Impact of the novel coronavirus infection on pediatric surgery: an analysis of data from the National Clinical Database.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic limited the delivery of medical resources. Although surgeries are triaged according to disease severity and urgency, a delay in diagnosis and surgery can be detrimental. We conducted this study to analyze data on the impact of the COVID-19 pandemic on pediatric surgery for different diseases or disorders. METHODS: We compiled and compared data on pediatric surgical cases from 2018 to 2020, using the National Clinical Database. The number of diseases, severity, complication rates, mortality rates by disease/disorder, and the COVID-19 pandemic areas were analyzed. RESULTS: The total number of cases of pediatric surgery in 2018, 2019, and 2020 was 50,026, 49,794, and 45,621, respectively, reflecting an 8.8% decrease in 2020 from 2018 and an 8.4% decrease in 2020 from 2019. A decrease was observed when the number of patients with COVID-19 was high and was greater in areas with a low infection rate. There was a marked decrease in the number of inguinal hernia cases. The number of emergency room visits and emergency surgeries decreased, but their relative proportions increased. CONCLUSIONS: The COVID-19 pandemic decreased the number of pediatric surgeries, reflecting the limitations of scheduled surgeries and infection control measures.

Neonatal gastrointestinal perforation in Japan: a nationwide survey.

PURPOSE: The purpose of this study is to identify the current clinical features of neonatal gastrointestinal perforation in Japan. METHODS: A questionnaire about cases of neonatal gastrointestinal perforation treated in recent 5 years was sent to participating institutions of the Japanese Society of Pediatric Surgeons (JSPS). RESULTS: Five hundred and thirty-six neonates with gastrointestinal perforation were treated. They consisted of 42 patients with gastric rupture/perforation (GR), 33 patients with intestinal atresia/stenosis (IA), 3 patients with malrotation (ML), 118 patients with necrotizing enterocolitis (NEC), 160 patients with focal intestinal perforation (FIP), 46 patients with meconium-related ileus (MRI), 77 patients with meconium peritonitis (MP), and 57 patients with other conditions. The total mortality rate was 20.5 %. The mortality rates of the patients with GR, IA, ML, NEC, FIP, MRI, and MP were 9.5, 9.1, 0, 33.1, 20.6, 28.2, and 9.1 %, respectively. In 263 cases involving extremely low-birth-weight neonates (ELBW), 108 died (mortality rate 41.1 %). The mortality rates for ELBW with GR, NEC, FIP, MRI, MP, and other conditions were 27.3 % (3/11), 58.5 % (48/82), 21.6 % (24/111), 70.6 % (24/34), 57.1 % (4/7), and 27.8 % (5/18), respectively. CONCLUSIONS: The mortality rates for ELBW decreased from 62.8 % in the previous survey to 41.1 % by the time of this survey.

Surgical closure of the larynx for intractable aspiration pneumonia: cannula-free care and minimizing the risk of developing trachea-innominate artery fistula.

There is a risk of developing a fatal trachea-innominate artery fistula following laryngotracheal separation for the prevention of intractable aspiration pneumonia. We developed a novel technique of surgical closure of the larynx to avoid this complication and provide long-term cannula-free care.

Efficient Gene Transduction of Dispersed Islet Cells in Culture Using Fiber-Modified Adenoviral Vectors.

To establish novel islet-based therapies, our group has recently developed technologies for creating functional neo-islet tissues in the subcutaneous space by transplanting monolithic sheets of dispersed islet cells (islet cell sheets). Improving cellular function and viability are the next important challenges for enhancing the therapeutic effects. This article describes the adenoviral vector-mediated gene transduction of dispersed islet cells under culture conditions. Purified pancreatic islets were obtained from Lewis rats and dissociated into single islet cells. Cells were plated onto laminin-5-coated temperature-responsive polymer poly(N-isopropylacrylamide)-immobilized plastic dishes. At 0 h, islet cells were infected for 1 h with either conventional type 5 adenoviral vector (Ad-CA-GFP) or fiber-modified adenoviral vector (AdK7-CA-GFP) harboring a polylysine (K7) peptide in the C terminus of the fiber knob. We investigated gene transduction efficiency at 48 h after infection and found that AdK7-CA-GFP yielded higher transduction efficiencies than Ad-CA-GFP at a multiplicity of infection (MOI) of 5 and 10. For AdK7-CA-GFP at MOI = 10, 84.4 ± 1.5% of islet cells were found to be genetically transduced without marked vector infection-related cellular damage as determined by viable cell number and lactate dehydrogenase (LDH) release assay. After AdK7-CA-GFP infection at MOI = 10, cells remained attached and expanded to nearly full confluency, showing that this adenoviral infection protocol is a feasible approach for creating islet cell sheets. We have shown that dispersed and cultured islet cells can be genetically modified efficiently using fiber-modified adenoviral vectors. Therefore, this gene therapy technique could be used for cellular modification or biological assessment of dispersed islet cells.

Prognostic value of peripheral and local forkhead box P3+ regulatory T cells in patients with non-small-cell lung cancer.

Several types of immunosuppressive mechanisms in cancer patients have been reported to date. Regulatory T cells (Tregs), which express the master control transcription factor forkhead box P3 (FoxP3), are considered to play a major role in hampering antitumor immune response. However, the clinical significance of Tregs in patients with lung cancer has not been fully elucidated. The aim of this study was to investigate the clinical significance of Tregs in the peripheral blood and in resected cancer tissue specimens. We analyzed peripheral blood mononuclear cells (PBMCs) collected prior to surgery and resected specimens obtained from 67 patients with non-small-cell lung cancer (NSCLC). Peripheral Tregs (pTregs) were detected as CD4+ and FoxP3+ cells by flow cytometry. Immunohistochemical staining for CD4, CD8 and FoxP3 expression was also performed quantitatively by analyzing three randomly selected fields from central regions (cCD4, cCD8 and cFoxP3) and interstitial regions of the tumors (iCD4, iCD8 and iFoxP3). The associations between the expression frequencies in selected cells and clinicopathological parameters were statistically analyzed. The frequency of pTregs was found to be significantly higher in patients with pleural invasion (P=0.0049), vessel invasion (P=0.0009), lymphatic vessel invasion (P=0.0053) and recurrent disease (P=0.0112). Patients with T1 exhibited a significantly higher frequency of cCD4 (P=0.0199) and cCD8 (P=0.0058), although cFoxP3 expression was not significant (P=0.0935). Patients with low levels of cFoxP3/iFoxP3 exhibited a significantly higher frequency of pTregs (P=0.0338) and patients with a high frequency of pTregs exhibited significantly poorer recurrence-free survival (P=0.0071). The multivariate analysis identified pTreg frequency as an independent prognostic factor (P=0.0458). Although the pathological analysis remains controversial, the frequency of pTregs in NSCLC patients may be a useful prognostic biomarker.

Multiple therapeutic peptide vaccines consisting of combined novel cancer testis antigens and anti-angiogenic peptides for patients with non-small cell lung cancer.

BACKGROUND: Vaccine treatment using multiple peptides derived from multiple proteins is considered to be a promising option for cancer immune therapy, but scientific evidence supporting the therapeutic efficacy of multiple peptides is limited. METHODS: We conducted phase I trials using a mixture of multiple therapeutic peptide vaccines to evaluate their safety, immunogenicity and clinical response in patients with advanced/recurrent NSCLC. We administered two different combinations of four HLA-A24-restricted peptides. Two were peptides derived from vascular endothelial growth factor receptor 1 (VEGFR1) and 2 (VEGFR2), and the third was a peptide derived from up-regulated lung cancer 10 (URLC10, which is also called lymphocyte antigen 6 complex locus K [LY6K]). The fourth peptide used was derived from TTK protein kinase (TTK) or cell division associated 1 (CDCA1). Vaccines were administered weekly by subcutaneous injection into the axillary region of patients with montanide ISA-51 incomplete Freund's adjuvant, until the disease was judged to have progressed or patients requested to be withdrawn from the trial. Immunological responses were primarily evaluated using an IFN-gamma ELiSPOT assay. RESULTS: Vaccinations were well tolerated with no severe treatment-associated adverse events except for the reactions that occurred at the injection sites. Peptide-specific T cell responses against at least one peptide were observed in 13 of the 15 patients enrolled. Although no patient exhibited complete or partial responses, seven patients (47%) had stable disease for at least 2 months. The median overall survival time was 398 days, and the 1- and 2-year survival rates were 58.3% and 32.8%, respectively. CONCLUSION: Peptide vaccine therapy using a mixture of four novel peptides was found to be safe, and is expected to induce strong specific T cell responses. TRIAL REGISTRATION: These studies were registered with ClinicalTrials.gov NCT00633724 and NCT00874588.

A model to evaluate toxic factors influencing islets during collagenase digestion: the role of serine protease inhibitor in the protection of islets.

The recovery of all of the islets contained in a pancreas is the goal of islet isolation for transplantation. This study reveals an environment that injures the isolated islets during digestion and proposes a new model for optimal islet isolation. Islets were isolated from Wistar rat pancreases by stationary collagenase digestion while the digestion time was varied at 15, 30, 60, and 120 min. The digested pancreas and islets were analyzed histologically and adenosine nucleotides were measured. Overnight cultured islets (40 islets) were cocultured for 30 min with the supernatants obtained from pancreatic collagenase digestion at different digestion periods in order to assess the toxic environment. The peak yields of islets were obtained at 30 min of digestion. The histological study of digested pancreas showed that the exocrine cells lost their cellular integrity at 120 min of digestion, but the islet cells were left intact. Accordingly, the ATP levels of the pancreatic tissue decreased during the digestion period. The coculture experiment demonstrated that the islets cultured with the supernatants from the collagenase digestion showed digestion time-dependent disruption of the cellular integrity of islets in accordance with a rapid decrease of ATP levels in the islets. The addition of serine protease inhibitors into this coculture clearly showed protection of islets, which maintained high ATP levels in association with intact membrane integrity as assessed by AO/PI staining. Morphological deterioration of islets as well as a marked ATP decrease was evident in the entire digested pancreas as well as in islets cocultured in the supernatants from the collagenase digestion. Various factors toxic to the islets can therefore be analyzed in future experiments using this coculture model for obtaining a good yield of viable islets.

Adenine nucleotide levels in a closed enzymatic digestion system for porcine islet isolation.

Obtaining viable islets is a crucial step for successful islet transplantation. Adenosine triphosphate (ATP) is a marker of cell viability. However, little is known about any changes in the energy status of the tissues that are being digested during the digestion phase. We herein examined whether the ATP content in serially digested pancreatic tissue samples could be specific objective parameters that signal the optimal point to stop the digestion process. We obtained partial pancreata (body to tail) from 4- to 5-year-old pigs from a slaughterhouse. The tissue samples were preserved in M-Kyoto solution for less than 3 h. They were digested using an automated enzymatic and mechanical dissociation system at 37°C for 90 min following intraductal injection of Liberase HI. Samples were collected from the digestive circuit every 5 or 10 min to determine the ATP level, total adenine nucleotide (TAN) level, islet count (count/g), and yield of islet equivalent (IEQ) in the serial digestive fluids. The ATP and TAN levels, IEQ and islet count were increased and then decreased during digestion process. The profile of these parameters differed from case to case. However, when ATP changing ratio (respective value/precedent value) was compared with IEQ changing ratio, a greater than threefold increase in the ATP changing ratio followed by an increase in the islet count changing ratio within 5 min was consistently observed, indicating the optimal time to stop the digestion. The ATP levels of the handpicked islets in the digested samples were lower in the overdigested phase in comparison to those in the earlier digested phase. These results indicate that the ATP level in digested fluid could be an effective indicator to estimate the viability of cells as well as determine the optimal time to terminate the digestion process in order to obtain viable islets.

Mizoribine as sole immunosuppressive agent in islet xenotransplantation models: a candidate immunosuppressant causing no adverse effects on islets.

Mizoribine (MZ) inhibits the differentiation and proliferation of helper T and B cells after antigen recognition by suppressing the purine biosynthesis pathway and nucleic acid synthesis. MZ has been used in kidney transplantation, but distinct data are unavailable for islet transplantation. The present study investigated the efficacy of MZ for islet xenotransplantation. Immunosuppressive effects of MZ were determined by mixed lymphocyte reaction (MLR) assay in vitro. Toxicities for Wistar rat islets were determined by adenosine triphosphate (ATP) contents of islets during 3-day culture and stimulation index in response to glucose after culture. Immunosuppressive effects in vivo were tested in a Wistar-to-B6 islet xenotransplantation model. MZ was administered continuously for 28 days subcutaneously or intramuscularly. MZ inhibited MLR response by approximately 50% at 0.1 µg/ml. ATP contents decreased with MZ >100 µg/ml, while stimulation index was maintained. Continuous infusion of MZ at 10 mg/kg maintained blood concentrations at 0.13-0.19 µg/ml, while intramuscular injection of MZ at 100 mg/kg/day (peak 520 µg/ml at 1 h postinjection) resulted in below measurable levels (<0.03 µg/ml) within 24 h. Graft survival was significantly prolonged following continuous infusion of 10 mg/kg/day compared to controls (31.0 ± 9.5 vs. 13.2 ± 5.2 days; p = 0.002). Furthermore, animals with intramuscular injection at doses of 3.2, 10, or 100 mg/kg/day showed significantly longer graft survival (20.0 ± 7.5, 22.0 ± 7.31, and 24.5 ± 8.1 days, respectively; p < 0.05 each). Histological examination showed significant suppression of lymphocyte infiltration by MZ administration. MZ showed immunosuppressive effects in an experimental islet xenotransplantation model without adverse effects on endocrine function of islet grafts.

Preservation of pancreatic islets in cold UW solution before transplantation.

Culture of islets prior to transplantation needs to be revisited for maintaining functional islet capacity. This study was conducted to compare cold UW (University of Wisconsin) preservation with conventional culture based on insulin secretory capacity in vitro and in vivo. Islets isolated from Wistar rats were either cultured for 24 h at 37°C in RPMI1640 medium or DMEM containing various concentrations of glucose or preserved for the same period in UW solution or in DMEM solution at 4°C. The islet yield in UW group, but not in other groups, was maintained as comparable with that of fresh islets. Insulin secretory capacity in response to glucose was maintained only in the islets of UW group, but not in other groups. SCID mice given 300 IEQ islets of UW group showed gradual restoration of normoglycemia as found in the mice given freshly isolated islets. Meanwhile, those mice given cultured islets for 24 h at 37°C in RPMI1640 medium showed rapid decrease of blood glucose levels on day 1 followed by relatively elevated levels on day 2, suggesting unstable insulin secretory capacity of islets.   Morphological staining with anti-HMGB1 (high mobility group B1) antibody revealed central damage of islets in all culture groups regardless of glucose concentration and in islets of cold DMEM group, whereas those in the UW group were quite intact. These results suggest that cold preservation in UW solution is simple and beneficial in protecting islets morphologically and functionally before transplantation.

Mitomycin C treatment significantly reduces central damage of islets in culture.

OBJECTIVES: We recently reported that mitomycin C (MMC) treatment and subsequent culture of islets significantly prolongs graft survival in allotransplantation and xenotransplantation models. The present study was performed to determine the changes in morphology and signal transduction in pancreatic islets after MMC treatment. METHODS: Freshly isolated rat islets were treated with 10 µg/mL MMC for 30 minutes and then cultured for up to 3 days. The samples were processed for immunohistologic studies and electron microscopic examination at various times after treatment. A DNA fragmentation assay was performed to detect apoptotic cell death. Western blotting was performed to determine the effects of MMC on signal transduction. RESULTS: As early as 4 hours after culture, the islets showed central damage; most cells were necrotic and stained with anti-high mobility group box 1 antibody, and a few were apoptotic. The ratio of the damaged area to the whole area was significantly decreased after MMC treatment. Western blotting showed that MMC treatment increased the levels of activated forms of p53 and p21, whereas levels of the activated forms of Akt and caspase-3 were unchanged. CONCLUSIONS: Mitomycin C treatment protects islets from the progression of central damage during culture. The p53-p21 pathway might be involved in these effects. ABBREVIATIONS: MMC - mitomycin C, HMGB1 - high mobility group box 1.

Reversal of diabetes by the creation of neo-islet tissues into a subcutaneous site using islet cell sheets.

BACKGROUND: There remains a paucity of therapeutic approaches to completely treat diabetes mellitus. This study was designed to develop a dispersed islet cell-based tissue engineering approach to engineer functional neo-islet tissues in the absence of traditional bioabsorbable scaffold matrices. METHODS: Specialized coated plastic dishes were prepared by covalently immobilizing a temperature-responsive polymer, poly(N-isopropylacrylamide), onto the plastic followed by coating with laminin-5. Dispersed rat islet cells were plated on the laminin-5-poly(N-isopropylacrylamide) dishes. After 2 days of culturing, islet cells were harvested as a uniformly connected tissue sheet by lowering the culture temperature from 37°C to 20°C for 30 min. Two harvested islet cell sheets were transplanted into the subcutaneous space of streptozotocin-induced diabetic severe combined immunodeficiency (SCID) mice to engineer neo-islet tissues in vivo. Therapeutic effects were investigated after the tissue engineering procedures. RESULTS: In all of the diabetic SCID mice transplanted with the islet sheets, serum hyperglycemia was successfully reverted to a steady normoglycemic level. The recipient SCID mice demonstrated positive for serum rat C-peptide and elevated serum insulin levels. Moreover, the islet cell sheet-transplanted SCID mice demonstrated rapid glucose clearance and return of serum glucose levels after intraperitoneal glucose tolerance test. Histological examination revealed that the transplanted islet cell sheets were structured as flat clusters of islet tissues in which an active vascular network manifested within and surrounding the newly formed tissues. CONCLUSIONS: This study describes a new proof-of-concept therapeutic approach to engineer functional neo-islet tissues for the treatment of type 1 diabetes mellitus.

Bioengineering of a functional sheet of islet cells for the treatment of diabetes mellitus.

The present study was designed to establish a novel tissue engineering approach for diabetes mellitus (DM) by fabricating a tissue sheet composed of pancreatic islet cells for in vivo transplantation. Pancreatic islet cell suspensions were obtained from Lewis rats, and plated onto temperature-responsive culture dishes coated with extracellular matrix (ECM) proteins. After the cells reached confluency, islet cells cultured on laminin-5 coated dishes were successfully harvested as a uniformly spread tissue sheet by lowering the culture temperature to 20 degrees C for 20 min. The functional activity of the islet cell sheets was confirmed by histological examination and Insulin secretion assay prior to in vivo transplantation. Histological examination revealed that the harvested islet cell sheet was comprised of insulin- (76%) and glucagon- (19%) positive cells, respectively. In vivo functionality of the islet cell sheet was maintained even 7 days after transplantation into the subcutaneous space of Lewis rats. The present study describes an approach to generate a functional sheet of pancreatic islet cells on laminin-5 coated temperature-responsive dishes, which can be subsequently transplanted in vivo. This study serves as the foundation for the creation of a novel cell-based therapy for DM to provide patients an alternative method.

Mitomycin-C treatment followed by culture produces long-term survival of islet xenografts in a rat-to mouse model.

One of the goals of islet transplantation is to transplant viable islets without host immunosuppression. The present study was designed to determine whether pretreatment of islets with mitomycin-C (MMC) followed by culture enhances islet survival in a rat-to-mouse xenogeneic combination. WS(RT1k) rat islets pretreated with various concentrations of MMC (0, 3.2, 10, 32, 100, 320, and 1000 microg/ml) were tested for viability by in vitro insulin secretory capacity and vital staining of islets. The MMC-treated islets (10 microg/ml) cultured for various periods (4, 20, or 40 h, 3 or 7 days) were transplanted into the renal subcapsular space of STZ-induced diabetic C57BL/6 (B6: H-2b) mice. MMC-treated or nontreated islets were subjected to microarray gene analysis and immunohistological study. Evaluation of in vitro insulin secretory capacity and vital staining of islets indicated that MMC at a dose < or =32 microg/ml is nontoxic and preserves islet function. Marked prolongation of graft survival was noted with half of islet grafts surviving indefinitely (>100 days) when 10 microg/ml of MMC-treated islets was transplanted after 40 h or 3 days in culture, but not when they were transplanted within 4 h following treatment or at 7 days following treatment, indicating that there is a critical culture period necessary for successful islet graft survival. Microarray analysis suggested possible genes for this prolongation with TGF-beta highly expressed in MMC-treated islets subjected to culture for 3 days. Our results indicate that MMC treatment followed by a critical culture period induces marked prolongation of rat islet xenograft survival in nonimmunosuppressed recipient mice, offering a strategy for islet transplantation without immunosuppression.

Congenital esophageal stenosis because of tracheobronchial remnant and treated by circular myectomy: a case report.

Congenital esophageal stenosis (CES) is a rare anomaly, and appropriate management is not well established. We performed myectomy of the esophageal wall in a child with critical esophageal stenosis caused by tracheobronchial remnant (TBR). An 18-month-old boy was admitted to our hospital having frequent vomiting and failure to thrive. Esophagography and esophagoscopy showed abrupt stenosis at the lower esophageal wall. Balloon dilatation was performed but was ineffective. Surgery was performed under a diagnosis of CES because of TBR. Cartilage was palpable in the stenotic esophageal wall, and extirpation of the muscular layer of the stenotic portion was performed, leaving the mucosal layer intact. The muscular layer was closed loosely using interrupted 5-0 absorbable sutures to match the oral and anal sides together. Postoperatively, the esophageal passage was improved to the point that the patient was able to take solid foods without vomiting. This successful outcome suggests that circular myectomy of the TBR is worth recommending as a surgical procedure for short segment and stenosis of patients with CES because of TBR.

A case of rapidly expanding and increasing focal nodular hyperplasia.

We report a case of 14-year-old male patient who underwent bile-duct-to-jejunum anastomosis because of congenital biliary atresia at the age of 2 months. A 15 mm hypervascular nodule was detected for the first time in the S1 region of the liver at the age of 9 years. Two years later, 6 hypervascular nodules were found in the liver. A tumor biopsy was performed. It was diagnosed as a focal nodular hyperplasia (FNH). However, the number of nodules increased from 6 to 12 and those diameters were enlarged two to seven times one year later; the tumor biopsy was performed again. Histologically, the findings were consistent with those obtained previously, which indicated FNH. We consider that this is a very rare case of FNH in which both the number of nodules and the size were increased in a short period of time. We present it here as a valuable case report.

[Islet transplantation program in Japan].

In Japan, pancreas donation had been possible from cadaveric donors, either heartbeating or non-heart beating (NHB) donors. Pancreas allografts were distributed on organ allocation system of Japan Organ Transplant Network. Meanwhile, islet transplantation is categorized as tissue transplantation, and is free from legal restraints. Thus, pancreases for islet isolation should be obtained from NHB donors. Here, we report the starting program and preliminary results of islet transplantation in Japan. Selection and listing criteria for transplantation include regional priority, ABO blood type, previous islet transplant who can be insulin-independent, and a longer waiting time. Five institutes in Japan (Fukushima, Chiba, Kyoto, Kobe, and Fukuoka) are ready to start programs.

Survival of mitomycin C-treated pancreatic islet xenografts is mediated by increased expression of transforming growth factor-beta.

BACKGROUND: Mitomycin C (MMC) can trigger various intracellular signals. The authors previously showed that pretreatment of highly immunogenic crude pancreatic islets with MMC improved their survival in a rat-to-mouse transplantation model. The aim of this study was to investigate the role of transforming growth factor (TGF)-beta in mediating MMC-induced survival of islet xenografts. METHODS: : Collagenase-digested islets obtained from WS rats (RT1k) were incubated for 30 min with 10 microg/mL MMC and then transplanted into streptozotocin-induced diabetic C57BL/6 (H-2b) mice after 20 hr of culture at 37 degrees C. RESULTS: Survival of xenografts was enhanced by pretreatment of islets with MMC. MMC-treated xenografts showed a mild inflammatory cell response and significantly minimal infiltration of macrophages, CD4 T cells, and CD8 T cells compared with untreated grafts. TGF-beta mRNA was increased at 20 hr after MMC treatment, and TGF-beta protein expression was also increased compared with untreated islet xenografts. TGF-beta concentration in blebs formed around the xenografts (but not in the serum) was higher in animals that underwent transplantation with MMC-treated islets than with untreated islets. Simultaneous transplantation of MMC-treated and untreated islets separately in each kidney of recipient mice showed that protection was only found in MMC-treated islets. Treatment of islets before transplantation by neutralizing anti-TGF-beta antibody suppressed the MMC-protective effects on graft survival, whereas no such effect was noted with isotype-matched immunoglobulin. CONCLUSIONS: : The authors' results indicate that MMC treatment effectively reduces local inflammatory response and that such effects are mediated by increase of TGF-beta during the early period of islet transplantation.

Permanent acceptance of mitomycin C-treated islet allograft.

BACKGROUND: Mitomycin C (MMC) treatment produces genotoxic stress and exerts various biologic effects on cell function. This study determines the feasibility of MMC pretreatment of islet grafts as a sole immunomodulatory regimen to protect murine crude-digested islet allografts. METHODS: Collagenase-digested BALB/c (H-2d) islets were incubated for 30 min with MMC at different doses (0, 3.2, 10, 32, and 100 microg/mL; n=20, 15, 55, 15, 15, respectively), cultured for 20 hr, and transplanted into the renal subcapsular space of streptozotocin-induced diabetic C57BL/6 (B6; H-2b) mice. RESULTS: All mice that received MMC-treated islets showed restoration of normoglycemia within 5 days postgrafting, which was maintained until rejection. All untreated islets were acutely rejected with a mean survival time of 15.1+/-3.5 days. Significant prolongation of graft survival was noted in mice undergoing transplantation with islets treated with 10 microg/mL MMC compared with untreated islets (58.9+/-37.7 days, P<0.01). Notably, the grafts of 24 of 55 animals (43%) that received islets treated with 10 microg/mL MMC survived more than 100 days without any other treatment. Furthermore, antigen-specific prolongation of graft survival of secondary untreated islets was observed in mice bearing long-term functioning islet grafts. CONCLUSIONS: Our results indicate that pretreatment of islets with MMC alone protects the graft against rejection and produces long-term graft survival with normal blood glucose levels, and that pretreatment with MMC offers a new strategy for allogeneic islet transplantation.

Surgical management for intractable cholangitis in biliary atresia.

BACKGROUND/PURPOSE: The efficacy of antireflux surgical procedures involving the Roux-en-Y jejunal limb for cholangitis was evaluated retrospectively in patients with biliary atresia (BA). METHODS: From July 1993 to December 2001, 41 patients with BA underwent hepatic portojejunostomy with Roux-en-Y reconstruction. Of these patients, 11 had intractable cholangitis that was treated by creation of a value with or without lengthening of the Roux-en-Y limb. RESULTS: Among the 11 patients, the first episode of cholangitis occurred within 6 months after portojejunostomy in 10 patients and at the age of 4 years in one patient. Cholangitis developed at various intervals from once every week to once every 2 months requiring hospitalization each time. All patients underwent valve creation at 2 months to 5 years postoperatively, whereas 2 had an additional lengthening of the limb. Cholangitis resolved completely after surgery in all cases. Two patients underwent liver transplantation, and the third patient died of an unrelated cause. The 8 survivors with native livers are doing well after 1 to 8 years of follow-up. CONCLUSION: Early surgical intervention could control intractable cholangitis in all patients, both delaying the time of liver transplantation and improving the quality of life.