Surgical tricks of handling a needle and grasping forceps during laparoscopic percutaneous extraperitoneal closure (LPEC) for pediatric inguinal hernia

INTRODUCTION

Laparoscopic percutaneous extraperitoneal closure (LPEC) is an alternative to open repair for pediatric inguinal hernias; however, its application for boys remains controversial. In this study, we developed a technique to enhance the safety and feasibility of LPEC.

MATERIAL AND SURGICAL TECHNIQUE

In our technique, forceps are used to pull up the peritoneum ahead on the route, creating a space between the peritoneum and structures, including gonadal vessels and vas deferens. This potentially decreases the risk of perioperative injury of these structures. This technique also allows the needle to pass on the shortest course around the inguinal ring without crossing the vas deferens, possibly lowering the likelihood of injury and preventing excessively high ligation of the vaginalis process.

DISCUSSION

Our technique diversifies the LPEC methods, thereby augmenting the feasibility and safety of the procedure.

Efficacy of adhesive strapping on umbilical hernia in children: a systematic review and meta-analysis of cohort studies

Background

Although adhesive strapping (AS) for pediatric umbilical hernia (UH), which was once obsolete, has been reconsidered as a common practice in Japan, its efficacy is still unclear. This study aimed to evaluate its efficacy by reviewing related articles.

Methods

A comprehensive literature search of PubMed, Cochrane, Google Scholar, and Igaku Chuo Zasshi via Ichushi-Web was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Cohort studies reporting on the UH closure rate after AS compared with observation-only management were included.

Results

A total of 10 cohort studies were included, and the overall UH closure rate was not statistically significant (p=0.31, risk ratio (RR)=0.76, 95% confidence interval (CI) 0.45 to 1.28). However, there were significant differences in the UH closure rate at the age of 6 months (p<0.01, RR=0.55, 95% CI 0.41 to 0.75) and the efficacy of preventing protruding umbilici with redundant skin (p=0.049, RR=0.16, 95% CI 0.03 to 0.99).

Conclusions

Although the efficacy of AS on UH compared with observation-only management did not differ in terms of the UH closure rate, the application of AS may be effective for faster UH closure and the prevention of protruding umbilici. However, due to the high heterogeneity of the study, further large-scale studies, particularly randomized controlled trials, are warranted to reach a conclusion.

PROSPERO registration number

CRD42022314417.

Efficacy and safety of sclerotherapy with polidocanol in children with internal hemorrhoids

BACKGROUND

Hemorrhoids are an extremely rare condition in children, and data on its incidence and treatment in the pediatric population remains scarce. We retrospectively reviewed children who underwent sclerotherapy for internal hemorrhoids, and analyzed patients' characteristics and outcomes.

METHODS

A total of 14 pediatric patients who underwent sclerotherapy were included. Patients' ages and the required amount of polidocanol, depending on the grade of hemorrhoids, and the correlation between age and volume of sclerosant, were statistically analyzed.

RESULTS

Patients had a male predominance with a ratio of 2.5:1 (grade 2:6 patients, grade 3:8 patients). Four children had underlying conditions including portal hypertension and Klippel-Trenaunay syndrome. Of the 14 patients, 43% had constipation requiring medication or enema. Only one minor complication, a perianal ulceration, was found to be associated with sclerotherapy. Patients with grade 3 hemorrhoids required a significantly larger amount of polidocanol than those with grade 2 hemorrhoids. Two patients with grade 3 hemorrhoids required a second session of treatment for recurrence. The success rate of sclerotherapy with polidocanol was 86%.

CONCLUSIONS

Sclerotherapy with polidocanol is a safe, effective, and less invasive treatment option for internal hemorrhoids in children. Further studies are needed to investigate this treatment approach.

Definitive Tumor Resection after Myeloablative High Dose Chemotherapy Is a Feasible and Effective Option in the Multimodal Treatment of High-Risk Neuroblastoma: A Single Institution Experience

BACKGROUND/PURPOSE

The delayed local treatment approach (DL) in high-risk neuroblastoma (HR-NB) refers to the process in which tumor resection is performed after the completion of all the courses of chemotherapy, including myeloablative high-dose chemotherapy (HDC). Alternatively, in the conventional local treatment approach (CL), tumor resection is performed during induction chemotherapy. In this study, we compared the surgical outcomes in HR-NB patients treated by CL and DL.

METHOD

Forty-seven patients with abdominal HR-NB underwent primary tumor resection from 2002 to 2018. The timing of surgery was generally determined by following the trials and guidelines available at the time. The outcomes and surgical complications between the two strategies were compared.

RESULT

Operation time, blood loss, and postoperative WBC counts were lower in the DL group (n = 25) when compared to the CL group (n = 22), statistical significance notwithstanding. Major vascular structures were less frequently encased in the DL group tumors, while immediate surgical complications were significantly more frequent in the CL group (P < 0.05). Furthermore, the 3-year EFSs were 50.0% and 53.9% in the DL and CL groups, respectively.

CONCLUSION

DL appears to be a feasible and effective treatment option for HR-NB. Nonetheless, further verifications using larger cohorts are warranted.

LEVEL OF EVIDENCE

Treatment study, Level III.

Congenital high airway obstruction syndrome complicated with foregut malformation and high airway fistula to the alimentary tract – a case series with four distinct types

Background

Congenital high airway obstruction syndrome (CHAOS) is a rare disease and recently has been noticed to show typical prenatal images, such as hyperinflated lungs and flattened or inverted diaphragms. However, in some cases correct diagnosis may be difficult and in such cases the mortality rate increases.

Case presentation

We report four cases of CHAOS complicated with a high airway fistula to the alimentary tract and foregut malformation. The patients did not show the typical features of CHAOS in the fetus. This may be attributed to the high airway fistula acting as a decompression route for the accumulated lung fluids to the alimentary tract.

Conclusion

The combination of CHAOS, foregut malformation and a high airway fistula is very rare and classified into four distinct types: (1) CHAOS with a high airway fistula but not with a foregut malformation; (2) CHAOS with esophageal atresia and tracheoesophageal fistula; (3) CHAOS with a high airway fistula and duodenal atresia; and (4) CHAOS with esophageal atresia, tracheoesophageal fistula and duodenal atresia. It may be useful for treating physicians to be aware of these four distinct types and the typical characteristics of each type.

An investigation on clinical differences between congenital pulmonary airway malformation and bronchial atresia

BACKGROUND/PURPOSE

Differences in clinical features between congenital pulmonary airway malformation (CPAM) and bronchial atresia (BA) have not yet been clearly described.

METHODS

We retrospectively reviewed 112 patients with a pathological diagnosis of CPAM or BA. The clinical parameters were statistically analyzed between these diseases.

RESULTS

Seventy-one patients received prenatal diagnosis and 41 received postnatal diagnosis. The percentage of prenatal diagnosis was significantly higher in CPAM patients (84% vs 50%, p < 0.001). Among patients with prenatal diagnosis, the backgrounds were not different between the two diseases except for the number of Caesarean sections (81% vs 9%, p < 0.0001). The numbers of patients that underwent fetal interventions and emergent neonatal surgery were higher in CPAM (51% vs 15%, p < 0.01 and 76% vs 12%, p < 0.0001), although there was no statistical difference in survival rate (86% vs 97%, p = 0.2). In patients receiving postnatal diagnosis, pneumonia was the primary symptom in most BA patients, whereas respiratory distress was the major symptom in patients with CPAM. Age at presentation of the primary symptom was significantly older in BA patients (4.2 years vs 1.2 years, p < 0.005).

CONCLUSION

CPAM and BA have distinct clinical features in terms of therapeutic and natural history. Careful imaging evaluation and pathological analysis can lead to an accurate diagnosis of BA.

TYPE OF STUDY

Prognostic study.

LEVEL OF EVIDENCE

Level II. This study is categorized as a "Prognostic Study" with LEVEL III of Evidence.

Improving the electron spin properties of nitrogen-vacancy centres in nanodiamonds by near-field etching

The nitrogen-vacancy (NV) centre in diamond is a promising candidate for quantum computing applications and magnetic sensing applications, because it is an atomic-scale defect with stable coherence time (T2) and reliable accessibility at room temperature. We demonstrated a method for improving the NV spin properties (the full width half maximum (FWHM) value of the magnetic resonance spectrum and T2) through a near-field (NF) etching method under ambient conditions. The NF etching method, based on a He-Cd ultraviolet laser (325 nm), which is longer than the absorption edge of the oxygen molecule, enabled selective removal of defects on the nanodiamond surface. We observed a decrease in the FWHM value close to 15% and an increase in T2 close to 25%. Since our technique can be easily reproduced, a wide range of NV centre applications could be improved, especially magnetic sensing applications. Our results are especially attractive, because they have been obtained under ambient conditions and only require a light source with wavelength slightly above the O2 absorption edge.

Rapid immunosurveillance by recirculating lymphocytes in the rat intestine: critical role of unsulfated sialyl-Lewis X on high endothelial venules of the Peyer's patches

Naive lymphocytes systemically recirculate for immunosurveillance inspecting foreign antigens and pathogens in the body. Trafficking behavior such as the migration pathway and transit time within the gastrointestinal tract, however, remains to be elucidated. Rat thoracic duct lymphocytes (TDLs) were transferred to a congeneic host that had undergone mesenteric lymphadenectomy. The migration pathway was investigated using newly developed four-color immunohistochemistry and immunofluorescence. Donor TDLs showed rapid transition in gut tissues from which they emerged in mesenteric lymph around 4 h after intravenous injection. Immunohistochemistry showed that donor TDLs predominantly transmigrated across high endothelial venules (HEVs) at the interfollicular area of the Peyer's patches (PPs), then exited into the LYVE-1+ efferent lymphatics, that were close to the venules. The rapid recirculation depended largely on the local expression of unsulfated sialyl-Lewis X on these venules where putative dendritic cells (DCs) were associated underneath. Recruited naive T cells briefly made contact with resident DCs before exiting to the lymphatics in the steady state. In some transplant settings, however, the T cells retained contact with DCs and were sensitized and differentiated into activated T cells. In conclusion, we directly demonstrated that lymphocyte recirculation within the gut is a very rapid process. The interfollicular area of PPs functions as a strategically central site for rapid immunosurveillance where HEVs, efferent lymphatics and resident DCs converge. PPs can, however, generate alloreactive T cells, leading to exacerbation of graft-versus-host disease or gut allograft rejection.

Safety and efficacy of selective sac extraction method of inguinal hernia repair in children: results of a prospective study

PURPOSE

A prospective study was conducted to confirm the safety and efficacy of the selective sac extraction method (SSEM) of inguinal hernia repairs in children.

METHODS

Primary endpoints of the study were the incidence of any complication related to the SSEM, or hernia recurrence. Secondary endpoints included the success rate of the SSEM, length of incision at the end of operation, and duration of operation. The incidence of contralateral manifestation of hernia was also examined.

RESULTS

Between October 2009 and December 2011, a total of 317 repairs, 145 male repairs and 172 female repairs, were performed by applying the SSEM. There were three operative conversions, and the success rate of the SSEM was 99% in both male and female patients. The length of incision ranged from 4.0 to 12.5 mm (median 6.0 mm) and was ≤7.0 mm in 93% repairs. The incisional length for male repairs ranged from 4.0 to 12.5 mm (median 6.0 mm) and was ≤7.0 mm in 86% repairs, while it ranged from 4.0 to 9.0 mm (median 5.5 mm) in female repairs and was ≤6.5 mm in 96% repairs. The duration of the operation for unilateral repair ranged from 9 to 66 min (median 21 min). Eighty percent of repairs were examined 6-44 months (median 12 months) after the operation. There was one (0.4%) recurrence among 250 repairs and two (1.7%) cases of testicular dislocation among 115 male repairs. Contralateral hernia presented in 19 (9.5%) of 199 patients with unilateral hernia who underwent the follow-up.

CONCLUSIONS

The feasibility of the SSEM was reconfirmed, and it was revealed that the complication and recurrence rates were low and acceptable. The SSEM is safe and effective, and should be a standard method for repairing inguinal hernia in children.

Antimicrobial photodynamic therapy using a diode laser with a potential new photosensitizer, indocyanine green-loaded nanospheres, may be effective for the clearance of Porphyromonas gingivalis

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) is a new treatment method for the removal of infectious pathogens using a photosensitizer and light of a specific wavelength, e.g., toluidine blue with a wavelength of about 600 nm. We explored a new photosensitizer and focused on indocyanine green (ICG), which has high absorption at a wavelength of 800-805 nm. We investigated the bactericidal effect of PDT on Porphyromonas gingivalis using a new photosensitizer, ICG-loaded nanospheres with an 805 nm wavelength low-level diode laser irradiation.

METHODS

We designed ICG-loaded nanospheres coated with chitosan (ICG-Nano/c) as a photosensitizer. A solution containing Porphyromonas gingivalis (10(8)  CFU/mL) with or without ICG-Nano/c (or ICG) was prepared and irradiated with a diode laser or without laser irradiation as a negative control. The irradiation settings were 0.5 W with a duty ratio of 10%, for 3-100 ms in repeated pulse (RPT) or continuous wave mode. CFU were counted after 7 d of anaerobic culture.

RESULTS

We observed that ICG-Nano/c could adhere to the surface of P. gingivalis. When ICG-Nano/c was used for aPDT, irradiation with RPT 100 ms mode gave the lowest increase in temperature. Laser irradiation with ICG-Nano/c significantly reduced the number of P. gingivalis (i.e., approximately 2-log10 bacterial killing). The greatest bactericidal effect was found in the RPT 100 ms group. However, laser irradiation (RPT 100 ms) with ICG, as well as without photosensitizer, had no effect on the number of bacteria.

CONCLUSIONS

Within the limits of this study, ICG-Nano/c with low-level diode laser (0.5 W; 805 nm) irradiation showed an aPDT-like effect, which might be useful for a potential photodynamic periodontal therapy.

[Diagnosis and treatment of acute appendicitis in children]

In this review article, we discussed the pathogenesis, pathophysiology, diagnosis and treatment of acute appendicitis in children. Indications for early surgery, the operative methods of laparoscopic appendectomy and the treatment outcome are also presented.

Association of extrahepatic bile duct duplication with pancreaticobiliary maljunction and congenital biliary dilatation in children: a case report and literature review

We herein report a case of cystic-type congenital biliary dilatation (CBD) in whom an extremely rare anomalous duplication of the common bile duct and pancreaticobiliary maljunction were diagnosed intraoperatively by meticulous surgical manipulations via conventional open surgery. By performing a dissection at the outer epicholedochal layer of the cyst, a thin cord-like structure shown to be the distal part of the common bile duct was identified. A further exploration revealed that the most distal (extra- and intrapancreatic) part of the common bile duct was duplicated, and each branch of the duct was connected to the main and accessory pancreatic ducts. The experience with our case and a literature review showed that extrahepatic bile duct duplication is generally associated with pancreaticobiliary maljunction and CBD. We conclude that an extremely careful exploration with delicate and meticulous surgical manipulation is essential to identify these morphological anomalies and prevent intraoperative and postoperative complications of CBD, such as pancreatic duct injury or pancreatitis.

Experimental orthotopic lung transplantation model in rats with cold storage

This report describes a new experimental procedure, a rat unilateral, orthotopic lung transplantation with cold storage, and evaluates its relevancy and reliability to study the early events during cold ischemia/reperfusion (I/R) injury. This model, using the cuff technique, does not require extensive training and is relatively easy to be established. The model can induce reproducible degrees of pulmonary graft injury including impaired gas exchange, proinflammatory cytokine upregulation, or inflammatory infiltrates, depending on the preservation time. The results are consistent with the previous clinical evidence, thus suggesting that this model is a valid and reliable animal model of cold I/R injury.

Resident macrophages are involved in intestinal transplantation-associated inflammation and motoric dysfunction of the graft muscularis

Gut manipulation and ischemia/reperfusion evoke an inflammatory response within the intestinal muscularis that contributes to dysmotility. We hypothesize that resident macrophages play a key role in initiating the inflammatory cascade. Isogenic small bowel transplantation was performed in Lewis rats. The impact of recovery of organs on muscularis inflammation was investigated by comparing cold whole-body perfusion after versus prior to recovery. The role of macrophages was investigated by transplantation of macrophage-depleted gut. Leukocytes were counted using muscularis whole mounts. Mediator expression was determined by real-time RT-PCR. Contractility was assessed in a standard organ bath. Both organ recovery and ischemia/reperfusion induced leukocyte recruitment and a significant upregulation in IL-6, MCP-1, ICAM-1 and iNOS mRNAs. Although organ recovery in cold ischemia prevented early gene expression, peak expression was not changed by modification of the recovery technique. Compared to controls, transplanted animals showed a 65% decrease in smooth muscle contractility. In contrast, transplanted macrophage-depleted isografts exhibited significant less leukocyte infiltration and only a 19% decrease in contractile activity. In summary, intestinal manipulation during recovery of organs initiates a functionally relevant inflammatory response within the intestinal muscularis that is massively intensified by the ischemia reperfusion injury. Resident muscularis macrophages participate in initiating this inflammatory response.

Visceral coverage with absorbable mesh followed by split-thickness skin graft in the treatment of ruptured giant omphalocele

We report a case of ruptured giant omphalocele in whom herniated organs were successfully covered by an absorbable mesh and a subsequent skin graft. A 2,200 g male baby was born at 35 weeks of gestation. An abdominal wall abnormality was detected by prenatal ultrasound at 21 weeks of gestation. At birth, the entire liver, stomach, and small and large bowel had herniated from the defect of the abdominal wall. The thorax and abdomen were highly underdeveloped, and attempts to reduce the organs into the abdomen were unsuccessful due to the extremely small abdominal cavity and associated pulmonary hypoplasia. To protect the herniated organs and prevent abdominal infections, the organs were covered by a polyglycan mesh and subsequently a meshed split-thickness skin graft. Ten weeks later, it was confirmed that the organs were completely covered by epithelialized tissue. However, the patient suffered from frequent respiratory infections and finally died of respiratory insufficiency. Based on the experience of the patient, we conclude that coverage of the herniated organs with an absorbable mesh and a skin graft is a recommendable treatment in ruptured giant omphalocele.

Splenic autotransplantation for a congested and enlarged wandering spleen with torsion: report of a case

In children with diseases of the spleen, every effort should be made to preserve the organ, to prevent severe infections postsplenectomy. We report the case of a 7-year-old girl with torsion of a wandering spleen who we treated by autotransplantation of splenic tissues following splenectomy, when fixation of the enlarged spleen seemed impossible. Spleen scintigraphy showed uptake in the regenerating splenic tissues 9 months after surgery, and evidence of an increase in the size of the tissues 23 months after surgery. Howell-Jolly bodies had disappeared by 16 months after surgery. These findings suggested that the transplanted splenic tissues were resuming splenic functions. Based on our experience with this case, we conclude that autotransplantation after splenectomy is a treatment option for wandering spleen with torsion when fixation seems difficult because of splenic congestion and enlargement.

Efficacy of granulocyte apheresis in pediatric patients with ulcerative colitis: a pilot study

OBJECTIVES

Granulocyte apheresis (GCAP), involving the removal of granulocytes from the blood, may improve clinical symptoms and facilitate a reduction in the dose of steroids in adult patients with ulcerative colitis. As a preliminary trial, GCAP was used to taper the dose of steroids in 4 pediatric patients with ulcerative colitis.

METHODS

Three males and 1 female ranging from 11 to 17 years old were treated with GCAP once per week for 5 consecutive weeks/course. The ages of patients at clinical onset ranged from 8 to 12 years and the length of time from the clinical onset to GCAP treatment ranged from 28 to 58 months (median, 38.5 months).

RESULTS

In 2 patients, symptoms and signs indicating disease activity improved after 2 courses of GCAP. Laboratory data and endoscopic findings also improved after treatment and the clinical efficacy was judged to be excellent in these patients. In 1 patient, GCAP improved laboratory and endoscopic hallmarks, but bloody stools persisted. Finally, the treatment was ineffective in the fourth patient who eventually underwent surgery.

CONCLUSIONS

GCAP is effective in improving clinical symptoms and may play an important role in converting steroid therapy to other treatments in children with steroid-refractory or steroid-dependent ulcerative colitis.

Acute Rejection in Allogeneic Rodent Small Bowel Transplantation Causes Smooth Muscle Dysfunction via an Inflammatory Response Within the Intestinal Muscularis

INTRODUCTION

Isogeneic intestinal transplantation elicits an inflammatory response within the intestinal muscularis that is associated with dysmotility. Usually the inflammation and the postoperative motor dysfunction resolve within a few days after small bowel transplantation (SBTx). However, the onset of acute rejection in allogeneic SBTx is again associated with dysmotility. We hypothesized that dysmotility during acute rejection is based on coexpression of kinetically active mediators by the alloreactive leucocyte infiltrate.

MATERIALS AND METHODS

Rat SBTx (BN to Lew and BN to BN) was performed without immunosuppression. Animals were sacrificed at 1, 4, and 7 days after SBTx. Leukocyte infiltration was investigated in muscularis whole mounts by immunohistochemistry. Mediator mRNA expression was determined by reverse transcriptase polymerase chain reaction. Muscle contractility was assessed in a standard organ bath.

RESULTS

Transplanted animals showed a significant inflammatory response within the muscularis at day 1 after SBTx. However, allogeneic transplanted animals exhibited a significant second inflammatory peak at day 7 (mRNA induction: iNOS 150-fold; tumor necrosis factor-alpha 18-fold; interferon-gamma 397-fold), parallel to the onset of rejection. This change was associated with a significant leukocyte infiltration. Compared to controls, allogeneic transplanted animals showed a 29% decrease in smooth muscle contractility on days 1 and 4 and a 71% decrease of contractility on postoperative day 7.

CONCLUSIONS

The motor dysfunction of transplanted small bowel during acute rejection is associated with an inflammatory reaction in the intestinal muscularis. The initial unspecific inflammation process immediately after transplantation is reactivated and intensified during acute rejection.

Mechanism and Impact of Organ Harvesting and Ischemia-Reperfusion Injury Within the Graft Muscularis in Rat Small Bowel Transplantation

INTRODUCTION

Inflammatory events within the gut muscularis contribute to dysmotility. We hypothesized that manipulation during organ harvesting initiated an inflammatory response via muscularis macrophages and that this cascade was amplified during reperfusion.

METHODS

Small bowel transplantation was performed in Lewis rats. To investigate the impact of organ harvesting on muscularis inflammation, cold whole-body perfusion was performed after versus prior to organ harvesting. The role of macrophages was investigated by transplantation of the macrophage-depleted gut. Leukocyte infiltration was investigated in muscularis whole mounts. Mediator mRNA expression was determined by real-time reverse transcriptase polymerase chain reaction. Contractility was assessed in a standard organ bath.

RESULTS

Organ harvesting and ischemia-reperfusion induced leukocyte recruitment and mRNA upregulation in the muscularis: interleukin-6 12217-fold, monocyte chemoattractant protein-1 62-fold, ICAM-1 12-fold, cyclooxygenase-2: 8-fold, iNOS: 150-fold. Although organ harvesting with cold ischemia prevented early gene expression, peak expression at 3-hour reperfusion was not changed by modification of the harvesting technique. Compared to controls, transplanted animals showed a 63% decrease in smooth muscle contractility. In contrast, transplanted macrophage-depleted gut exhibited significantly fewer leukocytes and only a 16% decrease in contractility.

CONCLUSIONS

Gut manipulation during organ harvesting initiates an inflammatory response within the muscularis that is massively intensified during reperfusion. This change contributes to muscular dysfunction. Furthermore, the results suggested that resident macrophages play a key role in initiating this process.

Regeneration of the rat neonatal intestine in transplantation

OBJECTIVE

Based on development of stem cell technology, newborn tissue, even undergoing cryopreservation, possesses promising potential as a donor source in the field of organ transplantation. However, the precise regeneration processes remains unclear. This study was designed to investigate the regenerative potential of newborn intestine with or without cryopreservation in the transplantation.

METHODS

Newborn rat intestines with or without cryopreservation were transplanted subcutaneously into the syngeneic host, and specimens were evaluated by histology, multiple immunostaining, and comprehensive gene expression analysis.

RESULTS

We determined that newborn rat intestine possessed regenerative potential in the syngeneic host even after cryopreservation, where angiogenesis was induced early in the submucosa with subsequent maturation in the crypts. Furthermore, newborn intestinal graft could facilitate the survival of maturation-incompetent 10-day-old graft that lacked regenerating activity (P < 0.01, n = 13). Tissue aggregates from the maturation-incompetent graft underwent reconstitution of their histologic configuration in the presence of newborn intestinal aggregates. Comprehensive gene expression analysis showed that 37 genes were preferentially up-regulated, while 19 genes were down-regulated in the regenerating 10-day-old graft (supported by the newborn graft).

CONCLUSIONS

Regeneration of newborn intestine is implicated in neo-angiogenesis in the host, and the newborn intestinal graft is capable of mediating the survival of the maturation-incompetent 10-day-old graft. Notwithstanding ethical and legal limitations in the clinic, these results may provide new insights into the regenerative role of newborn grafts.

Immunologic Benefits of Longer Graft in Rat Allogenic Small Bowel Transplantation

BACKGROUND

The effect of graft length on rejection reaction in small bowel transplantation (SBT), which is poorly understood, is tested using rat allogenic SBT models with a short course of tacrolimus.

MATERIALS AND METHODS

Inbred Brown Norway rats (major histocompatibility complex: RT1) and Lewis rats (RT1) were used as donors and recipients, respectively. The intestinal tract of the recipient was partially or totally replaced by segmental (15 cm) or whole (70 cm) donor intestine, using two different SBT models. With tacrolimus treatment (0.64 mg/kg per day, 0-13 postoperative days, intramuscularly), recipients' body weights and their survival were evaluated. To compare the extent of peripheral chimerism, donor passenger leukocytes were followed using flow cytometry with a donor-specific monoclonal antibody, OX-27. For the periodical histologic analysis, heterotopic SBT and protocol biopsies of the graft were also performed with short or long intestinal grafts.

RESULTS

In a classical Monchik and Russell orthotopic SBT model, whole SBT recipients survived more than 60 days. However, all of the allogenic segmental SBT recipients died within 14 days without histologic sign of graft rejection. In the modified orthotopic SBT model using a cuff technique without systemic clamping, all recipients with segmental allograft survived longer than 29 days. However, recipients with whole graft tended to survive longer than those with segmental graft. The suffering period, lasting from the onset of rejection to death, was significantly shorter in the segmental group than in the whole group. Flow cytometric analysis showed that recipients with whole intestinal grafts had significantly higher ratio of donor passenger leukocytes in peripheral blood. Histologic studies of the protocol biopsies showed that the shorter graft tended to be more severely rejected than the longer graft.

CONCLUSIONS

We have demonstrated experimentally that long intestinal grafts have immunologic advantage over short grafts.

Effect of conversion from cyclosporine A to mizoribine on transplant arteriosclerosis in rat aortic allograft models

Recent studies suggested that conversion from cyclosporine A (CsA) to antimetabolic agents protects allograft vasculopathy. However, the mechanism of this beneficial effect by the conversion therapy is not fully understood. In the present study, we investigated the effects of conversion from CsA to antimetabolic agent mizoribine (MZR) on the formation of transplant arteriosclerosis in rat aortic allografts. Conversion from CsA to MZR significantly prevented intimal hyperplasia and perivascular inflammatory cell infiltration at 28 days after aortic transplantation. These findings suggest that conversion therapy from CsA to antimetabolic agents might have therapeutic potential in transplant patients with chronic vascular rejection.

Rat liver transplantation for total vascular reconstruction, using a suture method

We developed a novel protocol for rat orthotopic liver transplantation (OLT), using a suture method to establish hepatic artery flow. After determining that early inferior vena cava (IVC) unclamping maintained better circulation compared with the portal vein (PV) using porto-systemic shunted recipients, we developed a rat OLT model with total vascular reconstruction using a suture method. After connecting the suprahepatic IVC, the infrahepatic IVC was anastomosed, using a running suture method. IVC circulation was established immediately. The PV was anastomosed without intestinal congestion, using porto-systemic shunted recipients. The aortic conduit, including the donor celiac and hepatic artery, was anastomosed to the recipient abdominal aorta end-to-side. Eight of 11 OLT cases (72.7%) survived indefinitely. Biliary connection was achieved using a one-stent method. Three cases died 3-5 days postoperatively. Hepatic angiography showed good patency. The graft liver was histologically normal in long-surviving rats.

Indoleamine 2,3-Dioxygenase is Necessary for Cytolytic Activity of Natural Killer Cells

Indoleamine 2,3-dioxygenase (IDO) is a tryptophan catabolic enzyme that is widely distributed in various tissues. In peripheral blood mononuclear cells (PBMCs), production of IDO by macrophages or dendritic cells has been reported to inhibit T-cell activation and proliferation. In the present study, we have determined that other phenotypes of PBMCs also express IDO. In cultures of PBMCs, IDO was found predominantly in monocyte by immunohistochemistry. Reverse transcriptase polymerase chain reaction analysis showed that IDO mRNA was expressed in T lymphocytes, B lymphocytes and natural killer (NK) cells and that expression was increased upon activation with interferon-gamma. The cytotoxicity of NK cells against K562 and HepG2 cells was reduced by IDO inhibitor. These results suggest that IDO in NK cells is essential for NK cells to generate killing activity against cancer cells.

Long-lasting donor passenger leukocytes after hepatic and intestinal transplantation in rats

BACKGROUND

Donor passenger leukocytes (DPLs) that migrate after organ transplantation stimulate the recipient immune system and normally cause rejection and graft vs. host reaction. However, DPLs also contribute to the unresponsiveness to the donor organ. The quantity and quality of these migrating cells are considered dependent on individual transplanted organs. We compared the DPLs of the liver, which might contain somatic stem cells, with those of intestinal grafts that have highly immunogenetic cells. To study DPLs over a long period, we used green fluorescent protein (GFP) transgenic (Tg) rats developed by us as donors.

METHODS

We performed orthotopic liver transplantation (OLT) and small bowel transplantation (SBT) from GFP Tg rats to wild recipients. A short course of tacrolimus (0.64 mg/kg, intramuscularly) was used to prevent antigenicity of the GFP. The fate of the DPLs in the peripheral blood and the recipient bone marrow was monitored by flow cytometry. Using long-surviving recipients, the GFP(+) cells in the graft and various host immunologic organs were measured and characterized by immunohistochemical staining.

RESULTS

In both groups, the numbers of the GFP(+) cells in the peripheral blood increased transiently and then gradually decreased to undetectable levels. While no GFP(+) cells were identified in the long-surviving-recipient bone marrow, there were a few GFP(+) cells in the graft liver, graft mesenteric lymph nodes and the recipient spleen. These cells showed major histocompatibility complex (MHC) class II antigen. There was no significant difference in the migration patterns of the GFP(+) cells in the OLT and SBT rats.

CONCLUSIONS

In both the OLT and SBT groups, the DPLs migrated transiently in the recipient peripheral blood. A small numbers of MHC class II-positive DPLs were present at the graft site and in the host spleen, but not in the bone marrow. There were no significant differences in the migration patterns of the DPLs between the OLT and SBT rats over the long term.

DeltaFosB, but not FosB, induces delayed apoptosis independent of cell proliferation in the Rat1a embryo cell line

The fates of Rat1a cells expressing FosB and DeltaFosB as fusion proteins (ER-FosB, ER-DeltaFosB) with the ligand binding domain of human estrogen receptor were examined. The binding of estrogen to the fusion proteins resulted in their nuclear translocation and triggered cell proliferation, and thereafter delayed cell death was observed only in cells expressing ER-DeltaFosB. The proliferation of Rat1a cells, but not cell death triggered by ER-DeltaFosB, was completely abolished by butyrolactone I, an inhibitor of cycline-dependent kinases, and was partly suppressed by antisense oligonucleotides against galectin-1, whose expression is induced after estrogen administration. The cell death was accompanied by the activation of caspase-3 and -9, the fragmentation of the nuclear genome and cytochrome c release from the mitochondria, and was suppressed by zDEVD-fmk and zLEHD-fmk but not zIETD-fmk. The cell death was not suppressed by exogenous His-PTD-Bcl-x(L) at all, suggesting involvement of a Bcl-x(L)-resistant pathway for cytochrome c release.

Auxiliary partial liver grafting in rats: effect of host hepatectomy on graft regeneration, and review of literature on surgical technique

Auxiliary partial liver transplantation (APLT) is beneficial for fulminant liver failure when there is potential for recovery of the diseased liver. However, the impact of host hepatectomy on regeneration of the grafted liver is unclear. In this study, we modified a previous rat model of auxiliary whole liver transplantation without portal vein reconstruction, and studied the effect of host hepatectomy on regeneration of the cut liver graft. Thirty percent of the liver was heterotopically transplanted, to connect the recipient's left renal artery and vein with the graft's aortic cuff of the hepatic artery and inferior vena cava, respectively, using a cuff technique; 30% of the recipient liver then was cut. The control group was left intact. The liver grafts were weighed preoperatively and 2 weeks postoperatively. This procedure prevented congestion of the graft liver and achieved a high success rate, even when performed by a surgeon who was relatively inexperienced with the technique. The weight of the grafted liver in the host hepatectomized group significantly increased (P < 0.05) compared with that of the control group. We developed an experimental model of APLT and reviewed the literature on rat heterotopic liver transplantation, and compared the surgical techniques.