Exponential stabilization of neural networks with various activation functions and mixed time-varying delays.

This paper presents some results on the global exponential stabilization for neural networks with various activation functions and time-varying continuously distributed delays. Based on augmented time-varying Lyapunov-Krasovskii functionals, new delay-dependent conditions for the global exponential stabilization are obtained in terms of linear matrix inequalities. A numerical example is given to illustrate the feasibility of our results.

Surface healing and histologic maturation of patent polytetrafluoroethylene grafts implanted in patients for up to 60 months.

Histologic, transmission, and scanning electron microscopic observations were made of 26 biopsy specimens from patent polytetrafluoroethylene grafts that had been implanted as arterial bypasses for up to 60 months. The results showed the rarity of host connective tissue ingrowth, the absence of neovascularization, and the limited neointimal proliferation. The defect of staining for factor VIII-related antigen by immunohistochemistry confirmed the absence of true endothelial cells at a distance from the anastomoses. Under electron microscopy the thin neointimal layer consisted mainly of fibrin, platelets, blood cells, and cellular debris. Even in prostheses implanted for the longest periods, mature collagen and elastin were not found. Tubular microfibrils (9- to 12-nm thick) could be observed. The source of such microfibrils, probably glycoproteins, remains under investigation.

[Fibromyolipoma of the uterus. Apropos of a case with a review of the medical literature]. / Fibromyolipome du corps utérin. A propos d'une observation avec revue de la littérature médicale.

A case of uterine fibromyolipoma in a 75 year old woman suffering from an uterine prolapse is reported. The clinical course, the macroscopic and microscopic characteristics are presented and compared with those in the medical literature. The possible histogenesis is discussed. Our case seems to results from metamorphosis of uterine smooth muscle cells in a leiomyoma.

[Detection of endometrial stromal sarcoma using endometrial cytology. Apropos of a case]. / Dépistage du sarcome du chorion cytogène par la cytologie endométriale. A propos d'une observation.

The authors report a case of endometrial stromal sarcoma which was detected by endometrial cytology. The tumour originates either in the stroma of the endometrium or in foci of myometrial adenomyosis. It occurs most frequently in patients who are more than 60 years of age. It appears as an intra-uterine polypoid mass and causes bleeding and pelvic pain. Its incidence is difficult to establish. Endometrial cytology is highly suggestive of stromal sarcoma when smears harbour numerous atypical sarcomatous cells mixed with regular endometrial cells. Biopsies of the endometrium show decidua-like arrangements of malignant cells. Stromal sarcoma constitutes the homologous form of mesenchymal tumours of the uterus. The prognosis depends on whether local recurrences occur and on the sites of metastases in which the sarcomatous component seems to be latent with lesions that resemble adenocarcinomata . The five years salvage rate is approximately 26 to 28%. Treatment is surgical with or without irradiation.

Early histological changes in acute necrotizing hemorrhagic pancreatitis. A retrospective pathological study of 20 total pancreatectomy specimens.

Settled lesions of acute necrotizing hemorrhagic pancreatitis have been commonly reported. Early alterations remained unknown. In a retrospective pathological study of 20 total pancreatectomy specimens, early changes have been evidenced in "grossly unmodified" areas of pancreas: acinar cells homogenization, ductal dilatation with epithelial degeneration, diffuse interstitial edema and fibroblastic reaction, necrotic angeitis . These alterations were identical to the changes described in experimental studies.

[Unusual cytologic aspects of cervico-vaginal trichomoniasis. Study of cervico-vaginal smears stained by the Papanicolaou's method]. / Aspects cytologiques particuliers de la trichomonase cervico-vaginale. Etude sur les frottis cervico-vaginaux colorés par la méthode de Papanicolaou.

Trichomonas vaginalis has been recognized by cytologists in Papanicolaou-stained smears of cervical and vaginal secretions for some years. The highest percentage of positive Trichomonas vaginalis detection was obtained with this technique. Classical cytologic aspects of Trichomonas vaginalis infection on Papanicolaou-stained smears have been commonly reported: cytoplasmic alterations with amphophilia, eosinophilia, perinuclear halo, vacuolisation; nuclear abnormalities with pycnosis, dysplasia-like atypia. These cytologic changes represented the indirect cytologic signs of Trichomonas vaginalis infection. But for some authors, they might constitute a possible relationship between the incidence of Trichomonas vaginalis infection and epithelial cell atypia or carcinoma.

[Clear cell ductal adenocarcinoma or epithelio-myoepithelial carcinoma of the salivary glands. Apropos of 2 cases with review of the literature]. / Adénocarcinome canalaire à cellules claires ou carcinome épithélio-myoépithélial des glandes salivaires. A propos de deux observations avec revue de la littérature.

The authors reported two cases of epithelial myoepithelial carcinoma or clear cell adenocarcinoma of salivary intercalated duct with medical literature review. This rare tumor discovered in adults and old patients is frequently localized in parotid gland. Histologically it is composed of two types of cells: epithelial cylindrical cells bordering ductal lumen, clear myoepithelial cells rich in glycogen. This tumor is particular for its local recurrencies but is capable of metastasizing. Its prognosis is uncertain and its treatment is not yet codified.

Immunohistochemistry of renin in human diseased kidney.

The distribution of renin in human kidney was investigated by immunofluorescence and the peroxidase-antiperoxidase (PAP) procedure at the light and ultrastructural level. In three cases of juxtaglomerular renin-secreting tumors, renin was localized within the cytoplasm of tumor cells. In kidney biopsies, a semi-quantitative assessment was carried out, taking into account the size and the number of immunostained juxtaglomerular apparatuses. In 12 cases of ischemic kidneys and 8 cases of segmental renal hypoplasia, the increase in immunostaining for renin was striking in altered areas, while spared areas remained negative. In 2 cases of Bartter's syndrome, the pattern was similar to that found in ischemic kidneys. The study was extended to a series of 133 needle kidney biopsies from patients with various glomerular and vascular diseases; the immunomorphological parameters were correlated with serum creatinine levels but not with blood pressure values. Post-embedding immunoelectronmicroscopy using the PAP procedure performed on two of the cases of renin-secreting tumors, showed renin in all types of secretory granules.

Immunohistochemical characterization of renin-containing cells in the human juxtaglomerular apparatus during embryonal and fetal development.

Thirty kidneys from nine embryos, 20 fetuses, and one full-term baby were examined for their renin content by immunofluorescence and the peroxidase antiperoxidase method, using an antihuman renin antiserum. Renin-containing cells were found in the early metanephros (5-week-old fetuses). Most of them were located in the wall of well-developed renal arteries in the vicinity of the prospective vascular pole of the glomeruli. In the poorly differentiated peripheral renal cortex, intracellular fluorescence was seen in nearby arterioles of pocket-like s-shaped tubules. Rarely, labeled cells were found in the wall of major branches of renal arteries. In all locations, the renin-containing cells appear to be clearly linked to the development of the renal vascular system.

Renin localization in segmental renal hypoplasia. Immunohistochemical demonstration in two cases.

The distribution of renin in two cases of segmental renal hypoplasia was investigated by immunofluorescence and the peroxidase anti-peroxidase (PAP) method using an anti-human renin antiserum. Renin-containing cells were found only in hypoplasic segments in the vicinity of altered glomeruli and small arteries. Well-preserved renal cortex and areas of chronic atrophic pyelonephritis failed to show any demonstrable site of renin production. Whatever is the mechanism of the disease, the characterization of large numbers of renin-containing cells in the affected kidney support a role for the renin-angiotensin system stimulation in this form of hypertension.

Use of a specific antiserum for renin detection in human kidney.

The use of anti-human renin antibodies made possible the intrarenal localization of renin in human kidney by immunofluorescence. In normal kidney, only some juxtaglomerular apparatus (JGA) were fluorescent. In these JGA, granular or diffuse fluorescence was only seen in afferent arterioles and was not present in all cells. In the ischemic areas of partially infarcted kidney, fluorescence was seen in all JGA and in interlobular arteries. In these arteries the most eccentric cells were often the most positive. In the nonischemic areas of the same kidneys, fluorescence was not seen in JGA, but was observed in proximal tubular cells, suggesting the reabsorption of filtered renin at this site.

Primary myenteric plexus alterations as a cause of megacolon in Von Recklinghausen's disease.

This is a case report of a megacolon in a 26 years old male patient having typical von Recklinghausen's disease. Exploratory laparotomy shows no neurofibroma on digestive tract. Myenteric plexus study of colic resection specimen following B. Smith technique reveals marked alterations. These alterations are both quantitative (hyperhypoganglionosis) and qualitative (ganglion cells are irregular in shape and size, dendritic processes are hypertrophic, irregular; schwannosis; no inflammatory infiltration). The patient suffers no more transit disorders after adequate resection of this megacolon.