Biomedical subjects

N Sakata

Publications and source records attributed to N Sakata.

At least 55 records · Page 3Linked to original sources

PubMed2000

CD40 and adenosine A2 receptor agonist-cyclic adenosine monophosphate rescue B-cell antigen receptor-induced apoptosis through independent pathways and converge to prevent caspase activation.

BACKGROUND: Antigen receptor ligation induces apoptosis of B lymphocytes, but the molecular mechanisms underlying induction of apoptosis remain unclear, although the growing family of IL-1beta-converting enzyme cysteine proteases (caspases) are recognized to be major effectors of cellular death. OBJECTIVE: We sought to delineate and compare the rescue of B-cell apoptosis through CD40 ligand-CD40 interaction and cyclic adenosine monophosphate (cAMP)-dependent protein kinase A in human B cells. METHODS: By using tonsillar B cells and the B-lymphoblastoid cell line Ramos, rescue from B-cell apoptosis was compared, as were signaling pathways after activation of cells through CD40 and the adenosine A2 receptor. RESULTS: Both CD40 ligand-CD40 interaction and activation of intracellular cAMP rescue B cells from apoptosis after antigen receptor ligation. Although these pathways do not overlap, they converge by preventing the anti-IgM-induced activation of CPP32 (caspase 3), a member of the IL-1beta-converting enzyme protease family. CONCLUSION: These data indicate that the cAMP-protein kinase A-dependent and CD40-signaling pathways regulate B-cell survival and converge at a common point, the inhibition of antigen receptor-induced activation of caspases.

Antibodies↗

PubMed2000

Intracystic papillary carcinoma in the male breast. A case report.

Male breast cancer is a rare disease with an incidence between 0.5% and 2.4% of that in women. We report a case of intracystic papillary carcinoma of the breast in a 75-year-old Japanese man. The macroscopic features of the carcinoma could be accurately demonstrated by pneumocystography and ultrasonography preoperatively.

Aged↗

PubMed2000

Glycoxidative modification of AA amyloid deposits in renal tissue.

BACKGROUND: N(epsilon)-carboxymethyllysine (CML) is a product of the oxidative modification of glycated proteins, which damages proteins with ageing, diabetes, uraemia and Alzheimer's disease. In contrast, pyrraline is one of the advanced glycation end products, which is independent of oxidative processes. CML has been identified in beta-amyloid of Alzheimer's disease and beta(2)-microglobulin-associated amyloid. We investigated whether CML and pyrraline are formed in AA and AL amyloid of the kidney. METHOD: Renal specimens from 19 cases of AA amyloidosis and 14 cases of AL amyloidosis were investigated for immunolocalization of CML, pyrraline, collagen type IV and laminin in amyloid deposits. Renal biopsies of 10 age-matched cases with thin basement membrane disease and normal renal function were used as controls. The fractional areas of amyloid, CML, laminin and collagen IV in glomeruli and interstitium (%amyloid, %CML, %laminin and %collagen, respectively) were calculated using the point counting method. The correlation between these parameters was evaluated using Spearman's rank correlation test. RESULTS: CML colocalized with AA amyloid, but not AL amyloid, except in two cases of the latter with a long history of nephropathy exceeding 14 years. In contrast, pyrraline was not observed in either type of amyloid. Mean %CML in AA amyloid was significantly higher than %collagen and %laminin in glomeruli and interstitium, indicating that AA amyloid is modified by CML independent of colocalized extracellular matrix. %CML significantly correlated with %amyloid both in glomeruli and interstitium in AA amyloidosis. AL amyloid cases with a long history of nephropathy showed positive staining for CML in glomeruli and interstitium but no staining for collagen IV and laminin in amyloid deposits. CONCLUSION: CML modification may occur in amyloid deposits of AA amyloidosis, independent of extracellular matrix components. Glycoxidative modification may have a functional link to AA amyloid deposition in renal tissues.

Adult↗

PubMed2000

Increased chymase activity in internal thoracic artery of patients with hypercholesterolemia.

Apart from ACE, various angiotensin II (Ang II)-forming serine proteinases (eg, chymase, kallikrein, and cathepsin G) are known to exist in human tissues, but their clinical significance or the regulatory mechanisms that control their activities are not well established. A recent clinical study has shown that chymase activity was significantly increased in human atherosclerotic or aneurysmal aorta. The association between vascular Ang II-forming activities (AIIFAs) in the human internal thoracic artery (ITA) and various clinical parameters was studied with the use of ITAs obtained from 32 patients who underwent coronary artery bypass graft surgery. Total and ACE- and chymase-dependent AIIFAs in homogenates of ITAs were determined. Total AIIFA was 8.67+/-0.86 (nmol Ang II formed. min(-1). mg protein(-1) [U]), and approximately 95% of the activities were due to chymase. Serum total cholesterol level, but no other risk factors, significantly correlated with chymase- (r=0. 60, P<0.001) and ACE- (r=0.35, P<0.05) dependent AIIFAs, respectively. LDL cholesterol level was also correlated with chymase-dependent AIIFAs (r=0.47, P<0.05). Mast cells identified through the use of toluidine blue or immunohistochemical staining appeared in the adventitia but not in the intima or media of ITAs. Our results suggest that an increased plasma LDL cholesterol level may induce increased arterial chymase and ACE activity.

Aged↗

PubMed2000

Evaluating the role of inducible nitric oxide synthase using a novel and selective inducible nitric oxide synthase inhibitor in septic lung injury produced by cecal ligation and puncture.

We studied the role of inducible nitric oxide synthase (iNOS) in septic lung injury using a novel and selective iNOS inhibitor (a fused piperidine derivative; ONO-1714) following a cecal ligation and puncture (CLP) procedure. All rats that received CLP died within 48 h after the intervention. The subcutaneous injection of ONO-1714 at 0.03 mg/kg every 12 h resulted in a significantly longer survival time than the saline control only when administration was started 12 h after the CLP procedure. The other administration schedules, which started immediately or 6 h after the intervention, did not show any improvement in the survival rates in comparison with the saline control. The administration of ONO-1714 at higher (0.1 mg/ kg) or lower (0.01 mg/kg) doses when given anytime after the intervention did not improve the survival rates. The NO(x) (NO(2)(-) + NO(3)(-)) levels in the plasma significantly increased 12 h after intervention in comparison with NO(x) at 0 h and thereafter further increased in parallel with the time elapsed. The CLP rats that were initially treated with ONO-1714 (0.03 mg/kg subcutaneously every 12 h) 12 h after intervention showed significantly reduced NO(x) levels in the plasma in comparison with the saline control. The NO synthase activity in lung homogenates increased from 6 to 24 h after the CLP and thereafter decreased to 42 h. The administration of ONO-1714 inhibited iNOS activity (under calcium-free conditions) in preference to total iNOS activity (under calcium-dependent conditions) in lung homogenates, which thus suggested that this compound selectively inhibited iNOS in lung tissue. The iNOS protein expression in the lung and liver homogenates showed a similar time course with alterations of NOS activity, namely a maximum level at 24 h after the intervention followed by decreasing levels to 42 h. On the other hand, other isozymes of NOS, eNOS, and nNOS in lung homogenates, were constantly expressed over the time course after the CLP. Since the iNOS mRNA expression in lung homogenates continued to elevate until 42 h, the decrease in iNOS activity and protein expression later than 24 h after the CLP was thus considered to be due to some posttranscriptional mechanism during the late phase of sepsis. In conclusion, intervention with a potent and selective iNOS inhibitor seemed to improve survival in CLP rats when used at the appropriate doses and time points. However, the self-limited mechanism of iNOS regulation in the lungs may also indicate that iNOS plays only a limited role in sepsis and septic shock.

Amidines↗

PubMed2000

Possible involvement of altered RGD sequence in reduced adhesive and spreading activities of advanced glycation end product-modified fibronectin to vascular smooth muscle cells.

Although fibronectin (FN) modified by advanced glycation end products (AGEs) has been shown to contribute to the development of diabetic vascular complications through its reduced adhesive activity to vascular cells, little is known about changes in the cell binding domain of AGE-modified FN. Here we examined the mechanism of reduced adhesive and spreading activities of AGE-modified FN to vascular smooth muscle cells (SMCs), particularly the contribution of modification of Arg-Gly-Asp (RGD) sequence. Incubation with glucose caused not only the formation of N(epsilon) -carboxymethyllysine and pentosidine, but also polymerization of FN in a dose- and time-dependent manner. AGE-modified FN had significantly low adhesive and spreading activities to cultured SMCs. On the other hand, multimeric FN formed by disulfide bonds did not show any effect on either cell adhesion or spreading. The adhesive activity of type I collagen, one of the RGD sequence-containing proteins, to SMCs also decreased by AGE-modification. The inhibitory effect of AGE-modification on cell adhesion was significantly greater in type I collagen than in FN. Although the extent of AGE-modification of type I collagen was indistinguishable from that of FN, AGE-modification decreased the arginine content of type I collagen by 69.5% and of FN by 30.6%, compared with their non-glycated forms. The addition of RGD peptides caused a decrease in adhesion of SMCs to non-glycated FN, but not to AGE-modified FN. Modification of RGD sequence with glyoxal eliminated its inhibitory effect on cell adhesion. Our results suggest that a marked decrease in adhesive and spreading activities of AGE-modified FN to SMCs might largely be due to a modification of its RGD sequence by AGE, thus suggesting a potential link between AGE modification of FN and the pathogenesis of diabetic angiopathy.

Amino Acids↗

PubMed2000

Causal relationship between conformational change and inhibition of domain functions of glycoxidative fibronectin.

Glycoxidative modification of various body proteins, including fibronectin (FN), has been shown to change their structural and functional properties, and be implicated in pathogenesis of diabetic complications. Little is known about the role of secondary structure of glycoxidative FN (gFN) in its domain functions. gFN was prepared by incubation with 25 and 200 mM glucose in 0.2 M sodium phosphate buffer at 37 degrees C on a shaking plate under aerobic and sterile conditions for various time intervals up to 49 days, being defined as gFN25 and gFN200, respectively. Unmodified FN (uFN) was prepared by incubation in 0.2 M sodium phosphate buffer without any glucose at 4 degrees C for 49 days. The extent of glycoxidative modification was examined using a noncompetitive enzyme-linked immunosorbent assay with an antibody against N(epsilon) -(carboxymethyl)lysine (CML), one of the major glycoxidation products. The binding activities of uFN and gFN to collagen, gelatin and heparin were determined by a solid phase enzyme immunoassay or heparin-affinity HPLC. Cell attachment was estimated by the extent of adhesion of FITC-labeled smooth muscle cells to uFN or gFN. Conformational change in gFN was detected by SDS-polyacrylamide gel electrophoresis and spectroscopy (circular dichroism). CML was detected in gFN25 and gFN200 after 49 and 21 days of incubation, respectively. Levels of CML were about six-fold higher in gFN200 than in gFN25 after 49 days. Both gFN25 and gFN200 showed a significant decrease in the ability of binding to collagen and gelatin after 7 days of incubation. The binding activity for heparin was significantly decreased in both gFN25 and gFN200 after one day. Cell attachment activity was reduced to 89% and 76% of the unmodified form in both gFN25 and gFN200 after 49 days, respectively. High molecular weight materials were found in gFN25 and gFN200 after 21 and 7 days, respectively. CD spectrum showed that gFN25 had lost its native conformation after 3 days of incubation, depending upon the concentration and incubation interval of the applied glucose. These in vitro results suggest that the loss of native conformation may reduce the domain functions of gFN, including binding activity to macromolecular ligands and cell attachment, and may play a major role in the pathogenesis of diabetic complications.

Cell Adhesion↗

PubMed2000

Effects of advanced glycation end products on the proliferation and fibronectin production of smooth muscle cells.

The aim of this study was to evaluate the effects of advanced glycation end-products (AGEs) on the proliferative activity and fibronectin production of smooth muscle cells (SMCs). AGE-bovine serum albumin (AGE-BSA) was prepared by incubation with D-glucose at 37 degrees C for 60 days. Cultured SMCs were obtained from explants isolated from porcine abdominal aorta and used between passages 3 and 10. The proliferative activity of SMCs was examined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and by incorporation of 3H-thymidine into DNA. Fibronectin production was assessed by competitive ELISA assay for both fibronectin secreted into the culture medium (M-FN) and cell-associated fibronectin (C-FN), i.e., both intra- and peri-cellular fibronectin. Theassay revealed that AGE-BSA did not produce any change in optical density (A570) of SMCs at concentrations of up to 20 microg/ml, but decreased that of SMCs at a concentration of 40 microg/ml. The addition of PDGF (5 ng/ml) induced an increase in 3H-thymidine incorporation into DNA of quiescent SMCs, while the addition of AGE-BSA (20 microg/ml) had no effect. In contrast, AGE-BSA significantly increased C-FN of SMCs (30.8+/-8.58 ng/microg TP), compared to unmodified BSA (16.5+/-4.19 ng/microg TP). However, no difference in M-FN levels was observed between cells treated with AGE-BSA and unmodified BSA. The addition of anti-transforming growth factor (TGF)-beta antibody restored the levels of C-FN in SMCs cultured in 20 microg/ml of AGE-BSA, suggesting that TGF-beta might act as an intermediate factor in AGE-induced fibronectin production by SMCs. Our results suggest that interaction of AGE-modified proteins with SMCs may play a role in the development of atherosclerosis in diabetic and non-diabetic patients.

Animals↗

PubMed2000

Chronic graft-versus-host disease in children and adolescents after bone marrow transplantation from HLA-matched donors.

We analyzed 98 pediatric patients who underwent bone marrow transplantation (BMT) from serologically HLA-matched related donors (RD) or unrelated donors (UD) at our institute to clarify the actual status of chronic graft-versus-host disease (cGVHD). There were 36 evaluable cases of RD-BMT and 35 of UD-BMT. cGVHD was observed in 8 RD-BMT cases (22.2%) and in 23 UD-BMT cases (65.7%). In the RD-BMT cases, the limited and extensive types of cGVHD were observed in 4 cases each, whereas in the UD-BMT cases, the limited type was seen in 11 cases and the extensive type in 12. Prior acute GVHD was observed in 6 RD-BMT cases and in 18 UD-BMT cases. Two RD-BMT patients with extensive type cGVHD died of relapse and cytomegalovirus infection, and 4 UD-BMT patients died because of bronchiolitis obliterans, fungal infection, liver failure, and multiple organ failure, respectively. The incidence of cGVHD in these pediatric patients was as high as that in adult patients when UD-BMT was performed. Some UD-BMT patients required long-term immunosuppressive therapy after BMT. These findings suggest that cGVHD is a serious problem in pediatric UD-BMT. Therefore, intensive prophylaxis and treatment of GVHD must always be performed after UD-BMT.

Adolescent↗

PubMed2000

[Prophylaxis with FK-506 for graft-versus-host disease after transplantation of bone marrow from unrelated donors].

Forty-eight patients who underwent bone marrow transplantation (BMT) from serologically HLA-matched unrelated donors received tacrolimus (FK506) alone or with methotrexate (MTX) and/or methylprednisolone (mPSL) to prevent graft-versus-host disease (GVHD). We analyzed retrospectively the efficacy of FK506 for GVHD prophylaxis, and its toxicity, by comparing three groups of patients: those given FK506 alone, those given FK506 + mPSL, and those given FK506 + MTX + mPSL. Grade III and IV acute GVHD occurred in five of 10 patients given FK506 alone and in 11 of 30 patients given FK506 + mPSL. In these groups, severe acute GVHD was commonly seen in the patients who discontinued FK506 administration early after BMT and in those who received bone marrow from genotypically HLA-mismatched donors. Early withdrawal of FK506 was due mainly to severe nephrotoxicity. The incidence of nephrotoxicity was very high in patients who received high-dose FK506 as well as melphalan-containing preconditioning (80% and 50%). None of eight patients who received FK506 + mPSL + MTX developed grade III-IV acute GVHD even though five of them received bone marrow from genotypically HLA-mismatched donors. In patients receiving bone marrow from unrelated donors, adjustment of the initial dose of FK506 seems essential in order to avoid severe nephrotoxicity, and combination of MTX and FK506 is useful for preventing severe acute GVHD.

Adolescent↗

PubMed1999

Quantitative and qualitative signals determine T-cell cycle entry and progression.

Cell growth and proliferation as well as cell cycle arrest and apoptosis all play integral roles in the cellular immune response. The signals that lead to cytokine production by antigen- or mitogen-stimulated T cells have been studied in detail. However, it is not fully understood how these signals promote cell cycle entry and progression to DNA synthesis in T lymphocytes, especially in primary cells. We used a model distinguishing between competence and progression phases to examine quantitative and qualitative differences in signal transduction that resulted in cell cycle entry and G1 phase arrest or led to DNA synthesis in human T cells. Resting peripheral blood T cells were rendered competent by stimulation with submitogenic concentrations of phytohemagglutinin (PHA) or they were stimulated to proliferate using mitogenic concentrations of PHA. The competent state (that is, the capacity to proliferate in response to exogenous IL-2) was characterized by calcium mobilization, a protein kinase C-dependent internalization of CD3, increased mitogen-activated protein kinase (MAPK) activity, transient translocation of AP-1 transcription factors to the nucleus, expression of immediate early genes, activation of G1-phase cyclin-dependent kinases, and increased CD25 (IL-2Ralpha) expression. However, all of these events were of lesser magnitude in T cells rendered competent than in T cells stimulated to proliferate. Furthermore, the mitogenic stimulus induced a different pattern of MAPK activation and sustained translocation of AP-1 to the nucleus with concomitant IL-2 production. The data indicate that quantitative and qualitative differences in early signaling events distinguish the acquisition of the competent state or the induction of cytokine production with a commitment to T-cell proliferation.

CD3 Complex↗

PubMed1999

Cytosolic components are required for proteasomal degradation of newly synthesized apolipoprotein B in permeabilized HepG2 cells.

Recent studies have proposed that post-translational degradation of apolipoprotein B100 (apoB) involves the cytosolic ubiquitin-proteasome pathway. In this study, immunocytochemistry indicated that endoplasmic reticulum (ER)-associated proteasome molecules were concentrated in perinuclear regions of digitonin-permeabilized HepG2 cells. Signals produced by antibodies that recognize both alpha- and beta-subunits of the proteasome co-localized in the ER with specific domains of apoB. The mechanism of apoB degradation in the ER by the ubiquitin-proteasome pathway was studied using pulse-chase labeling and digitonin-permeabilized cells. ApoB in permeabilized cells incubated at 37 degrees C in buffer alone was relatively stable. When permeabilized cells were incubated with both exogenous ATP and rabbit reticulocyte lysate (RRL) as a source of ubiquitin-proteasome factors, >50% of [3H]apoB was degraded in 30 min. The degradation of apoB in the intact ER of permeabilized cells was much more rapid than that of extracted [3H]apoB incubated with RRL and ATP in vitro. The degradation of apoB was reduced by clasto-lactacystin beta-lactone, a potent proteasome inhibitor, and by ubiquitin K48R mutant protein, an inhibitor of polyubiquitination. ApoB in HepG2 cells was ubiquitinated, and polyubiquitination of apoB was stimulated by incubation of permeabilized cells with RRL. These results suggest that newly synthesized apoB in the ER is accessible to the cytoplasmic ubiquitin-proteasome pathway and that factors in RRL stimulate polyubiquitination of apoB, leading to rapid degradation of apoB in permeabilized cells.

Animals↗

PubMed1999

Synergistic effects of pranlukast and leukotriene B4 receptor antagonist on antigen-induced pulmonary reaction.

We now attempted to differentiate effects of cysteinyl-leukotrienes and leukotriene B4 on antigen-induced pulmonary reaction by using a selective leukotriene D4/E4 (CysLT1) receptor antagonist and a selective LTB4 (BLT) receptor antagonist in rats. An intratracheal challenge with ovalbumin to Brown-Norway rats actively sensitized with ovalbumin produced two phases of airway responses which were estimated based on airway resistance, the immediate-type airway response within 30 min, and the delayed-type airway response beginning from 4 to 6 h after the challenge. Pretreatment of the rats with a CysLT1 receptor antagonist (pranlukast) failed to reduce the elevation of airway resistance, and pretreatment with a BLT receptor antagonist (ONO-4057; 5-[2-(2-carboxyethyl)-3-[6-(4-methoxyphenyl)-5E-hexenyl]- oxyphenoxy] valeric acid) also produced no decrease. In contrast, combined pretreatment of the rats with pranlukast and ONO-4057 did not reduce the amplitude of the immediate-type airway response, but did allow the elevated airway resistance to return to its baseline level and also significantly inhibited the delayed-type airway response. Histological examination at 6 h after ovalbumin challenge showed infiltration of inflammatory cells with a predominance of neutrophils and scattered eosinophils in the bronchial submucosa. While pretreatment with neither pranlukast nor with ONO-4057 inhibited the infiltration of inflammatory cells in the bronchial submucosa, pretreatment with the two antagonists combined significantly inhibited the infiltration of granulocytes into the bronchial submucosa. On the contrary, intratracheal administration of either leukotriene D4 or leukotriene B4 up to 10 microg resulted in the infiltration of granulocytes into the bronchial submucosa, but no synergism for the infiltration of granulocytes was observed after combined administration. These results suggest that leukotriene B4 appears to play a significant role in the antigen-induced pulmonary reaction in association with cysteinyl-leukotrienes. Accordingly, the combined antagonism at the CysLT1 receptor and BLT receptor may be a useful intervention for the treatment of bronchial asthma.

Animals↗

PubMed1999

Ubiquitin-proteasome-dependent degradation of apolipoprotein B100 in vitro.

Apolipoprotein B100 (apoB) is a large secretory protein that forms very low density lipoprotein in liver. An in vitro degradation assay was developed using rabbit reticulocyte (RR) lysate in order to investigate the mechanism of intracellular degradation of newly synthesized apoB by the ubiquitin-proteasome pathway. [3H]apoB, isolated from [3H]leucine pulsed/chased Hep G2 cells, was degraded 51% when incubated for 2 h at 37 degreesC in an assay mixture that included RR lysate (source of the ubiquitin conjugation system and proteasome) and an exogenous ATP regenerating system. ApoB degradation was ATP-dependent and degradation fragments were not observed suggesting that the very large apoB molecule was extensively degraded. ApoB degradation was decreased to 50% when potent proteasome inhibitors, clasto-lactacystin beta-lactone (10 microM) or MG-132 (50 microM), were added to the reaction mixture, but was not affected by the cysteine protease inhibitor, E-64, or the serine protease inhibitor, phenylmethylsulfonyl fluoride. ApoB degradation was inhibited by the mutant ubiquitin protein K48R and by ubiquitin aldehyde, an inhibitor of ubiquitin-protein isopeptidases. During incubation ubiquitination of apoB increased even as apoB was being degraded. These results suggest that in vitro degradation of apoB, a large secretory protein that is normally found in the endoplasmic reticulum (ER) lumen or associated with the ER membrane, was proteasome-dependent and involved both ubiquitination and deubiquitination steps.

Adenosine Triphosphate↗

PubMed1999

Differential activation and regulation of mitogen-activated protein kinases through the antigen receptor and CD40 in human B cells.

In human B cells, antigen receptor ligation and CD40 ligation are known to activate the extracellular-regulated kinases (ERK) and c-Jun N-terminal kinase (JNK) pathways, which in turn regulate many important B cell functions. We previously reported that antigen receptor ligation activated the ERK pathway whereas CD40 ligation activated the JNK/stress-activated protein kinase (SAPK) pathway. Here, we demonstrate that another SAPK, p38/Hog1, is activated by both antigen receptor ligation or CD40 ligation in a human B-lymphoblastoid cell line and tonsillar B cells. Wortmannin, an inhibitor of phosphatidylinositol 3-kinase, partially inhibited ERK2 and p38 activation triggered through the B cell receptor whereas activation of JNK1 and p38 through CD40 was not affected. PD98059, a specific inhibitor of mitogen-activated extracellular response kinase kinase (MEK), significantly inhibited ERK2 activation and partially inhibited p38 activation triggered by anti-IgM antibody treatment, but did not affect CD40-dependent signaling events. In addition, anti-IgM antibody-induced signaling pathways were shown to be PKC-dependent in contrast to the CD40-induced signaling pathways. Thus, the B cell receptor and CD40 recruit the ERK, JNK and p38 pathways by using different upstream effectors.

Antigens, Differentiation, T-Lymphocyte↗

PubMed1999

Increased advanced glycation end products in atherosclerotic lesions of patients with end-stage renal disease.

Although advanced glycation end products (AGEs) are increased in the serum and tissues of patients with end-stage renal disease, little is known about the role of AGEs in atherogenesis. We therefore carried out an immunohistochemical study on the accumulation of AGEs and apolipoprotein B in the human aortas of diabetic and nondiabetic subjects with end-stage renal disease. The atherosclerotic lesions included diffuse intimal thickening, fatty streaks and atherosclerotic plaque. We used antibodies against two different epitopes of AGE structures, i.e. an Nepsilon-(carboxymethyl)lysine-protein adduct (CML) and a structure(s) other than CML (nonCML). The area that was positive for an antigen as a percentage of the total area (%Ar) was determined morphometrically, using an NIH-image program. In diffuse intimal thickening, atherosclerotic plaque and tunica media, the %Ar of CML and nonCML was significantly greater in diabetic or nondiabetic subjects with end-stage renal disease than in control subjects without end-stage renal disease. In fatty streaks, the %Ar of nonCML was significantly greater in nondiabetic subjects with end-stage renal disease than in control subjects, while no difference in the %Ar of CML was found between the subjects with or without end-stage renal disease. Nondiabetic subjects with end-stage renal disease showed a significantly increased %Ar of apolipoprotein B in fatty streaks and atherosclerotic plaque than the control subjects. The %Ar of CML and nonCML significantly correlated with the duration of hemodialysis in diffuse intimal thickening and atherosclerotic plaque of subjects with end-stage renal disease, but not in fatty streaks. On the other hand, the %Ar was not related to the duration of diabetes in any of the lesions in the diabetic subjects with end-stage renal disease. In diffuse intimal thickening and atherosclerotic plaque, subjects with end-stage renal disease showed a significant correlation between the %Ar of apolipoprotein B and AGEs (CML and nonCML), as well as their immunohistochemical colocalization. These results suggest that impaired AGE clearance may cause the increased accumulation of AGEs in the aortic wall of subjects with end-stage renal disease, thus resulting in the rapid progression of atherosclerosis. The accumulation of AGEs may be related to an enhanced LDL deposition in atherosclerotic lesions of subjects with end-stage renal disease.

Aged↗

PubMed1999

Extracellular product(s) of Staphylococcus aureus stimulate their own growth.

The effect of extracellular products obtained from culture supernatant of Staphylococcus aureus strain Cowan I on the bacterial growth was studied in a synthetic medium. Addition of the extracellular products to a fresh medium stimulated growth already after 2 h of incubation, with an approximately two-fold increase in cell density as compared to an unsupplemented medium, probably by promoting an initiation of growth accompanied by a reduction of the initial lag phase. The growth-stimulating effect was also monitored as an increase of adenosine triphosphate (ATP) in the bacterial culture during the different phases of growth.

Culture Media↗

PubMed1999

Identification of a 21 kDa laminin-binding component of Candida albicans.

Binding of Candida albicans strain JCM0239 to radiolabelled laminin was studied to identify possible receptors. When two forms of the organism were examined, laminin was found to bind to germinating blastoconidia. There was only weak binding to blastoconidia without germ tubes. Laminin-binding to germinating blastoconidia was inhibited by non-labelled laminin or fibrinogen but not by fibronectin, a fibronectin peptide (Gly-Arg-Gly-Asp-Ser), or a laminin peptide (Tyr-Ile-Gly-Ser-Arg). A cell extract from germinating blastoconidia was analyzed by using SDS-PAGE and Western blotting, and 125I-labelled laminin was shown to bind to a 21 kDa component.

Animals↗