Low-Level HIV RNA in Cerebrospinal Fluid and Neurocognitive Performance: A Longitudinal Cohort Study.

BACKGROUND: Cognitive complications persist in persons with HIV during suppressive antiretroviral therapy (ART). Low levels of HIV during ART could contribute to these complications. In this study, we measured cerebrospinal fluid (CSF) HIV using a single-copy assay (SCA) to investigate a possible relationship between low-level HIV and cognition. DESIGN/METHODS: SCA data were analyzed from 3 consecutively paired CSF-plasma specimens collected over a mean of 456 days from 96 participants on suppressive ART. Using mixed models, the presence of CSF HIV by SCA as a risk factor for worse neurocognitive performance was examined. RESULTS: At baseline on the SCA, 45.8% of participants had detectable plasma HIV RNA (median 8 copies/mL and interquartile range = 3-17 among detectable values) and 17.7% had detectable CSF HIV RNA (median CSF concentration= 3 copies/mL and interquartile range= 2-13 among detectable values). The frequency of CSF HIV RNA detection declined over time in CSF (P = 0.018) with a trend toward decline in plasma (P = 0.064). Detectable CSF HIV RNA during the study was associated with worse performance in the domains of recall (P = 0.014) and motor (P = 0.040) and a trend with worse overall global performance (P = 0.078). Integrase inhibitor use, although very infrequent in this cohort, was associated with better performance in 2 domains. CONCLUSIONS: Low-level CSF HIV RNA declines with time but is associated with worse cognitive performance in 2 domains. Additional research is needed to better understand the relationship between HIV RNA persistence during long-term ART and central nervous system complications in persons with HIV.

Cerebrospinal fluid CXCL10 is associated with the presence of low level CSF HIV during suppressive antiretroviral therapy.

Surrogate markers of HIV central nervous system (CNS) persistence are needed because direct HIV measurements from the CNS require specialized protocols and are not always detectable or quantifiable. We analyzed paired plasma and CSF samples from people with HIV (PWH) on suppressive therapy (ART) with a validated HIV single copy RNA assay. Two potential markers of CNS persistence were measured (CXCL10 and sCD30). We then examined associations with CSF HIV RNA positivity in univariable and multivariable analyses. Among 66 individuals, 18.2% had detectable CSF HIV. Individuals who had detectable HIV in CSF had higher CSF CXCL10 concentrations (median 514 pg/ml versus median 317 pg/ml, p = 0.019), but did not have significantly different CSF sCD30 concentrations (median 7.5 ng/ml versus median 7.6 ng/ml, p = 0.78). In the multiple logistic analysis, both higher CSF CXCL10 (p = 0.038) and plasma HIV detectability (p = 0.035) were significantly associated with detectable CSF HIV. Both sCD30 and CXCL10 correlated positively with NfL and NSE, two neuronal markers. This study demonstrates that CSF CXCL10 concentrations reflect low level HIV CNS persistence despite virologic suppression on ART. Given that it is readily detectable and quantifiable, this chemokine may be a promising biomarker to evaluate HIV eradication therapies that target the CNS.

Neurocognitive impairment is worse in HIV/HCV-coinfected individuals with liver dysfunction.

Infections with HIV and hepatitis C virus (HCV) can individually and jointly contribute to neurocognitive impairment (NCI). Rates of NCI in HIV/HCV-coinfected persons range from 40 to 63% but its correlates have not been described. In this study, we examined HIV/HCV-coinfected adults on antiretroviral therapy (ART) with undetectable HIV RNA in blood (n = 412) who were assessed using a comprehensive neuropsychological test battery. Demographics, host and viral biomarkers, and markers of liver dysfunction were compared between impaired (n = 198) and unimpaired (n = 214) participants using logistic regression. The cohort was predominantly middle-aged men, half of whom (48%) had NCI. The odds of NCI increased by almost two-fold when serum albumin was < 4 g/dL, 1.7-fold when alanine aminotransferase (ALT) levels were > 50 IU/L, and 2.2-fold with every unit increase in log10 AST to Platelet Ratio Index (APRI). These readily available clinical biomarkers of NCI measure hepatic injury and/or dysfunction, suggesting a mechanism for the effects of HCV infection on NCI. They may identify patients at increased risk of NCI who could be prioritized for early initiation of HCV treatment to protect or improve cognition.

Accuracy of predictive ability measures for survival models.

One aspect of an analysis of survival data based on the proportional hazards model that has been receiving increasing attention is that of the predictive ability or explained variation of the model. A number of contending measures have been suggested, including one measure, R2 (ß), which has been proposed given its several desirable properties, including its capacity to accommodate time-dependent covariates, a major feature of the model and one that gives rise to great generality. A thorough study of the properties of available measures, including the aforementioned measure, has been carried out recently. In that work, the authors used bootstrap techniques, particularly complex in the setting of censored data, in order to obtain estimates of precision. The motivation of this work is to provide analytical expressions of precision, in particular confidence interval estimates for R2 (ß). We use Taylor series approximations with and without local linearizing transforms. We also consider a very simple expression based on the Fisher's transformation. This latter approach has two great advantages. It is very easy and quick to calculate, and secondly, it can be obtained for any of the methods given in the recent review. A large simulation study is carried out to investigate the properties of the different methods. Finally, three well-known datasets in breast cancer, lymphoma and lung cancer research are given as illustrations. Copyright © 2017 John Wiley & Sons, Ltd.

Latent Toxoplasma Infection and Higher Toxoplasma gondii Immunoglobulin G Levels Are Associated With Worse Neurocognitive Functioning in HIV-Infected Adults.

BACKGROUND: Human immunodeficiency virus (HIV)-associated neurocognitive disorders persist despite suppressive antiretroviral therapy (ART). Because latent Toxoplasma infection (LTI) may adversely impact brain function, we investigated its impact on neurocognitive impairment (NCI) in people living with HIV disease. METHODS: Two hundred sixty-three HIV-infected adults underwent comprehensive neurocognitive assessments and had anti-Toxoplasma gondii immunoglobulin G (anti-Toxo IgG) measured by qualitative and quantitative enzyme-linked immunosorbent assays. RESULTS: Participants were mostly middle-aged white men who were taking ART (70%). LTI was detected in 30 (11.4%) participants and was associated with a significantly greater prevalence of global NCI (LTI positive [LTI+] = 57% and LTI negative [LTI-] = 34%) (odds ratio, 1.67; 95% confidence interval, 1.17-2.40; P = .017). Deficits were more prevalent in the LTI+ vs the LTI- group in 6 of 7 cognitive domains with statistical significance reached for delayed recall (P < .01). The probability of NCI increased with higher CD4+ T-cell counts among LTI+ individuals but with lower CD4+ T-cell counts in LTI- persons. A strong correlation (r = .93) between anti-Toxo IgG levels and global deficit score was found in a subgroup of 9 patients. Biomarkers indicative of central nervous system inflammation did not differ between LTI+ and LTI- participants. CONCLUSIONS: In this cross-sectional analysis, LTI was associated with NCI, especially in those with higher CD4+ T-cell counts. Longitudinal studies to investigate the role of neuroinflammation and neuronal injury in LTI patients with NCI and trials of anti-Toxoplasma therapy should be pursued.

A concise panel of biomarkers identifies neurocognitive functioning changes in HIV-infected individuals.

Neurocognitive (NC) impairment (NCI) occurs commonly in people living with HIV. Despite substantial effort, no biomarkers have been sufficiently validated for diagnosis and prognosis of NCI in the clinic. The goal of this project was to identify diagnostic or prognostic biomarkers for NCI in a comprehensively characterized HIV cohort. Multidisciplinary case review selected 98 HIV-infected individuals and categorized them into four NC groups using normative data: stably normal (SN), stably impaired (SI), worsening (Wo), or improving (Im). All subjects underwent comprehensive NC testing, phlebotomy, and lumbar puncture at two timepoints separated by a median of 6.2 months. Eight biomarkers were measured in CSF and blood by immunoassay. Results were analyzed using mixed model linear regression and staged recursive partitioning. At the first visit, subjects were mostly middle-aged (median 45) white (58 %) men (84 %) who had AIDS (70 %). Of the 73 % who took antiretroviral therapy (ART), 54 % had HIV RNA levels below 50 c/mL in plasma. Mixed model linear regression identified that only MCP-1 in CSF was associated with neurocognitive change group. Recursive partitioning models aimed at diagnosis (i.e., correctly classifying neurocognitive status at the first visit) were complex and required most biomarkers to achieve misclassification limits. In contrast, prognostic models were more efficient. A combination of three biomarkers (sCD14, MCP-1, SDF-1α) correctly classified 82 % of Wo and SN subjects, including 88 % of SN subjects. A combination of two biomarkers (MCP-1, TNF-α) correctly classified 81 % of Im and SI subjects, including 100 % of SI subjects. This analysis of well-characterized individuals identified concise panels of biomarkers associated with NC change. Across all analyses, the two most frequently identified biomarkers were sCD14 and MCP-1, indicators of monocyte/macrophage activation. While the panels differed depending on the outcome and on the degree of misclassification, nearly all stable patients were correctly classified.

Neurocognitive impact of substance use in HIV infection.

BACKGROUND: : To determine how serious a confound substance use (SU) might be in studies on HIV-associated neurocognitive disorder (HAND), we examined the relationship of SU history to neurocognitive impairment (NCI) in participants enrolled in the Central Nervous System HIV Antiretroviral Therapy Effects Research study. METHODS: : After excluding cases with behavioral evidence of acute intoxication and histories of factors that independently could account for NCI (eg, stroke), baseline demographic, medical, SU, and neurocognitive data were analyzed from 399 participants. Potential SU risk for NCI was determined by the following criteria: lifetime SU Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis, self-report of marked lifetime SU, or positive urine toxicology. Participants were divided into 3 groups as follows: no SU (n = 134), nonsyndromic SU (n = 131), syndromic SU (n = 134) and matched on literacy level, nadir CD4, and depressive symptoms. RESULTS: : Although approximately 50% of the participants were diagnosed with HAND, a multivariate analysis of covariance of neurocogntive summary scores, covarying for urine toxicology, revealed no significant effect of SU status. Correlational analyses indicated weak associations between lifetime heroin dosage and poor recall and working memory and between cannabis and cocaine use and better verbal fluency. CONCLUSIONS: : These data indicate that HIV neurocognitive effects are seen at about the same frequency in those with and without historic substance abuse in cases that are equated on other factors that might contribute to NCI. Therefore, studies on neuroAIDS and its treatment need not exclude such cases. However, the effects of acute SU and current SU disorders on HAND require further study.

Dopamine receptor D3 genetic polymorphism (rs6280TC) is associated with rates of cognitive impairment in methamphetamine-dependent men with HIV: preliminary findings.

Macrophages are one of HIV-1's principal targets and chiefly responsible for translocating HIV into the central nervous system (CNS). Previous research suggested an increase in macrophages being infected by HIV in the presence of methamphetamine (METH) or increased extracellular dopamine (DA). Experimental studies indicate that this is mediated by DA receptors, including DA receptor D3 (DRD3), which is expressed in macrophages. A single nucleotide polymorphism (SNP) of the DRD3 gene (rs6280TC) modulates its dopamine binding affinity, resulting in the possibility that inheriting a variant of this SNP increases macrophage susceptibility to HIV infection in the presence of METH and DA, particularly in the CNS where METH is sequestered, leading to cognitive impairment (CI). Thus, we conducted a retrospective clinical investigation to evaluate whether rs6280TC is associated with CI among HIV-positive METH users. We stratified 310 males by HIV serostatus (HIV-positive, -negative) and METH dependence (METH-positive, -negative) and then by rs6280TC genotype (CC, CT, and TT). Genotypic groups within each of four HIV/METH groups were compared for rates of CI. We hypothesized that only HIV-positive/METH-positive carriers of the C allele, which increases the DRD3's binding to DA, would be more likely to develop CI. Cochran-Armitage test for trends in proportions yielded significant (p < 0.05) association between three genotypes and impairment rates in the hypothesized order, but only among HIV-positive/METH-positive subjects. The results also confirmed that C allele carriers (CC and CT, 53.3%) in this group had higher impairment rates (p = 0.05) than TT carriers (33.3%). These findings support the theory that rs6280TC influences the frequency of CI in HIV-positive/METH-positive males.

Evaluating the use and timing of opioids for the treatment of migraine headaches in the emergency department.

The objective of this study was to evaluate the throughput times of patients administered opioids for the treatment of migraine headaches in the frequent emergency department (ED) visitor. A retrospective review of ED patient records was conducted. Repeat patients were significantly more likely to receive opioids as a treatment, receive multiple doses of opioids, and receive opioids as the initial pharmacological treatment compared to non-repeaters. Patients administered opioids, regardless of repeater status, had significantly longer ED stays; 142 min (95% confidence interval [CI] 124-160) vs. 111 min (95% CI 93-129), respectively, p = 0.015. Patients given multiple doses of opioids had significantly longer ED stays than patients given a single dose of an opioid; 191 min (95% CI 156-225) vs. 125 min (95% CI 101-149), respectively, p = 0.003. Delayed administration of opioids did not result in longer ED stays in those patients eventually treated with opioids. Administration of opioids for migraine headache may result in longer ED stays when compared with non-opioid migraine treatments. Judicious use of opioids as a treatment for migraine headaches is recommended.

Pharmacokinetics of cysteamine bitartrate following gastrointestinal infusion.

AIMS: Although cysteamine was first used in the treatment of cystinosis in 1976 and approved by the FDA as cysteamine bitartrate (Cystagon) in 1994, surprisingly little pharmacological data are available for this compound. Cysteamine and its related drugs are currently being evaluated for the treatment of Huntington's and Parkinson's disease. The aim of te study was to understand the pharmacokinetics of cysteamine bitartrate following gastrointestinal infusion. METHOD: Cysteamine bitartrate was delivered through a naso-enteric catheter into the stomach (n = 8), small intestine (n = 8) and caecum (n = 4) of normal subjects. Plasma cysteamine concentrations were determined using LC-MS/MS. RESULTS: The rate and extent of drug absorption were assessed by comparing AUC(0, infinity), C(max) and t(max), among the gastrointestinal infusion sites. Total cysteamine exposure, expressed as area under the curve (AUC(0, infinity)) was greatest when the drug was infused into the small intestine (4331.3 +/- 1907.6 min x microM) followed by stomach (3901.9 +/- 1591.9 min x microM) and caecum (3141.4 +/- 1627.6 min x microM). Cysteamine infusion into the small intestine resulted in the most rapid rise to maximal plasma concentrations (t(max) = 21 +/- 0.56 min); t(max) was delayed to 50 +/- 26 min and 64 +/- 26 min after gastric and caecal infusion, respectively. The maximum cysteamine plasma concentration (C(max)) was reached after infusion of the drug into the small intestine (51 +/- 21 microM), which was higher than plasma C(max) concentrations after gastric (39 +/- 16 microM) and caecal infusion (23 +/- 15 microM). CONCLUSIONS: The pharmacokinetic data generated help extend our understanding of cysteamine.

Understanding intestinal cysteamine bitartrate absorption.

OBJECTIVES: To test the hypothesis that a controlled-release preparation of cysteamine, with fewer daily administrations, would improve the quality of life for patients with cystinosis. STUDY DESIGN: A specifically designed nasoenteric tube was used to administer cysteamine directly into the stomach, small intestine (SI) and colon and serial plasma cysteamine, serum gastrin and leukocyte cystine levels were measured. RESULTS: Eight control subjects (mean age 23.2 years) and 6 subjects with cystinosis (mean age 15.2 years) were studied. Cysteamine absorption (maximum concentration and area under the curve of the concentration-time gradient) was greater from the SI than stomach or cecum (P < .01). Leukocyte cystine depletion was greater after delivery of cysteamine into the SI than stomach or cecum; this effect was associated with the plasma cysteamine maximum concentration and area under the curve (P < .001 and < .02, respectively). Gastrin levels were not affected by site of drug delivery and were elevated only in patients with cystinosis with gastrointestinal symptoms. CONCLUSIONS: The absorption of cysteamine and the effect of this agent on leukocyte cystine depletion are more profound after SI administration. Enteric-coated cysteamine, targeted for SI release, may require fewer daily dosages. Not all patients with cystinosis require acid-suppression therapy.

Hypoxia-inducible factor 1-alpha reduces infarction and attenuates progression of cardiac dysfunction after myocardial infarction in the mouse.

OBJECTIVES: The aim of this research was to test whether constitutive expression of hypoxia-inducible factor 1-alpha (HIF-1alpha) influences infarction size and cardiac performance after myocardial infarction. BACKGROUND: A major question in clinical medicine is whether infarction size and border zone remodeling of the heart can be influenced by the overexpression of specific genes in the peri-infarction region. METHODS: We investigated the role of constitutive HIF-1alpha expression in acute myocardial infarction using a transgenic model. Transgenic mice containing the HIF-1alpha gene under the control of the alpha-myosin heavy chain promoter were constructed. Myocardial infarction was produced by coronary ligation in HIF-1alpha transgenic mice and control animals. Extent of infarction was then quantitated by two-dimensional and M-mode echocardiography as well as by molecular and pathologic analysis of heart samples in infarct, peri-infarct, and remote heart regions at serial time points. RESULTS: Constitutive overexpression of HIF-1alpha in the murine heart resulted in attenuated infarct size and improved cardiac function 4 weeks after myocardial infarction. Significantly, we found an increase in both capillary density as well as vascular endothelial growth factor and inducible nitric oxide synthase expression in peri-infarct and infarct regions in the hearts of constitutive HIF-1alpha-expressing animals compared to control animals. CONCLUSIONS: These observations suggest the involvement of HIF-1alpha in myocardial remodeling and peri-infarct vascularization. Our results show that supranormal amounts of this peptide protect against extension of infarction and improve border zone survival in myocardial infarction.

Esomeprazole therapy for gastric acid hypersecretion in children with cystinosis.

Oral cysteamine therapy prevents natural disease progression in children with cystinosis, but it may cause severe gastrointestinal (GI) symptoms through gastric acid-hypersecretion. The purpose of this study was to assess the value of esomeprazole in controlling cysteamine-induced acid-hypersecretion and GI symptoms in children with cystinosis. Subjects underwent upper GI endoscopy and biopsy, serum gastrin and cysteamine measurements as well as acid secretion studies (basal, maximal and peak acid output, BAO, MAO, PAO) before and during esomeprazole therapy. A symptom score (maximum 14 points) was devised to monitor symptoms. Twelve children (mean age 5.8 years) were studied. Cysteamine ingestion resulted in mean MAO and PAO significantly higher than mean BAO, both before and during esomeprazole therapy. PAO was usually within 60 min of cysteamine ingestion. Esomeprazole therapy significantly reduced MAO (P<0.01) and PAO (P<0.01). The mean symptom score fell from 6.4 to 0.7 (P<0.0001) during esomeprazole therapy. The mean final dose of esomeprazole was 1.7 mg/kg per day (range 0.7 mg/kg per day to 2.75 mg/kg per day). Plasma cysteamine levels were not affected by acid-suppression therapy. One child had multi-nucleated parietal cells. Cysteamine-induced gastric acid-hypersecretion and GI symptoms are dramatically reduced with esomeprazole therapy. Esomeprazole does not alter cysteamine absorption and is very well tolerated in children.

Fcgamma receptor type IIIA polymorphisms influence treatment outcomes in patients with inflammatory arthritis treated with tumor necrosis factor alpha-blocking agents.

OBJECTIVE: To determine whether polymorphisms in Fcgamma receptor type IIIA (FcgammaRIIIA) correlate with clinical efficacy in patients with rheumatoid arthritis (RA) and patients with psoriatic arthritis (PsA) being treated with tumor necrosis factor alpha (TNFalpha) inhibitors. METHODS: The study group comprised 30 patients with RA and 5 patients with PsA. Patients were classified as being very good responders (n = 23) or nonresponders (n = 12) to therapy with TNF blocking agents. Whole blood was obtained from all patients, and DNA was extracted for FcgammaRIIIA analysis. The FcgammaRIIIA-158 polymorphism was determined using an allele-specific polymerase chain reaction assay. RESULTS: The distribution of FcgammaRIIIA-158 genotypes was as follows: for F homozygous (F/F), 31.5%; for V homozygous (V/V), 11.5%; and for V/F heterozygous (V/F), 57%. Among very good responders, the distribution of alleles was as follows: for F/F, 48%; for V/V, 13%; and for V/F, 39%. Among nonresponders, the distribution of alleles was as follows: for F/F, 0%; for V/V, 8%; and for V/F, 92%. The low-affinity F/F homozygous genotype was found to be significantly associated with response to TNF inhibitor therapy (P < 0.01 by Fisher's exact test). CONCLUSION: These results suggest that FcgammaRIIIA-158 polymorphisms may affect the outcome of treatment with TNF blocking agents. Better understanding of the factors affecting responses to these agents could result in improved outcomes of treatment.

Histopathology of pediatric nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are common in children and adolescents. However, standard histological criteria for pediatric NAFLD and NASH are undeveloped. We reviewed consecutive patients ages 2 to 18 years with biopsy-proven NAFLD diagnosed between 1997 and 2003. Biopsies were evaluated by two pathologists for individual features of steatohepatitis. Agglomerative hierarchical cluster analysis demonstrated two different forms of steatohepatitis. Type 1 was characterized by steatosis, ballooning degeneration, and perisinusoidal fibrosis; type 2 was characterized by steatosis, portal inflammation, and portal fibrosis. The study included 100 children with NAFLD. Simple steatosis was present in 16% of subjects, and advanced fibrosis was present in 8%. Type 1 NASH was present in 17% of subjects, and type 2 NASH was present in 51%. Boys were significantly (P < .01) more likely to have type 2 NASH and less likely to have type 1 NASH than girls. The NASH type differed significantly (P < .001) by race and ethnicity. Type 1 NASH was more common in white children, whereas type 2 NASH was more common in children of Asian, Native American, and Hispanic ethnicity. In cases of advanced fibrosis, the pattern was generally that of type 2 NASH. In conclusion, type 1 and type 2 NASH are distinct subtypes of pediatric NAFLD, and type 2 is the most common pattern in children. NASH subtypes should be considered when interpreting liver biopsies and planning studies of the pathophysiology, genetics, natural history, or response to treatment in pediatric NAFLD.

Rapid foot and calf compression increases walking distance in patients with intermittent claudication: results of a randomized study.

OBJECTIVE: The aim of our pilot study was to determine the usefulness of rapid, high-pressure, intermittent pneumatic calf and foot compression (IPCFC) in patients with stable intermittent claudication, with reference to the end points of improvement in initial claudication distance (ICD) (distance at which patient feels pain or discomfort in the legs), and improvement in absolute claudication distance (ACD) (distance at which patient stops walking because the pain or discomfort becomes severe). METHODS: Thirty male patients presenting with stable, intermittent claudication (ACD between 50 and 150 meters on treadmill testing at 3.8 km/h, 10 degrees gradient) were recruited into this pilot study from a single center. Fifteen patients were randomized to treatment with IPCFC (applied for 1 hour twice daily in the sitting position) and were also advised to have daily exercise, and 15 patients served as controls, who were advised exercise alone. All patients received aspirin and had resting and postexercise ankle/brachial index (ABI) measured at enrollment along with ICD and ACD on treadmill testing (3.8 km/h, 10 degrees gradient). The mean age, baseline ICD, and ACD of the treatment and control groups were 70.4 +/- 7 years and 70.7 +/- 9 years, 55.8 +/- 15 meters and 68.4 +/- 17 meters, and 86.7 +/- 19 meters and 103.9 +/- 27 meters, respectively. Both groups were equally matched for risk factors, including smoking, type II diabetes mellitus, and hypercholesterolemia. IPCFC was applied. The study protocol included follow-up visits at 1, 2, 3, 4, 6, and 12 months with the ABI, ICD and ACD being measured at every visit. RESULTS: The percent change from baseline for ICD and ACD for each patient visit and the mean +/- standard deviation (SD), standard error (SE), and median were calculated for the control and treatment groups. The percent change from baseline measurements (mean +/- SD) for ICD and ACD in the control group at 4, 6, and 12 months were 2.2 +/- 18 and 2.3 +/- 18, 2.9 +/- 17 and 5.2 +/- 20, and 3.6 +/- 18 and 5.8 +/- 20, respectively. In contrast, the changes in ICD and ACD at 4, 6, and 12 months in the treatment group were 137.1 +/- 128 (P < .01) and 84.3 +/- 82 (P < .01), 140.6 +/- 127 (P < .01) and 96.4 +/- 106 (P = .01), and 150.8 +/- 124 (P <0.01) and 101.2 +/- 104 (P <0.01), respectively. Although the ABI showed a slight increase in the treatment group, these differences were not statistically significant. CONCLUSIONS: The results of this pilot study show that IPCFC improves walking distance in patients with stable intermittent claudication. A significant increase in ICD and ACD was seen at 4 and 6 months of treatment, respectively, and the improvement was sustained at 1 year. The combination of IPCFC with other treatment such as risk-factor modification and daily exercise may prove useful in patients with peripheral arterial occlusive disease. It may be a useful first line of therapy in patients with disabling claudication who are unfit for major reconstructive surgery. Improved walking on long-term follow-up and experience from different centers may establish a role for this treatment modality in the future.

Gene transfer of a TIE2 receptor antagonist prevents pulmonary hypertension in rodents.

OBJECTIVES: Overexpression of angiopoietin 1 in the lung has been associated with human pulmonary hypertension. We hypothesized that inhibiting angiopoietin 1 signaling in the lung by administration of a receptor antagonist would block the development of pulmonary hypertensive vasculopathy in rodent models. METHODS: We injected 2 and 4 x 10(10) genomic particles of adeno-associated virus containing an extracellular fragment of the TIE2 receptor (AAV-sTIE2) into the pulmonary artery of 60 rats by using adeno-associated virus-lacZ and carrier-injected rats as control animals. Pulmonary hypertension was then induced by each of the following methods: (1) monocrotaline (group 1); (2) angiopoietin 1 expression in pulmonary vascular smooth muscle by adeno-associated virus gene transfer (group 2); or (3) oxygen deprivation (group 3). Animals were sacrificed at serial time points. At each time point, pulmonary artery pressures were measured, and pulmonary angiography was performed. Lungs were harvested for pathologic-molecular analysis. RESULTS: Each rodent pulmonary hypertension model demonstrated a significant increase in pulmonary artery pressures compared with that seen in control animals (P < .01). Administration of AAV-sTIE2 prevented pulmonary hypertension in the monocrotaline and angiopoietin 1 groups (from 44.6 +/- 2.1 to 18.8 +/- 1.9 mm Hg in the monocrotaline group and from 31.2 +/- 3.7 to 18.2 +/- 1.8 mm Hg in the angiopoietin 1 group, P < .001) but did not affect pulmonary hypertension in the hypoxia group. Pathologic analysis of group 1 and 2 lungs treated with AAV-sTIE2 demonstrated absence of smooth muscle cell proliferation within arterioles. Pulmonary angiography confirmed a lack of small pulmonary vessel occlusion in group 1 and 2 animals treated with AAV-sTIE2. CONCLUSIONS: Molecular blocking of the interaction between angiopoietin 1 and its endothelial receptor, TIE2, in the lung prevents pulmonary hypertension in 2 animal models of the disease. These experiments suggest a new strategy for understanding pulmonary hypertension based on the molecular biology of the pulmonary vascular wall.

Relationship of GnRH-stimulated LH release to episodic LH secretion and baseline endocrine-metabolic measures in women with polycystic ovary syndrome.

BACKGROUND AND OBJECTIVE: In polycystic ovary syndrome (PCOS) inappropriate gonadotrophin secretion is characterized by increased pulse frequency and amplitude, elevated 24-h mean serum concentrations, and greater responses to GnRH. While the mechanism(s) responsible for this increased release of LH are not well understood, enhanced LH secretion has been attributed to increased pituitary sensitivity to GnRH and feedback influences from circulating steroid hormones. To address these considerations, we conducted a study to examine the relationships between GnRH-stimulated LH responses, episodic gonadotrophin secretion, and baseline measurements of endocrine-metabolic function in PCOS. PATIENTS: Serum LH responses to sequential multidose GnRH administration and pulsatile gonadotrophin secretion were examined in 13 PCOS and 13 normal women. MEASUREMENTS: Serum LH, steroid hormone, insulin and glucose levels were determined in blood samples obtained during assessment of episodic gonadotrophin secretion and LH responses to GnRH stimulation. DESIGN: Each subject was studied on two consecutive days. On study day 1 each subject underwent frequent blood sampling every 10 min for 12 h. On study day 2 each received sequential doses of GnRH, 2 microg, 10 microg and 20 microg, administered intravenously at 4-h intervals over a continuous 12-h period. RESULTS: Serum LH responses following GnRH were markedly greater in PCOS compared to normal women, as expected. In individual PCOS, peak LH responses to GnRH were significantly correlated with corresponding basal LH and LH pulse amplitude, but not LH pulse frequency. In the PCOS group, LH responses were positively correlated with serum oestradiol (E2) and inversely related to body mass index (BMI). Between-group differences in LH responsiveness disappeared when controlling for serum testosterone (T) levels. CONCLUSIONS: These results indicate that the absolute LH increment following GnRH is largely dependent on baseline LH levels and may account for the well-documented difference in LH responsiveness between PCOS and normal women. That neither LH responses to GnRH nor LH pulse amplitude were correlated to LH pulse frequency suggests involvement of other factors along with GnRH to account for increased LH secretion in PCOS. In addition to E2 and BMI, serum testosterone appears to be, at least in part, responsible for differences in LH secretion and release between PCOS and normal women.

Obesity, insulin resistance, and other clinicopathological correlates of pediatric nonalcoholic fatty liver disease.

OBJECTIVE: To describe the clinical characteristics of nonalcoholic fatty liver disease (NAFLD) in children, including insulin resistance, and to test for correlation with liver pathology. STUDY DESIGN: A retrospective review of children with biopsy-proven NAFLD at Children's Hospital San Diego from 1999 to 2002. Liver biopsy specimens were independently reviewed by two pathologists. RESULTS: Children with NAFLD (n=43) were mostly male (70%), Hispanic American (53%) and obese (88%). The criteria for insulin resistance were met by 95% of subjects. Steatosis was predicted by the combination of quantitative insulin sensitivity check index, age, and ethnicity (P<.0001). Portal inflammation was predicted by the combination of ALT and fasting insulin (P=.0009). Perisinusoidal fibrosis was predicted by the combination of AST, fasting insulin, and BMI Z score (P<.0001). Portal fibrosis was predicted by the combination of right upper quadrant pain and homeostasis model assessment of insulin resistance (P=.0028). CONCLUSIONS: We identified significant predictors of liver pathology in children with NAFLD. Children being evaluated for NAFLD should be screened for insulin resistance, which is nearly universal and correlates with liver histology.

The evaluation and treatment of gastrointestinal disease in children with cystinosis receiving cysteamine.

OBJECTIVES: Cysteamine prevents organ damage in children with cystinosis, but may cause gastrointestinal (GI) symptoms. In this study we evaluated the nature of GI disease, and the value of omeprazole in controlling GI symptoms in these children. STUDY DESIGN: Upper GI disease was evaluated with endoscopy, gastrin levels, and acid secretion studies after oral administration of cysteamine, before and after 16 weeks of therapy with omeprazole. A symptom score was devised. RESULTS: Eleven children (mean age, 5.7 years) were studied. After cysteamine ingestion, before and after omeprazole therapy, the mean maximum acid output was significantly higher than the mean basal acid output. The maximum acid output was measured within 60 minutes of cysteamine ingestion and was reduced by omeprazole therapy (P<.01). The mean peak gastrin level was 30 minutes postcysteamine and was higher than baseline (P<.01). The initial mean symptom score (maximum score, 14) was 6.9 and fell to 0.7 (P<.0001) after 16 weeks of omeprazole therapy. At endoscopy, two children had diffuse gastric nodularity, and nearly all had cystine crystal deposits. CONCLUSIONS: GI symptoms in children with cystinosis receiving cysteamine are often acid-mediated and improve with omeprazole. Cystine crystals were detected in the GI tract and may signify inadequate treatment with cysteamine.