Average and statistical properties of coherent radiation from steady-state microbunching.

A promising accelerator light source mechanism called steady-state microbunching (SSMB) is being actively studied. With the combination of strong coherent radiation from microbunching and high repetition rate of a storage ring, high-average-power narrow-band radiation can be anticipated from an SSMB storage ring, with wavelengths ranging from THz to soft X-ray. Such a novel light source could provide new opportunities for accelerator photon science like high-resolution angle-resolved photoemission spectroscopy and industrial applications like extreme ultraviolet (EUV) lithography. In this paper, a theoretical and numerical study of the average and statistical properties of coherent radiation from SSMB are presented. The results show that 1 kW average-power quasi-continuous-wave EUV radiation can be obtained from an SSMB ring provided that an average current of 1 A and a microbunch train with bunch length of 3 nm can be formed at the radiator which is assumed to be an undulator. Together with the narrow-band feature, the EUV photon flux can reach 6 × 1015 photons s-1 within a 0.1 meV energy bandwidth, which is three orders of magnitude higher than that in a conventional synchrotron source and is appealing for fundamental condensed matter physics and other research. In this theoretical investigation, we have generalized the definition and derivation of the transverse form factor of an electron beam which can quantify the impact of its transverse size on coherent radiation. In particular, it has been shown that the narrow-band feature of SSMB radiation is strongly correlated with the finite transverse electron beam size. Considering the pointlike nature of electrons and quantum nature of radiation, the coherent radiation fluctuates from microbunch to microbunch, or for a single microbunch from turn to turn. Some important results concerning the statistical properties of SSMB radiation are presented, with a brief discussion on its potential applications, for example the beam diagnostics. The presented work is of value for the development of SSMB to better serve potential synchrotron radiation users. In addition, this also sheds light on understanding the radiation characteristics of free-electron lasers, coherent harmonic generation, etc.

Immunogenicity of the mRNA-1273 and ChAdOx1 nCoV-19 vaccines in Asian patients with autoimmune rheumatic diseases under biologic and/or conventional immunosuppressant treatments.

OBJECTIVE: Nucleic acid-based vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection are effective in the general population. However, it is unknown whether this is true in Asian patients with autoimmune rheumatic diseases (ARDs) who have received various combinations of disease-modifying anti-rheumatic drugs (DMARDs). METHOD: We designed a large prospective observational study recruiting 228 patients with ARDs in a tertiary rheumatology centre in Taiwan. Altogether, 142 received biological or targeted synthetic DMARDs and 86 received only conventional synthetic (cs) DMARDs. Serum levels of immunoglobulin G antibody against SARS-CoV-2 spike proteins were measured 2-6 weeks after COVID-19 vaccination with mRNA-1273 (Moderna®) or ChAdOx1 nCoV-19 (Oxford/AstraZeneca®). The immunomodulatory therapies were not modified before or after vaccination. RESULTS: Overall, 194 patients (85.09%) exhibited antibodies (758.33 ± 808.43 ng/mL) but 34 patients did not (103.24 ± 41.08 ng/mL). Patients with systemic lupus erythematosus or rheumatoid arthritis had significantly lower humoral responses to COVID-19 vaccination than those with other ARDs (p < 0.05). There was no significant difference in immunogenicity among patients on different csDMARD treatments. Compared to patients treated with only csDMARDs, those on rituximab or abatacept therapy had significantly lower immune response to the vaccination (p = 0.008 and p = 0.035, respectively). Patients who were treated with anti-tumour necrosis factor-α or interleukin-6 inhibitor exhibited higher titres of vaccination antibodies than those treated with direct lymphocyte inhibitors. CONCLUSIONS: mRNA-1273 and ChAdOx1 nCoV-19 vaccines were immunogenic in the majority of ARD patients. Rituximab and abatacept were associated with significantly diminished COVID-19 vaccination immunogenicity.

Clinical benefits of routine examination and synchronous repair of occult inguinal hernia during laparoscopic peritoneal dialysis catheter insertion: a single-center experience.

PURPOSE: Occult inguinal hernias (IH) predispose peritoneal dialysis (PD) patients to the symptomatic IH formation after starting PD, which may cause complications. We conducted a retrospective study to assess the benefit/risk profile of routine laparoscopic examination for occult IH (RLEOH) with a synchronous repair in patients receiving PD catheter placement. METHODS: 432 patients were enrolled in this study. Patients with an internal hernia sac at all sizes were deemed to have occult IH. We retrospectively reviewed data including demographic characteristics and operative details. We also measured incidence rates of symptomatic IH, metachronous IH repair, and catheter survival over a follow-up period after starting PD. RESULTS: These patients were classified into the RLEOH group (n = 365) and the non-RLEOH group (n = 67). The RLEOH group was subdivided into occult IH with a synchronous repair (n = 17; the subgroup A), no occult IH (n = 339; the subgroup B), and occult IH without a synchronous repair (n = 9; the subgroup C). The incidence rates of symptomatic IH developed after staring PD in subgroups A, B, and C were 0, 5.6, and 22.2%, respectively, whereas that in the non-RLEOH group was 13.4%. The RLEOH group had a reduced hazard ratio for metachronous IH repair compared with the non-RLEOH group (HR = 0.426; 95% CI 0.195-0.930, p = 0.032). None of our patients suffered from herniorrhaphy-related complications. CONCLUSION: RLEOH with a synchronous repair during PD catheter insertion confers clinical benefits in reducing the risk of developing IH after starting PD and the need for a metachronous repair. This is a safe and reasonable approach.

CD56+ B-cell Neurolymphomatosis in a Cat.

A 16-year-old male Russian blue cat was presented with acute onset of paraparesis of the forelimbs that progressed to tetraparesis. Neurological examination revealed non-ambulatory tetraparesis with decreased postural reactions in all four limbs. Magnetic resonance imaging revealed multifocal nerve root swelling on the right at C6/C7 and C7/T1, while ultrasonography demonstrated swelling of the right brachial plexus. To understand the cause of the nerve swelling, the right musculocutaneous nerve arising from the brachial plexus and the pectoralis muscle were biopsied. Histologically, there was evidence of neurolymphomatosis (neurotropic lymphoma) with Wallerian degeneration and denervation atrophy of myofibres. The neoplastic lymphoid cells expressed CD79a, CD20 and CD56. Based on these findings, a diagnosis of B-cell neurolymphomatosis was made. Expression of CD56, synonymous with neural cell adhesion molecule, is rare in B-cell lymphomas and has not been reported in feline B-cell lymphomas or feline neurolymphomatosis. CD56 expression was suspected to have played an important role in neurotropism of the neoplastic cells in this case.

Incidence and risk factors of osteomyelitis in adult and pediatric systemic lupus erythematosus: a nationwide, population-based cohort study.

OBJECTIVE: The objective of this paper is to investigate the incidence rate, risk factors and outcome of osteomyelitis among patients with systemic lupus erythematosus (SLE). MATERIALS AND METHODS: We conducted a cohort study using data for patients enrolled in the Taiwan National Health Insurance Database from 2000 to 2012. Patients with SLE and age- and sex-matched controls without SLE were enrolled. Primary endpoint was the first occurrence of osteomyelitis. Risks of osteomyelitis in SLE patients were analyzed with Cox proportional hazards regression models, including age, sex, comorbidities and medications. RESULTS: Among 24,705 SLE patients (88.4% women, mean age 35.8 years) with a median follow-up of 9.1 years, 386 patients had osteomyelitis. The incidence rate ratio (IRR) of osteomyelitis in the SLE group vs the control group was 8.52 (95% confidence interval (CI) 7.24-10.05). The SLE group had higher incidence rates of osteomyelitis than the control group, especially in pediatric subgroups (IRR 41.1 95% CI 18.57-107.35). Compared to controls, SLE patients experienced osteomyelitis at a younger age (42.3 vs 58.1 years) but did not have an increased risk of mortality (hazard ratio 0.7; 95% CI 0.21-2.38). Age >60 years, male gender, malignancy within five years, prior bone fracture and higher daily prednisolone dose (>7.5 mg) cumulatively for >180 days increased risk for osteomyelitis. CONCLUSIONS: SLE patients have a higher IRR of osteomyelitis than controls. Pediatric and elder SLE patients, patients with a history of bone fracture, malignancy within five years and higher-dose glucocorticoid use have a higher risk of osteomyelitis and should be carefully monitored.

Risk of complications of ultrasound-guided renal biopsy for adult and pediatric patients with systemic lupus erythematosus.

Objective The objective of this paper is to identify the risk of complications of real-time ultrasound-guided renal biopsy in adult and pediatric patients with systemic lupus erythematosus (SLE). Materials and methods This retrospective study examined outcomes of 296 renal biopsy procedures in 275 SLE patients. Imaging-confirmed symptomatic hematoma was regarded as a major complication when intervention (blood transfusion, angiographic embolization, or surgery) was required or as a minor complication otherwise. Clinical and laboratory data were compared between groups with or without complications after initial or subsequent renal biopsy. Binary logistic regressions were used to evaluate complication risk of initial renal biopsy. Results Overall complication rate of initial renal biopsy was 8.7% (major: 2.9%, minor: 5.8%). Three patients expired from pulmonary hemorrhage, thrombotic microangiopathy, and pneumonia. Pediatric SLE patients tended to have a higher rate of major complications (12.5%) than adult patients (2.3%). According to multivariable analysis results, elevated serum creatinine (SCr) level (OR 1.45; 95% CI 1.17-1.81 per mg/dl), prolonged prothrombin time (PT) (OR 2.2; 95% CI 1.05-4.62 per second), and thrombocytopenia (OR 4.3; 95% CI 1.56-11.9) increased overall complication risk of initial renal biopsy. Age < 18 years (OR 8.43; 95% CI 1.21-58.8), thrombocytopenia (OR 16.4; 95% CI 2.44-110.5), and elevated SCr level (OR 1.97; 95% CI 1.36-2.86 per md/dl) increased risk of major complications. Thrombocytopenia, prolonged PT, and elevated SCr level were associated with complications after subsequent renal biopsy (all p = 0.01). Conclusions SLE patients, particularly patients under 18 years old or with elevated SCr level, prolonged PT, or thrombocytopenia, have an increased risk of complications after initial or subsequent renal biopsy.

Perineural invasion through the sheath in posttherapy esophagectomy specimens predicts poor survival in patients with esophageal squamous cell carcinoma.

BACKGROUND: The prognostic impact of perineural invasion (PNI) in patients with esophageal cancer who receive neoadjuvant chemoradiotherapy (nCRT) remains unclear. METHODS: A thorough pathological review of PNI was performed on post-nCRT esophagectomy specimens obtained from non-ypT0 patients with esophageal squamous cell carcinoma (ESCC). When PNI was identified, it was classified according to the presence or absence of penetration through the nerve sheath (i.e., PNI surrounding the nerve sheath [PNI-SS] versus PNI penetrating through the nerve sheath [PNI-TS]). The impact of PNI on overall survival (OS) was assessed in combination with clinical and pathological risk factors. RESULTS: A total of 177 eligible patients were identified between 1998 and 2008. PNI was identified in 43.5% (77/177) of participants. Of them, 33 and 44 had PNI-SS and PNI-TS, respectively. The 5-year OS rate of patients with PNI-TS was significantly lower (6.7%) than that observed in those without PNI (30.6%, P < 0.001). However, the 5-year OS observed in the latter group did not differ significantly from that of patients with PNI-SS (26%, P = 0.68). Multivariate analysis identified PNI-TS (hazard ratio [HR] = 1.965, P = 0.02), LVI (HR = 1.514, P = 0.048), and ypN2 stage (HR = 2.39, P = 0.007) as independent adverse prognostic factors for OS. CONCLUSIONS: The presence of PNI-TS after nCRT is associated with poor survival. A thorough assessment of distinct PNI patterns (i.e., PNI-TS versus PNI-SS) should be part of the routine post-nCRT histopathological work-up of ESCC patients.

Thyroid hormone protects hepatocytes from HBx-induced carcinogenesis by enhancing mitochondrial turnover.

Infection by hepatitis B virus (HBV) accounts for 50-80% of hepatocellular carcinoma (HCC) development worldwide, in which the HBV-encoded X protein (HBx) has critical role in the induction of carcinogenesis. Several studies have shown that thyroid hormone (TH) suppresses HCC development and protects hepatocytes from HBx-induced damage, thus it is of interest to examine whether TH can protect hepatocytes from HBx-induced carcinogenesis. By treating HBx- transgenic mice with or without TH, we confirmed the protective effects of TH on HBx-induced hepatocarcinogenesis, which was achieved via reduction of reactive oxygen species (ROS) inflicted DNA damage. We further found that TH induced biogenesis of mitochondria (MITO) and autophagy of HBx-targeted MITO simultaneously, consequently leading to suppression of HBx-promoted ROS and carcinogenesis. Using microarray data analysis, this protective effect of TH was found to be mediated via activation of PTEN-induced kinase 1 (PINK1) in hepatocytes. PINK1, in turn, activated and recruited Parkin, an E3 ligase, to ubiquitinate MITO-associated HBx protein and trigger selective mitophagy. The pathological significance of the TH/PINK1 pathway in liver protection was confirmed by the concomitant decrease in expression of both TR and PINK1 in matched HCC tumor tissues and negatively correlated with aggressive progression of cancer and poor prognosis. Our data indicate that TH/PINK1/Parkin pathway has a critical role in protecting hepatocytes from HBx-induced carcinogenesis. Notably, several liver-targeting therapeutic derivatives of TH facilitating prevention or therapy of steatosis have been identified. Furthermore, our proof-of-concept experiments suggest that application of T3 constitutes an effective novel therapeutic or preventive option for HCC. Thus, the utilization of the agonists of TRs could be the meaningful strategy in liver relative diseases, ranging from simple hepatic steatosis to HCC.

Dental extraction without stopping single or dual antiplatelet therapy: results of a retrospective cohort study.

The aim of this study was to investigate the incidence of bleeding after dental extraction without stopping antiplatelet therapy. Postoperative bleeding was assessed in a total of 1271 patients who were divided into two groups: a study group comprising 183 patients on antiplatelet therapy (aspirin 125 patients/185 occasions; clopidogrel 42 patients/65 occasions; dual therapy 16 patients/24 occasions) who underwent 548 dental extractions on 274 occasions, and a control group comprising 1088 patients who were not receiving any antiplatelet or anticoagulant therapy and underwent 2487 dental extractions on 1472 occasions. The incidence of postoperative bleeding was higher in the study group (5/274, 1.8%) than in the control group (10/1472, 0.7%), and also in the dual antiplatelet subgroup (1/24, 4.2%) than in the single antiplatelet subgroups (clopidogrel: 2/65, 3.1%; aspirin: 2/185, 1.1%); however, these differences were not significant. Postoperative bleeding was managed successfully by repacking with Gelfoam impregnated with tranexamic acid powder in 12 patients and by resuturing in three of the control patients undergoing extraction of impacted teeth with flap elevation. These findings indicate that there is no need to interrupt antiplatelet drugs before dental extraction.

Changes of masseter muscle activity following injection of botulinum toxin type A in adult rats.

OBJECTIVES: To investigate changes in masseter muscle function following intramuscular injection of different dose-dependent botulinum toxin type A (BTXA). SETTING AND SAMPLE POPULATION: Department of Orthodontics at Taipei Medical University. Fifty-two, 70-day-old male Wistar rats were randomly divided into four groups. Group I received 7.5 U of BTXA (0.3 ml), Group II received 5.0 U, and Group III received 2.5 U in the right masseter muscle, respectively. Group IV is the control and received no BTXA injection. MATERIALS AND METHODS: A wire electrode device was implanted to record muscle activity. One week after implantation, the rats were fed every 2 h and EMG signals were recorded during the first hour. All signals were recorded for 12 weeks. Thereafter, EMG data were analyzed for statistical calculation and weights of masseter muscles were measured. RESULTS: Masseter muscle activity decreased 99% during the first week after BTXA injection and gradually recovered from the 3rd week on in Groups I-III. By the 12th week, muscle activity recovered to 41% in Groups I and II and 56.26% in Group III. No significant changes of muscle activity were observed in Group IV. CONCLUSION: BTXA induced a reduction in masseter muscle activity and an increased toxin dose resulted in greater depression of muscle activity.

Novel small molecules disrupting Hec1/Nek2 interaction ablate tumor progression by triggering Nek2 degradation through a death-trap mechanism.

Hec1 (highly expressed in cancer 1) or Nek2 (NIMA-related kinase 2) is often overexpressed in cancers with poor prognosis. Both are critical mitotic regulators, and phosphorylation of Hec1 S165 by Nek2 is required for proper chromosome segregation. Therefore, inactivation of Hec1 and Nek2 by targeting their interaction with small molecules represents an ideal strategy for tackling these types of cancers. Here we showed that new derivatives of INH (inhibitor for Nek2 and Hec1 binding) bind to Hec1 at amino acids 394-408 on W395, L399 and K400 residues, effectively blocking Hec1 phosphorylation on S165 by Nek2, and killing cancer cells at the nanomolar range. Mechanistically, the D-box (destruction-box) region of Nek2 specifically binds to Hec1 at amino acids 408-422, immediately adjacent to the INH binding motif. Subsequent binding of Nek2 to INH-bound Hec1 triggered proteasome-mediated Nek2 degradation, whereas the Hec1 binding defective Nek2 mutant, Nek2 R361L, resisted INH-induced Nek2 degradation. This finding unveils a novel drug-action mechanism where the binding of INHs to Hec1 forms a virtual death-trap to trigger Nek2 degradation and eventually cell death. Furthermore, analysis of the gene expression profiles of breast cancer patient samples revealed that co-elevated expressions of Hec1 and Nek2 correlated with the shortest survival. Treatment of mice with this kind of tumor with INHs significantly suppressed tumor growth without obvious toxicity. Taken together, the new INH derivatives are suitable for translation into clinical application.

Increased 8-hydroxy-2'-deoxyguanosine in plasma and decreased mRNA expression of human 8-oxoguanine DNA glycosylase 1, anti-oxidant enzymes, mitochondrial biogenesis-related proteins and glycolytic enzymes in leucocytes in patients with systemic lupus erythematosus.

We measured plasma levels of the oxidative DNA damage marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) and leucocyte mRNA expression levels of the genes encoding the 8-OHdG repair enzyme human 8-oxoguanine DNA glycosylase 1 (hOGG1), the anti-oxidant enzymes copper/zinc superoxide dismutase (Cu/ZnSOD), manganese superoxide dismutase (MnSOD), catalase, glutathione peroxidase-1 (GPx-1), GPx-4, glutathione reductase (GR) and glutathione synthetase (GS), the mitochondrial biogenesis-related proteins mtDNA-encoded ND 1 polypeptide (ND1), ND6, ATPase 6, mitochondrial transcription factor A (Tfam), nuclear respiratory factor 1(NRF-1), pyruvate dehydrogenase E1 component alpha subunit (PDHA1), pyruvate dehydrogenase kinase isoenzyme 1 (PDK-1) and hypoxia inducible factor-1α (HIF-1α) and the glycolytic enzymes hexokinase-II (HK-II), glucose 6-phosphate isomerase (GPI), phosphofructokinase (PFK), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and lactate dehydrogenase A (LDHa). We analysed their relevance to oxidative damage in 85 systemic lupus erythematosus (SLE) patients, four complicated SLE patients undergoing rituximab treatment and 45 healthy individuals. SLE patients had higher plasma 8-OHdG levels (P < 0·01) but lower leucocyte expression of the genes encoding hOGG1(P < 0·01), anti-oxidant enzymes (P < 0·05), mitochondrial biogenesis-related proteins (P < 0·05) and glycolytic enzymes (P < 0·05) than healthy individuals. The increase in plasma 8-OHdG was correlated positively with the elevation of leucocyte expression of the genes encoding hOGG1 (P < 0·05), anti-oxidant enzymes (P < 0·05), several mitochondrial biogenesis-related proteins (P < 0·05) and glycolytic enzymes (P < 0·05) in lupus patients. The patients, whose leucocyte mtDNA harboured D310 heteroplasmy, exhibited a positive correlation between the mtDNA copy number and expression of ND1, ND6 and ATPase 6 (P < 0·05) and a negative correlation between mtDNA copy number and systemic lupus erythematosus disease activity index (SLEDAI) (P < 0·05), as well as plasma 8-OHdG (P < 0·05). In particular, four complicated SLE patients with increased expression of the genes encoding the anti-oxidant enzymes, GAPDH, Tfam and PDHA1, experienced better therapeutic outcomes after rituximab therapy. In conclusion, higher oxidative damage with suboptimal increases in DNA repair, anti-oxidant capacity, mitochondrial biogenesis and glucose metabolism may be implicated in SLE deterioration, and this impairment might be improved by targeted biological therapy.

Prediction of lymph node metastasis in T1/T2 tongue squamous cell carcinoma.

OBJECTIVES: In T1, T2, and clinically NO squamous cell carcinoma of the tongue, there is no reliable predictive variable to determine whether or not neck dissection is needed. Thus, we established a predictive score model based on tumour depth and other pathological variables. METHODS: We retrospectively reviewed 115 patients with T1 and T2 stage squamous cell carcinoma of the tongue. Their pathological variables were used to construct a score model for predicting the risk of cervical lymph node metastasis. RESULTS: A predictive score model was proposed using multivariate logistic regression analysis: Score = (2.694 x tumour depth (cm)) + (1.814 x lymphovascular invasion (yes = 1, no = 0)) + (1.175 x perineural invasion (yes = 1, no = 0)). The cutoff point was set at 2.7427. This predictive score model has a sensitivity of 91.2% and specificity of 65.4%. CONCLUSION: A predictive score model was built and a two-stage surgical approach was suggested for T1 and T2 squamous cell carcinoma of the tongue.

Thyroid hormone receptor represses miR-17 expression to enhance tumor metastasis in human hepatoma cells.

MicroRNAs (miRNAs) are thought to control tumor metastasis through direct interactions with target genes. Thyroid hormone (T3) and its receptor (TR) are involved in cell growth and cancer progression. However, the issue of whether miRNAs participate in T3/TR-mediated tumor migration is yet to be established. In the current study, we demonstrated that T3/TR negatively regulates mature miR-17 transcript expression, both in vitro and in vivo. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays localized the regions responding to TR-mediated repression to positions -2234/-2000 of the miR-17 promoter sequence. Overexpression of miR-17 markedly inhibited cell migration and invasion in vitro and in vivo, mediated via suppression of matrix metalloproteinases (MMP)-3. Moreover, p-AKT expression was increased in miR-17-knockdown cells that led to enhanced cell invasion, which was blocked by LY294002. Notably, low miR-17 expression was evident in highly metastatic cells. The cell migration ability was increased by T3, but partially reduced upon miR-17 overexpression. Notably, TRα1 was frequently upregulated in hepatocellular carcinoma (HCC) samples and associated with low overall survival (P=0.023). miR-17 expression was significantly negatively associated with TRα1 (P=0.033) and MMP3 (P=0.043) in HCC specimens. Data from our study suggest that T3/TR, miR-17, p-AKT and MMP3 activities are interlinked in the regulation of cancer cell metastasis.

Thyroid hormone suppresses cell proliferation through endoglin-mediated promotion of p21 stability.

Hypothyroidism has been associated with significantly elevated risk for hepatocellular carcinoma (HCC), although the precise underlying mechanisms remain unknown at present. Thyroid hormone (T3) and its receptor (TR) are involved in metabolism and growth. Endoglin is a T3/TR candidate target gene identified from our previous studies. Here, we demonstrated that T3 positively regulates endoglin mRNA and protein levels, both in vitro and in vivo. The thyroid hormone response elements of endoglin were identified at positions -2114/-2004 and -2032/-1973 of the promoter region using the electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Endoglin was downregulated in the subgroups of HCC patients and significantly associated with histology grade (negative association, P=0.001), and this expression level was significantly associated with TRα1 in these HCC patients. Our results clearly indicate that p21 is involved in T3-mediated suppression of cell proliferation. Knock down of endoglin expression in HCC cells facilitated p21 polyubiquitination and promoted cell proliferation in the presence of T3. The data collectively suggest that T3/TR signaling suppresses cell proliferation by upregulating endoglin, in turn, affecting p21 stability. The results indicate that endoglin has a suppressor role to inhibit cell proliferation in HCC cell lines.

Thyroid hormone receptors promote metastasis of human hepatoma cells via regulation of TRAIL.

Although accumulating evidence has confirmed the important roles of thyroid hormone (T(3)) and its receptors (TRs) in tumor progression, the specific functions of TRs in carcinogenesis remain unclear. In the present study, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) was directly upregulated by T(3) in TR-overexpressing hepatoma cell lines. TRAIL is an apoptotic inducer, but it can nonetheless trigger non-apoptotic signals favoring tumorigenesis in apoptosis-resistant cancer cells. We found that TR-overexpressing hepatoma cells treated with T(3) were apoptosis resistant, even when TRAIL was upregulated. This apoptotic resistance may be attributable to simultaneous upregulation of Bcl-xL by T(3), because (1) knockdown of T(3)-induced Bcl-xL expression suppressed T(3)-mediated protection against apoptosis, and (2) overexpression of Bcl-xL further protected hepatoma cells from TRAIL-induced apoptotic death, consequently leading to TRAIL-promoted metastasis of hepatoma cells. Moreover, T(3)-enhanced metastasis in vivo was repressed by the treatment of TRAIL-blocking antibody. Notably, TRAIL was highly expressed in a subset of hepatocellular carcinoma (HCC) patients, and this high-level expression was significantly correlated with that of TRs in these HCC tissues. Together, our findings provide evidence for the existence of a novel mechanistic link between increased TR and TRAIL levels in HCC. Thus, TRs induce TRAIL expression, and TRAIL thus synthesized acts in concert with simultaneously synthesized Bcl-xL to promote metastasis, but not apoptosis.

Masseter muscle fibre changes following reduction of masticatory function.

This study evaluated histological changes in masseter muscle fibres following reduced masticatory function by injection of botulinum toxin type A (BTX). Sixty 30-day-old Long-Evans male rats were randomly separated into four groups (15 per group): group I BTX masseter, 25U/ml (0.04ml each muscle) BTX was injected in bilateral masseter muscle whilst bilateral temporalis muscles received an equal amount of normal saline; group II BTX temporalis, 25U/ml (0.04ml each muscle) BTX was injected in bilateral temporalis muscle whilst bilateral masseter muscle received an equal amount of normal saline; group III BTX temporalis and masseter, bilateral temporalis and masseter were given 25U/ml (0.04ml each muscle) BTX; group IV normal saline (control), bilateral temporalis and masseter were given normal saline (0.04ml each muscle). After 45 days, the rats were killed, the muscles dissected and mean muscle mass recorded. The superficial masseter muscles were immunohistochemically analysed. Fibre sizes in group III were bigger than those in other groups. There was a small percentage of type IIa fibres in group III. Reduction in muscle fibre size and transition of muscle fibre subtypes from type IIa to IIx or IIb fibres may occur due to reduced masticatory function.

The influence of masticatory hypofunction on developing rat craniofacial structure.

The purpose of this study was to use botulinum neurotoxin type A (BoNT/A) selectively to evaluate the influence of localized masticatory atrophy and paresis on craniofacial growth and development. 60 growing rats, 4 weeks old, weighing approximately 120g, were randomly divided according as follows (Long-Evans, N=15 per group): I (Mb+Tns); II (Mns+Tb); III (Mb+Tb); IV (Mns+Tns), where Mb or Tb is the BoNT/A-injected masseter or temporalis muscles (1.0U/muscle, 2.5ml) and Mns or Tns is the saline-injected muscles (2.5ml). After 7 weeks, the mature rats were killed, the muscles dissected and mean muscle mass recorded. Anthropometric cranial, maxillary and mandibular measurements were taken from the dried skulls. Changes in animal weight during the growth period were not statistically significant. The mean masticatory muscle mass was smaller for the BoNT/A-injected muscles of Mb and Tb. Anthropometric measurements of bony structures inserted by masseter and temporalis muscles revealed a significant treatment effect. The measurements showed a facial morphology typical of a dolichofacial profile: short upper face accompanied by a long lower face with an extended mandibular length and ramus height and constricted bicoronoidal and bigonial widths. The results suggest that induction of localized masticatory muscle atrophy with BoNT/A alters craniofacial growth and development.