Análisis de la relación solicitud-implante de injerto para trasplante osteomuscular / Analysis of the order-implantation relationship for musculoskeletal tissue transplantation

Objetivo: Analizar los pedidos solicitados a un banco musculoesquelético y evaluar el porcentaje de utilización de los tejidos. Material y métodos: Se analizaron 265 pedidos de tejido osteomuscular en el transcurso de un año. Exclusiones: 5 duplicaciones y 5 pedidos en los cuales no hubo disponibilidad para cubrir la necesidad. Se analizó la cantidad de cirugías en las que finalmente se utilizó el injerto. Resultados: De 255 pedidos solicitados, en 178 (70%) el injerto fue utilizado, mientras que en 77 (30%) el injerto no fue utilizado. De los 178 utilizados, en 23 (10%) hubo una devolución parcial. De los 77 pedidos de injerto no utilizado, en 32 (13%) la cirugía fue realizada sin necesidad de utilizar tejido de banco, mientras que en los 45 (17%) restantes la cirugía fue suspendida. Discusión: Un 30% de los injertos solicitados no fueron utilizados; un 17% debido a que la cirugía fue suspendida y un 13% porque el tejido fue devuelto, ya que la cirugía no lo requirió. En otro 10% hubo una devolución parcial del tejido. Con base en este análisis, consideramos que es importante tener una confirmación directa de la realización de la cirugía para evitar enviar tejido a cirugías suspendidas, ya que además del impacto económico, el banco debe asegurar un adecuado mantenimiento de la temperatura durante el transporte y almacenamiento en el centro trasplantológico, para evitar el descarte de dicho tejido, en caso de ser devuelto

Objective: To analyze orders requested from a musculoskeletal tissue bank and to evaluate the percentage of tissue implantation. Material and methods: Two hundred and sixty-five orders for musculoskeletal tissue were analyzed over the course of a year. Exclusions: 5 duplications and 5 orders for which there was no availability to cover the need. We analyzed the number of surgeries in which the graft was finally used. Results: Of a total of 255 orders, the graft was used in 178 (70%), and the graft was not used in 77 (30%). Of the 178 used, there was a partial refund in 23 (10%). Of the 77 orders not used, surgery was performed in 32 (13%) without the use of bank tissue, while surgery was discontinued in the remaining 45 (17%). Discussion: A non-utilization rate of 30% was identified, of which 17% was from surgery that was not performed and 13% from surgery that was performed, but the tissue was returned to the tissue bank, because it was not required. In a further 10% there was partial return of the tissue. Based on this analysis, we consider that it is important to have direct confirmation of the surgery to avoid sending tissue for discontinued surgeries, since in addition to the economic impact, the bank must ensure adequate temperature maintenance during transportation and storage in the transplantation centre, to avoid discarding said tissue if it is returned

Analysis of the order-implantation relationship for musculoskeletal tissue transplantation. / Análisis de la relación solicitud-implante de injerto para trasplante osteomuscular.

OBJECTIVE: To analyze orders requested from a musculoskeletal tissue bank and to evaluate the percentage of tissue implantation. MATERIAL AND METHODS: Two hundred and sixty-five orders for musculoskeletal tissue were analyzed over the course of a year. EXCLUSIONS: 5 duplications and 5 orders for which there was no availability to cover the need. We analyzed the number of surgeries in which the graft was finally used. RESULTS: Of a total of 255 orders, the graft was used in 178 (70%), and the graft was not used in 77 (30%). Of the 178 used, there was a partial refund in 23 (10%). Of the 77 orders not used, surgery was performed in 32 (13%) without the use of bank tissue, while surgery was discontinued in the remaining 45 (17%). DISCUSSION: A non-utilization rate of 30% was identified, of which 17% was from surgery that was not performed and 13% from surgery that was performed, but the tissue was returned to the tissue bank, because it was not required. In a further 10% there was partial return of the tissue. Based on this analysis, we consider that it is important to have direct confirmation of the surgery to avoid sending tissue for discontinued surgeries, since in addition to the economic impact, the bank must ensure adequate temperature maintenance during transportation and storage in the transplantation centre, to avoid discarding said tissue if it is returned.

Participation of membrane progesterone receptor α in the inhibitory effect of progesterone on prolactin secretion.

The membrane progesterone receptors (mPRα, mPRß, mPRγ, mPRδ and mPRε) are known to mediate rapid nongenomic progesterone functions in different cell types. However, the functions of these receptors in the pituitary have not been reported to date. In the present study, we show that the expression of mPRα was the highest among the mPRs in the rat anterior pituitary gland. Immunostaining of mPRα was detected in somatotrophs, gonadotrophs and lactotrophs. Interestingly, 63% of mPRα-positive cells within the pituitary were lactotrophs, suggesting that mPRα is involved in controlling prolactin (PRL) secretion in the pituitary. To test this hypothesis, rat pituitaries were incubated (1 hour) with either progesterone (P4) or the mPRα-specific agonist Org OD 02-0. PRL secretion was then measured by radioimmunoassay. The results of this experiment revealed that both P4 and Org OD 02-0 decreased PRL secretion. Moreover, the results from the GH3 cell line (CCL-82.1) showed that P4 and Org OD 02-0 inhibited PRL release, although the nuclear PR agonist R5020 was ineffective. Our investigation of the cellular mechanisms behind mPRα activity indicated that both P4 and Org OD 02-0 decreased cAMP accumulation, whereas R5020 was ineffective. In addition, the Org OD 02-0-effect on PRL release was blocked by pretreatment with pertussis toxin, an inhibitor of Go/Gi proteins. Because transforming growth factor (TGF)ß1 is a potent inhibitor of PRL secretion in lactotrophs, we lastly evaluated whether TGFß1 was activated by progesterone and whether this effect was mediated by mPRα. Our results showed that P4 and Org OD 02-0, but not R5020, increased active TGFß1 levels. This effect was not observed when cells were transfected with mPRα-small interfering RNA. Taken together, these data provide new evidence suggesting that mPRα mediates the progesterone inhibitory effect on PRL secretion through both decreases in cAMP levels and activation of TGFß1 in the lactotroph population.

Estradiol Upregulates c-FLIPlong Expression in Anterior Pituitary Cells.

Anterior pituitary cell turnover depends on a tight balance between proliferation and apoptosis. We have previously shown that estrogens sensitize anterior pituitary cells to pro-apoptotic stimuli. c-FLIP (cellular-FLICE-inhibitory-protein) isoforms are regulatory proteins of apoptosis triggered by death receptors. c-FLIPshort isoform competes with procaspase-8 inhibiting its activation. However, c-FLIPlong isoform may have a pro- or anti-apoptotic function depending on its expression level. In the present study, we explored whether estrogens modulate c-FLIP expression in anterior pituitary cells from ovariectomized (OVX) rats and in GH3 cells, a somatolactotrope cell line. Acute administration of 17ß-estradiol to OVX rats increased c-FLIPlong expression in the anterior pituitary gland without changing c-FLIPshort expression as assessed by Western blot. Estradiol in vitro also increased c-FLIPlong expression in anterior pituitary cells but not in GH3 cells. As determined by flow cytometry, the percentage of anterior pituitary cells expressing c-FLIP was higher than in GH3 cells. However, c-FLIP fluorescence intensity in GH3 cells was higher than in anterior pituitary cells. FasL increased the percentage of TUNEL-positive GH3 cells incubated either with or without estradiol suggesting that the pro-apoptotic action of Fas activation is estrogen-independent. Our results show that unlike what happens in nontumoral pituitary cells, estrogens do not modulate either c-FLIPlong expression or FasL-induced apoptosis in GH3 cells. The stimulatory effect of estradiol on c-FLIPlong expression could be involved in the sensitizing effect of this steroid to apoptosis in anterior pituitary cells. The absence of this estrogenic action in tumor pituitary cells could be involved in their tumor-like behavior.

Activation of the alternative pathway of complement during the acute phase of typical haemolytic uraemic syndrome.

Haemolytic uraemic syndrome (HUS) is characterized by haemolytic anaemia, thrombocytopenia and acute renal failure. We studied the activation state of classical and alternative pathways of complement during the acute phase of Shiga toxin-associated HUS by performing a prospective study of 18 patients and 17 age-matched healthy controls to evaluate C3, C3c, C4, C4d, Bb and SC5b-9 levels. SC5b-9 levels were increased significantly in all patients at admission compared to healthy and end-stage renal disease controls, but were significantly higher in patients presenting with oliguria compared to those with preserved diuresis. C3 and C4 levels were elevated significantly at admission in the non-oliguric group when compared to controls. No significant differences were found for C4d values, whereas factor Bb was elevated in all patients and significantly higher in oliguric patients when compared to both controls and non-oliguric individuals. A positive and significant association was detected when Bb formation was plotted as a function of plasma SC5b-9 at admission. Bb levels declined rapidly during the first week, with values not significantly different from controls by days 3 and 5 for non-oligurics and oligurics, respectively. Our data demonstrate the activation of the alternative pathway of complement during the acute phase of Stx-associated HUS. This finding suggests that complement activation may represent an important trigger for the cell damage that occurs during the syndrome.

Inhibition of nuclear factor-kappa B sensitises anterior pituitary cells to tumour necrosis factor-α- and lipopolysaccharide-induced apoptosis.

Nuclear factor-kappa B (NF-κB), an important pro-inflammatory factor, is a crucial regulator of cell survival. Both lipopolysaccharide (LPS) and tumour necrosis factor (TNF)-α activate NF-κB signalling. Oestrogens were shown to suppress NF-κB activation. Oestrogens exert a sensitising action to pro-apoptotic stimuli such as LPS and TNF-α in anterior pituitary cells. In the present study, we show by western blotting that 17ß-oestradiol (E(2)) decreases TNF-α-induced NF-κB/p65 and p50 nuclear translocation in primary cultures of anterior pituitary cells from ovariectomised (OVX) rats. Also, the in vivo administration of E(2) decreases LPS-induced NF-κB/p65 and p50 nuclear translocation. To investigate whether the inhibition of NF-κB pathway sensitises anterior pituitary cells to pro-apoptotic stimuli, we used an inhibitor of NF-κB activity, BAY 11-7082 (BAY). BAY, at a concentration that fails to induce apoptosis, has permissive action on TNF-α-induced apoptosis of lactotrophs and somatotrophs from OVX rats, as assessed by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Pharmacological inhibition of NF-κB signalling enhances E(2)-sensitising effect to TNF-α-induced apoptosis in lactotrophs but not in somatotrophs. In vivo administration of BAY allowed LPS-induced apoptosis in anterior pituitary cells from OVX rats (determined by fluorescence activated cell sorting). Furthermore, LPS-induced expression of Bcl-xL in pituitaries of OVX rats is decreased by E(2) administration. Our results show that inhibition of the NF-κB signalling pathway sensitises anterior pituitary cells to the pro-apoptotic action of LPS and TNF-α. Because E(2) inhibits LPS- and TNF-α-activated NF-κB nuclear translocation, the present study suggests that E(2) sensitises anterior pituitary cells to TNF-α- and LPS-induced apoptosis by inhibiting NF-κB activity.

Integrated coastal zone management perspectives to ensure the sustainability of coral reefs in New Caledonia.

Based on a pluridisciplinary research programme on New Caledonia's lagoon (2004-2008), this paper addresses economic, ecological and political issues in order to implement integrated coastal zone management (ICZM) in this French Pacific territory. The nickel mining industry constitutes the core of the re-balancing economic and social strategy between the Northern and Southern provinces. But major impacts on the coastal environment of metal-processing plants, harbours, and decades of mine exploitation have released a controversy. A short diachronic analysis suggests that such environmental concerns prompted the emergence of collective actions to among civil society, customary and institutional stakeholders. The inscription of New Caledonia lagoon and reef areas in the UNESCO World Heritage List in 2008 would be both an outcome and a catalyst of this on-going process. Looking beyond the reefs towards the mainland and watersheds for the construction of local socio-ecological systems, we assume that the current stakes could result in the initiation of ICZM in New Caledonia.

Geographical aspects of informal reef fishery systems in New Caledonia.

The coral reefs in New Caledonia have long been used by the local population for subsistence as well as commercial and recreational purposes. The impact of informal fisheries on reef ecosystems illustrated the idiosyncrasies of New Caledonian fisheries in the southwest Pacific. This paper compared informal fishery systems on the southwest coast (close to the capital and economic center of the country) and the northwest coast (where an industrial mining complex has been under development) of New Caledonia to analyze their spatial structure and characteristics. Four geosystems were defined. These depended on the natural, social and economical environments as well as management strategies. The way of life of the fishers proved to be a major factor in how the informal fishery systems were structured. Our observations suggested that ongoing socio-economic changes in New Caledonia have shaped informal fishing activities since the 1900s. The findings from this study validate the suitability of spatial approaches to coral reef fisheries and provide local stakeholders with original management clues for marine resources sustainability.

Estrogens exert a rapid apoptotic action in anterior pituitary cells.

It is now accepted that estrogens not only stimulate lactotrope proliferation but also sensitize anterior pituitary cells to proapoptotic stimuli. In addition to their classical mechanism of action through binding to intracellular estrogen receptors (ERs), there is increasing evidence that estrogens exert rapid actions mediated by cell membrane-localized ERs (mERs). In the present study, we examined the involvement of membrane-initiated steroid signaling in the proapoptotic action of estradiol in primary cultures of anterior pituitary cells from ovariectomized rats by using estren, a synthetic estrogen with no effect on classical transcription and a cell-impermeable 17beta-estradiol conjugate (E2-BSA). Both compounds induced cell death of anterior pituitary cells after 60 min of incubation as assessed by flow cytometry and the [3-(4,5-dimethylthiazol-2-yl)]-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. Estren, E2, and E2-BSA induced apoptosis of lactotropes and somatotropes as evaluated by the deoxynucleotidyltransferase-mediated dUTP nick end-labeling assay and immunodetection of prolactin (PRL) and growth hormone (GH). The proapoptotic effect of E2-BSA was abrogated by ICI-182,780, an antagonist of ERs. The expression of membrane-associated ERalpha was observed in PRL- and GH-bearing cells. Our results indicate that estradiol is able to exert a rapid apoptotic action in anterior pituitary cells, especially lactotropes and somatotropes, by a mechanism triggered by mERs. This mechanism could be involved in anterior pituitary cell turnover.

Citoquinas reguladoras de la respuesta al trasplante renal alogénico / Regulatory cytokines in the response to the allogeneic renal transplant

The outcome of the kidney allograft mainly depends on the immune response and on its complex regulation, where the cytokine network and other mediators play an important role. At present, kidney biopsy is the most useful tool for monitoring the transplant rejection and the diagnosis of the associated nephropathies, in spite of the invasiveness of the procedure. Thus, it is of great interest to find alternative tools for diagnosis. The evaluation of regulatory cytokines is a simple procedure of low cost that could be useful to increase the sensitivity of the detection of polymorphic differences, to predict the graft acceptance and for the early detection of rejection. Recent studies suggest that the high production of pro-inflammatory mediators, such as Th1 cytokines, could be detrimental, whereas the production of anti-inflammatory regulatory cytokines, such as interleukin (IL)-10 and tumor necrosis factor (TGF)-beta, could be beneficial for graft survival. In the early stages, the cellular cytotoxicity is activated by the Th1 response and the detection of cytotoxic molecules is associated to the acute rejection. Later, the balance between pro and anti-inflammatory mediators and the regulation of their levels could be more important. In this regard, TGF-beta is also fibrogenic and a high local production can contribute to kidney damage. On the other hand, the increased production of IL-10 in response to the allogeneic stimuli could be, in most cases, an important marker of long-term acceptance.

La aceptación o el rechazo del riñón alogénico dependen principalmente de la respuesta inmune y de su compleja regulación en la cual la red de citoquinas y otros mediadores juegan un importantepapel. Actualmente, la biopsia renal es, a pesar de lo invasor del procedimiento, la herramienta de mayor utilidadpara el control del rechazo al trasplante y el diagnóstico de las nefropatías asociadas. Por ello, es de graninterés encontrar métodos alternativos para el diagnóstico. La evaluación de citoquinas reguladoras de la respuestainmune es un procedimiento sencillo y de bajo costo que podría ser de utilidad para incrementar la sensibilidadde la detección de diferencias polimórficas, para pronosticar la aceptación del trasplante y para ladetección precoz del rechazo. Los estudios recientes sugieren que la producción exagerada de mediadores proinflamatorios, incluyendo a citoquinas Th1, sería desventajosa para la sobrevida del trasplante, mientras que la producción de citoquinas reguladoras anti-inflamatorias, como la interleuquina (IL)-10 y el factor de crecimiento tumoral (TGF)-β, sería beneficiosa. En las primeras etapas, la respuesta Th1 puede incrementar la actividad citotóxica y la detección de moléculas citotóxicas está asociada al rechazo agudo. Luego podría ser más importante considerar el balance entre la producción de mediadores pro- y anti-inflamatorios y la regulación desus niveles. Así, el TGF-β es también fibrogénico y su excesiva producción local puede contribuir al daño renal.Por otro lado, el incremento de la producción de IL-10 en respuesta al estímulo alogénico sería, en la mayoríade los casos, un marcador importante para pronosticar la aceptación prolongada.

Citoquinas reguladoras de la respuesta al trasplante renal alogénico / Regulatory cytokines in the response to the allogeneic renal transplant

The outcome of the kidney allograft mainly depends on the immune response and on its complex regulation, where the cytokine network and other mediators play an important role. At present, kidney biopsy is the most useful tool for monitoring the transplant rejection and the diagnosis of the associated nephropathies, in spite of the invasiveness of the procedure. Thus, it is of great interest to find alternative tools for diagnosis. The evaluation of regulatory cytokines is a simple procedure of low cost that could be useful to increase the sensitivity of the detection of polymorphic differences, to predict the graft acceptance and for the early detection of rejection. Recent studies suggest that the high production of pro-inflammatory mediators, such as Th1 cytokines, could be detrimental, whereas the production of anti-inflammatory regulatory cytokines, such as interleukin (IL)-10 and tumor necrosis factor (TGF)-beta, could be beneficial for graft survival. In the early stages, the cellular cytotoxicity is activated by the Th1 response and the detection of cytotoxic molecules is associated to the acute rejection. Later, the balance between pro and anti-inflammatory mediators and the regulation of their levels could be more important. In this regard, TGF-beta is also fibrogenic and a high local production can contribute to kidney damage. On the other hand, the increased production of IL-10 in response to the allogeneic stimuli could be, in most cases, an important marker of long-term acceptance.(AU)

La aceptación o el rechazo del riñón alogénico dependen principalmente de la respuesta inmune y de su compleja regulación en la cual la red de citoquinas y otros mediadores juegan un importantepapel. Actualmente, la biopsia renal es, a pesar de lo invasor del procedimiento, la herramienta de mayor utilidadpara el control del rechazo al trasplante y el diagnóstico de las nefropatías asociadas. Por ello, es de graninterés encontrar métodos alternativos para el diagnóstico. La evaluación de citoquinas reguladoras de la respuestainmune es un procedimiento sencillo y de bajo costo que podría ser de utilidad para incrementar la sensibilidadde la detección de diferencias polimórficas, para pronosticar la aceptación del trasplante y para ladetección precoz del rechazo. Los estudios recientes sugieren que la producción exagerada de mediadores proinflamatorios, incluyendo a citoquinas Th1, sería desventajosa para la sobrevida del trasplante, mientras que la producción de citoquinas reguladoras anti-inflamatorias, como la interleuquina (IL)-10 y el factor de crecimiento tumoral (TGF)-β, sería beneficiosa. En las primeras etapas, la respuesta Th1 puede incrementar la actividad citotóxica y la detección de moléculas citotóxicas está asociada al rechazo agudo. Luego podría ser más importante considerar el balance entre la producción de mediadores pro- y anti-inflamatorios y la regulación desus niveles. Así, el TGF-β es también fibrogénico y su excesiva producción local puede contribuir al daño renal.Por otro lado, el incremento de la producción de IL-10 en respuesta al estímulo alogénico sería, en la mayoríade los casos, un marcador importante para pronosticar la aceptación prolongada.(AU)

Estrogens sensitize anterior pituitary gland to apoptosis.

Tissue homeostasis results from a balance between cell proliferation and cell death by apoptosis. Estradiol affects proliferation as well as apoptosis in hormone-dependent tissues. In the present study, we investigated the apoptotic response of the anterior pituitary gland to lipopolysaccharide (LPS) in cycling female rats, and the influence of estradiol in this response in ovariectomized (OVX) rats. The OVX rats were chronically estrogenized with implanted Silastic capsules containing 1 mg of 17beta-estradiol (E2). Cycling or OVX and E2-treated rats were injected with LPS (250 microg/rat ip). Apoptosis was determined by the terminal deoxynucleotidyl-mediated dUTP nick-end labeling (TUNEL) method in sections of the anterior pituitary gland and spleen. Chronic estrogenization induced apoptosis in the anterior pituitary gland. Acute endotoxemia triggered apoptosis of cells in the anterior pituitary gland of E2-treated rats but not of OVX rats. No differences were observed in the apoptotic response to LPS in spleen between OVX and E2-treated rats. The apoptotic response of the anterior pituitary to LPS was variable along the estrous cycle, being higher at proestrus than at estrus or diestrus I. Approximately 75% of the apoptotic cells were identified as lactotropes by immunofluorescence. In conclusion, our results indicate that estradiol induces apoptosis and enables the proapoptotic action of LPS in the anterior pituitary gland. Also, our study suggests that estrogens may be involved in anterior pituitary cell renewal during the estrous cycle, sensitizing lactotropes to proapoptotic stimuli.

Ambulatory blood pressure monitoring after recovery from hemolytic uremic syndrome.

The outcome of acute renal failure due to diarrhea-associated hemolytic uremic syndrome (D+ HUS) is generally predicted to be good. However, there are only a few long-term observations with detailed reports on long-term sequelae. Specifically, adequate long-term blood pressure (BP) evaluations are scarce. The present study evaluated BP in pediatric patients after childhood D+ HUS. The study group comprised 28 patients (20 males) aged 6-23.5 years (median 10.1 years). All patients had a history of D+ HUS at a median age of 1.1 years (range 0.5-6 years). Based on the duration of oliguria and/or anuria, the primary disease was classified as mild (n=6), moderate (n=6), or severe (n=16). The BP in these patients was studied at a median time of 8.4 years (range 2.3-22.9 years) after manifestation of D+ HUS by means of office BP measurements and 24-h ambulatory BP monitoring (ABPM) using a Spacelabs 90207 oscillometric monitor. Measurements were compared with normal values of published standards for healthy children and adolescents. Conventional office BP measurements were above the 95th percentile in 1 patient. By ABPM, 2 patients were diagnosed to have mean systolic daytime and nighttime values in the hypertensive range, and systolic and diastolic hypertension was confirmed in the first patient. All these patients had a severe form of D+ HUS in the past. By applying ABPM, BP anomalies were detected in 5 additional patients. Elevated systolic BP loads were found in 4 patients, and daytime systolic and diastolic hypertension in the other 1. At the time of the study, 2 of them were classified as "recovered." The late outcome of D+ HUS may be worse than anticipated. BP anomalies as long-term sequelae of D+ HUS could be identified by ABPM but not by office BP measurements. These findings may represent an isolated sign of residual renal disturbance.

Hyperhomocysteinemia in stable pediatric, adolescents, and young adult renal transplant recipients.

BACKGROUND: High total plasma homocysteine (tHcy) levels are accompanied by an increased risk for premature development of atherosclerosis and atherothrombosis. Adult renal transplant recipients have elevated tHcy levels. Corresponding data in pediatric, adolescent, and young adult renal transplant recipients are scarce. We investigated whether tHcy levels were elevated in stable renal transplant recipients who received kidney grafts before age 18. METHODS: This cross-sectional study was conducted during routine posttransplantation follow-up. Fasting tHcy levels, serum creatinine, and lipoprotein profile were measured in 38 clinically stable renal transplant recipients with different degrees of renal function. No patient was receiving B vitamin or folic acid supplementation. Estimated glomerular filtration rate (GFR) was assessed according to Schwartz's formula. All patients followed a triple-drug immunosuppressive regimen, with the exception of three patients (deflazacort and azathioprine). Forty-one apparently healthy subjects constituted the control group. tHcy levels were determined by fluorescence polarization immunoassay in an IMx analyzer. RESULTS: Mean tHcy levels in transplant recipients were significantly higher than in controls (16.8+/-8.7 micromol/L and 9.5+/-2.3 micromol/L, respectively; P<0.01). A significant positive correlation between tHcy and serum creatinine levels was observed for both transplant recipients (rS=0.70, P<0.01) and controls (rS=0.54, P<0.01). In transplant recipients, tHcy correlated negatively with estimated GFR (rS=[minus]0.47, P<0.05). Fasting tHcy levels in excess of 14.6 micromol/L (>95th percentile in controls) were present in 19 (50%) patients; 14 of these patients had an estimated GFR<60 ml/min per 1.73 m2. When the renal transplant recipients were analyzed by renal function, mean tHcy was significantly higher in patients with an estimated GFR<60 ml/min per 1.73 m2 compared with patients with an estimated GFR> or =60 ml/min per 1.73 m2 (20.5+/-9.9 vs. 13.2+/-5.8 micromol/L, P<0.01). Both groups were significantly different from controls (P<0.01). No relationship was found between tHcy level and either cumulative cyclosporine or cumulative methylprednisone doses. No differences were observed in tHcy levels or lipoprotein profile between patients who were receiving deflazacort and those on methylprednisone. CONCLUSIONS: Hyperhomocysteinemia in renal transplant recipients is a common condition. Testing for fasting tHcy level might be a useful tool to identify patients at increased risk for development of vascular disease.

Regulation of aquaporin-2 trafficking by vasopressin in the renal collecting duct. Roles of ryanodine-sensitive Ca2+ stores and calmodulin.

In the renal collecting duct, vasopressin increases osmotic water permeability (P(f)) by triggering trafficking of aquaporin-2 vesicles to the apical plasma membrane. We investigated the role of vasopressin-induced intracellular Ca(2+) mobilization in this process. In isolated inner medullary collecting ducts (IMCDs), vasopressin (0.1 nm) and 8-(4-chlorophenylthio)-cAMP (0.1 mm) elicited marked increases in [Ca(2+)](i) (fluo-4). Vasopressin-induced Ca(2+) mobilization was completely blocked by preloading with the Ca(2+) chelator BAPTA. In parallel experiments, BAPTA completely blocked the vasopressin-induced increase in P(f) without affecting adenosine 3',5'-cyclic monophosphate (cAMP) production. Previously, we demonstrated the lack of activation of the phosphoinositide-signaling pathway by vasopressin in IMCD, suggesting an inositol 1,4,5-trisphosphate-independent mechanism of Ca(2+) release. Evidence for expression of the type 1 ryanodine receptor (RyR1) in IMCD was obtained by immunofluorescence, immunoblotting, and reverse transcription-polymerase chain reaction. Ryanodine (100 microm), a ryanodine receptor antagonist, blocked the arginine vasopressin-mediated increase in P(f) and blocked vasopressin-stimulated redistribution of aquaporin-2 to the plasma membrane domain in primary cultures of IMCD cells, as assessed by immunofluorescence immunocytochemistry. Calmodulin inhibitors (W7 and trifluoperazine) blocked the P(f) response to vasopressin and the vasopressin-stimulated redistribution of aquaporin-2. The results suggest that Ca(2+) release from ryanodine-sensitive stores plays an essential role in vasopressin-mediated aquaporin-2 trafficking via a calmodulin-dependent mechanism.

Growth in four patients on combined treatment with LHRH analogue and growth hormone after renal transplantation.

Four short pubertal boys were treated with LHRHa (leuprolide) and GH after renal transplantation, and followed until adult height. This combined therapy was not successful in increasing growth. Although this study must be considered preliminary because of the small number of patients and the lack of a matched control group, it shows for the first time that this combined therapy (GH + LHRHa) administered to short, pubertal boys after renal transplantation was not successful in increasing growth. Further studies are required to reach definitive conclusions.

Differences in anthropometric parameters and the IFG-I-IGFBP3 axis between liver and renal transplant children.

BACKGROUND: Growth can be differently altered after liver and renal transplantation (Tx) in childhood. METHODS: We compared graft function, linear growth, immunosuppression and serum IGF-I (RIA) and IGFBP3 (IRMA) concentrations in 15 liver (5.6+/-1.1 years old) and 17 renal (7.4+/-0.1 years old) Tx patients who were followed for 4-6 years. RESULTS: Graft function was normal post-liver Tx, although in renal recipients creatinine clearance decreased significantly during follow-up. Liver Tx children presented an increase in mean height of 0.92+/-0.2 SDS (P<0.01) beyond the 2nd year post-Tx, although in renal Tx patients height SDS did not improve. Immunosuppressive corticoid dosage could be decreased and discontinued in liver Tx patients, while in renal recipients it was maintained between 0.18+/-0.01 and 0.16+/-0.02 mg/kg/day. At 3.7+/-0.4 years post Tx, liver Tx patients presented higher mean serum IGF-I level, lower mean serum IGFBP3 value, leading to a higher mean IGF-I/IGFBP3 molar ratio, P<0.001. CONCLUSIONS: We found that while catch up growth coud be achieved after liver Tx, height SDS did not improve after renal Tx. This may be related to a reduced renal graft function and/or to differences in immunosuppressive corticoid dosage. In children with renal transplants a challenge for the future will reside in making it possible to substitute steroid therapy without altering graft function.

Conversion from azathioprine [correction of azathioprina] to mycophenolate mofetil in pediatric renal transplant recipients with chronic rejection.

BACKGROUND: Chronic rejection is the leading cause of graft failure. Both nonimmunological and immunological mechanisms contribute to this pathology. METHODS: We studied changes in kidney function, mixed lymphocyte culture, cell-mediated lympholysis, serum HLA class I antigens, cytotoxic antibodies, and lymphocyte population before and after 6 months of follow-up in 22 pediatric renal transplanted patients. The immunosuppressive protocol used was: cyclosporine, azathioprine, and corticosteroids. Eight patients demonstrated chronic graft rejection (by biopsy), group I; and eight patients had no clinical evidence of chronic and/or acute rejection, group II. Substitution of mycophenolate mofetil (MMF) (600 mg/m2 bid for azathioprine was done in patients of groups I and II. Another six patients with chronic rejection, did not receive MMF, group III. RESULTS: Creatinine clearance increased in group I (44+/-5 vs. 51.1+/- ml/min/1.73 m2, P<0.03) but it decreased in group III (30+/-3 vs. 25+/-2, P<0.01). Urinary protein excretion decreased only in group I (0.3+/-0.03 to 0.06+/-0.03 g/24 hr, P<0.03). During MMF therapy antidonor mixed lymphocyte culture decreased 62 and 70% (P<0.05) in group I and II. Cell-mediated lympholysis against lymphocyte of the donor decreased 65% (P<0.05) in group I. Cell-mediated lympholysis toward control cells decreased 54% (P<0.01) in group II. Serum HLA class I antigens, only decreased from 0.7+/-0.1 to 0.5+/-0.1 microl/ml, P<0.05, in group I. CD19+ decreased from 7.9+/-1.1 to 5.6+/-0.8%, P<0.05, and 7.8+/-1.2 to 5.5+/-0.9%, P<0.05, in groups I and II, respectively. CD16+ increased from 5.7+/-1.1 to 8.6+/-1.3 (P<0.05) only in group I. CONCLUSIONS: Our data suggest that substituting MMF for azathioprine therapy leads to an improvement in the immunosuppression and renal function in children with on-going chronic rejection.

Effect of deflazacort versus methylprednisone on growth, body composition, lipid profile, and bone mass after renal transplantation. The Deflazacort Study Group.

Kidney function, growth velocity, weight/height ratio, body composition, lipid profile, and bone mass were studied in a randomized, multicenter trial of deflazacort versus methylprednisone in 27 prepubertal patients with kidney transplantation. Methylprednisone (0.20+/-0.03) was replaced by deflazacort (13 patients, 0.30+/-0.03 mg/kg per day). After 12 months, creatinine clearance decreased significantly only during methylprednisone therapy. Growth velocity increased only in patients treated with deflazacort from 3.3+/-0.6 to 5.6+/-0.5 cm/year. Serum levels of several components of the insulin-like growth factor axis did not change. Weight/height ratio was increased in methylprednisone-treated patients (P<0.05) and decreased in deflazacort-treated patients (P<0.005). Lean body mass increased in both groups (P<0.005). Fat body mass and serum leptin increased only in methylprednisone-treated patients (P<0.025). Total cholesterol and low-density lipoprotein-cholesterol increased in methylprednisone-treated patients by 9.9% (P<0.05) and 12.5% (P<0.025). High-density lipoprotein-cholesterol increased by 21% (P<0.005) and apolipoprotein B decreased by 11% (P<0.005) in deflazacort-treated patients. Total skeleton and lumbar spine bone mineral density decreased in both groups, but at 1 year methylprednisone-treated patients had lost 50% more bone. Bone mineral content decreased only in methylprednisone-treated patients (P<0.01). Our data suggest that substituting deflazacort for maintenance methylprednisone might prevent height loss, excessive bone loss, and fat accumulation; and leads to an improvement in the lipoproteins of these children.

A randomized, double-blind, placebo-controlled trial of the effects of prophylactic theophylline on renal function in term neonates with perinatal asphyxia.

BACKGROUND: The kidney is the most damaged organ in asphyxiated full-term infants. Experiments in rabbits and rats have shown that renal adenosine acts as a vasoconstrictive metabolite in the kidney after hypoxemia and/or ischemia, contributing to the fall in glomerular filtration rate (GFR) and filtration fraction. Vasoconstriction produced by adenosine can be inhibited by the nonspecific adenosine receptor antagonist, theophylline. Gouyon and Guignard performed studies in newborn and adult rabbits subjected to normocapnic hypoxemia. Their results clearly showed that the hypoxemia-induced drop in GFR could be avoided by the administration of low doses of theophylline. OBJECTIVE: This study was designed to determine whether theophylline could prevent and/or ameliorate renal dysfunction in term neonates with perinatal asphyxia. SETTING: Buenos Aires, Argentina. STUDY DESIGN: We randomized 51 severe asphyxiated term infants to receive intravenously a single dose of either theophylline (8 mg/kg; study group: n = 24) or placebo (control group: n = 27) during the first 60 minutes of life. The 24-hour fluid intake and the urine volumes formed were recorded during the first 5 days of life. Daily volume balances (water output/input ratio and weights) were determined. Severe renal dysfunction was defined as serum creatinine elevated above 1.50 mg/dL, for at least 2 consecutive days after a fluid challenge, or rising levels of serum creatinine (.3 mg/dL/day). The GFR was estimated during the second to third days of life by endogenous creatinine clearance (mL/minute/1.73 m2) and using Schwartz's formula: GFR (mL/minute/1.73 m2) =.45 x length (cm)/plasma creatinine (mg/100 mL) during the first 5 days of life. Tubular performance was assessed as the concentration of beta2-microglobulin (beta2M) determined by enzyme immunoassay, on the first voided urine 12 hours after theophylline administration. The statistical analysis for the evaluation of the differences between the groups was performed with Student's t and chi(2) tests as appropriate. RESULTS: During the first day of life, the 24-hour fluid balance was significantly more positive in the infants receiving placebo compared with the infants receiving theophyline. Over the next few days, the change in fluid balance favored the theophyline group. Significantly higher mean plasma values were recorded in the placebo group from the second to the fifth days of life. Severe renal dysfunction was present in 4 of 24 (17%) infants of the theophylline group and in 15 of 27 (55%) infants of the control group (relative risk:.30; 95% confidence interval:.12-.78). Mean endogenous creatinine clearance of the theophylline group was significantly increased compared with the creatinine clearance in infants receiving placebo (21.84 +/- 7.96 vs 6.42 +/- 4.16). The GFR (estimated by Schwartz's formula) was markedly decreased in the placebo group. Urinary beta2M concentrations were significantly reduced in the theophylline group (5.01 +/- 2.3 mg/L vs 11.5 +/- 7.1 mg/L). Moreover, 9 (33%) patients of the theophylline group versus 20 (63%) infants of the control group had urinary beta2M above the normal limit (<.018). There was no difference in the severity of the asphyxia between infants belonging to the theophylline and control groups in regards of Portman's score. Except for renal involvement, a similar frequency of multiorganic dysfunction, including neurologic impairment, was observed in both groups. The theophylline group achieved an average serum level of 12.7 microg/mL (range: 7.5-18.9 microg/mL) at 36 to 48 hours of live versus traces (an average serum level of .87 microg/mg) in the placebo group. CONCLUSIONS: Our data suggest that prophylactic theophylline, given early after birth, has beneficial effects on reducing the renal dysfunction in asphyxiated full-term infants. (ABSTRACT TRUNCATED)