Maintenance of blood oxygen saturation dictates supplemental oxygen administration to premature infants, but hyperoxia predisposes survivors to respiratory diseases such as asthma. Although much research has focused on oxygen effects on alveoli in the setting of bronchopulmonary dysplasia, the mechanisms by which oxygen affects airway structure or function relevant to asthma are still under investigation. We used isolated human fetal airway smooth muscle (fASM) cells from 18-20 postconceptual age lungs (canalicular stage) to examine oxygen effects on intracellular Ca(2+) ([Ca(2+)](i)) and cellular proliferation. fASM cells expressed substantial smooth muscle actin and myosin and several Ca(2+) regulatory proteins but not fibroblast or epithelial markers, profiles qualitatively comparable to adult human ASM. Fluorescence Ca(2+) imaging showed robust [Ca(2+)](i) responses to 1 μM acetylcholine (ACh) and 10 μM histamine (albeit smaller and slower than adult ASM), partly sensitive to zero extracellular Ca(2+). Compared with adult, fASM showed greater baseline proliferation. Based on this validation, we assessed fASM responses to 10% hypoxia through 90% hyperoxia and found enhanced proliferation at <60% oxygen but increased apoptosis at >60%, effects accompanied by appropriate changes in proliferative vs. apoptotic markers and enhanced mitochondrial fission at >60% oxygen. [Ca(2+)](i) responses to ACh were enhanced for <60% but blunted at >60% oxygen. These results suggest that hyperoxia has dose-dependent effects on structure and function of developing ASM, which could have consequences for airway diseases of childhood. Thus detrimental effects on ASM should be an additional consideration in assessing risks of supplemental oxygen in prematurity.
Kaposi sarcoma inflammatory cytokine syndrome (KICS) is a newly-described condition affecting individuals who are HIV-positive and are infected with human herpesvirus 8 (HHV-8). This is a syndrome that in some ways mimics severe sepsis with associated acute respiratory distress syndrome, possibly requiring a ventilator and vasopressor support. However, unlike severe sepsis, antibiotics provide no benefit. Management of KICS has not been fully elucidated because of its high mortality rate. However, the syndrome has been successfully treated in some cases with immunomodulatory therapy. It is crucial for oncologists to be able to recognize this syndrome and to institute the appropriate therapy. 2017;22:623-625.
Introduction: PDAC is a lethal malignancy with a clear unmet need; almost all patients fail 1 st , 2 nd , and 3 rd line multi-agent cytotoxic chemotherapy. The mammalian target of rapamycin (mTOR) has been identified as a key signaling node enhancing tumor survival and drug resistance in PDAC, hence it is considered a promising therapeutic target.
Areas covered:We comprehensively reviewed the evidence from preclinical and phase I and II clinical trials, based on the authors'clinical experience and a pubmed, Chochrane library, Embase, and Google Scholar search everolimus + pancreatic cancer.
Expert opinion:Everolimus has not demonstrated efficacy in PDAC; however, an mTOR inhibitor in combination with stroma-targeted therapies may be a promising area to explore in clinical trials.
Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder characterized by hypersensitivity of the skin and eyes to UV-radiation as a result of a defect in one of eight genes. Seven genes (XPA-XPG) have a defect in Nucletoide Excision Repair (NER), while the eighth gene XPV has a defect in polymerase η, which is responsible for replication of UV-damaged DNA to produce corrected daughter strands. We present the varied clinical courses of three African-American female patients with XP. Additionally, we present a review of the literature that focuses on the various clinical manifestations as well as the genetic and molecular mechanisms underlying this disease.
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