Hypofibronectinaemia and severity of sickle cell anaemia in Nigeria.

Plasma fibronectin levels in sickle cell anaemia and apparently healthy Nigerians were investigated to determine any correlation with disease severity. A cheaper in-house plasma fibronectin assay was also developed that could be adapted for use in Africa and elsewhere. Plasma fibronectin assay was concurrently carried out using the newly developed inhibition enzyme-linked immunosorbent assay (ELISA) and a commercial competitive binding ELISA. The in-house assay compared favourably with that of the commercial kit. The mean plasma fibronectin levels in sickle cell anaemia subjects were significantly lower than that of control subjects (P < 0.001). Plasma fibronectin concentration could therefore be useful in assessing the severity of sickle cell anaemia.

Frequency of MNSs blood groups in south eastern Nigeria.

A total of 614 inhabitants of Calabar, south eastern Nigeria were tested with anti-M, anti-N and anti-S sera to determine the frequency of MNSs blood groups in that population. The results showed that neither ABO blood group nor sex has influence on the occurrence of MNSs blood groups in the population. It was also observed that whereas S antigen was more frequently associated with M antigen, s associated more frequently with N antigen. One half of the Su antigen occurred with MN phenotype. Significantly, the Su antigen occurred in 94% of the male subjects.

Blood donation and patterns of use in southeastern Nigeria.

A retrospective study of donor blood availability and patterns of use from 1984 through 1988 was conducted in a 400-bed university teaching hospital in Nigeria by extraction of data from the master registers for blood donors and recipients. Blood transfusion requests, number of persons who underwent phlebotomy, number of crossmatches performed, and blood use increased each year during the period of study. Average wastage rate and crossmatch-to-transfusion ratio were 3.5 percent and 1.61, respectively. Replacement blood donation constituted 98 percent of available donor blood. Obstetrics and gynecology and surgery patients used 70.4 percent of the donor blood. The donor blood units were used as whole blood (81%) because of a lack of infrastructure such as a refrigerated centrifuge. Less than 5 percent of the donors were females. It is concluded that the levels of voluntary blood donation and general blood supply are unacceptably low. The need for a functional National Blood Transfusion Service is highlighted.

ABO blood groups distribution in relation to hepatitis B surface antigen and the presence of lipoidophil antibodies.

Three hundred and thirty donors were screened for HBs Ag using direct passive haemagglutination and the presence of Lipoidophil antibodies as detected by VDRL test. Blood group O donors had the highest HBs Ag prevalence rate of 4.3% as against the 0% frequency for group AB donors. There were no significant association between ABO blood group distribution and the presence of HBs Ag (P greater than 0.05). 11 donors in all were positive for HBs Ag giving a total prevalence of 3.3%. The sera of 27 blood donors (8.2%) contained lipoidophil antibodies. The highest percentage of VDRL test positivity was in blood group B donors (22.7%) followed by group O (9.1%). None of the 6 group AB donors had a reactive sera. Test of significance showed that there was no association between ABO distribution and the presence of lipoidophil antibodies. In conclusion, it is stated that since none of the blood donors that was reactive to the VDRL reagin carried HBs Ag, hepatitis virus B unlike other viral infection, may not elicit the production of lipoidophil antibodies.

ABH secretor status in saliva of Calabar Municipality residents.

One hundred and seventy six healthy residents of Calabar Municipality were investigated for the presence of salivary ABH substances. Saliva and blood samples collected were analysed by haemagglutination inhibition and standard tube ABO grouping methods respectively. 86.90% and 13.10% of the subjects were ABH secretors and non-secretors respectively. A significant correlation was established between the secretor status frequency and ABO blood group phenotypes (P less than 0.001). No correlation was established with age or sex. O blood group subjects had higher titre of H-substances than A and B subjects while AB subjects had the lowest. In AB subjects, the A titre was usually higher than that of B substances. The gene frequencies for Se and se were 0.6390 and 0.3610 respectively while the phenotype prevalence rates for Se/se, Se se and se se were 40.83%, 46.15% and 13.10% respectively. It is concluded that the prevalence rate of non-secretors which has been associated with the occurrence of duodenal ulcer is low in the locality.

In vivo platelet aggregation in acute malaria.

Thirteen patients suffering from acute malaria attack and thirteen apparently healthy human volunteers (control) were used for the study. Platelet aggregation was determined by platelet count ratio technique in which a reduction in platelet count ratio signified an increase in platelet aggregation. Platelet count ratio in acute malaria patients was 0.75 +/- 0.03 (SEM). Platelet count ratio in subjects used as control was 0.88 +/- 0.02. This value was significantly higher than the former (P less than 0.001). Platelet count ratio correlated negatively with the degree of parasitaemia (r = -0.71; P less than 0.01). ADP, a platelet aggregating drug, also reduced platelet count ratio in rats significantly. Acute malaria attack therefore enhances platelet aggregation in vivo.

Haematology of experimental Trypanosoma brucei gambiense infection. II. Erythrocyte and leucocyte changes.

Chronic Trypanosoma b. gambiense infection of rabbits induced mild anaemia which was initially macrocytic normochromic, but became later microcytic hypochromic. Moderate anisocytosis and poikilocytosis were evident from 14 days post infection (p.i.). Nucleated red cells which were observed prior to the infection (normal feature of rabbits) declined in number as the infection progressed. Leucocytosis with neutrophilia, eosinophilia, monocytosis and terminal lymphopaenia were also observed. The main changes in the morphology of leucocytes were the presence of atypical lymphocytes as well as increased levels of band neutrophils in the peripheral circulation. It is concluded that the main erythrocytic and leucocytic changes in the T.b. gambiense infection were mild anaemia which was terminally microcytic hypochromic and transient leucocytosis due to neutrophilia and monocytosis.

Problems of chloroquine-resistant P. falciparum in Nigeria: one antimalaria drugs' utilisation in metropolitan Calabar.

We studied the antimalarial drugs utilisation pattern in urban Calabar, with a view to determining what drugs people take when they have malaria attack and who diagnoses and prescribes the drugs. We used a standard questionnaire data sheet to record the results of the interview carried out by the authors. Malaria symptoms and the drugs consumed were diagnosed and prescribed respectively by self (54pc), qualified medical doctor (32pc) and others including paramedical staff (2pc). The rest (12pc) took traditional remedies. The antimalarial drugs (chloroquine, fansidar, camouqin) were chosen because of their efficacy/popularity (21pc), cheapness (43pc) and availability (34pc). Among those interviewed, only 21.2pc took the adequate curative dose of 25 mg/kg chloroquine for 3 days according to WHO recommendations. Majority of the consumers took their drugs orally, but some (17pc) had chloroquine injections, administered, in some cases, by ill-qualified patient medicine dealer. The results show that there is an association between the level of education and the pattern of remedy sought by the respondents (p less than 0.05). Self-medication was practised significantly more by those with formal education than by those without (p less than 0.05). The trend of consulting patent medicine dealers for prescription decreased with acquisition of more formal education. Conversely, significantly more of the respondents with higher education consulted qualified medical doctors or paramedical staff (P less than 0.05). Two aspects of drug abuse observed here, i.e. the utilisation of sub-curative doses of chloroquine and monotherapy are believed to be two of the factors that lead to the several chloroquine treatment failures which have been recently reported in Calabar, and other areas of Nigeria.

The status of alpha and beta haemolysins in Nigerian blood donors.

Six hundred and two blood donors were screened for alpha (alpha) and beta (beta) haemolysins using standard tube technique at 37 degrees C for 1 hour. The prevalence of beta haemolysin in group A donors was 12.1% while that of alpha haemolysin in group B donors was 5%. 21.4% of the donors had alpha, beta and alpha + beta haemolysins in their sera. The frequency of group O donors with alpha only in their sera was 5.7% which is comparable to that in B donors. beta haemolysin occurring alone in group O subjects was 8.6% which is not statistically significant from the 12.1% prevalence in A donors (P greater than 0.05). Total haemolysin frequency in O donors was 30.6% which is significantly higher than the 21.4% prevalence of the entire donors (P less than 0.005). Summation of occurrence of beta haemolysins appearing singly in group O donors (14.3%) is comparable to the prevalence of alpha + beta appearing concurrently (16.3%). Rhesus D distribution had no significant influence on prevalence of alpha and beta haemolysins. There was no significant difference between the different age groups of the donors. It is concluded that the use of O blood for A or B recipients be discontinued considering the high frequency rate of 30.6% for alpha and beta haemolysins in group O donors.

Platelet aggregation inhibition in Trypanosoma vivax infection of sheep.

We have investigated in vitro platelet aggregation in platelet rich plasma from Trypanosoma vivax infected and control sheep using the dual channel Payton Aggregometer. Final concentrations of the following inducing agents were used: 1.2 um ADP, 6.2 ug collagen, 1.2 ug ristocetin and 1 u thrombin. These showed that there was a significantly reduced aggregation of platelets from infected sheep (13.4 +/- 1.1 pc at week 3 post infection when compared with control sheep PRP 95.0 +/- 1.0pc; P less than 0.001) using ADP. Similar differences were also obtained with other inducing agents. Preliminary 14C-5HT uptake and release studies showed that there was difference in the uptake of label between platelets from infected (18.6pc) and control (28.4pc) sheep. However, when release was inducted, comparable results were obtained for both infected and control sheep platelets. It is concluded that the degree of aggregation inhibiting varies directly with the level of parasitaemia.

Haemoparasites of blood donors in Calabar.

The study of haemoparasites in our blood donors revealed the following parasite prevalences: microfilaria (mf) of Loa loa (1.3%); Dipetalonema perstans (15.6%); Loa loa and D. perstans (0.2%), Plasmodium falciparum (3.3%), Plasmodium malariae (1.0%) and a mixture of P. falciparum and P. malariae (0.2%). No trypanosomes were observed in the 480 blood samples screened. There were more cases of D. perstans infection in the 24-30 year age group, indicating their increased exposure frequencies. Matching of ABO blood group and mf infection rates shows that the O blood group has a higher prevalence rate with regard to D. perstans than Loa loa. The B blood group, however, had the highest cumulative % of mf infection (23.4%), but these values are consistent with the preponderance of the various blood groups in the study population. Commercial donors, most of whom come from the less affluent social classes, had higher prevalence rates of mf. It is recommended that blood be properly screened for mf before donation for transfusion. Recipients of infected blood should be followed up so that any consequent infection would be treated immediately.