128 research outputs found
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éºäŒåã®äžã€ãXæè²äœäžã«ããããšã瀺åãããããšã¯ä»åŸã® NIDDM ã®éºäŒè§£æã«è²ŽéãªããŒã¿ãæäŸããããšãšãªãã§ããããAbstract The characteristic features of OLETF rats are 1) late onset of hyperglycemia (after 18 weeks of age), 2) a chronic course of disease, 3) mild obesity, 4) clinical onset of diabetes mellitus (DM) mostly in males, 5) hereditary trait a); multiple recessive genes are involved in the induction of DM, b); rat MHC, RT1 has no diabetogenic effect, c); control strain, LETO appears to share some of diabetogenic genes with OLETF rats, d); female OLETF rats also carry diabetogenic genes, and e); one of the diabetogenic genes, designated as ODB-1, is transmitted linked with the X-chromosome of OLETF rats, however testosterone is an important factor involved in developing diabetes. 6) the changes of pancreatic islets can be classified into three stages: (1) an early stage (at less than 9 weeks of age) mild lymphocyte infiltration, (2) a hyperplastic stage (10-40 weeks of age); hyperplastic change and fibrosis in or around islets, (3) a final stage (at more than 40 weeks of age) showing atrophy of islets. 7) Diabetic nephropathy; after wk 50, glomeruli of OLETF rat enlarged, diffuse glomerulosclerosis, nodular glomerulosclerosis, the fibrin cap lesion, capsular drop lesion. These clinical and pathologic features of disease in OLETF rats resemble those of human NIDDM.Introduction We have reported a new inbred strain of Long-Evans Tokushima Lean (LETL) rats with IDDM without lymphopenia (1). This LETL strain was established in 1989 from an outbred colony of Long-Evans rats that had been purchased from Charles River Canada Inc. From the same colony of rats, we established another inbred strain of rats, Otsuka Long-Evans Tokushima Fatty (OLETF), that develops spontaneous persistent hyperglycemia (2). In this paper, we report here that pathophysiological characteristics and genetic profiles of the OLETF rats. The value of this strain as an animal model of human type 2 diabetes is discussed.Establishment of OLETF strain A spontaneously diabetic rat with polyuria, polydipsia and mild obesity was discovered in 1984 in an outbred colony of Long-Evans rats, which had been purchased from Charles River Canada (St.Constant, Quebec, Canada) in 1982. A strain of rats developed from this rat by selective breeding has since been maintained at the Tokushima Research Institute (Otsuka Pharmaceutical, Tokushima, Japan) and named Otsuka Long-Evans Tokushima Fatty (OLETF). Selective brother-sister matings were then started using males of more than 400g and apparently normal females at 9-10 weeks old. The males used for mating were examined by the OGTT at 25 weeks old, and normal glucose toleranced rats and their offspring were killed. The LETO line was obtained by different original matings from those for OLETF rats, but both strain originated from the same colony of Long-Evans rats. The LETO line has not shown the diabetic syndrome.Clinical features Male OLETF rats began to gain weight faster than LETO rats from 5 weeks and the difference gradually increased with age, being about 200g at 40 weeks of age. Then in the early stage of diabetes mellitus (DM) with glycosuria, the body weight decreased slightly, the decrease becoming more prominent with increase in severity of DM. After the onset of glycosuria at 40 weeks, water and food intakes and urine production increased gradually, and after persistent glycosuria for more than 10 months, the rats showed marked polyphagia, polydipsia and polyuria. However, they survived and death from diabetes was very rare.Incidence of DM The cumulative incidences of male rats with diabetic or IGT type were 86.0% (301/350) or 9.7% (34/350), respectively, after the 20th generation. However, incidence of DM in female OLETF was 33.3% at 65 wk-old.Biochemical analysis The plasma glucose level of male OLETF rats became higher than that of LETO rats from 18 weeks. The triglyceride level increased from 8 weeks. The plasma cholesterol level became slightly higher than that of control rats. At 30 weeks of age, the level of plasma glucose was twice that of controls, and the plasma triglyceride level was 5 times that of controls, whereas the plasma cholesterol level was elevated only slightly. At 40 weeks of age, the plasma cholesterol level was 4.73±O.68mM in OLETF rats and 2.71±O.15mM in LETO rats and the plasma triglyceride level was 6.45±2.26mM in OLETF rats and 1.31±O.35mM in LETO rats, both differences being highly significant (P<O.OO1).Oral Glucose Tolerance test (OGTT) The results of OGTTs at various ages are shown in Fig.1. After 24 weeks of age, elevation of plasma glucose in the OGTT became marked, indicating the development of DM. At 55 weeks, the peak values exceeded 400mg/dl. At 24 weeks, the basal value and the values of plasma IRI during the OGTT were increased in OLETF rats and these increases were more prominent at 55 weeks. When OLETF rats developed glycosuria, their plasma glucose levels increased, whereas their IRI values decreased. At 65 weeks of age, plasma glucose level elevated to over 450mg/dl, and the IRI value became less than 300pg/ml, and these rats were rescued by insulin injection and their body weights increased gradually. The plasma glucose and IRI responses of LETO rats in the OGTT were within the normal ranges throughout the term of observation.(Fig. 1)Hereditary trait The mode of inheritance of DM in OLETF rats was examined by genetic segregation studies using F1, F2 and backcross male progenies. The results shown in Table 1 and Fig.2 are summarized as follows: 1) no diabetic rat was found in reciprocal F1 hybrids of OLETF and F344/Ducrj rats, 2) approximately 46 % of (OLETF à LETO) F1 hybrids were diabetic, whereas in the reverse combination only 2 of 63 F1 hybrids (3.2%) were diabetic, 3) approximately 12 % of the (OLETF à F344) F2 hybrids were diabetic, whereas the approximately 29-35% of (OLETF à LETO) F2 and (LETO à OLETF) F2 rats were diabetic, 4) on backcross with OLETF rats, more than 60% of the progenies were diabetic, whereas those obtained by backcrosses with LETO or F344 developed no diabetes except those of (OLETF à LETO) F1 à LETO mating which showed a relatively high incidence of diabetes (21.5%). No association of diabetes with the RT1.A phenotype was observed (data not shown). These results clearly indicate that 1) more than two recessive genes are involved in the development of diabetes, 2) both male and female OLETF rats carry a set of diabetogenic genes, and 3) one of the diabetogenic genes designated as ODB-1, is transmitted linked with the X-chromosome of OLETF rats, and 4) LETO rats appear to share some diabetogenic genes with the OLETF strain.Histopathological finding Pancreas: Histopathologic changes were classified into three stages: 1) an early stage (at less than 9 weeks), 2) a hyperplastic stage (at 10-40 weeks) and 3) a final stage (at more than 40 weeks). An early stage, mild to moderate lymphocyte infiltration into or around almost all pancreatic islets and partially in the acinus area were seen in both male and female OLETF rats. However, at this stage, the islet structure was normal and insulin granules were clearly identified by immunohistochemical staining. After week 12, fibrosis of the islets became apparent. A characteristic feature is hyperplasia of pancreatic ducts in or around the islets. After week 20, fibrosis of the islets became prominent; the islets were either divided or completely replaced by fibrotic fibers. In the final stage, after 40 weeks, replacement of islets by connective tissues became more marked. After 70 weeks, the pancreas was extremely atrophic and the tissue was replaced by fatty and connective tissue. Both the number and size of islets were significantly decreased. Loss of the islets was seen in the final stage.(Table 1)(Fig. 2)Diabetic nephropathy The results of urinary protein levels at various ages are shown in Fig.3. Urinary protein levels in male OLETF rats began to increase more than LETO rats from 30 weeks and drastically increased thereafter, ultimately reached over 800 mg/day.(Fig. 3) The early histological change of the kidney was focal mesangial lesion with proliferation of mesangial cells at 23 weeks of age before the stage of clinical diabetic nephropathy. At 29 weeks of age, besides mesangial lesion, a few glomeruli showed the segmental lesion with PAS-positive deposits in the mesangium or capillary that seemed to be identical with the fibrin (hyalin) cap in the exudative lesion commonly observed in human diabetic glomerulopathy. After 50 week of age, the glomeruli showing the exudative lesion with prominent fibrin caps became numerous and more dominant finding than the mesangial lesion. Most of these lesions were characteristic in that they arose as the focal and segmental lesions in the early stage and showed the segmental obsolescence in the later stage. However, a few lesions of them advanced so much as to be the global exudative lesions. The similar deposits were often observed at inside of Bowmann\u27s capsule which had same finestructure with fibrin cap and were located between the basement membrane and parietal epithelial cells of the capsule. This was identical with the lesion called the capsular drop, one of characteristic findings for human diabetic glomerulopathy. On the other hand, the aneurysmal dilatation of intraglomerular vessels, another characteristic finding in glomerulus, was frequently observed. These dilated vessels were contoured with thickened wall of mesangial tissue. However, the vascular changes in the interstitium or vascular pole of the glomerulus such as the arteriolo-hyalinosis and -sclerosis were not seen. Through all stages, the severity of mesangial lesions increased with aging, some of which showed nodular expansion of the mesangial matrix. However, they were not identical with the typical nodular lesion described by Kimmelstiel-Wilson(3) because they were at most a minor proportion and, if present, lacked the consolidated appearance with acellular core. After 55 weeks of age, the segmental or global obsolescence (sclerosis) of glomeruli and involved numerous glomeruli so advanced ultimately as to be the end stage kidney at 96 weeks of age.References1. Kawano,K., Hirashima,T., Mori,S., Saitoh,Y., Kurosumi,M. and Natori,T. (1991) New inbred strain of Long-Evans Tokushima Lean rats with IDDM without lymphopenia. Diabetes 40, 1375-1381.2. Kawano,K., Hirashima,T., Mori,S., Kurosumi,M., Saitoh,Y. and Natori,T. (1991) Spontaneous long-term hyperglycemic rat with diabetic complications Otsuka Long-Evans Tokushima Fatty (OLETF) strain. Diabetes 41,1422-1428. 3. kimmelstiel P. Wilson C. (1936) Intercapillary lesions in the glomeruli of the kidney. Am J Pathol 12: 83-97å士(ç£å»åŠ)麻åžå€§
Recovery from heat shock injury by activation of Na+-glucose cotransporter in renal epithelial cells
AbstractExposure of cells or organs to sublethal physical or chemical stresses induces disruption of cellular structures and functions. Here, we examined whether Na+-glucose cotransporter (SGLT1) is involved in the recovery from heat shock (HS) injury in porcine renal epithelial LLC-PK1 cells. Recovery from HS (42 °C for 3 h, then 37 °C for 12 h) increased SGLT1 activity, assessed by [14C]α-methyl glucopyranoside uptake, and a maximal transport rate (Vmax) from 2.4 to 5.9 nmol/mg protein/30 min, but did not alter an apparent affinity constant (Km). Protein distribution of SGLT1 in apical membrane fraction was also increased after recovery from HS without changing in total membrane fraction. Membrane integrity assessed by calcein accumulation was decreased by HS, and then returned to basal level. This recovery was inhibited by phloridzin, a potent SGLT1 inhibitor, and nonmetabolizable glucose analogues. Anti-transforming growth factor-β1 (TGF-β1) antibody inhibited both elevation of SGLT1 distribution in apical membrane and recovery of calcein accumulation induced by HS. Taken together, HS increases in the number of SGLT1 protein in apical membrane mediated via TGF-β1 signaling pathway. The increase of glucose uptake is necessary to repair plasma membrane integrity
Investigation of Effective Modification Treatments for Titanium Membranes
Titanium membranes are used for guided bone regeneration in implant therapy. However, as a bioinert material, titanium does not have the ability to accelerate bone formation. Various titanium surface treatments to confer bioactivity have been demonstrated; however, there are concerns about the influence of chemical treatments for thin titanium membranes. This study investigated the influence of surface modifications on the structure of titanium membranes. Titanium membranes of 20 ÎŒm thickness were treated with acid or alkali solutions, and we evaluated their surface structure, wettability, thickness, and mechanical strength compared to non-treated membranes. Alkali-treated titanium membranes displayed the formation of nanoscale pore structures on their surfaces, enhanced hydrophilicity, and almost same thickness compared with acid-treated membranes. Furthermore, the tensile strength of alkali-treated membranes was comparable to non-treated membranes. These results suggest that alkali treatment is an appropriate surface modification method for titanium membranes
Optimizing Charge Switching in Membrane Lytic Peptides for Endosomal Release of Biomacromolecules.
Endocytic pathways are practical routes for the intracellular delivery of biomacromolecules. Along with this, effective strategies for endosomal cargo release into the cytosol are desired to achieve successful delivery. Focusing on compositional differences between the cell and endosomal membranes and the pH decrease within endosomes, we designed the lipid-sensitive and pH-responsive endosome-lytic peptide HAad. This peptide contains aminoadipic acid (Aad) residues, which serve as a safety catch for preferential permeabilization of endosomal membranes over cell membranes, and His-to-Ala substitutions enhance the endosomolytic activity. The ability of HAad to destabilize endosomal membranes was supported by model studies using large unilamellar vesicles (LUVs) and by increased intracellular delivery of biomacromolecules (including antibodies) into live cells. Cerebral ventricle injection of Cre recombinase with HAad led to Cre/loxP recombination in a mouse model, thus demonstrating potential applicability of HAad inâ
vivo
Fibrocytes activate fibroblasts by PDGF.
Fibrocytes, which are bone marrow-derived collagen-producing cells, were reported to play a role in the pathogenesis of pulmonary fibrosis. However, their function in pulmonary fibrosis is unclear. We analyzed their function compared with that of monocytes and localization in fibrotic tissues in patients with idiopathic pulmonary fibrosis (IPF). We compared the gene expression profile of monocyte-derived fibrocytes with that of monocytes by microarray analysis. Proliferation and differentiation into myofibroblasts were examined by 3H-thymidine incorporation assay and Western blotting. We measured the level of growth factors in the culture supernatant of fibrocytes by ELISA. The localization of fibrocytes in lung tissues of patients with IPF was determined by immunofluorescence staining. Compared with monocytes, fibrocytes had higher expression of extracellular matrix- and growth factor-encoding genes, including PDGF-B, FGF-2 and VEGF-B. Although fibrocytes did not proliferate in response to PDGF, co-culture of fibrocytes stimulated the growth of lung fibroblasts through the production of PDGF-BB. In the lung of IPF patients, CD45+Collagen-I+FSP-1+ cells, which have a similar phenotype to fibrocytes, were detected and co-stained with anti-PDGF antibody. This study suggested that fibrocytes function in pulmonary fibrosis partly by producing PDGF in the lungs of IPF patients
Development of improved method to identify and analyze lung fibrocytes with flow cytometry in a reporter mouse strain
Introduction
Fibrocytes are emerging myeloid-derived circulating cells that can migrate into damaged tissues and usually contribute to their repair. Key features of fibrocytes include the expression myeloid markers, production of extracellular matrix proteins, and secretion of various humoral factors that activate resident fibroblasts; they also have the potential to differentiate into fibroblasts. However, no specific surface markers have been identified to identify fibrocytes in vivo. One reason could be that the method used to detect fibrocytes requires intracellular collagen staining.
Methods
In the present study, to establish an improved method for the detection of lung fibrocytes and to analyze viable fibrocytes, we used collagen I(α)2-green fluorescent protein (Col-GFP) reporter mice, which had undergone the intratracheal instillation of bleomycin (BLM).
Results
Using flow cytometry to gate out cells with autofluorescence, we clearly found that CD45+ GFP+ cells resided in the lungs of Col-GFP mice at a steady state and these cells increased after BLM injury, peaking at Day 14. These cells expressed not only known cell surface markers of fibrocytes, but also some novel markers, in addition to a low level of collagen I in comparison to CD45â GFP+ cells.
Conclusion
Our findings suggest that the improved method can be a useful for the detection of pure lung fibrocytes and allows us to further analyze the characteristics of viable fibrocytes
Lck inhibition attenuate lung fibrosis by suppressing Treg activity
Background
Lymphocyte-specific protein tyrosine kinase (Lck) is a member of the Src family of tyrosine kinases. The significance of Lck inhibition in lung fibrosis has not yet been fully elucidated, even though lung fibrosis is commonly preceded by inflammation caused by infiltration of Tcells expressing Lck. In this study, we examined the effect of Lck inhibition in an experimental mouse model of lung fibrosis. We also evaluated the effect of Lck inhibition on the expression of TGF-β1, an inhibitory cytokine regulating the immune function, in regulatory T-cells (Tregs).
Methods
Lung fibrosis was induced in mice by intratracheal administration of bleomycin. A-770041, a Lck-specific inhibitor, was administrated daily by gavage. Tregs were isolated from the lung using a CD4+CD25+ Regulatory T-cell Isolation Kit. The expression of Tgfb on Tregs was examined by flow cytometry and quantitative polymerase chain reaction. The concentration of TGF-β in bronchoalveolar lavage fluid (BALF) and cell culture supernatant from Tregs was quantified by an enzyme-linked immunosorbent assay.
Results
A-770041 inhibited the phosphorylation of Lck in murine lymphocytes to the same degree as nintedanib. A-770041 attenuated lung fibrosis in bleomycin-treated mice and reduced the concentration of TGF-β in BALF. A flow-cytometry analysis showed that A-770041 reduced the number of Tregs producing TGF-β1 in the lung. In isolated Tregs, Lck inhibition by A-770041 decreased the Tgfb mRNA level as well as the concentration of TGF-β in the supernatant.
Conclusions
These results suggest that Lck inhibition attenuated lung fibrosis by suppressing TGF-β production in Tregs and support the role of Tregs in the pathogenesis of lung fibrosis
Imaging tools for mediastinal cystic lesions
Objective : To identify and differentiate patients with mediastinal cysts from those with cystic tumors requiring surgery. Methods : A total of 36 patients with mediastinal cystic lesions were enrolled. The patients were separated into two groups based on pathological findings : those with mediastinal cysts (n=23) and those with mediastinal tumors (n=13). The cystic components were measured using imaging parameters including mean computed tomography (CT) value, apparent diffusion coefficient (ADC), T1 signal intensity ratio (T1SI-ratio), and T2 signal intensity ratio (T2SI-ratio), acquired from magnetic resonance imaging (MRI) ; and standardized maximum uptake value (SUVmax) from 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Both groups were statistically compared. Results : Comparative parameters between the cysts and tumors revealed the following ratios : CT value, 40.9±21.2 versus (vs) 24.8±12.9 (p = 0.019) ; SUVmax, 1.18±0.50 vs 4.32±3.52 (p = 0.003) ; ADC, 3.46±0.96 vs 2.68±0.74 (p = 0.022) ; T1SI-ratio, 1.06±0.60 vs 1.35±0.92 (p = 0.648) ; T2SI-ratio, 5.40±1.80 vs 4.33±1.58 (p = 0.194). However, there was no correlation between FDG uptake and ADC value. Conclusions : SUVmax from 18F-FDG PET/CT and ADC derived from MRI were effective in facilitating preoperative diagnosis to differentiate mediastinal cysts from tumors. However, these examinations may be complementary to one another, not dominant
An annual report 2014 on campus wide Faculty Development programs at The University of Tokushima
FD promotion programs have started from 2002, promoting systematization, organization and routinization of Faculty Development. In 2014, based on the results of 12 years of FD, we have aimed to enhance the quality of higher education of our university, building new educational system for assurance of higher education. The Center for the Enhancement of Teaching & Learning was restructured into the Center of University Education. Thus, based on the guideline for educational innovation of our university, the organization for promoting FD was strengthened. Concretely, we carried out 3 programs; 1) educational innovation FD, 2) educational development FD, 3) comprehensive FD. As to each program, we showed their outlines and considered their results and problems shown from the questionnaire to their attendants
LPA, C1P, and S1P in IPF
Idiopathic pulmonary fibrosis (IPF) is the most common idiopathic interstitial pneumonias. Lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) are signaling lipids that evoke growth factor-like responses to many cells. Recent studies revealed the involvement of LPA and S1P in the pathology of IPF. In this study, we determined LPA, S1P and ceramide 1-phosphate (C1P) in peripheral blood plasma of IPF patients, and examined correlation to the vital capacity of lung (VC), an indicator of development of fibrosis. Blood plasma samples were taken from eleven patients with IPF and seven healthy volunteers. The lipids of the sample were extracted and subjected to liquid chromatography-tandem mass spectrometry for analysis. Results showed that there is a significant negative correlation between VC and plasma LPA levels, indicating that IPF patients with advanced fibrosis had higher concentration of LPA in their plasma. Average of S1P levels were significantly higher in IPF patients than those in healthy subjects. Although it is not statistically significant, a similar correlation trend that observed in LPA levels also found between VC and S1P levels. These results indicated that plasma LPA and S1P may be associated with deterioration of pulmonary function of IPF patients
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