Influence of internal fixator flexibility on murine fracture healing as characterized by mechanical testing and microCT imaging

Mechanically well‐defined stabilization systems have only recently become available, providing standardized conditions for studying the role of the mechanical environment on mouse bone fracture healing. The aim of this study was to characterize the time course of strength recovery and callus development of mouse femoral osteotomies stabilized with either low or high flexibility (in bending and torsion) internal fixation plates. Animals were euthanized and femora excised at 14, 21, and 28 days post‐osteotomy for microCT analysis and torsional strength testing. While a larger mineralized callus was observed in osteotomies under more flexible conditions at all time points, the earlier bridging of the mineralized callus under less flexible conditions by 1 week resulted in an earlier recovery of torsional strength in mice stabilized with low flexibility fixation. Ultimate torque values for these bones were significantly higher at 14 and 21 days post‐osteotomy compared to bones with the more flexible stabilization. Our study confirms the high reproducibility of the results that are achieved with this new implant system, therefore making it ideal for studying the influence of the mechanical environment on murine fracture healing under highly standardized conditions. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29: 1245–1250, 2011     

A case of Wegener's granulomatosis complicated by hypopituitarism]

A 71-year-old male complaining of chest pain was admitted to our hospital. A single cavitary mass shadow was observed on chest X-ray films. Urinalysis revealed microscopic hematuria. CT examination demonstrated a tumorous shadow in the maxillary sinus. The diagnosis of Wegener's granulomatosis was histologically established by biopsy specimens from the nasal mucosa which showed necrotizing vasculitis and granuloma with fibrinoid degeneration. He was treated with combination therapy of prednisolone and cyclophosphamide. The abnormal shadows on chest X-ray and in the maxillary sinus on CT improved rapidly, but the patient developed progressive weight loss and complained of cold intolerance, weakness and dysphagia. Serum T3, T4 and TSH were found to be reduced. Anterior pituitary function tests showed reduction of TSH, GH and ACTH responses, which was probably due to irreversible vasculitis.     

Telomerase activity, P53 mutation and Ki-ras codon 12 point mutation of the peripheral blood in patients with hepato pancreato biliary diseases

Background

With progress in molecular biology, the presence of telomerase activity, P53 mutation and Ki-ras codon 12 point mutation has been reported in malignant tumours of the liver, pancreas and biliary tree. The purpose of this paper is to clarify the clinical implications of finding these three biomarkers in the peripheral blood of affected patients.

Methods

Telomerase activity, P53 mutation, and Ki-ras codon 12 point mutation in the peripheral blood were examined among 86 patients with hepato pancreato biliary disease, both benign and malignant, and the results were compared with clinical findings.

Results

Of 20 patients with benign conditions, only one patient with intraductal papillary adenoma showing severe dysplasia exhibited a biomarker (telomerase activity) in the peripheral blood. In total, there were 66 patients with various HPB carcinomas. Of 56 cancer patients studied pre-operatively, 16 were positive for more than one biomarker, 13 were positive for telomerase activity, 4 for P53 mutation (three at exon 7 and another at exon 8), and 2 for Kiras codon 12 point mutation (both in the second letter). Twelve of the 16 biomarker-postiive patients had stage IV disease as opposed to 23 of 40 biomarker-negative patients. The resectability rate of the cancer was 38% in positive patients and 50% in negative patients. The one-year survival rate after resection was zero in positive patients and 15% in negative patients, but the difference was not significant (P=0.65). Of 32 patients with liver metastasis at the time of the molecular examination, eight were positive and 24 negative. Of 34 patients without liver metastasis, nine were positive and 25 negative. The development of subsequent liver metastases in those without them at the start was not significantly different in those with and without biomarkers (56 vs 36%: P=0.31).

Conclusions

The three novel biomarkers of the peripheral blood seemed to be of little value for screening of early malignant HPB neoplasms but may help to predict liver metastasis.     

Determination of Hepatitis Delta Virus (HDV)-RNA in Asymptomatic Cases of HDV Infection

Objectives: To assess the frequency of hepatitis delta virus (HDV) viremia in asymptomatic cases of HDV infection and the clinical significance of the HDV viremia, we conducted a cross-sectional community-based study. Methods : Of 2207 examinees, 210 (9.5%) were found to be positive for hepatitis B surface antigen (HBsAg). Antibody to HDV was detected in 47 (22.4%) of the 210 examinees, and 43 of the 47 were further evaluated for serum HDV-RNA by polymerase chain reaction. Results : Twenty-one (48.8%) of the 43 had detectable levels of HDV-RNA in serum, and 22 (51.2%) were negative for serum HDV-RNA. The majority (61.9%) of the HDV-RNA-positive HBsAg carriers had high levels of serum ALT. In contrast, the frequency of an abnormally high level of serum ALT was only 9.1% in the HBsAg carriers positive for HDV antibody but negative for HDV-RNA and the frequency did not differ from that seen in the HBsAg-negative individuals. The semi-quantified HDV-RNA levels did not correlate with the serum ALT levels. Conclusion : Seropositivity of HDV-RNA was strongly associated with liver cell damage, even in asymptomatic cases. The absence of a detectable level of serum HDV-RNA might be related to previous HDV infection.     

Mitochondrial complex I activity is significantly decreased in a patient with maternally inherited type 2 diabetes mellitus and hypertrophic cardiomyopathy associated with mitochondrial DNA C3310T mutation: a cybrid study

Mitochondrial respiratory function in a patient with maternally inherited type 2 diabetes mellitus and hypertrophic cardiomyopathy associated with heteroplasmic mitochondrial DNA (mtDNA) C3310T mutation, which replaces the second amino acid of NADH dehydrogenase 1 (ND1) from a hydrophobic Proline to a hydrophilic Serine, was investigated. Mitochondrial respiratory function solely due to mtDNA C3310T mutation was investigated in cybrid system by the fusion of mtDNA-deleted (rho(0)) HeLa cells and exogenous mtDNA either from the proband or from controls. Total oxygen consumption of the proband cybrid cells was significantly decreased compared with those of controls (2.468+/-0.475 versus 2.871+/-0.484 micromol/h/10(7) cells, p=0.0392). Mitochondrial respiratory chain complex I activity of the proband cybrid cells was also significantly decreased compared with those of controls (0.191+/-0.080 versus 0.288+/-0.113 micromol/h/mg protein, p=0.0223). Furthermore, ATP content in the proband cybrid cells was also significantly decreased compared with those in controls (1.119+/-0.344 versus 1.419+/-0.378 pmol/10(5) cells, p=0.044). The present study indicates that mtDNA C3310T mutation may be a pathogenic mutation of maternally inherited type 2 diabetes mellitus and hypertrophic cardiomyopathy in the proband and the family.     

Plasma sLOX-1 is a potent biomarker of clinical remission and disease activity in patients with seropositive RA

Objectives: Soluble lectin-like oxidized low-density lipoprotein receptor 1 (sLOX-1) is present in the circulation and synovial fluid in patients with rheumatoid arthritis (RA). The aim of this study was to assess whether sLOX-1 level is associated with clinical remission and disease activity in patients with RA.

Methods: Clinical and laboratory data were analyzed for 282 patients with RA. Plasma sLOX-1 level was measured by enzyme-linked immunosorbent assay (ELISA). The remission status and sLOX-1 levels were compared between four groups of patients based on the positivity of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPAs). Relationships between sLOX-1 level and the 28-joint Disease Activity Score with erythrocyte sedimentation rate (DAS28-ESR) were analyzed by multivariate logistic regression.

Results: The patients in the RF?+?ACPA?+?group tended to exhibit higher sLOX-1 levels when compared to the other three groups. In the RF?+?ACPA?+?group, the sLOX-1 level was significantly higher in the non-remission group than in the remission group, irrespective of treatment. Multivariate logistic regression showed significant correlations between sLOX-1 level and DAS28-ESR.

Conclusions: sLOX-1 level might be a useful biomarker for assessing clinical remission and disease activity in double-positive RA patients.     

Amino acid taste receptor regulates insulin secretion in pancreatic β-cell line MIN6 cells

Amino acids such as L-glutamate and L-arginine are potent stimuli for insulin secretion from pancreatic β-cells. However, the precise molecular mechanisms of amino acid-induced insulin secretion have only partly understood. In this study, we show here that mouse pancreatic β-cell line MIN6 cells expressed amino acid taste receptor (heterodimer of type 1 taste G protein-coupled receptor member 1 and member 3; Tas1R1 and Tas1R3, respectively). We found that administration of L-glutamate or L-arginine to MIN6 cells caused the increase in free intracellular concentrations of both inositol-1,4,5-triphosphate (IP(3)) and Ca(2+) , and umami substance inocinate enhanced the effects of l-glutamate. Effects of amino acids on intracellular IP(3) and Ca(2+) concentration were diminished by application of lactisole, a Tas1R3 receptor antagonist. Furthermore, we investigated the effect of amino acids on the insulin release from MIN6 cells by both ELISA and total internal reflection fluorescence microscopy. Application of L-glutamate or L-arginine significantly increased the release of insulin, whereas inhibited by the application of lactisole. Based on these findings, we propose that heterodimer of Tas1R1 and Tas1R3 is the fundamental receptor for the sensing amino acids and regulates the amino acid-induced insulin secretion in pancreatic β-cells.     

Cell-contact-dependent activation of CD4+ T cells by adhesion molecules on synovial fibroblasts

Objective: To determine how cell–cell contact with synovial fibroblasts (SF) influence on the proliferation and cytokine production of CD4^+?T cells.

Methods: Naïve CD4^+?T cells were cultured with SF from rheumatoid arthritis patients, stimulated by anti-CD3/28 antibody, and CD4^+?T cell proliferation and IFN-γ/IL-17 production were analyzed. To study the role of adhesion molecules, cell contact was blocked by transwell plate or anti-intracellular adhesion molecule-1 (ICAM-1)/vascular cell adhesion molecule-1(VCAM-1) antibody. To study the direct role of adhesion molecules for CD4^+?T cells, CD161^+?or CD161^- naïve CD4^+?T cells were stimulated on plastic plates coated by recombinant ICAM-1 or VCAM-1, and the source of IFN-γ/IL-17 were analyzed.

Results: SF enhanced naïve CD4^+?T cell proliferation and IFN-γ/IL-17 production in cell-contact and in part ICAM-1-/VCAM-1-dependent manner. Plate-coated ICAM-1 and VCAM-1 enhanced naïve CD4^+?T cell proliferation and IFN-γ production, while VCAM-1 efficiently promoting IL-17 production. CD161^+?naïve T cells upregulating LFA-1 and VLA-4 were the major source of IFN-γ/IL-17 upon interaction with ICAM-1/VCAM-1.

Conclusion: CD4^+?T cells rapidly expand and secrete IFN-γ/IL-17 upon cell-contact with SF via adhesion molecules. Interfering with ICAM-1-/VCAM-1 may be beneficial for inhibiting RA synovitis.     

Analysis of T-helper type 1 and 2 cells and T-cytotoxic type 1 and 2 cells of sentinel lymph nodes in breast cancer

The immune suppression of sentinel lymph node (SN) is directly influenced by primary tumors. It has been reported that the T-helper type 1 (Th1) to T-helper type 2 (Th2) ratio or T-cytotoxic type 1 (Tc1) to T-cytotoxic type 2 (Tc2) ratio of lymph node lymphocytes could be used to evaluate direct immunological circumstances. We attempted to evaluate the Th1 to Th2 cell and Tc1 to Tc2 cell balance in SN and non-SN and to clarify the immunological status of sentinel nodes in breast cancer. To evaluate this balance, SN and non-SN were identified by radioguided methods and lymph node lymphocytes were collected, and prepared for flow cytometry. The Th1 to Th2 and Tc1 to Tc2 ratio were calculated by 3-color flow cytometry. The ratio of SN and non-SN was compared. The results demonstrated that SN was detected in 24 out of 24 patients (100%). As regards the correlation between SN and non-SN in the same patients, the Th1 to Th2 ratio in SN was significantly lower than that in non-SN for all patients (p<0.05). Among clinicopathological factors, a larger tumor diameter, histology and nodal involvement affected the decreased Th1 to Th2 ratio in SN significantly (p<0.05). We reached the conclusion that the increasing immunosuppressive conditions derived from the tumor may deteriorate the Th1 to Th2 ratio of SN in an earlier stage as compared with non-SN. According to the tumor extension and nodal involvement, the Th1 to Th2 ratio in SN was significantly suppressed. The current result supports that mainly helper T-cell paralysis occurred first in SN and this seems to be a favorable condition in forming lymph node metastases in SN. Moreover, the immunologic interaction between the primary site and regional lymph nodes may serve as useful criteria for identifying sentinel nodes.