New evidence in severe pneumonia: imipenem/ cilastatin/relebactam

Imipenem combined with beta-lactamase inhibitor relebactam (IMI/REL) has an extensive bactericidal activity against Gram-negative pathogens producing class A or class C beta-lactamases, not active against class B and class D. The phase 3 clinical trial (RESTORE-IMI-2), double-blind, randomized, evaluated IMI/REL vs. piperacillin-tazobactam (PIP/TAZ) for treatment of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), demonstrated non-inferiority at all-cause mortality at 28 days (15.9% vs 21.3%), favorable clinical response at 7-14 days end of treatment (61% vs 59.8%) and with minor serious adverse effects (26.7% vs 32%). IMI/REL is a therapeutic option in HAP and VAP at approved dosage imipenem 500 mg, cilastatin 500 mg and relebactam 250 mg once every 6h, by an IV infusion over 30 min.

A longitudinal study of gene expression in first-episode schizophrenia; exploring relapse mechanisms by co-expression analysis in peripheral blood

Little is known about the pathophysiological mechanisms of relapse in first-episode schizophrenia, which limits the study of potential biomarkers. To explore relapse mechanisms and identify potential biomarkers for relapse prediction, we analyzed gene expression in peripheral blood in a cohort of first-episode schizophrenia patients with less than 5 years of evolution who had been evaluated over a 3-year follow-up period. A total of 91 participants of the 2EPs project formed the sample for baseline gene expression analysis. Of these, 67 provided biological samples at follow-up (36 after 3 years and 31 at relapse). Gene expression was assessed using the Clariom S Human Array. Weighted gene co-expression network analysis was applied to identify modules of co-expressed genes and to analyze their preservation after 3 years of follow-up or at relapse. Among the 25 modules identified, one module was semi-conserved at relapse (DarkTurquoise) and was enriched with risk genes for schizophrenia, showing a dysregulation of the TCF4 gene network in the module. Two modules were semi-conserved both at relapse and after 3 years of follow-up (DarkRed and DarkGrey) and were found to be biologically associated with protein modification and protein location processes. Higher expression of DarkRed genes was associated with higher risk of suffering a relapse and early appearance of relapse (p = 0.045). Our findings suggest that a dysregulation of the TCF4 network could be an important step in the biological process that leads to relapse and suggest that genes related to the ubiquitin proteosome system could be potential biomarkers of relapse.

Influence of social cognition as a mediator between cognitive reserve and psychosocial functioning in patients with first episode psychosis

BACKGROUND

Social cognition has been associated with functional outcome in patients with first episode psychosis (FEP). Social cognition has also been associated with neurocognition and cognitive reserve. Although cognitive reserve, neurocognitive functioning, social cognition, and functional outcome are related, the direction of their associations is not clear. Therefore, the main aim of this study was to analyze the influence of social cognition as a mediator between cognitive reserve and cognitive domains on functioning in FEP both at baseline and at 2 years.

METHODS

The sample of the study was composed of 282 FEP patients followed up for 2 years. To analyze whether social cognition mediates the influence of cognitive reserve and cognitive domains on functioning, a path analysis was performed. The statistical significance of any mediation effects was evaluated by bootstrap analysis.

RESULTS

At baseline, as neither cognitive reserve nor the cognitive domains studied were related to functioning, the conditions for mediation were not satisfied. Nevertheless, at 2 years of follow-up, social cognition acted as a mediator between cognitive reserve and functioning. Likewise, social cognition was a mediator between verbal memory and functional outcome. The results of the bootstrap analysis confirmed these significant mediations (95% bootstrapped CI (-10.215 to -0.337) and (-4.731 to -0.605) respectively).

CONCLUSIONS

Cognitive reserve and neurocognition are related to functioning, and social cognition mediates in this relationship.

Advances in the assessment of self-determination: internal structure of a scale for people with intellectual disabilities aged 11 to 40

BACKGROUND

Advances in theoretical frameworks of self-determination require the development of new assessment instruments. This study examines the dimensional structure of a self-determination scale and analyses the factorial invariance of its measurement across age and gender.

METHOD

The AUTODDIS Scale was used to assess the self-determination of 541 people with intellectual disabilities aged from 11 to 40.

RESULTS

Different models (correlational and hierarchical structures) of the scale were tested. The correlational model obtained from the exploratory structural equation model approach provided the best fit for the data. The results also supported measurement invariance across youths (aged 11 to 21 years) and adults (aged 21 to 40 years) and across genders.

CONCLUSIONS

This study contributes to international research on self-determination and the development of assessment tools in this field, offering a better understanding of this multifaceted and complex construct. The results provide construct validity evidence regarding a new measurement tool tested across people aged 11 to 40, using information from third parties. However, further research is needed to explore the best ways to understand and assess the different factors related to self-determination.

Factors associated with poor functional outcome in bipolar disorder: sociodemographic, clinical, and neurocognitive variables

OBJECTIVE

The current investigation aimed at studying the sociodemographic, clinical, and neuropsychological variables related to functional outcome in a sample of euthymic patients with bipolar disorder(BD) presenting moderate-severe levels of functional impairment.

METHODS

Two-hundred and thirty-nine participants with BD disorders and with Functioning Assessment Short Test(FAST) scores equal or above 18 were administered a clinical and diagnostic interview, and the administration of mood measure scales and a comprehensive neuropsychological battery. Analyses involved preliminary Pearson bivariate correlations to identify sociodemographic and clinical variables associated with the FAST total score. Regarding neuropsychological variables, a principal component analysis (PCA) was performed to group the variables in orthogonal factors. Finally, a hierarchical multiple regression was run.

RESULTS

The best fitting model for the variables associated with functioning was a linear combination of gender, age, estimated IQ, Hamilton Depression Rating Scale (HAM-D), number of previous manic episodes, Factor 1 and Factor 2 extracted from the PCA. The model, including all these previous variables, explained up to 29.4% of the observed variance.

CONCLUSIONS

Male gender, older age, lower premorbid IQ, subdepressive symptoms, higher number of manic episodes, and lower performance in verbal memory, working memory, verbal fluency, and processing speed were associated with lower functioning in patients with BD.

The inner world of overactive monitoring: neural markers of interoception in obsessive-compulsive disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) patients typically overmonitor their own behavior, as shown by symptoms of excessive doubt and checking. Although this is well established for the patients' relationship with external stimuli in the environment, no study has explored their monitoring of internal body signals, a process known to be affected in anxiety-related syndromes. Here, we explored this issue through a cardiac interoception task that measures sensing of heartbeats. Our aim was to explore key behavioral and electrophysiological aspects of internal-cue monitoring in OCD, while examining their potential distinctiveness in this condition.

METHOD

We administered a heartbeat detection (HBD) task (with related interoceptive confidence and awareness measures) to three matched groups (OCD patients, panic disorder patients, healthy controls) and recorded ongoing modulations of two task-relevant electrophysiological markers: the heart evoked potential (HEP) and the motor potential (MP).

RESULTS

Behaviorally, OCD patients outperformed controls and panic patients in the HBD task. Moreover, they exhibited greater amplitude modulation of both the HEP and the MP during cardiac interoception. However, they evinced poorer confidence and awareness of their interoceptive skills.

CONCLUSIONS

Convergent behavioral and electrophysiological data showed that overactive monitoring in OCD extends to the sensing of internal bodily signals. Moreover, this pattern discriminated OCD from panic patients, suggesting a condition-distinctive alteration. Our results highlight the potential of exploring interoceptive processes in the OCD spectrum to better characterize the population's cognitive profile. Finally, these findings may lay new bridges between somatic theories of emotion and cognitive models of OCD.

Effects of functional remediation on neurocognitively impaired bipolar patients: enhancement of verbal memory

BACKGROUND

Functional remediation is a novel intervention with demonstrated efficacy at improving functional outcome in euthymic bipolar patients. However, in a previous trial no significant changes in neurocognitive measures were detected. The objective of the present analysis was to test the efficacy of this therapy in the enhancement of neuropsychological functions in a subgroup of neurocognitively impaired bipolar patients.

METHOD

A total of 188 out of 239 DSM-IV euthymic bipolar patients performing below two standard deviations from the mean of normative data in any neurocognitive test were included in this subanalysis. Repeated-measures analyses of variance were conducted to assess the impact of the treatment arms [functional remediation, psychoeducation, or treatment as usual (TAU)] on participants' neurocognitive and functional outcomes in the subgroup of neurocognitively impaired patients.

RESULTS

Patients receiving functional remediation (n = 56) showed an improvement on delayed free recall when compared with the TAU (n = 63) and psychoeducation (n = 69) groups as shown by the group × time interaction at 6-month follow-up [F 2,158 = 3.37, degrees of freedom (df) = 2, p = 0.037]. However, Tukey post-hoc analyses revealed that functional remediation was only superior when compared with TAU (p = 0.04), but not with psychoeducation (p = 0.10). Finally, the patients in the functional remediation group also benefited from the treatment in terms of functional outcome (F 2,158 = 4.26, df = 2, p = 0.016).

CONCLUSIONS

Functional remediation is effective at improving verbal memory and psychosocial functioning in a sample of neurocognitively impaired bipolar patients at 6-month follow-up. Neurocognitive enhancement may be one of the active ingredients of this novel intervention, and, specifically, verbal memory appears to be the most sensitive function that improves with functional remediation.

Lipochoristoma of the internal auditory canal

PROBLEM

Approximately 90% of tumours of cerebellopontine angle and internal auditory canal are vestibular schwannomas (acoustic neuromas) and meningiomas. Lipochoristomas are rare benign masses that represent only 0.15% of cases.

METHODOLOGY

We report the case of a 39-year-old man who consulted us for right-sided hearing loss and tinnitus.

RESULTS

Tonal audiometry showed a down-sloping right sensorineural hearing loss in frequencies above 2000 Hz. Magnetic resonance imaging (MRI) revealed a heterogeneous lesion in the right internal auditory canal with areas of hyperintensity on noncontrast T1-weighted MRI and suppression of much of the signal of the lesion with persistence of some areas of enhancement on T1-weighted fat-suppressed images.

CONCLUSION

Correct imaging diagnosis through MRI (high signal intensity on noncontrast T1-weighted images together with a missing signal in fat suppression sequences) is essential in order to avoid unnecessary surgery or radiation therapy, which are not recommended in the treatment of these lesions.

Biofilm colonisation in nasolacrimal stents

PROBLEM/OBJECTIVE

Nasolacrimal duct obstruction is a common problem. A Song stent is a useful and simple treatment with low morbidity. However, the success rate is limited, especially in long-term follow-up. The aim of the present study is to determine the presence of biofilms in failing nasolacrimal stents.

METHODOLOGY

Thirty-three polyurethane nasolacrimal stents were implanted between January 2006 and December 2007 using Song's technique. Patients were followed for a mean of 21.5 months (range 11-30 months). Removed nasolacrimal stents were preserved in saline and examined using environmental scanning electron microscopy (ESEM).

RESULTS

Eighteen nasolacrimal stents were removed because of the failure of the device (follow-up range 11-30 months). Seven stents were recovered for this study. Biofilms were identified in all the specimens studied. Five prostheses showed occlusion caused by mucus or granulation tissue.

CONCLUSIONS

Biofilm colonisation of nasolacrimal stents could play a major role in prosthetic failure leading to stent occlusion. Mucus, granulation tissue and irregularities of the biomaterial are factors that facilitate biofilm colonisation. Non-stick material for newly developed stents or drugs capable of destroying the polysaccharide matrix should be considered as future therapeutic options.

beta-Glucanases as a tool for the control of wine spoilage yeasts

In this study, the antimicrobial activity of a commercial beta-glucanase preparation against wine spoilage yeasts such as Cryptococcus albidus, Dekkera bruxellensis, Pichia membranifaciens, Saccharomyces cerevisiae, Zygosaccharomyces bailii, and Zygosaccharomyces bisporus has been evaluated. Yeast species tested showed different sensitivities to the enzyme preparation. In vitro assays in laboratory medium (GPY) showed inhibition by the beta-glucanase preparation of D. bruxellensis and Z. bailii growth with IC(50) and MIC values approximately 3 to 4-fold greater than the recommended dose for improving wine filtration. Wine spoilage experiments showed antimicrobial action against D. bruxellensis and Z. bailii although with reduced effectiveness to that showed in laboratory medium. Under the conditions tested, the addition of beta-glucanase did not affect wine enological parameters. Our data suggest the potential use of beta-glucanases as antimicrobial agents in wine and indicate that the application of antimicrobial enzymes for yeast spoilage control deserves further investigation.

[Drug-drug interactions in patients from an internal medicine service]

OBJECTIVE

Drug interactions are the cause of serious adverse reactions, the incidence and morbi-mortality of which are not yet well established. The aim of this study is to carry out an initial estimate of drug interactions in an internal medicine service and to look at any factors associated with their appearance.

METHOD

A prospective study was carried out with 120 patients randomly selected from a total of 376 patients admitted to an internal medicine service over a period of three months (February-April 2007). A protocol was designed on an ad-hoc basis to record the interactions.

RESULTS

It was observed that 43% of the patients had at least one potential adverse drug interaction and 14% showed associated adverse interactions. The drug with the highest implications in pharmacokinetic interactions was omeprazole when prescribed with acenocoumarol, phenytoin and digoxin. The most significant pharmacodynamic interactions were with associations between NSAID and saluretic-diuretics, insulin and beta-blockers, and aspirin and prednisone. The number of interactions did relate to the number of prescriptions (p < .001), however this was not the case for gender, age and co-morbidity.

CONCLUSIONS

Drug interaction is a serious clinical problem which requires the availability of more in depth information and medical attention.

[Clinical aspects and endoscopic management of gastrointestinal bleeding from Dieulafoy's lesion]

OBJECTIVE

the aim of the study was to assess the incidence, clinical presentation, location, and response to endoscopic therapy of gastrointestinal bleeding from Dieulafoy's lesion.

MATERIAL AND METHOD

ALL consecutive episodes of gastrointestinal bleeding due to Dieulafoy's lesion seen between 2000 and 2006 were retrospectively reviewed. All main clinical and endoscopic data were collected: type and effectiveness of endoscopic therapy, rebleeding, complications, and mortality during hospitalization.

RESULTS

WE found 41 patients, 26 males and 15 females, median age of 71.19 years. Dieulafoy's lesion accounted for 1.55% of all gastrointestinal bleeding episodes during the study period. The incidence of Dieulafoy's lesion was 2.2 cases/100.000 inhabitants/year. Active bleeding at endoscopy was present in 85.36%, and comorbidity in 92.68%. The stomach was the most frequent location (60.97%), followed by duodenum (29.26%). Endoscopic therapy achieved initial hemostasis in all cases. Three patients (7.31%) initially treated with epinephrine injection showed rebleeding and properly responded to a second session of endoscopic therapy. No surgery was needed. The mortality rate during hospitalization was 4.87%.

CONCLUSIONS

Dieulafoy's lesion is an uncommon, but potentially severe cause of gastrointestinal bleeding. It may be found in any location within the gastrointestinal tract. Endoscopic therapy is effective and safe. Injected epinephrine alone is associated with a higher risk of rebleeding.

[The neurodynamic core of consciousness and neural Darwinism]

INTRODUCTION

In the last decades, the scientific study of consciousness in the scope of the cognitive neurosciences can be considered one of the greatest challenges of contemporary science. The Gerald Edelman theory of consciousness is one of the most promising and controversial perspectives. This theory stands out by its approach to topics usually rejected by other neurophysiologic theories of consciousness, as the case of the neurophysiologic explanation of qualia.

AIM

The goal of this paper is to review the dynamic core theory of consciousness, presenting the main features of the theory, analyzing the explanation strategies, their empirical extensions, and elaborating some critical considerations about the possibility of the neuroscientific study of qualia.

DEVELOPMENT

The central and additional theoretical components are analyzed, emphasizing its ontological, restrictive and explanatory assumptions. The properties of conscious phenomena and their cerebral correlates as advanced by the theory are described, and finally its experiments and empirical extensions are examined. The explanatory strategies of the theory are analyzed, based on conceptual isomorphism between the phenomenological properties and the neurophysiological and mathematical measures. Some criticisms could be raised about the limitations of the dynamic core theory, especially regarding its account of the so-called 'hard problem' of consciousness or qualia.

Central role of supporting cells in cochlear homeostasis and pathology

HYPOTHESIS

Supporting cells have a crucial role in degenerative and regenerative events of primary sensorial hair cells of the organ of Corti. This new role should determine future studies about pathophysiology of hearing loss and its regenerative treatment.

SUPPORTING EVIDENCE

Recent findings suggest an active role of supporting cells in the maintenance of hair cell function and structure. Evidences of high energy consumption and close proximity to auditory nervous fibers suggesting K+ active exchange, preferential expression of specific proteins and antigens, presence of glucocorticoids receptors, affinity for cisplatin and regenerative potential give the supporting cells an important role in homeostasis of the organ of Corti and in some specific diseases affecting this structure.

CONCLUSION

As well as glial cells provide protection and regeneration to neural tissues, supporting cells may provide the necessary metabolic and electrolitic conditions for hair cells mechanical and bioelectrical function. This opens new possibilities for the treatment of apparently "irreversible" destruction of the inner ear.

Phenotypic variability in familial prion diseases due to the D178N mutation

BACKGROUND

Between January 1993 and December 2003, 19 patients with familial prion diseases due to the D178N mutation were referred to the regional epidemiological registry for spongiform encephalopathies in the Basque Country in Spain, a small community of some 2,100,000 inhabitants.

METHODS

Ten further patients belonging to the same pedigrees were retrospectively ascertained through neurological or neuropathological records. In four of the patients, the diagnosis was confirmed by analysing DNA obtained from paraffin blocks. In this article, we report on the clinical, genetic, and pathological features of the 23 patients carrying the D178N mutation confirmed by genetic molecular analysis. Haplotyping studies suggest a founder effect among Basque born families, explaining in part this unusually high incidence of the D178N mutation in a small community. Only two patients (8%) lack familial antecedents.

RESULTS

We have observed a phenotypic variability even among homozygous 129MM patients. Our findings challenge the currently accepted belief that MM homozygosity in codon 129 is always related to a fatal familial insomnia (FFI) phenotype. Indeed, seven out of 17 patients with a 129MM genotype in this series presented with a Creutzfeldt-Jakob disease (CJD) clinicopathological picture.

CONCLUSIONS

The considerable clinical and pathological overlapping observed among homozygous 129MM patients favours the view that FFI and CJD178 are the extremes of a spectrum rather than two discrete and separate entities. Other genetic or environmental factors apart from the polymorphism in codon 129 may play a role in determining the phenotypic expression of the D178N mutation in the PRNP gene.

Plasma von Willebrand factor, soluble thrombomodulin, and fibrin D-dimer concentrations in acute onset non-rheumatic atrial fibrillation

OBJECTIVE

To investigate whether new onset acute atrial fibrillation (AF) of < 48 hours' duration creates a prothrombotic state in the absence of anticoagulation and to assess the evolution in research indices after spontaneous or pharmacological cardioversion.

METHODS

24 patients were recruited with first onset acute non-rheumatic AF, in whom sinus rhythm was restored within 48 hours of arrhythmia onset, without anticoagulant treatment. Atrial mechanical function was assessed by transmitral inflow. Soluble thrombomodulin and von Willebrand factor concentrations (both as indices of endothelial damage or dysfunction) and fibrin D-dimer concentrations (as an index of thrombogenesis) were measured. Blood samples were drawn and echocardiographic studies were performed at days 1, 3, 7, and 30 after cardioversion. Research indices were compared with those of 24 healthy participants, 24 patients with chronic AF, and 24 patients with ischaemic heart disease in sinus rhythm.

RESULTS

Patients with AF had higher concentrations of soluble thrombomodulin (acute AF 12.1 (4.1) ng/ml; chronic AF 11.8 (4.6) ng/ml), von Willebrand factor (acute AF 137.2 (36.9) ng/ml; chronic AF 133.1 (25.0) ng/ml), and fibrin D-dimer concentrations (acute AF 2.35 (2.68) microg/ml; chronic AF 1.12 (0.65) microg/ml) than did healthy controls (5.9 (2.7) ng/ml, 86.7 (33.2) ng/ml, and 0.39 (0.28) microg/ml, respectively) and patients with ischaemic heart disease (7.4 (3.7) ng/ml, 110.0 (29.0) ng/ml, and 0.99 (0.73) microg/ml, respectively) (all p < 0.05). Day 30 concentrations of fibrin D-dimer were higher in patients with acute AF than in patients with chronic AF (p = 0.038) but sTM and von Willebrand factor concentrations were not different (both not significant). There were no significant changes in research indices or echocardiographic parameters after cardioversion (all p > 0.05).

CONCLUSIONS

There was evidence among patients with acute onset AF of endothelial damage or dysfunction and increased thrombogenesis, which persisted up to 30 days after cardioversion.

Plasma testosterone and pathological gambling

The authors studied plasma testosterone levels and psychological characteristics of male pathological gamblers. Twenty-nine male pathological gamblers and a group of healthy volunteers matched for age and gender were compared on levels of plasma testosterone and scores on the Eysenck Personality Questionnaire (EPQ) and the Psychopathic Deviance scale of the Minnesota Multiphasic Personality Inventory (MMPI). Plasma testosterone levels were similar in the pathological gambling and comparison group (476.06 ng/100 ml vs. 560.71 ng/100 ml). Patients had higher scores on the Neuroticism subscales of the EPQ (13.83 vs. 10.83) and the Psychopathic Deviance scale of the MMPI (27.03 vs. 21.03), but not on any of the other subscales of the EPQ. Testosterone levels did not correlate with the psychological ratings. Testosterone levels are probably not related to impulsivity in pathological gambling.

Electrochemical enzyme immunoassays on microchip platforms

A microfluidic device for conducting electrochemical enzyme immunoassays is described. The new "lab-on-a-chip" protocol integrates precolumn reactions of alkaline phosphatase-labeled antibody (anti-mouse IgG) with the antigen (mouse IgG), followed by electrophoretic separation of the free antibody and antibody-antigen complex. The separation is followed by a postcolumn reaction of the enzyme tracer with the 4-aminophenyl phosphate substrate and a downstream amperometric detection of the liberated 4-aminophenol product Factors influencing the reaction, separation, and detection processes were optimized, and the analytical performance was characterized. An applied field strength of 256 V/cm results in free antibody and antibody-antigen complex migration times of 125 and 340 s, respectively. A remarkably low detection limit of 2.5 x 10(-16) g/mL (1.7 x 10(-18) M) is obtained for the mouse IgG model analyte. Such combination of a complete integrated immunoassay, an attractive analytical performance, and the distinct miniaturization/portability advantages of electrochemical microsystems offers considerable promise for designing self-contained and disposable chips for decentralized clinical diagnostics or on-site environmental testing.

Psychiatric comorbidity in pathological gamblers seeking treatment

OBJECTIVE

The authors' goal was to determine the frequency of psychiatric comorbidity among treatment-seeking pathological gamblers, compare the severity of gambling and psychological problems in gamblers with and without comorbid disorders, and investigate differences between gamblers with and without comorbid disorders in the dopamine D(2) receptor gene (DRD(2)).

METHOD

Sixty-nine pathological gamblers who consecutively applied to a specialized outpatient treatment program were evaluated with structured interviews, self-report questionnaires, and psychological scales and were genotyped for a DRD(2) polymorphism.

RESULTS

A comorbid psychiatric disorder was present in 43 (62.3%) of the gamblers. The most frequent diagnoses were personality disorders (N=29 [42.0%]), alcohol abuse or dependence (N=23 [33.3%]), and adjustment disorders (N=12 [17.4%]). Gamblers with comorbid psychiatric disorders had gambling scores and psychological scale scores indicating greater severity of gambling and psychopathology. Significant differences in DRD(2) allele distribution were found in gamblers with and without comorbid disorders.

CONCLUSIONS

Psychiatric comorbidity is common among pathological gamblers and is associated with greater severity of clinical problems. The DRD(2) gene could be a liability genetic factor for psychiatric comorbidity in pathological gambling.

Pathological gambling: addiction or compulsion?

There is considerable debate about the appropriate conceptualization of pathological gambling and its place in psychiatric nosology. The authors examined the existing research on different areas of pathological gambling to find evidence for a particular model of this disorder. There are 2 dominant models of pathological gambling: as a nonpharmacologic addiction and as an obsessive-compulsive spectrum disorder. The data available from different areas seem to converge in suggesting that pathological gambling has characteristics that are similar to those of substance abuse, and less close to those of obsessive-compulsive disorder, although those conceptualizations are not mutually exclusive. An alternative model of pathological gambling is that it constitutes a heterogeneous disorder with some subtypes resembling obsessive-compulsive disorder, and other subtypes being closer to substance abuse disorders. Improved understanding of the conceptualization of this disorder may help improve the quality of the treatments available.

Absence of genetic diversity reduction in the HIV-1 integrated proviral LTR sequence population during successful combination therapy

We report the integrated proviral LTR sequence variation in four patients on highly active antiretroviral therapy (HAART). Integrated proviral fragments of LTR taken from four time points were PCR amplified from PBMCs and 10 to 12 individual clones were sequenced for each time point. Intrasample genetic distances and phylogenetic reconstruction of all LTR sequences demonstrated that 1-2 years of successful HAART did not significantly reduce the genetic repertoire of the integrated reservoir of HIV-1.

Genetic evolution of GB virus C/hepatitis G virus (GBV-C/HGV) under interferon pressure

The epidemiology and clinical features of chronic GBV-C/HGV infection have largely been explored, but there is little information about the mechanisms enabling GBV-C/HGV to cause persistent infection. Since analysis of the genomic variation of GBV-C/HGV under interferon pressure might provide some insight into this issue, we analyzed the nucleotide sequence variation of the 5'NC and NS3 regions in GBV-C/HGV isolates obtained sequentially from seven patients co-infected with HCV and treated with interferon. A reduction of GBV-C/HGV-RNA serum level below the detection limit of the RT-PCR assay was observed during treatment in all patients, but upon interferon withdrawal, viral RNA remained undetectable in only two patients. Among the five patients who did not clear GBV-C/HGV-RNA, viral strains emerging after treatment were identical to those present at baseline in three cases. In a further case, in whom GBV-C/HGV-RNA re-emerged during therapy (breakthrough episode), several mutations appeared in relapse samples. In the remaining patient, with a mixed infection before therapy, only one of the two GBV-C/HGV strains present at baseline was detected upon treatment withdrawal. These data raise the possibility that positive selection may act over GBV-C/HGV genome during interferon therapy, and contribute to persistence of infection with this virus.

Human immunodeficiency virus type 1 population bottleneck during indinavir therapy causes a genetic drift in the env quasispecies

The impact of emergence of genetic resistance, soon after the beginning of antiretroviral therapy, on the genotype of other viral loci not implicated in the development of resistance was studied in four human immunodeficiency type 1 (HIV-1)-infected patients subjected to indinavir monotherapy. Two patients were chosen because they showed no decrease in virus load during the study period and two were selected because they showed a rapid decline in plasma viraemia after the initiation of therapy and a virus rebound after 12 weeks of treatment. The evolution of virus sequences was analysed within the four infected patients by examining virus sequences spanning the protease and C2-V3 env genes by RT-PCR of plasma samples obtained at the beginning and after 12 weeks of therapy. PCR products from the two genomic regions from the two sample points per patient were cloned and 10-15 clones from each sample were sequenced. Genotypic indinavir resistance was present in the four patients after 12 weeks of therapy. The overall protease and C2-V3 env regions quasispecies diversity at time zero was higher than that after 12 weeks of therapy, but this difference was more significant in the two patients who showed a reduction in virus load soon after the initiation of treatment. C2-V3 env sequences indicated that changes during emergence of resistance to indinavir were only detected in the two patients who showed a drastic reduction in virus load. Thus, a temporal relationship was observed between the start of therapy, a drastic reduction in virus load and a drift in the HIV-1 env quasispecies.

Mutational analysis of Phe160 within the "palm" subdomain of human immunodeficiency virus type 1 reverse transcriptase

The highly conserved Phe160 residue is located in the "palm" subdomain of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT), and makes contact with Tyr115, a residue which is involved in deoxynucleoside triphosphate (dNTP) binding and fidelity of DNA synthesis. Five mutant RTs having Tyr, Trp, Ile, Ala or Gln instead of Phe160 were obtained by site-directed mutagenesis. F160Y and F160W retained substantial DNA polymerase activity, whereas the catalytic efficiency of nucleotide incorporation of mutants F160I, F160A and F160Q was less than 10 % that of the wild-type RT, using poly(rA).oligo(dT)20 as the template-primer. The low catalytic efficiency of mutants F160I, F160A and F160Q was due to their lower affinity for the dNTP substrate. F160Y displayed similar kinetic parameters as the wild-type RT in nucleotide insertion assays carried out with heteropolymeric DNA/DNA template-primers. However, nucleotide affinity was two- to sixfold reduced in the case of mutant F160W. Fidelity assays revealed similar misinsertion and mispair extension ratios for the three enzymes, although F160W showed a slightly higher accuracy of DNA synthesis, particularly in the presence of high concentrations of dNTP. When introduced in an infectious proviral clone, mutations F160I, F160A and F160Q rendered non-viable virus. The importance of Phe160 for polymerase function and viral replication could be mediated by its interaction with Tyr115, as suggested by the analysis of the available crystal structures of HIV-1 RT.

Quantification of integrated and total HIV-1 DNA after long-term highly active antiretroviral therapy in HIV-1-infected patients

OBJECTIVE

To assess the impact of long-term virus suppression on the peripheral blood CD4 T cells integrated and total HIV-1 DNA loads in patients receiving highly active antiretroviral therapy (HAART).

METHODS

A total of 10 HIV-1-infected patients receiving a triple combination therapy (two nucleoside analogues and one protease inhibitor) were longitudinally studied to compare integrated and total HIV-1 DNA loads. HIV-1 DNA quantification was performed using a quantitative nested polymerase chain reaction (PCR) on genomic peripheral blood mononuclear cell (PBMC) DNA obtained at baseline and at 48 weeks of HAART.

RESULTS

All the study patients showed an early and sustained decrease in plasma HIV-1 RNA to below the limit of detection (200 copies/ml). Concordant with the plasma viral decline, a significant increase in the CD4 T cell count was observed (P = 0.007). A statistically significant fivefold decrease in total HIV-1 DNA was detected after 48 weeks of HAART (P = 0.005). However, no statistically significant change was noted after the therapy when the integrated HIV-1 DNA copy number was compared (P = 0.333). Taken together, these results suggest that in the patients analysed the integrated HIV-1 DNA does not decay rapidly after HAART.

CONCLUSION

Within the study cohort the total amount of PBMC HIV-1 DNA decreased drastically after 48 weeks of HAART. Nevertheless, the integrated HIV-1 DNA did not significantly decay during this period. Although the data presented here are limited by the number of patients analysed, our findings suggest that 48 weeks of HAART does not significantly reduce the integrated HIV-1 proviral DNA load in the latently infected CD4 T cell reservoir.

Human immunodeficiency virus type 1 genetic evolution in patients with prolonged suppression of plasma viremia

Treatment of human immunodeficiency virus type 1 (HIV-1)-infected patients with combination drug regimens results in a reduction of plasma viral load to levels below the limit of detection. To investigate the genomic fluctuations in HIV-1 populations from long-term responders to antiviral therapies we analyzed the viral sequence evolution of env and pol genes from sequential peripheral blood mononuclear cell (PBMC) DNA samples of three infected patients. Analyses of sequences covering the V3 and flanking env regions obtained from blood samples at the beginning of the therapy and at 14 or 24 months from baseline revealed that HIV-1 quasispecies continue to evolve in the three patients following combination antiretroviral therapy. Minor drug-resistant mutant subpopulations were also searched for and found in one patient. Interestingly, no minor resistant subpopulations were found in the other two patients despite the fact that they showed evidence of ongoing viral replication. Finally, the genetic analysis of the env gene shows a reduction in PBMC env viral population diversity after long-term response to the therapy in all the patients analyzed.

Genetic evolution of hepatitis G virus in chronically infected individual patients

Comparative sequence analysis of different isolates of hepatitis G virus (HGV) has demonstrated significant intersubject genetic heterogeneity, but few data on intrasubject genetic evolution have been reported. To further investigate the genetic diversification of the HGV genome, 36 plasma samples from eleven patients chronically infected with HGV serially obtained 2-4 years apart were analysed. We determined the viral nucleotide sequence of the 5' non-coding (NC) and the NS3 regions by directly sequencing the RT-PCR amplified products obtained from the viral RNAs. Intrasubject sequence variation was found to be 1.3-2.4 x 10(-3) base substitutions per genome site per year within the 5' NC region and 1.3-9.4 x 10(-3) base substitutions per genome site per year within the NS3 region. Depending on the genomic region analysed (i.e. 5' NC or NS3 region), pairwise comparisons and phylogenetic reconstructions showed that intersubject genetic distances were 17.5- to 20.8-fold greater than intrasubject ones. Overall, the evolution rate of HGV in the regions analysed is not significantly different from that found in hepatitis C virus.

Prevalence and genotypes of GB virus C/hepatitis G virus (GBV-C/HGV) and hepatitis C virus among patients infected with human immunodeficiency virus: evidence of GBV-C/HGV sexual transmission

The development of new antiretroviral agents may improve survival of HIV-infected individuals, and therefore chronic viral hepatitis may become more relevant in these patients. The presence of GBV-C/HGV and hepatitis C virus (HCV) RNA were investigated by reverse transcriptase-nested polymerase chain reaction in plasma from 168 Spanish HIV-infected patients belonging to four different risk groups: intravenous drug users (IVDUs), hemophiliacs, homosexuals, and heterosexuals. GBV-C/HGV-RNA and HCV-RNA were detected in 18% and 43% of the patients, respectively. The prevalence of current infection with these viruses was notably high, 19% for GBV-C/HGV and 69% for HCV, among individuals with parenteral risk of infection (intravenous drug abusers and hemophiliacs), but sexual transmission with GBV-C/HGV was also suggested because 16.5% of patients with sexual risk, either homosexual or heterosexual, had GBV-C/HGV-RNA in plasma. Although investigation of GBV-C/HGV-RNA possibly underestimates the actual prevalence of infection with GBV-C/HGV, the above data suggest that sexual contact may play a relevant role in the spread of this virus. Phylogenetic analysis showed no evidence for clustering of NS3 sequences into different genotypes or subtypes of GBV-C/HGV.

Synaptophysin immunoreactivity in the cat cochlear nuclei

The presence of synaptophysin, a presynaptic Ca2+ binding glycoprotein, has been analyzed in the cochlear nucleus complex of the adult cat using an antisynaptophysin monoclonal antibody. Synaptophysin immunoreactivity was differently distributed between regions of cochlear nuclei. Terminal boutons contacting directly with neurons (cell bodies and dendrites) or in the neuropil of ventral and dorsal cochlear nuclei appeared immunostained. In the ventral cochlear nucleus, synaptophysin-labelled boutons were clearly defined in contact with spherical, globular, multipolar, octopus and cochlear-nerve root neurons. However, the dorsal cochlear nucleus showed a dense immunostained network of synaptophysin-labelled puncta, inside which some neuron cell bodies were observed. The present findings show a differential distribution of synaptophysin-immunostained boutons between the ventral and the dorsal cochlear nuclei of the cat. The present description of the different synaptophysin-labelled terminal boutons in the cochlear nuclei complex and their pattern of distribution, will be useful for further studies on development, degeneration or regeneration of the peripheral auditory pathway.

Genetic association study between pathological gambling and a functional DNA polymorphism at the D4 receptor gene

A Spanish sample consisting of 68 Caucasian pathological gambling patients (47 males and 21 females) and 68 unaffected controls were screened by the molecular analysis of a functional DNA polymorphism in the locus for the D4 dopamine receptor gene. Our results are consistent with the existence of a significant association between genetic variants at a DRD4 gene polymorphism and pathological gambling (chi 2 = 11.82; P = 0.037). This association seems to be sex-influenced, since there was no significant association when only males were considered (chi 2 = 9.45; P = 0.09), but there was a more significant association if we only considered female subjects (chi 2 = 8.73; P = 0.033). Individuals with the longest allele (D7) were the most frequent in affected females (chi 2 = 4.50; P = 0.033). This work provides a new evidence of the implication of the dopaminergic reward pathways, now through the involvement of DRD4, in the aetiology of this impulsive disorder.

Immunological and virological activity of zalcitabine and zidovudine in combination in HIV-positive people with CD4 cell counts of between 200-500 cells/mm3

We evaluated the effect of combination therapy with zidovudine (AZT) plus zalcitabine (ddC) in human immunodeficiency virus type 1 (HIV-1)-infected patients who had not previously received antiretroviral treatment ('naive' patients). The immunological and virological parameters evaluated were CD4 cell count, syncytium-inducing (SI) viral phenotype and plasma HIV-1 RNA copies/ml (HIV viral load). A total of 75 patients entered the study, with CD4 cell counts between 200 and 500 cells/mm3. All received zidovudine (200 mg) plus zalcitabine (0.75 mg) three times daily for 24 weeks. Treatment was well tolerated. However, four patients presented with anaemia (haemoglobin < 10.0 g/dl) and one patient had both anaemia and neutropenia (0.8 x 10(9) neutrophils/l). Combination therapy with zidovudine plus zalcitabine resulted in a pronounced improvement of virological and immunological markers. Approximately 25% of patients achieved undetectable plasma HIV RNA levels (< 200 copies/ml) at week 24. At the end of the study (24 weeks) a significant reduction (> 0.5 log) of plasma HIV RNA was observed in approximately 70% of patients and in 50% an even greater decrease (> 1 log) was achieved. The most significant decrease in mean plasma HIV RNA levels was observed at week 4, whereas the highest increase in CD4 cell count was found at week 24. Approximately 80% of patients who showed baseline plasma HIV RNA levels below 20000 copies/ml had less than 5000 copies/ml at week 24. The plasma HIV RNA reduction observed at week 4 was significantly maintained at week 24. Therefore, we can rapidly select those who will not respond to therapy and adjust the treatment after a short interval. Our study supports the idea of early therapy because all patients who reached undetectable levels of plasma HIV RNA at week 24 had at baseline a median plasma HIV RNA load of 2560 copies/ml. In conclusion, zidovudine in combination with zalcitabine was well tolerated in the majority of patients and led to a significant reduction in plasma HIV RNA copies in most of the patients with initial viraemia lower than 20000 copies/ml.

Plasma HIV-1 RNA as a predictor of the efficacy of adding zalcitabine to a previous regimen with zidovudine

The objective of this study was to determine whether or not plasma HIV-1 RNA levels, the syncytium-inducing phenotype assay or mutations at codon 215 of the gene encoding HIV-1 reverse transcriptase could have prognostic value in patients already undergoing therapy with zidovudine who were started on combination therapy with zidovudine and zalcitabine. A prospective study was performed in 37 HIV-1-infected individuals who had received at least 6 months (mean: 9 months; range: 6-24 months) of zidovudine to which zalcitabine was added. The mean initial CD4 cell count was 330 cells/mm3 (range: 20-520 cells/mm3). At baseline and at the end of the study (12 months), we analysed CD4 and CD8 cell counts, plasma HIV-1 RNA levels, the syncytium-inducing phenotype of virus isolated from peripheral blood mononuclear cells and mutations at codon 215 of the gene encoding reverse transcriptase. These variables were studied by Fisher's exact and U Mann-Whitney tests. There were statistically significant differences between progressor and non-progressor groups at baseline and after a 12-month period in the following parameters: CD4 and CD8 cell counts and HIV-1 RNA level (P < 0.05). Clinical progression occurred significantly more often in patients with CD4 cell counts < or = 300 cells/mm3 and HIV-1 RNA > 30000 copies/ml at baseline (P = 0.003). Moreover, we found that progression to AIDS only occurred in those patients whose viral load increased during the follow-up period and who had a CD4 cell count < 300 cells/mm3. Our results show the usefulness of HIV-1 RNA level as a surrogate marker for clinical outcome.

Quantitative HIV-1 RNA as a marker of clinical stability and survival in a cohort of 302 patients with a mean CD4 cell count of 300 x 10(6)/l

OBJECTIVE

To analyse plasma HIV-1 RNA levels as a marker of clinical stability and survival in a cohort of HIV-infected patients whose time of seroconversion is unknown.

DESIGN

Retrospective cohort study.

SETTING

Retrovirology laboratory and AIDS Unit in a teaching hospital.

PATIENTS

A total of 916 samples from 302 patients, most on antiretroviral therapy, were analysed. Mean initial CD4 cell counts and HIV-1 RNA were 299 x 10(6)/l (range: 0-1600) and 134,261 copies/ml (range: < 200-4,300,000), respectively. Sixty-six cases had been diagnosed previously with AIDS.

METHODS

Analysis of progression to AIDS and survival, according to initial and longitudinal viral load (VL) and CD4 cell count measurements was performed by Kaplan-Meier test. Relative risks were calculated by Cox's proportional hazards model.

RESULTS

During a mean follow-up of 444 +/- 309 days, 29 patients developed AIDS and 21 died. Relative risk (RR) of progression related to the group with VL < 35,000 was: 10.4 when CD4 > or = 250 x 10(6)/l and VL > or = 35,000 (P = 0.001); and 45.3 when CD4 < 250 x 10(6)/l and VL > or = 35,000 (P < 0.0001). Cumulative probability of progression was: 0%, 0% and 12.3%, at the first, second and third year respectively, for patients with all their sequential VL determinations < 60,000; and 13.3%, 34.7% and 79.3% for patients who did not maintain VL values always < 60,000 (RR = 23; P < 0.0001). The minimum value of VL that reached statistical significance for the survival analysis was 100,000 copies/ml (P < 0.0001).

CONCLUSIONS

VL > or = or < 35,000 is a better discriminant for progression than a CD4 cell count > or = or < 250 x 10(6)/l. Sequential VL determinations < 60,000 are associated with a better prognosis.

Short-term anti-HIV activity of the combination of didanosine and hydroxyurea

The synergistic action of hydroxyurea with some other antiretroviral drugs led us to evaluate the effect of therapy with the combination of didanosine and hydroxyurea in HIV-1-infected patients. We aimed to assess the anti-HIV activity of therapy with this combination by measuring variations in viral load and in CD4 cell counts. We also evaluated the potential side effects of this drug combination in HIV-1-positive patients with advanced disease. A total of 15 HIV-1-seropositive homosexual men with a mean baseline CD4 cell count of 149 cells/mm3 (range: 1-430 cells/mm3) were recruited to the study, and received didanosine (200 mg) plus hydroxyurea (500 mg) twice daily for 12 weeks. Ten patients were didanosine naive and five had previously received didanosine (for > 3 months). The combination therapy was well tolerated, although grade 2-3 alopecia appeared in four patients who had very low CD4 cell counts (< 50 cells/mm3). No significant variation in renal, hepatic and pancreatic functions occurred. A significant reduction in the plasma HIV-1 RNA (> 0.5 logs) was observed in seven of ten patients naive to didanosine after weeks 4 and 12 of the study; five of these patients had a decrease in plasma HIV-1 RNA of > 1.5 logs, with two having a decrease of > 2.0 logs. The viral load became undetectable (below 200 copies/ml) in three patients. The patients whose plasma HIV-1 RNA levels were not significantly reduced by the combination therapy had a higher baseline viral load. CD4 cell counts did not increase significantly in most patients. We observed a better response in those patients who had virus of the non-syncytium-inducing phenotype. In conclusion, hydroxyurea in combination with didanosine was well tolerated and led to a reduction in viral load mainly in patients who were initially naive to didanosine.

[Chylopericardium after acute pericarditis]

We present an 18 year-old man with chylopericardium after acute pericarditis with severe pericardial effusion and cardiac tamponade secondary to Mycoplasma pneumoniae infection. We review the etiology, diagnostic procedures and therapeutic possibilities for chylopericardium.

H and B human blood-group antigen expression in cochlear hair cells is modulated by thyroxine

The presence of human blood-group antigens in developing and adult hypothyroid rat cochleas was analyzed using antibodies directed against antigens H and B. During postnatal development, hypothyroid rat cochleas exhibited a highly selective expression of both B and H antigens, mainly at the hair cell level. Labeling for antigen B was found throughout the hair cells, whereas the antibody directed against antigen H selectively labeled the apical part of these cells. These immunostaining patterns were similar to those found in normal (euthyroid) rat cochleas, but antigenic expression periods were clearly prolonged. Thus, whereas in normal rat cochleas, the B and H antigenic expression disappears from postnatal day (PD) 9 on, in cochleas of hypothyroid rats the reactivity was intense until PD15; it decreased from this developmental stage, and was negative or only faintly positive at PD30. Therefore, in congenital hypothyroidism, hair cell immunoreactivity is present at developmental stages that are negative in normal rat cochleas. These results suggest that human blood-group antigen expression on the developing cochlear hair cells of rats is modulated by thyroxine and that thyroxine is necessary for the temporal expression pattern and secretion of normal glycoproteins.

Hemophilic pseudotumor: multicenter experience over a 25-year period

Pseudotumor is an infrequent manifestation of bleeding diathesis seen in hemophiliacs, the management of which is still controversial. To ascertain the effectiveness of the main therapies of choice, we have reviewed 1,831 patients affected by hemophilias A (1,108) and B (172), von Willebrand's disease (329), and other miscellaneous coagulopathies (222) diagnosed between 1965 and 1990 in a multicentric, retrospective study. Pseudotumor was proven in 21 patients. Replacement therapy was given in 15 cases as the first therapeutic approach, with complete success attained in only two, whereas surgery, which was carried out in 14 patients, completely resolved the process in eight (P = 0.017). Patients over 40 years of age demonstrated worse prognosis than younger patients (P = 0.02), but no other clinical parameters were shown to have influenced the patients' evolution. Surgical management was the most effective treatment for pseudotumor, although more conservative therapies cannot be overlooked in selected cases.