Species-specific, postentry barriers to primate immunodeficiency virus infection

By using replication-defective vectors derived from human immunodeficiency virus type 1 (HIV-1), simian immunodeficiency virus (SIV(mac)), and murine leukemia virus (MuLV), all of which were pseudotyped with the vesicular stomatitis virus (VSV) G glycoprotein, the efficiency of postentry, early infection events was examined in target cells of several mammalian species. Titers of HIV-1 vectors were significantly lower than those of SIV(mac) and MuLV vectors in most cell lines and primary cells from Old World monkeys. By contrast, most New World monkey cells exhibited much lower titers for the SIV(mac) vector compared with those of the HIV-1 vector. Prosimian cells were resistant to both HIV-1 and SIV(mac) vectors, although the MuLV vector was able to infect these cells. Cells from other mammalian species were roughly equivalent in susceptibility to the three vectors, with the exception of rabbit cells, which were specifically resistant to the HIV-1 vector. The level of HIV-1 vector expression was very low in transduced cells of rodent, rabbit, cow, and pig origin. Early postentry restriction of primate immunodeficiency virus infection exhibits patterns largely coincident with species borders and applies to diverse cell types within an individual host, suggesting the involvement of species-specific, widely expressed cellular factors.

Schizophrenia and HLA: No association with PCR-SSOP typed classical loci in a large Irish familial sample

Susceptibility to autoimmunity is strongly influence by genes clustered in the MHC region, particularly class I and class II antigens. It has been proposed that there is an immune component in the aetiology of schizophrenia, and the distribution of human leukocyte antigens (HLA) in schizophrenic patients and controls has been investigated in numerous studies. Positive associations have been reported between schizophrenia and the HLA-A1, A2, A9, B5, Cw4, and DR8 and negative associations with HLA-DR4 and HLA-DQbeta*0602. Small sample size, variable diagnostic methodology, unreliable laboratory and statistical procedures, and possible mismatching of cases and controls may have contributed to a lack of consistency of results to date. Therefore, in this investigation we used a large and carefully diagnosed homogeneous Irish familial schizophrenic sample compared with ethnically matched controls. All alleles were determined using polymerase chain reaction amplification followed by short specific oligoprobes. We found no evidence of association with 80 HLA alleles (some previously not examined) from 4 genes. Our data therefore do not support the involvement of these classical HLA loci in the aetiology of schizophrenia at least in these Irish families. The remaining classical HLA loci (HLA-B and HLA-C) should be typed when reliable DNA-based methods become available.

HLA and schizophrenia: refutation of reported associations with A9 (A23/A24), DR4, and DQbeta1*0602

The aim of this study was to test previous hypotheses of association between schizophrenia and human leukocyte antigen (HLA) specificities A9 (A23/24), DR4, and allele DQbeta1*0602. Using sequence-specific oligonucleotide probes, 256 familial schizophrenic patients and 261 unrelated controls were genotyped at polymorphisms for HLA-A, DRbeta1, and DQbeta1 loci. No significant (p < 0.05) differences in the allele frequencies between schizophrenics and controls were found, either when examining the sample as a whole or when subdivided by clinical subtype or gender. The present data do not support association between these HLA specificities and schizophrenia, and our review of previous studies suggests that reported associations may well be false positive results.

Experience journals: using computers to share personal stories about illness and medical intervention

Medical advances make it increasingly possible for children with previously fatal illness to live and thrive. However, a significant number still experience repeated operations, hospitalization, and invasive procedures, or need special care at home. Many do so with little or no intervention to help them and their families cope with the emotional stresses involved. One significant source of emotional and cognitive support is the community of patients and families who have experienced similar medical procedures. However, in spite of a general willingness to share experiences, communication among patients and families is usually limited. To facilitate this process, we are investigating the use of computer technology to record, organize, and display stories about the experiences of families with children who have been treated for cardiac and neurological illness at Children's Hospital, Boston. We are asking children and their families to record text and multimedia vignettes describing some aspect of their illness, coping strategies, or care that might be useful to others. These contributions will be available for browsing at a secure World-Wide-Web site. However, economic realities preclude reliance on a professional site administrator to organize and monitor what we hope to be a rapidly growing Web site with a large, distributed authorship. The need to make the Web site fully accessible to users who have varying familiarity with computers and Web browsing imposes further constraints. We are therefore developing software to automate the process of managing and organizing an easily accessed Web site that contains an "Experience Journal." We describe this software, the rationale for its development, and our plans for its use in the coming year.

Epidermal growth factor protects epithelial cells against Fas-induced apoptosis. Requirement for Akt activation

Chemotherapeutic drugs that damage DNA kill tumor cells, in part, by inducing the expression of a death receptor such as Fas or its ligand, FasL. Here, we demonstrate that epidermal growth factor (EGF) stimulation of T47D breast adenocarcinoma and embryonic kidney epithelial (HEK293) cells protects these cells from Fas-induced apoptosis. EGF stimulation of epithelial cells also inhibited Fas-induced caspase activation and the proteolysis of signaling proteins downstream of the EGF receptor, Cbl and Akt/protein kinase B (Akt). EGF stimulation of Akt kinase activity blocked Fas-induced apoptosis. Expression of activated Akt in MCF-7 breast adenocarcinoma cells was sufficient to block Fas-mediated apoptosis. Inhibition of EGF-stimulated extracellular signal-regulated kinase (ERK) activity did not affect EGF protection from Fas-mediated apoptosis. The findings indicate that EGF receptor stimulation of epithelial cells has a significant survival function against death receptor-induced apoptosis mediated by Akt.

MEK kinase 1 (MEKK1) transduces c-Jun NH2-terminal kinase activation in response to changes in the microtubule cytoskeleton

Cell shape change and the restructuring of the cytoskeleton are important regulatory responses that influence the growth, differentiation, and commitment to apoptosis of different cell types. MEK kinase 1 (MEKK1) activates the c-Jun NH2-terminal kinase (JNK) pathway in response to exposure of cells to microtubule toxins, including taxol. MEKK1 expression is elevated 3-fold in mitosis and microtubule toxin-treated cells accumulated at G2/M of the cell cycle. Targeted disruption of MEKK1 expression in embryonic stem cells resulted in the loss of JNK activation and increased apoptosis in response to taxol. Targeted disruption of the MEK kinase 2 gene had no effect on activation of the JNK pathway in response to microtubule toxins demonstrating a specific role of MEKK1 in this response. Cytochalasin D-mediated disruption of actin fibers activates JNK and stimulates apoptosis similarly in MEKK1(-/-) and wild type cells. The results show that MEKK1 is required for JNK activation in response to microtubule but not actin fiber toxins in embryonic stem cells. MEKK1 activation can protect cells from apoptosis in response to change in the integrity of the microtubule cytoskeleton.

Differential involvement of MEK kinase 1 (MEKK1) in the induction of apoptosis in response to microtubule-targeted drugs versus DNA damaging agents

MEK kinase 1 (MEKK1) is a 196-kDa enzyme that is involved in the regulation of the c-Jun N-terminal kinase (JNK) pathway and apoptosis. In cells exposed to genotoxic agents including etoposide and cytosine arabinoside, MEKK1 is cleaved at Asp874 by caspases. The cleaved kinase domain of MEKK1, itself, stimulates caspase activity leading to apoptosis. Kinase-inactive MEKK1 expressed in HEK293 cells effectively blocks genotoxin-induced apoptosis. Treatment of cells with taxol, a microtubule stabilizing agent, did not induce MEKK1 cleavage in cells, and kinase-inactive MEKK1 expression failed to block taxol-induced apoptosis. MEKK1 became activated in HEK293 cells exposed to taxol, but in contrast to etoposide-treatment, taxol failed to increase JNK activity. Taxol treatment of cells, therefore, dissociates MEKK1 activation from the regulation of the JNK pathway. Overexpression of anti-apoptotic Bcl2 blocked MEKK1 and taxol-induced apoptosis but did not block the caspase-dependent cleavage of MEKK1 in response to etoposide. This indicates Bcl2 inhibition of apoptosis is, therefore, downstream of caspase-dependent MEKK1 cleavage. The results define the involvement of MEKK1 in the induction of apoptosis by genotoxins but not microtubule altering drugs.

Religious support from parish clergy for hospitalized parishioners: availability, evaluation, implications

Reports the results of interviews with a random sample (N = 500) of hospital patients responding to the following questions: What percentage of hospital patients consider themselves part of a church or synagogue? How many patients identify a specific parish clergy or some other source who could provide them pastoral support? How many patients received pastoral support during hospitalization from clergy or some other person, and by visit or phone call (excluding hospital chaplains)? How do hospital patients evaluate the helpfulness of these pastoral visits? Discusses the results of the survey, implications for pastoral caregivers, and suggests future research possibilities.

Experiences of 100 men who have sex with men using the Reality condom for anal sex

A self-administered, anonymous questionnaire examining opinions and experiences of using Reality, the "female" condom, for anal sex was completed by a convenience sample of 100 men who have sex with men (MSM). Eighty-six percent of respondents said they would use Reality again; 54% would rather use Reality than penile condoms. Acceptability was higher among MSM who were HIV positive, in nonmonogamous relationships, or who had serodiscordant partners. Negative experiences included: difficulty inserting (33%), irritation (17%), bunching up (12%), unpleasant texture (10%), and noise (9%). Breakage was reported three times in 334 episodes of use. Although no available data compare preferences and efficacy of Reality to penile condoms, Reality is a welcome alternative for some MSM who have difficulty consistently using penile condoms and probably reduces HIV transmission compared with unprotected anal sex. Research to more definitively assess Reality as a risk reduction method for MSM is greatly needed.

Dietary amino acids as new and novel agents to enhance allograft survival

Dietary supplementation with arginine was previously found to enhance cardiac allograft survival in rats when given with a donor-specific transfusion and a short low-dose course of cyclosporine. This study was performed to determine further the role of amino acid supplementation in prolonging allograft survival. Standard isocaloric, isonitrogenous diets were modified to contain 2 or 4% of energy from arginine, 2 or 4% from glutamine, 4% from glycine or the following combinations: 2% arginine with 2% glutamine, 2% arginine with 4% glutamine, or 1% arginine with 2% glutamine. These diets were started along with a donor-specific transfusion and a 7-d course of cyclosporine the day before cardiac transplantation from an ACI to Lewis strain rat. Median survival times in days for the groups were as follows: control without amino acids, 19.0; 2% arginine, 68.0; 4% arginine, 35.5; 2% glutamine, 28.5; 4% glutamine, 53.5; 4% glycine, 31.5; 2% arginine with 2% glutamine, 39.5; 2% arginine with 4% glutamine, 42.5 and 1% arginine with 2% glutamine, 35.5. Each experimental diet except 2% glutamine and 4% glycine significantly enhanced allograft survival (P < 0.05) with the 2% arginine diet being the best (91.6 +/- 32.3 d [mean +/- SEM] versus 20.1 +/- 3.2 d for control). It is concluded that both arginine and glutamine enhance the immunosuppressive effects of donor-specific transfusion and cyclosporine.

Mitogen-activated protein kinase: conservation of a three-kinase module from yeast to human

Mitogen-activated protein kinases (MAPK) are serine-threonine protein kinases that are activated by diverse stimuli ranging from cytokines, growth factors, neurotransmitters, hormones, cellular stress, and cell adherence. Mitogen-activated protein kinases are expressed in all eukaryotic cells. The basic assembly of MAPK pathways is a three-component module conserved from yeast to humans. The MAPK module includes three kinases that establish a sequential activation pathway comprising a MAPK kinase kinase (MKKK), MAPK kinase (MKK), and MAPK. Currently, there have been 14 MKKK, 7 MKK, and 12 MAPK identified in mammalian cells. The mammalian MAPK can be subdivided into five families: MAPKerk1/2, MAPKp38, MAPKjnk, MAPKerk3/4, and MAPKerk5. Each MAPK family has distinct biological functions. In Saccharomyces cerevisiae, there are five MAPK pathways involved in mating, cell wall remodelling, nutrient deprivation, and responses to stress stimuli such as osmolarity changes. Component members of the yeast pathways have conserved counterparts in mammalian cells. The number of different MKKK in MAPK modules allows for the diversity of inputs capable of activating MAPK pathways. In this review, we define all known MAPK module kinases from yeast to humans, what is known about their regulation, defined MAPK substrates, and the function of MAPK in cell physiology.

Analysis and interpretation of short tandem repeat microvariants and three-banded allele patterns using multiple allele detection systems

The Palm Beach County Sheriffs Office (PBSO) Crime Laboratory and the Alabama Department of Forensic Sciences (ADFS) have validated and implemented analysis of short tandem repeat (STR) sequences on casework using silver staining kit and SYBR Green I detection systems and are presently validating fluorescently tagged STR alleles using the Hitachi FMBIO 100 instrument. Concurrently, the Broward County Sheriff's Office (BSO) Crime Laboratory is validating the ABI Prism310 Genetic Analyzer capillary electrophoresis STR detection system (ABI CE310) from Perkin Elmer Applied BioSystems. During the course of analyzing over 10,000 individuals for the STR loci CSF1PO, TPOX and THO1 (CTT) using silver staining for allele detection, 42 samples demonstrated alleles that were "off ladder," contained three-banded patterns at a single locus, or exhibited an apparent THO1 "9.3,10" allele pattern. PBSO, ADFS and BSO Crime Laboratories have collaborated on the verification of the allele patterns observed in these 42 samples using the following allele detection systems: (1) manual silver staining, (2) SYBR Green I staining, and/or (3) fluorescently tagged amplified products separated by polyacrylamide gel electrophoresis or capillary electrophoresis followed by laser detection. Regardless of the CTT allele detection system utilized, concordant results were obtained for 41 of the 42 samples. The only exception was a sample in which a wide band within the THO1 locus was identified as a THO1 "9.3, 10" genotype by silver staining kit and SYBR Green I staining but was verified to be a THO1 "9.3" homozygote by all other allele detection systems. Manual allele detection could readily identify microvariants, as a visual assessment of stained gels clearly shows that alleles do not migrate coincident with well-characterized allele size standards. As would be predicted, however, the manual detection systems did not provide adequate resolution to approximate the basepair size for off-ladder variants. All fluorescent software program systems were consistent in designating alleles "not in range" or "off ladder," thereby indicating true microvariants. All single-locus three-banded patterns were detected using all of the STR multiplex systems. In addition, individual locus-specific primers verified multiplexed amplified products were specific for the locus in question.

Phosphatidylinositol 3-kinase is required for CD28 but not CD3 regulation of the TEC family tyrosine kinase EMT/ITK/TSK: functional and physical interaction of EMT with phosphatidylinositol 3-kinase

Ligation of the TCR or CD28 induces activation of phosphatidylinositol 3-kinase (PI3K), the TEC family protein tyrosine kinase, EMT/ITK/TSK (EMT), and the SRC family tyrosine kinase, LCK. LCK is required for the activation and phosphorylation of EMT induced by ligation of the TCR or CD28 placing LCK upstream of EMT in T cell signaling cascades. We report herein that inhibition of PI3K activity with the specific inhibitors LY294002 and wortmannin markedly decreased EMT activation induced by CD28 cross-linking but not by CD3 cross-linking. Further, inhibition of PI3K markedly decreased EMT in vitro autokinase activity induced by activated LCK. In contrast, PI3K inhibitors did not alter CD28 or CD3 cross-linking or LCK-induced EMT phosphorylation. Consistent with the requirement of PI3K activity for CD28 but not CD3-induced stimulation of the EMT in vitro autokinase activity, a small but significant portion of cellular EMT associates with PI3K following CD28 cross-linking but not following CD3 cross-linking. CD28-induced association of EMT with PI3K also requires functional expression of LCK. Fusion proteins containing the SRC homology 2 domain of EMT interact with PI3K or a PI3K-associated molecule in a tyrosine phosphorylation-dependent manner. Taken together, the data suggest that EMT is differentially regulated and recruited to different signaling complexes following ligation of CD28 or the TCR complex, perhaps contributing to the disparate roles that EMT appears to play downstream of CD28 and the TCR.

Anti-apoptotic versus pro-apoptotic signal transduction: checkpoints and stop signs along the road to death

The activation of caspases is a final commitment step for apoptosis. It is now evident that signal transduction pathways involving specific protein kinases modulate the apoptotic response. Both pro-apoptotic and anti-apoptotic pathways integrate environmental cues that control the decision to undergo apoptosis. Pro- and anti-apoptotic signal pathways regulate the activation of the caspases. In this review we describe our current understanding of apoptotic signal transduction.

Spontaneous bacterial peritonitis caused by infection with Listeria monocytogenes: a case report and review of the literature

Spontaneous bacterial peritonitis is a frequent and often serious complication of long-standing ascites in the presence of advanced liver disease. Coliform bacteria account for the infection in most cases and are thought to be related to translocation of bacteria from the bowel into the peritoneal cavity. The empiric use of cefotaxime is well established as most of the causative organisms are sensitive to this antibiotic. However, we report on a case of spontaneous bacterial peritonitis in a patient with hepatitis C related cirrhosis who was awaiting liver transplantation caused by infection with Listeria monocytogenes, in which the patient did not improve with empiric antibiotic therapy. This case adds to the 23 others reported in the literature since 1966. Our case raises some concerns about the universal empiric usage of cefotaxime for spontaneous bacterial peritonitis because it does not offer adequate coverage against organisms such as Listeria, enterococci, Pasturella, and anaerobes.

Procorticotrophin-releasing hormone: endoproteolytic processing and differential release of its derived peptides within AtT20 cells

Procorticotrophin-releasing hormone (proCRH) is expressed mainly in the hypothalamus and in the placenta, where it undergoes tissue-specific endoproteolysis. Our results show that within stably transfected AtT20/D16V cells proCRH is cleaved to generate two fragments of approximately 8 and 3 kDa which could account for proCRH(125-194) and proCRH(125-151), respectively, and a 4.5 kDa product which could account for mature IR-CRH(1-41). The immunofluorescence staining patterns for IR-CRH and IR-ACTH and their response of secretagogues indicate targeting of proCRH and POMC to the secretory pathway in transfected AtT20 cells. In this work, we have used a unique set of specific RIAs and IRMAs to the full length POMC and proCRH molecules and several products of endoproteolytic processing to assess if they could be released differentially in response to stimulation. Although the release of both IR-ACTH and IR-CRH peptides from transfected AtT20 cells is stimulated in response to exposure to high potassium stimulation (51 mM KCl/SmM CaCl2), the sorting index (SI) suggests that mature ACTH is sorted to the regulated secretory pathway 2.1-fold more efficiently than mature CRH(1-41). Mature ACTH is also sorted to the regulated secretory pathway 9-fold more efficiently than IR-proCRH(125-151). Also, mature CRH(1-41) is sorted to the regulated secretory pathway 3-fold more efficiently than IR-proCRH(125-151). These results therefore indicate that the intracellular mechanisms for the storage and release of POMC, proCRH and their endoproteolytic products differ and would sustain the hypothesis that within mammalian peptidergic cells, different biologically active peptides originating from the same or different precursor molecules, could be differentially released in response to specific stimuli. This would give these cells the capacity to finely regulate neurotransmitter release in response to environmental and physiological demands.

Volumetric object modeling for surgical simulation

Surgical simulation has many applications in medical education, surgical training, surgical planning and intra-operative assistance. However, extending current surface-based computer graphics methods to model phenomena such as the deformation, cutting, tearing or repairing of soft tissues poses significant challenges for real-time interactions. This paper discusses the use of volumetric methods for modeling complex anatomy and tissue interactions. New techniques are introduced that use volumetric methods for modeling soft-tissue deformation and tissue cutting at interactive rates. An initial prototype for simulating arthroscopic knee surgery is described which uses volumetric models of the knee derived from 3-D magnetic resonance imaging, visual feedback via real-time volume and polygon rendering, and haptic feedback provided by a force-feedback device.

Caspase-dependent cleavage of signaling proteins during apoptosis. A turn-off mechanism for anti-apoptotic signals

Caspases are activated during apoptosis and cleave specific proteins, resulting in the irreversible commitment to cell death. The signal transduction proteins MEKK1, p21-activated kinase 2, and focal adhesion kinase are caspase substrates that contribute to the cell death response when cleaved. Thirty additional signaling proteins were screened for their ability to be cleaved during apoptosis. Twenty-two of these proteins were not affected in Jurkat cells stimulated to undergo apoptosis by Fas ligation, exposure to ultraviolet-C or incubation with etoposide. Ras GTPase-activating protein was found to be a caspase substrate whose cleavage followed the same time course as that for activation of caspase activity and the cleavage of MEKK1 and focal adhesion kinase. Four additional proteins, Cbl, Cbl-b, Raf-1, and Akt-1, were cleaved later in the apoptotic response. These signaling proteins were similarly cleaved in U937 cells undergoing apoptosis. Cleavage of the proteins was blocked by caspase inhibitors in Jurkat cells or in U937 cells expressing BclxL, demonstrating that the cleavage was dependent on caspase activation. Cleavage of Raf-1 and Akt correlated with the loss of extracellular signal-regulated kinase and Akt activities in apoptotic cells. Neither c-Jun N-terminal kinase nor p38 mitogen-activated protein kinase was cleaved in cells undergoing apoptosis, and the activation of the c-Jun N-terminal kinase and p38 mitogen-activated protein kinase pathways was not compromised in apoptotic cells. These results indicate that caspase-dependent cleavage of specific proteins induces the turn off of survival pathways, such as the extracellular signal-regulated kinase and phosphatidylinositol-3 kinase/Akt pathways, that could otherwise interfere with the apoptotic response.

Efficient CD28 signalling leads to increases in the kinase activities of the TEC family tyrosine kinase EMT/ITK/TSK and the SRC family tyrosine kinase LCK

Optimal T cell activation requires crosslinking of the T cell receptor (TCR) concurrently with an accessory receptor, most efficiently CD28. Crosslinking of CD28 leads to increased interleukin 2 (IL2) production, inhibition of anergy and prevention of programmed cell death. Crosslinking of CD28 leads to rapid increases in tyrosine phosphorylation of specific intracellular substrates including CD28 itself. Since CD28 does not encode an intrinsic tyrosine kinase domain, CD28 must activate an intracellular tyrosine kinase(s). Indeed, crosslinking of CD28 increases the activity of the intracellular tyrosine kinases EMT/ITK and LCK. The phosphatidylinositol 3-kinase (PI3K) and GRB2 binding site in CD28 is dispensable for optimal IL2 production in Jurkat T cells. We demonstrate herein that murine Y170 (equivalent to human Y173) in CD28 is also dispensable for activation of the SRC family tyrosine kinase LCK and the TEC family tyrosine kinase EMT/ITK. In contrast, the distal three tyrosines in CD28 are required for optimal IL2 production as well as for optimal activation of the LCK and EMT/ITK tyrosine kinases. The distal three tyrosines of CD28, however, are not required for recruitment of PI3K to CD28. Furthermore, PI3K is recruited to CD28 in JCaM1 cells which lack LCK and in which EMT/ITK is not activated by ligation of CD28. Thus optimal activation of LCK or EMT/ITK is not obligatory for recruitment of PI3K to CD28 and thus is also not required for tyrosine phosphorylation of the YMNM motif in CD28. Taken together the data indicate that the distal three tyrosines in CD28 are integral to the activation of LCK and EMT/ITK and for subsequent IL2 production.

Evaluation of a primary care counselling service in Dorset

BACKGROUND

Research into the effectiveness of counselling in primary care is rare. This study attempts to provide a thorough evaluation of the effects of a new counselling service introduced throughout Dorset.

AIM

To evaluate the impact of counselling on client symptomatology, self-esteem, and quality of life. The effect of counselling on drug prescribing, referrals to other mental health professionals, and client and general practitioner (GP) satisfaction were also assessed.

METHOD

All new clients referred for counselling were asked to complete and return questionnaires before and after counselling. A total of 385 clients took part in the study. The first and second assessments were compared statistically. Clients were ascribed a psychiatric diagnosis using a simplified version of DSM-IIIR (Diagnostic and Statistical Manual of the American Psychiatric Association). GPs' views of the service were determined using a specially designed questionnaire. Drug data were obtained from the Prescription Pricing Authority and referral statistics from Dorset HealthCare National Health Service (NHS) Trust.

RESULTS

The number of psychiatric symptoms and their severity were significantly reduced by counselling. There were no significant differences in the prescription of anxiolytic/hypnotic and anti-depressant medication between matched practices with and without counsellors. The presence of a counsellor did not affect the rate of referral to other mental health professionals. Clients and GPs valued the service highly.

CONCLUSIONS

The Psychology Managed Counselling Service is an effective method of running a counselling service and is well received by both clients and GPs. Counselled clients improved significantly on several measures.