Modification and optimization of PCR methods for detection of MIE region from human herpesvirus 5

Human herpesvirus 5 (HHV-5, formerly known as CMV) is a beta-herpesvirus widely spread within a population. Thus, HHV-5 infections are a serious matter of concern in a group of immunocompromised patients. The goal of the study was modification and optimization of conventional PCR method developed for the detection of HHV-5 DNA to the real-time variant (RTmPCR) and determination of analytical resolution of the modified methods. Thirty plasma samples were tested for the presence of HHV-5 DNA using the LightCycler system with two different methods--one with SYBR Green I fluorochrome method and second one using TaqMan fluorescent probes and a qualitative in-house gel-stained PCR assay using primers that amplify part of HHV-5 MIE gene. The analytical sensitivity of real-time PCR assay was tested using serial dilutions of HHV-5 DNA in range between 10(0) and 10(-6). For comparison typical end-point detected PCR for cytomegalovirus detection with the same DNA dilutions was made. The sensitivity of novel method was about 100-fold higher than older one. Both LightCycler assays detected HHV-5 DNA in 27 samples, also which were negative by the gel-stained PCR. Analysis of the available clinical and serological data associated with these samples suggested that the real-time results in all of these cases were true positive. The conclusion is that real-time PCR methods are more sensitive than the conventional PCR used in this study. The additional sensitivity was valuable for detection of patients with low-copy viremia. The high level of sensitivity, specificity, accuracy, and rapidity provided by the LightCycler instrument are favorable for the use of this system in the detection of HHV-5 DNA in clinical specimens.     

Towards malaria elimination in Savannakhet,Lao PDR: mathematical modelling driven strategy design

Background

The number of Plasmodium falciparum malaria cases around the world has decreased substantially over the last 15 years, but with the spread of resistance against anti-malarial drugs and insecticides, this decline may not continue. There is an urgent need to consider alternative, accelerated strategies to eliminate malaria in countries like Lao PDR, where there are a few remaining endemic areas. A deterministic compartmental modelling tool was used to develop an integrated strategy for P. falciparum elimination in the Savannakhet province of Lao PDR. The model was designed to include key aspects of malaria transmission and integrated control measures, along with a user-friendly interface.

Results

Universal coverage was the foundation of the integrated strategy, which took the form of the deployment of community health workers who provided universal access to early diagnosis, treatment and long-lasting insecticidal nets. Acceleration was included as the deployment of three monthly rounds of mass drug administration targeted towards high prevalence villages, with the addition of three monthly doses of the RTS,S vaccine delivered en masse to the same high prevalence sub-population. A booster dose of vaccine was added 1 year later. The surveillance-as-intervention component of the package involved the screening and treatment of individuals entering the simulated population.

Conclusions

In this modelling approach, the sequential introduction of a series of five available interventions in an integrated strategy was predicted to be sufficient to stop malaria transmission within a 3-year period. These interventions comprised universal access to early diagnosis and adequate treatment, improved access to long-lasting insecticidal nets, three monthly rounds of mass drug administration together with RTS,S vaccination followed by a booster dose of vaccine, and screening and treatment of imported cases.

     

Chilling stress effects on corpus allatum proliferation in the Hawaiian cockroach, Diploptera punctata: a role for ecdysteroids

Endocrine regulation of corpus allatum (CA) cell proliferation in response to chilling was studied in mated females of the Hawaiian cockroach, Diploptera punctata. Chilling alone, when applied 24 h post-mating, suppressed CA cell division, and elevated ecdysteroid levels in Diploptera's haemolymph. Application of 20-hydroxyecdysone (20E) at 24 h post-mating similarly suppressed CA cell division, but had no effects at 48 h or 72 h post-mating. Severance of the ventral nerve cord prior to chilling or to the application of 20E prevented suppression of CA cell division, indicating that the effects of either chilling or 20E application are mediated by the ventral nerve cord.     

Angiogenesis measured by expression of CD34 antigen in lymph nodes of patients with non-Hodgkin's lymphoma

Angiogenesis is important in development, maintenance and progression of haematological malignancies. Some clinical observations have indicated that in non-Hodgkin's lymphoma (nHL) tumour microvessel density (MVD) may correlate with tumour staging and outcome. The aim of the study was to examine relationship between MVD as a parameter of tumour angiogenesis measured by expression of CD34 and the grade of nHL histological malignancy as determined by REAL classification. 40 lymph node samples of patients with newly diagnosed nHL (17 women, 23 men; aged 48-70 yrs, median age 64 yrs; stage III and IV) and treated at the Department of Haematology, Wroc?aw Medical University in 1999-2002 were fixed in 10% buffered formalin and embedded in paraffin. In all the studied cases, sections were incubated with antibodies against CD34. The slides were stained with hematoxylin and eosin and evaluated histopathologically. Patients were divided into two groups according to histological malignancy: indolent nHL (19 patients) and aggressive nHL (21 patients). Mean MVD measured by expression of CD34 in aggressive and indolent nHL groups amounted to 19.45 +/- 11.24 vessels/0.375 mm2 and 21.7 +/- 12.4 vessels/0.375 mm2, respectively. Statistical analysis of microvessel staining demonstrated no correlation between tumour MVD and grade of histological malignancy in lymph nodes of nHL patients. Nevertheless, angiogenesis observed in nHL provides rationale for use of angiogenesis inhibitors in lymphoma therapy.     

Molecular basis of the differential sensitivity of nematode and mammalian muscle to the anthelmintic agent levamisole

Levamisole is an anthelmintic agent that exerts its therapeutic effect by acting as a full agonist of the nicotinic receptor (AChR) of nematode muscle. Its action at the mammalian muscle AChR has not been elucidated to date despite its wide use as an anthelmintic in humans and cattle. By single channel and macroscopic current recordings, we investigated the interaction of levamisole with the mammalian muscle AChR. Levamisole activates mammalian AChRs. However, single channel openings are briefer than those activated by acetylcholine (ACh) and do not appear in clusters at high concentrations. The peak current induced by levamisole is about 3% that activated by ACh. Thus, the anthelmintic acts as a weak agonist of the mammalian AChR. Levamisole also produces open channel blockade of the AChR. The apparent affinity for block (190 microm at -70 mV) is similar to that of the nematode AChR, suggesting that differences in channel activation kinetics govern the different sensitivity of nematode and mammalian muscle to anthelmintics. To identify the structural basis of this different sensitivity, we performed mutagenesis targeting residues in the alpha subunit that differ between vertebrates and nematodes. The replacement of the conserved alphaGly-153 with the homologous glutamic acid of nematode AChR significantly increases the efficacy of levamisole to activate channels. Channel activity takes place in clusters having two different kinetic modes. The kinetics of the high open probability mode are almost identical when the agonist is ACh or levamisole. It is concluded that alphaGly-153 is involved in the low efficacy of levamisole to activate mammalian muscle AChRs.     

Chemiluminescence quenching of pteroic acid-N-sulfonyl-acridinium-9-carboxamide conjugates by folate binding protein

N(10)-Trifluoroacetylpteroic acid was conjugated to chemiluminescent N-sulfonylacridinium-9-carboxamide labels at the N(10) or 9-position carboxamide. Upon binding to folate binding protein the light output of the N(10) derivative (9) was quenched up to 62% upon triggering with basic peroxide, while the 9-position carboxamide conjugate (7) was quenched only 12%. The utility of this effect was demonstrated in a model homogeneous chemiluminescent assay for folic acid.     

Synthesis, biological, and chiroptical activity of 3-phenyl-clavams

The [2+2]cycloaddition of chlorosulfonyl isocyanate to simple vinyl ethers derived from the 2-O-sulfonylated (R) and (S) 1-phenyl-1,2-ethanediol leads to 4-alkoxy-azetidin-2-ones with a moderate stereoselectivity. The cycloaddition to analogous (Z)-propenyl ethers proceeds stereospecifically with the retention of the olefin configuration. The intramolecular alkylation of beta-lactam nitrogen atom furnished all possible stereoisomers of 3-phenyl- and 6-methyl-3-phenyl-clavams. The biological and chiroptical activity of synthesized clavams was investigated. The (3R,5R)-diastereomer 30 showed higher inhibition of bacterial enzymes than other related compounds.     

Red blood cell magnetophoresis

The existence of unpaired electrons in the four heme groups of deoxy and methemoglobin (metHb) gives these species paramagnetic properties as contrasted to the diamagnetic character of oxyhemoglobin. Based on the measured magnetic moments of hemoglobin and its compounds, and on the relatively high hemoglobin concentration of human erythrocytes, we hypothesized that differential migration of these cells was possible if exposed to a high magnetic field. With the development of a new technology, cell tracking velocimetry, we were able to measure the migration velocity of deoxygenated and metHb-containing erythrocytes, exposed to a mean magnetic field of 1.40 T and a mean gradient of 0.131 T/mm, in a process we call cell magnetophoresis. Our results show a similar magnetophoretic mobility of 3.86 x 10(-6) mm(3) s/kg for erythrocytes with 100% deoxygenated hemoglobin and 3.66 x 10(-6) mm(3) s/kg for erythrocytes containing 100% metHb. Oxygenated erythrocytes had a magnetophoretic mobility of from -0.2 x 10(-6) mm(3) s/kg to +0.30 x 10(-6) mm(3) s/kg, indicating a significant diamagnetic component relative to the suspension medium, in agreement with previous studies on the hemoglobin magnetic susceptibility. Magnetophoresis may open up an approach to characterize and separate cells for biochemical analysis based on intrinsic and extrinsic magnetic properties of biological macromolecules.     

Reactive oxygen species and sperm cells

There is a dynamic interplay between pro- and anti-oxidant substances in human ejaculate. Excessive reactive oxygen species (ROS) generation can overwhelm protective mechanism and initiate changes in lipid and/or protein layers of sperm plasma membranes. Additionally, changes in DNA can be induced. The essential steps of lipid peroxidation have been listed as well as antioxidant substances of semen. A variety of detection techniques of lipid peroxidation have been summarized together with the lipid components of sperm membranes that can be subjected to stress. It is unsolved, a threshold for ROS levels that may induce functional sperm ability or may lead to male infertility.