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Biomedical subjects

G Gaillard

Publications and source records attributed to G Gaillard.

At least 37 records · Page 2Linked to original sources

[Diagnostic value of SCC-TA4 determination in 4 localizations of epidermoid cancers. An experience of the FNCLCC subgroup of radio-analysis].

A multicenter and retrospective study of the diagnosis value of SCC-TA4 in squamous cell carcinomas of 4 localisations was made with the 2 thresholds of 2 and 2.5 ng/ml. However, 3.1% of controls have a SCC value above 2.5 ng/ml. Sixteen benign gynecologic pathologies had no positive level. The benign digestive (N = 73), bronchial (N = 345) pathologies and no squamous cell carcinomas (N = 93, N = 220 respectively), had SCC-TA4 mean levels significantly lower than corresponding squamous cell carcinomas (N = 153, N = 128 respectively). Sensitivity of the test varied from 40% in the squamous cell carcinomas of the lung, to 72% in the squamous cell carcinomas of the uterine cervix. Specificity was always very high and varied from 91% in the SCC of lung, to 100% in the SCC of uterine cervix. For the SCC of uterine cervix, oesophagus and head and neck, the mean values and incidence of positive levels increased significantly with increasing tumor size and advancing disease stage. For the SCC of uterine cervix, mean SCC-TA4 levels and percentages of positive levels above 2 ng/ml were significantly higher for the patients with recurrence (22.5 +/- 4.6 ng/ml; 76%) or with metastasis appearance (23.6 +/- 5.4 ng/ml; 77%) than for the patients in remission (less than 1.5 ng/ml; 0%). In the SCC of oesophagus, we report levels before treatment that are significantly higher for the patients with metastasis at the first attempt (4.2 +/- 5.1 ng/ml; 59%), and an elevated SCC level at the diagnosis evoked a SCC of lung already disseminated (8.8 +/- 12.1 ng/ml; 50%) that will fail to respond to treatment (4.0 +/- 4.2 ng/ml; 48%).

Adult↗

Effect of apomorphine on adrenal medullary catecholamine levels.

The effects of the dopamine receptor agonist, apomorphine, on the total catecholamine content of the adrenal medulla were studied in normotensive rats. Apomorphine (3, 15, 30 mg/kg SC) induced a dose-dependent decrease in catecholamine content of the adrenal gland. The action of apomorphine was suppressed by previous treatment with the non specific dopamine receptor antagonist, haloperidol (9 mg/kg IP), or the D2 antagonist domperidone (2 mg/kg IP), but not by the D1 antagonist SCH 23390 (1 mg/kg IP). The apomorphine-induced decrease in adrenal catecholamine concentration was suppressed by denervation of the adrenal medulla, i.e. unilateral section of splanchnic fibers performed 5 days before. These results show that, under our experimental conditions, the effect of apomorphine is due to the activation of D2 dopamine receptors probably located on splanchnic nerve endings and suggest the existence of a peripheral D2 dopaminergic system which modulates adrenal medullary catecholamine content.

Adrenal Medulla↗

[Inhibition of transducin by lithium: electrophysiological demonstration using the isolated retina].

Recently Avissar et al. have established that Li+ can inhibit G proteins implicated in brain function. In order to investigate the effect of Li+ on transducin, the evolution of the electroretinogram (ERG) recorded on isolated rat retina has been studied in presence of lithium. Results indicate that 10(-5) M Li+ had no effect on ERG while 10(-3) M Li+, which corresponds to therapeutic blood levels, significantly decreases ERG amplitude. This effect being nearly totally inhibited by cholera toxin (75 micrograms/l), it is concluded that Li+ acts on transducin and so inhibits the visual transduction process.

Animals↗

[Chondrosarcoma of the soft parts of the thoracic wall. Apropos of a case after surgery and irradiation of breast adenocarcinoma].

We are reporting here a case of chondrosarcoma of the soft tissues of the thoracic wall. As far as we can tell it is the first case published in the world. The tumour appeared 13 years after radical mastectomy and radiotherapy for an adenocarcinoma of the breast. The tumor was greyish-white in appearance and hard, but friable and haemorrhagic. Clinically and biologically it looked like an inflammatory mass. This disappeared when the tumour had been removed but recurred 6 days post-operatively when nodules showing that it had permeated the tissues appeared. Histological and immunohistochemical examination confirmed the diagnosis. We discuss the clinical and histological aspects of the case and state what we found in the literature about other sarcomas that have followed adenocarcinomata of the breast that had been irradiated and operated on. The role of radiotherapy in bringing about this tumour is discussed, including the relationship between the site of the tumour and the dose and field of irradiation. The prognosis is particularly bad in this type of sarcoma which was induced by irradiation.

Adenocarcinoma↗

Enzymatic and hormonal responses following a 24 h endurance run and a 10 h triathlon race.

Muscle cell leakage and hormonal changes were compared immediately after and during the 3 days following a 24 h endurance run (R24h) in 8 subjects, and a 10 h triathlon non-competitive race (T10h) in 6 subjects. The study showed three main differences: 1) plasma enzyme increases were considerably more significant in R24h than in T10h: compared with resting levels, creatine kinase increased x 120 after R24h but only x 2 after T10h; lactic dehydrogenase x 4, as opposed to x 1.5; and transaminases only showed an increase after R24h. The plasma myoglobin increase after R24h was double that found after T10h; 2) for the same magnitude of plasma aldosterone and cortisol after R24h and T10h (3 times the resting levels), a highly significant decrease in urinary Na+ (p less than 0.001) and an increase in urinary K+ (p less than 0.01) were found only after R24h; and 3) the plasma free noradrenaline level increased significantly after R24h (x 2.6) whereas it was unchanged after T10h. In contrast, the plasma level of conjugated dopamine increased only after T10h (x 3.7, p less than 0.05). These results suggest that long-distance running causes more muscular lesions than the triathlon, and that important factors other than aldosterone are probably involved in the regulation of urinary electrolyte excretions during T10h.

Adult↗

Evidence of 3 beta-hydroxysteroid dehydrogenase activity in several murine embryonal carcinoma cell lines.

This report describes, for the first time to our knowledge, a possible steroidogenic activity in established murine embryonal carcinoma cell lines (PCC3, PCC4, F9), revealed by a 3 beta-hydroxysteroid dehydrogenase activity (revelation of NADH2 by staining, and RIA assessment of delta 4-androstenedione). The remarkable analogy between such totipotent cells and embryonal cells may suggest that this activity could be present before histologic organization of the embryonal testis. Nonmalignant embryonal cells such as fibroblasts (3/A/1/D-3) or myoblasts (T984) were also found to possess a 3 beta-hydroxysteroid dehydrogenase activity, thus suggesting that this enzyme is not specific to hormone-secreting cells, but the sign of a more general phenomenon.

3-Hydroxysteroid Dehydrogenases↗

[Value of the study of circulating adrenergic receptors in the diagnosis and surveillance after surgery of pheochromocytoma].

The purpose of the study was to investigate leukocyte beta adrenoceptors and platelet alpha 2 adrenoceptors in pheochromocytoma. The study concerned nine hypertensive patients, five men and four women (aged 42 +/- 8 years) with a pheochromocytoma demonstrated by high levels of urinary catecholamines and radiological data. Catecholamine plasma levels, assayed by HPLC were wide-ranging: 10.7 to 172.8 nM for noradrenaline and 0.7 to 3.9 nM for adrenaline. In each case the number of leukocyte beta adrenoceptors sites (measured with 125 I-cyanopindolol) significantly decreased: Bmax was 20.6 +/- 2.8 versus 48.5 +/- 1.5 fmol/mg protein in controls (p less than 0.05). In contrast, the number of platelet alpha 2 adrenoceptors sites (measured with 3H-yohimbine) was not modified: 206 +/- 22.6 versus 186.0 +/- 12.1 fmole/mg protein in controls. There was no change in affinity constant (Kd), neither for beta nor alpha2 adrenoceptors. After tumor removal, there was a significant increase in beta adrenoceptor number. We conclude that down regulation occurs in vivo for beta adrenoceptors but not for alpha2 adrenoceptors and that the decrease in leukocyte beta adrenoceptor number is an interesting and suitable index in the management of pheochromocytoma.

Adrenal Gland Neoplasms↗

[Decrease of HCG level after conservative laparoscopic treatment of extra-uterine pregnancy].

HCG levels have been studied in 76 patients following laparoscopic treatment using laparotomy. This shows that early detection of treatment failure is possible of ectopic pregnancy. The decrease of HCG was the same as after conservative treatment from the third or fifth post-operative day onwards. The authors report a scheme for the post-operative follow-up after laparoscopic treatment of ectopic pregnancy based on the rate of HCG decrease.

Chorionic Gonadotropin↗

[Natural history of arterial hypertension due to primary hyperreninism].

This case report deals with an eight-year duration severe high renin hypertension and its consequences. In 1975, a 13 years old girl was found to have blood pressure (BP) levels of 240/150 mmHg with bilateral papilloedema. Hypokalemic alkalosis, a 45 mm Sokolow index (SI) and very high peripheral renin activity (PRA) were also noticed. Renal vein renin sampling (RVRS) suggested secretion from the left kidney but intravenous pyelography and renal arteriography were normal. BP levels were first controlled by triple treatment but rose one year later, despite adjunction of beta-blockers. High PRA was again found, but without hormonal gradient on a second RVRS. From 1977 to 1982, BP never fell to normal levels despite quadruple treatment. In 1982, a stage II optic fundus, a 58 mm SI and 2 g/day proteinuria are noticed, so that a new complete etiologic work up is undertaken in 1983: PRA is still high, with a dramatic acute BP fall after captopril and no gradient on a third RVRS, but intravenous pyelography, tomodensitometry and selective arteriography disclose a 4 cm diameter poorly vascularized tumour on the surface of the lower pole of the right kidney. BP levels are controlled for three months by captopril + chlorothiazide. The tumour is removed in january 1984. RVRS by direct peroperative punction indicates (a posteriori) hormonal secretion from the right kidney lower pole. Histologic examination and immunofluorescence with antirenin serum corroborate the juxtaglomerular origin of the tumour. Eighteen months later, BP is permanently normal, SI is 30 mm, and there is no proteinuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Is adrenal medulla involved in the antihypertensive effect of nicardipine?

The effects of nicardipine, a dihydropyridine calcium channel blocker, on adrenal medulla were investigated in chloralose-anesthetized dogs. For analysis of the adrenal medullary function, adrenal venous catecholamine rates were determined. Intravenous administration of nicardipine (50 micrograms/kg) induced a marked increase in both adrenal catecholamine rates and heart rate and a simultaneous decrease in blood pressure. This effect on epinephrine and norepinephrine release is probably explained by the involvement of baroreflex mechanisms. After acute splanchnicectomy, nicardipine (50 and 100 micrograms/kg i.v.) failed to modify catecholamine secretion rates from the denervated adrenal medulla during electrical stimulation of the splanchnic nerve at low (2 Hz) and high (5 Hz) frequencies. In conclusion, these results suggest that in vivo a functional dihydropyridine-sensitive calcium channel is not required for calcium entry mechanisms into dog chromaffin cells. Moreover, adrenal medulla is not involved in the antihypertensive action of nicardipine.

Adrenal Medulla↗

Effect of clonidine on adrenal medulla catecholamine levels in rats.

The effects of clonidine on adrenal medulla catecholamines levels were studied in normotensive rats. Intraperitoneal injections (50,100 micrograms/kg) of clonidine caused a dose-dependent decrease in adrenaline content of the gland. This effect was suppressed by denervation of the adrenal medulla, i.e. unilateral section of splanchnic fibers performed 5 days before. These results demonstrate that clonidine decreases the catecholamine content of the adrenal medulla only through a central action. They suggest that the adrenal medulla is involved in the hypotensive effect of clonidine.

Adrenal Medulla↗

Effects of calcium entry blockers on blood pressure and heart rate in neurogenic hypertensive dogs.

The hypotensive and negative chronotropic effects of 5 calcium entry blockers (verapamil 200 micrograms/kg IV; diltiazem 300 micrograms/kg IV; nifedipine 5 micrograms/kg IV; nicardipine 50 micrograms/kg IV; and bepridil 5 mg/kg IV) were compared in control normotensive and acute neurogenic hypertensive anaesthetized dogs. Acute neurogenic hypertension was induced by sino-aortic denervation (SAD). In control normotensive dogs, all drugs (except bepridil) induced a slight and transient decrease in blood pressure. Nifedipine and nicardipine increased heart rate whereas the three other drugs remained ineffective. SAD caused a 2-2.5-fold increase in the hypotensive properties of the 5 drugs in dogs. Moreover, the duration of this induced hypotension was longer than in control normotensive animals. In SAD dogs, all calcium entry blockers significantly decreased heart rate. This study indicates that the direct cardiac inhibitory action of calcium channel blockers is modulated by baroreceptor activity in intact animals. The mechanism of the selective action of calcium entry blockers in hypertensive SAD in contrast to normotensive dogs is discussed.

Animals↗

A study of the action of clonidine on secretion from the adrenal medulla in dogs.

The effects of clonidine on adrenal catecholamine (adrenaline and noradrenaline) secretion were investigated in chloralose-anaesthetized dogs. Intravenous administration of clonidine (10 and 20 micrograms kg-1) induced a decrease in both adrenal catecholamine secretion rates and cardiovascular parameters (blood pressure and heart rate). In contrast, a dose of 5 micrograms kg-1 was ineffective. Intracisternal clonidine (in a lower dose of 3 micrograms kg-1) also decreased adrenaline and noradrenaline release from the adrenal gland. Clonidine failed to modify adrenal catecholamine release evoked by electrical stimulation of the splanchnic nerve. These results demonstrate that clonidine decreases adrenaline release from the adrenal gland through a central and not a peripheral mechanism in dogs. This action might contribute to its antihypertensive effects.

Adrenal Medulla↗