Are published standards for haematological indices in pregnancy applicable across populations: an evaluation in healthy pregnant Jamaican women

<p>Abstract</p> <p>Background</p> <p>The haematological profile of the pregnant woman has an impact on the outcome of the pregnancy. Published guidelines indicate acceptable levels for haematological indices in pregnancy but they are population specific. Indicators of haemoglobin concentration are the most commonly utilized of the indices. These published international norms are used across populations, however, there is no evidence confirming their applicability to a population such as the Jamaican pregnant woman. This study was therefore undertaken with the intent of documenting the haematological profile of pregnant primigravid Jamaican women and comparing these to the established norms to determine whether the norms apply or whether there was a need to establish local norms.</p> <p>Methods</p> <p>This was a longitudinal study done on a cohort of 157 healthy primigravid women ages 15 to 25 and without anaemia, and who were recruited from the antenatal clinic of the University Hospital of the West Indies, Kingston, Jamaica. The haemoglobin concentration, packed cell volume, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, white blood cell count, red blood cell count and platelet count were measured on samples of blood obtained from each consenting participant during each of the three trimesters. The results were analysed using SPSS for windows (Version 11) and the data expressed as means ± S.D. Means were compared using the student's paired <it>t-test</it>. Comparison was then made with the international norms as recommended by the United States Center for Disease Control (1989). Ethical approval for this study was obtained from the University Hospital of the West Indies/University of the West Indies Ethics Committee.</p> <p>Results</p> <p>The results showed changes by trimester in all measured variables. For most of the indices the changes achieved levels of significance across trimesters. These changes were however in keeping with the expected physiological response in pregnancy and the values were similar to the published international norms.</p> <p>Conclusion</p> <p>The findings suggest that the international norms for haematological indices in pregnancy are applicable across populations and to the pregnant Jamaican primigravid woman. This finding may be reassuring to others with a similar population and stage of development as Jamaica.</p

The in vitro effect of delta-9-tetrahydrocannabinol and cannabidiol on whole blood viscosity, elasticity and membrane integrity.

BACKGROUND: The main biological activities of cannabis are due to the presence of several compounds known as cannabinoids. Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are two of the main cannabinoids. Studies have shown that the effects of THC can be modulated by CBD. OBJECTIVE: This study aims to look at the effect of different concentrations of THC and CBD separately and in combination, on blood viscosity, elasticity and membrane integrity. METHODS: Blood samples were collected from twenty-four healthy adult non-smokers. Blood viscosity and elasticity were determined using the Vilastic Scientific Bioprofiler for different concentrations (0, 2.5, 25, 50 and 100 ng/ml) of CBD and THC respectively, as well as in extracts with combinations of CBD and THC in 4:1 and 1:1 ratios respectively. Repeated measures analysis of variance (ANOVA) was used to determine the difference between the means of the groups. RESULTS: Blood viscosity increased significantly with increasing concentrations of both THC and CBD from 25 ng/ml up to 100 ng/ml ranging from 6.45 ± 0.36 mPa·s to 11.60 ± 1.12 mPa·s for THC and ranging from 5.46 ± 0.24 mPa·s to 9.91 ± 1.10 mPa·s for CBD respectively, being more pronounced in the extracts at 21.33 ± 2.17 mPa·s for the 4THC:1CBD extract and 21.76 ± 1.88 mPa·s for the 1THC:1CBD extract. There was no significant increase in elasticity for THC and CBD separately. However, a significant increase in elasticity was observed in the extracts. THC and CBD affected red cell morphology resulting in complete disintegration at the highest concentrations. CONCLUSIONS: THC and CBD increased red blood cell viscosity and elasticity separately and in combination. They also adversely affected membrane integrity

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health