We assessed smoking data from the Veterans Health Administration (VHA) electronic medical record (EMR) Health Factors dataset.
To assess the validity of the EMR Health Factors smoking data, we first created an algorithm to convert text entries into a 3-category smoking variable (never, former, and current). We compared this EMR smoking variable to 2 different sources of patient self-reported smoking survey data: (a) 6,816 HIV-infected and -uninfected participants in the 8-site Veterans Aging Cohort Study (VACS-8) and (b) a subset of 13,689 participants from the national VACS Virtual Cohort (VACS-VC), who also completed the 1999 Large Health Study (LHS) survey. Sensitivity, specificity, and kappa statistics were used to evaluate agreement of EMR Health Factors smoking data with self-report smoking data.
For the EMR Health Factors and VACS-8 comparison of current, former, and never smoking categories, the kappa statistic was .66. For EMR Health Factors and VACS-VC/LHS comparison of smoking, the kappa statistic was .61.
Based on kappa statistics, agreement between the EMR Health Factors and survey sources is substantial. Identification of current smokers nationally within the VHA can be used in future studies to track smoking status over time, to evaluate smoking interventions, and to adjust for smoking status in research. Our methodology may provide insights for other organizations seeking to use EMR data for accurate determination of smoking status.
The impact of alcohol consumption on depressive symptoms over time among patients who do not meet criteria for alcohol abuse or dependence is not known.
To evaluate the impact of varying levels of alcohol consumption on depressive symptoms over time in patients with and without HIV infection.
We used data from the Veterans Aging Cohort Study (VACS). We used generalized estimating equations models to assess the association of alcohol-related categories, as a fixed effect, on the time-varying outcome of depressive symptoms.
VACS is a prospectively enrolled cohort study of HIV-infected patients and age-, race- and site-matched HIV uninfected patients.
Hazardous, binge drinking, alcohol abuse and alcohol dependence were defined using standard criteria. Depressive symptoms were measured by the Patient Health Questionnaire (PHQ-9).
Among the 2446 patients, 19% reported past but not current alcohol use, 50% non-hazardous drinking, 8% hazardous drinking, 14% binge drinking, and 10% met criteria for alcohol or dependence. At baseline, depressive symptoms were higher in hazardous and binge drinkers than in past and non-hazardous drinkers (OR=2.65; CI=1.50/4.69; p<.001) and similar to those with abuse or dependence. There was no difference in the association between alcohol-related category and depressive symptoms by HIV status (OR=0.99; CI=.83/1.18; p=.88). Hazardous drinkers were 2.53 (95% CI = 1.34/4.81) times and binge drinkers were 2.14 (95% CI = 1.49/3.07) times more likely to meet criteria for depression when compared to non-hazardous drinkers. The associations between alcohol consumption and depressive symptoms persisted over three years and were responsive to changes in alcohol-related categories.
HIV-infected and HIV-uninfected hazardous and binge drinkers have depressive symptoms that are more severe than non-hazardous and non-drinkers and similar to those with alcohol abuse or dependence. Patients who switch to a higher or lower level of drinking experience a similar alteration in their depressive symptoms. Interventions to decrease unhealthy alcohol consumption may improve depressive symptoms.
Alcohol drinking; Alcoholism; Depression; Depressive disorder; HIV; Acquired Immunodeficiency Syndrome
Serologic studies can provide important insights into the epidemiology and transmission of Pneumocystis jirovecii. Exposure to P. jirovecii can be assessed by serum antibody responses to recombinant antigens from the major surface glycoprotein (MsgC), although factors that influence the magnitude of the antibody response are incompletely understood. We determined the magnitudes of antibody responses to P. jirovecii in comparison to adenovirus and respiratory syncytial virus (RSV) in HIV-infected and uninfected patients and identified predictors associated with the magnitude of the response. We performed a cross-sectional analysis using serum samples and data from 153 HIV-positive and 92 HIV-negative subjects enrolled in a feasibility study of the Veterans Aging Cohort 5 Site Study (VACS 5). Antibodies were measured using an enzyme-linked immunosorbent assay (ELISA). Independent predictors of antibody responses were determined using multivariate Tobit regression models. The results showed that serum antibody responses to P. jirovecii MsgC fragments were significantly and independently decreased in current smokers. Antibodies to P. jirovecii also tended to be lower with chronic obstructive pulmonary disease (COPD), hazardous alcohol use, injection drug use, and HIV infection, although these results were not statistically significant. These results were specific to P. jirovecii and did not correlate with adenovirus. Antibody responses to RSV were in the inverse direction. Thus, current smoking was independently associated with decreased P. jirovecii antibody responses. Whether smoking exerts an immunosuppressive effect that affects the P. jirovecii antibody response, colonization, or subsequent risk for disease is unclear; prospective, longitudinal studies are needed to evaluate these findings further.
This study characterized the extent and patterns self-reported drug use among aging adults with and without HIV, assessed differences in patterns by HIV status, and examined pattern correlates. Data derived from 6351 HIV infected and uninfected adults enrolled in an eight-site matched cohort, the Veterans Aging Cohort Study (VACS). Using clinical variables from electronic medical records and sociodemographics, drug use consequences, and frequency of drug use from baseline surveys, we performed latent class analyses (LCA) stratified by HIV status and adjusted for clinical and socio-demographic covariates. Participants were, on average, age 50 (range 22–86), primarily male (95%) and African-American (64%). Five distinct patterns emerged: non-users, past primarily marijuana users, past multidrug users, current high consequence multidrug users, and current low consequence primarily marijuana users. HIV status strongly influenced class membership. Non -users were most p revalent among HIV uninfected (36.4%) and current high consequence multidrug users (25.5%) were most prevalent among HIV infected. While problems of obesity marked those not currently u sing drugs, current users experienced higher prevalences of medical or mental health disorders. Multimorbidity was highest among past and current multidrug users. HIV-infected participants were more likely than HIV-uninfected participants to be current low consequence primarily marijuana users. In this sample, active drug use and abuse were common. HIV infected and uninfected Veterans differed on extent and patterns of drug use and on important characteristics within identified classes. Findings have the potential to inform screening and intervention efforts in aging drug users with and without HIV.
aging; Veterans; HIV; substance-related disorders; latent class analysis; illicit drugs; cohort studies
Depression is one of the most common comorbid conditions affecting persons with HIV. We compared depressive symptoms and depression treatment using data from the Veterans Aging Cohort Study (VACS), a prospective cohort of HIV-infected and uninfected subjects. We identified subjects with a Patient Health Questionnaire score of 10 or greater. Treatment was defined as prescription of a selective serotonin reuptake inhibitor (SSRI) or mental health counseling. Overall, 16% of 4,480 subjects had depressive symptoms, and HIV-infected patients were more likely to have had depressive symptoms (OR = 1.38, 95% CI = 1.18, 1.62). Geographic site of care and having a mental health provider at the clinic was associated with treatment. In multivariable models restricted to 732 patients with depressive symptoms, receipt of depression treatment did not differ by HIV status (Adjusted OR = 1.11, 95% CI = 0.80, 1.54). Non-Hispanic whites were more likely to receive treatment (Adjusted OR = 2.09, 95% CI 1.04, 4.24). Primary care and HIV providers were equally unlikely to treat active depressive symptoms. Treatment variation by race, site, and availability of a mental health provider, suggests targets for intervention.
HIV-infection; Depression; Psychiatric status rating scales; Anti-depressive agents
HIV clinical care now involves prevention and treatment of age-associated comorbidity. Although physical function is an established correlate to comorbidity in older adults without HIV infection, its role in aging of HIV-infected adults is not well understood. To investigate this question we conducted cross-sectional analyses including linear regression models of physical function in 3227 HIV-infected and 3240 uninfected patients enrolled 2002–2006 in the Veterans Aging Cohort Study-8-site (VACS-8). Baseline self-reported physical function correlated with the Short Form-12 physical subscale (ρ = 0.74, p < 0.001), and predicted survival. Across the age groups decline in physical function per year was greater in HIV-infected patients (βcoef −0.25, p < 0.001) compared to uninfected patients (βcoef −0.08, p = 0.03). This difference, although statistically significant (p < 0.01), was small. Function in the average 50-year old HIV-infected subject was equivalent to the average 51.5-year-old uninfected subject. History of cardiovascular disease was a significant predictor of poor function, but the effect was similar across groups. Chronic pulmonary disease had a differential effect on function by HIV status (Δβcoef −3.5, p = 0.03). A 50-year-old HIV-infected subject with chronic pulmonary disease had the equivalent level of function as a 68.1-year-old uninfected subject with chronic pulmonary disease. We conclude that age-associated comorbidity affects physical function in HIV-infected patients, and may modify the effect of aging. Longitudinal research with markers of disease severity is needed to investigate loss of physical function with aging, and to develop age-specific HIV care guidelines.
HIV infection has been associated with an increased risk of fragility fracture. We explored whether or not this increased risk persisted in HIV infected and uninfected men when controlling for traditional fragility fracture risk factors.
Cox regression models were used to assess the association of HIV infection with the risk for incident hip, vertebral, or upper arm fracture in male Veterans enrolled in the Veterans Aging Cohort Study Virtual Cohort (VACS-VC). We calculated adjusted hazard ratios comparing HIV status and controlling for demographics and other established risk factors. The sample consisted of 119,318 men, 33% of whom were HIV infected (34% aged 50 years or older at baseline, and 55% black or Hispanic). Median body mass index (BMI) was lower in HIV infected compared with uninfected men (25 vs. 28 kg/m2; p<0.0001). Unadjusted risk for fracture was higher among HIV infected compared with uninfected men [HR: 1.32 (95% CI: 1.20, 1.47)]. After adjusting for demographics, comorbid disease, smoking and alcohol abuse, HIV infection remained associated with an increased fracture risk [HR: 1.24 (95% CI: 1.11, 1.39)]. However, adjusting for BMI attenuated this association [HR: 1.10 (95% CI: 0.97, 1.25)]. The only HIV-specific factor associated with fragility fracture was current protease inhibitor use [HR: 1.41 (95% CI: 1.16, 1.70)].
HIV infection is associated with fragility fracture risk. This risk is attenuated by BMI.
As those with HIV infection live longer, ‘non-AIDS’ condition associated with immunodeficiency and chronic inflammation are more common. We ask whether ‘non-HIV’ biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART).
Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers (CD4 cell count, HIV RNA and AIDS-defining conditions); ‘non-HIV’ biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data.
Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and ‘non-HIV’ markers were associated with each other (P<0.0001) and discriminated mortality (C statistics 0.68–0.73); when combined, discrimination improved (P<0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80–0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72–0.74). Results were robust to adjustment for missing data.
When added to HIV biomarkers, ‘non-HIV’ biomarkers improve differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research.
anaemia; CD4 cell count; hepatitis C coinfection; hepatology; injecting drug use; outcomes; renal/kidney; risk groups; viral load
It was previously demonstrated that the vaccinia virus recombinants expressing the respiratory syncytial virus (RSV) F, G, or M2 (also designated as 22K) protein (Vac-F, Vac-G, or Vac-M2, respectively) induced almost complete resistance to RSV challenge in BALB/c mice. In the present study, we sought to identify the humoral and/or cellular mediators of this resistance. Mice were immunized by infection with a single recombinant vaccinia virus and were subsequently given a monoclonal antibody directed against CD4+ or CD8+ T cells or gamma interferon (IFN-gamma) to cause depletion of effector T cells or IFN-gamma, respectively, at the time of RSV challenge (10 days after immunization). Mice immunized with Vac-F or Vac-G were completely or almost completely resistant to RSV challenge after depletion of both CD4+ and CD8+ T cells prior to challenge, indicating that these cells were not required at the time of virus challenge for expression of resistance to RSV infection induced by the recombinants. In contrast, the high level of protection of mice immunized with Vac-M2 was completely abrogated by depletion of CD8+ T cells, whereas depletion of CD4+ T cells or IFN-gamma resulted in intermediate levels of resistance. These results demonstrate that antibodies are sufficient to mediate the resistance to RSV induced by the F and G proteins, whereas the resistance induced by the M2 protein is mediated primarily by CD8+ T cells, with CD4+ T cells and IFN-gamma also contributing to resistance.
Rationale: In aging HIV-infected populations comorbid diseases are important determinants of morbidity and mortality. Pulmonary diseases have not been systematically assessed in the combination antiretroviral therapy (ART) era.
Objectives: To determine the incidence of pulmonary diseases in HIV-infected persons compared with HIV-uninfected persons.
Methods: We analyzed data from the Veterans Aging Cohort Study Virtual Cohort, consisting of 33,420 HIV-infected veterans and 66,840 age, sex, race and ethnicity, and site-matched HIV-uninfected veterans. Using Poisson regression, incidence rates and adjusted incidence rate ratios were calculated to determine the association of HIV with pulmonary disease. The Virtual Cohort was merged with the 1999 Veterans Large Health Survey to adjust for self-reported smoking in a nested sample (14%).
Measurements and Main Results: Incident chronic obstructive pulmonary disease, lung cancer, pulmonary hypertension, and pulmonary fibrosis, as well as pulmonary infections, were significantly more likely among HIV-infected patients compared with uninfected patients in adjusted analyses, although rates of asthma did not differ by HIV status. Bacterial pneumonia and chronic obstructive pulmonary disease were the two most common incident pulmonary diseases, whereas opportunistic pneumonias were less common. Absolute rates of most pulmonary diseases increased with age, although the relative differences between those with and without HIV infection were greatest in younger persons. Chronic obstructive pulmonary disease and asthma, as well as pulmonary infections, were less likely in those with lower HIV RNA levels and use of ART at baseline.
Conclusions: Pulmonary diseases among HIV-infected patients receiving care within the Veterans Affairs Healthcare System in the combination ART era reflect a substantial burden of non–AIDS-defining and chronic conditions, many of which are associated with aging.
HIV; respiratory tract diseases; lung diseases, obstructive; pneumonia; pneumonia, bacterial
The antibody response elicited after immunization with vaccinia virus (VacV) is known to be sufficient to confer host protection against VacV or smallpox. In humans it has been shown that such anti-VacV antibody production can be sustained for decades. Nevertheless, little is known about the kinetics and the role in protection of the early antibody response after vaccination. In this study we identify VacV neutralizing IgM antibodies as early as four days after infection of C57BL/6 mice. Most of this IgM production is T cell dependent and predominantly independent of the germinal center reaction (SAP / SH2D1A independent). Importantly, the IgM neutralized both infectious forms of VacV: the intracellular mature virion (MV, IMV) and the extracellular enveloped virion (EV, EEV). Moreover, in mice primed with MHCII restricted peptides, an increase in the total VacV neutralizing antibody titers was seen, a large component of which was neutralizing IgM against the same protein from which the priming peptide was derived. To further demonstrate the biological relevance of this early neutralizing response, we examined anti-VacV antibodies in humans after vaccination. Human subjects could be divided into two groups early after immunization: IgGhi and IgGlo. VacV IgM neutralizing antibodies were detected in the IgGlo group. Taken together these results indicate that both in a small animal model and in humans an early neutralizing IgM response after VacV immunization is present and likely contributes to control of the infection prior to the development of a robust IgG response.
Smallpox vaccine; Vaccinia virus; IgM; Neutralizing antibodies
The purpose of this study was to compare the outcome of patients with intermediate-risk rhabdomyosarcoma (RMS) treated with standard VAC (vincristine, dactinomycin, and cyclophosphamide) chemotherapy to that of patients treated with VAC alternating with vincristine, topotecan, and cyclophosphamide (VAC/VTC).
Patients and Methods
Patients were randomly assigned to 39 weeks of VAC versus VAC/VTC; local therapy began after week 12. Patients with parameningeal RMS with intracranial extension (PME) were treated with VAC and immediate x-ray therapy. The primary study end point was failure-free survival (FFS). The study was designed with 80% power (5% two-sided α level) to detect an increase in 5-year FFS from 64% to 75% with VAC/VTC.
A total of 617 eligible patients were entered onto the study: 264 were randomly assigned to VAC and 252 to VAC/VTC; 101 PME patients were nonrandomly treated with VAC. Treatment strata were embryonal RMS, stage 2/3, group III (33%); embryonal RMS, group IV, less than age 10 years (7%); alveolar RMS or undifferentiated sarcoma (UDS), stage 1 or group I (17%); alveolar RMS/UDS (27%); and PME (16%). At a median follow-up of 4.3 years, 4-year FFS was 73% with VAC and 68% with VAC/VTC (P = .3). There was no difference in effect of VAC versus VAC/VTC across risk groups. The frequency of second malignancies was similar between the two treatment groups.
For intermediate-risk RMS, VAC/VTC does not significantly improve FFS compared with VAC.
The Timeline Followback (TLFB) interview has become state-of-the-science for the collection of retrospective self-reports of daily alcohol consumption. Such data are especially useful for addressing questions of the co-occurrence of quantity of alcohol consumption and other behaviors, such as HIV-related risky sex, on the event level. The purpose of this study was to determine if the TLFB could be used effectively by self-administration compared with the more costly telephone interview in a large, multisite observational study of HIV-positive and HIV-negative adults.
An experimental design was used to compare self-administered and telephone-administered TLFB modes in a subsample (N = 70) of the Veterans Aging Cohort Study, an ongoing longitudinal study of more than 6,000 HIV-positive and HIV-negative men and women presenting for treatment at eight Department of Veterans Affairs Infectious Disease or General Medicine clinics. Participants were randomly assigned to one of four experimental groups defined by mode and sequence of a TLFB administration on two occasions occurring within 1 week: telephone-telephone, telephone-self, self-telephone, and self-self.
Analyses showed no differences in median total number of drinks reported between modes of TLFB administration or sequence of mode of administration. The same findings held for classification of participants as “hazardous” drinkers. Additional analyses showed good-to-excellent test-retest reliability of self-reports for both modes of TLFB administration.
The data derived from this study provide strong experimental evidence for the utility of the self-administered, 30-day TLFB in collecting daily alcohol consumption in large observational studies of HIV-positive and HIV-negative individuals.
The absence of validated methods to identify hepatic decompensation in cohort studies has prevented a full understanding of the natural history of chronic liver diseases and impact of medications on this outcome. We determined the ability of diagnostic codes and liver-related laboratory abnormalities to identify hepatic decompensation events within the Veterans Aging Cohort Study (VACS).
Medical records of patients with hepatic decompensation codes and/or laboratory abnormalities of liver dysfunction (total bilirubin ≥5.0 gm/dL, albumin ≤2.0 gm/dL, international normalized ratio ≥1.7) recorded one year before through six months after VACS entry were reviewed to identify decompensation events (i.e., ascites, spontaneous bacterial peritonitis, variceal hemorrhage, hepatic encephalopathy, hepatocellular carcinoma) at VACS enrollment. Positive predictive values (PPVs) of diagnostic codes, laboratory abnormalities, and their combinations for confirmed outcomes were determined.
Among 137 patients with a hepatic decompensation code and 197 with a laboratory abnormality, the diagnosis was confirmed in 57 (PPV, 42%; 95% CI, 33% – 50%) and 56 (PPV, 28%; 95% CI, 22% – 35%), respectively. The combination of any code plus laboratory abnormality increased PPV (64%; 95% CI, 47% - 79%). One inpatient or ≥2 outpatient diagnostic codes for ascites, spontaneous bacterial peritonitis, or variceal hemorrhage had high PPV (91%; 95% CI, 77% – 98%) for confirmed hepatic decompensation events.
An algorithm of 1 inpatient or ≥2 outpatient codes for ascites, peritonitis, or variceal hemorrhage has sufficiently high PPV for hepatic decompensation to enable its use for epidemiologic research in VACS. This algorithm may be applicable to other cohorts.
hepatic decompensation; end-stage liver disease; epidemiologic methods; outcomes; validation studies
Human CD4+ T cells are major targets for human immunodeficiency virus (HIV) infection. Resting T cells are resistant to HIV infection unless activated through the T-cell receptor (TCR) or by cytokine signals. How T-cell signaling promotes susceptibility of T cells to HIV infection remains poorly understood. Here we demonstrate that the VacA toxin produced by Helicobacter pylori can inhibit HIV infection of primary T cells, stimulated through the TCR or by cytokines alone. This activity of VacA was dependent on its ability to form membrane channels. VacA suppressed HIV infection of T cells at a stage after viral entry, post-reverse transcription and pre-two-long-terminal-repeat circle formation, similar to the cytokine signaling inhibitor rapamycin. Mechanistically, neither VacA nor rapamycin inhibited the activation of cytokine signal transduction components (STAT5, p42/44 mitogen-activated protein kinase, or p38), but both blocked activation of key regulatory proteins required for G1 cell cycle transition. In contrast to rapamycin, VacA did not suppress phosphorylation of p70 S6 kinase but caused mitochondrial depolarization and ATP depletion within primary T cells. These results suggest that VacA inhibits T-cell activation and HIV infection via a novel mechanism. Identifying the host cell targets of VacA could be useful for elucidating the HIV life cycle within primary T cells.
Postoperative deep infections are relatively common in children with instrumented spinal deformities, whose healing potential is somewhat compromised. Children with underlying diagnosis of cerebral palsy, spina bifida and other chronic debilitating conditions are particularly susceptible. Vacuum-assisted closure (VAC) is a newer technique to promote healing of wounds resistant to treatment by established methods. This article aims to review the efficacy of the VAC system in the treatment of deep spinal infections following spinal instrumentation and fusion in children and adolescents.
Materials and Methods:
We reviewed 33 patients with deep postoperative surgical site infection treated with wound VAC technique. We reviewed clinical and laboratory data, including the ability to retain the spinal hardware, loss of correction and recurrent infections.
All patients successfully completed their wound VAC treatment regime. None had significant loss of correction and one had persistent infection requiring partial hardware removal. The laboratory indices normalized in all but three patients.
Wound VAC technique is a useful tool in the armamentarium of the spinal surgeon dealing with patients susceptible to wound infections, especially those with neuromuscular diseases. It allows for retention of the instrumentation and maintenance of the spinal correction. It is reliable and easy to use.
VAC therapy; deep wound infection; spinal deformity
The early consequences of Helicobacter pylori infection and the role of bacterial virulence determinants in disease outcome remain to be established. The present study sought to measure the development of host inflammatory and immune responses and their relationship to the putative bacterial virulence factors cag pathogenicity island (cagPAI), vacA allele, and oipA in combination with bacterial colonization density in a feline model of the early stages of H. pylori infection. Gastric tissues obtained from infected and uninfected cats were evaluated for H. pylori ureB, cagPAI, vacA allele, and oipA and colonization density (urease, histology, and real-time PCR). Inflammation was assessed by measuring mRNA upregulation of gamma interferon (IFN-γ), interleukin (IL)-1α, IL-1β, IL-4, IL-6, IL-8, IL-10, and IL-12 p40 and histopathology. The mucosal immune response was characterized by morphometric analysis of lymphoid follicles and by differentiating lymphocyte populations with antibodies against surface markers. Infecting H. pylori strains were positive for vacAs1 but lacked cagPAI and an active oipA gene. Colonization density was uniform throughout the stomach. Upregulation of IFN-γ, IL-1α, IL-1β, and IL-8 and increased severity of inflammatory infiltrates and fibrosis were observed in infected cats. The median number and total area of lymphoid aggregates were 5 and 10 times greater, respectively, in the stomachs of infected than uninfected cats. Secondary lymphoid follicles in uninfected cats were rare and positive for BLA.36 and B220 but negative for CD3 and CD79α, whereas in infected cats they were frequent and positive for BLA.36, CD79α, and CD3 but negative for B220. Upregulation of IFN-γ, IL-1α, IL-1β, and IL-8 and marked hyperplasia of secondary lymphoid follicles are early consequences of H. pylori infection in cats. The response appears to be similar to that of infected people, particularly children, can develop independently of the pathogenicity factors cagPAI and oipA, and is not correlated with the degree of colonization density or urease activity.
Helicobacter pylori infection is common in Alaska. The development of severe H. pylori disease is partially determined by the virulence of the infecting strain. Here we present vacA and cagA genotype data for H. pylori strains isolated from Alaskans and their correlation with clinical disease. We enrolled patients scheduled for esophagogastroduodenoscopy and positive for H. pylori infection. Gastric biopsy specimens from the stomach antrum and fundus were cultured. We performed PCR analysis of the H. pylori vacA gene and for the presence of the cagA gene and cagA empty site. We genotyped 515 H. pylori samples from 220 Native and 66 non-Native Alaskans. We detected the cagA gene in 242/286 (85%) persons; of 222 strains that could be subtyped, 95% (212) were non-Asian cagA and 3% (6) were East Asian cagA. After removing mixed infections (n = 17), 83% of H. pylori strains had either the vacA s1m1 (120/269) or s2m2 (103/269) genotype. Sixty-six percent (68/103) of H. pylori strains with the vacA s2m2 genotype also contained the cagA gene. Infection with an H. pylori strain having the cagA gene or vacA s1m1 genotype (compared with s1m2 and s2m2) was associated with a decreased risk of esophagitis (P = 0.003 and 0.0003, respectively). Infection with an H. pylori strain having the vacA s1m1 genotype (compared with s1m2 and s2m2) was associated with an increased risk of peptic ulcer disease (PUD) (P = 0.003). The majority of H. pylori strains in this study carried the non-Asian cagA gene and either the vacA s1m1 or s2m2 genotype. A majority of H. pylori strains with the vacA s2m2 genotype also contained the cagA gene. There was an association of H. pylori genotype with esophagitis and PUD.
The Helicobacter pylori vacuolating cytotoxin (VacA) binds and enters mammalian cells to induce cellular vacuolation. To investigate the quaternary structure of VacA within the intracellular environment where toxin cytotoxicity is elaborated, we employed fluorescence resonance energy transfer (FRET) microscopy. HeLa cells coexpressing full-length and truncated forms of VacA fused to cyan fluorescent protein (CFP) or yellow fluorescent protein (YFP) were analyzed for FRET to indicate direct associations. These studies revealed that VacA-CFP and VacA-YFP interact within vacuolated cells, supporting the belief that monomer associations at an intracellular site are important for the toxin's vacuolating activity. In addition, the two fragments of proteolytically nicked VacA, p37 and p58, interact when coexpressed within mammalian cells. Because p37 and p58 function in trans when expressed separately within mammalian cells, these data suggest that the mechanism by which these two fragments induce vacuolation requires direct association. FRET microscopy also demonstrated interactions between mutant forms of VacA, as well as wild-type VacA with mutant forms of the toxin within vacuolated cells. Finally, a dominant-negative form of the toxin directly associates with wild-type VacA in cells where vacuolation was not detectable, suggesting that the formation of complexes comprising wild-type and dominant-negative forms of toxin acts to block intracellular toxin function.
Methods: CSF samples from 13 patients with GBS (electrophysiologically classified as eight acute inflammatory demyelinating polyradiculoneuropathy (AIDP), four acute motor axonal neuropathy (AMAN), and one unexcitable nerve conduction) and eight disease control patients were studied. The r-VacA protein was separated by SDS/PAGE, and Western blot analysis was carried out.
Results: Six of the 13 patients with GBS had a specific IgG antibody to VacA of H pylori, which was confirmed by absorption experiments using r-VacA. Every patient with positive CSF anti-r-VacA IgG had AIDP.
Conclusion: The sequence homology previously found between VacA and human (Na++K+)-ATPase A subunit suggests that antibodies to VacA involve ion channels in abaxonal Schwann cell plasmalemma resulting in demyelination in some patients with GBS.
Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer.
Three gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008), and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003). A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036). A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003). Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins.
High H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work.
Forty-three children with malignant soft tissue sarcomas (IRS Groups II-IV) were treated with rapid dose delivery chemotherapy protocol comprising six courses of vincristine, adriamycin and cyclophosphamide, given in most cases within 8 weeks (Rapid VAC). This was followed in 36 patients by high dose melphalan with autologous bone marrow rescue. Twenty-six patients also received irradiation to the site of primary tumour. The Rapid VAC regimen was well tolerated and largely administered as an out-patient. There was one toxic death which occurred 2 months after high dose melphalan due to a combination of infection and possible anthracycline cardiomyopathy. Stages were, (Intergroup Rhabdomyosarcoma Study (IRS) system) Group, Group II--four patients. Group III--27 patients and Group IV--12 patients; International Society of Paediatric Oncology (SIOP) staging, Stage I--11, Stage II--13, Stage III--7, Stage IV--12. Actuarial survival at 5 years for all stages is 57% and event free survival 44%. For patients with non-metastatic diseases, 62% and 53% respectively. This treatment strategy utilises the philosophy of rapid drug delivery with high dose consolidation and enables all chemotherapy to be finished within a 4 month period. In general, a conservative approach was applied to both radiation and surgery to minimise late sequelae related to these treatment modalities. Although the small number of high risk patients in this study limits conclusions regarding efficacy in these subgroups the overall results with this regimen appear to be comparable to that with other approaches.
Human cytomegalovirus (HCMV) induces extensive remodeling of the secretory apparatus to form the cytoplasmic virion assembly compartment (cVAC), where virion tegumentation and envelopment take place. We studied the structure of the cVAC by confocal microscopy to assess the three-dimensional distribution of proteins specifically associated with individual secretory organelles. In infected cells, early endosome antigen 1 (EEA1)-positive vesicles are concentrated at the center of the cVAC and, as previously seen, are distinct from structures visualized by markers for the endoplasmic reticulum, Golgi apparatus, and trans-Golgi network (TGN). EEA1-positive vesicles can be strongly associated with markers for recycling endosomes, to a lesser extent with markers associated with components of the endosomal sorting complex required for transport III (ESCRT III) machinery, and then with markers of late endosomes. In comparisons of uninfected and infected cells, we found significant changes in the structural associations and colocalization of organelle markers, as well as in net organelle volumes. These results provide new evidence that the HCMV-induced remodeling of the membrane transport apparatus involves much more than simple relocation and expansion of preexisting structures and are consistent with the hypothesis that the shift in identity of secretory organelles in HCMV-infected cells results in new functional profiles.
To examine the association between HIV infection status and the receipt of lipid lowering therapy based on National Cholesterol Education Program/Adult Treatment Panel (NCEP/ATP III) guidelines and to assess whether HIV viral load and hepatitis C (HCV) status alters that association.
PARTICIPANTS AND DESIGN
A cross-sectional analysis of survey, laboratory, and pharmacy data from 1,577 male participants (59% HIV infected) of the Veterans Aging Cohort Five-Site Study, a prospective observational cohort of U.S. veterans with and without HIV infection.
Receipt of lipid lowering therapy obtained from the VA pharmacy benefits management system was the main outcome.
The prevalence of lipid lowering therapy among HIV-infected and HIV-uninfected veterans was 15.4% vs. 37.9%, respectively, < 0.01. Among veterans who met NCEP/ATP III criteria for lipid lowering therapy, HIV-infected veterans had a significantly lower prevalence for the receipt of lipid lowering therapy (adjusted odds ratio (OR) = 0.43, 95% confidence interval (C.I.) 0.28–0.67) as compared with HIV-uninfected veterans. Among HIV-infected veterans, log HIV viral load (adjusted OR = 0.57, 95% CI, 0.41–0.81) and HIV-HCV co-infection (adjusted OR = 0.31, 95% CI = 0.13–0.75) were negatively associated with receipt of lipid lowering therapy. Exposure to HAART was not associated with receipt of lipid lowering therapy.
Among those who met NCEP/ATP III criteria for lipid lowering therapy, HIV-infected veterans, particularly those with high HIV viral loads and HCV co-infection, were significantly less likely to receive lipid lowering therapy. This may be a modifiable mediator of cardiovascular disease among HIV-infected individuals.
HIV; cholesterol; hepatitis C; men; veterans; cardiovascular diseases
Helicobacter pylori infection is associated with inflammation of the gastric mucosa and with gastric mucosal damage. In this study, we sought to test the hypothesis that two H. pylori virulence factors (VacA and CagA) impair gastric epithelial cell migration and proliferation, the main processes involved in gastric mucosal healing in vivo. Human gastric epithelial cells (MKN 28) were incubated with undialyzed or dialyzed broth culture filtrates from wild-type H. pylori strains or isogenic mutants defective in production of VacA, CagA, or both products. We found that (i) VacA specifically inhibited cell proliferation without affecting cell migration, (ii) CagA exerted no effect on either cell migration or proliferation, and (iii) undialyzed H. pylori broth culture filtrates inhibited both cell migration and proliferation through a VacA- and CagA-independent mechanism. These findings demonstrate that, in addition to damaging the gastric mucosa, H. pylori products may also impair physiological processes required for mucosal repair.