The stem cell factor (SCF)/c-KIT axis plays an important role in the hematopoietic differentiation of human pluripotent stem cells (hPSCs), but its regulatory mechanisms involving microRNAs (miRs) ...are not fully elucidated. Here, we demonstrated that supplementation with SCF increases the hematopoietic differentiation of hPSCs via the interaction with its receptor tyrosine kinase c-KIT, which is modulated by miR-221 and miR-222. c-KIT is comparably expressed in undifferentiated human embryonic and induced pluripotent stem cells. The inhibition of SCF signaling via treatment with a c-KIT antagonist (imatinib) during hPSC-derived hematopoiesis resulted in reductions in the yield and multi-lineage potential of hematopoietic progenitors. We found that the transcript levels of miR-221 and miR-222 targeting c-KIT were significantly lower in the pluripotent state than they were in terminally differentiated somatic cells. Furthermore, suppression of miR-221 and miR-222 in undifferentiated hPSC cultures induced more hematopoiesis by increasing c-KIT expression. Collectively, our data implied that the modulation of c-KIT by miRs may provide further potential strategies to expedite the generation of functional blood cells for therapeutic approaches and the study of the cellular machinery related to hematologic malignant diseases such as leukemia.
The surfaces of carbon molecular sieves (CMSs) were thermally fluorinated to adsorb water vapor. The fluorination of the CMSs was performed at various temperatures (100, 200, 300, and 400°C) to ...investigate the effects of the fluorine gas (F2) content on the surface properties. Fluorine-related functional groups formed were effectively generated on the surface of the CMSs via thermal fluorination process, and the total pore volume and specific surface area of the pores in the CMSs increased during the thermal fluorination process, especially those with diameters ≤ 8 Å. The water vapor adsorption capacity of the thermally fluorinated CMSs increased compared with the as-received CMSs, which is attributable to the increased specific surface area and to the semicovalent bonds of the C–F groups.
The surfaces of carbon molecular sieves (CMSs) were thermally fluorinated to adsorb water vapor. The fluorination of the CMSs was performed at various temperatures (100, 200, 300, and 400°C) to ...investigate the effects of the fluorine gas (F 2 ) content on the surface properties. Fluorine-related functional groups formed were effectively generated on the surface of the CMSs via thermal fluorination process, and the total pore volume and specific surface area of the pores in the CMSs increased during the thermal fluorination process, especially those with diameters ≤ 8 Å. The water vapor adsorption capacity of the thermally fluorinated CMSs increased compared with the as-received CMSs, which is attributable to the increased specific surface area and to the semicovalent bonds of the C–F groups.
Stenotrophomonas maltophilia is a gram-negative bacillus that has become increasingly recognized as an important nosocomial pathogen, particularly in individuals with severe debilitation or ...immunosuppression. S. maltophilia is also characterized by its resistance to multiple antibiotics. S maltophilia peritonitis in CAPD (continuous ambulatory peritoneal dialysis) patients is associated with a poor prognosis and loss of CAPD catheter. No report concerning this entity has been presented in Korea. Therefore, we describe and discuss five cases of the S. maltophilia infection associated with CAPD in three patients with peritonitis and two with exit-site infections.
We performed a retrospective search for episodes of S. maltophilia infections related to CAPD in our renal unit. The baseline levels of hemoglobin, albumin, cholesterol, BUN and creatinine were compared with age, sex and, if possible, the underlying disease-matched controls.
All the patients with S. maltophilia peritonitis had diabetes mellitus as the underlying disease. The individual patients also had other significant combined morbidities, such as panhypopituitarism, COPD chronic obstructive pulmonary disease, cerebrovascular accident and myocardial infarction. The level of hemoglobin in these patients was significantly lower than in the controls, and the mean values of serum albumin, creatinine and BUN were also low.
Immune dysfunction due to uremia, anemia, malnutrition, other comorbidities (e.g. diabetes mellitus), and also, an indwelling peritoneal catheter may be predisposing factors for the S. maltophilia infection in CAPD patients. Once the S. maltophilia infection is diagnosed in CAPD patient, the patient should be treated based on the understanding of this particular organism.
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