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Biomedical subjects

D Dumont

Publications and source records attributed to D Dumont.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Anatomic and histologic study of the valves of the internal jugular veins].

In 200 dissections of internal jugular veins, the valves were investigated with regard to their constitution, their macroscopic and their microscopic anatomy. In 88% of the cases, an ostial valve was found. The cusp of each consists of two parts in 77%, of only one part in 16%, and in 7% of three parts. In 12% these valves are not found. The structure, the configuration, the topography of these valves are explained. The stroma of the valve consists of collagen and elastic fibrils. The surface of the luminal and parietal part is covered by endothelial cells with elastic and muscular fibers close to the attachment of the cusp to the vein wall.

Collagen↗
PubMed1987

Ventilatory dysfunction in palatal myoclonus.

A patient with palatal myoclonus and involvement of respiratory muscles is described. Partial characterization of the mechanism of ventilatory dysfunction was achieved using noninvasive tests. Ventilatory dysfunction in this disorder can be manifested in different patterns depending on which respiratory muscles are involved predominantly.

Electromyography↗
PubMed1986

A note on the anastomoses between the hypoglossal nerve and the cervical plexus.

A series of 80 dissections was performed to define the anastomoses between the cervical plexus and the hypoglossal nerve (XII), the superior anastomosis between the trunk of XII and the ansa of the atlas from the cervical plexus; the ansa cervicalis, traditionally known as the ansa of the XIIth cranial nerve or hypoglossal ansa, formed by the direct junctional anastomosis of the descending branch of XII and the internal descending branch of the cervical plexus. The origins, form, branches and chief relations are defined in in the present study.

Cervical Plexus↗
PubMed1985

In vitro and in vivo activation of L-serine deaminase in Escherichia coli K-12.

Escherichia coli L-serine deaminase (L-SD) in crude extracts made in glycylglycine could be activated by incubation with iron sulfate and dithiothreitol. This activation could also be demonstrated in vitro in two mutants which were physiologically deficient in L-SD activity in vivo. This suggests that these mutants were deficient not in L-SD but in an enzyme(s) activating L-SD. The suggestion is made that production of a functional L-SD in vivo requires activation of the structural gene product by an enzyme or enzymes that reduce the protein to an active form.

Buffers↗
PubMed1984

[Osteoradionecrosis in adults].

Osteoradionecrosis (ORN) is not exceptional, despite advances in irradiation techniques. Six cases are reported, involving the pelvis, coxofemoral joint, mandible and vertebrae; in this last case, the semiologic value of the lucent intrasomatic image seen on plain films and tomographies of the vertebrae is underscored. The irradiation dose (above 3 000 rad) is the chief factor in osteoradionecrosis, which may be precipitated by adjuvant factors and potentiating events such as trauma and infection. Pathologic study shows several lesions whose association is suggestive: cell lesions, osteoporosis, vascular lesions, and foci of necrosis. The pathogenic significance of lesions of bone cells is demonstrated, while the part played by vascular lesions is controversial. Involvement of the pelvis and hips following irradiation of pelvic carcinoma is the most common. The scapular girdle and ribs may be involved in irradiation for breast cancer. In involvement of the mandible, remarkable features are its frequency following irradiation of carcinoma of the mouth, the significant part played by potentiating factors, i.e. infection and trauma, severity of complications, i.e. fistulae and hemorrhage, and lastly difficulties of management. Among infrequent sites, involvement of the vertebrae is of interest as it may mimic collapse due to osteoporosis or metastasis. Diagnosis rests on an association of criteria, and fortunately bone biopsy is usually unnecessary. The clinical features, topographical characteristics and course of the disease allow differentiation from bone metastasis; it may be more difficult to distinguish postirradiation sarcoma, which is exceptional, or a number of benign conditions, such as aseptic necrosis, infectious osteoarthritis, and destructive coxarthrosis.

Aged↗
PubMed1984

[Yellow-nail syndrome. Review of the literature apropos of 2 cases associated with cancer].

Two cases of "yellow-nail syndrome" are reported: in the first, nail changes began eight months after the diagnosis of a breast cancer; in the second, yellow dystrophic nails were associated with hypertrophic osteoarthropathy due to pleuro-pulmonary metastatic lesions. Clinical features are described: characteristic nail changes, lymphoedema, pleural effusions, and, often bronchopulmonary infections and sinusitis. Various combinations are seen, and the time between the development of the different manifestations may vary from several months to many years. Among associated diseases, immunological changes and malignancy are emphasized. The pathogenesis remains obscure. Accurate part taken by lymphoedema, immunological changes, is unknown, and the relationships between "yellow-nail syndrome" and malignancy are still uncertain.

Aged↗
PubMed1983

Multiple factors involved in the control of ACTH and alpha-MSH secretion.

Alpha 1-adrenergic agents are potent stimulators of ACTH secretion directly at the pituitary level as observed using anterior pituitary cells in primary culture and by in vivo studies. On the other hand, beta-adrenergic as well as antidopaminergic agents are also potent stimulators of ACTH secretion but at a suprapituitary level, since no effect of these compounds are observed in vitro. CRF administration has been found to lead to rapid and parallel increases in ACTH and alpha-MSH concentrations in rat plasma and the mechanism of action of CRF has been studied in vitro using rat anterior and intermediate lobe of pituitary gland for ACTH and alpha-MSH secretion, respectively. In both cases, CRF stimulates adenylate cyclase activity at ED50 values of 70 and 350 nM for ACTH and alpha-MSH, respectively. CRF stimulates adenylate cyclase activity at least partly through a guanyl nucleotide-dependent mechanism. Using rat pars intermedia cells in culture, we have demonstrated the presence, in addition of a CRF receptor, of a beta 2-adrenergic receptor which stimulates cyclic AMP accumulation and alpha-MSH secretion and of a dopaminergic receptor which inhibits cellular activity. These results have been confirmed in in vivo studies where isoproterenol and thioproperazine (a dopamine antagonist) lead to a rapid increase of alpha-MSH secretion.

Adrenocorticotropic Hormone↗