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Biomedical subjects

A Lambert

Publications and source records attributed to A Lambert.

At least 163 records · Page 9Linked to original sources
PubMed1980

Chloride-bicarbonate exchange in human red cells measured using a stopped flow apparatus.

1. A new stopped-flow apparatus has been used to measure the exchange of intracellular chloride and extracellular bicarbonate across the human erythrocyte membrane at 37 degrees C. 2. The concentration dependence of the activation of the anion exchange system by extracellular bicarbonate was consistent with the existence of a saturable membrane-carrier. Analysis of the results assuming Michaelis--Menten kinetics indicated a Vmax for chloride--bicarbonate exchange of 73 . 4 +/- 14 . 4 mol. (3 x 10(13) cells.min)-1 and Km for bicarbonate of 11 . 1 +/- 2 . 8 mM at 37 degrees C (pH 7 . 1). 3. Correction of the directly computed values of Vmax for incomplete saturation of the carrier by intracellular chloride and the inhibitory effects of intracellular bicarbonate and extracellular chloride gave a Vmax of 157 +/- 43 . 8 mol (3 x 10(13) cells.min)-1 and a Km of 15 . 5 +/- 5 . 2 mM-bicarbonate at 37 degrees C. 4. Comparison of Vmax obtained at 37 and 10 degrees C indicates that the activation energy for chloride--bicarbonate exchange in this temperature range is 18 . 7 --19 . 6 kcal.mol-1 depending on whether corrected or uncorrected values are used. 5. Extracellular furosemide inhibited chloride--bicarbonate exchange with a KI of 0 . 12 microM assuming competition between furosemide and bicarbonate and 0 . 17 microM assuming non-competitive inhibition. 6. Extracellular chloride also inhibited chloride--bicarbonate exchange but the kinetics of inhibition were complex.

Bicarbonates↗
PubMed1980

[Changes in intestinal motility after intravenous injection of alcohol].

It has been well established that the electrical activity of the small intestine consists, in the fasting state, in a cyclic phenomenon - the myoelectric complex - that recurs at about 90 minutes intervals in the dog. The myoelectric complex is disrupted by oral feeding whereas intravenous feeding does not change the cyclically recurring myoelectric activity. The aim of our work was to investigate whether intravenous ethanol was followed by changes in the myoelectric complex. 5 dogs were prepared with Ag AgCl electrodes sewn in the jejunum. After 15 days recovery, the electrical activity was recorded in the dogs fasted for 24 hours, after injection of 100% ethanol at doses of 2, 5 and 10 ml, the total volume of the solution being adjusted to 20 ml with saline. Controls were made with saline 154 mM. Each experiment was repeated twice. The effects of alcohol were studied on the 3 interdigestive cycles following injections of alcohol. The results showed that neither saline nor ethanol at dose of 2 ml did change the myoelectric complex with cycle was meanly of 90 +/- 3 minutes +/- SEM. On the contrary injection of ethanol at doses of 5 and 10 ml was followed by a disruption of the myoelectric complex during respectively 195 +/- 9 and 200 +/- 8 minutes. These results indicate that intravenous ethanol significantly interrupts the myoelectric complex. Therefore, ethanol cannot be considered as a usual nutriment as far as its effect on the electrical activity of the intestine is concerned.

Animals↗
PubMed1978

Chloride/bicarbonate exchange in human erythrocytes.

1. The exchange of chloride and bicarbonate across the human erythrocyte membrane has been followed by measuring the changes in extracellular pH which occur when chloride-rich erythrocytes are added to chloride-free media containing varying concentrations of bicarbonate and carbonic anhydrase. 2. The dependence of the rate of chloride/bicarbonate exchange on the extracellular concentration of bicarbonate was consistent with the existence of a saturable membrane anion transporter exhibiting Michaelis--Menten kinetics. In a medium containing sodium gluconate buffered to pH 7.0 with imidazole--malate the Km for bicarbonate activation of transport was 0.39 (+/- 0.03) mM and the Vmax was 2033 (+/- 80 m-mole anions exchanged/3 X 10(13) cells. min, at 10 degrees C. 3. Chloride/bicarbonate exchange was temperature-dependent with an Arrhenius activation energy of 19.4 kcal/mole in the temperature range 2--10 degrees C. 4. Exchange of intracellular chloride for extracellular bicarbonate was inhibited by the presence of extracellular halides. Inhibition by chloride, bromide and fluoride was competitive and the affinity of the transport system decreased in the order HCO-3 greater than Cl- greater than Br- greater than F-. The kinetics of inhibition by iodide were complex, but inhibitory effects of low concentrations of iodide were less than those of chloride and bromide.

Bicarbonates↗
PubMed1978

Specific effects of different food components on intestinal motility. Electromyographic study in dogs.

Interdigestive intestinal myoelectric activity is characterized by repetitive aborally migrating complexes which are inhibited by feeding. The aim of the present work was to study the effects of different food components on the duration of inhibition of the myoelectric complex and on the number of spike potentials during this period. 4 dogs were prepared for chronic recordings with electrodes implanted on the jejunum and an alimentary cannula placed into the duodenum. Glucose, peptides and lipids were given into the cannula at doses of 7.5 and 15 kcal/kg. The results indicated that the inhibition of the myoelectric complex was longer for lipids than for glucose and even longer than for peptides. When the caloric load was increased, the duration of inhibition was also increased. As concerns the spike potentials, their number was increased after administration of glucose and of peptides, whereas it was decreased after lipids. Lastly, the increase of the caloric load did not change the number of spike potentials significantly. These results indicated that the duration of inhibition of the myoelectric complex depended on both the nature and the caloric load of the food components, whereas the number of spike potentials was determined only by the composition of food.

Action Potentials↗
PubMed1978

[Intestinal motility after intraduodenal and intrajejunal feeding].

Post-prandial intestinal motility, analysed through two electromyographic parameters, duration of inhibition of myoelectric complex (DIMC) and percentage of spike potentials (PSP), was studied after ingestion of glucids, proteins and lipids. Post-prandial intestinal motility depends on both chemical nature and caloric load of nutriments: DICM depends on those two factors but PSP only depends on nature of nutriments. Post-prandial intestinal motility also depends on route of administration of nutriments. Intra-jejunal administration versus intra-duodenal administration increases DIMC observed for glucids and proteins, diminishes DIMC observed for lipids and diminishes PSP observed for glucids and proteins. These results indicate a specificity of intestinal post-prandial motility with characteristics of nutriments. Intestinal digestion and absorption of nutriments, just as hormonal secretion in response to intestinal passage of nutriments could explain such a specificity.

Action Potentials↗
PubMed1977

[Phyletic affinities among Polystomatidae (Monogenea)].

The chaetotaxy and ciliated cells in two Monogenean larvae of marine fishes are described for the first time: a Monopisthocotylea Diplectanum aequans (Wagener, 1857) Diesing, 1858 parasite of Dicentrarchus Labrax (L) and a Polyopisthocotylea, Microcotyle mormyri Lorenz, 1878 parasite of Pagellus mormyrus (L). A comparative study with the known larvae shows evidence of two larval types in the Monogenea of fishes, related to the two great phyla of the class: the Monopisthocoytylea and Polyopisthocotylea. The Polystomatidae, Monogenea from Amphibia and Chelonia, belong to the Polyopisthocotylea on account of their larval chaetotaxy. But the proximity of the Polystomatidae with the Tetraonchidae, within the Polyonchoinea Bychowsky, 1975 is not confirmed.

Animals↗
PubMed1977

Larval and post-larval development of Ergenstrema mugilis Paperna, 1964 (monogenea, ancyrocephalidae) parasite of Liza ramada (Risso, 1826) (teleostel, mugilidae).

The ciliated cells, chaetotaxy and excretory system of the oncomiracidium are fully described in Ergenstrema mugilis Paperna, 1964. The study of the post larval development shows a phase of cutaneous infestation in the fish host and the mode of transmission is discussed among Dactylogyroidea. The morphogenesis of the parasite haptor is described. The origin and migration of the hamuli in Dactylogyroidea are discussed.

Animals↗
PubMed1976

[Viral infection in a platyhelminth parasite].

In parenchyme cells of the parasitic Plathelminthe Diplectanum aequans virus-like cytoplasmic particles were observed. Their formation is noted in virogenic areas and they are often gathered in regular geometric arrangements. The infected cells show important lesions.

Animals↗
PubMed1976

Simultaneous recording of circular and longitudinal muscle contractions of the canine jejunum.

A method has been developed for monitoring the mechanical activities of individual longitudinal and circular muscles in a 5 millimeters long segment of intact intestine in the anesthetized dog. The longitudinal contractions were recorded by means of a new movement transducer. The circular contractions were recorded simultaneously using a water-filled intraluminal balloon. A precise separation of longitudinal and circular motor activities was obtained with this method. The two muscle layers manifested motor activity most of the time, but their contractions were out of phase. Phase locking was observed only during short periods of time. The contractions were then sequential, the circular one being first.

Animals↗
PubMed1976

[Evidence and importance of the larval chaetotaxy in the Monogenea Monopisthocotylea].

The larva of Ergentrema mugilis Paperna, 1964 (Ancyrocephalidae) occurring in Liza ramada (Risso, 1826) is described for the first time including the primary haptor description as well as the chaetotaxy. In addition, the sensillae position, previously unknown in the larva of Dactylogyrus extensus Muëller and Van Cleave, 1932 (Dactylogyridae) a parasite of Cyprinus carpio L., is specified. The comparison between these two chaetotaxies shows a proximity which was not obvious through the adult and larval haptor structure. The respective value of both criteria for the Monopisthocotylea phylogeny is discussed.

Animals↗
PubMed1976

Transducer for recording electrical and mechanical chronic intestinal activity.

An extraluminal displacement transducer has been developed for simultaneously recording the mechanical activity in two perpendicular directions and the electrical activity of the intestinal serosa. The length variations in two perpendicular directions were measured by means of strain gauges bounded on two pairs of lamellae embedded in a rigid stand. The electrical activity was recorded by means of four electrodes situated at the extremity of these lamellae. The electrical gauges of each pair of lamellae are connected to form a Wheatstone bridge. This device allows establishment of a correlation between the mechanical displacement of the intestinal wall serosa and electrical potentials by means of studies of long duration.

Electrophysiology↗
PubMed1976

[A new synthetic antiparkinsonian drug, tropatepine hydrochloride in extrapyramidal syndromes induced by neuroleptics].

Tropatepine hydrochloride was given per oral route to 184 patients and per injections to 34 patients. Average prescribed doses were about 20 mg (2 tablets). This clinical study has shown that tropatepine hydrochloride has an antiparkinson activity against neuroleptic-induced extra-pyramidal syndrome. In comparison to the activity of the other synthetic antiparkinson drugs, the activity of tropatepine hydrochloride is: -- similar on akineto-hypertonia and on tremor; -- better on akathisia and, though less frequently, on anormal dyskinetic movements due to long term neuroleptic treatment. Tolerance is good ; furthermore clinical and biological performed examinations have shown that the drug seems free of toxic effects In more than 200 treated patients no severe mental aberration and no habituation have been reported.

Adult↗
PubMed1975

Primary closure of radical mastectomy. A new method.

A transverse incision is reported with an oblique counterincision performed in such a manner as to satisfy all Halstedian criteria for tissue removal and to allow as little as possible skin incision to approach the clavicular area. Closure is planned so that there is no tenting of skin or limitation of shoulder motion.

Aged↗
PubMed1975

[Serum immunoglobulins in cardiovascular pathology].

The authors measured as a routine IgA, IgG and IgM serum immunoglobulins in a hundred subjects free from any cardiac or hypertensive disease, in 51 patients with coronary heart disease in in 50 hypertensive subjects. They found that in 2% of the normal subjects and in 28% of the coronary heart disease or hypertension, the level of one of the three serum immunoglobulins was outside the following limits: IgA 100 to 480 mg/100 ml, IgG 500 to 1900 mg/100 ml and IgM 45 to 380 mg/100 ml. The 2 normal subjects and 12% of the patients with coronary heart disease or hypertension presented an abnormally low level of one of the immunoglobulins, while an abnormally high level was observed in 16% of the subjects with coronary heart disease or hypertension. The abnormal serum levels may concern any class of immunoglobulin and persist in the case of some patients with coronary heart disease several years after the acute ischemic incident.

Adult↗