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Biomedical subjects

W Sacks

Publications and source records attributed to W Sacks.

33 records · Page 2Linked to original sources
PubMed1982

A proposed method for the determination of cerebral regional intermediary glucose metabolism in humans in vivo using specifically labeled 11C-glucose and positron emission transverse tomography (PETT). I. An animal model with 14C-glucose and rat brain autoradiography.

Based upon data obtained with our arterio-venous technique for the determination of cerebral metabolism in humans in vivo we have proposed a method for the determination of cerebral regional intermediary glucose metabolism in humans in vivo using specifically labeled 11C-glucose and positron emission transverse tomography (PETT). In it we would give the subject successive intravenous injections of [3,4-11C] glucose, [2,5-11C] glucose and [1-11C] glucose. There would be a 30 min period of continuous PETT measurements following each injection and a 2 hr interval after the first and second injections. The data would be used with suitable equations and algorithms to estimate for each specific region of the subject's brain the dynamics of the Embden-Meyerhof-Parnas (EMP) and the tricarboxylic acid cycle (TCA) metabolic pathways and the incorporation of glucose carbons into lactate, and the extent of dilution of glucose carbons into lactate, and the extent of dilution of glucose carbons in traversing the TCA with their subsequent incorporation into other carbon pools of the brain (ie, glutamate, glutamine, GABA, alanine). Using 14C as a model for 11C and autoradiographs made with rat brain slices, we have produced an animal model to demonstrate the feasibility of our proposed method. The resulting autoradiographs have provided evidence of the validity of the predictions made from our arterio-venous data. The model was employed to show the selective reductions in the rates of incorporation of specific carbon atoms of glucose into regions of the rat brain and evidence of altered metabolic pathways following a single electroconvulsive shock (ECS) and after a series of nine ECS.

Animals↗
PubMed1982

Yeast killer plasmid mutations affecting toxin secretion and activity and toxin immunity function.

M double-stranded RNA (MdsRNA) plasmid mutants were obtained by mutagenesis and screening of a diploid killer culture partially heat cured of the plasmid, so that a high proportion of the cells could be expected to have only on M plasmid. Mutants with neutral (nonkiller [K-], immune [R+]) or suicide (killer [K+], sensitive [R-] phenotypes were examined. All mutants became K- R- sensitives on heat curing of the MdsRNA plasmid, and showed cytoplasmic inheritance by random spore analysis. In some cases, M plasmid mutations were indicated by altered mobility of the MdsRNA by agarose gel electrophoresis or by altered size of in vitro translation products from denatured dsRNA. Neutral mutants were of two types: nonsecretors of the toxin protein or secretors of an inactive toxin. Of three neutral nonsecretors examined, one (NLP-1), probably a nonsense mutation, made a smaller protoxin precursor in vitro and in vivo, and two made full-size protoxin molecules. The in vivo protoxin of 43,000 molecular weight was unstable in the wild type and kinetically showed a precursor-product relationship to the processed, secreted 11,000-molecular-weight toxin. In one nonsecretor (N1), the protoxin appeared more stable in a pulse-chase experiment, and could be altered in a recognition site required for protein processing.

Hot Temperature↗
PubMed1981

A difference in the in vivo cerebral production of [1-14C] lactate from D-[3-14C] glucose in chronic mental patients.

Data from a study in which 12 chronic mental patients and 12 control subject were given D-[3-14C] glucose intravenously in our arterio-venous technique for determining cerebral metabolism in vivo were reexamined. Previously unpublished whole-blood lactate determinations in these experiments indicated a cerebral production of much higher specific activity of [1-14C]-lactate from the D-[3-14C] glucose by mental patients. Of several possible explanations offered for this difference, the most likely was that involving a small lactate compartment(s) in some specific region(s) in which decarboxylation of the endogenously formed cerebral lactate was partially inhibited. Two other experiments with mental patients (one given [U-14C] glucose and the other, [1-14C] glucose) whose extraordinary results were described, in part, in a previous report, were interpreted as more extreme examples of the production of higher specific activity 14C-lactate from 14C-glucose by mental patients' brains upon their very unusual whole blood lactate data.

Adult↗
PubMed1980

The use of an isopyrine-phenylbutazone compound in migraine.

A randomized double-blind study of 40 patients with migraine attacks was carried out to compare an intravenous injection of isopyrine 240 mg plus phenylbutazone 130 mg (Tomanol; Byk-Gulden) with a placebo. Isopyrine is an analgesic with a central sedative action which potentiates the action of phenylbutazone, an inhibitor of prostaglandin biosynthesis and circulation. In 15 patients who received the drug the migraine attack was terminated within 5 minutes of administration, apart from a mild residual headache in 2 cases. No recurrence was reported after 24 hours. The placebo administered to 25 patients gave total relief in 3, a slight improvement of symptoms in 12 and had no effect in 10. Treatment with isopyrine-phenylbutazone compound was based on the immediate central analgesic and sedative action of isopyrine, and the inhibition of the vaso-active action of prostaglandins by phenylbutazone.

Adolescent↗
PubMed1980

Computer communication and the elderly.

Elderly's involvement with a society's information resources has been thought to indicate their social status. Moreover, as the societal status of information resources themselves is greater, the status of elderly may be even greater. Computer-based communication systems are leading the transformation of post-industrial societies from previously industrial to primarily informational. As elderly become effective computer users, they may enhance their social status and personal well-being. The present research examines effects of elderly's participation with computer-mediated communication on attitudes toward computers and themselves. A quasi-experimental design involving residents of a retirement community is used with a sample of 30 pre- and 13 post-treatment subjects. The treatment consists of using recreational computer games and computer messaging. Self-administered questionnaires and observer ratings are the primary data collection instruments. Results show that computer use may increase favorability towards computers and self-esteem. Also, the greater the degree of interactiveness of specific computer use activities, the greater user preference. Facilitator and inhibitors of elderly's interaction with computers are suggested.

Aged↗
PubMed1967

Mutarotase in erythrocytes: isolation and properties.

Mutarotase was found in lysed human erythrocytes and in hemoglobin. The enzyme was partially purified by treatment with ethanol and chloroform at -15 degrees C. It was nondialyzable and heat sensitive, and was inhibited by D-galactose, L-arabinose, D-ribose, D-xylose, and D-arabinose.

Arabinose↗