Transcutaneous gas monitoring is a useful tool to detect respiratory depression during bronchoscopy performed under propofol sedation.

BACKGROUND: Bronchoscopy is a relatively invasive procedure where patients are often sedated. However, adequate sedation is not always achieved. Propofol is often used for difficult-to-sedate patients undergoing bronchoscopy despite a potential risk of respiratory depression. Transcutaneous carbon dioxide (tcpCO2) monitoring, introduced recently, is recognized as a convenient surrogate method for continuous monitoring of the partial pressure of arterial carbon dioxide (PaCO2). This study examined the safety of switching to propofol during bronchoscopy by using transcutaneous carbon dioxide monitoring. METHODS: Patients in whom transcutaneous gas monitoring had been performed during bronchoscopy were included in this study. The participants were divided into two groups: 1) the midazolam + fentanyl group (MF group), and 2) the group in which midazolam was switched to propofol owing to inadequate sedation obtained with midazolam + fentanyl (MFP group). We retrospectively analyzed the transcutaneous gas measurement data collected in patients under propofol sedation for bronchoscopy. RESULTS: This study included 61 (MF, n = 41; MFP, n = 20) patients. The duration of elevated tcpCO2 (>50 mm Hg) was greater in the MFP group (MF 8.5 min vs. MFP 22.1 min, p = 0.042). CONCLUSION: Switching midazolam to propofol during bronchoscopy was significantly associated with a higher risk of elevated tcpCO2, which is indicative of respiratory depression. Therefore, continuous tcpCO2 monitoring is required to ensure the safety of patients under propofol sedation for bronchoscopy.

A Protective Effect of Pirfenidone in Lung Fibroblast-Endothelial Cell Network via Inhibition of Rho-Kinase Activity.

Pulmonary fibrosis is a life-threatening disease that has been attributed to several causes. Specifically, vascular injury is thought to be involved in the pathogenesis of fibrosis. The effects of the antifibrotic drug pirfenidone on angiogenesis have not been fully elucidated. This study aimed to investigate the effects of pirfenidone in human lung fibroblast-endothelial cell co-culture network formation and to analyze the underlying molecular mechanisms. Human lung fibroblasts were co-cultured with human umbilical vein endothelial cells to establish a co-culture network cell sheet. The influence of pirfenidone was evaluated for protective effect on the endothelial network in cell sheets stimulated with transforming growth factor ß (TGF-ß). Results indicated that TGF-ß disrupted the network formation. Pirfenidone and Y27632 (Rho-associated coiled-coil containing protein kinase [Rho-kinase or ROCK] inhibitor) protected against the TGF-ß-induced endothelial network disruption. TGF-ß activated Rho-kinase signaling in cells composing the co-culture cell sheet, whereas pirfenidone and Y27632 inhibited these effects. In conclusion, TGF-ß-induced Rho-kinase activation and disrupted endothelial network formation. Pirfenidone suppressed TGF-ß-induced Rho-kinase activity in cell sheets, thereby enabling vascular endothelial cells networks to be preserved in the cell sheets. These findings suggest that pirfenidone has potential vascular network-preserving effect via inhibiting Rho-kinase activity in vascular injury, which is a precursor to pulmonary fibrosis.

Metabolic changes induced by TGF-ß1 via reduced expression of phosphatidylserine decarboxylase during myofibroblast transition.

Metabolic alteration is increasingly recognized as an important pathogenic process that underlies fibrosis across many organ types, and metabolically targeted therapies could become important strategies for reducing fibrosis. In present study, target enzymes that are involved in changes in phospholipid metabolism during fibroblast-to-myofibroblast transition induced by transforming growth factor beta 1 (TGF-ß1) were examined. Different amounts of phospholipids were found in the 2 groups. In response to TGF-ß1 stimulation, 17 lipids decreased and 17 increased. The latter included the phospholipids phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE). Furthermore, among the rate-limiting enzymes that regulate these phospholipids, phosphatidylserine decarboxylase (PISD), which controls conversion of PS to PE and is localized in mitochondria, decreased in response to TGF-ß1. Knockdown of PISD alone without TGF-ß1 stimulation increased expression of α-smooth muscle actin mRNA and production of total collagen. Taken together, these results indicate that PISD is involved in the mechanism of fibrogenesis by regulating phospholipid metabolism.

Carboplatin plus nab-paclitaxel for recurrent small cell lung cancer: A phase II study.

BACKGROUND: We conducted a phase II study of carboplatin plus nab-paclitaxel for the treatment of small cell lung cancer (SCLC) after the failure of a prior standard chemotherapy containing platinum, etoposide, irinotecan, and amrubicin if indicated. Patients with interstitial pneumonia complications were included in the study. METHODS: Patients received 100 mg/m2 of nab-paclitaxel weekly (on days 1, 8, and 15) and an AUC 5 of carboplatin on day 1. The study treatment was repeated every 3 weeks until disease progression or the appearance of unacceptable toxicities. The primary endpoint was the objective response rate. RESULTS: A total of 21 patients were enrolled, all of whom were eligible for inclusion in the analysis. Twelve patients had pre-existing interstitial pneumonia. The overall response rate was 19.0% (90% confidence interval [CI]: 6.8%-38.4%). The lower limit of the 90% CI for the response rate did not exceed the prespecified threshold value of 10%. Among the 12 patients with pre-existing interstitial pneumonia, the response rate was 25%. The median progression-free survival time was 2.5 months (95% CI: 1.5-3.4 months), and the median survival time was 5.1 months (95% CI: 2.1-8.1 months). Two patients developed interstitial lung disease; both of these patients had pre-existing interstitial pneumonia. One of the patients died from interstitial lung disease. CONCLUSION: Combination chemotherapy with carboplatin plus nab-paclitaxel for recurrent SCLC had a modest activity, although the primary study endpoint was not met. Further investigation of this regimen for patients with recurrent SCLC and interstitial pneumonia is warranted.

Imaging of lysophosphatidylcholine in an induced pluripotent stem cell-derived endothelial cell network.

INTRODUCTION: Vascular endothelial cell disorders are closely related to cardiovascular disease (CVD) and pulmonary diseases. Abnormal lipid metabolism in the endothelium leads to changes in cell signalling, and the expression of genes related to immunity and inflammation. It is therefore important to investigate the pathophysiology of vascular endothelial disorders in terms of lipid metabolism, using a disease model of endothelium. METHODS: Human induced pluripotent stem cell-derived endothelial cells (iECs) were cultured on a matrigel to form an iEC network. Lipids in the iEC network were investigated by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) imaging mass spectrometry (IMS) analysis. Ion fragments obtained by mass spectrometry were analysed using an infusion method, involving precursor ion scanning with fragment ion. RESULTS: The MALDI TOF IMS analysis revealed co-localized intensity of peaks at m/z 592.1 and 593.1 in the iEC network. Tandem mass spectrometry (MS/MS) analysis by MALDI-imaging, in conjunction with precursor ion scanning using an infusion method with lipid extracts, identified that these precursor ions were lysophosphatidylcholine (LPC) (22:5) and its isotype. CONCLUSION: The MALDI-imaging analysis showed that LPC (22:5) was abundant in an iEC network. As an in vitro test model for disease and potential therapy, present analysis methods using MALDI-imaging combined with, for example, mesenchymal stem cells (MSC) to a disease derived iEC network may be useful in revealing the changes in the amount and distribution of lipids under various stimuli.

Comparison of inducible nitric oxide synthase mRNA expression in different airway portions and association with nitric oxide parameters from patients with asthma.

BACKGROUND: Fractional exhaled nitric oxide concentration (FeNO) is widely used to support diagnosis and monitoring of bronchial asthma (BA). Tsoukias and George proposed a two-compartment model (2CM) for assessing the alveolar concentration of NO, referred to as CANO(2CM), while Condorelli et al proposed a model based on the trumpet shape of the airway tree and axial diffusion (TMAD), referred to as CANO(TMAD). In addition, Högman et al proposed non-linear model, referred to as CANO(non-linear). OBJECTIVE: We examined associations between the expression of inducible nitric oxide synthase (iNOS) mRNA in airway cells (ACs) by bronchoscopy and NO-parameters calculated by the three methods and identified which of them accurately reflected expression of iNOS mRNA from different airway portions. METHODS: We retrospectively analysed data of 18 patients with stable, mild-moderate asthma, including 10 steroid-naïve BA (snBA) patients. Samples were obtained from airway brushings and bronchoalveolar lavage (BAL). Expressions of iNOS protein in tissue samples were evaluated by immunostaining. The iNOS mRNA in ACs was measured by qPCR. NO-parameters calculated by the three methods above and evaluated whether they were associated with iNOS mRNA in ACs derived from proximal (2nd carina), distal (10-15th) airways and alveolar regions. RESULTS: Immunostaining revealed expression of iNOS proteins mainly in epithelial cells in the airways, while it was mainly expressed in macrophages in the alveolar region in the snBA group. The iNOS mRNA expression was increased in both proximal and distal ACs in the snBA group compared with steroid-treated BA group (stBA). CANO(2CM) negatively associated with FEV1 (%predicted) and also associated with iNOS mRNA in distal ACs significantly. However, CANO(TMAD) and CANO(non-linear) showed no correlation with lung function nor iNOS mRNA expression in any portions of ACs. CONCLUSIONS: These results suggested that CANO(2CM) reflected distal airway inflammation in steroid-naïve asthma.

Detection of neurotrophic factors in taste buds by laser capture microdissection, immunohistochemistry, and in situ hybridization.

Neurotrophic factors are thought to function in the survival and maintenance of the taste buds and nerve fibers innervating them. Laser capture microdissection (LCM) coupled with the reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the mRNA of neurotrophic factors and their receptors in the taste buds of adult mouse circumvallate papillae. Results showed mRNAs of the ciliary neurotrophic factor (CNTF), its receptor (CNTFR), glial cell line-derived neurotrophic factor (GDNF), GDNF family receptors alpha-1 (GFRalpha-1), GFRalpha-2, and RET tyrosine kinase receptor (RET), neurotrophin (NT)3, NT4/5, tyrosine kinase (Trk) C, nerve growth factor (NGF), and TrkA were expressed in the isolated taste buds. Among these neurotrophic factors, GDNF, GFRalpha-1, GFRalpha-2, NT3, NT4/5, NGF, and TrkA were previously found in the taste buds immunohistochemically and were detected at the mRNA level in the present study. The present immunohistochemical study revealed that CNTF, CNTFR, and the RET tyrosine kinase receptor, which binds GDNF family/ receptor complexes, were also expressed in the taste buds. However, by in situ hybridization, mRNAs of CNTF and RET were not detected in the taste buds from adult mice although they were found in those from early postnatal mice. CNTFR mRNA did not show any specific pattern in the taste buds. Moreover, mRNA expressions of NT4/5 and TrkC was re-examined by in situ hybridization; however no specific pattern was found for them in the taste buds. In summary, LCM is a useful tool for the detection of a relatively small amount of mRNA, such as that of neurotrophic factors and receptors in the taste buds.

Expression of glial cell line-derived neurotrophic factor (GDNF) and GDNF family receptor alpha1 in mouse taste bud cells after denervation.

Glial cell line-derived neurotrophic' factor (GDNF) has been isolated as a neurotrophic factor that affects the survival and maintenance of central and peripheral neurons. Using immunocytochemical methods, we examined whether the taste bud cells in mouse circumvallate papillae after transection of the glossopharyngeal nerves expressed GDNF and its receptor, GDNF family receptor alpha1 (GFRalpha1). By 5 and 10 days after denervation, the number of taste buds had decreased markedly; however, the remaining taste bud cells still expressed GDNF and GFRalpha1. By 14 days after denervation, most of the taste buds had disappeared and GDNF- and GFRalpha1-immunoreactive cells were not seen. By 4 weeks after denervation, numerous TrkB-immunoreactive nerve fibers had invaded the papilla and a few taste buds expressing GDNF and GFRalpha1 had regenerated. Thus, GDNF- and GFRalpha1-immunoreactive taste bud cells after denervation vanished following the disappearance of the taste buds and reappeared at the same time as the taste buds reappeared.

Expression of GDNF and GFR alpha 1 in mouse taste bud cells.

GDNF (glial cell line-derived neurotrophic factor) affects the survival and maintenance of central and peripheral neurons. Using an immunocytochemical method, we examined whether the taste bud cells in the circumvallate papillae of normal mice expressed GDNF and its GFR alpha 1 receptor. Using double immunostaining for either of them and NCAM, PGP 9.5, or alpha-gustducin, we additionally sought to determine what type of taste bud cells expressed GDNF or GFR alpha 1, because NCAM is reported to be expressed in type-III cells, PGP 9.5, in type-III and some type-II cells, and alpha-gustducin, in some type-II cells. Normal taste bud cells expressed both GDNF and GFR alpha 1. The percentage of GDNF-immunoreactive cells among all taste bud cells was 31.63%, and that of GFR alpha 1-immunoreactive cells, 83.21%. Confocal laser scanning microscopic observations after double immunostaining showed that almost none of the GDNF-immunoreactive cells in the taste buds were reactive with anti-NCAM or anti-PGP 9.5 antibody, but could be stained with anti-alpha-gustducin antibody. On the other hand, almost all anti-PGP 9.5- or anti-alpha-gustducin-immunoreactive cells were positive for GFR alpha 1. Thus, GDNF-immunoreactive cells did not include type-III cells, but type-II cells, which are alpha-gustducin-immunoreactive; on the other hand, GFR alpha 1-immunoreactive cells included type-II and -III cells, and perhaps type-I cells. We conclude that GDNF in the type-II cells may exert trophic actions on type-I, -II, and -III taste bud cells by binding to their GFR alpha 1 receptors.

Expression of BDNF and TrkB in mouse taste buds after denervation and in circumvallate papillae during development.

BDNF (brain-derived neurotrophic factor) is a member of the neurotrophin family which affects the proliferation and survival of neurons. Using an immunocytochemical method, we examined the expression of BDNF and its receptor, TrkB, in the taste bud cells of the circumvallate papillae of normal mice and of mice after transection of the glossopharyngeal nerves. We additionally observed the expression of BDNF and TrkB in the developing circumvallate papillae of late prenatal and early postnatal mice. In normal untreated mice, BDNF was expressed in most of the taste bud cells; TrkB was detected in the plasma membrane of taste bud cells and in the nerve fibers. Double-labeling studies showed that BDNF and NCAM (neural cell adhesion molecule) or TrkB and NCAM colocalized in some of the taste bud cells, but that most taste bud cells were immunopositive for only BDNF or TrkB. NCAM-immunoreactive cells are known to be type-III cells, which have afferent synaptic contacts with the nerve terminals. Five days after denervation, the number of taste buds and nerve fibers markedly decreased; however, the remaining taste bud cells still expressed BDNF and TrkB. By 10 days after denervation, most of the taste buds had disappeared, and there were a few TrkB-immunoreactive nerve fibers in the connective tissue core. By 4 weeks after denervation, numerous TrkB-immunoreactive nerve fibers had invaded the papillae, and a few taste buds expressing BDNF and TrkB had regenerated. At E (embryonic day) 15 during development, the circumvallate papillae appeared, and then TrkB-immunoreactive nerve fibers entered the connective tissue core, and some of these fibers further invaded among the dorsal epithelial cells of the papillae. TrkB-immunoreactive oval-shaped cells were occasionally found in the dorsal epithelium. Such TrkB-immunoreactive nerve fibers and cells were also observed at E16-18. However, BDNF was not expressed in the papillae through the late prenatal days of E15 to E18. At P (postnatal day) 0, a cluster of BDNF-and TrkB-immunoreactive cells appeared in the dorsal epithelium of the papillae, and was presumed to be primitive taste buds. We conclude that TrkB-immunoreactive nerve fibers are necessary for papillary and taste bud formation during development and for the regeneration of taste buds after denervation. BDNF in the taste bud cells may act as a neurotrophic factor for innervating sensory neurons--through TrkB receptors of the axons of those neurons, and also may exert autocrine and paracrine trophic actions on neighboring taste bud cells by binding to their TrkB receptors.