Headspace solid-phase microextraction with 1-pyrenyldiazomethane in-fibre derivatisation for analysis of faecal short-chain fatty acids.

Short chain fatty acids (SFCAs) are nutritionally important products of colonic bacteria. Their analysis in faeces is problematic. We report a headspace solid-phase microextraction procedure in which faecal SCFAs are derivatised on the fibre in-situ with 1-pyrenyldiazomethane. With this method sharp, well-resolved chromatographic peaks were obtained with no interferences. Inclusion of deuterated analogues enabled accurate quantification. Good linearity, recoveries and precision were achieved. Differences observed between the SCFA profiles of normal subjects and patients with cystic fibrosis indicate the potential of this new technique for clinical studies. 2-Methylbutyric acid was found in all faecal samples. Few have reported this before.

Quantitative determination of trimethylamine in urine by solid-phase microextraction and gas chromatography-mass spectrometry.

Trimethylaminuria (fish odour syndrome) is diagnosed from an increase in urinary excretion of trimethylamine with decreased trimethylamine oxide. We report a new quantitative stable isotope dilution gas chromatography-mass spectrometry procedure for the analysis of these metabolites using solid-phase microextraction (SPME). Both polydimethylsiloxane and mixed Carboxen-polydimethylsiloxane SPME fibres were found to be suitable for the headspace extraction of TMA. This new sampling technique could have wide application for the analysis of volatile and semi-volatile compounds by metabolic screening laboratories.

Epidemiological profile, mineral metabolic pattern and crystallographic analysis of urolithiasis in Kuwait.

This study was conducted to determine the epidemiological profile of urolithiasis in Kuwaiti patients and the associated metabolic abnormalities favouring stone formation in this patient population. Between 1986 and 1994, a total of 421 Kuwaiti patients were studied in Al-Amiri renal stone laboratory. The mineral composition of stones was determined using a combination of stereoscopic microscopy and infrared spectrophotometry. Mineral metabolic screen (MMS) was available in 306 (72.7%) of those patients. The average annual incidence of new stone formation in Kuwaiti patients was 23.9 per 100,000 population. The incidence was only 6.9 per 100,000 population in those from pediatric age group, 33.4 in adults and 73.6 in the elderly. The frequency of new stone formation was higher among males as compared to females at different age groups. Calcium oxalate (CaO) constituted 72.1% of renal stones encountered in adults as compared to only 52.1% and 40.7% in elderly and pediatric age groups. Eighty four patients had recurrent and/or high stone load. Detailed family history was available in 57 of those 84 patients and was suggestive of strong family aggregation of stone disease in 30 (53%) patients. The proportion of urate stones was 15.4% of all stones formed and constituted a major cause of renal stones in children (24.1%), adults (14.4%) and elderly (12.5%). Cystine stones were found in 10 patients (2.4%). Hyperuricemia was detected in 1/3 of patients from pediatric age group. In adults, 89 (38.4%) of 232 patients had abnormal MMS, of which hyperuricosuria with or without hyperuricemia accounted for 79.8% of those abnormalities. In elderly patients, metabolic disorders were detected in 7 (17.5%) of the 40 patients. In the latter group, all except one, had hyperuricosuria with or without hyperuricemia. Cystinuria, distal renal tubular acidosis (d-RTA) and hyperparathyroidism constituted 6.6% of metabolic abnormalities in the patients studied. Primary abnormalities of upper and lower urinary tract was detected in 6% of adult patients as compared to 47% in children and 30% in the elderly. In conclusion; the incidence rate of new stone former in Kuwait is significantly lower from that reported in Europe and USA. This latter finding and the high familial aggregation of urolithiasis in our area constitute a cogent argument against the role of hot climate in the pathogensis of urolithiasis and are in favour of genetic predisposition. Isolated hyperuricosuria was detected in 17% of idiopathic CaO stone formers. The latter finding is of practical importance since red-meat is a common food item in our area and restriction of purine-intake may help to decrease the frequency of urate and CaO stone formation in predisposed patients.

Towards improving care for children with diabetes in Kuwait.

Presents the results of a medical audit of the records of 199 children diagnosed as diabetic and admitted to Al-Amiri Hospital, Kuwait. Uses the measurement of glycosylated haemoglobin (HbA1) to indicate the levels of control achieved. Finds that the degree of glycaemic control compares favourably with studies done in other hospitals, but unfavourably with specialized diabetic clinics. Proposes that glycaemic control could be improved by provision of the services of specialized support staff such as dietitian, educator, psychologist and health visitor.