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Biomedical subjects

D Mabin

Publications and source records attributed to D Mabin.

At least 55 records · Page 3Linked to original sources
PubMed1985

Spontaneous multiple unit activity from the preoptic nucleus and changes in blood pressure in the rainbow trout Salmo gairdneri under acute experimental conditions.

Multiple unit activity (MUA) from the preoptic nucleus (NPO) blood pressure and heart rate were recorded in 41 anaesthetized and curarized rainbow trout. Mayer waves were frequently observed in blood pressure recordings (83%). Rhythmic MUA from the NPO, recorded in 46% of the experimented trout, occurred preferentially during Mayer waves. The initiation of the period of MUA occurred during low pressure vasomotor tone and large vasomotor pulse pressure inhibited MUA. Sustained decrease in blood pressure induced proportional rise in MUA. These results suggest that cardiovascular inputs influence the electrical activity of neurosecretory cells within the NPO and so may modulate the neurohypophysial hormones secretion.

Animals↗
PubMed1985

Evidence for biorhythmicity from the preoptic nucleus of the rainbow trout Salmo gairdnerii under freely swimming conditions--an electrophysiological study.

This study describes a technique which allows continuous recording of MUA (Multiple Unit Activity), from the NPO (Preoptic Nucleus), DAP (Dorsal Aortic blood Pressure) and ECG (Electrocardiogram) in freely swimming rainbow trout. From the 21 trout tested, six trout (29%) clearly showed rhythmic patterns of MUA during the five post-operative days (D2-D6). The mean length of rhythmic MUA was about 18 hr (range 6-33 hr) among the six trout during the recording days. Periodic MUA occurred approximately eight times/hr and lasted about 2 min. The maximal frequency of discharges was 20-30 spikes per sec. No change occurred in the mean level of blood pressure from the first operative day to the following post-operative days, where rhythmic MUA appeared or reappeared. These results demonstrate the existence of biorhythmicity within the NPO of freely swimming trout and suggest parallel oscillations in neurohormones secretion.

Animals↗
PubMed1985

[Value of visual and somatosensory evoked potentials and the electroencephalogram in chronic respiratory insufficiency].

The visual evoked potentials (VEPs), somatosensory evoked potentials (SEPs) and the electroencephalogram (EEG) have been studied in 16 subjects presenting chronic respiratory insufficiency (CRI) with normal consciousness. The SEPs latencies were increased but the VEPs latencies were not. The EEG was little disturbed and did not seem to provide useful information in CRI without encephalopathy.

Aged↗
PubMed1985

[Brain stem auditory evoked potentials and chronic alcoholism].

Brain-stem auditory evoked potentials (BAEPs) were obtained from 25 chronic alcoholic patients. The patients had been drinking heavily for an average of 15 years and a minimum of 5 years. All patients were totally abstinent for a minimum of 3 weeks. The morphology of waves were often altered. All presented prolonged I-III, III-V, inter-peak latencies (IPLs) and a loss of amplitude of wave V. The I-III, III-V and I-VIPLs were increased between 30 and 40 years, and III-V and I-VIPLs between 40 and 50 years. The incidence of abnormal BAEPs in patients with alcoholic epilepsy was not different from that of patients without a history of alcoholic seizures. Patients with clinical manifestations of alcoholic polyneuropathy had the highest incidence of abnormal BAEPs. BAEPs are more reliable in chronic alcoholic patients than EEG. The mechanisms of the increase in neural transmission time within the auditory brain-stem are discussed.

Adult↗
PubMed1984

[Pituitary adenoma secreting somatotropic hormone. Gigantism and peripheral neuropathy. A case].

Gigantism, an extremely rare condition, develops before puberty or in subjects in whom puberty is not yet completed. Hypersecretion of somatotropic hormone results in a tremendous surge in growth (our patient was 2.36 m tall). Among other clinical symptoms disabling peripheral neuropathy predominates and changes in nerve conduction velocity are not merely due to the increase in height. The increase in growth hormone concentrations combined with hypogonadotrophic hypogonadism with normal prolactinaemia is associated with peculiar cutaneous symptoms and with low levels of sex hormone-binding protein.

Adenoma↗
PubMed1983

[Infant encephalopathies with rapid EEG rhythms. Apropos of 2 cases].

The authors report two cases of infant encephalopathies with psychomotor retardation. The cerebrospinal fluid, the electroretinogram, the electromyogram and the motor conduction velocity are normal. The neuromuscular cutaneous conjunctival biopsies are normal. No biochemical abnormalities are found. The electroencephalogram presents continuous high voltage fast rhythms (250-400 microV) with reduced or absent evoked responses. Early infantile neuroaxonal dystrophy and lissencephaly are suggested.

Axons↗
PubMed1982

[Influence of glycemic control on peripheral nerve conduction in insulin-dependent diabetic subjects (author's transl)].

In order to better evaluate the influence of glycemic control on diabetic neuropathy, 73 diabetic patients were considered: 42 males and 31 females who had been treated with insulin during 9 years. Twenty-one subjects were examined during 2-12 months. Motor nerve conduction velocity (MCV) was measured on the external sciatic popliteus (ESP). The H reflex parameters from soleus were: latency time for H response (HL), the ratio between the maximum amplitude of the H reflex response and the M motor response: (formula: see text) was determined by a chromatographic method. The reduction of MCV, the rise in HL and the decrease of E in diabetics are more pronounced according to the duration of the disease and are significantly correlated with the rate of HbA1c (respectively MCV: r = -0.39, P less than 0.001; HL: r = 0.42, P less than 0.001; E: r = -0.37, P less than 0.01). There is a slight correlation between HbA1c level and the duration of diabetes. For the 21 diabetics observed during many months there is a very significant correlation between the slope of the evolution curves of HbA2c, MCV and HL.

Adolescent↗
PubMed1982

[Prognostic value of the trigemino-facial reflex in severe post-traumatic comas].

The blink reflex (BR) study has been carried out on 40 severe head injury cases (average age 24.3 years). The recording was conducted several times between the 2nd and the 12th day and was repeated during the first month and beyond in prolonged comas. 23 patients did not respond even to high intensity stimuli. 17 patients displayed delayed and low amplitude latency responses: one of the components, early R1 or late R2 could be missing. The existence of a detectable focalized hemispheric lesion had no effect on the disappearance of the delayed lateral response. No BR was observed in mesencephalic, protubering comas and in 4 cases of subcortical and diencephalic comas. BR was observed in subcortical or diencephalic comas and in 5 cases of mesencephalic comas. The evolution of patients who did not display any electrical response during the first recording was unfavourable in 15 cases. Among the 5/8 remaining comatose cases, the BR was missing on the 2nd day and back on the 7th day. Among the 17 patients who displayed BR their evolution proved to be very favourable or favourable in 13 cases. In all the patients who survived beyond a month the response latencies proved normal, yet their amplitude was considerably lowered. The lack of BR is temporary but it is an element of unfavourable prognosis if it persists beyond a span of 8 days.

Adolescent↗
PubMed1980

[Contribution of motor nerve conduction velocity and Hoffmann reflex in early detection of neuropathy in diabetics. Results and correlations with duration and other long-term complications in 117 patients (author's transl)].

Motor nerve conduction velocity and H. reflex parameters were studied in 85 insulin-treated diabetics classified in groups I to VI, according to the duration of the disease, in 32 maturity-onset diabetics (groupe V) and in 92 healthy control subjects. Each diabetic subject was examined prior to testing for clinical evidence of neuropathy and also had funduscopic examination, fluorescein angiography and an estimation of renal status by serum creatinine measurement and proteinuria. Electrical parameters were significantly different in all groups of diabetics from results in the control group. Neuropathy, as judged by these electrical studies, was frequently present in the absence of clinical expression, worsened with the duration of the disease in groups I to IV and preceeded other degenerative changes of diabetes. H. reflex parameters are an earlier index of neuropathy than motor nerve conduction velocity and may be used as a monitor of diabetic neuropathy.

Adult↗
PubMed1978

[Experimental lymphocytic choriomeningitis of the mouse. Pathologic, virologic and electric correlations (author's transl)].

The brain electrographic activity of mouse experimental LCM has been systematically compared with the pathology and the virus growth in brain. There is an excellent correlation between anatomic lesions and brain electrographic activity which begins in slow waves followed with electric discharges attendant upon clinical paroxysms. The different records have been described and a physiopathological interpretation of these electroclinical paroxysms is proposed.

Animals↗
PubMed1977

[Electrical activity of the brain of the eel (Anguilla anguilla L.) subjected to hypoxia and hypercapnia].

The effects of hypoxia and hypercapnia on the electric activity of cerebral vesicles have been studied in 48 unrestrained eels placed in water in a soundproof location. 1. Hypoxia (PwO2 less than 5 torr) was well endured for 8 hours after which sharp bursts appeared, rapidly followed by cerebral death. 2. Hypercapnia (PwCO2 congruent to 14 torr) gave an amplitude decrease in cerebral activity beginning with the first hour, and after 8 hours there was an appearance of slow waves which progressively invaded the recording while the latency of average VER increased. 3. The large resistance of eels to hypoxia, is discussed in relation to the importance of anaerobic glycolysis in fish. The effects of hypercapnia on cerebral electric activity in eels are comparable to those observed in mammals and may be due to metabolic and electrolytic modification in CRL and in nervous cells.

Animals↗
PubMed1976

[Electroencephalographic activity of a fish (Anguilla anguilla L.) exposed to various hyperbaric conditions (author's transl)].

1. As a continuation of previous work where our methods were fully described (Barthelemy et al., J. Physiol., Paris, 1975, 70, 173-183), the present paper consists of research on EEG activity modifications in the eel (Anguilla anguilla L.) submitted to different hyperbaric conditions (fig. 1). 2. In contrast with mammals, the fish makes it possible to isolate the specific effects of per se pressure: those were researched to a maximum pressure of 101 ATA. Slow and sharp-pointed theta waves appear on EEG tracings of the telencephale, and especially of the tectum opticum (fig. 3), at pressures reaching or beyond 21 ATA, and then they dissappear gradually at higher pressures (101 ATA). The comparison between these effects of per se pressure on the EEG of the fish and the modifications of the EEG of mammals under hyperbaric conditions drives the authors to assume that per se pressure plays a part in the determinism of High Pressure Nervous Syndrome as described for mammals. 3. When submitted to a 21 ATA pressure (below the threshold of per se pressure effects), but when the water and his organism are satured with the N2-O2 mixture (99-1%), the fish shows no EEG modifications to be attributed to inert gas and similar to the EEG symptoms of inert gas narcosis described for mammals when exposed to the same inert gas partial pressures (fig. 5).

Animals↗