Heme oxygenase system in hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (IRI) limits access to transplantation. Heme oxygenase-1 (HO-1) is a powerful antioxidant enzyme which degrades free heme into biliverdin, free iron and carbon monoxide. HO-1 and its metabolites have the ability to modulate a wide variety of inflammatory disorders including hepatic IRI. Mechanisms of this protective effect include reduction of oxygen free radicals, alteration of macrophage and T cell phenotype. Further work is required to understand the physiological importance of the many actions of HO-1 identified experimentally, and to harness the protective effect of HO-1 for therapeutic potential.

Autografting of Renal Progenitor Cells Ameliorates Kidney Damage in Experimental Model of Pyelonephritis

Current therapies for pyelonephritic renal damage have severe limitations; stem cells may offer an exciting potential in regenerating nephrology. We aimed to investigate the feasibility of direct intrarenal injection of autologous renal progenitor cells (RPCs; originated from epithelial cells in Bowman's capsule) in chronic pyelonephritis rat model. Twenty-seven rats were divided into three groups. The control group (GI, n = 3) underwent sham subcapsular injection of isotonic saline. Pyelonephritis was induced in the right kidney of the remaining 24 rats and isotonic saline (GII, n = 12) or labeled autologous RPCs, obtained from a biopsy of left kidney (GIII, n = 12), were injected into the subcapsular space 6 weeks later. At 7, 14, 28, and 60 days, dimercaptosuccinic acid scan was performed in three animals of each group at every interval and subsequently renal sections were obtained for the evaluation of tubular and glomerular regeneration and proliferation. Cell transplantation resulted in the reduction of tubular and glomerular atrophy after 2 weeks. The transplanted cells were observed in the reconstructed region of the kidneys as evidenced by the presence of fluorescently labeled cells both in tubules and glomeruli. We also observed significant decrease in interstitial fibrosis in the fourth week and there were higher amount of Ki-67-positive cells in GIII. Notably, the right renal tissue integrity was significantly improved in this group and revealed normal cortical function on day 60. Transplanting RPCs showed the potential for partial augmentation of kidney structure and function in pyelonephritis. Cellular repair was seen predominantly in the proximal tubule, the major site of injury in pyelonephritis. Our findings may pave the way toward the future regeneration of renal scarring of pyelonephritis in children.

Pancreas transplantation

Diabetes mellitus is generally treated with oral diabetic drugs and/or insulin. However, the morbidity and mortality associated with this condition increases over time, even in patients receiving intensive insulin treatment, and this is largely attributable to diabetic complications or the insulin therapy itself. Pancreas transplantation in humans was first conducted in 1966, since when there has been much debate regarding the legitimacy of this procedure. Technical refinements and the development of better immunosuppressants and better postoperative care have brought about marked improvements in patient and graft survival and a reduction in postoperative morbidity. Consequently, pancreas transplantation has become the curative treatment modality for diabetes, particularly for type I diabetes. An overview of pancreas transplantation is provided herein, covering the history of pancreas transplantation, indications for transplantation, cadaveric and living donors, surgical techniques, immunosuppressants, and outcome following pancreas transplantation. The impact of successful pancreas transplantation on the complications of diabetes will also be reviewed briefly.

Robotic kidney implantation for kidney transplantation: initial experience

Despite improvements in minimally invasive techniques over recent decades, kidney implantation into the iliac fossa has remained a domain of open surgery. However, it was hypothesized that it would be feasible to perform robotic transplant kidney implantation as a means of reducing surgical trauma. Two robotic kidney transplantations into the iliac fossa were attempted in human cadavers. In the first cadaver, a 5 cm incision was placed in the right lower abdomen, the peritoneum was mobilized in a cranial direction, the iliac vessels were identified, and the kidney placed in the pre-peritoneal space. The incision was sealed with a gel port through which the Vinci(©) Surgical System was installed. In the second cadaver, a robotic kidney implantation with robotically sutured vascular and ureteric anastomoses was performed trans-abdominally. Open incision, identification, placement of gel port, and robotic docking were feasible. Robotic performance of vascular anastomosis was not possible in the first cadaver because of advanced decay and excess fat in the surgical field. Robotic kidney positioning was feasible and anastomoses were performed successfully in the second cadaver within 35, 25, and 20 min (arterial, venous, and ureteric, respectively). Robotic kidney transplantation seems feasible in human cadavers if tissue condition is suitable, but is very technically challenging. Because of the delicacy of anatomical structures, the cadaveric model with the risk of advanced decay and the absence of circulation sets limits on the exploration of this complex procedure. Hence, further research and animal work in this area is critical to improve understanding of the benefits and limitations of robotic kidney implantation.

MRI of magnetically labeled mesenchymal stem cells in hepatic failure model

AIM: To track intravascularly transplanted mesenchymal stem cells (MSCs) labeled with superparamagnetic iron oxide (SPIO) by using magnetic resonance imaging (MRI) in an experimental rabbit model of hepatic failure.

METHODS: Human MSCs labeled with FDA-approved SPIO particles (Feridex) were transplanted via the mesenteric vein into rabbits (n = 16) with carbon tetrachloride-induced hepatic failure. Magnetic resonance (MR) examinations were performed with a 3.0 T clinical scanner immediately before and 2 h and 1, 3, and 7 d after transplantation. Signal intensity (SI) changes on T2*-weighted MRI were measured, and correlation between MR findings and histomorphologic findings was also investigated.

RESULTS: SI on T2*-weighted MRI decreased significantly in the liver 2 h after injection of human MSCs and returned gradually to the levels found before injection in 7 d. Changes in SI in the liver at 2 h, 1, 3, and 7 d were 41.87% ± 9.63%, 10.42% ± 4.3%, 5.12% ± 1.9%, 3.75% ± 1.2%, respectively (P < 0.001). Histologic analyses confirmed the presence of MSCs in the liver, localized mainly in the sinusoids in early period (2 h and 1 d) and concentrated to the border zone in late period (3 and 7 d). The number of iron-positive cells in the liver at 2 h and on 1, 3 and 7 d after transplantation was 29.2 ± 4.8, 10.1 ± 3.7, 6.7 ± 2.2, and 5.8 ± 2.1, respectively (P = 0.013).

CONCLUSION: Intravascularly injected SPIO-labeled MSCs in an experimental rabbit model of hepatic failure can be detected and followed with MRI.

Role of dendritic cells in cardiovascular diseases

Dendritic cells (DCs) are potent antigen-presenting cells that bridge innate and adaptive immune responses. Recent work has elucidated the DC life cycle, including several important stages such as maturation, migration and homeostasis, as well as DC classification and subsets/locations, which provided etiological insights on the role of DCs in disease processes. DCs have a close relationship to endothelial cells and they interact with each other to maintain immunity. DCs are deposited in the atherosclerotic plaque and contribute to the pathogenesis of atherosclerosis. In addition, the necrotic cardiac cells induced by ischemia activate DCs by Toll-like receptors, which initiate innate and adaptive immune responses to renal, hepatic and cardiac ischemia reperfusion injury (IRI). Furthermore, DCs are involved in the acute/chronic rejection of solid organ transplantation and mediate transplant tolerance as well. Advancing our knowledge of the biology of DCs will aid development of new approaches to treat many cardiovascular diseases, including atherosclerosis, cardiac IRI and transplantation.

Current concepts on cytomegalovirus infection after liver transplantation

Cytomegalovirus (CMV) is the most common viral pathogen that negatively impacts on the outcome of liver transplantation. CMV cause febrile illness often accompanied by bone marrow suppression, and in some cases, invades tissues including the transplanted allograft. In addition, CMV has been significantly associated with an increased predisposition to allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. To negate the adverse effects of CMV on outcome, its prevention, whether through antiviral prophylaxis or preemptive therapy, is regarded as an essential component to the medical management of liver transplant patients. Two recent guidelines have suggested that antiviral prophylaxis or preemptive therapy are similarly effective in preventing CMV disease in modest-risk CMV-seropositive liver transplant recipients, while antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in high-risk recipients [CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-)]. However, antiviral prophylaxis has only delayed the onset of CMV disease in many CMV D+/R- liver transplant recipients, and at least in one study, such occurrence of late-onset primary CMV disease was significantly associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention are needed, and aggressive treatment of CMV infection and disease should be pursued. The standard treatment of CMV disease consists of intravenous ganciclovir or oral valganciclovir, and if feasible, one should also reduce the degree of immunosuppression. In one recent controlled clinical trial, valganciclovir was found to be as effective and safe as intravenous ganciclovir for the treatment of mild to moderate CMV disease in solid organ (including liver) transplant recipients. In this article, the authors review the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

Fertility preservation for boys with cancer

Childhood cancer is a curable disease due to the development of chemo- and radiation therapies, but long-term survivors suffer late side-effects including infertility. Cytotoxic agents and radiation impair spermatogenesis and cause oligospermia or azoospermia as well as genetic damage in sperm. To date, the only established option to preserve fertility is cryopreservation of sperm before treatment and artificial reproduction techniques, if men with cancer can ejaculate, but only a quarter of men have banked sperm. Lack of information is the most common reason for failing to bank sperm. However, prepubertal patients who have only spermatogonia and spermatocytes in their testes do not benefit from cryopreservation of their sperm and assisted reproductive techniques. Thus, the only available option is to harvest testicular tissues before treatment for cryopreservation, from which immature germ cells can somehow be maturated. Autotransplantation of germ cells into the testis holds promise for fertility restoration, but contamination by malignant cells may induce relapse. Fluorescence-activated cell sorting (FACS) with two surface markers could exclude contaminated leukemic cells from murine germ cells, and transplantation of sorted germ cells successfully restored fertility without transmission of leukemia. Human germ cells could be also isolated from human leukemia and lymphoma cell lines by FACS using surface markers. Before autotransplantation can be applied clinically, some issues, including the risk of contamination by malignant cells and in vitro propagation of spermatogonial stem cells, should be resolved.

Treatment of different types of cirrhosis by autologous bone marrow stem cell transplantation via the hepatic artery: an analysis of 12 cases

AIM: To evaluate the efficacy and feasibility of autologous bone marrow stem cell transplantation via the hepatic artery in the treatment of different types and degrees of cirrhosis.

METHODS: Twelve patients with different types and degrees of decompensated cirrhosis, including 8 with hepatitis B-associated cirrhosis, 2 with alcoholic cirrhosis, and 2 with cryptogenic cirrhosis, were investigated retrospectively. Of all the patients, 4 had Child-Pugh grade B cirrhosis and 8 had grade C disease. At 2, 4 and 8 weeks after transplantation, the changes in symptoms (acratia, anorexia and abdominal distension), liver function and coagulation function were observed to analyze the efficacy and feasibility of autologous bone marrow stem cell transplantation via the hepatic artery in the treatment of cirrhosis.

RESULTS: Successful transplantation was achieved in all the 12 patients without obvious complications. The levels of plasma ALT and AST decreased after transplantation. TBIL decreased from 47.68 μmol/L ± 19.8 μmol/L at pretreatment to 36.45 μmol/L ± 20.78 μmol/L at 4 wk post-transplantation. Albumin increased from 18.79 g/L ± 7.02 g/L at pretreatment to 25.67 g/L ± 5.33 g/L at 2 wk. Although PT and PTA showed obvious improvement at 2 wk (P < 0.05), no significant improvement was noted at 4 and 8 wk (both P > 0.05). The total effective rate was 83.33% and 83.33% at 2 and 4 wk, respectively, but decreased to 66.67% at 8 wk. The improvement of TBIL and ALB in patients with alcoholic and cryptogenic cirrhosis at 2 and 4 wk was better than that in patients with hepatitis B-associated cirrhosis. The effective rate in patients with Child-Pugh B disease at 8 wk was significantly higher than that in patients with Child-Pugh C disease (100% vs 50%, P < 0.05).

CONCLUSION: Autologous bone marrow stem cell transplantation via the hepatic artery can improve hepatic cirrhosis, especially in patients with alcoholic or cryptogenic cirrhosis and those with a mild degree of cirrhosis.

The role of B cells in transplantation and immunopathic diseases

B cells, by virtue of their diverse roles in immune responses to foreign and self antigens, have become of increasing interest to the clinician as well as the basic immunologist. In particular, it is now apparent that the development of B cell unresponsiveness in antibody and T cell mediated autoimmune disorders and the transplant setting is both worthwhile and achievable.

Transplantation of neural stem cells in anosmic mice

OBJECTIVES

Treating olfactory dysfunction is a challenge for physicians. One of the therapeutic options could be transplantation of stem cells. In this study, neural stem cells were transplanted into anosmic mice.

METHODS

Neural stem cells were generated from the olfactory bulb of green fluorescent protein (GFP)-transgenic C57BL6 mice. Anosmia were induced by injection of intraperitoneal 3-methylindole. The neural stem cells were transplanted transnasally on the next day. The olfactory function was evaluated by a food-finding test once a week. The olfactory neuroepithelium was harvested for histologic examination and protein analysis at 4 weeks.

RESULTS

Twenty-five percent (6/24) of the control mice that were not transplanted with neural stem cells survived at 4 weeks while 67% (8/12) of the transplanted mice survived (P=0.029). The food finding test showed that the transplanted mice resumed finding food at 3 weeks while the control mice resumed finding food at 4 weeks. GFP-positive cells were observed in the olfactory neuroepithelium of the transplanted mice. Western blotting revealed that the olfactory marker protein expression was significantly lower in the control mice than that in the transplanted mice.

CONCLUSION

This study demonstrated that improvement of mouse survival was achieved and recovery of olfactory function was promoted by transnasal transplantation of neural stem cells in the anosmic mouse model. These results indicate that stem cells might be one of the future modalities for treating olfactory impairment.

Small bowel transplantation

Intestinal transplantation is gradually becoming a therapeutic intervention rather than an experimental procedure. In the long term, the best outcome for patients with intestinal failure remains total parenteral nutrition, but where this is unlikely to allow long-term survival because of loss of venous access sites or severe cholestasis, intestinal transplantation should be considered. The technical aspects of the procedure are well described and advances in recent years in both immunosuppression and antimicrobial therapy have led to improved outcomes, particularly in the larger centers. Graft monitoring and the profound sepsis that accompanies graft dysfunction due to bacterial translocation remain major challenges, whereas the issues of denervation, lymphatic disruption, graft-versus-host disease (GVHD), and nonphysiological venous drainage have not proved to be major problems. Whether intestinal transplantation will become an alternative for the stable patient on total parenteral nutrition rather than a salvage procedure for when total parenteral nutrition fails remains to be seen.

Bone regeneration effects of human allogenous bone substitutes: a preliminary study

Purpose

The purpose of this study was to compare the bone regeneration effects of cortical, cancellous, and cortico-cancellous human bone substitutes on calvarial defects of rabbits.

Methods

Four 8-mm diameter calvarial defects were created in each of nine New Zealand white rabbits. Freeze-dried cortical bone, freeze-dried cortico-cancellous bone, and demineralized bone matrix with freeze-dried cancellous bone were inserted into the defects, while the non-grafted defect was regarded as the control. After 4, 8, and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. Micro-computed tomography (micro-CT) was performed to calculate the percent bone volume. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation.

Results

In micro-CT evaluation, freeze-dried cortico-cancellous human bone showed the highest percent bone volume value among the experimental groups at week 4. At week 8 and week 12, freeze-dried cortical human bone showed the highest percent bone volume value among the experimental groups. In histologic evaluation, at week 4, freeze-dried cortico-cancellous human bone showed more prominent osteoid tissue than any other group. New bone formation was increased in all of the experimental groups at week 8 and 12. Histomorphometric data showed that freeze-dried cortico-cancellous human bone showed a significantly higher new bone formation percentile value than any other experimental group at week 4. At week 8, freeze-dried cortical human bone showed the highest value, of which a significant difference existed between freeze-dried cortical human bone and demineralized bone matrix with freeze-dried cancellous human bone. At week 12, there were no significant differences among the experimental groups.

Conclusions

Freeze-dried cortico-cancellous human bone showed swift new bone formation at the 4-week healing phase, whereas there was less difference in new bone formation among the experimental groups in the following healing phases.

Subcostal mini incision: a good option for donor nephrectomy

OBJECTIVES

We describe the results of over one hundred nephrectomies performed using a subcostal mini incision.

INTRODUCTION

A major effort has been undertaken to encourage living donor renal transplantation. New techniques that use minimally invasive approaches to perform donor nephrectomy have been progressively accepted. Among these new procedures is the mini-incision approach.

METHODS

We prospectively analyzed one hundred and seventeen consecutive donors that were subjected to subcostal mini-incision nephrectomy at a single center. Surgical time, warm and cold ischemia time, intraoperative complications, time until hospital discharge, presence of infection, bleeding, the need for a second operation, and death were analyzed. Eventual loss of donor renal function was indicated by increases in serum creatinine and proteinuria.

RESULTS

The mean time of surgery was 180.5 +/- 26.2 minutes. The mean warm ischemia time was 93 +/-8.3 seconds, while the mean cold ischemia time was 85.9 (+/-23.5) minutes. We had one case with an intraoperative complication, and only two patients required another operation. An intra-abdominal abscess occurred in one patient (0.85%), proteinuria occurred in one patient (0.85%), and a transitory increase of creatinine levels occurred in two patients (1.7%).

DISCUSSION

Reducing the length of the abdominal incision did not influence surgical time or result in an increase in intraoperative complications relative to our historical data or literature reports. Organ preparation was accomplished successfully with a brief warm ischemia time. Additionally, the mean hospital stay was short, and few surgical complications occurred.

CONCLUSION

The use of a subcostal mini incision is both safe and similar to conventional techniques previously described in the literature.

Hematopoietic stem cells in research and clinical applications: The "CD34 issue"

In this paper, experimental findings concerning the kinetics of hematopoietic reconstitution are compared to corresponding clinical data. Although not clearly apparent, the transplantation practice seems to confirm the basic proposals of experimental hematology concerning hematopoietic reconstitution resulting from successive waves of repopulation stemming from different subpopulations of progenitor and stem cells. One of the "first rate" parameters in clinical transplantations in hematology; i.e. the CD34+ positive cell dose, has been discussed with respect to the functional heterogeneity and variability of cell populations endowed by expression of CD34. This parameter is useful only if the relative proportion of stem and progenitor cells in the CD34+ cell population is more or less maintained in a series of patients or donors. This proportion could vary with respect to the source, pathology, treatment, processing procedure, the graft ex vivo treatment and so on. Therefore, a universal dose of CD34+ cells cannot be defined. In addition, to avoid further confusion, the CD34+ cells should not be named "stem cells" or "progenitor cells" since these denominations only concern functionally characterized cell entities.

Beneficial effects of N-acetyl cysteine on pancreas and kidney following experimental pancreatic ischemia-reperfusion in rats

OBJECTIVE

To evaluate the protective effects of N-acetyl cysteine on the pancreas and kidney after pancreatic ischemia reperfusion injury in a rat model.

METHODS AND MATERIALS

Pancreatic ischemia reperfusion was performed in Wistar rats for 1 hour. Revascularization was achieved followed by 4 h of reperfusion. A total of 24 animals were divided into four groups: Group 1: sham; Group 2: pancreatic ischemia reperfusion without treatment; Group 3: pancreatic ischemia reperfusion plus N-acetyl cysteine intravenously; and Group 4: pancreatic ischemia reperfusion plus N-acetyl cysteine per os. Blood and tissue samples were collected after reperfusion.

RESULTS

There were significant differences in amylase levels between Group 1 (6.11+/-0.55) and Group 2 (10.30+/-0.50) [p=0.0002] as well as between Group 2 (10.30+/-0.50) and Group 4 (7.82+/-0.38) [p=0.003]; creatinine levels between Group 1 (0.52 +/- 0.07) and Group 2 (0.77+/-0.18) [p=0.035] as well as between Group 2 (0.77+/-0.18) and Group 3 (0.48+/-0.13) [p=0.012]; and pancreatic tissue thiobarbituric acid reactive substance levels between Group 1 (1.27+/-0.96) and Group 2 (2.60+/-3.01) [p=0.026] as well as between Group 2 (2.60+/-3.01) and Group 4 (0.52+/-0.56) [p=0.002]. A decrease in pancreatic tissue GST-alpha3 gene expression was observed in Group 2 in comparison to Group 1 (p =0.006), and an increase was observed in Groups 3 and 4 when compared to Group 2 (p= 0.025 and p=0.010, respectively).

CONCLUSION

This study provides evidence that N-acetyl cysteine has a beneficial effect on pancreatic ischemia reperfusion injury and renal function in a rat model.

Comparison of four pancreatic islet implantation sites

Although the liver is the most common site for pancreatic islet transplantation, it is not optimal. We compared kidney, liver, muscle, and omentum as transplantation sites with regard to operative feasibility, and the efficiency of implantation and glycemic control. Islets from C57BL/6 mice were transplanted into diabetic syngeneic recipients. The mean operative time and mortality were measured to assess feasibility. To assess implantation efficiency, the marginal mass required to cure diabetes and the mean time taken to achieve normoglycemia were measured. A glucose tolerance test was performed to assess glycemic control efficiency. The data are listed in the order of the kidney, liver, muscle, and omentum, respectively. The mean mortality rate was 6.7, 20.0, 7.1, and 12.5%; the mean operative time was 10.2, 27.4, 11.2, and 19.8 min; the marginal islet mass was 100, 600, 600, and 200 islet equivalence units and the mean time to reach euglycemia was 3.0, 15.1, 26.6, and 13.9 days. The glucose kinetics of omental pouch islets was the most similar to controls. Thus, a strategic approach is required for deciding on the best transplantation recipient sites after considering donor sources and islet volume. Alternatives can be chosen based on safety or efficacy.

IL-2 Receptor Antagonist (Basiliximab) Is Associated with Rapid Fibrosis Progression in Patients with Recurrent Hepatitis C after Liver Transplantation Using Serial Biopsy Specimens

BACKGROUND

Recurrence of hepatitis C virus (HCV) infection following orthotopic liver transplantation (OLT) is universal. There is paucity of data on the safety and efficacy of interleukin (IL)-2 receptor antagonist (IL-2RA) when added to the standard immunosuppression regimen in OLT recipients with recurrent HCV infection.

OBJECTIVES

To evaluate the efficacy of IL-2RA (Basiliximab) in preventing acute cellular rejection (ACR) in patients with recurrent HCV infection after OLT and to assess the impact of IL-2RA in promoting fibrosis progression in post-OLT recurrent HCV infection.

METHODS

Using an electronic pathology database, we identified all OLT/HCV patients with at least 2 post-OLT liver biopsies (1998-2006). Standard immunosuppression consisted of steroids and calcineurin inhibitor with and without mycophenolate mofetil. All patients who were transplanted after May 2004 received IL-2RA induction therapy. The Ludwig-Batts system was used to stage all biopsies (593 biopsies from 124 patients). The first biopsy that showed post-OLT fibrosis or the last follow-up biopsy was used for time-to-progression analysis. Univariate and multivariate Cox proportional hazards regression analyses were performed to identify factors associated with the progression of fibrosis.

RESULTS

ACR was significantly (p<0.001) lower in patients who received IL-2RA (20 of 70, 29%) compared to those who did not (33 of 54, 61%). The median (25%ile, 75%ile) follow-up was 12.1 (6.1, 23.9) months during which 61% of patients had progression of fibrosis. Univariate analysis revealed that a higher HCV RNA load at 4 months post-OLT (p=0.002), cytomegalovirus (CMV) infection (p<0.001), use of steroid therapy for ACR (p=0.043), and use of IL-2RA (p<0.001) were associated with higher hazards for the progression of fibrosis. Viral load at 4 months post-OLT was significantly (p=0.025) higher in patients who had IL-2RA therapy (median [25%ile, 75%ile]: 2.9 [1.0, 5.0] ×10(6) vs. 1.4 [1.0, 2.3] ×10(6)). In multivariate analysis, patients who received IL-2RA therapy were 3.1 (95% CI: 1.8-5.3) times more likely to develop fibrosis than those who did not treated with IL-2RA. Steroid therapy for ACR remained significantly (Hazard Ratio=2.9, p=0.002) associated with the progression of fibrosis.

CONCLUSION

IL-2RA (Basiliximab) decreases the rate of ACR. However, it may be associated with more rapid histological progression of the disease in post-OLT recurrent HCV.

The effect of human chorionic gonadotropin treatment on recipient mouse germ cell proliferation following spermatogonial stem cell transplantation of neonatal donor mice

Spermatogonia are the male germ line stem cells whose life long expansion is needed for permanent production of spermatozoa. The present study was designed to examine the effect of hCG treatment on germ cell proliferation following stem cell transplantation in mice. Spermatogonial stem cells were isolated from neonatal mice testes and characterized by alkaline phosphatase, immunoreactivity and morphological analysis. hCG was injected into normal and cell transplanted mice. We then evaluated the testosterone levels and cell number in normal mice. After that, cyclin B1 gene expression was investigated in transplanted mice. Different doses of busulfan were injected to investigate the effects of chemotherapy on morphological criteria and preparation of recipient mice for transplantation. In this report we show proliferative potential of spermatogonial stem cells after cytotoxic treatment, transplantation efficiency by semi-quantitative RT-PCR, and hCG effect on stem cell regeneration in normal mice and following cell transplantation. The results indicate that spermatogonial stem cells can proliferate after transplantation, and the efficiency of their transplantation depends on hormonal treatment. Therefore, hormonal treatment after stem cell transplantation will be a powerful avenue for increasing the efficiency of transplantation and fertility restoration.

Endocrine complications after hematopoietic stem cell transplantation during childhood and adolescence

Long-term survivors of hematopoietic stem cell transplantation (HSCT) during childhood and adolescence are at risk of developing endocrine complications. The purpose of this study was to evaluate the long-term endocrine complications and their associated risk factors among such patients. We reviewed the data from 111 patients (59 males and 52 females) who underwent HSCT at the mean age of 8.3+/-4.1 yr. Thirty patients (27.0%) had growth impairment, and seven (21.2%) out of 33 patients who attained final height reached final height below 2 standard deviation (SD). The final height SD score of the patients conditioned with total body irradiation (TBI) was significantly lower than that of the patients conditioned without TBI (-1.18+/-1.14 vs. -0.19+/-0.78, P=0.011). Thirteen patients (11.7%) developed hypothyroidism (11 subclinical, 2 central) 3.8+/-1.8 (range 1.6-6.2) yr after HSCT. Nineteen (65.5%) out of 29 females had evidence of gonadal dysfunction, and 18 (64.3%) out of 28 males had evidence of gonadal dysfunction. The risk for gonadal dysfunction was significantly higher in females conditioned with busulfan/cyclophosphamide (P=0.003). These results suggest that the majority of patients treated with HSCT during childhood and adolescence have one or more endocrine complications. Therefore, multiple endocrine functions should be monitored periodically after HSCT until they reach adult age.

Stromal cell derived factor-1 enhances bone marrow mononuclear cell migration in mice with acute liver failure

AIM: To evaluate the number of bone marrow mononuclear cells (BMMC) that are migrated to the liver following transplantation of murine BMMC into mice with acute liver injury.

METHODS: BMMC were isolated from the bone marrow of mice in a lymphocyte separation medium and then labeled with PKH26. The labeled cells were subsequently infused into the caudal veins of BALB/c mice with hepatic injury induced by carbon tetrachloride and 2-acetylaminofluorene. Mice in experimental group were treated with stromal cell-derived factor-1 (SDF-1) which was injected intraperitoneally after transplantation of BMMC. Mice in control group were injected intraperitoneally with 0.1 mL of saline (0.9% NaCl) after transplantation of BMMC. After 2 wk, migration of the cells in experimental group was studied by fluorescence microscopy. The expression of proliferating cell nuclear antigen and albumin was quantified with manual methods in both groups. The serum transaminase levels at different time points were compared between the two groups.

RESULTS: The labeled “cells” were found in the portal region and central veins of hepatic lobules. The PKH26-labeled cells appeared at an average frequency of 108 ± 8/high power field in the experiment group and 65 ± 8/high power field in the control group (P < 0.05). The total number of positive cells was 29 ± 7/high power field in the experimental group and 13 ± 2/high power field in the control group. The albumin expression level was also higher in the experimental group than in the control group (29 ± 7 vs 13 ± 2, P < 0.05). The total number of crossing points was 156 ± 5/high power field in the experimental group and 53 ± 5/high power field in the control group (P < 0.05). The serum alanine aminotransferase levels in experimental and control groups were measured at different time points (120 ± 40 vs 118.50 ± 1.75, P > 0.05; 80.60 ± 6.50 vs 101.08 ± 5.67, P < 0.05; 50.74 ± 5.38 vs 80.47 ± 4.62, P < 0.05; 30.54 ± 2.70 vs 60.72 ± 4.37, P < 0.05; 30.77 ± 5.36 vs 40.47 ± 6.50, P < 0.05). At the same time, the serum aspartate aminotransferase levels were measured in experimental and control groups at different time points (122.55 ± 1.46 vs 120.70 ± 4.22, P > 0.05; 54.26 ± 6.50 vs 98.70 ± 8.20, P < 0.05; 39.47 ± 5.39 vs 78.34 ± 4.50, P < 0.05; 28.94 ± 2.70 vs 56.44 ± 4.28, P < 0.05; 30.77 ± 5.45 vs 42.50 ± 6.28, P < 0.05).

CONCLUSION: SDF-1 can promote the migration of BMMC to the liver of mice with acute liver failure.

The ownership of human body: an islamic perspective

Using human dead body for medical purposes is a common practice in medical schools and hospitals throughout the world. Iran, as an Islamic country is not an exception. According to the Islamic view, the body, like the soul, is a "gift" from God; therefore, human being does not possess absolute ownership on his or her body. But, the ownership of human beings on their bodies can be described as a kind of "stewardship". Accordingly, any kind of dissection or mutilation of the corpse is forbidden, even with the informed consent of the dead or his/her relatives. The exception of this principle is when such procedures are necessary for saving lives of other persons. In this article using the human dead body for medical education, research and treatment is discussed and the perspective of Iranian Shiite religious scholars in this regard is explained.

Combined en bloc liver/pancreas transplantation in two different patients

Combined en bloc liver/pancreas transplantation (CLPT) was used primarily in the treatment of otherwise non-resectable upper abdominal malignancy. In fact, a more appropriate indication is in patients with liver disease and insulin-dependent diabetes mellitus (IDDM). Here, we report on two successful cases of CLPT at our hospital. One was a patient with non-resectable advanced liver cancer. The recipient survived for 23 mo and finally died of recurrent tumor. The other was a patient with severe biliary complication after orthotopic liver transplantation and preoperative IDDM. We performed CLPT with a modified surgical technique of preserving the native pancreas. He is currently liver-disease- and insulin-free more than 27 mo post-transplant. Based on our experience in two cases of abdominal cluster transplantation, we describe the technical details of CLPT and a modification of the surgical procedure.

Therapeutic effect of adipose tissue-derived mesenchymal stem cells transplantation for rat model of hepatic cirrhosis

AIM: To evaluate the therapeutic effect of adipose tissue-derived mesenchymal stem cells transplanted through caudal or portal vein for the hepatic cirrhosis model of rats induced by CCl₄.

METHODS: Forty-five healthy SD rats were randomly divided into control group, portal-vein group and caudal-vein group. All rats were subcutaneously injected carbon tetrachloride oily mixture continuously for 8 weeks. At the sixth week, portal-vein group and caudal-vein group were transplanted with rat adipose tissue-derived mesenchymal stem cells 2×10⁶ each rat, respectively from superior mesenteric vein and caudal vein. The control group was injected isometric cell culture media. Liver function of rat was examined before and after cell transplantation. HE staining was performed on all liver specimen slices. The degeneration and necrosis of hepatic cells and the degree of liver fibrosis were observed under microscope, and further pathological evaluation was made according to observation results. All experiment data were analyzed by statistics.

RESULTS: The liver function of portal-vein group and caudal-vein group was improved significantly in comparison with that of control group (AST: 142.2 ± 31.2 U/L, 167.9 ± 28.3 U/L vs 354.2 ± 26.4 U/L; ALT: 79.4 ± 18.9 U/L, 85.8 ± 21.4 U/L vs 456.7 ± 35.3 U/L; ALB: 26.3 ± 2.0 g/L, 24.5 ± 2.2 g/L vs 17.2 ± 1.7 g/L, all P < 0.05), but the level of TBIL wasn't improved. The transplantation of adipose tissue-derived mesenchymal stem cells inhibited the degeneration and necrosis of hepatic tissue and improved liver fibrosis of the rats. The difference of pathological evaluation between cell-transplanted group and control group was statistically significant (P < 0.05).

CONCLUSION: The transplantation of adipose tissue-derived mesenchymal stem cells through portal and caudal vein has therapeutic effect for the hepatic cirrhosis model of rats. It can improve liver function and inhibit liver fibrosis.

Transplantation and homing of mouse embryonic stem cells treated with erythropoietin in spleen and liver of irradiated mice

BACKGROUND

The present study was designed to evaluate the homing potential of mouse embryonic stem cells (ESC) treated with erythropoietin (EPO) in hematopoietic organs such as spleen and liver after transplantation using morphological and immuno-histochemical techniques.

METHODS

Day-four embryoid body (EB)-derived cells were dissociated and re-plated in medium in the presence and absence of EPO for three days. The EPO- and untreated differentiated cells were labeled with 5-bromo-2 deoxyuridine (BrdU) before transplantation and analyzed using flow cytometry and reverse transcription-PCR methods. BrdU-labeled cells were injected via the tail vein into irradiated adult mice in both groups. The spleen colony-forming unit assay (CFU-S) was performed 12 days after transplantation. Immuno-histochemistry was also carried out to trace transplanted cells.

RESULTS

The percentage of CD34 positive cells was 5.51 +/- 1.06% in the EPO-treated group and 1.63 +/- 0.225% in untreated group. The RT-PCR analysis showed that the EPO-treated cells expressed epsilon globin, betaH1 globin, RUNX1 and EPO receptor genes, but the beta-major globin gene was not expressed. The number of colonies formed in the spleens of treated group (17.33 +/- 4.726) was significantly different from the control group (6 +/- 1). The population of BrdU positive cells in spleen of EPO-treated cell-transplanted group was higher than that of the control group. Also, BrdU positive cells were observed in the central vein of the liver sections of EPO-treated and control groups but were not observed in the liver parenchyma. There were not BrdU positive cells in the spleen and liver sections of the sham group.

CONCLUSION

Our results confirm that ESC have the ability to home and form colonies in spleen after transplantation and EPO-treated EB-derived cells caused an increase in the number of colonies in spleen after CFU-S.

Intrahepatic transplantation of hepatic oval cells for fulminant hepatic failure in rats

AIM: To evaluate the effect of intrahepatic trans-plantation of hepatic oval cells (HOC) on fulminant hepatic failure (FHF) in rats.

METHODS: HOC obtained from rats were labeled with green fluocescent protein (GFP) or 5, 6-carboxyfluorescein diacetate succinmidyl ester (CFDA-SE). Cell fluorescence was observed under fluorescent microscope at 6, 24, 48 and 72 h after labeling. CFDA-SE labeled HOC (5 × 10⁶ cells each rat) were injected into livers of rats with FHF induced by D-galactosamine. Serum albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBil) levels were measured at different time points. Liver function of rats was examined on days 3, 7, 14 and 21 after HOC transplantation.

RESULTS: The positive rate of GFP and CFDA-SE labeled HOC was 10% and 90%, respectively, with no significant change in cell viabilities. The survival rate was higher in HOC transplantation group than in control group, especially 48 (9/15 vs 6/15) and 72 h (9/15 vs 4/15) after HOC transplantation. The serum ALT, AST and TBil levels were decreased while the serum Alb level was increased after HOC transplantation. Fluorescence became faded and diffused in liver tissues, suggesting that proliferation and differentiation occur in transplanted HOC.

CONCLUSION: CFDA-SE is superior to GFP in labeling HOC, although fluorescence intensity is decreased progressively with cell division. HOC transplantation can improve the liver function and increase the survival rate of recipients.

Anesthesia for synchronous liver and kidney transplantation in a child: A case report

Synchronous liver and kidney transplantation (SLK) is considered a treatment of choice for an end-stage liver disease patient with irreversible kidney disease. Several perioperative renal supportive treatments, especially continuous renal replacement therapy (CRRT), have contributed to the effective control of hypervolemia and electrolytes and acid-base disturbances leading to high success rate in adults. However, anesthesia for SLK in children is frequently difficult since the CRRT is seldom available because of difficulty in securing large venous lines. In addition, conventional techniques such as venovenous bypass and side-clamping of the inferior vena cava are less applicable in small children causing difficult volume control. Herein, we report a case of SLK in a child with glycogen storage disease type I with a review of literature.

THE ROLE OF FIBRIN GLUE AND SUTURE ON THE FIXATION OF ULTRA FROZEN PRESERVED MENISCUS TRANSPLANTATION IN RABBITS

Objective: To evaluate the ability of fibrin adhesive in promoting the meniscus fixation within two, four and eight weeks compared to the conventional soft-tissue suture technique. Materials and Methods: 36 right medial menisci of rabbits preserved at negative 73° Celsius for 30 days were transplanted to animals of the same sample and fixed with soft-tissue suture or fibrin glue. After 2, 4 or 8 weeks, the appearance of the menisci and the quality of fixation were macroscopically checked and evaluated by a scoring system. The findings were subjected to the statistical study of variance analysis (p ≤ 0.05%). Results: The deep-frozen meniscus preservation maintained the integrity of the meniscus transplant, and, macroscopically, there was no significant reduction of the length of the meniscus in all post-transplant periods (p = 0.015). The menisci fixed with fibrin showed slight changes in color and surface roughness. There were no signs of rejection or infection in both groups. Suture fixation scoring was superior (p = 0.015) in all periods (80% of total fixation) as compared to the setting promoted by fibrin (20% of total fixation). Conclusion: The homologous transplantation of the meniscus of rabbits experienced various degrees of integration to the knee according to the fixation method; the surgical soft tissues suturing technique was shown to be superior in the evaluation of scores compared to the fixation with fibrin adhesive.

Renal Transplantation: Experience at a Single Centre

BACKGROUND

Renal transplantation program in the Armed Forces commenced in Feb 1991 and till date 245 patients have undergone renal transplantation at INHS Asvini. We describe our protocols for donor and recipient evaluation and immunosuppression.

METHODS

245 patients received renal transplants during this period, 243 (99.2%) being from live donors. Most of them were started on triple immunosuppression comprising of cyclosporine, azathioprine and prednisolone. Newer drugs like mycophenolate, tacrolimus and sirolimus were administered in a select population.

RESULT

69 (28.1%) of them had at least one episode of acute rejection, most of which were steroid responsive and 13 (18.8%) of them required either anti CD3 monoclonal or anti-thymocyte globulin (ATG). Complete recovery with normal renal function occurred in 54 (78.2%) cases and 15 (21.7%) recovered with residual dysfunction with maximum serum creatinine being 2.1mg/dl. There were three (1.2%) cases of accelerated rejection during the first week of transplantation and one had graft rupture. All three lost their grafts. There were eight (3.2%) cases of acute tubular necrosis, who recovered completely within 8-14 days. Immediate infections included wound sepsis, lower respiratory tract infection, disseminated candidiasis and disseminated aspergillosis. Late infections included pulmonary tuberculosis, disseminated tuberculosis, cytomegalovirus infection and recurrent urinary tract infection. 28 (11.4%) patients developed post transplant diabetes mellitus. At the end of one year and five years, graft and patient survival were 97.2%, 93%, 80.9% and 85.7% respectively.

CONCLUSION

Our outcomes show that the transplantation is a viable mode of renal replacement therapy in patients of end stage kidney disease with a near normal rehabilitation.

Therapy with bone marrow cells reduces liver alterations in mice chronically infected by Schistosoma mansoni

AIM: To investigate the potential of bone marrow mononuclear cells (BM-MCs) in the regeneration of hepatic lesions induced by Schistosoma mansoni (S.mansoni) chronic infection.

METHODS: Female mice chronically infected with S.mansoni were treated with BM-MCs obtained from male green fluorescent protein (GFP) transgenic mice by intravenous or intralobular injections. Control mice received injections of saline in similar conditions. Enzyme-linked immunosorbent assay (ELISA) assay for transforming growth factor-beta (TGF-β), polymerase chain reaction (PCR) for GFP DNA, immunofluorescence and morphometric studies were performed.

RESULTS: Transplanted GFP⁺ cells migrated to granuloma areas and reduced the percentage of liver fibrosis. The presence of donor-derived cells was confirmed by Fluorescence in situ hybridization (FISH) analysis for detection of cells bearing Y chromosome and by PCR analysis for detection of GFP DNA. The levels of TGF-β, a cytokine associated with fibrosis deposition, in liver fragments of mice submitted to therapy were reduced. The number of oval cells in liver sections of S.mansoni-infected mice increased 3-4 fold after transplantation. A partial recovery in albumin expression, which is decreased upon infection with S.mansoni, was found in livers of infected mice after cellular therapy.

CONCLUSION: In conclusion, transplanted BMCs migrate to and reduce the damage of chronic fibrotic liver lesions caused by S.mansoni.

An optimal protocol for in vitro regeneration, efficient rooting and stable transplantation of chickpea

A rapid, reproducible and efficient regeneration method was developed for chickpea (Cicer arietinum L.) using single cotyledon with half embryonal axis as explants. MS medium supplemented with 4 ìM TDZ, 10 ìM 2-iP and 2 ìM kinetin induced 50-100 adventitious buds/shoots after 14 days of culture and elongated on MS medium supplemented with 5 ìM 2-iP and 2 ìM kinetin. Healthy, strong and 100 % rooting was achieved by exposing cut ends of the shoots to 10 sec pulse treatment with 100 ìmoles/ml IBA followed by their transfer to liquid MS basal medium within 10-14 d. 2-3 cm long shoots were most suitable for rooting. Potting-mixture with good aeration and lesser capacity to retain water was most suitable for achieving successful establishment of chickpea plantlets. Garden soil mixed with sand (gravel) and bio-manure in the ratio of 1:1:1 is most suitable for achieving cent percent transplantation success. Cent percent of plantlets got acclimatized, survived in the pots and showed normal growth, development, flowering followed by podding and seeds setting. Harvesting of seeds was done after the pods were fully matured and dry. In this communication, we have demonstrated for the first time that shoot length, pulse treatment of cut ends of shoots with 100 ìmoles/ml IBA and aeration of potting mixture are key factors for rapid micro-propagation and successful establishment of chickpea.

Several issues about bone marrow stem cell transplantation for liver diseases

Recently, many studies reported that bone marrow stem cells (BMSCs) had the ability to differentiate into hepatocytes and cholangiocytes in normal livers or in some pathologic environments and to generate functional hepatocytes to restore the injured livers by cell transplantation. This review is designed as a state-of-the-art survey taking into account current knowledge and published work, including the evidence from animal models, the possible mechanisms and conditions, future application modalities for the clinical use of cellular-derived therapeutics for patients with liver diseases.

Cytomegalovirus infection after liver transplantation: Current concepts and challenges

Cytomegalovirus (CMV) is a common viral pathogen that influences the outcome of liver transplantation. In addition to the direct effects of CMV syndrome and tissue-invasive diseases, CMV is associated with an increased predisposition to acute and chronic allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. Risk factors for CMV disease are often interrelated, and include CMV D+/R- serostatus, acute rejection, female gender, age, use of high-dose mycophenolate mofetil and prednisone, and the overall state of immunity. In addition to the role of CMV-specific CD4+ and CD8+ T lymphocytes, there are data to suggest that functionality of the innate immune system contributes to CMV disease pathogenesis. In one study, liver transplant recipients with a specific polymorphism in innate immune molecules known as Toll-like receptors were more likely to develop higher levels of CMV replication and clinical disease. Because of the direct and indirect adverse effects of CMV disease, its prevention, whether through antiviral prophylaxis or preemptive therapy, is an essential component in improving the outcome of liver transplantation. In the majority of transplant centers, antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-). However, the major drawback of antiviral prophylaxis is the occurrence of delayed-onset primary CMV disease. In several prospective and retrospective studies, the incidence of delayed-onset primary CMV disease ranged from 16% to 47% of CMV D+/R- liver transplant recipients. Current data suggests that delayed-onset CMV disease is associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention and novel drugs with unique modes of action are needed. Currently, a randomized controlled clinical trial is being performed comparing the efficacy and safety of maribavir, a novel benzimidazole riboside, and oral ganciclovir as prophylaxis against primary CMV disease in liver transplant recipients. The treatment of CMV disease consists mainly of intravenous (IV) ganciclovir, and if feasible, a reduction in the degree of immunosuppression. A recent controlled clinical trial demonstrated that valganciclovir is as effective and safe as IV ganciclovir for the treatment of CMV disease in solid organ (including liver) transplant recipients. In this article, the author reviews the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

Selection criteria for liver resection in patients with hepatocellular carcinoma and chronic liver disease

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide with an annual occurrence of one million new cases. An etiologic association between HBV infection and the development of HCC has been established with a relative risk 200-fold greater than in non-infected individuals. Hepatitis C virus is also proving an important predisposing factor for this malignancy with an incidence rate of 7% at 5 years and 14% at 10 years. The prognosis depends on tumor stage and degree of liver function, which affect the tolerance to invasive treatments. Although surgical resection is generally accepted as the treatment of choice for HCC, new treatment strategies, such as local ablative therapies, transarterial embolization and liver transplantation, have been developed nowadays. With increasing detection of small HCCs from screening programs for cirrhotic patients, it is foreseen that locoregional therapy will play an important role in the near future.

Repopulation of human fetal hepatocytes in nude mouse model with chimeric human liver using mouse-specific anti-Fas antibody

AIM: To investigate repopulation of human fetal hepatocytes in an animal model of nude mice with chimeric human liver following induction of mouse hepatocyte apoptosis using a mouse-specific anti-Fas monoclonal antibody (Jo2 mAb) that does not engage xenogeneic fas.

METHODS: For experiment group, nude mice were transplanted with human fetal hepatocytes intrasplenically and treated with 0.2 mg/kg Jo2 mAb intraperitoneally once a week for 12 weeks consistently. Nude mice in the control group were transplanted with human fetal hepatocytes but not administrated with Jo2 mAb. Liver section from non-transplanted nude mice administered with Jo2 mAb were analyzed using hematoxylin and eosin staining and terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Reverse transcription-polymerase chain reaction (RT-PCR) and S-P immunohistochemistry were used to detect human albumin mRNA, human albumin and specific proliferating cell nuclear antigen (PCNA) in chimeric liver tissues.

RESULTS: Liver sections from non-transplanted nude mice administered with Jo2 mAb showed hepatocyte death, massive apoptosis and hemorrhage. Nude mice in both experiment group and control group survived 24 weeks after transplantation. Human albumin and specific human PCNA were detected from the week 2 to week 20 after transplantation, but they could only be detected from the week 2 to week 12 in the controls. Human albumin mRNA (356 bp) was detected in mice livers from the week 4 to week 16 after transplantation, but they could only be detected from the week 4 to week 8 in the controls. The number of PCNA in experiment group is significantly higher than in the control group at 8, 12 wk (25.7% ± 8.5% vs 13.4% ± 7.8%, 29.4%± 5.0% vs 8.5% ± 2.3%, both P < 0.05).

CONCLUSION: Human fetal hepatocytes of xenogeneic graft can survive in nude mice. The repopulation of human fetal hepatocytes can be promoted and prolonged in nude mouse model with chimeric human liver using mouse-specific anti-Fas antibody intraperitoneally.

Retinal tissue engineering using mouse retinal progenitor cells and a novel biodegradable, thin-film poly(e-caprolactone) nanowire scaffold

Retinal progenitor cells (RPCs) can be combined with nanostructured polymer scaffolds to generate composite grafts in culture. One strategy for repair of diseased retinal tissue involves implantation of composite grafts of this type in the subretinal space. In the present study, mouse retinal progenitor cells (RPCs) were cultured on laminin-coated novel nanowire poly(e-caprolactone)(PCL) scaffolds, and the survival, differentiation, and migration of these cells into the retina of C57bl/6 and rhodospsin -/- mouse retinal explants and transplant recipients were analyzed. RPCs were cultured on smooth PCL and both short (2.5 mum) and long (27 mum) nanowire PCL scaffolds. Scaffolds with adherent mRPCs were then either co-cultured with, or transplanted to, wild-type and rhodopsin -/- mouse retina. Robust RPC proliferation on each type of PCL scaffold was observed. Immunohistochemistry revealed that RPCs cultured on nanowire scaffolds increased expression of mature bipolar and photoreceptor markers. Reverse transcription polymerase chain reaction revealed down-regulation of several early progenitor markers. PCL-delivered RPCs migrated into the retina of both wild-type and rhodopsin knockout mice. The results provide evidence that RPCs proliferate and express mature retinal proteins in response to interactions with nanowire scaffolds. These composite grafts allow for the migration and differentiation of new cells into normal and degenerated retina.

Proliferation of L02 human hepatocytes in tolerized genetically immunocompetent rats

AIM: To investigate whether human hepatocytes could proliferate after transplantation to normal immunocompetent rats treated with 2-acetaminofluorene or Retrorsine and partial hepatectomy.

METHODS: L02 hepatocyte-tolerant Sprague-Dawley rats were injected with Retrorsine, 2-acetaminofluorene or normal saline. L02 hepatocytes were then transplanted via the spleen. Human albumin and its mRNA, specific proliferating cell nuclear antigen (PCNA), L02 hepatocyte dynamic distribution, number density and area density of PCNA-positive cells in the liver were determined.

RESULTS: All the examined indicators were not significantly different between the rats treated with 2-acetaminofluorene and normal saline, which was not the case with rats treated with Retrorsine. A dynamic distribution of L02 hepatocytes in the rat liver was detected from wk 1 to mo 6 after transplantation in the Retrorsine group and from wk 1 to 10 in the 2-acetaminofluorene group. Human albumin and its mRNA were detected from wk 2 to mo 6 in the Retrorsine group and from wk 1 to 8 in the 2-acetaminofluorene group. Specific human PCNA was detected in the rat liver from wk 2 to mo 6 in the Retrorsine group and from wk 2 to 6 in the 2-acetaminofluorene group. Human albumin and its mRNA contents as well as the number of PCNA positive cells reached a peak at wk 4.

CONCLUSION: L02 human hepatocytes could not proliferate significiantly after transplantation to the normal, immunocompetent rats treated with 2-acetaminofluorene. L02 human hepatocytes can survive for 10 wk after transplantation and express human albumin for 8 wk. L02 human hepatocytes can proliferate and express human albumin for 6 mo after transplantation to the rats treated with Retrorsine. The chimeric L02 human hepatocytes, which then underwent transplantation into tolerant rats, were normal in morphogenesis, biochemistry and function.

A review of modern surgical hair restoration techniques

The field of hair restoration has had a chequered history. From the days of punch grafting to the present day techniques of follicular unit hair transplantation, the field has seen a number of new advances. This article reviews these developments.

Role of color Doppler sonography in post-transplant surveillance of vascular complications involving pancreatic allografts()

PURPOSE

To evaluate the role of color Doppler ultrasonography in the postoperative surveillance of the vascular complications involving pancreas allografts.

METHODS

A retrospective analysis of a consecutive series of 223 pancreas transplantations was performed. All recipients received antithrombotic prophylaxis, which was tailored to the individual's estimated risk of thrombosis. All patients were monitored with daily color Doppler ultrasonography during the first post-transplant week and thereafter whenever clinically indicated. Vascular complications were defined as all thrombotic events requiring: increased anticoagulant therapy, angiography with fibrinolytic therapy, or repeat surgery.

RESULTS

The overall patient survival rates at one, three, and five years after transplantation were 94.7%, 93.3%, and 91%, respectively. The overall graft survival rates at the same time points were 87.4%, 79.6%, and 75.6%, respectively. In 28 of the 223 cases (12.5%) graft thromboses were diagnosed with Doppler ultrasound within the first 10 days after transplantation. In 3 cases, graft pancreatectomies were performed because of a complete loss of blood flow in the parenchyma. An attempt to rescue the graft was made in 18 patients. Fourteen of these grafts were saved and are still functioning (77.7%); and 4 rescue attempts failed and the grafts were subsequently explanted (32.3%).

CONCLUSION

Color Doppler ultrasound is a suitable tool for postoperative surveillance of pancreas transplant recipients. Its use can lead to early diagnosis and timely treatment of vascular complications.

Relationship between acute rejection after heart transplantation and protein expression of perforin and granzyme B

AIM: To investigate the relationship between acute rejection after heart transplantation and protein expression of perforin and granzyme B in organ recipients.

METHODS: All ventral heterotopic cardiac transplantation models were divided into three groups: rejection, treated, and isograft (20 recipients in each). Mean survival time (MST), histopathological changes, and protein expression of perforin and granzyme B in spleen lymphocytes were measured by Western blotting. Immunofluorescence techniques were used to determine the graft expression of perforin and granzyme B.

RESULTS: MST of heart allografts in the rejection and treated groups was 7.8 ± 0.77 d and 14.80 ± 1.01 d, respectively. Graft survival time in the isograft group was > 28 d, The differences between the three groups were statistically significant. The number of infiltrating cells in the rejection group, most of which were positive for perforin and granzyme B protein expression, was much higher than that in the other groups, as was the extent of the histopathological changes. Seven days after transplantation, compared with those in the treated group and isograft group, perforin protein expression in recipient spleen lymphocytes in the rejection group increased by 3.02-fold and 4.13-fold, while granzyme B protein expression increased by 3.44-fold and 2.50-fold, respectively.

CONCLUSION: Perforin and granzyme B can serve as a diagnostic index for acute rejection after transplantation.

Hyperplastic Polyposis following Treatment of Gastric Vascular Ectasia: A Case Report and Review of Clinical Correlates

The etiology of gastric antral vascular ectasia (GAVE) and hyperplastic polyps (HP) is not fully understood, but there is no known overlap. We report a case of gastroduodenal HP arising in a patient treated for GAVE.

Reversal of hyperglycemia in diabetic rats by portal vein transplantation of islet-like cells generated from bone marrow mesenchymal stem cells

AIM: To study the capacity of bone marrow mesenchymal stem cells (BM-MSCs) trans-differentiating into islet-like cells and to observe the effect of portal vein transplantation of islet-like cells in the treatment of streptozotocin-induced diabetic rat.

METHODS: BM-MSCs were isolated from SD rats and induced to differentiate into islet-like cells under defined conditions. Differentiation was evaluated with electron microscopy, RT-PCR, immunofluorescence and flow cytometry. Insulin release after glucose challenge was tested with ELISA. Then allogeneic islet-like cells were transplanted into diabetic rats via portal vein. Blood glucose levels were monitored and islet hormones were detected in the liver and pancreas of the recipient by immunohistochemistry.

RESULTS: BM-MSCs were spheroid adherent monolayers with high CD90, CD29 and very low CD45 expression. Typical islet-like cells clusters were formed after induction. Electron microscopy revealed that secretory granules were densely packed within the cytoplasm of the differentiated cells. The spheroid cells expressed islet related genes and hormones. The insulin-positive cells accounted for 19.8% and mean fluorescence intensity increased by 2.6 fold after induction. The cells secreted a small amount of insulin that was increased 1.5 fold after glucose challenge. After transplantation, islet-like cells could locate in the liver expressing islet hormones and lower the glucose levels of diabetic rats during d 6 to d 20.

CONCLUSION: Rat BM-MSCs could be transdiffe-rentiated into islet-like cells in vitro. Portal vein transplantation of islet-like cells could alleviate the hyperglycemia of diabetic rats.

Clinical management of patients with recurrent viral hepatitis after liver transplantation

Liver transplantation is indicated in end-stage chronic viral liver disease, but unless adequate prophylaxis is administered, the patient will in most cases develop recurrent hepatitis B (HBV) and C (HCV) virus infection. Today, patients receiving prophylaxis using nucleoside analogue drugs with or without specific immune globulin drugs in connection with orthotopic liver transplantation for HBV related cirrhosis, present low risk of relapse and high 5-10 year survival rates. Lamivudine was the first drug used in the prophylactic treatment, but this drug has increasingly been combined with or replaced by adefovir due to the low genetic barrier, which causes viral resistance. Most patients develop viral recurrence after orthotopic liver transplantation for HCV related cirrhosis, and in an elevated number of cases, cirrhosis and hepatic insufficiency set in after a few years. Prophylaxis before transplantation and pre-emptive treatment using interferon and ribavirin present numerous side effects resulting in reduction of doses and suspension of therapy, with consequently low sustained virological remission rates and risk of rejection.The treatment is better tolerated by patients with histologically confirmed chronic disease, but also in these patients virological remission rates are low. This pathology requires new therapeutic protocols and/or new drugs in order to obtain better compliance and better responses.

Contribution of mononuclear bone marrow cells to carbon tetrachloride-induced liver fibrosis in rats

AIM: To study the inhibitory effect of mononuclear bone marrow cell (BMC) transplantation on carbon tetrachloride (CCl₄) -induced liver fibrosis in rats.

METHODS: Rat liver fibrosis models were induced by CCl₄ and alcohol administration. After 8 wk, twenty rats were randomly allocated into treatment group (n = 10) and control group (n = 10). BMC were infused into the rats in treatment group via the portal vein, while heparinized saline was infused in control group. CCl₄ was hypodermically injected into the rats twice a week for 4 wk. At the end of wk 12, all rats were humanely sacrificed. Liver samples were taken and stained with HE or Masson trichrome. The general conditions, liver fibrosis (hydroxyproline and collagen fibre) and liver pathological grades in rats were evaluated.

RESULTS: The general conditions of the rats in treatment group improved markedly, but not in control group. Hydroxyproline was 504.6 ± 128.8 μg/g in treatment group, and 596.0 ± 341.8 μg/g in control group. The percentage of collagen fibre was 3.75% ± 0.98% in treatment group and 5.02% ± 0.44% in control group. There was a significant difference between the two groups (P < 0.05). Liver pathological grade decreased from grade IV to grade III partially in treatment group (P < 0.05) with no obvious improvement in control group (P > 0.05). There was a significant difference between treatment group and control group (P < 0.05).

CONCLUSION: Transplantation of BMC can improve liver fibrosis due to chronic liver injury in rats.

Beneficial effect of an antibody against interleukin-2 receptor (daclizumab) in an experimental model of hepatocyte xenotransplantation

AIM: To investigate the use of Daclizumab (Dmab) as an immunosuppressive agent in an experimental model of hepatocyte xenotransplantation (XenoTx) in rats with fulminant hepatic failure (FHF).

METHODS: Two white male New Zealand rabbits were used as donors and 68 Wistar rats as recipients. FHF was induced by intravenous application of dimethylnitrosamine (DMNA). The isolated hepatocytes of the rabbits were xenotransplanted into the spleen of the rats 24 h after FHF induction. Group A (n = 13): no treatment; Group B (n = 14): FHF and XenoTx; Group C (n = 14): FHF and XenoTx and cyclosporin (CsA); Group D (n = 14): FHF and XenoTx and Dmab; Group E (n = 13): FHF and XenoTx and CsA and Dmab. The rats were followed for 15 d.

RESULTS: Statistical analysis showed better survival among groups D (92.86%) and E (76.92%) compared to group A (all rats died after 72 h), group B (28.57%) or group C (71.43%), although the differences were not statistically significant. Biochemical evaluation of the liver enzymes and histology confirmed satisfactory function and engraftment, respectively.

CONCLUSION: This experimental model has shown the safe, effective and beneficial use of Dmab in a xenotransplantation model of rabbit hepatocytes in rats.

Differentiation into hepatocytes and transplantation of bone marrow stromal stem cells

AIM: To investigate the differentiation of bone marrow stromal stem cells (BMSCs) into hepatocytes in vitro and the reparation of liver cells after BMSCs transplantation in mice with liver injury.

METHODS: BMSCs were induced by hepatic extract fluid (HE) to differentiate into hepatocytes in vitro, which was identified by immunocytochemistry and Indocyanine green (ICG) staining. The BrdU-labeled BMSCs were transplanted into the mice through caudal vein, and then the their distributions were detected by immunohistochemistry. The concentration changes of aspartate aminotransferase (AST, nkat/L), alanine aminotransferase (ALT, nkat/L) and alkaline phosphatase (AKP, nkat/L) were observed by serum enzymology test on the 7^th, 14^th, 28^th day after transplantation.

RESULTS: BMSCs were differentiated into hepatocytes under the induction of HE in vitro, but the expression levels of α1-antitrypsin (4 d: 52.5 ± 3.9 vs 76.8 ± 4.5, P < 0.05; 14 d: 60.3 ± 6.1 vs 85.4 ± 7.6, P < 0.05; 21 d: 80.5 ± 8.0 vs 105.7 ± 8.6, P < 0.05) and albumin (4 d: 43.2 ± 6.5 vs 71.6 ± 7.6, P < 0.05; 14 d: 61.5 ± 10.4 vs 93.6 ± 13.9, P < 0.05; 21 d: 80.6 ± 17.1 vs 128.3 ± 22.2, P < 0.05) in the HE-induced cells were significantly higher than those in the hepatic growth factor-induced ones. It was found that the transplanted BMSCs slowly transferred from the portal area to liver parenchyma, and fused with liver cells. The serum concentration of ALT (7 d: 493.43 ± 120.02 vs 696.81 ± 140.03, P < 0.01; 14 d: 558.45 ± 130.03 vs 780.16 ± 151.7, P < 0.01; 28 d: 583.45 ± 138.36 vs 880.18 ± 170.53, P < 0.01), AST (7 d: 1521.97 ± 186.7 vs 2342.14 ± 208.38, P < 0.01; 14 d: 1590.32 ± 200.04 vs 2692.21 ± 238.38, P < 0.01; 28 d: 1625.33 ± 208.38 vs 2872.24 ± 281.72, P < 0.01) and AKP (7 d: 1.24 ± 0.22 vs 1.78 ± 0.18, P < 0.01; 14 d: 1.21 ± 0.21 vs 2.00 ± 0.19, P < 0.01; 28 d: 1.32 ± 0.19 vs 2.27 ± 0.20, P < 0.01) were lower in the transplanted group than those in liver-injury group, but still higher than those in the normal controls.

CONCLUSION: BMSCs can differentiate into hepatocytes under the induction of HE in vitro, and the transplantation of BMSCs can be helpful in the repair of injured liver in mice.

Repopulation of human L02 hepatocytes in tolerant rats treated with retrorsine

AIM: To investigate whether human L02 hepatocytes can repopulate after transplantation into the normal and immunocompetent rats treated with retrorsine.

METHODS: Human L02 hepatocytes were injected into the peritoneal cavities of fetal Sprague Dawley rats to induce immune tolerance. The 3-week-old rats were injected with retrorsine or normal saline. After DiI (1, 1′-dioctadecyl-3, 3, 3′, 3′-tetramethylindocarbocyanine perchlorate) staining, L02 hepatocytes were transplanted into the 7-week-old rats via the spleen. Immunofluorescent staining, reverse transcription-polymerase chain reaction (RT-PCR), S-P immunohistochemistry, and DiI staining were used to detect human albumin, human albumin mRNA and specific proliferating cell nuclear antigen (PCNA) in rat livers. The distribution of human L02 hepatocytes was observed under fluorescent microscope. The number density and area density of PCNA were obtained with the help of computer-assisted image analyzer.

RESULTS: Dynamic distribution of human L02 hepatocytes in rat livers was observed from the 1^st week to 6^th month after transplantation, but it was from the 1^st to 10^th week in the controls. Human albumin and albumin mRNA (241 bp) were detected from the 2^nd week to the 6^th month after transplantation, but they could only be detected from the 1^st to 8^th week in the controls. The highest expression of human albumin and albumin mRNA appeared at the 4^th week. Specific human PCNA was detected in rat livers from the 2^nd week to the 6^th month after transplantation, but it could only be examined from the 2^nd to 6^th week in the controls. The number of PCNA-positive cells reached the peak at the 4^th week. The number density and area density of PCNA were significantly different between specific PCNA group and its control group (P < 0.05).

CONCLUSION: Retrorsine is able to promote the repopulation of transplanted human L02 hepatocytes, and L02 hepatocytes can survive more than 6 months, and repopulate at the same time.

Role of ischaemic preconditioning in liver regeneration following major liver resection and transplantation

Liver ischaemic preconditioning (IPC) is known to protect the liver from the detrimental effects of ischaemic-reperfusion injury (IRI), which contributes significantly to the morbidity and mortality following major liver surgery. Recent studies have focused on the role of IPC in liver regeneration, the precise mechanism of which are not completely understood. This review discusses the current understanding of the mechanism of liver regeneration and the role of IPC in this setting. Relevant articles were reviewed from the published literature using the Medline database. The search was performed using the keywords “liver”, “ischaemic reperfusion”, “ischaemic preconditioning”, “regeneration”, “hepatectomy” and “transplantation”. The underlying mechanism of liver regeneration is a complex process involving the interaction of cytokines, growth factors and the metabolic demand of the liver. IPC, through various mediators, promotes liver regeneration by up-regulating growth-promoting factors and suppresses growth-inhibiting factors as well as damaging stresses. The increased understanding of the cellular mechanisms involved in IPC will enable the development of alternative treatment modalities aimed at promoting liver regeneration following major liver resection and transplantation.

Research progress of human hepatocellular carcinoma models in nude mice

Animal models, which can factually simulate the natural growth, invasion, and metastasis in vivo, are needed in basic and clinical research on liver cancer. At present, nude mice with transplanted human hepatocellular carcinoma are the best models of human liver cancer in vitro, and it takes less time to establish the model, with a higher success rate. Mouse model of human hepatocellular carcinoma can be obtained by subcutaneous transplantation, in situ transplantation, and intraperitoneal transplantation. Metastasis model was also one of them. The following aspects, including the characteristics of human hepatocellular carcinoma cells or surgical specimens, transplanted location, numbers of the transplanted cells, strains and week age of nude mice, and growing environment, etc, are the influential factors for the establishment of this model.

Comparison between numbers of bone marrow stem cells migrated to liver after infusion into portal vein and caudal vein

AIM: To explore the amount of bone marrow mononuclear cells migrating to the liver during allografting in mice.

METHODS: Bone marrow stem cells were isolated from the bone marrow of mice by lymphocyte separation medium and labeled with PKH26. The labeled cells were subsequently infused into the caudal or portal veins of different mice with homogeneity, in which hepatic injury was induced by carbon tetrachloride and 2-acetylminofluorene. Two weeks after transplantation, the migration status of the cells was studied by fluorescence microscopy.

RESULTS: Liver cells were found at portal region and central veins of hepatic lobules in all the mice. The PKH26 labeled cells appeared at an average frequency of 175.4 per section from the livers of mice received transplantation via portal veins, and at an average frequency of 172.9 per section from the livers of mice underwent transplantation via caudal veins. There was no significant difference between them (P > 0.05).

CONCLUSION: Bone marrow stem cells are able to migrate to liver, the numbers of which have no correlation with the approach of transplantation.