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Biomedical subjects

K A Harrison

Publications and source records attributed to K A Harrison.

At least 55 records · Page 3Linked to original sources
PubMed1986

The prevention of anaemia in pregnancy in primigravidae in the guinea savanna of Nigeria.

Two hundred Hausa primigravidae at Zaria were divided into five groups in a randomized double-blind trial of antenatal oral antimalarial prophylaxis, and haematinic supplements. Group 1 received no active treatment. Groups 2 to 5 were given chloroquine 600 mg base once, followed by proguanil 100 mg per day. In addition, group 3 received iron 60 mg daily, group 4 folic acid 1 mg daily, and group 5 iron plus folic acid. Forty-five percent were anaemic (haemoglobin (Hb) less than 11.0 g dl-1) at first attendance before 24 weeks of gestation, and malaria parasitaemia (predominantly Plasmodium falciparum) was seen in 27%, of whom 60% were anaemic. The mean Hb fell during pregnancy in group 1, and seven patients in this group had to be removed from the trial and treated for severe anaemia (packed cell volume (PCV) less than 0.26). Only five patients in the other groups developed severe anaemia (P = 0.006), two of whom had malaria following failure to take treatment. Patients in group 1 had the lowest mean Hb at 28 and 36 weeks of gestation, and patients receiving antimalarials and iron (groups 3 and 5) had the highest Hb at 28 weeks, but differences were not significant, possibly due to removal from the trial of patients with severe anaemia. Anaemia (Hb less than 12.0 g dl-1) at six weeks after delivery was observed in 61% of those not receiving active treatment (group 1), in 39% of those protected against malaria but not receiving iron supplements (groups 2 and 4) and in only 18% of patients receiving both antimalarials and iron (groups 3 and 5). Folic acid had no significant effect on mean Hb. Proguanil was confirmed to be a highly effective causal prophylaxis. Prevention of malaria, without folic acid supplements, reduced the frequency of megaloblastic erythropoiesis from 56% to 25%. Folic acid supplements abolished megaloblastosis, except in three patients who were apparently not taking the treatment prescribed. Red cell folate (RCF) concentrations were higher in subjects with malaria, probably due to intracellular synthesis by plasmodia. Infants of mothers not receiving antimalarials appeared to have an erythroid hyperplasia. Maternal folate supplements raised infants' serum folate and RCF. Fourteen per cent had low birth weight (less than 2500 g), and the perinatal death rate was 11%; the greatest number were in group 1, but not significantly. A regime is proposed for the prevention of malaria, iron deficiency, folate deficiency and anaemia in pregnancy in the guinea savanna of Nigeria.

Adolescent↗
PubMed1984

Anaemia in young primigravidae in the guinea savanna of Nigeria: sickle-cell trait gives partial protection against malaria.

Haematological indices, malarial parasitaemia, serum and red cell folate (SFA, RCF), serum vitamin B12 and haemoglobin (Hb) electrophoretic patterns were studied in 228 non-elite young Hausa primigravidae at less than 24 weeks of gestation. The study was conducted in the guinea savanna of Nigeria, where malaria is hyperendemic. Ninety-nine (43%) were anaemic (Hb less than 11.0 g dl-1). The commonest cause of anaemia was malaria, in 28% of all and 40% of anaemic subjects. Plasmodium falciparum was predominant; P. malariae was seen in 1.3% and P. ovale was not recorded. Parasitaemia was more frequent and more dense in the wet than the dry season. Iron deficiency was diagnosed in 18% of all and 25% of anaemic women; 14% of all patients were folate-deficient; high MCV and MCH correlated with anaemia, and low SFA was associated weakly with anaemia and malaria. Serum vitamin B12 was normal or high in all 145 in whom it was measured; 3% had congenital elliptocytosis, but this did not contribute to the anaemia. Sickle-cell trait was present in 26% and Hb-AC in less than 1%. Hb-AS was associated with significantly lower frequency and density of P. falciparum; this has not been demonstrated in pregnancy in Africa previously. However, the parasitological advantage was not reflected in any haematological advantage. The roles of malaria, folate-deficiency and iron-deficiency in the causation of anaemia in Hausa primigravidae will be defined further by a double-blind trial of antimalarial prophylactics, iron supplements and folic acid supplements.

Adolescent↗
PubMed1982

In vitro plaque formation on commonly used dental materials.

An in vitro method has been developed for the study of microbial plaque formation on commonly used dental restorative materials. Standard samples of the materials to be studied are suspended in a complex culture medium inoculated with a bacterial suspension. The samples are transferred daily into freshly inoculated medium for a total of 4 days. The resultant microbial plaques are then graded, weighed and assessed for a number of colony forming units (viable count). In this preliminary experiment samples of amalgam, composite cement, gold and porcelain were examined. Significantly less plaque was formed on amalgam than on any of the other materials.

Composite Resins↗
PubMed1982

Anaemia, malaria and sickle cell disease.

Serious defects in the living conditions of the vast majority of people in the tropics, rather than racial factors, are the underlying reasons why anaemia is common, why malaria is rampant and why the complications of sickle cell disease are so serious. Mass illiteracy, poor environmental hygiene and widespread poverty with all their implications explain why malaria eradication programmes have so far failed in tropical Africa and why basic health-care schemes have been difficult to establish. Pregnant women are very vulnerable to the effects of anaemia, malaria and sickle cell disease. However, appropriate use of folic acid and iron supplements as well as malarial chemosuppression succeeds in maintaining haemoglobin concentrations at reasonable levels during pregnancy. If, for whatever reason, the haemoglobin level falls to under 4.4 g/dl or the haematocrit value is 0.14 or less, anaemia becomes an obstetric emergency. Both maternal and fetal mortality rise sharply, maternal death being due to anaemic heart failure, fulminating bacterial infection and shock from even small loss at delivery or abortion. With the haemoglobin concentration as low as 4.4 g/dl, blood transfusion greatly improves maternal but not necessarily fetal prognosis. Additional cause of morbidity in sickle cell disease is painful crises, the control of which remains largely unsatisfactory. Now that sickle cell disease can be diagnosed early in intrauterine life the idea of aborting the affected fetuses as a means of controlling or reducing sickle cell disease is well within the means of developed countries, but it is a line of approach which developing countries cannot afford at present.

Anemia↗
PubMed1979

Nigeria.

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Adolescent↗
PubMed1979

Endometriosis among the Hausa/Fulani population of Nigeria.

In three and half years at the Ahmadu Bello University Hospital, Zaria, Nigeria, endometriosis was found in 27 Nigerians (all negroid) and one Caucasian. Age and parity distribution were similar to what has been found in patients elsewhere. In other respects, there were striking differences. The frequency (8.2 percent) is one of the highest reported in the negro. Two fifths were menopausal, majority had associated pelvic inflammatory disease, and nearly all were in women of the lowest socio-economic status. The lesions were rare in the pouch of Douglas and were totally absent from the rectovaginal septum and in the extra peritoneal space.

Adult↗
PubMed1976

Sickle cell disease in pregnancy.

S-Homozygotes, SC heterozygotes, and S-beta-thalassaemia heterozygotes are the haemoglobinopathies which make up sickle cell disease. Although their clinical features are similar, as regards complications during pregnancy, Hb S-beta-thalassaemia most dangerous, the main causes of mortality being severe anemia, acute sequestration crisis, bacterial infections, painful episodes, and pulmonary bone marrow fat embolism. Folic acid and antimalarials (where these are indicated) are often successful in preventing severe anaemia. It is best to reserve blood transfusion to replace moderate loss or to correct gross anaemia quickly when this is considered severe enough to threaten life. Painful crises are particularly common towards the end of pregnancy and in treating these episodes, analgesics, antibiotics, and sometimes heparin are used. S-homozygote carries additional hazards. Because of the prevalence of pelvic contraction, fetopelvic disproportion is common and so the incidence of operative deliveries is high. Many fetuses are lost through an increased incidence of abortion and perinatal mortality. In the survivors, there is evidence of intrauterine growth retardation brought about by continuous maternal anaemia throughout pregnancy.

Anemia, Sickle Cell↗
PubMed1968

Ethacrynic acid in blood transfusion--its effects on plasma volume and urine flow in severe anaemia in pregnancy.

Thirty grossly anaemic pregnant Nigerian women with venous haematocrit levels varying between 6 and 17%, had their plasma volumes estimated by the Evans blue dye dilution technique, both before and immediately after direct transfusion of packed blood cells. Parenteral ethacrynic acid was added to the blood for transfusion in 20 patients, seven of whom were in anaemic heart failure on admission. Ethacrynic acid used in this way was successful in the prevention of acute pulmonary oedema, and it produced acute diuresis as well as a reduction of plasma volume in the majority of cases. This technique of direct transfusion with ethacrynic acid is simple, and it may well replace exchange transfusion as a means of treating patients with anaemic heart failure.

Anemia↗