Mechanism of beta-adrenergic agonist-induced transmural transport of glucose in rat small intestine. Regulation of phosphorylation of SGLT1 controls the function

The perfusion of rat small intestine with 10 microM epinephrine (Epi) or 10 microM norepinephrine resulted in significant increases in the amount of 3-O-[methyl-3H]-D-glucose transported from the mucosal to serosal side. The Epi-induced increases in glucose transport were coupled with selective increases in beta-adrenoceptor density in the mucosal membranes. Treatment with 0.1 microM okadaic acid increased glucose transport even in the absence of Epi, but that with 1 microM staurosporine or 60 microM N-[2-(methylamino)ethyl]-5-isoquinoline-sulfonamide dihydrochloride completely inhibited the increases in glucose transport induced by 10 microM Epi or 10 microM dibutyryl cAMP. The maximal binding sites (Bmax) of [3H]phlorizin in brush border membrane (BBM) from tissues perfused with Epi was increased, showing increases in the binding ability of the Na+/glucose cotransporter (SGLT1) to glucose. Phosphorylation and dephosphorylation of BBM with protein kinase A (PKA) and alkaline phosphatase resulted in increases and decreases in Bmax of [3H]phlorizin, respectively. The phosphorylation state of SGLT1 immunoprecipitated from BBM incubated with [gamma-32P]ATP-Mg2+ and PKA, and the analysis of phosphoamino acids composed of SGLT1 in rats given [32P]orthophosphate indicate the presence of potential sites for PKA-mediated phosphorylation of SGLT1 at serine. These findings indicate that the regulation of phosphorylation of SGLT1 leads to an alteration of its function and results in the control of glucose transport in the rat small intestine.

[The results of treatment for pancreatic cancer--statistic change]

Between 1981 and 1995, 17, 121 patients with pancreatic cancer were registered by Japan Pancreas Society (JPS). The resection rate was 36.1% with recent increase. The 1, 3, and 5 year actuarial survival rates of resected cases were 52.7%, 24.0%, and 18.6%, respectively. As for resectional procedures, there was a gradual decrease in TP and increase in PD. Lymph node metastases are found in 37.0% of patients with tumor size less than 2 cm, therefore, and extended lymphadenectomy and extended surgery including portal vein resection are more performed than before in Japan. Tubular adenocarcinoma are 60.6% in all registered pancreatic cancer, but its survival rate is only 10%. The survival rate of the National Cancer Data Base was almost the same as that of us with higher resection rate, but we cannot easily accepted its fact as the background of patients are various.

Suppressive effects of tranilast on the expression of inducible cyclooxygenase (COX2) in interleukin-1beta-stimulated fibroblasts

We investigated the effects of tranilast on inducible cyclooxygenase (COX2)-mediated prostaglandin E2 (PGE2) production and enzyme induction in interleukin-lbeta (IL-1beta)-stimulated cultured dermal fibroblasts. IL-1beta enhanced PGE2 production in cultured fibroblasts. Tranilast did not affect constitutive cyclooxygenase (COX1) or COX2 activity in non-stimulated or IL-lbeta-stimulated fibroblasts. However, the COX2 expression induced by IL-1beta was inhibited by tranilast. This result, that IL-1beta-induced COX2 expression was suppressed by tranilast, was confirmed by immunohistochemical analysis. Thus, it is possible for tranilast to regulate PGE2 production by inhibiting COX2 induction.

Gastric inhibitory polypeptide activates MAP kinase through the wortmannin-sensitive and -insensitive pathways

The signal transduction pathways of a cloned human gastric inhibitory polypeptide (GIP) receptor have been investigated in CHO cells stably expressing this receptor. Exposure of GIP receptor expressing cells to GIP significantly increased MAP kinase activity. Time course analysis showed that a rapid and marked increase in MAP kinase activation was detected and that this activation reached maximal levels 10 min after the addition of GIP. Dose-response analysis showed that GIP activated MAP kinase activity in a dose-dependent manner with an ED50 value of 5.9 x 10(-10) M of GIP. Wortmannin, a potent inhibitor of phosphatidylinositol 3-kinase (PI3-kinase), partially inhibited GIP-induced MAP kinase activation, suggesting that GIP activates MAP kinase through two different, wortmannin-sensitive and -insensitive pathways. It has been demonstrated that in CHO cells cAMP attenuates MAP kinase activity by inhibiting Raf-1. Since GIP elevates intracellular cAMP, we examined the effects of cAMP on MAP kinase activation. Interestingly, forskolin, which increased intracellular cAMP levels, significantly inhibited MAP kinase activation by GIP, but did not affect MAP kinase activation by GIP in the presence of wortmannin, suggesting that the wortmannin-sensitive pathway activates an MAP kinase cascade at or above the level of Raf-1 and that the wortmannin-insensitive pathway activates an MAP kinase cascade below the level of Raf-1. These findings demonstrate that the GIP receptor is linked to the MAP kinase cascade via at least two different pathways.

Design and synthesis of potent antitumor 5,4'-diaminoflavone derivatives based on metabolic considerations

Recently, we reported that 5,4'-diaminoflavone (1) exhibits potent and specific growth-inhibitory activity against the estrogen receptor (ER)-positive human breast cancer cell line MCF-7. However, when compound 1 was incubated with S-9 mix, its metabolites were observed. Moreover, addition of S-9 mix to the medium caused the drastic decrease in activity of compound 1. Since the 6-, 8-, and 3'-positions were considered to be metabolized oxidatively in vivo from MO calculations, a series of 5,4'-diaminoflavone derivatives substituted at such putative metabolic positions with various functional groups were synthesized aiming at the metabolically stable derivatives. Among them, 5,4'-diamino-6,8,3'-trifluoroflavone (14d) exhibited strong growth-inhibitory activity against MCF-7 cells even in the presence of S-9 mix. Moreover, orally administered compound 14d completely suppressed the growth of MCF-7 inoculated into nude mice, and the effect was more potent than that of compound 1. In addition to ER-positive breast cancer cells, compound 14d exhibited growth-inhibitory activity against a panel of human cancer cell lines including a part of ER-negative breast, endometrial, ovarian, and liver cancers. From these results, fluorine introduction to the putative metabolic positions of compound 1 was elucidated to be effective in the enhancement of the in vivo antitumor activity, probably due to the block of the metabolic deactivation.

Normothermic cardiopulmonary bypass: effect on the incidence of persistent postoperative neurological dysfunction following coronary artery bypass graft surgery

We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°-37°C) and hypothermic CPB (27°-28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.

[Clonal deletion and clonal anergy as the mechanism of self-tolerance induction]

In the immune system, it is most important to discriminate self from nonself and to acquire and maintain the unresponsiveness to self antigens, self-tolerance. Recently, the transgenic animals provides the evidence of the mechanism of self-tolerance induction. Self-tolerance is established mainly by elimination, clonal deletion, and functional inactivation, clonal energy, of the autoreactive T cells and B cells. Clonal deletion and clonal anergy are involved not only in the central tolerance, in thymus or bone marrow, but also in the peripheral tolerance. The failure of self-tolerance involves the induction of auto-immune disease.

[An imbalance between Th1 and Th2-like cytokines in patients with autoimmune diseases--differential diagnosis between Th1 dominant autoimmune diseases and Th2 dominant autoimmune diseases]

An imbalance between T helper cell (Th)1 and Th2-like cytokines has been described in several autoimmune diseases. Organ specific autoimmune diseases such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD) are caused by Th1 dominant immune responses. On the contrary, systemic autoimmune diseases such as systemic lupus erythematosus (SLE) and Sjögren's syndrome(SS) are characterized by Th2 dominant imbalance of cytokine production. It might be useful for differential diagnosis among patients with various autoimmune diseases such as SLE, SS, IBD, and MS to measure the serum levels of cytokines such as IL-10, IFN gamma, and TNF alpha using ultrasensitive enzyme-linked immunosorbent assay system.

Nisoldipine blocks the increase of intracellular free calcium-ion concentration associated with elevated sodium-lithium countertransport activity in erythrocytes in patients with NIDDM

To understand the mechanism by which elevated sodium-lithium countertransport activity (SLC) associates with increased intracellular free calcium-ion concentration ([Ca2+]i), we investigated the relationship between SLC and the effects of the extracellular Ca2+ concentration ([Ca2+]o) and a Ca2(+)-channel blocker, nisoldipine, on [Ca2+]i in erythrocytes from 48 patients with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM). There was a significant correlation between SLC and [Ca2+]i. Nisoldipine in the incubation medium significantly decreased [Ca2+]i, and there was a significant positive correlation between SLC and the degree of [Ca2+]i decrease. When the [Ca2+]o was elevated, [Ca2+]i was significantly increased, but nisoldipine almost completely suppressed this increase of [Ca2+]i. There was a significant positive correlation between SLC and the degree of the suppression. These data suggest that elevated SLC correlates with increased [Ca2+]i, and that the increased [Ca2i]i might be due to the increased Ca2+ influx through a dihydropyridine-sensitive Ca2+ pathway.

A synthetic approach to the c-series gangliosides containing sialyl-alpha(2-->8)sialyl-alpha(2-->8)sialic acid: synthesis of ganglioside GT4, alpha(2-->6) GT4 and GT3

Trimeric sialic acid [Neu5Ac alpha(2-->8)Neu5Ac alpha(2-->8)Neu5Ac, 1] residue-containing gangliosides, GT4, alpha(2-->6)GT4 and GT3, have been synthesized for the first time. Methyl [phenyl] 5-acetamido-8-O-[5-acetamido-8-O-(5-acetamido-4, 7, 8, 9-tetra-O-acetyl-3, 5-dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylono-1", 9'-lactone)-4,7-di-O-acetyl-3,5-dideoxy-D- glycero-alpha-D-galacto-2-nonulopyranosylono-1',9-lactone]-4,7-di- O-acetyl -3,5-dideoxy-2-thio-D- glycero-D-galacto-2-nonulopyranosid]onate (3) was prepared from 1, via lactonization, methyl esterification of the carboxyl group at the reducting end, O-acetylation and conversion of the anomeric acetoxy group into a phenylthio group. Iodonium-promoted glycosylation of 3 with 2-(trimethylsilyl)ethyl 2,6-di-O-benzyl-beta-D-galactopyranoside (5), 2-(trimethylsilyl)ethyl 3-O-benzyl-beta-D-galactopyranoside (6), 2-(trimethylsilyl)ethyl 2-O-benzoyl-3-O-benzyl-beta-D-galactopyranoside (9), and 2-(trimethylsilyl)ethyl 2, 3-di-O-benzyl-beta-D-galactopyranoside (11) gave the corresponding tetrasaccharides (13-15, 17) having the (Neu5Ac)3-Gal structure. The peracylated oligosaccharides 18 and 24 derived from 13 and 17, and the previously reported lactose derivative 29 were converted into the alpha-trichloroacetimidates 20, 26 and 31, and coupled with (2S,3R,4E)-2-azido-3-O-benzoyl-4-octadecene-1,3-diol (21) to afford the corresponding beta-glycosides 22, 27 and 32. These protected azidosphingosine derivatives were each transformed into the target gangliosides GT4, alpha(2-->6)GT4 and GT3 via selective reduction of the azido group, subsequent coupling with octadecanoic acid, O-deacylation and saponification of the methyl ester and lactone groups.

Favorable donor site for epidermal cultivation for the treatment of burn scars with autologous cultured epithelium

It is very important to determine from where we select the donor skin for epidermal cultivation in the treatment of burn scar disfigurement. To prove this point, we compared the appearance and histology of grafted sites according to the different donor sites. Thirty-eight patients with skin color difference and irregular contours of matured burn scars were superficially abraded and underwent autologous cultured epithelial grafting. These patients were followed more than 2 years. The donor skin for epidermal cultivations was taken from the buttock (group 1, 8 patients), sole (group 2, 6 patients), and adjacent to the site of the scar (group 3, 24 patients). In group 3, skin elasticity was also measured after 2 years. Hypo- and hyperpigmentation were well treated with autologous cultured epithelial grafting. The most favorable results in terms of color match were obtained in group 3, where the skin color resembled surrounding normal skin. The skin tension returned to almost normal. In group 2, the histology of the grafted site resembled the sole epidermis. It was concluded that the general principle of conventional skin grafting (i.e., "closer is best") was also correct in cultured epithelial grafting. Furthermore, it was revealed that cultured epithelium has a site specificity even after grafting.

Portal vein aneurysm: report of six cases and review of the literature

Portal vein aneurysm is very rare, and its relation to portal hypertension has been emphasized. We report six cases of portal vein aneurysm (five extrahepatic and one intrahepatic). All patients were asymptomatic and had no signs suggestive of portal hypertension; the lesion was incidentally detected by ultrasound. Color Doppler sonography showed a constant hepatopetal flow along the aneurysmal wall, which immediately led to the diagnosis. We stress the usefulness of color Doppler sonography for studying the hemodynamics of this vascular anomaly and briefly review the literature.

Docosahexanoic acid (DHA) improved glucose and lipid metabolism in KK-Ay mice with genetic non-insulin-dependent diabetes mellitus (NIDDM)

The hypoglycemic and hypolipidemic effect of docosahexaenoic acid (DHA; C22: 6omega-3) ethyl ester was examined in KK-Ay mice and neonatal streptozotocin-induced diabetic (NSZ) which are respectively obese and lean animal models of non-insulin-dependent diabetes mellitus (NIDDM), and in ddY normal mice. Single administration of DHA (500 mg/kg body weight) to KK-Ay mice significantly reduced (p<0.05) the blood glucose levels (BG) (p<0.05) and plasma free fatty acid levels (FFA) (p<0.05) at 10 h after oral administration when compared with control group. DHA (500 mg/kg body weight)-treated NSZ and normal mice, however, showed no change in these parameters. In addition, repeated administration of DHA (100 mg/kg) to KK-Ay mice significantly suppressed the increment of BG (p<0.05) and plasma triglyceride levels (TG) (p<0.01), and significantly decreased FFA (p<0.05) at 30 d compared with control group. DHA also significantly decreased the blood glucose at 60 and 120 min on insulin tolerance test (ITT). From these findings, it seems likely that DHA exhibits its hypoglycemic effects by increasing insulin sensitivity. It is concluded that DHA would be useful for treatment of obese type NIDDM with insulin resistance.

Identification of calprotectin, a calcium binding leukocyte protein, in human dental calculus matrix

Calprotectin is a calcium binding protein produced by leukocytes, macrophages and epithelial cells, and its levels in several tissues increase during infections and in many inflamed areas, suggesting that it may be an indicator of inflammatory activity. Osteopontin is a prominent phosphorylated glycoprotein in bone matrix, having calcium binding capacity. Recently, it has been reported that calprotectin and osteopontin are present in urinary stones (pathological mineralized masses in the body), and that these proteins may be involved in their formation. Dental calculus formed by mineralization of dental plaque is an inflammatory factor which may contribute to periodontal disease. It contains many organic components involved in mineralization. We recently found osteopontin molecules in human dental calculus and suggested that the components of its matrix may be similar to those of urinary stones. In this study, we investigated the presence of calprotectin in human dental calculus by immunohistochemical and immunoblotting analyses using a specific antibody for calprotectin. After fixation and demineralization of dental calculi adhered to tooth roots, sections embedded in paraffin were immunoreacted with the antibody for calprotectin and positive immunostaining for calprotectin was observed. Dental calculus proteins were then extracted with EDTA and separated by electrophoresis on 15% polyacrylamide gels. By immunoblotting analysis, 3 or 4 bands were observed at 11, 14.5, 22-25, 28 or 36.5 kDa and these patterns corresponded to those of calprotectin subunits. When non-immune rabbit serum was used instead of calprotectin-specific antibody as a negative control, no immunoreactivity was observed. These findings indicate that calprotectin is associated not only with antibacterial action but also with calcium binding capacity during dental calculus formation.

[A case of malignant hemangioendothelioma of the lung with rapid growth of pulmonary metastasis]

Malignant hemangioendothelioma of the lung is very rare and difficult to diagnose. The growth is rapid and the prognosis is very unfavorable. We report an operated case of the disease with rapid growth of pulmonary metastasis. The silver, vimentin and factor VIII stainings were available for diagnosis of this disease. The 46-year-old female patient died of bleeding from the pulmonary metastasis eight months after the operation without other distant metastasis. Even if a lung tumor is pointed out and thought to be benign, frequent follow up is necessary. Furthermore, we recommend positive lung biopsy by thoracotomy or video-assisted-thoracic-surgery.

A comparative study of high-fat diet containing fish oil or lard on blood glucose in genetically diabetic (db/db) mice

The effects of high-fat diets containing fish oil or lard on blood glucose and plasma insulin after oral glucose loading were compared in genetically diabetic (db/db) mice, one of the animal models of non-insulin-dependent diabetes mellitus (NIDDM) with hyperinsulinemia. The blood glucose levels were significantly decreased in 27% of the mice fed high-fat diets containing 20% fish oil 30 and 60 min after the oral administration of glucose (both; p < 0.05). Conversely, the plasma insulin levels were significantly increased 30 min after the glucose loading as compared to 27% of the mice fed high-fat diets containing 20% lard (p < 0.01). In addition, a significant hypoglycemic effect was observed 60 min after the subcutaneous administration of insulin to mice on the fish oil diet (p < 0.05), whereas no effect was demonstrated in the case of those on the lard diet. The average body weight of the fish oil-treated mice was not significantly different from that of the lard-treated mice. The fish oil diet has a beneficial effect on glucose tolerance by increasing the insulin secretory capacity from pancreatic beta cells and also ameliorating insulin resistance.

[Clinical studies on renal pelvic and ureteral carcinoma]

We reviewed 40 patients with renal pelvic and/or ureteral transitional cell carcinomas, consisting of 24 males and 16 females with a mean age of 65 years. The histopathological stage of surgically removed specimen was pTa in 6 patients, pT1 in 7, pT2 in 5, pT3 in 11 and pT4 in 6. Three patients with Tis and 2 with T3 did not undergo surgery. Of 35 patients pathologically examined, lymphatic and venous invasions were detected in 22 (63%) and 16 (46%), respectively, and were associated with pathological stage and grade. Overall the 5-year actuarial survival rate was 57.1%. Tumor staging and vascular invasion had a prognostic significance on the treatment outcome, but not metachronous or synchronous bladder cancer, identified in 55% of the patients. Adjuvant chemotherapy appeared to improve the survival of the patients with tumors pT2 or higher, grade 3 or vascular invasion without metastases.

Evaluation of combined therapy with chemoembolization and ethanol injection for advanced hepatocellular carcinoma

To evaluate the therapeutic efficacy of transcatheter arterial chemoembolization (TACE) combined with percutaneous ethanol injection therapy (PEIT) for advanced hepatocellular carcinoma, we studied the effectiveness of TACE therapy combined with PEIT (50 cases) and TACE alone (50 cases). In both groups, patients had multiple lesions, or a single lesion with a diameter exceeding 2 cm or with vascular invasion (stages II, III, and IV in the tumor staging classification of the Liver Cancer Study Group of Japan). The clinical features in the two groups were comparable. The cumulative survival rates with TACE-PEIT were 95.0% for 1 year, 72.5% for 2 years, and 50.0% for 3 years, whereas the rates with TACE alone were 92.5% for 1 year, 57.5% for 2 years, and 20.0% for 3 years. The survival rate in the TACE-PEIT group was significantly higher than that in the TACE alone group. Moreover, the survival rate of patients with stage II or III disease in the TACE-PEIT group was significantly better than that in the TACE alone group, and the survival rate of patients with Child's classification B or C in the TACE-PEIT group was significantly higher than that in the TACE alone group. Multivariate analysis using Cox's proportional hazard regression model showed that the most significant prognostic factors in the TACE-PEIT group were tumor embolus in the portal vein and the number of tumors. These results suggest the effectiveness of combining TACE and PEIT for the treatment of advanced hepatocellular carcinoma.

[Tokyo Centenarian Study. 4. Apolipoprotein E phenotype in Japanese centenarians living in the Tokyo Metropolitan area]

To examine the relationship between apolipoprotein E (apoE) phenotype and life span, we measured the frequently of the apoE phenotype and allele in 54 Japanese centenarians who lived in the Tokyo metropolitan area in 1994, 1995, and 1996. The control group consisted of 973 subjects, 883 healthy volunteers who were described previously and 90 healthy people who came to the Keio health consulting center. The apoE phenotypes in the centenarians was 2 E2/E2 (3.7%), 5 E2/E3 (9.3%), 38 E3/E3 (70.4%), and 9 3E/E4 (16.7%). No other phenotype was observed. In the control group, the phenotypes were 2 E2/E2 (0.2%), 57 E2/E3 (5.9%) 712 E3/E3 (73.2%), and 179 E3/E4 (18.4%). The frequency of E2 was higher in the centenarians. The frequencies of the apoE allele in the centenarians and the control subjects were epsilon 2 8.3% vs. 3.5%, epsilon 3 83.3% vs. 85.4%, and epsilon 4 8.3% vs. 10.9%. The frequency of the apoE allele differed significantly between centenarians and control subjects (chi 2 = 6.84, p = 0.033). Levels of serum cholesterol and apolipoprotein B were significantly lower in the E2/E2 + E2/E3 centenarians. Studies of the frequency of the apoE allele in Japanese, French, and Finnish subjects showed that epsilon 2 is more frequent and epsilon 4 is less frequent in centenarians. These data show the apoE phenotype may affect life span: epsilon 2 is positively and epsilon 4 is negatively associated with longevity.

Insulin secretion and its modulation by antiarrhythmic and sulfonylurea drugs

Cardiovascular drugs such as antiarrhythmic agents with Vaughan Williams class Ia action have been found to induce a sporadic hypoglycemia. Recent investigation has revealed that these drugs induce insulin secretion from pancreatic beta-cells by inhibiting ATP-sensitive K+ (KATP) channels in a manner similar to sulfonylurea drugs. The mechanism underlying block of KATP channels by antiarrhythmic drugs was different, however, from that of sulfonylureas: firstly, because binding of radioactive glibenclamide could not be inhibited by unlabelled antiarrhythmic agents, and vice versa; secondly, because the two compounds differ in the kinetics and sidedness of drug action-antiarrhythmic drugs act on the channel from the inner surface of the cell membrane, whereas glibenclamide binds through the intramembrane pathway; finally, it was shown that functional KATP channels in beta-cells are composed of two distinct molecules-a sulfonylurea receptor (SUR) and a channel pore-forming subunit, an inwardly-rectifying K channel with two transmembrane regions (Kir6.2). Antiarrhythmic drugs reversibly inhibit the K+ conductance displayed by the Kir6.1 (a putative KATP channel clone)-transfected NIH3T3 cells. Therefore they appear to interact directly with the pore-forming subunit, thereby inhibiting KATP channel currents and exerting an insulinotrophic effect.

The large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is fragmented into 37-kDa and 16-kDa polypeptides by active oxygen in the lysates of chloroplasts from primary leaves of wheat

Lysates of chloroplasts isolated from wheat (Triticum aestivum L. cv. Aoba) leaves were incubated on ice (pH 5.7) for 0 to 60 min in light (15 mumol quanta m-2 s-1), and degradation of the large subunit (LSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco: EC 4.1.1.39) was analyzed by applying immunoblotting with site-specific antibodies against the N-terminal, internal, and C-terminal amino acid sequences of the LSU of wheat Rubisco. The most dominant product of the breakdown of the LSU and that which was first to appear was an apparent molecular mass of 37-kDa fragment containing the N-terminal region of the LSU. A 16-kDa fragment containing the C-terminal region of the LSU was concomitantly seen. This fragmentation of the LSU was inhibited in the presence of EDTA or 1,10-phenanthroline. The addition of active oxygen scavengers, catalase (for H2O2) and n-propyl gallate (for hydroxyl radical) to the lysates also inhibited the fragmentation. When the purified Rubisco from wheat leaves was exposed to a hydroxyl radical-generating system comprising H2O2, FeSO4 and ascorbic acid, the LSU was degraded in the same manner as observed in the chloroplast lysates. The results suggest that the large subunit of Rubisco was directly degraded to the 37-kDa fragment containing the N-terminal region and the 16-kDa fragment containing the C-terminal region of the LSU by active oxygen, probably the hydroxyl radical, generated in the lysates of chloroplasts.

[Tokyo Centenarian Study. 5. Nutritional status of Japanese centenarians]

To establish the guideline for nutrition in the very old, we analyzed biochemical and hematological data from 45 Japanese centenarians living in Tokyo metropolitan area during 1994 and 1995. Levels of cholesterol, HDL-cholesterol, apolipoprotein A1 and B, albumin, prealbumin in serum were lower than in a control group or lower than the reference range, which indicates that these centenarians were undernourished. RBC counts, hemoglobin, and hematocrit were also low in the centenarians. The concentration of albumin correlated positively with those of HDL-cholesterol and apolipoprotein A1, and negatively with concentration of Lp(a). The value for transferrin correlated positively with energy intake and with the concentration of apolipoprotein A1. The concentration of prealbumin correlated positively with the concentration of hemoglobin, hematocrit and the total cholesterol concentration. According to their nutritional status, the centenarians were divided into 2 groups: well-nourished and undernourished. Those who were well-nourished had higher levels of cholesterol, HDL, Hb, and apolipoprotein A1, their levels of ADL and cognitive function were also high. The findings of blood-chemical data in the centenarians may be partly due to undernutrition. Centenarians who were well-nourished were considered to be aging successfully. These results and others previously published indicate that the concentrations of albumin, prealbumin, transferrin and either CRI or IL-6 are useful for nutritional assessment in the very old.

Effects of concanavalin A on chondrocyte hypertrophy and matrix calcification

Resting chondrocytes do not usually undergo differentiation to the hypertrophic stage and calcification. However, incubating these cells with concanavalin A resulted in 10-100-fold increases in alkaline phosphatase activity, binding of 1,25(OH)2-vitamin D3, type X collagen synthesis, 45Ca incorporation into insoluble material, and calcium content. On the other hand, other lectins tested (including wheat germ agglutinin, lentil lectin, pea lectin, phytohemagglutinin-L, and phytohemagglutinin-E) marginally affected alkaline phosphatase activity, although they activate lymphocytes. Methylmannoside reversed the effect of concanavalin A on alkaline phosphatase within 48 h. Concanavalin A did not increase alkaline phosphatase activity in articular chondrocyte cultures. In resting chondrocyte cultures, succinyl concanavalin A was as potent as concanavalin A in increasing alkaline phosphatase activity, the incorporation of [35S]sulfate, D-[3H]glucosamine, and [3H]serine into proteoglycans, and the incorporation of [3H]serine into protein, although concanavalin A, but not succinyl concanavalin A, induced a rapid change in the shape of the cells from flat to spherical. These findings suggest that concanavalin A induces a switch from the resting, to the growth-plate stage, and that this action of concanavalin A is not secondary to changes in the cytoskeleton. Chondrocytes exposed to concanavalin A may be useful as a novel model of endochondral bone formation.

[Lipid and lipoprotein profile of Japanese centenarians--high prevalence of hypo beta lipoproteinemia]

To study the relationship between lipids and longevity, we examined the level of serum lipids and apolipoproteins, and the susceptibility of low density lipoprotein (LDL) to oxidation of 45 centenarians (15 men, 30 women, mean age 101.1 +/- 1.4) living in the Tokyo metropolitan area. The average levels of total cholesterol (TC), of LDL-C of high-density lipoprotein cholesterol (HDL-C), and of apolipoproteins A1 and B were significantly lower in centenarians than in healthy middle-aged controls. The frequency of hypobeta-lipoproteinemia (apoB < 60 mg/dl) in centenarians was almost ten times as high as in controls. The time course of copper-mediated LDL, oxidation (assessed by monitoring 234 nm diene absorption (lag time)) did not significantly differ between the two groups. Analysis of LDL subfractions by non-denaturated gradient-gel electrophoresis showed a predominance of large, buoyant LDL particles (pattern A) in 75%, and a predominance of small dense LDL particles (pattern B) in 25% of centenarians. We also assessed activities of daily living (ADL) and cognitive function in the centenarians. Centenarians were divided into two groups according to the median ADL score, and were classified into five groups with a scale clinical dementia. In subjects with good ADL scores, the mean concentration of HDL-3-C was significantly higher than in those with poor ADL scores. Average levels of HDL-C were also significantly lower in subjects with moderate or severe dementia than in those with normal cognitive function. These findings suggest that centenarians have protective phenotypes of lipids and lipoproteins that protect them from atheroscierosis.