Association of low back pain and sleep quality with presenteeism

BACKGROUND

Low back pain (LBP) and poor subjective sleep quality (SSQ) are major risk factors for presenteeism. However, no studies have investigated whether combined LBP and poor SSQ are associated with presenteeism.

AIMS

We aimed to examine whether a combination of LBP and poor SSQ is associated with presenteeism.

METHODS

This cross-sectional study included 936 workers (median age, 38 years; men, 89%), with evaluated presenteeism using the work limitations questionnaire. We divided them into 'no presenteeism' and 'presenteeism' categories. The presence of LBP was defined as a numerical rating scale (NRS) score of ≥1 in current pain intensity. SSQ was assessed using a single question regarding whether the participants typically got enough sleep. We categorized the participants into four groups: (i) LBP + poor SSQ, (ii) non-LBP + poor SSQ, (iii) LBP + good SSQ and (iv) non-LBP + good SSQ. Logistic regression analysis was used to investigate the association between presenteeism and the presence of LBP and poor SSQ, adjusting for age, sex, work type, education, marital status, smoking status, body mass index and weekly working hours.

RESULTS

The data from 533 participants were used for analysis (median age, 38 years; men, 90%, response rate, 66%). Combined LBP and poor SSQ were significantly associated with presenteeism (non-LBP + poor SSQ: adjusted odds ratio = 0.56, 95% CI 0.32-0.96; LBP + good SSQ: 0.33, 0.20-0.56; non-LBP + good SSQ: 0.29, 0.18-0.48).

CONCLUSIONS

Evaluating both LBP and SSQ may be beneficial in considering presenteeism.

Inactivation of Notch4 Attenuated Pancreatic Tumorigenesis in Mice

Expression of the Notch family of receptors is often upregulated in pancreatic ductal adenocarcinoma (PDAC). In this study, we focused on Notch4, which had not been investigated in PDAC. We generated KC (LSL-KrasG12D;p48-Cre), N4 - / - KC (Notch4- / -;LSL-KrasG12D;p48-Cre), PKC (p16fl/fl;LSL-KrasG12D;p48-Cre), and N4 - / - PKC (Notch4-/ -; p16fl/f l;LSL-KrasG12D;p48-Cre) genetically engineered mouse models (GEMM). We performed caerulein treatment in both KC and N4 - / - KC mice, and the development of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) lesions were significantly diminished in the N4 - / - KC than in the KC GEMM (P = 0.01). This in vivo result was validated by in vitro ADM induction of the explant cultures of pancreatic acinar cells from the N4 - / - KC and KC mice (P < 0.001), confirming that Notch4 is an important contributor to early pancreatic tumorigenesis. To evaluate the role of Notch4 in the later stage of pancreatic tumorigenesis, we compared the PKC and N4 - / - PKC mice. The N4 - / - PKC mice had better overall survival (P = 0.012) and significantly reduced tumor burden (PanIN: P = 0.018 at 2 months, PDAC: P = 0.039 at 5 months) compared with the PKC GEMM. RNA-sequencing analysis of pancreatic tumor cell lines derived from the PKC and N4 - / - PKC GEMMs revealed that 408 genes were differentially expressed (FDR < 0.05) and Pcsk5 is a potential downstream effector of the Notch4 signaling pathway (P < 0.001). Low expression of Pcsk5 positively correlates with good survival in patients with PDAC (P = 0.028). We have identified a novel role for Notch4 signaling with tumor-promoting function in pancreatic tumorigenesis. Our study also uncovered a novel association between Pcsk5 and Notch4 signaling in PDAC.

Significance

We demonstrated that global inactivation of Notch4 significantly improved the survival of an aggressive mouse model for PDAC and provided preclinical evidence that Notch4 and Pcsk5 are novel targets for PDAC therapies.

Abstract PO-073: Inactivation of Notch4 attenuated pancreatic tumorigenesis in mice

Expression of the Notch family of receptors are often upregulated in pancreatic ductal adenocarcinoma (PDAC), however, the functional impacts of the Notch signaling network on pancreatic tumorigenesis remain unresolved. In this study, we focused on Notch4, which had not been investigated in PDAC. Leveraging the conventional Notch4 deficient mouse line and previously established genetically engineered mouse models (GEMM) for PDAC, we generated KC (LSL-KrasG12D;p48-Cre), N4−/−KC (Notch4−/−;LSL-KrasG12D;p48-Cre), PKC (p16flox/flox;LSL-KrasG12D;p48-Cre), and N4−/−PKC GEMMs (Notch4−/−; p16flox/lox;LSL-KrasG12D;p48-Cre). We performed caerulein treatment in both KC and N4−/−KC mice, and compared the development of acinar to ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) between them. The ADM/PanIN lesions were significantly smaller in the N4−/−KC than in the KC GEMM (p=0.01), suggesting that Notch4 deficiency attenuated early pancreatic tumorigenesis. This in vivo result was confirmed by in vitro ADM induction of the explant cultures of mouse pancreatic acinar cells. The number of ADM structures in the N4−/−KC acinar cultures was significantly lower than the KC acinar cultures (p&lt;0.001). To evaluate the role of Notch4 in the later stage of pancreatic tumorigenesis, we compared the histological progression and overall survival between the PKC and N4−/−PKC mice. We found that N4−/−PKC mice had better prognosis (p=0.012) and less tumor burden (PanIN: p=0.018 (2 months), PDAC: p=0.039 (5 months)) compared to the PKC GEMM. RNA-Seq analysis of pancreatic tumor cell lines derived from the PKC and N4−/−PKC GEMMs revealed 408 genes were differentially expressed (FDR&lt;0.05) and the genes related to the NGF processing as novel downstream effectors of the Notch4 signaling pathway(p&lt;0.001). Our study is a novel biological investigation that demonstrated that Notch4 signaling possesses tumor promoting function in pancreatic tumorigenesis. Our study revealed a novel association between the NGF processing pathway and Notch4 signaling in PDAC.

Citation Format: Kiyoshi Saeki, Wanglong Qiu, Richard Friedman, Carrie Shawber, Jan Kitajewski, Jianhua Hu, Gloria H. Su. Inactivation of Notch4 attenuated pancreatic tumorigenesis in mice [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-073.

Chronic inflammatory changes and oxidative stress in the background of "pancreatic ductal adenocarcinoma concomitant with intraductal papillary mucinous neoplasm"

Cases of "pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm" (IPMN) have multiple PDAC lesions more frequently than cases of "PDAC without IPMN". However, the mechanism of carcinogenesis in this former disease category remains unknown. The main objective of this work was thus to investigate the effects of chronic inflammation on carcinogenesis in PDAC cases. We selected 31 "PDAC concomitant with IPMN" patients and 58 "PDAC without IPMN" patients and pathologically evaluated their background pancreatic parenchyma. Fibrosis and inflammation scores of background pancreas were higher in "PDAC concomitant with IPMN" than in "PDAC without IPMN" (P < 0.0001 and P < 0.0001, respectively), whereas the fatty infiltration score of background pancreas was high in "PDAC without IPMN" (P = 0.0024). Immunohistochemically, the expression of 8-hydroxy-2'-deoxyguanosine (8-OHDG), an oxidative stress marker, in the background pancreas was high in "PDAC concomitant with IPMN" compared with that in "PDAC without IPMN" (P < 0.0001). Chronic inflammation activates oxidative stress in tissue throughout the pancreas and probably confers susceptibility to tumorigenesis in "PDAC concomitant with IPMN".

Evaluation of epithelial and mesenchymal cell markers in canine urinary bladder transitional cell carcinoma

Canine transitional cell carcinoma (cTCC) is the most common malignant tumour in the urinary bladder: it is highly invasive and exhibits metastatic characteristics. Inflammation is also strongly related to cTCC. Epithelial tumours often exhibit a mesenchymal cell phenotype during tumour invasion and metastasis owing to epithelial-mesenchymal transition (EMT), which is often induced in chronic inflammation. The aim of this retrospective study was to investigate the expression of epithelial and mesenchymal cell markers in tumour cells and to evaluate its relationship with prognosis of cTCC. In this study, 29 dogs with cTCC who underwent surgical treatment were enrolled. Clinical parameters were reviewed using medical records. Tissue expression of epithelial and mesenchymal markers was evaluated by immunohistochemical analysis. The association between the expression of mesenchymal cell markers and clinical parameters, including prognosis, was statistically examined. In five normal bladder tissues used as controls, no expression of mesenchymal markers was observed, except for one tissue that expressed fibronectin. Conversely, epithelial tumour cells expressed vimentin and fibronectin in 23/29 and 19/28 cTCC tissues, respectively. Regarding clinical parameters, vimentin score in Miniature Dachshunds was significantly higher than those in other dog breeds (P < 0.001). Multivariate survival analyses revealed that age>12 years was related to shorter progression-free survival (P = 0.02). Higher vimentin score, lower fibronectin score, and advanced clinical T stage were significantly correlated with shorter median survival time (P < 0.05). The results of this study indicate that vimentin expression was associated with cTCC progression. Further studies are needed to examine the incidence and relevance of EMT in cTCC.

PIK3CA and p53 Mutations Promote 4NQO-Initated Head and Neck Tumor Progression and Metastasis in Mice

The PI3K signaling pathway is frequently mutated in head and neck squamous cell carcinoma (HNSCC), often via gain-of-function (GOF) mutations in the PIK3CA gene. Here, we present novel genetically engineered mouse models (GEMM) carrying a GOF allele Loxp-STOP-Loxp(LSL)-PIK3CAH1047R (E20) alone or in combination with heterozygous LSL-p53+/R172H (p53) mutation with tissue-specific expression to interrogate the role of oncogenic PIK3CA in transformation of upper aerodigestive track epithelium. We demonstrated that the GOF PIK3CA mutation promoted progression of 4-nitroquinoline 1-oxide-induced oral squamous cell carcinoma (OSCC) in both E20 single mutant and E20/p53 double mutant mice, with frequent distal metastasis detected only in E20/p53 GEMM. Similar to in human OSCC, loss of p16 was associated with progression of OSCC in these mice. RNA-seq analyses revealed that among the common genes differentially expressed in primary OSCC cell lines derived from E20, p53, and E20/p53 GEMMs compared with those from the wild-type mice, genes associated with proliferation and cell cycle were predominantly represented, which is consistent with the progressive loss of p16 detected in these GEMMs. Importantly, all of these OSCC primary cell lines exhibited enhanced sensitivity to BYL719 and cisplatin combination treatment in comparison with cisplatin alone in vitro and in vivo, regardless of p53 and/or p16 status. Given the prevalence of mutations in p53 and the PI3K pathways in HNSCC in conjunction with loss of p16 genetically or epigenetically, this universal increased sensitivity to cisplatin and BYL719 combination therapy in cancer cells with PIK3CA mutation represents an opportunity to a subset of patients with HNSCC. IMPLICATIONS: Our results suggest that combination therapy of cisplatin and PI3K inhibitor may be worthy of consideration in patients with HNSCC with PIK3CA mutation.

FAM115C could be a novel tumor suppressor associated with prolonged survival in pancreatic cancer patients

Hypoxia is a characteristic feature of the tumor microenvironment in pancreatic ductal adenocarcinoma (PDAC). We have recently explored new targeting molecules and pathways in PDAC cells under hypoxic conditions. In this study, we performed a microarray experiment to analyze the genes up-regulated in PDAC cell lines under hypoxia compared to normoxia, and identified human family with sequence similarity 115, member C (FAM115C) as a candidate gene for further study. Our data showed that FAM115C was overexpressed in PDAC cell lines under hypoxia, and FAM115C inhibition promoted PDAC cell migration and invasion in vitro. FAM115C inhibition did not affect tumor cell proliferation in PDAC. Immunohistochemically, FAM115C expression was observed ubiquitously in normal pancreas, pancreatic intraepithelial neoplasia (PanIN) and PDAC tissue, and it was located mainly in the nucleus but also in the cytoplasm of cells. In qPCR analysis, high expression of FAM115C was correlated with better prognosis in patients with PDAC. Our findings suggest that FAM115C could be a novel tumor suppressor associated with prolonged survival in patients with PDAC.

"Pancreatic Mucoepidermoid Carcinoma" Is not a Pancreatic Counterpart of CRTC1/3-MAML2 Fusion Gene-related Mucoepidermoid Carcinoma of the Salivary Gland, and May More Appropriately be Termed Pancreatic Adenosquamous Carcinoma With Mucoepidermoid Carcinoma-like Features

"Mucoepidermoid carcinoma (MEC)" has been accepted as a synonym for pancreatic adenosquamous carcinoma (ASC). Pancreatic ASC can show salivary gland-type MEC-like morphology. CRTC1/3-MAML2 fusion gene is a characteristic molecular feature of MEC of the salivary gland. We conducted this study to clarify whether the pancreatic ASC with salivary gland-type MEC-like morphology (Pan-MEC) is a pancreatic counterpart of salivary gland-type MEC (Sal-MEC). We retrospectively analyzed 37 pancreatic ASCs including 16 Pan-MECs and 21 tumors without MEC-like features (ASC-NOS [not otherwise specified]), and we investigated (1) clinicopathologic features, (2) the presence of CRTC1/3-MAML2 fusion gene by reverse transcription polymerase chain reaction, (3) the presence of rearrangement of MAML2 gene by fluorescence in situ hybridization, and (4) mucin core proteins by immunohistochemistry. We also compared 16 Pan-MECs with 20 Sal-MECs by immunohistochemistry for mucin core protein. There were no significant differences of any clinicopathologic characteristics and survival analysis between the Pan-MECs and ASCs-NOS. Of note, the pancreatic ASCs (including Pan-MEC and ASC-NOS) were significantly more aggressive than conventional pancreatic ductal adenocarcinoma. In addition, all Pan-MECs were histologically high-grade. CRTC1/3-MAML2 fusion gene and MAML2 gene rearrangement were not detected in any ASCs including Pan-MECs. There were significant differences of MUC5AC and MUC6 between the Pan-MECs and Sal-MECs, but no significant differences of mucin core protein between the Pan-MECs and pancreatic ASCs-NOS. Pan-MEC is histologically and biologically high-grade and unrelated to CRTC1/3-MAML2 fusion gene, unlike Sal-MEC which is related to CRTC1/3-MAML2 fusion gene. Pan-MEC is not a pancreatic counterpart of CRTC1/3-MAML2 fusion gene-related Sal-MEC.

Pancreatic Juice Exosomal MicroRNAs as Biomarkers for Detection of Pancreatic Ductal Adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal neoplasm because of difficulties in early detection. Several studies have recently suggested that exosomes may have potential as novel biomarkers. This study aimed to isolate exosomes from pancreatic juice and to investigate whether exosomal microRNAs (ex-miRs) could be used as biomarkers for PDAC.

METHODS

Pancreatic juice was collected from patients with PDAC and chronic pancreatitis (CP) by endoscopic retrograde pancreatography. Exosomes were extracted by ultracentrifugation. The presence of exosomes was confirmed by electron microscopy and Western blotting using anti-CD63, -CD81, and -TSG101 antibodies. Relative levels of ex-miR-21 and ex-miR-155 were quantified and compared between PDAC and CP patients.

RESULTS

A total of 35 pancreatic juice samples (27 PDAC and 8 CP) were collected. Relative levels of both ex-miR-21 and ex-miR-155 were significantly higher in PDAC patients compared with CP patients (p < 0.001 and p = 0.008, respectively). By contrast, no significant difference was apparent in relative levels of miR-21 and miR-155 in whole pancreatic juice from PDAC patients compared with CP patients (p = 0.08 and p = 0.61, respectively). Ex-miR-21 and ex-miR-155 levels discriminated PDAC patients from CP patients with area under the curve values of 0.90 and 0.89, respectively. The accuracies of ex-miR-21 levels, ex-miR-155 levels, and pancreatic juice cytology were 83%, 89%, and 74%, respectively. When combining the results of ex-miR profiling with pancreatic juice cytology, the accuracy was improved to 91%.

CONCLUSIONS

We successfully extracted exosomes from pancreatic juice. Ex-miRs, including ex-miR-21 and ex-miR-155, in pancreatic juice may be developed as biomarkers for PDAC.

Pancreatic Juice Exosomal MicroRNAs as Biomarkers for Detection of Pancreatic Ductal Adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal neoplasm because of difficulties in early detection. Several studies have recently suggested that exosomes may have potential as novel biomarkers. This study aimed to isolate exosomes from pancreatic juice and to investigate whether exosomal microRNAs (ex-miRs) could be used as biomarkers for PDAC.

METHODS

Pancreatic juice was collected from patients with PDAC and chronic pancreatitis (CP) by endoscopic retrograde pancreatography. Exosomes were extracted by ultracentrifugation. The presence of exosomes was confirmed by electron microscopy and Western blotting using anti-CD63, -CD81, and -TSG101 antibodies. Relative levels of ex-miR-21 and ex-miR-155 were quantified and compared between PDAC and CP patients.

RESULTS

A total of 35 pancreatic juice samples (27 PDAC and 8 CP) were collected. Relative levels of both ex-miR-21 and ex-miR-155 were significantly higher in PDAC patients compared with CP patients (p < 0.001 and p = 0.008, respectively). By contrast, no significant difference was apparent in relative levels of miR-21 and miR-155 in whole pancreatic juice from PDAC patients compared with CP patients (p = 0.08 and p = 0.61, respectively). Ex-miR-21 and ex-miR-155 levels discriminated PDAC patients from CP patients with area under the curve values of 0.90 and 0.89, respectively. The accuracies of ex-miR-21 levels, ex-miR-155 levels, and pancreatic juice cytology were 83%, 89%, and 74%, respectively. When combining the results of ex-miR profiling with pancreatic juice cytology, the accuracy was improved to 91%.

CONCLUSIONS

We successfully extracted exosomes from pancreatic juice. Ex-miRs, including ex-miR-21 and ex-miR-155, in pancreatic juice may be developed as biomarkers for PDAC.

Expression of the Short Form of RON/STK in Feline Mammary Carcinoma

RON is a tyrosine kinase receptor activated by the macrophage-stimulating protein (MSP) ligand that is overexpressed in human breast cancer. In humans, RON protein can be present in different isoforms, and the most studied isoform is represented by the short form of RON ( sf-RON), which is generated by an alternative promoter located in intron 10 of the RON complementary DNA (cDNA). It plays an important role in breast cancer progression. Considering the many similarities between feline mammary carcinoma (FMC) and human breast cancer, the aim of this study was to investigate the expression of both RON and MSP in FMCs and to identify the presence of the sf-RON transcript. Tissue samples of spontaneous mammary tumors were collected from 60 queens (10 benign lesions, 50 carcinomas). All of the samples were tested for RON and MSP expression by immunohistochemistry; moreover, RNA was extracted from paraffin-embedded tissue samples, and the cDNA was tested by reverse transcription-polymerase chain reaction (RT-PCR) to identify the presence of sf-RON. Immunohistochemistry detected the expression of RON and MSP in 34 of 50 (68%) and 29 of 50 (58%) FMCs, respectively. RT-PCR revealed the presence of the short-form in 18 of 47 (38%) FMCs. This form originates, as in humans, from an alternative promoter (P2), and it codes for the proper feline short form ( sf-RON). sf-RON expression was associated with poorly differentiated tumors and with a shorter disease-free ( P < .05; hazard ratio [HR], 2.2) period and a shorter survival ( P < .05; HR, 2.2). These results support FMC as a suitable model in comparative oncology and identify sf-RON expression as potential predictor of outcomes for this disease.

Intrapancreatic recurrence of intraductal tubulopapillary neoplasm (ITPN) 16 years after the initial surgery for noninvasive ITPN: a case report

Background

Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic intraductal neoplasm. It is characterized by a tubulopapillary growth pattern, entirely high-grade atypical cells, minimal cytoplasmic mucin, and no obvious luminal mucin secretion. Most of its biological nature remains unclear.

Case presentation

We herein report a case of intrapancreatic recurrence of ITPN in the remnant pancreas of a patient who underwent pancreatoduodenectomy 16 years previously for a noninvasive intraductal pancreatic head tumor. We reexamined the primary tumor and compared it with the most recently resected specimen. Histologically, the primary tumor showed a tubulopapillary growth of high-grade atypical cells with scanty cytoplasmic mucin, which was similar to the recently resected specimen except for the invasive area. Immunohistochemically, the neoplastic cells in both specimens showed focal staining of MUC1 and positivity for MUC6 but negativity for MUC2, MUC5AC, CDX2, and trypsin. Molecular analysis revealed no KRAS/GNAS/BRAF/PIK3CA mutations in either of the specimens.

Conclusions

These findings of the original tumor and recently resected tumor were compatible with the features of ITPN. Thus, recurrence is possible even for a primary noninvasive ITPN, and long-term surveillance is recommended.

Adjunctive perampanel in partial-onset seizures: Asia-Pacific, randomized phase III study

OBJECTIVES

To evaluate the efficacy, safety, and tolerability of perampanel, a selective, non-competitive, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, as an adjunctive treatment for patients with refractory partial-onset seizures (POS) from Asia-Pacific.

MATERIALS & METHODS

This multicenter, randomized, double-blind, placebo-controlled trial (ClinicalTrials.gov identifier: NCT01618695) involved patients aged ≥12 years with refractory POS (receiving 1-3 antiepileptic drugs). Patients were randomized (1:1:1:1) to receive once-daily placebo or perampanel 4, 8, or 12 mg over a 6-week titration and 13-week maintenance double-blind period. Enzyme-inducing antiepileptic drugs were equally stratified between groups. The primary efficacy endpoint was percent change in POS frequency per 28 days (double-blind phase vs baseline). Other efficacy endpoints included ≥50% responder rate and seizure freedom. Treatment-emergent adverse events (TEAEs) were also monitored.

RESULTS

Of 710 randomized patients, seizure frequency data were available for 704 patients. Median percent changes in POS frequency per 28 days indicated dose-proportional reductions in seizure frequency: -10.8% with placebo and -17.3% (P = .2330), -29.0% (P = .0003), and -38.0% (P < .0001) with perampanel 4, 8, and 12 mg, respectively. In total, 108 (15.3%) patients discontinued treatment; 44 (6.2%) due to TEAEs. TEAEs occurring in ≥5% of patients, and reported at least twice as frequently with perampanel vs placebo, included dizziness and irritability.

CONCLUSIONS

Adjunctive perampanel (8 and 12 mg/d) significantly improved seizure control in patients with refractory POS. Safety and tolerability were acceptable at daily doses of perampanel 4-12 mg.

Pharmacokinetic/pharmacodynamic analysis of adjunctive perampanel in subjects with partial-onset seizures

OBJECTIVES

Explore perampanel pharmacokinetics (PK) in all subjects (aged ≥12 years) vs adolescents (aged ≥12 to ≤17 years) with partial-onset seizures (POS) and identify factors explaining between-subject variability in efficacy using a population PK/pharmacodynamic (PD) analysis.

MATERIALS & METHODS

Population PK analysis was performed using nonlinear mixed-effect modeling with data from phase II/III randomized, double-blind, placebo-controlled studies of adjunctive perampanel in POS. Perampanel exposure was predicted for all subjects and adolescents. Population PK/PD analyses were performed using data from phase III studies to explore the relationship between perampanel exposure and 28-day average seizure frequency and responder probability.

RESULTS

Pooled perampanel PK data from 1318 subjects were described by a one-compartment disposition model. In the absence of antiepileptic drugs (AEDs) affecting perampanel PK, estimated perampanel apparent clearance (CL/F) was 0.668 L/h (all subjects) and 0.682 L/h (adolescent subjects). Co-administration of carbamazepine and oxcarbazepine/phenytoin reduced perampanel exposure. Gender, Asian race (excluding Japanese or Chinese), and increasing alanine aminotransferase lowered perampanel CL/F, but differences were small and not considered clinically relevant. Adolescent outcomes were similar to the total population. Based on PK/PD data from 1748 subjects, percent reduction in 28-day average seizure frequency from baseline and responder probability increased with increasing perampanel exposure; concomitant CYP3A-inducing AEDs lowered perampanel exposure but did not impact the slope for responder probability.

CONCLUSIONS

These results are consistent with previous analyses but expand on these through inclusion of a larger number of patients from different ethnic groups, and demonstrate that outcomes were similar between adults and adolescents.

A case of Mirizzi syndrome that was successfully treated by laparoscopic choledochoplasty using a gallbladder patch

The use of laparoscopic surgery in the treatment of Mirizzi syndrome is considered controversial due to the degree of technical difficulty. We herein describe the case of a 36-year-old woman who was admitted to our hospital due to appetite loss, nausea and back pain. Endoscopic retrograde cholangiography revealed a round-shaped filling defect at the confluence of the bile duct. The patient was diagnosed with Mirizzi syndrome Type II according to the Csendes classification. Before surgery, an endoscopic nasobiliary drainage tube was placed for intraoperative cholangiography. Based on the intraoperative findings, the anterior wall of Hartmann’s pouch was excised to remove the impacted gallstone. The neck portion of the gallbladder wall was then used to make a gallbladder patch, which was sutured to cover the anterior wall of the common hepatic bile duct. Laparoscopic choledochoplasty using a gallbladder patch was a technically feasible treatment for Mirizzi syndrome Type II.

'Microcystic pattern' should be recognised as part of the morphological spectrum of solid-pseudopapillary neoplasm of the pancreas

AIM

Solid pseudopapillary neoplasm (SPN) is an uncommon pancreatic tumour characterised by solid and pseudopapillary growth patterns. We have observed SPNs can show a microcystic pattern (microcystic SPN), which has been poorly described and may be confused with microcystic neoplasms. We conducted the present study to clarify the clinicopathological and immunohistochemical features of microcystic SPNs.

METHODS AND RESULTS

We examined a consecutive series of 44 SPNs and 10 serous cystadenomas (SCAs), and classified them into 13 microcystic SPNs (29.5%) and 31 conventional SPNs (70.5%). Clinicopathological analysis, immunohistochemical staining and mucin histochemistry were performed. Clear cell change, hyalinised stroma and haemorrhage were observed significantly more frequently in the microcystic SPNs compared to the conventional SPNs. Immunohistochemically, the microcystic SPNs showed significantly lower frequencies of CD10 (0%) and CD56 expression (62%) compared to the conventional SPNs (87%; P < 0.001, 90%; P < 0.0085, respectively). There were no significant differences in other clinicopathological and immunohistochemical features between the two groups (i.e. the nuclear expression of β-catenin, E-cadherin, progesterone receptor (PgR), lack of forkhead box (Fox)L2 and occasional oestrogen receptor (ER), AE1/AE3 expression). Microcystic SCAs lack such a characteristic immunophenotype. The myxoid stroma of microcystic SPNs contained hyaluronan revealed by Alcian blue stain with hyaluronidase digestion.

CONCLUSION

We thus conclude that the microcystic pattern should be recognised as a part of the morphological spectrum of SPNs. Our findings may contribute to the correct diagnosis of the pancreatic neoplasms with the microcystic pattern. In addition, we speculate that stromal change caused by an accumulation of hyaluronan may contribute to the microcystic pattern of SPN.

Anti-tumour efficacy of etoposide alone and in combination with piroxicam against canine osteosarcoma in a xenograft model

Osteosarcoma (OSA) in dogs is locally invasive and highly malignant. Distant metastasis is the most common cause of death. To date, the survival rate in dogs with OSA remains poor. The cytotoxic effects of etoposide against canine OSA cell lines, either alone or in combination with piroxicam, have been previously demonstrated in vitro. The aim of this study was to evaluate the anti-tumour effect of etoposide alone and in combination with piroxicam on canine OSA using murine models. Etoposide single agent treatment significantly delayed tumour progression with a marked reduction in Ki-67 immunoreactivity in tumour tissue. Concomitant treatment with piroxicam did not enhance the anti-tumour efficacy of etoposide. Etoposide single agent treatment and combination treatment with piroxicam down-regulated survivin expression, but was not followed by increased apoptotic activity. These findings indicate that etoposide might be a promising novel therapeutic for canine OSA. Further investigations into its potential for clinical application in veterinary oncology are warranted.

Recovery after PILP remineralization of dentin lesions created with two cariogenic acids

OBJECTIVES

Acetate and lactate are important cariogenic acids produced by oral bacteria. They produced different residual dentin structures in artificial lesions of similar depth. We evaluated if such lesions responded in the same way to a polymer-induced-liquid-precursor (PILP) remineralization.

DESIGN

Dentin blocks obtained from human third molars, divided into 6 groups (n=3). Blocks were demineralized with acetate (66h) or lactate (168h) buffer at pH 5.0 to create 140μm target lesion depths. A-DEM and L-DEM groups received no remineralization. Other groups were remineralized for 14days. 100μg/mL polyaspartate was added into the remineralizing buffer for A-PIL and L-PIL, whereas A-CAP and L-CAP were treated with the same solution but without polyaspartate. Cross-sectioned blocks were examined for shrinkage and AFM-topography. Line profiles of reduced elastic modulus (E_r) were obtained by AFM-based nanoindentation across the lesion. Ultrastructures were examined with TEM.

RESULTS

A-PIL and L-PIL recovered in shrinkage to the original height of the dentin and it appeared normal with tubules, with increases in E_r at both outer flat and inner sloped zones. At the sloped zone, acetate lesions lost more E_r but recovery rate after PILP was not statistically different from lactate lesions. A-CAP and L-CAP showed surface precipitates, significantly less recovery in shrinkage or E_r as compared to PILP groups. TEM-ultrastructure of PILP groups showed similar structural and mineral components in the sloped zone for lesions produced by either acid.

CONCLUSIONS

The PILP process provided significant recovery of both structure and mechanical properties for artificial lesions produced with acetate or lactate.

Relationship between Breakfast Skipping and Obesity among Elderly: Cross-Sectional Analysis of the HEIJO-KYO Study

OBJECTIVE

Breakfast skipping is reported to be associated with obesity in children and younger populations; however, few studies report the association among elderly. The purpose of this study was to investigate the relationships between breakfast skipping and obesity prevalence among elderly.

DESIGN

Cross-sectional study.

SETTING

Community-dwelling elderly in Nara, Japan.

PARTICIPANTS

1052 elderly participants (mean age: 71.6 years).

MEASUREMENTS

Obesity and breakfast skipping were defined as body mass index of ≥25 kg/m2 and skipping breakfast one or more times per week, respectively.

RESULTS

Two hundred and seventy-two participants (25.9%) were classified as obese and forty-one (3.9%) were as breakfast skippers. Obesity prevalence was significantly higher in breakfast skippers than in breakfast eaters (43.9% vs. 25.1%, P = 0.007). In multivariable logistic regression analysis adjusted for potential confounders (age, sex and alcohol consumption), breakfast skippers showed significantly higher odds ratio (OR) for obesity than breakfast eaters (OR, 2.23; 95% confidence interval, 1.17-4.27; P = 0.015), which continued to be significant after further adjustment for socioeconomic status. In addition, breakfast skippers showed significantly lower daily potassium (P <0.001) and dietary fibre intakes (P = 0.001) and lower subjective physical activity (P = 0.035) than breakfast eaters.

CONCLUSIONS

Breakfast skipping was significantly associated with obesity among elderly. Poor diet quality and physical inactivity may be potential intermediators underlying the association between breakfast skipping and obesity.

Effects of etoposide alone and in combination with piroxicam on canine osteosarcoma cell lines

Osteosarcoma (OSA) is the most common primary bone tumour in dogs. The poor survival rate in dogs with OSA highlights the need for new therapeutic approaches. This study evaluated the cytotoxic effects of etoposide, alone and in combination with piroxicam, on canine OSA cell cultures. Etoposide alone significantly suppressed cell growth and viability, whereas etoposide in combination with piroxicam exhibited concentration dependent cytotoxicity. The anti-proliferative effect was a result of inactivity of the Cdc2-cyclin B1 complex, which correlated with an increase in the G₂/M fraction. This subsequently activated the apoptosis cascade, as indicated by elevated apoptosis levels and up-regulation of poly (ADP-ribose) polymerase proteolytic cleavage. Down-regulation of survivin expression induced by the combination treatment may have contributed to the enhanced cytotoxicity. The results of this study suggest that further investigation of etoposide and piroxicam as a therapeutic combination for canine OSA is warranted.

Repair of dentin defects from DSPP knockout mice by PILP mineralization

Dentinogenesis imperfecta type II (DGI-II) lacks intrafibrillar mineral with severe compromise of dentin mechanical properties. A Dspp knockout (Dspp-/-) mouse, with a phenotype similar to that of human DGI-II, was used to determine if poly-L-aspartic acid [poly(ASP)] in the "polymer-induced liquid-precursor" (PILP) system can restore its mechanical properties. Dentin from six-week old Dspp-/- and wild-type mice was treated with CaP solution containing poly(ASP) for up to 14 days. Elastic modulus and hardness before and after treatment were correlated with mineralization from Micro x-ray computed tomography (Micro-XCT). Transmission electron microscopy (TEM)/Selected area electron diffraction (SAED) were used to compare matrix mineralization and crystallography. Mechanical properties of the Dspp-/- dentin were significantly less than wild-type dentin and recovered significantly (P < 0.05) after PILP-treatment, reaching values comparable to wild-type dentin. Micro-XCT showed mineral recovery similar to wild-type dentin after PILP-treatment. TEM/SAED showed repair of patchy mineralization and complete mineralization of defective dentin. This approach may lead to new strategies for hard tissue repair.

Thymoglobulin for steroid-resistant immune-mediated graft dysfunction during simeprevir-based antiviral treatment for post-transplantation hepatitis C: case report

INTRODUCTION

Immune-mediated graft dysfunction (IGD), a recently established disease entity with unfavourable outcome, is an antigraft immune reaction during interferon-based antiviral treatment for hepatitis C virus (HCV) infection after liver transplantation (LT). We report a case having steroid-resistant acute cellular rejection (ACR) type IGD, which was successfully treated using thymoglobulin.

CASE REPORT

A 56-year-old woman with recurrent HCV after LT was commenced on antiviral treatment including simeprevir, pegylated-interferon (IFN) 2a, and ribavirin. A negative serum HCV-RNA was confirmed after 4 weeks. After 12 weeks of therapy, severe liver dysfunction developed, despite a constantly negative HCV-RNA. Liver biopsy revealed portal and periportal inflammatory infiltrates including numerous eosinophils, lymphocytes, and bile duct damages, indicating ACR. IFN therapy was ceased, and she was treated with steroid pulse treatment, followed by high-level immunosuppression maintenance. However, ACR was irremediable. Thereafter she was treated with thymoglobulin (75 mg/d for 5 days). Her serum alanine aminotransaminase and total bilirubin levels decreased immediately, and her liver biopsy specimen showed no activity. During these periods of the treatment, the HCV-RNA became positive and the liver enzyme elevated, but other liver function tests still remained within normal range.

CONCLUSION

Thymoglobulin could be the best choice in steroid-resistant IGD during antiviral treatment for post-transplantation recurrent hepatitis C.

Distinct decalcification process of dentin by different cariogenic organic acids: Kinetics, ultrastructure and mechanical properties

OBJECTIVES

We studied artificial dentin lesions in human teeth generated by lactate and acetate buffers (pH 5.0), the two most abundant acids in caries. The objective of this study was to determine differences in mechanical properties, mineral density profiles and ultrastructural variations of two different artificial lesions with the same approximate depth.

METHODS

0.05M (pH 5.0) acetate or lactate buffer was used to create 1) 180μm-deep lesions in non-carious human dentin blocks (acetate 130h; lactate 14days); (2) demineralized, ∼180μm-thick non-carious dentin discs (3 weeks). We performed nanoindentation to determine mechanical properties across the hydrated lesions, and micro X-ray computed tomography (MicroXCT) to determine mineral profiles. Ultrastructure in lesions was analyzed by TEM/selected area electron diffraction (SAED). Demineralized dentin discs were analyzed by small angle X-ray scattering (SAXS).

RESULTS

Diffusion-dominated demineralization was shown based on the linearity between lesion depths versus the square root of exposure time in either solution, with faster kinetics in acetate buffer. Nanoindentation revealed lactate induced a significantly sharper transition in reduced elastic modulus across the lesions. MicroXCT showed lactate demineralized lesions had swelling and more disorganized matrix structure, whereas acetate lesions had abrupt X-ray absorption near the margin. At the ultrastructural level, TEM showed lactate was more effective in removing minerals from the collagenous matrix, which was confirmed by SAXS analysis.

CONCLUSIONS

These findings indicated the different acids yielded lesions with different characteristics that could influence lesion formation resulting in their distinct predominance in different caries activities, and these differences may impact strategies for dentin caries remineralization.

Anti-tumour effect of metformin in canine mammary gland tumour cells

Metformin is an oral hypoglycaemic drug used in type 2 diabetes. Its pharmacological activity reportedly involves mitochondrial respiratory complex I, and mitochondrial respiratory complex inhibitors have a strong inhibitory effect on the growth of metastatic canine mammary gland tumour (CMGT) cell lines. It is hypothesised that metformin has selective anti-tumour effects on metastatic CMGT cells. The aim of this study was to investigate the in vitro effect of metformin on cell growth, production of ATP and reactive oxygen species (ROS), and the AMP-activated protein kinase (AMPK) mammalian target of rapamycin (mTOR) pathway in two CMGT clonal cell lines with different metastatic potential. In addition, transcriptome analysis was used to determine cellular processes disrupted by metformin and in vivo anti-tumour effects were examined in a mouse xenograft model. Metformin inhibited CMGT cell growth in vitro, with the metastatic clone (CHMp-5b) displaying greater sensitivity. ATP depletion and ROS elevation were observed to a similar extent in the metastatic and non-metastatic (CHMp-13a) cell lines after metformin exposure. However, subsequent AMPK activation and mTOR pathway inhibition were prominent only in metformin-insensitive non-metastatic cells. Microarray analysis revealed inhibition of cell cycle progression by metformin treatment in CHMp-5b cells, which was further confirmed by Western blotting and cell cycle analysis. Additionally, metformin significantly suppressed tumour growth in xenografted metastatic CMGT cells. In conclusion, metformin exhibited an anti-tumour effect in metastatic CMGT cells through AMPK-independent cell cycle arrest. Its mechanism of action differed in the non-metastatic clone, where AMPK activation and mTOR inhibition were observed.

226 IN VITRO PRODUCTION OF BOVINE EMBRYOS USING CHEMICAL PACKETS THAT REGULATE CO2 AND O2

Bovine embryos are now routinely produced with oocytes collected from slaughterhouse ovaries or by transvaginal ovum pickup. The oocytes are matured, fertilized, and cultured in a water-jacketed CO2/O2 incubator. Gas phase in incubators is usually maintained at 5% CO2 in air for in vitro maturation (IVM) and IVF of oocytes and at 5% CO2, 5% O2, and 90% N2 for in vitro culture (IVC) of embryos. Here we investigated whether two chemical packets that regulate CO2 and O2 for culturing bacteria (Mitsubishi Gas Chemical, Tokyo, Japan) could be used to control the gas phase in vitro production (IVP) of cattle embryos. One packet (Anaero Pack-CO2) was maintained at a CO2 level of ~5% in a 2.5-L container and the other (Anaero Pack-MicroAnaero) was maintained at a CO2 level of 5–8% and an O2 level of 6 to 12%. Bovine cumulus-oocyte complexes (COC, n = 970) were collected from slaughterhouse ovaries, matured in HEPES-buffered TCM-199 (catalog number 12340–030, Invitrogen) supplemented with 10% FCS, 0.02 Armour unit mL–1 FSH and 1 µg mL–1 E2 for 22 h, and fertilized in medium IVF100 [Research Institute for the Functional Peptides Co. Ltd. (IFP), Yamagata, Japan] with frozen-thawed sperm (4 × 106 cells mL–1) for 6 h. Sperm and cumulus cells were removed from the oocytes. The denuded oocytes were cultured in IVD101 (IFP, 20 to 30 embryos/50 μL) for 8 days (Day 0 = IVF). Culture was carried out at 39°C with maximum humidity. Five different combinations of gas conditions were used for incubation (Table 1). Experiments were repeated 3 times. Cleavage and blastocyst rates were assessed on Day 8. Data were analysed by ANOVA followed by Fisher's PLSD test. In the five conditions, rates of matured oocytes (oocytes at MII, n = 210) were 70 to 73% and rates of normal fertilized oocytes (oocytes with 2 pronuclei, n = 310) were 67 to 75%. Cleavage rates of embryos after 8 days of culture (n = 450) were 68 to 75%, and rates of blastocysts from cleaved embryos were 25 to 40%. None of the above measures were significantly different among the 5 conditions (P > 0.05). These results indicate that gas phase control is not needed for IVM and IVF of bovine oocytes for their subsequent development. Anaero Pack-MicroAnaero (5–8% CO2, 6–12% O2) can be used for IVC of bovine embryos. The CO2-generating and deoxidizing packets can be successfully used to control the gas phase during bovine embryo production. Table 1.Five different combinations of gas conditions used for incubation

166 MATURATION OF BOVINE OOCYTES IN POLY(DIMETHYLSILOXANE) MICROWELLS AND THEIR SUBSEQUENT DEVELOPMENT FOLLOWING IN VITRO FERTILIZATION

During bovine oocyte maturation, a lower density of cumulus cells surrounding oocytes reduces the developmental competence of the oocytes after IVF. Adding more cumulus cells (Hashimoto et al. 1998) rescues the developmental competence of the corona-enclosed oocytes. In this study, we examined the effects of poly(dimethylsiloxane) (PDMS) microwells (MW) for bovine oocyte maturation on the developmental competence of the oocytes following IVF. In experiment 1, MW were produced by making holes on 0.5-mm-thick PDMS plates using a 0.5-mm-diameter biopsy punch. The punched plates were placed on the bottoms of culture dishes. Bovine cumulus oocytes complexes (COC) were collected from slaughterhouse ovaries. Cumulus layers were removed from COC to prepare corona-enclosed oocytes (CEO) and denuded oocytes (DO). Then, COC, CEO, or DO were individually matured in single MW for 24 h at 39°C under 5% CO2 in air with high humidity. Ten oocytes of each group were matured in 50-μL droplets of maturation medium (group culture, GC) as controls. Maturation medium was TCM-199 supplemented with 10% FCS, 0.02 AU mL–1 FSH, and 1 μg mL–1 E2. The matured oocytes were fertilized with frozen–thawed spermatozoa. The embryos were cultured in CR1aa medium for 168 h under 5% CO2, 5% O2 and 90% N2 with high humidity. In experiment 2, effects of depth of MW for maturation on subsequent development following IVF were examined. Microwells were produced by making 0.5-mm-diameter holes on 0.5- or 1.5-mm-thick PDMS plates. Then, COC or CEO were individually matured in the MW for 24 h. Matured oocytes were fertilized in vitro and cultured for 168 h. Oocytes that were matured by GC were used as controls. In experiment 1(N = 4), rates of maturation (76–100%, n = 26 to 38), normal fertilization (53–70%, n = 44 to 49), and cleavage (61–77%, n = 114 to 117) were not different among all groups (P > 0.05; Fisher's PLSD test following ANOVA). Blastocyst rates were the same (P > 0.05) for COC matured in MW (50%) and by GC (43%). The rate for CEO that matured in MW (46%) tended to be higher (P = 0.061) than the rate for CEO that matured by GC (31%), and was comparable to the rate for COC matured by GC (43%). The blastocyst rates for DO that matured in MW and by GC were low (6%). In experiment 2 (N = 3), rates of maturation (86–100%, n = 13 to 28), normal fertilization (60–78%, n = 22 to 40), and cleavage (67–73%, n = 85 to 90) were not different among all groups (P > 0.05). However, the blastocyst rate for COC that matured in 1.5-mm-deep MW (53%) was significantly higher than the rates for COC that matured in 0.5-mm-deep MW (38%) and by GC (31%; P < 0.05). The results indicate that the developmental competence of oocytes that matured individually in PDMS MW was greater than that of oocytes that matured by GC. The deeper (1.5 mm) MW were found to be more effective for oocyte maturation than shallow (0.5 mm) MW and GC. The MW might increase density of cumulus cells surrounding oocytes, and the high cell-density enhanced the developmental competence of the oocytes.

Characterization of the use of liraglutide for glycemic control in healthy and Type 1 diabetes mellitus suffering dogs

Glucagon-like peptide 1 (GLP-1) is a glucose-lowering, intestinal-derived factor with multiple physiological effects, making it attractive for diabetes therapy. However, the therapeutic potential of endogenous GLP-1 is limited, because of rapid inactivation by dipeptidyl peptidase-4. Recently, enhanced incretin preparations, such as liraglutide, have emerged, which are more resistant to degradation and longer lasting. Liraglutide is a long-acting acylated human GLP-1 receptor agonist, with a 97% amino acid sequence identity to endogenous human GLP-1, and 100% amino acid sequence homology with canine GLP-1. Since liraglutide has yet to be examined for use in dogs, and the incretin effect has been reported to exist in dogs, we sought to initially characterize liraglutide's ability for glycemic control in healthy dogs, under an oral glucose tolerance test (OGTT) environment initially. This was followed up a more realistic scenario involving food with insulin injection +/- liraglutide injection resulting in a glucose curve based study involving dogs suffering from Type 1 diabetes mellitus (T1DM). Overall, liraglutide had a stabilizing effect on glucose levels, maintaining circulating levels between 77.0 and 137.0mg/ml throughout the OGTT test period, resulting in a significant reduction of 13.8% in glucose AUC0-120 min (total area under the curve for 0-120 min) as compared to baseline control in healthy dogs (n=5). Interestingly, the liraglutide associated reduction in circulating glucose was not accompanied by any significant increase in insulin. Moreover, T1DM dogs (n=4) responded favorably to liraglutide treatment, which lead to a significant reduction of 46.0% in glucose AUC0-12h (total area under the curve for 0-12h), and a significant reduction of 66.5% in serum glucose as compared to baseline controls (insulin treatment only). Therefore, liraglutide's prandial glucagon suppressive ability appears to play a key role in its glucose-lowering capability, and offers great potential for use with dogs suffering from T1DM.

Transforming growth factor-β transiently induces vimentin expression and invasive capacity in a canine mammary gland tumor cell line

The epithelial-mesenchymal transition (EMT) is a crucial event that occurs during cancer metastasis and can be induced by transforming growth factor-β (TGF-β) in various tumor cells in vitro. However, little is known about the effects of TGF-β in canine mammary gland tumors (CMGTs). Here, we investigated the role of TGF-β in CMGT. We observed that treatment of the CMGT cell line CHMp13a with TGF-β1 leads to transient induction of the mesenchymal marker vimentin. Real-time measurements of cellular electrical impedance also showed that CMGT invasiveness is transiently increased by TGF-β1 treatment, but is reversed after prolonged stimulation. This phenomenon is similar to the mesenchymal-epithelial transition (MET, the reverse phenomenon of EMT), and a process that is implicated in the establishment of secondary metastatic lesions.

180 EFFECT OF Dnmt1p mRNA KNOCK DOWN ON Dnmt1 PROTEIN TRANSLATION IN MOUSE TESTIS

We have reported that there was a significant reduction (P < 0.05) in the relative amount of Dnmt1p mRNA in spermatozoa from aged male mice (Kato et al. 2007 Reprod. Fertil. Dev. 19, 277 abst.). The reduction of mRNA levels of Dnmt1p in spermatozoa would lead to altered epigenetic modification of the genome. Dnmt1p is one of 5′ exon alternative isoforms of Dnmt1 and its mRNA is specifically expressed in the pachytene spermatocyte. However, the function of Dnmt1p still has not been elucidated. In this study, we tried to elucidate the function of Dnmt1p in the male mouse reproductive system. This was accomplished by suppressing the expression level of Dnmt1p in the whole testis by short hairpin RNA (shRNA) expression, which was specifically designed from mouse Dnmt1p mRNA. Dnmt1p cDNA was cloned from total RNA extracted from a piece of testis from a C57BL/6J male mouse. Four shRNA expression vectors were constructed and the knock-down efficiency of each shRNA expression vector was evaluated by flow cytometry. From these results, the 589 shRNA expression vector was picked out for further experimentation. The 589 shRNA expression vector was linearized and injected into the pronuclei of C57BL/6J mouse embryos. After injection, the embryos were cultured for 24 h and cleavage was evaluated. Cleaved embryos were transferred into oviducts of recipient ICR mice. After 18 to 19 days, fetuses were delivered by C-section. Two weeks after the birth, the existence of the 589 shRNA expression gene construct in its genome was evaluated by PCR. From founders with 589 shRNA expression gene construct in its genome, finally 1 TG strain was established and used for further experimentation. Two F2 -generation male mice with the 589 shRNA expression gene construct, 2 F2-generation male mice without the 589 shRNA expression gene construct and 1 C57BL/6J wild-type male mouse were used for evaluating the expression level of Dnmt1p mRNA in the whole testis by quantitative PCR. Then, thin sections of testis derived from the F2-generation mouse, which showed a suppressed expression level of Dnmt1p, was evaluated by immunostaining for Dnmt1 protein. The survival rate of mouse embryos after gene injection was 76.8% (202/263) and the cleavage rate of gene-injected embryos was 69.8% (141/202). The developmental rate of transferred embryos to the birth was 19% (27/139). The rate of newborn mice with the 589 shRNA expression gene construct was 37% (10/27). The fertility of established TG strain mouse was normal and there was no abnormality in the thin section figure of testis stained with hematoxylin-eosin double staining method. The relative expression level of Dnmt1p mRNA in the whole testis of the F2 TG mouse was ∼25% of C57BL/6J wild-type male mouse (P < 0.05, Student's t-test). There was Dnmt1 protein in seminiferous tubules, especially in spermatids of C57BL/6J wild-type male mouse. However, there was no Dnmt1 protein in seminiferous tubules of the F2 TG mouse. From these results, it was concluded that the expression of Dnmt1p mRNA was associated in some way with the translation of the Dnmt1 protein in the mouse testis.

Working hours, occupational stress and depression among physicians

BACKGROUND

Physicians report high prevalence of depression, work long hours and are exposed to many occupational stresses (OSs).

AIMS

To investigate the cross-sectional association between working hours, OS and depression among physicians.

METHODS

A self-administered questionnaire was mailed to 1902 alumni of a medical school. The questionnaire evaluated working hours in the previous week, OS assessed by the effort-reward imbalance model, social support and depression evaluated by the Center for Epidemiologic Studies Depression scale. The associations between these occupational factors and depression were analyzed using multiple logistic regression.

RESULTS

The questionnaire was returned by 795 alumni (response rate, 42%), and 706 respondents (534 men and 172 women) were suitable for analysis. The odds ratio (OR) of depression in the long working hours group (>70 h/week) was 1.8 (95% CI: 1.1-2.8) compared with the short working hours group (<54 h/week), adjusted for basic attributes. The adjusted ORs of depression in the upper effort-reward ratio (ERR) tertile versus the lower ERR tertile were 0.6 (0.2-1.8) in the short working hours group, 8.5 (3.0-24.0) in the middle working hours group and 9.9 (3.8-25.7) in the long working hours group. The adjusted ORs of depression stratified according to working hours and ERR tended to be higher in the groups with a higher ERR, but no association between working hours and depression was found.

CONCLUSIONS

This study indicates that the management of OS is needed as a countermeasure against depression among physicians.

Gene silencing of STAT6 with siRNA ameliorates contact hypersensitivity and allergic rhinitis

BACKGROUND

Silencing of genes using small interfering RNA (siRNA) is a recently developed strategy to regulate the synthesis of target molecules. Signal transducer and activator of transcription 6 (STAT6) is a nuclear transcription factor that mediates Th2-type immunity.

METHODS

To elucidate the therapeutic potential of using siRNA to inhibit STAT6 in allergic reactions, we determined the nucleotide sequences of siRNA specific for STAT6.

RESULTS

The selected sequences of STAT6 siRNA specifically inhibited the generation of STAT6 synthesis in dermal fibroblasts and eotaxin (CCL11) production in response to IL-4/TNF-α in vitro. Local administration of STAT6 siRNA in vivo alleviated contact hypersensitivity responses to chemical haptens. This was accompanied by reduced local production of IL-4, IL-13, eotaxin (CCL11), TARC (CCL17) and MDC (CCL22). Similarly, consecutive intranasal instillation of STAT6 siRNA markedly inhibited inflammatory cellular infiltration of mucosal tissues in allergic rhinitis responses in association with reduced IL-4 and IL-5 production from regional lymph node cells. Immediate responses, such as sneezing and nasal rubbing behaviors, were also improved by STAT6 siRNA.

CONCLUSIONS

Local administration of STAT6 siRNA is thus a promising therapeutic strategy for both Th2-mediated cutaneous diseases and allergic rhinitis.

70 FIBROBLAST GROWTH FACTOR 4 PROMOTES THE DEVELOPMENT OF SOMATIC CELL NUCLEAR TRANSFER EMBRYOS IN MICE

Somatic cell nuclear transfer (SCNT) embryos can develop during the preimplantation period; however, most of these die after implantation period. A transcription factor, Cdx2, promotes differentiation of extraembryonic tissues and appears to be involved in the segregation of inner cell mass (ICM) and trophectoderm (TE) in preimplantation embryos. So far, we have demonstrated that the expression of Cdx2 in mouse SCNT embryos is delayed and its expression level is significantly lower than that in intracytoplasmic sperm injection (ICSI) embryos. Moreover, the ectopic expression of Oct-3/4 was observed in the TE tissues of SCNT blastocysts, but not in ICSI blastocysts. Fibroblast growth factor (FGF) receptor 2 (FGFR2) is specifically expressed in 8-cell to morula-stage embryos and trophectoderm (TE) and is essential for implantation; however, FGFR2 expression in SCNT embryos significantly decreases compared with IVF embryos. Therefore, it is likely that abnormality of differentiation that is controlled in development of pre-implantation in SCNT embryos leads to a rapid decrease of subsequent developmental ability. Then, we investigated the effects of FGF4 on development of SCNT embryos. Mouse SCNT embryos were produced according to the method reported previously (Wakayama et al. 1998). B6D2F1 and B6C3F1 female mice were used for the collection of recipient oocytes and donor cells, respectively. Data were analyzed by Student’s t-test. First, the timing to start adding FGF4 was decided by FGFR2 expression time about 54 h after cell injection and treated for 3, 6, 12, 24, and 42 h thereafter. In the case of FGF4 concentration at 25 ng mL-1 with treating time of 6 h from the 4- to 8-cell stages, SCNT embryos significantly promoted the development to morula and blastocyst stages (91 and 45%, respectively) compared with IVF embryos (80 and 30%, respectively; P < 0.05). However, longer treatment of 42 h with FGF4 made their morphology considerably worse. Then, concentrations of FGF4 at 5, 25, 50, 250, and 500 ng mL-1 with treating time of 6 h was examined. In case of FGF4 concentration at 25 and 50 ng mL-1, SCNT embryos significantly promoted the development to morula and blastocyst stages (P < 0.05). Immunohistochemical analysis showed segregation of the expression of Oct-3/4 and Cdx2 in ICM and TE, respectively, in FGF4-treated SCNT embryos, unlike in the case of nontreated SCNT embryos, which showed an ectopic expression of Oct-3/4 in TE tissues. Furthermore, after the transplantation of SCNT embryos treated with FGF4 at 50 ng mL-1 and the treating time of 6 h to recipient mice, most of the transferred embryos implanted and cloned mice were successfully produced as well as nontreated SCNT embryos. Therefore, FGF4 facilitates the development of SCNT embryos especially to the morula and blastocyst stages. This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science.

Early morphological events of in vitro fertilized bovine oocytes with frozen-thawed spermatozoa

Bovine follicular oocytes were matured and inseminated in vitro with spermatozoa capacitated in vitro. The first evidence of sperm penetration was observed at 3 h after insemination. The penetration rate increased until 5 h, and reached a maximum rate (92%) at 5 h. Decondensation of the sperm head and pronuclear formation were observed 4 h and 7 h after insemination, respectively. Female chromatins of all penetrated oocytes were activated at 3 h, and female pronuclei were formed at 7 h after insemination. Percentages of oocytes with male and female pronuclei at 9 h were 88 and 94%. Polyspermy (4, 7, 19 and 29% at 4, 5, 7 and 9 h after insemination, respectively) and abnormal development of male pronuclei (6 and 7% at 7 and 9 h after insemination, respectively) were also seen.