Alarming high prevalence of overweight/obesity among Sudanese children.

The objective of this study was to estimate the prevalence of obesity among schoolchildren in Khartoum state, Sudan. Multistage stratified random sampling methodology was used. Sampling included different residential areas within the state. A total of 1138 children between the ages of 10 and 18 years were involved in the study. More than 9% of the children were obese, 10.8% were overweight whereas combined overweight/obesity scored 20.5%. The prevalence of combined overweight/obesity among higher, middle and lower socioeconomic class children was 56.8, 27.3 and 3.1%, respectively. These figures, being higher than those reported among Nigerian and South African children, living in similar conditions, may refer to an emerging problem of overweight and obesity especially among children of the higher and middle class families. Adoption of national programs of promoting healthy food habits and physical activity among children is recommended.

Carnitine supplement: Does it worth trial to improve semen quality among infertile Sudanese men?

Carnitine supplement proves to upgrade the quality of semen by increasing sperm count and motility. In this study we have determined the level of L - carnitine in the seminal plasma of men with normal and abnormal seminal analysis. L - carnitine levels among the normal group was significantly higher than the abnormal group. We recommend trials of carnitine supplements to evaluate its usefulness in correcting some infertility cases. Subjects and methods: A total of 52 men; recruited from fertility centers in Khartoum ;were included in this study. Colorimetric carnitine determination kits were used for estimation of L - carnitine in seminal plasma. Results: Collectively; men with normal values of semen analysis had significantly higher mean seminal plasma carnitine levels compared to abnormal values (p = 0.028). Oligospermic men had significantly lower levels of carnitine compared to normal (p = 0.046). Conclusion: Seminal plasma carnitine level seems to correlate with seminal quality and its deficiency may be a reason for infertility among some Sudanese men

Obesity and Cardiovascular Disease Risk Factors among Adult Sudanese

Abstract Subjects and methods: In this study; the effect of obesity on the development of dyslipidemia; hypertension and glucose intolerance among Sudanese adults attending weight reduction programs was investigated. According to the BMI (Body mass index); 98 overweight/obese and 60 normal weight adults were included. Anthropometric measures were taken; lipid profile and C reactive protein (CRP) were determined using commercial kits. Results: Obesity related dyslipidemia seems to affect overweight/obese males more than females. On the other hand; overweight /obesity among females; not like males; was found to be associated with high blood pressure probably due inflammation; as determined by CRP level. Conclusion and recommendation: Obesity related dyslipidemia is more prominent among males while obesity related hypertension is a phenomenon among females probably due to release of CRP. We recommend a more detailed study of inflammatory cytokines; in relation to obesity; that may reflect the mass and/or activity of the adipose tissue

Differential expression of cytokine genes among sickle-cell-trait (HbAS) and normal (HbAA) children infected with Plasmodium falciparum.

The human immune response to Plasmodium falciparum infection involves the release of cytokines that may contribute to the control of the parasites' replication. These cytokines are also involved in the pathogenesis of the malaria caused by the infection, leading to the appearance of symptoms of varying severity. In a cross-sectional study, the expression of the genes that code for pro-inflammatory cytokines (tumour necrosis factor, interferon-gamma, interleukin-6 and interleukin-12) and anti-inflammatory cytokines (interleukin-10 and interleukin-4) among 80 children infected with P. falciparum (from a malaria-endemic area of Sudan) and five healthy controls (from a non-endemic area) was explored. The infected children were either non-sicklers, with severe malaria (18 children), mild malaria (30) or no symptoms of malaria (18), or asymptomatic sicklers (14). Interleukin-12 was found to be weakly expressed by all the groups of children. In general, compared with the other groups, the asymptomatic non-sicklers had lower expression of all the cytokines studied. The asymptomatic sicklers had significantly lower expression of tumour necrosis factor than the non-sicklers with severe malaria, but these two groups showed similar expression of interferon-gamma, interleukin-4 and interleukin-6. Gene expression of the regulatory cytokine, interleukin-10, by the asymptomatic sicklers was significantly lower than that by the non-sicklers with severe malaria but higher than that recorded in the non-sicklers with mild malaria. Their regulation of cytokine release appears to protect sicklers from clinical malaria.

Iron overload and pregnancy outcome among Sudanese women

Dispensing iron tablets to pregnant women at antenatal clinics is a common practice in Sudan.Iron overload and; consequently; oxidative stress is a possible risk.Objective: In this study; we examined the iron status in pregnant women in correlation to pregnancy outcome.Subjects and methods: The study was conducted in Khartoum state; Sudan in the period December 2007 February 2009. Venous blood samples were obtained from 123 women at delivery.Undesirable pregnancy outcomes as preeclampsia; low birth weight; caesarean sections and preterm delivery; if any; were recorded. Serum iron and hematological parameters were determined.Results: Mothers were grouped; according to their serum iron levels; as low serum iron (LSI: 50 7g/dl; n170 7g/dl;n=11) groups. The incidence of preeclampsia was highest among the IOL group (72.7); followed by the LSI group (35.7) and lowest among the NSI (19.4) group; p=. The mean babies' birth weights were comparable among the IOL and the LSI groups but both were significantly lower than that among the NSI group.Conclusion: Iron supplementation to pregnant women must be rationalized so that women will benefit without developing undesirable effects

Glucose 6 phosphate dehydrogenase (G6PD) deficiency is a possible risk factor for the development of preeclampsia.

Preeclampsia is partially attributed to lipid peroxidation of the syncytitrophoblast plasma membranes (SPMs). Peroxidation of the SPMs could be augmented when the capacity of the cells to produce antioxidant molecules is diminished. One of the most important antioxidant molecules that protects the SPMs is the reduced glutathione (GSH). The latter is produced in the pentose phosphate pathway that requires normal activity of glucose 6 phosphate dehydrogenase (G6PD). Therefore, it is hypothesized that pregnant women with G6PD deficiency are at higher risk for development of preeclampsia than those with normal G6PD activity. Deficiency of this enzyme leads to the deficiency of reduced GSH which is required to protect SPMs against lipid peroxidation and the consequent obstetric morbidity.

Protection against severe clinical manifestations of Plasmodium falciparum malaria among sickle cell trait subjects is due to modification of the release of cytokines and/or cytoadherence of infected erythrocytes to the host vascular beds.

It is proposed that the surface ligands of Plasmodium falciparum infected HbAS erythrocytes, not like infected HbAA erythrocytes, are altered due to the sickling that soon takes place once a HbAS erythrocyte gets infected with P. falciparum parasite. This alteration modulates cytoadherence and/or binding of the sickled erythrocytes to the peripheral blood mononuclear cells (PBMCs). Both cytoadherence and binding to PBMCs are responsible for the pathogenesis of malaria. Therefore, subjects of the HbAS genotype experience mild symptoms of malaria. The hypothesis could be tested in vitro by comparing the binding of P. falciparum infected HbAS and HbAA erythrocytes to platelet-endothelial cell adhesion molecule-1 (CD31) and by comparing the levels of tumor necrosis factor (TNF) and interferon gamma (IFN-gamma) following in vitro stimulation of PBMCs by HbAS and HbAA infected erythrocytes.

Modulation of the cellular immune response during Plasmodium falciparum infections in sickle cell trait individuals.

Plasma and peripheral blood mononuclear cells (PBMC) were obtained from P. falciparum-infected individuals with and without the sickle cell trait at diagnosis and 7 days after treatment. HbAA and HbAS patients were compared for levels of plasma soluble IL-2 receptors (IL-2R) and the in vitro cellular reactivity to affinity-purified soluble P. falciparum antigens (SPAg), PPD and phytohaemagglutinin (PHA). At diagnosis, HbAS patients with clinical disease had lower plasma-soluble IL-2R levels and parasite counts than the corresponding HbAA patients, whereas HbAS and HbAA patients with asymptomatic infections had comparable soluble IL-2R levels and parasite counts. PBMC from HbAS patients had higher proliferation and IFN-gamma production in response to SPAg than PBMC from HbAA patients. The difference in the lymphoproliferative responses to SPAg between the two groups was evident in patients with asymptomatic infections. In all patients, the clinical severity, the soluble IL-2R levels and the parasite counts were directly related. The former two were inversely related to the proliferative responses to SPAg. After treatment, all the studied parameters were comparable in the two groups. The study indicates that during P. falciparum infection, HbAS compared with HbAA patients had lower in vivo cellular activation and higher in vitro cellular reactivity in response to soluble malaria antigens.

Seasonal changes in cell mediated immune responses to soluble Plasmodium falciparum antigens in children with haemoglobin AA and haemoglobin AS.

In this longitudinal study peripheral blood mononuclear cells (PBMC) were obtained before and during the malaria season from healthy HbAA and HbAS children. Cells were compared for proliferation in response to stimulation by soluble Plasmodium falciparum antigens (SPAg) or purified derivative of tuberculin (PPD). The lymphoproliferative responses to SPAg of the paired PBMC samples showed 2 distinct seasonal changes in relation to the haemoglobin phenotype. In HbAA children, the lymphoproliferative responses to SPAg were suppressed during the malaria season. In contrast, they were enhanced in HbAS children during the malaria season. No distinct seasonal change in the response to PPD was found in relation to the haemoglobin phenotype. The study points to the role of the sickle cell trait in modulating the cellular immune responses to falciparum malaria.

Loss of cellular immune reactivity during acute Plasmodium falciparum malaria.

Sixteen patients suffering from acute Plasmodium falciparum malaria were studied. All were residents of an area of unstable malaria-transmission in Eastern Sudan. Blood-samples were drawn at diagnosis, and 7 and 30 days later. Blood-samples from thirteen donors, drawn outside the malaria transmission season 5 months prior to the attack, were included in the study. Lymphoproliferative responsiveness to purified soluble malarial antigens and to the unrelated antigen PPD was lost during the acute phase of the disease in most donors, but was regained during convalescence, except in four donors recrudescing or reinfected by day 30. In contrast to the suppression of antigenic responses, cellular responses to phytohaemagglutinin (PHA) remained virtually unaffected. All donors showed elevated plasma-levels of soluble IL-2 receptor during the acute phase of the disease which normalized during convalescence. Five donors examined by fluorescence-activated cell sorting (FACS) showed no increase in surface expression of IL-2 receptor on peripheral lymphocytes. The data indicate that acute P. falciparum malaria causes a depletion of antigen-reactive T-cells from the peripheral circulation, probably due to homing of this cell-population to lymphoid tissues. It was also found that acute-phase plasma was suppressive to PPD-induced proliferative responses, indicating an additional suppressive mechanism operating in vivo.

Lymphoproliferative responses to Plasmodium falciparum antigens in children with and without the sickle cell trait.

Blood mononuclear cells (BMNC) were isolated from sickle cell trait (HbAS) healthy donors and normal haemoglobin (HbAA) healthy donors resident in a P. falciparum endemic area of eastern Sudan. Blood samples were collected during the malaria season. BMNC were tested for their proliferative responses to phytohaemagglutinin (PHA), purified protein derivative of tuberculin (PPD) and to soluble P. falciparum antigens (SPAg). Higher responses to SPAg and PPD were observed in the HbAS children compared with the HbAA children, whereas no differences were observed among adults of the two phenotypes. Proliferative responses to PHA were comparable in all individuals tested. The significance of these findings in relation to haemoglobin phenotype, age and the possible immunoregulatory mechanisms operating in HbAS and HbAA children during the malaria season is discussed.

Transient depletion of T cells with high LFA-1 expression from peripheral circulation during acute Plasmodium falciparum malaria.

Acute P. falciparum malaria is associated with loss of in vitro T cell responsiveness to antigenic stimulation, and with high plasma levels of soluble interleukin 2 receptor (IL 2R). In the present study peripheral T cells from acute P. falciparum malaria patients from a malaria-endemic area of Sudan were analyzed for expression of cell surface antigens associated with T lymphocyte adhesion, activation and maturation. The results were compared to results from T cells obtained from the same donors either before the attack, or during convalescence. Most donors showed a remarkable loss of T cells with high expression of the surface marker LFA-1 (CD11a/CD18) during the clinical episode, in addition to the functional changes described above. Two donors that did not show phenotypic changes were furthermore characterized by having an unabated proliferative response and normal plasma IL 2R levels. All peripheral CD3+ T lymphocytes expressed LFA-1, which had a clearly bimodal distribution on these cells. The T cell subpopulation having high LFA-1 expression (LFA-1++) was composed of both memory and unprimed T cells, according to their expression of CD45RA and CD45R0. Analysis of expression of membrane-bound IL 2R (CD25) and ICAM-1 (CD54) did not reveal in vivo activated T cells in the peripheral blood of the patients. Taken together, these data suggest that circulating T cells recognizing parasite antigens are temporarily withdrawn from peripheral circulation during P. falciparum malaria.

Reduced cellular immune reactivity in healthy individuals during the malaria transmission season.

Antigen-induced cellular immune responses are suppressed during acute malaria. The present study engages the possibility that malaria-induced alterations in cellular immune reactivity extend beyond the clinical disease. Thus, lymphoproliferative responses of healthy individuals were diminished during the malaria transmission period in individuals living in an area of highly seasonal, unstable malaria transmission. This finding may have important implications for the design of studies of stimulatory properties of antigens using lymphocytes of endemic origin.

Cell-mediated immune responses to Plasmodium falciparum purified soluble antigens in sickle-cell trait subjects.

To determine the possible differences in the immune response to Plasmodium falciparum between sickle-cell trait (Hb AS) and normal haemoglobin (Hb AA) individuals, we examined 35 Hb AS and 24 Hb AA subjects matched for age and microenvironment. Their age was 2-55 years and all lived in a malaria endemic area 300 km south of Khartoum. Antibodies to ring-infected erythrocyte surface antigen (Pf155/RESA) and to circumsporozoite (CS) protein (anti-NANP40) indicated equal exposure to falciparum malaria. Peripheral blood mononuclear cells (BMNCs) from 20/35 (57%) Hb AS subjects compared with 10/24 (42%) Hb AA subjects, responded to affinity-purified P. falciparum soluble antigens (SPAg). Of those responding to SPAg, 9 (26%) Hb AS subjects and only two (8%) Hb AA subjects had high responses. The mean proliferative response to SPAg of BMNCs from Hb AS individuals was significantly higher than in Hb AA individuals (P less than 0.025). Responses of BMNCs to PPD and PHA were also higher among Hb AS individuals and correlated positively with responses to SPAg. These findings support the hypotheses that the sickle-cell trait protects individuals from P. falciparum infections, at least in part, by modulating the immune response.

Cell-mediated immune responses to soluble Plasmodium falciparum antigens in residents from an area of unstable malaria transmission in the Sudan.

This paper describes immune responses to P. falciparum infection in individuals living in an area of highly seasonal, unstable malaria transmission. The in vitro cellular immune responses of peripheral blood mononuclear cells (PBMC) from 36 Sudanese donors to a complex of affinity purified soluble P. falciparum antigens (SPag) and two components thereof (Ag1 and Ag7) were examined and compared to humoral immune parameters. In 29/36 Sudanese donors, SPag induced a significant lymphoproliferative response in vitro. In contrast only 3/27 Danish donors never exposed to malaria responded to SPag. Ag1 and Ag7 induced significant lymphoproliferation in 9/34 and 13/36 Sudanese donors respectively, whereas no Danish donors responded. Significant interferon-gamma production was observed in 16/27, 1/5 and 3/12 Sudanese donors when stimulated by SPag, Ag1 and Ag7 respectively. Lymphoproliferative responses to SPag correlated with proliferative responses to Ag1 and Ag7, and with Spag-induced interferon-gamma production. These results indicate that T-cell clones recognizing epitopes on Ag1 and Ag7 have been expanded in the studied population as a result of exposure to P. falciparum infection. The T-cell parameters did not correlate with the presence of antibodies to SPag, Pf155/RESA or a crude parasite sonicate or with the schizont IFA titers of the plasma. This indicates that parameters outside the degree of exposure to P. falciparum influence the cellular immune responses to malaria.

Resistance to falciparum malaria among adults in central Sudan.

Adults claiming resistance to malaria were identified in the Sennar region of central Sudan, where P. falciparum is hyperendemic but seasonal in transmission. Indirect fluorescent antibody (IFA) titers of sera from these individuals were comparable to those of malaria patients with positive blood films, indicating equal exposure, while in vitro antiparasitic activity of their sera tended to be higher, indicating an effective immunological response to falciparum malaria. Hemoglobin S (Hb S) was significantly more prevalent in adults resistant to malaria. This trait offers protection at the erythrocyte level and it is also possible that it could enhance the ability of carrier adults to acquire protective immunity. Erythrocyte 6-phosphogluconate dehydrogenase A (PGDA) and phosphoglucomutase 1 (PGM1), phenotypes of unknown relevance to protection against falciparum malaria, were also significantly more prevalent in those claiming resistance to malaria. A trend of higher prevalence for erythrocyte glucose-6-phosphate dehydrogenase deficiency (G6PD-), Kell (+) and transferrin D (TfD) was detected among resistant individuals and higher KP(a+) and P2 among malaria patients, but the numbers evaluated in this study did not allow determination of statistical significance. No association was found with erythrocyte glyoxalases, ABO and Duffy blood groups and serum haptoglobins.