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Biomedical subjects

G O Oyeyinka

Publications and source records attributed to G O Oyeyinka.

At least 19 recordsLinked to original sources
PubMed2004

Homogeneous immunoglobulins in Ghanaians living in Accra, Ghana.

Serum screening for homogeneous immunoglobulins (H-Ig) was done on 149 apparently healthy Ghanaians (aged 17-95 years) and 73 sick subjects who presented at the Korle-Bu Teaching Hospital from October 1999 to September 2000. Sera were screened by agarose gel electrophoresis and those with equivocal results were confirmed by immunoelectrophoresis. Immunoglobulin classes (IgG, IgA and IgM) and Bence Jones proteinuria were measured and determined by single radial immunodiffusion method and heating respectively. Total protein, albumin, calcium, uric acid, urea and creatinine were estimated on ACE chemistry autoanalyser. The laboratory profile of 5 Ghanaians with a picture of multiple myeloma and one with monoclonal gammopathy of undetermined significance drawn from the sick subjects (6 of 73) are presented. None of the 149 healthy subjects studied in three age groups (17-40; 41-64 and dollar 65 years) had H-Ig, and their serum IgG, IgA, IgM, urea, creatinine, uric acid, calcium, total protein and albumin levels were within the normal range. H-Ig were present in sera of 6 out of the 73 sick subjects (8.2%); 5 of them (4 males, 1 female) presented a picture of multiple myeloma. Three of these 5 patients had IgG, and the others IgA paraproteinaemia. All 5 patients had immunoparesis which was absent in the 6th patient (a male) who also had IgA paraproteinaemia (< 10 g/L), active bone marrow with < 2% mature plasma cells and no renal involvement. Results of bone marrow examination supported a diagnosis of multiple myeloma in the 3 patients with IgG paraproteinaemia, but were not available for the other two. Bence-Jones proteinuria was found in 2 (both with IgG paraproteinaemia) of 4 patients (50%) available for testing. Renal involvement was indicated in the 5 patients with a picture of multiple myeloma as urea and creatinine levels were significantly raised.

Adolescent↗
PubMed2003

The effects of ageing on the immune response to Schistosoma haematobium and hookworm by measuring circulating immune complexes, C3, IgG, IgA and IgM levels in residents of Omi dam area of Kogi State, Nigeria.

In this study, the effects of infestation (with Schistosoma haematobium or hookworm) during host ageing on the serum levels of circulating immune complexes (CIC), C3, IgG, IgA and IgM were examined in residents of Omi dam area of Kogi state, Nigeria. S. haematobium-infested and hookworm-infested individuals showed no significant alteration in the levels of CIC, C3, IgG, IgA and IgM in comparison with controls. These levels were the same in infested subjects and controls even when the patients were pooled. Infested old people had the same concentrations of serum CIC, C3 IgG and IgM in comparison with infested young people but IgA levels were higher in the aged group (t=2.100; P<0.05); and were significantly correlated with age (r=0.301; P<0.05). No significant increase in CIC levels with rising age (r=0.123; P>0.20) was observed in the overall population of infested subjects; and infestation in old age did not alter CIC, C3, IgG, IgA and IgM levels in comparison with uninfested young people. For the uninfested, IgG, IgA and IgM values were similar in the aged and the young but the levels of CIC were higher (t=2.156; P<0.05; r=0.280; P<0.05) and C3 lower (t=3.313; P<0.01; r=-0.236; P>0.10) in the aged. The results of this study suggest that the elevated CIC levels found in old people is age-related; and that the contribution of parasitic infestation to these raised levels is uncertain.

Adolescent↗
PubMed1995

The role of circulating immune complexes; antinuclear and rheumatoid factor autoantibodies in aging in Nigerians.

The concentrations of circulating immune complexes (CICs) have been measured in healthy Nigerians aged 6-95 years by the polyethylene glycol precipitation technique. The prevalence of antinuclear antibodies (ANAs) and rheumatoid factors (RFs) was also studied in these Nigerians. Significant positive correlation between CIC concentrations and age was observed; but no sex-related differences. Weakly reacting ANAs plus age-associated increase in ANA prevalence were noted. Positivity rate for RFs detected by latex agglutination was significantly higher (chi 2 = 3.948; P < 0.05) in old subjects (> 65 years of age; 9.4%) compared to younger ones (< 65 years of age; 2.7%). Semi-quantitative Rose-Waaler technique gave 22% RF seropositivity rate in subjects with age > 65 years. The age groups 46-65 years, 26-45 years, and 6-25 years had 13.5%, 7.5% and 2.5% positivity rates, respectively. There was significant positive correlation between RF concentrations and CIC levels; and increased prevalence of RF autoantibody in subjects with CIC (10%) compared with those without (4.7%). Four percent of subjects with CICs, and none of those without, were positive for ANAs. Autoantibodies may contribute to increased prevalence of CICs in old individuals.

Adolescent↗
PubMed1995

Leukocyte migration inhibition studies and neutrophil cell function during aging in Nigerians.

In this study, in vitro cell-mediated immune response was analysed in 150 healthy Nigerians between 6 and 95 years old by the leukocyte migration inhibitory factor (L-MIF) test. Lymphocytes were activated with the mitogen concanavalin A and candida, measles virus and mycobacterial antigens. Nonspecific cellular immune capacity was studied by the Nitroblue tetrazolium (NBT) test. Numerical estimates of leukocytes and lymphocyte subpopulations were done. Mean L-MIF activity obtained with the four lymphocyte activators decreased with rising age indicating a progressive decline in cellular immune function with age. There was no significant age-related change in formazan positivity rate for both unstimulated and stimulated NBT tests. No age-related change in number was observed for any of the leucocyte and lymphocyte subpopulations. These results show that cell-mediaging response in Nigerians immunity declines, but phagocyte function is unchanged during aging. Lymphocyte depletion or numerical alteration in resting T cell subsets could not be demonstrated to be responsible for depressed cell-mediated immunity in aging Nigerians.

Adult↗
PubMed1995

Complement and immunoglobulin levels in Ilorin Nigeria, and environ.

The levels of complement components C3 and C4 were determined in EDTA (ethylene-diamine-tetra-acetic acid) plasma of 106 apparently healthy people aged 11-50 years, and in 23 paired maternal and cord plasma in Ilorin. The immunoglobulins G,A and M concentrations of these paired samples were also assayed. Furthermore, serum IgG, IgA and IgM levels were quantitated in 501 apparently healthy residents of Ilorin (1-84 years old, n = 313) and its suburban community, Shao (11-80 years old, n = 188). Generally, there were no significant sex-related differences in C3 and C4 values, but these values increased steadily with age. C3 and C4 levels in cord plasma were high, representing 73% and 88% of adult levels respectively. Maternal levels of these complement components were higher (P < 0.02) than values obtained in non-pregnant females of comparable age. Immunoglobulin G values obtained for maternal and cord samples compare well with figures reported previously from other centres in Nigeria. Only 1 of 23 IgA and 2 of 23 IgM samples showed detectable values of these immunoglobulins in cord blood. The mean concentrations of immunoglobulins obtained were similar for IgG and lower for IgA and IgM in Ilorin, but higher for IgG and lower for IgA and IgM in Shao, when compared with data reported from Enugu and Zaria--both in Nigeria. Shao showed significantly higher mean level of IgG but similar levels of IgA and IgM to values obtained in Ilorin. Generally, IgG and IgA concentrations rose gradually up to age group 31-40 and 41-50 years respectively; and then declined. (ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Surveillance of humoral immunity to measles virus in Ilorin, Nigeria and environ.

Detection of measles specific IgG in serum was done on 618 samples obtained from Nigerians (aged 11 years or more) resident in Ilorin (urban) and Shao (a suburban outlay of Ilorin). An enzyme-linked immunosorbent assay (ELISA) method was used. Eighty-six percent of the sampled population had detectable antibody levels. Significant differences were found between positivity rates in the two locations studied and between the sexes in the urban samples.

Adult↗
PubMed1990

Secretory IgA and other proteins in semen from healthy Nigerian men.

The secretory IgA (SIgA) levels in semen and immunoglobulin A, G, M and D concentrations in semen and serum from 30 apparently healthy Nigerian men with various sperm counts were studied. Albumin levels in the samples were also measured to determine the contribution of serum transudation to the semen concentration. Nine of the participants (30%) had no detectable SIgA in their semen, while IgM and IgD were undetectable in all the semen samples. Analysis of proteins in the semen revealed an increase in the IgA:albumin ratio as compared to serum, while the IgG:albumin ratio was the same. The relative semen concentrations for IgA were generally slightly higher than and for IgG were lower than for albumin. Those levels did not correlate for IgA and albumin, while the IgG and albumin levels correlated with each other. A mathematical estimate of the amount of IgA produced locally showed no statistically significant difference between azoospermic and normospermic men. The data indicate that some men are capable of local IgG production.

Albumins↗
PubMed1988

The role of mitogenic factors in the pathogenesis of certain features of malarial infection.

The clinical and pathological features of malaria have been well recognized for a long time. Macroglobulinaemia accompanies malarial infections and these patients have increased susceptibility to secondary infection. They may also have splenic enlargement. However, how these changes are brought about is still not fully explained. For over a decade many researchers have looked into the possibility of a parasite-derived mitogen being partly responsible for some of these features. This paper appraises, in the light of evidence so far advanced, the role of mitogenic factors in the pathogenesis of hypergammaglobulinaemia, immunosuppression and splenomegaly associated with malarial infection. The nature of the stimulatory material in parasite extracts is also discussed.

Animals↗
PubMed1987

ABO blood group incompatibility and infertility in Nigerian couples.

ABO blood group substances were determined in either the seminal plasma (male patients) or saliva of 100 infertile couples and 100 control subjects. Comprehensive infertility evaluation was performed in all patients. Results were analysed in groups of couples with respect to their ABO blood group and compared with fertile control subjects. Over 70% of fertile marriages were compatible. Comparison of infertile and fertile couples for either ABO compatibility or incompatibility did not reveal any statistically significant difference (P greater than 0.05). This suggests some measure of low zone tolerance to ABO antigens on spermatozoa, for only a small minority of sperm introduced during coitus gains access to the oviduct and ultimately to the peritoneal cavity.

ABO Blood-Group System↗
PubMed1987

Neutrophil cell function and migration inhibition studies in Nigerian patients with tropical pyomyositis.

We investigated polymorphonuclear neutrophil (PMN) cell function and migration inhibition factor (MIF) in Nigerian patients with tropical pyomyositis (TP) and in healthy Nigerians as control subjects. The nitroblue tetrazolium (NBT) reduction test revealed that the ability of PMN to form formazan in patients was similar to that of the control subjects. This observation was taken to indicate that there may not be any metabolic defect in PMN of these patients. The MIF assay showed that the lymphocytes of the patients were significantly inefficient in responding in vitro to Staphylococcus aureus as compared with controls (S.D. 26 +/- 8 for patients, 53 +/- 10 for controls; P less than 0.01). This observation suggested that lymphocytes, particularly T-cells, of the patients were probably not primed adequately against S. aureus during the course of infection in vivo. The implications of these findings as they relate to tropical pyomyositis are discussed.

Adolescent↗
PubMed1987

Levels of some complement components in azoospermic, oligospermic and normospermic Nigerian men.

The levels of complement components (C1q, C4, C3 and C3d) were measured in the sera of nine azoospermic Nigerian men and compared with those of 12 oligospermic and 19 normospermic Nigerian men. The mean values of C1q, C4, C3 and C3d for azoospermic men showed no significant difference from those obtained for the other men. Generally, the individual sera from the azoospermic men did not show abnormally lowered levels of any of the complement components when compared with values obtained for the normospermic group.

Autoimmune Diseases↗
PubMed1985

Evidence against the red blood cell origin of mitogenic factors in mouse malarial infection.

The mean [3H]thymidine incorporation in response to stimulation of spleen cells of malaria-immune and non-immune BALB/c mice by normal mouse red blood cell culture supernatants were compared with unstimulated cultures of the same spleen cells. No significant difference was obtained between stimulated and unstimulated cultures for both immune and non-immune spleen cells. These findings do not support the hypothesis that erythrocyte-derived mitogenic factors occur in malarial infection.

Animals↗
PubMed1984

Control of epidemic meningococcal meningitis by mass vaccination. II. Persistence of antibody four years after vaccination.

Meningococcal antibody was measured in 928 persons vaccinated with combined groups A and C polysaccharide antigens in Bauchi State, Nigeria between 1979 and 1982. Protective amounts of antibody were detected by the indirect haemagglutination technique up to 4 years after vaccination. This persistence was observed mainly in adults, although a substantial proportion of older children also had persistent antibody. Titres in younger children fell progressively, and by the third year the mean log2 antibody titre was 1.4; this may not confer protection against disease. A rational policy for vaccination against meningococcal meningitis would be to revaccinate younger children after 2 years, older children after 4 years, and adults after 6-8 or more years.

Adolescent↗
PubMed1984

Age and sex differences in immunocompetence.

The probable role of an immunological component in ageing and senescence has attracted the attention of biologists, immunologists and gerontologists. Immune competence declines as man and experimental animals grow old. While lymphoid organs may be expected to 'age' along with other tissues, the possibility exists that lymphoid failure of itself accelerates senescence by predisposing individuals to infection and degenerative diseases. There is now enough evidence to differentiate effects that are due to age per se from other causes. Also, evidence of a greater female than male immunologic responsiveness is ample, but hypotheses to explain these observations are only partially adequate. This review attempts to summarise our knowledge of the effects of age and sex on immunocompetence with the aim of discussing the theories put forward to explain our observations.

Aged↗
PubMed1983

Failure to induce splenomegaly in BALB/c mice using rodent malaria culture supernatants.

Uninfected male and female BALB/c mice were given a twice weekly intraperitoneal injection, of supernatants obtained from 24-h cultures of Plasmodium berghei-infected and control mouse red blood cells, for 5 weeks. The mice were then weighed along with uninjected controls. All the animals were sacrificed by chloroform anaesthesia and their spleen weights measured. Mice receiving malaria culture supernatants had statistically similar spleen weights to those receiving control culture supernatants. The results fail to show the involvement of a malaria 'mitogen' in the pathogenesis of the splenomegaly associated with this infection.

Animals↗