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M C Machet

Publications and source records attributed to M C Machet.

At least 19 recordsLinked to original sources
PubMed2006

[Experimental study of the influence of the segmental transverse colic reversion on the intestinal transit time].

OBJECTIVE: to study the feasibility of the transverse segment colic reversion and to evaluate its impact on the intestinal transit time in the rat Wistar. METHOD: On a test group of the rats Wistar males anaesthetized, we isolated a segment from the transverse colon vascularized by a feeder pedicle. This segment colic was reversed and anastomosed into antiperistaltic out of termino-terminal on its site with polyglactine 6/0. Into post-operative, we studied, the weight, the volume of the ingestats, the intestinal transit time, the survival and the histological lesions of the reversed segment colic. On the group controls, we carried out the anastomosis of a segment of the transverse colon isolated and anastomosed into isoperisaltic. RESULTS: Thirty rats males of 231.5 +/- 8.3g had been operated, 15 for the test group and 15 for the control group. The average weight of the ingestats of the rats of the test group was of 21.87 +/- 3g and of 21.75 +/- 4.8g in the control group without significant difference. The intestinal transit occured at 3 +/- 1 post-operatives days in the test group and at 2 postoperative days in the control group. A mechanical obstruction of the bowels before the 15th post-operative day involved a mortality of 87% in the test group. Thirteen percent of the rats of the test group survived, with a regular catch of weight. The histological analysis showed inflammatory lesions on the proximal portion of the reversed segment and a normal wall without ischaemic injury on its distal portion. No death was observed in the group controls. CONCLUSION: The antiperistaltic anastomosis of a transverse segment colic within the colic in the rat Wistar, causes a stop of the intestinal transit time by mechanical occlusion without ischaemic lesion of the segment colic reversed.

Anastomosis, Surgical↗
PubMed2005

[Is procalcitonin able to help in pediatric appendicitis diagnosis?].

BACKGROUND: Appendicitis clinical diagnosis in children is difficult and the acute inflammatory markers hyperleucocytis and CRP do not contribute to it. OBJECTIVE: To study the predictive value of procalcitonin (PCT) and to assess variations of its serum level according to inflammatory lesions in paediatric appendicitis. PATIENTS AND METHOD: Among 101 children aged two and 15, hospitalized for painful abdominal syndromes, 70 underwent operation for acute appendicitis and appendiceal peritonitis, 31 had no operation. PCT was evaluated in all children, normal serum concentration was <0,5 microg/L. Every appendicectomy part has been examined through histological analysis to confirm the diagnosis and the histological lesions have been classified into three categories according to their severity. RESULTS: Out of 70 appendix analysed at histology, 68 (97%) were healthy and 2 (3%)were unhealthy. Among the 68 cases of healthy appendix, 19 had a PCT higher than 0,5 microg/L and among 33 cases of unhealthy appendix 4 had a PCT higher than 0,5 microg/L. The PCT mean of healthy children was not significantly different from unhealthy appendix population, appendicitis prevalence was 0,67, PCT sensitivity 28%: IC 95% [18-40], specificity 88%: IC 95% [72-97], positive predictive value 83%: IC 95% [61-95], and negative predictive value 37%: IC 95% [26-49]. PCT mean increases with the severity of inflammatory lesions of the appendix (P=0,0051). CONCLUSION: PCT has not a good predictive value in acute paediatric appendicitis but remains a good indicator of severity in paediatric appendicitis.

Abdominal Pain↗
PubMed2005

Supratentorial primitive neuroectodermal tumours of the brain: multidirectional differentiation does not influence prognosis. A clinicopathological report of 18 patients.

AIMS: To examine the clinical and pathological characteristics of supratentorial primitive neuroectodermal tumours (PNETs) in a retrospective series of 18 patients, according to the strict definition of the World Health Organization classification of tumours that excludes other types of malignant embryonal tumours of the brain. METHODS AND RESULTS: Eleven children and seven adults with supratentorial PNETs were diagnosed between 1993 and 2002 and their medical records were reviewed. An immunohistochemical study was performed on formalin-fixed paraffin-embedded tissue of 18 primary tumours and five recurrences with antibodies for neuronal (neuron specific enolase, synaptophysin, neurofilament, chromogranin A), epithelial [epithelial membrane antigen (EMA), cytokeratin], glial [glial fibrillary acidic protein (GFAP)], muscle (desmin, h-caldesmon, alpha-smooth muscle actin, myogenin) differentiation and with two anti-CD99 antibodies. All tumours showed at least one neuronal marker except chromogranin A; a variable number of cells were GFAP+ or EMA+ in 18/23 tumours. Six primary tumours and one recurrence were positive for cytokeratin and/or one muscle antigen except myogenin. CD99 was observed in 33% of the cases. The mean duration of overall survival was 20 months. The estimated overall survival rates were 61% at 1 year, 29% at 2 years, and 18% at 3 years. Two factors of poor prognosis were identified by univariate analysis: a positive cerebrospinal fluid cytology at diagnosis and the absence of complete resection. No distinct immunophenotype was statistically related to survival. CONCLUSIONS: A multidirectional differentiation is a frequent event in supratentorial PNETs but has no apparent influence on the outcome of this aggressive neoplasm.

12E7 Antigen↗
PubMed2005

[Evaluation after 20 years of a case of Takayasu's disease that presented with aortic regurgitation].

Takayasu's disease is a segmental multifocal affection of medium and large arteries. The diagnosis is based on the association of stenotic and aneurismal lesions of the aorta and its branches secondary to an inflammatory infiltration of the media and adventitia. Cases of aortic regurgitation associated with aneurismal dilatation of the ascending aorta as the presenting features of Takayasu's disease, as in this case, are rare. Histological examination of the aortic wall may help establish the diagnosis by showing signs of aortitis. The other usual arterial lesions are sometimes missing at the initial phase of the disease. A late histological diagnosis may be difficult as the inflammatory lesions tend to be progressively replaced by fibrotic lesions or a banal atheroma.

Aortic Valve↗
PubMed2003

[Conduction defects as the presenting feature of sarcoidosis or observed during the course of the disease: regression with corticoid steroid therapy].

Cardiac sarcoidosis is often unrecognised because of the absence of specific clinical and electrical signs. The consequences are serious, the main risk being sudden death due to conduction defects (24 to 31% of cases) or ventricular arrhythmias. Any conduction defect without an obvious cause in a young patient should suggest a possible diagnosis of sarcoidosis. The confirmation is histological when giant cell non-caseuting epithelioid granuloma is demonstrated but myocardial biopsies are only positive in 20% of cases. Therefore, biopsy of accessible organs such as salivary glands is recommended. Diagnostic strategy consists in searching for signs of systemic sarcoidosis, and, when the diagnosis has been established, perform a complete work-up with echocardiography, dipyridamole myocardial scintigraphy, cardiac MRI and 24 hour ambulatory ECG recordings (Holter). The only proven treatment is steroid therapy with occasional spectacular observations of reversibility of arrhythmias or conduction defects.

Adrenal Cortex Hormones↗
PubMed2001

In vitro study of low-frequency ultrasound-enhanced transdermal transport of fentanyl and caffeine across human and hairless rat skin.

The effect of low-frequency sonophoresis on fentanyl and caffeine permeation through human and hairless rat skin was studied in vitro. Experiments were performed using 20 kHz ultrasound applied at either continuous or discontinuous mode and with an average intensity of 2.5 W/cm(2). The results showed that low-frequency ultrasound enhanced the transdermal transport of both fentanyl and caffeine across human and hairless rat skin. This was explained by both increasing flux during sonication and shortening the lag time. Discontinuous mode was found to be more effective in increasing transdermal penetration of fentanyl while transdermal transport of caffeine was enhanced by both continuous and pulsed mode. Histological and electron microscopy studies showed that human and hairless rat skin was unaffected by ultrasound exposure. Further studies will be necessary to determine the relative contribution of ultrasound parameters in low-frequency ultrasound-induced percutaneous enhancement of drug transport.

Administration, Cutaneous↗
PubMed2001

Clinical, histologic, and electron microscopy study of skin exposed to low-frequency ultrasound.

The use of low-frequency ultrasound has been proposed to enhance the transdermal transport of various drugs, a technique referred to as sonophoresis. The aim of the present study was to determine the safety of low-frequency sonophoresis on human and rat skin by evaluating their structural modifications after ultrasound exposure. Human skin samples and hairless rats were exposed to 20 kHz ultrasound in vitro and in vivo, respectively. Ultrasound was used with average intensities ranging from 0.25 to 7 W/cm(2) in pulsed or continuous mode. Hairless rats were also exposed to a heat source mimicking the temperature versus time profile during sonication. Skin samples were observed under optical and electron microscopy to detect any structural changes. Human skin samples exposed to intensities lower than 2.5 W/cm(2) showed no modification. For hairless rats, slight and transient erythema was observed after 2.5 W/cm(2) exposure, whereas deep lesions (dermal and muscle necrosis) were observed 24 hr later. These lesions were also observed when a plastic film was placed between the coupling medium and the animals' skin during sonication. In contrast, no histologic lesion could be seen when a heat source was applied to animal skin. Low-frequency ultrasound induces delayed and deep lesions in hairless rat skin at 2.5 W/cm(2) which are not only attributable to the increase in temperature at the skin surface during ultrasound exposure. By using the same ultrasound conditions, human skin seems to be less sensitive in vitro.

Animals↗
PubMed2001

[Paraneoplastic pemphigus: a pustular form during chronic lymphoid leukemia].

BACKGROUND: Paraneoplastic pemphigus is an autoimmune disease of the skin and mucosa described in 1990. The condition is generally associated with lymphoma or chronic lymphoid leukemia. Lesions are often misleading, masquerading as polymorphous erythema or lichen. We report a case of paraneoplastic pemphigus with pustulous skin lesions. CASE REPORT: A 52-year-old man developed over a few weeks time erosive lesions of the oral cavity and lips associated with papulous skin lesions. Secondarily, large-sized pustules, sometimes a hypopion, were observed associated with bullae. The diagnosis of paraneoplastic pemphigus was confirmed by direct immunofluorescence that evidenced IgG deposits within the keratinocytes and along the basal membrane and by indirect immunofluorescence on rat bladder that evidenced circulating antibodies. This paraneoplastic pemphigus was the inaugural sign of chronic lymphoid leukemia. DISCUSSION: Skin lesions described in paraneoplastic pemphigus include: erosion, vesicles, bullae, and psoriasiform, lichen-like, plate-like or vegetative formations. To our knowledge, this is the first report of a pustulous form; clinically similar to Hallopeau pustulous pemphigus.

Anti-Inflammatory Agents↗
PubMed2000

Analysis of the distribution of histologic myocardial lesions during acute cardiac rejection. Experimental study in rodents.

BACKGROUND AND METHOD: Asymmetric distribution of histologic lesions have been reported in grafted hearts that could hamper the interpretation of right ventricular endomyocardial biopsy. Heterotopic heart transplantations were performed in rats (n=59) and guinea pigs (n=20). Grafted hearts were examined by a pathologist who established the degree of cardiac rejection in the four cardiac cavities. RESULTS: Forty cardiac rejections were diagnosed in rats and ten in guinea pigs. An asymmetric distribution of histologic lesions was observed in 34 (68%) rejected hearts with greater lesions in the auricular myocardium than in the ventricular myocardium (n=25, 50%). One (n=18) or two degrees (n=7) differentiated the severity of rejection between atria and ventricles. Cardiac rejection score was significantly greater in atria than in ventricles (3.12+/-0.18 vs. 2.6+/-0.2 (P<0.01) in rats and 2.35+/-0.37 vs. 1.6+/-0.47 (P<0.001) in guinea pigs. There were histologic lesions of rejection in the auricular myocardium in seven cases, although the ventricular myocardium was completely normal. In nine (18 %) other grafted hearts the degree of rejection was equal in the auricular myocardium and ventricular septum but was greater than the degree of rejection noted in the right and left ventricular free walls. CONCLUSION: The distribution of histologic lesions of acute cardiac rejection in rodents was heterogeneous in grafted hearts which exhibited greater lesions in the atria than in ventricles. This should be taken into consideration in the evaluation of new methods of detection of cardiac rejection and in the diagnosis of acute cardiac rejection in humans.

Animals↗
PubMed2000

Inherited palmoplantar keratoderma and sensorineural deafness associated with A7445G point mutation in the mitochondrial genome.

We report a French pedigree with members having an inherited combination of non-epidermolytic palmoplantar keratoderma (NEPPK) and sensorineural deafness. The penetrance of both features was incomplete. Additional ectodermal defects were absent. The expression of numerous epidermal proteins (keratins, fillagrin, cornified envelope proteins, intercellular junction proteins including connexin 26, and loricrin) defined with immunolabelling was normal in the proband. The combination was shown to be associated with the A7445G point mutation in the mitochondrial genome (mtDNA). This mutation is responsible for a subtype of NEPPK which is so far the only mtDNA mutation-associated keratoderma.

Adolescent↗
PubMed2000

Development of an ex vivo model of pig kidney perfused with human lymphocytes. Analysis of xenogeneic cellular reactions.

BACKGROUND: Because of the explosive nature and the extremely rapid process of hyperacute rejection (HAR), significant infiltration of the xenograft by immunocompetent cells is not observed, and the role and the mechanism of action of cell-mediated rejection in discordant xenografts are therefore still under discussion. METHOD: We developed an experimental approach using pig kidneys perfused with human peripheral blood lymphocytes (PBL) in which the immunologic barrier of hyperacute rejection was excluded and which mimics the in vivo situation. RESULTS: PBL retention in the kidney was evaluated at 20-minute intervals for 3 hours. Retention increased from 30% to 80% with the time of perfusion and was specific because significantly fewer syngeneic lymphocytes were retained. Phenotype analysis of recovered PBL showed a significant decrease in natural killer (NK) cells. Immunohistochemical studies revealed the presence of NK cells and T lymphocytes in the glomerular and interstitial tubular structures of the kidney. Functional studies showed a progressive cessation of diuresis and augmentation of renal vascular resistance when the kidney was perfused with PBL. Electron microscopy examinations of kidney sections perfused with PBL showed swollen endothelial zones, suggesting alterations to and damage of the endothelium. CONCLUSIONS: This system provides a valuable model for the study of early discordant xenogeneic cellular rejection and demonstrates the predominance of xenograft infiltration by NK cells.

Animals↗
PubMed1999

Bone involvement in a case of Kaposi sarcoma.

BACKGROUND: Extracutaneous involvement is rare in the classical form of Kaposi sarcoma (KS). OBSERVATION: We report a case of bone involvement revealed by bone pain. Magnetic resonance (MR) images demonstrated the local invasion of bone from cutaneous lesions. Bone biopsy confirmed bone involvement. The patient was treated with vindesine. Bone pain progressively disappeared. CONCLUSION: Bone involvement has rarely been reported in classical KS though 4.5% of the patients were affected when it was systematically sought. Treatment of symptomatic lesions requires radiotherapy or chemotherapy.

Aged↗