Direct cellular reprogramming and transdifferentiation of fibroblasts on wound healing-Fantasy or reality?

Induced pluripotent stem cell (iPSC) technology is one of the de novo approaches in regeneration medicine and has led to new research applications for wound healing in recent years. Fibroblasts have attracted wide attention as the first cell line used for differentiation into iPSCs. Researchers have found that fibroblasts can be induced into different types of cells in variable mediums or microenvironments. This indicates the potential "stem" characteristics of fibroblasts in terms of direct cellular reprogramming compared with the iPSC detour. In this review, we described the morphology and biological function of fibroblasts. The stem cell characteristics and activities of fibroblasts, including transdifferentiation into myofibroblasts, osteogenic cells, chondrogenic cells, neurons, and vascular tissue, are discussed. The biological values of fibroblasts are then briefly reviewed. Finally, we discussed the potential applications of fibroblasts in clinical practice.

Silver nanoparticles promote osteogenic differentiation of mouse embryonic fibroblasts in vitro.

OBJECTIVE: This study investigated if silver nanoparticles (AgNps) could promote the proliferation and osteogenic differentiation of mouse embryonic fibroblasts. METHODS: Mouse embryonic fibroblasts were divided into two groups: Group 1 cells were cultured in DMEM/F12 medium and Group 2 cells were cultured in osteogenic medium. Both groups were then treated with 16, 32, or 100 µM AgNps. Fibroblast proliferation and viability were measured using BrdU and MTT methods at varying time points. Alizarin red staining and alkaline phosphatase (ALP) activity were measured to observe fibroblast differentiation into osteoblasts. Proteomics (cytokine array) was used to detect 111 different cytokines during differentiation. RESULTS: AgNps stimulated proliferation of mouse embryonic fibroblasts at a concentration of 16 µM. Marked enhancement of calcium mineralization was observed in cells cultured with AgNps compared with cells cultured without AgNps. Group 2 cells displayed nodules around the center where the cell density was high. ALP activity of mouse embryonic fibroblasts cultured in osteogenic medium increased during the whole culture period. Addition of AgNps at concentrations of 32 µM and 100 µM induced higher ALP activity at days 7 and 14. Proteomic array results show that low density lipoprotein receptor (LDL-R) and proprotein convertase subtilisin/kexin type 9 (PCSK-9) were significantly increased, while osteoprotegerin (OPG) was significantly reduced in medium containing 16 µM AgNPs. CONCLUSION: AgNps could promote differentiation of mouse embryonic fibroblasts into osteoblastic cells. LDL-R and PCSK-9, as well as OPG, may play a critical role in this process.

Meconium peritonitis: A 22-year review in a tertiary referral center.

BACKGROUND: Meconium peritonitis (MP) is a sterile, chemical peritonitis resulting from in-utero fetal bowel perforation. Severe cases may lead to serious morbidities and mortalities. OBJECTIVE: To review the common antenatal ultrasound abnormalities associated with MP, and identify radiological and clinical prognostic factors. MATERIALS AND METHODS: Retrospective review of all neonates with MP from January 1997 to December 2019 treated in our hospital was performed. Antenatal ultrasound findings, clinical presentations and outcomes were analyzed. RESULTS: Thirty-five neonates (17 males, 18 females) were included in the study. Thirty-two (91.4%) attended antenatal screening, and 27 (84.4%) of them had abnormalities identified on antenatal ultrasound. The most common abnormality was polyhydramnios (43.8%). Nineteen (54.3%) patients were inborn. Twenty (57.1%) patients were born prematurely. Laparotomy was required in 85.7% of patients. The median time to laparotomy was shorter in the inborn group [1 day (0-9 days) vs 4 days (2-34 days), p = 0.001], but the duration of post-operative hospital stay was comparable [71 days (16-423 days) vs 73.5 days (23-231 days)]. However, such duration was found to be significantly longer in the pre-term group when compared to full-term [58.5 days (16-89 days) vs 85 (21-423 days), p = 0.01]. The most common pathology was small bowel atresia and there were two mortalities. CONCLUSION: Due to the advancement in prenatal detection, pediatric anesthesia, intensive care and surgical techniques, the morbidity and mortality of MP has much decreased. Effective multi-disciplinary antenatal counseling facilitated the perinatal management of MP and resulted in comparable prognosis and outcome in inborn and outborn neonates.

Gastrostomy tube migration causing gastric outlet obstruction and gastric perforation in children-two case reports.

Gastrostomy creation is a common procedure in paediatric surgery. It provides enteral nutrition to patients who cannot achieve adequate nutrition by mouth. Common indications of gastrostomy placement in children include syndromic or neurodevelopmental diseases, severe malformations of the aerodigestive tract, craniofacial abnormalities, and intractable gastroesophageal reflux disease with recurrent aspiration. It is also indicated in patients who suffer from failure to thrive and require extra caloric intake. In contrast to adults, paediatric patients have a weaker ability to complain about problems with their gastrostomy tubes when they occur, in particular when some of these neurological patients are non-communicable. Complications may arise when migration of the catheter goes unnoticed, causing obstruction. Due to the smaller stomach size, thinner gastric wall and narrower gastric outlet in paediatric patients, obstruction from the gastrostomy balloon may result in serious sequelae. Here we present two unusual but serious complications of gastrostomy tubes causing suspected duodenal obstruction and subsequent gastric perforation in paediatric patients, requiring emergency operations. Furthermore, we would like to emphasize the importance of proper gastrostomy tube care and alert the caretakers of the potential sinister complications that can arise. We would also like to take this opportunity to suggest measures to prevent their occurrence.

Long-term Results and Quality of Life Assessment in Biliary Atresia Patients: A 35-Year Experience in a Tertiary Hospital.

OBJECTIVES: To review long-term transplant-free survival and quality of life (QOL) of patients with biliary atresia (BA). METHODS: A retrospective study reviewing all patients with Kasai operation between January 1, 1980 and December 31, 2015 was performed to evaluate the transplant-free survival. Subgroup analysis of patients older than 20 years was carried out to assess the QOL using the Short Form-36 Health Survey and incidences of disease-related complications. Comparison between patients with native and transplanted liver was performed using two-tailed independent samples t-test (P value < 0.05, significant). RESULTS: The 20-year Kaplan-Meier transplant-free survival of the 141 patients in our study was 51%. The subgroup analysis of long-term survivors revealed a trend of increased prevalence of complications like esophageal varices, portal hypertension, and recurrent admissions in the patient groups with raised serum bilirubin (SB).Thirty-one patients were successfully contacted for QOL assessment, 26 (16 with native liver and 10 with transplanted liver) responded (76.5%). BA patients who were documented to have active complications have a significantly lower vitality score (50.7 vs 57.5, P = 0.015). There was no statistically significant difference in the scores between the transplanted group and the disease-free control group. However, the native liver group achieved a lower score in both the general health section (42.9 vs 49.6, P = 0.029) and the overall physical component (49.6 vs 54.4, P = 0.037). CONCLUSIONS: A significant proportion of our patients survive with their native liver for more than 20 years. These long-term survivors may suffer from complications that impair their QOL. They require continuous life-long care.

Assessing the long term manometric outcomes in patients with previous laparoscopic anorectoplasty (LARP) and posterior sagittal anorectoplasty (PSARP).

BACKGROUND/PURPOSE: The objective of this study is to compare the long term manometric outcomes in patients with previous laparoscopic anorectoplasty (LARP) and posterior sagittal anorectoplasty (PSARP). METHODS: This is a single-centered retrospective study and the participants were born with various types of anorectal malformation. Manometric assessment was carried out with high-resolution anorectomanometry performed as a day procedure. In addition, a seven-itemed bowel function score (BFS) was utilized to assess the functional outcomes. RESULTS: A total of 30 patients were included in this study (PSARP=14, LARP=16) and the median follow up periods were 15.5years and 9years in the PSARP and LARP groups respectively (p=0.06). The median value of BFS was significantly lower in the PSARP group (PSARP=12.5, range: 8-18; LARP=16, range: 10-20, p=0.03). The median value of sphincteric resting pressure was 20mmHg (range: 10-50mmHg) in the PSARP group and 40mmHg (range: 10-70mmHg) in the LARP group (p=0.05). There was no significant difference in following measurements: the percentage of patient having a normal sphincteric resting pressure (PSARP vs LARP=50% vs 75%, p=0.28); the median sphincteric squeeze pressure (PSARP vs LARP=30mmHg, range: 10-100 vs 50mmHg, range: 20-140mmHg, p=0.08); the incidence of rectoanal inhibitory reflex (RAIR) (PSARP vs LARP=42.9% vs 31.3%, p=0.14) and the median value for volume of air to elicit the first anal sensation (PSARP vs LARP=30ml, range: 20-60ml vs 40ml, range: 20-80ml, p=0.18). CONCLUSION: Anorectomanometry is a useful follow up study after anorectoplasty and majority of the patients with previous LARP could retain a normal sphincteric resting pressure during long term follow up. Comparing the two surgical approaches, patients with previous LARP could achieve a higher bowel function score as well as sphincter resting pressure in manometric assessment. LEVEL OF EVIDENCE: Level III.

Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development.

BACKGROUND: Platelet-derived growth factor receptor alpha (PDGFRα) is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures. PURPOSE: To address the temporal requirement of Pdgfra in embryonic development. METHODS: We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies. RESULTS: Current study showed that (i) conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5) resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii) the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives. CONCLUSION: Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a) the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b) if mutations / sequence variations of these regulatory elements cause these anomalies.

Is laparoscopic surgery better than open surgery for the repair of congenital duodenal obstruction? A review of the current evidences.

BACKGROUND/PURPOSE: Whether laparoscopic surgery is superior to open surgery in the repair of congenital duodenal obstruction remains controversial. The objective of this study is to systematically review the literatures, which compare the outcomes of these two operative approaches. METHODS: A systematic review of the studies comparing these two surgical approaches since 2000 was carried out. RESULTS: Four retrospective cohort studies comprising 180 patients were eligible for analysis. Duodenal atresia was the most common diagnosis (62.3%). Overall, there were no statistically significant differences in terms of operative duration (SMD: 0.75, 95% CI: 0.46-1.04), ventilator dependence (SMD: 0.04, 95% CI: -0.22 to 0.29), time to initial enteral feeding (SMD: 0.12, 95% CI: -0.14 to 0.38), time to full enteral feeding (SMD: 0.18, 95% CI: -0.15 to 0.50) and hospital stay (SMD: -0.03, 95% CI: -0.29 to 0.22). The overall incidences of anastomotic complications in laparoscopic vs open groups were 4.4% vs 1.8%. Two cases of missed distal pathology were reported in the laparoscopic group. CONCLUSIONS: Laparoscopic surgery is feasible in the repair of CDO. Study with larger sample size is needed for further analysis to examine whether open or laparoscopic approach is superior. Meanwhile, it is still safe to practice laparoscopic repair of CDO in skilled surgeons, with attention to the possibility of distal pathology.

Laparoscopic Nissen fundoplication for gastro-oesophageal reflux disease in infants.

INTRODUCTION: Data on laparoscopic Nissen fundoplication for gastro-oesophageal reflux disease (GERD) in infants remain limited. We describe our experience with this operation in children and in particular, infants younger than 12 months old. MATERIALS AND METHODS: Medical records of all paediatric patients who had laparoscopic fundoplication done for GERD from 1998 to 2013 were reviewed. Patients were divided into two groups based on age: group I: 0-12 months, and group II >12 months. Data on indications, patient's demographics, operative time, blood loss, conversions, complications, recurrences and duration of hospitalization were studied. RESULTS: A total of 86 patients were reviewed (group I, n = 21; group II, n = 65). While the mean age and body weight for group I were 8 ± 2.99 months and 6 ± 1.96 kg, the values for group II were 98 ± 65 months and 18 ± 9.6 kg, respectively. All patients had concurrent laparoscopic gastrostomy for feeding difficulties. The mean operative time was shorter in group I (157 ± 55 vs 169 ± 52 min, p = 0.66). Both groups had minimal blood loss only. The surgical outcomes in both groups were comparable in terms of recurrence (0 vs 3 %, p = 0.105) and complications (9.5 vs 6 %, p = 0.275). The median follow-up duration for group I and group II was 23 and 40 months, respectively. Sixteen (76 %) patients in group I and 45 (67 %) patients in group II did not develop pneumonia post fundoplication. CONCLUSION: Laparoscopic Nissen fundoplication can be safely performed in infants with outcomes comparable to older patients and a shorter operative duration. Low recurrence rate (up to 3 %) is shown by our long term follow-up data. We recommend laparoscopic Nissen fundoplication to be considered in managing infants with GERD.