Awareness of fertility preservation among Chinese medical students.

INTRODUCTION: The fertility preservation (FP) services offered in Hong Kong are underutilised. There have been no previous studies on Chinese medical students to investigate the underlying reasons for this underutilisation in terms of awareness, knowledge, and attitudes towards FP and age-related fertility. METHODS: This was a cross-sectional survey among Chinese medical students in Hong Kong. RESULTS: The majority of participants (77.8%) were not familiar with any clinics or specialists who provide FP services. The vast majority (88.1%) underestimated female infertility at age 45 years, and 89.8% overestimated the age of male fertility decline. The students' FP knowledge was mainly acquired from electronic media (58.4%) and medical school (57.6%). Medical students showed overwhelming support towards FP for medical reasons (97.9%) but had mixed responses about FP for elective reasons related to career development in women (58.8%). Of the participants, 80.2% agreed that the government should subsidise FP services for patients with medical reasons. CONCLUSION: This study highlights the limited awareness and knowledge of FP among Chinese medical students. There is a strong worldwide need to increase education about and exposure to FP in the medical curriculum and improve medical students' knowledge.

Rapid and specific determination of DNA adducts for clinical diagnosis of poisoning and disease associated with aristolochic acid.

1. A liquid chromatography-mass spectrometry method was developed to detect and characterise aristocholic acid-DNA adducts in biological samples. 2. The detection of DNA adducts in plasma, urine or the cells found in urine may be useful to support the diagnosis and monitoring of aristocholic acid-associated poisoning and disease. 3. Efforts should be made to improve the sensitivity and specificity of this approach for the detection and characterisation of exposure to other mutagens/carcinogens.

In search of the diagnosis, and the patient: transient galactosemia demystified after 14 years.

Infantile galactosemia can be caused by inborn errors of galactose metabolism or other rare causes like Fanconi-Bickel syndrome, congenital porto-systemic shunting and multiple hepatic arterio-venous malformations. All these disease entities are however not commonly seen. We report a case of transient infantile galactosemia who first presented in the 1990s, for which no underlying pathology could be identified despite extensive investigations. The diagnosis had not been apparent until after more than a decade, at that time the patient was lost to contact. Considering the potential diagnosis an important and significant one, efforts were made by the case pathologists and clinicians to search for the patient. Ethical dilemmas were encountered during the search of the patient, which involved issues of patient confidentiality and autonomy, and the doctors' duty-to-care. Modern biochemical and molecular testing confirmed the diagnosis after the patient was finally found. The case illustrates the power of molecular testing to retrospectively diagnose an inherited metabolic disease when biochemical abnormalities have subsided, the value of an accurate and precise diagnosis, and the importance of appropriate genetic counselling in an apparently asymptomatic patient in the era of personalized medicine.

Parental attitudes on expanded newborn screening in Hong Kong.

OBJECTIVES: Classical inborn errors of metabolism (IEM) affect about 1 in 4000 in Hong Kong. Despite the widespread implementation of expanded newborn screening in most countries, Hong Kong only screen for three conditions and the awareness of public has not been evaluated. This is the first study to examine the parental knowledge and attitudes towards expanded newborn screening in Hong Kong. METHODS: A cross-sectional survey was conducted in the Princess Margaret Hospital. Parents with babies born from 1st July to 31st October 2010 were randomly recruited. Fifteen questions relating to the knowledge of newborn screening and biochemical genetic disorders, preferences about the features of newborn screening, the economic values, and attitudes toward false positive results were asked. RESULTS: In total, 172 subjects were interviewed by phone (overall response rate 97.2%). There were 87.8% parents who had never heard of expanded newborn screening; 99.4% demanded more parental education; 83.5% thought the programme should be implemented immediately; 97.7% supported population screening, even though the diseases are incurable; 93.9% accepted the possibility of false positive and false negative results; 70.4% preferred a voluntary basis; 83.2% believed that the programme should be fully government funded as basic primary care; 98.8% agreed that Hong Kong should follow mainland China's policy on expanded newborn screening; 98.2% required pre-test counseling; and 96.4% required an explicit parental consent before blood sampling. CONCLUSIONS: The response from parents overwhelmingly favoured having expanded newborn screening in Hong Kong. Parental tolerance was high. Parents valued the parental autonomy with informed consent and pre-test counseling the most. The success of any screening programme requires the public participation and this study is the first to prove the parental call for an expanded newborn screening in Hong Kong.

RYR1-related central core myopathy in a Chinese adolescent boy.

Central core myopathy is a rare, inherited neuromuscular disorder with a wide spectrum of phenotypic presentations. It is also considered an allelic disease of malignant hyperthermia. We report a case of central core myopathy in a Chinese adolescent boy presenting with atypical clinical features and a moderately elevated serum creatine kinase level. The diagnosis was made from the histopathological findings of central cores on muscle biopsy, and confirmed by the molecular genetic testing for the RYR1 gene mutation. This is the first case of central core myopathy confirmed by molecular study in our locality.

Drug-induced hypoglycaemia--new insight into an old problem.

OBJECTIVE: To review the causes of drug-induced hypoglycaemia in patients not taking hypoglycaemic medications. DESIGN: Retrospective study. SETTING: Regional hospitals in Hong Kong. PATIENTS: Patients with suspected drug-induced hypoglycaemia without a known history of exposure to hypoglycaemic agents, referred to the Hospital Authority Toxicology Reference Laboratory from June 2005 to March 2006 inclusive. MAIN OUTCOME MEASURES: Rate of positive cases, laboratory findings, possible causes, age distribution, and final outcomes. RESULTS: A total of 51 such patients were referred, in whom the presence of oral hypoglycaemic agents was detected (or inferred) in 23 (45%). In 12 of the 23 patients, oral hypoglycaemic agents could only be detected by target analysis, not through broad-spectrum screening. Gliclazide and glibenclamide were detected in 14 and eight patients respectively, whereas glimepiride, nateglinide and rosiglitazone were detected in the remaining patient. Possible sources of oral hypoglycaemic agents included drug administration errors in residential care homes for the elderly (n=9), mistakenly taking medication of a family member or employer (n=6), taking stock medication by mistake (n=2), taking Chinese proprietary medicine adulterated with oral hypoglycaemic agents (n=1), taking unknown pills bought from a retail pharmacy (n=1), and unknown (n=4). Regarding these 23 patients, 17 (74%) were aged 70 years or above and 21 (91%) recovered uneventfully. CONCLUSION: Hypoglycaemia due to inadvertent use of oral hypoglycaemic agents is a recognised problem, particularly in cases where family members living in the same household are taking similar medications. Possible drug administration errors in residential care homes for the elderly should be investigated, and procedures rectified if confirmed. Health care providers should be vigilant to such potential errors, especially in cases of unexplained hypoglycaemia.

Aconite poisoning in camouflage.

The Toxicology Reference Laboratory has confirmed 10 cases of aconite poisoning from March 2004 to May 2006. In four of these 10 cases, the aconite herb was not listed in the written prescription. We report these four cases to highlight the problem of 'hidden' aconite poisoning.

A case of tetramine poisoning: a lethal rodenticide.

We report a fatal case of suicide presenting with convulsions and subsequently multi-organ failure. Rodenticide poisoning was not suspected until the next day when tetramine was detected in the patient's blood, urine, and food residues. Tetramine is a potent rodenticide with a rapid action and high mortality. The poison has been banned worldwide but is still readily available in Mainland China. Outbreaks of poisoning are reported frequently and doctors should be alert for this lethal toxin.

Spinocerebellar ataxia type 6.

We report a 39-year-old woman with spinocerebellar ataxia type 6. She presented with ataxia and a 3-year history of progressive ataxia and recurrent falls. There was no relevant family history. Genetic tests revealed an expanded allele of 24 CAG repeats at the spinocerebellar ataxia type 6 locus. This appears to be the first case reported in Hong Kong. As genetic testing becomes more widely available and clinical awareness increases, more such patients are expected to be diagnosed.

Primary immunosuppression with tacrolimus and low-dose mycophenolate mofetil in renal transplant recipients.

Both tacrolimus and mycophenolate mofetil (MMF) are potent immunosuppressive agents used in combination for prevention of acute rejection in renal transplantation. We studied the efficacy and safety of tacrolimus/MMF-based primary immunosuppression as well as their pharmacokinetics (PK) in Chinese renal transplant recipients. Oral tacrolimus was initiated at about 0.2 mg/kg/d, dose which was adjusted to achieve target trough levels of 10 to 20 ng/mL at 3 months and 5 to 10 ng/mL thereafter. The patients also received MMF (0.5 g bid) and prednisolone. PK profiles were studied at 1 week, and 1, 3, and 6 months posttransplant. Blood samples were taken at 0 (predose), 20, 40, 60, 75, and 90 minutes and 2, 4, 6, 8, 10, and 12 hours postdose for each profile. Plasma MPA and whole blood tacrolimus levels were determined by HPLC and EMIT methods respectively. Eight patients were studied with mean follow-up of 16.1 +/- 2.4 months. One patient (12.5%) experienced a borderline acute rejection episode. Both 1-year graft and patient survival rates were 100%. Posttransplant diabetes, diarrhea, and hand tremor occurred in 12.5%, 12.5%, and 37.5%, respectively. No patient had an opportunistic infection. Tacrolimus trough concentrations showed a fair correlation with AUC(0-12h) (R(2) = 0.587). Mean MPA AUC values at 1, 3, and 6 months were 40.5 +/- 9.4, 44.4 +/- 17.3, and 57.2 +/- 20.7 mug*h/mL, respectively (P = .0486, n = 7). In conclusion, primary immunosuppression with tacrolimus, low-dose MMF (0.5 g bid), and prednisolone is effective and safe with adequate systemic MPA exposure in renal transplant recipients.

Kennedy's disease.

Kennedy's disease is an X-linked, neurodegenerative disorder, characterised by lower motor neuron syndrome. This report gives the clinical details of six male patients with Kennedy's disease diagnosed at Princess Margaret Hospital. Three were initially diagnosed with other neurological diseases, with the diagnosis of Kennedy's disease made after genetic testing. This hereditary disease should be considered in male patients with muscle weakness, particularly those with a presentation suggesting atypical motor neuron disease.

Use of hair analysis in the diagnosis of heavy metal poisoning: report of three cases.

We report three paediatric cases of suspected heavy metal poisoning that presented with non-specific symptoms. Hair samples of the three patients were sent overseas for analysis; results showed abnormal levels of many elements, including some heavy metals. A diagnosis of heavy metal poisoning was made and chelation therapy was offered to each patient. Blood levels for some heavy metals were subsequently checked and all were within the normal range. The original diagnosis of heavy metal poisoning was therefore not substantiated. The patients did not have a history of exposure to heavy metals or specific clinical features of heavy metal poisoning. The non-invasive nature of hair analysis is tempting, but the validity of such testing in diagnosing heavy metal poisoning is questionable.

Infantile isolated sulphite oxidase deficiency in a Chinese family: a rare neurodegenerative disorder.

We report the clinical, biochemical, neuroradiological, and neurophysiological findings of a 4-year-old Chinese girl with infantile isolated sulphite oxidase deficiency. This is the first reported case in our locality. She presented at the age of 5 months with refractory seizures and developmental regression, and progressed rapidly to profound psychomotor retardation, spasticity, dystonia, microcephaly, and blindness. At the age of 3.5 years, she was admitted to the intensive care unit with septic shock. Ophthalmologic examination at this time revealed bilateral dislocation of the lens. Diagnosis of this very rare disorder was made on the basis of increased levels of urinary sulphite, thiosulphate, and sulphocysteine; normal urine xanthine and hypoxanthine; normal plasma uric acid; and low plasma cystine levels. The diagnosis was confirmed by the absence of sulphite oxidase activities in skin fibroblasts. Isolated sulphite oxidase deficiency is a rare inborn error of sulphur metabolism that is difficult to diagnose on clinical features and routine metabolic tests. The presence of ectopia lentis, seizures, and progressive neurological abnormalities should alert clinicians to the diagnosis.

Macroprolactin-a cause of pseudohyperprolactinaemia.

Macroprolactin is a complex of immunoglobulin G and monomeric prolactin with little biological activity in vivo. Macroprolactin cross-reacts in modern commercial prolactin assays, however, leading to pseudohyperprolactinaemia. This report is of three patients with macroprolactinaemia and the untoward consequences if this benign condition is misdiagnosed as genuine hyperprolactinaemia are discussed. One adult and one child without symptoms of hyperprolactinaemia were incidentally found to have elevated serum prolactin levels, one of whom had a pituitary incidentaloma. Repeat prolactin measurement after polyethylene glycol precipitation showed that the majority of circulating prolactin was macroprolactin. The third patient had galactorrhoea and pituitary microadenoma. Polyethylene glycol study showed that macroprolactinaemia exists simultaneously with genuine hyperprolactinaemia leading to falsely high serum prolactin levels. The recognition of this relatively common and benign condition is important in order to avoid misdiagnosis and unnecessary investigations and treatment. Particular attention must be paid to patients in whom the clinical and radiological findings are incompatible.

Diagnosis of dihydropyrimidine dehydrogenase deficiency in a neonate with thymine-uraciluria.

Dihydropyrimidine dehydrogenase deficiency is an inborn error of pyrimidine metabolism characterised by thymine-uraciluria, convulsive disorders and developmental delay in paediatric patients, and an increased risk of toxicity from 5-fluorouracil treatment. This report is of the first patient with dihydropyrimidine dehydrogenase deficiency diagnosed in Hong Kong. The patient was a 2-day-old male neonate of Pakistani origin who presented with convulsions. Diagnosis was made by gas chromatographic-mass spectrometric detection of thymine-uraciluria and by molecular detection of a G to A point mutation in a 5'-splicing site leading to skipping of exon 14 in the DPYD gene of chromosome location 1q22. The results showed that the patient and his mother were homozygous and the father heterozygous for the splice site mutation. The mother also had thymine-uraciluria but was clinically asymptomatic.

Clinical features of hereditary spinocerebellar ataxia diagnosed by molecular genetic analysis.

OBJECTIVE: To assess the frequency and clinical features of different types of hereditary spinocerebellar ataxia in Hong Kong. DESIGN: Cross-sectional study using a questionnaire and clinical examination, with the majority of the information retrospectively collected. SETTING: Three regional hospitals, Hong Kong. PARTICIPANTS: All patients with spinocerebellar ataxia that was confirmed by molecular genetic tests between January 2001 and October 2003. MAIN OUTCOME MEASURES: History, latest physical examination results, clinical investigation results, and genetic profiles. RESULTS: A total of 16 Chinese patients had received diagnoses of spinocerebellar ataxia. These patients had spinocerebellar ataxia type 1 (n=3), spinocerebellar ataxia type 3 (Machado-Joseph disease; n=12), and dentatorubro-pallidoluysian atrophy (n=1). The most common manifestation was ataxia (15/16), followed by pyramidal signs (12/16). Other features such as bulbar dysfunction, ophthalmoplegia, neuropathy, and cognitive impairment were present but variable. CONCLUSIONS: The clinical manifestations of different types of spinocerebellar ataxia overlap, and genetic study is necessary to confirm the diagnosis. The frequency of spinocerebellar ataxia type 3 is greater than that of other types among these Chinese patients. The age of onset of this type may correlate inversely with the number of CAG repeats.

Nitrite-induced methaemoglobinaemia - aetiology, diagnosis and treatment.

A 41-year-old woman presented with the clinical features of methaemoglobinaemia after drinking Chinese herbal medicine. A life threatening methaemoglobin level of 68% was measured. Both clinical and laboratory diagnostic difficulties were encountered. The pitfalls of pulse oximeter, blood gas analysis and co-oximeter interpretation during diagnosis and after methylene blue administration are discussed.