Toward targets for initiation of chronic dialysis

OBJECTIVES: To better define the targets for initiation of chronic dialysis, we compared the relationship between the normalized protein equivalent of nitrogen appearance (nPNA, g/kg standard weight/day) and weekly urea clearance (Kt) normalized to total body water (V) in predialysis chronic renal failure (CRF) patients and in patients on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis (HD). We also studied the relationships of other nutritional parameters to weekly Kt/Vurea in CRF patients. DESIGN: This cross-sectional study was a prospective observational design meant to study each patient once. SETTING: The University Hospital and Clinics and Harry S. Truman VA Medical Center, Columbia, Missouri. PATIENTS: Forty-five consecutive predialysis CRF patients were enrolled and the results compared with patients on CAPD and HD. RESULTS: In CRF, the nPNA calculated from urea appearance correlated with the weekly Kt/Vurea (r = 0.57, p < 0.0001) and, using exponential best-fit, nPNA = 1.217 x (1-e-0.769Kt/V). This exponential relationship was similar to that for CAPD and both were different from that in patients on HD. Likewise, nPNAs, calculated from Kjeldahl nitrogen output, and weekly Kt/Vurea were correlated (r = 0.37, p = 0.014) and, using exponential best-fit, nPNA = 1.102(1-e-0.867Kt/V), similar to the relationship in patients on CAPD. Evidence is presented that these relationships are not explained only by mathematical coupling. There was a significant correlation between the weekly Kt/Vurea and 24-hour urinary creatinine excretion. CONCLUSIONS: The findings suggest that in CRF, as in CAPD, a weekly Kt/Vurea less than 2.0 is likely to be associated with a nPNA less than 0.9 g/kg standard weight. In CRF patients, initiation of chronic dialysis should be considered if weekly renal Kt/Vurea falls below 2.0 and a nPNA greater than 0.8 is desired.     

Effects of ligand priming and multiple-dose injection on tissue uptake of 111In-pentetreotide in rats

In patients undergoing somatostatin receptor scintigraphy, treatment with octreotide (Sandostatin) is usually discontinued 24-48 h before and after injection with the radioligand 111In-pentetreotide ([111In-DTPA(O)]octreotide) (Octreoscan) because octreotide competes with radioligand for the same receptors. However, D?rr et al. and Soresi et al. reported improved visualization of carcinoid and small cell lung cancer lesions, respectively, during continued octreotide treatment. We found that intravenous administration of unlabeled octreotide to rats inhibited the binding of an optimal dose (0.5 microg) of 111In-pentetreotide to somatostatin receptors in pancreas and adrenals in a mass- and time-dependent way. Pretreatment with unlabeled octreotide never increased receptor binding of 111In-pentetreotide. Administration of 100 microg of octreotide decreased receptor-bound radioactivity if given simultaneously with or 10 or 20 min after injection of the radioligand, but had no effect if given 30 min after the radioligand. These findings indicate rapid processing of receptor-bound octreotide and suggest that octreotide treatment of patients undergoing 111In-pentetreotide scintigraphy may be reinitiated as soon as 1 h after radioligand administration.     

Communicating breast cancer on-line: support and empowerment on the Internet

Using participant-observation and discourse analysis, this study explores the communication occurring on the Breast Cancer List, an on-line discussion group which continues to grow in membership and activity. Issues discussed include the evolution of the List, who participates, what topics are discussed. Three major dimensions are identified: exchange of information, social support, and personal empowerment. Social support via computer is compared with face-to-face groups. Empowerment centers on enhanced decision-making and preparation for new illness-related experiences. The influence of gender is considered in terms of communicative style and limitations of access. It is concluded that the List fulfills the functions of a community, with future concerns about information control and the potential to enhance patient-provider understanding.     

Occupational blood exposures in dentistry: a decade in review

This review summarizes data from self-reported and observational studies describing the nature, frequency, and circumstances of occupational blood exposures among US dental workers between 1986 and 1995. These studies suggest that, among US dentists, percutaneous injuries have declined steadily over the 10-year period. Data also suggest that, in 1995, most dental workers (dentists, hygienists assistants, and oral surgeons) experienced approximately three injuries per year. Work practices (eg, using an instrument instead of fingers to retract tissue), safer instrumentation or design (eg, self-sheathing needles, changes in dental-unit design), and continued worker education may reduce occupational blood exposures in dentistry further.     

Comparison of aspirin with a thromboxane antagonist for patients with prolonged chest pain and ST segment depression

AIM: To compare a thromboxane antagonist (GR3219) with aspirin in patients with prolonged chest pain and ST segment depression to see if the frequency of attacks of chest pain was reduced. METHODS: The trial was part of a study comparing GR3219 with aspirin, and streptokinase with placebo and comprised the GR3219/aspirin leg. Thirty one patients were randomly assigned to GR3219 80 mg twice daily and 28 to aspirin 300 mg daily. The patients were under the age of 76 and admitted to a coronary care unit within 6 hours of continuous chest pain. The ECG showed at least 1 mm of flat or down-going ST segment. The patients kept diaries of their pain over the subsequent 31 days. RESULTS: Seventy percent of patients developed further chest pain. There was no difference between the pattern of recurrent chest pain according to which drug was used. CONCLUSIONS: The hypothesis that specific thromboxane A blockade with GR3219 would be more efficacious than aspirin was not supported by these results.     

Distinction between differentiation and senescence and the absence of increased apoptosis in human keratinocytes undergoing cellular aging in vitro

OBJECTIVE: Changes in calcium homeostasis and bone mass around the climacteric are poorly understood. We examined relations between endocrine factors and indices of bone mass and metabolism in healthy women approaching the menopause. DESIGN: Cross-section study. PATIENTS: Sixty-eight spontaneously menstruating women aged 45-55. MEASUREMENTS: Bone density measured at lumbar spine (LS) and femoral neck (FN) using dual energy X-ray absorptiometry and distal non-dominant forearm using peripheral quantitative computed tomography. We recorded menstrual history, physical activity and dietary calcium, and measured serum calcium, phosphate, alkaline phosphatase, osteocalcin, vitamin D, fT3, T4, TSH, PTH, FSH and oestradiol (E2), and urinary pyridinoline (PYD) and deoxypyridinoline (DPD) excretion. RESULTS: Using serum FSH level as a marker of ovarian function, 63 subjects could be classified into one of three groups: group A (serum FSH < 10 U/l, n = 29), group B (10-35 U/l, n = 27) and group C (> 35 U/l, n = 7). Bone density fell with declining ovarian function at the LS, FN and forearm trabecular (but not cortical) sites. Serum PTH was lower in group A vs B (mean (SD) 2.68 (0.97) vs 3.52 (1.17) pmol/l, P < 0.05), but similar to group C (2.90 (1.09) pmol/l, P = NS). Serum phosphate was elevated in group C compared to groups A and B (1.17 (0.15) vs 1.04 (0.11) and 1.05 (0.13) mmol/l, P < 0.05), and urinary PYD (61.1 (8.0) vs 50.4 (11.6) and 43.9 (8.1) mumol/mol creatinine) and DPD (15.9 (3.9) vs 12.0 (3.6) and 11.4 (3.6) mumol/mol creatinine) excretion were also increased. There were no significant differences in vitamin D metabolites or osteocalcin. Multivariate analysis suggested serum osteocalcin was positively related to physical activity and serum 1,25-dihydroxycholecalciferol levels. Serum free T3 was positively correlated with urinary DPD excretion, and inversely related to serum PTH. In all subjects, serum PTH was related to body weight (r = 0.38, P = 0.002). CONCLUSIONS: Declining ovarian function before menopause is accompanied by reductions in bone mass and altered calcium metabolism. Free T3 may regulate bone resorption and indirectly modulate PTH release.     

Hospital utilization of Saskatchewan people with fetal alcohol syndrome

Endometriosis is defined as the presence of both functioning endometrial glands and stroma outside their usual location lining the uterine cavity. It has been identified in virtually all tissues and organs of the female body with the exception of the spleen. There have been many theories proposed regarding the etiology and pathogenesis of endometriosis. One is the transport of cells through lymphatics and blood vessels. A 44-year-old female suffering from an episode of endometriosis of the umbilicus, left inguinal, uterus, and bilateral ovaries in association with a Múllerian anomaly is presented. Histopathological findings of a skin biopsy from her umbilicus showed aggregated cells within the lymphatic vessel of the upper dermis. This case provides evidence suggesting that cutaneous endometriosis could occur by transport of endometrial cells through lymphatics or blood vessels.     

Individualizing the treatment of gout

Rectal cancer affects 40,000 people annually in the United States. Traditionally, operative therapy has involved abdominoperineal resection. This procedure results in a permanent colostomy and carries a high incidence of impotence and urinary retention. Because of improvements in operative techniques, perioperative care, and adjuvant tumor therapy, less invasive local techniques of tumor resection have become excellent options.