Identification of amino acids in herpes simplex virus DNA polymerase involved in substrate and drug recognition.

Herpes simplex virus (HSV) encodes a DNA polymerase that is similar in several respects to the replicative mammalian DNA polymerase alpha. Recently, these and other DNA polymerases have been shown to share several regions of protein sequence similarity. Despite these similarities, antiviral drugs that mimic natural polymerase substrates specifically inhibit herpesvirus DNA polymerases. To study amino acids involved in substrate and drug recognition, we have characterized and mapped altered drug sensitivity markers of nine HSV pol mutants and sequenced the relevant portions of these mutants. The mutations were found to occur within four relatively small regions. One such region, which we designate region A, has sequence similarity only to DNA polymerases that are sensitive to certain antiviral drugs. The other three regions contain sequences that are similar among various DNA polymerases. The multiple mutations occurring within two of these regions make it likely that the regions interact directly with drugs and substrates. Our results lead us to favor a model in which protein folding allows interactions among the four regions to form the substrate and drug binding sites.     

Poor prognosis of end-stage renal disease in systemic lupus erythematosus: a cohort of Chinese patients

We studied the clinical course of 26 systemic lupus erythematosus (SLE) patients who started regular dialysis at our hospital and whose stay exceeded a three-month duration in order to investigate the long-term prognosis in a Chinese cohort. Clinical and serological activities of lupus before and after dialysis were analysed. To compare the long-term survival rate, controls were set using 78 age-matched end-stage renal disease (ESRD) patients who did not have SLE or diabetes mellitus and entered the chronic dialysis program at a similar period with SLE dialysis patients. There was a significant decrease in clinical lupus activity after starting regular dialysis (P < 0.05); however, the serological activity remained the same. The five-and ten-year survival rates were significantly lower in the SLE patients (73 and 38% in the SLE group versus 95 and 88% in the non-SLE group, P < 0.05). SLE patients had a 4.3-times higher risk of death than non-SLE patients (P < 0.05, 95% confidence interval, 1.2-15.2). Also, the deceased SLE patients had persistent lower serum levels of complement 3. SLE patients with ESRD remain clinically quiescent despite persistent serological abnormalities and have a worse prognosis than other uremia patients in the Chinese population.     

Antiatherogenic effect of Pistacia lentiscus via GSH restoration and downregulation of CD36 mRNA expression

Pistacia lentiscus var. Chia (Anacardiaceae) grows almost exclusively on Chios Island, Greece, and gives a resinous exudate resin used for culinary purposes by Mediterranean people. We investigated the molecular mechanisms through which total polar extract of the resin inhibits oxidized low-density lipoprotein (oxLDL) cytotoxic effect on peripheral blood mononuclear cell (PBMC). Cells exposed to oxLDL underwent apoptosis and necrosis, dependent on the duration of exposure. When culturing cells with oxLDL and the polar extract concurrently, we observed inhibition of both the phenomena. Because under oxidative stress the pro-oxidant systems outbalance the antioxidant, potentially producing oxidative damage and ultimately leading to cell death, we measured the levels of intracellular antioxidant glutathione (GSH). Additionally, we measured CD36 expression, a class B scavenger receptor, on CD14-positive cells, as CD36 has been identified as the oxLDL receptor in macrophages and may play a pivotal role in atherosclerotic foam cell formation. oxLDL decreased GSH levels and upregulated CD36 expression. P. lentiscus extract restored GSH levels and downregulated CD36 expression, even at the mRNA level. In order to find out the biologically drastic constituents of the resin's polar extract, fractions derived from RP-HPLC analysis were examined for their antioxidant effect on oxidatively stressed PBMC. The triterpenoid fraction revealed remarkable increase in intracellular GSH. We suggest GSH restoration and downregulation of CD36 mRNA expression as the pathways via which P. lentiscus triterpenes exert antioxidant/antiatherogenic effect. Additionally, our results provide strong evidence of the resin's antiatherogenic effect; therefore it is credited with beneficial health aspects.     

Effects of mobile health on HIV risk reduction for men who have sex with men

ABSTRACT

Mobile health (M-Health) has become a novel method for HIV prevention and the effects need to be promoted. The study purpose was to exam how a smartphone application (app) reduces HIV risky behaviour in men who have sex with men (MSM). The Safe Behaviour and Screening (SBS) app was developed, and included five features: record, output, and resources connection; information provision; testing services; interaction; and online statistics. A random assignment was used. The experimental group used the SBS app for six months. The control group did not use any intervention. There were 130 participants in the experimental group, and 135 in the control group. The average age of all subjects was 27.38 (SD?=?5.56). Compared to the control group, the experimental group had significantly higher mean score of safe behaviour knowledge, motivation, and skills; percentage of condom use during anal intercourse; frequency of searching for testing resources and getting HIV and syphilis tests. The frequency of anal intercourse and recreational drug usage were significantly lower in the experimental group. The SBS app could decrease the HIV risky behaviour among MSM and be applied to HIV prevention and nursing intervention.     

Assessing culprit lesions and active complex lesions in patients with early acute myocardial infarction by multidetector computed tomography

BACKGROUND: Accurate, non-invasive characterization of culprit lesions in patients after acute myocardial infarction (AMI) remains challenging. In this prospective study, multidetector row computed tomography (MDCT) is used to assess culprit and active complex lesions in patients early after AMI. METHODS AND RESULTS: We enrolled 103 patients with first non ST-elevation AMI who underwent 64-slices MDCT and conventional coronary angiography (CCAG). The definition of culprit lesion, stable non-culprit lesions and non-culprit active complex lesions was based on the findings of CCAG. The lesions were analyzed with MDCT data. In culprit lesions (n=103), luminal artery stenosis, remodeling index, plaque area and burden were significantly higher than non-culprit lesions (n=129). Multivariate discriminant analysis showed that MDCT density could discriminate culprit from non-culprit lesions. Receiver-operator characteristic curve analysis identified the optimal cutoff value of lesion density for discrimination between culprit and non-culprit lesion as 49.6 Hounsfield units (HU); this value was associated with a sensitivity, specificity and accuracy of 88.4%, 87.4%, and 87.9%, respectively. The MDCT in the stable non-culprit lesions (81.8+/-15.5 HU) was significantly higher than that in culprit lesions or non-culprit active complex lesions (33.2+/-13.8 and 48.3+/-15.7 HU, p<0.001). CONCLUSIONS: MDCT can predict culprit lesions in patients early after AMI, and identify multiple complex lesions.     

Absolute lymphocyte count and risk of short-term infection in patients with immune thrombocytopenia

Patients with immune thrombocytopenia (ITP) may be at increased risk of infection because of the steroids and other immunosuppressive agents used in its treatment. This study aimed to identify events that are associated with infection within 6 months of diagnosis and the impact that infection has on survival. We retrospectively evaluated 239 patients (107 men, 132 women; median age 61 years) diagnosed between January 1997 and August 2011. Every patient received steroid treatment according to the platelet count and the extent of bleeding. Logistic regression analysis was used to identify risk factors associated with the development of infection within 6 months of ITP being diagnosed. Sixty-two patients (25.9 %) developed an infection within 6 months of diagnosis. Multivariate analysis revealed that a lower absolute lymphocyte count (ALC) at diagnosis (<1?×?10⁹/l) was an independent risk factor for infection (P?=?0.039; 95 % confidence interval, 1.033–3.599; odds ratio, 1.928). The time to infection event is significant shorter in those of low ALC, compared with those of higher ALC (P?=?0.032). Furthermore, the 1-year mortality rate after ITP diagnosis was significantly higher in those patients who developed an infection (P?=?0.001). ITP patients with a low absolute lymphocyte count at diagnosis have an increased risk of infection, and those who develop infections have lower 1-year survival.     

A “Bone Marrow Score” for Predicting Hematological Disease in Immunocompetent Patients With Fevers of Unknown Origin

Delayed diagnosis of hematological malignancies in immunocompetent patients with fever of unknown origin (FUO) remains an exhausting challenge for non-hematologist physicians. This retrospective cohort study aimed to establish a scoring system, “bone marrow (BM) score”, to identify FUO patients who require early bone marrow biopsy (BMB) to diagnose hematological disease.Two cohorts, comprising 85 (training) and 20 (validation) eligible immunocompetent patients, with FUOs diagnosed between January 1, 2006 and July 31, 2013, underwent BMBs and were enrolled in the study. Demographic, laboratory, imaging, diagnostic, and outcome data were collected and retrospectively analyzed. Factors associated with hematological etiologies diagnosed using BMBs in the training cohort were identified and scored according to the relative hazards. These were further validated using the validation cohort.For the training cohort, 29 of 85 (34.1%) patients had hematological etiologies diagnosed using BMB. Seven factors significantly predicted the diagnostic yield of hematological diseases in the BM and were scored, with the 6 points for leucoerythroblastic changes in peripheral blood smears, 5.5 for elevated ferritin level (>1000 ng/mL), 4 for splenomegaly, 2 for thrombocytopenia, 1.5 for each of elevated lactate dehydrogenase levels and anemia, and 1 for neutropenia. When the cut-off value of the scoring system was set to 6, its sensitivity and specificity to diagnose hematological diseases in the BM of immunocompetent FUO patients were 93% and 58%, respectively. For the validation cohort, 7 of 20 (35%) patients had hematological disease, and all had BM scores higher than the cut-off, with the sensitivity and specificity at 100% and 77%, respectively.As immunocompetent FUO patients with hematological disease have poor prognoses, the “BM score” is valuable for non-hematologist physicians to identify immunocompetent FUO patients requiring early BMB.     

Expression of protocadherin-γC4 protein in the rat brain

It has been proposed that the combinatorial expression of γ-protocadherins (Pcdh-γs) and other clustered protocadherins (Pcdhs) provides a code of molecular identity and individuality to neurons, which plays a major role in the establishment of specific synaptic connectivity and formation of neuronal circuits. Particular attention has been directed to the Pcdh-γ family, for which experimental evidence derived from Pcdh-γ-deficient mice shows that they are involved in dendrite self-avoidance, synapse development, dendritic arborization, spine maturation, and prevention of apoptosis of some neurons. Moreover, a triple-mutant mouse deficient in the three C-type members of the Pcdh-γ family (Pcdh-γC3, Pcdh-γC4, and Pcdh-γC5) shows a phenotype similar to the mouse deficient in whole Pcdh-γ family, indicating that the latter is largely due to the absence of C-type Pcdh-γs. The role of each individual C-type Pcdh-γ is not known. We have developed a specific antibody to Pcdh-γC4 to reveal the expression of this protein in the rat brain. The results show that although Pcdh-γC4 is expressed at higher levels in the embryo and earlier postnatal weeks, it is also expressed in the adult rat brain. Pcdh-γC4 is expressed in both neurons and astrocytes. In the adult brain, the regional distribution of Pcdh-γC4 immunoreactivity is similar to that of Pcdh-γC4 mRNA, being highest in the olfactory bulb, dentate gyrus, and cerebellum. Pcdh-γC4 forms puncta that are frequently apposed to glutamatergic and GABAergic synapses. They are also frequently associated with neuron-astrocyte contacts. The results provide new insights into the cell recognition function of Pcdh-γC4 in neurons and astrocytes.