Search PubMed⌕ Search

Biomedical subjects

P Hamel

Publications and source records attributed to P Hamel.

45 records · Page 3Linked to original sources
PubMed1984

A test of aerobic capacity: description and reliability.

The purposes of this study were 1) to describe a maximal aerobic capacity (MAC) test and 2) to report on its reliability. Thirty subjects (16 males and 14 females) were tested for maximal aerobic power (MAP) with a progressive bicycle ergometer test and the ventilatory anaerobic threshold (VANT) was determined. MAC was measured as the amount of work that could be performed in 90 min on a bicycle ergometer at an intensity set individually from VANT. Subjects were asked to perform as much work as possible during this non-stop 90 min period. For females and males respectively, MAP reached 42.9 +/- 5.9 (mean +/- SD) and 56.0 +/- 4.7 ml O2/kg X min-1 (p less than .01), VANT 36.3 +/- 6.1 and 46.0 +/- 5.2 ml O2/kg X min-1 (p less than .01), max HR 198 +/- 8 and 195 +/- 9 (p greater than .05) and HR at VANT 187 +/- 9 and 180 +/- 10 (p greater than .05). The same subjects were tested twice for MAC within 7 days. Results expressed in kJ/kg reached 10.6 +/- 2.1 and 10.8 +/- 2.4 for females, 14.7 +/- 2.1 and 14.9 +/- 2.2 for males. Mean HR maintained during MAC were 174 +/- 11 and 174 +/- 9 for females and 169 +/- 10 and 170 +/- 10 for males. There was a non significant difference between means (p greater than .05) of the first and second test in total work performed in kJ/kg. This difference reached about 2% of the first test score, 32.7% of this difference occurring in the first 10 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1980

Inhibitors of indoleethylamine N-methyltransferase. Derivatives of 3-methyl-2-thiazolidinimine. In vitro, in vivo, and metabolic studies.

A variety of substituent groups has been attached to the exocyclic imine function of 2-imino-3-methylthiazolidine (1) in a search for metabolic precursors of this potent inhibitor of the enzyme indoleethylamine N-methyltransferase (INMT) which would exhibit superior pharmacodynamic properties in animals. It has been determined that chemically stable derivatives of 1 based on succinic, nicotinic, and N-acylated amino acids, although they lack in vitro efficacy, are potent inhibitors of INMT when administered orally or intravenously to rabbits. Metabolic studies carried out with 14C-labeled N,N'-bix(3-methyl-2-thiazolidinylidene)succinamide (3) have established that conversion of this compound to 1 occurs both in the whole rabbit and in the isolated rabbit liver. 1 itself has been shown to be metabolically inert in rabbits, being excreted primarily in the urine.

Administration, Oral↗
PubMed1979

Cyclic amidine inhibitors of indolamine N-methyltransferase.

Syntheses of a large number of mono- and bicyclic, as well as a few tricyclic, amidine derivatives related to 2,3,4,6,7,8,-hexahydropyrrolo[1,2-a]pyrimidine (DBN) are reported. In vitro potencies for inhibition of the enzyme indolamine N-methyltransferase (INMT) from rabbit and human lung are presented. Four bicyclic amidine derivatives and 11 monocyclic derivatives were found to be equal or superior to DBN in in vitro potencies. With the bicyclic amidines, increasing ring size or introduction of substituents reduced activity. Among the monocyclic analogues, the most potent representatives were five- or six-membered systems with an exocyclic imino group, combined with methyl of ethyl substituents on the endocyclic nitrogen. Introduction of additonal substituents decreased inhibitory potency. 2,3,5,6-Tetrahydro-8H-imidazo[2,1-c][1,4]thiazine and 3-methyl-2-iminothiazolidine have been shown to cause inhibition of lung INMT when administered orally to rabbits.

Amidines↗
PubMed1978

[Clandestine places: illegal sale of alcohol for urban worker populations].

The authors have studied the illegal commerce of alcohol in popular urban communities. This sale is done in so called clandestine places. The study was approached from a cultural-anthropological point of view and its objective is a descriptive-exploratory study based on observation and interview techniques. A definition and a tipology of these places was attempted, emphasizing group dynamics and interpersonal relations between the owner of the place and the customer; among the customers; among the place itself and the rest of the community organizations, formal and informal ones. A primary analysis was done, according to which these clandestine places appear legitimized by nets of interpersonal relations, critical economic situations and places that satisfy recreational needs of the inhabitants. In order to eliminate the former, adecuate substitutes for recreation and social interaction ought to be considered.

Aged↗
PubMedDate not supplied

Assembly of chloroplast cytochromes b and c.

The synthesis of holocytochromes in plastids is a catalyzed process. Several proteins, including plastid CcsA, Ccs1, possibly CcdA and a thioredoxin, plus at least two additional Ccs factors, are required in sub-stoichiometric amounts for the conversion of apocytochromes f and c(6) to their respective holoforms. CcsA, proposed to be a heme delivery factor, and Ccs1, an apoprotein chaperone, are speculated to interact physically in vivo. The formation of holocytochrome b(6) is a multi-step pathway in which at least four, as yet unidentified, Ccb factors are required for association of the b(H) heme. The specific requirement of reduced heme for in vitro synthesis of a cytochrome b(559)-derived holo-beta(2) suggests that cytochrome b synthesis in PSII might also be catalyzed in vivo.

Amino Acid Sequence↗
PubMedDate not supplied

[Diagnostic procedures in internal medicine. Thoracentesis, paracentesis and arthrocentesis in hospital practice].

The aim of this paper is to give a rapid and concise guide for the diagnostic procedures frequently used in internist's clinical practice. Thoracentesis, paracentesis and arthrocentesis were analyzed as regards to indications, contraindications, procedure of execution and interpretation of findings. Addressed to the young physician, the present paper could also be useful as a rapid guide for the experienced physician which does not frequently use these procedures.

Arthritis, Infectious↗
PubMedDate not supplied

[Is extracorporeal membrane oxygenation necessary?].

In order to evaluate our hospital center needs for extracorporeal membrane oxygenation (ECMO), a retrospective study was carried out over a two-year-period to determine the mortality rates of infants < or = 35 weeks of gestation and > or = 2000 grams with severe respiratory failure. The data was obtained from a perinatal center that serves a population that has 50,000 newborn deliveries per year. During the period of the study there were 75 infants meeting the above criteria admitted to the NICU with severe respiratory failure (defined as need for mechanical ventilation and 100% O2). Forty-four patients were excluded because of improvement of their respiratory status on conventional therapy, and 16 were ineligible for ECMO because of their primary diagnosis. Of the 15 infants considered ECMO candidates, there were 2 deaths as a result of streptococcal beta hemolytic septicemia. The result of this study showed that few infants in the population served by this perinatal center would have benefited from ECMO.

Carbon Dioxide↗