Incomplete catch-up growth in low birthweight Chinese infants in Hong Kong

OBJECTIVE

To describe the early catch-up growth in length in Chinese low birthweight (< 2500 g) infants.

METHODOLOGY

The infants (n = 181) were delivered between 1988 and 1993 and followed up at Queen Mary and Tsan Yuk Hospitals, Hong Kong. One third had a birthweight below -2SDS, most of whom were term or close-to-term babies small-for-gestational-age (SGA). The remaining babies were appropriate-for-gestational-age (AGA) in birthweight, but frequently born prematurely.

RESULTS

The SGA group did not show a catch-up growth in height comparable to that reported on other recent studies, as 33-35% of the patients were still short at 6 and 12 months (7-12% for the AGA group). When comparing the postnatal mean growth curve of the SGA group with the mean curve of the AGA group there was little sign of catch-up growth.

CONCLUSIONS

The results showed that Hong Kong SGA infants have an incomplete catch-up growth and for successful intervention the causative mechanisms have to be identified.

Prevalence of and factors associated with childhood asthma in Hong Kong

The prevalence of asthma and eczema in children between 3 and 10 years of age living in Hong Kong was determined by a questionnaire survey administered to the parents of 535 children in 1989. The prevalence of asthma was 6.0% (95% confidence limit (CI) 4.0-8.0%) and the prevalence of eczema 6.8% (95% CI 4.6-9.0%). Age, sex, parental smoking and breast feeding in early life did not show significant associations with asthma. However, four different measures were associated with the prevalence of asthma: the presence of eczema, high serum IgE level, high number of upper respiratory infections and a relatively high family income, with odds ratios of 7.6, 4.9, 4.5 and 2.7, respectively.

On the dynamics of the growth process

Recent publications have provided evidence that the short-term growth process may be regarded as pulsatile rather than constant over time. The possible influence of changes in soft tissue thickness is one reason why it is not possible to draw any final conclusion about the existence or not of such a pulsatile short-term growth pattern. An answer can probably not be reached until a method has been developed that measures longitudinal bone growth without any soft tissue involvement, especially since such a method has recently been used in the rabbit showing that the day-to-day growth rate was linear or continuous.

Seroprevalence of antibodies to human herpesviruses in England and Hong Kong

The age-related prevalence of antibodies to herpesviruses was compared in England and Hong Kong. Altogether 327 sera from England and 266 sera from Hong Kong were tested for antibodies to herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpesvirus 6 (HHV-6). Herpesvirus infections were common in both countries but generally were acquired earlier and were more prevalent in Hong Kong. Over 90% of children in Hong Kong were infected with VZV, EBV, and HHV-6 by 8 years of age. HSV and CMV were the least prevalent childhood infections in both countries, although, 30-40% of babies in Hong Kong became infected during the first year of life. CMV infections were rare throughout childhood in the English cohort. Overcrowding and early attendance at kindergarten may aid more efficient and earlier transmission of herpesvirus in Hong Kong. The high prevalence of CMV in particular may have implications for the management of young pregnant women and organ transplant recipients in Hong Kong.

Early postnatal cerebral Doppler changes in relation to birth weight

Serial Doppler studies of the anterior cerebral artery were performed on 50 healthy term infants in the first 5 days of life. This study aims to establish a normative database for cerebral Doppler measurements in infants born appropriate for gestational age (AGA) and to compare them with those born small for gestational age (SGA). The difference between SGA and AGA infants was documented. In AGA infants, the Pourcelot's resistance index (PI) decreased over the first 5 days, while both the peak systolic flow velocity and end diastolic flow velocity increased. In SGA infants, the PI was significantly lower in the first 24 h of life. This was accounted for by an increase in the end diastolic flow velocity which may be a continuation of the intrauterine situation. The significance of the difference is discussed.

An experience of renal replacement therapy in a combined neonatal and paediatric intensive care unit of Hong Kong

Intensive care services are expensive. The experience of developing a combined paediatric and neonatal intensive care unit (ICU) in a regional hospital is reported with reference to the provision of renal support for the critically ill patients. The combined unit is staffed by a team of paediatric intensivists, each of whom has special interest in a subspecialty, including cardiology, respiratory medicine, nephrology and neonatology. In the past 7 years, renal replacement therapy (peritoneal dialysis and haemofiltration) was provided to 40 patients, with comparable mortality and complication rates to other reports. This arrangement has been feasible and might be more efficient than running separate paediatric and neonatal ICUs or combining the paediatric ICU with the adult ICU.

Epstein-Barr virus associated aplastic anaemia and hepatitis

We report a Chinese girl with Epstein-Barr virus (EBV) associated aplastic anaemia and hepatitis. Epstein-Barr virus genome was demonstrated in her bone marrow cells and EBV-specific serology suggested reactivation of EBV infection. She was initially treated with anti-thymocyte globulin (ATG) and methylprednisolone but with no haematologic response, and liver function continued to deteriorate. She was then treated with acyclovir. Her aplastic anaemia improved and hepatitis resolved, and there was eradication of EBV genome from her bone marrow cells.

Somatostatin therapy in L-asparaginase-induced pancreatitis

L-Asparaginase-induced pancreatitis is an uncommon but potentially lethal complication. An 8-year-old girl with acute lymphoblastic leukaemia developed acute pancreatitis following treatment with asparaginase. Clinical and laboratory improvements were evident after treatment with somatostatin, with no complications of pancreatitis. Induction therapy for the leukaemia was able to be continued and complete remission was documented during the course of pancreatitis and somatostatin treatment, suggesting a beneficial role of somatostatin in the management of asparaginase-induced pancreatitis.

The minimal self-sufficient element in a murine G+C-rich promoter is a large element with imperfect dyad symmetry

The murine adenosine deaminase gene has a structurally archetypal TATAA-box-deficient G+C-rich promoter. The three Sp1 binding sites of the promoter are neither necessary nor sufficient for promoter function. Minimal basal promoter activity resides within a 48-bp element downstream of the Sp1 binding sites. This element shows an imperfect dyad symmetry around the promoter's major transcriptional initiation site and contains at least two nuclear protein binding sites. The distinctive sequence characteristics and nuclear protein binding locations of this element led us to propose a model for how such promoters may function.

Maple syrup urine disease: report of two cases

Two cases of maple syrup urine disease (MSUD) are reported. Case 1 was a 10-day-old male infant who had cyanotic episodes and recurrent generalized convulsions; the odor of burned sugar from the body and urine was also noted. Plasma and urine amino acid analysis disclosed a marked increase in the concentration of branched chain amino acids (BCAA). As a result of a BCAA-free diet and mega-doses of thiamine, the condition stabilized. However, the patient was lost to follow-up and expired at two months of age due to inadequate management. Case 2 was a 20-day-old female infant with poor feeding, vomiting for one week, generalized convulsions and a peculiar burned sugar smell from the body and urine. Based on our experience with the first case, MSUD was suspected, and the infant was treated accordingly. However, subsequent follow-up revealed delayed developmental milestones. We present the first two reported cases of MSUD in Taiwan and review the relevant literature.

An old traditional herbal remedy for neonatal jaundice with a newly identified risk

Yin-chen (Artemisia scoparia) is a very popular intravenous herbal preparation used for the treatment of neonatal jaundice in China. Bilirubin-protein titration studies with the horse radish peroxidase method have shown that the herb is highly effective in displacing bilirubin from its protein binding. Free bilirubin is liberated in this process and this could increase the risk of brain damage in jaundiced infants. With the present state of knowledge, the use of traditional herbal therapies should be strongly discouraged in neonates.

Outcome and management of babies with prenatal ultrasonographic renal abnormalities

Between January 1987 and December 1990, 60 fetuses were found to have renal abnormalities on antenatal ultrasonography. Six fetuses were aborted because of major renal abnormalities with or without associated chromosomal aberrations. Twelve babies with major renal abnormalities died in the immediate neonatal period. Forty-two babies were studied after birth and followed up. Babies who were found to have mild dilation of the renal pelvis of 6 to 10 mm during fetal life revealed either normal renal findings in the postnatal period or complete resolution of the abnormalities within the first year. Significant pelvic dilation of more than 10 mm occurred in 32 babies. A significant proportion (34%) had transitional hydronephrosis that resolved spontaneously during the follow-up period (mean, 2 1/2 years; range, 1 1/2 to 4 1/2 years). Extrarenal pelvis, another benign condition, accounted for 15.6%. Most babies with pelviureteral junction obstruction (15%) and vesicoureteral junction obstruction (6.2%) required early neonatal surgery. The technetium-99m diethylenetriamine renal scan with the diuretic renogram half-time was found to be a very useful tool to distinguish between obstructive and nonobstructive hydronephrosis. With early diagnosis and intervention, the prognosis for many of these renal abnormalities is much more favorable and such information is invaluable for antenatal counseling.

Cefadroxil reduces the production of IgE in a 3 year old asthmatic with juvenile rheumatoid arthritis

Cefadroxil, a cephalosporin, had been prescribed to children with superinfected atopic dermatitis, and was shown to improve both the infection, the clinical status and induced a dramatic lowering of the serum total IgE levels. Further studies have confirmed the IgE immunomodulating properties of cefadroxil. We report the case of a 3 year old asthmatic child who was hospitalized for superimposed pneumonia and was included in a study evaluating cefadroxil. The child was also suffering of juvenile rheumatoid arthritis. After treatment with cefadroxil and oral salbutamol, the child fully recovered. The initially elevated serum IgE (day 1:556 IU/ml) dropped to normal values (day 21: 52 IU/ml), while the production of IgE in vitro by peripheral blood B cells was normalized. We suggest that one mechanism of action of cefadroxil is the stimulation of production of gamma interferon in patients with atopic disorders; this mechanism interferes with the IL-4 primary signal, as well as with other second signals recognized for the synthesis of IgE. Gamma interferon may also prove beneficial for the control of juvenile rheumatoid arthritis.

Percentile ranges for serum IgG subclass concentrations in healthy Chinese children

In order to establish normal reference ranges of serum immunoglobulin G subclasses for different age groups in Chinese, we measured the four IgG subclasses by radial immunodiffusion using polyclonal antisera in 350 normal healthy subjects (148 males and 202 females) recruited from the community. There was no significant sex difference for all the four IgG subclasses. Using Box-Cox transformation, we constructed smooth age-dependent percentile curves for the four IgG subclasses. For the 50th percentile values, the plateaus for IgG1 to IgG4 are respectively 970 mg/dl at 13 years old, 481 mg/dl at 18, 48 mg/dl at 17 and 80 mg/dl at 13. Methodology, reagents, environmental and genetic factors might be responsible for the observed difference among the various reports. The IgG2 level in our Chinese population seemed to be higher than that in Caucasians, which might account for the very low incidence of invasive Haemophilus influenzae type b disease among the Chinese. Our IgG1 level also plateaued later and at a higher level than that in other studies.

Bone marrow transplantation for thalassemia in Hong Kong: the early experience

The first experience of bone marrow transplantation (BMT) for thalassemia in Hong Kong is reported. Of the three children transplanted using a matched allogeneic donor, two have been surviving disease free 291 and 256 days post-BMT respectively. The other child rejected the graft and remained transfusion dependent. Mild graft versus host disease occurred in one of the children which subsided on cyclosporin A alone. The regimen-related toxicities were mild and easily manageable. Thus the result is encouraging and the procedure is now accepted as an option of treatment for good risk patients in Hong Kong.

Response of preterm infants to hepatitis B vaccine

Ninety-nine preterm infants with birth weights < 1750 gm had three doses of hepatitis B vaccine. Fifty-seven received the first dose when they weighed > or = 1000 gm (group 1) and 42 when they weighed > or = 2000 gm (group 2). The final seropositive rates and geometric mean titers of group 1 infants (79%, 61 mIU/ml) and group 2 infants (91%, 262 mIU/ml) were less than that of 43 normal term infants (100%, 679 mIU/ml).

Parental perception of the effect of venepuncture in preschool children in non-therapeutic research

Non-therapeutic research in children is said to be justified in part if the risk involved is no more than minimal, but there is little information on the risk of venepuncture to make that judgement. This prospective study was carried out to assess the effect of venepuncture on 425 healthy children aged between 3.6 and 6.6 years old who participated in a non-therapeutic research project. A parental questionnaire was sent out 1 month after the blood was taken. Three hundred and ninety-one parents (92%) returned the questionnaires. Parental responses indicated the risk of complications was of the order considered to be minimal. A large majority of parents (78%) felt this experience would be helpful for the child if blood had to be taken again and a significant proportion (40%) felt the child would be more confident when going to see a doctor or dentist afterwards. Venepuncture in preschool children causes minimal harm and might even have some positive effects.

Deletions, duplications and novel restriction fragment length polymorphism in Duchenne and Becker muscular dystrophies

To determine the mutations of Southern Chinese with Duchenne and Becker muscular dystrophies (DMD, BMD), we analysed 28 DMD and BMD patients in 24 unrelated families for intragenic deletions and duplications by using cDNA probes covering the entire 14 kb of the dystrophin gene. Deletions were detected in nine unrelated patients (seven patients by probe 8 and two by probe 2b-3). Gene duplications were detected by probe 1-2a in two patients with the duplication bands confirmed in both Hind III and Bgl II digests and by densitometry. A third patient was found to have a junction fragment with Bgl II and a duplication band with Hind III by probe 5b-7. Therefore 50% of the 24 unrelated families were found to have either deletions or duplications. A previously undescribed restriction fragment length polymorphism (RFLP) was found in one family with probe 5b-7 in Bgl II digests which was found to segregate with the disease phenotype. This new RFLP was not detected in over 70 unrelated X chromosomes we have examined so far, and appeared to be "private" for this family. The presence of this new restriction site may or may not be the mutation responsible for the disease phenotype.

Biphasic rise of serum immunoglobulins G and A and sex influence on serum immunoglobulin M in normal Chinese children

A study was conducted on 751 healthy children from child health clinics, kindergartens and schools, and 80 normal adults to establish reference ranges for serum immunoglobulins (Ig) G, A and M concentrations in normal Chinese. Serum IgG, IgA and IgM concentrations were determined by nephelometry. Serum IgG and IgA were shown to have a significant rise during the preschool age as well as at puberty with a plateau phase in between. This biphasic maturation profile has not been reported in Caucasians and the reasons for the observed difference have yet to be elucidated. Serum IgM concentrations were shown to be higher in females than in males, reaching significance in most age groups beyond 4 years of age. The difference between the two sexes in Chinese was of similar magnitude as that reported for Blacks and Caucasians, that is, 30%. Our findings support the hypothesis that the human X chromosome may carry quantitative genes for IgM.

IgG4-anti-IgE antibodies in Chinese allergic children

IgG4-anti-IgE antibodies have been identified in normal nonatopic subjects, as well as in allergic patients. Their potential role remains controversial. We studied 44 Chinese children with allergic symptoms, and measured their IgG4-anti-IgE serum levels using a modified IgG4 FAST assay. The levels of IgG4-anti-IgE antibodies did not correlate with clinical status. The usefulness and relevance of these measurements remain questionable in allergic patients.

Effects of anticoagulants and incubation time on neutrophil nitroblue tetrazolium score

We studied the effect of anticoagulants and incubation time on neutrophil nitroblue tetrazolium (NBT) scores. Heparin (10 IU/ml) and EDTA (1.5 mg/ml) were used, and the preparations were incubated for periods ranging from 20 to 180 min. Heparin, in contrast to EDTA, was found to be associated with cell destruction, cell aggregates and higher NBT scores; the effects were more profound with endotoxin stimulation. The duration of incubation significantly affects NBT scores in both the heparin- and EDTA-anticoagulated samples, and the effect is more marked with heparin. Cell destruction and cell clumping are both enhanced with incubation, again more so with heparin. It is concluded that when performing NBT tests, blood samples would best be anticoagulated with EDTA to ensure more consistent results.

Evaluation of serum total IgE in Chinese allergic children using different assays

Since differences in HLA groups have been found in Chinese populations, as well as differences in the values of total IgE in China, Japan and Thailand, a study has been done in 44 Chinese children, all of them with a history of atopic conditions divided into five groups: asthma, rhinitis, conjunctivitis, allergic bronchitis and atopic dermatitis. 34 of them were positive against D. pteronyssimus, 8 against cats, 3 against dogs and 3 against fish. The only adult patient studied was positive against gramineal plants (all positivities were tested with the prick test). IVT ELISA Screen is performed against 10 allergens, as well as 3 M FAST-Test and 3 M Total IgE FAST Plus Test. The results show that the majority of children had an elevation of the total IgE in the three tests. There is quite a good agreement between FAST and IgE-IVT and a better correlation between IgE-IVT and IgE FAST Plus. The correlation between IgE FAST and IgE FAST Plus was excellent.

Perinatal features of birth asphyxia and neurologic outcome

The perinatal events of 40 term newborn infants who had severe birth asphyxia were reviewed and correlated with the neurological outcome at a mean age of 2 1/2 years. Severe birth asphyxia was defined as an Apgar Score of less than or equal to 3 at 1 min. The majority (68.5%) of the babies had an abnormal fetal heart pattern before delivery. Persistent fetal bradycardia was most frequently associated with poor outcome. The neurological staging, the need for assisted ventilation for more than 24 hours and severe renal impairment were the best predictors of neonatal death or subsequent poor neurological outcome. The overall mortality was 10% and 15% of the surviving babies had varying degrees of neurological handicap.