All-in-One Silk Fibroin Sponge as the Vitrification Cryodevice of Rat Pancreatic Islets and the VEGF-Embedded Scaffold for Subrenal Transplantation

Islet transplantation is a promising option for the clinical treatment of insulin-dependent diabetes, but a reliable islet cryopreservation/transplantation protocol should be established to overcome the donor shortage. The current study reports that a silk fibroin (SF) sponge disk can be used as a cryodevice for vitrification of large quantity pancreatic islets and the scaffold for subsequent subrenal transplantation in a rat model. The marginal islet mass (550 islet equivalents [IEQs]) on an SF sponge disk was vitrified-warmed and transplanted beneath the kidney capsule of a streptozotocin-induced diabetic rat with or without vascular endothelial growth factor (VEGF). Subrenal transplantation (no scaffold) of 550 IEQ fresh islets and post-warm islets vitrified on a nylon mesh device resulted in achieving euglycemia of recipient rats at 60% and 0%, respectively. Transplantation of 550 IEQ islets vitrified-warmed on an SF sponge disk failed to achieve euglycemia of recipient rats (0%), but the VEGF inclusion in the SF sponge disk contributed to acquiring the euglycemic recipients (33%). All cured recipient rats regained hyperglycemia after nephrectomy, and the histopathologic analysis exhibited a well-developing blood vessel network into the islet engrafts. Thus, an SF sponge disc was successively available as the cryodevice for islet vitrification, the transporter of the angiogenic VEGF, and the scaffold for subrenal transplantation in the rat model.     

Influence of mild-to-moderate alcohol consumption on cardiovascular diseases in men from the general population

Background and methodsThere is controversy about the association between mild-to-moderate alcohol consumption and a reduced risk of cardiovascular diseases. The relationships between daily alcohol consumption and the incidence of acute myocardial infarction (MI) or ischemic stroke (IS) were examined in men in a community-based, prospective cohort study (n = 8014, age 40–80 years, mean age = 64.1 years). Alcohol consumption was categorized into 3 groups (A1, none or occasional; A2, ≤25 g/day; A3, >25 g/day as ethanol) at baseline.ResultsDuring the mean follow-up of 5.5 years, 53 MIs and 186 ISs occurred. On Cox regression analysis adjusted for age, hypertension, diabetes, dyslipidemia, smoking index, and body mass index (BMI), the hazard ratio (HR) for incident MI was significantly lower in the A2 group than in the A1 group (HR = 0.49, p = 0.043). The HR for incident MI in the A3 group tended to be lower than in the A1 group (HR = 0.53, p = 0.10). In obese subjects, while a significantly lower HR for incident MI in the A2 group was retained (HR = 0.29, p = 0.049), no significant difference in the HR of the A3 group compared with the A1 group was found. No significant differences were found in the IS-free curve among the 3 groups of alcohol consumption.ConclusionsAlcohol consumption may have a protective effect on the onset of MI but not on IS in the general population. A U-shaped relation between alcohol consumption and incident MI was found in obese subjects. An appropriate limit for daily alcohol consumption, depending on the risk of ischemic heart disease, may need to be established.     

Subchondral insufficiency fracture of the femoral head after liver transplantation

A 53-year-old woman developed a subchondral insufficiency fracture of the right femoral head after undergoing a liver transplantation. Radiographs obtained at her first visit demonstrated a slight subchondral collapse in the superolateral portion of the femoral head. Magnetic resonance imaging (MRI) disclosed an irregular, discontinuous, low-intensity band on the T1-weighted image. After 7 months of conservative treatment, the hip pain and the radiograph abnormalities had both disappeared. On the follow-up T1-weighted MR image obtained 17 months after the onset, the band of low signal intensity was not obvious. A subchondral insufficiency fracture is one of the diagnoses to be considered in patients presenting with hip pain after a liver transplantation. This work was supported in part by a research grant for intractable disease from the Ministry of Health and Welfare of Japan and a research grant from the Univers Foundation.     

In Vitro Studies on a New Method for Islet Microencapsulation Using a Thermoreversible Gelation Polymer, N-Isopropylacrylamide-Based Copolymer

Abstract: Various materials for the semipermeable mem- brane for microencapsulation of islets, such as alginate complex and agarose, have been used. In this study, a thermoreversible gelation polymer, N-isopropylacrylamide based copolymer was used to make microencapsulated islets and was examined in vitro. The polymer has little or no cytotoxicity for human dermal fibroblasts. The characteristics of viscoelasticity below the soluble gel transition temperature (SGTT) and of thermoreversibility, the water soluble polymer below the SGTT (22^oC) becoming water insoluble upon heating, contributed to simplifying the encapsulation technique. We obtained viable islets at the center of the membrane with a thickness of approximately 20–50 pm, accounting for a 40% yield of encapsulated islets. Static glucose challenge test with mi- croencapsulated islets revealed the insulin response to the concentration of glucose. The insulin concentrations of the culture medium in the microencapsulated islet group were the same as those in a similar free islet group up to 42 days. These results indicate that the morpholog- ical and functional stability of the new method for mi- croencapsulation may be sufficient for it to be used for transplantation in diabetic animals.     

Sarcopenia and physical function are associated with inflammation and arteriosclerosis in community-dwelling people: The Yakumo study

Objectives: Sarcopenia reduces physical function, while chronic inflammation causes arteriosclerosis and decreases skeletal muscle. We conducted a cross-sectional study to elucidate the associations among sarcopenia, physical function, arteriosclerosis, and inflammation in community-dwelling people.

Methods: We recruited 335 participants in an annual health checkup. We diagnosed sarcopenia based on appendicular skeletal muscle mass index (aSMI) assessed by bioelectrical impedance analysis. We measured several physical function tests, blood pressure, and serum levels of high-sensitivity C-reactive protein (hs-CRP), total cholesterol, and low-density lipoprotein cholesterol.

Results: After controlling for age, sex, and BMI, participants in the sarcopenia group showed lower performance in all measured physical tests than the normal group. Arteriosclerosis risk factors, including blood pressure, cholesterol levels, and hs-CRP, were significantly higher in the sarcopenia group than in the normal group. hs-CRP and total cholesterol levels were significant risk factors of sarcopenia. The aSMI, grip strength, and maximum stride length were negatively related to hs-CRP level.

Conclusions: Community-dwelling people with sarcopenia had higher levels of hs-CRP and a higher risk for arteriosclerosis. The serum level of hs-CRP was an independent risk factor for sarcopenia and was associated with physical function. These findings indicate that chronic inflammation may relate arteriosclerosis and sarcopenia simultaneously.     

Clinical outcome of lumbar spinal stenosis based on new classification according to hypertrophied ligamentum flavum

Background

The ligamentum flavum hypertrophy is considered to be one of the important causes of development of lumbar spinal stenosis (LSS). Several histologic and biologic mechanisms in hypertrophied flavum have proposed. However, no study that investigated the relationship between clinical outcome and ligamentum flavum hypertrophy has been published. The purpose of this study was to identify a new classification of LSS, in ligamentous and nonligamentous stenosis, according to the cutoff value of the area proportion of the ligamentum flavum in the spinal canal, and to assess the value of surgical and conservative treatments for LSS based on the classification of the ligamentous stenosis.

Radiological morphology variances of transient osteoporosis of the hip

Background

Although several morphological abnormalities or variances of the hip joint have been proposed to be associated with hip joint degeneration, few studies have investigated any radiological features in patients with transient osteoporosis of the hip (TOH). The purpose of this study is to evaluate the morphological variances of the hip joint in TOH patients radiographically.