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Biomedical subjects

Y Y Lam

Publications and source records attributed to Y Y Lam.

10 recordsLinked to original sources
PubMed2006

Triple-A syndrome--the first Chinese patient with novel mutations in the AAAS gene.

We report on the first Chinese patient with triple-A syndrome, who presented at 22 months with status epilepticus secondary to hyponatraemia and hypoglycaemia. Subsequent endocrine investigations confirmed primary adrenal insufficiency and aldosterone deficiency. In the presence of achalasia and alacrima, this patient satisfies the diagnostic criteria of triple-A syndrome. Further molecular testing detected compound heterozygous mutations in the AAAS gene: a c.580C --> T transition in exon 7 and a c.771delG single nucleotide deletion in exon 8. Testing of parents and brother confirmed their heterozygous carrier status.

Adrenal Cortex Diseases↗
PubMed2006

An unusual case of non-malignant superior vena cava obstruction.

An 81-year-old Chinese woman presented with a 1-week history of increasing facial puffiness. She had 2:1 second-degree heart block and a permanent pacemaker that had been inserted 3 years previously because of syncopal episodes. Physical examination revealed facial plethora, dilated upper trunk veins, and oedematous upper limbs suggestive of superior vena cava obstruction syndrome. This was confirmed on urgent computed tomographic scan of the thorax. There was no evidence of extrinsic compression or formation of intraluminal thrombus. The underlying aetiology was a pacemaker-induced fibrotic stricture that was successfully treated with balloon venoplasty. At 3-month follow-up, the patient remained symptom-free with normal pacemaker function.

Aged, 80 and over↗
PubMed2004

Obstructive sleep apnoea syndrome and obesity in children.

OBJECTIVE: To review data on children who have both obesity and obstructive sleep apnoea syndrome. DATA SOURCE: Pubmed and MEDLINE (Ovid) literature search using the following key words: obstructive sleep apnea syndrome, obesity, and children. STUDY SELECTION: Literature and data on obesity-associated obstructive sleep apnoea syndrome in children. DATA EXTRACTION: Review of relevant information and data. DATA SYNTHESIS: Different definitions of obesity and obstructive sleep apnoea syndrome in children were used in different studies, which made it difficult to compare results from different studies conducted in different countries. Nonetheless, obstructive sleep apnoea syndrome was found to be moderately prevalent among obese children-namely, 13% to 36%. The severity of obstructive sleep apnoea syndrome was positively related to the degree of obesity. Blood pressure was found to be elevated in obese children with obstructive sleep apnoea syndrome. Weight reduction is an effective treatment. CONCLUSION: Children with obesity and obstructive sleep apnoea syndrome face a double challenge. A holistic approach to management requires a clear understanding of how both problems interact.

Child↗
PubMed2003

Consensus statement on iodine deficiency disorders in Hong Kong.

This article reviews the available data on the study of iodine deficiency disorders in Hong Kong and to discuss the approach towards preventing such disorders in Hong Kong. The importance of iodine and iodine deficiency disorders is described, and the available data on the dietary iodine intake and urinary iodine concentration in different populations of Hong Kong are summarised and discussed. Dietary iodine insufficiency among pregnant women in Hong Kong is associated with maternal goitrogenesis and hypothyroxinaemia as well as neonatal hypothyroidism. Borderline iodine deficiency exists in the expectant mothers in Hong Kong. Women of reproductive age, and pregnant and lactating women should be made aware and educated to have an adequate iodine intake, such as iodised salt, as an interim measure. A steering group involving all stakeholders should be formed to advise on the strategy of ensuring adequate iodine intake, including universal iodisation of salt in Hong Kong. Continuous surveillance of iodine status in the Hong Kong population is necessary.

Deficiency Diseases↗
PubMed2000

Prenatal diagnosis of glycogen storage disease type 1b using denaturing high performance liquid chromatography.

Glycogen storage disease type 1b (GSD1b) is an autosomal recessive inborn error of metabolism caused by deficiency of glucose-6-phosphate translocase (G6PT1). Current laboratory diagnosis for GSD1b is established by a functional enzyme assay of glucose-6-phosphatase in both fresh and detergent-treated liver homogenates. This procedure requires liver biopsy and is impractical for routine prenatal diagnosis owing to the high morbidity of fetal liver biopsy. Recently, the gene for GSD1b has been cloned and the prevalent mutations in different ethnic groups have been determined. In this study, prenatal molecular diagnosis was performed for a Chinese family in which a previous child was born homozygous for the G149E mutation. We detected genomic sequence variants by heteroduplex formation, followed by denaturing high performance liquid chromatography (DHPLC). With this method, post-PCR analysis was shortened to 7 min. In the case we analysed, PCR products amplified from the fetal DNA yielded a single peak in the chromatogram, indicating a homozygous state in the fetus. When wild-type PCR products were mixed with fetal PCR products, two peaks were observed, indicating that the fetus was homozygous for the parental (G149E) mutation. Sequencing results confirmed this diagnosis. As a result, the pregnancy was terminated and the diagnosis was confirmed on DNA analysis of the aborted fetus. We show here that DNA mutation analysis can be used in the prenatal diagnosis of GSD1b and that DHPLC promises to be a robust technique for this and other prenatal molecular diagnoses.

Abortion, Eugenic↗
PubMed2000

Recurrent and novel mutations of GCDH gene in Chinese glutaric acidemia type I families.

Glutaric acidemia type I is caused by mutations of the glutaryl-CoA dehydrogenase (GCDH) gene resulting in loss of GCDH enzyme activity. Patients present with progressive dystonia and lesions in basal ganglia. Dietary treatment, when instituted from the early neonatal period, markedly reduces dystonia and morbidity. Early diagnosis and prenatal diagnosis will be facilitated by knowledge of locally prevalent GCDH mutations. Several common GCDH mutations have been found in different ethnic groups. GCDH mutations were studied in 5 Chinese glutaric acidemia type I families. We detected two novel recurrent mutations (A219T and IVS10-2A>C) which were found in two unrelated families. An asymptomatic carrier of IVS10-2A>C was also found on screening of 120 individuals. Other mutations were identified, including two other novel (R386G & IVS3+1G>A) and two known mutations (G178R & R355H). Fibroblasts from patients carrying the novel mutations were confirmed to be deficient for GCDH activity. This is the first report of GCDH mutations describing recurrent mutations in Chinese patients. The carrier rate of IVS10-2A>C may be particularly high in Chinese.

Alternative Splicing↗
PubMed2000

Epidemiology of diabetes mellitus in children in Hong Kong: the Hong Kong childhood diabetes register.

OBJECTIVES: To establish a registry for Chinese children with onset of type 1 (insulin dependent) diabetes mellitus before 15 years of age and to determine the incidence of childhood onset type 1 diabetes mellitus in Chinese children in Hong Kong. RESEARCH DESIGN AND METHODS: A registry was established in 1997 to collect childhood diabetes cases retrospectively from all districts in Hong Kong. The study included all newly diagnosed cases of diabetes with onset < 15 yr of age from 1st January 1984 to 31 December 1996. Primary ascertainment was based on review of medical records at all regional public hospitals in Hong Kong and survey of all the registered practitioners in Hong Kong. The secondary source of validation was made impractical, if not impossible, because of the recent implementation of the Personal Data Privacy Ordinance in Hong Kong. RESULTS: A total of 255 diabetic cases were identified, 227 type 1 diabetes mellitus (218 were Chinese), 18 type 2 diabetes mellitus and 11 secondary diabetes. 246 patients were Chinese and 9 non-Chinese. The age-standardized incidence of type 1 and type 2 diabetes mellitus in southern Chinese children in Hong Kong was 1.4/100,000/yr and 0.1/100,000/yr respectively for children < 15 yr of age during the study period. The incidence rates for type 1 diabetes were 0.9, 1.5 and 1.7 per 100,000/yr for 0-4 years, 5 to 9 years and 10 to 14 years age-groups respectively. The incidence for males was 1.2/100,000/yr and for females 1.7/100,000/yr. A significant increase in the incidence was demonstrated during the study period by simple linear regression (slope 0.14/100,000/year, r2 = 0.73, p = 0.0002) CONCLUSIONS: A diabetic registry is established in Hong Kong. This study documents a very low incidence rate of childhood type 1 diabetes mellitus in southern Chinese children in Hong Kong and we have seen an increasing incidence of the disease in the past 13 years.

Adolescent↗
PubMed1999

The prevalence of domestic violence against pregnant women in a Chinese community.

OBJECTIVE: To study the incidence of domestic violence in pregnant women attending the antenatal clinic of a local teaching hospital. STUDY DESIGN: All pregnant women attending their first antenatal clinic in Tsan Yuk Hospital between 11th August and 3rd November, 1998 were interviewed by a designated research nurse (Y.Y.J.L.) using a standard questionnaire (Abuse Assessment Screen) to detect the incidence of domestic violence, the nature of violence, the frequency of violence and the perpetrator of abuse. Demographic factors of the abused group were compared with those of the non-abused group using student's t-test and chi-square test. RESULTS: Pregnant women (631) were interviewed; 113 of them (17.9%) had a history of abuse; 99 women (15.7%) had been abused in the last year; 27 of them (4.3%) had been abused during their current pregnancy; 59 women (9.4%) had been sexually abused in the last year. The husband was the perpetrator in the majority of cases. The nature of violence during pregnancy was mainly psychological in the form of threats of abuse without any physical injury. Risk factors included unplanned pregnancy (P = 0.002) and women with husbands/partners who were unemployed or manual workers (P < 0.05). Unexpectedly, domestic violence occurred more commonly in permanent local residents rather than new immigrants (P < 0.05). CONCLUSION: This is probably the first study on the incidence of domestic violence in pregnant women in a Chinese community. The incidence is comparable to that from American studies. Routine screening with structured questions during the antenatal visits is necessary in order to identify the abused women so as to prevent potential trauma and to interrupt existing abuse.

China↗
PubMed1980

Temperate coliphages: classification and correlation with habitats.

Temperate coliphages were recovered from sewage, mammalian feces, and lysogenic strains of Escherichia coli. A total of 32 phages of independent origin were divided into six groups by applying the criteria of host range, antigenic homology, and the ultraviolet inducibility of the prophage. The demonstration of genetic interactions in some cases has confirmed the classification scheme. Nine phages were assigned to the P2 family and 19 to the lambda family. The remaining four isolates may represent some novel phylogenetic types. Phages recovered from the lysogenic strains of E. coli were all found to be P2 related, whereas a majority of the phages recovered as cell-free plaque-forming units were assignable to the lambda family. It is proposed that the biological attributes of the phages belonging to the two principal families are reflected in the distribution patterns observed. The virions of phage HK256 show multiple tail fibers and may thus represent a "new" virion form among the temperate coliphages.

Bacteriophage lambda↗