid synthesis was markedly reduced in the early stages of cirrhosis and continued to decrease with the advancement of the liver disease. There was an inverse correlation between synthesis of cholic acid and the severity of cirrhosis. Nine of the 10 patients with advanced cirrhosis and a very low cholic acid synthetic rate (average 68 mg per day) died within one to 13 months from the start of the study. Patients with mild cirrhosis also had significantly reduced cholic acid synthesis (average 152 mg per day) but they all were well and alive three to 23 months after the study. In contrast, chenodeoxycholic acid synthesis was not markedly affected in either patients with mild or advanced cirrhosis. There was also a high degree of correlation between the fractional daily turnover rate of cholic acid and the severity of liver disease. The fractional daily turnover rate of cholic acid was greatly reduced (50%) in patients with advanced cirrhosis. Deoxycholic acid was reduced in patients with mild cirrhosis and virtually absent from the bile of patients with advanced cirrhosis. The findings of the present report provide evidence that cholic acid synthesis is a sensitive indicator of the hepatocellular damage, whereas chenodeoxycholic acid synthesis is relatively unaffected by cirrhosis. The selective alteration in cholic acid synthesis probably resides in a deficiency of one or more enzymes regulating the formation of the 3-keto, 7 alpha, 12 alpha-dihydroxy precursor of cholic acid.

Adult↗
PubMedDate not supplied

Long-term care preferences of hospitalized persons with AIDS.

OBJECTIVE: To determine in a cohort of hospitalized persons with AIDS: 1) their preferences for various postdischarge long-term care settings, 2) the postdischarge settings recommended by primary care providers (doctors, nurses, and social workers), and 3) the impact of these views on the resulting discharge dispositions. DESIGN: Prospective cohort study. SETTING: Medical wards of five Seattle tertiary care hospitals. PARTICIPANTS: 120 consecutive hospitalized persons with AIDS and their primary care providers. MEASUREMENTS AND MAIN RESULTS: Although 70 (58%) of the patients found care in an AIDS long-term care facility acceptable, 87 (73%) preferred home care. Thirty-eight (32%) of the cohort were appropriate for long-term care after hospitalization, according to primary care providers. Eleven of the 38 patients deemed appropriate for long-term care were discharged to long-term care settings; among these, three had preferred home care. Likelihood of discharge to long-term care settings increased if patients found it acceptable (OR = 7.1; 95% CI = 3.2, 15.5), if they did not prefer home care (OR = 7.7; 95% CI = 4.7, 13.5), and if providers judged them to be appropriate for long-term care (OR = 29; 95% CI = 13, 64). In unstructured interviews, availability of emotional and medical support and privacy emerged as important factors to persons with AIDS considering long-term care. CONCLUSIONS: Hospitalized persons with AIDS willingly express their desires for various postdischarge care settings. A majority find long-term care in AIDS facilities acceptable, although they generally prefer home care. Discharge disposition is associated with acceptability, preference, and appropriateness for long-term care.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Long-term care needs of hospitalized persons with AIDS: a prospective cohort study.

OBJECTIVE: As the treatment for HIV infection has improved, AIDS has become a chronic disease, and the demand for long-term care has increased. The authors studied a cohort of hospitalized persons with AIDS to determine the proportion and characteristics of AIDS patients who could appropriately be cared for in long-term care facilities with skilled nursing. DESIGN: Prospective cohort study. SETTING: Medical wards of five Seattle tertiary care hospitals. PARTICIPANTS: 120 consecutive hospitalized persons with AIDS and their primary care physicians, nurses, and social workers. MEASUREMENTS AND MAIN RESULTS: Appropriateness for long-term care was determined by the patients' physicians, nurses, and social workers. Persons with AIDS who were appropriate for long-term care constituted 32% of the cohort (38 of 120), accounting for 35% of hospital days (11 of these 38 were discharged to long-term care facilities). Four admission characteristics were independently related to appropriateness: impaired activities of daily living, diagnosis of central nervous system illness or poor cognition, living alone, and weight loss. A discriminant function correctly classified over 80% of patients for appropriateness and was developed into a predictive index for planning patient care (sensitivity = 0.74, specificity = 0.85). CONCLUSIONS: The authors conclude that one-third of hospitalized persons with AIDS may be appropriate for care in long-term care settings, accounting for one-third of the days AIDS patients currently spend in hospitals. These patients can be identified early in hospital stays using a simple predictive index at the bedside.

Acquired Immunodeficiency Syndrome↗