PubMed Health⌕ Search

Biomedical subjects

John Burkart

Publications and source records attributed to John Burkart.

9 recordsLinked to original sources
PubMed2005

Changes in cardiovascular calcification after parathyroidectomy in patients with ESRD.

BACKGROUND: The effect of parathyroidectomy on vascular calcification in patients with end-stage renal disease has been a subject of interest for many years, although studies in this area have not been definitive. The purpose of this investigation is to determine changes in vascular calcification after subtotal parathyroidectomy by using fast-gated helical computed axial tomographic imaging to measure coronary and carotid artery calcification. METHODS: Computed tomographic imaging was performed at baseline and in follow-up on 10 patients who had undergone subtotal parathyroidectomy and 10 reference patients who had not undergone parathyroidectomy. RESULTS: Patients who underwent subtotal parathyroidectomy had a mean change in coronary calcification of -92.3 +/- 469/y, and reference patients had a mean change of +479 +/- 630/y (P = 0.03). The 2 parathyroidectomy patients with the highest baseline scores had significant declines in both coronary and carotid calcification. CONCLUSION: In this study, subtotal parathyroidectomy is associated with a significant decrease in vascular calcification in 2 of 10 dialysis patients with high coronary artery calcium scores and stabilization in 7 of 10 patients with low baseline scores.

Adult↗
PubMed2003

Peritoneal dialysis.

Explore the source record for details and available documents.

Bacterial Infections↗
PubMed2003

Nutritional status assessed from anthropometric measures in the HEMO study.

OBJECTIVE: Anthropometric methods are screening techniques for assessing nutritional stores of fat and lean tissues among persons with renal disease. This report presents cross-sectional baseline data on anthropometric indicators of nutritional status from a group of hemodialysis patients in a multicenter clinical trial, the Hemodialysis (HEMO) Study. DESIGN: The HEMO Study is a prospective, multicenter, randomized, 2 x 2 factorial clinical trial to evaluate the efficacy of the delivered dose of dialysis, defined by Kt/V, and membrane flux in reducing morbidity and mortality in (maintenance) hemodialysis patients. Standardized measures of weight, stature, body mass index (BMI), arm and calf circumference, and triceps and subscapular skinfolds were taken immediately after dialysis. The analytic methods consisted of univariate statistics, including means, standard deviations, and selected percentiles presented as tables of descriptive statistics. Study findings were compared with corresponding national reference data from the Second National Health and Nutrition Examination Survey (NHANES II). PATIENTS: Eligible patients between 18 and 80 years of age on chronic hemodialysis for at least 3 months, receiving hemodialysis 3 times per week and with a residual renal clearance of < 1.5 mL/min were examined. Patients also had to be able to attain an eKt/V of > or = 1.45 in 4.5 hours or an anthropometric volume < 45 to 50 L thus excluding persons with body weights over about 85 kg. The study sample consisted of the first 1,000 randomized patients, 464 men and 536 women; 642 blacks, 318 whites; and 40 of other racial backgrounds out of 1,847 randomized. RESULTS: Differences in nutritional status by sex, race, duration of dialysis, and comorbid disease were found among these patients enrolled in the HEMO Study. In comparison with NHANES II, these hemodialysis patients were, on average, lighter with less adipose and muscle tissue than healthy persons of the same ages. These findings can be indicators of persons with chronic disease. Those with diabetes were overweight based on their BMI values. CONCLUSION: These HEMO Study data provide a clinical reference for the use of these anthropometric indicators in assessing the nutritional status of contemporary hemodialysis patients weighing < 85 kg.

Adolescent↗
PubMed2002

Selective ablation of surface enamel caries with a pulsed Nd:YAG dental laser.

BACKGROUND AND OBJECTIVE: High intensity infrared light from the pulsed Nd:YAG dental laser is absorbed by carious enamel and not absorbed by healthy enamel. Consequently, this system has potential for selective removal of surface enamel caries. Safety and efficacy of the clinical procedure was evaluated in two sets of clinical trials at three dental schools. Selective ablation was evaluated with FTIR spectroscopy. STUDY DESIGN/MATERIALS AND METHODS: Carious lesions were randomized to drill or laser treatment. Pulp diagnosis, enamel surface condition, preparations, and restorations were evaluated by blinded evaluators. In Study I, surface caries were removed from 104 third molars scheduled for extraction. One-week post-treatment teeth were evaluated clinically, extracted, and the pulp was examined histologically. In Study II, 90 patients with 462 lesions on 374 teeth were randomized to laser or drill and followed for 6 months. RESULTS: Pulsed Nd:YAG laser removal of surface enamel caries was demonstrated to be both safe and effective. Caries were removed in all conditions. There were no adverse events and both clinical and histological evaluations of pulp vitality showed no abnormalities. A significantly greater number of preparations in the drill groups vs. laser groups entered dentin (drill = 11, laser = 1, P = 0.007). CONCLUSION: The more conservative laser treatment removed the caries but not the sound enamel below the lesion. The pulsed Nd:YAG dental laser was found to be both safe and effective for surface caries removal.

Adult↗
PubMedDate not supplied

Metabolic consequences of peritoneal dialysis.

Optimization of the peritoneal dialysis (PD) prescription includes attempts to normalize the patient's blood pressure and extracellular volume. To do so, one must utilize crystalloid or colloid osmotic agents to achieve ultrafiltration. These osmotic agents are systemically absorbed and thus have both potential benefits and adverse effects. With glucose-based dialysate solutions, the average patient absorbs 300-450 kcal of glucose per day on either continuous ambulatory peritoneal dialysis (CAPD) or the cycler. The amount of glucose absorbed varies based on peritoneal transport characteristics, prescription, and tonicity of fluids used. Alternative osmotic agents such as amino acids and macromolecular solutions, including polypeptides and polyglucose (icodextrin) solutions, have a different rate of systemic absorption and thus a different caloric load profile. In addition, there are protein losses that average about 10 g/day with glucose-based solutions and glucose losses with either amino acid or icodextrin dialysate solutions. There are also potential advantages of these alternative solutions with regard to ultrafiltration. Glucose-based solutions require the development of significant crystalloid osmotic forces, which are dissipated as glucose is absorbed systemically. In contrast, macromolecular solutions achieve ultrafiltration via differences in colloid osmotic pressure, and the absorption of these agents is of a lesser magnitude than glucose-based solutions. Further research is needed to determine other potential risks and benefits of these alternative dialysate solutions.

Amino Acids↗