Vimentin expression and myofibroblast infiltration are early markers of renal dysfunction in kidney transplantation: an early stage of chronic allograft dysfunction?

Introduction

The objective of this study was to show the morphologic characteristics of allograft renal biopsies in renal transplant patients with stable renal function, which can potentially be early markers of allograft dysfunction, after 5 years of follow-up.

Methods

Forty-nine renal transplant patients with stable renal function were submitted to renal biopsies and simultaneous measurement of serum creatinine (Cr). Histology was evaluated using Banff scores, determination of interstitial fibrosis by Sirius red staining and immunohistochemical study of proximal tubule and interstitial compartment (using cytokeratin, vimentin, and myofibroblasts as markers). Biopsies were evaluated according to the presence or absence of the epitheliomesenchymal transition (EMT). The interstitial presence of myofibroblasts and tubular presence of vimentin was also analyzed simultaneously. Renal function was measured over the follow-up period to estimate the reduction of graft function.

Results

Median posttransplant time at enrollment was 105 days. Patients were followed for 64.3 ± 8.5 months. The mean Cr at biopsy time was 1.44 ± 0.33 mg/dL, and after the follow-up it was 1.29 ± 0.27 mg/dL. Nine patients (19%) had a reduction of their graft function. Eleven biopsies (22%) had tubulointerstitial alterations according to Banff score. Seventeen biopsies (34%) presented EMT. Fifteen biopsies (32%) had high interstitial expression of myofibroblasts and tubular vimentin. Using Cox multivariate analysis, HLA and high expression of interstitial myofibroblasts and tubular vimentin were associated with reduction of graft function, yielding a risk of 3.3 (P = .033) and 9.8 (P = .015), respectively.

Conclusion

Fibrogenesis mechanisms occur very early after transplantation and are risk factors for long-term renal function deterioration.     

Motor cortical hyperexcitability in idiopathic scoliosis: could focal dystonia be a subclinical etiological factor?

The aetiology of idiopathic scoliosis (IS) remains unknown; however, there is a growing body of evidence suggesting that the spine deformity could be the expression of a subclinical nervous system disorder. A defective sensory input or an anomalous sensorimotor integration may lead to an abnormal postural tone and therefore the development of a spine deformity. Inhibition of the motor cortico-cortical excitability is abnormal in dystonia. Therefore, the study of cortico-cortical inhibition may shed some insight into the dystonia hypothesis regarding the pathophysiology of IS. Paired pulse transcranial magnetic stimulation was used to study cortico-cortical inhibition and facilitation in nine adolescents with IS, five teenagers with congenital scoliosis (CS) and eight healthy age-matched controls. The effect of a previous conditioning stimulus (80% intensity of resting motor threshold) on the amplitude of the motor-evoked potential induced by the test stimulus (120% of resting motor threshold) was examined at various interstimulus intervals (ISIs) in both abductor pollicis brevis muscles. The results of healthy adolescents and those with CS showed a marked inhibitory effect of the conditioning stimulus on the response to the test stimulus at interstimulus intervals shorter than 6 ms. These findings do not differ from those reported for normal adults. However, children with IS revealed an abnormally reduced cortico-cortical inhibition at the short ISIs. Cortico-cortical inhibition was practically normal on the side of the scoliotic convexity while it was significantly reduced on the side of the scoliotic concavity. In conclusion, these findings support the hypothesis that a dystonic dysfunction underlies in IS. Asymmetrical cortical hyperexcitability may play an important role in the pathogenesis of IS and represents an objective neurophysiological finding that could be used clinically.     

Immediate placebo effect in Parkinson's disease--is the subjective relief accompanied by objective improvement?

BACKGROUND: A recent well-conducted meta-analysis showed that placebo effect is associated with a possible small benefit for subjective outcomes, but has no significant effects on objective outcomes. Objective: Herein, we aimed to investigate the immediate effects of two different types of placebo [placebo pill and sham transcranial magnetic stimulation (TMS)] in Parkinson's disease (PD) patients and compared them to the standard treatment (levodopa) in a proper randomized, double-blind, crossover clinical trial. METHODS: PD patients received three different interventions on different days: levodopa, placebo pill, and sham TMS. The motor function was assessed using simple and choice reaction time, Unified Parkinson's Disease Rating Scale (UPDRS), finger tapping, Purdue Pegboard test, time to button up, walking time and supination-pronation. The subjective motor function was measured by a visual analogue scale (VAS). RESULTS: The results showed that there was a significant motor function in the motor function only after the treatment with levodopa, but not after treatment with placebo pills or sham TMS. However, patients reported a similar subjective improvement in motor function indexed by VAS following these three treatments. CONCLUSION: These results suggest that placebo interventions in PD may have an immediate subjective sensation of improvement but result in no significant objective motor changes compared with levodopa treatment. Although physiological changes are possible after a placebo intervention, our findings suggest that the acute placebo effect in PD may be the result of the subjective change in the motor rating only.     

Protein-tyrosine phosphatase 1B-deficient myocytes show increased insulin sensitivity and protection against tumor necrosis factor-alpha-induced insulin resistance

Protein-tyrosine phosphatase (PTP)1B is a negative regulator of insulin signaling and a therapeutic target for type 2 diabetes. In this study, we have assessed the role of PTP1B in the insulin sensitivity of skeletal muscle under physiological and insulin-resistant conditions. Immortalized myocytes have been generated from PTP1B-deficient and wild-type neonatal mice. PTP1B(-/-) myocytes showed enhanced insulin-dependent activation of insulin receptor autophosphorylation and downstream signaling (tyrosine phosphorylation of insulin receptor substrate [IRS]-1 and IRS-2, activation of phosphatidylinositol 3-kinase, and serine phosphorylation of AKT), compared with wild-type cells. Accordingly, PTP1B(-/-) myocytes displayed higher insulin-dependent stimulation of glucose uptake and GLUT4 translocation to the plasma membrane than wild-type cells. Treatment with tumor necrosis factor-alpha (TNF-alpha) induced insulin resistance on glucose uptake, impaired insulin signaling, and increased PTP1B activity in wild-type cells. Conversely, the lack of PTP1B confers protection against insulin resistance by TNF-alpha in myocyte cell lines and in adult male mice. Wild-type mice treated with TNF-alpha developed a pronounced hyperglycemia along the glucose tolerance test, accompanied by an impaired insulin signaling and increased PTP1B activity in muscle. However, mice lacking PTP1B maintained a rapid clearance of glucose and insulin sensitivity and displayed normal muscle insulin signaling regardless the presence of TNF-alpha.     

Timing of CMV‐specific effector memory T cells predicts viral replication and survival after allogeneic hematopoietic stem cell transplantation

The aim of this study was to characterize timing, kinetic, and magnitude of CMV‐specific immune response after hematopoietic stem cell transplantation (HSCT) and its ability to predict CMV replication and clinical outcomes. Using cell surface and intracellular cytokine staining by flow cytometry, CMV‐specific T‐cell response was measured in blood, while CMV viral load and chimerism were determined by real‐time PCR. Patients that reconstituted CMV‐specific T‐cell response within 6 weeks after Allo‐SCT showed a more robust immune response (CD8⁺: 0.7 cells/μl vs. 0.3/μl; P‐value = 0.01), less incidence of CMV replication (33% vs. 89.5%; P‐value = 0.007), reduced viral loads (1.81 log copies/ml vs. 0 copies/ml; P‐value = 0.04), and better overall survival (72%; CI: 0.53–0.96 vs. 42% CI: 0.24–0.71; P‐value = 0.07) than patients with a delayed immune reconstitution. Viremic patients had significantly higher transplant‐related mortality than nonviremic patients after 1 year (33% CI: 0.15–0.52 vs. 0% CI: 0.05–0.34; P‐value = 0.01). Risk factors independently associated with viral replication were receptor pretransplant CMV‐positive serostatus (P‐value = 0.02) and acquiring CMV‐specific T‐cell response after 6 weeks post‐transplantation (P‐value = 0.009). In conclusion, timing of acquiring a positive CMV‐specific T‐cell immune response after transplantation may identify patients with different risk for viral replication and different clinical outcomes, including survival.     

Human plasma as a dermal scaffold for the generation of a completely autologous bioengineered skin

BACKGROUND: Keratinocyte cultures have been used for the treatment of severe burn patients. Here, we describe a new cultured bioengineered skin based on (1) keratinocytes and fibroblasts obtained from a single skin biopsy and (2) a dermal matrix based on human plasma. A high expansion capacity achieved by keratinocytes grown on this plasma-based matrix is reported. In addition, the results of successful preclinical and clinical tests are presented. METHODS: Keratinocytes and fibroblasts were obtained by a double enzymatic digestion (trypsin and collagenase, respectively). In this setting, human fibroblasts are embedded in a clotted plasma-based matrix that serves as a three-dimensional scaffold. Human keratinocytes are seeded on the plasma-based scaffold to form the epidermal component of the skin construct. Regeneration performance of the plasma-based bioengineered skin was tested on immunodeficient mice as a preclinical approach. Finally, this skin equivalent was grafted on two severely burned patients. RESULTS: Keratinocytes seeded on the plasma-based scaffold grew to confluence, allowing a 1,000-fold cultured-area expansion after 24 to 26 days of culture. Experimental transplantation of human keratinocytes expanded on the engineered plasma scaffold yielded optimum epidermal architecture and phenotype, including the expression of structural intracellular proteins and basement-membrane components. In addition, we report here the successful engraftment and stable skin regeneration in two severely burned patients at 1 and 2 years follow-up. CONCLUSIONS: Our data demonstrate that this new dermal equivalent allows for (1) generation of large bioengineered skin surfaces, (2) restoration of both the epidermal and dermal skin compartments, and (3) functional epidermal stem-cell preservation.     

Extracorporeal tourniquet method for intermittent hepatic pedicle clamping during laparoscopic liver surgery: an easy,cheap, and effective technique

Purpose  

This paper aims to describe an extracorporeal tourniquet (ET) method for laparoscopic Pringle maneuver (PM).     

Application of fibrin glue in microvascular anastomoses: comparative analysis with the conventional suture technique using a free flap model

Background: Several studies have already reported the utilization of fibrin glue in microvascular anastomoses to minimize the number of sutures and to decrease the operative time. Despite the good results obtained in most of these experiments, its clinical application has not launched. The aim of this study was to clarify the controversies around the safeness of fibrin glue application in microvascular anastomoses, and also to demonstrate the potential benefits of fibrin glue application in a realistic free flap model. Methods: Twenty‐seven rabbits were used in this study. The experimental model consisted of a free groin flap transfer to the anterior cervical region. The flap's circulation was restored by means of an end‐to‐side anastomosis between the femoral and carotid arteries, and an end‐to‐end anastomosis between the femoral and external jugular veins. The animals were divided into two groups (n = 10) according to the anastomosis technique: Group I (conventional suture) and group II (fibrin glue). Results: The number of sutures required to complete the arterial and venous anastomoses was reduced in 39 and 37% in group II, respectively. Despite this reduction, the anastomoses maintained adequate patency rates and mechanical strength. Both arterial and venous anastomoses benefited from fibrin glue application, which made them easier and faster to perform. The flaps' ischemic time and the total operative time were also significantly shortened. Conclusions: In this study, the application of fibrin glue in microvascular anastomoses was safe and reliable. The risk‐benefit ratio of fibrin glue application in microvascular anastomoses is favorable for its use. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.     

Testosterone administration to men with testosterone deficiency syndrome after external beam radiotherapy for localized prostate cancer: preliminary observations

OBJECTIVE

To assess the effects of testosterone supplementation in men with testosterone deficiency syndrome (TDS) after external beam radiotherapy (EBRT) for localized prostate cancer.

PATIENTS AND METHODS

Five men with significant signs of TDS after treatment for localized prostate cancer with EBRT were treated with testosterone once their prostate‐specific antigen (PSA) level had reached the nadir.

RESULTS

The mean (range) level of testosterone before supplementation was 5.2 (1.1–9.2) nmol/L and the duration of follow‐up while on supplementation was 14.5 (6–27) months. At the last visit, the testosterone levels were 17.6 (8.5–32.4) nmol/L. One of the five patients had a transitory increase in PSA level but none had levels of >1.5 ng/mL. All patients reported a marked response in the manifestations of TDS, i.e. four each reported decreased hot flushes, decreased fatigue and improved libido, and two reported improved erectile function.

CONCLUSION

Men with TDS after EBRT for localised prostate cancer are candidates for testosterone therapy. The patients must be aware of the advantages and disadvantages of the treatment. PSA levels must have reached a nadir before starting treatment and the follow‐up must be particularly close. In these few patients there were no adverse effects from testosterone supplementation. There is a need for more information about the safety and efficacy of testosterone therapy in men successfully treated for localized prostate cancer, because there is evidence indicating hypogonadism in these patients, compromising their quality of life and longevity, independent of the cancer.