An epidemiological assessment of blood pressure determinants in an adolescent population of Nigerians.

An epidemiological assessment of blood pressure determinants in a random sample of 254 Nigerian adolescents aged 6-17 years in Benin City, Nigeria, was conducted. None of the adolescents reported cigarette smoking. Only 2.6% of the males and 0% of the females were alcohol users. Socio-economic status of the children according to parental education revealed that approximately 23% of the mothers and 9.8% of the fathers received less than a secondary (high school) education. At the other end of the education spectrum, a college education was received by 64.1% and 30.8% of the fathers and mothers, respectively. Two percent of the females and 1.3% of the males either had systolic blood pressures of greater than or equal to 140 mmHg or diastolic blood pressures of greater than or equal to 90 mmHg. No significant blood pressure differences existed between the two sexes. Among the males, it was demonstrated that age, body mass index, and heart rate were significant independent predictors of systolic blood pressure, explaining 49% of the variance. Forty-seven per cent of systolic blood pressure variance was explained by age and heart rate, for females. It was interesting to note that age was the only independent predictor of diastolic blood pressure for both males and females after control for heart rate and body mass index.

Changes in serum lysosomal hydrolases in marasmus.

The activities of several lysosomal hydrolases including beta-glucuronidase, acid phosphatase and hexosaminidase were compared in serum from 19 well-nourished subjects and 13 children (age 5--24 months) who were suffering from marasmus. The marasmic children exhibited growth retardation and muscle wastage but had normal serum protein values and absence of psychomotor retardation or oedema. Significant changes were observed in serum beta-glucuronidase and acid phosphatase activities. Compared to the control group, serum beta-glucuronidase (determined at pH 4.5 using the fluorogenic substrate, 4-methylumbelliferyl-beta-D-glucuronide) was 2.3-fold higher (p less than 0.001) in the marasmic children. In contrast, serum acid phosphatase values were approximately 50% lower (p less than 0.01) in the marasmic population. Serum hexosaminidase values in the two groups under study were not significantly different. Determination of the beta-glucuronidase to acid phosphatase ratio permitted effective discrimination (p less than 0.001) of serum from normal and protein-calorie malnourished children. The finding that the elevated value of the beta-glucuronidase : acid phosphatase ratio (0.64--1.37) decreased to within the normal range of values (0.10--0.43) after nutritional rehabilitation of several marasmic cases indicates that the determination of serum lysosomal hydrolases using fluorogenic substrates might provide a rapid and sensitive quantitative method for objectively evaluating the status of protein-calorie malnourished children and their responsiveness to nutritional therapy.

Tracking of blood pressure and anthropometric measures in Nigerian children.

Persistence in ranks (tracking) for blood pressure and anthropometric measures over a one year period was examined in 208 Nigerian children (age 6-17 years). Systolic blood pressure tracked better than diastolic blood pressure (r = 0.52 to 0.72) and r = 0.25 to 0.55, respectively). For systolic blood pressure, 56.5%-70.6% of the Nigerian children remained in the top tertile after one year compared with 45.5%-69.2% for diastolic blood pressure. Weight showed the strongest correlation over the one year period (r = 0.88 to 0.97), whereas skinfolds demonstrated the weakest association (r = 0.54 to 0.82). The association between anthropometric measures at baseline and blood pressure one year later revealed for both males and females that height and weight were positively and significantly correlated with blood pressure.

Factors related to blood pressure among urban Nigerian workers.

This cross-sectional study of urban, Nigerian civil servants found that age, body mass index, alcohol drinking and high socioeconomic status were all positively and independently related to blood pressure among 438 males. Among 121 females, only body mass index was significantly related to blood pressure.

Vertical transmission of HIV in New York State: a basis for statewide testing of newborns.

Infants (n = 313) of HIV-infected mothers were enrolled (mean age 1.9 weeks, range 0-8 weeks) in a 3-year prospective study of vertical transmission. Fifty-six infants (17.9%) had laboratory and clinical evidence of HIV infection. Polymerase chain reaction (PCR) provided early and reliable identification of infected infants. Thirty-one of the 56 infected infants had specimens submitted when the infants were 4 weeks of age or less and 30 (97%) tested PCR positive. This percentage increased to 100% by 8 weeks of age when 51 of the 56 infected infants had specimens tested for that time period. Immune complex dissociation (ICD) antigen testing was a sensitive method for diagnosis of infection but only in infants older than 1 month. p24 antigen testing, although free of false positives, is less sensitive than either of the other methods. Among surrogate markers of HIV infection, elevation of soluble CD8 levels precedes an increase in immunoglobulin levels or a decline in CD4 T lymphocytes. Vertical transmission is significantly lower in Central and Western New York State than other regions. Transmission is significantly higher in low birthweight babies and in infants whose mothers have CD4 counts < 500. This study provided the basis for establishing a Pediatric HIV PCR Testing Service for the early diagnosis of HIV infection in neonates.

Assessment of gestational age of Nigerian newborns using teeth calcification.

The relationship between fetal teeth calcification and gestational age was evaluated in 54 Nigerian newborn chest radiographs. The first deciduous molar was found to calcify at the 33rd week of gestation and the second molar at the 36th week. The pattern of calcification of fetal teeth is no significant difference in teeth calcification between the sexes.

Trends in neonatal mortality in Benin City, Nigeria.

A total of 18,334 live births and 376 neonatal deaths at the University of Benin Teaching Hospital were analyzed. The neonatal mortality rate has declined significantly from 49.5/1000 in 1974 to 16.4/1000 live births in 1981. The decrease mainly resulted from the reduction of mortality of full size infants (greater than 2500 g) and deaths resulting from perinatal asphyxia. Further reduction may be anticipated if careful attention is paid to the management of breech delivery and if a more intensive care for low birth weight infants is provided.

Seizures in the Nigerian neonate: perinatal factors.

A prospective study of 55 infants with neonatal seizures admitted to the Special Care Baby Unit of the University of Benin Teaching Hospital over a 5.5-year period revealed that perinatal asphyxia and hypoglycemia were the principal aetiologic factors in about 71% of the cases. The most frequently encountered seizure types were unilateral clonic (51.5%). Generalized clonic and massive generalized myoclonic seizures were found in 14 (25.5%) and seven (12.7%) cases, respectively, and subtle seizures in three. The overall incidence was 3.5/1000 live births, with a preponderance of male infants in the seizure population, among whom preterm infants were significantly more common. The mortality, (34.5%) was closely related to the etiology. Since the associated adverse perinatal events are largely preventable, improved prenatal and perinatal health care delivery should lead to a decline in the frequency of neonatal seizures.

Heat loss in Nigerian newborn infants in the delivery room.

Fifty-three vigorous infants were randomly assigned to six different groups (A-F). The babies in groups A and F were not dried and were either exposed wet to room air or warmed under the radiant heater. The other groups of infants were quickly dried and exposed to room air (group B), wrapped with one sterile sheet (group C), wrapped with two towels (group D) or placed under the radiant heater (group E). The infants exposed to room air lost twice the amount of heat when compared with those insulated with two towels. The amount of heat loss by evaporation could not be demonstrated. The role of high relative humidity as an important determinant of the degree of heat loss by evaporation is stressed.

Serum beta-carotene deficiency in HIV-infected children.

Representative levels of serum micronutrients specifically, beta-carotene and vitamins A and E, were studied in symptomatic human immunodeficiency virus (HIV)-infected children. The nutritional status of 23 symptomatic African-American and Hispanic HIV-infected children were compared with an appropriate control group comprised of 36 uninfected children matched for age and sex, using body mass index. Serum beta-carotene and vitamin A and E levels were randomly determined on 15 of the infected children. Beta-carotene concentration was 4.9-fold reduced in symptomatic HIV-infected children when compared with the control group. There was a 6.5-fold decrease in the serum level for children without acquired immunodeficiency syndrome (AIDS) and a 13-fold reduction in children with AIDS. No differences in the mean values for serum vitamins A and E were observed in the groups studied. Although the nutritional status of the symptomatic HIV-infected children was not different from that of the control population, their serum beta-carotene levels were profoundly deficient. This finding may have immunologic and clinical implications for children with rapidly progressing HIV disease.

Body fat distribution patterns and blood pressure in black and white women.

The prevalence of obesity and being overweight and the distribution of body fat in relation to blood pressure were assessed in a college population of 181 black and white US women and 124 black Nigerian women. The mean ages ranged from 18.6 to 22.4 years. Twenty-nine percent of black US women were overweight and 12.9% were obese; whereas 13.6% of white US women were overweight and 2.3% were obese. Only 18.6% of Nigerians were overweight and 1.6% were obese. More upper body fat was found among the black US women and Nigerians than among white US women. There was no significant correlation between body fat distribution and blood pressure among Nigerians. In general, among US blacks and whites, there were positive associations among body mass index, waist-hip girth measurements, and blood pressure, particularly for systolic blood pressure.

A point prevalence of otitis media in a Nigerian village.

One hundred seventy children and 103 adults from a rural Nigerian village were examined for the presence of middle and external ear pathology. Ear, nose and throat examination included: (1) pneumatic otoscopic exam, (2) tympanometry and (3) contralateral acoustic reflex. A diagnostic algorithm was applied to these 3 findings for each subject and each ear. Our data showed a point prevalence of otitis media in children (less than or equal to 15 years) to be 21.2% compared to 4% in adults (greater than 15 years). Of the 36 children with otitis media, only 3 had perforation and otorrhea; a diagnosis of otitis media with effusion behind an intact tympanic membrane was made in the other 33 children. The prevalence of otitis media varied significantly with age and evidence of upper respiratory tract infection. There was no significant difference between sexes. External ear pathology was found as an independent variable in 24% of the 170 children; three-fourths of these children had concurrent middle ear pathology. The results are discussed in relation to the current understanding of the differences that exist in the epidemiology and pathogenesis of otitis media in different racial groups.

Estimation of gestational age of Nigerian newborn infants by measurement of thoracic spine length on chest radiographs.

Thoracic spine length was measured on chest radiographs of forty-nine Nigerian neonates of known gestational age. There is a strong correlation between gestational age and thoracic spine length (r = 0.93). The small-for-gestational-age (SGA) infants had thoracic spine lengths below two standard deviations (s.d.) of the mean for the appropriate-for-gestational-age infants. This method is useful for identifying SGA infants on chest radiographs particularly when they are too ill to be subjected to the usual physical and neurological assessment of gestational age.

Neonatal ascites in Benin, Nigeria.

Seven cases of neonatal ascites are presented. The commonest cause is obstructive uropathy from posterior urethral valves which was present in four patients. Two infants had septicaemia and meconium peritonitis was found in the seventh case. Radiological evaluation often revealed the anatomic lesion. The mortality rate was 100%.

The risks of umbilical vessel catheterization in a neonatal intensive care unit.

Five hundred and fourteen high-risk neonates who had indwelling umbilical catheters at the neonatal intensive care unit of the University of Benin Teaching Hospital were studied. of these 514 neonates, 122 (23.8%) had their catheters in-situ for longer than 24 h. Of the 122, fifty-four (44%) had positive bacterial cultures from their catheter tips. Seven (5.7%) and four (3.2%) of the 122 neonates studied developed septicaemia and necrotizing enterocolitis respectively. Catheterization for periods in excess of 48 h significantly increased the risk of bacterial colonization. Malposition of umbilical catheter tips include: insertion into the right portal vein (thirty-six cases); superior mesenteric vein (three cases) and the left atrium (four cases). The complications related specifically to the malposition were: air collection in the hepatic venous system (two cases); cardiac arrest (one case); necrotising enterocolitis (one case) and a case of blanching of the abdominal wall. Because of these complications, the indications for catheterization should be restricted to carefully selected patients and strict aseptic technique be adhered to during the procedure.

Changes in lysosomal hydrolases from cord blood of vigorous and asphyxiated Nigerian newborn infants.

The activities of lysosomal hydrolases, beta-glucuronidase and acid phosphatase, were assayed in cord sera from forty-seven non asphyxiated babies and eleven babies who were severely asphyxiated at birth. Significant changes of these enzymes were observed in cord serum. Compared to the control group, serum beta glucuronidase (determined at pH 4.5 using fluorogenic substrate, 4-methyl-umbelliferyl-B-D glucuronide) was 2.2 fold higher (P less than 0.01) in the asphyxiated babies. Similarly, serum acid phosphatase activity estimated by using 4-methyl-umbelliferyl-phosphate was 1.8 fold higher (P less than 0.01) in asphyxia neonatorum. The clinical relevance of this finding lies in its ultimate application, using the lysosomal hydrolase activity in scalp blood sample to evaluate objectively the foetal well-being.

Determination of serum acid and alkaline phosphatase using 4-methylumbelliferyl phosphate.

The present report compares the performance of several colorimetric substrates presently employed in clinical laboratories for the determination of serum acid and alkaline phosphatase with that of the fluorogenic phosphatase reagent 4-methylumbelliferyl phosphate. Acid and alkaline phosphatase assays were performed on reference hospital populations in Nigeria and the United States. The results of both acid and alkaline phosphatase determinations indicate that the coefficient of variation is smaller for the fluorometric assay than for the colorimetric methods that employ either phenyl phosphate or p-nitrophenyl phosphate as the substrate. Furthermore, serum acid phosphatase determinations using 4-methylumbelliferyl phosphate identified increased serum enzyme levels in 6/6 cases of prostatic carcinoma and 9/9 cases of Gaucher's disease. The occurrence of elevated serum alkaline phosphatase levels in 24/24 cases involving liver and bone disease was also confirmed by the fluorometric alkaline phosphatase assay. In addition, sera from eight patients with the connective tissue disease, osteogenesis imperfecta, were found to contain normal levels of acid and alkaline phosphatase by the fluorometric assays. From these results it appears that the sensitive and rapid fluorometric assay procedures can be readily employed in the clinical pathology laboratory for the determination of serum acid and alkaline phosphatase levels.