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M Alexander

Publications and source records attributed to M Alexander.

At least 469 records · Page 26Linked to original sources
PubMed1966

Susceptibility and resistance of several fungi to microbial lysis.

Potgieter, H. J. (Cornell University, Ithaca, N.Y.), and M. Alexander. Susceptibility and resistance of several fungi to microbial lysis. J. Bacteriol. 91:1526-1532. 1966.-Strains of Streptomyces, Nocardia, and Pseudomonas capable of lysing hyphae of Fusarium solani or Neurospora crassa were obtained by selective culture, but attempts to isolate an organism lysing Rhizoctonia solani failed. When provided with F. solani or N. crassa as carbon sources, the actinomycetes tested produced beta-(1 --> 3) glucanase and chitinase. A mixture containing purified chitinase and beta-(1 --> 3) glucanase induced spheroplast formation in F. solani, caused some morphological changes in N. crassa, but had almost no effect on R. solani hyphae. The polysaccharides in R. solani walls, which contain a large amount of glucose as well as galactose, mannose, and glucosamine, were not hydrolyzed appreciably by the two enzymes. Laminaribiose and laminaritriose were released by enzymatic hydrolysis of F. solani and N. crassa walls, and gentiobiose was liberated from R. solani and N. crassa walls. Melaninlike materials were found in R. solani walls, accounting for 8.50% of the wall weight. A role for melanin in protecting hyphae from microbial lysis is suggested.

Basidiomycota↗
PubMed1965

[Encephalitis].

Explore the source record for details and available documents.

Adult↗
PubMed1965

Permeability of Nitrobacter agilis to Organic Compounds.

Ida, S. (Cornell University, Ithaca, N.Y.), and M. Alexander. Permeability of Nitrobacter agilis to organic compounds. J. Bacteriol. 90:151-156. 1965.-None of a variety of inorganic ions or organic compounds served as a sole energy source for the growth of Nitrobacter agilis, and the test substrates were not oxidized by either intact cells or extracts of the obligate chemoautotroph. The organic substances did not serve as sole carbon sources for the bacterium in a synthetic medium, and they failed to enhance the rate of nitrite oxidation. The organism was permeable to acetate and a number of other simple carbon compounds, however, and exogenously supplied acetate was converted to a number of products. On the basis of these findings, possible reasons are examined for the inability of the chemoautotroph to use exogenous organic compounds as energy or carbon sources.

Journal Article↗
PubMedDate not supplied

Evaluating hypertension control in a managed care setting.

BACKGROUND: We conducted a retrospective cohort study on a random sample of adult patients with hypertension in a large health maintenance organization to assess the feasibility of documenting blood pressure (BP) control and to compare different measures for defining BP control. METHODS: Three criteria for BP control were assessed: systolic BP less than 140 mm Hg; diastolic BP less than 90 mm Hg; and combined BP control, with systolic BP less than 140 mm Hg and diastolic BP less than 90 mm Hg. Four methods of assessing hypertension control by the above criteria were examined: proportion of patients with BP under control at 75% and 50% or more of their office visits; the mean of all pressures during the study period; and the BP from the last visit during the study period. RESULTS: The proportion of patients meeting each criterion for control was similar whether we used the mean BP for all visits, the last recorded BP, or control at 50% or more of visits. Control rates were substantially lower when the more stringent assessment, 75% of visits, was used. The proportion of patients with combined BP control at 75% or more of their visits was half that of the other methods. CONCLUSIONS: In this health maintenance organization population, results with the use of the simplest approach, the last BP measurement recorded, were similar to results with the mean BP. Our findings indicate that evaluation of BP control in a large health maintenance organization will find substantial room for improvement, and clinicians should be encouraged to be more aggressive in their management of hypertension, especially with regard to the systolic BP, which until recent years has been underemphasized.

Aged↗
PubMedDate not supplied

A nonhuman primate model of Gilbert's syndrome.

A Bolivian population of squirrel monkeys, Saimiri sciureus, exhibits several features of Gilbert's syndrome in man, and is proposed as a nonhuman primate model of the condition. The Bolivian population was found to have higher fasting (40.6 +/- 2.7 microM; mean +/- S.E.) and postcibal (9.9 +/- 0.9 microM) plasma unconjugated bilirubin concentrations (p less than 0.001) than a closely related Brazilian population (fasting 5.5 +/- 0.7 microM); postcibal (2.4 +/- 0.7 microM). After intravenous administration of [3H]bilirubin as a tracer dose or at 3.4 mumoles per kg body weight, there was delayed plasma clearance in the Bolivian monkeys. Hepatic UDP-glucuronyl transferase activity for bilirubin (164 +/- 25 nmoles per 30 min per gm liver) and biliary bilirubin diglucuronide to monoglucuronide ratios (2.9 +/- 0.2) were lower in Bolivian monkeys than in Brazilians (421 +/- 36 nmoles per 30 min per gm liver--p less than 0.01 and 4.1 +/- 0.1--p less than 0.02, respectively). Hepatic cytosol glutathione-S-transferase B activity (ligandin) levels were similar for the two populations. After phenobarbital therapy, fasting (11.1 +/- 0.9 microM) and postcibal (5.3 +/- 1 microM) plasma bilirubin concentrations in Bolivian monkeys were significantly reduced (p less than 0.001). Sulfobromophthalein clearance was slightly slower in the Bolivian than in the Brazilian monkeys. SGOT, lactate dehydrogenase, gamma-glutamyl transpeptidase and alkaline phosphatase activities were not increased in Bolivians. Fasting serum conjugated bile salt concentrations in Bolivian monkeys were lower than that in Brazilian monkeys (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

The effects of nutrition on unconjugated plasma bilirubin concentrations in squirrel monkeys.

Bolivian squirrel monkeys (Saimiri sciureus) have fasting unconjugated hyperbilirubinemia (males: 2.0 +/- 0.14; females: 3.0 +/- 0.26 mg per dl) which resembles that of humans with Gilbert's syndrome. Closely related Brazilian squirrel monkeys have fasting levels (males: 0.29 +/- 0.045; females: 0.36 +/- 0.073 mg per dl) similar to normal people. The purpose of this study was to identify the underlying mechanisms and the nutritional factors involved. Both Bolivian and Brazilian squirrel monkeys had higher plasma bilirubin concentrations after an 18 hr fast than 4 hr after feeding. The development of fasting hyperbilirubinemia was progressive for at least 24 hr. Both populations that received a semipurified diet containing 5% fat had lower fasting and postprandial plasma bilirubin concentrations than did animals receiving 0.3% fat but much lower than those receiving 20% fat. The emulsified complete meal, or glucose, sucrose, casein, or lactalbumin alone when given by intragastric tube lowered the plasma bilirubin levels of Bolivian monkeys to less than one-half of fasting values within 1 to 4 hr. Water or butter did not have a significant effect. Glucose or fructose, when given intravenously, lowered the plasma bilirubin levels to less than half of fasting values; the fat emulsion, Intralipid, did not have a statistically significant effect. Subcutaneous epinephrine increased plasma glucose concentrations and reduced plasma bilirubin concentrations. When glucose or glucose plus butter were given by stomach tube to Bolivian squirrel monkeys for 48 hr, a very low plasma bilirubin concentration resulted whereas butter given alone resulted in high values.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗