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Biomedical subjects

G Franck

Publications and source records attributed to G Franck.

At least 109 records · Page 6Linked to original sources
PubMed1986

Central dopaminergic and noradrenergic receptor blockade in a patient with neuroleptic malignant syndrome.

During treatment with clomipramine and haloperidol, a 54-year-old depressed woman exhibited a typical neuroleptic malignant syndrome (NMS). Among results of biologic tests performed at least 2 weeks after discontinuation of all psychotropic treatment, the absence of normal growth hormone response after both apomorphine and clonidine challenge tests and increased levels of cerebrospinal fluid homovanillic acid and urinary 3-methoxy-4-hydroxyphenylglycol suggest that NMS may be related to central dopaminergic and possible alpha-noradrenergic receptor blockade.

Clomipramine↗
PubMed1986

Regional cerebral blood flow and metabolic rates in human focal epilepsy and status epilepticus.

Positron emission tomography with the oxygen-15 steady state or bolus inhalation technique was used to provide quantitative values of regional cerebral blood flow (CBF), oxygen extraction ratio (OER) and oxygen consumption (CMRO2) in 25 patients with partial complex seizures during the interictal state and in 5 patients during status epilepticus. Glucose utilization (CMRglu) was also studied in one case of status epilepticus with the 18F-fluorodeoxyglucose technique (18FDG). Interictal scans showed zone(s) of hypoperfusion and hypometabolism without significant variation of the OER in approximately 80% of patients. In 62%, there was a strong correlation between the overall EEG localization and the area(s) of hypoperfusion and hypometabolism. In all cases, ictal scans revealed a focal or multifocal increase in CBF and CMRO2. The localization of the most affected regions correlated well with the spatial distribution of the electroencephalograph (EEG) abnormalities. Comparison of the different values of CBF, CMRO2, and OER showed that the increase in perfusion always exceeded that of oxygen consumption and hence was accompanied by a significant decrease of OER; the latter was always the most prominent in the region of the epilepticus focus determined by serial EEG recordings. These results showed that the supply of oxygen by blood flow is large enough to meet metabolic demand. When comparing these values with CMRglu, it appeared that the relative changes in CMRglu and CBF were very similar, indicating that the increase in blood flow correlated with the enhancement in glucose utilization. The observed imbalance between blood flow, glucose utilization, and oxygen consumption could suggest that an impairment of oxygen utilization by the mitochondria could occur in the epileptic focus during prolonged status epilepticus.

Cerebrovascular Circulation↗
PubMed1986

[Hemodynamic and metabolic study using positron emission tomography in a case of right thalamo-capsular ischemic stroke].

The authors report the results of a Positron Emission Tomographic (PET) study of local cerebral blood flow and oxygen consumption in one patient with a right capsulo-thalamic ischemic lesion. That lesion is well demonstrated using X-ray CT Scan. PET study demonstrates a decreased perfusion and metabolism at three levels: first in right thalamus region, second in whole right hemisphere, more marked at orbitofrontal area and third at the level of the left cerebellar hemisphere. The authors point out the usefulness of PET studies which allow a better understanding of clinical signs by demonstrating functional consequences of damage in deeply located structures such as thalamus and internal capsule on cerebral and cerebellar cortices.

Brain↗
PubMed1985

[Value of the sleep EEG as a biological marker of depressive states. Comparison with 3 neuroendocrine tests].

In a sample of 12 endogenous depressive inpatients (8 primary and 4 secondary depressives), we compared the diagnostic usefulness of REM latency (recorded during at least 4 consecutive nights) with 3 neuroendocrine tests: dexamethasone suppression test and GH response after clonidine (a alpha-adrenergic agonist) and apomorphine (a dopaminergic agonist) challenges. Shortened REM latency (less than 50 min during at least 1 night) was present in 67% of depressives. However, REM latency presented a clear night to night intra-patient variability that makes it necessary to record at least 3 consecutive nights for the best sensitivity. Non-suppression after dexamethasone was present in 50% of depressives, blunted GH response after clonidine, in 75% and blunted response after apomorphine, in 42%. A total of 92% of patients exhibited at least one abnormal biological parameter (100% of primary and 75% of secondary depressives); 67% of patients exhibited at least two disturbed parameters and these patients constituted the whole primary depressive group (100%). These results show that these 4 potential biological markers of depression are not necessarily distributed in the same population. This suggests the potential usefulness of their concurrent use for improved accuracy of diagnosis.

Adult↗
PubMed1985

Blood and urinary magnesium, zinc, calcium, free fatty acids, and catecholamines in type A and type B subjects.

Twenty type A male students were compared to nineteen type B male students (all in apparently good health), before and after exposure to combined stress (noise and task). Before stress, red blood cell (RBC) Zn concentration is higher (P less than .05) and Zn excretion lower (P less than .05) in type A than in type B people. After stress, type A subjects exhibit changes that are larger and more significant than those of type B individuals. After stress, the type A group shows an important increase of urinary catecholamines (P = 2.10(-5), serum free fatty acids, and urinary Zn (P = .001); a slight increase in plasma magnesium (P less than .05); and a small but significant decrease in RBC Mg (P less than .02). These results suggest that type A subjects are more sensitive to stress than are type B people and more readily lose their intracellular Mg, the rise in plasma Mg being a transient one, probably consecutive to the cellular loss. The present observations are in good agreement with published data: ie, the psychological characteristics of type A personalities; their greater susceptibility to ischemic heart disease, which has been associated with Mg deficiency; the possible role of hypomagnesemia in the pathogenesis of hypertension and coronary vasospasm; and the high RBC Zn levels found in hypertensive patients.

Adult↗
PubMed1985

[Changes in plasma prolactin and magnesium in male rats treated with thioproperazine and/or bromocriptine].

The Ca2+ dependent release of both dopamine (DA) and prolactin (Prl) is modified by stress. Plasma magnesium (Mg) concentrations are also modified. Therefore, we have investigated on plasma (P) Mg and Prl, the immediate and delayed effects of one, five or six daily injections of bromocriptine (BMC, 200 micrograms/100 g) and thioproperazine (100 micrograms/100 g), respectively agonist and antagonist of pituitary DA receptors. One hour after injection of either drugs, an increased P Mg is observed while P Prl is increased or decreased. No correlation is, thus, established between P Prl and P Mg changes. The P Mg increase is long-lasting after BMC, transitory after thioproperazine as shown by determinations performed 23 h after the 5th injection. When the two drugs are simultaneously given, no important modifications of P Mg are observed. The mechanisms and consequences of this P Mg increase are discussed. During stress, the hypermagnesemia could modulate the Prl secretion and action, hindering its secretion on one hand, and potentiating its action on target-organs, on the other hand.

Animals↗
PubMed1984

Concurrent use of REM latency, dexamethasone suppression, clonidine, and apomorphine tests as biological markers of endogenous depression: a pilot study.

In a sample of 12 major depressive inpatients, endogenous subtype (8 primary and 4 secondary) defined by Research Diagnostic Criteria, we compared the sensitivity of four potential biological markers: latency of rapid eye movement (REM) sleep (recorded during at least 4 consecutive nights), dexamethasone suppression, and the clonidine and apomorphine tests. Shortened REM latency (less than 50 minutes during at least 1 night) identified 67% of depressives (87% of primary and 25% of secondary); nonsuppression after dexamethasone identified 50% of depressives (62% of primary and 25% of secondary); blunted growth hormone (GH) response after clonidine identified 75% of depressives (100% of primary and 25% of secondary); and blunted GH response after apomorphine identified 42% of depressives (62% of primary and 0% of secondary). Ninety-two percent of patients were correctly identified by at least one biological marker (100% of primary and 75% of secondary depressives). Of 67% of patients positive on at least two biological markers, all were primary depressives (100%). These four biological markers do not necessarily identify the same population, suggesting that their concurrent use may yield the highest level of diagnostic sensitivity.

Adult↗
PubMed1982

Border zone ("watershed area") cerebral ischemia.

Twenty subjects showing clinical and electroencephalographic patterns of the so-called "diffuse cortical ischemic syndrome with an extraterritorial (border zone) predilection," as described by Gastaut and Naquet (1965) and Gastaut et al. (1971) were studied. This syndrome occurs in elderly patients presenting a sudden disturbance of consciousness of various degree, neurological deficits, and epileptic seizures consisting of focal motor attacks and epilepsia partialis continua. Periodic lateralized epileptiform discharges were recorded. They could be bilateral or more often predominated over one hemisphere, usually in the parieto-temporo-occipital areas. The various pathological factors are discussed. Four main types of abnormalities, sometimes combined, seem to be important for the occurrence of this syndrome: generalized underperfusion, hypertension, embolic processes and sometimes metabolic factors (alcohol, anoxic anoxia, electrolyte imbalance or nonketotic hyperglycemia) and, particularly, in the presence of pre-existing cerebral infarcts, either symptomatic or asymptomatic.

Adult↗
PubMed1981

Effect of changing potassium ion concentrations on rat cerebral slices in vitro: a study during development.

Adult rat cerebral cortex slices when incubated in media in increasing K+ concentrations, from 3 to 20 mM ("physiological" conditions), exhibited an increase of Ki+ and a decrease of Nai+ and Cli-. This phenomenon appeared at 30 days postnatally, which is fairly late during development. Over 20 mM-K+ ("pathological" conditions) an intense water uptake was observed together with an increase of Nai+ and Cli-. This was observed in both adult and young animals. The results are discussed in relation to the well known properties of glial (Na+,K+)-ATPase and carbonic anhydrase.

Animals↗