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Biomedical subjects

A O Johnson

Publications and source records attributed to A O Johnson.

At least 37 records · Page 2Linked to original sources
PubMed1986

Intradermal vaccination against hepatitis B virus infection in an endemic area (Nigeria), two year results.

To determine the efficacy and safety of hepatitis B vaccine (Hevac B) given intradermally, 125 Nigerians (aged 1 year to 45 years), who were negative for hepatitis B virus markers, and randomised into two groups were vaccinated. Group 1 (64 volunteers) was given 3 monthly doses of 2 micrograms vaccine mixed with adjuvant subcutaneously (Institut Pasteur Production-Hevac B) while group 2 (61 volunteers) received 3 doses of 2 micrograms non-adjuvated vaccine intradermally given 1 month apart. A month after the third dose 83 per cent of group 1, 71 per cent of group 2 showed positive response by developing antibody to hepatitis B surface antigen. The levels of antibody were significantly higher in group 1 at each stage of the follow-up period, including a month after a booster vaccination was given. The positive response was maintained in almost all the initial responders for the 24 month duration of the study. No significant side effect was documented in any of the participants. The results suggest that population at risk in developing countries could be protected with small doses of vaccine administered intradermally.

Adolescent↗
PubMed1986

Slow release nifedipine and atenolol as initial treatment in blacks with malignant hypertension.

We have compared the efficacy and safety of slow release nifedipine and atenolol given orally as initial treatment for malignant hypertension. Twenty consecutive black patients with untreated malignant hypertension, whose diastolic pressure remained greater than 120 mm Hg after 3 h bed rest, were randomized to receive either slow release nifedipine 40 mg at 1 and 12 h, or atenolol 100 mg at 0 h only. Patients remained supine throughout the study. Blood pressure was measured using a semi-automatic recorder (Omega 1000) at 15 min intervals from -3 to 24 h. Baseline blood pressure was similar in the nifedipine (233/142 mm Hg) and atenolol (226/141 mm Hg) groups. The rate of fall of pressure was greater after nifedipine whose maximum hypotensive effect occurred 4-5 h after each dose. Blood pressure decreased more slowly and more enduringly after atenolol, although the extent of fall was the same (delta BP 5 h after first dose nifedipine = 67/41 mm Hg; delta BP 16 h after atenolol = 64/40 mm Hg). There were no precipitous falls in pressure. No patient developed focal neurological signs, nor was heart failure precipitated by either form of treatment. These results support recommendations that most patients with malignant hypertension can be managed without recourse to parenteral therapy.

Adult↗
PubMed1984

Human T-cell leukaemia virus in Africa: possible roles in health and disease.

Observation of clustering of adult T-cell leukaemia/lymphoma (ATL) in the coastal areas of southern Japan led to speculations about its association with an environmental agent. Human T-cell lymphoma/leukaemia virus (HTLV) was later identified as the probable causal agent in these and similar cases of lymphoma/leukaemia, which were subsequently observed in first-generation West Indian Black emigrants living in England and the USA, in the forest areas of South America and in some south-eastern states of the USA. HTLV antibodies have also been identified in cases of malignant lymphoproliferative diseases (MLPD) in Ibadan and Zaria in Nigeria and in the sera of cancer patients from various parts of Africa, thus indicating that Africa is a major region for HTLV infection. Evidence is presented of the association of HTLV infection in Africa not only with T-cell but also B-cell neoplasia, such as Burkitt's lymphoma and chronic lymphocytic leukaemia (CLL). The prevalence rates of infection in normal blood donors appear to range from 3.7% in sub-Sahelian northern Nigeria to 10-15% in the south-western rain-forest area of Nigeria.

Adolescent↗
PubMed1984

Patterns of childhood hepatitis in the Nigerian African.

A total of 133 children aged between less than a month to 14 years presenting consecutively with hepatitis were prospectively studied over a 6-year period. Most cases were acute and presented at the icteric phase. The peak incidence was in very young infants whose illness had to be differentiated from congenital biliary tract obstruction. The older children exhibited the usual manifestations of lethargy, anorexia and tenderness over the liver area to varying degrees. There were 2 cases of chronic active hepatitis in children aged 13 and 14 years, one a female and the other a male. Their illness was controlled with steroid therapy. The serum biochemistry was characteristic in all cases. Serological tests revealed that about 55% of the children had antibody to hepatitis A virus but only 4% demonstrated HAV-specific IgM, while 15% had hepatitis B surface antigen (HBsAg) and 23% demonstrated antibody to core antigen (HBcAg). While most of the children with acute hepatitis made a full clinical and biochemical recovery, 2 have persistent HBs antigenaemia. There were 3 deaths in children who had fulminant hepatitis. Our results show that exposure to hepatitis A virus appears to be prevalent in Nigerian children and probably occurs quite early in life, and infections with hepatitis B virus and perhaps other hepatotropic viruses are also not uncommon. The surveillance of such children and long-term follow-up are necessary. There is already compelling evidence to indicate that hepatocellular carcinoma, prevalent among young adults in our environment, may be related to hepatitis B antigenaemia persisting over several years. The need for an effective vaccine against hepatitis B virus infection cannot, therefore, be over-emphasized.

Adolescent↗
PubMed1983

Depressed natural killer cell activity in children with protein--calorie malnutrition. II. Correction of the impaired activity after nutritional recovery.

Natural killer (NK) cell activity and responsiveness to interferon (IFN) were measured in the peripheral blood of infants having kwashiorkor or marasmus and of nutritionally recovered malnourished children. Depression of NK activity in the peripheral blood lymphocytes (PBLs) of the malnourished children was noted, while normal levels of activity were observed in the nutritionally recovered infants. Addition of exogeneous interferon in vitro potentiated the NK levels of PBLs from well-nourished and nutritionally recovered infants, but had either a nonsignificant impact on cells from the marasmic infants or a suppressive effect on the cells from infants with kwashiorkor. The success of exogenous interferon to potentiate the NK levels of PBLs from nutritionally recovered infants suggests that nutritional repletion corrects the impaired cellular responsiveness in these patients.

Child, Preschool↗
PubMed1982

High-density-lipoprotein-cholesterol in protein-energy malnutrition.

1. Plasma total cholesterol, high-density-lipoprotein (HDL)-cholesterol total protein, albumin and globulin levels were estimated in blood samples from thirty children with kwashiorkor, thirty-five with marasmus, twenty-eight with marasmic-kwashiorkor and twenty-seven control children. 2. HDL-cholesterol was estimated after the very-low-density and low-density lipoproteins were precipitated from the plasma with heparin and manganese chloride. 3. The distribution of HDL-cholesterol in the control and in the children with PEM was skewed and the range of values was wide. The values were independent of age and sex. 4. After logarithmic transformation of the HDL-cholesterol and HDL-cholesterol:total cholesterol values, the geometric mean values for the three groups of children with PEM were significantly decreased when compared with values for the control children. 5. The decrease in the mean HDL-cholesterol value for the children with kwashiorkor was more than for children with marasmus and marasmic-kwashiorkor.

Blood Proteins↗
PubMed1982

Lymphocyte subpopulations and antibody levels in immunized malnourished children.

1. The proportions of lymphocyte subpopulations (by rosette tests) and the serum antibody levels (using haemagglutination techniques) were estimated in malnourished and well fed Nigerian children before and up to 21 d after immunization with tetanus toxoid or measles virus vaccine. 2. Significantly diminished (P less than 0.01) mean percentage T lymphocyte levels and considerably higher mean percentage null cell levels were observed in the malnourished children before immunization with either of the vaccines. 3. There was comparable in vivo increases in percentage T lymphocytes in malnourished and control children following the administration of each antigen. 4. The mean percentage B lymphocyte levels were similar in the control and malnourished children before and after the immunization. 5. There was a slight depression in the tetanus antibody levels (P greater than 0.2) but a significant diminution (P less than 0.01) in measles virus antibody concentrations in the malnourished children. 6. Rise in mean percentage T lymphocytes corresponded with the elevation in mean tetanus antibody levels in both malnourished and control children following tetanus toxoid immunization. This was however not the situation in the malnourished children following immunization with measles virus. 7. The observed depressed T lymphocyte number in malnourished children may in practice affect their handling of antigens such as measles virus in vivo.

Antibodies, Bacterial↗
PubMed1982

The occurrence and properties of E rosette inhibitory substance in the sera of malnourished children.

In vitro sheep erythrocyte (E) rosette inhibitory activity was observed in the sera of nine out of 22 (41%) children with kwashiorkor, three of 15 (20%) marasmic children, neither of the two children with marasmic-kwashiorkor and in one of 42 (2%) well nourished control children. Sera of children with kwashiorkor containing the E rosette inhibitory substance did not inhibit in vitro rosette formations by autologous lymphocytes whereas rosette formations by homologous lymphocytes were inhibited. Inhibition of E rosette formation occurred when lymphocytes were pretreated with serum having the inhibitory substance before incubation with sheep red cells, but there was no such inhibition when sheep red cells were pretreated with the same serum before incubation with lymphocytes. The inhibitory substance was observed to be stable at 4 degrees C up to about 1 week and migrated electrophoretically with the alpha-2 globulins. It was digested by papain. It is probable that the E rosette inhibitory substance demonstrated in the present study is attached to markers on T lymphocyte surfaces in some malnourished children thereby making the lymphocytes unreactive in vitro and presumably in vivo as well.

Blood Proteins↗
PubMed1981

Antibodies to Herpesvirus hominis types 1 and 2 in malnourished Nigerian children.

Antibodies to Herpesvirus hominis (HVH) types 1 and 2 were determined by a micro-neutralisation method in 37 children with kwashiorkor, 16 with marasmus, and in 64 well-nourished control children. All the children were aged between 1 and 4 years. The prevalence of antibodies was similar in the two sexes and at different ages. HVH-1 antibodies were present in 51% of children with kwashiorkor, in 44% with marasmus, and in 26% of well-nourished children, reflecting the very poor socioeconomic conditions of malnourished children. HVH-2 antibodies too were present in about 19% of children with kwashiorkor, and in 2% of well-nourished controls; they were absent in marasmic children. It is suggested that HVH-2 infection in malnourished children is facilitated by the communal use of fomites--such as bedclothes and underwear.

Antibodies, Viral↗
PubMed1981

Enteric fever in childhood.

A detailed analysis of 117 cases of enteric fever in Nigerian children shows that fever, abdominal pain, vomiting and diarrhoea were the main presenting features. Disorders of sensorium occurred in 50%. Associated conditions and bizarre manifestations often delayed the diagnosis and this, coupled with complications such as intestinal haemorrhage and perforation, adversely affected the mortality which was 32% in this study.

Child↗
PubMed1980

The effects of dietary protein quality and carbohydrate quantity on the activity of intestinal disaccharidase in Wistar rats.

Intestinal disaccharidase activities were determined in groups of rats fed diets containing (a) 64% carbohydrate/19% protein, (b) 19% carbohydrate/64% protein, and (3) carbohydrate diets containing 19% proteins of different qualities. The intestinal disaccharidase activity was related not only to the quantity of the carbohydrate substrate but also to the quality of the protein in the diet. It is suggested that regular ingestion of a high-carbohydrate poor-quality protein diet will result in both protein and carbohydrate malnutrition.

Amino Acids↗
PubMed1980

Esophagopleural fistula: a complication of chest intubation for empyema.

This report documents the first recorded patient in the recent literature with an esophageal perforation and an esophagopleural fistula following chest intubation for empyema. It was treated successfully by conservative method with feeding gastrostomy. It is important to realize that tube thoracostomy drainage is not an innocuous procedure and to be alert to this complication, especially in the presence of empyema.

Child, Preschool↗
PubMed1980

Social-cultural problems affecting management of diabetes mellitus in Nigerian children.

The case histories of five children with diabetes mellitus have been analysed and socio-cultural problems affecting management examined. Difficult family situations have been highlighted and their effects discussed. Suggestions have been made on how such negative factors can be detected early and/or averted particularly by making use of Home Visitors trained on the job. It is concluded that juvenile diabetes can be managed successfully in our community provided the patients and their parents or guardians are willing to participate actively in the management of the disorder and are given necessary physical, emotional and sometime economic support on a continuous basis.

Attitude to Health↗
PubMed1979

Selective deficiency of hepatic triglyceride lipase and hypertriglyceridaemia in kwashiorkor.

1. Serum postheparin lipolytic activities (PHLA), triglyceride and free fatty acid concentrations were determined in children with kwashiorkor before and after treatment and also in normal control children. 2. Using the range (571-1650 mumol/l) of serum triglyceride of the control children as normal, five (20%) of the twenty-five children with kwashiorkor had low (less than 570 mumol/l), thirteen (52%) had normal (571-1650 mumol/l) and seven (28%) had high (more than 1650 mumol/l) serum triglyceride levels. 3. The serum PHLA did not show any definite correlation with the level of circulating triglycerides, although the lowest levels of PHLA were found in the malnourished children with highest triglyceride level. 4. While the hepatic PHLA in the malnourished children was significantly less than control value, the extrahepatic PHLA did not differ significantly. 5. After treatment, serum PHLA rose significantly and the mean levels were within normal range. 6. Our findings suggest that a defect in catabolism of very-low-density lipoprotein caused by a low hepatic PHLA may cause hypertriglyceridaemia in children with kwashiorkor.

Body Weight↗
PubMed1979

Studies on hepatic and extrahepatic lipoprotein lipases in protein-calorie malnutrition.

Postheparin serum lipolytic activities (hepatic and extrahepatic), serum free fatty acid, and triglyceride levels were measured in 16 kwashiorkor, 14 marasmic, and 14 control children. The results showed that the reduction in total postheparin lipolytic activity in kwashiorkor was in the activity of hepatic origin. In marasmus, the total postheparin lipolytic activity, hepatic and extrahepatic activities, were within normal range. The was no evidence for the presence of inhibitors of postheparin lipolytic activity in the serum of kwashiorkor or marasmic children. Fasting serum-free fatty acid level was significantly elevated in kwashiorkor, while the level in marasmus was not significantly different from control value. The serum triglyceride levels in both conditions showed no significant differences from the control value. These findings suggest that the defective production of hepatic lipoprotein lipase, as well as increased influx of free fatty acid into the liver, could account for the accumulation of fat in the liver of kwashiorkor and not in that of marasmic children.

Child, Preschool↗