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Biomedical subjects

A Chan

Publications and source records attributed to A Chan.

319 records · Page 18Linked to original sources
PubMedDate not supplied

Use of oral sodium phosphate colonic lavage solution by Canadian colonoscopists: pitfalls and complications.

Oral sodium phosphate (NaP) has become an attractive alternative to polyethylene glycol (PEG) for colonic cleansing before colonoscopy, but it potentially has greater complications. This study surveyed members of the Canadian Association of Gastroenterology (CAG) to determine how these colonic lavage agents are used and what complications have been encountered. The Dillman survey technique produced responses from 67% of the 400 members who perform colonoscopy. For the larger out-patient group, respondents used NaP more frequently than PEG (46% versus 35%, respectively, P < 0.015). Respondents used NaP and PEG with similar frequencies for the in-patient group (44% versus 43%). Of respondents using NaP, 45% reported excluding its use in patients with renal failure, 30% with heart disease, 13% with incomplete bowel obstruction and 9% with extreme age. Symptoms suggestive of hypovolemia were reported in 9% of those using NaP compared with 3% using PEG (P < 0.02). Three patients receiving NaP developed acute renal failure. A greater proportion of those using NaP had small unexplained aphthous ulcers (16%) and excessive luminal bubbling (24%) compared with PEG users (3%, P < 0.00001 and 14%, P < 0.03, respectively). These data demonstrate that members of CAG use NaP more frequently than PEG as the colonic lavage solution before colonoscopy. A greater number reported complications with NaP versus PEG, and a significant proportion of the respondents appeared to be unaware of the potential for these complications in specific clinical circumstances.

Canada↗
PubMedDate not supplied

Diabetes microvascular complications in prepubertal children.

These are the baseline findings of a group of 68 prepubertal children enrolled in a longitudinal study of the development of early diabetes microvascular complications prior to gonadarche. The median age of the children was 9.8 years, the median diabetes duration 3.6 years and the mean HbA1c 8.4%. Mild nonproliferative retinopathy was present in 6 of 67 (9%) children, assessed by 7-field stereoscopic fundus photography. Those with retinopathy had higher total cholesterol (p < 0.05) and lower DHEAS (p < 0.01). Albumin excretion rate (AER) was calculated as the mean of three overnight consecutive urine collections. AER > 7.5 micrograms/min was present in 5 of 64 (8%), and one boy had a mean AER > 15 micrograms/min. Those with AER > 7.5 micrograms/min had higher diastolic blood pressure and diastolic blood pressure percentiles (p < 0.05). Longitudinal study of this cohort will establish which factors in the prepubertal years are important for the development of diabetes microvascular complications.

Albuminuria↗
PubMedDate not supplied

Diabetes complication screening in 937 children and adolescents.

Results are presented of diabetes complication screening in children and adolescents aged 6-20 years. Their diabetes duration was 0.02-18.4 yr and median HbA1c over the preceding 36 months was 8.4% [IQR 7.8-9.3]. Gradable retinal photographs were obtained in 937: 110 less than 11 years (< 11 yr Gp). Albumin excretion rate (AER) was obtained from 3 timed overnight urine collections in 691: 100 in < 11 yr Gp. Early retinopathy was found in 27% (9% in < 11 yr Gp). Microalbuminuria (AER > or = 20 micrograms/min) was found in 4%. Significant individual risk factors for both complications were higher blood pressure, cholesterol, HbA1c, pubertal staging, older age and longer diabetes duration. Using multiple logistic regression, significant risk factors for retinopathy were longer duration and older age and in addition higher HbA1c. Diabetes complication screening detected early subclinical disease in children and adolescents who may benefit from lowering blood pressure and improving metabolic control. Screening should commence after five years of duration in young children, and after two years of duration in adolescents.

Adolescent↗
PubMedDate not supplied

Children with coeliac disease and insulin dependent diabetes mellitus--growth, diabetes control and dietary intake.

We aimed to assess the growth, diabetes control, dietary intake and compliance with a gluten-free diet in children with insulin dependent diabetes mellitus (IDDM) and coeliac disease in a major paediatric and adolescent diabetes clinic. Children with IDDM and biopsy-proven coeliac disease aged <18 years were included and compared with IDDM controls matched for age, sex and duration of diabetes. Twenty patients with coeliac disease and IDDM participated (15 female, age 7.4-17.3 yr), with two matched IDDM controls for each (age 6.9-17.4 yr). The prevalence of coeliac disease in this diabetes clinic population was 2.6%. All patients completed a 3 day food record (3DFR) and a 7 day food frequency questionnaire (FFQ) to assess dietary intake and gluten-free compliance. Diabetes control measured by HbA1c was not different between groups or compared to the overall clinic population (8.48 +/- 0.98% for coeliac patients vs 8.87 +/- 1.46 for IDDM controls vs 8.60 +/- 1.30 for overall clinic population aged 5.0-17.9 yr). Height, weight and BMI standard deviation scores were not different between coeliac patients and IDDM controls. No clinically significant differences were found in intake of energy, macronutrients or micronutrients. The proportion of energy intake from carbohydrate, protein and fat was within recommended ranges, except for a higher saturated fat intake. Only 30% of coeliac patients complied with a strict gluten-free diet, but growth parameters were unaffected by dietary compliance. Thus, we found that children and adolescents with coexisting IDDM and coeliac disease have normal growth, equivalent diabetes control and no differences in energy or nutrient intake compared to matched IDDM controls in our clinic population.

Adolescent↗
PubMedDate not supplied

Carotid artery disease in NIDDM diabetes.

A prospective study of 135 controls, 286 non-insulin-dependent diabetic patients, and 31 subjects with an elevated fasting plasma glucose was performed to assess the prevalence of high-grade carotid artery stenosis. The carotid artery evaluation was performed using an ultrasonic duplex scanner. When those patients with an elevated fasting plasma glucose and non-insulin-dependent diabetes were considered together, the prevalence was 8.2% as compared with 0.7% for the controls (P = 0.0007). Those risk factors found to be significantly related to the higher prevalence of carotid disease in the combined groups of patients included age, ratio of systolic blood pressure to diastolic blood pressure, plasma cholesterol, and cigarette smoking. These findings may be an explanation for the greater incidence of stroke in patients with diabetes mellitus.

Adult↗
PubMedDate not supplied

Planned homebirths in South Australia 1976-1987.

Homebirths booked with a group of general practitioners and midwives in South Australia in 1976-1987 are described using data obtained from midwives' and hospital records. The births represented 84.7% of all births occurring at home in South Australia in 1984-1987, as assessed by official birth registrations. Of the 799 women intending to deliver at home, 136 (17.0%) required transfer to hospital before or during labour. A further 38 mothers or babies (4.8%) required transfer after delivery. The women tended to be of a relatively high socioeconomic status and older age distribution when compared with women who had hospital births as identified from the State perinatal data collection. Some had recognised pregnancy risk factors. They had lower frequencies of ultrasound examination, induced labour, epidural analgesia, episiotomy, forceps delivery and caesarean section, and a low frequency of use of oxytocics for the third stage. Their rates of postpartum haemorrhage and, in particular, perinatal mortality were higher. Potential sources of risk and difficulty in homebirth care and evaluation of this care are identified and an approach to providing an effective homebirth service is proposed.

Adolescent↗
PubMedDate not supplied

Measuring abutment/implant joint integrity with the Periotest instrument.

Maintenance of the integrity of the abutment/implant interface is essential and is dependent on the abutment screw retaining a preload. Evaluation of this joint is usually done by manual assessment. The purpose of the current study was to determine whether the Periotest instrument could be used to evaluate abutment screw loosening. A custom-designed apparatus was constructed to measure abutment screw loosening. Abutment screws were torqued to 10, 20, 32, and 45 Ncm and then loosened. Objective assessment of screw loosening was carried out with the Periotest device. Subjective evaluation was done by 3 experienced clinicians. The Periotest was found to be more sensitive than manual detection of abutment screw loosening. With a change of 2 in the Periotest value, it was found that the tensile preload in the joint was lost. While the Periotest was more sensitive than manual evaluation, the instrument was not sensitive enough to indicate deterioration of abutment screw loosening prior to loss of tensile preload.

Dental Abutments↗
PubMedDate not supplied

S-adenosyl methionine: A connection between nutritional and genetic risk factors for neurodegeneration in Alzheimer's disease.

Clinical manifestation of Alzheimer's disease may depend upon interaction among its risk factors. Apolipoprotein E-deficient mice undergo oxidative damage and cognitive impairment when deprived of folate. We demonstrate herein that these mice were depleted in the methyl donor S-adenosyl methionine (SAM), which inhibited glutathione S-transferase, since this enzyme requires methylation of oxidative species prior to glutathione-dependent reduction. Dietary supplementation with SAM alleviated neuropathology. Since SAM deficiency promotes presenilin-1 overexpression, which increases gamma-secretase expression and Abeta generation, these findings directly link nutritional deficiency and genetic risk factors, and support supplementation with SAM for Alzheimer's therapy.

Adenosine↗
PubMedDate not supplied

Noninvasive imaging of the superficial femoral artery using ultrasound Duplex scanning.

A total of 56 lower extremities in 28 patients were evaluated by both conventional arteriography and ultrasound duplex scanning. Overall sensitivity for duplex scanning compared to arteriography in detecting stenotic or occlusive disease was 91%, specificity was 94%, positive predictive value 85% and negative predictive value 97%. Results for Duplex scanning were better in the proximal and middle segment compared to the distal third of the superficial femoral artery. The sensitivity of segmental lower extremity pressures and pulse volume recordings for predicting proximal superficial femoral artery disease compared to arteriography was 82%; specificity was 79% and accuracy 80%, all inferior to that of Duplex scanning. Duplex scanning is a promising technique suitable for noninvasive assessment of patients presenting with suspected superficial femoral artery disease. It should readily identify candidates for percutaneous interventional techniques in which a patent segment of proximal superficial femoral artery is required for access. It will also be useful in follow-up studies of patency of the superficial femoral artery following interventional procedures such as balloon dilatation and laser angioplasty.

Aged↗
PubMedDate not supplied

Tamoxifen therapy in unresectable adenocarcinoma of the pancreas.

Twenty-four patients with biopsy-documented unresectable ductal adenocarcinoma of the pancreas were treated with tamoxifen. Six of 15 postmenopausal female patients had documented prolonged survival, with three living greater than 2 years.

Adenocarcinoma↗
PubMedDate not supplied

Local control after the use of adjuvant electron beam intraoperative radiotherapy in patients with high-risk head and neck cancer: the UCSF experience.

PURPOSE: We assess the effect of electron beam intraoperative radiotherapy (EB-IORT) on local-regional control and any associated complications in patients with locally advanced or recurrent head and neck cancer. MATERIALS AND METHODS: The records of 30 patients with head and neck cancer who received EB-IORT from March 1991 to December 1994 were retrospectively reviewed. The indications for EB-IORT in 25 patients were recurrent or persistent disease despite previous treatment with full-course external-beam radiotherapy and/or one or more resections. In five other cases the indication was extensive primary disease with multiple high-risk factors for local recurrence, including extension into the base of the skull, advanced extensive disease, and perineural or bony invasion. All patients had a Karnofsky performance score > or = 70 prior to EB-IORT. Median age was 65 years. Final pathology revealed positive or close surgical margins in all patients. The areas treated were generally inaccessible to catheter placement for brachytherapy. The most common histology was squamous cell carcinoma. EB-IORT was given as a single fraction of 1500 cGy to the 90% isodose with 6 or 9 Mev electrons using cone sizes ranging from 2.5 to 7 cm in diameter. Data were analyzed to determine the local-regional control rate, survival, and complications after EB-IORT. RESULTS: With a median follow-up time of 30 months, nine patients (27%) had only local recurrence. Of these, only one recurrence was inside the EB-IORT field and eight were outside the EB-IORT field. Two patients (7%) developed distant metastases only and one patient (3%) had both local recurrence and distant metastasis. Seven patients died, five with disease. Twenty-two patients are known to be alive, 15 (68%) of whom have no evidence of disease. One patient was lost to follow-up after 12 months; when last examined he was free of disease. Five patients (16%) have had mild-to-moderate transient complications probably related to EB-IORT. The 3-year actuarial local-regional control rate was 60%. CONCLUSIONS: Our data suggest that EB-IORT may play an important role in decreasing local recurrence in patients with multiple high-risk factors. Despite previous full-course external beam radiotherapy and extensive resections, EB-IORT did not confer significant additional long-term morbidity. Although results are encouraging, randomized studies are required to definitively establish the role of EB-IORT in the management of advanced or recurrent head and neck cancer.

Adenocarcinoma↗