Search PubMed⌕ Search

Biomedical subjects

P J Ojwang

Publications and source records attributed to P J Ojwang.

At least 19 recordsLinked to original sources
PubMed2002

Leptin and pre-eclampsia in black African parturients.

OBJECTIVE: To measure serum concentrations of the hormone leptin during late pregnancy in Black African women with pre-eclampsia, healthy normotensive pregnant women as controls and healthy normotensive non-pregnant women; secondly, to explore the relationship between leptin and obesity. DESIGN: Observational, cross sectional study. SETTING: Antenatal clinics, antenatal wards, gynaecology out patient and family planning clinics of a tertiary hospital, Durban, South Africa. POPULATION: Pregnant and non-pregnant Black African women. METHOD: Serum leptin was measured by a homologous radio-immunoassay technique. Simple anthropometric parameters were used to explore the relationship between leptin and obesity. In each group, leptin levels were compared between obese (body mass index, BMI > or = 30 kg m(-2)) and lean women. MAIN OUTCOME MEASURES: Serum leptin concentrations, anthropometric parameters, mean blood pressures and proteinuria. RESULTS: There were 68 women with pre-eclampsia, 92 healthy normotensive pregnant women (controls) and 32 healthy normotensive non-pregnant women. Serum leptin levels were higher in pregnant compared with non-pregnant women [26.66 (1.96) and 25.89 (1.65) vs 17.97 (2.11) ng/mL, P = 0.02]. Weight and BMI showed the greatest correlation with leptin both in pregnant (r = 0.61 and r = 0.58, respectively) and non-pregnant women (r = 0.74 and 0.79, respectively). There was no significant difference in the mean concentrations of leptin between women with and those without pre-eclampsia [26.66 (1.96) vs 25.89 (1.65) ng/mL, respectively, P = 0.95]. CONCLUSION: Pregnancy is a hyperleptinaemic state. There is no difference in serum leptin levels between Black African women with pre-eclampsia and healthy normotensive pregnant women. Serum leptin concentration is largely determined by the degree of adiposity.

Adult↗
PubMed2001

Soluble transferrin receptors in anaemia of pregnancy.

Anaemia is one of the most common disorders in pregnancy. The most common cause is iron deficiency. Iron deficiency anaemia is relatively easy to diagnose using a serum ferritin of <15 ng/ml. However, because ferritin is an acute phase reactant, the diagnosis of iron deficiency anaemia in hospitalised or ill patients may be difficult, since serum ferritin may be normal or raised, even in the face of iron deficiency. Soluble transferrin receptor assay (STfR) may be useful in these situations because it reflects the degree of iron requirement in relation to supply, and it is not an acute phase reactant. This study was undertaken to detect subclinical anaemia in pregnant women and to correlate STfR assay with the current diagnostic tests for iron deficiency anaemia. One hundred and fifty-three consenting pregnant women seen at the antenatal clinic at King Edward VIII Hospital (KEH) were recruited. Women on haemantinics, who had renal failure, haemoglinopathy and blood transfusion in the past 3 months, were excluded. An ELISA technique was used for the assay of STfR while standard methodology was used for the other biochemical and haematological assays (FBC, urea, creatinine, c reactive protein and iron studies). One hundred and fifty subjects were included in the final analysis. Seventy-two (48%) had varying degrees of iron deficiency anaemia. In 70% (105) of the samples analysed, serum ferritin and STfR agreed on the presence/absence of iron deficiency anaemia. STfR and S:F were 75% and 86% sensitive; 63% and 82% specific, respectively. The calculated positive and negative predictive values are: STfR 64% and 75%; S:F 84% and 87%; Hb 58% and 57%; mean corpuscular volume 91% and 55%, respectively. Ferritin remains the gold standard for the diagnosis of iron deficiency anaemia. However, because ferritin is an acute phase reactant, soluble transferrin receptor assay may be a better test in ill and hospitalised patients where ferritin may be normal or elevated, despite iron deficiency.

Journal Article↗
PubMed2001

Collagen Ialpha1 and vitamin D receptor gene polymorphisms in South African whites, blacks and Indians.

OBJECTIVE: To determine whether polymorphic differences exist between black, white and Indian South Africans in genes associated with bone mineral density and osteoporosis. DESIGN: Genes selected were the vitamin D receptor (Apa I and Taq I polymorphisms) and collagen (Sp I transcription factor polymorphism) using standard molecular biology techniques. SETTING: Department of Chemical Pathology, Nelson R Mandela School of Medicine, University of Natal, Durban, South Africa. SUBJECTS: Healthy male and female blood donors living in the Durban metropolitan region, South Africa. The group comprised black Africans (n=264), white Caucasians (n=247) and Asians of Indian origin (n=194). RESULTS: No significant differences in genotypes were seen between white and Indian subjects. Blacks had a significantly higher frequency of the TT Taq I genotype and a significantly lower frequency of the Ss Sp I genotype. No ss genotype was detected in blacks. CONCLUSION: The very low frequency of the collagen Sp I s allele and higher frequency of the VDR T allele in blacks may be associated with the lower incidence of osteoporosis in this ethnic group.

Black People↗
PubMed2001

Biochemical and molecular diagnosis of glutaric aciduria type 1 in a black South African male child: case report.

Glutaric aciduria type 1 (GA-1) is an inborn error of metabolism caused by a deficiency of the mitochondrial enzyme glutaryl-Co enzyme A dehydrogenase. GA-1 is not uncommon amongst Caucasians but to the best of our knowledge, it has previously not been reported in black African children. We present a case of GA-1 in a black South African boy who was referred to hospital at the age of five years and ten 10 months with dyskinesia and dystonia accompanied by chorea and athetosis. Radiological examination revealed enlarged basal cisterns with bilateral fluid collection around the sylvian fissures suggestive of GA-1. Analysis of urine showed raised levels of glutaric acid at 520 micromol/mmol creatinine (normal <2.0), 3-hydroxyglutaric acid at 113 micromol/mmol creatinine (normal <3.0) and a low blood carnitine level of 31.5 micromol/l (normal 35-84). A definitive diagnosis was reached through DNA analysis which revealed homozygosity for an A293T mutation in the glutaryl-Co-enzyme A dehydrogenase (GCDH) gene.

Amino Acid Metabolism, Inborn Errors↗
PubMed1999

Galactosaemia in black South African children.

OBJECTIVE: To evaluate the clinical and biochemical features of all black children confirmed to have galactosaemia from the KwaZulu Natal Province of South Africa. DESIGN: Prospective laboratory study. SUBJECTS: These included all black children with the presenting clinical features suggestive of the diagnosis of galactosaemia. SETTING: Department of Chemical Pathology, King Edward VIII Hospital, Durban, South Africa. METHOD: In each case, urine was screened for the presence of a reducing substance using urinary dipstick followed by thin layer chromatography to establish the presence of galactosaemia. The diagnosis of galacotosaemia was then confirmed by analysis of galactose-1 phosphate uridyl transferase (GALT) activity in the erythrocytes using the established Beutler enzyme assay procedure. Age and sex-matched samples were used as controls for GALT activity. The presenting clinical features of each patient on admission were also recorded. INTERVENTIONS: Patients confirmed to have galactosaemia were immediately placed on a galactose free diet. RESULTS: The age distribution of affected individuals varied from six weeks to 27 months with 60% of the children being males. The most common presenting clinical features were jaundice in 77% of the patients, failure to thrive 62%, and cataracts 54%. Four patients had complete absence of GALT activity. Two infants who displayed acute toxicity symptoms and positive urine galactose, exhibited normal GALT activity. CONCLUSION: GALT deficiency is the most common form of galactosaemia in black children in the KwaZulu Natal region. Cases of galactokinase or epimerase enzyme deficiency appear to be present. Further investigation is required to establish the occurrence and prevalence of the latter in affected individuals in this region.

Age Distribution↗
PubMed1994

Reference intervals for some biochemical parameters in the aged Kenyan population.

Serum levels for sodium, potassium, calcium, inorganic phosphate, urea nitrogen and creatinine were determined in 1101 male and 181 female patients aged 50 years and above. The determinations were carried out on the SMA II (Technicon Instruments Corp. Tarrytown, NY 10591) with a view to establish the reference intervals for this age group. Quality control of the analytical methods was carried alongside with the determinations. The data collected was used to determine the reference intervals using a simple statistical method. The results indicate that sodium and calcium intervals are low with values of 131-142 mMol/L and 1.94-2.32 mMol/L respectively, in the aged Kenyan population as compared to subjects living in the temperate environment while the interval for inorganic phosphate is comparatively high with a value of 1.2-1.97 mMol/L. Reference values for urea nitrogen, potassium and creatinine were found to be similar to those quoted for caucasians.

Age Factors↗
PubMed1993

External quality control performance in clinical chemistry: experience in Kenya.

Analysis of eleven biochemical laboratory tests was done during an International External Quality Assessment Scheme (IEQAS) in which the clinical chemistry laboratory at Kenyatta National Hospital participated. Technicon SMA II continuous flow system was used in the biochemical analyses apart from glucose which was assayed manually by the glucose oxidase method. Using the standard deviation index (SDI), twenty six percent of the results were found to be outside the two standard deviation (2SD) limit. However, when variance index score (VIS) was used, 42% of the results were found to be outliers. Overall, our laboratory performed poorly compared to other laboratories in both the IEQAS and the United Kingdom External Quality Assurance Scheme (UKEQAS). This poor performance is attributed to the use of improper equipment which is not regularly maintained, lack of diagnostic reagents, lack of quality control (QC) materials and inadequate staff training in the field of quality control.

Animals↗
PubMed1991

Maternal levels of alpha-fetoprotein in African women.

In a prospective and cross-sectional study, 147 serum samples from normal antenatal indigenous Kenyan women were analysed for alpha-fetoprotein (AFP) concentrations between 8 and 28 weeks gestation. There was progressive rise in AFP levels with gestation, most rapid between 12 and 24 weeks. There were wide variations in AFP concentrations at every gestation but no correlation was established with maternal age or parity. All the eleven women with very high AFP values had subsequent complications, including 2 abortions, 1 APH, 7 PET and one pair of twins. The need for more studies on the value of AFP in monitoring of pregnancy in the African set up is emphasised.

Adult↗
PubMed1989

beta S-haplotypes and alpha-thalassemia along the coastal belt of Kenya.

In this paper, we present data on studies of beta S-haplotypes and alpha-thalassemia gene in subjects from the indigenous population of the Coast Province of Kenya Of the 7SS patients studied, four were homozygous for beta S-haplotype 20 characteristically associated with the severe form of sickle cell anemia found in the Central African Republic and Western Kenya. Two had haplotype 20 combined with haplotype 19 (Benin Type) and one had haplotype 20 combined with a new haplotype (20x). Alpha thalassaemia-2 gene (-3.7kb deletion) was detected in 45.6% of the 57AA subjects studied. An alpha globin gene triplication was detected in one subject whereas eight had gamma globin gene triplication.

Adolescent↗
PubMed1987

Characterization of chromosomes with hybrid genes for Hb Lepore-Washington, Hb Lepore-Baltimore, Hb P-Nilotic, and Hb Kenya.

This study concerns the characterization of chromosomes with hybrid genes for Hb Lepore-Washington (44 chromosomes), for Hb Lepore-Baltimore (5 chromosomes), for Hb P-Nilotic (8 chromosomes), and for Hb Kenya (7 chromosomes) by determining a relatively large number of restriction enzyme polymorphism. Two, and possibly three, different Hb Lepore-Washington chromosomes were identified by specific haplotypes, while the haplotype of the Hb Lepore-Baltimore chromosome had its own characteristic pattern. A likely conclusion is that the crossovers leading to the formation of these chromosomes have occurred as independent events within the populations. Chromosomes with the delta beta-Lepore-Washington hybrid gene maintained specific characteristics (such as increased Hb F levels in heterozygotes, and high or low G gamma values in this Hb F) which have been observed in normal individuals with chromosomes having comparable haplotypes. Only one haplotype was observed for each of the chromosomes carrying either the beta delta-P-Nilotic hybrid gene or the A gamma beta hybrid gene of Hb Kenya.

Chromosome Mapping↗
PubMed1987

Haplotypes and alpha globin gene analyses in sickle cell anaemia patients from Kenya.

Over 60 patients from the Luo and Luhya tribes of Western Kenya, aged 1-23 years, with severe sickle cell anaemia were evaluated through haematological and gene mapping analyses. Nearly all (56 of 58 tested) were homozygous for haplotype 20 (Antonarakis et al, 1984) which is also frequently present in SS patients of the Central African Republic. All patients had a severe haemolytic anaemia with low Hb F levels and low levels of G gamma chains. An alpha-thalassaemia-2 heterozygosity (-alpha/alpha alpha; -3.7 kb deletion) was present in 26 of 53 patients tested; one patient was a homozygote [f(-alpha) = 0.255]. The alpha-thal-2 was type I in all but one subject with this deficiency; the one exception had an alpha-thal-2 heterozygosity, type II. Heterozygosity for the alpha-thal-2 did not affect the clinical condition nor the haematology; Hb F levels were somewhat lower in SS patients with -alpha/alpha alpha than in those with alpha alpha/alpha alpha. A high frequency was observed for the absence of an Xba I restriction site 5' to the zeta globin gene; the frequency of this anomaly [f(Xba I-)] was estimated at 0.39 for the chromosome with two alpha globin genes and at 0.74 for that with the alpha-thal-2 deletion. An Apa I restriction site polymorphism was observed in the IVS-II of the alpha 2 globin gene; 13 alpha 2 genes of 53 normal (alpha alpha/) chromosomes had this restriction site which was absent in the hybrid alpha globin gene of the -alpha/chromosome.

Adolescent↗
PubMed1986

The effect of alpha-thalassemia on the level of hybrid hemoglobin variants in heterozygotes.

The influence of a relative deficiency in alpha chain production on the amount of Hemoglobins Kenya, P-Nilotic, and Lepore was determined. The level of these hybrid hemoglobins in heterozygotes was correlated to various states of alpha chain deficiency by: 1) quantitation of the variants in blood samples and comparing these data with the number of alpha globin genes determined by gene mapping, 2) in vitro recombination experiments involving isolated non-alpha chains and normal alpha chains, and 3) in vitro heat stability analyses of the isolated hemoglobins. Hb Kenya, composed of normal alpha and gamma-beta hybrid chains, is heat labile, has a decreased ability to combine with alpha chains, and its level in heterozygotes is greatly decreased when a concomitant alpha-chain deficiency (alpha-thalassemia) is present. Such a posttranslational control mechanism was not observed for Hb Lepore, with normal alpha chains and delta-beta hybrid chains, and Hb P-Nilotic, with normal alpha chains and beta-delta hybrid chains. The latter two variants are heat stable, and their hybrid chains combine equally well as normal beta chains with normal alpha chains. Hb P-Nilotic is more heat stable than Hb A and its in vitro formation is increased over that of Hb S, and perhaps even Hb A, in conditions of severe alpha chain deficiency.

Fetal Hemoglobin↗