Genetic heterogeneity among the Negroid and Arab tribes of the Sudan

Genetic distance analysis was carried out among seven tribes of the Sudan comprising three Negroid (Nuba, Fur, and Nilotes) and four Arab tribes (Beja, Gaalin, Hawazma, and Messeria) on the basis of six polymorphic loci (ABO and Rhesus blood groups; haemoglobin and red cell glucose-6-phosphate dehydrogenase; serum haptoglobin and transferrin polymorphisms) controlling 21 alleles and compared with the Arab and Negroid populations in neighbouring countries. The Nuba and Nilotes have been found to have Negroid genetic characteristics, while the Fur are intermediate between the Arabs and Negroids. The Beja and Gaalin tribes have more pronounced Arab genetic characteristics than the Hawazma and Messeria, who have a great deal of Negroid admixture.

A 10 year review of systemic lupus erythematosus in Singapore children

A 10 year retrospective analysis of the clinical features and survival of 24 Singapore children with systemic lupus erythematosus was made. The female to male sex ratio was 11:1. The median age at diagnosis was 9.3 years (range: 3.5-17.6 years), and the median duration of follow-up was 3.6 years (range: 3 months-10 years). The common modes of presentation were prolonged fever and malar rash (both 46%). Renal involvement (71%) was frequent. There were six deaths, three from chronic renal failure, two from infection, and one from carditis. The overall survival at 5 years was 0.800 (s.e.m. = 0.090), and at 10 years 0.698 (s.e.m. = 0.103). The survival for lupus nephritis was 0.727 at 5 years (s.e.m. = 0.116), and 0.586 at 10 years (s.e.m. = 0.130). Although the 5 year survival rate is comparable with other series, there were more deaths after the first 5 years, and morbidity from the disease as well as from therapy was considerable.

Efficacy of verapamil in the conversion of supraventricular tachycardia in Singapore children

The efficacy of verapamil in the conversion of 47 episodes of supraventricular tachycardia in 22 children was evaluated. The age of the patients ranged from 15 days to 10 years. Tachycardia was the main mode of presentation. Ten out of 22 children had viral infections. Two patients developed mild cardiac failure. Six patients had underlying cardiac abnormalities. Forty-four out of 47 episodes of supraventricular tachycardia were converted to sinus rhythm by a single dose of verapamil (0.11 +/- 0.08 mg/kg). No significant side-effects were observed. Intravenous verapamil is an effective and safe drug for the conversion of supraventricular tachycardia in children.

Cholelithiasis in an infant with polycythemia

An 11-week-old infant with polycythemia presented with cholestasis secondary to cholelithiasis. It is likely that hemolysis secondary to polycythemia predisposed our patient to cholelithiasis. We suggest that polycythemia may be a new cause of cholelithiasis in infancy.

Serious head injuries from lawn darts

Serious injuries secondary to lawn darts have not been reported. In this article two cases of penetrating skull injuries are reported. One patient developed a polymicrobial brain abscess necessitating surgical drainage and a prolonged hospitalization. Psychologic function was diminished at discharge. The second child required surgical repair of a depressed skull fracture. Thirteen lawn dart head injuries have been reported to the Consumer Product Safety Commission between 1983 and 1985. These injuries are summarized along with the reported cases to point out the seriousness (neurologic impairment in 5/10 head injuries) of such injuries and warn parents and physicians of the potential dangers of this game.

Emotional and social effects of congenital heart disease in Singapore

A cohort of patients with congenital heart disease (n = 29) who had undergone corrective cardiac surgery was studied and compared with normal controls. The mean age of cardiac patients was 10.3 years with a range of 6 years to 16 years. Their emotional maladjustment as measured on a behavioural checklist was significantly higher (P less than 0.01) than controls, and their social adjustment was also similarly less satisfactory (P less than 0.05). Regression analysis indicated that emotional maladjustment in the child was related to maternal maladjustment (P less than 0.01), maternal guilt (P less than 0.01) and maternal anxiety (P less than 0.05). Social maladjustment in the child was significantly related to maternal guilt (P less than 0.05) and pampering (P less than 0.02). It was considered that the child with heart disease was perceived and 'labelled' by the mother as abnormal even after surgery and was therefore the object and focus of maternal guilt and anxiety. Hence, the child's emotional and social maladjustment is probably the result of maternal factors rather than the physical handicaps of the illness.

Estimation of glomerular filtration rate in children using 99m-technetium DTPA. A comparison with 51-chromium EDTA clearance

The usefulness of radionuclide imaging studies with 99m-technetium diethylenetriaminepentaacetic acid (Tc-DTPA) for quantitating the glomerular filtration rate (GFR) in children was studied. This was compared to the conventional methods for measuring GFR using 51-chromium-EDTA clearance (Cr-EDTA), creatinine clearance and a height/plasma creatinine formula. In the 22 children studied, the correlation coefficient between renal uptake of DTPA and Cr-EDTA was 0.90 (p less than 0.001). In contrast, there was a poorer correlation between Cr-EDTA and creatinine clearance (r = 0.69) or the derived GFR using height/creatinine formula (r = 0.83). The regression line between Tc-DTPA uptake and Cr-EDTA clearance was used to derive a formula for calculating the predicted GFR. This was tested in 10 additional children, and the correlation between the predicted GFR and measured GFR (using Cr-EDTA clearance studies) was 0.92 (p less than 0.001). Quantitative estimation of the GFR during renal imaging studies is a feasible and convenient method of assessing renal function.

Transcutaneous estimation of oxygen tension in unusual clinical situations

Transcutaneous oxygen monitoring has been used successfully in the assessment of trend in tissue oxygenation in neonates and children. This study highlights the application of transcutaneous oxygen monitoring in three unusual clinical situations: dual channel oxygen monitoring in persistent foetal circulation, hyperoxia test in the differentiation of cardiac or pulmonary central cyanosis and the effect of endotracheal intubation on tissue oxygenation. Its usefulness and potential application in these situations are discussed.

Parental age and birth order effects in children with febrile convulsions

This is a study of the parental age and birth order of 100 Chinese children with febrile convulsions compared with 100 controls. The birth order of children with febrile convulsions (1.6 +/- 0.8) was found to be lower than that of the controls (2.1 +/- 1.0), a difference significant at P less than 0.001, whereas there was no significant difference for both paternal and maternal age. Using multiple regression analysis, it was found that the birth order effect was significant at P less than 0.0001. This finding suggests that perinatal factors may play a role in the pathogenesis of febrile convulsions.

Dermatoglyphs in children with mitral valve prolapse

The dermatoglyphs of 50 Singapore school children with mitral valve prolapse (MVP) were studied, with special reference to the frequency of digital arches. The MVP was diagnosed clinically and substantiated by two dimensional echocardiography. In the study there were 35 Chinese and 15 Malay children, with ages ranging from 6 to 19 years. Four Chinese children had one or more arches on the digits but none of the Malay children was found to have arches. It was shown that the frequency of arches on the digits was not significantly higher than that among 50 controls (who were shown not to have MVP on two dimensional echocardiography) or when compared with the frequency of arches among the Chinese and Malay population in Singapore (2.0% and 2.9% respectively). No other dermatoglyphic abnormalities (including atd angle) were found.

Ultrasonic systolic blood pressure gradient between upper and lower limbs in normal term Chinese neonates

The determination of a normal pattern of systolic blood pressure (SBP) gradient between upper limbs (UL) and lower limbs (LL) in neonates is important in the diagnosis of the coarctation syndrome. The scarcity of studies of normal neonates and the conflict of opinion prompted us to evaluate this problem. The UL and LL systolic blood pressures of 100 normal term Chinese neonates were measured by the Doppler Ultrasonic method (Roche Arteriosonde 1020). Under resting condition, the majority (89%) of our neonates had a negative SBP gradient (LL greater than UL). The mean LL SBP (70.1 mmHg) was significantly higher than that of the UL (59.5 mmHg), p less than 0.001. Eleven out of 100 of our neonates had a positive (UL greater than LL) SBP gradient. Eight of these were less than 1 week old. None had a positive gradient of more than 20 mmHg. According to the results of our study, during the first week of life, normal neonates may have upper limb pressure greater than lower limb of up to 20 mmHg.

Normal standards of in vitro induced platelet aggregation

Measurement of in vitro induced platelet aggregation by turbidimetric method is a very important investigative tool when patients are evaluated for bleeding diasthesis due to possible underlying platelet functional disorders. As commercial controls are not available, it is important that each laboratory establishes its own normal pattern of platelet aggregation induced by standard aggregating agents. The aggregation curves in terms of maximal % aggregation, Vmax and lag time in 50 normal Chinese controls are reported. The final concentrations of the aggregating agents used, namely adenosine diphosphate, adrenaline, collagen and ristocetin, are 20 microM, 10 microM, 0.2 mg/ml and 1.0 mg/ml, respectively. 20% of the controls had either no aggregation or only primary aggregation with adrenaline. Lag time by collagen-induced aggregation is significantly longer, but other parameters of platelet aggregation by adenosine diphosphate, adrenaline and collagen in Chinese are comparable to one reported control study. The maximal % aggregation induced by ristocetin in Chinese does not differ significantly from the reported values in whites but is significantly higher than in Blacks at a concentration of 1.0 mg/ml. Interpretation of platelet aggregometry in patients with bleeding tendency should be based on the normal patterns established from a group of normal controls in each laboratory rather than by comparison with a single control alone.

The estimation of inbreeding from isonymy: relationship to the average inbreeding coefficient

The inbreeding coefficient estimated by the isonymy method is often much larger than the average inbreeding coefficient (FD). One reason commonly stated is that the surnames are polyphyletic in origin in such cases. The purpose of this paper is to examine the relationship between the inbreeding calculated from isonymy and the average inbreeding coefficient. It was found that when the level of inbreeding is low, especially when the random isonymy (Pr) is much larger than FD, or when the number of surnames is small (which results in a larger value of Pr), isonymy tends to grossly overestimate FD. A small number of surnames per se (not necessarily due to polyphyletic origin of surnames) will be likely to result in an unduly high estimate of inbreeding. The equations established are illustrated by numerical examples.

Intestinal lymphangiectasia--a report in two Chinese children

Two Chinese infants with asymmetrical lymphoedema and steatorrhoea were investigated. The laboratory investigations showed that they had hypoproteinaemia without proteinuria. One of them showed peripheral lymphopenia and hypogammaglobulinaemia. Radiologically, they had evidence of extensive lymphangiectasia of the small intestine. This was confirmed histologically. Endoscopy of one of them showed diffuse milky nodular duodenal mucosa. The appearance of the mucosa was rather typical of intestinal lymphangiectasia.

Mathematical function for maternal age in Down's syndrome

The purpose of this study is to fit a mathematic function to the observed risk figures for Down's syndrome at various maternal ages. Data from the New York State and Swedish studies were used. It was found that the estimated risks fitted the exponential relationship very well, with a correlation coefficient of over 0.94. An even better correlation was found (over 0.97) for each 5-yr period in the New York State study. The exponential relationship was given by: I = aebx, where 1/I is the estimated risk; x, the maternal age in years; and a and b, the constants. In both studies there was considerable variation in the values of a and b with maternal age as well as an excellent correlation between ln a and b for the 5-yr periods. This function may be used to test various hypotheses for the effect of maternal age in Down's syndrome.

Value and limitations of bilirubin binding capacity in predicting the development of kernicterus

The serum bilirubin (SBR) and the bilirubin binding capacity (BBC) were determined on hospital admission in 181 consecutive neonates with neonatal jaundice. Twenty-three babies were less than 2500 g and two were of birth weight less than 2000 g. Fifteen babies were preterm. There were eight cases of kernicterus. Although the serum bilirubin was generally higher in infants with a BBC less than 34 mumol/l, there was no correlation between the bilirubin binding capacity and the presence of kernicterus (r = 0.28, P greater than 0.05). However, when both the serum bilirubin and the bilirubin binding capacity were used, a low value of BBC less than 34 mumol/l increased the risk of kernicterus. Higher values of BBC, on the other hand, did not mean that there was less risk of kernicterus, other factors being equal. This, while the bilirubin binding capacity may provide an additional source of information, its limitations should always be borne in mind.

Beta-2-microglobulin in mesangial IgA nephropathy

This study measured plasma beta 2-microglobulin (beta 2-m) in patients with mesangial IgA nephritis. Plasma beta 2-m was measured in 51 patients with IgA mesangial nephritis and in 50 normal controls using a Phadebas beta 2-m RIA kit available from Pharmacia Diagnostics (Uppsala, Sweden). The mean plasma beta 2-m in IgA nephritic patients (1.92 +/- 0.67 mg/l) was significantly different from that of healthy controls (1.33 +/- 0.41 mg/l; p less than 0.001). The mean plasma beta 2-m in non-IgA nephritic patients (1.83 +/- 0.73 mg/l) was also significantly different (p less than 0.001). Patients with IgA nephritis with glomerular sclerosis (n = 33) had significantly higher levels of beta 2-m (2.02 +/- 0.70 mg/l) than IgA nephritic patients without glomerular sclerosis (n = 18, 1.72 +/- 0.65 mg/l; p less than 0.025). In the group with IgA nephritis and glomerulosclerosis, raised beta 2-m levels were correlated with the severity of proteinuria (r = 0.41) (p less than 0.02) as well as the intensity of IgA staining on immunofluorescence (r = 0.34; p less than 0.05). Elevated beta 2-m levels in IgA nephritis may serve as a useful prognostic marker.