Wear and mechanical properties of composite resins consisting of different filler particles

To investigate the effects of different fillers and their contents on the wear of composite resins, four composites (CS: non-porous spherical silica, AS: porous spherical silica, AZ: porous spherical zirconium silicate, and IS: non-porous irregular-shaped silica) were experimentally prepared using different fillers (CS, AZ, AS and IS). Simulated occlusal wear and toothbrush wear were evaluated for these composites and their worn surfaces were observed. The mechanical properties (flexural strength, elastic modulus and hardness) of these composites were determined to examine the relationships between wear and these mechanical properties. CS showed the highest occlusal wear, but the lowest toothbrush wear among four composites. AS and AZ had lower occlusal wear than CS and IS, while their toothbrush wear was higher than CS and close to that of IS. All composites showed increase in the occlusal wear as filler content increased. CS and IS showed decrease in the toothbrush wear as the filler content increased, whereas AS and AZ did not. The occlusal wear surfaces of CS and IS had concavities, while those of AZ and AS were relatively smooth with flattened filler. The toothbrush wear surfaces of CS and IS revealed the extrusion of filler from resin matrix, whereas those of AZ and AS were smooth with flattened filler. The toothbrush wear of CS and IS decreased as the mechanical properties increased, whereas those of AS and AZ did not. The occlusal wear of all composites increased as the mechanical properties increased, which would not reflect effects of these mechanical properties.     

Efficacy of adipose tissue-derived mesenchymal stem cells for fulminant hepatitis in mice induced by concanavalin A

Background and Aim: Fulminant hepatitis is mainly caused by excessive immune response‐mediated liver injury and its definitive therapy is liver transplantation. Mesenchymal stem cells, one of the adult stem cells, have an immunomodulatory effect on immune cells and reside in various tissues. The aim of this study was to investigate a therapeutic effect of adipose tissue‐derived mesenchymal stem cells (ASCs) on fulminant hepatitis induced by concanavalin A (ConA). Methods: The ASCs were isolated from adipose tissues of BALB/c mice and confirmed by detection of cell surface markers and induction of multi‐lineage differentiation. BALB/c mice were injected with ConA and treated with ASCs, phosphate buffered saline (PBS) or splenocytes (SPLCs). Survival rates, levels of serum liver enzymes, titers of serum cytokines, histopathology and localization of ASCs were investigated. Result: The survival rate of ASC‐injected mice significantly increased compared to PBS or SPLC‐injected mice. This effect was dependent on doses and timing of ASCs injected. Improvement of liver enzyme levels, histopathological changes and suppression of inflammatory cytokine production were observed in ASC‐injected mice. Fluorescent stained ASCs were detected in inflammatory liver, but not in normal liver. Conclusion: These results suggest that ASC treatment has a high potential to be an innovative therapy for fulminant hepatitis.     

Less invasive transjugular approach with Fallopian bridge technique for facial nerve protection and hearing preservation in surgery of glomus jugulare tumors

For the past three decades, surgery of glomus jugulare tumors (GJTs) has been characterized by extensive combined head and neck, neuro-otologic, and neurosurgical approaches. In recent years, the authors have modified the operative technique to a less invasive approach for preservation of cranial nerves while achieving satisfactory tumor resection. We evaluated and compared the clinical outcomes of our current less invasive approach with our previous more extensive procedures. The clinical records of 39 cases of GJT surgically treated between 1992 and 2011 were retrospectively reviewed. The less invasive transjugular approach with Fallopian bridge technique (LI-TJ) was used for the most recent five cases. The combined transmastoid–transjugular and high cervical (TM-HC) approach was performed in 30 cases, while four cases were treated with a transmastoid–transsigmoid approach with facial nerve translocation. Operative technique, extent of tumor resection, operating time, hospital stay, and morbidity were examined through the operative records, and a comparison was made between the LI-TJ cases and the more invasive cases. No facial nerve palsy was seen in the LI-TJ group while the TM-HC group demonstrated six cases (17.6 %) of facial palsy (House–Brackmann facial nerve function grading scale grade II and III). The complication rate was 0 % in the LI-TJ group and 16.7 % in the more invasive group. The mean operative time and hospital stay were shorter in the LI-TJ group (6.4 h and 4.3 days, respectively) compared with the more invasive group (10.7 h and 8.0 days, respectively). The LI-TJ approach with Fallopian bridge technique provided adequate tumor resection with cranial preservation and definitive advantage over the more extensive approach.     

Pulmonary lobar root clamping and stapling technique: return of the “en masse lobectomy”

Purpose

Most thoracic surgeons have experienced difficulty dissecting the pulmonary hilus because of scarring. In such potentially dangerous situations, we advocate a method of clamping and severing the pulmonary lobar root structure en masse. The aim of this study was to evaluate en masse lobectomy, particularly considering the constellation of pulmonary vessels and the bronchus.

Methods

Twelve patients (median age 70 years) underwent en masse lobectomy. We retrospectively evaluated the surgical procedures and clinical outcomes. Care was taken to consider the remaining vessels and bronchus, which regulate the direction of device placement.

Results

Seven patients had inflammatory lung disease, four had primary pulmonary carcinoma, and one had suffered blunt chest trauma. Ten operations were elective and two were emergent. Lobectomy included the right upper lobe in two cases, the right middle lobe in three, the right lower lobe in two, the right middle-lower lobe in two, and the left lower lobe in three. A stapler was used in ten patients, and sutures were applied in three (both were used in one case). Morbidities included a pyothorax and a persistent air leak; both made a recovery. Mortality included one emergency case of acute respiratory distress syndrome. No bronchopleural or bronchovascular fistulas occurred.

Conclusions

We believe that the en masse lobectomy is an alternative and necessary technique in critical or unexpected situations, possibly as a last resort. Trauma and severe inflammation may be good indications for en masse lobectomy.     

Diagnostic and management difficulties in a case of multiple intracranial juvenile xanthogranuloma

Introduction

Juvenile xanthogranuloma (JXG) preferentially occurs in childhood, and its characteristics have been thought to be benign and with slow growth. JXG is classified as an inflammatory disease, which forms multiple lesions in the patients’ head, neck, and other organs and typically skin. JXG is rare, and few case reports have been published in the past, particularly with multiple intracranial lesions, which as in our case, is an extremely rare finding.

Case

Patient is a 4-year-old boy who presented with polydypsia and polyuria for 1 year. He had been followed up only under l-deamino-8-d-arginine vasopressin until he started vomiting and his level of consciousness deteriorated. Then, magnetic resonance imaging (MRI) revealed multiple intracranial lesions. He underwent biopsy via small craniotomy, and pathology was confirmed as juvenile xanthogranuloma. The patient received chemotherapy, in complete compliance with JLSG-02 protocol.

Findings

JXG is characteristic with homogenous enhancement with contrast matter and, most importantly, high intensity on diffusion-weighted image (DWI). The DWI was high when the degree of diffusion of water is restricted, as seen in inflammation and, additionally, the change of intensity after administration of steroid would reflect its anti-inflammatory nature. However, though the steroid therapy made high-intensity lesions decrease signal intensity, the size and the number of lesions did not change at all. As we expected, after we stopped steroid administration to the patient, his consciousness deteriorated and we found again the very-high-intensity lesions. We consider the intensity on DWI to reflect progression of the lesions.     

Microliter-ordered automatic blood sampling system for fully quantitative analysis of small-animal PET

Annals of Nuclear Medicine - The objective of the present study was to develop a fully automated blood sampling system for kinetic analysis in mice positron emission tomography (PET) studies....