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Biomedical subjects

G Chomette

Publications and source records attributed to G Chomette.

At least 253 records · Page 14Linked to original sources
PubMed1981

[Tendinous hyperlipoproteinaemic xanthomatosis associated with supravalvular aortic xanthomatosis (author's transl)].

A 56-year-old woman with familial heterozygous type II hyperlipoproteinaemia and tendinous xanthomas, presented the unusual findings of acquired supravalvular aortic stenosis associated with a congenital stenosis of the orifice. Analysis of clinical, paraclinical, and particularly pathological data confirmed the existence of several associated lesions: congenital hypoplasia of the aortic ring and proximal aorta, calcified valve stenosis probably increased by the dyslipidaemia, and finally and principally, supravalvular stenosis formed of a veritable circular rim of atheromatous material, making up a second haemodynamic obstacle. It is probable that the pre-existing congenital aortic lesions in this case, apart from the hyperlipoproteinaemia, account for the observation, not previously reported in a heterozygous type II hyperlipoproteinaemia, of massive supravalvular atheromatous deposits. This latter of acquired lesion is described in 9 cases reported in the literature with a homozygous form of familial hypercholesterolaemic xanthomatosis, the atheromatous deposits in the proximal aorta appearing earlier in these patients, and in the absence of pre-existing anatomical anomalies.

Aorta↗
PubMed1981

[Odontogenic induction and ameloblastoma. Histoenzymological and ultrastructural studies (author's transl)].

The ameloblastoma is usually thought to be devoid of any odontogenic capacity. However, the histological, ultrastructural and histoenzymological study of 5 cases demonstrates the fairly high level of differentiation of some ameloblastic cells in such neoplasms. Furthermore, it suggests very early stage of epithelio-conjunctive interaction. The tumours consist, in addition to stellate, squamous, clear and dark epithelial cells, of densely packed peripheral columnar cells similar to the differentiated ameloblasts of the inner epithelium of enamel organ (median nucleus, well-developed rough-surfaced endoplasmic reticulum, mitochondria and lysosomal-vacuolar system located in the distal end of the cells). Besides, the cytoplasmic membrane shows some pocket-like apical invaginations similar to early Tomes processes. On the other hand, similarly to physiological odontogenesis, an abundant amount of granulo-filamentous material is found along the lateral cellular membranes, and the basement membrane. This substance, sometimes, is intermingled with vertical collagenous fibers. In some areas, it is disrupted and cytoplasmic invaginations of epithelial cells, passing through these gaps, are connected with neighbouring mesenchymatous cells. In other respects, despite the lack of any odontoblastic differentiation, the high level of alkaline phosphatase activity found in these cells by means of histo and cytoenzymological technics, looks like that of odontogenic mesenchymal cells. These findings seem to demonstrate the histogenetic unicity of odontogenic tumours. These neoplasms, like the embryonary dental organ, are provided with two types of cells (epithelial and stromal cells). Thus, they are able to induce odontogenesis. But, in ameloblastoma, this power of induction is restricted to a very early stage of odontogenesis.

Ameloblastoma↗
PubMed1980

[Thyroid metastases from renal tumours: 3 cases (author's transl)].

Metastatic tumours from clear cell renal cancer were found in 3 out of 4 000 thyroidectomy specimens. These tumours appeared on scintigrams as low density nodules, one to three in number, and were accompanied in one case by signs of hyperthyroidism. They were treated by partial excision 4, 5 and 7 years after nephrectomy. One patient relapsed, was re-operated upon 2 years later and is still alive after one year. The other two patients showed no sign of relapse after 2 and 4 years respectively. When the renal history is unknown it is difficult histologically to differentiate these tumours from clear cell epitheliomas of the thyroid gland.

Adenocarcinoma↗
PubMed1980

[Metastatic pulmonary emboli: clinical types and incidence (author's transl)].

Pathological examinations during autopsy of 1457 cases of cancer demonstrated the presence of metastatic pulmonary emboli in 10 p. cent (148 cases). The were divided, as a function of their site and histological type of the primary neoplasm, as follows: hepatoma 33 p. cent, chorioepithelioma 25 p. cent, endocrine glands 19 p. cent, biliary tract 17.6 p. cent, hypernephroma 15.6 p. cent, sarcoma 13 p. cent, and various other tumors such as cancer of the pancreas, and breast. Two anatomical types of these emboli can be distinguished: one mixed type associated with a pulmonary cancerous lymphangitis (90 cases), and observed at a later stage in the disease. This may be latent or cause a subacute cor pulmonale. The other type is not associated with lymphangitis (58 cases), results from hematogenic cancers (hepatoma, hypernephroma, etc...), is often seen at an early stage, and causes sudden death. Histological examination enabled the consequences of any infarct developing as a result of the emboli to be demonstrated, and the origin of the emboli from neoplasmatic thromboses in the primary cancer drainage routes or from metastases in the liver to be determined.

Breast Neoplasms↗
PubMed1980

[Histogenesis of lobular cancer of the breast. Histoenzymatic and ultrastructural study of a muciparous cell invasive epithelioma].

A comparative light microscopy, histoenzymological and ultrastructural study enabled the authors, in a case of invasive lobular carcinoma of the breast, to emphasise certain special morphological traits of this tumour type and to make a contribution to the understanding of its histogenesis. By light microscopy, the only special features of the case were the abundance of mucus secreting tumour cells in the perilobular infiltrating zones and in the stromal texture with marked perigalactophoric hyalinosis and active elastic neogenesis. From an ultrastructural standpoint, intralobular malignant zones contained epithelial type cells, rich in microfilaments and with numerous desmosomal junctions. Two other cell types were identified at the periphery of the lobules. On consisted of round cells with intracytoplasmic cavities filled with mucus (signet ring cells). This group, in common with the intralobular cells, contained abundant amounts of alkaline phosphatase. The other consisted of elongated "pseudo-fibroblastic" cells, rich in microfibrils and in granular ergastoplasm with secretion at points of contact of collagen and elastin. These cells showed marked ATPase activity. They no doubt represented "hybrid" cells, intermediate in terms of their morphology and enzyme activity between myoepithelial and epithelial cells. These findings would thus appear to offer arguments in favour of the double cell origin -- duct and myoepithelial -- of lobular carcinoma.

Adenocarcinoma, Mucinous↗
PubMed1980

[Relapsing polychondritis. Histochemical, histoenzymological, immunofluorescent and ultrastructural studies of ear cartilage in three cases (author's transl)].

Ear cartilage has been studied by histochemistry, histoenzymology, immunofluorescence and electron microscopy in three cases of relapsing polychondritis. The most significant lesions have been observed at the cellular level, both by enzymology and electron microscopy: chondrocytes of peripheral zones seem to be first hypertrophic and then necrotic; at the opposite, their is no correlation between histochemical and electron microscopic studies about the chondroid intercellular substance whom lesions are probably secondary to the cellular ones. A few chondrocytes are positive with antiimmunoglobulins sera (IgM and IgA); this fact could be a proof of the dysimmune nature of this disease.

Ear Cartilage↗
PubMed1980

[Diabetic glomerulosclerosis in the DBM mouse. Correlated study of quantitative morphology, immunofluorescence and electronic microscopy].

Using an experimental model of genetic diabetes (DBM mouse) a comparison was made of the results of quantitative data obtained by light and electron microscopy (measurement of glomerular and mesangial surface areas, assessment of the thickness of the basal membrane and its irregularities) and was used to demonstrate the actual presence of glomerulosclerosis in the renal parenchyma of 31 diabetic animals. In addition, immunofluorescent investigations in these same animals demonstrated the presence of serum proteins (in particular immunoglobulins and albumin) in the glomerulus and the tubular basal membrane. These substances transude through the vessels as a result of increased vascular permeability. In this area, membrane abnormalities are not a consequence of hyperglycaemia. In the group, one batch of animals in which hyperglycaemia was partially reduced by glycoregulatory therapy showed the same glomerular changes. Amongst other factors, the possible role of hyperinsulinaemia constantly present in these animals, regardless of their blood glucose level, is worthy of considération.

Animals↗
PubMed1980

[Non-bacterial thrombotic endocarditis. Autopsy study, clinico-pathological correlations (author's transl)].

During the course of 6 000 autopsies, the number of cases of non-bacterial thrombotic endocarditis discovered was 130 (absolute frequency of 2.1 p. cent). Frequency was highest among patients with cancer, of which there were many in this series (4 p. cent of 2 287 autopsies). In 83 p. cent of cases, therefore, the endocarditis was of paraneoplasic origin, usually associated with adenocarcinomas, especially those of bronchopulmonary, pancreatic or gastric origin. Less frequently, they developed during the course of shock or debilitating affections. The endocarditis lesion consists of a coagulated fibrin and platelet mass without microbial germs, located electively on the mitral and aortal valves. Emboli are a frequent consequence (47 p. cent of cases) affecting primarily the central nervous system, the kidneys, spleen, and hart. Ischemic effects of these latter, observed in 75 p. cent of cases, are generally latent. In some cases they produce clinical manifestations, and they may be the cause of death from a cerebral or myocardial infarct. Pathological examination demonstrates the frequent association of these endocarditis lesions with often multiple vascular thromboses, and disseminated intravascular coagulation affecting the same regions as the emboli. This emphasizes the major role of coagulation disorders in their genesis.

Disseminated Intravascular Coagulation↗
PubMed1980

[Osteogenesis imperfecta and aortic incompetence. One case with pathological findings. Review of the literature (author's transl)].

Cardiovascular manifestations of Lobstein's disease are rare, probably unrecognized, and determining factors for the final prognosis, the most frequent lesion being aortic incompetence. The eleventh case to be reported with pathological findings in the literature is described. This complication is usually found in men, blood regurgitation being large in amount, symptomatic, and progressive. Its mechanism is related less to dilatation of the aorta and its ring than to valvular changes, they being frequently bicuspid and dysplasic. Histological findings, not however pathognomonic, are myxoid degeneration in the valves and parietal cystic necrosis in the aortic wall. Apart from the absence of an aneurysm and aortic dissection, macro- and microscopic lesions are similar to those observed in Marfan's syndrome and osteogenesis imperfecta. Operative therapy was employed in all eleven cases, with three postoperative deaths and three later deaths. Certain complications arise from uncontrollable severe hemorrhage, which justifies the use of valve heterografts not requiring antivitamin K administration.

Adolescent↗
PubMed1980

[Histogenesis of giant cell tumors of bone. comparative, ultrastructural and histo-enzymologic study of osteoforming tumors and malignant and giant cell tumors].

Comparative ultrastructural and histoenzymological study of 10 osteogenic (4 osteosarcomas), osteolytic (3 benign giant cell tumours, 2 malignant osteoclastomas) and fibrosarcomatous osseous tumours of the jaw emphasised the analogies between osteoblasts and fibroblastic stromal cells of giant cell tumours. These two cell types, with their abundant granular ergastoplasm, secrete a collagen interstitial fibrillary substance which is capable of secondary calcification. Their enzyme activities, with regard to oxidative mechanisms and protein synthesis are identical. Osteogenic activity as assessed by ATPase and alkaline phosphatase, more marked than in osteosarcomas, is also found in the stroma of benign giant cell tumours. With regard to the plasmodes characteristic of giant cell tumours, they are certainly original from both a morphological and enzymological standpoint : richness in mitochondria and lysosomes, intensity of oxidative reactions (B.O.H.B.D. +++). Nevertheless, the morphological appearances seen would be more in favour of their stromal origin than in their arising from monocytes-macrophages coming from the blood.

Bone Neoplasms↗
PubMed1980

[White sponge nevus-type familial leucodysplasia of the oral cavity. Electron microscopic study of a case].

In a case of white sponge naevus type congenital buccal keratosis, electron microscopic study revealed severe disturbances in filamentogenesis which was insufficient (pale cells) or on the contrary excessive and anarchic (dark cells) and, to a lesser degree, corneal maturation. This was accompanied by slight abnormalities of the cellular junctions, rarely described in such a condition up to the present time. With regard to the delayed epithelial exfoliation typical of this condition, the manner and causes of its development are discussed in the light of ultrastructural findings.

Adolescent↗
PubMed1979

[Cytoenzymological, immunological and scanning electron microscopic studies on 49 cases (author's transl)].

Light cytology, enzymology, immunofluorescence and scanning electron microscopy have been performed on 49 bronchoalveolar fluids recovered by bronchoscopic lavage. The patients had the following lung diseases: infectious pneumonitis (19 cases), pulmonary fibrosis (13 cases) including 5 sarcoïdosis, 3 idiopathic pulmonary fibrosis and 5 silicosis, hypersensitivity pneumonitis (5 cases) and miscellaneous lung tumors (12 cases). Cytologic studies in comparison with clinical aspects show 4 groups: Group I (chronic bronchopneumopathy and inactive fibrosis) presents numerous cells but few lymphocytes (less than 5%); in Group II (evolutive fibrosis) have an increase percentage of lymphocytes (20%); in Group III (hypersensitivity pneumonitis) is observed a very high percentage of lymphocytes (45%); and in Group IV (cancerous lung diseases) values are not far from normal percentage except for lymphomas. Small macrophages (diameter: 10 microns) with a central monocytoïde nucleus and few cytoplasma, are abundant in groups II and III where lymphocytosis is higher. Scanning electron microscopy shows irregular and rough surface, and numerous spontaneous adherences with erythrocytes, lymphocytes, or bacterias. Enzymatic activity (acid hydrolase, esterase, oxydase) increases in these cells. Lymphocytes have a smooth surface ovocative of T origin which is confirmed by granular acid phosphatase positivity and rosette forming test. Immunofluorescence shows positive granules with IgG, C1Q and C3 in macrophages only for Groups II and III while free immunoglobulins were present in the recovered lavage fluid.

Bronchi↗
PubMed1979

[Conduction disorders after aortic valve replacement. Apropos of 200 cases].

The following points become apparent after the study of 200 cases of aortic valve replacement:--Conduction defects are very common after this type of surgery, affecting one in three patients in this series;--Above all, the frequency of conduction defects of the left bundle branch (2/3 cases) must be underlined. They are much more common than complete atrioventricular block, bifascicular block or isolated right bundle branch block;--Diagnosed immediately after operation in almost all cases, regression is common (50%) especially of left anterior hemiblock;--The long term prognosis is good. There was no long or short term mortality due to this cause in this series;--Apart from traumatic lesions which are difficult to avoid when the aortic orifice is calcified, ischaemia of the conduction pathways due to insufficient myocardial protection probably plays a role in the aetiology of these conduction defects.

Aortic Valve↗