Mitochondrial import and enzymatic activity of PINK1 mutants associated to recessive parkinsonism

Parkinson's disease (PD) is a progressive neurodegenerative illness associated with a selective loss of dopaminergic neurons in the nigrostriatal pathway of the brain. Despite the overall rarity of the familial forms of PD, the identification of single genes linked to the disease has yielded crucial insights into possible mechanisms of neurodegeneration. Recently, a putative mitochondrial kinase, PINK1, has been found mutated in an inherited form of parkinsonism. Here, we describe that PINK1 mutations confer different autophosphorylation activity, which is regulated by the C-terminal portion of the protein. We also demonstrate the mitochondrial localization of both wild-type and mutant PINK1 proteins unequivocally and prove that a short N-terminal part of PINK1 is sufficient for its mitochondrial targeting.     

In vitro Metabolism of Bumetanide

A new metabolite of the diuretic drug bumetanide, the 4-[(4-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment.     

Lumacaftor/ivacaftor improves liver cholesterol metabolism but does not influence hypocholesterolemia in patients with cystic fibrosis

BackgroundCystic fibrosis (CF) patients have reduced intestinal absorption of sterols and, despite enhanced endogenous synthesis, low plasma cholesterol. Lumacaftor/ivacaftor CFTR protein modulator therapy is used to improve the clinical outcome of CF patients homozygous for F508del mutation (homo-deltaF508). Aim of the study is to evaluate the cholesterol metabolism and hepatobiliary injury/function in adult homo-deltaF508 patients, before and after lumacaftor/ivacaftor treatment. Baseline parameters in homo-deltaF508 patients were compared to those in CF patients compound heterozygous for F508del mutation and another severe mutation (hetero-deltaF508).MethodsCholesterol metabolism was evaluated measuring plasma phytosterols and cholestanol, as intestinal absorption markers, and lathosterol, as liver biosynthesis marker. We quantified serum vitamin E, as nutritional marker. We evaluated liver injury by aspartate aminotransferase (AST) and alanine transaminase (ALT), biliary injury by γ-glutamyltransferase (γGT) and AP, and the liver function by bilirubin and albumin.ResultsBefore the treatment, homo-deltaF508 patients (n = 20) had significantly lower cholesterol and vitamin E compared to hetero-deltaF508 (n = 20). Lumacaftor/ivacaftor treatment caused: 1) further reduction of cholesterol; 2) lathosterol reduction, suggesting a normalization of endogenous synthesis; 3) cholestanol and vitamin E increment, indicating an improvement of lipid digestion/absorption. Vitamin E difference (after-before treatment) was positively associated to treatment months. Alkaline phosphatase was also reduced.ConclusionsThese data suggest an effect of lumacaftor/ivacaftor on cholesterol metabolism and enterohepatic flux in CF patients. However, lumacaftor/ivacaftor does not promote the increase of cholesterol serum concentration that on the contrary declines. Further studies are needed to research the real mechanism causing this reduction.     

A role for mucosal immunity in resistance to HIV infection

In a recent, thought-provoking novel by Elizabeth McCracken (The Giant's House. Avon Books, New York, 1997), two characters discuss love and its impossibilities. One brashly claims to be "immune to love", explaining the concept to his perplexed interlocutor, "...people become immune to love like they become immune to any disease. Either they had it bad early in life, like chicken pox and that's that; or they keep getting exposed to it in little doses and build up an immunity; or somehow they just don't catch it, something in'em is born resistant. I'm the last type. I'm immune to love and poison ivy". (p. 275) (E. McCracken, The Giant's House. Avon Books, New York, 1997). Substitute the words 'HIV infection' for 'love' and this intriguing metaphor summarizes the state of the art working hypotheses for the phenomenon of resistance to HIV infection in HIV-exposed individuals who, against all odds, do not seroconvert. These hypotheses will be discussed hereafter and particular emphasis will be placed upon a possible role for mucosal immunity in this phenomenon.     

The role of health care attributes and demographic characteristics in the determination of health care satisfaction

The authors investigate the influence of demographic characteristics and health care attributes on overall health care satisfaction. They use a national cross-section sample of HMO members and another of non-HMO members. Demographic characteristics are treated as antecedent to satisfaction with the health care attributes in the determination of overall health care satisfaction. The health care attributes are very similar in impact for both samples, suggesting HMOs should emphasize those attributes both to ensure reenrollment and to encourage new enrollment. Findings also show that satisfaction with several health care attributes varies along a few demographic dimensions, suggesting demographic bases along which the health care market can be segmented.     

A case of gamma-hydroxybutyric acid withdrawal syndrome during alcohol addiction treatment: utility of diazepam administration

Gamma-hydroxybutyric acid (GHB) is an emerging drug for alcoholism therapy. We present a case of GHB withdrawal syndrome secondary to GHB addiction during alcoholism treatment. A complete disappearance of drug withdrawal syndrome was achieved with oral diazepam and the symptoms resolved without sequelae. GHB has been used for alcoholism therapy for only a few years now, but the trend is increasing, and other cases similar to this one are foreseeable. This risk could be higher in some countries in which GHB use is increasing not for alcoholism therapy, but for its euphoric and anabolic effects. The present experience indicates that administration of benzodiazepines would seem to be sufficient to achieve total regression of the withdrawal syndrome in a short time, at least if recognized early.     

Medullary carcinoma of the thyroid. A clinical case

A case of medullary thyroid carcinoma is reported. Moreover, the main peculiarity, the correct diagnostic approach and the therapeutic indication of this rare pathology are described.     

Adding a competitive dimension to importance-performance analysis: an application to traditional health care systems

This study introduced an extension of importance-performance analysis by further including the performance of competitors. It demonstrated its value by applying it to a national sample of fee-for-service health care users. This study found that inappropriate strategies may result from importance-performance analysis that excludes a dimension of competition. In particular, the two attributes, availability of both physicians and emergency services, were found to be "high" on importance and "good" on fee-for-service performance. From the basic classic importance-performance approach, a relatively passive strategy would be recommended for each of these attributes. When also considering competition, however, a more appropriate, vigorous strategy of head-to-head competition clearly emerges.     

Molecular evidences for a role of HSV-1 in multiple sclerosis clinical acute attack

To verify the possible role of human herpesviruses as triggering or aggravating factors in relapsing-remitting multiple sclerosis (RRMS) clinical acute attack, we studied the prevalence of some herpesviruses in the peripheral blood mononuclear cells (PBMCs) collected from 22 MS patients during an MS relapse and in a stable phase and from 18 healthy controls (HC). DNA belonging to Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), Human cytomegalovirus (HCMV), Epstein-Barr virus (EBV) and Human Herpes virus 6 (HHV-6) has been searched by specific nested polymerase chain reaction (n-PCR). EBV and HHV6 DNA has been detected with high frequency in acute and stable MS and in healthy controls without significant differences. HCMV DNA was observed both in acute and stable MS but not in HC, and, more interestingly, HSV-1 DNA was only found in 13% of acute MS, while both stable MS and healthy controls were negative. On the basis of these results we focused on HSV-1, and to confirm them and to demonstrate that HSV-1 is actively replicating in MS patients during clinical relapse, we searched both messenger RNA (mRNA) and DNA of HSV-1 in the PBMCs of 15 acute MS patients and 15 healthy controls. We found HSV-1 mRNA and DNA in a significant number of acute MS patients but not in the control group. On the whole these data indicate that HSV-1 reactivate in the peripheral blood of MS patients during clinical acute attack and probably play a role in the triggering of MS relapses.