c-Jun N-terminal kinase pathway inhibition in intracerebral hemorrhage.

Background: Inhibition of the c-Jun N-terminal kinase (JNK) pathway by the TAT-coupled peptide XG-102 (formerly D-JNKI1) induces strong neuroprotection in ischemic stroke in rodents. We investigated the effect of JNK inhibition in intracerebral hemorrhage (ICH). Methods: Three hours after induction of ICH by intrastriatal collagenase injection in mice, the animals received an intravenous injection of 100 mu g/kg of XG-102. The neurological outcome was assessed daily and the mice were sacrificed at 6 h, 1, 2 or 5 days after ICH. Results: XG-102 administration significantly improved the neurological outcome at 1 day (p < 0.01). The lesion volume was significantly decreased after 2 days (29 +/- 11 vs. 39 +/- 5 mm(3) in vehicle-treated animals, p < 0.05). There was also a decreased hemispheric swelling (14 +/- 13 vs. 26 +/- 9% in vehicle-treated animals, p < 0.05) correlating with increased aquaporin 4 expression. Conclusions: XG-102 attenuates cerebral edema in ICH and functional impairment at early time points. The beneficial effects observed with XG-102 in ICH, as well as in ischemic stroke, open the possibility to rapidly treat stroke patients before imaging, thereby saving precious time.

Acute antihypertensive effect of angiotensin converting enzyme inhibition and calcium entry blockade.

The acute blood pressure response to an angiotensin converting enzyme inhibitor (enalaprilat) was compared in patients with uncomplicated essential hypertension with that obtained under similar conditions with a calcium entry blocker (nifedipine). The patients were studied after a 3 week washout period. At a 48 h interval, each patient received in randomized order either enalaprilat (5 mg i.v.) or nifedipine (10 mg p.o.). Enalaprilat and nifedipine were equally effective in acutely lowering blood pressure. However, good responders to one agent were not necessarily good responders to the other.

Comparison of quantiferon-TB gold with tuberculin skin test for detecting latent tuberculosis infection prior to liver transplantation.

Screening for latent tuberculosis infection (LTBI) is recommended prior to organ transplantation. The Quantiferon-TB Gold assay (QFT-G) may be more accurate than the tuberculin skin test (TST) in the detection of LTBI. We prospectively compared the results of QFT-G to TST in patients with chronic liver disease awaiting transplantation. Patients were screened for LTBI with both the QFT-G test and a TST. Concordance between test results and predictors of a discordant result were determined. Of the 153 evaluable patients, 37 (24.2%) had a positive TST and 34 (22.2%) had a positive QFT-G. Overall agreement between tests was 85.1% (kappa= 0.60, p < 0.0001). Discordant test results were seen in 12 TST positive/QFT-G negative patients and in 9 TST negative/QFT-G positive patients. Prior BCG vaccination was not associated with discordant test results. Twelve patients (7.8%), all with a negative TST, had an indeterminate result of the QFT-G and this was more likely in patients with a low lymphocyte count (p = 0.01) and a high MELD score (p = 0.001). In patients awaiting liver transplantation, both the TST and QFT-G were comparable for the diagnosis of LTBI with reasonable concordance between tests. Indeterminate QFT-G result was more likely in those with more advanced liver disease.

La fonction rénale sous inhibition de l'enzyme de conversion de l'angiotensine [Renal function after administration of angiotensin-converting enzyme inhibitors]

Angiotensin converting enzyme (ACE) inhibitors are widely used today for the management of hypertension and congestive heart failure. These agents inhibit angiotensin II synthesis. In some particular circumstances they may be responsible for deterioration of renal function, e.g. in hypertensive patients with bilateral renal artery stenosis or with stenosis of the artery supplying a single kidney, or in patients with severe congestive heart failure or marked nephroangiosclerosis. In these patients renal perfusion pressure may become too low to maintain adequate glomerular filtration as there remains no angiotensin II to increase the tone of the efferent arteriole. In high risk patients it is therefore recommended that serum creatinine be checked after initiating therapy with an ACE inhibitor.

Functional analysis and structural modeling of human APOBEC3G reveal the role of evolutionarily conserved elements in the inhibition of human immunodeficiency virus type 1 infection and Alu transposition.

Retroelements are important evolutionary forces but can be deleterious if left uncontrolled. Members of the human APOBEC3 family of cytidine deaminases can inhibit a wide range of endogenous, as well as exogenous, retroelements. These enzymes are structurally organized in one or two domains comprising a zinc-coordinating motif. APOBEC3G contains two such domains, only the C terminal of which is endowed with editing activity, while its N-terminal counterpart binds RNA, promotes homo-oligomerization, and is necessary for packaging into human immunodeficiency virus type 1 (HIV-1) virions. Here, we performed a large-scale mutagenesis-based analysis of the APOBEC3G N terminus, testing mutants for (i) inhibition of vif-defective HIV-1 infection and Alu retrotransposition, (ii) RNA binding, and (iii) oligomerization. Furthermore, in the absence of structural information on this domain, we used homology modeling to examine the positions of functionally important residues and of residues found to be under positive selection by phylogenetic analyses of primate APOBEC3G genes. Our results reveal the importance of a predicted RNA binding dimerization interface both for packaging into HIV-1 virions and inhibition of both HIV-1 infection and Alu transposition. We further found that the HIV-1-blocking activity of APOBEC3G N-terminal mutants defective for packaging can be almost entirely rescued if their virion incorporation is forced by fusion with Vpr, indicating that the corresponding region of APOBEC3G plays little role in other aspects of its action against this pathogen. Interestingly, residues forming the APOBEC3G dimer interface are highly conserved, contrasting with the rapid evolution of two neighboring surface-exposed amino acid patches, one targeted by the Vif protein of primate lentiviruses and the other of yet-undefined function.

JNK inhibition and inflammation after cerebral ischemia.

The c-Jun-N-terminal kinase signaling pathway (JNK) is highly activated during ischemia and plays an important role in apoptosis and inflammation. We have previously demonstrated that D-JNKI1, a specific JNK inhibitor, is strongly neuroprotective in animal models of stroke. We presently evaluated if D-JNKI1 modulates post-ischemic inflammation such as the activation and accumulation of microglial cells. Outbred CD1 mice were subjected to 45 min middle cerebral artery occlusion (MCAo). D-JNKI1 (0.1 mg/kg) or vehicle (saline) was administered intravenously 3 h after MCAo onset. Lesion size at 48 h was significantly reduced, from 28.2+/-8.5 mm(3) (n=7) to 13.9+/-6.2 mm(3) in the treated group (n=6). Activation of the JNK pathway (phosphorylation of c-Jun) was observed in neurons as well as in Isolectin B4 positive microglia. We quantified activated microglia (CD11b) by measuring the average intensity of CD11b labelling (infra-red emission) within the ischemic tissue. No significant difference was found between groups. Cerebral ischemia was modelled in vitro by subjecting rat organotypic hippocampal slice cultures to oxygen (5%) and glucose deprivation for 30 min. In vitro, D-JNKI1 was found predominantly in NeuN positive neurons of the CA1 region and in few Isolectin B4 positive microglia. Furthermore, 48 h after OGD, microglia were activated whereas resting microglia were found in controls and in D-JNKI1-treated slices. Our study shows that D-JNKI1 reduces the infarct volume 48 h after transient MCAo and does not act on the activation and accumulation of microglia at this time point. In contrast, in vitro data show an indirect effect of D-JNKI1 on the modulation of microglial activation.

Infection latente a M. tuberculosis, mise a jour 2011 [Latent M. tuberculosis infection, update 2011].

It is estimated that one third of the world population is latently infected by Mycobacterium tuberculosis and thus at risk of reactivation. Latent tuberculosis (TB) impact in Switzerland is often overlooked. Diagnosis and prophylaxis are insufficiently undertaken, especially for people at higher risk of reactivation due to immunosuppression. Interferon-gamma release assays replace tuberculosis skin tests for diagnosis of latent infection in adults. It is still recommended to treat prophylactically a case of latent TB infection with 9 months of isoniazid; however therapy with rifampicin for 4 months, currently an alternative option, is linked to improved adherence and favorable cost-benefit ratio.

SOCS-1 protein prevents Janus Kinase/STAT-dependent inhibition of beta cell insulin gene transcription and secretion in response to interferon-gamma.

In the pathogenesis of type I diabetes mellitus, activated leukocytes infiltrate pancreatic islets and induce beta cell dysfunction and destruction. Interferon (IFN)-gamma, tumor necrosis factor-alpha and interleukin (IL)-1 beta play important, although not completely defined, roles in these mechanisms. Here, using the highly differentiated beta Tc-Tet insulin-secreting cell line, we showed that IFN-gamma dose- and time-dependently suppressed insulin synthesis and glucose-stimulated secretion. As described previously IFN-gamma, in combination with IL-1 beta, also induces inducible NO synthase expression and apoptosis (Dupraz, P., Cottet, S., Hamburger, F., Dolci, W., Felley-Bosco, E., and Thorens, B. (2000) J. Biol. Chem. 275, 37672--37678). To assess the role of the Janus kinase/signal transducer and activator of transcription (STAT) pathway in IFN-gamma intracellular signaling, we stably overexpressed SOCS-1 (suppressor of cytokine signaling-1) in the beta cell line. We demonstrated that SOCS-1 suppressed cytokine-induced STAT-1 phosphorylation and increased cellular accumulation. This was accompanied by a suppression of the effect of IFN-gamma on: (i) reduction in insulin promoter-luciferase reporter gene transcription, (ii) decrease in insulin mRNA and peptide content, and (iii) suppression of glucose-stimulated insulin secretion. Furthermore, SOCS-1 also suppressed the cellular effects that require the combined presence of IL-1 beta and IFN-gamma: induction of nitric oxide production and apoptosis. Together our data demonstrate that IFN-gamma is responsible for the cytokine-induced defect in insulin gene expression and secretion and that this effect can be completely blocked by constitutive inhibition of the Janus kinase/STAT pathway.

Inhibition of the polymerase chain reaction by sputum samples from tuberculosis patients after processing using a silica-guanidiniumthiocyanate DNA isolation procedure

With the objective to evaluate PCR-mediated detection of Mycobacterium tuberculosis DNA as a diagnostic procedure for diagnosis of tuberculosis in individuals attending ambulatory services in Primary Health Units of the City Tuberculosis Program in Rio de Janeiro, Brazil, their sputum samples were collected and treated with a DNA extraction procedure using silica-guanidiniumthiocyanate. This procedure has been described to be highly efficient for extraction of different kind of nucleic acids from bacteria and clinical samples. Upon comparing PCR results with the number of acid-fast bacilli, no direct relation was observed between the number of bacilli present in the sample and PCR positivity. Part of the processed samples was therefore spiked with pure DNA of M. tuberculosis and inhibition of the PCR reaction was verified in 22 out of 36 (61%) of the samples, demonstrating that the extraction procedure as originally described should not be used for PCR analysis of sputum samples.

Sex-related and non-sex-related comorbidity subtypes of tic disorders: a latent class approach.

BACKGROUND AND PURPOSE: Recent evidence suggests that there may be more than one Gilles de la Tourette syndrome (GTS)/tic disorder phenotype. However, little is known about the common patterns of these GTS/tic disorder-related comorbidities. In addition, sex-specific phenomenological data of GTS/tic disorder-affected adults are rare. Therefore, this community-based study used latent class analyses (LCA) to investigate sex-related and non-sex-related subtypes of GTS/tic disorders and their most common comorbidities. METHODS: The data were drawn from the PsyCoLaus study (n = 3691), a population-based survey conducted in Lausanne, Switzerland. LCA were performed on the data of 80 subjects manifesting motor/vocal tics during their childhood/adolescence. Comorbid attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, depressive, phobia and panic symptoms/syndromes comprised the selected indicators. The resultant classes were characterized by psychosocial correlates. RESULTS: In LCA, four latent classes provided the best fit to the data. We identified two male-related classes. The first class exhibited both ADHD and depression. The second class comprised males with only depression. Class three was a female-related class depicting obsessive thoughts/compulsive acts, phobias and panic attacks. This class manifested high psychosocial impairment. Class four had a balanced sex proportion and comorbid symptoms/syndromes such as phobias and panic attacks. The complementary occurrence of comorbid obsessive thoughts/compulsive acts and ADHD impulsivity was remarkable. CONCLUSIONS: To the best of our knowledge, this is the first study applying LCA to community data of GTS symptoms/tic disorder-affected persons. Our findings support the utility of differentiating GTS/tic disorder subphenotypes on the basis of comorbid syndromes.

Immunogenicity test of tetanus component in adsorbed vaccines by toxin binding inhibition test

Samples from 20 lots of diphtheria-tetanus (adult use dT) vaccine and from 20 lots of diphtheria-tetanus-pertussis (DTP) vaccine were used to standardize and validate the in vitro toxin binding inhibition (ToBI) test for the immunogenicity test of the tetanus component. The levels of tetanus antitoxin obtained by ToBI test were compared to those obtained using the toxin neutralization (TN) test in mice routinely employed to perform the quality control of the tetanus component in adsorbed vaccines. The results ranged from 1.8 to 3.5 IU/ml for dT and 2 to 4 IU/ml for DTP by ToBI test and 1.4 to 3 IU/ml for dT and 1.8 to 3.5 IU/ml for DTP by TN in mice. These results were significantly correlated. From this study, it is concluded that the ToBI test is an alternative to the in vivo neutralization procedure in the immunogenicity test of the tetanus component in adsorbed vaccines. A substantial refinement and a reduction in use of animals can be achieved.

Discrepancy between antihypertensive effect and angiotensin converting enzyme inhibition by captopril

Captopril, an inhibitor of angiotensin converting enzyme, was administered twice daily to 13 hypertensive patients for a mean period of 9 weeks. Continuous blood pressure control in the ambulatory patients was established with a portable blood pressure recorder. Notwithstanding, in eight patients with normal renal function, plasma converting enzyme was found to resume normal activity before administration of the morning dose of captopril. Only in 5 patients with impaired renal function did some blockade of plasma converting enzyme persist for more than 12 hours. Measured plasma converting enzyme activity seemed to reflect total conversion of angiotensin I, including conversion in the pulmonary vascular bed, since changes in its activity were closely paralled by changes in plasma aldosterone levels. Bradykinin accumulation seems unlikely when converting enzyme and thus, presumably, kininase II has resumed normal activity. Captopril administration does not seem to alter plasma epinephrine or norepinephrine levels. Blood pressure reduction in the face of normal angiotensin converting enzyme activity is probably due to hyporesponsiveness of the arterioles to pressor hormones, which may be due to specific renin-related and/or nonspecific effects of captopril.

Risk factors of latent tuberculosis infection among asylum-seekers recently arrived in Switzerland : A pilot study in Vaud county

Background: Asylum seekers may have a higher rate of latenttuberculosis infection (LTBI) than resident populations in Westerncountries. LTBI can be detected by an Interferon Gamma ReleaseAssay (IGRA). Screening asylum seekers at highest risk for LTBI orfuture tuberculosis by IGRA could be considered. The aims of this pilotstudy were to assess the prevalence and the risk factors of LTBI amonga group of asylum seekers recently arrived in Switzerland.Methods: A prospective cross-sectional study was performed amongadult asylum seekers, staying in two migrant centers of the Vaud county,Switzerland, after a first screening for active tuberculosis at the border.The participants were offered IGRA screening using T-SPOT.TB andwere questioned about risk factors associated with LTBI. Migrants with apositive test had a chest radiograph and a medical examination. Thosewith active tuberculosis were excluded and were treated. The migrantswith LTBI received a preventive treatment, if indicated. The risk factorswere analyzed by univariate and multivariate logistical regression.Results: Among 788 migrants recently arrived, 639 were adults, 393agreed to be screened (61.50%) and 98 of them had a positive T-SPOT.TB (24.93%) of which 5 (5.1%) had an active tuberculosis (previouslynot detected at the border), and 2 had already been treated for activetuberculosis. In univariate analysis, the major risk factors associatedwith LTBI were country of origin and travel conditions. Compared withmigrants from Balkanic countries, migrants from Africa had an OR forLTBI of 3.68, migrants from Asia an OR of 4.3 and migrants fromFormer Soviet Union an OR of 4.5. Migrants who crossed severalborders before arriving in Switzerland had an OR of LTBI of 2.49compared with migrants who came directly from the home country.Age, cough and prior exposure to tuberculosis had a non-significantinfluence on the rate of test positivity. In multivariate analysis, thecombination of country of origin, travel conditions, age, cough andexposure to tuberculosis resulted in a score with optimal predictivevalue (Roc = 81%).Conclusions: Asylum seekers recently arrived in Vaud county had ahigh prevalence of LTBI and active tuberculosis. The major risk factorswere country of origin and travel conditions. Selecting for screening byIGRA the asylum seekers with the highest risk factors seems possible.