The Pakistan Risk of Myocardial Infarction Study: a resource for the study of genetic, lifestyle and other determinants of myocardial infarction in South Asia

The burden of coronary heart disease (CHD) is increasing at a greater rate in South Asia than in any other region globally, but there is little direct evidence about its determinants. The Pakistan Risk of Myocardial Infarction Study (PROMIS) is an epidemiological resource to enable reliable study of genetic, lifestyle and other determinants of CHD in South Asia. By March 2009, PROMIS had recruited over 5,000 cases of first-ever confirmed acute myocardial infarction (MI) and over 5,000 matched controls aged 30–80 years. For each participant, information has been recorded on demographic factors, lifestyle, medical and family history, anthropometry, and a 12-lead electrocardiogram. A range of biological samples has been collected and stored, including DNA, plasma, serum and whole blood. During its next stage, the study aims to expand recruitment to achieve a total of about 20,000 cases and about 20,000 controls, and, in subsets of participants, to enrich the resource by collection of monocytes, establishment of lymphoblastoid cell lines, and by resurveying participants. Measurements in progress include profiling of candidate biochemical factors, assay of 45,000 variants in 2,100 candidate genes, and a genomewide association scan of over 650,000 genetic markers. We have established a large epidemiological resource for CHD in South Asia. In parallel with its further expansion and enrichment, the PROMIS resource will be systematically harvested to help identify and evaluate genetic and other determinants of MI in South Asia. Findings from this study should advance scientific understanding and inform regionally appropriate disease prevention and control strategies.     

Arsenic-associated oxidative stress, inflammation, and immune disruption in human placenta and cord blood

Background

Arsenic (As) exposure during pregnancy induces oxidative stress and increases the risk of fetal loss and low birth weight.

Objectives

In this study we aimed to elucidate the effects of As exposure on immune markers in the placenta and cord blood, and the involvement of oxidative stress.

Methods

Pregnant women were enrolled around gestational week (GW) 8 in our longitudinal, population-based, mother–child cohort in Matlab, an area in rural Bangladesh with large variations in As concentrations in well water. Women (n = 130) delivering at local clinics were included in the present study. We collected maternal urine twice during pregnancy (GW8 and GW30) for measurements of As, and placenta and cord blood at delivery for assessment of immune and inflammatory markers. Placental markers were measured by immunohistochemistry, and cord blood cytokines by multiplex cytokine assay.

Results

In multivariable adjusted models, maternal urinary As (U-As) exposure both at GW8 and at GW30 was significantly positively associated with placental markers of 8-oxoguanine (8-oxoG) and interleukin-1β (IL-1β); U-As at GW8, with tumor necrosis factor-α (TNFα) and interferon-γ (IFNγ); and U-As at GW30, with leptin; U-As at GW8 was inversely associated with CD3⁺ T cells in the placenta. Cord blood cytokines (IL-1β, IL-8, IFNγ, TNFα) showed a U-shaped association with U-As at GW30. Placental 8-oxoG was significantly positively associated with placental proinflammatory cytokines. Multivariable adjusted analyses suggested that enhanced placental cytokine expression (TNFα and IFNγ) was primarily influenced by oxidative stress, whereas leptin expression appeared to be mostly mediated by As, and IL-1β appeared to be influenced by both oxidative stress and As.

Conclusion

As exposure during pregnancy appeared to enhance placental inflammatory responses (in part by increasing oxidative stress), reduce placental T cells, and alter cord blood cytokines. These findings suggest that effects of As on immune function may contribute to impaired fetal and infant health.     

Partial Intra‐Aortic Occlusion Improves Perfusion Deficits and Infarct Size Following Focal Cerebral Ischemia

Reperfusion with intravenous tissue plasminogen activator (tPA) has been the goal of therapy for acute ischemic stroke; however, tPA is contraindicated in many patients, has low recanalization rates in major occlusions, and carries a substantial risk of symptomatic intracerebral hemorrhage. In the present study, we hypothesized that partial intra‐aortic occlusion of the abdominal aorta would increase salvage of ischemic penumbra and reduce infarct volume after focal embolic stroke in rats. We examined the effects of aortic occlusion on infarct volume, expression and activation of matrix metalloprotease‐9, and hemorrhagic transformation with or without treatment with tPA. We then examined the effects of aortic occlusion on perfusion deficits following embolic occlusion. Results showed that partial aortic occlusion significantly reduces brain infarction volume with or without treatment with tPA after focal ischemia, but does not increase risk for hemorrhagic transformation or matrix metalloprotease‐9 expression and activation. Partial intra‐aortic occlusion also reduces perfusion deficits after focal cerebral ischemia as compared to control. The present study shows that partial intra‐aortic occlusion significantly decreases infarction volume and perfusion deficits following ischemic injury in an embolic model of cerebral ischemia. Moreover, combination treatment with tPA and partial intra‐aortic occlusion further reduces infarction volume without any increase in hemorrhagic transformation.     

A novel deletion mutation in CENPJ gene in a Pakistani family with autosomal recessive primary microcephaly

Autosomal recessive primary microcephaly (MCPH) is a rare human genetic disorder in which the head circumference is reduced because of abnormality in fetal brain growth. To date, six loci and four genes have been identified for this condition. Our study of primary MCPH led to the identification of 33 Pakistani families with different ethnic backgrounds. Most of these families showed linkage to MCPH5 locus on chromosome 1q31. Only one family with Pashtoon origin from a remote region in Pakistan linked to MCPH6 locus on chromosome 13q12.12–q12.13. Sequence analysis of exon 11 of CENPJ gene, located at MCPH6 locus, revealed a novel four base pair deletion mutation, which is predicted to be protein truncating.     

Developing counseling skills through pre-recorded videos and role play: a pre- and post-intervention study in a Pakistani medical school

Background

Interactive methods like role play, recorded video scenarios and objective structured clinical exam (OSCE) are being regularly used to teach and assess communication skills of medical students in the western world. In developing countries however, they are still in the preliminary phases of execution in most institutes. Our study was conducted in a naïve under resourced setup to assess the impact of such teaching methodologies on the counseling skills of medical students.

Methods

Fifty four 4^th year MBBS students were identified to be evaluated for communication skills by trained facilitators in a pre-intervention OSCE. The same group of students was given a demonstration of ideal skill level by means of videos and role playing sessions in addition to real life interaction with patients during hospital and community rotations. A post-intervention evaluation was carried out six months later through OSCE and direct observation through structured checklist (DOS) in hospital and community settings. The combined and individual performance levels of these students were analyzed.

Results

There was a statistically significant difference in the communication skills of students when assessed in the post-intervention OSCE (p = 0.000). Individual post-intervention percentages of study participants displayed improvement as well (n = 45, p = 0.02). No difference was observed between the scores of male and female students when assessed for two specific competencies of antenatal care and breast feeding counseling (p = 0.11). The mean DOS (%) score of 12 randomly selected students was much lower as compared to the post-intervention (%) score but the difference between them was statistically non significant, a result that may have been affected by the small sample size as well as other factors that may come into play in real clinical settings and were not explored in this study (59.41 ± 7.8 against 82.43 ± 22.08, p = 0.88).

Conclusions

Videos and role play in combination with community and clinical exposure are effective modes of teaching counseling skills to medical students. They can be successfully utilized even in a limited resource setup, as demonstrated by our trial.

     

Infliximab leads to a rapid but transient improvement in endothelial function in patients with primary systemic vasculitis

OBJECTIVE: To assess the immediate effects of tumour necrosis factor alpha (TNFalpha) blockade on endothelial function in systemic vasculitis. METHODS: Endothelial function was assessed by laser Doppler flowmetry in patients with active vasculitis after 10 infusions of infliximab. For comparison endothelial responses were assessed after five infusions of cyclophosphamide plus methylprednisolone. RESULTS: Endothelial dependent vasodilatation (EDV) improved significantly within 24 hours of infliximab infusion. The median change in red blood cell flux (interquartile range) was 5.7 (4.3-8.2) before infusion v 8.4 (7.5-10.9) at 24 hours; p=0.027. This was not maintained at day 14. No improvement was seen in EDV after cyclophosphamide plus methylprednisolone infusion. CONCLUSION: The rapid but transient improvement in EDV after TNFalpha inhibition suggests that TNFalpha may have a direct role in the impairment of endothelial function.     

Low multiplication rates of African Plasmodium falciparum isolates and lack of association of multiplication rate and red blood cell selectivity with malaria virulence

Two potential malaria virulence factors, parasite multiplication rate (PMR) and red blood cell selectivity (measured as selectivity index [SI]), were assessed in Plasmodium falciparum clinical isolates from Mali and Kenya. At both sites, PMRs were low (Kenya median = 2.2, n = 33; Mali median = 2.6, n = 61) and did not differ significantly between uncomplicated and severe malaria cases. Malian isolates from hyperparasitemic patients had significantly lower PMRs (median = 1.8, n = 19) than other Malian isolates (uncomplicated malaria median = 3.1, n = 23; severe malaria median = 2.8, n = 19; P = 0.03, by Kruskal-Wallis test). Selective invasion occurred at both sites (Kenya geometric mean SI = 1.9, n = 98; Mali geometric mean SI = 1.6, n = 104), and there was no significant association between the SI and malaria severity. Therefore, in contrast to previous results from Thailand, we found no association of PMR and SI with malaria severity in African children. This raises the possibility of differences in the mechanisms of malaria virulence between sub-Saharan Africa and Asia.