Vitamin E supplementation reverses renal altered vascular reactivity in chronic bile duct-ligated rats

An altered vascular reactivity is an important manifestation of the hemodynamic and renal dysfunction during liver cirrhosis. Oxidative stress-derived substances and nitric oxide (NO) have been shown to be involved in those alterations. In fact, both can affect vascular contractile function, directly or by influencing intracellular signaling pathways. Nevertheless, it is unknown whether oxidative stress contributes to the impaired systemic and renal vascular reactivity observed in cirrhosis. To test this, we evaluated the effect of vitamin E supplementation (5,000 IU/kg diet) on the vasoconstrictor and vasodilator responses of isolated perfused kidneys and aortic rings of rats with cirrhosis induced by bile duct ligation (BDL), and on the expression of renal and aortic phospho-extracellular regulated kinase 1/2 (p-ERK1/2). BDL induced a blunted renal vascular response to phenylephrine and ACh, while BDL aortic rings responded less to phenylephrine but normally to ACh. Cirrhotic rats had higher levels of oxidative stress-derived substances [measured as thiobarbituric acid-reactive substances (TBARS)] and NO (measured as urinary nitrite excretion) than controls. Vitamin E supplementation normalized the renal hyporesponse to phenylephrine and ACh in BDL, although failed to modify it in aortic rings. Furthermore, vitamin E decreased levels of TBARS, increased levels of NO, and normalized the increased kidney expression of p-ERK1/2 of the BDL rats. In conclusion, BDL rats showed a blunted vascular reactivity to phenylephrine and ACh, more pronounced in the kidney and reversed by vitamin E pretreatment, suggesting a role for oxidative stress in those abnormalities.

Phase II trial of weekly docetaxel (D) and complete androgen blockade (CAB) prior to radical prostatectomy (RP) in high-risk localized prostate cancer (PC) patients (pts)

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Background: Pts with high-risk localized PC have an increased risk of positive margins and recurrence after RP or radiotherapy alone. Neoadjuvant hormonotherapy (HT) has not shown a survival benefit prior to surgery, while outcomes are improved when HT is combined with radiotherapy. D-based chemotherapy improves survival in metastatic PC. These data support the investigation of multi-modality approaches to improve the aggressive behavior of high-risk localized PC. The main objective of this study was to assess the pathologic complete response (pCR) rate of the study combination. Secondary objectives were clinical activity, toxicity profile, time to progression and survival. Methods: Pts with clinical stage T1–2 (+ Gleason ≥ 7 (4+3) and/or PSA≥20 ng/mL) and T3 PC received 3 cycles of D (35 mg/m2 i.v. days 1, 8 and 15, every 28 days) concomitant with a depot goserelin (10.8 mg sc) plus flutamide (750 mg po daily for 3 months). RP was performed 2–4 weeks after the end of neoadjuvant therapy. Results: Fifty six pts have been included into the trial. Available data from 32 pts receiving neoadjuvant therapy were analyzed for this presentation. Median age was 69 years (53–75). Median follow-up was 3.6 months. Clinical stage was T1 (20%), T2 (53%) and T3 (27%); Gleason was ≥ 7 (4+3) in 25 (78%) pts. Eight (28%) pts had a PSA ≥ 20 ng/ml. A total of 85 cycles were administered (median 3) with a 100% median relative dose intensity for D. Grade III/IV toxicities per patient were liver toxicity (15.6%) and diarrhea (9.4%). Among the 16 pts who underwent RP to date, one (6%) achieved pCR, 11 (69%) had negative surgical margins and 9 (56%) had organ-confined disease. Conclusions: Neoadjuvant weekly D plus 3-month CAB is well tolerated and induces pCR in high-risk localized PC pts. Updated results will be available for the meeting. These results are encouraging while the true impact of neoadjuvant chemo-HT in this group of pts has to be determined in randomized trials.

No significant financial relationships to disclose.

Nephron-sparing surgery for renal tumor: a choice of treatment in an allograft kidney

The incidence of de novo malignancies is an accepted complication of organ transplantation. Renal cell carcinoma (RCC) was 4.6% of cancers occurring de novo in organ allograft recipients compared with 3% in the general population. Less than 10% of these renal cancers affected the renal allograft. Among patients developing a renal tumor in the kidney allograft, transplant nephrectomy reduced the quality of life. For these patients for whom preservation of renal function is a relevant clinical consideration, partial nephrectomy may be considered the choice for treatment. Fifteen cases have been reported regarding conservative surgery on kidney transplant tumors. Herein we have reported three cases of renal masses in well-functioning kidney transplants that were successfully treated with nephon-sparing surgery. Our experience demonstrated that in selected patients, nephron-sparing surgery on a renal allograft represents a feasible approach for tumor removal with preservation of graft function.

[Living donor kidney transplantation: helical CT evaluation of candidates]

OBJECTIVES

Computed tomography (CT) is a diagnostic tool that has won acceptance in the past years for the vascular evaluation of living renal donor (LRD) candidates. We show the findings observed in a series of 102 candidates consecutively evaluated in our centre and present the correlation with the surgical data obtained in those individuals finally operated.

METHODS

From May 1995 to June 2005, 102 LRD candidates were evaluated with CT. Eighteen were also studied with digital subtraction angiography (DSA). Fifty-eight donors underwent nephrectomy. Prevalence of arterial and venous variants found on CT exams were analyzed, as well as the correlation with surgical and DSA data when they were obtained.

RESULTS

Forty-four percent candidates showed multiple renal arteries at least in one kidney. Seventy-one percent of right kidneys and 76% of left kidneys had a single arterial pedicle. Early branching was observed in 7.8% and 15.7% in right and left kidneys respectively. Venous variants were present in 17.5% and the 13.7% in right and left sides respectively. Sensitivity, specificity and accuracy of CT to detect accessory arteries were 89%, 100% and 97% respectively when it was compared to DSA. Correlation with surgical data raised 93% for the presence of arterial variants.

CONCLUSIONS

Vascular variants in renal pedicle showed a high prevalence. Helical CT can effectively achieve all the information required prior to surgery as a sole imaging procedure in LRD candidates.

Endourological management is better in early-onset ureteral stenosis in kidney transplantation

INTRODUCTION

The incidence of ureteral stenosis in kidney transplant recipients is 3%-8%. The treatment of ureteral stenosis has been traditionally operative reconstruction, although such intervention is associated with high rates of serious complications, including graft loss and even perioperative mortality. More recently, endourological treatment has been proposed due to its low morbidity.

OBJECTIVE

The objective of this study was to assess the usefulness of balloon percutaneous dilatation as a treatment technique for ureteral stenosis in kidney transplant recipients.

PATIENTS AND METHODS

Among 1000 kidney transplantations performed between 1980 and 2004, the coexistence of high creatinine values and urinary tract dilatation in the postoperative period, after discarding concomitant causes, was managed with a percutaneous nephrostomy. Once renal function recovered, antegrade pyelography was performed to confirm the presence and determine the location of ureteral stenosis. Ureteral dilatation was performed using a 5-French balloon-fitted angioplasty catheter.

RESULTS

Fifty-six patients were diagnosed with ureteral stenosis during follow-up, an incidence of 5.6%. Transluminal balloon dilatation was the first therapeutic option in 45 cases, whereas surgery was performed directly on 11 patients. Disappearance of the stenosis as well as maintenance of an improved creatinine level was verified in 45% of cases (20 patients). Two patients experienced graft loss. Both a short time to diagnosis after transplantation (P = .06) and the presence of a previous acute rejection episode (P < .05) were good prognosis factors for the endourologic solution of a ureteral stricture.

CONCLUSIONS

Balloon dilatation may be considered the definitive procedure for treatment of ureteral stenosis in selected cases. Percutaneous nephrostomy should be used for initial diagnosis and improvement in the renal function before attempting an open procedure.

Age, Comorbidity and Hypertensive Co-Medication do Not Affect Cardiovascular Tolerability of 10 Mg Alfuzosin Once Daily

PURPOSE

We assessed in real-life practice the impact of age, cardiovascular comorbidity and co-medication on the tolerability and efficacy of 10 mg alfuzosin OD in men with lower urinary tract symptoms suggestive of benign prostatic obstruction.

MATERIALS AND METHODS

A total of 6,523 men with a mean age of 64.7 years were enrolled in a 6-month open label study of 10 mg alfuzosin OD. They were stratified by age quartile (younger than 60, 60 to 64, 65 to 70 and older than 70 years), comorbidity (hypertension, ischemic heart disease and diabetes) and antihypertensive co-medication (diuretics, beta-blockers, angiotensin converting enzyme inhibitors, angiotensin II inhibitors and calcium channel antagonists).

RESULTS

Alfuzosin was effective and well tolerated. Despite an increased prevalence of cardiovascular comorbidity and antihypertensive co-medication with age changes in blood pressure did not significantly differ among age groups. In controls, ie those with no cardiovascular comorbidity or co-medication, alfuzosin produced minimal decreases in sitting systolic (mean -2.6 to -2.8 mm Hg) and diastolic (mean -1.7 to -1.8 mm Hg) blood pressure. In men with cardiovascular comorbidity mean decreases in systolic (-3.5 to 5.8 mm Hg) and diastolic (-2.0 to -3.3 mm Hg) blood pressure remained marginal. Of the 6,523 exposed patients 19.3% withdrew from the study, mainly for adverse events (6.4%) or a lack of efficacy (5.3%), while 229 (3.5%) experienced serious adverse events and 1,558 (23.9%) reported at least 1 treatment emergent adverse event. The most commonly reported adverse event was dizziness/postural dizziness (4.8%). Hypotension/postural hypotension was uncommon (0.7%). Age, cardiovascular comorbidity and antihypertensive co-medication had no impact on the safety profile of 10 mg alfuzosin OD.

CONCLUSIONS

Alfuzosin (10 mg) OD is effective and well tolerated, and it has marginal effects on blood pressure, including in elderly patients and those with hypertension, ischemic heart disease or diabetes and those receiving antihypertensive agents.

Molecular staging of bladder cancer with RT-PCR assay for CK20 in peripheral blood, bone marrow and lymph nodes: comparison with standard histological staging

BACKGROUND

The aim of this study was to analyze whether the CK20 reverse transcriptase polymerase chain reaction (RT-PCR) is suitable for detecting circulating tumor cells and residual tumor cells in lymph nodes, in patients with muscle invasive transitional cell carcinoma (TCC) of the bladder, and to compare these results with standard histological staging.

PATIENTS AND METHODS

The nested RT-PCR assay was used to analyze the CK20 transcript in the peripheral blood, bone marrow, lymph nodes, the tumor and normal biopsies of bladder from 57 patients with invasive TCC of the bladder, who underwent radical cystectomy, and from 9 patients with noninvasive TCC.

RESULTS

Lymph node pathological status was positive in 24 out of the 57 patients studied and all of them except I showed expression of CK20, with a correlation between histological technique and RT-PCR of 95.8%. A statistically significant correlation of lymph node CK20 RT-PCR with the standard risk factor of pathological stage (p = 0.04) was observed Blood and bone marrow CK20 RT-PCR showed no correlation with pathological stage.

CONCLUSION

Lymph node CK 20 RT-PCR correlates with pathological stage in bladder cancer. The CK20 RT-PCR assay appears to be a highly sensitive and specific method for detecting circulating tumor cells and residual disease in lymph nodes in patients with invasive bladder cancer. Further evaluation of the significance of CK20 as a molecular marker for staging and follow-up in these patients is necessary.

Theoretical Description of the Ion Transport Across Nanopores With Titratable Fixed Charges: Analogies Between Ion Channels and Synthetic Pores

Recently developed nanometer-sized synthetic pores display several properties so far believed to be distinctive features of a large variety of biological wide ion channels. Thus conductance in the pS-nS range, pH-dependent ion selectivity, fluctuations of current between open and closed states, flux inhibition caused by protons or divalent cations, current rectification, and the ability to perform selective macromolecule sizing and counting are found in synthetic and biological channels alike. Despite other differences such as pore size and geometry, the similarities open a new field for exploring specific technological applications via the chemical modification of synthetic pores with biological molecules. This article reviews some of the basic concepts and theories relevant to ion transport in nanopores with titratable charges stressing the analogies between synthetic pores and biological ion channels. The ultimate goal is to show that continuum theories may account for the essential features of these systems. A simple electrodiffusion model and its comparison with experimental results are chosen as a case study.

Results and Complications of 50 Laparoscopic Nephrectomies For Live Donor Renal Transplantation

Living donors represent 30% of kidneys for renal transplantation. Laparoscopic nephrectomy is the best surgical procedure due to its clear advantages: low morbidity, less blood transfusion requirements, and shorter donor hospitalization. From March 2002 to August 2004, we performed 50 laparoscopic nephrectomies for transplantation to recipients who were prescribed tacrolimus (0.1 mg/kg bid), mycophenolate mofetil (1 gr bid), and prednisone (0.5-1 mg/kg per day PO from 48 hours before transplantation). Mean surgery time was 170 minutes (120-260); warm ischemia time, 3.1 minutes (1.5-10); and cold ischemia time, 1.27 hours (0.85-4). Mean bleeding was 270 cc (100-900), and mean donor hospitalization was 5.5 days (3-9). Four cases required conversion of the laparoscopic procedure to open surgery because of bleeding. Seventy-two hours posttransplantation, the mean plasma creatinine was 170 micromol/L. None of the patients suffered delayed graft function. Eighteen percent experienced acute rejection episodes. Donor and recipient survivals were 100% at 1 year, and graft survival, 94% (kidney losses were due to acute rejection, severe acute pancreatitis, and surgical complications).

Percutaneous management of transplant ureteral fistulae is feasible in selected cases

INTRODUCTION

Ureteral fistulae in renal transplants may develop as a consequence of compromised ureteral vascularity or from a technical factor related to the ureteroneocystostomy, the latter typically developing within the first 72 hours posttransplant. Recently, percutaneous nephrostomy drainage has been used with increasing frequency for the initial management. It alone can lead to resolution of the fistula in at least some patients. The aim of the study was the evaluation of endourological management of ureteral fistulae in renal transplants.

MATERIAL AND METHODS

Between August 1981 and February 2004, 1000 adult recipients underwent renal transplantation. Sixteen out of 29 patients who developed ureteral fistulae were managed endourologically; 13, open surgery. The items recorded on these patients included the type of ureteroneocystostomy, the time to fistula diagnosis, the image technique, the type of ureteral stents, and the clinical evolution.

RESULTS

The 13 patients who underwent open surgery did well. Endourological management of ureteral fistula was successfully performed in 10 of 16 cases. In all of them percutaneous nephrostomy drainage with stenting of the ureter with a double-J catheter did not prove any advantage to no stent (66.6% vs 57%). In 13 of these 16 patients in which the passage of contrast into the bladder was demonstrated, the fistula resolved in 10 cases (77%), while none of the three cases with no flow into the bladder were helped by this approach.

CONCLUSION

Percutaneous techniques can provide definitive management for 62% of renal allograft patients who develop ureteral fistula beyond 72 hours after renal transplant.

Udder development, lactation and ascites in a ewe with an ovarian granulosa cell tumour

A 20-month-old sexually intact female mixed breed sheep was examined for lameness, unexpected udder development, lactation and anorexia. Tachycardia, tachypnoea, severe abdominal distension and vaginal prolapse were evident upon physical examination. A right hindlimb lameness was present at the walk. The udder was well-developed and milk, normal in appearance, was easily expressed from each teat. Ultrasonographic evaluation revealed a non-pregnant uterus, severe ascites and a large (12 cm diameter) abdominal mass. Although surgical treatment was discussed, the owners elected to euthanase the ewe. Necropsy examination confirmed the presence of severe ascites due to a ruptured ovarian tumour. The tumour was characterised as a granulosa cell tumour histologically. Unexpected udder development and lactation presumably occurred secondary to oestrogen and progesterone production by the tumour. To the authors' knowledge, this is the first report of udder development, lactation and ascites in a ewe secondary to an ovarian granulosa cell tumour.

[Outcomes of transplantation from living renal donor]

Living donors represent 30% of our kidneys for renal transplantation. Laparoscopic nephrectomy is the best surgical procedure to obtain them due to its clear advantages such as low morbidity, less blood supply and donor time in hospital. From March 2002 to August 2004 we performed 50 laparoscopic nephrectomies for renal transplantation. Kidneys were transplanted to recipients receiving tacrolimus 0.1 mg/kg/bid, mycophenolate mofetil 1 g/bid and prednisone 0.5-1 mg/kg/day p.o 48 hours before transplantation. Mean time for surgery was 170 minutes (120-260), warm ischaemia time 3.1 minutes (1.5-10) and cold ischaemia time 1.27 hours (0.85-4). Mean bleeding was 270 cc (100-900) and donor time in hospital 5.5 days (3-9). Four cases required conversion of the laparoscopic procedure to open surgery because of bleeding. 72 hours post-transplant mean plasmatic creatinine was 170 micromol/l. None of the patients suffered delayed graft function. 18% presented acute rejection. Survival of donor and recipient was 100% at 1 year and graft survival was 94% at 1 year (kidney losses were due to acute rejection, severe acute pancreatitis and surgical problem).

[The living kidney donor: laparoscopy versus open surgery]

INTRODUCTION

Living renal donors are an important source of transplanted kidneys due to the number of patients on waiting list is progressively increasing. On the other side, they allow the pre-emptive kidney transplantation. With the aim of reducing donor obstacles such as pain, hospital stay or cosmetic results and in creasing the number of living donors, in 1995 Ratner performed the first laparoscopic nephrectomy (LLDN). By now, LLDN is a routine procedure in more than 200 centres worldwide.

METHODS

Literature databases are searched. We have reviewed the data from our experience after performing 50 laparoscopic nephrectomies.

RESULTS

Preoperative living donor assessment and contraindications to LLDN do not differ from the open approach. Results are very influenced by the surgeon's situation in the learnig curve. Operating times use to be longer in laparoscopic procedures. The overall complication rate and mortality of LLDN are the same for both of the approaches. Conversion to open-donor nephrectomy has been reported in 0-13% of cases (8% in our data). Postoperative pain and donor estimated blood loss are lower for LLDN, as well as the convalescence period. To avoid the possible negative effects of the laparoscopic technique on kidney graft function a lot of method's variations have been proposed for gaining access and harvesting the kidney, including the hand-assistance techniques, with the aim of minimizing operative time, pneumoperitoneus negative effect on graft function and warm ischemia time (WIT). The higher WIT is not related to delayed graft function or acute rejections when it is less than ten minutes. Delayed graft function does not differ in both approaches and creatinine values from the first month until the third year after transplantation show no differences in randomized studies.

CONCLUSIONS

The laparoscopic approach to harvest the allograft from the living donor is a save and effective technique and has the advantage of being less invasive and allowing the donor a shorter convalescence. It has no negative effects on allograft function in the short term follow-up. Further studies are required to evaluate long term donor complications and allograft function and survival.

[Living donor nephrectomy for kidney transplantation. Experience in the first two years]

OBJECTIVES

Laparoscopic surgery offers potential advantages in terms of diminishment of postoperative pain, shorter hospital stay, faster convalescence, and better cosmetic results. These advantages may increase kidney donation, making donation be accepted by more candidates. We report our first 2 years' experience with laparoscopic donor nephrectomy

METHODS

Between March 2002 and February 2004 we performed 38 laparoscopic living donor nephrectomies for kidney transplantation. The technique of choice was the transperitoneal laparoscopic approach with four trocars, usually three of them from the start of the procedure--two 10-12 mm and one 5 mm--, and a 6.5 cm perumbilical midline incision for kidney retrieval at the end of the procedure.

RESULTS

Receptor and donor survivals were 100%. Graft survival was 97.6%. There was not any case of delayed graft function. Donor: Mean operative time was 161 minutes (115-260). Mean estimated blood loss was 270 ml (100-1200). Three patients required blood transfusions, 2 units of packed red blood cells each. Mean hospital stay was 5.1 days (3-11). Mean warm ischemia time was 3.2 min. (2-10). Conversion to open surgery was necessary in four cases. Receptor: there have been three significant complications requiring surgical repair: one case of low arterial flow, one vesico ureteral leak, and one midurethra stenosis. Initial renal function: mean serum creatinine at one month was 147mmol/l, with a trend to improve to 126 mmol/l at one year, which is considered optimum. First postoperative day mean serum creatinine was 192mmol/l and the nadir was on second postoperative day with a value of 152mmol/l.

CONCLUSIONS

We believe laparoscopic living donor nephrectomy is a real alternative to open surgery because it offers better recovery to the donor with the same capacity to preserve renal function in the receptor.

Chromosomal High-Polysomies Predict Tumour Progression in T1 Transitional Cell Carcinoma of the Bladder

The main prognostic factor generally accepted for tumour progression in T1 transitional cell carcinoma (TCC) of the bladder is histological grade. Despite this fact it is considered inaccurate to make clinical decisions on individuals. It appears that progression from minimally invasive to deeply invasive cancer is concurrent with the acquisition of genomic alterations that increase the malignant potential of cancer cells. The aim of this study is to determine if changes in chromosomes 7, 8, 9 and 17 copy number can be used to predict recurrence and progression in patients with T1 TCC of the urinary bladder.

METHODS

Thirty-one T1 TCC samples were analyzed for chromosomal alterations by fluorescence in situ hybridization using centromeric probes for chromosomes 7, 8, 9 and 17. Clinical data were collected from the patients' clinical records and correlated with chromosomal studies.

RESULTS

Histological grade was confirmed as a prognostic factor of tumour progression (p=0.01). None of the cytogenetic alterations demonstrated in the studied group could be related to tumour recurrence. The high-polysomies (five or more copies) of chromosomes 8, 9 and 17 showed predictive value (p=0.05, 0.05, 0.03 respectively) for tumour progression since it was observed that patients with high-polysomy of these chromosomes showed more risk of tumour progression towards muscle-invasive disease than those without high-polysomy alteration.

CONCLUSION

Our findings suggest a possible prognostic significance of highly aneuploid cells (high-polysomies of chromosomes 8, 9 and 17) in tumour progression of T1 TCC bladder tumours. FISH analysis is a reproducible technique for evaluating cytogenetic alterations and could contribute to the assessment of the individual prognosis of T1 transitional cell carcinoma of the bladder.

Risk factors for cardiovascular disease after renal transplantation

Cardiovascular diseases (CVD) have become the leading cause of mortality in renal transplant recipients. Well-known cardiovascular (CV) risk factors and graft dysfunction both play an important role in the development of the posttransplantation CV events. We studied 233 stable kidney transplant patients to establish the prevalence of CVD and to assess CV risk factors that can be evaluated (and modified) in daily clinical practice. While 6.2% of the patients had coronary heart disease (CHD) before the transplantation, 16% displayed at least 1 CV event posttransplantation. The most significant factors associated with CV events were as follows: gender, length of smoking, diabetes mellitus, hepatitis C virus antibodies (HCV), dyslipidemia, proteinuria, and serum creatinine levels.

Use of recombinant human erythropoietin in kidney transplant patients with stable graft function

The purpose of this work was to determine the necessity for rhuEPO for 50 kidney transplant patients with stable graft function. We analyzed the red cell series, blood pressure, renal function, anthropometric data of the donor and recipient, proteinuria, and relationship with other factors, including immunosuppressants, angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB). The patients were divided into three groups depending on renal function: group A (with plasma creatinine <150 micromol/L), group B (151-250 micromol/L), and group C (>250 micromol/L). All patients were studied for 1 year. Erythropoietin use did not affect renal function, proteinuria or number of antihypertensive drugs group. The degree of renal dysfunction determined the time necessary to reach an adequate hemoglobin level (>12 g/L) and and the mean dose of weekly rhuEPO needed. The use of ACE inhibitors or ARBs increased the rhuEPO requirements in each group.

Tacrolimus in induction immunosuppressive treatment in renal transplantation: comparison with cyclosporine

The aim of the study was to compare the efficacy and safety of induction immunosuppression therapies based on tacrolimus or cyclosporine (CsA) in kidney transplantation. The 240 kidney allograft recipients were divided into two groups: group 1 (n=94) received tacrolimus (.01 mg/kg per day), mycophenolate mofetil (MMF, 2 g/d), and steroids (30 mg/d); and group 2 (n=146) CsA (6 mg/kg per day), MMF (2 g/d), and steroids (30 mg/d). Antilymphocyte serum was administered in cases of acute tubular necrosis. The acute rejection rate was higher among group 2 (30.6%) compared with group 1 patients (12.2%) (P=.001). There were no significant differences between the groups in terms of age, gender, body surface area, serologic virus markers (in donor and recipient), baseline creatinine levels, cause of death, HLA incompatibilities, response to acute tubular necrosis, and number of dialysis sessions. We conclude that both immunosuppressive regimens are effective and safe in kidney transplantation. The survival rates of patients and grafts were similar, but the incidence and degree of acute rejection events were reduced in group 1; this finding may forecast a decreased incidence of chronic renal allograft nephropathy.

Assessment of cyclosporine therapeutic monitoring with C2 concentrations in stable renal allograft recipients

The optimal long-term C2 target to minimize the risk of chronic allograft nephropathy (CAN) has not yet been established in a prospective study. Furthermore, it is not known whether the target is the same in patients who also receive mycophenolate mofetil (MMF). We determined the 2-hour postdose concentration (C2) in a cohort of 65 maintenance renal transplant patients. The mean C0 level was 0.12 microg/mL and the C2 was 0.62 microg/mL. The overexposed patients are 14%. There was a good correlation between C0 and C2, and between C2 and the cyclosporine (CsA) dose. Patients receiving MMF display lower levels of C0 and C2, lower dosages of CsA, and higher levels of plasma creatinines. We did not observe significant differences on relating the level of absorption to patient age and sex, creatinine level, CsA dose, or coadministration of MMF. In conclusion, there is a low incidence of overexposed patients. C2 levels of approximately 0.6 microg/mL (and possibly may be sufficient in renal transplant patients. somewhat lower [0.5 microg/mL] in patients receiving MMF) Patients who display slow or fast absorption of CsA do not have any apparent characteristic.

Significance of cytomegalovirus infection in renal transplantation

The aim of this study was to establish the relationship between vascular lesion chronic allograft nephropathy (CAN) and the presence of cytomegalovirus (CMV) in kidney transplanted patients. We studied 259 consecutive kidney transplant recipients with a minimum follow-up of 6 months; the induction immunosuppressive therapy included a calcineurin inhibitor, mycophenolate mofetil, steroids, and the use of an antilymphocyte serum if the patients developed delayed graft function. CMV early antigen detection (pp65) was performed on a weekly basis between days 30 and 90 post transplantation. Prophylactic treatment was administered in the donor +/recipient-risk group, and preemptive therapy delivered for positive antigenemia namely 3 days of intravenous [IV] gancyclovir [GCV] plus 11 days of oral therapy [in the case of infection], or 14 days of IV GCV [in the case of disease]). An acute kidney allograft rejection episode preceded CMV in 64.3% of the patients, and CMV preceded acute rejection in 35.7% of the cases. We conclude that CMV disease is an independent risk factor for CAN. CMV infection is probably associated with CAN, suggesting that the greater the viral load, the higher the risk of CAN. It may be advisable to perform universal prophylaxis to lower the viral load and CAN.

Synthetic nanopores with fixed charges: an electrodiffusion model for ionic transport

Synthetic nanopores with fixed charges exhibit ionic equilibrium and transport properties that resemble those displayed by biological ion channels. We present an electrodiffusion model based on the Nernst-Planck flux equations, which allows for a qualitative description of the steady state ionic transport through a nanopore when the membrane fixed charges and all mobile carriers (including the water ions) are properly taken into account. In particular, we study the current-voltage curve, the electrical conductance, the reversal potential (a measure of the nanopore ionic selectivity), as well as the flux inhibition by protons and divalent cations in the nanopore. The model clearly shows how the changes in the ionization state of the fixed charges with pH and salt concentration dictate the electrical properties of the nanopore. The agreement between the model predictions and previous experimental data allows us to identify which are the main characteristics that permit a simple description of this complex system.

Diffuse large B-cell lymphoma arising from donor lymphoid cells after renal and pancreatic transplantation

A patient with both a renal and pancreatic transplantation developed a diffuse large B-cell lymphoma, Epstein-Barr virus-related, 14 months after the surgical procedure. Tumor was confined to the transplanted organs: head of the pancreas and hilar lymph node of the transplanted kidney. Chimerism analysis demonstrated the tumor origin from donor lymphoid cells. Immunosuppression was discontinued and chemotherapy with cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone (CHOP) was started. However, no response was observed after three courses of this regimen. Finally, a transplantectomy was carried out, followed by rituximab (anti-CD20 antibody), with the patient achieving a complete response (CR). Two years later the patient remains in CR.