Interaction Effects between HIV and Aging on Selective Neurocognitive Impairment

HIV infection and aging are each associated with neurocognitive impairment (NCI). This study examined the combined effects of HIV infection and aging on NCI. We performed a cross-sectional survey among 345 HIV-infected and 345 HIV-uninfected participants aged at least 40 years. The International HIV Dementia Scale (IHDS) and Chinese version of Mini-mental State Examination (MMSE) were administered to screen for NCI. HIV-infected individuals had higher prevalence of NCI than uninfected individuals (46.7% vs 15.1% for IHDS using cut-off of ≤ 10; 17.1% vs 2.6% for MMSE). Significant main effects of HIV and age were observed on IHDS and MMSE composite scores and all domains except for HIV on attention and calculation. Significant interaction effects between HIV and age were observed on motor speed, orientation, registration and recall, and mainly attributed to the inferior performance of HIV-infected patients aged over 60 years. Among HIV-infected individuals, in multivariable logistic models, older age, depressive symptoms and history of nevirapine treatment were associated with NCI using both IHDS and MMSE, whereas lower education current smoker and current CD4 ≥ 800 cells/μL were associated only with NCI using IHDS, and hypertension was associated only with NCI using MMSE. Findings suggest that HIV and older age may confer interactive effects on cognitive function in several domains with older HIV-infected adults experiencing greater NCI, which requires further longitudinal investigation. Furthermore, HIV early diagnosis and treatment may prevent or reverse NCI, but extra attention should be given to adverse effects including metabolic changes associated with long-term treatment.     

Applications and Limitations of Inflammatory Biomarkers for Studies on Neurocognitive Impairment in HIV Infection

Despite reduced prevalence of severe forms of HIV-associated neurocognitive disorders (HAND) on current antiretroviral therapy (ART) regimens, milder forms of neurocognitive impairment (NCI) remain prevalent in HIV-infected populations. These mild forms of HAND consist of subtypes, probably reflecting distinct, though possibly overlapping, pathophysiological mechanisms. Factors associated with HAND in HIV patients with prolonged viral suppression on ART include older age, low nadir CD4, active HCV co-infection, and cardiovascular risk factors, but underlying mechanisms and their relationship to innate immune activation, chronic inflammation, and other features of systemic disease are poorly understood. In this article, we discuss applications and limitations of plasma inflammatory biomarkers for studies on HAND in HIV patients on ART and describe an analysis pipeline to reduce common sources of noise and increase likelihood of identifying relevant inflammatory biomarkers. Clinical covariates and comorbidities that influence inflammatory biomarkers, such as aging, obesity, metabolic abnormalities, HCV co-infection, and substance abuse, are also reviewed. As an example for using this analytic pipeline, we present an exploratory study of 22 plasma inflammatory biomarkers (IFN-α 2b and -γ, 16 cytokines/chemokines, sIL-2R, sCD14, HA, and YKL-40) in a cohort of HIV-infected individuals with advanced disease, frequent HCV co-infection, and viral suppression on ART. The identification of inflammatory biomarkers associated with HAND in HIV+ patients on ART may be useful to distinguish between HAND subtypes with distinct pathophysiology, and is important for achieving a systems-level understanding of the biology of these disorders, developing effective therapies, and evaluating therapeutic outcomes.     

Chronic Tobacco-Smoking on Psychopathological Symptoms,Impulsivity and Cognitive Deficits in HIV-Infected Individuals

HIV-infected individuals (HIV+) has 2–3 times the rate of tobacco smoking than the general population, and whether smoking may lead to greater psychiatric symptoms or cognitive deficits remains unclear. We evaluated the independent and combined effects of being HIV+ and chronic tobacco-smoking on impulsivity, psychopathological symptoms and cognition. 104 participants [27 seronegative (SN)-non-Smokers, 26 SN-Smokers, 29 HIV+ non-Smokers, 22 HIV+ Smokers] were assessed for psychopathology symptoms (Symptom Checklist-90, SCL-90), depressive symptoms (Center for Epidemiologic Studies-Depression Scale, CES-D), impulsivity (Barratt Impulsiveness Scale, BIS), decision-making (The Iowa Gambling Task, IGT, and Wisconsin Card Sorting Test, WCST), and cognition (seven neurocognitive domains). Both HIV+ and Smoker groups had higher SCL-90 and CES-D scores, with highest scores in HIV+ Smokers. On BIS, both HIV+ and Smokers had higher Total Impulsiveness scores, with higher behavioral impulsivity in Smokers, highest in HIV+ Smokers. Furthermore, across the four groups, HIV+ Smokers lost most money and made fewest advantageous choices on the IGT, and had highest percent errors on WCST. Lastly, HIV+ had lower z-scores on all cognitive domains, with the lowest scores in HIV+ Smokers. These findings suggest that HIV-infection and chronic tobacco smoking may lead to additive deleterious effects on impulsivity, psychopathological (especially depressive) symptoms and cognitive dysfunction. Although greater impulsivity may be premorbid in HIV+ and Smokers, the lack of benefits of nicotine in chronic Smokers on attention and psychopathology, especially those with HIV-infection, may be due to the negative effects of chronic smoking on dopaminergic and cardio-neurovascular systems. Tobacco smoking may contribute to psychopathology and neurocognitive disorders in HIV+ individuals.     

Altered Associations between Pain Symptoms and Brain Morphometry in the Pain Matrix of HIV-Seropositive Individuals

Pain remains highly prevalent in HIV-seropositive (HIV+) patients despite their well-suppressed viremia with combined antiretroviral therapy. Investigating brain abnormalities within the pain matrix, and in relation to pain symptoms, in HIV+ participants may provide objective biomarkers and insights regarding their pain symptoms. We used Patient-Reported Outcome Measurement Information System (PROMIS®) pain questionnaire to evaluate pain symptoms (pain intensity, pain interference and pain behavior), and structural MRI to assess brain morphometry using FreeSurfer (cortical area, cortical thickness and subcortical volumes were evaluated in 12 regions within the pain matrix). Compared to seronegative (SN) controls, HIV+ participants had smaller surface areas in prefrontal pars triangularis (right: p = 0.04, left: p = 0.007) and right anterior cingulate cortex (p = 0.03) and smaller subcortical regions (thalamus: p ≤ 0.003 bilaterally; right putamen: p = 0.01), as well as higher pain scores (pain intensity-p = 0.005; pain interference-p = 0.008; pain-behavior-p = 0.04). Furthermore, higher pain scores were associated with larger cortical areas, thinner cortices and larger subcortical volumes in HIV+ participants; but smaller cortical areas, thicker cortices and smaller subcortical volumes in SN controls (interaction-p = 0.009 to p = 0.04). These group differences in the pain-associated brain abnormalities suggest that HIV+ individuals have abnormal pain responses. Since these abnormal pain-associated brain regions belong to the affective component of the pain matrix, affective symptoms may influence pain perception in HIV+ patients and should be treated along with their physical pain symptoms. Lastly, associations of lower pain scores with better physical or mental health scores, regardless of HIV-serostatus (p < 0.001), suggest adequate pain treatment would lead to better quality of life in all participants.     

Blood Brain Barrier Impairment in HIV-Positive Naïve and Effectively Treated Patients: Immune Activation Versus Astrocytosis

Blood brain barrier (BBB) damage is a common feature in central nervous system infections by HIV and it may persist despite effective antiretroviral therapy. Astrocyte involvement has not been studied in this setting. Patients were enrolled in an ongoing prospective study and subjects with central nervous system-affecting disorders were excluded. Patients were divided into two groups: treated subjects with cerebrospinal fluid (CSF) HIV RNA <50 copies/mL (CSF-controllers) and in late-presenters CD4+ T lymphocytes <100/uL. CSF biomarkers of neuronal or astrocyte damage were measured and compared to CSF serum-to-albumin ratio. 134 patients were included; 67 subjects in each group (50 %) with similar demographic characteristics (with the exception of older age in CSF controllers). CD4 (cells/uL), plasma and CSF HIV RNA (Log₁₀ copies/mL) were 43 (20-96), 5.6 (5.2-6) and 3.9 (3.2-4.7) in LPs and 439 (245-615), <1.69 (9 patients <2.6) and <1.69 in CSFc. BBB impairment was observed in 17 late-presenters (25.4 %) and in 9 CSF-controllers (13.4 %). CSF biomarkers were similar but for higher CSF neopterin values in late-presenters (2.3 vs. 0.6 ng/mL, p?<?0.001). CSARs were associated with CSF neopterin (rho?=?0.31, p?=?0.03) and HIV RNA (rho?=?0.24, p?=?0.05) in late-presenters and with CSF tau (rho?=?0.51, p?<?0.001), p-tau (rho?=?0.47, p?<?0.001) and S100beta (rho?=?0.33, p?=?0.009) in CSF-controllers. In HAART-treated subjects with suppressed CSF HIV RNA, BBB altered permeability was associated with markers of neuronal damage and astrocytosis. Additional treatment targeting astrocytosis and/or viral protein production might be needed in order to reduce HIV effects in the central nervous system.     

Geographic location of antiretroviral clinical trials in HIV infected pediatric patients

Background Some medicines regulatory authorities are encouraging research in pediatrics. However, children are a vulnerable population, and previous studies have suggested that research is increasingly being conducted outside of developed countries. Objective The purpose of this study is to determine the location of trials in the pediatric population with human immunodeficiency virus (HIV). Setting Not applicable. Methods Clinical trials registered in the largest international clinical trials registry (clinicaltrials.gov) evaluating antiretrovirals in pediatric HIV infected patients were included. Data were collected on the location, funding, study purpose, design, initiation date, age of subjects, and medication classes tested. Main outcome measures We assessed frequencies of characteristics of pediatric HIV trials registered in the clinicaltrials.gov database. Results Overall, 288 studies were included in the analysis. Most trials were conducted in ages 12–17 years (83 %), followed by studies in those <6 years (25 %) and 6–11 years (21 %). The location of most trials included at least one site in developed countries (83 %). The number of trials completed exclusively in developing countries increased from 1989 to 2011. Conclusions The majority of pediatric antiretroviral trials registered in clinicaltrials.gov were conducted in adolescent subjects in developed countries. The number of pediatric HIV studies in developing countries increased while studies conducted in developed countries decreased similar to trends of HIV.     

Identifying Risk Factors for HIV-Associated Neurocognitive Disorders Using the International HIV Dementia Scale

HIV-associated neurocognitive disorders (HAND) persist despite great advancements in combination antiretroviral therapy (cART). The gold standard for diagnosing cognitive impairment consists of a time-consuming neuropsychological battery of tests given by a trained neuropsychologist, however in the outpatient HIV clinic this is not feasible. The International HIV Dementia Scale (IHDS) was developed to help identify individuals with cognitive impairment in the outpatient setting. The IHDS is moderately sensitive for detecting more symptomatic forms of HAND but sensitivity has been shown to be poor in mild impairment. The IHDS has not been evaluated in developed countries in large cohort populations. We conducted a prospective cross-sectional study of only HIV+ individuals in an urban clinic and evaluated the prevalence of HAND and associated risk factors for cognitive impairment using the IHDS. A total of 507 HIV+ individuals participated in the study of which the majority were male (65 %) and African American (68 %); and 41 % had cognitive impairment. On multivariate analysis, African American race (p?=?2.21), older age (p?=?1.03), high school education or less (p?=?2.03) and depression (p?=?1.05) were associated with cognitive impairment. The high prevalence of HAND in this group suggests that more severe forms of HAND persist despite cART. Identified risk factors were non-HIV-related and suggest that environmental and sociodemographic factors have a significant impact on cognitive functioning and should be given more attention. The IHDS should be further evaluated in large cohort HIV+ and HIV- populations in the United States, as there remains a significant need to identify an effective brief screening tool for cognitive impairment.     

Greater Than Age-Related Changes in Brain Diffusion of HIV Patients After 1 Year

Chronic infection with HIV is associated with neuroinflammation. Prior diffusion tensor imaging (DTI) studies demonstrated increased mean diffusion (MD) and decreased fractional anisotropy (FA) in the white matter (WM) and subcortical brain regions of HIV patients. The current study aims to detect whether there are greater than age-related brain changes in HIV patients after a 1-year follow-up period using DTI. Thirty-nine antiretroviral-stable HIV subjects and 32 HIV-seronegative (SN) controls were evaluated, with neuropsychological tests and DTI, at baseline and after 1 year. MD and FA in the genu and splenium of the corpus callosum and in six other subcortical and white matter regions were evaluated bilaterally. Compared to SN controls, HIV subjects had significantly higher MD in the frontal WM (p = 0.0104) and lower FA in the parietal WM (p = 0.006). After 1 year, HIV subjects showed increase in MD in frontal and parietal WM, putamen, and genu; HIV subjects also showed greater increased genu diffusion than SN controls (p = 0.005). Changes in global cognitive deficit score correlated with changes in MD in the genu and FA in the parietal and frontal WM and putamen (multiple regression, p = 0.0008). Lastly, normal age-dependent changes in frontal WM diffusion and FA in genu and putamen were not observed in HIV subjects. Since increased MD may reflect increased neuroinflammation, our findings suggest greater than normal age-related inflammatory changes in the genu of these HIV patients, which may contribute to the cognitive deficits. Measurements of MD in the genu may be useful for monitoring disease progression in HIV brain infection.     

APOE ��4 allele and CSF APOE on Cognition in HIV-Infected Subjects

The significance of the cerebrospinal fluid (CSF) Apolipoprotein E (APOE) level and whether it might have differential effects on brain function due to the presence of APOE ??4 allele(s) in HIV-infected patients are unknown. However, APOE ??4 allele has been associated with greater incidence of HIV-associated dementia and accelerated progression of HIV infection. Here, we show further evidence for the role of APOE ??4 in promoting cognitive impairment. We measured the APOE levels in the CSF of HIV-infected individuals. HIV+ subjects showed lower CSF APOE proteins than SN controls (?19%, p?=?0.03). While SN subjects with or without ??4 allele showed no difference in CSF APOE levels, ??4+ HIV+ subjects had similar levels to the SN subjects but higher levels than ??4? HIV+ subjects (+34%, p?=?0.01). Furthermore, while HIV+ subjects with ??2 or ??3 allele(s) showed a positive relationship between their CSF APOE levels and cognitive performance on the speed of processing domain (r?=?+0.35, p?=?0.05), ??4+ HIV+ subjects, in contrast, exhibited a negative relationship such that those with higher levels of CSF APOE(4) performed worse on the HIV Dementia Scale (r?=??0.61, p?=?0.02), had lower Global Cognitive Scores (r?=??0.57, p?=?0.03), and had poorer performance on tests involving learning (??4 allele x [APOE] interaction, p?=?0.01). Our findings also suggest that the relatively higher levels of CSF APOE in ??4+ HIV+ (having primarily APOE4 isoforms) may negatively impact the brain and lead to poorer cognitive outcomes, while those individuals without the ??4 allele (with primarily APOE2 or APOE3 isoforms) may show compensatory responses that lead to better cognitive performance.     

More Than Two HANDs to Tango

Developing a validated tool for the rapid and efficient assessment of cognitive functioning in HIV-infected patients in a typical outpatient clinical setting has been an unmet goal of HIV research since the recognition of the syndrome of HIV-associated dementia (HAD) nearly 20 years ago. In this issue of JNIP Cross et al. report the application of the International HIV Dementia Scale (IHDS) in a U.S.-based urban outpatient clinic to evaluate its utility as a substitute for the more time- and effort-demanding formalized testing criteria known as the Frascati criteria that was developed in 2007 to define the syndrome of HIV-associated neurocognitive disorders (HAND). In this study an unselected cohort of 507 individuals (68 % African American) that were assessed using the IHDS in a cross-sectional study revealed a 41 % prevalence of cognitive impairment (labeled ‘symptomatic HAND’) that was associated with African American race, older age, unemployment, education level, and depression. While the associations between cognitive impairment and older age, education, unemployment status and depression in HIV-infected patients are not surprising, the association with African American ancestry and cognitive impairment in the setting of HIV infection is a novel finding of this study. This commentary discusses several important issues raised by the study, including the pitfalls of assessing cognitive functioning with rapid screening tools, cognitive testing criteria, normative testing control groups, accounting for HAND co-morbidity factors, considerations for clinical trials assessing HAND, and selective population vulnerability to HAND.     

Time and Time Again: Temporal Processing Demands Implicate Perceptual and Gating Deficits in the HIV-1 Transgenic Rat

HIV-1-associated neurocognitive disorders (HAND) afflict up to 50 % of HIV-1+ individuals, despite the effectiveness of combination antiretroviral therapy (CART) in reducing the prevalence of more severe neurocognitive impairment. Alterations in brainstem auditory evoked potentials (BAEP), a measure of temporal processing, are one of the earliest neurological abnormalities of HIV-1-positive individuals. Prepulse inhibition (PPI) of the auditory startle response (ASR), a measure of sensorimotor gating, was studied in HIV-1 transgenic (Tg) rats, which express 7 of the 9 HIV-1 genes. Ovariectomized female Fischer HIV-1 Tg and control rats (ns?=?41–42) were tested for PPI at three test periods, with at least 2 months separating each test period, using auditory and visual prepulses, an auditory startle stimulus, and interstimulus intervals (ISI) ranging from 0 to 4000 msec. Auditory and visual prepulse trial blocks were presented in counterbalanced order. For both auditory and visual prepulses, HIV-1 Tg animals exhibited a flatter ISI function, which did not sharpen with age, as it did in controls. Over time, auditory prepulses precipitated a temporal shift in peak inhibition in HIV-1 Tg animals relative to controls, whereas with visual prepulses, both groups displayed peak inhibition at the 40 msec ISI. A lack of perceptual sharpening with age and a relative insensitivity to the temporal dimension of sensorimotor gating are evident in the HIV-1 Tg rat prior to clinical signs of wasting. Deficits in sensorimotor gating may not only provide an early subtle diagnostic marker of HAND, but may also afford a key target for development of potential therapeutics.     

Role of HIV in Amyloid Metabolism

HIV infection has changed from an acute devastating disease to a more chronic illness due to combination anti-retroviral treatment (cART). In the cART era, the life expectancy of HIV-infected (HIV+) individuals has increased. More HIV?+?individuals are aging with current projections suggesting that 50 % of HIV?+?individuals will be over 50 years old by 2015. With advancing age, HIV?+?individuals may be at increased risk of developing other potential neurodegenerative disorders [especially Alzheimer’s disease (AD)]. Pathology studies have shown that HIV increases intra and possibly extracellular amyloid beta (Aβ42), a hallmark of AD. We review the synthesis and clearance of Aβ42; the effects of HIV on the amyloid pathway; and contrast the impact of AD and HIV on Aβ42 metabolism. Biomarker studies (cerebrospinal fluid AB and amyloid imaging) in HIV?+?participants have shown mixed results. CSF Aβ42 has been shown to be either normal or diminished in with HIV associated neurocognitive disorders (HAND). Amyloid imaging using [¹¹C] PiB has also not demonstrated increased extracellular amyloid fibrillar deposits in HAND. We further demonstrate that Aβ42 deposition is not increased in older HIV?+?participants using [¹¹C] PiB amyloid imaging. Together, these results suggest that HIV and aging each independently affect Aβ42 deposition with no significant interaction present. Older HIV?+?individuals are probably not at increased risk for developing AD. However, future longitudinal studies of older HIV?+?individuals using multiple modalities (including the combination of CSF markers and amyloid imaging) are necessary for investigating the effects of HIV on Aβ42 metabolism.     

Elaborate ligand-based modeling reveals new human neutrophil elastase inhibitors

Human neutrophil elastase inhibitors (HNE-Is) have been recently implicated in inflammatory diseases. Accordingly, we applied a drug discovery workflow to unveil novel inhibitory HNE leads via combining pharmacophore modeling, quantitative structure–activity relationship (QSAR) analysis, and in silico screening. We employed the pharmacophoric models and associated QSAR equation to screen the National Cancer Institute (NCI) list of compounds. Virtual screening identified 14 novel leads from NCI compounds. The most potent hit 126 exhibited 93 % inhibition at 10 μM.     

Effect of atorvastatin on soluble CD14, CD40 Ligand, sE- and sP-selectins and MCP-1 in patients with type 2 diabetes mellitus: Relationship to cholesterol turnover

Metabolic abnormalities frequently associated with type 2 diabetes, feature besides endothelial dysfunction a novel factor of low cholesterol absorption and high cholesterol synthesis. We hypothesized an association between endothelial dysfunction and disturbances in cholesterol turnover, predisposing advanced atherosclerosis in patients with type 2 diabetes. We studied 75 patients: 30 with type 2 diabetes, 30 non-diabetic subjects with a history of cardiovascular disease, and 15 healthy subjects. Plasma sterols, soluble adhesion molecules sCD14, sCD40 Ligand, monocyte chemo-attractant protein-1 (MCP-1), sE- and sP-selectins were measured with and without atorvastatin therapy. The diabetic patients showed significantly higher levels of lathosterol and lower levels of sitosterol and campesterol. Non-diabetic subjects showed no significant differences in non-cholesterol based sterols. Plasma levels of hsCRP, sE- and sP-selectins and MCP-1 were significantly increased in patients with diabetes. The plasma levels of sCD40L correlate significantly with clinical parameters of BMI and glycaemia, and the plasma levels of sP-selectin correlate significantly with parameters of glycaemia and HbA(1c). The diabetic patients without statin therapy showed a significant correlation of sE-selectin with the marker of cholesterol absorption-sitosterol and sitosterol/cholesterol ratio. The diabetic patients without statin therapy showed a significant inverse correlation of sP-selectin with the marker of cholesterol synthesis-lathosterol. Both relationships disappeared with statin treatment. We conclude that endothelial dysfunction in obese patients with type 2 diabetes mellitus and cardiovascular disease associates with obesity and glycaemic control. The relation of parameters of endothelial dysfunction (such as sP-selectin and sE-selectin) with cholesterol synthesis and absorption may be influenced by reverse cholesterol transport.     

Independent and Combined Effects of Chronic HIV-Infection and Tobacco Smoking on Brain Microstructure

HIV-infected individuals (HIV+) have 2–3 times higher prevalence of tobacco smoking than the general U.S. population. This study aims to evaluate the independent and combined effects of tobacco-smoking and HIV-infection on brain microstructure and cognition using a 2?×?2 design. 21 HIV?+?Smokers, 25 HIV?+?Nonsmokers, 25 Seronegative (SN)-Smokers and 23 SN-Nonsmokers were evaluated using diffusion tensor imaging. Fractional anisotropy (FA), mean (MD), radial (RD) and axial (AD) diffusivity were assessed in 8 major cerebral fiber tracts and 5 subcortical regions. Cognitive performance in 7 neurocognitive domains was also assessed. Compared to SN, HIV+ had higher AD in genu of corpus callosum (GCC, p?=?0.002). Smokers also had higher diffusivities in GCC, splenium of corpus callosum (SCC), anterior corona radiata (ACR), sagittal stratum (SS) and superior fronto-occipital fasciculus (SFO), than Nonsmokers (p-values<0.001–0.003). Tobacco-Smoking and HIV-infection showed synergistic effects on AD_SS (p?=?0.002) and RD_SFO (p?=?0.02), but opposite effects in FA_putamen (p?=?0.024). Additive effects from HIV+ and Tobacco-Smoking were observed in 9 other white matter tracts, with highest diffusivities and lowest FA in HIV?+?Smokers. Higher diffusivities in the GCC, SCC, ACR and SS predicted poorer cognitive performance across all participants (p?≤?0.001). Higher AD_GCC also predicted slower Speed of information processing and poorer Fluency and Attention only in HIV?+?Smokers (p?=?0.001–0.003). Chronic tobacco smoking and HIV-infection appear to have additive and synergistic adverse effects on brain diffusivities, suggesting greater neuroinflammation, which may contribute to poorer cognition. Therefore, chronic tobacco-smoking may be a risk factor for HIV-associated neurocognitive disorders.

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Graphical Abstract ?

     

Differences in accuracy of offspring assessment based on parental smoking status

To investigate the accuracy of offspring assessments of parental smoking status, we studied 116 parents and 151 adult children (276 parent-child dyads) who provided data on both their own and their parents' smoking status. All currently smoking and all ex-smoking parents were correctly classified as ever-smokers by their offspring (n = 79 and 100, respectively). Of the 97 offspring who reported on never-smoking parents, 88 correctly classified their parents as never-smokers. Thus, sensitivity for detecting ever-smoking in parents was 100%, and specificity, 91%. Because all incorrect classifications involved never-smoking parents, further analyses focused on this group. Too few parents were misclassified to permit testing of parental characteristics. Offspring who misclassified their parents were significantly older than those who did not; neither sex nor smoking status of the offspring was associated with the increased likelihood of misclassification. No significant differences were discovered for dyadic factors (concordance/discordance for sex; parent-offspring age difference). Overall, these results support the utility of proxy reports of parental smoking phenotype by adult informants when self-report is unavailable.     

Development of simultaneous analysis for marker constituents in Hwangryunhaedok-tang (黄連解毒湯) and its application in commercial herbal formulas

This study was performed to develop methods for the chromatographic determination of biomarkers in Hwangryunhaedok-tang (HHT) and the quantitative evaluation of commercial HHT. To develop an analytical method, an RP-amide column (2.7 μm, 4.6 × 100 mm, Halo: Supelco, Bellefonte, PA) was used with a gradient solvent system of mixed acetonitrile and 0.1 % phosphoric acid/water and an ultra performance liquid chromatography-diode array detector. The method was validated by specificity, linearity, accuracy (recovery) and precision tests (repeatability, intra and inter-day). The correlation coefficients (R ²) of biomarkers were calculated as 0.9998–1.000 and their ranges were as follows: geniposide (62.5–1,000.0 μg/ml), berberine (31.3–500.0 mg/ml), palmatine (31.3–500.0 μg/ml), baicalin (125.0–1,500.0 μg/ml), baicalein (15.6–250.0 μg/ml) and wogonin (5.2–125.0 μg/ml), respectively. The limit of detection was 0.34–4.01 μg/ml, and the limit of quantification was 1.02–12.16 μg/ml. The intra-day and inter-day precision of six components were revealed as 0.02–2.48 % as a relative standard deviation (RSD). The repeatability value of biomarkers in three different concentrations of HHT was 0.29–2.98 % (RSD value) and recovery was 95.72–104.90 %. Among several extraction methods tested, biomarker content was higher with the 20 times extraction (20TE) and mixture of extract powder (MEP) methods than with any other method, and some differences among diverse pharmaceutical medicines were revealed. The validation data indicated that the method developed is suited to the determination of six marker compounds in HHT. The content of biomarkers by simultaneous analysis was evaluated in 20TE, MEP, USA formula and Taiwan formula.     

Oxidative Stress and the HIV-Infected Brain Proteome

Human immunodeficiency virus (HIV) is capable of infiltrating the brain and infecting brain cells. In the years following HIV infection, patients show signs of various levels of neurocognitive problems termed HIV-associated neurocognitive disorders (HAND). Although the introduction of highly active antiretroviral therapy (HAART) has reduced the incidence of HIV-dementia, which is the most severe form of HAND, the milder forms have become more prevalent today due to the increased life expectancy of infected individuals. Pre-HAART era markers such as HIV RNA level, CD4+ count, TNF-α, MCP-1 and M-CSF are not able to clearly distinguish mild from advanced HAND. One promising approach for new biomarker discovery is the identification and quantitation of proteins that are post-translationally modified by oxidative and nitrosative species. The occurrence of oxidative and nitrosative stress in HIV-infected brain, both through the early direct and indirect effects of viral proteins and through the later effect on mitochondrial integrity during apoptosis, is well-established. This review will focus on how the reactive species are produced in the brain after HIV infection, the specific oxidative and nitrosative species that are involved in the post-translational modification of the brain proteome, and the methods that are currently used for the detection of such modified proteins. This review also provides an overview of related research pertaining to oxidative stress-related HAND using cerebrospinal fluid and human brain tissue.     

霉酚酸酯对糖尿病大鼠肾小管-间质损伤的保护作用

目的观察免疫抑制剂霉酚酸酯(MMF)对糖尿病大鼠肾小管-间质单核细胞趋化蛋白-1(MCP-1)及CD68表达的影响,探讨MMF对糖尿病大鼠肾小管间质损伤的保护作用及机制。方法Wistar大鼠行右肾切除术2wk后,随机分为右肾切除对照组(NC)、糖尿病组(DM),霉酚酸酯治疗组(DM+MMF,MMF15mg·kg-1.d-1灌胃)。腹腔注射链脲佐菌素(STZ,65mg·kg-1)诱发糖尿病模型。检测各组8wk末的左肾重/体重比值、24h尿蛋白(Upro)、血糖(BG)、血肌酐(Scr),观察肾小管-间质形态学变化,免疫组化检测肾组织中MCP-1及CD68表达,RT-PCR测定肾组织中MCP-1 mRNA表达。结果与NC组相比,DM组大鼠血糖、Upro及左肾重/体重比值均上升(P<0.01);肾间质纤维化面积扩大(P<0.01);肾组织内MCP-1蛋白、CD68表达及MCP-1 mRNA的表达均上调(P<0.01)。DM+MMF组上述指标除BG和Scr外均被抑制(P<0.05或P<0.01)。结论MMF对糖尿病大鼠肾小管-间质损害具有明显的保护作用,可能与抑制MCP-1基因及蛋白表达有关。