Efficient Production of Hepatocyte-like Cells from Human-induced Pluripotent Stem Cells by Optimizing Growth Factors.

BACKGROUND: Generating hepatocytes with complete liver functions is still a challenge and developing more functional hepatocytes is needed. OBJECTIVE: To compare various differentiation factors and protocols and introducing a preferable protocol to differentiate human-induced pluripotent stem cells (hiPSCs) into hepatocyte-like cells (HLCs). METHODS: After 3 days of the endoderm differentiation of hiPSCs, the cells were incubated with 5 hepatocyte differentiation culture media, protocols (P), for 14 days-P1: hepatocyte growth factor and fibroblast growth factor-4 (FGF-4) for the first week and oncostatin-M and dexamethasone for the second week; P2: similar to P1 but FGF4 was used in both the first and second weeks; P3: similar to P1 but FGF-4 was not used; P4: similar to P1 but FGF-4 and dexamethasone were not used; and P5: similar to P1 but FGF-4 and oncostatin-M were not used. After 17 days, characterization was done by qRT-PCR, immunofluorescence and ELISA. RESULTS: The mRNA expression levels of hepatocyte markers (albumin, cytokeratin-18, tyrosine aminotransferase, hepatocyte nuclear factor-4α, cytochrome-P450 7A1) increased significantly (p<0.05) in the differentiated cells by 5 different protocols. Furthermore, significant protein expression and secretion of albumin were detected in the differentiated cells by 5 different protocols. In P3, the differentiated cells had the highest exhibit of hepatocyte characteristics and in P4 they had the lowest. Moreover, in P1 and P2 similar results were observed. CONCLUSION: Since P3 gave us the best results among all protocols, we recommend it as an efficient protocol to differentiate the functional HLCs from hiPSCs, which can improve cell therapies.

Antibiotic selective pressure and development of bacterial resistance detected in bacteriuria following kidney transplantation.

INTRODUCTION: Bacteriuria (symptomatic and asymptomatic) is the most common infectious complication after kidney transplantation. This study aimed to determine its prevalence among kidney transplant recipients hospitalized after transplantation, respective risk factors, and frequency of isolates and antibacterial susceptibility. METHODS: Retrospectively, we divided hospitalized patients into 3 groups. Groups 1 and 2 included 78 and 152 recipients with and without bacteriuria, respectively, and the potential risk factors were compared. Cefixime was prescribed as early postsurgical prophylaxis. Group 3 patients were 116 randomly selected nontransplantation patients with urinary tract infection. Frequency of uropathogens and their antibiotic susceptibility were compared in groups 1 and 3. RESULTS: In total, 103 bacteriuria episodes were detected in 15.2% of the patients. The frequency of risk factors in groups 1 and 2 was similar. Escherichia coli was the most common isolate in groups 1 (40.8%) and 3 (68.1%; P = .03). Streptococcus faecalis was the most common gram-positive isolate in groups 1 (17.5%) and 3 (6.9%; P = .03). Sensitivity rates in group 1 were 9% to trimethoprim-sulfamethoxazole, 20% to ciprofloxacin, and 38.4% to gentamicin, which was not significantly different from group 3. However, the sensitivity rates of gram-negative isolates to ceftriaxone were 9.5% and 28.4% (P = .004) in groups 1 and 3, respectively, and to cefixime 4.5% and 22% (P = .01). DISCUSSION: High antibacterial resistance of uropathogens isolated from kidney transplantation and nontransplantation patients is alarming. The higher resistance to third-generation cephalosporins in transplant recipients may be due to antibiotic selection pressure secondary to postsurgical prophylaxis with cefixime.

Orbital mucormycosis in an immunocompetent individual.

BACKGROUND: Orbital mucormycosis caused by Zygomycetes is a rare and fatal infection that generally affects the patients who are immunocompromised. Despite antifungal therapy and aggressive surgical intervention, mucormycosis can cause serious and rapidly fatal infections if delayed diagnosis or therapeutic management occurs. Here, we report orbital mucormycosis in a healthy boy, with a favorable outcome after aggressive treatment. He has had no recurrence since the end of his treatment. CASE PRESENT: A 2-year old healthy boy, some days after entry of dust particle to his left eye presented with swelling and redness of the eye. With diagnosis of "periorbital cellulitis" intravenous antibiotics vancomycin (40 mg/kg/day) and ceftriaxone (75 mg/kg/day) were started but no improvement was observed. The results of biopsy and tissue culture led us to a diagnosis of mucormycosis. Orbital exenteration, combined with intravenous amphotericin B (1 mg/kg/day), resulted in the patient's survival. CONCLUSION: Due to the high mortality rate of mucormycosis, early diagnosis based on clinical findings and biopsy could be effective for management of the patients suffering from this infection.