The influence of placental malaria infection and maternal hypergammaglobulinemia on transplacental transfer of antibodies and IgG subclasses in a rural West African population

Two hundred thirteen mother-baby pairs in The Gambia were studied to determine the influence of placental malaria infection and maternal hypergammaglobulinemia on transplacental antibody transfer. Antibody transfer for herpes simplex virus 1 (HSV-1), respiratory syncytial virus (RSV), and varicella-zoster virus (VZV) was significantly reduced by placental malaria infection by 69%, 58%, and 55%, respectively. Maternal hypergammaglobulinemia was associated with a significant reduction in antibody transfer for HSV-1, RSV, VZV, and pneumococcus by 89%, 90%, 91%, and 88%, respectively. In addition, placental malaria infection was associated with a significant reduction in transfer of IgG1, IgG2, and IgG4 (P<.01, P=.01, and P=.03, respectively) but not of IgG3 (P=.59). Maternal hypergammaglobulinemia significantly impaired the transfer of IgG1 and IgG2 (P=.01) but not of IgG3 or IgG4 (P=.62 and P=.59, respectively). Placental malaria infection and maternal hypergammaglobulinemia were associated with reduction in the transplacental transfer of these specific antibodies, IgG1, and IgG2 in this Gambian population.     

Inhibitory activity of quercetin and its metabolite on lipopolysaccharide-induced activation of macrophage U937 cells

The potential of quercetin and its metabolite 3-O-methyl quercetin in inhibiting lipopolysaccharide (LPS)-mediated activation of macrophage U937 cells was investigated. Cells were pre-incubated for different periods with 100 ng/mL phorbol myristate acetate (PMA), and later with LPS and quercetin or 3-O-methyl quercetin (30 μM). Later, the supernatant of each cell culture was assessed for catalase activity, nitric oxide, and the production of tumour necrosis factor-α (TNF-α), interleukin 6 (IL-6), and interleukin 1 (IL-1). The results showed that when the cells were incubated with LPS, there were elevations in the levels of all the markers over the cells not incubated with LPS (P < 0.05). For the cells that were incubated with LPS, there were significant differences between the various cells when they were pre-incubated with PMA for various periods (P < 0.05). However, greatest production of the markers was attained when the cells were pre-treated with PMA for 48 h. Both quercetin and 3-O-methyl quercetin (at 30 mM) reduced the levels of all the markers with 3-O-methyl quercetin possessing more inhibitory potential (P < 0.05). This suggests that the flavonoids possessed significant immunomodulatory activities which depend on methylation especially at position 3.     

Medical transportation of Congolese children by the Foundation "Terre des hommes" Netherlands (1989--1998)

We report the 10 year assessment of collaboration with the Foundation "Terre des hommes" concerning the medical transfer in the Netherlands of 41 children carrying pathologies which couldn't be treated or operated on in Brazzaville. The average age was 3 years and 6 months old (extremes: 2 months - 15 years). 33 non-cyanotic cardiopathies dominated by ventricular septal defect (VSD) (n = 10) and 11 cyanotic cardiopathies among them the tetralogy of Fallot (n = 5) were admitted. The other pathologies were respectively: osseous (n = 3), vesical (n = 2), pulmonary tumoral, ophthalmic in 1 case. The surgery consisted in a complete repair in 19 cases, palliative in 9 cases. Two children proved to be inoperable. Eight other extra-cardiac pathologies had a specific surgery for each case. The average stay in the Netherlands was 1 month 13 days (extremes: 1 - 12 months). The evolution was favourable for 35 children all pathologies included. Four deaths occurred in the Netherlands and 2 in Congo. The organization of the technology transfer would be probably a better choice in the future.     

Prospects and challenges with introduction of a mono-valent meningococcal conjugate vaccine in Africa

Epidemic meningococcal meningitis is a priority disease for prevention and control in Africa. The current World Health Organization (WHO) approach to the control of meningitis epidemics is based on early detection of cases and emergency vaccination of the population at risk with meningococcal polysaccharide (PS) vaccines. But this is a tall order for the developing nations of Africa where experts operate from an ineffective health system. Although the widespread use of meningococal polysaccharide vaccines has had a major and much appreciated public health impact on the disease it has not prevented epidemics of this dreaded infection. The current partnership between WHO and the PATH aims to develop, evaluate and introduce an appropriate and affordable meningococcal conjugate vaccine that could potentially provide for a means of preventing epidemic meningitis caused by N. meningitidis group A. In this paper, we review the prospects and challenges facing the introduction of the mono-valent conjugate vaccine in Africa.     

In vitro antioxidant and free radical scavenging activities of Garcinia kola seeds

Garcinia kola Heckel – a tropical plant which grows in moist forest, has found wide applications in traditional medicine especially in the West and Central African sub-region. The seeds have been demonstrated to possess numerous bioactivities but research is highly limited on the link between its fractions and the bioactivities. In this work, the methanolic extract of Garcinia kola seeds was subjected to silica gel column chromatography into five fractions ME1–ME5 and the free radical scavenging activities and antioxidant potentials were determined for each fraction using various in vitro models. The ME4 fraction possessed the greatest activities. It was also demonstrated that the ME4 fraction strongly inhibited nitric oxide production in lipopolysaccharide activated macrophage U937 cells. Chromatographic fractionation and spectroscopic analysis of the ME4 fraction revealed the presence of four compounds namely garcinia biflavonoids GB1 and GB2, garcinal and garcinoic acid. These findings show that these four compounds are partly responsible for the great antioxidant potential of Garcinia kola seeds. This gives further evidence to the nutraceutical and pharmaceutical potential of Garcinia kola.