Genome analysis of dengue type-1 virus isolated between 1990 and 2001 in Brazil reveals a remarkable conservation of the structural proteins but amino acid differences in the non-structural proteins

We have investigated the genetic diversity of dengue type-1 (DEN-1) virus in Brazil. The full nucleotide sequences of three DEN-1 virus isolated from DEN fever (DF) and DEN hemorrhagic fever patients in northeastern Brazil in 1997 (BR/97) and one from a DF patient in the south of Brazil in 2001 (BR/01) were compared to that of the reference strain BR/90 obtained in the city of Rio de Janeiro in 1990. Sequence analysis showed that the structural proteins were remarkably conserved between all isolates. A total of 27 amino acid changes occurred throughout the non-structural proteins. Among them, nine amino acid substitutions were specific of BR/97 and BR/01 isolates, indicating that in situ evolution of these strains had occurred. Within the BR/97 and BR/01 samples, some amino acid substitutions have been previously identified in DEN-1 virus strains sequenced so far, suggesting that recombination events might have occurred.     

Toward a refined phenomenology of mania: combining clinician-assessment and self-report in the French EPIMAN study

BACKGROUND: Because manic patients lack insight, they are generally considered unreliable observers of their own psychopathology. The present analyses sought to examine to what extent patient reports could improve formal diagnostic criteria for mania--and be validated against the Carroll-Klein (CK) psychobiological model of bipolarity. METHOD: 104 DSM-IV acutely manic (hospitalized) patients provided self-assessment on the Ahearn--Carroll scale, the Multiple Visual Analogue Scales of Bipolarity (MVAS-BP). A principal component analysis (PCA) was performed on MVAS-BP, and the data on factorial scores were then compared to dimensional scores according to the CK model and to factors on the Beigel-Murphy Manic State Rating Scale (MSRS) completed by psychiatrists. RESULTS: The PCA identified a general factor accounting for 33% of the total variance; after varimax rotation, seven independent factors emerged, essentially in coherence with the signs and symptoms of DSM-IV mania, except for the 'social disinhibition' factor, which does not figure out as a distinct criterion in DSM-IV. Strong correlations were obtained (r > or = 0.80) between the four major factors of MVAS-BP and the four dimensional categories of the CK model: 'Consummatory Reward' with F1 'Elation and Inflated Self-esteem' (r=0.93), 'Incentive Reward' with F2 'Activation' (r=0.84), 'Psychomotor Pressure' with F3 'Acceleration' (r=0.85), and 'Central Pain' with F4 'Anxiety-Depression' (r=0.84). The F2 'Activation' appeared to be strongly correlated (r > or = 0.70) to all categories of the CK model. Correlational analysis between the factor structure of MVAS-BP and the MSRS showed significant coefficients on the scores assessing the emotional factors of 'Elation' and 'Depression.' Among the MVAS-BP factors, only 'Activation' was correlated to the majority of clinician ratings as obtained by the MSRS. CONCLUSIONS: These findings provide overall construct validity to the DSM-IV criteria for mania. Self-assessment of this disorder appears feasible and potentially useful in practice; lack of insight, poor judgment, and distractibility obviously require assessment by a clinician. Although our data are correlational and require prospective validation, they nonetheless suggest that (1) activation should be raised to the status of the stem criterion for mania, (2) to specify mood as elated, depressive, anxious, or irritable, and (3) to give individual status to social disinhibition (indiscriminate gregariousness) as a core pathological behavior in mania. Combining clinician- and self-observation thus produces a more precise and complete phenomenology of mania. We finally submit that the foregoing reformulation provides a psychobiological basis to the manic construct as formulated in the Carroll-Klein model.     

Nitric oxide detoxification systems enhance survival of Neisseria meningitidis in human macrophages and in nasopharyngeal mucosa

Nitric oxide (NO) contributes to mammalian host defense by direct microbicidal activity and as a signaling molecule of innate immune responses. Macrophages produce NO via the inducible NO synthase (iNOS). The genome of Neisseria meningitidis includes two genes, norB (encoding nitric oxide reductase) and cycP (encoding cytochrome c'), both of which detoxify NO in pure cultures of N. meningitidis. We show here that norB, and to a lesser extent cycP, enhance survival of N. meningitidis within primary human macrophages. Furthermore, accumulation of lysosome-associated membrane protein 1 (LAMP-1) is modified in phagosomes containing an isogenic norB mutant of N. meningitidis compared to the wild type. The survival enhancement conferred by norB and cycP is ablated by pretreatment of macrophages with the nitric oxide synthase inhibitor N(G)-monomethyl-L-arginine (L-NMMA). Despite this evidence that NO detoxification confers advantage, we find, using a highly sensitive chemiluminescence technique, that human macrophage-associated [NO] is low even after activation by lipopolysaccharide and interferon alpha. Furthermore, wild-type N. meningitidis further depletes cell-associated NO during phagocytosis by an active mechanism and survives relatively poorly in the presence of L-NMMA, suggesting that the wild-type organism may utilize NO for optimal survival during intracellular life. The natural habitat of N. meningitidis is the human nasopharynx. Using a nasopharyngeal mucosa organ culture system, we show that mutants lacking norB and cycP also survive poorly in nasopharyngeal tissue compared to wild-type N. meningitidis. These findings indicate that the meningococcus requires active NO detoxification systems for optimal survival during experimental nasopharyngeal colonization and processing by human phagocytic cells.     

Intrahepatic HCV RNA loads in 37 HIV-HCV co-infected patients with controlled HIV infection

Serum and intrahepatic hepatitis C virus (HCV) RNA were measured in 37 HIV-HCV co-infected patients with controlled human immunodeficiency virus (HIV) infection and correlated with clinical, biological, and histological parameters. Thirty-seven interferon-naive patients underwent liver biopsy. HCV-induced activity (A) and fibrosis (F) were evaluated with METAVIR score. The 37 patients included had HIV plasma loads < 10,000 copies/ml, CD4(+) count > 250/microl. All the patients but two were receiving antiretroviral treatment. Liver tissue and sera were used for measurement of HCV RNA by the Cobas Amplicor HCV Monitor. All patients had serum and liver HCV RNA, and both levels were correlated (r = 0.47; P = 0.003). Intrahepatic HCV load did not depend on age, sex, duration of HCV infection, CD4(+), HCV genotype, or fibrosis. AST levels correlated with intrahepatic HCV load (r = 0.52; P = 0.001). Patients with METAVIR A1/A2 had significantly lower levels of liver HCV-RNA than were found in patients with METAVIR A3 (P = 0.026). Highly active antiretroviral therapy (HAART) including protease inhibitors(PI)-treated patients had significantly lower intrahepatic HCV load (P = 0.04). A weak but significant correlation between serum and liver HCV RNA was found. The amount of hepatic HCV RNA was correlated with AST levels, histological activity, but not with HCV genotype or fibrosis. The immune improvement associated with PI regimens could help reduce HCV load, supporting a protective effect of PI-induced immune restoration.     

Voltage-dependent 40-Hz oscillations in rat reticular thalamic neurons in vivo.

Extra- and intracellular recordings of thalamic reticular and relay neurons were performed in rats under urethane anaesthesia. Under this type of anaesthesia it was found that, throughout the whole reticular thalamic nucleus, a large proportion of cells (approximately 34%) discharged like clocks within a 25-60 Hz frequency band width (i.e. 40 Hz). Simultaneous recordings of pairs of reticular cells showed that the regular discharges of nearby units were not synchronous. Thus, the asynchronous 40-Hz firing of reticular thalamic cells was not correlated with any 40-Hz extracellular activity as revealed by the spectral analysis of the electroencephalogram and by recordings performed in various thalamic nuclei. In relay cells of the ventrobasal, ventral lateral and posterior thalamic nuclei, the regular firing of reticular thalamic neurons induced a rhythmic inhibitory modulation that was detected by the time-series analysis of the inhibitory postsynaptic potentials. In many relay cells, however, the disclosure of this inhibitory modulation required cellular depolarization since the resting potential in these cells was maintained at the reversal potential of the inhibitory events. Intracellular recordings of reticular thalamic cells showed that their regular firing was not driven in an all-or-nothing manner by 40-Hz synaptic inputs but rather that it depended upon the activation of a voltage-dependent pacemaker mechanism; this pacemaker activity was manifested by the presence of subthreshold oscillations that drove spike discharges and whose frequency was voltage dependent. In the context of data already published on the genesis of 40-Hz oscillations in the brain, and given the key position of reticular thalamic neurons in thalamocortical networks, the present results indicate that the reticular thalamic nucleus might play a pacemaker function in the genesis of 40-Hz oscillations in the thalamus and cortex during states of focused arousal.     

Kallmann syndrome: 14 novel mutations in KAL1 and FGFR1 (KAL2)

Kallmann syndrome (KAL) combines hypogonadotropic hypogonadism and anosmia. Hypogonadism is due to Gonadotropin Releasing Hormone (GnRH) deficiency and anosmia is related to hypoplasia of the olfactory bulbs. Occasional symptoms include renal agenesis, bimanual synkinesia, cleft lip palate, dental agenesis. KAL is genetically heterogeneous and two genes have so far been identified, namely KAL1 (Xp22.3) and FGFR1/KAL2 (8p12), which underlie the X chromosome‐linked form and an autosomal dominant form of the disease, respectively. We studied a cohort of 98 unrelated Caucasian KAL patients. We identified KAL1 mutations in 14 patients, of which 7 (c.3G>A (p.M1?), g.IVS1+1G>T, c.570_571insA (p.R191fsX14), c.784G>C (p.R262P), c.958G>T (p.E320X), c.1651_1654delinsAGCT (p.P551_E552delinsSX), c.1711T>A (p.W571R)) have not been previously reported. In addition, we found FGFR1 mutations in 7 patients, namely c.303G>A (p.V102I), C.385A>C (p.D129A), c.810G>A (p.V273M), c.1093_1094delAG (p.R365fsX41), c.1561G>A (p.A520T), c.1836_1837insT (p.Y613fsX42), c.2190C>G (p.Y730X), all of which were novel mutations. In this study, unilateral renal agenesis and bimanual synkinesia were exclusively found associated with KAL1mutations, cleft palate and dental agenesia with FGFR1mutations. © 2004 Wiley‐Liss, Inc.     

Estimation of dynamical model parameters taking into account undetectable marker values

Background  

Mathematical models are widely used for studying the dynamic of infectious agents such as hepatitis C virus (HCV). Most often, model parameters are estimated using standard least-square procedures for each individual. Hierarchical models have been proposed in such applications. However, another issue is the left-censoring (undetectable values) of plasma viral load due to the lack of sensitivity of assays used for quantification. A method is proposed to take into account left-censored values for estimating parameters of non linear mixed models and its impact is demonstrated through a simulation study and an actual clinical trial of anti-HCV drugs.     

TNF inhibits malaria hepatic stages in vitro via synthesis of IL-6

We examined the capacity of murine recombinant tumor necrosis factor (rmTNF) to induce an inhibitory effect at the hepatic stage on malaria induced by Plasmodium yoelii sporozoites. When injected three times, 1.0 micrograms of rmTNF was found to protect 78% of mice against a sporozoite challenge. In contrast, whatever the dose and the schedule of administration, no inhibition was observed when purified hepatocyte cultures were infected with P. yoelii. The addition of non-parenchymal hepatic cells to hepatocyte cultures restored the capacity of TNF to modulate hepatic stage development, leading to up to 44% inhibition. Antibodies to interleukin 6 reversed the anti-parasite activity in the co-culture system.