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Biomedical subjects

G Noel

Publications and source records attributed to G Noel.

At least 37 records · Page 2Linked to original sources
PubMed1983

Regulation of ketonaemia in hyperthyroidism: study of the role of free fatty acids.

We have indirectly assessed the role of free fatty acids (FFA) and of hepatic ketogenesis in the regulation of ketone body levels in euthyroid and hyperthyroid subjects. All studies were performed under controlled dietary conditions (35 and 45 kcal/kg body weight/day respectively for euthyroid and hyperthyroid subjects). In the post-absorptive state hyperthyroid patients had normal, glucagon levels and, in spite of increased insulinemia (p less than 0.02), elevated concentrations of blood glucose (p less than 0.01), glycerol (p less than 0.001) and ketone bodies (p less than 0.05). In the face of this hyperketonaemia, there was no significant increase of plasma FFA, suggesting possible increased hepatic conversion of FFA to ketone bodies. However, when FFA were acutely raised to high levels, the induced rise of ketone bodies was similar in hyperthyroid and euthyroid subjects. Oral propranolol administration to hyperthyroid patients in the post-absorptive state decreased the concentrations of glycerol (p less than 0.05) and ketone bodies (p less than 0.05) without altering insulin concentrations. Ketone bodies fell without any significant decrease of FFA suggesting a possible direct effect of propranolol administration on hepatic ketogenesis. However, the ketone body response to raised FFA levels was unaffected by propranolol. We have evidence in hyperthyroid patients of increased lipolysis and ketogenesis in spite of increased daily caloric intake. These results suggest that these metabolic abnormalities are not merely due to relative starvation. We have tentative evidence for modification of the intra-hepatic conversion of FFA to ketone bodies in the post-absorptive state but no supporting evidence when FFA levels were experimentally raised.

Adult↗
PubMed1983

[Serum lipids in diabetes mellitus. Relation to equilibration and microangiopathy].

We have determined in 128 diabetic (57 non insulin-dependent (NIDDM) and 71 insulin-dependent (IDDM) patients) and in control subjects, serum total cholesterol, HDL cholesterol, triglycerides and Hb Alc levels. Presence of macroangiopathy was assessed by clinical findings. In IDDM increasingly poor control of diabetes was associated with significant increases in total cholesterol (p less than 0.001) and triglycerides (p less than 0.01). HDL cholesterol (1.19 +/- 0.39 mM/l) did not differ from control subjects (1.30 +/- 0.35 mM/l) and was not related to Hb Alc levels. NIDDM had increased total cholesterol (5.91 +/- 1.45 vs 5.38 +/- 0.93 mM/l, p less than 0.05) and triglycerides (2.06 - 0.32 to 8.80- vs 1.03 - 0.22 à 2.20 mM/l, p less than 0.01) and decreased HDL cholesterol (1.08 +/- 0.44 vs 1.31 +/- 0.36 mM/l, p less than 0.01). These differences could be explained only in part by the overweight of the NIDDM patients. There was no significant correlation in NIDDM between Hb Alc and serum lipids levels but overweight and triglycerides were positively correlated (p less than 0.02) and triglycerides and HDL cholesterol negatively correlated (p less than 0.05). IDDM with macroangiopathy had higher total cholesterol levels than those without (6.44 +/- 1.60 vs 5.29 +/- 1.22 mM/l, p less than 0.01). IDDM and NIDDM with macroangiopathy had slightly decreased HDL cholesterol; however, the diabetic subjects with macroangiopathy were older and had a longer duration of diabetes than subjects without macroangiopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Abnormalities of heart rate and arterial blood pressure regulation in diabetes mellitus. Relation with age, duration of diabetes and presence of peripheral neuropathy.

We have determined in 46 control subjects and 117 diabetic patients with or without peripheral neuropathy (PN) the blood pressure response to standing and the heart rate variations during deep breathing (HRV) and standing (T/B ratio). HRV was abnormal in 20% of diabetics and T/B ratio only in 8%. HRV and T/B ratio decreased with age both in control and diabetic group and significant alterations of these two tests in diabetic patients were found only for the youngest subjects; HRV and T/B ratio were not related to the duration of diabetes. Ten diabetics had orthostatic hypotension. Diabetics with PN had lower HRV and T/B ratio than the others and, excluding the 10 subjects with large orthostatic hypotension, a lack of increase in diastolic blood pressure and a transient fall in systolic blood pressure on standing. T/B ratio appears in our subjects of less value than HRV for the diagnosis of cardiac autonomic neuropathy; because of the spontaneous alterations with age of the response to these tests interpretation of the results in diabetics is possible only in the presence of appropriate data in control subjects. PN in diabetic patients is strongly associated with abnormalities of heart rate regulation suggestive of cardiac vagal neuropathy and with abnormalities of blood pressure regulation suggestive of peripheral sympathetic lesions.

Adolescent↗
PubMed1981

Serotonin and dopamine disturbances in patients with unipolar depression and Parkinsonism.

Probenecid was administered to 7 unipolar depressed patients, 7 parkinsonians and 7 extrapyramidal patients with senile dementia matched for age and sex. Before and after the administration of probenecid, the levels of 5 hydroxyindoleacetic acid (5HIAA) and homovanillic acid (HVA) were determined in the cerebrospinal fluid (CSF) of all patients in order to study the central turnover rate of serotonin and dopamine. Unipolar depressed patients showed a significantly lower increase in CSF 5HIAA levels after probenecid than parkinsonians. Patients with Parkinsonism had a reduced increment of CSF HVA levels following probenecid administration when compared to unipolar depressed and extrapyramidal patients with senile dementia.

Brain↗
PubMed1981

Plasma and urinary cortisol levels after dexamethasone in affective disorders.

The validity of the dexamethasone suppression test was evaluated for the differential diagnosis of primary and secondary depressions. Forty hospitalized psychiatric patients (14 primary depressed, 15 secondary depressed and 11 non-depressed controls) were studied. The Research Diagnostic Criteria of Spitzer et al. (1978) were used to classify these patients. Eight out of the 14 primary depressed patients had an abnormally high plasma cortisol at 4 p.m. after dexamethasone. Only 2 out of the 15 secondary depressed patients and none of the 11 controls had an abnormal response to dexamethasone. Based on these results, the dexamethasone suppression test has a sensitivity of 57%, a specificity of 87% and a predictive value of 80%. The determination of urinary free cortisol excretion does not improve the performance of the test.

Adult↗
PubMed1981

Biogenic amine disturbances in cerebrospinal fluid in parkinsonism and unipolar depression: use of the probenecid method.

Probenecid was administered to 7 unipolar depressed patients, 7 parkinsonians and 7 extrapyramidal patients with senile dementia matched for age and sex. Before and after the administration of probenecid, the levels of 5-hydroxindoleacetic acid (5HIAA) and homovanillic acid (HVA) were determined in the cerebrospinal fluid (CSF) of all patients in order to study the central turnover rate of serotonin and dopamine. Unipolar depressed patients showed a significantly lower increase in CSF 5HIAA levels after probenecid than parkinsonians. Patients with parkinsonism had a reduced increment of CSF HVA levels following probenecid administration when compared to unipolar depressed and extrapyramidal patients with senile dementia. The authors conclude that the biochemical study of CSF biogenic amines using the probenecid method can be used as a highly sensitive biological screening test for diagnosing Parkinson and depressive syndromes among an aging population of retarded, tremoring, rigid and hypokinetic patients.

Aged↗
PubMed1977

Regional cerebral blood flow in children. A rheoencephalographic study of the modifications induced by reading.

Cerebral impedance changes (F changes) indicating cerebral blood flow were studied in 17 children aged 6-11 years and in 10 normal adults. At rest, large values were found in children, who never exhibited the 'hyperfrontality' pattern of the adults. Reading induced an F increase in both the dominant and non-dominant hemispheres, in contrast with a larger increase in the dominant hemisphere in adults. A spatial test was designed in adults which triggered a larger increase in the non-dominant hemisphere.

Adult↗
PubMed1977

Regional cerebral blood flow during voluntary movements of the hand. A rheoencephalography study.

Cerebral impedance changes (F changes) indicating cerebral blood flow variations in the central and precentral areas were measured with a rheographic technique in normal subjects preparing for and carrying out a motor task. The time course of the F changes was studied and several significant correlations were established between the amount of F changes, their distribution and the motor performance. Our findings confirm that frontal and premotor regions play an important part in decision making.

Adult↗
PubMed1977

Cerebral vasoreactivity in senile dementia.

A group of clinical senile dementia patients underwent a series of cerebrovascular examinations. Some of them were standard examinations (fundus oculi, electroencephalogram, rheoencephalogram, cerebral angiogram and pneumonencephalogram) while the others were studying regional cerebral blood flow (rCBF) and modification of flow under fonctional tests (hypercapnia, hypocapnia and intravenous injection of 50 mg chl. papaverine) using the 133Xe clearance technique. The senile dementia group (III) was compared with 'normal' old patients group (I) and with patients suffering from sequelae of a previous stroke or from minor mental disorders (group II). Elderly subjects regarded as 'normal' often present alterations in usual vascular examinations but reveal a relative integrity of cerebral autoregulation. Some patients considered irreversibly 'sclerotic' still have a good grey matter flow (r1CBF) with real vasomotor possibilities. In each of the three groups of elderly subjects, there seemed to be a lack of correlation between the clinical symptoms and certain specific vascular examination.

Aged↗