Effects of streptozotocin-induced diabetes on leg muscle contractile properties and motor neuron morphology in rats

Skeletal muscle fiber subtypes are differentially sensitive to diabetes-related pathology; For example, fast-twitch muscles exhibit severe decreases in contraction force while slow-twitch muscles demonstrate prolonged half-relaxation time. However, such alterations have only been examined after a relatively short period following diabetes onset, with no information available regarding muscle damage caused by longer disease periods (>20 weeks). This study examined alterations in the contractile properties of the medial gastrocnemius (fast-twitch) and soleus (slow-twitch) muscles, as well as morphological changes in their motor neurons 12 and 22 weeks after diabetes onset. Adult male Wistar rats were divided into diabetic (12- or 22-week post-streptozotocin injection) and age-matched control groups. Electrically evoked maximum twitch and tetanic tension were recorded from leg muscles. Additionally, motor neuron number and cell body size were examined. At 12 weeks after diabetes onset, decreases in twitch force were observed predominantly in medial gastrocnemius muscles, while soleus muscles exhibited prolonged half-relaxation time. However, these differences became ambiguous at 22 weeks, with decreased twitch force and prolonged half-relaxation time observed in both muscles. On the other hand, reduction in soleus motor neurons was observed 12 weeks after diabetes onset, while medial gastrocnemius motor neurons were diminished at 22 weeks. These data indicate that experimental diabetes induces differential damage to medial gastrocnemius and soleus muscles as well as motor neurons. These diabetes-induced differences may partly underlie the differential deficits observed in gastrocnemius and soleus.     

One-step sandwich enzyme immunoassay for human laminin using monoclonal antibodies

A one-step sandwich enzyme immunoassay (one step sandwich EIA) for human serum immunoreactive laminin was set up with a pair of monoclonal antibodies prepared against human placental laminin P1 fragment. The assay was characterized by carrying out two immunoreactions simultaneously, laminin P1 fragment reacting with both a monoclonal antibody as a solid phase and a horseradish peroxidase-labeled monoclonal antibody (Fab') against human laminin P1 fragment as conjugate. Sensitivity of the immunoassay was 0.01 ng/well (0.5 microgram/l), and linearity was obtained between 0.01-20 ng/well (0.5-1,000 micrograms/l). The levels of laminin in sera from normal individuals and patients with liver cirrhosis, hepatocellular carcinoma and primary biliary cirrhosis were 103 +/- 15 micrograms/l, 228 +/- 70 micrograms/l, 341 +/- 163 micrograms/l and 232 +/- 93 micrograms/l, respectively. Protein immunoblotting showed that the serum immunoreactive laminin measured by the assay was a fragment with rel mol mass of 200 kDa.     

Investigation of the function of the putative self-association site of Epstein-Barr virus (EBV) glycoprotein 42 (gp42)

The Epstein-Barr virus (EBV) glycoprotein 42 (gp42) is a type II membrane protein essential for entry into B cells but inhibits entry into epithelial cells. X-ray crystallography suggests that gp42 may form dimers when bound to human leukocyte antigen (HLA) class II receptor (Mullen et al., 2002) or multimerize when not bound to HLA class II (Kirschner et al., 2009). We investigated this self-association of gp42 using several different approaches. We generated soluble mutants of gp42 containing mutations within the self-association site and found that these mutants have a defect in fusion. The gp42 mutants bound to gH/gL and HLA class II, but were unable to bind wild-type gp42 or a cleavage mutant of gp42. Using purified gp42, gH/gL, and HLA, we found these proteins associate 1:1:1 by gel filtration suggesting that gp42 dimerization or multimerization does not occur or is a transient event undetectable by our methods.     

An infected pseudoaneurysm following a modified Blalock-Taussig shunt

A two-month-old male infant with tetralogy of Fallot underwent a right-sided modified Blalock-Taussig shunt using a 4 mm expanded polytetrafluoroethylene graft through a right thoracotomy. Five months later, the patient developed otitis media, followed by repeated relapses of pneumonia and fever of unknown origin. Multidetector-row computed tomography and angiography, performed at 12 months of age, revealed a pseudoaneurysm of the subclavian artery at the insertion of the modified Blalock-Taussig shunt. After 20 days of antibiotic therapy, the pseudoaneurysm and infected graft were successfully resected through a median sternotomy approach. This report describes the treatment strategy of this rare but potentially fatal complication after a modified Blalock-Taussig shunt operation.     

Characteristics of patients with early systemic sclerosis and severe gastrointestinal tract involvement

OBJECTIVE:To clarify the clinical features of patients with systemic sclerosis (SSc) who developed severe gastrointestinal tract (GIT) involvement in the early stage of the disease. METHODS: Three hundred two consecutive Japanese patients with SSc were investigated: Group 1 comprised 14 patients with severe GIT involvement (malabsorption syndrome and/or pseudo-obstruction) within 2 years of onset of SSc; group 2 consisted of all patients without severe GIT involvement (n = 288); and group 3 consisted of 117 patients without severe GIT involvement within 2 years of onset of SSc. Autoantibodies were evaluated using double immunodiffusion, ELISA, and immunoprecipitation. RESULTS: We found significant differences in clinical features among the 3 groups. Diffuse cutaneous type, erosive esophagitis, and myositis were more common in group 1 than in group 2 (p = 0.007, 0.003, and 0.003, respectively) or group 3 (p = 0.04, 0.002, and 0.01, respectively), whereas interstitial lung disease (ILD) was more frequent in group 2 (p = 0.005) and group 3 (p = 0.02) versus group 1. Antinuclear antibodies showed a nucleolar pattern significantly more frequently in group 1. Myositis-related autoantibodies, including anti-U1RNP, anti-U3RNP, anti-Ku, and anti-signal recognition particle antibodies, were observed in 57% of group 1. CONCLUSION: Our findings strongly suggest the existence of a subgroup of SSc patients with severe GIT involvement in the early stage. Among the Japanese individuals, these patients never developed severe ILD, even though they were classified as having diffuse cutaneous SSc.     

Social capital,income inequality and self-rated health in Chita peninsula,Japan: a multilevel analysis of older people in 25 communities

The effect of social capital on one's health has drawn researchers' attention. In East-Asian countries, however, such an effect has been less studied than in Western countries. Mindful of this background, this study aimed to investigate the linkage between social capital and health at the level of a small area in Japan, and also to examine whether social capital mediates the relation between income inequality and health.