Integrase-LEDGF/p75 complex triggers the formation of biomolecular condensates that modulate HIV-1 integration efficiency in vitro

The pre-integration steps of the HIV-1 viral cycle are some of the most valuable targets of recent therapeutic innovations. HIV-1 integrase (IN) displays multiple functions, thanks to its considerable conformational flexibility. Recently, such flexible proteins have been characterized by their ability to form biomolecular condensates as a result of Liquid-Liquid-Phase-Separation (LLPS), allowing them to evolve in a restricted microenvironment within cells called membrane less organelles (MLO). The LLPS context constitutes a more physiological approach to study the integration molecular mechanisms performed by intasomes (complexes containing viral DNA, IN and its cellular cofactor LEDGF/p75). We investigated here if such complexes can form LLPS in vitro and if IN enzymatic activities were affected by this LLPS environment. We observed that the LLPS formed by IN-LEDGF/p75 functional complexes modulate the in vitro IN activities. While the 3'-processing of viral DNA ends was drastically reduced inside LLPS, viral DNA strand transfer was strongly enhanced. These two catalytic IN activities appear thus tightly regulated by the environment encountered by intasomes.

Cognitive and clinical predictors of a long-term course in obsessive compulsive disorder: A machine learning approach in a prospective cohort study

BACKGROUND

Obsessive compulsive disorder (OCD) is a disabling illness with a chronic course, yet data on long-term outcomes are scarce. This study aimed to examine the long-term course of OCD in patients treated with different approaches (drugs, psychotherapy, and psychosurgery) and to identify predictors of clinical outcome by machine learning.

METHOD

We included outpatients with OCD treated at our referral unit. Demographic and neuropsychological data were collected at baseline using standardized instruments. Clinical data were collected at baseline, 12 weeks after starting pharmacological treatment prescribed at study inclusion, and after follow-up.

RESULTS

Of the 60 outpatients included, with follow-up data available for 5-17 years (mean = 10.6 years), 40 (67.7 %) were considered non-responders to adequate treatment at the end of the study. The best machine learning model achieved a correlation of 0.63 for predicting the long-term Yale-Brown Obsessive Compulsive Scale (Y-BOCS) score by adding clinical response (to the first pharmacological treatment) to the baseline clinical and neuropsychological characteristics.

LIMITATIONS

Our main limitations were the sample size, modest in the context of traditional ML studies, and the sample composition, more representative of rather severe OCD cases than of patients from the general community.

CONCLUSIONS

Many patients with OCD showed persistent and disabling symptoms at the end of follow-up despite comprehensive treatment that could include medication, psychotherapy, and psychosurgery. Machine learning algorithms can predict the long-term course of OCD using clinical and cognitive information to optimize treatment options.

Pathogenic missense variation in PABPC1L/EPAB causes female infertility due to oocyte maturation arrest at the germinal vesicle stage

Women undergoing controlled ovarian hyperstimulation prior to in vitro fertilization (IVF) are treated using various protocols to induce multiple follicular growths. Complete failure of all oocytes to mature during IVF cycles is rare; however, it is a known cause of primary female infertility. Recently, pathogenic variations in a few genes have been identified in women with oocyte maturation defects; however, the underlying genetic causes remain largely unknown.This study included a Turkish family comprising three sisters with recurring oocyte maturation arrest at the germinal vesicle stage after multiple ovarian stimulations. Exome sequencing revealed a homozygous missense variant (c.1037C>T, p.Ala346Val) in the EPAB gene (also known as PABPC1L) in all three affected sisters, which was either absent or heterozygous in the unaffected family members. Functional experiments confirming the pathogenicity of the variant were performed by transfecting HEK293T cells and demonstrated the instability and increased rate of proteolysis of the mutated PABPC1L/EPAB protein. The identified variant, located in the well-conserved fourth RNA recognition motif (RRM4), in silico 3D modelling suggested changes in the physical properties of the pathogenic variant of PABPC1L/EPAB. Our findings validate PABPC1L/EPAB as an essential genetic contributor to the oocyte maturation process in humans and have direct implications for the genetic counselling of patients and their family members.

The genomics of visuospatial neurocognition in obsessive-compulsive disorder: A preliminary GWAS

BACKGROUND

The study of Obsessive-Compulsive Disorder (OCD) genomics has primarily been tackled by Genome-wide association studies (GWAS), which have encountered troubles in identifying replicable single nucleotide polymorphisms (SNPs). Endophenotypes have emerged as a promising avenue of study in trying to elucidate the genomic bases of complex traits such as OCD.

METHODS

We analyzed the association of SNPs across the whole genome with the construction of visuospatial information and executive performance through four neurocognitive variables assessed by the Rey-Osterrieth Complex Figure Test (ROCFT) in a sample of 133 OCD probands. Analyses were performed at SNP- and gene-level.

RESULTS

No SNP reached genome-wide significance, although there was one SNP almost reaching significant association with copy organization (rs60360940; P = 9.98E-08). Suggestive signals were found for the four variables at both SNP- (P < 1E-05) and gene-levels (P < 1E-04). Most of the suggestive signals pointed to genes and genomic regions previously associated with neurological function and neuropsychological traits.

LIMITATIONS

Our main limitations were the sample size, which was limited to identify associated signals at a genome-wide level, and the composition of the sample, more representative of rather severe OCD cases than a population-based OCD sample with a broad severity spectrum.

CONCLUSIONS

Our results suggest that studying neurocognitive variables in GWAS would be more informative on the genetic basis of OCD than the classical case/control GWAS, facilitating the genetic characterization of OCD and its different clinical profiles, the development of individualized treatment approaches, and the improvement of prognosis and treatment response.

Neuropsychological performance and predictors of pharmacological treatment response in obsessive compulsive disorder

BACKGROUND

Obsessive Compulsive Disorder (OCD) is characterized by the presence of executive dysfunctions. As organizational strategies may play an important role as a possible endophenotype of the disorder, we decided to investigate non-verbal memory and organizational abilities in OCD. We also investigated how organization and non-verbal memory differ between responder and non-responder patients to pharmacological treatment, to test whether cognitive functions can predict the response to pharmacological treatment.

METHODS

In Study 1, executive and clinical functioning measures were applied to 162 OCD and 95 controls. In Study 2, clinical, intelligence and executive functioning measures were applied to 72 OCD responders and 63 OCD non-responder patients.

RESULTS

OCD patients and controls from Study 1 differed in copy organization (p < 0.01) and delayed recall (p = 0.048). In Study 2, the OCD responders displayed better copy organization (p = 0.013) and lower depressive, anxious and OCD symptoms (p < 0.01 in the three cases). Scores in the following instruments were found to predict the response to pharmacological treatment: HDRS, Y-BOCS, Raven progressive matrices, and Direct digit subtest from the Wechsler's scale (p < 0.01 in all four cases).

LIMITATIONS

In Study 1, the imbalance of the sample can be considered a limitation, whilst in Study 2, some of the levels of pharmacological resistance were not represented.

CONCLUSIONS

In this study, non-verbal memory and organization was affected in OCD. Responder patients also displayed better executive functioning and fluid intelligence. Organizational ability is a predictor of pharmacological response to SSRI monotherapy in a predictive model controlling for anxious symptoms.

How is COVID-19 affecting patients with obsessive-compulsive disorder? A longitudinal study on the initial phase of the pandemic in a Spanish cohort

BACKGROUND

Although the consequences of the COVID-19 pandemic on emotional health are evident, little is known about its impact on patients with obsessive-compulsive disorder (OCD).

METHODS

One hundred and twenty-seven patients with OCD who attended a specialist OCD Clinic in Barcelona, Spain, were assessed by phone from April 27 to May 25, 2020, during the early phase of the pandemic, using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and a structured interview that collected clinical and sociodemographic information. Results were compared with those for 237 healthy controls from the same geographic area who completed an online survey.

RESULTS

Although 65.3% of the patients with OCD described a worsening of their symptoms, only 31.4% had Y-BOCS scores that increased >25%. The risk of getting infected by SARS-CoV2 was reported as a new obsession by 44.8%, but this only became the main obsessive concern in approximately 10% of the patients. Suicide-related thoughts were more frequent among the OCD cohort than among healthy controls. The presence of prepandemic depression, higher Y-BOCS scores, contamination/washing symptoms, and lower perceived social support all predicted a significantly increased risk of OCD worsening.

CONCLUSIONS

Most patients with OCD appear to be capable of coping with the emotional stress of the COVID-19 outbreak and its consequences during the initial phase of the pandemic. Nevertheless, the current crisis constitutes a risk factor for a significant worsening of symptoms and suicidal ideation. Action is needed to ensure effective and individualized follow-up care for patients with OCD in the COVID-19 era.

Neurofunctional predictive biomarkers of cognitive-behavioral therapy during fear conditioning in patients with obsessive-compulsive disorder

Introduction

Altered fear learning processes could be mechanistically linked to the development and/or maintenance of obsessive-compulsive disorder (OCD). From a clinical perspective, the first-line psychological treatment for OCD is cognitive-behavioral therapy (CBT), which is based on the principles of fear learning. However, no previous functional magnetic resonance imaging (fMRI) studies have evaluated the predictive capacity of regional brain activations during fear learning on CBT response in patients with OCD.

Objectives

We aimed at exploring whether brain activation during fear learning in patients with OCD are associated with CBT outcome.

Methods

We assessed 18 patients with OCD and 18 healthy participants during a 2-day experimental protocol where brain activation and skin conductance responses (SCR) where assessed during fear conditioning, extinction learning, and extinction recall within the fMRI scanner. Following the protocol, patients with OCD received CBT.

Results

We found non-significant between-group differences in SCR during fear learning. Patients with OCD showed significantly diminished activation of the dorsal anterior cingulate cortex and the right insula during fear conditioning. Importantly, our analyses revealed a significant negative association between clinical improvement after CBT and activity at the right insula during fear conditioning (x = 39, y = 12, z = -11; t = 5.64; p<0.001; k = 928). This finding is displayed in Figure 1 below.

Conclusions

Patients with OCD may require less fear-conditioned brain responses to achieve the same level of psychophysiological fear conditioning as healthy participants. Interestingly, insula activations during fear-conditioned responses may represent a potential predictor biomarker of response to CBT for OCD.

Disclosure

No significant relationships.

Is glutamate associated with fear extinction and cognitive behavior therapy outcome in OCD? A pilot study

Cognitive behavioral therapy (CBT) including exposure and response prevention is a well-established treatment for obsessive-compulsive disorder (OCD) and is based on the principles of fear extinction. Fear extinction is linked to structural and functional variability in the ventromedial prefrontal cortex (vmPFC) and has been consistently associated with glutamate neurotransmission. The relationship between vmPFC glutamate and fear extinction and its effects on CBT outcome have not yet been explored in adults with OCD. We assessed glutamate levels in the vmPFC using 3T magnetic resonance spectroscopy, and fear extinction (learning and recall) using skin conductance responses during a 2-day experimental paradigm in OCD patients (n = 17) and in healthy controls (HC; n = 13). Obsessive-compulsive patients (n = 12) then received manualized CBT. Glutamate in the vmPFC was negatively associated with fear extinction recall and positively associated with CBT outcome (with higher glutamate levels predicting a better outcome) in OCD patients. Glutamate levels in the vmPFC in OCD patients were not significantly different from those in HC, and were not associated with OCD severity. Our results suggest that glutamate in the vmPFC is associated with fear extinction recall and CBT outcome in adult OCD patients.

5,6-Dihydroxypyrimidine Scaffold to Target HIV-1 Nucleocapsid Protein

The HIV-1 nucleocapsid (NC) protein is a small basic DNA and RNA binding protein that is absolutely necessary for viral replication and thus represents a target of great interest to develop new anti-HIV agents. Moreover, the highly conserved sequence offers the opportunity to escape the drug resistance (DR) that emerged following the highly active antiretroviral therapy (HAART) treatment. On the basis of our previous research, nordihydroguaiaretic acid 1 acts as a NC inhibitor showing moderate antiviral activity and suboptimal drug-like properties due to the presence of the catechol moieties. A bioisosteric catechol replacement approach led us to identify the 5-dihydroxypyrimidine-6-carboxamide substructure as a privileged scaffold of a new class of HIV-1 NC inhibitors. Hit validation efforts led to the identification of optimized analogs, as represented by compound 28, showing improved NC inhibition and antiviral activity as well as good ADME and PK properties.

(Thia)calixarenephosphonic Acids as Potent Inhibitors of the Nucleic Acid Chaperone Activity of the HIV-1 Nucleocapsid Protein with a New Binding Mode and Multitarget Antiviral Activity

The nucleocapsid protein (NC) is a highly conserved protein that plays key roles in HIV-1 replication through its nucleic acid chaperone properties mediated by its two zinc fingers and basic residues. NC is a promising target for antiviral therapy, particularly to control viral strains resistant to currently available drugs. Since calixarenes with antiviral properties have been described, we explored the ability of calixarene hydroxymethylphosphonic or sulfonic acids to inhibit NC chaperone properties and exhibit antiviral activity. By using fluorescence-based assays, we selected four calixarenes inhibiting NC chaperone activity with submicromolar IC₅₀ values. These compounds were further shown by mass spectrometry, isothermal titration calorimetry, and fluorescence anisotropy to bind NC with no zinc ejection and to compete with nucleic acids for the binding to NC. Molecular dynamic simulations further indicated that these compounds interact via their phosphonate or sulfonate groups with the basic surface of NC but not with the hydrophobic plateau at the top of the folded fingers. Cellular studies showed that the most soluble compound CIP201 inhibited the infectivity of wild-type and drug-resistant HIV-1 strains at low micromolar concentrations, primarily targeting the early steps of HIV-1 replication. Moreover, CIP201 was also found to inhibit the flipping and polymerization activity of reverse transcriptase. Calixarenes thus form a class of noncovalent NC inhibitors, endowed with a new binding mode and multitarget antiviral activity.

Altered functional connectivity of the subthalamus and the bed nucleus of the stria terminalis in obsessive-compulsive disorder

BACKGROUND

The assessment of inter-regional functional connectivity (FC) has allowed for the description of the putative mechanism of action of treatments such as deep brain stimulation (DBS) of the nucleus accumbens in patients with obsessive-compulsive disorder (OCD). Nevertheless, the possible FC alterations of other clinically-effective DBS targets have not been explored. Here we evaluated the FC patterns of the subthalamic nucleus (STN) and the bed nucleus of the stria terminalis (BNST) in patients with OCD, as well as their association with symptom severity.

METHODS

Eighty-six patients with OCD and 104 healthy participants were recruited. A resting-state image was acquired for each participant and a seed-based analysis focused on our two regions of interest was performed using statistical parametric mapping software (SPM8). Between-group differences in FC patterns were assessed with two-sample t test models, while the association between symptom severity and FC patterns was assessed with multiple regression analyses.

RESULTS

In comparison with controls, patients with OCD showed: (1) increased FC between the left STN and the right pre-motor cortex, (2) decreased FC between the right STN and the lenticular nuclei, and (3) increased FC between the left BNST and the right frontopolar cortex. Multiple regression analyses revealed a negative association between clinical severity and FC between the right STN and lenticular nucleus.

CONCLUSIONS

This study provides a neurobiological framework to understand the mechanism of action of DBS on the STN and the BNST, which seems to involve brain circuits related with motor response inhibition and anxiety control, respectively.

Structure-Based Identification of HIV-1 Nucleocapsid Protein Inhibitors Active against Wild-Type and Drug-Resistant HIV-1 Strains

HIV/AIDS is still one of the leading causes of death worldwide. Current drugs that target the canonical steps of the HIV-1 life cycle are efficient in blocking viral replication but are unable to eradicate HIV-1 from infected patients. Moreover, drug resistance (DR) is often associated with the clinical use of these molecules, thus raising the need for novel drug candidates as well as novel putative drug targets. In this respect, pharmacological inhibition of the highly conserved and multifunctional nucleocapsid protein (NC) of HIV-1 is considered a promising alternative to current drugs, particularly to overcome DR. Here, using a multidisciplinary approach combining in silico screening, fluorescence-based molecular assays, and cellular antiviral assays, we identified nordihydroguaiaretic acid (6), as a novel natural product inhibitor of NC. By using NMR, mass spectrometry, fluorescence spectroscopy, and molecular modeling, 6 was found to act through a dual mechanism of action never highlighted before for NC inhibitors (NCIs). First, the molecule recognizes and binds NC noncovalently, which results in the inhibition of the nucleic acid chaperone properties of NC. In a second step, chemical oxidation of 6 induces a potent chemical inactivation of the protein. Overall, 6 inhibits NC and the replication of wild-type and drug-resistant HIV-1 strains in the low micromolar range with moderate cytotoxicity that makes it a profitable tool compound as well as a good starting point for the development of pharmacologically relevant NCIs.

Brain structural correlates of obsessive-compulsive disorder with and without preceding stressful life events

Objectives There is growing evidence supporting a role for stressful life events (SLEs) at obsessive-compulsive disorder (OCD) onset, but neurobiological correlates of such effect are not known. We evaluated regional grey matter (GM) changes associated with the presence/absence of SLEs at OCD onset. Methods One hundred and twenty-four OCD patients and 112 healthy controls were recruited. Patients were split into two groups according to the presence (n = 56) or absence (n = 68) of SLEs at disorder's onset. A structural magnetic resonance image was acquired for each participant and pre-processed with Statistical Parametric Mapping software (SPM8) to obtain a volume-modulated GM map. Between-group differences in sociodemographic, clinical and whole-brain regional GM volumes were assessed. Results SLEs were associated with female sex, later age at disorder's onset, more contamination/cleaning and less hoarding symptoms. In comparison with controls, patients without SLEs showed GM volume increases in bilateral dorsal putamen and the central tegmental tract of the brainstem. By contrast, patients with SLEs showed specific GM volume increases in the right anterior cerebellum. Conclusions Our findings support the idea that neuroanatomical alterations of OCD patients partially depend on the presence of SLEs at disorder's onset.

Discovery and Structure-Based Optimization of 2-Ureidothiophene-3-carboxylic Acids as Dual Bacterial RNA Polymerase and Viral Reverse Transcriptase Inhibitors

We are concerned with the development of novel anti-infectives with dual antibacterial and antiretroviral activities for MRSA/HIV-1 co-infection. To achieve this goal, we exploited for the first time the mechanistic function similarity between the bacterial RNA polymerase (RNAP) "switch region" and the viral non-nucleoside reverse transcriptase inhibitor (NNRTI) binding site. Starting from our previously discovered RNAP inhibitors, we managed to develop potent RT inhibitors effective against several resistant HIV-1 strains with maintained or enhanced RNAP inhibitory properties following a structure-based design approach. A quantitative structure-activity relationship (QSAR) analysis revealed distinct molecular features necessary for RT inhibition. Furthermore, mode of action (MoA) studies revealed that these compounds inhibit RT noncompetitively, through a new mechanism via closing of the RT clamp. In addition, the novel RNAP/RT inhibitors are characterized by a potent antibacterial activity against S. aureus and in cellulo antiretroviral activity against NNRTI-resistant strains. In HeLa and HEK 293 cells, the compounds showed only marginal cytotoxicity.

Exon-focused genome-wide association study of obsessive-compulsive disorder and shared polygenic risk with schizophrenia

Common single-nucleotide polymorphisms (SNPs) account for a large proportion of the heritability of obsessive-compulsive disorder (OCD). Co-ocurrence of OCD and schizophrenia is commoner than expected based on their respective prevalences, complicating the clinical management of patients. This study addresses two main objectives: to identify particular genes associated with OCD by SNP-based and gene-based tests; and to test the existence of a polygenic risk shared with schizophrenia. The primary analysis was an exon-focused genome-wide association study of 370 OCD cases and 443 controls from Spain. A polygenic risk model based on the Psychiatric Genetics Consortium schizophrenia data set (PGC-SCZ2) was tested in our OCD data. A polygenic risk model based on our OCD data was tested on previous data of schizophrenia from our group. The most significant association at the gene-based test was found at DNM3 (P=7.9 × 10(-5)), a gene involved in synaptic vesicle endocytosis. The polygenic risk model from PGC-SCZ2 data was strongly associated with disease status in our OCD sample, reaching its most significant value after removal of the major histocompatibility complex region (lowest P=2.3 × 10(-6), explaining 3.7% of the variance). The shared polygenic risk was confirmed in our schizophrenia data. In conclusion, DNM3 may be involved in risk to OCD. The shared polygenic risk between schizophrenia and OCD may be partially responsible for the frequent comorbidity of both disorders, explaining epidemiological data on cross-disorder risk. This common etiology may have clinical implications.

Blue fluorogenic probes for cell plasma membranes fill the gap in multicolour imaging

Newly synthesized blue membrane probes, due to high brightness, large Stokes shift and fluorogenic response, overcome the problem of cell auto-fluorescence and enable multicolor cellular imaging with common green and red markers.

Brain regions related to fear extinction in obsessive-compulsive disorder and its relation to exposure therapy outcome: a morphometric study

BACKGROUND

The size of particular sub-regions within the ventromedial prefrontal cortex (vmPFC) has been associated with fear extinction in humans. Exposure therapy is a form of extinction learning widely used in the treatment of obsessive-compulsive disorder (OCD). Here we investigated the relationship between morphometric measurements of different sub-regions of the vmPFC and exposure therapy outcome in OCD.

METHOD

A total of 74 OCD patients and 86 healthy controls underwent magnetic resonance imaging (MRI). Cortical thickness and volumetric measurements were obtained for the rostral anterior cingulate cortex (rACC), the medial orbital frontal cortex and the subcallosal cortex. After MRI acquisition, patients were enrolled in an exposure therapy protocol, and we assessed the relationship between MRI-derived measurements and treatment outcome. Baseline between-group differences for such measurements were also assessed.

RESULTS

Compared with healthy controls, OCD patients showed a thinner left rACC (p = 0.008). Also, left rACC thickness was inversely associated with exposure therapy outcome (r - 0.32, p = 0.008), and this region was significantly thinner in OCD patients who responded to exposure therapy than in those who did not (p = 0.006). Analyses based on regional volumetry did not yield any significant results.

CONCLUSIONS

OCD patients showed cortical thickness reductions in the left rACC, and these alterations were related to exposure therapy outcome. The precise characterization of neuroimaging predictors of treatment response derived from the study of the brain areas involved in fear extinction may optimize exposure therapy planning in OCD and other anxiety disorders.

Interaction of SLC1A1 gene variants and life stress on pharmacological resistance in obsessive-compulsive disorder

Genetic and environmental factors seem to interact and influence both the onset and the course of obsessive-compulsive disorder (OCD), but the role of glutamate transporter variants (SLC1A1) in pharmacological resistance is not known. We aimed to assess whether genetic variants in SLC1A1 and life stress at onset of the disorder interact and modulate pharmacological resistance in OCD. A single-marker association study of several single-nucleotide polymorphisms in the SLC1A1 genomic region was performed in a sample of 238 OCD patients. For the most strongly associated SNP (rs3087879), one copy of the risk allele increased the probability of higher treatment resistance (odds ratio=2.42; 95% confidence interval=1.39-4.21; P=0.0018), but only in OCD patients without life stress at onset of the disorder. These results suggest a gene-by-environment interaction effect on treatment resistance in OCD and strengthen the existing evidence of the role of the glutamatergic system in the phenomenology of OCD.

Variation in the BDNF Val66Met polymorphism and response to cognitive-behavior therapy in obsessive-compulsive disorder

BACKGROUND

Recent research suggests that the brain-derived neurotrophic factor (BDNF) may play a role in extinction learning. The goal of this study was to test whether variation in the BDNF Val66Met polymorphism is related to treatment response to exposure-based cognitive-behavior therapy (CBT), a form of extinction learning, in obsessive-compulsive disorder (OCD).

METHODS

One hundred and six OCD patients from a specialized clinic, who underwent a standardized CBT treatment after partial or non-response to a 12-week pharmacological trial, were genotyped for the BDNF Val66Met and the relationship between genotype and treatment response was analyzed.

RESULTS

Among 98 CBT completers, 36% of those carrying the BDNF Met allele were rated as CBT responders compared to 60% of nonMet allele carriers (P=0.027). When analyzing the different obsessive-compulsive symptom dimensions, in patients with contamination/cleaning symptoms, the Met allele was associated with a significantly worse CBT response (P<0.0001) and a lower obsessions severity decrease from pre- to posttreatment (P=0.046).

CONCLUSION

Genetic variation in BDNF may be associated with treatment response in exposure-based CBT in OCD, especially in those patients exhibiting contamination/cleaning symptoms.

Variants in estrogen receptor alpha gene are associated with phenotypical expression of obsessive-compulsive disorder

Compelling data from animal and clinical studies suggest that sex steroids may play a role in the etiopathology of obsessive-compulsive disorder (OCD). The aim of this study was to investigate whether variants in estrogen receptor genes ESR1 and ESR2 may contribute to the genetic susceptibility to OCD, through a case-control association study using an extensive linkage disequilibrium-mapping approach. Twenty tag single-nucleotide polymorphisms (tagSNPs) covering the ESR2 region and nine tagSNPS from regions of ESR1 reported to be related to transcriptional control were genotyped in 229 OCD patients and 279 controls. SNP association and haplotype analysis were performed. The association of these genes and OCD subphenotypes was tested, considering early-onset OCD, comorbid tic and affective disorders, and OCD symptom dimensions. No significant difference in the distribution of alleles or genotypes was detected between controls and OCD subjects. Nevertheless, on analyzing OCD subphenotypes, SNP rs34535804 in ESR1 and a five SNPs haplotype, located at the 5' end of intron 1 of ESR1, were associated with the presence of contamination obsessions and cleaning compulsions. Specifically, carriers of the ACCCG haplotype, a combination of functional alleles related to higher ER alpha expression, showed a reduced risk of suffering from these symptoms. Our results suggest that the ESR1 gene may contribute to the genetic vulnerability to certain OCD manifestations. The dissection of OCD into more homogeneous subphenotypes may well help to identify susceptibility genes for the disorder.

Memory and strategic processing in first-degree relatives of obsessive compulsive patients

BACKGROUND

The same executive dysfunctions and alterations in neuroimaging tests (both functional and structural) have been found in obsessive-compulsive patients and their first-degree relatives. These neurobiological findings are considered to be intermediate markers of the disease. The aim of our study was to assess verbal and non-verbal memory in unaffected first-degree relatives, in order to determine whether these neuropsychological functions constitute a new cognitive marker for obsessive-compulsive disorder (OCD).

METHOD

Recall and use of organizational strategies in verbal and non-verbal memory tasks were measured in 25 obsessive-compulsive patients, 25 unaffected first-degree relatives and 25 healthy volunteers.

RESULTS

First-degree relatives and healthy volunteers did not show differences on most measures of verbal memory. However, during the recall and processing of non-verbal information, deficits were found in first-degree relatives and patients compared with healthy volunteers.

CONCLUSIONS

The presence of the same deficits in the execution of non-verbal memory tasks in OCD patients and unaffected first-degree relatives suggests the influence of certain genetic and/or familial factors on this cognitive function in OCD and supports the hypothesis that deficits in non-verbal memory tasks could be considered as cognitive markers of the disorder.

Comorbidity in pathological gambling: clinical variables, personality and treatment response

INTRODUCTION

Pathological gambling shows high comorbidity rates, especially with substance use disorders, although affective, anxiety and other impulse control disorders, as well as personality disorders, are also frequently associated.

OBJECTIVES

To explore comorbidity in pathological gambling with other mental disorders in a consecutive sample of patients attending a unit specialized in pathological gambling, and specifically the relationship between substance-related disorders, on the one hand, and personality and clinical variables in pathological gamblers, on the other.

METHOD

A total of 498 patients with a DSM-IV-TR diagnosis of Pathological Gambling (11.8% women) were assessed with a semi-structured clinical interview and several clinical and personality scales.

RESULTS

Higher comorbidity with affective disorders was found in women (30.5%), while higher comorbidity with substance-related disorders was found in men (11.2%). A positive association was also detected between a history of psychiatric disorders and current comorbidity with substance-use disorders, as well as between alcohol abuse and age. Finally, some personality traits such as low reward dependence (OR=0.964) and high impulsivity (OR=1.02) predicted other substance abuse (not alcohol). High selftranscendence scores predicted both alcohol and other substance abuse (OR=1.06).

CONCLUSIONS

Our results suggest a high prevalence of comorbid disorders in pathologic gambling, mainly with affective and substance-related disorders. The results of the present study, conducted in a broad sample of consecutively admitted pathologic gamblers, may contribute to understanding of this complex disorder and treatment improvement.

Monitoring of chloride and activity of glycine receptor channels using genetically encoded fluorescent sensors

Genetically encoded probes have become powerful tools for non-invasive monitoring of ions, distributions of proteins and the migration and formation of cellular components. We describe the functional expression of two molecular probes for non-invasive fluorescent monitoring of intracellular Cl ([Cl]i) and the functioning of glycine receptor (GlyR) channels. The first probe is a recently developed cyan fluorescent protein-yellow fluorescent protein-based construct, termed Cl-Sensor, with relatively high sensitivity to Cl (Kapp approximately 30 mM). In this study, we describe its expression in retina cells using in vivo electroporation and analyse changes in [Cl]i at depolarization and during the first three weeks of post-natal development. An application of 40 mM K+ causes an elevation in [Cl]i of approximately 40 mM. In photoreceptors from retina slices of a 6-day-old rat (P6 rat), the mean [Cl]i is approximately 50 mM, and for P16 and P21 rats it is approximately 30-35 mM. The second construct, termed BioSensor-GlyR, is a GlyR channel with Cl-Sensor incorporated into the cytoplasmic domain. This is the first molecular probe for spectroscopic monitoring of the functioning of receptor-operated channels. These types of probes offer a means of screening pharmacological agents and monitoring Cl under different physiological and pathological conditions and permit spectroscopic monitoring of the activity of GlyRs expressed in heterologous systems and neurons.

Genetic susceptibility to obsessive-compulsive hoarding: the contribution of neurotrophic tyrosine kinase receptor type 3 gene

Recent work suggests that neurotrophic factors may contribute to the genetic susceptibility to obsessive-compulsive disorder (OCD). Among other clinical dimensions, the presence of hoarding obsessions and compulsions has been shown to be correlated with a number of clinical and neuroimaging findings, as well as with a different pattern of genetic inheritance. We used a linkage disequilibrium (LD)-mapping approach to investigate whether neurotrophic tyrosine kinase receptor type 3 (NTRK3), the high-affinity receptor of neurotrophin 3 (NT-3), plays a role in increasing susceptibility to hoarding in OCD. We performed an association study of 52 tag single nucleotide polymorphisms (tagSNPs) covering the whole NTRK3 gene in a sample comprising 120 OCD patients and 342 controls. Single nucleotide polymorphism association and haplotype analysis were performed. Thirty-six of our patients (30%) exhibited significant hoarding obsessions and compulsions. A significant association of two SNPs in the 3' downstream region of NTRK3 gene and obsessive-compulsive hoarding was identified: rs1017412 [odds ratio (OR) = 2.16; P = 0.001] and rs7176429 (OR = 2.78; P = 0.0001), although only the latter remained significant after Bonferroni correction. Although the haplotype analysis did not show significant results, a more extended block of LD in the OCD hoarders with respect to the control group was observed, suggesting a lower haplotype diversity in these individuals. Our findings suggest that NTRK3 may contribute to the genetic susceptibility to hoarding in OCD and may constitute an interesting gene to focus on in studies of the genetic basis of obsessive-compulsive hoarding.

Genetically encoded chloride indicator with improved sensitivity

Chloride (Cl) is the most abundant physiological anion. Abnormalities in Cl regulation are instrumental in the development of several important diseases including motor disorders and epilepsy. Because of difficulties in the spectroscopic measurement of Cl in live tissues there is little knowledge available regarding the mechanisms of regulation of intracellular Cl concentration. Several years ago, a CFP-YFP based ratiometric Cl indicator (Clomeleon) was introduced [Kuner, T., Augustine, G.J. A genetically encoded ratiometric indicator for chloride: capturing chloride transients in cultured hippocampal neurons. Neuron 2000; 27: 447-59]. This construct with relatively low sensitivity to Cl (K(app) approximately 160 mM) allows ratiometric monitoring of Cl using fluorescence emission ratio. Here, we propose a new CFP-YFP-based construct (Cl-sensor) with relatively high sensitivity to Cl (K(app) approximately 30 mM) due to triple YFP mutant. The construct also exhibits good pH sensitivity with pK(alpha) ranging from 7.1 to 8.0 pH units at different Cl concentrations. Using Cl-sensor we determined non-invasively the distribution of [Cl](i) in cultured CHO cells, in neurons of primary hippocampal cultures and in photoreceptors of rat retina. This genetically encoded indicator offers a means for monitoring Cl and pH under different physiological conditions and high-throughput screening of pharmacological agents.

Analysis of synaptic ultrastructure without fixative using high-pressure freezing and tomography

Electron microscopy allows the analysis of synaptic ultrastructure and its modifications during learning or in pathological conditions. However, conventional electron microscopy uses aldehyde fixatives that alter the morphology of the synapse by changing osmolarity and collapsing its molecular components. We have used high-pressure freezing (HPF) to capture within a few milliseconds structural features without aldehyde fixative, and thus to provide a snapshot of living synapses. CA1 hippocampal area slices from P21 rats were frozen at -173 degrees C under high pressure to reduce crystal formation, and synapses on dendritic spines were analysed after cryosubstitution and embedding. Synaptic terminals were larger than after aldehyde fixation, and synaptic vesicles in these terminals were less densely packed. Small filaments linked the vesicles in subgroups. The postsynaptic densities (PSDs) exhibited filamentous projections extending into the spine cytoplasm. Tomographic analysis showed that these projections were connected with the spine cytoskeletal meshwork. Using immunocytochemistry, we found as expected GluR1 at the synaptic cleft and CaMKII in the PSD. Actin immunoreactivity (IR) labelled the cytoskeletal meshwork beneath the filamentous projections, but was very scarce within the PSD itself. ProSAP2/Shank3, cortactin and Ena/VASP-IRs were concentrated on the cytoplasmic face of the PSD, at the level of the PSD projections. Synaptic ultrastructure after HPF was different from that observed after aldehyde fixative. The boutons were larger, and filamentous components were preserved. Particularly, filamentous projections were observed linking the PSD to the actin cytoskeleton. Thus, synaptic ultrastructure can be analysed under more realistic conditions following HPF.

[Ca-dependent modulation of human glycine receptors expressed in cultured cell lines]

Glycine receptors (GlyRs) provide the main inhibitory neurotransmission in spinal cord and brainstem synapses of vertebrates. Fucile et al. (2000) discovered that elevation of intracellular Ca2+ caused rapid potentiation of GlyRs. This modulation develops in less than 100 ms. It is characterized by an increase in GlyR apparent affinity for glycine. It has been suggested that the phenomenon of Ca-induced potentiation involves an unknown Ca2+-binding protein (CaBP). Using the yeast two-hybrid system, screening of human brain cDNA library against the cytoplasmic loop of human alpha 1 subunit (GlyRhl) allowed us to identify five new interactors. One of them belongs to a family of Ca-binding proteins. We analyzed effect of "short" forms of this protein (CaBP-S) on functional properties of GlyRhl expressed in HEK-293 and CHO cells. Using whole-cell recordings and rapid agonist application we constructed concentration dependencies of glycine-induced currents. This analysis revealed statistical differences in EC50s between control cells (expressing only GlyRhl) and those expressing CaBP-S. In HEK-293 cells recorded under conditions of low intracellular Ca concentration (BAPTA 20 mM in the recording pipette), EC50 for glycine in control cells and expressing GlyRhl + CaBP-S were, correspondently, 68+/-49 microM (n = 29) and 409 +/-421 microM (n = 60). In CHO cells EC50 were 54+/-43 microM (n = 25) and 123 +/-104 microM (n = 28). These differences were statistically not significant at recording with intracellular solution containing high Ca concentration (50 microM). In this case EC50 were correspondently 35+/-28 microM (n = 7) and 64 +/-38 microM (n = 7). These results suggest that CaBP-S causes decrease of GlyR sensitivity to agonist through interaction with cytoplasmic domain of GlyR.

Targeting of incoming retroviral Gag to the centrosome involves a direct interaction with the dynein light chain 8

The role of cellular proteins in the replication of retroviruses, especially during virus assembly, has been partly unraveled by recent studies. Paradoxically, little is known about the route taken by retroviruses to reach the nucleus at the early stages of infection. To get insight into this stage of virus replication, we have studied the trafficking of foamy retroviruses and have previously shown that incoming viral proteins reach the microtubule organizing center (MTOC) prior to nuclear translocation of the viral genome. Here, we show that incoming viruses concentrate around the MTOC as free and structured capsids. Interestingly, the Gag protein, the scaffold component of viral capsids, targets the pericentrosomal region in transfected cells in the absence of any other viral components but in a microtubule- and dynein/dynactin-dependent manner. Trafficking of Gag towards the centrosome requires a minimal 30 amino acid coiled-coil motif in the N-terminus of the molecule. Finally, we describe a direct interaction between Gag and dynein light chain 8 that probably accounts for the specific routing of the incoming capsids to the centrosome prior to nuclear import of the viral genome.

Molecular basis for the interaction between rabies virus phosphoprotein P and the dynein light chain LC8: dissociation of dynein-binding properties and transcriptional functionality of P

The lyssavirus phosphoprotein P is a co-factor of the viral RNA polymerase and plays a central role in virus transcription and replication. It has been shown previously that P interacts with the dynein light chain LC8, which is involved in minus end-directed movement of organelles along microtubules. Co-immunoprecipitation experiments and the two-hybrid system were used to map the LC8-binding site to the sequence (139)RSSEDKSTQTTGR(151). Site-directed mutagenesis of residues D(143) and Q(147) to an A residue abolished binding to LC8. The P-LC8 association is not required for virus transcription, since the double mutant was not affected in its transcription ability in a minigenome assay. Based on the crystal structure of LC8 bound to a peptide from neuronal nitric oxide synthase, a model for the complex between the peptide spanning residues 140-150 of P and LC8 is proposed. This model suggests that P binds LC8 in a manner similar to other LC8 cellular partners.

Functional interaction map of lyssavirus phosphoprotein: identification of the minimal transcription domains

Lyssaviruses, the causative agents of rabies encephalitis, are distributed in seven genotypes. The phylogenetically distant rabies virus (PV strain, genotype 1) and Mokola virus (genotype 3) were used to develop a strategy to identify functional homologous interactive domains from two proteins (P and N) which participate in the viral ribonucleoprotein (RNP) transcription-replication complex. This strategy combined two-hybrid and green fluorescent protein-reverse two-hybrid assays in Saccharomyces cerevisiae to analyze protein-protein interactions and a reverse genetic assay in mammalian cells to study the transcriptional activity of the reconstituted RNP complex. Lyssavirus P proteins contain two N-binding domains (N-BDs), a strong one encompassing amino acid (aa) 176 to the C terminus and a weak one in the 189 N-terminal aa. The N-terminal portion of P (aa 52 to 189) also contains a homomultimerization site. Here we demonstrate that N-P interactions, although weaker, are maintained between proteins of the different genotypes. A minimal transcriptional module of the P protein was obtained by fusing the first 60 N-terminal aa containing the L protein binding site to the C-terminal strong N-BD. Random mutation of the strong N-BD on P protein identified three highly conserved K residues crucial for N-P interaction. Their mutagenesis in full-length P induced a transcriptionally defective RNP. The analysis of homologous interactive domains presented here and previously reported dissections of the P protein allowed us to propose a model of the functional interaction network of the lyssavirus P protein. This model underscores the central role of P at the interface between L protein and N-RNA template.

Hyperosmotic stress response and regulation of cell wall integrity in Saccharomyces cerevisiae share common functional aspects

The osmosensitive phenotype of the hog1 strain is suppressed at elevated temperature. Here, we show that the same holds true for the other commonly used HOG pathway mutant strains pbs2 and sho1ssk2ssk22, but not for ste11ssk2ssk22. Instead, the ste11ssk2ssk2 strain displayed a hyperosmosensitive phenotype at 37 degrees C. This phenotype is suppressed by overexpression of LRE1, HLR1 and WSC3, all genes known to influence cell wall composition. The suppression of the temperature-induced hyperosmosensitivity by these genes prompted us to investigate the role of STE11 and other HOG pathway components in cellular integrity and, indeed, we were able show that HOG pathway mutants display sensitivity to cell wall-degrading enzymes. LRE1 and HLR1 were also shown to suppress the cell wall phenotypes associated with the HOG pathway mutants. In addition, the isolated multicopy suppressor genes suppress temperature-induced cell lysis phenotypes of PKC pathway mutants that could be an indication for shared targets of the PKC pathway and high-osmolarity response routes.

Home treatment of deep venous thrombosis with low molecular weight heparin: Long-term incidence of recurrent venous thromboembolism

Outpatient treatment of deep venous thrombosis (DVT) with low molecular weight heparin (LMWH) seems as safe and effective as inpatient treatment with unfractionated heparin (UFH). However, most of the randomized trials comparing a LMWH with UFH described clinical outcomes within 3-6 months. The long-term incidence of recurrent VTE after treatment of DVT with LMWH remains to be established. The primary objective of this retrospective study was to document the long-term incidence of recurrent venous thromboembolism (VTE) in patients with DVT treated with a LMWH, nadroparin in an outpatient basis. The patients were evaluated 46 months after inclusion in two cohorts comparing home treatment with nadroparin (n = 130) with in-hospital treatment with intravenous UFH (n = 149). More than 60% of the patients in the nadroparin group could be treated at home, either entirely or after a short stay in hospital. The age-adjusted thrombosis-free survival was not statistically significant between nadroparin and UFH-treated patients (P = 0.084). There was a nonsignificant trend favoring nadroparin as compared with UFH. The hazard ratio (HR) for recurrent VTE in the nadroparin group with respect to the UFH group was 0.44 (95% confidence interval, 0.17-1.12). No significant differences were observed in overall mortality or major hemorrhage between the two treatment groups. Our study suggests that home treatment of DVT with LMWH is at least as effective and safe as in-hospital UFH after a long-term follow-up period.

Recurrent venous thromboembolism in a Spanish population: incidence, risk factors, and management in a hospital setting

The major concern in the management of venous thromboembolism is the propagation of thrombus and rethrombosis. The incidence of recurrences and the duration of oral anticoagulant therapy in these patients are still controversial. The aim of this study was to determine the incidence, timing, and outcome of further thrombotic events after an initial episode of venous thromboembolism in a hospital setting. In addition, we evaluated potential risk factors for all these outcomes. This was designed as a retrospective analysis of all patients admitted to our Center with an episode of deep vein thrombosis and/or pulmonary embolism between 1986 and 1996. The patients included in the study had to be treated with unfractionated heparin or low molecular weight heparin, followed by at least 3 months of oral anticoagulants. Natural and acquired hemostasis inhibitors were assayed in patients aged less than 50 years. A total of 290 patients with a first episode of venous thromboembolism were included in the study. A total of 33 patients (11.9%, 95% confidence interval. 7.4-14.6) had recurrent episodes. The cumulative incidence of recurrent venous thromboembolism after 2, 5, and 10 years was 7.68, 10, and 12.4%, respectively. The incidence of rethrombosis was significantly higher in patients with idiopathic venous thromboembolism than in patients with secondary thrombosis. Abnormalities of hemostasis were found in 54.5% (95% confidence interval, 37.6-71.4) of the patients with recurrences and under the age of 50 years. Three of seven patients who stopped anticoagulant therapy after the second episode presented a third thrombotic event. In our study population, those patients with idiopathic venous thromboembolism seem to have an increased risk of recurrence. The second thrombotic episode occurs more frequently during the following 2 years after cessation of anticoagulation therapy. Our findings strongly support the use of long-term anticoagulant therapy in patients with recurrent venous thromboembolism.

Population pharmacokinetic approach to compare oral and i.v. administration of etoposide

The antitumor effect of etoposide (ETO) may be related to duration of exposure to a relatively low serum level while myelosuppression may be dependent on peak ETO serum levels. With regard to such therapeutic ranges, duration of exposure to predefined plasma ETO concentration ranges and the related AUC (expressed as percent of total AUC, pAUC) were used to compare pharmacokinetic profiles after oral and short time i.v. (1 h infusion) administration of identical ETO doses (100 mg/m2). Patients included in this study received i.v. (18 patients, short-term infusions) or oral (16 patients) ETO on different treatment schedules. Plasma ETO concentrations were determined by HPLC and population pharmacokinetic parameters were calculated (P-Pharm 1.4). Despite an 'apparent bioavailability' of 59%, oral administration of ETO was associated with the same time of exposure to a predefined 'therapeutic range' of 0.5-3 mg/l and a significantly higher pAUC compared to i.v. administration. By contrast, time of exposure to the probably more myelotoxic concentration range above 3 mg/l was significantly shorter and the related pAUC was highly significantly lower after oral than after i.v. administration. These findings demonstrate that oral ETO therapy is at least equivalent to short time i.v. therapy in terms of achieving specific target concentration ranges and avoiding peak concentrations.

Monitoring oral anticoagulant treatment from plasma stored for up to 48 hours and frozen plasma

BACKGROUND AND OBJECTIVE

The number of patients being referred for lifelong anticoagulant treatment has increased markedly in the last years. The prothrombin time test is sometimes difficult to perform the same day as sample collection. The aim of this study is to determine International Normalized Ratio (INR) and vitamin-K dependent factor levels of frozen plasma and plasma stored for up 48 hours.

DESIGN AND METHODS

The INR of 84 patients receiving acenocoumarol were determined fresh (0 hours), on samples stored between 2 degrees C and 8 degrees C for 24 hours and 48 hours, and on frozen samples (-40 degrees C) using 4 different thromboplastin reagents (Thromboplastin IS; Thromborel; Simplastin; and Thromboplastin D+G). In addition, factors II, VII, IX, X were determined in 34 of these patients in all these situations. We used the interclass correlation coefficient to compare the results obtained at 0 hours and the results obtained in the subsequent measurements. Both measurement and proportional errors were also estimated by linear regression analysis.

RESULTS

The correlation coefficient of the INR between fresh and frozen plasma was 0.98, 0.98, 0.92 and 0.97 for IS, Thromborel, Simplastin and D+G respectively. The correlation between 0 and 24 hours was 0. 98, 0.91, 0.95 and 0.85 for IS, Thromborel, Simplastin and D+G respectively. By 48 hours although IS still had r=0.94, Thromborel, Simplastin, and D+G had r=0.55, r=0.50 and r=0.81, respectively. By 24 hours in stored plasma and in frozen plasma the activity of vitamin-K dependent factors was slightly reduced (r=0.97 at 24h/r=0. 94 with frozen plasma for factor II, r=0.92/0.96 for factor VII, r=0. 83/0.98 for factor IX, and r=0.98/0.95 for factor X). By 48 hours however, significant reductions were noted in the activity of these factors (r=0.94 for factor II, r=0.88 for factor VII, r=0.70 for factor IX, and r=0.98 for factor X).

INTERPRETATION AND CONCLUSIONS

The INR can be reliable determined in frozen plasma and in plasma stored at 2-8 degrees C for up to 24 hours.

Elective splenectomy in relapsing thrombotic thrombocytopenic purpura

Between 20 and 40% of surviving patients with thrombotic thrombocytopenic purpura (TTP) have relapses. Plasma exchange therapy is usually effective in treating relapses, but this treatment does not prevent TTP recurrence. The role of splenectomy in relapsing TTP is still controversial. We describe a patient with multiple relapses of TTP who was successfully treated with elective splenectomy.

Home treatment of deep vein thrombosis: a two-years experience of a single institution

BACKGROUND AND OBJECTIVE

Low molecular weight heparin (LMWH) is known to be safe and effective for the initial treatment of patients with acute deep-vein thrombosis (DVT). Moreover, LMWH allows patients to be treated at home. However, only limited data are available on the feasibility of LMWH treatment at home in daily clinical practice.

DESIGN AND METHODS

We evaluated the feasibility, efficacy and safety of home treatment of DVT in a consecutive series of outpatients using LMWH over a two year period. The two main reasons for exclusion were concomitant pulmonary embolism and a high hemorrhagic risk. Patients were treated with 95 IU/kg bid of nadroparin for a minimum of 7 days. The study design allowed patients to go home immediately after diagnosis or to be discharged after a short hospital stay. Anticoagulation with acenocoumarol was started 2 days before discontinuing nadroparin.

RESULTS

From 1995 to 1997, 71 consecutive outpatients with DVT were treated with nadroparin. Ambulatory treatment was feasible in 39 patients (24 patients did not require admission and 15 patients were discharged in less than 48 hours). The remaining 32 patients were treated in hospital. The main causes for admission were the presence of serious comorbid conditions, the severity of symptoms in the involved leg and the inability to obtain a diagnosis. None of the patients had clinical recurrent venous thromboembolism during the initial treatment with nadroparin. One patient receiving nadroparin at home had a non-fatal major bleeding. None of the patients to whom the possibility of home therapy was offered wished to remain at hospital. However, only 26% of the home-treated patients injected the drug by themselves.

INTERPRETATION AND CONCLUSIONS

Home therapy of DVT with LMWH bid at doses adjusted to patient's body weight is feasible, efficient and safe. Over 50% of outpatients with DVT can be treated at home, either entirely or after a short stay in hospital. Nevertheless, before using this therapeutic alternative as a standard of practice, an adequate assessment of embolic and hemorrhagic risks, and comorbid conditions, should be made.

[Cutaneous B-cell lymphoma with aggressive clinical presentation: apropos of a case]

A patient with an atypical clinical presentation of cutaneous B-cell lymphoma is reported. He showed a rapidly growing tumour with areas of skin necrosis, haemorrhage, ulceration and suppuration in his upper back. There were involvement of contiguous anatomic site and extracutaneous spread. The histology showed diffuse lymphoid infiltration of the dermis. The cell morphology was that of a monotonous population of centroblasts. Treatment with CHOP and radiotherapy provided long-term complete remission. This case illustrates that primary cutaneous B-cell lymphoma may behave as a high-grade malignancy. Vigorous treatment with chemotherapy and radiotherapy is recommended in such cases.