Linkage disequilibrium pattern in the L-myc gene in Italian and Japanese non-small-cell lung-cancer patients

Italian and Japanese non-small-cell lung-cancer patients were genotyped for an intragenic L-myc EcoRI restriction site polymorphism previously reported to be associated with lung-tumor prognosis in Asian populations but not in Caucasians. Screening of the L-myc sequence in Italian samples allowed identification of 2 additional 3'-UTR SNPs, located 2.3-3.0 kb from the EcoRI polymorphism, but no coding polymorphism was found. No significant association was found between any of the 3 SNPs and lung-tumor prognosis in Italian patients, consistent with the reported difference between Caucasian and Asian populations. Moreover, the newly discovered polymorphisms in the Italian group were not present in Japanese patients. Significant LD between EcoRI and the 2 other SNPs was detected in the Italian population, whereas no significant LD between the 2 3'-UTR markers was detected despite their close proximity (0.7 kb). Thus, the disparate conclusions about the role of L-myc polymorphism in tumor prognosis among different populations may rest in population-specific LD between the functional gene and the L-myc polymorphism.     

Effect of rhTNF-alpha injection into rat sciatic nerve.

To assess whether TNF-alpha causes inflammatory demyelination or axonal degeneration, we injected into rat sciatic nerve saline, 100 U and 1000 U of rhTNF-alpha and studied the electrophysiological and pathological effects. At day 1 electrophysiology showed a slight reduction of proximal compound muscle action potential amplitude and pathology showed edema, inflammatory infiltration of vessel walls and endoneurium only in nerves injected with 1000 U of rhTNF-alpha. At day 5, there was no demyelination and a percentage of degenerated fibers similar in the three groups. To study the blood-nerve barrier, fluorescein isothiocyanate-labelled albumin was given intravenously after intraneural injection. The nerves injected with 1000 U rhTNF-alpha showed a leakage of the tracer in the endoneurium. TNF-alpha does not appear, at the doses used, to have myelinotoxic or axonopathic properties. The electrophysiological effect at day 1 may be due to mechanical compression of nerve fibers as a result of the blood-nerve barrier damage with consequent endoneurial edema.     

Effect of naloxone on morphine-induced changes in striatal dopamine metabolism and glutamate, ascorbic acid and uric acid release in freely moving rats

Recent findings have shown that systemic morphine increases extracellular dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), ascorbic acid (AA) and uric acid concentrations in the striatum of freely moving rats. The morphine-induced increase in DA oxidative metabolism is highly correlated with that of xanthine. In the present study, we evaluated the effects of subcutaneous (s.c.) naloxone (1 mg/kg) on morphine-induced changes in DA, DOPAC, HVA, 5-hydroxyindoleacetic acid (5-HIAA), AA, uric acid and glutamate in the striatum of freely moving rats using microdialysis. Dialysates were assayed by high performance liquid chromatography with electrochemical detection or (glutamate) ultraviolet detection. Morphine (5–20 mg/kg) given s.c. increased DA, DOPAC+HVA, 5-HIAA, AA and uric acid and decreased glutamate dialysate concentrations over a 3 h period after morphine. Morphine (1 mM), given intrastriatally, did not affect all the above parameters, with the exception of an early short-lasting decrease in AA concentration. Naloxone antagonised all morphine-induced changes with the exception of AA increase and glutamate decrease in dialysate concentrations. Systemic or intrastrial (0.2–2 mM) naloxone increased AA and decreased glutamate dialysate concentrations. When given intranigrally, morphine (1 mM) increased DOPAC+HVA, AA and uric acid and decreased glutamate dialysate concentrations over a 2 h period after morphine; DA and 5-HIAA concentrations were unaffected. These results suggest that: (i) morphine increases striatal DA release and 5-hydroxytryptamine oxidative metabolism by a μ-opioid receptor-mediated mechanism mainly at extranigrostriatal sites; (ii) morphine increases DA and xanthine oxidative metabolism and affects glutamate and AA release by a μ-opioid receptor mediated mechanism acting also at nigral sites; and (iii) a μ-opioid receptor-mediated mechanism tonically controls at striatal sites extracellular AA and glutamate concentrations.     

Beneficial Hemodynamic Effects of Dipyridamole on Portal Circulation in Cirrhosis

Objective : Dipyridamole is a vasodilator that inhibits the cellular uptake of adenosine, which physiologically reduces the resistance to hepatic arterial flow inside the liver. This study aims at assessing the acute effect of dipyridamole on functional liver plasma flow (measured as the extrarenal sorbitol clearance) and on the Doppler US Congestion Index of the portal vein (the ratio between the cross-sectional area of this vein and the mean velocity of portal flow), which correlates with the severity of portal hypertension. Methods : We have determined the extrarenal sorbitol clearance (14 cases) and the Congestion Index (seven cases) before and at 30, 60, and 90 min after the oral administration of 25 mg dipyridamole in patients with liver cirrhosis. We also measured the effect of dipyridamole on functional liver plasma flow in six healthy subjects. Results : Dipyridamole increased the extrarenal sorbitol clearance in controls (+17%,   p < 0.01  ) and in cirrhotic patients (+15%,   p < 0.01  ). The drug decreased the portal Congestion Index in all patients, averaging -24%(   p < 0.05  ) 90 min after its oral administration. Conclusions : This result was due both to a mean decrease of the portal sectional area and to a mean increase in portal flow velocity. In conclusion, these data suggest that dipyridamole should decrease the vascular resistance to portal flow in cirrhosis; this effect may be mediated by an adenosine-dependent vasodilation in the intrahepatic site or along the portosystemic collaterals.     

Evidence for hepatitis B virus infection in patients with chronic hepatitis C with and without serological markers of hepatitis B

To assess the influence of HBV infection on anti-HCV-positive chronic liver disease, we performed a prospective case-control study comparing 19 HBsAg-positive, anti-HCV-positive patients with 38 HBsAg-negative, anti-HCV-positive patients, pair-matched for age, sex, and ALT levels. HBV and HCV infections were investigated by standard serology and polymerase chain reaction. HCV RNA was found in all patients with CAH and in 90.0% with cirrhosis (33% HBsAg-positive). HBV DNA sequences were found, in the HBsAg-positive subjects, in 71.4% of CAH and in 83.3% of cirrhotics; in the HBsAg-negative ones, only 10% of CAH but 77.7% of cirrhotics had demonstrable HBV DNA sequences. Consequently, 80.0% of cirrhotics had evidence of both HBV and HCV infection. Conventional serology gives partial information on the true occurrence of HBV infection in HBsAg-negative patients, while PCR defines more accurately the HBV status. When the rate of double infection is defined in this way, it correlates with the presence of cirrhosis.This work was supported by grants 40% (Progetto Virus) of MURST (Ministero dell'Università e della Ricerca Scientifica) and AIRC (Associazione Italiana per la Ricerca sul Cancro). A.G. is a recipient of a fellowship from Wellcome Italia.     

17Beta-eEstradiol stimulates arachidonate release from human amnion-like WISH cells through a rapid mechanism involving a membrane receptor

17beta-Estradiol (17beta-E(2)) greatly and dose-dependently stimulates [(3)H]arachidonic acid (AA) release from the human amnion-like Wistar Institute Susan Hayflick (WISH) cells. This action is abolished by the phospholipase A(2) inhibitor AACOCF(3), significantly reduced by the estrogen receptor (ER) antagonist ICI 182,780, and uninfluenced by cycloheximide. The estradiol-BSA conjugate E(2)coBSA, which binds putative membrane ERs and is unable to enter the cell, also highly stimulates [(3)H]AA release from WISH cells, although to a lesser extent compared with 17beta-E(2). The fluorescent conjugate E(2)coBSA-FITC specifically binds to the surface of a subset of intact WISH cells, and labeling intensity appears dose and time dependent. Cell permeabilization results in a dense intracellular staining, mainly in the peripheral cytoplasm. H-150, an antibody against the N terminus of human ERbeta, also labels the plasma membrane of intact WISH cells and the cytoplasm of permeabilized cells. Almost no labeling is observed using ER-21, an antibody against the N terminus of human ERalpha. RT-PCR evidences the presence of mRNA for ERbeta, not for ERalpha. Our data suggest that 17beta-E(2) stimulates [(3)H]AA release from WISH cells through an apparently nongenomic pathway and interaction with membrane binding sites. These last are, at least in part, similar if not identical to ERbeta.     

Retrospective study of a large population of patients with asymptomatic or minimally symptomatic raised serum creatine kinase levels

A retrospective evaluation of asymptomatic subjects with persistent elevation of serum creatine kinase (CK) levels (hyperCKemia) was made in order to verify the presence of subclinical myopathy or idiopathic hyperCKemia and to define the most appropriate diagnostic pathway. Persistently increased serum CK levels are occasionally encountered in healthy individuals. In 1980 Rowland coined for them the term idiopathic hyperCKemia. Despite the increase of scientific knowledge, several healthy subjects with hyperCKemia still represent a problem for the clinician. We made a retrospective evaluation of 114 asymptomatic or minimally symptomatic individuals with incidentally detected persistent hyperCKemia. They underwent neurological examination and laboratory/instrumental evaluation. Skeletal muscle biopsy was performed and thoroughly investigated. Biochemical and genetic investigations were added in selected cases. Logistic regression analysis was applied. We diagnosed a neuromuscular disorder in 21 patients (18.4 %), and found, by muscle biopsy and/or EMG, pathological but not conclusive findings in 57 subjects (50 %). The statistic correlation between elevated serum CK levels and the probability of making a diagnosis changed according to the age of the patient. Conclusions Muscle biopsy is the basic tool for screening asymptomatic subjects with hyperCkemia. It allowed us to make a diagnosis of disease in 18.4 % of patients, and to detect skeletal muscle abnormalities in 38.6 % of the subjects. Interestingly, 31.6 % of individuals had completely normal muscle findings. These best fit the “diagnosis” of idiopathic hyperCKemia. Received: 13 March 2001, Received in revised form: 3 July 2001, Accepted: 5 July 2001