Comparison of three PET methods to assess peritoneal membrane transport

The peritoneal equilibration test (PET) is the most widespread method for assessing water and solute transport across the peritoneal membrane. This study compared three methods: traditional PET (t-PET), mini-PET, and modified PET (mod-PET). Non-diabetic adults (n=21) who had been on peritoneal dialysis (PD) for at least three months underwent t-PET (glucose 2.5%-4 h), mini-PET (glucose 3.86%-1 h), and mod-PET (glucose 3.86%-4 h) to determine dialysate-to-plasma concentration ratio (D/P) for creatinine and dialysate-to-baseline dialysate concentration ratio (D/D0) for glucose. Agreement between methods regarding D/P creatinine and D/D0 glucose was assessed using analysis of variance (ANOVA), Pearson's correlation coefficient, and Bland-Altman analysis. D/P creatinine differed between t-PET and mini-PET (P<0.001) and between mod-PET and mini-PET (P<0.01) but not between t-PET and mod-PET (P=0.746). The correlation of D/P creatinine with t-PET vs mod-PET was significant (r=0.387, P=0.009) but not that of t-PET vs mini-PET (r=0.088, P=0.241). Estimated bias was −0.029 (P=0.201) between t-PET and mod-PET, and 0.206 (P<0.001) between t-PET and mini-PET. D/D0 glucose differed between t-PET and mod-PET (P=0.003) and between mod-PET and mini-PET (P=0.002) but not between t-PET and mini-PET (P=0.885). The correlations of D/D0 glucose in t-PET vs mod-PET (r=−0.017, P=0.421) or t-PET vs mini-PET (r=0.152, P=0.609) were not significant. Estimated bias was 0.122 (P=0.026) between t-PET and mod-PET, and 0.122 (P=0.026) between t-PET and mini-PET. The significant correlation of D/P creatinine between t-PET and mod-PET suggested that the latter is a good alternative to t-PET. There was no such correlation between t-PET and mini-PET.

Fisiologia do transporte de fluidos e solutos atraves da membrana peritoneal / Physiology of fluid and solute transport across the peritoneal membrane

Nesta revisão, são explicados os fenômenos envolvidos nas trocas de fluidos e solutos através da membrana peritoneal, tanto na situação fisiológica quanto no contexto da diálise peritoneal. Para tanto, são utilizados os modelos matemáticos desenvolvidos para estudo do transporte pela membrana, tais como o "Modelo de Poros" e o "Modelo Distributivo". Os ganhos científicos com as pesquisas nesse campo são contemplados e as áreas que merecem pesquisas adicionais também são citadas. Assim, o estado atual do conhecimento fisiológico a respeito dessa modalidade de terapia renal substitutiva, no que se refere aos eventos relacionados à membrana peritoneal, encontra-se sintetizado nesse manuscrito.

In this review, phenomena involved in fluid and solute exchange through the peritoneal membrane, both in the physiologic and in the peritoneal dialysis settings, are explained. For that purpose, mathematical models developed for the study of molecule transport through the membrane, such as the "Pore Model" and the "Distributive Model" are used. Scientific accomplishments in the field are described and areas that require additional research are also cited. Knowledge about the physiologic mechanisms involved in this renal replacement therapy modality, concerning events directly related to the peritoneal membrane itself, is synthesized in this manuscript.

Retroperitoneal Extraskeletal Ewing's Sarcoma / 대한소화기학회지

No abstract available.

The effects of angiotensin-converting enzyme inhibitors on peritoneal protein loss and solute transport in peritoneal dialysis patients

OBJECTIVE: The objective of this study was to examine the effects of angiotensin-converting enzyme inhibitors on peritoneal membrane transport, peritoneal protein loss, and proteinuria in peritoneal dialysis patients. METHODS: Fifty-four peritoneal dialysis patients were included in the study. The patients were divided into two groups. Group 1 (n = 34) was treated with angiotensin-converting enzyme inhibitors. Group 2 (n = 20) did not receive any antihypertensive drugs during the entire follow-up. Eleven patients were excluded from the study thereafter. Thus, a total of 30 patients in Group 1 and 13 patients in Group 2 completed the study. We observed the patients for six months. Group 1 patients received maximal doses of angiotensin-converting enzyme inhibitors for six months. Parameters at the beginning of study and at the end of six months were evaluated. RESULTS: At the end of six months, total peritoneal protein loss in 24-hour dialysate effluent was significantly decreased in Group 1, whereas it was increased in Group 2. Compared to the baseline level, peritoneal albumin loss in 24-hour dialysate effluent and 4-hour D/P creatinine were significantly increased in Group 2 but were not significantly changed in Group 1. A covariance analysis between the groups revealed a significant difference only in the decreased amount of total protein loss in 24-hour dialysate. Proteinuria was decreased significantly in Group 1. CONCLUSION: This study suggests that angiotensin-converting enzyme inhibitors reduce peritoneal protein loss and small-solute transport and effectively protect peritoneal membrane transport in peritoneal dialysis patients.

Pérdidas proteicas peritoneales en niños portadores de síndrome nefrótico en diálisis peritoneal / Peritoneal protein loss in children suffering from nephrotic syndrome undergoing peritoneal dialysis

Primary Nephrotic Syndrome (NS) responds favorably to steroids in 80-90 percent of cases. Most corticoresistant (CR) patients evolve into Chronic Renal Failure (CRF), Of unknown origin, a permeability factor in these patient's serum has been reported, with some known effects in membranes including the peritoneum. Objective: To evaluate peritoneal protein loss in CR children on Chronic Peritoneal Dialysis (CPD). Patients and Methods: Four year retrospective analysis. Group 1 included 9 CR children, Group 2 was a control group of 10 children with CRF of other causes on CPD. Children in both groups were comparable in age, gender, weight, body surface, duration of CPD, concentration of solution, modality and dose of dialysis. Both groups were evaluated at 1, 6 and 12 months after admission. Results: No differences were observes in biochemical parameters: creatinine, urea nitrogen, calcium, phosphorus. PTH (Parathyroid hormone) was significantly higher in the control group (164 +/- 144 vs 564 +/- 454 pg/dl p < 0,05), albumin was lower in NS patients at the beginning (2.27 +/- 0.63 gr/dl vs 3.62 +/- 1.45 gr/dl p < 0,05) and end (2.8 +/- 0.5 gr/ dl vs 3.9 +/- 0.86 gr/dl, p < 0,05) of the evaluation. Peritoneal protein loss was significantly larger in the index group at the beginning (3,41 +/- 2,01 vs 1,76 +/- 1,45 gr/m7dia), and end (4,27 +/- 3,47 vs 1,66 +/-1,31 gr/m7dia, (p < 0.05) of the evaluation. The same happened with urinary loss: while there was no difference in protein intake, peritoneal KtV or total KtV between groups, residual KtV was significantly lower among NS patients at the end of the study, suggesting an earlier drop in residual renal function. No differences were observed in rates of peritonitis between groups in the study period. Conclusion: Peritoneal protein loss in CPD children with NS are significantly larger than other patients in CPD, suggesting a possible systemic permeability factor in these patients.

El Síndrome Nefrótico primario (SN) responde favorablemente a corticoides en un 80-90 por ciento de los casos. Los pacientes cortico resistentes (SNCR) evolucionan, en su gran mayoría, a insuficiencia renal crónica (IRC). De etiología desconocida, se ha reportado la presencia de un factor de permeabilidad (FP) en el suero de estos pacientes, con algunos efectos conocidos a nivel de otras membranas biológicas, incluyendo el peritoneo. Objetivo: Evaluar las pérdidas proteicas vía peritoneo en niños con SNCR en diálisis peritoneal crónica (DP). Pacientes y Método: Análisis retrospectivo de 4 años (2003-2007), Se incluyeron 9 pacientes portadores de SNCR (grupo 1), y un grupo control de 10 niños en DP portadores de IRC por otra etiología (grupo 2). Se evaluó a los 2 grupos al mes 1 y 6 ó 12 de su ingreso. Los grupos fueron comparables respecto a edad, sexo, peso, superficie corporal, tiempo en DP, concentración de dextrosa utilizada, modalidad dialítica y dosis de diálisis. Resultados: No se observó diferencias de los parámetros bioquímicos (creatinina, nitrógeno ureico, calcio, fósforo). La hormona paratiroidea (PTH) fue significativamente mayor en el grupo control (164 +/- 144 vs 564 +/- 454 pg/dl p < 0,05), y la albúmina fue menor en los pacientes con SN al inicio (2,27 +/- 0,63 gr/dl vs 3,62 +/- 1,45 gr/dl p < 0,05) y al final de la evaluación (2,8 +/- 0,5 gr/dl vs 3,9 +/- 0,86 gr/dl, p < 0,05). Las pérdidas proteicas peritoneales fueron significativamente mayores en el grupo 1 vs el grupo 2 al ingreso: 3,41 +/- 2,01 vs 1,76 +/- 1,45 gr/m²/día, y al final de la evaluación: 4,27 +/- 3,47 vs 1,66 +/-1,31 gr/m²/día, (p < 0,05) respectivamente. Lo mismo ocurrió con las pérdidas urinarias. No hubo diferencias en la ingesta proteica, KtV peritoneal ni KtV total entre los grupos, mientras que el KtV residual fue significativamente menor en los pacientes nefróticos al término del estudio, sugiriendo una caída más precoz de la función renal residual. Tampoco...

The Breakdown of Preformed Peritoneal Advanced Glycation End Products by Intraperitoneal Alagebrium

It has been demonstrated that inhibitors of advanced glycation end products (AGE), such as aminoguanidine, can suppress peritoneal AGE in rats on peritoneal dialysis (PD). However, it is unknown whether late administration of a putative crosslink breaker, alagebrium, could reverse peritoneal AGE. We therefore compared alagebrium with aminoguanidine in their ability to reverse peritoneal AGE in rats on PD. Male Sprague-Dawley rats were randomly divided into 3 groups: group I dialyzed with 4.25% glucose solution for all exchanges; group II dialyzed with 4.25% glucose solution containing aminoguanidine, and group III dialyzed with 4.25% glucose solution containing alagebrium for last 8 weeks of 12-week dialysis period. Dialysis exchanges were performed 2 times a day for 12 weeks. Immunohistochemistry was performed using a monoclonal anti-AGE antibody. One-hour PET was performed for comparison of transport characteristics. The immunolabelling of AGE in peritoneal membrane was markedly decreased in the alagebrium group. Consistent with this, the alagebrium group exhibited significantly higher D/Do glucose and lower D/P urea, suggesting low peritoneal membrane transport. But there were no significant differences between the control and the aminoguanidine group. These results suggest that the alagebrium may be the optimal therapeutic approach, compared with treatment with inhibitors of AGE formation, in rats on PD.

Histopathologic evaluation of the peritoneum exposed to heat shock: experimental study in rats

PURPOSE: To evaluate histopathologic alterations of the peritoneum exposed to heat shock. METHODS: Sixty rats were randomly distributed into 6 groups: Heat Shock (HS), High Temperature (HT), Body Temperature (BT), Temperature 0oC (TZ), Sham (SH) and Control (CG) with 10 animals each. The peritoneal cavity of animals from groups HS, HT, BT and TZ was irrigated with NaCl solution 0.9 percent at temperatures 50°C, 0°C, 50°C, 37°C and 0°C, respectively. For animals from group SH, the procedures were simulated and those from group CG, laparotomy and biopsies were conducted. Twenty-four hours later, biopsies of the peritoneum for exams under light and electronic microscopy were performed. RESULTS: Edema was found in groups HS 80 percent, HT 60 percent, BT 30 percent TZ 70 percent, SH 40 percent and CG 30 percent. Vascular congestion was found in groups HS 20 percent, HT 30 percent, BT 10 percent and TZ 20 percent. Erythrocyte extravasation was found in groups HT 60 percent and SH 10 percent. Mesothelium destruction was found in 100 percent of specimens from groups HS, HT, BT, TZ, SH and CG 90 percent. Necrosis was found in groups HS 30 percent, HT 20 percent and BT 10 percent. The mean peritoneal thickness ranged from 42.26 μm (TZ) to 26.42 μm (CG). CONCLUSION: The heat shock caused no deaths, but promoted significant peritoneal edema without affecting the other histopathologic indicatives.

OBJETIVO: Avaliar alterações histopatológicas do peritônio exposto a choque térmico. MÉTODOS: Sessenta ratos foram distribuídos aleatoriamente em seis grupos: Choque Térmico (CT), Temperatura Elevada (TE), Temperatura 0°C (TZ) Sham (SH) e Controle (GC) com 10 animais. A cavidade peritoneal dos animais dos grupos CT, TE, TC e TZ foi irrigada com solução de NaCl 0,9 por cento nas temperaturas, 50°C e 0°C, 50°C, 37°C e 0°C, respectivamente. Nos animais do grupo SH foram simulados os procedimentos e nos do GC laparotomia e biópsias. Depois de 24 horas foram realizadas biópsias do peritônio para exames sob microscopia de luz e eletrônica. RESULTADOS: Edema foi encontrado nos grupos CT 80 por cento, TE 60 por cento, TC 30 por cento, TZ 70 por cento, SH 40 por cento e GC 30 por cento. Congestão vascular foi encontrada nos grupos CT 20 por cento, TE 30 por cento, TC 10 por cento e TZ 20 por cento. Extravasamento de hemácias foi encontrado nos grupos TE 60 por cento e SH 10 por cento. Destruição de mesotélio foi encontrada em 100 por cento dos espécimes dos grupos CT, TE, TC, TZ, SH e no grupo GC 90 por cento. Necrose foi encontrada nos grupos CT 30 por cento, TE 20 por cento e TC 10 por cento. A espessura média do peritônio variou de 42,26 μm (TZ) a 26,42 μm (GC). CONCLUSÃO: O choque térmico não causou óbitos, mas promoveu edema peritoneal significante sem alterar os demais indicadores histopatológicos.

The effect of ligustrazine on peritoneal transport in peritoneal dialysis / 华中科技大学学报（医学）（英德文版）

In order to investigate the effect of ligustrazine (Lig) i.p. on peritoneal permeability in peritoneal dialysis and its side effects, creatinine was given intravenously and continuously to maintain the high plasma creatinine level. All the rabbits were divided into three groups: normal control group (group A), group B treated with 0.12% Lig and group C treated with 0.24% Lig. The peritoneal dialysis of all rabbits lasted 2 h. The plasma and dialysate levels of glucose, protein and creatinine were observed immediate, 30 min, 60 min, 90 min, 120 min after dialysis. Creastinine dialysate/plasma ratio (D/P), protein D/P ratio, glucose D/Do at different time points after dialysis and creatinine mass transfer area coefficient (MTAC) at 120 min were calculated. The structures of peritoneum were observed under optical microscope and electron microscope after continuously intraperitoneal injection of Lig for 14 days. The results showed that the 90-min and 120-min creatinine D/P ratios in the group C were higher than in the group A. The 120-min creatinine MATC in the group C was higher than in the group A. The rabbits treated with Lig did not show significant structure changes of peritoneum and signs of peritoneal irritation. It was suggested that Lig could increase mass transfer ability of peritoneum without significant side effects.

Heterogeneous response of adipose tissue to cancer cachexia

Cancer cachexia causes disruption of lipid metabolism. Since it has been well established that the various adipose tissue depots demonstrate different responses to stimuli, we assessed the effect of cachexia on some biochemical and morphological parameters of adipocytes obtained from the mesenteric (MES), retroperitoneal (RPAT), and epididymal (EAT) adipose tissues of rats bearing Walker 256 carcinosarcoma, compared with controls. Relative weight and total fat content of tissues did not differ between tumor-bearing rats and controls, but fatty acid composition was modified by cachexia. Adipocyte dimensions were increased in MES and RPAT from tumor-bearing rats, but not in EAT, in relation to control. Ultrastructural alterations were observed in the adipocytes of tumor-bearing rat RPAT (membrane projections) and EAT (nuclear bodies)

Evaluación longitudinal de la capacidad de transporte del peritoneo en diálisis peritoneal pediátrica / A longitudinal study of the peritoneal transport capacity in paediatric peritoneal dialysis

El paciente pediátrico en diálisis peritoneal debe ser periódicamente evaluado para adecuar el procedimiento. Objetivo: evaluar la evolución de los parámetros de adecuación dialítica en pacientes pediátricos urémicos en diálisis peritoneal crónica. Se estudiaron a 24 pacientes de la Unidad de Nefrología del Hospital Luis Calvo Mackenna, Universidad de Chile, ingresados al programa de diálisis peritoneal crónica entre enero 1995 y octubre 1999. Se evaluó la dosis de diálisis (Kt/V) peritoneal y residual, a los 3,6 y 12 meses de iniciado el procedimiento, y el test de equilibrio peritoneal (PET) en los mismos tiempos. Se midió el crecimiento a través del puntaje Z talla/edad al ingreso y a los 12 meses de diálisis. Resultados: el valor promedio del Kt/V peritoneal y residual fue de 1,77 (DE = 1,08) y 1,04 (DE = 0,66) al inicio del procedimiento, y a los 12 meses los valores fueron 2,34 (DE = 0,89) y 0,35 (DE = 0,37) respectivamente. El cambio en el Kt/V residual mostró un p < 0,05. El PET promedio de glucosa y creatinina hora 4 fue de 0,72 (DE = 0,16) y 0,31 (DE = 0,12) al inicio, variando a 0,73 (DE = 0,2) y 0,40 (DE = 0,19) a los 12 meses de evolución, sin significancia estadística. El crecimiento expresado como Z talla/edad mostró al inicio del estudio un valor de -1,86 (DE = 1,06) y a los 12 meses de -2,05 (DE = 0,9). En el grupo de pacientes que ingresaron antes de los 12 meses de vida el Z talla/edad inicial vs el control a 1 año después fue de -2,5 y -1,65 respectivamente. Conclusión: los resultados muestran una estabilidad de la membrana peritoneal a lo largo del período estudiado, una pérdida de talla progresiva durante la terapia, y un crecimiento positivo en el grupo que inició la diálisis antes de los 12 meses

Efecto modulador de las secreciones del tracto reproductivo femenino sobre la función del espermatozoide humano / Modulating effect of the secretions of the feminine reproductive tract on the function of the human spermatozoa

El objetivo de éste trabajo fue determinar mediante un modelo in vitro, el efecto que ejerce el fluido peritoneal sobre la función del espermatozoide humano, tomando como control al fluido folicular. Para ello se obtuvieron fluidos peritoneales provenientes de pacientes que realizaron laparascopia diagnóstica en fecha periovulatoria y que no presentaron enfermedad tubo-peritoneal (n=9). El fluido folicular se obtuvo de pacientes que realizaron recuperación ovocitaria en un programa de fertilización in vitro (n=4). Ambos fluidos fueron centrifugados, filtrados y congelados a -20§C. Los sémenes de pacientes normozoospérmicos (n=21) fueron procesados mediante un gradiente discontínuo de Percoll y capacitados en medio sintético Human Tubal Fluid suplementado con albúmina, a una concentración de 2-10 por 10 esp./ml durante 3 a 4 horas. En experimentos apareados, los espermatozoides capacitados fueron expuestos en relación 1:1 v/v al medio control, al fluido folicular o al peritoneal durante 1 hora, luego de lo cual se procedió a estudiar la función espermática mediante los siguientes tests: a) viabilidad b) motilidad progresiva c) la reacción acrosomal inducida por ionóforo de calcio y d) la expresión del receptor espermático para D-manosa. Nuestros resultados muestran que ni la viabilidad ni la motilidad resultaron afectadas por el pre-tratamiento. Si bien la ocurrencia de la reacción acrosomal espontánea no fue diferente entre los distintos grupos (6.3 a 7.5 por ciento, NS), la inducida por ionóforo disminuyó significativamente luego de la exposición al fluido peritoneal y al folicular (18.9ñ5.1 por ciento y 29.0ñ6.1 por ciento vs control 45.6ñ5.0 por ciento, p <0.001 y 0.01 respectivamente). Si bien la detección del receptor para D-manosa aumentó durante la capacitación, resultó significativamente menor a los controles luego del tratamiento previo (FP: 15.4ñ2.9 por ciento y FF: 15.5ñ3.1 por ciento vs control 23.7ñ3.1 por ciento, p<0.05. Nuestros resultados sugieren que al menos in vitro, tanto el fluido peritoneal como el folicular modularían la función del espermatozoide humano manteniéndolo vivo y móvil, pero en un estado no reaccionado

Effect of peritoneal glucose load on plasma leptin concentration in continuous ambulatory peritoneal dialysis patients

This study was performed to investigate the effect of peritoneal glucose load on plasma leptin concentrations in the continuous ambulatory peritoneal dialysis (CAPD) performed on 13 non-diabetic ESRD patients. Plasma leptin and insulin concentrations were measured for 2 hours during a single 2 liter exchange of 1.5% glucose-based dialysate (SPD, n = 6), for 7 days of daily peritoneal dialysis (DPD, n = 7). In DPD, standard full volume (2,000 ml x 4 times/day) exchange was performed immediately after operation. In SPD, plasma leptin and insulin concentrations remained unchanged during the study. In DPD, the plasma leptin concentration increased significantly after CAPD on the first day (PD1) (11.2 +/- 5.4 to 17.0 +/- 6.0 ng/mL, p < 0.05) and this elevation seemed to persist until 7 days after operation. After CAPD, there was no significant day-to-day variation in peritoneal glucose absorption (391-465 cal). Oral intake seemed to decrease on operation day (PD0) and PD1 and then increased slowly. Plasma insulin and glucose concentrations did not significantly change after CAPD. Changes of leptin concentration were significantly correlated with the changes of peritoneal glucose absorption at PD1. In conclusion, continuous peritoneal glucose load may affect plasma leptin concentrations in CAPD patients.

Evaluación de la vía de absorción linfática durante peritonitis experimentales / Evaluation of lymphatic absortion during experimental peritonitis

Se evaluó la vía linfática de absorción de toxinas durante peritonitis experimentales. Durante la 1a parte de la investigación se controló la cantidad de absorción por vía linfática del Tc 99 en ratas con y sin bloqueo del peritoneo subdiafragmático. En la 2a parte se comprobó la absorción linfática con y sin bloqueo subdiafragmático bajo condiciones de sepsis abdominal en un modelo de asa ileal aislada y desvascularizada. En la 1a parte se observó una disminución significativa de la absorción del radioisótopo en los animales con bloqueo, poniendo de manifiesto la importancia de esta vía. En la 2a parte las diferencias de absorción no fueron significativas probablemente debidos a la hipovalemia en la 1a etapa de la sepsis abdominal. Se destaca el importante rol de la vía linfática subdiafragmática y del conducto torácico en la absorción y transporte de endotoxinas en la sepsis.

Evaluación por gammagrafía de la permeabilidad peritoneal durante peritonitis experimentales / Evaluation by scintigraphy of peritoneal absortion during experimental peritonitis

Se evalúan las variaciones de la permeabilidad del peritoneo de la rata durante las primeras horas de una peritonitis y se determina la función de la heparina en la absorción peritoneal, inyectando Tc 99 en la cavidad y midiendo con gamma cámara la reactividad residual a las 12 hs. No se observaron diferencias estadísticamente significativas entre el grupo control y los con peritonitis y con peritonitis más heparina. La distribución y captación del Tc 99 fue uniforme, excepto en 3 animales del grupo de peritonitis sin heparina que mostraron menor captación en un área de la región inferior del abdómen. Se observó una importante exudación en la cavidad peritoneal al parecer superior a la absorción. Se puede deducir que las endotoxinas bacterianas se incorporarían lenta y progresivamente a través de la membrana, cumpliendo en la sepsis un rol secundario durante las primeras horas de una peritonitis.