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Biomedical subjects

J Burkart

Publications and source records attributed to J Burkart.

At least 19 recordsLinked to original sources
PubMed2000

Patients on chronic peritoneal dialysis for ten years or more in North America.

Thirty-six patients on peritoneal dialysis (PD) for more than ten years in six North American centers were analyzed retrospectively. In the six centers, the percentage of patients surviving for more than ten years varied between 0.8% and 7.3%. The study group included 27 females and 9 males aged 38.6 +/- 14.2 years [mean +/- standard deviation (SD)] at the start of treatment. Of the 36 patients, 28 were Caucasian. The most common cause of end-stage renal disease (ESRD), present in 12 patients, was chronic glomerulonephritis. Only 4 patients had diabetes. At the beginning of the study, 19 patients had hypertension (the most common comorbid condition); 11 had no comorbid conditions at the start. Creatinine clearance at the start was 4.12 +/- 3.5 mL per minute, and the mean duration to anuria was 51 +/- 25 months. Mean initial body weight was 55 +/- 9 kg, and mean body surface area was 1.5 +/- 0.2 m2. Serum albumin levels showed an increase from 33.8 +/- 3.6 g/L at the start of the study to 38.2 +/- 3.9 g/L at the end. Hospitalization rate was low at 0.5 +/- 0.3 admissions per patient-year, and duration of hospitalization was 4.8 +/- 3.7 days per patient-year. Peritonitis was the most common cause of hospitalization. The mean peritonitis rate was 1 episode every 52 +/- 48 patient-months. There were 36 catheter changes in 18 patients; 16 patients had a single PD catheter throughout the period of study. Autonomous hyperparathyroidism was the most common long-term complication. At the end of the study period, 11 patients were still on PD, 9 had died, 5 had been transferred to hemodialysis (HD), 1 was alive with a functioning allograft, and 1 was lost to follow-up. We conclude that patients who survive longer than ten years on PD are most likely to be young Caucasian females, small in body size, who are non diabetic, with few comorbid conditions. These long-term survivors have few hospitalizations, and their peritonitis rate is low. In this group of patients, severe autonomous hyperparathyroidism is the most common long-term complication.

Adolescent↗
PubMed1999

Eyelid resurfacing.

BACKGROUND AND OBJECTIVE: Laser resurfacing of eyelids was examined in a series of experiments designed to measure beam parameters, surface temperatures, ablation characteristics, thermal damage, tissue responses and clinical outcomes. These data were collected for the purpose of developing a logical basis for clinical dosimetry. STUDY DESIGN: All experiments were conducted with similar short-pulse CO(2) lasers (TruPulse, Albuquerque, NM) where the beam had been carefully characterized and calibrated. The chronological sequence examined begins with the photophysical laser/tissue interactions during the first few microsec of irradiation and ends with an evaluation of the efficacy of wrinkle reduction nine months after treatment. RESULTS: Eyelid tissue removed by the first and second passes consisted mostly of epidermis with about 38 microm of thermal damage into the papillary dermis. Erythema resolved within four weeks and most patients experienced 70-100% wrinkle reduction by nine months. CONCLUSION: A layer of contracted dermal scar tissue that replaced the thermally challenged zone in the dermis is identified as the substrate for wrinkle reduction. The data support the following dosimetry for periorbital wrinkle reduction: One pass 4-6 J/cm(2) (350-500 mJ into a 3 x 3 mm spot). A second treatment after 9-12 months may be more beneficial than a second pass.

Animals↗
PubMed1998

Treatment of malnutrition with 1.1% amino acid peritoneal dialysis solution: results of a multicenter outpatient study.

A peritoneal dialysis (PD) solution containing 1.1% amino acids as the osmotic agent was evaluated in a 3-month randomized, prospective, open-label study in malnourished PD patients. Patients in the treatment group (DAA) received one or two exchanges daily with the amino acid solution, depending on tolerance, in place of glucose solutions. Controls (DD) received their usual therapy with glucose dialysate. Fifty-four DAA and 51 DD patients completed the study. In DAA, but not in DD patients, there was a significant increase at month 3 in serum insulin-like growth factor-1 (IGF-1) levels and significant decreases in serum potassium (all 3 months) and inorganic phosphorus levels (months 1 and 3), indicating a general anabolic response. Prealbumin and transferrin levels were significantly increased in DAA but not in DD patients at month 1, but the groups did not differ at months 2 and 3. In patients with baseline albumin levels less than 3.5 g/dL (bromcresol green [BCG] method), DAA patients showed increases in albumin, transferrin (months 1 and 2), and prealbumin levels (all 3 months) relative to baseline values, whereas these serum protein levels were unchanged in DD patients, although the changes from baseline did not differ between groups. In this subgroup, midarm muscle circumference (MAMC) did not change in DD or DAA patients. In patients with baseline albumin levels of 3.5 g/dL or greater, DD patients had decreases in albumin and total protein levels at all 3 months and in prealbumin levels at months 1 and 2, relative to baseline. In DAA patients, there were fewer changes in serum proteins. MAMC increased significantly from baseline in DAA but not in DD patients, although changes from baseline did not differ between DAA and DD groups. DAA patients showed no changes in peritoneal membrane transport characteristics. The results indicate that treatment with one or two exchanges daily of this amino acid-based PD solution is safe and provides nutritional benefit for malnourished PD patients.

Amino Acids↗
PubMed1996

Racial differences in the incidence of end-stage renal disease.

OBJECTIVE: To examine trends in the incidence of treated end-stage renal disease (ESRD) and variations between blacks and whites. DESIGN: Retrospective record reviews of all new patients > or = 15 years starting chronic dialysis during 1980-1988 at the Piedmont Dialysis Center, Forsyth County, North Carolina. RESULTS: The cumulative nine-year incidence rate for hypertensive ESRD was 570 per million, and for diabetic ESRD 497 per million. Among men, hypertensive ESRD accounted for the largest proportion of cases (39.2% and 28.4%, blacks and whites respectively), while diabetic ESRD contributed 33.9% of black female cases and 24.4% of white female cases. Compared to whites, blacks were at significantly increased risk, with an adjusted risk odds ratio (OR) of 4.4 (95% confidence interval (CI) 3.5-6.0) for all causes combined, 6.0 (CI 3.9-9.0) for hypertensive renal disease, 6.0 (CI 3.8-9.3) for renal disease due to insulin-dependent diabetes mellitus, and 12.2 (CI 6.9-21.7) due to non-insulin dependent diabetes mellitus (NIDDM). The greatest risk among blacks was seen in the 55-64 year age group, with ORs of 9.1 for all causes combined and 30.6 for hypertensive renal disease. The OR for renal disease due to NIDDM for black versus white women was 20.0 (CI 9.5-41.7). Compared to 1980, 1981, 1982 and 1983, increased incidence rates were seen in each year after 1984. CONCLUSION: These findings show even greater excess risk of ESRD among blacks than previously reported. The majority of the excess risk is seen for ESRD due to hypertension and diabetes, especially NIDDM. The reasons for the increased risk among blacks, and for the increasing incidence rates of ESRD are not known.

Adolescent↗
PubMed1996

Field test to evaluate telepathology in telemedicine.

Telepathology is currently performed only on prototype systems. The application of telepathology consultations differs from the conventional procedure because of the technical and cost restrictions. This paper outlines technical concepts and the principal hardware and software modules necessary for telemicroscopy equipment. A field test to gather information concerning the user needs and to evaluate parameters of telepathology consultation sessions is reported.

Computer Communication Networks↗
PubMed1995

The importance of monitoring dialysis adequacy in chronic peritoneal dialysis.

The case of a patient who was noted to be malnourished but improved after his dialysis dose was increased is presented. This case and the discussion that follows emphasize the importance of proactively monitoring peritoneal dialysis adequacy and nutritional intake, supporting the notion that the dose of peritoneal dialysis is a major determinant of appetite and, consequently, of nutritional status. In the clinical setting, this influence is best indicated by changes in the serum albumin level and ultimately in long-term patient survival. The case discussion reviews the major principles and supporting literature, describing how we target peritoneal dialysis delivery and optimize nutritional status in an effort to reduce morbidity and mortality.

Adult↗
PubMed1995

Multicenter trial of erythropoietin in patients on peritoneal dialysis.

A randomized, double-blind, placebo-controlled, multicenter trial was performed to assess the safety and efficacy of subcutaneous recombinant erythropoietin (EPO) in peritoneal dialysis patients. Seventy-eight patients were randomized to receive EPO and 74 received placebo during the first 12 wk. After this, placebo patients with hematocrit less than 32% entered the EPO maintenance phase along with the initial EPO patients. Hematocrit rose significantly in the EPO group from 23.8 to 32% after 6 wk, and this was sustained at 33.7% at 12 wk. In the placebo group, the prestudy hematocrit was 23.8% as well, and no significant change in hematocrit occurred over 12 wk. Concomitant with the rise in hematocrit, transfusion requirements fell only in the EPO group. Eighty-eight percent of patients receiving EPO had their anemia ameliorated by Week 12 of the study. There was a wide range of dosage requirements during the maintenance phase, ranging from 8,000 U thrice weekly to 4,000 U every other week. Adverse events after EPO were similar to those seen in hemodialysis patients given this agent, with hypertension developing or worsening in 55% of EPO patients during the initial 12 wk of therapy. Blood pressure was more likely to rise in patients with hypertension before receiving EPO. EPO is safe and effective in peritoneal dialysis patients, as it is in hemodialysis patients. Other than a rise in blood pressure, which is manageable with antihypertensives and ultrafiltration with dialysis, no serious side effects are seen. The optimal target hematocrit, effects of anemia improvement on quality of life, and end-organ (heart, brain) effects of anemia improvement in this patient population require further study.

Adult↗
PubMed1991

Effect of intraperitoneal fluid volume changes on esophageal pressures: studies in patients on continuous ambulatory peritoneal dialysis.

Esophageal manometric studies were performed in 11 patients on continuous ambulatory peritoneal dialysis (CAPD) with the dialysis fluid in the peritoneal cavity, after emptying and again after reinfusion. No systematic changes were found in intragastric or lower esophageal sphincter (LES) pressures at any time. No differences in mean distal esophageal amplitude (DEA), duration, or velocity of peristalsis were noted. Although upper gastrointestinal problems are common in CAPD patients and were reported by eight of 11 patients, this study suggests that these symptoms cannot be explained by changes in gastric and esophageal pressures.

Adult↗
PubMed1991

Usefulness of peritoneal fluid amylase levels in the differential diagnosis of peritonitis in peritoneal dialysis patients.

Peritonitis continues to be a major cause of morbidity in peritoneal dialysis patients despite recent technological advances (Y systems) that have reduced peritonitis rates to much more acceptable levels. Most of the time when a peritoneal dialysis patient presents with peritonitis, it is infectious in origin. However, these patients occasionally develop other intra-abdominal pathology that requires more intensive medical care or, at times, surgical intervention. To help in the early differential diagnosis of the cause of peritonitis in these patients, peritoneal fluid amylase levels were prospectively obtained from 50 patients presenting to the hospital with peritonitis. Thirty-nine of them had typical infectious peritonitis, and their mean peritoneal fluid amylase level was 11.1 (range, 0 to 90). Six patients had pancreatitis and a mean peritoneal fluid amylase level of 550 U/L (range, 100 to 1,140 U/L). Five patients were found to have other intra-abdominal pathology, and their mean peritoneal fluid amylase level was 816 U/L (range, 142 to 1,746 U/L). In patients who did not respond to initial therapy, sequential peritoneal fluid amylase levels did not increase in patients with typical infectious peritonitis whereas it did increase in patients with other intra-abdominal pathology. In conclusion, it was found that peritoneal fluid amylase levels were helpful in the differential diagnosis of peritonitis in these patients. An elevated level (greater than 100 U/L) differentiated those patients with other intra-abdominal causes of peritonitis from those with typical infectious peritonitis.

Amylases↗
PubMed1987

Serum and peritoneal fluid amylase levels in CAPD. Normal values and clinical usefulness.

The mean serum amylase of 42 asymptomatic CAPD patients was elevated but was not significantly different from that of a group of chronic hemodialysis patients. Serum amylase levels in CAPD patients with peritonitis were not elevated with respect to asymptomatic patients. Amylase activity was not detectable in the peritoneal fluid of 38/42 asymptomatic patients and 6/13 peritonitis patients and was present at low levels in the other 11 patients. Patients with other abdominal conditions (pancreatitis, cholecystitis and small bowel perforation) had very marked elevations of serum and/or peritoneal fluid amylase which differentiated them from the asymptomatic and peritonitis patients. Although hyperamylasemia is common in asymptomatic CAPD patients and in those with peritonitis, measurement of serum and peritoneal fluid amylase levels is useful in the evaluation of CAPD patients presenting with abdominal symptoms.

Acute Disease↗
PubMedDate not supplied

Morbidity survey of U.S. oil shale workers employed during 1948-1969.

The health status of 325 oil shale workers employed at the Anvil Points, Colorado, demonstration facility from 1948 to 1969 was evaluated. As a comparison population, 323 Utah coal miners frequency matched for age were studied. The prevalence of respiratory symptoms among oil shale workers who smoked were similar to the coal miners who smoked, although nonsmoking oil shale workers had fewer symptoms compared to nonsmoking coal workers. Four cases of skin cancers were found on the oil shale workers and eight cases in the controls. Similar numbers of nevi, telangiectasiae, possible pitch warts, pigment changes (solar/senile lentigo), and papillomata (seborrheic keratoses and skin tags) were seen in both groups, while actinic keratoses were more frequent in the oil shale workers. The prevalence of actinic keratoses was significantly associated with oil shale work after allowing for age, sun exposure, and other exposures. The prevalence of pulmonary cytology metaplasia was associated with years of production work in oil shale among both smokers and exsmokers. More of the oil shale workers had atypical cells in the urine, but the excess was mostly found among exsmokers. Although these workers had short-term and limited oil shale exposure work exposure, we recommend that medical surveillance of oil shale workers consider the skin, respiratory, and urinary systems for special observation.

Coal Mining↗