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Biomedical subjects

D Morin

Publications and source records attributed to D Morin.

At least 181 records · Page 10Linked to original sources
PubMed1982

[Heart metastasis, possibilities of surgical treatment? Apropos of 2 cases].

The pathological aspects of cardiac metastases are nowadays well known, but, whatever the treatment proposed, their clinical evolution is usually disappointing. Two cases of cardiac metastases are reported, one from carcinoma of the uterine cervix and one from a costal chondrosarcoma. Both patients died soon after surgical excision of heart metastases. It seems that whatever the treatment elected (chemotherapy, radiotherapy, or cardiac surgery), the patient with a cardiac metastasis dies on the average within the year of the diagnosis. This poor prognosis makes it important to select the appropriate mode of therapy, probably with a rather restrictive approach to the use of heart surgery in this situation.

Adult↗
PubMed1982

[Evaluation of aortic dissection by transverse computerized tomography (CT scan)].

Twenty patients with dissection of the thoracic aorta were studied by CT-scanning. In 9 patients the diagnosis was previously documented by aortography, while in the other 11 patients the diagnosis of aortic dissection was first established by CT-scanning. The latter demonstrated the characteristic signs of aortic dissection and particularly the following features: a) the false channel (95%) and the intimal flap (90%), b) the displacement of aortic wall calcifications (60%), especially when the false channel is partially thrombosed (80%). In 19 patients, a bolus injection of contrast medium was performed. In the majority of cases opacification of the false channel occurred only partially, with some delay and with a non-homogeneous pattern. Six out of the 20 patients underwent one or more follow-up examinations performed between 15 days and 2 years later. CT-scanning clearly demonstrated the late persistence of a patent false channel and particularly the delayed thrombosis, even after surgical treatment of aortic dissection. CT-scanning appears to be a reliable non-invasive method for - establishing the diagnosis of aortic dissection, - delineating the extent of dissection, - follow-up of evolution after surgical or medical therapy.

Aged↗
PubMed1982

Effect of excessive vitamin A intake on muscle protein turnover in the rat.

3-Methylhistidine excretion in vivo and in vitro was monitored in hypervitaminotic and pair-fed control rats. Feeding with excess of retinyl palmitate (40 000 i.u./day per 100 g body wt.) significantly increased urinary 3-methylhistidine and creatinine output during a 4-day treatment interval. 3-Methylhistidine release from perfused rat hindquarters was also elevated after 5 days of vitamin treatment. To determine whether the adrenals were involved in mediating the above response, a study was conducted on adrenalectomized and sham-operated rats. Excessive vitamin A intake stimulated 3-methylhistidine excretion in vivo and in vitro in both adrenalectomized and sham-operated animals, thus suggesting that the vitamin A-induced acceleration in myofibrillar protein breakdown was not mediated by the adrenals. In both groups of rats, vitamin A treatment had no effect on the rate of protein synthesis, on the basis of incorporation in vitro of [3H]phenylalanine into muscle protein. Additional studies revealed that the addition of excess retinol to the perfusion medium (10 i.u./ml) had no significant effect on the rates of 3-methylhistidine release or [3H]phenylalanine incorporation in vitro. Finally, high doses of cortisol (7 mg/day per 100g body wt.) administered to intact rats for 5 days significantly increased rates of 3-methylhistidine excretion, both in vivo and in vitro.

Adrenalectomy↗
PubMed1982

[Reintervention for recurrent angina pectoris after aortocoronary bypass].

In this department between 1969 and 1980, 1116 angina patients underwent aorto-coronary venous bypass operation for revascularization of the myocardium. Thirty-four (3%) of these patients later underwent reoperation for anginal recurrence. Recurrence of angina was due principally to obstruction of an aorto-coronary venous bypass graft (48.6%) and progression of atheromatous disease in non-grafted coronary arteries. 9% of reoperated patients had a myocardial infarction postoperatively. Overall mortality was 6%. Quality of life must be considered excellent when it is observed that 87% of these patients enjoyed symptomatic improvement and as many as 63% were still asymptomatic following an average observation period of more than three years (38.7 months). On the basis of these encouraging results, all patients with recurrence of angina should undergo further coronary investigations with a view to reoperation.

Adult↗
PubMed1982

Iatrogenic myocardial infarction. A possible complication of mitral valve surgery related to anatomical variation of the circumflex coronary artery.

Following mitral valve replacement, a 43-year-old male presented electrocardiographic signs of myocardial ischemia-injury in the postero-inferior wall, and subsequently died. The post mortem examination revealed a subendocardial myocardial infarction in the postero-inferior wall. The myocardial infarction was related to the accidental ligation of the circumflex coronary artery by one of the sutures fixing the prosthetic valve. Technically, this surgical accident can be explained by the anomalous origin and course of the circumflex coronary artery found in this patient at the time of the post mortem examination. Anatomical variations of the coronary arteries and their surgical implications are discussed. This iatrogenic complication could have been avoided by performing a preoperative coronary angiography, which was not done in the reported case for medical reasons.

Adult↗
PubMed1981

Myofibrillar protein degradation in the chicken. 3-Methylhistidine release in vivo and in vitro in normal and genetically muscular-dystrophic chickens.

Myofibrillar protein degradation was measured in 4-week-old normal (line 412) and genetically muscular-dystrophic (line 413) New Hampshire chickens by monitoring the rates of 3-methylhistidine excretion in vivo and in vitro. A method of perfusing breast and wing muscles was developed and the rate of 3-methylhistidine release in vitro was measured between 30 and 90min of perfusion. During this perfusion period, 3-methylhistidine release from the muscle preparation was linear, indicating that changes in 3-methylhistidine concentration of the perfusate were the result of myofibrillar protein degradation. Furthermore, the viability of the perfused muscle was maintained during this interval. After 60min of perfusion, ATP, ADP and creatine phosphate concentrations in pectoral muscle were similar to muscle freeze-clamped in vivo. Rates of glucose uptake and lactate production were constant during the perfusion. In dystrophic-muscle preparations, the rate of 3-methylhistidine release in vitro (nmol/h per g of dried muscle) was elevated 2-fold when compared with that in normal muscle. From these data the fractional degradation rates of myofibrillar protein in normal and dystrophic pectoral muscle were calculated to be 12 and 24% respectively. Daily 3-methylhistidine excretion (nmol/day per g body wt.) in vivo was elevated 1.35-fold in dystrophic chickens. Additional studies revealed that the anti-dystrophic drugs diphenylhydantoin and methylsergide, which improve righting ability of dystrophic chickens, did not alter 3-methylhistidine release in vitro. This result implies that changes in myofibrillar protein turnover are not the primary lesion in avian muscular dystrophy. From tissue amino acid analysis, the myofibrillar 3-methylhistidine content per g dry weight of muscle was similar in normal and dystrophic pectoral muscle. More than 96% of the 3-methylhistidine present in pectoral muscle was associated with the myofibrillar fraction. Dystrophic myofibrillar protein contained significantly less 3-methylhistidine (nmol/g of myofibrillar protein) than protein from normal muscle. This observation supports the hypothesis that there may be a block in the biochemical maturation and development of dystrophic muscle after hatching. Free 3-methylhistidine (nmol/g wet wt.) was elevated in dystrophic muscle, whereas blood 3-methylhistidine concentrations were similar in both lines. In summary, the increased myofibrillar protein catabolism demonstrated in dystrophic pectoral muscle correlates with the increased lysosomal cathepsin activity in this tissue as reported by others.

Animals↗
PubMed1981

Development from primary to augmenting responses in the somatosensory system.

The development from primary to augmenting responses of somatosensory (SI) cortical area to low-frequency stimulation of the ventrobasal (VB) thalamus or white matter (WM) beneath SI in VB-lesioned preparations was studied by field potential analysis and extracellular unit recording. Compared to the major postsynaptic components of the primary field response, which reverse at 0.25--0.35 mm and whose sink extends from 0.6 to 1.8 mm, the augmenting potential reverses more superficially (0.1--0.15 mm) and its large depth-negativity is located in layers III and IV (0.4--1 mm). Augmentation is visible by the second shock of a 10/sec train; it grows from a late (15--20 msec) depth-negative wave in conjunction with the decrement of the early rapid components of the primary response. Out of 47 neurons that responded to the first shock in the 10/sec VB or WM train with early (less than 5 msec) discharges, 23 fulfilled stringent criteria for augmentation at the second shock: greater than 100% increased discharge probability and greater than 100% increased mean latency of response. The necessary condition for the generation of an augmented potential is a given temporal relation between the evoking stimulus and the declining phase of inhibition or the onset of rebound in the preceding response. The augmented potential cannot appear if the stimulus is delivered following the rebound of the preceding response. Not only this finding, but the similarity between the depth-profiles of the rebound and augmenting potential suggest that the same elements are responsible for both events. While the patterns of augmenting responses to WM stimulation in VB-lesioned preparations differ slightly from thalamically evoked augmenting waves, the intrinsic cortical organization is sufficient for the development of a primary potential into augmenting responses.

Animals↗
PubMed1981

Reticular influences on primary and augmenting responses in the somatosensory cortex.

The effects of brief, conditioning trains of high-frequency pulses to the midbrain reticular formation (RF) on primary and augmenting responses of somatosensory (SI) cortex were investigated. Testing stimulation was applied to the ventrobasal (VB) thalamus or to the white matter (WM) beneath SI in VB-lesioned animals. The RF-elicited EEG activation was associated with increased firing rates of SI neurons, enhanced probability of early synaptic discharges to VB or WM stimuli, and significantly reduced duration of the suppressed firing period following an afferent VB or WM volley. The diminished latency of the postinhibitory rebound under RF stimulation had the consequence that, within 10/sec shock-train, the second stimulus was delivered following completion of the rebound component and, instead of an augmented potential, generated a field response of primary-type. The dependence of the RF-induced change in augmenting potentials upon the sharpening effect exerted on the preceding inhibitory-rebound sequence was corroborated by analyzing the RF influence on neurons with different time-course of recovery from inhibition. The replacement of augmenting potentials by primary responses under RF stimulation is advanced as the mechanism behind the obliteration of spontaneously developing 'type I' spindle-waves during EEG arousal. The demonstration of RF influences on SI responses to WM stimulation in VB-lesioned animals points out the cortical level of the effects. The reticulo-thalamo-cortical pathways underlying these influences are discussed.

Animals↗
PubMed1980

[Current aspects of the treatment of deep venous thromboses by heparin (author's transl)].

The use of heparin by continuous infusion from a electric pump gives very good immediate results in the treatment of venous thromboses. In 58 patients, there was a constant improvement in clinical signs and recurrence of the venous thrombosis was exceptional (2%), pulmonary embolism rare (3.5%) and well tolerated. Constant flow and the surveillance of treatment led to the method ensuring stable blood heparin levels. Mid-term results (8 months) in 43 patients appeared to be less favourable, the prevalence of venous sequelae reaching 50% for iliac phlebitis, 28% for sural phlebitis. The respective advantages and disadvantages of heparin and fibrinolytic agents are discussed.

Adult↗
PubMed1978

[Surgical treatment of associated coronary disease and heart valve disease].

25 patients underwent combined surgery for coronary artery and valvular heart disease. Although patients suffering from associated coronary artery and valvular lesions represent a high operative risk group, the combined surgical procedure is clearly justified by the functional improvement of the patients. Selective coronaro-angiography should be carried out in the assessment of patients over 40 years of age with valvular disease, since not all patients present angina in spite of diseased coronary arteries. Three hospital deaths (13.5%) indicate the gravity of the procedure, but the absence of intra- or postoperative myocardial infarction and the comparatively rapid recovery of the patients with relatively few complications are very encouraging.

Adult↗
PubMed1978

[Bronchopulmonary hamartomas, chondromas, fibromas and myxomas].

The observation of 23 bronchopulmonary hamartomas, 9 chondromas, one fibroma and one myxoma has provided insight into the particularities of these tumors. The group of hamartomas, tumors of "erroneous mixture of tissue", included 20 cases which can be considered a malformation of the entodermal bronchial anlage, and 3 cases which can be regarded as a malformation of the mesenchymal anlage. The first type consists of multiple cleft-like spaces surrounded by ciliated and cuboidal epithelium. There are no alveolar cells. Cartilaginous, fibrous, myxomatous and lipomatous tissue and lymphocytes are also found. The second type consists mainly of undifferentiated mesenchymal cells with tubules, lined by cuboidal epithelial cells or an intestinal type of mucus-secreting epithelium. There may be some immature alveoli, but no ciliated epithelium is found. In contrast to the hamartomas, the chondromas are not derived from a dysontogenetic malformation of the bronchopulmonary tissue but are tumors which develop directly from the bronchial cartilage and are for this reason mainly localized in the endobronchial region. A special form seen in one case is association of pulmonary chondromas, gastric leiomyomas or leiosarcomas and extra-adrenal paraganglioma, though the latter is not always present.

Adult↗
PubMed1977

Possible persistent endocrine function of a rejected renal allograft.

The case is described of a patient on intermittent hemodialysis who had had a bilateral nephrectomy but had hypertension and a surprisingly mild degree of anemia. Repeated determinations showed high plasma renin activity and plasma erythropoietin activity within the detectable range. These results were thought to be related to a completely calcified renal allograft which had been inserted 8 years before and which had been rejected four years later, but left in situ. The patient had become anuric. It is suggested that chronically rejected renal allografts, even calcified, may maintain some endocrine activity in the absence of any excretory function.

Adult↗