Psychosis-inducing effects of cannabis are related to both childhood abuse and COMT genotypes.

OBJECTIVE: To test whether the association between childhood abuse, cannabis use and psychotic experiences (PEs) was moderated by the COMT (catechol-O-methyltransferase) gene. METHOD: Psychotic experiences (PEs), childhood abuse, cannabis use and COMT Val158Met genotypes were assessed in 533 individuals from the general population. Data were analysed hierarchically by means of multiple linear regression models. RESULTS: Childhood abuse showed a significant main effect on both positive (ß = 0.09; SE = 0.04; P = 0.047) and negative PEs (ß = 0.11; SE = 0.05; P = 0.038). A significant three-way interaction effect was found among childhood abuse, cannabis use and the COMT gene on positive PEs (ß = -0.30; SE = 0.11; P = 0.006). This result suggests that COMT genotypes and cannabis use only influenced PE scores among individuals exposed to childhood abuse. Furthermore, exposure to childhood abuse and cannabis use increased PE scores in Val carriers. However, in individuals exposed to childhood abuse but who did not use cannabis, PEs increased as a function of the Met allele copies of the COMT gene. CONCLUSION: Cannabis use after exposure to childhood abuse may have opposite effects on the risk of PEs, depending on the COMT genotypes providing evidence for a qualitative interaction. Val carriers exposed to childhood abuse are vulnerable to the psychosis-inducing effects of cannabis.

The role of genetic variability in the SLC6A4, BDNF and GABRA6 genes in anxiety-related traits.

OBJECTIVE: The aims of this study were to test the individual association of the serotonin transporter gene (SLC6A4), the brain-derived neurotrophic factor gene (BDNF) and the GABA(A) α(6) receptor subunit gene (GABRA6) with anxiety-related traits and to explore putative gene-gene interactions in a Spanish healthy sample. METHOD: A sample of 937 individuals from the general population completed the Temperament and Character Inventory questionnaire to explore Harm Avoidance (HA) dimension; a subsample of 553 individuals also filled in the Big Five Questionnaire to explore the Neuroticism dimension. The whole sample was genotyped for the 5-HTTLPR polymorphism (SLC6A4 gene), the Val66Met polymorphism (BDNF gene) and the T1521C polymorphism (GABRA6 gene). RESULTS: Homozygous individuals for the T allele of the T1512C polymorphism presented slightly higher scores for HA than C allele carriers (F = 2.96, P = 0.019). In addition, there was a significant gene-gene interaction on HA between the 5-HTTLPR and Val66Met polymorphisms (F = 3.4, P = 0.009). CONCLUSION: GABRA6 emerges as a candidate gene involved in the variability of HA. The effect of a significant gene-gene interaction between the SLC6A4 and BDNF genes on HA could explain part of the genetic basis underlying anxiety-related traits.

Early adversity and 5-HTT/BDNF genes: new evidence of gene-environment interactions on depressive symptoms in a general population.

BACKGROUND: Adverse childhood experiences have been described as one of the major environmental risk factors for depressive disorder. Similarly, the deleterious impact of early traumatic experiences on depression seems to be moderated by individual genetic variability. Serotonin transporter (5-HTT) and brain-derived neurotrophic factor (BDNF) modulate the effect of childhood adversity on adult depression, although inconsistencies across studies have been found. Moreover, the gene x environment (GxE) interaction concerning the different types of childhood adversity remains poorly understood. The aim of this study was to analyse the putative interaction between the 5-HTT gene (5-HTTLPR polymorphism), the BDNF gene (Val66Met polymorphism) and childhood adversity in accounting for adult depressive symptoms. METHOD: A sample of 534 healthy individuals filled in self-report questionnaires of depressive symptomatology [the Symptom Check List 90 Revised (SCL-90-R)] and different types of childhood adversities [the Childhood Trauma Questionnaire (CTQ)]. The 5-HTTLPR polymorphism (5-HTT gene) and the Val66Met polymorphism (BDNF gene) were genotyped in the whole sample. RESULTS: Total childhood adversity (beta=0.27, p<0.001), childhood sexual abuse (CSA; beta=0.17, p<0.001), childhood emotional abuse (beta=0.27, p<0.001) and childhood emotional neglect (beta=0.22, p<0.001) had an impact on adult depressive symptoms. CSA had a greater impact on depressive symptoms in Met allele carriers of the BDNF gene than in the Val/Val group (F=5.87, p<0.0001), and in S carriers of the 5-HTTLPR polymorphism (5-HTT gene) (F=5.80, p<0.0001). CONCLUSIONS: Childhood adversity per se predicted higher levels of adult depressive symptoms. In addition, BDNF Val66Met and 5-HTTLPR polymorphisms seemed to moderate the effect of CSA on adult depressive symptoms.

Putative role of the COMT gene polymorphism (Val158Met) on verbal working memory functioning in a healthy population.

Working memory has been described as a neurocognitive probe of prefrontal brain functioning. Genetic variability related with catechol-O-methyltransferase (COMT) gene (Val158Met polymorphism) has received increasing attention as a possible modulator of working memory tasks in both schizophrenic patients and healthy subjects, although inconsistencies across studies have been found. This may be related to the existence of different working memory components, processes and modalities, which may have different sensitivities to subtle changes in dopamine levels and, therefore, the effect of the underlying COMT Val158Met genetic variability. To test this out a large sample of 521 healthy individuals from the general population were tested on the WCST and three working memory tasks that cover the assessment of verbal and spatial working modalities as well as different components and processes (Letter and Number Sequencing, CPT-IP, Backwards Visual Span). All individuals were genotyped for the rs4680 (Val158Met) polymorphism at the COMT gene. Met carriers showed near-significant better performance in the LNS compared with Val/Val individuals (F = 3.9, df = 1, P = 0.046). Moreover, the analysis for linear trend found that Met allele carriers showed significantly better performance than Val/Val individuals (B = 0.58 P = 0.031), although evidence for a linear trend was not found. None of the WCST indices differed among genotypes. Consistent with the hypothesis that Val158Met polymorphism (COMT gene) might account for individual differences on dopamine-dependent prefrontally related neurocognitive functions, the Letter-Number Sequencing task, which requires not only maintenance but also active manipulation of information seemed to be more sensitive to the disadvantageous Val/Val genotype in a large non-clinical sample.

Genetic heterogeneity of Fasciola hepatica isolates in the northwest of Spain.

The liver fluke Fasciola hepatica is a worldwide distributed trematode parasite of great veterinary importance. In Spain, the prevalence of the infection is up to 56% in sheep. Its control is mainly based on the use of anthelmitics, although some resistant populations have been described. Genetic studies of the genus Fasciola have been focused on the 28S ribosomal deoxyribonucleic acid (rDNA) gene, with no intraspecific variations and a few interspecific nucleotide differences. We have designed a specific polymerase chain reaction to amplify and sequence a 510-bp-long fragment of the gene to characterize several F. hepatica ovine isolates from the northwest of Spain. All the isolates rendered the expected results on the agarose gel, while sequencing revealed some differences in the 34 site. The anthelmintic-resistant specimens showed the same nucleotide differing of the sensitive ones. Comparing to other studies, our results conclude that there are some genetic variations in F. hepatica (at the level of the 28S rDNA), including heterozygous specimens. In conclusion, a genetic heterogeneity has been found in the F. hepatica populations of ovine origin in the northwest of Spain, using an assay that could be useful for further epidemiology and characterization studies.

The treatment of claustrophobia with virtual reality: changes in other phobic behaviors not specifically treated.

This study was designed to determine the effectiveness of Virtual Reality (VR) exposure in the case of a patient with a diagnosis of two specific phobias (claustrophobia and storms) and panic disorder with agoraphobia. The treatment consisted of eight, individual, VR-graded exposure sessions designed specifically to treat claustrophobia. We obtained data at pretreatment, posttreatment, and 3-month follow-up on several clinical measures. Results point out the effectiveness of the VR procedure for the treatment of claustrophobia. An important change appeared in all measures after treatment completion. We also observed a generalization of improvement from claustrophobic situations to the other specific phobic and agoraphobic situations that were not treated. We can conclude that VR exposure was effective in reducing fear in closed spaces, in increasing self-efficacy in claustrophobic situations, and in improving other problems not specifically treated. Moreover, changes were maintained at 3 months after treatment.

Psychological variables and reality judgment in virtual environments: the roles of absorption and dissociation.

Literature on virtual reality (VR) and psychology has focused on the influence that some basic psychological processes have on VR. Although psychological processes may be defined as common to all humans, there are individual differences that might make it difficult to provide the same VR experience for everyone. Of the several personality and psychological variables that might be relevant to the VR field, this study focuses on two: absorption and dissociation. Both psychological dimensions are deeply interrelated and might play an important role in the immersion of subjects in virtual environments and in the reality attributions they make. Thus, the purpose of this study was to ascertain personality correlates on differences regarding the VR experience. The subjects were 39 psychology undergraduate students who were immersed in a VR environment for 15 minutes. Our data suggest that both absorption and dissociation influenced central issues regarding reality judgment in VR.

Differences on presence and reality judgment using a high impact workstation and a PC workstation.

The purpose of this study was to analyze differences in reality judgements made by subjects and their sense of presence when using the virtual reality (VR) settings of different VR workstations. The two workstations were (1) a high impact computer graphics workstation (Silicon Graphics) with a high quality head mounted display (FS5, Virtual Research) and a 3D joystick (Division) and (2) PC Pentium II-based platform with an AccelEclipse Graphical Card (AccelGraphics) with a medium quality head mounted display (V6, Virtual Research) and a 2D mouse. For measuring the sense of presence and reality, we used a 15-item questionnaire designed for this purpose that assesses the level of immersion and reality of the VR settings, availability of interaction with the VR environment, and emotions and bodily sensations experienced while immersed in the VR world. The subjects were 69 undergraduate students that volunteered for this study and were assigned at random to the two experimental workstations. Results indicated that there are no statistical differences in presence or reality judgment between both experimental conditions. This is an interesting finding because of the importance of reducing the cost of the equipment in the VR field.

Virtual reality treatment of claustrophobia: a case report.

The efficacy of a treatment for claustrophobia using only Virtual Reality (VR) exposure was examined. The subject was a 43-year-old female who suffered from clinically significant distress and impairment and sought psychological therapy. Eight individual VR graded exposure sessions were conducted. All self-report measures were reduced following VR exposure and were maintained at one month follow-up. The necessity of a theoretical framework for this new medium for exposure therapy is discussed.

[Mortality in geriatric patients in the Hospital General of Mexico]. / Mortalidad en pacientes geriátricos del Hospital General de México.

In order to define the main diseases of the elderly and a possible changes of mortality causes at Hospital General of Mexico, SSA, the authors studied 586 autopsy reports of individuals over sixty years old, deceased between 1960 and 1965 and of 625 individuals of similar characteristics deceased between 1981 and 1985. The analysis of diseases showed qualitative and quantitative changes in the ten principal causes of death at each period: some of the most frequent diseases in the 60's, for instance, amebiasis, were not included among the then principal causes of death in the 80's. On the other hand, malignant neoplasms persisted as one of the principal death causes in both periods, but the most frequent carcinoma in the 60's, gastric carcinoma, was substituted in the 80's by bronchogenic carcinoma. This study suggests that great technical and sanitary interventions are necessary to promote health of third age persons, an increasing but poorly protected population in our country.

[Mycetoma in northern Argentina]. / Micetomas en el norte argentino.

From 1972 to October 1982 we have observed 39 cases of mycetoma in the Skin Department of the Hospital del Milagro, Salta (Argentina). The diagnosis was based on the clinical aspect, mycological studies and in most cases histopathology was done as well. The mayoritary of the patients were farmers. From the clinical point of view there si a true prevalence of Nocardia Brasiliensis. Most of the mycetomas can be found in the lower limbs. Some of the patients presented quite severe lesions and eight of them had bone involvement. The combination of long action sulphas with sulphonas has been efficient enough in the treatment of mycetomas caused by Nocardia Brasiliensis.

Resultado del 1o. ano busqueda y seguimiento activo de casos por la campana antileprosa de Salta. / Results of the 1st year of search and active follow up of cases by the campaign against leprosy in Salta

Los trabajos publicados sobre lepra por el Servicio de Piel del Hospital del Milagro, interesaron a las autoridades sanitarias provinciales y nacionales, implementandose a partir de 1979 una campana activa de investigacion de focos y deteccion de nuevos enfermos en la provincia de Salta. Los 66 casos nuevos detectados en el primer ano, mas los 50 enfermos diagnosticados en 1980 hasta el 30 de setiembre, delatan una cifra muy significativa para que esta campana antileprosa prosiga con el plan trazado

Resultado del 1o. ano busqueda y seguimiento activo de casos por la campana antileprosa de Salta. / Results of the 1st year of search and active follow up of cases by the campaign against leprosy in Salta

Los trabajos publicados sobre lepra por el Servicio de Piel del Hospital del Milagro, interesaron a las autoridades sanitarias provinciales y nacionales, implementandose a partir de 1979 una campana activa de investigacion de focos y deteccion de nuevos enfermos en la provincia de Salta. Los 66 casos nuevos detectados en el primer ano, mas los 50 enfermos diagnosticados en 1980 hasta el 30 de setiembre, delatan una cifra muy significativa para que esta campana antileprosa prosiga con el plan trazado