Two-dimensional pattern reverse Monte Carlo method for modelling the structures of nano-particles in uniaxial elongated rubbers

Two-dimensional pattern reverse Monte Carlo (2D pattern RMC) analysis is performed to model the structures of nano-particles in uniaxially elongated rubbers using two-dimensional patterns of structure factor of the nano-particles obtained by time-resolved two-dimensional ultra-small angle x-ray scattering. Four spot patterns are observed for a large elongation ratio and the shapes change with increasing elongation ratio. We performed the 2D pattern RMC method for the uniaxial system in order to make a model of the structures from the two-dimensional structure factors. The preliminary results of the 2D pattern RMC analysis of the two-dimensional structure factors of silica particles in a uniaxially elongated styrene-butadiene rubber are presented.

A double-blind dose-ranging study of risedronate in Japanese patients with osteoporosis (a study by the Risedronate Late Phase II Research Group)

To determine the clinical recommended dosage regimen of risedronate for the treatment of involutional osteoporosis in Japanese patients, dose-response relationships for the efficacy and safety of this drug were investigated using a multi-center, randomized, double-blind, parallel group comparative design with four dose levels of risedronate (placebo, 1 mg, 2.5 mg and 5 mg per day). A total of 211 patients diagnosed with involutional osteoporosis according to the criteria proposed by the Japanese Society for Bone and Mineral Research were randomized and received one of the four doses once daily for 36 weeks. All patients were supplemented with 200 mg of calcium daily in the form of calcium lactate. The primary efficacy endpoint was the percent change in bone mineral density of the lumbar spine (L2-L4 BMD) determined by dual-energy X-ray absorptiometry (DXA) from baseline to the time of final evaluation. Changes in biochemical markers of bone turnover and safety profile were also compared. Percent changes in L2-L4 BMD at final evaluation in the placebo, and 1-, 2.5-, and 5-mg risedronate groups were 0.79+/-5.30, 2.71+/-4.93, 5.29+/-3.96, and 5.15+/-4.25% (mean+/-SD), respectively. A linear dose-response relationship was obtained up to a dose of 2.5 mg, whereas no further increase in BMD was observed at 5 mg. The decrease in bone turnover markers, including N-terminal osteocalcin, phosphorus, and urinary deoxypyridinoline, also showed a linear dose-response relationship up to a dose of 2.5 mg. Alkaline phosphatase level decreased linearly up to a dose of 5 mg. Risedronate was well tolerated in this 36-week study with 1- to 5-mg doses. Neither the overall incidence of adverse events nor the percentage of patients without problem in overall safety assessment differed significantly among the dose groups including the placebo group. Based on these results, a once-daily dose of 2.5 mg of risedronate, which is half that used in Caucasians, is recommended for the treatment of involutional osteoporosis in Japanese patients.

Paradoxical enhancement of spinal-cord-evoked potentials rostral and caudal to the site of progressive cord compression in the cat

STUDY DESIGN

Analysis of the sequential waveform changes of the spinal-cord-evoked potentials (SCEPs) associated with progressive cord compression in the cat.

OBJECTIVES

To document the phenomenon of paradoxical enhancement of SCEPs despite conduction abnormalities and to evaluate its possible significance.

SETTING

Kochi Medical School, Kochi, Japan.

METHODS

SCEPs were recorded simultaneously at four serial intervertebral levels, from T6-7 to T9-10 caudal to, and at three serial levels from T2-3 to T4-5 rostral to the compression site at T5-6 following epidural stimulation at L6 in 14 cats.

RESULTS

Caudal to the compression site, the area of negative peak significantly increased toward maximal values of 277+/-36 (mean+/-SE), 151+/-9 and 110+/-4% as compared to the baseline precompression values (100%) at T6-7, T7-8, and T8-9, respectively. Rostral to the compression site, the area of negative peak significantly increased before subsequent deterioration and reached 105+/-2, 106+/-2, and 104+/-2% at T4-5, T3-4, and T2-3, respectively. The onset of negative peak enhancement, recorded either caudal or rostral to the compression site, showed a close temporal correlation (r>0.8, P&<0.001) with that of the prolongation in latency of SCEPs at T2-3.

CONCLUSIONS

A progressive focal conduction block induced by compression of the spinal cord can paradoxically enhance the ascending SCEPs both caudally and, though less consistently, rostrally, representing a warning of the impending risk of paraplegia.

A comparison of the effect of risedronate and etidronate on lumbar bone mineral density in Japanese patients with osteoporosis: a randomized controlled trial

To demonstrate the clinical benefit of 2.5 mg daily risedronate in the treatment of involutional osteoporosis, the effect of risedronate on bone mineral density (BMD) of the lumbar spine was compared with that of etidronate, selected as a representative of the bisphosphonates currently marketed in Japan. In this multicenter, randomized, double-masked, active (etidronate) controlled comparative study, a total of 235 Japanese patients with involutional osteoporosis were randomized to receive either treatment with 2.5 mg/day of risedronate for 48 weeks or intermittent treatment with etidronate (4 cycles of 2 weeks of treatment with 200 mg/day followed by 10-week medication-free periods). All patients received 200 mg of calcium supplement daily in the form of the calcium lactate. Bone mineral density of the lumbar spine (L2-L4 BMD) was determined at 12, 24, 36 and 48 weeks by dual-energy X-ray absorptiometry. The primary endpoint was the percent change in L2-L4 BMD from baseline to the time of final evaluation. Changes in biochemical markers of bone turnover and safety profiles were also compared. A significant increase in L2-L4 BMD was observed at 12 weeks after initiation of therapy in both the risedronate (2.8%) and etidronate (1.8%) groups. The increase in L2-L4 BMD at the time of final evaluation in the risedronate group (4.9%) was significantly greater ( p = 0.002) than that in the etidronate group (3.1%). The changes in bone resorption markers (urinary total deoxypyridinoline and N-terminal telopeptide of type I collagen) from baseline to 48 weeks were -37.6% and -41.3% for risedronate and -22.5% and -26.6% for etidronate, respectively. New vertebral fractures or deterioration of existing fractures were observed in 2.8% (3/106) of the patients in the etidronate group, while no such cases (0/101) were observed in the risedronate group. No significant difference in the incidence of adverse events was found between two treatments. Daily oral risedronate (2.5 mg) exhibited efficacy superior to that of intermittent cyclical etidronate (200 mg) in increasing L2-L4 BMD, and was well tolerated by Japanese patients with involutional osteoporosis.

Chronic active Epstein-Barr virus infection (CAEBV) successfully treated with allogeneic peripheral blood stem cell transplantation

We report a pediatric case of CAEBV and T cell-based Hodgkin's-like disease successfully treated with allo PBSCT from an HLA-matched sibling. The diagnosis of CAEBV was made from clinical signs and the presence of the EBV genome in PBMC and tumor cells. Conditioning with busulfan (BU) + etoposide (VP16) + cyclophosphamide (CY) was effective and well tolerated. EBV was totally eradicated by 3 months after allo PBSCT. Although she suffered from chronic GVHD of the liver, she has been well and free of disease for 47 months since PBSCT. We suggest allo PBSCT for CAEBV as a potent therapeutic strategy for eradication of the EBV genome and allowing immunological reconstitution.

Effect of short-term low-intensity exercise on insulin sensitivity, insulin secretion, and glucose and lipid metabolism in non-obese Japanese type 2 diabetic patients

The aim of the present study was to investigate the effects of short-term physical exercise that did not change body mass on insulin sensitivity, insulin secretion, and glucose and lipid metabolism in 39 non-obese Japanese type 2 diabetic patients. Insulin sensitivity and insulin secretion were estimated with homeostasis model assessment insulin resistance (HOMA-IR) and HOMA-B-cell function proposed by Matthews et al., respectively. All patients were hospitalized and were engaged in low-intensity exercise that consisted of walking and dumbbell exercise for successive 7 days. There were no changes in hospital diet and the dose of any medications used throughout the study. Fasting glucose, insulin, and lipids were measured before and after exercise. After exercise, serum triglyceride levels significantly decreased, but no significant changes were observed in total and HDL cholesterol concentrations. Fasting glucose, insulin, and HOMA-IR levels significantly decreased after exercise, but HOMA-B-cell function did not change during the study. There was no significant difference between BMI levels before and after exercise. From these results, it can be concluded that short-term (7 days) low-intensity physical exercise combined with hospital diet reduces serum triglycerides, insulin resistance, and fasting glucose levels without affecting BMI in non-obese Japanese type 2 diabetic patients.

[Orthopaedic management for severe osteoporosis]

In severe-osteoporotic patients with vertebral fractures, back pain is usually a major complaint and can be acute or chronic. Acute back pain is usually due to a recent vertebral fracture. Chronic pain may be due to vertebral fractures per se or could result from kyphotic or scoliotic changes in the spine, with inappropriate stretching of ligaments, facet joint capsules and paraspinal muscles. Treatment of vertebral fractures must focus on relief of pain and prevention of further fractures. In many patients, significant symptomatic relief can be achieved through physical therapy, rehabilitation, and bracing. Muscle-strengthening and weight-loading exercises could be needed for prevention of further bone loss and fractures.

A defect in central tolerance in NOD mice

The predisposition of nonobese diabetic (NOD) mice to develop autoimmune disease is usually attributed to defects in peripheral tolerance mechanisms. Here, evidence is presented that NOD mice display a defect in central tolerance (negative selection) of thymocytes. Impaired central tolerance in NOD mice was most prominent in a population of semi-mature thymocytes found in the medulla. The defect was apparent in vivo as well as in vitro, was independent of IAbetag7 expression and affected both Fas-dependent and Fas-independent pathways of apoptosis; for Fas-dependent apoptosis, the defective tolerance of NOD thymocytes correlated with the strong T cell receptor-mediated up-regulation of caspase 8-homologous FLICE (Fas-associated death-domain-like interleukin 1beta-converting enzyme)-inhibitory protein. In light of these findings, disease onset in NOD mice may reflect defects in central as well as peripheral tolerance.

Maturation of mass-screened localized adrenal neuroblastoma

BACKGROUND/PURPOSE

In infants, neuroblastoma has been known to spontaneously differentiate into a benign ganglioneuroma. Although several investigators have compared mass-screened with unscreened, disseminated with localized, and adrenal with retroperitoneal neuroblastoma, there are very few cross-comparisons of the above parameters. Herein, the authors report the maturation of mass-screened, localized adrenal neuroblastoma.

METHODS

Fifty-one mass-screened adrenal neuroblastomas were divided into 2 groups. In infants less than 1 year of age (Group A), 45 neuroblastomas were resected, whereas 6 neuroblastomas were resected after observation in 1- to 4-year-old children (group B). Histopathology of the tumors in the 2 groups was compared. Data were analyzed by X(2) test, and P <.05 was considered significant.

RESULTS

According to the International Neuroblastoma Pathological Classification, 41 of 45 tumors of group A were "differentiating neuroblastoma" and 4 of 6 tumors of group B were "maturing ganglioneuroma." Maturation toward ganglioneuroblastoma was observed in 16 neuroblastomas of group A (36%) and 6 neuroblastomas of group B (100%). In group A, 58% had low mitosis karyorrhexis index (MKI); all patients in group B had low MKI.

CONCLUSIONS

If left untreated, maturation of mass-screened, localized adrenal neuroblastomas is a common phenomenon. These children do not need to undergo early operation.

[Field epidemiological investigation on an outbreak of Chlamydia pneumoniae infection--first recognized incidence in a nursing home for elderly in Japan]

Chlamydia pneumoniae (C. pneumoniae) is an emerging pathogen recognized in 1989. Although C. pneumoniae infection is known to give a great impact on public health in western countries, many aspects remain unclarified in Japan. During December 1999 and March 2000, respiratory symptoms among residents and employees in a nursing home for elderly implicated an outbreak of C. pneumoniae infection. Field epidemiological investigation confirmed that this is the first outbreak recognized in a nursing home setting in Japan, involving 31/59 (15 confirmed) residents and 9/41 (2 confirmed) employees. Fifteen residents developed severe C. pneumoniae infections including one fatal outcome with pneumonia. Epidemiological analysis did not identify risk factors which induce infection or severe illness by C. pneumoniae for the residents. However, for the employees, frequent contact with the residents was demonstrated as a significant risk factor for the infection. None of 13 employees who had no contact with the residents presented C. pneumoniae infection, while nine out of 28 employees who had frequent contact developed C. pneumoniae infections (RR infinite, P = 0.04). These results indicated that C. pneumoniae infection spread gradually by human-to-human droplet transmission without specific risk factors. This study raised current problems in diagnosing and treating the C. pneumoniae infection and the need to enhance the awareness of this disease.

Increased expression of cyclooxygenase-2 in human salivary gland tumors

We examined the immunohistochemical localization of cyclooxygenase (COX)-2 in human salivary gland tumors. Thirty salivary gland adenomas (SGA), 40 salivary gland carcinomas (SGC) and 15 normal salivary glands (NSG) were studied. NSG showed restricted COX-2 staining only in the epithelial cells of salivary ducts. In contrast, COX-2 protein was detected in 27 cases of SGA (90%), except for three myoepitheliomas, and in all cases of SGC (100%) at various intensities and in various fashions. Thirteen SGA (43%) and 36 SGC (90%) cases showed strong COX-2 staining predominantly in tumor cells containing ductal components, as did serous and mucous acinic components of acinic cell carcinomas, mucoepidermoid carcinomas and mucinous carcinomas. These findings may suggest that COX-2 in salivary gland tumors is expressed in tumor cells derived from pluripotential ductal epithelium that can histologically develop into either serous or mucinous acinar cells.

The thymus and central tolerance

T-cell differentiation in the thymus generates a peripheral repertoire of mature T cells that mounts strong responses to foreign antigens but is largely unresponsive to self-antigens. This state of specific immunological tolerance to self-components involves both central and peripheral mechanisms. Here we review the process whereby many T cells with potential reactivity for self-antigens are eliminated in the thymus during early T-cell differentiation. This process of central tolerance (negative selection) reflects apoptosis and is a consequence of immature T cells receiving strong intracellular signalling through T-cell receptor (TCR) recognition of peptides bound to major histocompatibility complex (MHC) molecules. Central tolerance occurs mainly in the medullary region of the thymus and depends upon contact with peptide-MHC complexes expressed on bone-marrow-derived antigen-presenting cells (APCs); whether tolerance also occurs in the cortex is still controversial. Tolerance induction requires a combination of TCR ligation and co-stimulatory signals. Co-stimulation reflects interaction between complementary molecules on T cells and APCs and probably involves multiple molecules acting in consort, which may account for why deletion of individual molecules with known or potential co-stimulatory function has little or no effect on central tolerance. The range of self-antigens that induce central tolerance is considerable and, via low-level expression in the thymus, may also include tissue-specific antigens; central tolerance to these latter antigens, however, is likely to be limited to high-affinity T cells, leaving low-affinity cells to escape. Tolerance to alloantigens and the possibility of using central tolerance to promote acceptance of allografts are discussed.

Impaired synergistic activation of stress-activated protein kinase SAPK/JNK in mouse embryonic stem cells lacking SEK1/MKK4: different contribution of SEK2/MKK7 isoforms to the synergistic activation

Stress-activated protein kinase/c-Jun NH(2)-terminal kinase (SAPK/JNK), which is a member of the mitogen-activated protein kinase (MAPK) family, plays an important role in a stress-induced signaling cascade. SAPK/JNK activation requires the phosphorylation of Thr and Tyr residues in its Thr-Pro-Tyr motif, and SEK1 (MKK4) and MKK7 (SEK2) have been identified as the upstream MAPK kinases. Here we examined the activation and phosphorylation sites of SAPK/JNK and differentiated the contribution of SEK1 and MKK7alpha1, -gamma1, and -gamma2 isoforms to the MAPK activation. In SEK1-deficient mouse embryonic stem cells, stress-induced SAPK/JNK activation was markedly impaired, and this defect was accompanied with a decreased level of the Tyr phosphorylation. Analysis in HeLa cells co-transfected with the two MAPK kinases revealed that the Thr and Tyr of SAPK/JNK were independently phosphorylated in response to heat shock by MKK7gamma1 and SEK1, respectively. However, MKK7alpha1 failed to phosphorylate the Thr of SAPK/JNK unless its Tyr residue was phosphorylated by SEK1. In contrast, MKK7gamma2 had the ability to phosphorylate both Thr and Tyr residues. In all cases, the dual phosphorylation of the Thr and Tyr residues was essentially required for the full activation of SAPK/JNK. These data provide the first evidence that synergistic activation of SAPK/JNK requires both phosphorylation at the Thr and Tyr residues in living cells and that the preference for the Thr and Tyr phosphorylation was different among the members of MAPK kinases.