CHHIPS (Controlling Hypertension and Hypotension Immediately Post-Stroke) Pilot Trial: rationale and design

RATIONALE

High and low blood pressure (BP) levels are common following acute stroke, with up to 60% of patients being hypertensive (SBP > 160 mmHg) and nearly 20% having relative hypotension (SBP < or = 140 mmHg), within the first few hours of ictus, both conditions being associated with an adverse prognosis. At present, the optimum management of blood pressure in the immediate post-stroke period is unclear.

OBJECTIVE

The primary aim of the Controlling Hypertension and Hypotension Immediately Post-Stroke (CHHIPS) Pilot Trial is to assess whether hypertension and relative hypotension, manipulated therapeutically in the first 24 h following acute stroke, affects short-term outcome measures.

DESIGN

The CHHIPS Pilot Trial is a UK based multi-centre, randomized, double-blind, placebo-controlled, titrated dose trial.

SETTING

Acute stroke and medical units in teaching and district general hospitals, in the UK.

PATIENTS

The CHHIPS Pilot Study aims to recruit 2050 patients, with clinically suspected stroke, confirmed by brain imaging, who have no compelling indication or contraindication for BP manipulation.

STUDY OUTCOMES

The primary outcome measure will be the effects of acute pressor therapy (initiated < or = 12 h from stroke onset) or depressor therapy (started < or = 24 h post-ictus) on death and dependency at 14 days post-stroke. Secondary outcome measures will include the influence of therapy on early neurological deterioration, the effectiveness of treatment in manipulating BP levels, the influence of time to treatment and stroke type on response and a cost-effectiveness analysis.

Docosahexaenoic acid restores endothelial function in children with hyperlipidemia: results from the EARLY study

OBJECTIVE

The primary objective of this study was to determine whether the National Cholesterol Education Program Step II (NCEP-II) diet or supplementation with docosahexaenoic acid (DHA) with the diet, affects endothelial function in children with familial hypercholesterolemia (FH) or the phenotype of familial combined hyperlipidemia (FCH). As secondary endpoints, the influence of diet and DHA supplementation on lipid profiles as well as biomarkers for oxidative stress and inflammation, and asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, were all evaluated.

METHODS

In a double-blind, placebo-controlled, randomized, crossover study design, 20 children (ages 9-19 years) with FH (n = 12) and FCH (n = 8) received nutritional counseling based on the National Cholesterol Education Program Step II (NCEP-II) and food guide pyramid dietary guidelines for 6 weeks. They were then randomly assigned to supplementation with docosahexaenoic acid (DHA 1.2 g/d) or placebo for 6 weeks, followed by a washout phase of 6 weeks and crossover phase of 6 weeks while continuing the NCEP-II diet. Endothelium-dependent flow-mediated dilation (FMD) of the brachial artery was determined by high-resolution ultrasound. Plasma levels of total cholesterol, triglycerides and lipoprotein classes (LDL, HDL, VLDL) were measured by ultracentrifugation and enzymatic methods, plasma F2 isoprostanes by gas chromatography/mass spectrometry, urinary 8-OH-2' deoxyguanosine by liquid chromatography, high sensitivity C-reactive protein by immunonephelometry and ADMA by liquid chromatography.

RESULTS

FMD increased significantly after DHA supplementation compared to baseline (p < 0.001), diet alone (p < 0.002), placebo (p < 0.012) and washout (p < 0.001) phases of the study without affecting biomarkers for oxidative stress, inflammation or ADMA. DHA supplementation was associated with increased levels of total cholesterol (p < 0.01), LDL- and HDL cholesterol concentrations (p < 0.001) compared to the NCEP-II diet.

CONCLUSION

This study demonstrates that DHA supplementation restores endothelial-dependent FMD in hyperlipidemic children. The endothelium may thus be a therapeutic target for DHA. This is consistent with a hypothesis of increasing NO bioavailability, with the potential for preventing the progression of early coronary heart disease in high-risk children.

Directional ligation of long-flanking homology regions to selection cassettes for efficient targeted gene-disruption in Candida albicans

PCR-product directed gene disruption with a marker cassette having short homology regions is often used in Candida albicans. However, it is quite inefficient due to the high frequency of non-homologous recombination at non-targeted loci, which necessitates extensive screening to identify the correct disruptants. Thus, many PCR-based methods to introduce long flanking homology regions have been developed to increase the frequency of integration at the targeted loci. However, these methods are not that amenable for use with the widely employed C. albicans marker cassettes having direct repeats, as these repeats tend to recombine during PCR, resulting in shorter amplified products without the selection marker. To circumvent this limitation, we have developed a dinucleotide-sticky-end-ligation strategy to add one flanking homology region to one side of the selection cassette, and the other flanking homology region to the other side of the selection cassette. This method involves release of the selection cassette from the plasmid by digestion with two different restriction enzymes, followed by partial fill-in, to provide a unique two base overhang at each end of the cassette. The flanking homology regions, corresponding to the gene to be disrupted, are individually PCR-amplified, and treated with T4-DNA Polymerase in the presence of appropriate dNTPs to yield two base-5' overhangs. The primers used for the PCR have additional bases at the 5' ends such that after T4 DNA Polymerase treatment, the two flanks will have distinct overhangs compatible with the overhangs of the partially filled-in selection cassette. The selection cassette and the flanks are then ligated together and directly used to transform C. albicans. We have successfully used this method for disruption of several C. albicans genes. We have also used this method to recreate insertion mutations obtained with transposons to reconfirm the mutant phenotypes. This approach can be extended to other organisms like Schizosaccharomyces pombe which also require long flanking regions of homology for targeted gene disruption.

Interferon-gamma (IFN-gamma) response to different hepatitis B virus antigens in hepatitis B virus infection

The IFN-gamma levels in serum and cultured supernatant of peripheral blood mononuclear cells (PBMCs) were compared after stimulation by HBsAg ad, HBsAg ay and HBcAg among 3 groups of subjects i.e. patients with acute HBV infection, patients with chronic HBV infection and subjects recovered from HBV infection. Uninfected vaccinated group was taken as control. Serum and PBMCs were obtained from 38 individuals between 18-50 years of age. PBMCs were separated from heparinised blood by Ficoll-Hypaque density gradient centrifugation technique and cultured in CO2 incubator after stimulation by HBV surface and core antigens. IFN-gamma concentration was measured in serum and culture supernatant of PBMCs by an in-house ELISA technique. The mean serum IFN-gamma levels in acute, chronic, recovered and control groups were 88 pg/ml, 96.6 pg/ml, 155 pg/ml and 205 pg/ml respectively. On stimulation by HBsAg ad, IFN-gamma levels in cultured PBMCs of the above mentioned groups were 282.50 pg/ml, 307.45 pg/ml, 915.62 pg/ml and 511.67 pg/ml respectively, while in the same group on HBsAg ay stimulation, IFN-gamma levels were 246.25 pg/ml, 374.70 pg/ml, 1040 pg/ml and 465.83 pg/ml respectively. On stimulation by HBcAg, the IFN-gamma levels were 875 pg/ml, 128.50 pg/ml, 905 pg/ml and 235.33 pg/ml respectively in the acute, chronic, recovered and control groups. When compared with serum, significantly higher levels of IFN-gamma in cultured supernatant of PBMCs were observed after stimulation by HBsAg ad and HBsAg ay subtype in cases of chronic (p<0.05) and recovered groups (p<0.01 and p<0.001 respectively). However, no statistically significant difference of IFN-gamma level was observed between serum and PBMCs amongst the acute and control groups when stimulated by either of the HBsAg subtypes or HBcAg. In the recovered group, IFN-gamma levels produced by PBMCs after stimulation by HBcAg were significantly higher than that of serum (p<0.01). The study concludes that on subsequent exposure, PBMCs of the recovered group produces higher levels of IFN-gamma in response to different hepatitis B antigens. This response perhaps is able to protect individuals who are unable to develop anti-HBs.

A study on interferon-gamma (IFN-gamma) response by T cells stimulated by hepatitis B virus core antigen

Cell-mediated immune response by lymphocyte induced through recognition of HBV core antigen during acute HBV infection, chronic HBV infection and in subjects recovered from HBV infection was investigated in the present study by assessing the competence of IFN-gamma secretion by cultured PBMCs on stimulation by HBV nucleocapsid antigen (HBcAg). Fresh blood was collected in heparin from acute, chronic and recovered groups of HBV infected patients and uninfected vaccinated healthy controls aged between 18-50 years. PBMCs were separated by Ficoll-Hypaque density gradient centrifugation technique and were stimulated with hepatitis B virus core antigen (HBcAg) and mitogen (lectin). Stimulated PBMCs were cultured in CO2 and IFN-gamma levels were measured from the culture supernatant by an in-house ELISA technique. The mean+/-SE levels of IFN-gamma in HBcAg stimulated PBMCs in acute, chronic, recovered and controls groups were 875 pg/ml+/-297.56, 128.50 pg/ml+/-33.66, 905 pg/ml+/-172.51 and 235.33 pg/ml+/-111.28 respectively. IFN-gamma levels produced by HBcAg stimulated PBMCs of acute and recovered groups were significantly higher than that of chronic and control group (p<0.001). All groups responded strongly to lectin stimulation. Thus, it may be concluded that patients with acute HBV infection and those who had recovered from HBV infection show vigorous response to HBcAg stimulation in contrast to patients with chronic HBV infection.

Amnesic shellfish poison

Amnesic shellfish poisoning (ASP) is caused by consumption of shellfish that have accumulated domoic acid, a neurotoxin produced by some strains of phytoplankton. The neurotoxic properties of domoic acid result in neuronal degeneration and necrosis in specific regions of the hippocampus. A serious outbreak of ASP occurred in Canada in 1987 and involved 150 reported cases, 19 hospitalisations and 4 deaths after consumption of contaminated mussels. Symptoms ranged from gastrointestinal disturbances, to neurotoxic effects such as hallucinations, memory loss and coma. Monitoring programmes are in place in numerous countries worldwide and closures of shellfish harvesting areas occur when domoic acid concentrations exceed regulatory limits. This paper reviews the chemistry, sources, metabolism and toxicology of domoic acid as well as human case reports of ASP and discusses a possible mechanism of toxicity.

Late post radiation laryngeal chondronecrosis with pharyngooesophageal fibrosis

Chondroradionecrosis of larynx is a well recognized complication of radiation therapy, which usually occur with in the 1st year. Review of literature shows very few accounts of late radiation induced clinical chondroradionecrosis of the larynx. This condition can mimic a local recurrence and severe and life threatening involvement will require aggressive surgical management as reported in the present case.

A high-density linkage map of the RN region in pigs

The porcine RN locus affects muscle glycogen content and meat quality. We previously mapped the RN locus to chromosome 15. This study describes the identification of polymorphisms for four class I and four class II markers located in the RN region. Resource families were genotyped with F-SSCP markers (fluorescent single strand conformation polymorphism) and microsatellite markers. Subsequent multipoint linkage analysis revealed the order FN1-IGFBP5-S1000-S1001-IL8RB-VIL1-RN-Sw936-Sw906. The gene order is identical to the previously reported porcine RH map of the same region. The described map will facilitate positional cloning of the RN gene.

The DGAT1 K232A mutation is not solely responsible for the milk production quantitative trait locus on the bovine chromosome 14

The gene, acyl-CoA:diacylglycerol acyltransferase1 (DGAT1), was recently identified as the one underlying the quantitative trait locus (QTL) for milk production traits in the centromeric region of the bovine chromosome 14. Until now, 2 alleles, the lysine variant (increasing fat yield, fat and protein percentage) and the alanine variant (increasing protein and milk yield), were postulated at DGAT1. This study investigated whether the diallelic DGAT1 polymorphism is responsible for all the genetic variation at the centromeric region of this chromosome for milk, fat, and protein yield and fat and protein percentage. A statistical model was applied to a granddaughter design to analyze 16 German Holstein families. The model included the diallelic DGAT1 effect and the QTL transition probability estimated for each chromosomal position by a multiple marker approach. Because the regression coefficient of this probability was corrected for the diallelic DGAT1 polymorphism, it represented a putative conditional QTL effect. The effect of the DGAT1 gene was always highly significant. The conditional QTL effect was significant genomewise for fat percentage at the proximal end of the chromosome and for protein percentage at a more distal chromosomal region. Additional chromosomewise significance was found for fat and protein yield. Our results suggest an additional source of genetic variance on this chromosome for these traits; either one or more additional alleles segregating at DGAT1 that were not previously detected, a second quantitative trait locus affecting these traits, or both.

Clinical correlates of early medication adherence: West London first episode schizophrenia study

OBJECTIVE

Little is known about factors that mediate adherence with medication during the early stages of antipsychotic treatment in schizophrenia. This study sought to identify factors that may be associated with medication adherence in first-episode schizophrenia.

METHOD

In 101 patients, adherence was assessed along with potentially relevant variables, including attitudes toward medication, insight, substance misuse, side effects and psychopathology.

RESULTS

In a linear regression analysis, negative attitudes toward medication and a relative lack of insight contributed significantly towards poor adherence. Although poorly adherent patients had significantly higher scores on negative and disorganization syndromes, these did not contribute significantly towards adherence. Adverse medication side effects, subjective well-being and substance misuse showed no significant association with adherence.

CONCLUSION

At the initiation of drug treatment, attitudes toward medication and insight appear more relevant to medication adherence than side effects. Adherence appears to reflect a complex interaction of influences, which may change over time.