The Structure of DNA within Cationic Lipid/DNA Complexes

The structure of DNA within CLDCs used for gene delivery is controversial. Previous studies using CD have been interpreted to indicate that the DNA is converted from normal B to C form in complexes. This investigation reexamines this interpretation using CD of model complexes, FTIR as well as Raman spectroscopy and molecular dynamics simulations to address this issue. CD spectra of supercoiled plasmid DNA undergo a significant loss of rotational strength in the signal near 275 nm upon interaction with either the cationic lipid dimethyldioctadecylammonium bromide or 1,2-dioleoyltrimethylammonium propane. This loss of rotational strength is shown, however, by both FTIR and Raman spectroscopy to occur within the parameters of the B-type conformation. Contributions of absorption flattening and differential scattering to the CD spectra of complexes are unable to account for the observed spectra. Model studies of the CD of complexes prepared from synthetic oligonucleotides of varying length suggest that significant reductions in rotational strength can occur within short stretches of DNA. Furthermore, some alteration in the hydrogen bonding of bases within CLDCs is indicated in the FTIR and Raman spectroscopy results. In addition, alterations in base stacking interactions as well as hydrogen bonding are suggested by molecular dynamics simulations. A global interpretation of all of the data suggests the DNA component of CLDCs remains in a variant B form in which base/base interactions are perturbed

Durability of Stavudine, Lamivudine and Nevirapine among Advanced HIV-1 Infected Patients with/without Prior Co-administration of Rifampicin: A 144-week Prospective Study

<p>Abstract</p> <p>Background</p> <p>To date, data on the durability of a regimen of stavudine, lamivudine and nevirapine are very limited, particularly from the resource-limited settings.</p> <p>Methods</p> <p>A prospective cohort study was conducted among 140 antiretroviral-naïve patients who were enrolled to initiate d4T, 3TC and NVP between November 2004 and March 2005. The objectives were to determine immunological and virological responses after 144 weeks of antiretroviral therapy. Seventy patients with tuberculosis also received rifampicin during the early period of antiviral treatment (TB group).</p> <p>Results</p> <p>Of all, median (IQR) baseline CD4 cell count was 31 (14–79) cells/mm³; median (IQR) baseline HIV-1 RNA was 433,500 (169,000–750,000) copies/mL. The average body weight was 55 kilograms. By intention-to-treat analysis at 144 weeks, the overall percentage of patients who achieved plasma HIV-1 RNA <50 copies/mL was 59.3% (83/140). In subgroup analysis, 61.4% (43/70) patients in TB group and 57.1% (40/70) patients in control group achieved plasma HIV-1 RNA <50 copies/mL (RR = 1.194, 95%CI = 0.608–2.346, <it>P </it>= 0.731). Eight (5.8%) patients discontinued d4T due to neuropathy and/or symptomatic lactic acidosis.</p> <p>Conclusion</p> <p>The overall durability and efficacy of antiviral response of d4T, 3TC and NVP are satisfied and they are not different between HIV-1 infected patients with and without co-administration of rifampicin due to tuberculosis. However, stavudine-related adverse effects are concerns.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Identifier NCT00703898</p

Viral hepatitis and HIV-associated tuberculosis: Risk factors and TB treatment outcomes in Thailand

<p>Abstract</p> <p>Background</p> <p>The occurrence of tuberculosis (TB), human immunodeficiency virus (HIV), and viral hepatitis infections in the same patient poses unique clinical and public health challenges, because medications to treat TB and HIV are hepatotoxic. We conducted an observational study to evaluate risk factors for HBsAg and/or anti-HCV reactivity and to assess differences in adverse events and TB treatment outcomes among HIV-infected TB patients.</p> <p>Methods</p> <p>Patients were evaluated at the beginning, during, and at the end of TB treatment. Blood samples were tested for aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (BR), complete blood count, and CD4+ T lymphocyte cell count. TB treatment outcomes were assessed at the end of TB treatment according to international guidelines.</p> <p>Results</p> <p>Of 769 enrolled patients, 752 (98%) had serologic testing performed for viral hepatitis: 70 (9%) were reactive for HBsAg, 237 (31%) for anti-HCV, and 472 (63%) non-reactive for both markers. At the beginning of TB treatment, 18 (26%) patients with HBsAg reactivity had elevated liver function tests compared with 69 (15%) patients non-reactive to any viral marker (p = 0.02). At the end of TB treatment, 493 (64%) were successfully treated. Factors independently associated with HBsAg reactivity included being a man who had sex with men (adjusted odds ratio [AOR], 2.1; 95% confidence interval [CI], 1.1–4.3) and having low TB knowledge (AOR, 1.8; CI, 1.0–3.0). Factors most strongly associated with anti-HCV reactivity were having injection drug use history (AOR, 12.8; CI, 7.0–23.2) and living in Bangkok (AOR, 15.8; CI, 9.4–26.5). The rate of clinical hepatitis and death during TB treatment was similar in patients HBsAg reactive, anti-HCV reactive, both HBsAg and anti-HCV reactive, and non-reactive to any viral marker.</p> <p>Conclusion</p> <p>Among HIV-infected TB patients living in Thailand, markers of viral hepatitis infection, particularly hepatitis C virus infection, were common and strongly associated with known behavioral risk factors. Viral hepatitis infection markers were not strongly associated with death or the development of clinical hepatitis during TB treatment.</p

Microscopic Analysis and Quality Assessment of Induced Sputum From Children With Pneumonia in the PERCH Study.

BACKGROUND.: It is standard practice for laboratories to assess the cellular quality of expectorated sputum specimens to check that they originated from the lower respiratory tract. The presence of low numbers of squamous epithelial cells (SECs) and high numbers of polymorphonuclear (PMN) cells are regarded as indicative of a lower respiratory tract specimen. However, these quality ratings have never been evaluated for induced sputum specimens from children with suspected pneumonia. METHODS.: We evaluated induced sputum Gram stain smears and cultures from hospitalized children aged 1-59 months enrolled in a large study of community-acquired pneumonia. We hypothesized that a specimen representative of the lower respiratory tract will contain smaller quantities of oropharyngeal flora and be more likely to have a predominance of potential pathogens compared to a specimen containing mainly saliva. The prevalence of potential pathogens cultured from induced sputum specimens and quantity of oropharyngeal flora were compared for different quantities of SECs and PMNs. RESULTS.: Of 3772 induced sputum specimens, 2608 (69%) had 25 PMNs per LPF, measures traditionally associated with specimens from the lower respiratory tract in adults. Using isolation of low quantities of oropharyngeal flora and higher prevalence of potential pathogens as markers of higher quality, 25 PMNs per LPF) was the microscopic variable most associated with high quality of induced sputum. CONCLUSIONS.: Quantity of SECs may be a useful quality measure of induced sputum from young children with pneumonia

The Diagnostic Utility of Induced Sputum Microscopy and Culture in Childhood Pneumonia.

BACKGROUND.: Sputum microscopy and culture are commonly used for diagnosing the cause of pneumonia in adults but are rarely performed in children due to difficulties in obtaining specimens. Induced sputum is occasionally used to investigate lower respiratory infections in children but has not been widely used in pneumonia etiology studies. METHODS.: We evaluated the diagnostic utility of induced sputum microscopy and culture in patients enrolled in the Pneumonia Etiology Research for Child Health (PERCH) study, a large study of community-acquired pneumonia in children aged 1-59 months. Comparisons were made between induced sputum samples from hospitalized children with radiographically confirmed pneumonia and children categorized as nonpneumonia (due to the absence of prespecified clinical and laboratory signs and absence of infiltrate on chest radiograph). RESULTS.: One induced sputum sample was available for analysis from 3772 (89.1%) of 4232 suspected pneumonia cases enrolled in PERCH. Of these, sputum from 2608 (69.1%) met the quality criterion of <10 squamous epithelial cells per low-power field, and 1162 (44.6%) had radiographic pneumonia. Induced sputum microscopy and culture results were not associated with radiographic pneumonia, regardless of prior antibiotic use, stratification by specific bacteria, or interpretative criteria used. CONCLUSIONS.: The findings of this study do not support the culture of induced sputum specimens as a diagnostic tool for pneumonia in young children as part of routine clinical practice

Detection of Pneumococcal DNA in Blood by Polymerase Chain Reaction for Diagnosing Pneumococcal Pneumonia in Young Children From Low- and Middle-Income Countries.

BACKGROUND.: We investigated the performance of polymerase chain reaction (PCR) on blood in the diagnosis of pneumococcal pneumonia among children from 7 low- and middle-income countries. METHODS.: We tested blood by PCR for the pneumococcal autolysin gene in children aged 1-59 months in the Pneumonia Etiology Research for Child Health (PERCH) study. Children had World Health Organization-defined severe or very severe pneumonia or were age-frequency-matched community controls. Additionally, we tested blood from general pediatric admissions in Kilifi, Kenya, a PERCH site. The proportion PCR-positive was compared among cases with microbiologically confirmed pneumococcal pneumonia (MCPP), cases without a confirmed bacterial infection (nonconfirmed), cases confirmed for nonpneumococcal bacteria, and controls. RESULTS.: In PERCH, 7.3% (n = 291/3995) of cases and 5.5% (n = 273/4987) of controls were blood pneumococcal PCR-positive (P < .001), compared with 64.3% (n = 36/56) of MCPP cases and 6.3% (n = 243/3832) of nonconfirmed cases (P < .001). Blood pneumococcal PCR positivity was higher in children from the 5 African countries (5.5%-11.5% among cases and 5.3%-10.2% among controls) than from the 2 Asian countries (1.3% and 1.0% among cases and 0.8% and 0.8% among controls). Among Kilifi general pediatric admissions, 3.9% (n = 274/6968) were PCR-positive, including 61.7% (n = 37/60) of those with positive blood cultures for pneumococcus. DISCUSSION.: The utility of pneumococcal PCR on blood for diagnosing childhood pneumococcal pneumonia in the 7 low- and middle-income countries studied is limited by poor specificity and by poor sensitivity among MCPP cases

The theoretical underpinnings of Internet addiction and its association with psychopathology in adolescence

This paper reviews the psychological and theoretical underpinnings that might help to explain the reported relationship between Internet addiction (IA) and psychopathology in both children and adolescents. Drawing on cognitive-behavioural models and social-skills theory, IA shows a strong relationship with depression, attention deficit hyperactivity disorder (ADHD) and time spent using the Internet use. Mixed findings are reported for social anxiety. Loneliness and hostility were also found to be associated with IA. Gender and age moderated these relationships with greater psychopathology generally reported among males and younger Internet users. This paper adds to the growing body of literature showing an association between IA and a range of mental health problems in both children and adolescents. A dependence on the Internet can potentially result in significant harm both socially and psychologically. While research has identified a potential pathway commencing with mental health problems and concluding with IA, few studies have examined the alternative direction and this may provide the impetus for future research endeavours. © 2017 Walter de Gruyter GmbH, Berlin/Boston

Neuropsychological assessment of 86-year-old man with Broca's aphasia complaining of memory difficulties

We report the clinical assessment of J.P., an 86 year-old man with Broca’s aphasia complaining of memory problems. Our aim was to objectively investigate his level of cognitive functioning using standardized neuropsychological tests in order to determine the nature of his memory impairment. J.P.’s medical history included left-middle cerebral artery (left-MCA) stroke, high frequency hearing loss, macular degeneration, and a recent hospitalization related to a fall. Results from his neuropsychological testing and from information gathered during the clinical interview with his wife suggested that a deficit in executive functioning might have been the source for some of his perceived memory problems. We were unable to detect any progressive cognitive decline that might have been suggestive of something more sinister. Despite his age J.P. was a fully functioning and highly contributing member of his society who was completing quite complex activities of daily living (ADLs). We provided J.P. with a compensatory set of strategies in order for him to circumvent his executive difficulties and impairment in expressive language. In the elderly population survivors of stroke are continuing to rise with improvements in drug treatment and primary care. This case study is important as it provides information on neuropsychological assessment in aphasia; and draws attention to valuable information in a client’s clinical history that might help clarify the prognosis. © 2017 Taylor & Francis Group, LLC

The theoretical underpinnings of Internet addiction and its association with psychopathology in adolescence

This paper reviews the psychological and theoretical underpinnings that might help to explain the reported relationship between Internet addiction (IA) and psychopathology in both children and adolescents. Drawing on cognitive-behavioural models and social-skills theory, IA shows a strong relationship with depression, attention deficit hyperactivity disorder (ADHD) and time spent using the Internet use. Mixed findings are reported for social anxiety. Loneliness and hostility were also found to be associated with IA. Gender and age moderated these relationships with greater psychopathology generally reported among males and younger Internet users. This paper adds to the growing body of literature showing an association between IA and a range of mental health problems in both children and adolescents. A dependence on the Internet can potentially result in significant harm both socially and psychologically. While research has identified a potential pathway commencing with mental health problems and concluding with IA, few studies have examined the alternative direction and this may provide the impetus for future research endeavours. © 2017 Walter de Gruyter GmbH, Berlin/Boston

Neuropsychological assessment of 86-year-old man with Broca's aphasia complaining of memory difficulties

We report the clinical assessment of J.P., an 86 year-old man with Broca’s aphasia complaining of memory problems. Our aim was to objectively investigate his level of cognitive functioning using standardized neuropsychological tests in order to determine the nature of his memory impairment. J.P.’s medical history included left-middle cerebral artery (left-MCA) stroke, high frequency hearing loss, macular degeneration, and a recent hospitalization related to a fall. Results from his neuropsychological testing and from information gathered during the clinical interview with his wife suggested that a deficit in executive functioning might have been the source for some of his perceived memory problems. We were unable to detect any progressive cognitive decline that might have been suggestive of something more sinister. Despite his age J.P. was a fully functioning and highly contributing member of his society who was completing quite complex activities of daily living (ADLs). We provided J.P. with a compensatory set of strategies in order for him to circumvent his executive difficulties and impairment in expressive language. In the elderly population survivors of stroke are continuing to rise with improvements in drug treatment and primary care. This case study is important as it provides information on neuropsychological assessment in aphasia; and draws attention to valuable information in a client’s clinical history that might help clarify the prognosis. © 2017 Taylor & Francis Group, LLC