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Hiatal hernia (HH) is a common disease in the general population. It is often asymptomatic, but if it does present clinical manifestations, these are usually gastrointestinal. Gastroesophageal reflux is the main symptom that accompanies it. Depending on the severity of the hernia, it is classified into several subtypes from I-IV. Especially, IV type (giant HH) can lead to various cardiopulmonary symptoms with several degrees of severity. It is necessary to keep this possibility in mind among the various differential diagnoses that may occur in this clinical setting. The current paper aims to review the literature on classic and novel information on the HH - cardiovascular system relationship. Epidemiological data, physiological aspects of the heart compressed by HH, cardiovascular symptoms, electrocardiographic changes, echocardiographic alterations and clinical implications are discussed.

BACKGROUND Heart transplantation is a therapeutic option for patients with severe coronary artery disease or heart failure. One of the difficulties to overcome is the apoptosis of cardiomyocytes in the donor organ. To prevent apoptosis in the donor organ, we developed a fusion protein containing FLIP (FADD-like interleukin beta-converting enzyme (FLICE)-like inhibitory protein) to inhibit caspase-8. MATERIAL AND METHODS We linked the cDNA coding for the FLIP protein to the transduction domain of HIV (human immunodeficiency virus) to allow the protein to enter cells. The recombinant protein was used at two different concentrations, 3 nM and 30 nM, for treatment of the donor heart in rat transplantation experiments. After transplantation, apoptosis was measured by ELISA, and the levels of active caspase-3, caspase-8, Bid, and PUMA were determined by western blotting using specific antibodies. RESULTS We observed that treatment of the donor organ with a solution containing this protein reduced the apoptosis level in the donor organ after 30 minutes post-transplantation as measured by the total of apoptotic cells with ELISA assay, and caspase-8 and caspase-3 activation and decreased levels of BH3-only proteins such as Bid and PUMA. Furthermore, this treatment also reduced the total tyrosine phosphorylation levels, which may be a possible measurement of lower oxidative stress levels in cardiomyocytes. CONCLUSIONS Protein FLIP solution reduced apoptosis at 30 minutes post-transplantation and decreased levels of several regulators of apoptosis.

Ack1 (activated Cdc42-associated tyrosine kinase) is a non-receptor tyrosine kinase that is highly expressed in brain. This kinase contains several protein-protein interaction domains and its action is partially regulated by phosphorylation. As a first step to address the neuronal functions of Ack1, here we screened mouse brain samples to identify proteins that interact with this kinase. Using mass spectrometry analysis, we identified new putative partners for Ack1 including cytoskeletal proteins such as Drebrin or MAP4; adhesion regulators such as NCAM1 and neurabin-2; and synapse mediators such as SynGAP, GRIN1 and GRIN3. In addition, we confirmed that Ack1 and CAMKII both co-immunoprecipitate and co-localize in neurons. We also identified that adult and P5 samples contained the phosphorylated residues Thr 104 and Ser 825, and only P5 samples contained phosphorylated Ser 722, a site linked to cancer and interleukin signaling when phosphorylated. All these findings support the notion that Ack1 could be involved in neuronal plasticity., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interest.

The regulation of focal adhesion kinase (FAK) involves phosphorylation and multiple interactions with other signaling proteins. Some of these pathways are relevant for nervous system functions such as branching, axonal guidance, and plasticity. In this study, we screened mouse brain to identify FAK-interactive proteins and phosphorylatable residues as a first step to address the neuronal functions of this kinase. Using mass spectrometry analysis, we identified new phosphorylated sites (Thr 952, Thr 1048, and Ser 1049), which lie in the FAT domain; and putative new partners for FAK, which include cytoskeletal proteins such as drebrin and MAP 6, adhesion regulators such as neurabin-2 and plakophilin 1, and synapse-associated proteins such as SynGAP and a NMDA receptor subunit. Our findings support the participation of brain-localized FAK in neuronal plasticity., (Copyright © 2016 Elsevier B.V. All rights reserved.)

This paper analyses late presentation (LP) of HIV infection, and its determinants, among men who have sex with men (MSM) in Spain, newly diagnosed with HIV (2003-2011) in 15 sexually transmitted infection/HIV counselling and testing clinics. LP was defined as <350 CD4 cells/µL or AIDS. In total, 3,081 MSM were included (2,499 having CD4/AIDS); overall LP was 25.3%. LP was higher in men older than 34 years, those not previously HIV-tested (adjusted odds ratio (aOR):3.1; 95% confidence intervals (CI):2.3-4.2) , and those tested > 12 months before diagnosis (12-24 months (aOR:1.4; 95% CI:1.0-2.0); > 24 months (aOR:2.2; 95% CI:1.7-3.0)). LP was less likely in MSM reporting a known HIV-infected partner as infection source or symptoms compatible with acute retroviral syndrome. 'Region of birth' interacted with 'educational level' and 'steady partner as infection source': only African and Latin-American MSM with low educational level were more likely to present late; Latin-American men attributing their infection to steady partner, but no other MSM, had LP more frequently. In Spain, HIV testing among MSM should be promoted, especially those > 34 years old and migrants with low educational level. The current recommendation that MSM be tested at least once a year is appropriate.

Although it was originally characterized as a constituent of focal adhesions in fibroblasts, focal adhesion kinase (FAK) is now considered to be not only a mediator of adhesion processes but also a crucial regulator of guidance and a modulator of gene expression. FAK is the main transducer of the integrin signaling required to stabilize the actin cytoskeleton. However, additional activities have been described over the years. In the brain, FAK deserves particular attention as it is found in various alternatively spliced forms - these distributed in multiple subcellular compartments or bound to multiple partners. Moreover, its signaling involves not only phosphorylation but also ubiquitination and proteolysis. Several experimental cell models demonstrate that FAK increases or decreases migration, participates in differentiation and contributes to plasticity events. In addition, this kinase is linked to cell survival in cancer and apoptosis. This review focuses on the diversity of events involving brain-located forms of FAK., (© 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Background: Gonorrhoea infection is one of the most common bacterial sexually transmitted infections and an important cause of morbidity and serious complications. The objectives of this paper are: a) to describe gonorrhoea cases diagnosed in a network of 15 (out of 16) STI clinics in Spain during 2006-2010; b) to analyse differences among men who have sex with men (MSM), men who have sex exclusively with women (MSW) and women; and c) to evaluate factors associated to with HIV co-infection., Methods: All gonorrhoea cases diagnosed in the network were included (25.7% of total cases notified in Spain). Data were collected by clinical staff. Descriptive/bivariate analyses were carried out stratifying by sex and transmission category; association and trends were evaluated using the chi-square test. Factors associated with HIV co-infection were estimated using a logistic regression model., Results: 2385 cases were included: 55.3% among MSM, 31.3% among MSW and 13.3% among females; cases among MSM increased from 55.8% in 2006 to 62.9% in 2010 while no trends were found among the other two groups.Most MSM cases were Spaniards (72%), aged 25-34 years (46%), 49% reported previous STI and 25% concurrent STI (excluding HIV); casual partners were the commonest source of infection, and 21% of cases had rectal gonorrhoea. MSW cases did not differ from MSM by age, origin or source of infection, but frequencies of prior or concurrent STI were lower. Female cases were younger than male, were mostly foreigners (58%), and 41% were sex workers; concurrent STI (other than HIV) were diagnosed in 30%; 20.4% had symptoms (72.5% and 89.2% in MSM and MSW), and pharyngeal location was present in 30%.HIV co-infection was highest in MSM (20.9%). Co-infection was associated with age > 35 years, low educational level, being Western European or Latin-American, being MSM, having previous or concurrent STI and reporting contact with an HIV-infected partner; it was inversely associated with female sex., Conclusion: Differences by sex, transmission route and origin should be considered when implementing care and preventive programmes for gonorrhoea, and MSM are a priority group for intervention, in particular HIV-infected MSM.

Neurotrophins are involved in many crucial cellular functions, including neurite outgrowth, synapse formation, and plasticity. Although these events have long been known, the molecular determinants underlying neuritogenesis have not been fully characterized. Ack1 (activated Cdc42-associated tyrosine kinase) is a non-receptor tyrosine kinase that is highly expressed in the brain. Here, we demonstrate that Ack1 is a molecular constituent of neurotrophin signaling cascades in neurons and PC12 cells. We report that Ack1 interacts with Trk receptors and becomes tyrosine phosphorylated and its kinase activity is increased in response to neurotrophins. Moreover, our data indicate that Ack1 acts upstream of the Akt and MAPK pathways. We show that Ack1 overexpression induces neuritic outgrowth and promotes branching in neurotrophin-treated neuronal cells, whereas the expression of Ack1 dominant negatives or short-hairpin RNAs counteract neurotrophin-stimulated differentiation. Our results identify Ack1 as a novel regulator of neurotrophin-mediated events in primary neurons and in PC12 cells.

In Spain, neither the HIV nor the STI national surveillance systems collect information on HIV/STI co-infection. However, there are two networks based on HIV/STI clinics which gather this data. We describe HIV prevalence in men who have sex with men (MSM) diagnosed with infectious syphilis and/or gonorrhoea in 15 STI clinics; and concurrent diagnoses of STI in MSM newly diagnosed with HIV in 19 HIV/STI clinics. In total, 572 MSM were diagnosed with infectious syphilis and 580 with gonorrhoea during 2005-2007. HIV prevalence among syphilis and gonorrhoea cases was 29.8% and 15.2% respectively. In the multivariate analysis, HIV/syphilis co-infection was associated with being Latin American; having a history of STI; reporting exclusively anal intercourse; and having sex with casual or several types of partners. HIV and gonorrhoea co-infection was associated with age older than 45 years; having no education or only primary education completed; and having a history of STI. In total, 1,462 HIV infections were newly diagnosed among MSM during 2003-2007. Of these, 31.0% were diagnosed with other STI at the same time. Factors associated with STI co-infection among new HIV cases in MSM were being Latin American; and having sex with casual partners or with both steady and casual partners. In Spain, a considerable proportion of MSM are co-infected with HIV and STI.

The family of CREB (cAMP response element-binding protein) transcription factors are involved in a variety of biological processes including the development and plasticity of the nervous system. In the maturing and adult brain, CREB genes are required for activity-dependent processes, including synaptogenesis, refinement of connections and long-term potentiation. Here, we use CREB1(Nescre)CREM(-/-) (cAMP-responsive element modulator) mutants to investigate the role of these genes in stimulus-independent patterns of neural activity at early stages. We show that lack of CREB/CREM genes specifically in neural tissue leads to increased synaptogenesis and to a dramatic increase in the levels of spontaneous network activity at embryonic stages. Thus, the functions of CREB/CREM genes in neural activity differ in distinct periods of neural development.

The family of CREB transcription factors is involved in a variety of biological processes including the development and plasticity of the nervous system. To gain further insight into the roles of CREB family members in the development of the embryonic brain, we examined the migratory phenotype of CREB1(Nescre)CREM(-/-) mutants. We found that the lack of CREB/CREM genes is accompanied by anatomical defects in specific layers of the olfactory bulb, hippocampus and cerebral cortex. These changes are associated with decreased Dab1 expression in CREB1(Nescre)CREM(-/-) mutants. Our results indicate that the lack of CREB/CREM genes, specifically in neural and glial progenitors, leads to migration abnormalities during brain development, suggesting that unidentified age-dependent factors modulate the role of CREB/CREM genes in neural development.

The pattern of expression by using in situ hybridization in whole mouse embryos of the neuroleukin/glucose-6-phosphate isomerase (NK/GPI) gene and its receptor (AMF-R) is reported. NK/GPI expression was first seen at embryonic day 9 whereas AMF-R was detected at embryonic day 8; both were detected up to day 12 with NK/GPI showing peaking in the limbs around day 11. The main regions of expression are limb buds, spinal cord and brain. This work contributes to understanding how both proteins act in the development of somatosensory and motoric neural structures.

Prnp knockout mice that overexpress an amino-truncated form of PrPc (deltaPrP) are ataxic and display cerebellar cell loss and premature death. Studies on the molecular and intracellular events that trigger cell death in these mutants may contribute to elucidate the functions of PrPc and to the design of treatments for prion disease. Here we examined the effects of Bcl-2 overexpression in neurons on the development of the neurological syndrome and cerebellar pathology of deltaPrP. We show that deltaPrP overexpression activates the stress-associated kinases ERK1-2 in reactive astroglia, p38 and the phosphorylation of p53, which leads to the death of cerebellar neurons in mutant mice. We found that the expression of deltaPrP in cell lines expressing very low levels of PrPc strongly induces the activation of apoptotic pathways, thereby leading to caspase-3 activation and cell death, which can be prevented by coexpressing Bcl-2. Finally, we corroborate in vivo that neuronal-directed Bcl-2 overexpression in deltaPrP mice (deltaPrP Bcl-2) markedly reduces caspase-3 activation, glial activation, and neuronal cell death in cerebellum by improving locomotor deficits and life expectancy.

Reelin binds to very low-density lipoprotein receptor and apolipoprotein E receptor 2, thereby inducing mDab1 phosphorylation and activation of the phosphatidylinositide 3 kinase (PI3K) pathway. Here we demonstrate that Reelin activates the mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) pathway, which leads to the phosphorylation of Erk1/2 proteins. The inhibition of Src family kinases (SFK) blocked Reelin-dependent Erk1/2 activation. This was also shown in neuronal cultures from mDab1-deficient mice. Although rat sarcoma viral oncogene was weakly activated upon Reelin treatment, pharmacological inhibition of the PI3K pathway blocked Reelin-dependent ERK activation, which indicates cross talk between the ERK and PI3K pathways. We show that blockade of the ERK pathway does not prevent the chain migration of neurons from the subventricular zone (SVZ) but does inhibit the Reelin-dependent detachment of migrating neurons. We also show that Reelin induces the transcription of the early growth response 1 transcription factor. Our findings demonstrate that Reelin triggers ERK signaling in an SFK/mDab1- and PI3K-dependent manner and that ERK activation is required for Reelin-dependent transcriptional activation and the detachment of neurons migrating from the SVZ.

Ack1 is a non-receptor tyrosine kinase that is highly expressed in the adult central nervous system (CNS). Here, we studied the distribution of Ack1 mRNA throughout the development of mouse CNS. Expression was detected in all areas of the brain but especially high levels were observed in the neocortex, hippocampus, and cerebellum. Interestingly, expression levels were prominent in areas of proliferation such as the subventricular zone and areas that originate other structures such the pontine nucleus and the ganglionic eminence. During development, several areas showed an increase in Ack1 expression, especially the dentate gyrus and CA3 in the hippocampus, layer V in the neocortex, and the Purkinje cell layer in the cerebellum. These results demonstrate that this kinase is up-regulated during development and that it is expressed in proliferative areas and in migratory pathways in the developing brain.

Discoidin domain receptor 1 is a tyrosine kinase receptor expressed in a variety of tissues including the brain. This study describes mRNA and protein expression of discoidin domain receptor 1 in mouse brain during development and provides new insights into its role during gliogenesis and neurogenesis. We performed in situ hybridization for discoidin domain receptor 1 in mouse brains at embryonic day 18, postnatal days 5, 9, 15, 21 and adulthood and observed a diffuse pattern in the proliferative areas during embryogenesis. From postnatal day 5 onwards, a defined cellular expression pattern of discoidin domain receptor 1 was observed, mainly located in white matter tracts and following a spatio-temporal pattern that overlapped the progress of myelination. Next, we performed double-labeling reactions (in situ hybridization followed by immunohistochemistry) that confirmed that discoidin domain receptor 1 was expressed by mature oligodendrocytes. We observed that cells positive for discoidin domain receptor 1 also expressed carnosine and anti-adenomatous polyposis coli, two mature oligodendrocyte markers. Based on the localization of discoidin domain receptor 1 specifically in the white matter fiber tracts during postnatal development, we suggest that discoidin domain receptor 1 participates in the development and maintenance of the myelin sheath.

Myelin-associated proteins are involved in the formation and stabilization of myelin sheaths. In addition, they prevent axon regeneration and plasticity in the adult brain. Recent evidence suggests that the expression of certain myelin-associated proteins (e.g. Nogo-A) can be regulated by synaptic activity or by over-expression after neural lesions in brain syndromes such as temporal lobe epilepsy. However, no studies on Alzheimer disease (AD) have been reported in which cell loss and significant synaptic reorganization occurs. In the present study, we analyze in detail the expression of Nogo-A in the hippocampal formation in normal human aging and in AD. Our results indicate that Nogo-A is expressed by oligodendrocytes and neurons in the aged hippocampal formation. In addition, both granule cells and mossy fiber connections are also labeled in the old-aged hippocampi. Interestingly, Nogo-A is over-expressed by hippocampal neurons in AD and is associated with beta-amyloid deposits in senile plaques. Taken together, our results reinforce the hypothesis that Reticulon proteins such as Nogo-A participate in the neuronal responses stemming from hippocampal formation during senescence, and particularly in AD. These findings also indicate that Reticulon proteins could be considered as new putative drug targets in therapies of neurodegenerative disorders.

Reelin is a glycoprotein that is essential for the correct cytoarchitectonic organization of the developing CNS. Its function in the adult brain is less understood, although it has been proposed that Reelin is involved in signaling pathways linked to neurodegeneration. Here we analyzed Reelin expression in brains and cerebrospinal fluid (CSF) from Alzheimer's disease (AD) patients and nondemented controls. We found a 40% increase in the Reelin protein levels in the cortex of AD patients compared with controls. Similar increases were detected at the Reelin mRNA transcriptional level. This expression correlates with parallel increases in CSF but not in plasma samples. Next, we examined whether CSF Reelin levels were also altered in neurological diseases, including frontotemporal dementia, progressive supranuclear palsy, and Parkinson's disease. The Reelin 180-kDa band increased in all of the neurodegenerative disorders analyzed. Moreover, the 180-kDa Reelin levels correlated positively with Tau protein in CSF. Finally, we studied the pattern of Reelin glycosylation by using several lectins and the anti-HNK-1 antibody. Glycosylation differed in plasma and CSF. Furthermore, the pattern of Reelin lectin binding differed between the CSF of controls and in AD. Our results show that Reelin is up-regulated in the brain and CSF in several neurodegenerative diseases and that CSF and plasma Reelin have distinct cellular origins, thereby supporting that Reelin is involved in the pathogenesis of a number of neurodegenerative diseases.

Cytosolic tyrosine kinases play a critical role both in neural development and in adult brain function and plasticity. Here we isolated a cDNA with high homology to human Ack1 and mouse Tnk2. This cDNA directs the expression of a 125-kD protein that can be autophosphorylated in tyrosines. Initially, this clone was named Pyk1 for proline-rich tyrosine kinase (Lev et al., 1995); however, since it corresponds to the mouse homolog of Ack1, here we called it Ack1/Pyk1. In this study we show that Ack1/Pyk1 mRNA and protein is highly expressed in the developing and adult brain. The highest levels of Ack1/Pyk1 expression were detected in the hippocampus, neocortex, and cerebellum. Electron microscopy studies showed that Ack1/Pyk1 protein is expressed in these regions both at dendritic spines and presynaptic axon terminals, indicating a role in synaptic function. Furthermore, we demonstrate that Ack1/Pyk1 mRNA levels are strongly upregulated by increased neural activity, produced by intraperitoneal kainate injections. During development, Ack1/Pyk1 was also expressed in the proliferative ventricular zones and in postmitotic maturing neurons. In neuronal cultures, Ack1/Pyk1 was detected in developing dendrites and axons, including dendritic tips and growth cones. Moreover, Ack1/Pyk1 colocalized with Cdc42 GTPase in neuronal cultures and coimmunoprecipitated with Cdc42 in HEK 293T cells. Altogether, our findings indicate that Ack1/Pyk1 tyrosine kinase may be involved both in adult synaptic function and plasticity and in brain development., ((c) 2005 Wiley-Liss, Inc.)

Prion diseases are characterised by severe neural lesions linked to the presence of an abnormal protease-resistant isoform of cellular prion protein (PrPc). The peptide PrP(106-126) is widely used as a model of neurotoxicity in prion diseases. Here, we examine in detail the intracellular signalling cascades induced by PrP(106-126) in cortical neurons and the participation of PrPc. We show that PrP(106-126) induces the activation of subsets of intracellular kinases (e.g., ERK1/2), early growth response 1 synthesis and induces caspase-3 activity, all of which are mediated by nicotinamide adenine dinucleotide phosphate hydrogen-oxidase activity and oxidative stress. However, cells lacking PrPc are similarly affected after peptide exposure, and this questions the involvement of PrPc in these effects.

The signaling cascades governing neuronal migration are believed to link extracellular signals to cytoskeletal components. MAP1B is a neuron-specific microtubule-associated protein implicated in the control of the dynamic stability of microtubules and in the cross-talk between microtubules and actin filaments. Here we show that Reelin can induce mode I MAP1B phosphorylation, both in vivo and in vitro, through gsk3 and cdk5 activation. Additionally, mDab1 participates in the signaling cascade responsible for mode I MAP1B phosphorylation. Conversely, MAP1B-deficient mice display an abnormal structuring of the nervous system, especially in brain laminated areas, indicating a failure in neuronal migration. Therefore, we propose that Reelin can induce post-translational modifications on MAP1B that could correlate with its function in neuronal migration.

Background: The human immunodeficiency virus (HIV) epidemic in Spain was characterized throughout the first few years by the predominance of infections among injected drug users (IDU's), but everything currently points to a progressive predominance of sexual transmission. This study is aimed at describing the trend in HIV infection among several heterosexual populations groups and at characterizing the situations in which the infections occurred., Methods: Descriptive study of the individualls who had the test conducted for the first time at nine HIV diagnosis centres within the 1992-2003 period due to high-risk heterosexual exposures, not including injected drug users., Results: A total of 47,870 individuals had serology performed during the period under study. The HIV prevalence among the population under study dropped from 3.2% to 1.0% (p< 0.001). Among the individuals with an HIV infected partners, the prevalence remained at around 10%, the male users of prostitution having dropped from 1.9% to 1.0% (p=0.049); among women involved in prostitution, from 1.4% to 0.7% (p=0.008); and among all other heterosexuals, having dropped from 1.6% to 1.0% among males (p=0.014) and from 1.1% to 0.7% among women (p=0.012)., Conclusions: The results indicate advances in the control of heterosexual human immunodeficiency virus transmission, mainly among women, although it is necessary to still continue stressing prevention.

Objective: To describe the prevalence of HIV infection in persons tested between 1992 and 2001., Design: Descriptive, cross-sectional epidemiological study., Setting: 10 ambulatory centers specialized in diagnosing HIV, located in 9 cities in Spain., Participants: 53,183 persons older than 12 years, tested for the first time for HIV., Main Measures: Number of persons tested per year, number of persons diagnosed as seropositive for HIV according to sex, age group and category of exposure., Results: The number of persons tested increased from 4401 in 1992 to 6407 in 2001. Approximately half reported heterosexual risk exposure/exposure through high-risk heterosexual behaviors, excluding prostitution. Intravenous drug users (IVDU) increased from 15.3% in 1992-1993 to 1.4% in 2000-2001, and women prostitutes/female sex workers increased from 6.7% to 25.1%. A total of 2898 persons were diagnosed as having HIV infection; 78% of them were men. The number of diagnoses decreased from a high of 1058 in 1992-1993 to 304 in 2000-2001, and this trend was seen for all categories of exposure except female prostitutes and men with heterosexual risk factors. The prevalence decreased from 14% in 1992 to 2% in 2001. There were decreases in all categories of exposure, especially during the first years of the study, with a tendency to level off. In 2001 the prevalence figures were 23.8% for IVDU, 7.9% for homosexual men and women, 0.8% for female sex workers and 1% for other heterosexual men and women., Conclusions: The specialized diagnostic centers play an important role in diagnosing HIV, and this service complements primary care services. Greater efforts are needed in the prevention of HIV infection.

Background: The signaling cascades governing neuronal migration and axonal guidance link extracellular signals to cytoskeletal components. MAP1B is a neuron-specific microtubule-associated protein implicated in the crosstalk between microtubules and actin filaments., Results: Here we show that Netrin 1 regulates, both in vivo and in vitro, mode I MAP1B phosphorylation, which controls MAP1B activity, in a signaling pathway that depends essentially on the kinases GSK3 and CDK5. We also show that map1B-deficient neurons from the lower rhombic lip and other brain regions have reduced chemoattractive responses to Netrin 1 in vitro. Furthermore, map1B mutant mice have severe abnormalities, similar to those described in netrin 1-deficient mice, in axonal tracts and in the pontine nuclei., Conclusions: These data indicate that MAP1B phosphorylation is controlled by Netrin 1 and that the lack of MAP1B impairs Netrin 1-mediated chemoattraction in vitro and in vivo. Thus, MAP1B may be a downstream effector in the Netrin 1-signaling pathway.

HIV infection in Spain was monitored in persons undergoing voluntary HIV testing in ten sentinel clinics between 1992 and 2002. Only patients on their first visit were considered for inclusion, and their numbers rose from 4426 in 1992 to 6649 in 2002. Most of them recognised their risk exposure as heterosexual. The proportion of injecting drug users decreased from 19% to 2% of the study population, and the proportion of female sex workers increased from 6% to 26%. The number of patients diagnosed with HIV infection declined from 604 in 1992 to 153 in 2002, and HIV prevalence fell from 13.6% to 2.3% in the same period. In all risk exposure categories, a decrease in HIV prevalence was observed, more pronounced during the first few years and stabilised in the later years. In 2002, the highest HIV prevalence was found in injecting drug users (IDUs) (14.2%), homo/bisexual men (7.5%) and individuals who had an HIV infected heterosexual partner (10.2%).

Axonal regeneration in the adult CNS is limited by the presence of several inhibitory proteins associated with myelin. Nogo-A, a myelin-associated inhibitor, is responsible for axonal outgrowth inhibition in vivo and in vitro. Here we study the onset and maturation of Nogo-A and Nogo receptor in the entorhino-hippocampal formation of developing and adult mice. We also provide evidence that Nogo-A does not inhibit embryonic hippocampal neurons, in contrast to other cell types such as cerebellar granule cells. Our results also show that Nogo and Nogo receptor mRNA are expressed in the adult by both principal and local-circuit hippocampal neurons, and that after lesion, Nogo-A is also transiently expressed by a subset of reactive astrocytes. Furthermore, we analyzed their regulation after kainic acid (KA) treatment and in response to the transection of the entorhino-hippocampal connection. We found that Nogo-A and Nogo receptor are differentially regulated after kainic acid or perforant pathway lesions. Lastly, we show that the regenerative potential of lesioned entorhino-hippocampal organotypic slice co-cultures is increased after blockage of Nogo-A with two IN-1 blocking antibodies. In conclusion, our results show that Nogo and its receptor might play key roles during development of hippocampal connections and that they are implicated in neuronal plasticity in the adult.

Background: Our purpose was to describe the time trend in HIV seroprevalence among homo/ bisexual men., Subjects and Method: We analyzed 9,383 homo/ bisexual men who had a first voluntary test for HIV in 10 Spanish clinics from 1992 to 2000., Results: HIV prevalence decreased from 20.3% in 1992 to 8.4% in 2000. In the multivariate analysis this decline appeared independently associated with the testing year and the birth cohort., Conclusions: New generations of voluntarily tested homo/bisexual men are less infected by HIV, but it is yet necessary to intensify the prevention programs.

The syndecans, a family of transmembrane heparan sulfate proteoglycans, are ubiquitous molecules whose intracellular function is still unknown. To examine the function of syndecan-2, one of the most abundant heparan sulfate proteoglycan in fibroblasts, we performed transfection studies in COS-1 and Swiss 3T3 cells. Endogenous syndecan-2 colocalized with F-actin in cortical structures. Overexpression of full-length syndecan-2 induced the formation of long filopodia-like structures. These changes correlated with a rearrangement of the actin cytoskeleton, which strongly colocalized with syndecan-2. Overexpression of syndecan-2 lacking the extracellular domain increased the number of microspikes on the cell surface but failed to induce filopodia. Addition of heparin blocked the effect of full-length syndecan-2, suggesting that heparan sulfate chains in the extracellular domain are necessary to induce filopodia. Coexpression of cdc42Hs negative-dominant N17 blocked syndecan-2-induced filopodia and cdc42Hs positive-dominant V12 had a synergic effect. This indicates that active cdc42Hs is necessary for syndecan-2 induction of filopodia. These results provide a link between syndecan-2, actin cytoskeleton, and cdc42Hs., (Copyright 1999 Academic Press.)

In general, plasma membrane integral proteins, such as the membrane-anchored growth factor proTGF-alpha, are assumed to be transported to the cell surface via a nonregulated, constitutive pathway. proTGF-alpha C-terminal mutants are retained in an early secretory compartment. Here, using a two-hybrid screen, we identify two TACIPs (proTGF-alpha cytoplasmic domain-interacting proteins) that contain PDZ domains and do not interact with proTGF-alpha C-terminal mutants. The binding specificity of one of them, TACIP18 (previously identified and named Syntenin or mda-9), coincides with that of the component that possibly mediates the normal trafficking of proTGF-alpha. TACIP18 colocalizes and interacts specifically with immature, intracellular forms of proTGF-alpha. Therefore, it appears that the interaction of TACIP18 with proTGF-alpha in the early secretory pathway is necessary for the targeting of the latter to the cell surface.

Transforming growth factor alpha (TGF-(alpha)) is synthesized as a precursor transmembrane molecule (proTGF-(alpha)) whose ectodomain is shed from the cell surface generating mature, soluble, growth factor. In agreement with recent reports, here we show that the structural determinant that targets proTGF-(alpha) to the cell surface maps to the very C-terminal cytoplasmic amino acid, valine. The primary localization of proTGF-(alpha) C-terminal mutants is a perinuclear area that colocalizes with ER markers. Since the ectodomain shedding machinery that acts on proTGF-(alpha) is known to be located at the cell surface, deficient transport provides an explanation for the previously reported lack of PKC activated ectodomain shedding of proTGF-(alpha) C-terminal mutants. The transport of wild-type proTGF-(alpha) to the cell surface was found to be mediated by a mechanism that includes a specific component saturable by wild-type proTGF-(alpha) but not by cell surface transmembrane proteins whose trafficking is independent of their cytoplasmic tail such as betaglycan. C-terminal valines are likely to be a general determinant of the subcellular location of cell surface transmembrane proteins since the maturation and trafficking of MT1-MMP C-terminal mutants are severely impaired. Our data suggest the existence of a targeting mechanism that acts on cell surface transmembrane molecules as diverse as proTGF-(alpha) and MT1-MMP and that the interaction with such a mechanism depends on the identity of the C-terminal amino acid of the targeted molecules.

We analyzed the binding site(s) for Grb2 on the epidermal growth factor (EGF) receptor (EGFR), using cell lines overexpressing EGFRs containing various point and deletion mutations in the carboxy-terminal tail. Results of co-immunoprecipitation experiments suggest that phosphotyrosines Y-1068 and Y-1173 mediate the binding of Grb2 to the EGFR. Competition experiments with synthetic phosphopeptides corresponding to known autophosphorylation sites on the EGFR demonstrated that phosphopeptides containing Y-1068, and to a lesser extent Y-1086, were able to inhibit the binding of Grb2 to the EGFR, while a Y-1173 peptide did not. These findings were confirmed by using a dephosphorylation protection assay and by measuring the dissociation constants of Grb2's SH2 domain to tyrosine-phosphorylated peptides, using real-time biospecific interaction analysis (BIAcore). From these studies, we concluded that Grb2 binds directly to the EGFR at Y-1068, to a lesser extent at Y-1086, and indirectly at Y-1173. Since Grb2 also binds Shc after EGF stimulation, we investigated whether Y-1173 is a binding site for the SH2 domain of Shc on the EGFR. Both competition experiments with synthetic phosphopeptides and dephosphorylation protection analysis demonstrated that Y-1173 and Y-992 are major and minor binding sites, respectively, for Shc on the EGFR. However, other phosphorylation sites in the carboxy-terminal tail of the EGFR are able to compensate for the loss of the main binding sites for Shc. These analyses reveal a hierarchy of interactions between Grb2 and Shc with the EGFR and indicate that Grb2 can bind the tyrosine-phosphorylated EGFR directly, as well as indirectly via Shc.

The primary sequence of maize 2,3-bisphosphoglycerate-independent phosphoglycerate mutase was deduced from cDNAs isolated from maize cDNA libraries by screening with specific antibodies to the cofactor-independent enzyme and from a maize genomic clone. The genomic clone provided the 5'-nucleotide sequence encoding the N-terminal amino acids which could not be obtained from the cDNA. Confirmation that the nucleotide sequence was for the cofactor-independent phosphoglycerate mutase was obtained by sequencing the peptides generated from cyanogen bromide cleavage of the purified protein. This is the first report of the amino acid sequence of a 2,3-bisphosphoglycerate cofactor-independent phosphoglycerate mutase, which consists of 559 amino acids and is twice the molecular size of the mammalian cofactor-dependent enzyme subunit. Analysis of the cofactor-independent phosphoglycerate mutase amino acid sequence revealed no identity with the cofactor-dependent mutase types. Northern blot analysis confirmed this difference since the maize cofactor-independent phosphoglycerate mutase cDNA did not hybridize with mRNA of the cofactor-dependent mutase. The lack of amino acid identity between cofactor-dependent and -independent enzymes is consistent with their different catalytic mechanisms and suggests that both enzymes are unrelated evolutionarily and arose from two independent ancestral genes. However, a constellation of residues which are involved in metal ion binding in various alkaline phosphatases is conserved in the maize cofactor-independent phosphoglycerate mutase, which suggests that the enzyme is a member of the alkaline phosphatase family of enzymes.

Phosphoglycerate mutase consists of two kinds of different subunits, M and B. We previously sequenced a rat cDNA encoding the type-M subunit. Here, we report the sequence of the type-B subunit-encoding cDNA. This cDNA has 1754 bp and contains a long 3'-untranslated region of 897 bp.

We have previously reported (Ureña et al. Eur. J. Cell Biol. 1990) that in skeletal muscle, type MM phosphoglycerate mutase isozyme is present in the nucleus as well as in the cytosol. To determine whether type BB phosphoglycerate mutase isozyme is also present in nucleus, the subcellular location of this isozyme was studied in different rat tissues by cell fractionation and immunogold techniques. With the aid of high affinity-purified anti-phosphoglycerate mutase BB isozyme antibodies, the isozyme was located in the nucleus of neuronal, astroglial and liver cells but not in the nucleus of oligodendroglial and endothelial cells. Biochemical studies on purified nuclear fractions also demonstrated the presence of phosphoglycerate mutase activity in the nucleus. Both immunocytochemical and biochemical techniques showed that nuclear phosphoglycerate mutase-specific activity depended on the type of cell.

The subcellular distribution of phosphoglycerate mutase was studied by immunogold techniques. With the aid of highly affinity-purified anti-phosphoglycerate mutase antibodies, the enzyme was found in both cytosol and nucleus of rat skeletal muscle. No evidence of interaction with contractile proteins was observed in cytosol. Nuclear location was also confirmed biochemically using purified nuclear preparations from rat skeletal muscle. Only one immunoreactive nuclear band was observed by Western blot experiments and corresponded to that of phosphoglycerate mutase mobility. Activity measurements from nuclear extracts showed that 25% of total specific activity is found in the nuclei.