Showing papers by "University of Modena and Reggio Emilia published in 1990"

Endogenous benzodiazepine receptor ligands in human and animal hepatic encephalopathy.

Abstract: The role of endogenous benzodiazepine receptor ligands in the pathogenesis of hepatic encephalopathy was studied in humans and in rat models of hepatic encephalopathy. Endogenous benzodiazepine ligands were extracted from rat brain and human CSF by acid treatment and purification by HPLC. Detection and partial characterization of these endogenous benzodiazepine ligands were carried out using both radioreceptor binding assays and radioimmunoassays with anti-benzodiazepine antibodies. Four different benzodiazepine receptor ligands were identified in human and rat tissue, two of which may be diazepam and desmethyldiazepam, based on elution profiles and anti-benzo-diazepine antibody reactivity. Human CSF and serum from patients with hepatic encephalopathy contained approximately 10 times more endogenous benzodiazepine receptor ligand than CSF from controls or nonencephalopathic patients with liver disease. The levels of brain benzodiazepine receptor ligand compounds were also increased approximately 10-fold in rats suffering from fulminant hepatic failure, but not in rats with portacaval shunts, a model of chronic hepatic disease. The increased concentrations of these substances could be behaviorally significant and may contribute to the pathogenesis of hepatic encephalopathy.

Anisotropy of surface optical properties from first-principles calculations

Abstract: On considere des surfaces GaAs(110) et GaP(110). Une tres large contribution a l'anisotropie de la reflectance est liee aux transitions qui n'impliquent pas d'etats de surface. Comparaison avec des donnees experimentales

Evidence for the existence of different types of large bowel tumor: suggestions from the clinical data of a population-based registry.

Abstract: The clinical findings of a population-based colorectal tumor registry have been analyzed to determine elements of supporting or not supporting the existence of different types of large bowel cancer. Age-specific incidence rate of the 409 registered patients rose sharply with increasing age in all segments of the large bowel; however, regarding left colon and rectum, the male: female ratio showed a marked male preponderance, more evident in the more advanced age groups. Histopathology, studied in 87% of patients, revealed adenocarcinoma as the most frequent feature; however, adenocarcinoma with concomitant adenoma (i.e., presumably arising in adenoma) was observed in 14.3% of cancers of the left colon, in 17.7% of rectal tumors, but in only 5.7% of neoplasms of the proximal colon (P < 0.05 and P < 0.01, respectively, vs. left colon and rectum). Some histological features (carcinoid and mucinous carcinoma) were observed in right-side tumors only. Analysis of the familial occurrence of cancer showed that a significantly larger proportion of patients with neoplasms located in proximal colonic segments had three or more first-degree relatives affected by (or deceased from) cancer of all sites. Similarly, colorectal tumors among relatives were more frequent in patients with right-side cancer. The location of the 793 polyps observed during 3 years of registration showed that more than 70% of adenomas were located beyond the splenic flexure, overlapping the distribution of cancers. In conclusion, the differences of sex ratio at different colonic subsites, the higher fraction of adenocarcinomas with adenomas in cancer of the more distal tracts of the large bowel, and the more marked familial occurrence of colorectal cancer in patients with right-side neoplasms tend to support the view that cancer of the proximal colon, cancer of the distal colon, and cancer of the rectum may actually be three different types of tumors.

Circannual rhythm of plasma thyrotropin in middle-aged and old euthyroid subjects

Abstract: The circannual rhythm of plasma thyrotropin (TSH) was evaluated in 8,310 euthyroid, serially independent, young, middle-aged and old men and women. A statistically significant circannual rhythm of pla

Ultrastructural study of the skin in a case of juvenile ceroid-lipofuscinosis

Abstract: Ceroid-lipofuscinosis (CL) is a neurometabolic disorder due to an as yet unknown enzymatic deficiency. The electron-microscopic study of various organs shows a storage of a lipofuscin-like material. The ultrastructural study of clinically uninvolved skin in a typical case of juvenile CL is reported. Granular osmiophilic deposits were found in several cell types in the dermis, including fibroblasts, endothelial cells, macrophages, Schwann cells, pericytes, and muscle cells. Neither fingerprint nor curvilinear profiles could be observed. These findings demonstrate the involvement of clinically normal skin in CL and confirm the usefulness of the EM study of the skin in the diagnosis of this rare disorder.

Biological Monitoring of Occupational Exposure to Styrene

Abstract: Styrene concentration in venous blood and in urine and urinary mandelic acid were measured in 64 subjects occupationally exposed to styrene. Samples were collected before and after each half of the shift at the beginning and end of the working week. The styrene concentration in venous blood and in urine and the urinary mandelic acid were correlated with the mean-weighted environmental concentration of styrene, measured in the breathing zone by means of passive personal samplers. The results indicate that the urinary styrene concentration can be used as a biological index of exposure to styrene. This parameter could be considered complementary to measurements of mandelic acid in urine, styrene in mixed-exhaled air, phenylglyoxylic acid in urine, and styrene in blood.

Effects of bile acid pool composition on hepatic metabolism of cholesterol in man.

Abstract: This work reviews the evidence concerning the role of the bile acid pool composition in the regulation of the overall hepatic metabolism of cholesterol in man. It has been known that bile acids regulate bile secretion, biliary lipid transport and hepatic cholesterol metabolism. However, the intimate mechanisms of these regulatory functions are not well understood. Current thinking attributes most of this regulation to the size of the bile acid pool. A typical example is represented by the negative feed-back mechanism by which bile acids returning to the liver control their own synthesis. Recent evidence however tend to suggest that not only the size but also the composition contributes to the regulatory activity of the bile acid pool. Specifically the hydrophobic-hydrophilic balance of the pool, as resulting from the characteristics and the proportions of the individual bile acids present within the pool, seems to dictate most of the effects of bile acids on hepatic cholesterol metabolism. Thus abundance within the pool of hydrophobic bile acids, such as deoxycholic or chenodeoxycholic acid, seems to induce a greater biliary lipid secretion and to exert inhibition of cholesterol and bile acid synthesis whereas hydrophilic bile acids such as ursodeoxycholic acid seem to be uneffective. It follows that by changing the composition of the bile acid pool it is possible to influence the hepatic metabolism of cholesterol.

Anisotropy in the optical spectrum of the GaAs(110) surface.

Abstract: Mise en cause de resultats publies par Zhu et al. concernant la structure electronique de la surface de GaAs et permettant le calcul de l'anisotropie de la reflexion optique des etats de surfaces voisins de la bande interdite