Phytosterolemia and pseudohomozygous type II hypercholesterolemia in two Chinese patients.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to L C Low.
Explore the source record for details and available documents.
We report a Chinese girl with the moderate phenotype of leucocyte adhesion deficiency (LAD), presenting with persistent omphalitis and recurrent soft tissue infections. She had subnormal adhesion-dependent neutrophil functions, such as chemotaxis and chemiluminescence response to a particulate stimulant (opsonised zymosan). Despite her adequate humoral response to documented herpes simplex virus type 1, parainfluenza type 2 and adenovirus infection in vivo, there was marked impairment in the generation of plaque-forming cells (PFC) driven by pokeweed mitogen (PWM) in vitro. IgM PFC were less severely affected than IgG and IgA PFC, probably because IgM production is less dependent on T cell help than IgA and IgG production. The patient's B cells and accessory cells had reduced function compared with the control subsets, while helper function of her CD4+ cells was virtually absent in the PWM-driven PFC assay. She also had marked defect in natural killer cell activity. The proliferation of her lymphocytes was normal to several plant lectins, including phytohaemagglutinin, concanavalin A and PWM, but markedly defective to OKT3.
Growth hormone-releasing hormone (GHRH) stimulates GH secretion in man and the hormonal response is specific. The attenuation of GH response to bolus GHRH after prior exposure of GHRH of up to 24 h was not demonstrated in normal or GH-deficient subjects after more prolonged exposure. This suggests that the partial loss of responsiveness to GHRH may reflect short-term negative feedback by GH. The stimulatory effect of clonidine and L-dopa on GH release is mediated via GHRH. Other stimuli like hypoglycaemia, arginine and propranolol augment GH release in man by modulating hypothalamic somatostatin secretion. Although GHRH test can differentiate between hypothalamic or pituitary cause of GH deficiency, it is of little diagnostic value in children with short stature. Favourable results have been observed in 60-70% of GH-deficient children treated with GHRH, but the dose and mode of administration are still being explored. We found that low dose (1-2 micrograms/kg) GHRH given subcutaneously every 3 h by a pump was effective in promoting growth in 5 of 7 patients after 1 year. Treatment was continued for 2-4 years in 4 patients and growth velocities ranging from 4.5 to 8.2 cm/year were maintained using a dose of 3 micrograms/kg/pulse.
We studied the serum immunoreactive (immuno) and bioactive (bio) FSH concentrations in 16 prepubertal children (1.3-9 yr old), 6 girls with premature thelarche (0.8-2 yr old), and 9 girls with central precocious puberty (2.5-9.3 yr old). The serum bio-FSH was measured by the granulosa cell aromatase bioassay. The basal serum bio-FSH levels were not significantly different in patients with central precocious puberty (6.4 +/- 1.5 IU/L), premature thelarche (7.5 +/- 0.5 IU/L), and prepubertal controls (4.4 +/- 0.7 IU/L). However, the peak responses of both serum immuno- and bio-FSH levels to iv GnRH were higher in patients with premature thelarche (immuno-FSH, 29.3 +/- 2.3 IU/L; bio-FSH, 100.7 +/- 12.2 IU/L) than in those with central precocious puberty [immuno-FSH, 17.5 +/- 3.1 IU/L (p less than 0.05); bio-FSH, 42.4 +/- 9.8 IU/L (p less than 0.01)]. This suggests that in children with premature thelarche, there is a predominant immuno- as well as bio-FSH response to GnRH. After 12 months of GnRH agonist therapy, both serum immuno- and bio-FSH levels were suppressed in patients with central precocious puberty. The differences in clinical presentation between central precocious puberty and premature thelarche cannot be explained by the differences in FSH bioactivity.
Five infants with persistent hypoglycaemia due to hyperinsulinism were reported. Provocative tests for insulin release were unhelpful. Diazoxide was useful in the treatment of three patients but many side-effects were observed. These included petechial rash, hypertrichosis, acute renal failure, fluid retention and cardiac failure. Two patients underwent spontaneous remission. Three patients had nesidioblastosis, two of whom were subjected to 95% pancreatectomy. Postoperatively, recurrence of hypoglycaemia was due to hyperinsulinism in one patient and to presumed glucagon deficiency in the other. Phenytoin effectively corrected the hypoglycaemia in the patient who had postoperative hyperinsulinism. It is recommended that medical therapy with diazoxide (10-15 mg/kg per day) together with a diuretic be commenced once hyperinsulinism is diagnosed. Subtotal pancreatectomy should be performed early in these patients if hypoglycaemia cannot be controlled with medical therapy or if side-effects of treatment are documented.
Fourteen patients with precocious puberty were treated for 1-3 years with 900-1800 micrograms/day of intranasal (i.n.) Buserelin. The peak luteinizing hormone and follicle-stimulating hormone responses to intravenous luteinizing hormone-releasing hormone were reduced significantly 4 weeks after starting treatment and remained suppressed while the patients were on treatment. Two patients were withdrawn because of drug non-compliance. Three patients showed regression of pubertal changes, four patients showed no progression and five patients showed progression of breast size or pubic hair staging after 1.5-2 years of treatment. Treatment was changed to the subcutaneous route in two patients because of hormonal escape and accelerated skeletal maturation. The mean growth velocity decreased from 10.78 cm/year (s.e.m. = 0.64) to 7.06 cm/year (s.e.m. = 0.85) after 1 year of treatment (P less than 0.005). After an increase in dosage (from 900 micrograms/day to 1800 micrograms/day) in most patients, further significant falls in growth velocity to 5.29 cm/year (s.e.m. = 0.45), 4.63 cm/year (s.e.m. = 0.8) and 5.06 cm/year (s.e.m. = 0.5) were observed at 18, 24 and 30 months, respectively, compared with the pretreatment value (P less than 0.001). With treatment, the increased rate of skeletal maturation normalized. In 10 patients who had completed 2 years of treatment, the height standard deviation score for bone age improved from a pretreatment value of -2.42 +/- 0.42 to -1.6 +/- 0.42 after 2 years of treatment (P less than 0.01), indicating an improvement in height prognosis. It is concluded that i.n. Buserelin at a dose of 1800 micrograms/day is effective in the treatment of most but not all patients with precocious puberty.
A patient with choreoathetosis and dystonia who had computerized tomography evidence of basal ganglia damage resulting from tuberculous meningitis is presented. It is important to distinguish these extrapyramidal movements from fits, and the observation of such movements in a clinical setting of meningitis should alert physicians to the diagnosis of tuberculous meningitis.
We treated seven GH-deficient children with 3-hourly 1 microgram/kg sc pulses of GHRH-(1-44) for 6 months and 2 micrograms/kg.pulse for another 6 months. Four patients had a serum GH response to iv GHRH before treatment, and an additional patient responded to iv GHRH after 1 month of pulsatile sc GHRH administration. The mean cumulative growth velocity increased from a pretreatment mean of 2.7 +/- 0.2 (+/- SE) to 8.4 +/- 2.5 and 5.4 +/- 0.7 cm/yr after 2 months and 1 yr of treatment, respectively. Low dose pulsatile GHRH therapy was effective in promoting growth in five of seven children, with height gain ranging from 4.4-7.5 cm at the end of 1 yr's therapy. Only one of the two patients who did not respond to GHRH had an improvement in linear growth when they were subsequently treated with synthetic GH. The other patient, a 16.5-yr-old pubertal girl who had both satisfactory GH and somatomedin-C responses during GHRH therapy, did not respond to either GHRH or, later, synthetic GH. The pretreatment serum GH response to iv GHRH, the serum somatomedin-C concentrations, and the peak serum GH response during sc GHRH therapy were not reliable predictors of clinical response.
A boy aged 7.5 years presented with precocious onset of secondary sexual characteristics and symptoms and signs of neurological dysfunction. A CT brain scan demonstrated a suprasellar mass lesion. The elevated beta-hCG and alpha-fetoprotein concentrations in cerebrospinal fluid and in serum were consistent with a diagnosis of intracranial embryonal carcinoma, although histological diagnosis was not available. The tumour markers beta-hCG and alpha-FP should be looked for in all children with precocious puberty presenting with midline brain tumours.
Studies of Caucasian and Japanese patients with insulin-dependent diabetes mellitus (IDDM) have shown that heterozygosity for certain HLA-DR antigens confers a high risk of developing the disease. The HLA antigens of 75 Chinese patients and 100 Chinese controls in Hong Kong were studied to investigate the role of HLA-DR heterozygosity in Chinese individuals. Some of the patients and controls were also tested for allotypic variation in the complement components C2, C4, and BF. Three alleles, Aw33, B17, and DR3, had increased frequencies in patients compared with controls and frequently occurred together in the same phenotype, which suggested their existence as a haplotype. There were no statistically significant differences in complement allotype frequencies between patients and controls, although the C4B null allele seemed to be associated with Aw33, B17, and DR3. No other HLA-DR antigen appeared to be associated with IDDM. However, when the patients were separated on the basis of age at onset, the frequency of DR3/DRw9 heterozygosity was markedly increased in patients presenting in the first decade of life, but there was no increase in patients presenting at greater than 20 yr of age. DRw9 is strongly associated with autoimmune disease in Chinese, whereas DR3 is not. We suggest that the major IDDM susceptibility locus in Chinese is associated with HLA-DR3 and that patients with HLA-DR3 and HLA-DRw9 have an added predisposition to autoimmune disease and therefore develop IDDM earlier than patients without DRw9.
A pilot cord blood TSH screening program for congenital hypothyroidism was commenced in Hong Kong in April 1982. By April 1984, 14 411 neonates born in two hospitals were screened for this disorder. Five cases of primary hypothyroidism and two cases of transient hypothyroidism were detected. The detection of cases of congenital hypothyroidism with only moderately elevated cord blood TSH values means that the recall rate will remain high.
Two siblings with consanguineous parents began having myoclonic jerks at age 5 months after introduction of mixed feeding. There was later developmental regression. The elder girl died without diagnosis aged 1 year, after prolonged continuous hyperventilation. The younger sibling did not have metabolic acidosis when first investigated for myoclonus and hypotonia aged 5 months. At 9.5 months, when intermittently decerebrate and hyperventilating, she had a metabolic acidosis with elevated blood lactic, pyruvic and beta-hydroxybutyric acids, and beta-hydroxyisovaleric aciduria. On the assumption that she had beta-methylcrotonyl-CoA carboxylase deficiency she was started on biotin, 10 mg daily. Within 36 h there was dramatic clinical and biochemical improvement. Previously defective eye movement control and gaze became normal, hyperventilation ceased, and excessive organic acid excretion in urine was abolished. She remains on long-term biotin and at age 2 years her development appears normal in all respects. Fibroblast culture however revealed normal quantities of the enzymes beta-methylcrotonyl-CoA carboxylase, propionyl-CoA carboxylase and pyruvate carboxylase. Irrespective of niceties of enzyme and organic acid biochemistry, the clinician must be aware of biotin-reversible regressive brain disease which may present before manifest metabolic acidosis.
Two siblings presented with symptoms suggestive of myopathy: the true diagnosis of Engelmann's disease was delayed until X-rays revealed the characteristic sclerosis and widening of long bone diaphyses. Dominant inheritance from their father had not been suspected because of his lack of symptoms. Biochemical studies of bone metabolism did not elucidate the underlying mechanism. Prednisolone dramatically improved the clinical condition, particularly in the more severely affected child. While research into the biochemical basis must continue, paediatricians should remember to X-ray the long bones of 'myopathic' children, and offer steroids when the clinical condition warrants.
Two children in a Chinese family with progressive dystonia with marked diurnal variation in symptoms are described. Treatment with L-dopa resulted in complete disappearance of symptoms in one patient and marked improvement in the other patient.
Despite adequate treatment, mortality and morbidity were high among the 13 cases of Salmonella meningitis in this series. Chloramphenicol, being a bacteriostatic agent against Salmonella species, is not a suitable antibiotic for the treatment of Salmonella meningitis. Treatment for 4-6 weeks is recommended with use of an antibiotic capable of achieving an adequate bactericidal concentration in the cerebrospinal fluid such as moxalactam. Intraventricular antibiotic treatment should be considered if there is a delay in the eradication of the Salmonella organisms from the cerebrospinal fluid after starting treatment.
The authors describe a Chinese girl with myasthenia gravis and progressive dystonia with marked diurnal fluctuation. A combination of L-dopa and pyridostigmine therapy resulted in control of the myasthenic symptoms and disappearance of the dystonia.
1 The effect of small doses of carbimazole on the binding rate constant of intrathyroidal iodide, plasma methimazole concentrations and circulating thyroid hormone concentrations in five hyperthyroid patients is presented. 2 In all patients there was a marked reduction in iodide binding with carbimazole doses as low as 5 to 10 mg daily. 3 In three patients little further reduction in the observed binding rate occurred with daily doses in excess of 10 mg despite progressive increases in plasma methimazole concentrations. 4 At the end of 4 weeks' treatment with 10 mg carbimazole daily, the reduction in thyroid hormone concentrations and clinical improvement were such as to suggest that this dose may be an effective starting dose in many patients.
15 children with metoclopramide (Maxolon) poisoning are reported. One of the 5 children accidentally poisoned developed slight extrapyramidal signs. All 10 children who experienced extrapyramidal side effects while being treated with metoclopramide had received a dose greater than that recommended by the manufacturer of 0.5 mg/kg per day. Dystonic reactions are likely to occur if the recommended dose is exceeded, but individual susceptibility to metoclopramide and the cumulative effect of repeated doses of the drug may also be important.