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Biomedical subjects

C Y Genton

Publications and source records attributed to C Y Genton.

At least 37 records · Page 2Linked to original sources
PubMed1999

Selective distribution of calretinin in adenocarcinomas of the human colon and adjacent tissues.

The expression of calretinin, a calcium-binding protein, has been studied in a series of 82 human colorectal adenocarcinomas. In 22.5% of the cases, part of the tumor cells were calretinin-positive, whereas the cells of the normal and paratumoral mucosa were always negative. Two types of cells from the tumoral mass reacted positively and selectively with calretinin-antisera: the tumor cells and giant fibroblasts. The neurons of enteric ganglia and reactive mesothelial cells also reacted positively to the same antibody. The results obtained by immunochemistry have been confirmed by Western blot analysis and in situ hybridization for calretinin mRNA. There is a correlation between the expression of calretinin and the degree of differentiation of the tumor. Well-differentiated tumors express calretinin in only 5% of the cases, whereas this percentage is 20% for moderately differentiated tumors and 66.6% for poorly differentiated or undifferentiated tumors. We conclude that calretinin is expressed by most undifferentiated colorectal adenocarcinomas, but only by a limited number of cells in well-differentiated tumors. The degree of its expression coincides also with additional signs of malignancy, such as an increase in the number of metastases in the regional lymph nodes and in other organs.

Adenocarcinoma↗
PubMed1998

Selective immunocytochemical localisation of calretinin in the human ovary.

Calretinin is a calcium-binding protein which is primarily expressed by certain cells of the nervous system, both central and peripheral. Its presence in nonexcitable cells has been little studied. Using a polyclonal antibody and paraffin sections we have analysed the presence of calretinin in the human ovary of different ages, and in polycystic ovaries. Our results revealed the selective presence of calretinin, specifically localised in the cells of the germinal epithelium, those of the theca interna and the theca lutein cells, in the cells of the neurovaso-epithelial association and of the canalicular structures of the mesovarium. Calretinin was also present in a few cells of the theca externa and some interstitial cells. No appreciable quantitative differences in the strength of the positive reaction were seen between the ovaries of different ages or between the normal and the polycystic ovaries. The presence of calretinin was confirmed by western blot analysis. The selective presence of calretinin in the human ovary, in androgenic cells and in the cells of the germinal epithelium is discussed in relation to its possible function as a Ca2+ buffer.

Adult↗
PubMed1998

Pathologic fracture of the femur neck as first manifestation of a minute columnar cell carcinoma of the thyroid gland.

This case report concerns a 64 year-old woman who presented a pathologic fracture of the femur neck. Histologic examination of the performed bone biopsy disclosed the presence of a carcinomatous metastasis with unusual microscopic features. The site of the primary tumor could be unequivocally determined as being the thyroid gland, as immunostaining of the tumor cells showed positivity with anti-thyroglobulin. The thyroidectomy specimen weighed 149 g, was nodular and partially calcified. Exhaustive microscopic examination finally revealed the presence of a minute columnar cell carcinoma, 0.6 cm in diameter, with obvious vascular invasion. This case illustrates well 1) the usefulness of immunostaining with anti-thyroglobulin in cases of bone metastasis with unusual microscopic features and unknown primary, as well as 2) the aggressiveness of this rare type of carcinoma of the thyroid.

Carcinoma, Papillary↗
PubMed1998

Transmyocardial laser revascularisation in acutely ischaemic myocardium.

OBJECTIVE: Although recent experience suggests that transmyocardial laser revascularisation (TMLR) relieves angina, its mechanism of action remains undefined. We examined its functional effects and analysed its morphological features in an animal model of acute ischaemia. METHODS: A total of 15 pigs were randomised to ligation of left marginal arteries (infarction group, n = 5), to TMLR of the left lateral wall using a holmium:yttrium-aluminium garnet (Ho:YAG) laser (laser group, n = 5), and to both (laser-infarction group, n = 5). All the animals were sacrificed 1 month after the procedure. Haemodynamics and echocardiography with segmental wall motion score were carried out at both time intervals (scale 0-3: 0, normal; 1, hypokinesia; 2, akinesia; 3, dyskinesia). Histology of the involved area was analysed. RESULTS: Laser group showed no change of the segmental wall motion score of the involved area 30 min after the laser channels were made (score: 0 +/- 0). Infarction and laser infarction groups both showed a persistent and definitive increase of the segmental wall motion score (at 30 min: 1.6 +/- 0.3 and 2 +/- 0, respectively; at 1 month: 1.8 +/- 0.2 and 1.8 +/- 0.4, respectively). These increases were all statistically significant in comparison with baseline values (P < 0.5), however comparison between infarction and laser-infarction groups showed no significant difference. On macroscopic examination of the endocardial surface, no channel was opened. On histology, there were signs of neovascularisation around the channels in the laser group, whereas in the laser-infarction group the channels were embedded in the infarction scar. CONCLUSIONS: In this acute pig model, TMLR did not provide improvement of contractility of the ischaemic myocardium. To the degree that the present study pertains to the clinical setting, the results suggest that mechanisms other than blood flow through the channels should be considered, such as a laser-induced triggering of neovascularisation or neural destruction.

Animals↗
PubMed1998

Localized fibrous tumours of the pleura: 15 new cases and review of the literature.

OBJECTIVE: To present a series of localized fibrous tumours of the pleura (LFTP), to define the clinical and histopathological diagnostic criteria of this tumour, and to determine the optimal treatment and follow-up. METHODS: Review of the charts of the patients with the diagnosis of LFTP (formerly called benign fibrous mesothelioma), as well as of all the histological sections, including immunohistochemical stains. Review of the literature with special emphasis on the clinical and histological criteria of malignancy. RESULTS: During the last 30 years, we found 15 patients with a complete clinical chart and histological material, particularly paraffin blocks of the tumour. The mean age was 57 years (range 27-79). Eight patients were asymptomatic, and the remaining seven presented with non-specific symptoms. All but one had complete resection of the tumour, including partial lung resection in two and partial chest wall resection in three. The diagnosis was confirmed by histological review in 15 cases. Immunohistochemical stainings showed positivity for vimentin in all cases, for CD 34 in 80%, but were consistently negative for cytokeratins. Nine tumours were histologically classified as malignant. Among them, five recurred, two of which were responsible for death. One benign tumour recurred after 1 year, and was treated successfully by repeat resection and radiotherapy. Overall, 13 patients (86%) were alive with no evidence of disease between 10 months and 27 years after the first resection. CONCLUSIONS: LFTP is a rare tumour which has a benign clinical course in over 80% of the cases, and is asymptomatic in half the patients. The diagnosis is difficult to establish before operation. Treatment consists of complete resection including adjacent structures if necessary. The clinical behaviour of LFTP cannot be predicted on the basis of histological aspects only. If histologically malignant tumours are more prone to recurrence and poor outcome, broad-based and locally invasive tumours bear a higher risk of recurrence. Long term follow-up is therefore mandatory in all cases in order to perform early re-resection when recurrence occurs.

Female↗
PubMed1997

Drawback of aortoplasty for aneurysm of the ascending aorta associated with aortic valve disease.

BACKGROUND: Aortoplasty has been advocated for moderate dilatation of the ascending aorta associated with aortic valve disease. We report our results with this conservative approach. METHODS: Seventeen consecutive patients with unsupported aortoplasty were reviewed. Twelve patients had aortic valve regurgitation and 5 had stenosis. The aortic wall was analyzed histologically in 14 patients. Follow-up was complete, with a mean time of 6 years (range, 2.3 to 10.5 years). RESULTS: Two patients among the 15 hospital survivors died during follow-up of causes unrelated to aortic pathology. Survival at 7 years was 86.7% (+/- 8.8%). Recurring aortic aneurysms developed in 4 patients after a mean time of 63 months, with an event-free survival at 7 years of 41% (+/- 21%). All of these 4 patients had aortic valve regurgitation and cystic medial necrosis. CONCLUSIONS: The recurrence rate of aneurysms after unsupported aortoplasty and aortic valve replacement is high in patients with aortic regurgitation. This strongly suggests that in these patients, the aortic dilatation is related to an underlying wall deficiency, associated with the aortic valve pathology, rather than to the hemodynamic stress imposed by the aortic valve disease.

Actuarial Analysis↗
PubMed1997

[Mucinous tumors of the ovary. Anatomo-clinical aspects, histological classification, prognostic factors and histogenesis].

In contrast with other malignant tumors, the prognosis of malignant ovarian mucinous tumors has not been improved. In fact, their are diagnosed late and their therapy is often inadequate. The absence of consensus concerning the histological criteria of borderline tumors and mucinous carcinomas has led to diverse classifications which are often not reproducible and are also responsible for heterogeneous results concerning patient survival. Unfortunately, none of the biochemical, molecular biology or cytometric markers which have been studied up until now can be used for differential diagnosis. Another particularity of mucinous tumors consists of their association with other ovarian tumors, mural nodules which are reactive or tumor proliferations and which might influence the prognosis of the mucinous tumor, when their are malignant, and peritoneal pseudomyxoma and appendicular mucocele which give rise to problems related to their relation.

Adenocarcinoma, Mucinous↗
PubMed1995

[Patient management following cardiac transplantation].

Prognosis of heart transplant patients has dramatically improved in the last decade thanks to the use of cyclosporine as immunosuppressive treatment. Optimal follow-up and early recognition of complications and side effects of treatment lead to longer survival and marked improvement of these patients' quality of life. However, the incidence of complications remains high and their management calls for particular care. We review our experience of heart transplantation in Lausanne and describe in detail the results and complications such as rejection, transplant coronary artery disease, hypertension, renal failure, metabolic disorders, cancer and conduction problems. Cooperation of the medical team (cardiologist, surgeon, anesthetist, general practitioner) is essential to long term success of the transplant program.

Arrhythmias, Cardiac↗
PubMed1995

[Polyarthralgia, fever and purpura in a patient known to have splenomegaly].

A 43-year-old patient was admitted for swollen and painful ankles, knees and elbows, palpable purpura of the lower extremities and fever. Splenomegaly had been diagnosed 5 years previously. At clinical workup, spleen and liver size were increased and purplish papular skin lesions were noted above the ankles. Erythrocyte sedimentation rate was 2 mm/h. ASAT and ALAT as well as rheumatoid factor were moderately elevated. Serology was positive for hepatitis C. Differential diagnosis of palpable purpura and complementary diagnostic procedures are discussed.

Adult↗
PubMed1995

[Comparative study of preliminary and definitive anatomo-pathological diagnoses in 375 autopsies in adults].

For the past 5 years the institute of pathology of the University of Lausanne has been delivering both provisional and final autopsy reports. The provisional reports are based mainly upon macroscopic findings, whereas the final reports include the information provided by supplementary investigations such as microscopy, histochemistry, more rarely electron microscopy, immunohistochemistry and/or microbiology. The reliability and usefulness of the provisional reports were analyzed by systematic comparison between the provisional and final reports of 375 adult post-mortems as well as through an inquiry among requesting physicians. No significant difference was found between the two reports in 77.1% of the cases. In 22.1% the supplementary investigations provided information which had a bearing on the final diagnosis and made it possible to complete or correct the macroscopic diagnosis. In 0.8% the significant difference was due to the omission, in the provisional report, of an obvious macroscopic diagnosis. Finally, 95% of the consulted physicians found the provisional reports useful because of the precise written and particularly rapid information they provided. These results not only demonstrated that the establishment of such provisional reports is fully justified, but further emphasize the fundamental and complementary role played by the final autopsy reports.

Autopsy↗
PubMed1994

[Infectious complications in cardiac transplantation: Lausanne experience].

Infectious complications, a major cause of morbidity and mortality after heart transplantation, were reviewed in 49 heart transplant patients at Lausanne. The follow-up lasted 32 months on average. 43 patients (88%) presented 108 infections (2.20 episodes of infection/patient). 38 severe infections (0.78 episodes/patient) were diagnosed in 27 patients (55%). 2 of the 9 deaths which occurred were due to infection. The viruses, principally of the herpes group, were responsible for 37% of all the infections, and bacteria for 28%. About a third of the viral and bacterial infections were severe. The other documented infections were caused by fungi (13%), which were most often responsible for superficial infections, and rarely by protozoa (5%). Finally, in 17% of infectious episodes, the pathogen could not be identified. Cytomegalovirus was the pathogen the most frequently responsible in severe infections. The highest incidence of infections occurred during the first 2-3 months after transplantation and was reduced considerably after the 6th month. The distribution of different pathogens was related to specific periods after the transplant. Our results confirm that infection is a major complication of heart transplantation. Clinical and prophylactic aspects of some infections are reviewed.

Cytomegalovirus Infections↗
PubMed1994

Long-term nitric oxide synthase inhibition and distensibility of carotid artery in intact rats.

The goal of the present study was to evaluate the effect of long-term nitric oxide synthase inhibition by NG-nitro-L-arginine-methyl ester (L-NAME) on the morphology and viscoelastic properties of the carotid arteries in rats. Twelve-week-old Wistar-Kyoto rats were treated for 6 weeks with either the nitric oxide synthase inhibitor L-NAME (0.4 g/L in drinking water; L-NAME rats, n = 13) or tap water (control rats, n = 13). Age-matched spontaneously hypertensive rats (SHR, n = 14) received tap water for the same period. The internal diameter of the common carotid artery was measured continuously with an echo-tracking device with the rats under anesthesia with halothane. Intra-arterial pressure was monitored on the contralateral side. L-NAME rats exhibited arterial pressures similar to those of SHR. The distensibility pressure-curve determined in L-NAME rats was a direct continuation of that obtained in control rats. In contrast the distensibility in SHR was increased (P < .01, SHR versus L-NAME rats). Carotid artery cross-sectional area and left ventricular weight index were increased similarly in SHR and L-NAME rats compared with control rats. Thus the hypertension caused by long-term nitric oxide synthesis inhibition was not associated with the increased arterial distensibility observed in SHR despite similar blood pressure elevations, similar arterial hypertrophy, and consequently similar wall stress. This suggests a role for nitric oxide in regulating the mechanical behavior of arteries exposed to high blood pressure.

Amino Acid Oxidoreductases↗
PubMed1993

Coronary artery rupture during transluminal coronary recanalization and angioplasty in a case of acute myocardial infarction and shock.

Percutaneous transluminal coronary angioplasty (PTCA) is a widely performed and effective therapy for coronary artery disease. Evolution of the dilatation instruments during the last decade has led to an increased success rate of PTCA and to the development of newer techniques such as recanalization of totally occluded coronary arteries. We report a case of coronary artery recanalization complicated by fatal coronary artery rupture.

Aged↗
PubMed1993

Elastic behaviour of the carotid artery in intact spontaneously hypertensive rats.

Intact spontaneously hypertensive rats (SHR) were studied to assess the effect of prolonged antihypertensive treatment on the elastic behaviour of the external carotid artery. Thirty-week-old SHR received the ACE inhibitor captopril, the arteriolar dilator hydralazine or their vehicle for 6 weeks. These rats were compared to normotensive, vehicle treated WKY rats. The internal diameter of the carotid artery was measured continuously in halothane-anaesthetized rats using an echo-tracking device, and intra-arterial pressure was also monitored continuously, on the contralateral side. Captopril- and hydralazine-treated SHR as well as normotensive controls had similar blood pressure values. No significant shift in the distensibility-pressure curves was observed among vehicle-treated SHR and WKY rats or the SHR which had received captopril or hydralazine. Histological examination of the carotid artery fixed ex vivo with paraformaldehyde showed a significant increase in cross-sectional area in vehicle-treated SHR as compared to their normotensive counterparts. These results therefore suggest that the elastic behaviour of elastic arteries is not necessarily altered by the structural changes developing in response to hypertension.

Animals↗
PubMed1993

Localization and production of plasminogen activator inhibitor-1 in human healthy and atherosclerotic arteries.

High plasma levels of plasminogen activator inhibitor type-1 (PAI-1), the principal inhibitor of the fibrinolytic system, have been associated with thrombotic and arterial disease. To study PAI-1 expression in healthy and atherosclerotic human arteries, a detailed analysis was made by light and electron microscopy immunocytochemistry and by in situ hybridization. In healthy arteries PAI-1 was found both at the level of endothelial cells and of smooth muscle cells (SMCs) of the arterial media. In early atherosclerotic lesions PAI-1 was also detected in intimal SMCs and in extracellular areas in association with vitronectin. Immunogold analysis by electron microscopy revealed PAI-1 in vesicular structures in endothelial cells and in SMCs with normal or foam cell characteristics. In advanced atheromatous plaques, PAI-1 mRNA expression in SMCs within the fibrous cap was increased compared with SMCs located in the adjacent media or in normal arterial tissue. PAI-1 mRNA was also detected in macrophages located at the periphery of the necrotic core. The increased synthesis of PAI-1 by cellular components of the atherosclerotic plaque and the extracellular accumulation of PAI-1 may contribute to the thrombotic complications associated with plaque rupture and possibly play a role in the accumulation of extracellular matrix deposits.

Arteries↗