Familial defective apolipoprotein B-100 in hypercholesterolemic Chinese Canadians: identification of a unique haplotype of the apolipoprotein B-100 allele.

Familial defective apo B-100 (FDB) is an autosomal dominant condition resulting in hypercholesterolemia. It is generally observed in 1-6% of hypercholesterolemic subjects in Caucasian populations studied. There are, thus far, no reports characterizing the frequency and phenotype of FDB in a Chinese population. We report on the frequency of the FDB (Arg(3500)--> Gln) mutation and the associated haplotype among 160 hypercholesterolemic (TC > or = 6.2 mmol/l) Chinese Canadians including 36 subjects with a clinical diagnosis of familial hypercholesterolemia (FH). Screening for the FDB mutation was done using a mutagenic polymerase chain reaction and haplotype analysis was undertaken using eight diallelic markers and the 3'HVR marker. One Chinese Canadian clinical FH heterozygote was positive for the FDB Arg(3500)--> Gln mutation while none of the remaining non-FH hypercholesterolemic subjects (n = 124) were carriers of this mutation. Haplotype analysis in the patient positive for this mutation revealed a unique haplotype which differed from both the common haplotype of this mutation observed in Caucasians and from the only other haplotype reported in a Chinese individual. The associated haplotype included a 9-base pair deletion in the signal peptide region and the presence of three restriction sites absent in previously reported haplotypes. These data suggest that the apo B-100 Arg(3500)--> Gln mutation does not appear to be a significant factor contributing to moderate hypercholesterolemia in a Chinese population residing in Canada. However, this mutation was rarely observed among Chinese individuals with a clinical diagnosis of FH. The presence among Chinese individuals of two different haplotypes associated with this mutation, which are different from what has been described among Caucasians is compatible with multiple recurrent origins for this mutation in the Chinese population.

Metformin monotherapy in lean women with polycystic ovary syndrome.

This study was carried out to compare ovulation and pregnancy rates in response to metformin therapy in lean and obese women with polycystic ovary syndrome (PCOS). A total of 34 (17 lean and 17 obese) women with PCOS were treated with 500 mg metformin 3 times daily for 12 weeks. In the lean and obese groups, the mean body mass index was 24 and 36, and the mean fasting insulin concentrations were 12 and 21 mIU/l respectively. There was no difference between the two groups as regarding age, DHEA-S, androstenedione, 17-OH progesterone and LH concentrations. In the lean and obese groups 15/17 women (88%) and 5/17 women (29%) ovulated while 11/17 women (65%) and 3/17 women (18%) conceived respectively. Comparison between the groups was found to be statistically significant. Metformin monotherapy is very effective in improving ovulation and pregnancy rates in lean women with PCOS as compared with obese women.

Neonatal hypernatremic dehydration associated with breast-feeding malnutrition: a retrospective survey.

BACKGROUND: Hypernatremic dehydration in neonates is a potentially devastating condition. Recent reports have identified breast-feeding malnutrition as a key factor in its pathophysiology. METHODS: Using a theoretical framework for breast-feeding kinetics, a retrospective chart review of all neonates less than 28 days of age who were seen at either British Columbia's Children's Hospital or the Vancouver Breastfeeding Centre between 1991-1994 was conducted to identify and classify possible causes of breast-feeding malnutrition among neonates who developed hypernatremic dehydration. RESULTS: Twenty-one cases hypernatremic dehydration were identified. Infant weight loss ranged from 8% to 30% of birth weight, and serum sodium levels ranged from 146 mmol/L to 207 mmol/L. In each case, maternal or infant factors (e.g., poor breast-feeding technique, lactation failure following postpartum hemorrhage and infant suckling disorders associated with cleft palate or ankyloglossia) that could interfere with either lactation or breast-feeding dynamics and account for insufficient breast milk intake were identified. INTERPRETATION: Prenatal and in-hospital screening for maternal and infant risk factors for breast-feeding malnutrition combined with early postpartum follow-up to detect excessive infant weight loss are important for the prevention of neonatal hypernatremic dehydration.

Spurious rise in total carbon dioxide and chloride with negative anion gap after cystogram.

We report a case of spurious hyperchloraemia, elevated total carbon dioxide and negative anion gap 9 days following a voiding cystourethrogram (VCU) in a patient with bladder exstrophy and obstructive uropathy. We believe that the spurious laboratory results were due to analytical interference of the absorbed iodine with the method of bicarbonate and chloride measurement. The absorbed iodine was retained in the circulation for an extended period because of associated renal impairment. Our patient was also on piperacillin which might have interfered with iodine clearance. Physicians and laboratory pathologists should be aware of this effect when interpreting laboratory results of patients who have undergone a VCU in association with obstructive uropathy and impaired renal function.