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1.  HIV-related symptoms and patient clusters among Chileans living with HIV 
AIDS care  2012;25(4):488-495.
Identifying both HIV-related and co-morbid symptoms experienced by people living with HIV (PLWH) who are receiving antiretroviral therapy treatment (ART) is a major challenge for health care providers globally. Yet little research to date has examined the symptoms of illness experienced by PLWH including patients living in Central and South American. To address this gap, this study was designed to identify symptoms of HIV by socio-demographic and/or clinical characteristics among Chilean patients living with the virus. A convenience sample of 209 Chilean PLWH was recruited from an outpatient clinic in Santiago, Chile. A structured interview was used to elicit socio-demographic information and HIV symptoms status. Additional clinical information was obtained through a review of the participants’ medical records. Results show that patients’ most commonly reported HIV-related symptoms were fear/worries (66%), anxiety (52%), gas/bloating (50%), and thirst (50%). Multivariate analysis revealed a positive association between the number of reported HIV-related symptoms and number of years living with HIV. Having completed college was negatively associated with number of symptoms. Latent class analysis indicated that PLWH in the sample who had completed college were two times more likely to experience a mild intensity of HIV-related symptoms than their lesser educated counterparts. Similarly, logistic regression revealed that college-educated PLWH were twice as likely to be classified in the subgroup reporting mild intensity of symptoms than those who lacked a college degree. Overall, the study’s results reveal that many Chilean PLWH, even those with high CD4 counts and low or undetectable viral loads, are not symptom free. The findings point to the need for clinicians to tailor a plan of care for individuals living with HIV that is based on their symptomatology.
doi:10.1080/09540121.2012.714457
PMCID: PMC3563858  PMID: 22909386
Symptoms; HIV infections; people living with HIV; clusters analysis; quantitative method
2.  Virus-Host Interactions in HIV Pathogenesis 
Advances in Dental Research  2011;23(1):13-18.
The challenge of controlling HIV infection involves an understanding of the heterogeneity of the virus, its wide cellular host range, its primary routes of transmission, and the immunologic and intrinsic cellular factors that can prevent its transmission and replication. Identification of HIV-infected individuals who have survived more than 10 years without signs of the infection and without therapy encourages studies examining the natural mechanisms for resistance to infection and disease. Within the immune system, emphasis should be given to the innate or natural response that appears within minutes of the infection and offers the optimal time for controlling HIV. All these parameters in HIV pathogenesis underline the information needed to develop optimal anti-HIV therapies and an effective AIDS vaccine.
doi:10.1177/0022034511398874
PMCID: PMC3144039  PMID: 21441474
HIV heterogeneity; innate immunity; intracellular antiviral activity
3.  Monsters are people too 
Biology Letters  2013;9(1):20120850.
Animals, including dogs, dolphins, monkeys and man, follow gaze. What mediates this bias towards the eyes? One hypothesis is that primates possess a distinct neural module that is uniquely tuned for the eyes of others. An alternative explanation is that configural face processing drives fixations to the middle of peoples' faces, which is where the eyes happen to be located. We distinguish between these two accounts. Observers were presented with images of people, non-human creatures with eyes in the middle of their faces (`humanoids’) or creatures with eyes positioned elsewhere (`monsters’). There was a profound and significant bias towards looking early and often at the eyes of humans and humanoids and also, critically, at the eyes of monsters. These findings demonstrate that the eyes, and not the middle of the head, are being targeted by the oculomotor system.
doi:10.1098/rsbl.2012.0850
PMCID: PMC3565496  PMID: 23118434
gaze following; gaze selection; social attention; primates
4.  Feline Non-repetitive Mitochondrial DNA Control Region Database for Forensic Evidence 
The domestic cat is the one of the most popular pets throughout the world. A by-product of owning, interacting with, or being in a household with a cat is the transfer of shed fur to clothing or personal objects. As trace evidence, transferred cat fur is a relatively untapped resource for forensic scientists. Both phenotypic and genotypic characteristics can be obtained from cat fur, but databases for neither aspect exist. Because cats incessantly groom, cat fur may have nucleated cells, not only in the hair bulb, but also as epithelial cells on the hair shaft deposited during the grooming process, thereby generally providing material for DNA profiling. To effectively exploit cat hair as a resource, representative databases must be established. This study evaluates 402 bp of the mtDNA control region (CR) from 1,394 cats, including cats from 25 distinct worldwide populations and 26 breeds. Eighty-three percent of the cats are represented by 12 major mitotypes. An additional 8.0% are clearly derived from the major mitotypes. Unique sequences were found in 7.5% of the cats. The overall genetic diversity for this data set was 0.8813 ± 0.0046 with a random match probability of 11.8%. This region of the cat mtDNA has discriminatory power suitable for forensic application worldwide.
doi:10.1016/j.fsigen.2010.01.013
PMCID: PMC2921450  PMID: 20457082
Forensic science; domestic cat; mtDNA; mitochondria; d-loop; control region
5.  Addressing the Question of the Effect of RBC Storage on Clinical Outcomes: The Red Cell Storage Duration Study (RECESS) (Section 7) 
The question of whether storage of red blood cells (RBCs) alters their capacity to deliver oxygen and affects patient outcomes remains in a state of clinical equipoise. Studies of the changes which occur while RBC are stored have led to several physiologically plausible hypotheses that these changes impair RBC function when the units are transfused. Although there is some evidence of this effect in vivo from animal model experiments, the results of several largely retrospective patient studies have not been consistent. Some studies have shown an association between worse clinical outcomes and transfusion of RBC which have been stored for longer periods of time, while others have found no effect. Three multicenter, randomized, controlled trials have been developed to address this important, but currently unanswered, question. Two clinical trials, one in low birth weight neonates and the other in intensive care unit patients, are enrolling subjects in Canada (the Age of Red Blood Cells in Premature Infants; the Age of Blood Study). The third trial, which is being developed in the United States, is the Red Cell Storage Duration Study (RECESS). This is a multicenter, randomized, controlled trial in which patients undergoing complex cardiac surgical procedures who are likely to require RBC transfusion will be randomized to receive RBC units stored for either 10 or fewer days or 21 or more days. Randomization will only occur if the blood bank has enough units of RBC of both storage times to meet the crossmatch request; hence, subjects randomized to the ≥ 21 day arm will receive RBC of the same storage time as they would have following standard inventory practice of “oldest units out first”. The primary outcome is the change in the Multiple Organ Dysfunction Score (MODS), a composite measure of multiorgan dysfunction, by day 7. Secondary outcomes include the change in the MODS by day 28, all-cause mortality, and several composite and single measures of specific organ system function. The estimated total sample size required will be 1434 evaluable subjects (717 per arm). The RECESS trial is registered through the US National Institutes of Health (clinicaltrials.gov) as NCT00991341.
doi:10.1016/j.transci.2010.05.014
PMCID: PMC2918709  PMID: 20655807
6.  An association analysis of the HLA gene region in latent autoimmune diabetes in adults 
Diabetologia  2006;50(1):68-73.
Aims/hypothesis
Pathophysiological similarities between latent autoimmune diabetes in adults (LADA) and type 1 diabetes indicate an overlap in genetic susceptibility. HLA-DRB1 and HLA-DQB1 are major susceptibility genes for type 1 diabetes but studies of these genes in LADA have been limited. Our aim was to define patterns of HLA-encoded susceptibility/protection in a large, well characterised LADA cohort, and to establish association with disease and age at diagnosis.
Materials and methods
Patients with LADA (n=387, including 211 patients from the UK Prospective Diabetes Study) and non-diabetic control subjects (n=327) were of British/Irish European origin. The HLA-DRB1 and -DQB1 genes were genotyped by sequence-specific PCR.
Results
As in type 1 diabetes mellitus, DRB1*0301_DQB1*0201 (odds ratio [OR]=3.08, 95% CI 2.32–4.12, p=1.2× 10−16) and DRB1*0401_DQB1*0302 (OR=2.57, 95% CI 1.80–3.73, p=4.5×10−8) were the main susceptibility haplotypes in LADA, and DRB1*1501_DQB1*0602 was protective (OR=0.21, 95% CI 0.13–0.34, p=4.2×10−13). Differential susceptibility was conferred by DR4 subtypes: DRB1*0401 was predisposing (OR=1.79, 95% CI 1.35–2.38, p=2.7×10−5) whereas DRB1*0403 was protective (OR=0.37, 95% CI 0.13–0.97, p=0.033). The highest-risk genotypes were DRB1*0301/DRB1*0401 and DQB1*0201/DQB1*0302 (OR=5.14, 95% CI 2.68–10.69, p=1.3×10−8; and OR=6.88, 95% CI 3.54–14.68, p=1.2×10−11, respectively). These genotypes and those containing DRB1*0401 and DQB1*0302 associated with a younger age at diagnosis in LADA, whereas genotypes containing DRB1*1501 and DQB1*0602 associated with an older age at diagnosis.
Conclusions/interpretation
Patterns of susceptibility at the HLA-DRB1 and HLA-DQB1 loci in LADA are similar to those reported for type 1 diabetes, supporting the hypothesis that autoimmune diabetes occurring in adults is an age-related extension of the pathophysiological process presenting as childhood-onset type 1 diabetes.
doi:10.1007/s00125-006-0513-z
PMCID: PMC3076207  PMID: 17143607
Age of diagnosis; Genetic susceptibility; Protection; Type 1 diabetes
7.  Effect of weight loss by a low-fat diet and a low-carbohydrate diet on peptide YY levels 
Objective
To compare the effects of weight loss by an energy-restricted low-fat diet versus low-carbohydrate diet on serum peptide YY (PYY) levels.
Design
8-week prospective study of 30 obese adults (mean age: 42.8 ± 2.0 years, mean BMI 35.5 ± 0.6 kg/m2).
Results
After 8 weeks, subjects on the low-carbohydrate diet lost substantially more weight than those on the low-fat diet (5.8 kg vs. 0.99 kg, p<0.001). Weight loss by either diet resulted in a 9% reduction in both mean fasting serum PYY levels (baseline: 103.5 ± 8.8 pg/ml, after weight loss: 94.1 ± 6.5 pg/ml, p<0.01) and postprandial AUC PYY (baseline: (20.5 ± 1.5) × 103 pg·hr−1ml−1, after weight loss: mean AUC PYY (18.8 ± 1.4) × 103 pg·hr−1ml−1 p<0.001). There was a trend towards lower levels of PYY with greater degrees of weight loss.
Conclusions
Reduced PYY levels after weight loss by an energy-restricted low-fat or low-carbohydrate diet likely represents a compensatory response to maintain energy homeostasis and contributes to difficulty in weight loss during energy-restricted diets.
doi:10.1038/ijo.2010.48
PMCID: PMC2918684  PMID: 20351741
PYY; weight loss; low-fat diet; low-carbohydrate diet
8.  Demonstrating Circulation in Vasculogenic Mimicry Patterns of Uveal Melanoma by Confocal Indocyanine Green Angiography 
Eye (London, England)  2007;22(7):948-952.
Purpose
Vasculogenic mimicry patterns, formed by highly invasive melanoma cells, connect to endothelial cell lined blood vessels and contain fluid in vitro and in vivo. This study was designed to determine if fluid leaks into vasculogenic mimicry patterns without circulation, or if fluid circulates in and clears from these patterns.
Methods
Indocyanine green laser scanning confocal angiography (Heidelberg HRA, Heidelberg Engineering) was performed on 9 patients with posterior choroidal melanoma in an institutional setting. Blood was drawn before the ICG injection and from the contralateral arm of the ICG injection site and 1 minute after the injection. Outcome measures include time to first filling of retinal vessels and vasculogenic mimicry patterns and the time at which no fluorescence could be detected by the HRA instrument. After fluorescence was no longer detected in vessels or patterns, the tubes containing the patient’s blood was imaged by the Heidelberg HRA.
Results
Looping vasculogenic mimicry patterns were detected focally in 5 patients within 30 seconds after injection and were detectable up to 12 minutes post injection. Blood drawn before ICG injection did not autofluoresce but ICG-containing blood pooled in the tube continued to fluoresce at 1 month post injection.
Conclusions
Vasculogenic mimicry patterns are not part of the endothelial cell lined vascular system and fluid enters these patterns through leakage. The rapid infusion of ICG into these patterns after injection and the disappearance of fluorescence detectable by the Heidelberg HRA suggest that fluid circulates in these patterns and does not accumulate as a stagnant pool.
doi:10.1038/sj.eye.6702783
PMCID: PMC2551555  PMID: 17363922
Uveal melanoma; vasculogenic mimicry patterns; confocal angiography; ICG; circulation
10.  Assessing the public health benefits of reduced ozone concentrations. 
Environmental Health Perspectives  2001;109(12):1215-1226.
In this paper we examine scientific evidence and related uncertainties in two steps of benefit-cost analyses of ozone reduction: estimating the health improvements attributable to reductions in ozone and determining the appropriate monetary values of these improvements. Although substantial evidence exists on molecular and physiologic impacts, the evidence needed to establish concentration-response functions is somewhat limited. Furthermore, because exposure to ozone depends on factors such as air conditioning use, past epidemiologic studies may not be directly applicable in unstudied settings. To evaluate the evidence likely to contribute significantly to benefits, we focus on four health outcomes: premature mortality, chronic asthma, respiratory hospital admissions, and minor restricted activity days. We determine concentration-response functions for these health outcomes for a hypothetical case study in Houston, Texas, using probabilistic weighting reflecting our judgment of the strength of the evidence and the possibility of confounding. We make a similar presentation for valuation, where uncertainty is due primarily to the lack of willingness-to-pay data for the population affected by ozone. We estimate that the annual monetary value of health benefits from reducing ozone concentrations in Houston is approximately $10 per person per microgram per cubic meter (24-hr average) reduced (95% confidence interval, $0.70-$40). The central estimate exceeds past estimates by approximately a factor of five, driven by the inclusion of mortality. We discuss the implications of our findings for future analyses and determine areas of research that might help reduce the uncertainties in benefit estimation.
PMCID: PMC1240503  PMID: 11748028
11.  Fine particulate matter and polycyclic aromatic hydrocarbon concentration patterns in Roxbury, Massachusetts: a community-based GIS analysis. 
Environmental Health Perspectives  2001;109(4):341-347.
Given an elevated prevalence of respiratory disease and density of pollution sources, residents of Roxbury, Massachusetts, have been interested in better understanding their exposures to air pollution. To determine whether local transportation sources contribute significantly to exposures, we conducted a community-based pilot investigation to measure concentrations of fine particulate matter (particulate matter < 2.5 microm; PM(2.5)) and particle-bound polycyclic aromatic hydrocarbons (PAHs) in Roxbury in the summer of 1999. Community members carried portable monitors on the streets in a 1-mile radius around a large bus terminal to create a geographic information system (GIS) map of concentrations and gathered data on site characteristics that could predict ambient concentrations. Both PM(2.5) and PAH concentrations were greater during morning rush hours and on weekdays. In linear mixed-effects regressions controlling for temporal autocorrelation, PAH concentrations were significantly higher with closer proximity to the bus terminal (p < 0.05), and both pollutants were elevated, but not statistically significantly so, on bus routes. Regressions on a subset of measurements for which detailed site characteristics were gathered showed higher concentrations of both pollutants on roads reported to have heavy bus traffic. Although a more comprehensive monitoring protocol would be needed to develop robust predictive functions for air pollution, our study demonstrates that pollution patterns in an urban area can be characterized with limited monitoring equipment and that university-community partnerships can yield relevant exposure information.
PMCID: PMC1240273  PMID: 11335181
12.  Particle concentrations in urban microenvironments. 
Environmental Health Perspectives  2000;108(11):1051-1057.
Although ambient particulate matter has been associated with a range of health outcomes, the health risks for individuals depend in part on their daily activities. Information about particle mass concentrations and size distributions in indoor and outdoor microenvironments can help identify high-risk individuals and the significant contributors to personal exposure. To address these issues in an urban setting, we measured particle count concentrations in four size ranges and particulate matter (3/4) 10 microm (PM(10)) concentrations outdoors and in seven indoor microenvironments in Boston, Massachusetts. Particle counts and PM(10) concentrations were continuously measured with two light-scattering devices. Because of the autocorrelation between sequential measurements, we used linear mixed effects models with an AR-1 autoregressive correlation structure to evaluate whether differences between microenvironments were statistically significant. In general, larger particles were elevated in the vicinity of significant human activity, and smaller particles were elevated in the vicinity of combustion sources, with indoor PM(10) concentrations significantly higher than the outdoors on buses and trolleys. Statistical models demonstrated significant variability among some indoor microenvironments, with greater variability for smaller particles. These findings imply that personal exposures can depend on activity patterns and that microenvironmental concentration information can improve the accuracy of personal exposure estimation.
PMCID: PMC1240162  PMID: 11102296
13.  Estimating the mortality impacts of particulate matter: what can be learned from between-study variability? 
Environmental Health Perspectives  2000;108(2):109-117.
Epidemiologic studies of the link between particulate matter (PM) concentrations and mortality rates have yielded a range of estimates, leading to disagreement about the magnitude of the relationship and the strength of the causal connection. Previous meta-analyses of this literature have provided pooled effect estimates, but have not addressed between-study variability that may be associated with analytical models, pollution patterns, and exposed populations. To determine whether study-specific factors can explain some of the variability in the time-series studies on mortality from particulate matter [less than/equal to] 10 microm in aerodynamic diameter (PM(10)), we applied an empirical Bayes meta-analysis. We estimate that mortality rates increase on average by 0.7% per 10 microg/m(3) increase in PM(10) concentrations, with greater effects at sites with higher ratios of particulate matter [less than/equal to] 2.5 microm in aerodynamic diameter (PM(2.5))/PM(10). This finding did not change with the inclusion of a number of potential confounders and effect modifiers, although there is some evidence that PM effects are influenced by climate, housing characteristics, demographics, and the presence of sulfur dioxide and ozone. Although further analysis would be needed to determine which factors causally influence the relationship between PM(10) and mortality, these findings can help guide future epidemiologic investigations and policy decisions.
Images
PMCID: PMC1637882  PMID: 10656850
14.  Bcl-2 overexpression blocks caspase activation and downstream apoptotic events instigated by photodynamic therapy 
British Journal of Cancer  1999;79(1):95-100.
Treatment with the photosensitizer benzoporphyrin derivative monoacid ring A (BPD-MA, verteporfin) followed by irradiation with visible light induces apoptosis in human acute myelogenous leukaemia HL-60 cells. Photoactivation of BPD-MA induces procaspase 3 (CPP32/Yama/apopain) and procaspase 6 (Mch2) cleavage into their proteolytically active subunits in these cells. The Bcl-2 proto-oncogene product has been shown to protect cells from a number of proapoptotic stimuli. In the present study, the influence of Bcl-2 overexpression on cellular resistance to photoactivation of BPD-MA was studied. Overexpression of Bcl-2 in HL-60 cells prevented apoptosis-related events including caspase 3 and 6 activation, poly(ADP-ribose) polymerase cleavage and the formation of hypodiploid DNA produced by BPD-MA (0–200 ng ml−1) and light. However, Bcl-2 overexpression was less effective at preventing cell death that occurred after photoactivation at high levels (50–100 ng ml−1) compared with lower doses (10–25 ng ml−1) of BPD-MA. These results indicate that caspase 3 and 6 activation and their regulation by Bcl-2 may play important roles in photodynamic therapy (PDT)-induced cell killing. © 1999 Cancer Research Campaign
doi:10.1038/sj.bjc.6690017
PMCID: PMC2362171  PMID: 10408699
apoptosis; photodynamic therapy; Bcl-2; caspase; resistance; leukaemic cells
15.  The outreach-assisted model of partner notification with IDUs. 
Public Health Reports  1998;113(Suppl 1):160-169.
OBJECTIVE: This analysis describes the Outreach-Assisted Model of Partner Notification, an innovative strategy for encouraging seropositive injecting drug users (IDUs) to inform their partners of shared human immunodeficiency virus (HIV) exposure. The analysis focuses on two core components of the notification process: the identification of at-risk partners and preferences for self-tell vs. outreach assistance in informing partners of possible exposure to the virus. METHODS: Using community outreach techniques, 386 IDUs were recruited for HIV pretest counseling, testing, and partner notification over a 12-month period. Of these, 63 tested HIV seropositive, and all but three returned for their test results. The 60 who were informed of their serostatus were randomly assigned to either a minimal or an enhanced intervention condition. Participants assigned to the minimal (self-tell) group were strongly encouraged to inform their partners of possible exposure. Those assigned to the enhanced (outreach-assisted) group had the option of either informing one or more of their partner(s) themselves or choosing to have the project's outreach team do so. RESULTS: Together, the 60 index persons who received their results provided names or at least one piece of locating information for a total of 142 partners with whom they perceived having shared possible exposure to the virus within the past five years. By itself, drug use accounted for half of all partners named. Sexual behavior alone accounted for 25% of named partners. Eighty-two percent of the enhanced group preferred to have the outreach team tell at least one partner; the team was requested to notify 71% of the total number of partners whom this group named. CONCLUSIONS: Findings suggest that IDUs want to notify their partners of shared HIV exposure. Outreach assistance was the preferred mode in the majority of cases. Expanding traditional community-based HIV outreach activities to include delivering street-based counseling, test, a partner notification appears to be a positive and workable prevention strategy.
PMCID: PMC1307738  PMID: 9722821
16.  Lessons learned from the study of immigrants to Israel from areas of Russia, Belarus, and Ukraine contaminated by the Chernobyl accident. 
Environmental Health Perspectives  1997;105(Suppl 6):1523-1527.
During the past 6 years, immigration to Israel of 700,000 persons from the former Soviet Union (FSU) included about 140,000 from radiocontaminated regions of Belarus, Ukraine, and Russia near Chernobyl. In Beer Sheva, a major center for immigrant absorption in Israel, a primary objective was to evaluate their health status and to refer them for care. 137Cs levels in 1228 men, women, and children were measured with a portable whole-body counter. Whole-body counts showed clear correlation with the degree of 137Cs ground contamination in previous regions of residence. The population could thus be sub-divided according to degree of exposure, based on previous regions of residence. The thyroid status of 300 local immigrant children was evaluated because of the increased risk of childhood thyroid cancer in the regions from which they came. This group was subdivided into comparative groups of children who came from less and more contaminated areas according to the International Atomic Energy Agency soil 137Cs contamination maps. Enlarged thyroids were found in about 40% of both groups. One 12-year-old girl from Gomel had a malignant papillary carcinoma. Thyroid-stimulating hormone levels, though within normal limits, were significantly greater (p < 0.02) for girls from high exposure regions. Liquidators showed significant increases in serum clastogenic factor and in the number of circulating glycophorin A-mutated red cells. In studies of over 700 people from both radiocontaminated and unaffected regions of the FSU, evidence for posttraumatic stress disorder was found more frequently in persons coming from the more contaminated areas.
PMCID: PMC1469938  PMID: 9467076
17.  Thyroid-stimulating hormone levels in children from Chernobyl. 
Environmental Health Perspectives  1997;105(Suppl 6):1497-1498.
This study assesses parameters of thyroid function in persons who resided in Ukraine, Belarus, and southern Russia and exposed at 0 to 16 years of age to radioiodine contamination from the Chernobyl accident. Six to eight years after the accident a group of 300 young people who had immigrated to Israel were interviewed, underwent physical and ultrasound thyroid examination, and had their serum tested for thyroid-stimulating hormones (TSH), thyroid hormones, thyroglobulin, and antithyroid antibodies. Comparative groups came from areas with high (>1 Ci/km2) or low (< 1 Ci/km2) 137Cs ground contamination. Girls from high contamination areas, when compared to girls from areas with low ground contamination, showed significant upward shifts in levels of serum TSH (p = 0.023) although remaining within normal limits. Boys showed no significant differences. There was no evidence for differences in thyroid size or nodularity between the two groups of girls. A working hypothesis is proposed by which the shift in TSH levels in girls from high radiocontamination areas was associated with subclinical radiation damage from environmental radioiodine at the time of the accident.
PMCID: PMC1469923  PMID: 9467071
18.  Colony-stimulating factor-1 induces cytoskeletal reorganization and c-src-dependent tyrosine phosphorylation of selected cellular proteins in rodent osteoclasts. 
Journal of Clinical Investigation  1997;100(10):2476-2485.
Colony-stimulating factor-1 (CSF-1) stimulates motility and cytoplasmic spreading in mature osteoclasts. Therefore, we examined the cellular events and intracellular signaling pathways that accompany CSF-1-induced spreading in normal osteoclasts. To explore the role c-src plays in these processes, we also studied osteoclasts prepared from animals with targeted disruption of the src gene. In normal osteoclasts, CSF-1 treatment induces rapid cytoplasmic spreading, with redistribution of F-actin from a well-delineated central attachment ring to the periphery of the cell. CSF-1 increases membrane phosphotyrosine staining in osteoclasts and induces the phosphorylation of several cellular proteins in cultured, osteoclast-like cells, including c-fms, c-src, and an 85-kD Grb2-binding protein. Src kinase activity is increased threefold after CSF-1 treatment. In src- cells, no attachment ring is present, and CSF-1 fails to induce spreading or a change in the pattern of F-actin distribution. Although c-fms becomes phosphorylated after CSF-1 treatment, the 85-kD protein is significantly less phosphorylated in src- osteoclast-like cells. These results indicate that c-src is critical for the normal cytoskeletal architecture of the osteoclast, and, in its absence, the spreading response induced by CSF-1 is abrogated, and downstream signaling from c-fms is altered.
PMCID: PMC508448  PMID: 9366562
19.  Do beta-chemokines have clinical relevance in HIV infection? 
Journal of Clinical Investigation  1997;100(4):921-930.
The role of beta-chemokines in HIV infection was evaluated. The kinetics of regulated upon activation of normal T cell expressed and secreted, macrophage inflammatory protein-1alpha, and macrophage inflammatory protein 1beta production by stimulated T lymphocytes did not differ substantially between HIV-infected (asymptomatic and with AIDS) and uninfected subjects. Maximal production of these beta-chemokines by activated peripheral blood cells was higher in the infected individuals than in uninfected individuals, but no significant difference was observed between healthy infected subjects and AIDS patients. Evaluation of the effect of HIV replication on beta-chemokine production indicated that acute infection of CD4+ T cells with non-syncytia-inducing (NSI) viruses generally increased beta-chemokine production two to eightfold, whereas with SI strains, it led to decreased production. The sensitivity of an individual's virus to beta-chemokine-mediated inhibition correlated with the NSI virus phenotype and a healthy clinical state. 50% of the AIDS patients, however, had NSI viruses that were sensitive to beta-chemokines. Finally, anti-beta-chemokine-neutralizing antibodies caused a more rapid release of HIV by CD4+ T cells naturally infected by NSI, but not SI, viruses indicating that endogenously produced chemokines can affect HIV production in culture. These findings suggest that beta-chemokines may affect HIV replication when an NSI virus is involved, but provide little evidence that they substantially influence HIV infection and pathogenesis.
PMCID: PMC508265  PMID: 9259592
20.  Deletion of nef slows but does not prevent CD4-positive T-cell depletion in human immunodeficiency virus type 1-infected human-PBL-SCID mice. 
Journal of Virology  1997;71(5):4161-4164.
The pathogenicity of four human immunodeficiency virus type 1 (HIV-1) isolates with nef deleted for SCID mice repopulated with human peripheral blood leukocytes (hu-PBL-SCID mice) was studied. Deletion of nef led to a substantial reduction in CD4-positive T-cell depletion and delayed kinetics of plasma viremia in infected hu-PBL-SCID mice. Deletion of the nef gene impacts both the efficiency of primary infection and the cytopathicity of virus for infected CD4-positive T cells in this animal model of HIV-1 infection.
PMCID: PMC191576  PMID: 9094701
21.  Selenium deficiency, reversible cardiomyopathy and short-term intravenous feeding. 
Postgraduate Medical Journal  1994;70(821):235-236.
We report the case of a patient with Crohn's disease receiving short-term postoperative parenteral nutrition supplemented with trace elements who nevertheless became selenium deficient with evidence of a cardiomyopathy. This was fully reversible with oral selenium supplementation. Current parenteral feeding regimes may not contain enough selenium for malnourished patients.
PMCID: PMC2397862  PMID: 8183763
23.  Alteration of intracellular potassium and sodium concentrations correlates with induction of cytopathic effects by human immunodeficiency virus. 
Journal of Virology  1996;70(8):5447-5454.
Increases in intracellular concentrations of potassium ([K+]i) and sodium ([Na+]i) occur concomitantly with cytopathic effects induced in a CD4+ T-lymphoblastoid cell line acutely infected by human immunodeficiency virus (HIV). This [K+]i increase was greater in cells infected by cytopathic HIV strains than in cells infected by less cytopathic strains. T cells persistently infected by HIV had an increased [K+]i but displayed an [Na+]i similar to that of mock-infected cells. HIV induced increases in [K+]i and [Na+]i after cytopathic infection of human peripheral blood mononuclear cells, but the magnitude of the Na+ changes did not correlate with the extent of the cytopathic effect. Enhanced movement of cations may osmotically drive water entry, resulting in balloon degeneration and lysis of HIV-infected cells. These observations offer potential approaches for antiviral therapies.
PMCID: PMC190502  PMID: 8764056
24.  The envelope gp120 gene of human immunodeficiency virus type 1 determines the rate of CD4-positive T-cell depletion in SCID mice engrafted with human peripheral blood leukocytes. 
Journal of Virology  1996;70(6):4184-4187.
We have used envelope recombinant viruses generated between two molecular clones of human immunodeficiency virus type 1 (HIV-1), T-cell-tropic HIV-1SF2 and macrophage-tropic HIV-1SF162, to assess pathogenic potential in the human peripheral blood leukocyte-reconstituted severe combined immune deficiency mouse model. Recombinant HIV-1SF2 viruses expressing the envelope gp120 gene of HIV-ISF162 caused as rapid a CD4+ T-cell depletion as did HIV-1SF162. The reciprocal HIV-1SF162 recombinant virus with the HIV-1SF2 envelope caused slower CD4+ T-cell loss. Although changing the V3 loop sequence of HIV-1SF162 to that of HIV-1SF2 did not change the rate of CD4+ T-cell depletion, replacing the V3 of HIV-1SF2 with the sequence of HIV-1SF162 resulted in virus that was poorly infectious in vivo but not in vitro. These studies suggest that the envelope gene determines properties important for pathogenesis in vivo as well as for cell tropism in vitro. HIV-1 infection in vivo may have more stringent requirements for envelope conformation.
PMCID: PMC190315  PMID: 8648765
25.  Molecularly cloned feline immunodeficiency virus NCSU1 JSY3 induces immunodeficiency in specific-pathogen-free cats. 
Journal of Virology  1996;70(5):3011-3017.
A full-length feline immunodeficiency virus NCSU1 (FIV-NCSU1) genome (JSY3) was cloned directly from FIV-NCSU1-infected feline CD4+ lymphocyte (FCD4E) genomic DNA and identified by PCR amplification with 5' long terminal repeat, gag, env, and 3' long terminal repeat primer sets. Supernatant from FCD4E cells cocultured with JSY3-transfected Crandell feline kidney (CrFK) cells was used as an inoculum. Cell-free JSY3 virus was cytopathogenic for FCD4E lymphocytes but did not infect CrFK cells in vitro. To determine in vivo infectivity and pathogenesis, six young adult specific-pathogen-free cats were inoculated with cell-free JSY3 virus. Provirus was detected at 2 weeks postinfection (p.i.) and was still detectable at 25 weeks p.i. as determined by gag region PCR-Southern blot analysis of peripheral blood mononuclear cell lysates. Infectious virus was recovered from peripheral blood mononuclear cells at 6 and 25 weeks p.i., and an antibody response to FIV was detected by 4 weeks. In the acute phase of infection, JSY3 provirus was found only in the CD4+ lymphocyte subset; however, by 14 weeks p.i., the greatest provirus burden was detected in B lymphocytes. All six cats were panlymphopenic at 2 weeks p.i., CD4+/CD8+ ratios were inverted by 6 weeks p.i., and five of the six cats developed lymphadenopathy by 10 weeks p.i. To determine if the JSY3 molecular clone caused immunodeficiency similar to that of the parental wild-type FIV-NCSU1, the cats were challenged with the low-virulence ME49 strain of Toxoplasma gondii at 29 weeks p.i. Five of six cats developed clinical signs consistent with generalized toxoplasmosis, and three of six cats developed acute respiratory distress and required euthanasia. Histopathologic examination of the severely affected cats revealed generalized inflammatory reactions and the presence of T. gondii tachyzoites in multiple tissues. None of the six age- and sex-matched specific-pathogen-free cats inoculated with only T. gondii developed clinical disease. Our results suggest that the pathogenesis of the molecularly cloned NCSU1 JSY3 is similar to that of wild-type FIV-NCSU1.
PMCID: PMC190160  PMID: 8627777

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