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Biomedical subjects

S Bianchi

Publications and source records attributed to S Bianchi.

At least 271 records · Page 15Linked to original sources
PubMed1991

The effect of nitric oxide generators on ischemia reperfusion injury and histamine release in isolated perfused guinea-pig heart.

Experiments were carried out to provide evidence of the effect of L-arginine (L-Arg), its analogue NG-monomethyl-L-arginine (MeArg) and of some nitrovasodilators (sodium nitroprusside, NaNP; 3-morpholino-sydnonimine, SIN-1) which spontaneously release nitric oxide (NO) on ischemia-reperfusion injury, histamine release and mast cell degranulation, occurring after multiple ligature and release of the left anterior descending (LAD) coronary artery in isolated perfused guinea-pig hearts. The reopening of the LAD coronary artery leads to a release of histamine related to a decrease in microdensitometry of cardiac mast cells and to calcium overload. The perfusion of the heart with NO-donors significantly reduces either the release of histamine, the loss of mast cell metachromasia and the overload of calcium. These effects were potentiated by SOD. The results suggest that the endogenous formation of NO and molecules able to generate NO have a role in the prevention of post-ischemic tissue injury.

Animals↗
PubMed1991

Pelvic denervation for chronic pain associated with endometriosis: fact or fancy?

The efficacy of presacral neurectomy and amputation of the uterosacral ligaments in the treatment of chronic pelvic pain has been debated for decades. These procedures used to be done mainly in women with normal pelves, but more recently they have been performed during conservative surgery for treatment of endometriosis. In the 1980s the rapid spread of laparoscopic surgery has led to an increasing number of endoscopic denervations in patients with chronic pelvic pain associated with endometriosis. However, an analysis of literature data has failed to prove that presacral neurectomy and amputation of the uterosacral ligaments are effective and did not demonstrate better results with the use of lasers rather than electrocoagulation. Moreover, no valid comparison has yet been made between laparotomy and laparoscopic methods.

Chronic Disease↗
PubMed1991

Rabies virus infection in Aedes pseudoscutellaris cells: a study on receptorial structures.

Rabies virus is able to infect in vitro a wide range of homeothermic and poikilothermic cells but little is known about its multiplication in arthropod cells. In this research the infection of rabies virus in Aedes pseudoscutellaris cells, a mosquito cell line susceptible to mosquito-borne viruses, was studied. After 60 days of incubation at 26 degrees C up to 70% of infected cells showed the synthesis of both viral nucleocapsid and envelope antigens, although viral yield and cell damage could not be detected. Research performed in order to investigate the role of membrane carbohydrate moieties in rabies virus-mosquito cell interaction suggested the participation of galactose and N-acetylglucosamine whereas sialic acid, known to be a rabies binding site in many homeothermic cell lines, was not involved.

Aedes↗
PubMed1991

Secretory changes in preovulatory endometrium during controlled ovarian hyperstimulation with buserelin acetate and human gonadotropins.

Twenty-one patients with unexplained infertility underwent controlled ovarian hyperstimulation with buserelin acetate and human menopausal and chorionic gonadotropins, and follicular growth was monitored by ultrasonography and daily 17 beta-estradiol (E2) assays. Endometrial biopsy was performed when E2 levels were greater than or equal to 250 pg/mL per follicle and the follicular diameter was greater than or equal to 17 mm. As controls, we studied 20 preovulatory endometrial biopsies from patients with a male infertility factor. The biopsy material was examined at light, scanning, and transmission electron microscopes, and a morphometric analysis was performed. Preovulatory endometrial mucosa during controlled ovarian hyperstimulation showed accentuated proliferative aspects in both the glandular and stromal components and more frequent early secretory phenomena compared with the controls. The preovulatory progesterone (P) levels observed in our study seem to exclude the possibility that such early secretory aspects of the hyperstimulated endometrium are because of higher P concentrations in patients compared with controls.

Buserelin↗
PubMed1991

Prognostic significance of accessory cells and lymphocytes in nasopharyngeal carcinoma.

Forty-five consecutive biopsy specimens of nasopharyngeal carcinoma (NPC) and 10 biopsies of healthy nasopharyngeal mucosa obtained from non-cancer patients were investigated by immunohistochemical methods. Monoclonal (B2, T1) and policlonal antibodies (against S-100 protein and lysozyme) with reference to infiltrating lymphocytes and accessory cells (monocytic/macrophagic and dendritic cells) were used. Variable population densities of dendritic cells (S100+) were demonstrated in 22 out of the 45 cases (49%) of NPC; the distribution of these cells was typically within the cancer nests. Monocytic/macrophagic cells (Lys+) were found along the tumor margins and interspersed among the tumor cells in 14 out of 45 (31%) cases. No significant statistical correlation between density of accessory cells and histological type of NPC (classified according to Micheau criteria) was found. Cases with a moderate to marked density of dendritic and monocytic/macrophagic cells survived longer than those with a slight one (mean survival of 63%, 67% and 29%, 27% respectively). In NPC tissues T-lymphocyte infiltration was prevalent. In contrast, B cells were numerous and T cells rare in normal control tissues. The intensity of T-cell infiltration was significantly high in cases with a marked density of S-100+ cells, according to the ability of these cells to present antigens to sensitized T-cells. This study suggests a prognostic significance for reactive cells infiltrating NPC, which means longer survival for cases associated with marked infiltration density of accessory cells.

Adolescent↗
PubMed1991

Reproducibility of histologic classification of gastric cancer.

A panel review of histologic specimens was carried out as part of a multi-centre case-control study of gastric cancer (GC) and diet. Comparisons of diagnoses of 100 GCs by six pathologists revealed agreement in histologic classification for about 70-80% of the cancers. Concordance was somewhat higher when using the Lauren rather than the Ming or World Health Organization classification systems. Histologic types from reading biopsy tissue agreed with those derived from surgical specimens for 65-75% of the 100 tumours. Intra-observer agreement in histologic classification, assessed by repeat readings up to 3 years apart by one pathologist, was 95%. The findings indicate that, although overall concordance was good, it is important to standardise diagnoses in multi-centre epidemiologic studies of GC by histologic type.

Case-Control Studies↗
PubMed1991

Differential effects of M2 and M3 muscarinic antagonists on the sleep-wake cycle.

To study the role of muscarinic receptor subtypes in sleep control, methoctramine (25, 50, 75 micrograms), a highly selective M2 antagonist, was injected intra-cerebroventricularly into freely moving rats. Methoctramine induced a dose-dependent increase in desynchronized sleep (DS) latency (from 62.7 +/- 10 min following saline to 122.4 +/- 13.8 min with the lowest dose) and a 75% decrease in the amount of DS in 6 h recordings. 4DAMP (a M3/M1 selective antagonist) did not significantly change DS latency and percentage time, but it reduced wakefulness (from 38 +/- 2.8% following saline to 25.3 +/- 3.7% with a dose of 2.5), and increased slow wave sleep. The results suggest that M2 muscarinic receptors play a selective role in DS physiology.

Animals↗
PubMed1991

Conservative surgical treatment for severe endometriosis in infertile women: are we making progress?

Conservative surgery for severe endometriosis in infertile women is one of the most challenging situations for the pelvic surgeon. The second half of the 1980s saw an increase in the supporters of laparoscopic treatment even for more extensive disease. Two opposing factions were thus created: traditional gynecologic surgeons who accuse endoscopists of imprudence and technical inadequacy and enthusiastic supporters of operative laparoscopy who consider laparotomy obsolete and its associated morbidity needlessly high for the patient and health service. In the present review of the literature data we analyze laparotomy and laparoscopy techniques and compare the postoperative results in terms of reproductive success in an attempt to clarify whether conservative endoscopic treatment of severe endometriosis is only an inappropriate proposal with no future or whether, due to its efficacy, it will eventually limit interventions via laparotomy to exceptional circumstances.

Bias↗
PubMed1991

Long-term effects of enalapril and nicardipine on urinary albumin excretion in patients with chronic renal insufficiency: a 1-year follow-up.

The long-term effects of converting enzyme inhibitors and calcium channel blockers on proteinuria and the progression of renal disease in patients with hypertension and chronic renal insufficiency are not well established. We have studied the long-term effects of treating hypertension with an angiotensin-converting enzyme inhibitor, enalapril, and a calcium channel blocker, nicardipine, on urinary albumin excretion (UAE) and on renal function in 16 patients with hypertension and chronic renal insufficiency (creatinine clearance ranging between 17 and 62 ml/min). After 1 year of treatment, these agents caused a similar decrease in blood pressure. Only enalapril, however, caused a significant decrease in UAE (from 641 +/- 98 to 292 +/- 47 mg/24 h, p less than 0.01), whereas UAE did not change in the group treated with nicardipine (675 +/- 78 vs. 601 +/- 75 mg/24 h). Creatinine clearance at the beginning of the study was similar in the group treated with enalapril and in the group treated with nicardipine (35 +/- 3.6 vs. 40 +/- 4.1 ml/min). After 1 year of follow-up, creatinine clearance remained unchanged in both groups of patients. These studies demonstrate that both enalapril and nicardipine can effectively reduce blood pressure in patients with hypertension and chronic renal insufficiency. Enalapril but not nicardipine, however, appears to reduce urinary albumin excretion in these patients. Whether the reduction in UAE has any significant impact on the progression of renal disease remains to be established.

Albuminuria↗
PubMed1991

Effect of nitric oxide generators on ischemia-reperfusion injury and histamine release in isolated perfused guinea pig heart.

In an ischemia-reperfusion model obtained in isolated perfused guinea pig heart by means of a double ligature of the left anterior descending coronary artery, the reperfusion of the ischemic myocardium leads to a release of lactate dehydrogenase and histamine, related to a decrease in the microdensitometry of cardiac mast cells and to a tissue calcium overload. The perfusion of the heart with L-arginine and with nitric oxide donors significantly reduces the release of histamine, the loss of mast cell metachromasia and calcium overload. These effects were potentiated by superoxide dismutase.

Animals↗
PubMed1991

Correlations between histopathological and biological findings in nasopharyngeal carcinoma and its prognostic significance.

Forty-five consecutive cases of nasopharyngeal carcinoma were morphologically and immunocytochemically studied using monoclonal (anti-B and anti-T cell) and polyclonal (anti-S100 protein and antilysozyme) antibodies with the peroxidase-anti-peroxidase method to identify infiltrating lymphocytes (T and B cell) and histiocytes (monocytic/macrophagic and dendritic cells) in nasopharyngeal carcinoma. A variable density of dendritic cells was found within the tumor nests in 22 (49%) of 45 nasopharyngeal carcinomas examined; infiltrating macrophages were demonstrated in 15 (33%) specimens and around the tumor in almost all cases. Cases with moderate or marked density of dendritic cells (S100+) survived longer than those without such infiltration (mean 5-year survival rates of 31%, 55%, or 64% in patients with absent, moderate, or marked densities, respectively; P less than 0.05). A significant relationship between monocytic/macrophagic cells (lysozyme+) within the tumor and survival was also found (mean 5-year survival rate of 27% or 61% in patients with absent, moderate, or marked densities, respectively). However, lymphocytic infiltration was not statistically related to a better survival. Analyzing lymphocytic infiltration, we found a large prevalence of T cells in the neoplastic tissue without any prognostic significance. These data were correlated to different histological subtypes according to the principal histological classifications of nasopharyngeal carcinomas (Micheau, et al.; World Health Organization; Cologne University) to individualize the scheme which correlates best with prognosis and biological features of nasopharyngeal carcinomas. Our data suggest that, considering dendritic cells and macrophages within cancer nests, nasopharyngeal carcinoma histiotypes can be correlated to patient prognosis.

Adult↗
PubMed1991

Ultrastructural modifications of the muscle coat of the infundibulum and ampulla of the mouse oviduct during pregnancy and post-partum.

The muscle coat of the upper region of the mouse oviduct undergoes morphological changes in both the muscular and the connective matrix components during pregnancy and the post-partum period. During pregnancy, there is a significant increase in the number of mitochondria and caveolae and in the extension of the smooth endoplasmic reticulum in smooth muscle cells, suggesting the enhancement of their contractile activity. Within two days after delivery, these changes regress completely. The interstitial connective matrix in pregnancy undergoes a de novo genesis of basal lamina-like material and of collagen fibers, which vary in diameter and are irregular in outline. Both these connective components appear in relation to deep, round shaped pits present all along the smooth muscle cell surface. After delivery, characteristic morphological patterns appear associated with the active role which the smooth muscle cells play in resorption and reorganization of the intercellular connective matrix.

Animals↗
PubMed1991

Mast cell fixation and staining in image analysis.

Modern image analysers automatically perform densitometric measurements and elaborate digital images. Elaboration however is subject to operator interpretation and often eliminates precious information from the areas of interest. For this reason, it was appropriate to find a staining method which would overcome this drawback and, in the case of mast cell histochemistry, limit staining to granule content. The following current staining techniques were tested: Toluidine Blue in buffered solution (solut. a) and in 0.003% alcoholic solution (solut. b) and alcoholic Astra Blue, pH 0.2 Densitometric analysis was performed on both 5 microns and semithin sections of mouse tongue fixed in Isotonic formaldehyde-acetic acid (IFAA). Digital images were obtained using 630 nm and 546 nm wavelengths for Toluidine Blue and 610 nm for Astra Blue. Direct comparison between the two Toluidine Blue solutions revealed that more pixels were captured by the 5 microns sections stained with solut. a, whilst the opposite occurred in semithin sections. Both dyes introduced a certain amount of error due to the orthochromatic component of the nucleus and cytoplasmic basophily, which had to be eliminated through image elaboration. Because of its subjective nature, this operation may in turn lead to further errors. The choice of Astra Blue as an alternative to Toluidine Blue in densitometric analysis of mastocytes is based on its property to restrict staining to the granules of mast cells. A comparison between Astra Blue and the two Toluidine Blue solutions showed that, at all transmission levels, preparations stained with Astra Blue captured more pixels than those stained with Toluidine Blue. Consequently our results suggest that the most suitable technique for densitometric image analysis is fixation of mast cells in IFAA followed with Astra Blue.

Animals↗
PubMed1991

[Thyroid carcinoma as cystic nodule. The diagnostic role of cytology by needle aspiration].

195 patients affected by a cystic thyroid lesion were studied by a Fine Needle Aspiration biopsy (FNAb). 42 patients were operated on account of clinical data, compressive phenomena or cytologic results suggesting a neoplasia. Out of the operated patients, 3 were affected by a carcinoma in the cystic lesion (one "pure" cystic nodule and two "mixed" ones), while three more patients with multinodular goiters showed a carcinomatous lesion in a nodule different from the cystic one. Macroscopic characteristics of the aspirated fluid (quantity and quality) didn't affect the cytologic diagnosis. Cytology was useful in the preoperative diagnosis of benign thyroid nodules (only two false positives out of 42 patients) and was diagnostic in all the three patients affected by a carcinoma in the cystic nodule.

Adolescent↗