Expression of Pancreatic Endocrine Markers by Prolactin-Treated Rat Bone Marrow Mesenchymal Stem Cells

Background

Mesenchymal stem cells (MSCs) are an attractive source for generation of cells with β-cell properties. Previous studies have demonstrated the ability of prolactin to induce an increase in β-cell mass and maturation, which suggests beneficial effects of its use in MSC differentiation protocols.

Objective

To evaluate the expression of endocrine differentiation markers in rat MSCs treated in vitro with prolactin.

Methods

Mesenchymal stem cells from bone marrow of Wistar rats were isolated, expanded, and characterized. Differentiation of MSCs was induced in medium containing 23 mmol/L of glucose, and nicotinamide, 2-mercaptoethanol, and exendin-4, in the presence or absence of 500 ng/mL of rat recombinant prolactin. Expression of endocrine markers and prolactin receptor genes was evaluated using real-time polymerase chain reaction, and compared between culture stages and presence vs absence of prolactin in the culture medium. Expression of insulin, somatostatin, glucagon, and pancreatic and duodenal homeobox 1 was also evaluated at immunofluorescence microscopy.

Results

Isolated cells were mostly MSCs, as confirmed at fluorescent-activated cell sorting and cytochemistry. Pax6, Ngn-3, Isl1, NeuroD1, Nkx2.2, and Nkx6.1 exhibited varied expression during culture stages. The long form of the prolactin receptor messenger RNA was induced in prolactin-treated cultures (P < .05). The somatostatin gene was induced in early stages of differentiation (P < .05), and its expression was induced by prolactin, as confirmed using immunofluorescence.

Conclusion

Culture of rat bone marrow MSCs in differentiation medium induces expression of pancreatic endocrine-specific genes, and somatostatin and prolactin receptor expression was also induced by prolactin.     

Human cytokine expression profile in various conditioned media for in vitro expansion bone marrow and umbilical cord blood immunophenotyped mesenchymal stem cells

Introduction

Bone marrow (BM) represents the major source of mesenchymal stem cells (MSCs); however, umbilical cord blood (UCB) MSCs have some advantages over BM, such as a higher differentiation capability and noninvasive collection methods.

Objectives

We compared antigen expression and cytokine-secretion by MSC from BM and UCB expanded with media supplemented with fetal bovine serum (FBS) or human platelet lysate (HPL).

Materials and Methods

We compared protocols for the expansion of hMSC starting from samples of BM or UCB by morphological analysis, calculation of population doubling numbers, and cytometry techniques using monoclonal antibodies (BD Biosciences). Using the last technique, cytokines were detected in brain homogenate supernatant fluids of MSC cultured in various media, using the Bio-Plex cytokine assay system (BD Biosciences).

Results

Calculating the number population doubling (PD) and colony-forming unit-¹fibroblast (CFU-F) assays showed significantly better expansion with HPL compared with a selected batch of FBS and within fewer days: PD about 5 for 10%HPL versus 25 for fibroblast growth factor2 (FGF2) medium. By flow cytometry, we observed a greater number of BM MSCs compared with UCB MSCs, as well as differences in the expression of some MSC antigens, particularly CD105, CD90, and CD31. Analysis of cytokines: FGFb, RANTES, VEGF, IL-6, IL-8, G-CSF, and GM-CSF showed only some of them to be expressed: namely, IL-6, IL-8, and VEGF. MSCs derived from UCB showed low concentrations of these cytokines compared with MSCs derived from BM.     

Mesenchymal Stem Cells Treated With Rat Pancreatic Extract Secrete Cytokines That Improve the Glycometabolism of Diabetic Rats

Background

Mesenchymal stem cells (MSCs) under favorable conditions secrete a spectrum of cytokines that promote the survival of surrounding cells via paracrine mechanisms. We explored the impact of rat pancreatic extract (RPE) on cytokine secretion by MSCs and examined the influence of administration of conditioned media of MSCs treated with RPE on blood glucose levels in diabetic rats.

Methods

Cytokine levels (IGF-1, VEGF, bFGF) in conditioned media of MSCs treated with RPE were measured using enzyme-linked immunosorbent assays. We estimated blood glucose levels of STZ-induced diabetic rats following intraperitoneal injection of conditioned media from RPE-treated MSCs. We analyzed histopathology of pancreatic islets by insulin immunostaining and apoptosis through a TUNEL assay.

Results

Levels of IGF-1, VEGF, and bFGF were significantly increased in RPE-CM compared with control media. Administration of conditioned media of RPE-treated MSCs significantly lowered the blood glucose levels of diabetic rats. After RPE treatment the insulin-positive area was increased and apoptosis of pancreatic beta cells decreased.

Conclusion

RPE enhanced the secretion of cytokines by MSCs. MSCs in the pancreatic microenvironment may exert indirect salutary effects via paracrine mediators on injured pancreatic cells in an STZ-induced diabetic animal model. The secreted factors may exert their therapeutic benefits by preventing apoptosis of pancreatic beta cells.     

Effects of bone marrow stromal cells and umbilical cord blood-derived stromal cells on daunorubicin-resistant residual Jurkat cells

Objective

To observe the effects of the hematopoietic inductive microenvironment (HIM) simulated by stromal cells of different origins on daunorubicin-resistant residual Jurkat cells (Jurkat/DNR cells).

Methods

Jurkat/DNR cells were cultured and identified. Human umbilical cord blood-derived stromal cells (UCBDSCs) and normal human bone marrow stromal cells (BMSCs) were isolated and cocultured with Jurkat/DNR cells. Jurkat/DNR cells were collected after 14 days of coculture and analyzed with regard to cell proliferation and differentiation abilities, apoptosis, drug sensitivity, and MRD1 multidrug resistance gene mRNA expression.

Results

UCBDSC-simulated HIM suppressed proliferation and promoted apoptosis, differentiation, and drug sensitivity of Jurkat/DNR cells more significantly than BMSC-simulated HIM.

Conclusions

Both BMSCs and UCBDSCs reconstruct the leukemic HIM and reverse drug resistance in Jurkat/DNR cells. UCBDSCs reconstruct the leukemic HIM and reverse drug resistance more significantly than BMSCs.     

Typical carcinoids and neuroendocrine carcinomas of the stomach: differing clinical courses and prognoses

Background

Gastric endocrine tumors are usually classified as 3 types of well-differentiated endocrine tumors (typical carcinoids or carcinoids) and poorly differentiated carcinomas (neuroendocrine carcinomas [NECs]).

Methods

From 1993 to 2008, 97 patients (73 men and 24 women) were diagnosed with gastric neuroendocrine tumors at the Asan Medical Center.

Results

Of the 45 patients with typical carcinoids, 37 underwent surgery (eg, endoscopic resection). Of the 52 patients with NECs, 43 underwent surgery (eg, radical gastrectomy). One patient died of recurrence of the typical carcinoids, whereas 26 patients with NECs died of related diseases (P < .05). The rates of survival and recurrence did not significantly differ by type of typical carcinoid (P > .05).

Conclusions

Regardless of the type, carcinoids that are not yet advanced can be effectively treated with minimal endoscopic or laparoscopic surgery. However, all NECs and advanced carcinoids should be treated with radical gastrectomy.     

Portoumbilical Anastomosis as a Simple Method of Transient Portosystemic Shunt During Liver Transplantation

Background

This article describes a new method of transient intraoperative portosystemic shunting, Splachnic edema after portal cross-clamping can be a dangerous complication during the anhepatic phase of the liver transplant operation. The current method seeks to avoid this problem, without the use of external venovenous bypass pump, by a temporary portocaval shunt, with retrohepatic cava preservation as first described experimentally in dogs by Fonkalsrud et al in 1966.

Methods and Results

Among 227 liver transplant operations, we utilized a transient portosystemic shunt in 29 cases. The indication to perform a temporary shunt in all cases was the development of splachnic edema. In 3 instances, we performed a portoumbilical anastomosis using a prominent umbilical vein. The other 26 procedures employed the usual portocaval shunts. In these cases, splachnic congestion and onset of edema developed after cross-clamping of the round ligament and the portal vein, which resolved after the portoumbilical anastomosis.

Discussion

The flow in the shunt was in all cases greater than 1 L/min. The most important risk factor for the development of splachnic edema was the presence of a patent umbilical vein, which occurred in 34.5% of shunted patients.

Conclusion

The use of a patent umbilical vein to perform a portoumbilical shunt was an effective, easy method to decompress the splachnic area, avoiding dangerous congestion and edema.     

Antithymocyte Globulins Bind to Human Umbilical Vein Endothelial Cells

Objective

Polyclonal antithymocyte globulins (ATGs) are immunosuppressive agents used for the treatment of organ rejection after transplantation. ATGs induce complement-mediated cell death of T lymphocytes and may decrease leukocyte adhesion. However, little is known about their effects on endothelial cells (ECs). Our aim was to study whether they bind to human umbilical vein endothelial cells (HUVECs).

Materials and Methods

HUVECs obtained from umbilical cords were cultured and incubated with ATGs. A group incubated without ATG served as controls. All groups were coincubated with an anti-rabbit-IgG. Binding of ATGs to HUVECs was investigated by means of flow cytometry. Statistical analysis was performed using one-way analysis of variance (ANOVA).

Results

ATGs were bound to HUVECs with or without prior stimulation by tumor necrosis factor-α (TNF-α). Binding of ATGs to HUVECs was >99% in all treated groups. The mean intensity of fluorescence was constant in the ATG-treated groups.

Conclusions

Our results demonstrated that ATGs bind to HUVECs before and after stimulation with TNF-α. Binding of ATGs to HUVECs suggests an independent endothelial mechanism of ATG action.     

Induction of Insulin-Producing Cells From Human Pancreatic Progenitor Cells

Introduction

We previously established a mouse pancreatic stem cell line without genetic manipulation. In this study, we sought to identify and isolate human pancreatic stem/progenitor cells. We also tested whether growth factors and protein transduction of pancreatic and duodenal homeobox factor-1 (PDX-1) and BETA2/NeuroD into human pancreatic stem/progenitor cells induced insulin or pancreas-related gene expressions.

Materials and method

Human pancreata from brain-dead donors were used for islet isolation with the standard Ricordi technique modified by the Edmonton protocol. The cells from a duct-rich population were cultured in several media, based on those designed for mouse pancreatic or for human embryonic stem cells. To induce cell differentiation, cells were cultured for 2 weeks with exendin-4, nicotinamide, keratinocyte growth factor, PDX-1 protein, or BETA2/NeuroD protein.

Results

The cells in serum-free media showed morphologies similar to a mouse pancreatic stem cell line, while the cells in the medium for human embryonic stem cells formed fibroblast-like morphologies. The nucleus/cytoplasm ratios of the cells in each culture medium decreased during the culture. The cells stopped dividing after 30 days, suggesting that they had entered senescence. The cells treated with induction medium differentiated into insulin-producing cells, expressing pancreas-related genes.

Conclusion

Duplications of cells from a duct-rich population were limited. Induction therapy with several growth factors and transduction proteins might provide a potential new strategy for induction of transplantable insulin-producing cells.     

Neurogenic Differentiation 1 Directs Differentiation of Cytokeratin 19-Positive Human Pancreatic Nonendocrine Cells into Insulin-Producing Cells

Background

It has been reported that the human pancreatic nonendocrine fraction, which remains after islet isolation, can be differentiated toward beta cells. However, the optimal method to accomplish this goal has not been established. In this study, we introduced the human neurogenic differentiation 1 (NeuroD1) gene into human nonendocrine pancreatic epithelial cells (NEPECs) and promoted insulin-producing cells in vitro.

Methods

The human pancreatic nonislet fractions were obtained from brain-dead donors and cultured in suspension for 2-3 days followed by culture with G418 for 4 days. These cells (NEPECs) were then plated on dishes. The NEPECs spread into a cell monolayer within 7 days and all of the cells were cytokeratin-19 (CK19) positive. Seven days after plating, plasmids encoding human NeuroD1 gene under human CK19 promoter were transfected 3 times every other day (termed NEPEC+ND). Seven days after starting induction, these cells were characterized.

Results

Seven days after starting the induction of human NeuroD1, NEPEC+ND strongly expressed NeuroD1 and insulin mRNA. The ratio of NeuroD1-positive cells in NEPEC+ND was significantly higher than in NEPEC. Human insulin-positive cells in NEPEC+ND were also significantly greater than in NEPEC. Human insulin and C-peptide levels in culture medium in NEPEC+ND were significantly higher than in NEPEC.

Conclusions

These findings demonstrated that human NeuroD1 under control of the CK19 promoter can induce the differentiation of CK19-positive NEPECs into insulin-producing cells.     

Human umbilical cord blood-derived stromal cells: a new resource in hematopoietic reconstitution in mouse haploidentical transplantation

Objective

Our previous study showed that human umbilical cord blood-derived stromal cells (hUcBdSCs) expanded CD34⁺ cells in vitro. This study further explored the role of hUcBdSCs in vivo.

Methods

The cultured hUcBdSCs were infused into transplanted haploidentical mice to observe hematopoietic recovery and complications.

Results

The engraftment was faster in transplantation with hUcBdSCs than without hUcBdSCs. The numbers of fibroblast (CFU-F), granulocyte/monocyte (CFU-GM), erythrocytic (CFU-E), and megakaryocyte (CFU-Mg) colony-forming units were greater among mice transplanted with hUcBdSCs than without hUcBdSCs. The scoring of graft-versus-host disease was significantly lower in mice that had been subjected to transplantation with hUcBdSCs than without hUcBdSCs. The infused hUcBdSCs migrated to the bone marrow of the recipients.

Conclusions

These data indicated that hUcBdSCs improved hematopoietic reconstitution in haploidentical transplantation in mice.     

ISL-1 is induced in stomach mesenchyme in the presence of pancreatic epithelia

Background/Purpose

β-Cell replacement offers a potential cure for type 1 diabetes mellitus in children. We have previously shown that stomach mesenchyme (SM) is competent to derive islet tissue by mesenchymal-to-epithelial transition (iMET). The aim of this study was to further characterize the developmental fate of this SM in the presence of pancreatic epithelia (PE) in SM/PE recombinants. The homeobox ISL-1 was examined in these recombinants because this gene is restricted to the dorsal pancreatic mesenchyme and endocrine cells in early pancreatic development.

Methods

Chick-quail recombinants of SM + PE (n = 15) and whole stomach controls (n = 8) were cultured for 7 days. In addition, organ blocks were examined after normal development at days 4 to 10 (n = 4 for each stage). Tissues were analyzed using immunochemistry against quail-specific antigen and ISL-1.

Results

Thirteen of 15 SM + PE recombinants expressed the ISL-1 protein in cells from SM origin. Nine of 15 of these recombinants showed iMET and coexpression of insulin, and ISL-1 was recorded.

Conclusions

Pancreatic epithelium is able to reprogram SM to a more caudal pancreatic fate when cocultured. Islet tissue by mesenchymal-to-epithelial transition observed in recombinants showed coexpression of insulin and ISL-1. These experiments are important to identify the molecular mechanisms behind iMET for potential therapeutic use for treating children with diabetes.     

Renal transplantation in old recipients from expanded criteria donors selected by kidney biopsy

Background

In Spain, the number of ideal kidney transplant donors has fallen, with at the same time an increase in the number of older recipients on the waiting list.

Aim

To analyze the results of expanded criteria cadaveric donor kidney transplants into older recipients using grafts selected by kidney biopsy.

Patients and methods

We studied 360 kidney transplant recipients who had been followed to December 2009: 180 in the study group and 180 in a control group composed of younger patients who received grafts from non-expanded criteria donors between 1999 and 2006. A paraffin-embedded kidney biopsy was evaluated by the percentages of sclerosed glomeruli, arteriolar hyalinosis, intimal wall thickening, interstitial fibrosis, and tubular atrophy.

Results

Significant differences were observed in donor age (63.50 ± 5.46 vs 31.90 ± 13.29 years; P < .001) and recipient age (58.40 ± 8.80 vs 40.71 ± 13.23 years; P < .001). Donor renal function was significantly worse among the expanded criteria group (90.80 vs 108.11 mL/min/1.73 m²; P = .006), remaining so over time in the recipient (at 1 year: 42.08 vs 63.71 [P < .001]; at 3 years: 41.25 vs 62.31 [P < .001], and at 7 years: 38.17 vs 64.18 [P < .001]). Censored 7-year graft survivals were 73% versus 87% (P < .001) with similar patient survivals (90.5% vs 95%; P = .39).

Conclusions

Selection of expanded criteria donors by kidney biopsy resulted in good renal function as well as graft and patient survivals at 7 years in older recipients.     

Laparoscopy-assisted orchiopexy for recurrent undescended testes in children

Objective

Reoperative orchidopexy is a technical challenge to pediatric surgeons. The laparoscopy-assisted procedure is described for securing the testis in the scrotum in patients with a past history of open orchidopexy and testes in an unsatisfactory position.

Patients and Methods

Thirty-one patients with 35 abnormally positioned testes (4 bilateral) were evaluated. All patients had a past history of inguinal surgery, and ages ranged between 2.5 and 13 years (mean, 5.5 years). Previous surgical procedures included 32 orchiopexies and 3 testicular detorsion of undescended testis. If needed, inguinal dissection was performed to loose the adherence between the cord and inguinal canal. Laparoscopic orchidopexy was applied to allow the testis to remain in the scrotum without tension. Patients underwent follow-up every 3 months after the operation with physical and ultrasound examinations.

Results

Ten low inguinal testes were treated directly with open inguinal redo orchidopexy, whereas laparoscopy-assisted orchidopexy was possible in 23 (92%) of the remaining 25 reoperations. In 2 (8%) of these cases, severe scarring was present between the cord and the inguinal canal impeding the laparoscopy-assisted orchidopexy. For laparoscopy-assisted procedure, the operation time was 42 to 67 minutes (mean = 52 min). After the laparoscopy-assisted reoperations, 23 (92%) testes remain within the scrotum after a mean follow-up of 22 months (range, 6-32 months).

Conclusion

When feasible, laparoscopy-assisted orchiopexy is a simple and effective technique for securing testicles in reoperative orchiopexy procedures.     

Absence of the p53 tumor suppressor gene promotes osteogenesis in mesenchymal stem cells

Objective

Osteosarcoma arises predominantly in the metaphyseal growth plate of children during the growth spurt years. These tumors develop during physiological growth from an expanding cell population, suggesting that the transformed cell is a bone-forming progenitor. An absence of the p53 oncogene has been implicated in the origin and progression of osteosarcoma, and because mesenchymal stem cells (MSCs) are the physiological osteogenic progenitor cell population, we hypothesized that a p53^−/− mutation would enhance bone differentiation of MSC in a mouse model of in vitro osteogenesis.

Methods

Clonal MSC populations were derived from p53^−/− mice. P53^−/− and wild-type cells were placed in osteogenic culture and assessed via Alizarin Red quantification and alkaline phosphatase staining. The osteogenic marker genes Cbfa1, osteopontin, and osteocalcin were assessed by quantitative real time polymerase chain reaction during differentiation.

Results

Bone nodule formation and alkaline phosphatase staining was accelerated and enhanced in the p53^−/− cells. The early and intermediate osteogenic markers, Cbfa1 and osteopontin, were upregulated in p53^−/− MSCs compared with wild-type cells during osteogenesis. The terminal osteogenic marker gene osteocalcin was paradoxically lower in p53^−/− MSCs indicating impaired terminal differentiation.

Conclusion

The p53^−/− mutation enhances and accelerates early osteogenesis in MSCs, but prevents terminal differentiation toward a mature osteocyte phenotype. These findings may have important implications for the regulation of the MSC compartment during the derivation of osteosarcoma in children.     

Intermediate-term patency of upper arm arteriovenous fistulae for hemodialysis access in children

Purpose

The goal of this study was to estimate the 2-year cumulative thrombosis-free survival of basilic vein transposition (BVT) and brachiocephalic fistulae in children.

Methods

All children who underwent BVT or brachiocephalic fistula construction at a tertiary care children's hospital from June 2001 to July 2006 were reviewed. Kaplan-Meier analysis, log-rank test, and proportional hazards regression were done.

Results

Sixteen children (7 girls) with inadequate forearm veins underwent creation of 18 fistulae (12 BVT, 6 brachiocephalic). Median age was 14 (9-19) years. Mean (±SE) operative times for BVT and brachiocephalic fistulae were 3.4 (± 0.6) hours and 1.9 (±0.4) hours, respectively. The overall 2-year cumulative survival rate was 74% (BVT, 66%; brachiocephalic fistula, 83%). Four fistulae failed (1 brachiocephalic, 3 BVT) and 14 fistulae were censored (5, patent fistula; 4, renal transplantation; 2, unrelated death; 1, elective conversion to peritoneal dialysis; 1, surgical ligation of fistula; 1, lost to follow-up). Of 18 fistulae, 6 underwent additional interventions (4, percutaneous angioplasty; 2, surgical thrombectomy). There were no significant differences in survival times based on fistula type, prior transplant status, age, or operative time.

Conclusions

Brachiocephalic and BVT fistulae create reliable hemodialysis access for children who have inadequate forearm veins to allow construction of more distal fistulae.     

Generation of functional human vascular network

Background

One of the major obstacles in regenerating thick, complex tissues such as the liver is their need for vascularization, which is essential to maintain cell viability during tissue growth and to induce structural organization. Herein, we have described a method to engineer a functional human vascular network.

Methods

Enhanced green fluorescence protein-labeled human umbilical vein endothelial cells (GFP-HUVECs) were cocultivated with kusabira orange-labeled human mesenchymal stem cells (KO-hMSCs) inside a collagen/fibronectin matrix. Premature vascular network formation was visualized by fluorescence microscopy imaging. Furthermore, constructs prevascularized in vitro were implanted into a transparency window in immunodeficient mice.

Results

Following several days of cultivation, GFP-HUVECs formed vessel-like structures that were stabilized by pericytes differentiated from KO-hMSCs. After implantation in vivo, the patency of human vascular structures was proved by rhodamine dextran infusion. These functional vascular structures remained for over 2 months.

Discussion

Vascularization is the key challenge to organ generation. We successfully generated human vascular networks inside a matrix. Integration of parenchymal cells using our engineering technique should facilitate future efforts to reconstitute vascularized human organ systems in vitro.     

Non-operative treatment of non-displaced scaphoid fractures may be preferred

Aim

To evaluate the outcome of non-displaced scaphoid fractures treated with 6 weeks of cast immobilisation, and to establish whether the benefits of non-operative treatment might outweigh those of early operation.

Methods

A retrospective study analysed 89 consecutive cases of scaphoid fracture treated at our institution between 2004 and 2007. Diagnosis and treatment methods and complication rates were evaluated.

Results

Among 71 non-displaced scaphoid fractures, >80% showed clinical consolidation after 6 weeks of cast immobilisation, and the remaining cases after 8-12 weeks. Two cases needed a longer period of cast immobilisation.

Conclusion

A restricted period of cast immobilisation is usually adequate for the treatment of non-displaced scaphoid fractures.     

Isolation and characterization of mouse mesenchymal stem cells

Objective

Mesenchymal stem cells (MSCs) have been studied in regenerative medicine because of their unique immunologic characteristics. However, before clinical application in humans, animal models are needed to confirm their safety and efficacy. To date, appropriate methods and sources to obtain mouse MSCs have not been identified. Therefore, we investigated MSCs isolated from 3 strains of mice and 3 sources for the development of MSCs in a mouse model.

Materials and Methods

Male BALB/c, C3H and C57BL/6 mice were used to isolate MSCs from various tissues including bone marrow (BM), compact bone, and adipose tissue. The MSCs were maintained in StemXVivo medium. Immunophenotypes of the MSCs were analyzed by FACS and their growth potential estimated by the number of colony-forming unit fibroblasts.

Results

All MSCs that were isolated from BM, compact bone, and adipose tissue showed plastic-adherent, fibroblastic-like morphologic characteristics regardless of the mouse strain or cell source. However, culture of BM MSCs was less successful than the other tissue types. The FACS phenotype analysis revealed that the MSCs were positive for CD29, CD44, CD105, and Sca-1, but negative for CD34, TER-119, CD45, and CD11b. According to the results of the characterization, the adipose tissue MSCs showed higher growth potential than did other MSCs.

Conclusion

The results of this study showed that culture of adipose tissue and compact bone-MSCs was easier than BM MSCs. Based on the results of immunophenotype and growth potential, C57BL/6 AT-MSCs might be a suitable source to establish a mouse model of MSCs.     

Pathogenic implications of remnant vitelline structures in gastroschisis

Purpose

The pathogenesis of gastroschisis is unknown. It may be helpful in understanding its pathogenesis to know the structural relationships among umbilical components including umbilical vessels, urachus, and vitelline structures, and thus, the authors investigated the remnants of vitelline structures in a series of cases of gastroschisis.

Methods

Medical records of 41 cases with gastroschisis treated in our institute from 1979 to 2009 were retrospectively reviewed.

Results

Paraumbilical bands, possible remnants of vitelline structures, were observed in 4 cases (9.8%). All 4 bands were attached to the skin edge of the abdominal defect without incorporation into the umbilical cord. The band ended at the mesentery in 3 cases and at the antimesenteric site of the ileum in the remaining case. Histologic findings showed fibrous tissues in all cases. One was possibly associated with the development of colonic atresia. Another was noticed after silo reduction when herniated bowels became strangulated by the band. The other 2 cases were uncomplicated.

Conclusions

Our findings may support the recently proposed hypothesis that the developmental failure of the yolk sac and related vitelline structures to merge with or to be incorporated into the umbilical stalk might be associated with the pathogenesis of the abdominal wall defect in gastroschisis. Paraumbilical bands derived from vitelline structures may possibly cause intestinal ischemia prenatally or postnatally.     

Mesoportal bypass for extrahepatic portal vein obstruction in children: close to a cure for most!

Aim

Extrahepatic portal vein obstruction (EPVO) is a common cause of portal hypertension in children and can lead to life-threatening bleeding, thrombocytopenia, and coagulation disorders. Mesoportal bypass (MPB) restores normal physiologic portal flow to the liver and corrects portal hypertension. There is, however, little long-term outcome data after MPB.The aim of our study was to analyze the long-term outcome after MPB in children.

Methods

Retrospective single-center review of all MPB with more than 5-year follow-up was performed in children between 1998 and 2003.

Results

Thirty children underwent MPB, which was successful in 29. Long-term follow-up is available for 24. Median age at the time of bypass was 8.5 years (range, 0.4-14.2 years). Material used for bypass was as follows: left internal jugular vein (n = 20), recanalized umbilical vein (n = 2), gastric vein, and a large colic vein (n = 2). Median time since MPB is 8 years (range, 5.3-8.8 years).One MPB using recanalized umbilical vein thrombosed at 4 months but was successfully refashioned using Gortex. One MPB with left internal jugular vein was thrombosed at 1 year after cardiac surgery. Overall, 23 of 24 children have a patent bypass and resolution of portal hypertension. All showed an decrease in spleen size. Recurrent blood flow in the cavernoma with secondary increase in spleen size occurred in 5 children (median time, 3.4 years after MPB). Further evaluation of these 5 revealed no recurrence of portal hypertension.

Conclusion

The MPB provides long-term correction of portal hypertension owing to EPVO. Where technically feasible, MPB is the preferred surgical procedure for treatment of EPVO.