Isolation and characterization of dental epithelial cells derived from amelogenesis imperfecta rat

OBJECTIVE

Disruption of the third zinc finger domain of specificity protein 6 (SP6) presents an enamel-specific defect in a rat model of amelogenesis imperfecta (AMI rats). To understand the molecular basis of amelogenesis imperfecta caused by the Sp6 mutation, we established and characterized AMI-derived rat dental epithelial (ARE) cells.

MATERIALS AND METHODS

ARE cell clones were isolated from the mandibular incisors of AMI rats, and amelogenesis-related gene expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR). Localization of wild-type SP6 (SP6WT) and mutant-type SP6 (SP6AMI) was analyzed by immunocytochemistry. SP6 transcriptional activity was monitored by rho-associated protein kinase 1 (Rock1) promoter activity with its specific binding to the promoter region in dental (G5 and ARE) and non-dental (COS-7) epithelial cells.

RESULTS

Isolated ARE cells were varied in morphology and gene expression. Both SP6WT and SP6AMI were mainly detected in nuclei. The promoter analysis revealed that SP6WT and SP6AMI enhanced Rock1 promoter activity in G5 cells but that enhancement by SP6AMI was weaker, whereas no enhancement was observed in the ARE and COS-7 cells, even though SP6WT and SP6AMI bound to the promoter in all instances.

CONCLUSION

ARE cell clones can provide a useful in vitro model to study the mechanism of SP6-mediated amelogenesis imperfecta.

A case of diffuse panbronchiolitis, associated with severe pulmonary hypertension, managed with bilateral lung transplantation from a brain-dead donor

Diffuse panbronchiolitis (DPB) is a chronic respiratory disease that mainly involves the respiratory bronchioles, and has historically been associated with a very poor prognosis. The development of long-term low dose macrolide therapy in the 1980s has dramatically improved the prognosis of DPB. Nevertheless, some cases are resistant to macrolide therapy, and ultimately develop severe respiratory failure and pulmonary hypertension; in such cases lung transplantation is a viable treatment option. Here we report the case of a 40-year-old patient with a 20-year history of DPB, who underwent bilateral lung transplantation due to severe respiratory failure with pulmonary hypertension.

De novo expression of Nav1.7 in injured putative proprioceptive afferents: Multiple tetrodotoxin-sensitive sodium channels are retained in the rat dorsal root after spinal nerve ligation

Tetrodotoxin-sensitive (TTX-s) spontaneous activity is recorded from the dorsal roots after peripheral nerve injury. Primary sensory neurons in the dorsal root ganglion (DRG) express multiple TTX-s voltage-gated sodium channel α-subunits (Navs). Since Nav1.3 increases, whereas all other Navs decrease, in the DRG neurons after peripheral nerve lesion, Nav1.3 is proposed to be critical for the generation of these spontaneous discharges and the contributions of other Navs have been ignored. Here, we re-evaluate the changes in expression of three other TTX-s Navs, Nav1.1, Nav1.6 and Nav1.7, in the injured 5th lumbar (L5) primary afferent components following L5 spinal nerve ligation (SNL) using in situ hybridization histochemistry and immunohistochemistry. While the overall signal intensities for these Nav mRNAs decreased, many injured DRG neurons still expressed these transcripts at clearly detectable levels. All these Nav proteins accumulated at the proximal stump of the ligated L5 spinal nerve. The immunostaining patterns of Nav1.6 and Nav1.7 associated with the nodes of Ranvier were maintained in the ipsilateral L5 dorsal root. Interestingly, putative proprioceptive neurons characterized by α3 Na+/K+ ATPase-immunostaining specifically lacked Nav1.7 mRNA in naïve DRG but displayed de novo expression of this transcript following SNL. Nav1.7-immunoreactive fibers were significantly increased in the ipsilateral gracile nucleus where central axonal branches of the injured A-fiber afferents terminated. These data indicate that multiple TTX-s channel subunits could contribute to the generation and propagation of the spontaneous discharges in the injured primary afferents. Specifically, Nav1.7 may cause some functional changes in sensory processing in the gracile nucleus after peripheral nerve injury.

[The role of 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) in liposarcoma of the chest wall]

18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT)imaging is valuable in biopsy guidance, response assessment, grading, follow-up and prognostication for soft-tissue sarcoma. In liposarcoma, the maximum standardized uptake value (SUVmax) on PET/CT scan is correlated with the histological subtypes. We briefly review the role of FDG PET/CT in liposarcoma, and describe a case of chest wall liposarcoma treated based on the assessment with PET/CT. A 76-year-old man, with a 10-cm tumor at the thoracic outlet of the right chest wall, underwent the complete resection of the tumor according to the assessment with PET/CT that showed high FDG uptakeonly in the central area of the tumor with SUVmax of 5.89, but low uptake in the peripheral area. In accordance with the PET/CT findings, pathological examination revealed dedifferentiated liposarcoma in the central area and well-differentiated liposarcoma in the peripheral area. Pretherapy PET/CT should be performed for the appropriate treatment of liposarcoma.

CYP2C19 genotype-based phase I studies of a c-Met inhibitor tivantinib in combination with erlotinib, in advanced/metastatic non-small cell lung cancer

Background:

A previous clinical study in non-small cell lung cancer (NSCLC) patients in Western countries suggested the potential for combination of a first-in-class non-ATP-competitive c-Met inhibitor tivantinib with an epidermal growth factor receptor-tyrosine kinase inhibitor erlotinib. Polymorphisms of CYP2C19, the key metabolic enzyme for tivantinib, should be addressed to translate the previous Western study to Asian population, because higher incidence of poor metabolisers (PMs) is reported in Asian population.

Methods:

Japanese patients with advanced/metastatic NSCLC received tivantinib in combination with erlotinib to evaluate safety and pharmacokinetics. Doses of tivantinib were escalated separately for extensive metabolisers (EMs) and PMs.

Results:

Tivantinib, when combined with erlotinib, was well tolerated up to 360 mg BID for EMs and 240 mg BID for PMs, respectively. Among 25 patients (16 EMs and 9 PMs), the adverse events (AEs) related to tivantinib and/or erlotinib (>20%, any grade) were rash, diarrhoea, dry skin and nausea. Grade ⩾3 AEs were leukopenia, anaemia and neutropenia. No dose-limiting toxicity was observed. Pharmacokinetics profile of tivantinib was not clearly different between the combination and monotherapy. Three partial response and three long-term stable disease (⩾24 weeks) were reported.

Conclusion:

Two doses of tivantinib in combination with erlotinib were recommended based on CYP2C19 genotype: 360 mg BID for EMs and 240 mg BID for PMs.

Impact of lithium-ion ordering on surface electronic states of Li(x)CoO2

Li(x)CoO(2) exhibits intriguing electronic properties due to a strong electron correlation and complex interplay between Co and Li ions. However, fundamental understanding of the nanoscale distribution of Li ions and its effect on the electronic properties remains unclear. We use scanning tunneling microscopy and density functional theory to elucidate the degree of Li(x)CoO(2) surface electronic state modification that can be achieved by Li ordering. The surface Li ions are highly mobile and preferentially form a (1 × 1) hexagonal lattice, whereas the surface CoO(2) layer shows metallic and insulating phases, indicating the coexistence of ordered and disordered Li ions in the subsurface layer. These results provide evidence of novel electronic properties produced by spatially inhomogeneous Li-ordering patterns.

Detection of airway ischaemic damage after lung transplantation by using autofluorescence imaging bronchoscopy

OBJECTIVES

Airway complications related to ischaemia are a major cause of morbidity after lung transplantation. Early detection of airway ischaemia and optimal management of the anastomotic site could reduce the risk of airway complications. Autofluorescence imaging (AFI) bronchoscopy has been increasingly recognized as an effective technique for detecting abnormal mucosal thickening. The aim of this study was to investigate whether AFI bronchoscopy can facilitate the detection of airway ischaemic damage in lung transplant patients.

METHODS

Twenty Landrace pigs were used to create a tracheal autotransplantation model. A four-ring length of trachea was excised and implanted orthotopically. The tracheal autograft was observed on postoperative days 0, 2, 4 and 7 with AFI bronchoscopy. The extent and origin of graft autofluorescence were examined using histology and measured according to fluorescence intensity.

RESULTS

The lesions on the tracheal autografts appeared as bright green fluorescence on AFI bronchoscopy. On confocal fluorescence microscopy, high-intensity green fluorescence was observed in the elastin fibre layer of the submucosa. The fluorescence intensity of elastin was significantly higher in the graft showing fluorescence than the graft that did not show fluorescence and that at the control site.

CONCLUSIONS

Bright green fluorescence was seen in an elastin fibre layer in the submucosa, which was likely a result of epithelial sloughing. There is a close relationship between the bright green fluorescence pattern observed using AFI bronchoscopy and airway ischaemic damage. We conclude that AFI bronchoscopy may detect airway ischaemic damage after lung transplantation.

Role of oxygen holes in Li(x)CoO(2) revealed by soft X-ray spectroscopy

The fundamental electronic structure of the widely used battery material Li(x)CoO(2) still remains a mystery. Soft x-ray absorption spectroscopy of Li(x)CoO(2) reveals that holes with strong O 2p character play an essential role in the electronic conductivity of the Co(3+)/Co(4+) mixed valence CoO(2) layer. The oxygen holes are bound to the Co(4+) sites and the Li-ion vacancy, suggesting that the Li-ion flow can be stabilized by oxygen hole back flow. Such an oxygen hole state of Li(x)CoO(2) is unique among the various oxide-based battery materials and is one of the key ingredients to improving their electronic and Li-ion conductivities.

Combination therapy with cisplatin, 5'-deoxy-5-fluorouridine (5'-DFUR) and mitomycin (MMC) in patients with inoperable, advanced gastric cancer

The optimal dose of cisplatin (CDDP) for combination chemotherapy for the treatment of inoperable, advanced gastric cancer has yet to be established. We therefore performed a randomized study to compare the therapeutic usefulness of two dose levels of cisplatin. 5'-deoxy-5-fluorouridine (5'-DFUR 1,400 mg/m(2)/d) was given orally on days 1 to 4 and 15 to 18. Mitomycin C (MMC, 5.75 mg/m(2)/d) was injected intravenously on day 5. In addition, 80 mg/m2/d of CDDP (regimen A) or 60 mg/m(2)/d of CDDP (regimen B) was given by 2-h intravenous drip infusion on day 5. This treatment cycle was repeated every four weeks. Fifty-six patients were enrolled. Clinical response was evaluated in 32 patients (regimen A, 16 patients; regimen B? 16 patients) with measurable lesions. The response rate was significantly higher with regimen A (9 PR/16, 56.3%) than with regimen B (3 PR/16, 18.9%) (p=0.028, chi(2) test). Median survival was slightly but not significantly longer with regimen A (7.4 months) than with regimen B (6.3 months). Drug toxicity included myelosuppression and gastrointestinal symptoms, but there were no serious adverse reactions or differences in safety between the treatment regimens. Regimen A was associated with a high response rate and low toxicity. The optimal dose of CDDP in combination with 5'-DFUR and MMC for the treatment of advanced gastric cancer is regarded to be 80 mg/m(2).

Intrathoracic irrigation with arbekacin for methicillin-resistant Staphylococcus aureus empyema following lung resection

OBJECTIVES

Empyema is a well-known complication following lung resection. In particular, empyema caused by methicillin-resistant Staphylococcus aureus (MRSA) is difficult to treat. Here, we present our experience of MRSA empyema treated with local irrigation using arbekacin.

METHODS

Six patients consisted of 4 males and 2 females with an average age of 65.7 years. They developed MRSA empyema following lung resection and were treated at our institution between 2007 and 2011. Cases comprised four primary and one metastatic lung cancer, and 1 patient was a living lung transplantation donor. The surgical procedure consisted of four lobectomies, one segmentectomy and one wedge resection. After diagnosis of MRSA empyema, anti-MRSA drugs were administered intravenously in all cases. In addition, arbekacin irrigation at a dose of 100 mg dissolved in saline was performed after irrigation with saline only.

RESULTS

The average number of postoperative days for the diagnosis of MRSA empyema was 13 (range 4-19). The period of irrigation ranged from 6 to 46 days. Arbekacin irrigation did not induce nephrotoxicity or other complications, and no bacteria resistant to arbekacin was detected in the thoracic cavity. We re-operated on 1 case because he had pulmonary fistula and severe wound infection. At the time of removing the thoracic catheter, MRSA in the pleural effusion disappeared completely in 3 patients. The period until MRSA concentration in the pleural effusion became negative after starting arbekacin irrigation ranged from 4 to 9 days. In the remaining cases, in which MRSA did not disappear, the catheter was removed because of no inflammatory reaction after stopping irrigation and clamping the catheters. All patients were discharged from our institution without thoracic catheterization and no patients had relapsed during the follow-up period ranging from 6 to 44 months.

CONCLUSIONS

Irrigation of the thoracic cavity with arbekacin proved to be an effective, safe and readily available method for treating MRSA empyema following lung resection.

Determination of the optimal concentration of several selective drugs useful for generating multi-transgenic porcine embryonic fibroblasts

Porcine embryonic fibroblasts (PEFs) are widely used as donor cells for somatic cell nuclear transfer (SCNT) in pigs. Transfection of PEFs with exogenous DNA is essential for producing genetically modified (GM; transgenic or knockout) pigs via SCNT. In this case, selectable markers are strictly required selecting and enriching stably transfected cells. The most frequently used selective drug for this purpose is a neomycin analogue (G418/geneticin); neo has been widely used as a selectable marker gene in the genomic manipulation of pigs. However, little is known about optimal concentrations of other selection drugs. This often hampers functional analysis of the porcine genome and development of individual GM pigs. This study explores the optimal concentrations of selective drugs, other than neomycin, that can be used for the selection of transfected PEFs. Porcine embryonic fibroblasts were incubated in media containing different concentrations of drugs for up to 10 days, to determine the optimal drug concentrations fatal for PEFs. The following concentrations were found to be optimal selective concentrations for use with PEFs: G418/geneticin, 400 μg/ml; blasticidin S, 8 μg/ml; hygromycin B, 40 μg/ml; puromycin, 2 μg/ml; and zeocin, 800 μg/ml. Repeated transfections with plasmids carrying selectable markers resulted in the generation of multidrug-resistant swine transfectants. Furthermore, these markers were found to be independent. The present information will be useful for the production of SCNT-mediated GM piglets that express multiple transgenes.

Gene expression differences in oocytes derived from adult and prepubertal Japanese Black cattle during in vitro maturation

The present study was carried out to compare the gene expression profiles in oocytes derived from adult and prepubertal Japanese Black cattle during in vitro maturation (IVM) using microarray gene chips (Bovine genome array containing 24,072 probe sets representing over 23,000 transcripts). Microarray experiments were conducted using total RNA isolated from immature [germinal vesicle (GV)] and in vitro matured [metaphase II, (MII)] oocytes derived from adult and prepubertal animals. A total of 333 (1.4%) and 549 (2.3%) genes were differentially expressed between prepubertal vs adult bovine GV and MII stages oocytes, respectively. Of these, 176 and 312 genes were up-regulated, while 157 and 237 were down-regulated in prepubertal when compared with adult GV and MII oocytes, respectively. It was also observed that 695 (2.9%) and 553 (2.3%) genes were differentially expressed between GV vs MII stage oocytes in the adult and prepubertal groups, respectively. Gene ontological classification of the differentially expressed genes revealed that up-regulated genes in adult oocytes were involved in signal transduction, transcriptional control and transport. Quantitative reverse transcription-PCR validated the expression profile of some selected transcripts and confirmed differences in the expression levels of transcripts between adult vs prepubertal groups in both GV and MII stages oocytes as identified by microarray data analysis. This study indicated for the first time that significant number of genes were differentially expressed (>2-fold, p < 0.01) between oocytes derived from adult and those from prepubertal Japanese Black cattle, and this difference increased during IVM.