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Biomedical subjects

L Leger

Publications and source records attributed to L Leger.

At least 73 records · Page 4Linked to original sources
PubMed1978

Serotonin nerve terminals in the locus coeruleus of adult rat: a radioautographic study.

Serotonin (5-HT) nerve terminals in the locus coeruleus (LC) of adult rat were visualized by high-resolution radioautography, in order to examine their distribution, fine structural features and intimate relationships with norepinephrine neurons. In animals pretreated with a monoamine oxidase inhibitor, prolonged intraventricular perfusion of 10(-4) M [3H]5-HT resulted in a specific identification of most if not all 5-HT axonal varicosities in LC. These terminals were equally distributed between the dorsal and ventral divisions of the nucleus. Their density was approximated at 10(7) per cu.mm within the middle third of the LC. In electron microscope radioautographs, the labeled 5-HT varicosities averaged 0.9 micron in diameter. They all exhibited a distinctive storage organelle, in the form of microvesicles and microcanaliculi (15-25 nm in diameter) partly filled with electron-dense material and usually aggregated in association with several large dense-core vesicles. While this finding of intrinsic morphological characteristics appeared compatible with a special cellular origin or regional differentiation, it was also suggestive of particular functional properties and/or mode of action. In a sample comprised of some 500 sectional profiles from labeled 5-HT varicosities in LC, a small proportion only (less than 10%) exhibited morphologically defined synaptic junctions. These rare contacts were invariably made with dendritic processes and never observed on the noradrenergic perikarya. It is therefore concluded that, in the LC, non-synaptic as well as synaptic mechanisms might be involved in the modulation and transneuronal regulation of norepinephrine neurons by 5-HT afferents.

Animals↗
PubMed1978

[Cystic pneumatosis of the small intestine following jejuno-ileal by-pass for obesity (author's transl)].

The case reported is that of a young woman who underwent a termino-terminal jejno-ileal by-pass procedure for obesity which was refactory to usual forms of treatment. Eight months later, a cholecystectomy was carried out for lithiasis, presenting with abdominal pain. At the time of operation, lesions of cystic pneumatosis were discovered on the excluded length of small bowel. This complication frequently manifests itself in the form of pseudosurgical abdominal pain, or as diarrhoea. More rarly, it is a radiological finding. The pathogenesis remains a subject of discussion. The mechanical theory would seem the most logical, since colonic intraluminal pressure is higher than that in the intestine excluded from the circuit. Bacterial proliferation, classical in blind loops, would be a farourising factor.

Adult↗
PubMed1978

[Acute pancreatitis. Superficial capsular necrosis and parenchymatous involvement. 115 cases, 11 resections (author's transl)].

The authors report 115 cases of acute pancreatitis who were either operated on or autopsied and emphasise the severity of the glandular parenchymatous involvement which remains, furthermore, difficult to recognise during manual exploration. Necrosis is sometimes limited to the peripheral interstitial tissue and spares the gland itself (the prognosis is then less serious) and has led many surgeons to resections which did not always seem justified a posteriori. The authors refer to pancreatic decapsulation, described by rumanian authors, and suggest a method of operative diagnosis of the extent of glandular necrosis.

Humans↗
PubMed1977

[A study of pancreatic insulinomas by electron microscopy. 9 cases (author's transl)].

Nine hypoglycaemia-inducing pancreatic tumours were studied by electron microscopy. In 8 of these tumours, it was possible to identify, within the cell cytoplasm, secretory granules with a "paracrystalline" content, identical in appearance to the granules of the B cell of the normal human pancreas. Thus electron microscopy would appear to be a reliable and sensitive method for the morphological identification of these endocrine tumours of the pancreas.

Adenoma, Islet Cell↗
PubMed1977

[Necrosis in acute pancreatitis. Surgical and anatomopathological comparisons. 7 cases].

The surgeon should take pains to section and study himself the operative specimen after excision for acute pancreatitis, in order to understand the true nature of the lesions, which the most attentive and competent pathological examination cannot describe as vividly as direct examination by the operator. Often he will be surprised to find that the lesions, predominant in the capsule, are less profound and less severe than he had thought at first sight. Findings of this sort, if they were to be confirmed, would put into doubt the principle itself of routine pancreatectomy for acute pancreatitis.

Acute Disease↗
PubMed1977

[Continuous and interrupted intestinal sutures. Experimental and clinical study (author's transl)].

The authors report a clinical study of 101 cases of continuous digestive suture and an experiment comparing intestinal healing after continuous and interrupted sutures. A certain discrepancy exists between the excellent clinical results and the pathological and microscopic findings with continuous sutures, and in particular the presence of pseudo-diverticular pouches in 20% of cases developing at the expense of a mucosal evagination within the suture. If carefully performed, continuous suture seems excellent, preventing by its watertightness, the onset of early fistula.

Animals↗