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Biomedical subjects

D Georges

Publications and source records attributed to D Georges.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Use of a slow-release form of salbutamol in the treatment of threatened premature labor. A comparative study of 52 randomized cases compared with the immediate release form].

A randomised study was carried out to compare the effect of ordinary salbutamol with controlled release salbutamol as far as the sedative effect on the uterine muscle was concerned. Modifying the molecule for salbutamol gives it characteristics of a true "retard" form. This makes it possible to prescribe 2 tablets a day in 2 doses to copy the sedative effect on uterine muscle achieved when the treatment is given intravenously in cases of threatened onset of labour. The study was a double blind one with a placebo being used in two parallel groups after the populations had been compared for similar characteristics as far as the past history, the body build and the number of pregnancies was concerned. This made it possible to show that the two forms are strictly comparable and that there are no adverse side effects. This form of "retard" salbutamol seems to be particularly useful in repeated attacks of threatened premature labour and makes it likely that it will be taken more regularly with the avoidance of peaks in plasma and therefore improved tolerance. Furthermore, the action is longer and effective overnight.

Albuterol↗
PubMed1989

[Effect of the time of ingestion of 300 mg of ranitidine on cicatrization of duodenal ulcer in crisis (ingestion after dinner versus ingestion at bedtime].

Recent studies have shown that a single dose of ranitidine given for 2 weeks at 6 p.m. resulted in a higher healing rate of duodenal ulcer than the same dose given at 10 p.m. Our study was designed to confirm these results in a large population in France. Three hundred and fifty patients with endoscopically proven duodenal ulcer were randomly assigned to open treatment with ranitidine 300 mg, immediately after dinner (dinner group), or at bedtime (bedtime group). Endoscopy was performed after 2 and 4 weeks. Forty six patients were excluded from analysis (default: 3, date of endoscopies not respected: 43). Of the 304 patients analysed (mean age: 45.5 years, sex ration M/F: 3.2), 146 received ranitidine after dinner, 158 at bedtime. Age, sex, ethnic groups, smoking habits and alcohol consumption were comparable in the two groups. At endoscopy, before treatment, the mean diameter of ulcers was greater in the bedtime group than in the dinner group (bedtime: 9.6 mm, dinner: 7.9 mm). Healing rates after 2 weeks were 58 p. 100 in the dinner group and 40 p. 100 in the bedtime group (p = 0.002). After 4 weeks treatment, cumulative healing rates were 87.5 p. 100 and 83.5 p. 100, respectively. Smoking had an influence on healing after 2 weeks but not after 4 weeks of treatment. In conclusion, a single dose of 300 mg of ranitidine resulted in a higher healing rate of duodenal ulcer when given immediately after dinner than when given at bedtime.

Duodenal Ulcer↗
PubMed1988

Effect of monosodium glutamate on the neural complex of Ciona intestinalis (Tunicata).

Short-term treatment of the ascidian (tunicate) Ciona intestinalis with monosodium glutamate produces a transient decrease in methionine-enkephalin-like immunoreactivity of neurones in the nervous ganglion. Moreover, it causes vacuolisation of the cells in the neural complex, particularly in the neural gland. Similar damages occur after ovariectomy. These results suggest that the ovary exerts an indirect influence on the neural gland via the nervous ganglion, and that the methionine-enkephalin-like substance could be the responsible "neuromediator".

Animals↗
PubMed1984

Methionine-enkephalin-like immunoreactivity in the nervous ganglion and the ovary of a protochordate, Ciona intestinalis.

When methionine-enkephalin antiserum was applied to paraffin sections of adult Ciona intestinalis it reacted with neurons in the ganglion and along the visceral nerve. The fluorescence was strong before and during spawning season, but partially disappeared at the end of August. With the same antibody a positive immunoreactivity was detected in the ovary during the growth of oocytes. The distribution of positive granules in the cytoplasm did not change significantly with varying lighting conditions (normal photoperiod, permanent light or darkness) in which the animals were maintained. In contrast, treatment with a substance isolated from crude extracts of Ciona ("peroxide 1") induced a dense, crescent-like concentration of positive granules near the nucleus of oocytes. The follicular cells did not show any immunofluorescent reaction.

Animals↗
PubMed1984

A "once a day administration" sustained-release theophylline formulation: disposition and pharmacokinetics.

The pharmacokinetics of a new sustained-release preparation of theophylline (Dilatrane à Action Prolongée capsules filled with homogenous microgranules) has been after its studied administration to 7 healthy volunteers at 8 p.m. in order to achieve therapeutic levels at night and in the morning. In separate trials the test dose of 500 or 600 mg was administered for 7 days, once daily at 8 p.m. Plasma theophylline levels were measured by capillary gas chromatography with a mass specific detector after pentylation, using internal standards labelled with stable isotopes (15N-1,3 and 13C-2 theophylline). The new sustained-release preparation showed a monophasic regular absorption phase with very low inter-individual variability. After administration, the plasma level stayed within 80% of the peak levels for 8.5 +/- 1.5 h. There was a good correlation between the dose and the steady state plasma level (r = 0.9587; p less than 0.05). This preparation can be chronically administered once daily day at 8 p.m. in order to achieve a therapeutic level during the night and the morning, and to provide sufficient protection during the nycterohemeral period, with a once dose a day schedule.

Adult↗
PubMed1982

[Distribution of collagen, fibronectin, and laminin during morphogenesis of skin and cutaneous appendages in the chick embryo (author's transl)].

In the dermis of inter-appendage and glabrous skin, interstitial collagen types I, III, and V are abundant, while fibronectin is scarce. Conversely, in the morphogenetically active foci of cutaneous appendages, interstitial collagen is scarce or absent, whereas fibronectin is abundant. Type IV collagen and laminin are localized at the dermal-epidermal junction and distributed evenly.

Animals↗
PubMed1980

[Observation, by immunofluorescence, of an LH-RH-like antigen in the nervous system of Ciona inteesinalis (Tunicier ascidiacea)].

Using Rabbit anti-LH-RH antiserum for immunofluorescence, the presence of an LH-RH-like antigen was observed in the nervous system of a Protochordate Ciona intestinalis. Few immunoreactive cells are localized on the ventral posterior part between the nervous ganglion and the neural gland. Another group of cells are visible along the small nervous fibers near the dorsal vessel.

Animals↗
PubMed1980

[Clinical pharmacology of the antihypertensive action of guanfacine].

The clinical pharmacology of a central antihypertensive drug, guanfacine, was studied in sustained essential hypertension. The study of the haemodynamics, performed in 7 patients demonstrated a significant decrease in blood pressure and a fall in heart rate (less than the one observed with clonidine): the peripheral resistances remained unchanged after 4 days treatment. A clinical trial was carried out in 20 patients with sustained essential hypertension. Guanfacine was given orally (2 to 4 mg/day) during 2 months; the results of this study confirmed the antihypertensive effect of the drug. The most frequent side effects were dryness of the mouth and sleepiness. Guanfacine kinetics were studied in patients after single and repeated oral doses. The plasma concentrations were fitted in a two compartments open model with first order absorption. Steady state plasma level during a long term treatment can be determined with the predicted values derived from simulation of the initial individual kinetic studies. For a 2 mg dosage the biological half-life was 22.8 +/- 3.6 h. Guanfacine kinetics were linear according to the dosage. In moderate permanent essential hypertension guanfacine can be easily prescribed in monotherapy at a posology of 2 to 4 mg/day.

Adult↗
PubMed1979

Gap and tight junctions in tunicates. Study in conventional and freeze-fracture techniques.

Intercellular junctions have been investigated in epidermis and pharyngeal epithelium of larvae and adults of various species of tunicates with conventional and freeze-fracture techniques. Gap and tight junctions were found, similar to those observed in vertebrate tissues. Gap junctions were frequent in glandular epithelia and in larval tissues. They were interpreted as ways of intercellular communication in these developing tissues. They were also particularly numerous in Phallusia pharyngeal cells. Tight junctions were found preferentially in adult pharyngeal and epidermal epithelia, where they were arranged in strands of distinct particles forming a belt-like network at the apical part of cells. These junctions were interpreted as providing a tight barrier between the internal medium and the external environment. In larvae, tight junctions were found only between epidermal cells of the tail. These junctions thus characterized completely differentiated tissues, where they might play, in tunicates and in vertebrates, the same role as septate junctions do in invertebrates.

Animals↗
PubMed1977

[The relation between anti-hypertensive action and plasmatic concentration of pindolol. Preliminary study].

A correlation study between the antihypertensive effect and the plasma level of pindolol was performed in 10 patients with permanent essential hypertension. Pindolol was given orally (20 mg/day) during 9 days. The highly significant fall in blood pressure (delta SBP and delta DBP) is directly correlated negatively correlated, to the pretreatment pressure (p less than 0.02 for deltaSBP and p less than 0.05 deltaDBP) and negatively correlated to the pindolol plasma level (P less than 0.001 for delta SBP and p less than 0.05 for delta DBP). Multiple regression analysis shows, for delta SBP, a stronger influence of plasma level than of basal blood pressure. These results suggest that pindolol could have a specific effect in some hypertensive patients.

Adult↗
PubMedDate not supplied

Pharmacokinetics and hepatic extraction ratio of pindolol in hypertensive patients with normal and impaired renal function.

The intravenous and oral pharmacokinetics and the hepatic extraction ratio of pindolol were determined in 24 hypertensive patients with normal or impaired renal function. In patients with normal renal function, the total clearance was the sum of equal parts of the renal and nonrenal clearances. The nonrenal clearance was found to be equal to the hepatic clearance directly measured from the hepatic extraction ratio. Compared to patients with normal renal function, patients with chronic renal failure exhibited (i) unchanged K12 and K21 and nonrenal clearances, and (ii) significantly decreased values in half-life of the beta phase, Kel, and total renal clearance. The renal clearance was positively correlated (P less than 0.01) to the creatinine clearance. Bioavailability was significantly reduced (P less than 0.01) in the patients with renal failure. Assuming that the nonrenal clearance was equal to the hepatic clearance, the study provides evidence that, in patients with renal insufficiency, (i) no increased metabolism accompanies the decrease in renal function, and (ii) decreased availability is due to reduced absorption.

Administration, Oral↗