Collybistin SH3-protein isoforms are expressed in the rat brain promoting gephyrin and GABA-A receptor clustering at GABAergic synapses.

Collybistin (CB) is a guanine nucleotide exchange factor (GEF) selectively localized at GABAergic and glycinergic postsynapses. Analysis of mRNA shows that several isoforms of collybistin are expressed in the brain. Some of the isoforms have a SH3 domain (CBSH3+) and some have no SH3 domain (CBSH3-). The CBSH3+ mRNAs are predominantly expressed over CBSH3-. However, in an immunoblot study of mouse brain homogenates, only CBSH3+ protein isoforms were detected, proposing that CBSH3- protein might not be expressed in the brain. The expression or lack of expression of CBSH3- protein is an important issue because CBSH3- has a strong effect in promoting the postsynaptic clustering of gephyrin and GABA-A receptors (GABAA Rs). Moreover CBSH3- is constitutively active; therefore lower expression of CBSH3- protein might play a relatively stronger functional role than the more abundant but self-inhibited CBSH3+ isoforms, which need to be activated. We are now showing that: (a) CBSH3- protein is expressed in the brain; (b) parvalbumin positive (PV+) interneurons show higher expression of CBSH3- protein than other neurons; (c) CBSH3- is associated with GABAergic synapses in various regions of the brain and (d) knocking down CBSH3- in hippocampal neurons decreases the synaptic clustering of gephyrin and GABAA Rs. The results show that CBSH3- protein is expressed in the brain and that it plays a significant role in the size regulation of the GABAergic postsynapse.

[Prevalence study of the genetic markers associated with slow progression of human inmunodefiency virus type 1 in the Galician population (Northwest of Spain)]. / Estudio de la prevalencia de marcadores genéticos asociados a la lenta progresión del virus de la inmunodeficiencia humana tipo 1 en la población gallega.

INTRODUCTION: The deletion in the CCR5 gene (CCR5Δ32), the HLA-B*27:05, and polymorphisms rs2395029 and rs9264942 have been associated with slower progression of HIV-1. METHODS: An analysis was performed on 408 patients on follow-up. The analysis of viral load, CD4+ Tlymphocytes and other clinical variables since the diagnosis of the infection were collected. RESULTS: The prevalence of the genetic markers rs9264942, CCR5wt/Δ32, rs2395029, HLA-B*27:05 was 17.9%, 11.5%, 7.6%, and 6.4%, respectively. Of all the patients, 354 were classified as progressors and 46 as long-term non-progressors (LTNPs). Except for the HLA-B*27:05 allele, other genetic markers were associated with slower progression: CCR5wt/Δ32 (P=.011) and SNPs rs2395029 and rs9264942 (P<.0001), as well as their association (P<.0001). CONCLUSION: The prevalence of the HLA-B*57:01 allele was higher than described nationally. No association could be found between the HLA-B*27:05 allele and the presence of slower disease progression.

Executive summary: Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015.

Opportunistic infections continue to be a cause of morbidity and mortality in HIV-infected patients. They often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an opportunistic infection. The present article is an executive summary of the document that updates the previous recommendations on the prevention and treatment of opportunistic infections in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome. This document is intended for all professionals who work in clinical practice in the field of HIV infection.

Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015.

Despite the huge advance that antiretroviral therapy represents for the prognosis of infection by the human immunodeficiency virus (HIV), opportunistic infections (OIs) continue to be a cause of morbidity and mortality in HIV-infected patients. OIs often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an OI. The present article updates our previous guidelines on the prevention and treatment of various OIs in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome.

Ring finger protein 34 (RNF34) interacts with and promotes γ-aminobutyric acid type-A receptor degradation via ubiquitination of the γ2 subunit.

We have found that the large intracellular loop of the γ2 GABAA receptor (R) subunit (γ2IL) interacts with RNF34 (an E3 ubiquitin ligase), as shown by yeast two-hybrid and in vitro pulldown assays. In brain extracts, RNF34 co-immunoprecipitates with assembled GABAARs. In co-transfected HEK293 cells, RNF34 reduces the expression of the γ2 GABAAR subunit by increasing the ratio of ubiquitinated/nonubiquitinated γ2. Mutating several lysines of the γ2IL into arginines makes the γ2 subunit resistant to RNF34-induced degradation. RNF34 also reduces the expression of the γ2 subunit when α1 and ß3 subunits are co-assembled with γ2. This effect is partially reversed by leupeptin or MG132, indicating that both the lysosomal and proteasomal degradation pathways are involved. Immunofluorescence of cultured hippocampal neurons shows that RNF34 forms clusters and that a subset of these clusters is associated with GABAergic synapses. This association is also observed in the intact rat brain by electron microscopy immunocytochemistry. RNF34 is not expressed until the 2nd postnatal week of rat brain development, being highly expressed in some interneurons. Overexpression of RNF34 in hippocampal neurons decreases the density of γ2 GABAAR clusters and the number of GABAergic contacts that these neurons receive. Knocking down endogenous RNF34 with shRNA leads to increased γ2 GABAAR cluster density and GABAergic innervation. The results indicate that RNF34 regulates postsynaptic γ2-GABAAR clustering and GABAergic synaptic innervation by interacting with and ubiquitinating the γ2-GABAAR subunit promoting GABAAR degradation.

Cardiovascular risk factors and lifetime risk estimation in HIV-infected patients under antiretroviral treatment in Spain.

BACKGROUND AND OBJECTIVES: Cardiovascular disease is a major concern in HIV-infected patients. Lifetime risk estimations use the risk of developing it over the course of remaining lifetime, and are useful in communicating this risk to young patients. We aim to describe the prevalence of cardiovascular risk factors among a representative sample of HIV-infected subjects under antiretroviral therapy in Spain, and to estimate their lifetime risk of cardiovascular disease. METHODS: Cross-sectional survey about cardiovascular risk factors in 10 HIV units across Spain. Lifetime risk assessed according to Barry was classified in two major categories: low and high lifetime risk. RESULTS: We included 895 subjects, 72% men, median age 45.7 years; median CD4 lymphocyte count 598 cells/µl, median time since HIV diagnosis 11 years, median time on antiretroviral treatment 6.3 years, 87% had undetectable HIV viral load. Tobacco smoking was the most frequent risk factor (54%), followed by dyslipidemia (48.6%) and hypertension (38.6%). Estimated 10-year coronary risk (Framingham/Regicor Risk Score) risk was low ( < 5%) in 78% of the patients, and intermediate (5-10%) in 20%. Lifetime risk estimation showed a high risk profile for 71.4% of the population studied, which was associated with increasing age, prolonged antiretroviral therapy and patient's place of origin. CONCLUSIONS: Modifiable cardiovascular risk factors in this population are very common. There are significant disparities between the low 10-year risk estimated with the Framingham/Regicor score and the higher lifetime risk in HIV patients on antiretroviral therapy. A more aggressive management of modifiable cardiovascular risk factors in these patients seems advisable.

[Executive summary of the recommendations on the evaluation and management of renal disease in human immunodeficiency virus-infected patients]. / Resumen ejecutivo del documento de consenso sobre el manejo de la patología renal en pacientes con infección por el virus de la inmunodeficiencia humana.

The aim of this article is to update the 2010 recommendations on the evaluation and management of renal disease in human immunodeficiency virus (HIV)-infected patients. Renal function should be monitored in all HIV-infected patients. The basic renal work-up should include measurements of serum creatinine, estimated glomerular filtration rate by CKD-EPI, urine protein-to-creatinine ratio, and urinary sediment. Tubular function tests should include determination of serum phosphate levels and urine dipstick for glycosuria. In the absence of abnormal values, renal screening should be performed annually. In patients treated with tenofovir, or with risk factors for chronic kidney disease (CKD), more frequent renal screening is recommended. In order to prevent disease progression, potentially nephrotoxic antiretroviral drugs are not recommended in patients with CKD or risk factors for CKD. The document provides indications for renal biopsy and advises on the optimal time for referral of a patient to the nephrologist. The indications for and evaluation and management of dialysis and renal transplantation are also addressed.

Executive summary of the GeSIDA/National AIDS Plan consensus document on antiretroviral therapy in adults infected by the human immunodeficiency virus (updated January 2014).

In this update, antiretroviral therapy (ART) is recommended for all patients infected by type 1 human immunodeficiency virus (HIV-1). The strength and grade of the recommendation varies with clinical circumstances, number of CD4 cells, comorbid conditions and prevention of transmission of HIV. The objective of ART is to achieve an undetectable plasma viral load. Initial ART should always comprise a combination of 3 drugs, including 2 nucleoside reverse transcriptase inhibitors and a third drug from a different family (non-nucleoside reverse transcriptase inhibitor, protease inhibitor, or integrase inhibitor). This update presents the causes and criteria for switching ART in patients with undetectable plasma viral load and in cases of virological failure. An update is also provided for the specific criteria for ART in special situations (acute infection, HIV-2 infection, and pregnancy) and with comorbid conditions (tuberculosis or other opportunistic infections, kidney disease, liver disease, and cancer).

Anal Dysplasia Screening in People Living with HIV: Long-Term Follow-Up in a Large Cohort from Northwest Spain.

Anal squamous cell carcinoma (SCC) is not a common disease in the general population, although its incidence is higher in people living with human immunodeficiency virus (PLWH). Anal SCC is caused by human papillomavirus (HPV) infection and arises from premalignant lesions termed squamous intraepithelial lesions (SILs). SIL surveillance programs are based on the early detection and treatment of SILs, especially those with a higher risk of transforming into cancer. An anal surveillance program has been under development in our institution since 2011. In this context, we performed a retrospective cohort study at the anal dysplasia unit of Álvaro-Cunqueiro Hospital (Spain). Epidemiological and clinical data were gathered from our Infectious Diseases Sample Collection (an open sample cohort including PLWH) from January 2011 to January 2022. A total of 493 PLWH were considered, 122 (24.7%) of whom were diagnosed with anal dysplasia at baseline, including 2 cases of anal SCC. Briefly, most of individuals were young men (median age, 38 years old) born in Spain (76%), whose vaccination rate before their inclusion in the program was scarce (<3%). Throughout the study period, 81 (16.4%) cases were diagnosed with high-grade squamous-intraepithelial lesions (HSILs) and 3 with anal SCC. At the baseline, severe immunosuppression (i.e., nadir CD4+ lymphocyte count below 200 cell/µL), and prior diagnosis of condyloma acuminata were more frequent within the group with SILs. Conversely, the baseline CD4+ lymphocyte count was similar among both groups. HPV-16 was related to a higher risk of HSILs (odds ratio: 2.76). At the end of the follow-up, 385 PLWH had been retained in care; one patient had died of anal cancer. Anal dysplasia was common (25% of cases), especially among patients infected by HPV-16, diagnosed with condyloma acuminata, and who were severely immunosuppressed. HPV-16 was the main risk factor for the presentation of HSILs.

Molecular and functional interaction between protocadherin-γC5 and GABAA receptors.

We have found that the γ2 subunit of the GABA(A) receptor (γ2-GABA(A)R) specifically interacts with protocadherin-γC5 (Pcdh-γC5) in the rat brain. The interaction occurs between the large intracellular loop of the γ2-GABA(A)R and the cytoplasmic domain of Pcdh-γC5. In brain extracts, Pcdh-γC5 coimmunoprecipitates with GABA(A)Rs. In cotransfected HEK293 cells, Pcdh-γC5 promotes the transfer of γ2-GABA(A)R to the cell surface. We have previously shown that, in cultured hippocampal neurons, endogenous Pcdh-γC5 forms clusters, some of which associate with GABAergic synapses. Overexpression of Pcdh-γC5 in hippocampal neurons increases the density of γ2-GABA(A)R clusters but has no significant effect on the number of GABAergic contacts that these neurons receive, indicating that Pcdh-γC5 is not synaptogenic. Deletion of the cytoplasmic domain of Pcdh-γC5 enhanced its surface expression but decreased the association with both γ2-GABA(A)R clusters and presynaptic GABAergic contacts. Cultured hippocampal neurons from the Pcdh-γ triple C-type isoform knock-out (TCKO) mouse (Pcdhg(tcko/tcko)) showed plenty of GABAergic synaptic contacts, although their density was reduced compared with sister cultures from wild-type and heterozygous mice. Knocking down Pcdh-γC5 expression with shRNA decreased γ2-GABA(A)R cluster density and GABAergic innervation. The results indicate that, although Pcdh-γC5 is not essential for GABAergic synapse formation or GABA(A)R clustering, (1) Pcdh-γC5 regulates the surface expression of GABA(A)Rs via cis-cytoplasmic interaction with γ2-GABA(A)R, and (2) Pcdh-γC5 plays a role in the stabilization and maintenance of some GABAergic synapses.

Differential regulation of the postsynaptic clustering of γ-aminobutyric acid type A (GABAA) receptors by collybistin isoforms.

Collybistin promotes submembrane clustering of gephyrin and is essential for the postsynaptic localization of gephyrin and γ-aminobutyric acid type A (GABA(A)) receptors at GABAergic synapses in hippocampus and amygdala. Four collybistin isoforms are expressed in brain neurons; CB2 and CB3 differ in the C terminus and occur with and without the Src homology 3 (SH3) domain. We have found that in transfected hippocampal neurons, all collybistin isoforms (CB2(SH3+), CB2(SH3-), CB3(SH3+), and CB3(SH3-)) target to and concentrate at GABAergic postsynapses. Moreover, in non-transfected neurons, collybistin concentrates at GABAergic synapses. Hippocampal neurons co-transfected with CB2(SH3-) and gephyrin developed very large postsynaptic gephyrin and GABA(A) receptor clusters (superclusters). This effect was accompanied by a significant increase in the amplitude of miniature inhibitory postsynaptic currents. Co-transfection with CB2(SH3+) and gephyrin induced the formation of many (supernumerary) non-synaptic clusters. Transfection with gephyrin alone did not affect cluster number or size, but gephyrin potentiated the clustering effect of CB2(SH3-) or CB2(SH3+). Co-transfection with CB2(SH3-) or CB2(SH3+) and gephyrin did not affect the density of presynaptic GABAergic terminals contacting the transfected cells, indicating that collybistin is not synaptogenic. Nevertheless, the synaptic superclusters induced by CB2(SH3-) and gephyrin were accompanied by enlarged presynaptic GABAergic terminals. The enhanced clustering of gephyrin and GABA(A) receptors induced by collybistin isoforms was not accompanied by enhanced clustering of neuroligin 2. Moreover, during the development of GABAergic synapses, the clustering of gephyrin and GABA(A) receptors preceded the clustering of neuroligin 2. We propose a model in which the SH3- isoforms play a major role in the postsynaptic accumulation of GABA(A) receptors and in GABAergic synaptic strength.

Clinical, virological and biochemical evidence supporting the association of HIV-1 reverse transcriptase polymorphism R284K and thymidine analogue resistance mutations M41L, L210W and T215Y in patients failing tenofovir/emtricitabine therapy.

BACKGROUND: Thymidine analogue resistance mutations (TAMs) selected under treatment with nucleoside analogues generate two distinct genotypic profiles in the HIV-1 reverse transcriptase (RT): (i) TAM1: M41L, L210W and T215Y, and (ii) TAM2: D67N, K70R and K219E/Q, and sometimes T215F. Secondary mutations, including thumb subdomain polymorphisms (e.g. R284K) have been identified in association with TAMs. We have identified mutational clusters associated with virological failure during salvage therapy with tenofovir/emtricitabine-based regimens. In this context, we have studied the role of R284K as a secondary mutation associated with mutations of the TAM1 complex. RESULTS: The cross-sectional study carried out with > 200 HIV-1 genotypes showed that virological failure to tenofovir/emtricitabine was strongly associated with the presence of M184V (P < 10-10) and TAMs (P < 10-3), while K65R was relatively uncommon in previously-treated patients failing antiretroviral therapy. Clusters of mutations were identified, and among them, the TAM1 complex showed the highest correlation coefficients. Covariation of TAM1 mutations and V118I, V179I, M184V and R284K was observed. Virological studies showed that the combination of R284K with TAM1 mutations confers a fitness advantage in the presence of zidovudine or tenofovir. Studies with recombinant HIV-1 RTs showed that when associated with TAM1 mutations, R284K had a minimal impact on zidovudine or tenofovir inhibition, and in their ability to excise the inhibitors from blocked DNA primers. However, the mutant RT M41L/L210W/T215Y/R284K showed an increased catalytic rate for nucleotide incorporation and a higher RNase H activity in comparison with WT and mutant M41L/L210W/T215Y RTs. These effects were consistent with its enhanced chain-terminated primer rescue on DNA/DNA template-primers, but not on RNA/DNA complexes, and can explain the higher fitness of HIV-1 having TAM1/R284K mutations. CONCLUSIONS: Our study shows the association of R284K and TAM1 mutations in individuals failing therapy with tenofovir/emtricitabine, and unveils a novel mechanism by which secondary mutations are selected in the context of drug-resistance mutations.

Mutations in the protease gene associated with virological failure to lopinavir/ritonavir-containing regimens.

OBJECTIVES: To assess the most frequent resistance-associated mutations (RAMs) to lopinavir/ritonavir in a cohort of patients attended in daily practice. METHODS: We retrospectively identified 195 multitreated subjects with virological failure. Patients were classified as follows: (i) 71 (36.4%) never received lopinavir/ritonavir (lopinavir/ritonavir naive); (ii) 75 (38.5%) had previously failed on lopinavir/ritonavir; and (iii) 49 (25.1%) were on lopinavir/ritonavir at failure. RAM patterns were assessed. Medians, IQRs, percentages, Kruskal-Wallis, χ(2) or Fisher's exact test, and multinomial logistic regression were used whenever appropriate. RESULTS: L10I/F, K20R, L24I, L33F, M36I, M46I/L, I47V, G48V, F53L, I54V, A71V, G73S, V82A, I84V and L90M (all with P ≤ 0.037) were protease RAMs overexpressed in patients with lopinavir/ritonavir failure. L10I, M36I, M46I, I54V, L63P, A71V, V82A, I84V and L90M were the most common in lopinavir/ritonavir-naive patients. Other IAS-USA RAMs for lopinavir/ritonavir (L10R/V, K20M, V32I, I47A, I50V, I54L/A/M/T/S, A71T, L76V and V82F/T/S) were not associated with previous or current failure to lopinavir/ritonavir. Lopinavir/ritonavir failure was associated with the number of protease RAMs (OR = 1.146, 95% CI = 1.287, 1.626), higher exposure to protease inhibitors, and the presence of E44D, L33F, I54V and I84V. CONCLUSIONS: In multitreated patients with previous or current lopinavir/ritonavir failure, some protease mutations are selected at significantly greater rates. L10I, M36I, I54V, L63P, A71V, V82A and L90M were found in >50% of cases. Thus, their presence should be expected when genotypic testing results are not available. The number of protease RAMs and higher prior exposures to protease inhibitors were significantly associated with lopinavir/ritonavir failure.

Viruses Previously Identified in Brazil as Belonging to HIV-1 CRF72_BF1 Represent Two Closely Related Circulating Recombinant Forms, One of Which, Designated CRF122_BF1, Is Also Circulating in Spain.

Circulating recombinant forms (CRFs) are important components of the HIV-1 pandemic. Those derived from recombination between subtype B and subsubtype F1, with 18 reported, most of them of South American origin, are among the most diverse. In this study, we identified a HIV-1 BF1 recombinant cluster that is expanding in Spain, transmitted mainly via heterosexual contact, which, analyzed in near full-length genomes in four viruses, exhibited a coincident BF1 mosaic structure, with 12 breakpoints, that fully coincided with that of two viruses (10BR_MG003 and 10BR_MG005) from Brazil, previously classified as CRF72_BF1. The three remaining Brazilian viruses (10BR_MG002, 10BR_MG004, and 10BR_MG008) previously identified as CRF72_BF1 exhibited mosaic structures highly similar, but not identical, to that of the Spanish viruses and to 10BR_MG003 and 10BR_MG005, with discrepant subtypes in two short genome segments, located in pol and gp120env. Based on these results, we propose that the five viruses from Brazil previously identified as CRF72_BF1 actually belong to two closely related CRFs, one comprising 10BR_MG002, 10BR_MG004, and 10BR_MG008, which keep their CRF72_BF1 designation, and the other, designated CRF122_BF1, comprising 10BR_MG003, 10BR_MG005, and the viruses of the identified Spanish cluster. Three other BF1 recombinant genomes, two from Brazil and one from Italy, previously identified as unique recombinant forms, were classified as CRF72_BF1. CRF122_BF1, but not CRF72_BF1, was associated with protease L89M substitution, which was reported to contribute to antiretroviral drug resistance. Phylodynamic analyses estimate the emergence of CRF122_BF1 in Brazil around 1987. Given their close phylogenetic relationship and similar structures, the grouping of CRF72_BF1 and CRF122_BF1 in a CRF family is proposed.

Impact of inosine triphosphatase gene variants on the risk of anemia in HIV/hepatitis C virus-coinfected patients treated for chronic hepatitis C.

The role of rs1127354/rs7270101 alleles at the inosine triphosphatase (ITPA) gene on ribavirin-induced anemia was assessed in 74 patients with hepatitis C virus and human immunodeficiency virus coinfection. Anemia developed in 80% of patients with normal ITPA activity compared with 33% of those with reduced ITPA activity. In contrast, ITPA variants did not influence sustained virological response.

Recent advances in early stage lung cancer.

Treatment of early-stage non-small cell lung cancer has undergone considerable change in recent years. Areas of great interest to researchers include less invasive surgical methods with lower associated morbidity, indications for adjuvant chemotherapy and radiotherapy, the emergence of stereotactic body radiotherapy (SBRT) for peripheral and central or ultracentral tumors, and the probable role of adjuvant immunotherapy following surgery and SBRT, all of which may influence the management of these patients. RELEVANCE FOR PATIENTS: At present, the treatment of early stage non-small cell lung cancer is undergoing changes associated with the evolution of existing treatments and the advent of new treatments.

Mortality in Perinatally HIV-infected Adolescents After Transition to Adult Care in Spain.

INTRODUCTION: After the introduction of combination antiretroviral treatment, (ART) mortality in HIV-infected patients has dramatically decreased. However, it is still high in patients at risk, as adolescents transitioning to adult care (AC) without virologic control. The aim of this study was to characterize mortality and comorbidities of perinatally infected HIV (PHIV) patients after transition to AC. METHODS: A multicenter retrospective study from patients included in the CoRISpe-FARO Spanish cohort was conducted. PHIV patients who died after transition to AC between 2009 and 2019 were included. Clinical, immunovirologic characteristics, treatments received, comorbidities and causes of death were described. RESULTS: Among 401 PHIV patients, 14 died (3.5%). All were Spanish, 11/14 (78.6%) women. The median age at diagnosis was 1.5 years (interquartile range [IQR] 0.5-3.9), at transfer to AC was 18 years [16.1-19.9] and at death was 25.8 years [23.6-27.1]. In pediatric units [pediatric care (PC)], CD4+ nadir was 85 cells/µL [IQR 9.7-248.5] and 6/14 patients were classified as C-clinical stage. During AC, all patients were on C-clinical stage and CD4+ nadir dropped to 11.5 cells/µL [4.5-43.3]. cART adherence was extremely poor: in PC, 8/14 patients registered voluntary treatment interruptions; only one had undetectable VL at transition. In AC, 12/14 patients stopped treatment 2 or more periods of time. All deaths were related to advanced HIV disease. Mental health disorders were observed in 7/14 (50%). Main complications described: recurrent bacterial infections (57.1%), wasting syndrome (42.9%), esophageal candidiasis (28.6%) and Pneumocystis jirovecii pneumonia (28.6%). Four women had 11 pregnancies; 5 children were born (none infected). CONCLUSIONS: Young adults PHIV infected who transition to AC without virologic suppression or proven ability to adhere to ART are at high risk of mortality. Mortality was noted as a consequence of advanced HIV disease, frequent mental health problems and poor adherence to ART.

Septin 11 is present in GABAergic synapses and plays a functional role in the cytoarchitecture of neurons and GABAergic synaptic connectivity.

Mass spectrometry and immunoblot analysis of a rat brain fraction enriched in type-II postsynaptic densities and postsynaptic GABAergic markers showed enrichment in the protein septin 11. Septin 11 is expressed throughout the brain, being particularly high in the spiny branchlets of the Purkinje cells in the molecular layer of cerebellum and in the olfactory bulb. Immunofluorescence of cultured hippocampal neurons showed that 54 +/- 4% of the GABAergic synapses and 25 +/- 2% of the glutamatergic synapses had colocalizing septin 11 clusters. Similar colocalization numbers were found in the molecular layer of cerebellar sections. In cultured hippocampal neurons, septin 11 clusters were frequently present at the base of dendritic protrusions and at the bifurcation points of the dendritic branches. Electron microscopy immunocytochemistry of the rat brain cerebellum revealed the accumulation of septin 11 at the neck of dendritic spines, at the bifurcation of dendritic branches, and at some GABAergic synapses. Knocking down septin 11 in cultured hippocampal neurons with septin 11 small hairpin RNAs showed (i) reduced dendritic arborization; (ii) decreased density and increased length of dendritic protrusions; and (iii) decreased GABAergic synaptic contacts that these neurons receive. The results indicate that septin 11 plays important roles in the cytoarchitecture of neurons, including dendritic arborization and dendritic spines, and that septin 11 also plays a role in GABAergic synaptic connectivity.

Liver toxicity after switching or simplifying to nevirapine-based therapy is not related to CD4 cell counts: results of the TOSCANA study.

PURPOSE: The TOSCANA study aimed to determine the relationship between CD4 cell counts and liver toxicity in patients undergoing treatment simplification or substitution with nevirapine due to the toxicity or poor tolerability of a previous regimen. METHODS: A retrospective analysis was conducted of patients with prior viral suppression who were switched to nevirapine. RESULTS: Overall, 221 patients were included, representing 1134.83 patient-years. The median baseline CD4 cell count at the switch was 464 cells/microL, with 75.6% showing high CD4 cell counts (> or =250 cells/microL in women or > or =400 cells/microL in men). Hepatotoxicity, defined as liver aminotransferase levels 5 times above the upper limit of normal, was detected in 6.7% of the participants with high CD4 cell counts and 13.0% in those with low counts. The relative risk was 0.51 (95% CI 0.21-1.25), and the incidence rates were 2.63 and 1.26 per 100 patient-years for the low- and high-count subpopulations, respectively. Liver toxicity was mild, reversible upon discontinuation, and more likely to appear after 6 months of nevirapine therapy. CONCLUSIONS: Switching to nevirapine was associated with a low incidence of liver toxicity that was unrelated to high CD4 cell counts in patients on prior antiretroviral therapy undergoing simplification or substitution therapy.

[Asymptomatic osteonecrosis of the hip in HIV-infected patients]. / Osteonecrosis asintomática de la cadera en los pacientes infectados por el virus de inmunodeficiencia humana.

BACKGROUND: Osteonecrosis (ON) of the hip in human immunodeficiency virus (HIV)-infected patients has been related to corticosteroid use, dyslipidemia, alcoholism, lipodystrophy, antiretroviral drug use, and HIV infection, itself. The aim of this study was to evaluate the prevalence of silent ON of the hip in HIV-infected patients and its association with several risk factors. METHODS: From a total of 1200 patients followed up at the HIV clinic of Xeral-Cies Hospital in Vigo (Spain), we selected those diagnosed with HIV infection before January 2006, aged 20-70 years, who came to the clinic during the period of March to May 2008. Patients with a diagnosis of ON of the hip and those with current symptoms were excluded. A magnetic resonance imaging (MRI) study of the hips was performed. RESULTS: Ninety-seven Caucasian patients (68 men) with a median age of 44 years were included. ON of the hip was detected in 4 patients (4.1%), with bilateral involvement in 2 patients. All 4 patients were men, with a median age of 44.5 years. Several risk factors for ON of the hip were recorded in each patient. CD4 lymphocyte nadir (P=0.034), percentage of patients with CDC stage C (P=0.039), and number of patients with previous corticosteroid treatment (P=0.042) were significantly different between patients with ON of the hip and those with normal MRI findings. CONCLUSIONS: The prevalence of asymptomatic ON of the hip in HIV-infected patients was 4.1%. The most important risk factors for developing this condition were corticosteroid treatment, lower CD4 lymphocyte nadir, and AIDS-defining disease. Antiretroviral treatment was not associated with osteonecrosis.