The First Application of Intraumbilical Longitudinal Incision to Pyloromyotomy for Hypertrophic Pyloric Stenosis.

OBJECTIVE: There are several approaches to pyloromyotomy for the treatment of hypertrophic pyloric stenosis including open transumbilical pyloromyotomy and laparoscopic pyloromyotomy. Beginning in 2012, we adopted intraumbilical longitudinal incision as a new transumbilical approach for pyloromyotomy. We describe details of the operative technique and results of this new approach. METHODS: We reviewed records of patients undergoing transumbilical pyloromyotomy from 2005 to 2018. Perioperative outcomes were compared between intraumbilical longitudinal incision and supraumbilical incision, the latter of which is the conventional incision for transumbilical pyloromyotomy. RESULTS: Twenty-four patients underwent pyloromyotomy with intraumbilical longitudinal incision (intraumbilical group) and 28 patients with supraumbilical incision (supraumbilical group). The median operative time was longer in the intraumbilical group (58.0 vs. 43.5 min, p = 0.002). However, the time to full feeding did not differ significantly between the two groups, and the median postoperative stay was shorter in the intraumbilical group (3 vs. 5.5 days, p = 0.003). There was no difference in the rate of complications (4.2% vs. 7.1%, p = 1.0). Scars after intraumbilical longitudinal incision were localized inside the umbilicus. CONCLUSION: Pyloromyotomy can be performed through intraumbilical longitudinal incision as safely as supraumbilical incision and intraumbilical longitudinal incision may improve cosmetic results. This approach can be an alternative technique for pyloromyotomy.

Superior stemness of a rapidly growing subgroup of isolated human auricular chondrocytes and the potential for use in cartilage regenerative therapy.

INTRODUCTION: In cartilage regenerative medicine, transplanted chondrocytes contain a mixture of populations, that complicates the regeneration of uniform cartilage tissue. Our group previously reported that chondrocytes with higher chondrogenic ability could be enriched by selection of rapidly growing cells. In this study, the detailed properties of rapidly growing chondrocytes were examined and compared to slowly growing cells. METHODS: Human auricular chondrocytes were fluorescently labeled with carboxyfluorescein succinimidyl ester (CFSE) and analyzed using flow cytometry, focusing on division rates as indicated by fluorescence intensity and cell morphology according to the forward scatter and side scatter. Rapid and slow growing cell groups were harvested on days 2 and 4 after CFSE labeling, and their ability to produce cartilage matrix in vitro was examined. To compare the chondrogenic ability in vivo, the cells were seeded on poly-l-lactic acid scaffolds and transplanted into nude mice. Gene expression differences between the rapid and slow cell groups were investigated by microarray analysis. RESULTS: On day 2 after CFSE labeling, the rapidly growing cell group showed the highest proliferation rate. The results of pellet culture showed that the rapid cell group produced more glycosaminoglycans per cell than the slow cell group. The amount of glycosaminoglycan production was highest in the rapid cell group on day 2 after CFSE labeling, indicating high chondrogenic ability. Furthermore, microarray, gene ontology, and Kyoto Encyclopedia of Genes and Genomes pathway analyses showed upregulation of genes that promote cell division such as origin recognition complex subunit 1 and downregulation of genes that inhibit cell division such as cyclin dependent kinase inhibitor 1A. Besides cell cycle-related genes, chondrocyte-related genes such as serpin family B member 2, clusterin, bone morphogenetic protein 2, and matrix metalloproteinase 3 were downregulated, while fibroblast growth factor 5 which is involved in stem cell maintenance, and coiled-coil and C2 domain containing 2A, which is required for cilia formation, were upregulated. CONCLUSION: The results showed that the rapid cell group proliferated well and had more undifferentiated properties, suggesting a higher stemness. The present findings provide a basis for the use of the rapid cell group in cartilage regeneration.

A novel method of tracheal anastomosis healing using a single submucosal injection of basic fibroblast growth factor: initial report.

OBJECTIVES: For the technical management of tracheal anastomosis, developing new and simple methods is required to relieve anastomotic tension. This study aimed to investigate whether basic fibroblast growth factor (bFGF) only once injected immediately before anastomosis promotes cartilage regeneration at the tracheal anastomosis and whether the regenerated cartilage has the effect of reinforcing the anastomosis in a rabbit model. METHODS: New Zealand white rabbits were anaesthetized, and the cervical trachea was exposed through a cervical midline incision, followed by resection of the 10th tracheal cartilage. The rabbits were categorized into 2 groups: the bFGF group (n = 6) and the control group (n = 6). In the former group, bFGF (25 µg) was administered into the submucosal layer of the cartilage using a 27-G needle immediately before tracheal anastomosis. The animals were sacrificed 4 weeks later. Histological, mechanical and biochemical evaluations were performed on this anastomosed trachea. RESULTS: At 4 weeks of age, the anastomoses were spindle-shaped and displayed maximum diameter at the injection site compared with those in the control group. Histological evaluation showed that cartilage tissue had regenerated between the 9th and 11th tracheal cartilage rings. Tensile test showed that the anastomoses displayed a significantly high strain/stress ratio (P = 0.035). The collagen type II and glycosaminoglycan levels were significantly increased, and the collagen type I level was significantly decreased (P = 0.019, P = 0.013 and P = 0.045, respectively). CONCLUSIONS: A new wound-healing concept of airway anastomosis could be provided by the results that single injection of bFGF regenerated tracheal cartilage in rabbits and strengthened the anastomosis by bridging the regenerated and well-matured cartilage. Further investigation of this method will lead to potential clinical applications for reinforcement of tracheal anastomoses.

Mesenchymal stromal cells in the bone marrow niche consist of multi-populations with distinct transcriptional and epigenetic properties.

Although multiple studies have investigated the mesenchymal stem and progenitor cells (MSCs) that give rise to mature bone marrow, high heterogeneity in their morphologies and properties causes difficulties in molecular separation of their distinct populations. In this study, by taking advantage of the resolution of the single cell transcriptome, we analyzed Sca-1 and PDGFR-α fraction in the mouse bone marrow tissue. The single cell transcriptome enabled us to further classify the population into seven populations according to their gene expression profiles. We then separately obtained the seven populations based on candidate marker genes, and specified their gene expression properties and epigenetic landscape by ATAC-seq. Our findings will enable to elucidate the stem cell niche signal in the bone marrow microenvironment, reconstitute bone marrow in vitro, and shed light on the potentially important role of identified subpopulation in various clinical applications to the treatment of bone- and bone marrow-related diseases.

Impact of a Pharmacist-Led Antimicrobial Stewardship Program on the Number of Days of Antimicrobial Therapy for Uncomplicated Gram-Negative Bacteremia in a Community Hospital.

Introduction The need for pharmacist-led antimicrobial stewardship programs (ASP) is increasing. Objective We performed a retrospective study to assess whether pharmacist-led ASPs can decrease the duration of treatment for uncomplicated gram-negative bacteremia among patients admitted in a community hospital. Methods This research was conducted at a 325-bed regional general hospital in Japan, from January 2013 to June 2015. There are no infectious diseases specialists affiliated with the hospital. The outcomes of the pharmacist-led ASP group, who received pharmacist intervention, and the control group, who did not receive pharmacist intervention, were compared. The study included patients aged 18 years or older who were diagnosed with gram-negative bacteremia. The pharmacist performed an antimicrobial time-out at 72 hours after blood culture collection and optimized treatment based on the patient's clinical response and test results. The primary outcome was the duration of antibiotic treatment.  Results In total, 34 patients in the pharmacist-led ASP group and 32 in the control group were included in the final analysis. The median number of days of antimicrobial treatment was 8 (interquartile range [IQR]: 7-14) days in the pharmacist-led ASP group and 14 (IQR: 10-15) days in the control group. The number of days of antimicrobial treatment significantly reduced in the pharmacist-led ASP group (p < 0.001). The de-escalation rates were 11 (32.4%) cases in the pharmacist-led ASP group and 4 (12.5%) cases in the control group. Hence, the trend was higher in the pharmacist-led ASP group than in the control group (p = 0.08). Conclusion The pharmacist-led ASP reduced the number of days of antimicrobial therapy for uncomplicated gram-negative bacteremia among patients admitted in a community hospital without an infectious diseases specialist.

A new method of primary engineering of esophagus using orthotopic in-body tissue architecture.

PURPOSE: Tissue engineering of esophagus is required for management of long-gap esophageal atresia (LGEA). Collagenous connective tissue membranes fabricated by in-body tissue architecture (iBTA), called biosheets, can repair esophageal defects and generate tissues similar to native esophagus. However, iBTA requires second-stage surgery because of heterotopic preparation of biosheets. Our aim was to develop orthotopic iBTA for primary engineering of the esophagus by interposing a tubular mold to the esophageal defect. METHOD: The cervical esophagus of six rats was transected. An acrylic tube (internal diameter 2.6 mm, length 7.0 mm) was inserted and fixed between the ends of the upper and lower esophagus, and a 3 mm-long esophageal defect was created. Four weeks later, the rats were sacrificed for histological analysis. RESULTS: Postoperatively the rats could intake liquid food. After four weeks, the esophageal defects were filled with regenerated tissues. Histologically the new esophageal walls stained positive for collagen type I. The inner surfaces were covered with stratified squamous epithelium that expressed pan-cytokeratin. In only one of six rats, regeneration of muscular-like tissue was suggested by positive immunohistochemical staining for desmin. CONCLUSION: Orthotopic iBTA can regenerate a substitute esophagus with esophageal epithelium and collagenous wall. This technique may be a novel treatment for esophageal atresia with gaps of various lengths including LGEA.

Prospective monitoring of carbapenem use and pseudomonal resistance across pediatric institutions.

OBJECTIVE: To determine whether carbapenem consumption and Pseudomonas aeruginosa resistance rates can be used as benchmarks to compare and improve antimicrobial stewardship programs across multiple pediatric hospitals. DESIGN: A prospective study. SETTING AND PARTICIPANTS: Healthcare institutions in Japan with >100 pediatric beds. METHODS: An annual survey of the total days of therapy (DOT) per 1,000 patient days for carbapenem antibiotics (meropenem, imipenem-cilastatin, panipenem-betamipron, doripenem) and susceptibility rates of Pseudomonas aeruginosa to meropenem and imipenem-cilastatin from each institution was conducted over a 7-year period. Data were reported to the administration, as well as to the infection control team, of each institution annually. RESULTS: Data were obtained from 32 facilities. The median total carbapenem DOT per 1,000 patient days was 16.6 and varied widely, with a range of 2.7 to 59.0. The median susceptibility to meropenem was 86.6%, ranging from 78.6% to 96.6%. We detected an inverse correlation between total carbapenem DOT versus susceptibility (r = - 0.36; P < .01). Over the 7-year period, the DOT per 1,000 patient days of carbapenem decreased by 27% from a median of 16.0 to 11.7 (P < .01). We also observed an improvement in susceptibility to meropenem from a median of 87% to 89.7% (P = .01) and to imipenem-cilastatin from 79% to 85% (P < .01). The decreases in the use of carbapenem were greater in institutions with antimicrobial stewardship programs led by pediatric infectious disease specialists. CONCLUSIONS: Antimicrobial use and resistance, targeting carbapenems and P. aeruginosa, respectively, can serve as benchmarks that can be utilized to promote antimicrobial stewardship across pediatric healthcare institutions.

The effect of preauthorization and prospective audit and feedback system on oral antimicrobial prescription for outpatients at a children's hospital in Japan.

Antimicrobial stewardship programs (ASP) for oral antibiotics is still uncommon, despite the fact that oral antibiotics prescription accounts for 90% of total antibiotic consumption in developed countries. We introduced preauthorization and prospective audit and feedback (PAF) system on broad-spectrum oral antimicrobials as a part of ASP intervention from October 2015 in a tertiary children's hospital in Japan. Antimicrobial consumption and cost of targeted oral antimicrobials decreased from 11.1 days of therapy (DOT) per 1000 outpatient visits and 860,040 yen ($ 7167: 1 $ = 120 yen) to 1.9 DOT per 1000 outpatient visits and 142,200 yen ($ 1185) annually, respectively (p < 0.001). Interrupted time-series analysis showed that prescriptions for targeted antimicrobials decreased rapidly after initiation of preauthorization (p < 0.001). Prescriptions for non-targeted oral antimicrobial increased temporarily (p < 0.001), but a decreasing trend was found after the initiation (p < 0.001). In pre-intervention period, the main indications for using targeted antimicrobials were upper and lower respiratory infection, urinary tract infections, prophylaxis for medical procedures and otitis media, but only 21.4% of them were appropriate prescription. The appropriate prescription rate of post -intervention period increased to 58.5%. During the study period, the susceptibility pattern of major bacteria to these antimicrobials did not change. In conclusion, introduction of the preauthorization and PAF for selected oral antimicrobials decreased the antimicrobial use of both targeted and non-targeted antimicrobials. This intervention may be an effective method of ASP for other children's hospitals.

A case of secretory breast cancer in a 6 year-old girl: is it possible to make a correct preoperative diagnosis?

Secretory breast carcinoma constitutes the majority of breast cancers in children and young people less than 20 years of age. Noninvasive examination is particularly necessary for the diagnosis of breast carcinoma in children. Herein, we report a case of secretory breast carcinoma in a 6-year-old girl with psychomotor retardation. She was referred to our outpatient clinic for evaluation of a palpable mass in her left breast. A hard mass, rather than the increase in size typical of premature thelarche, was palpated. An excision biopsy was performed. Pathological findings revealed an invasive secretory breast carcinoma. We performed a retrospective review of the preoperative findings of this case, and compared it to the pathological diagnosis. Elastography, which can be performed without deep sedation or general anesthesia and without causing pain, resulted in a stiffness score of 4; however, the distinction between benign and malignant tumors on elastography, which is important to decide the intra-operative procedures, was not sufficient according to the Japanese breast cancer society clinical guidelines. This is the first report of secretory breast carcinoma in a child with a stiffness score determined by tissue elasticity imaging. A breast mass in a child with a high stiffness score of more than 4 on elastography should be referred for invasive diagnostic procedures, such as fine needle aspiration or excisional biopsy. According to our experience, an accurate preoperative diagnosis could be possible for malignant breast tumors in children. Such parameters as stiffness score on elastography are practical, noninvasive, and objective diagnostic tools for the accurate preoperative diagnosis of breast tumors in children.

Long-term observation of airway reconstruction using decellularized tracheal allografts in micro-miniature pigs at growing stage.

INTRODUCTION: Decellularized tissue exhibits cell matrix-like properties, along with reduced antigenicity. We explored the potential of decellularized allogeneic trachea to restore the upper respiratory tract, focusing on pediatric application. This study specifically aimed at long-term observation of tissue regeneration using a micro-miniature pig model. METHODS: Artificial defects (15 × 15 mm) in the subglottis and trachea of micro-miniature pigs were repaired by transplantation of either allogeneic decellularized or fresh (control) tracheal patches. Pigs were evaluated in situ, by bronchoscopy, every three months, and sacrificed for histological examination at six and twelve months after transplantation. RESULTS: No airway symptom was observed in any pig during the observation period. Bronchoscopy revealed the tracheal lumen to be restored by fresh grafts, showing an irregular surface with remarkable longitudinal compression; these changes were mild after restoration with decellularized grafts. Histologically, while fresh graft patches were denatured and replaced by calcified tissue, decellularized patches remained unchanged throughout the observation period. There were regeneration foci of cartilage adjacent to the grafts, and some foci joined the decellularized graft uniformly, suggesting the induction of tracheal reconstitution. CONCLUSION: Allogeneic decellularized tracheal tissue could serve as a promising biomaterial for tracheal restoration, especially for pediatric patients at the growing stage.

Tracheal cartilage growth promotion by intra-tracheal administration of basic FGF.

PURPOSE: This study aimed to investigate whether intra-tracheal administration of basic fibroblast growth factor (b-FGF) promotes the growth of tracheal cartilage. METHODS: Trachea of 4-week old mice were intubated and 2.5 µg b-FGF administered (Group 4) for periods from 1 to 5 days. Cervical tracheal outer diameter and tracheal ring length were compared in Group 1 (no intervention), Group 2 (tracheal intubation), Group 3 (intra-tracheal administration of distilled water) and Group 4, at 8 weeks of age. Outer diameter and tracheal ring length in Group 4 were also compared with that in Group 1 at 12 and 16 weeks of age. RESULTS: At 8 weeks of age, tracheal ring length with b-FGF administration for more than 4 days in Group 4 was significantly increased over that following 1-day administration. At 8 weeks of age, mean outer diameter and the mean tracheal ring length in Group 4 were significantly greater than in the other groups. Mean outer diameter and mean tracheal ring length were significantly greater in Group 4 than in Group 1 at 12 and 16 weeks of age. CONCLUSION: This study has shown that intra-tracheal administration of b-FGF enlarges the tracheal lumen.

Fabrication of an anatomy-mimicking BIO-AIR-TUBE with engineered cartilage.

INTRODUCTION: We devised a strategy for the fabrication of an 'anatomy-mimicking' cylinder-type engineered trachea combined with cartilage engineering. The engineered BIOTUBEs are used to support the architecture of the body tissue, for long-segment trachea (>5 cm) with carinal reconstruction. The aim of the present study was to fabricate an anatomy-mimicking cylinder-type regenerative airway, and investigate its applicability in a rabbit model. METHODS: Collagen sponge rings (diameter: 6 mm) were arranged on a silicon tube (diameter: 6 mm) at 2-mm intervals. Chondrocytes from the auricular cartilage were seeded onto collagen sponges immediately prior to implantation in an autologous manner. These constructs were embedded in dorsal subcutaneous pouches of rabbits. One month after implantation, the constructs were retrieved for histological examination. In addition, cervical tracheal sleeve resection was performed, and these engineered constructs were implanted into defective airways through end-to-end anastomosis. RESULTS: One month after implantation, the engineered constructs exhibited similar rigidity and flexibility to those observed with the native trachea. Through histological examination, the constructs showed an anatomy-mimicking tracheal architecture. In addition, the engineered constructs could be anastomosed to the native trachea without air leakage. CONCLUSION: The present study provides the possibility of generating anatomy-mimicking cylinder-type airways, termed BIO-AIR-TUBEs, that engineer cartilage in an in-vivo culture system. This approach involves the use of BIOTUBEs formed via in-body tissue architecture technology. Therefore, the BIO-AIR-TUBE may be useful as the basic architecture of artificial airways.

Age-Appropriate Pediatric Dosage Forms in Japan: Insights into End-User Perceptions From an Observational Cross-Sectional Survey Assessing the Acceptability of Oral Formulation.

BACKGROUND: The lack of appropriate pediatric formulations is a global issue and information on acceptability is urgently needed to develop standard pediatric formulations. This study aimed to assess perceptions of acceptability of several oral dosage forms among pediatric patients at a community and a pediatric hospital in Japan and collected information about age-appropriate pediatric formulations, aiming to contribute to drug development promotion worldwide. METHODS: A cross-sectional observational study was performed. A convenience sample of caregivers was recruited from available chain-owned retail pharmacies and inpatient pediatric units. The questionnaire was composed of 3 parts: (1) acceptability of the 5 dosage forms (tablets, capsules, powders, liquids, and orally disintegrating tablet) by age; (2) acceptability of dosage size, amount, and volume by age; and (3) the actual method of administration. Face-to-face interviews were conducted at 3 independent community pharmacies (324 parents) and tertiary care pediatric hospital wards (112 nursing staff). Acceptability scores and acceptable dosages were then determined. The survey was conducted from October 1 to December 1, 2017, for the hospital setting and November 1 to 30, 2017, for the outpatient setting. RESULTS: The acceptability of oral dosage forms was roughly similar to the matrix drafted by the European Medical Agency. Differences in perception of the powder forms between communities and hospitals were also observed, with the nursing staff perceiving powder as being acceptable from the neonatal period. CONCLUSIONS: The difference in caregivers' perception of the acceptability of oral formulations between Japan and Europe was small. The powder form was found to be more acceptable in Japan. Further intervention studies are needed to assess the preferred pediatric formulation worldwide.

Long-term follow-up of tracheal cartilage growth promotion by intratracheal injection of basic fibroblast growth factor.

BACKGROUND: Intratracheal injection of basic fibroblast growth factor (b-FGF) has been shown to enlarge the tracheal lumen 4 weeks after treatment. The objective of this study was to investigate the long-term effect of tracheal cartilage growth promotion by intratracheal injection of b-FGF. MATERIALS AND METHODS: New Zealand white rabbits were classified into four groups to receive either distilled water alone (Group 1; n = 16; control), 40 µg (Group 2; n = 10), 100 µg (Group 3; n = 13), or 200 µg (Group 4; n = 16) of b-FGF dissolved in water. The treatment was injected into the posterior wall of the cervical trachea using a tracheoscope. The animals were sacrificed 4 or 12 weeks later. RESULTS: Four weeks after treatment, the mean luminal areas of tracheas for Groups 1, 2, 3, and 4 were 27.2, 25.6, 32.2, and 36.2 mm2, respectively. At 12 weeks, these were 29.3, 37.9, 42.5, and 56.0 mm2, respectively. The levels of glycosaminoglycan at 12 weeks were 93.9, 152.5, 123.2, and 210.6 µg/mg, respectively. At 12 weeks, the levels of type II collagen were 77.2, 133.1, 99.2, and 148.9 µg/mg, respectively. CONCLUSION: Twelve weeks after a single injection of b-FGF, the mean luminal area of the trachea continued to increase.

Engineering and repair of diaphragm using biosheet (a collagenous connective tissue membrane) in rabbits.

BACKGROUND: Prosthetic patches can be used to repair large congenital diaphragmatic hernia defects but may be associated with infection, recurrence, and thoracic deformity. Biosheets (collagenous connective tissue membranes) have been used in regenerative medicine. We evaluated the efficacy of Biosheets in a rabbit model. METHODS: Biosheets were prepared by embedding silicone plates in dorsal subcutaneous pouches of rabbits for 4weeks. In group 1 (n=11), Gore-Tex® sheets (1.8×1.8cm) were implanted into a diaphragmatic defect. In group 2 (n=11), Seamdura®, a bioabsorbable artificial dural substitute, was implanted in the same manner. In group 3 (n=14), biosheets were autologously transplanted into the diaphragmatic defects. All rabbits were euthanized 3months after transplantation to evaluate their graft status. RESULTS: Herniation of liver was observed in 5 rabbits (45%) in group 1, 8 (73%) in group 2, and 3 (21%) in group 3. A significant difference was noted between groups 2 and 3 (P=0.017). Biosheets had equivalent burst strength and modulus of elasticity as native diaphragm. Muscular tissue regeneration in transplanted biosheets in group 3 was confirmed histologically. CONCLUSION: Biosheets may be applied to diaphragmatic repair and replacement of diaphragmatic muscular tissue. LEVEL OF EVIDENCE: Level III.

Airway reconstruction using decellularized tracheal allografts in a porcine model.

PURPOSE: Tracheal cartilage reconstruction is an essential approach for the treatment of tracheal congenital abnormalities or injury. Here, we evaluated the use of allogeneic decellularized tracheas as novel support scaffolds. METHODS: Six weaned pigs (4-week-old domestic males) were transplanted with allogeneic tracheal graft patches (three decellularized and three fresh tracheal scaffolds) onto artificial defects (approximately 15 × 15 mm). After 11 weeks, the tracheas were evaluated by bronchoscopy and histological studies. RESULTS: No pigs displayed airway symptoms during the observation period. Tracheal lumen restored by fresh graft patches showed more advanced narrowing than that treated with decellularized grafts by bronchoscopy. Histologically, fresh grafts induced typical cellular rejection; this was decreased with decellularized grafts. In addition, immunohistochemistry demonstrated regenerating foci of recipient cartilage along the adjacent surface of decellularized tracheal grafts. CONCLUSION: Decellularized allogeneic tracheal scaffolds could be effective materials for restoring impaired trachea.

Mosapride for gastroesophageal reflux disease in neurologically impaired patients.

BACKGROUND: The prokinetic agent cisapride is effective for the treatment of gastroesophageal reflux disease (GERD) in infants and children, but is no longer used for this purpose because of safety concerns. Therefore, other pharmacological agents need to be investigated for efficacy in GERD treatment. In this study, we examined the effectiveness and safety of mosapride for the treatment of neurologically impaired children and adolescents with GERD. METHODS: Mosapride (0.3 mg/kg/day) was administered to 11 neurologically impaired patients with GERD (five male; median age, 12.3 years). Esophageal acid exposure was measured using esophageal pH monitoring before and at >5 days after the start of mosapride treatment. The pressure and length of the lower esophageal sphincter were compared before and after mosapride treatment. RESULTS: In the 11 patients, median reflux index (percentage of the total monitoring period during which recorded pH was <4.0) was 17.5% (range, 4.4-59%) before and 8.2% (range, 2.8-20.7%) after mosapride treatment (P = 0.02). Median esophageal clearance was 1.0 min/reflux (range, 0.5-2.1 min/reflux) before and 0.7 min/reflux (range, 0.4-1.2 min/reflux) after treatment with mosapride (P = 0.02). The median number of reflux episodes before (219) and after (122) drug treatment did not differ significantly. CONCLUSION: The decreased reflux index in neurologically impaired patients with GERD is due to mosapride, therefore mosapride may be a candidate for GERD treatment.

Tracheal cartilage growth by intratracheal injection of basic fibroblast growth factor.

BACKGROUND/PURPOSE: We have previously shown that intratracheal injection of slowly released (in gelatin) basic fibroblast growth factor (bFGF) significantly enlarged the tracheal lumen by a slight margin. This study aimed to investigate differences in tracheal cartilage growth by the intratracheal injection of bFGF doses in a rabbit model. METHODS: Water (group 1; n=7; control) or 100µg (group 2; n=8) or 200µg (group 3; n=8) of bFGF dissolved in water was injected into the posterior wall of the cervical trachea of New Zealand white rabbits using a tracheoscope. All animals were sacrificed four weeks later. RESULTS: The mean circumferences of cervical tracheas for groups 1, 2, and 3 were 18.8±0.83, 21.1±2.0, and 22.1±1.3mm, respectively. A significant difference was found between groups 1 and 2 (P=0.034) and groups 1 and 3 (P=0.004). The mean luminal areas of cervical tracheas for groups 1, 2, and 3 were 27.0±2.1, 32.2±4.8, and 36.3±4.6mm2, respectively. A significant difference was found between groups 1 and 3 (P=0.001). CONCLUSION: Intratracheal injection of bFGF in the dose range used significantly promoted the growth of tracheal cartilage in a rabbit model. LEVELS OF EVIDENCE: Level II at treatment study (animal experiment).

Patch tracheoplasty in body tissue engineering using collagenous connective tissue membranes (biosheets).

BACKGROUND: Collagenous connective tissue membranes (biosheets) are useful for engineering cardiovascular tissue in tissue engineering. The aim was to evaluate the use of biosheets as a potential tracheal substitute material in vivo in a rabbit model. METHODS: Group 1: Rectangular-shaped Gore-Tex (4×7mm) was implanted into a 3×6mm defect created in the midventral portion of the cervical trachea. Group 2: Rectangular-shaped dermis was implanted into a tracheotomy of similar size. Group 3: Biosheets were prepared by embedding silicone moulds in dorsal subcutaneous pouches in rabbits for 1month. Rectangular-shaped biosheets were implanted into a tracheotomy of similar size in an autologous fashion. All groups (each containing 10 animals) were sacrificed 4weeks after implantation. MAIN RESULTS: All materials maintained airway structure for up to 4weeks after implantation. Regenerative cartilage in implanted Biosheets in group 3 was confirmed by histological analysis. Tracheal epithelial regeneration occurred in the internal lumen of group 3. There were significant differences in the amounts of collagen type II and glycosaminoglycan between group 3 and group 1 or 2. CONCLUSION: We confirm that cartilage can self-regenerate onto an airway patch using Biosheets.

Tracheoplasty with cartilage-engineered esophagus environments.

PURPOSE: Our objective was to investigate the feasibility of engineering cartilage on the esophagus layer and outside the esophagus. Moreover, we investigated the feasibility of tracheoplasty with cartilage engineered on the esophagus in rabbits. METHODS: Chondrocytes were isolated from auricular cartilages. 1. Engineered cartilage formation by histological findings on/into the esophageal layer was compared with that of injectable scaffold and preformed scaffold with chondrocytes. 2. Chondrocytes adhered to gelatin+vicryl mesh™ and b-FGF, were implanted on the outer esophageal surface. Four weeks after seeding, we found that cartilage was implanted in the midposterior portion of the cervical trachea (n=5), and it was retrieved 8weeks after seeding. RESULTS: 1. A gelatin sponge incorporating ß-TCP with vicryl mesh™ showed the best performance for fabricating engineered cartilage on the outer side of the esophagus. 2. Two of 5 rabbits died due to obstructed esophagus. Cartilage engineered outside the esophagus by a composite scaffold as the main material in the gelatin sponge, maintained the airway structure for up to 1month after implantation. Tracheal epithelial regeneration occurred in the internal lumen of this engineered cartilage. CONCLUSION: Tracheoplasty with cartilage engineered outside the esophagus may be useful for reconstructing airways.