Brazilian regulatory authority contribution to the shielding dimensioning model of radiotherapy rooms proposed by the NCRP 151.

The National Council on Radiation Protection and Measurements (NCRP) Report No. 151 is an essential document for bunker design commonly applied for radiotherapy treatment rooms. This document is used as a reference by several countries, including Brazil. The objective of this study is to evaluate the shielding dimensioning methodology recommended by NCRP 151, and compare it with the one adopted by the Brazilian regulatory authority. Radiotherapy rooms and respective doors were designed to use linear accelerators operating at 6, 10, 15, and 18 MeV under two different ways: (a) applying exclusively the methodology recommended by the NCRP 151, and (b) taking into consideration the complementary recommendations from the Brazilian authorities. The results suggest that designers in Brazil can count on at least 4 and 11% safety margin for dimensioning primary barriers in controlled and free areas respectively. Also 8% for secondary barriers in controlled areas, 9.7% for secondary barriers adjacent to the primary belt of free areas, and 6.6% for the lead of the doors.

Levantamento qualitativo de gêneros de parasitos em amostras fecais de jacarés criados comercialmente em sistema fechado no estado do Rio de Janeiro / Qualitative survey of parasites genera on fecal samples of alligators in a commercial closed farming system in the state of Rio de Janeiro

O objetivo desta pesquisa foi realizar um diagnóstico qualitativo dos gêneros de parasitos encontrados em amostras fecais ambientais de jacarés (Caiman latirostris Daudin, 1802), criados comercialmente em sistema fechado, no período de 2008 a 2009, no estado do Rio de Janeiro. Um total de 300 amostras foi coletado de 150 filhotes, 80 de animais de engorda e 70 de reprodução, e submetido a análises coproparasitológicas, de flutuação (método de Willis-Mollay) e sedimentação simples (método de Lutz), de acordo com Hoffmann (1987). As amostras foram visualizadas à luz da microscopia óptica. Os resultados obtidos evidenciaram a presença de oocistos de Eimeria e Isospora, cistos de Balantidium e ovos de Acanthostomum e Dujardinascaris.

The objective of this paper was to diagnose qualitatively parasite genera found in environmental fecal samples of alligators (Caiman latirostris Daudin, 1802) commercially bred from 2008 to 2009 in a closed farming system in the state of Rio de Janeiro. A total of 300 samples were collected from 150 young, 80 fattening and 70 breeding processed by two different methods, the flotation (method of Willis-Mollay) and simple sedimentation (method of Lutz), according to Hoffmann (1987). The samples were then examined by optical microscopy. The results revealed presence of Eimeria and Isospora oocysts, Balantidium cysts, and Acanthostomum and Dujardinascaris eggs.

Effects of in-center daily hemodialysis upon mineral metabolism and bone disease in end-stage renal disease patients.

CONTEXT: Alternative hemodialysis schedules have been proposed to improve the quality of the dialysis. Nonetheless, their influence upon mineral and bone disorders is unknown. OBJECTIVE: To report the impact of a daily hemodialysis schedule upon the lesions of renal osteodystrophy. TYPE OF STUDY: Prospective non-controlled study. SETTING: Public University Hospital. PARTICIPANTS: Five patients treated by daily hemodialysis for at least 24 months. INTERVENTION: Daily dialysis sessions were accomplished with non-proportional dialysis machines without an ultrafiltration control device, with blood flow of 300 ml/min, bicarbonate dialysate ([Ca]=3.5 mEq/L) at 500 ml/min, and low-flux membrane dialyzers. Sessions were started at 6:00 p.m. (except Sundays) and lasted 2 hours. MAIN MEASUREMENTS: Serum levels of Ca and P from the last 6 months on conventional hemodialysis for the same patients were used for comparison with each semester of daily hemodialysis. Bone biopsies and PTH levels were obtained at the end of the conventional hemodialysis period and then again after 2 years of daily hemodialysis. RESULTS: Mean serum calcium was significantly higher during the second and third semesters of daily dialysis [10.0 mg% (SD 0.6), and 10.0 mg% (SD 0.8), respectively] compared to standard dialysis [9.4 mg% (SD 0.8)], p < 0.05. Mean values for phosphorus were significantly lower during every semester of daily hemodialysis [6.3 mg% (SD 1.8), 5.8 mg% (SD 1.7), 6.0 mg% (SD 1.7), and 6.0 mg% (SD 1.8)] compared to standard dialysis [7.2 mg% (SD 2.7)], P < 0.05. Variations in mean Ca x P product followed the same pattern as for phosphorus [59.5 (SD 16.0), 57.1 (SD 16.3), 59.8 (SD 17.7), and 58.31 (SD 20.9) vs. 68.6 (SD 27.3), P < 0.05]. After 2 years on daily hemodialysis, 2 patients who had aplastic lesion were found to have mild bone disorder. In addition, one patient with mixed bone lesion and moderate bone aluminum accumulation had osteitis fibrosa with no aluminum. Intact PTH values at the beginning of study and after 2 years on daily hemodialysis did not differ [134 pg/ml (SD 66) vs. 109 pg/ml (SD 26), P = 0.60, respectively]. CONCLUSIONS: Patients treated using daily hemodialysis had better control of serum phosphorus and perhaps a lower risk of metastatic calcifications. Daily hemodialysis also seemed to be beneficial to low turnover bone disease and bone aluminum deposition.

Effects of dialyzer reuse on the permeability of low-flux membranes.

Little attention has been given to the effects of reuse on the permeability of low-flux membranes, especially regarding middle molecules. We studied two different types of low-flux membranes at reuses 0, 6, and 12 in five patients undergoing hemodialysis with the following combinations of membrane and sterilant: cellulose diacetate membrane and formaldehyde, polysulfone membrane and formaldehyde, cellulose diacetate membrane and peracetic acid, and polysulfone and peracetic acid. The permeability of the membranes was assessed through the hydraulic ultrafiltration coefficient (K(UF)), sieving coefficient for beta(2)-microglobulin (B2M), and vitamin B(12) and albumin concentrations in ultrafiltrate. After 12 reuses, total cell volume (TCV) tended to be reduced in both cellulose diacetate and polysulfone dialyzers irrespective of the sterilant used, but significance was only found for the first set of dialyzers. Cellulose diacetate dialyzers reprocessed with either formaldehyde or peracetic acid showed an important reduction in K(UF) (31% [P < 0.05] and 23% [P < 0.05], respectively). A significant elevation in K(UF) was found in polysulfone membranes reprocessed with peracetic acid (41%; P < 0.05), but no alterations in K(UF) were found in polysulfone membranes reprocessed with formaldehyde. Cellulose diacetate membranes were intrinsically more permeable to B2M than polysulfone membranes (sieving coefficient, 6. 85 +/- 2.53 versus 0.04 +/- 0.02 x 10(-2); P < 0.001), which was not modified by any of the sterilants. Vitamin B(12) levels in ultrafiltrate decreased to an undetectable level in four of five samples collected after 12 reuses in polysulfone membranes reprocessed with peracetic acid (90 +/- 71 to 3 +/- 8 pg/mL; P < 0. 05 versus reuse 0). Albumin leakage occurred in two of five samples after the 12th reuse, but only in polysulfone membranes reprocessed with peracetic acid. Our findings suggest that reuse of low-flux polysulfone dialyzers reprocessed with peracetic acid is associated with structural damage of the membrane and a reduced permeability to middle molecules.