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Biomedical subjects

C Guillet

Publications and source records attributed to C Guillet.

31 records · Page 2Linked to original sources
PubMed1993

Genes expressed during the differentiation of the pupal wings are also transiently expressed during the larval moult in Bombyx mori.

By a differential screening of cDNA libraries made with RNAs present in differentiating imaginal wing discs of Bombyx mori, we have isolated clones whose expression is dramatically modified during the formation of the pupal wings. The RNAs corresponding to all but one of these clones are also transiently accumulated in the wing primordia during the last larvo-larval moult and in response to 20-hydroxyecdysone injections. If the injections are made to juvenilized larvae the expression of the same genes is stimulated but the range of the stimulation is reduced. It is suggested that in Bombyx, cells of the wings reach the pupal stage of differentiation by steps corresponding to the phases during which high levels of ecdysteroids are present.

Animals↗
PubMed1993

Overview of novel renal properties of tertatolol.

The renal vasodilatating properties of tertatolol demonstrated in animals have been confirmed in man. In a first study [Paillard et al., 1986], tertatolol (T) 5 mg and propranolol (Pr) 160 mg (SR) were given orally for 15 days to 2 groups of 9 patients with essential hypertension. Glomerular filtration rate (GFR), measured by inulin clearance and renal plasma flow (RPF) measured by PAH clearance increased in T group (+8.9%, p = 0.038 and + 13.0%, p = 0.007, respectively) and decreased in Pr group (-2.8%, NS and -13.4%, p < 0.001, respectively). Two clinical pharmacology studies [Leeman et al., 1986; Nitenberg et al., 1990] have shown specific and selective effects of tertatolol on the renal vasculature. In 8 hypertensive patients with chronic renal failure, the effects of tertatolol 5 mg were evaluated before and after 3 months of treatment on GFR using inulin clearance, and RPF, using PAH clearance [Hannedouche et al., 1991]. After 3 months of treatment, GFR and effective RPF increased significantly by 10 and 13%, respectively, whereas RVR decreased by 16% and the filtration fraction was unchanged. In summary, tertatolol 5 mg, contrasting with other beta-blockers, possesses a selective effect on the renal circulation beneficial to hypertensive patients. The mechanisms of this renal vasodilatation are not fully understood but might involve renal 5-HT1A receptor stimulation.

Adrenergic beta-Antagonists↗
PubMed1993

Double-blind controlled study of rilmenidine versus hydrochlorothiazide in mild hypertension: clinical and renal haemodynamic evaluation.

Clinical and renal haemodynamic parameters were evaluated in 20 mild hypertensive patients after rilmenidine (RIL) administration during a one month double-blind randomised study compared with hydrochlorothiazide (HCT). At the beginning and at the end of the study, BP, heart rate and renal haemodynamic parameters were evaluated. Renal haemodynamic parameters included effective renal plasma flow (ERPF) evaluated by radionuclide study utilising 131I-Hippuran according to Schlegel's method, effective renal blood flow (ERBF = ERPF/(1-Ht)), glomerular filtration rate (GFR) by creatinine clearance, filtration fraction (FF = GFR/ERPF) and renal vascular resistances (RVR = DBP x 80/ERBF). RIL and HCT significantly (P < 0.01) reduced systolic, diastolic and mean blood pressure without relevant change in ERPF, ERBF, GFR and FF. RVR was significantly reduced both in the RIL group (P < 0.002 vs. baseline) and in the HCT group (P < 0.001 vs. baseline). No relevant side-effects were observed in either group. In conclusion, rilmenidine was effective in reducing BP in mild hypertensive patients and produced favourable effects on renal function.

Adult↗
PubMed1992

[Treatment with rilmenidine 1 mg per day: time-lag to maximum response. A multicenter ambulatory study. Le Groupe Français d'étude Multicentrique d'Hyperium].

Forty-four placebo-resistant patients (mean age: 59.2 +/- 2.1 years; mean weight: 70.14 +/- 1.95 kg: mean supine diastolic pressure: 101.6 +/- 0.70 mmHg) were treated during 8 weeks (D0-D56) with a single 1 mg tablet of rilmenidine taken every morning. The patients were seen at intervals of 14 days until their diastolic pressure returned to a normal value of 90 mmHg. Once this goal was achieved, they were not seen again until D56. The actuarial survival curve enabled us to evaluate, at a given moment, the cumulative number of normalized patients and the accuracy of this evaluation (confidence interval). After two weeks of rilmenidine treatment, 66 percent of the patients were normalized. The cumulative proportion of normalized patients increased with time, from 80 percent at D28 to 85 percent at D42 and 98 percent at D56. Confidence intervals were relatively small. Although these results were much better than those obtained in previous studies of this drug, our study shows that blood pressure was rapidly normalized in the majority of hypertensive patients by a daily 1 mg dose of rilmenidine and that doubling this dosage after two weeks of treatment is not necessarily justified, since the percentage of normalized patients increases up to 98 percent after eight weeks of treatment. The small number of adverse effects and the good patient's compliance with treatment (evaluated by tablet counts and rilmenidine plasma level values) testify that this drug respects the quality of life.

Adult↗
PubMed1991

Electrophysiological effects of intravenous rilmenidine in man.

Ten patients (44 y), 6 with the Wolff-Parkinson-White syndrome, and none with hypertensive disease, underwent electrophysiological studies before and after intravenous infusion of a single dose of 1 mg rilmenidine administered over 15 min. The regimen produced a mean plasma rilmenidine concentration of 3.16 ng.ml-1 at the end of the infusion. There was no significant change in sinus cycle length, PR interval, QRS, QT duration or in PA, AH and HV intervals. Estimated sinoatrial conduction time and corrected sinus node recovery time did not significantly change. In one patient, however, an abnormal pause was noted after termination of rapid atrial pacing. The right atrial effective refractory period decreased from 209 to 194 ms. There was no significant change in the anterograde and retrograde block cycle length or in the refractoriness of the nodal, ventricular and accessory pathways. The cycle length of induced reciprocating tachycardia decreased slightly from 374 to 351 ms. No patient exhibited an abnormal response to the carotid sinus massage. The findings indicate that intravenous administration of 1 mg rilmenidine exerts modest effects on the electrophysiological parameters of the human heart.

Administration, Oral↗
PubMed1989

[Multicenter, double-blind study comparing rilmenidine 1 mg and hydrochlorothiazide 25 mg in 244 patients].

The efficacy and acceptability of Rilmenidine (RIL) were assessed in a multicentre, controlled, double-blind trial versus hydrochlorothiazide (HCZ) in patients with mild to moderate hypertension. After an initial 4 week washout period on placebo, patients with diastolic BP of between 90 and 110 mmHg were administered in monotherapy either RIL 1 mg or HCZ 25 mg for four weeks (Day 0-Day 28). In the following four weeks (Day 28-Day 56), those with diastolic BP of over 90 mmHg were given, in association, the antihypertensive agent that they had not received initially. The other patients continued the trial with single daily doses of monotherapy. Two hundred and fourty four patients (48.4 +/- 0.6 years) with supine systolic and diastolic BP of 155.86 +/- 0.96 mmHg and 101.02 +/- 0.28 mmHg respectively were randomly allocated to two comparable treatment groups (RIL, n = 120 and HCZ, n = 124). The systolic and diastolic BP decreased significantly between Day 0 and Day 28, as much at Day 14 as at Day 28 in both treatment groups. The antihypertensive effect was comparable: at Day 28 the mean fall in systolic/diastolic BP was 16/10 mmHg in the RIL group and 15/9 mmHg in the HCZ group (NS). The clinical acceptability was equivalent in the two groups: secondary effects were responsible for one patient's withdrawal in each group and their incidence was 5% on average, 10% for the most common.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1982

[Radioisotopic study of bone growth and maturation. 160 cases].

Increases in blood supply, and certain metabolic and physical processes, are of special significance in epiphyseal growth centers. Such events are evidenced by the uptake of 99mTc methylene diphosphonate (MDP). Bone scans in children and young adults show increased radionuclide uptake in epiphyseal growth plates. Age-related changes in 99mTc MDP epiphyseal uptake can be used for determining a functional bone age. Radiation exposure is within the range of other routine diagnostic procedures. Scanning was done with a gamma scintillation camera, which supplies rapid, high resolution, studies. In the first five years of life, nearly all the main epiphyseal growth plates were visible symmetrically on routine scans. In six cases, growth plates were visible before the corresponding epiphyseal ossification foci became apparent on roentgenograms. Little bones (hands, wrists, feet, and ankles) were not assessed because of the poor resolution of the parallel collimator-camera system. A slow decrease in epiphyseal growth plate activity was demonstrated in subjects over sixteen years of age. In some instances, this decrease occurred only after epiphyseal closure became visible on roentgenograms. Data described here are not usually employed for clinical purposes, except when viability of a growth plate is doubtful. Functional analysis with 99mTc MDP is a useful complement to roentgenologic investigation of skeletal growth and maturation.

Adolescent↗
PubMed1980

[The functioning of the mitochondrial system and respiration at the 5th larval instar in Pieris brassicae (Lepidoptera)].

The profiles of respiratory rate, total proteins, mitochondrial proteins and mitochondrial activity have been described during the fifth instar of Pieris brassicae reared either under long-day or short-day photoperiod. There was no fundamental difference per unit of live weight between the long-day and short-day larvae. The biochemical characteristics of the larval mitochondria have been described, and the mitochondria were shown to oxidize succinate better than alpha-glycerophosphate. Two periods during the fifth instar were related to mitochondrial activity. During the first one, this specific activity was high during 50 to 60 p. 100 of the instar; it then decreased. This alteration was superimposed on changes in the hormonal balance. It is shown that the respiratory rate was not only a passive response to the energy demand, and that specific mitochondrial activity must be considered as a parameter of the development program.

Adenosine Triphosphate↗