Masked excitatory action of noradrenaline on rat islet β-cells via activation of phospholipase C

The effect of noradrenaline (NE) on rat islet -cells was examined. NE reduced insulin secretion from rat islets exposed to extracellular solutions containing glucose at 5.5 or 16.6 mM. In islets treated with pertussis toxin (PTX), however, NE increased insulin secretion. The NE-induced augmentation of insulin secretion was inhibited by prazosin. In intact islets, NE increased phospholipase C (PLC) activity, an effect that was prevented by treatment of islets with U-73122. NE elevated intracellular [Ca²⁺] ([Ca²⁺]_i) in isolated -cells independently of PTX. Although this NE effect was inhibited by prazosin, phenylephrine did not mimic it. The [Ca²⁺]_i response to NE was also prevented by the treatment of cells with U-73122. NE produced depolarization of -cells followed by nifedipine-sensitive action potentials. NE reduced the whole-cell membrane currents through ATP-sensitive K⁺ channels (K_ATP), responsible for the depolarization. This NE effect was prevented by treatment of -cells with U-73122 or BAPTA/AM. Although at least some of our results imply the presence of ₁-adrenoceptors, -cells were not stained by a polyclonal IgG antibody recognizing all adrenergic ₁-receptor subtypes so far identified. These results suggest that an interaction of NE with an unknown type of receptor activates rat islet -cells via a PLC-dependent signal pathway. This effect is, however, masked by the inhibitory action via a PTX-sensitive pathway also activated by NE.     

The role of IL-17 in systemic lupus erythematosus and its potential as a therapeutic target

Introduction: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by autoantibodies production and immune complex deposition with systemic clinical manifestations. Interleukin (IL)-17-producing cells play a crucial role in disease pathogenesis and represent an attractive therapeutic target.

Areas covered: This review provides an update on the possibility of targeting IL-17 in SLE. The rational for this approach as well as currently available and future targets are discussed.

Expert opinion: Although human expression studies and animal models indicate that IL-17 blocking may be a promising therapeutic strategy for SLE, direct evidence for IL-17 inhibition in SLE patients is unavailable. Biologic therapies and small-molecule drugs that target IL-17 production are required for the achievement of a favorable clinical effect in SLE patients.     

Suppression of cell attachment and protein adsorption onto amphiphilic polylactide-grafted dextran films

To develop novel biodegradable biomedical materials, polylactide-grafted dextrans (Dex-g-PLA)s having various lengths, numbers of graft chains and sugar units were synthesized using the trimethylsilyl (TMS) protection method. To explore the possibility of using Dex-g-PLA as a biomedical soft-material, the contact angle, cell attachment and protein adsorption properties of the films prepared from these biodegradable and amphiphilic graft co-polymers were investigated. The poly-L-lactide (PLLA) film did not absorb water at all because of its high hydrophobicity, while the graft co-polymer films started immediately to swell after immersion in PBS. The percentage of water absorption at equilibrium increased with increasing sugar unit content. The receding contact angle of the Dex-g-PLA films against water was smaller than that of the PLLA film. The receding contact angle of Dex-g-PLA films against water decreased with increasing the sugar unit content. The top surface of the Dex-g-PLA film was suggested to be covered with hydrophilic Dex segments by means of annealing in water and to afford the wettable surface. Such a wettable surface led to the suppression of cell attachment and protein adsorption onto the film.     

Human neutrophils express messenger RNA of vitamin D receptor and respond to 1alpha,25-dihydroxyvitamin D3

1Alpha,25-Dihydroxyvitamin D3 (1,25(OH)2D3) has been shown to modulate the production of various cytokines or the expression of certain differentiation markers in human T cells or monocytes. Its effects on neutrophils, however, are poorly understood. In this paper, we show several lines of evidence indicating that neutrophils express functional vitamin D receptors (VDR). Sort-purified neutrophils from human peripheral blood expressed VDR mRNA at a level comparable to that of monocytes. As reported to occur in monocytes, protein expression of CD14 on the cell surface of neutrophils was augmented when the cells were incubated with 1,25(OH)2D3. To investigate the physiological roles for VDR in neutrophils, we investigated possible modulating effects of 1,25(OH)2D3 on the expression of several genes in lipopolysaccharide-stimulated neutrophils by using differential display analysis. Of the genes we identified, trappin-2/elafin/SKALP, which was originally reported to be an inhibitor of elastase, was induced in neutrophils by lipopolysaccharide, but was suppressed significantly in the presence of 1,25(OH)2D3. Under the same conditions, interleukin-1beta expression was also inhibited. These findings suggest that 1,25(OH)2D3 has a potential to affect the inflammatory process by modulating the expression of neutrophil genes.     

A novel translocation involving chromosomes 2, 9, 14, and 22 in chronic myeloid leukemia

A 46-year-old man with chronic myelogenous leukemia was found to have a new complex translocation. In chronic phase, all of the bone marrow cells had a rearrangement of a t(2;9;14;22) (p21;q34;q32;q11). Southern blot analysis of leukocyte DNA revealed rearrangement of the breakpoint cluster region (bcr) within the 5.8-Kb bcr. The patient eventually died in blast crisis 28 months later. The cytogenetic findings of bone marrow cells showed a 46,XY,t(2;9;14;22)(p21;q34;q32;qll),add(lp),del(3q) karyotype in blast crisis.     

Feasibility of a self‐assembling peptide hydrogel scaffold for meniscal defect: An in vivo study in a rabbit model

The inner avascular zone of the meniscus has limited healing capacity as the area is poorly vascularized. Although peptide hydrogels have been reported to regenerate bone and cartilage, their effect on meniscus regeneration remains unknown. We tested whether the self‐assembling peptide hydrogel scaffold KI24RGDS stays in the meniscal lesion and facilitates meniscal repair and regeneration in an induced rabbit meniscal defect model. Full‐thickness (2.0 mm diameter) cylindrical defects were introduced into the inner avascular zones of the anterior portions of the medial menisci of rabbit knees (n = 40). Right knee defects were left empty (control group) while the left knee defects were transplanted with peptide hydrogel (KI24RGDS group). Macroscopic meniscus scores were significantly higher in the KI24RGDS group than in the control group at 2, 4, and 8 weeks after surgery. Histological examinations including quantitative and qualitative scores indicated that compared with the control group, the reparative tissue in the meniscus was significantly enhanced in the KI24RGDS group at 2, 4, 8, and 12 weeks after surgery. Immunohistochemical staining showed that the reparative tissue induced by KI24RGDS at 12 weeks postimplantation was positive for Type I and II collagen. KI24RGDS is highly biocompatible and biodegradable, with strong stiffness, and a three dimensional structure mimicking native extracellular matrix and RGDS sequences that enhance cell adhesion and proliferation. This in vivo study demonstrated that KI24RGDS remained in the meniscal lesion and facilitated the repair and regeneration in a rabbit meniscal defect model.     

Characteristics affecting cervical sagittal alignment in patients with chronic low back pain

BackgroundSagittal spino-pelvic malalignment in patients with chronic low back pain (CLBP) have been reported in the past, which may also affect cervical spine lesions. The purpose of this study is to investigate the cervical alignment in patients with CLBP.MethodOf the patients who visited an orthopedic specialist due to low back pain lasting more than three months, 121 cases (average 71.5-years-old, 46 male and 75 female) with whole standing spinal screening radiographs were reviewed (CLBP group). Cervical parameters included cervical lordosis (CL), C2–C7 sagittal vertical axis (C2-7 SVA), and the T1 slope minus CL (T1S-CL). Cervical spine deformity was defined as C2-7 SVA >4 cm, CL <0°, or T1S-CL ≧20°. We compared the cervical alignment of these patients with 121 age and gender matched volunteers (control group).ResultsThe prevalence of cervical spine deformity was significantly higher in the CLBP group than in the control group (20.7% vs. 10.7%, P = 0.034). The mean CL was smaller in the CLBP group than in the control group (16.1° vs. 21.4°, P = 0.002). The mean C2-7 SVA was 17.6 mm vs. 18.7 mm in the CLBP group and in the control group, respectively (P = 0.817). The mean T1S-CL was larger in the CLBP group than in the control group (9.1° vs. 3.5°, P < 0.001). Multivariate analysis showed that people with CLBP were more likely to have cervical deformities than people without CLBP (odds ratio 2.16, 95% confidence interval 1.006 to 4.637).ConclusionsThis study results suggest that people with CLBP present with worse cervical sagittal alignment and higher prevalence of cervical spine deformities than age and gender matched volunteers with no CLBP. This means CLBP impacts cervical spine lesions negatively.Level of evidenceⅣ     

How Are Indeterminate Pulmonary Nodules at Diagnosis Associated with Survival in Patients with High-Grade Osteosarcoma?

BackgroundPulmonary metastases are a poor prognostic factor in patients with osteosarcoma; however, the clinical significance of subcentimeter lung nodules and whether they represent a tumor is not fully known. Because the clinician is faced with decisions regarding biopsy, resection, or observation of lung nodules and the potential impact they have on decisions about resection of the primary tumor, this remains an area of uncertainty in patient treatment. Surgical management of the primary tumor is tailored to prognosis, and it is unclear how aggressively patients with indeterminate pulmonary nodules (IPNs), defined as nodules smaller than 1 cm at presentation, should be treated. There is a clear need to better understand the clinical importance of these nodules.Questions/purposes(1) What percentage of patients with high-grade osteosarcoma and spindle cell sarcoma of bone have IPNs at diagnosis? (2) Are IPNs at diagnosis associated with worse metastasis-free and overall survival? (3) Are there any clinical or radiologic factors associated with worse overall survival in patients with IPN?MethodsBetween 2008 and 2016, 484 patients with a first presentation of osteosarcoma or spindle cell sarcoma of bone were retrospectively identified from an institutional database. Patients with the following were excluded: treatment at another institution (6%, 27 of 484), death related to complications of neoadjuvant chemotherapy (1%, 3 of 484), Grade 1 or 2 on final pathology (4%, 21 of 484) and lack of staging chest CT available for review (0.4%, 2 of 484). All patients with abnormalities on their staging chest CT underwent imaging re-review by a senior radiology consultant and were divided into three groups for comparison: no metastases (70%, 302 of 431), IPN (16%, 68 of 431), and metastases (14%, 61 of 431) at the time of diagnosis. A random subset of CT scans was reviewed by a senior radiology registrar and there was very good agreement between the two reviewers (κ = 0.88). Demographic and oncologic variables as well as treatment details and clinical course were gleaned from a longitudinally maintained institutional database. The three groups did not differ with regard to age, gender, subtype, presence of pathological fracture, tumor site, or chemotherapy-induced necrosis. They differed according to local control strategy and tumor size, with a larger proportion of patients in the metastases group presenting with larger tumor size and undergoing nonoperative treatment. There was no differential loss to follow-up among the three groups. Two percent (6 of 302) of patients with no metastases, no patients with IPN, and 2% (1 of 61) of patients with metastases were lost to follow-up at 1 year postdiagnosis but were not known to have died. Individual treatment decisions were determined as part of a multidisciplinary conference, but in general, patients without obvious metastases received (neo)adjuvant chemotherapy and surgical resection for local control. Patients in the no metastases and IPN groups did not differ in local control strategy. For patients in the IPN group, staging CT images were inspected for IPN characteristics including number, distribution, size, location, presence of mineralization, and shape. Subsequent chest CT images were examined by the same radiologist to reevaluate known nodules for interval change in size and to identify the presence of new nodules. A random subset of chest CT scans were re-reviewed by a senior radiology resident (κ = 0.62). The association of demographic and oncologic variables with metastasis-free and overall survival was first explored using the Kaplan-Meier method (log-rank test) in univariable analyses. All variables that were statistically significant (p < 0.05) in univariable analyses were entered into Cox regression multivariable analyses.ResultsFollowing re-review of staging chest CTs, IPNs were found in 16% (68 of 431) of patients, while an additional 14% (61 of 431) of patients had lung metastases (parenchymal nodules 10 mm or larger). After controlling for potential confounding variables like local control strategy, tumor size, and chemotherapy-induced necrosis, we found that the presence of an IPN was associated with worse overall survival and a higher incidence of metastases (hazard ratio 1.9 [95% CI 1.3 to 2.8]; p = 0.001 and HR 3.6 [95% CI 2.5 to 5.2]; p < 0.001, respectively). Two-year overall survival for patients with no metastases, IPN, or metastases was 83% [95% CI 78 to 87], 65% [95% CI 52 to 75] and 45% [95% CI 32 to 57], respectively (p = 0.001). In 74% (50 of 68) of patients with IPNs, it became apparent that they were true metastatic lesions at a median of 5.3 months. Eighty-six percent (43 of 50) of these patients had disease progression by 2 years after diagnosis. In multivariable analysis, local control strategy and tumor subtype correlated with overall survival for patients with IPNs. Patients who were treated nonoperatively and who had a secondary sarcoma had worse outcomes (HR 3.6 [95% CI 1.5 to 8.3]; p = 0.003 and HR 3.4 [95% CI 1.1 to 10.0]; p = 0.03). The presence of nodule mineralization was associated with improved overall survival in the univariable analysis (87% [95% CI 39 to 98] versus 57% [95% CI 43 to 69]; p = 0.008), however, because we could not control for other factors in a multivariable analysis, the relationship between mineralization and survival could not be determined. We were unable to detect an association between any other nodule radiologic features and survival.ConclusionThe findings show that the presence of IPNs at diagnosis is associated with poorer survival of affected patients compared with those with normal staging chest CTs. IPNs noted at presentation in patients with high-grade osteosarcoma and spindle cell sarcoma of bone should be discussed with the patient and be considered when making treatment decisions. Further work is required to elucidate how the nodules should be managed.Level of EvidenceLevel III, prognostic study.