Morphological studies on the translocation of tubulovesicular system toward the intracellular canaliculus during stimulation of the gastric parietal cell

The gastric parietal has two characteristic membrane systems. One is the intracellular canaliculus, which is specialized networks of enfolded luminal membrane channels lined with numerous microvilli. The other structures common to all parietal cells are the tubulovesicles or the tubulovesicular membranes, a system of tubules and vesicles. The tubulovesicular compartment is drastically depleted during maximal gastric acid secretion and this is coincident with an increase in the canalicular cell surface membrane. A plausible explanation for this redistribution is the fusion and transfer of tubulovesicular membranes to the plasma membrane. However, for many years there was no convincing evidence of connections between these two membrane systems. The mechanism of the transformation of tubulovesicular membrane into the plasma membrane without demonstrable connections has been an enigma to electron microscopists. Using a recently developed fixation technique for parietal cells [Sugai et al. (1995) Acta Anat Nippon 74:S101], we have investigated the organization of the cytoplasmic membrane systems in the rat resting and tetragastrin stimulated stomachs by ultra-high-resolution scanning electron microscopy (SEM). Gastric mucosae were microwave-fixed in a cacodylate buffer, (334 milliosmoles/kgH(2)O (mOsm)), to which 1.0% glutaraldehyde and 0.5% formaldehyde were added. Specimens examined by TEM of thin sections revealed the cytoplasm packed with tubular membranes similar to images detected by rapid-freeze/freeze-substitution fixation. To render the cytoplasmic membranes visible by SEM, fixed mucosae were treated by the aldehyde-osmium-DMSO-osmium maceration procedure. With much of the cell matrix and filaments removed, SEM revealed numerous 30-60-nm tubules, which formed a meshwork with small cisternae. Vesicles or isolated tubules were not found in adequately macerated parietal cells. The cytoplasmic surface of the intracellular canaliculus was smooth except for round openings representing the bases of macerated microvilli. In favorable sites, connections of the tubular membranes to the canaliculi were clearly visible. Stereo pair views were particularly useful to demonstrate these continuities. Connections between these two membrane compartments suggest the probability of rapid membrane transposition. In this article, the form and distribution of membrane systems of parietal cells in the resting state and after tetragastrin stimulation will be presented and discussed. Special emphasis is made to demonstrate connections between the tubulovesicular system and the intracellular canaliculus.

Improved generation of catalytic antibodies by MRL/MPJ-lpr/lpr autoimmune mice

To compare the abilities of different strains of mice to elicit catalytic antibodies (Abs), we determined the occurrence of esterolytic Abs in BALB/c (normal strain) and MRL/MPJ-lpr/lpr (MRL/lpr, autoimmune) mice after immunization with the transition state analog (TSA) 1. Hybridoma supernatants elicited against TSA 1 were screened by ELISA for binding to the BSA-conjugated TSA 1 (=3b), and then screened for binding to the BSA-linked short TSA 2 (=4). We obtained eight times more positives from MRL/lpr mice than from BALB/c mice by these screening steps. The monoclonal antibodies (mAbs) obtained here were examined for binding and catalytic activity. Fifteen of 25 mAbs from MRL/lpr had esterolytic activity, compared with only two of 21 mAbs from BALB/c. These results demonstrated that the occurrence of catalytic Abs was much higher in MRL/lpr mice than in BALB/c mice, which is in good agreement with the previous report by Tawfik et al. [Tawfik, D.S., Chap, R., Green, B.S., Sela, M., Eshhar, Z., 1995. Proc. Natl. Acad. Sci. U.S.A. 92, 2145-2149] using a different kind of TSA. Thus, these studies strongly suggest that using the appropriate strain can be a key factor in the efficient production of catalytic Abs. Furthermore, these mAbs were characterized to elucidate the mechanism of strain difference, and determine whether MRL/lpr mice can be used with other TSAs for the efficient production of catalytic Abs.

Antiplatelet drugs attenuate progression of carotid intima-media thickness in subjects with type 2 diabetes

The intima-media thickness of the carotid artery has been established as a surrogate of definite atherosclerosis in subjects with high risk of vascular events. This study was done to evaluate the effectiveness of long-term antiplatelet therapy in attenuating progression of the intima-media thickness of the carotid artery of subjects with type 2 diabetes. Subjects who had an intima-media thickness over the threshold of the normal subjects but showed no symptoms of vascular events were randomly divided into groups given antiplatelet drugs [ticlopidine (n = 34) or a small dose of aspirin (n = 40)] or no drugs (n = 74). For the follow-up period (3.0+/-0.06 years), the subjects not given antiplatelet drugs showed a significantly higher progression of intima-media thickness (0.067+/-0.009 mm/year) than those given ticlopidine (0.034+/-0.013 mm/year) or aspirin (0.033+/-0.010 mm/year). Stepwise multivariant regression analysis showed that long-term administration of ticlopidine or aspirin significantly reduced the progression of intima-media thickness of diabetic subjects by 0.041 mm/year or 0.032 mm/ year, respectively. These data indicated that despite differences of their pharmacological mechanisms, antiplatelet drugs could attenuate the progression of intima-media thickness of the carotid artery wall of asymptomatic type 2 diabetics who had early-stage carotid atherosclerosis.

Scanning EM of resting gastric parietal cells reveals a network of cytoplasmic tubules and cisternae connected to the intracellular canaliculus

Using a recently developed fixation technique for parietal cells (Sugai et al., Acta Anat Nippon 1995:70:S79, 1999:74:S101), we have reinvestigated the organization of the cytoplasmic membrane system in the resting stomach by ultra-high-resolution scanning electron microscopy (SEM). Rat gastric mucosae were microwave-fixed in cacodylate buffer [334 milliosmoles/kg H(2)O (mOsm)], to which 1.0% glutaraldehyde and 0.5% formaldehyde were added. Specimens examined by transmission electron microscopy (TEM) of thin sections revealed cytoplasm packed with tubular membranes similar to images detected by rapid-freeze/freeze-substitution fixation which is generally considered to cause minimal structural alterations. To render the cytoplasmic membranes visible by SEM, fixed mucosae were frozen, fractured, and the exposed cytoplasm of parietal cells was macerated by the aldehyde-osmium-DMSO-osmium procedure. With much of the cell matrix and filaments removed, SEM revealed numerous 30-60 nm tubules which formed a meshwork and also small cisternae. The cytoplasmic surface of the tubules was smooth while some cisternal areas had attached polyribosomes. Vesicles or isolated tubules were not found in appropriately macerated parietal cells. The cytoplasmic surface of the intracellular canaliculus was smooth except for round openings representing the bases of macerated microvilli. In favorable sites connections of the tubular membranes to the canaliculi were clearly visible. Stereo pair views were particularly useful to demonstrate these continuities. Connections between these two membrane compartments suggest the probability of rapid membrane transposition.

Important role of the hepatic vagus nerve in glucose uptake and production by the liver

We examined the role of the hepatic vagus nerve in hepatic and peripheral glucose metabolism. To assess endogenous glucose production (EGP), hepatic uptake of first-pass glucose infused intraportally (HGU), and the metabolic clearance rate of glucose (MCR), rats were subjected to hepatic vagotomy (HV, n = 7) or sham operation (SH, n = 8), after 10 days, they were then subjected to a euglycemic-hyperinsulinemic clamp together with a portal glucose load in the 24-hour fasting state. Metabolic parameters were determined by the dual-tracer method using stable isotopes. During the experiment, [6,6-2H2]glucose was continuously infused into the peripheral vein. To maintain euglycemia (4.5 mmol/L), insulin (54 pmol x kg(-1) x min(-1)) and glucose were infused peripherally after the 90-minute tracer equilibration and 30-minute basal periods, and glucose containing 5% enriched [U-13C]glucose was infused intraportally (50 micromol x kg(-1) x min(-1)) for 120 minutes (clamp period). EGP was significantly higher in HV rats versus SH rats during the basal period (64.3 +/- 7.6 v 43.6 +/- 5.3 micromol x kg(-1) x min(-1), P < .005)) and was comparable to EGP in SH rats during the clamp period (9.3 +/- 21.5 v 1.1 +/- 11.7 micromol x kg(-1) x min(-1)). HGU was reduced in HV rats compared with SH rats during portal glucose infusion (5.9 +/- 2.4 v 10.1 +/- 3.2 micromol x kg(-1) x min(-1)). The MCR in HV rats was significantly higher than in SH rats in the basal period (11.0 +/- 2.0 v 7.9 +/- 0.8 mL x kg(-1) x min(-1), P < .01)) and was comparable to the MCR in SH rats during the clamp period (41.9 +/- 10.0 and 36.6 +/- 5.7 mL x kg(-1) x min(-1)). We conclude that innervation of the hepatic vagus nerve is important for the regulation of hepatic glucose production in the postabsorptive state and HGU in the postprandial state.

Caldesmon isoform associated with phenotypic modulation of mesangial cells

Caldesmon (CaD) is a major calmodulin- and actin-binding protein distributed in smooth muscle cells (SMC) and nonmuscle cells. There are at least two high-molecular-weight CaD (h-CaD) isoforms and four low-molecular-weight CaD (l-CaD) isoforms produced by alternative splicing. Isoformal interconversion is associated with phenotypic modulations of vascular SMC. We investigated the CaD isoform in human and rat glomerular mesangial cells (MC) to characterize the phenotypic changes of MC involved in glomerular diseases. A Western blot analysis and reverse-transcription analysis using exon-specific primers revealed that one l-CaD isoform lacking exons 1, 3b and 4 was predominantly expressed in human cultured MC. The expression of this isoform was markedly enhanced in anti-Thy1.1 nephritis rats and streptozotocin-induced diabetic rats, while little expression was observed in the normal glomerulus. Isoformal interconversion did not occur during the phenotypic changes of MC. These data suggested that the activated MC resembled dedifferentiated SMC in terms of the CaD expression pattern, and that CaD is a useful marker of the phenotypic modulations of MC.

Genetic determinants of plasma triglyceride levels in (OLETF x BN) x OLETF backcross rats

Altered lipid metabolism is closely associated with diabetes in humans, although predisposing genetic factors that affect hyperlipidemia have not yet been clarified. Our previously established OLETF strain is an obese rat model of type II diabetes, exhibiting hypertriglycemia as well as hyperinsulinemia, hyperglycemia, insulin resistance, and abundant abdominal fat. To identify genetic factors responsible for dyslipidemic phenotypes in OLETF rats, we performed a whole-genome scan using 293 male (OLETF x BN) x OLETF backcross rats. Our analysis identified two significant quantitative trait loci (QTLs), on rat chromosomes 1 and 8, that are related to fasting triglyceride levels. The chromosome 1 QTL colocalized with Dmo1 (diabetes mellitus, OLETF type 1), a locus previously shown to associate strongly with both fat levels and body weight. The other significant QTL localizes to the chromosome 8 marker D8Mit2, in a region where several apo-lipoprotein genes are clustered.

Induction of glycation suppresses glucokinase gene expression in HIT-T15 cells

AIMS/HYPOTHESIS

Chronic hyperglycaemia in patients with Type II (non-insulin-dependent) diabetes mellitus often leads to a decline in glucose-responsive insulin secretion from pancreatic beta cells, a phenomenon called glucose toxicity. Upon hyperglycaemia, glycation reaction occurs in the beta cells and induces oxidative stress. To understand the molecular basis of the beta-cell glucose toxicity, we investigated the possible effects of glycation on the expression and enzymatic activity of glucokinase, which plays a crucial part in glucose-responsive insulin secretion.

METHODS

Glycation and reactive oxygen species were induced in HIT-T15 cells by treatment with D-ribose and effects on glucokinase gene transcription, glucokinase protein amount, glucose phosphorylation activity, and DNA-binding activities of putative glucokinase gene transcription factors were evaluated.

RESULTS

When glycation was induced in HIT-T15 cells, the activity of the human glucokinase gene beta-cell-type promoter was suppressed substantially (83% reduction at 60 mmol/l D-ribose). Also, similar reductions in mRNA and protein amounts of glucokinase and in the Vmax of its enzymatic activity were observed. In agreement with the reduction in the promoter activity, the two major transcription factors of the glucokinase gene, the Pal-binding factor and PDX-1, reduced their binding to their target sequences in the glucokinase gene promoter in glycation-induced HIT cells. Because these effects of D-ribose were counteracted by aminoguanidine or N-acetylcysteine, reactive oxygen species, generated by the glycation reaction, appears to be involved in the phenomena.

CONCLUSION/INTERPRETATION

The induction of the glycation reaction, which is known to occur in pancreatic beta cells in chronic hyperglycaemia, suppresses the glucokinase gene transcription and its enzymatic activity. Thus, hyperglycaemia-dependent inhibition of glucokinase activity could in part explain beta-cell glucose toxicity.

Impaired diurnal cardiac autonomic function in subjects with type 2 diabetes

OBJECTIVE

To assess diurnal cardiac sympathetic and parasympathetic nerve functions in diabetic subjects with variable diabetic neuropathy.

RESEARCH DESIGN AND METHODS

Frequency domain analysis of 24-h Holter ECG was done for 132 diabetic subjects (84 without any symptomatic neuropathy; 37 with only symptomatic peripheral neuropathy; 11 with symptomatic autonomic neuropathy) and 57 normal volunteers to calculate the low frequency (LF) component representing the beta-adrenoceptor function and the high frequency (HF) component representing the cardiac parasympathetic nerve function.

RESULTS

Cardiac LF and HF components in diabetic subjects without peripheral neuropathy showed values comparable to those of normal volunteers and a similar circadian rhythm. Diabetic subjects with peripheral neuropathy or autonomic neuropathy showed significantly depressed LF and HF components and loss of the circadian rhythm of LF and HF components compared with diabetic subjects without neuropathy. Impairment of the LF component in the afternoon could be accounted for by the duration of diabetes and elevated HbA1c level. Impairment of the HF component at night could be accounted for by the duration of diabetes but not an elevated HbA1c level.

CONCLUSIONS

These data indicated that diabetic subjects with peripheral neuropathy and diabetic subjects with symptomatic autonomic neuropathy, but not diabetic subjects without neuropathy, showed a marked decrease in cardiac sympathetic and parasympathetic nerve functions and loss of circadian rhythm.

Identification of a portable repression domain and an E1A-responsive activation domain in Pax4: a possible role of Pax4 as a transcriptional repressor in the pancreas

Pax4 is a paired-domain (PD)-containing transcription factor which plays a crucial role in pancreatic beta/delta-cell development. In this study, we characterized the DNA-binding and transactivation properties of mouse Pax4. Repetitive rounds of PCR-based selection led to identification of the optimal DNA-binding sequences for the PD of Pax4. In agreement with the conservation of the optimal binding sequences among the Pax family transcription factors, Pax4 could bind to the potential binding sites for Pax6, another member of the Pax family also involved in endocrine pancreas development. The overexpression of Pax4 in HIT-T15 cells dose dependently inhibited the basal transcriptional activity as well as Pax6-induced activity. Detailed domain mapping analyses using GAL4-Pax4 chimeras revealed that the C-terminal region of Pax4 contains both activation and repression domains. The activation domain was active in the embryonic kidney-derived 293/293T cells and embryonal carcinoma-derived F9 cells, containing adenoviral E1A protein or E1A-like activity, respectively but was inactive or very weakly active in other cells including those of pancreatic beta- and alpha-cell origin. Indeed, the exogenous overexpression of type 13S E1A in heterologous cell types could convert the activation domain to an active one. On the other hand, the repression domain was active regardless of the cell type. When the repression domain was linked to the transactivation domain of a heterologous transcription factor, PDX-1, it could completely abolish the transactivation potential of PDX-1. These observations suggest a primary role of Pax4 as a transcriptional repressor whose function may involve the competitive inhibition of Pax6 function. The identification of the E1A-responsive transactivation domain, however, indicates that the function of Pax4 is subject to posttranslational regulation, providing further support for the complexity of mechanisms that regulate pancreas development.

Beneficial effects of antioxidants in diabetes: possible protection of pancreatic beta-cells against glucose toxicity

Oxidative stress is produced under diabetic conditions and possibly causes various forms of tissue damage in patients with diabetes. The aim of this study was to examine the involvement of oxidative stress in the progression of pancreatic beta-cell dysfunction in type 2 diabetes and to evaluate the potential usefulness of antioxidants in the treatment of type 2 diabetes. We used diabetic C57BL/KsJ-db/db mice, in whom antioxidant treatment (N-acetyl-L-cysteine [NAC], vitamins C plus E, or both) was started at 6 weeks of age; its effects were evaluated at 10 and 16 weeks of age. According to an intraperitoneal glucose tolerance test, the treatment with NAC retained glucose-stimulated insulin secretion and moderately decreased blood glucose levels. Vitamins C and E were not effective when used alone but slightly effective when used in combination with NAC. No effect on insulin secretion was observed when the same set of antioxidants was given to nondiabetic control mice. Histologic analyses of the pancreases revealed that the beta-cell mass was significantly larger in the diabetic mice treated with the antioxidants than in the untreated mice. As a possible cause, the antioxidant treatment suppressed apoptosis in beta-cells without changing the rate of beta-cell proliferation, supporting the hypothesis that in chronic hyperglycemia, apoptosis induced by oxidative stress causes reduction of beta-cell mass. The antioxidant treatment also preserved the amounts of insulin content and insulin mRNA, making the extent of insulin degranulation less evident. Furthermore, expression of pancreatic and duodenal homeobox factor-1 (PDX-1), a beta-cell-specific transcription factor, was more clearly visible in the nuclei of islet cells after the antioxidant treatment. In conclusion, our observations indicate that antioxidant treatment can exert beneficial effects in diabetes, with preservation of in vivo beta-cell function. This finding suggests a potential usefulness of antioxidants for treating diabetes and provides further support for the implication of oxidative stress in beta-cell dysfunction in diabetes.

Identification of oxidative stress-regulated genes in rat aortic smooth muscle cells by suppression subtractive hybridization

A suppression subtractive hybridization technique was used to identify reactive oxygen species (ROS)-regulated genes in rat vascular smooth muscle cells. Three genes out of 89 clones, identified as fibronectin, p105 coactivator and ECA39, showed increased expression after treatment with H(2)O(2). The mRNA expressions of these three genes were induced in a time- and dose-dependent manner, independent of protein kinase C activation. Immunohistochemical staining showed that the p105 coactivator expression was markedly induced in the neointima of balloon-injured rat carotid arteries. These results suggest that ROS may play an important role in the development of atherosclerosis by regulating the gene expressions we identified in this study.

The role of surgery in renal cell carcinoma with solitary metachronous metastasis to contralateral adrenal gland

We report a case of renal cell carcinoma with solitary metachronous metastasis to contralateral adrenal gland occurring 9 months after radical nephrectomy. The patient was treated with a contralateral adrenalectomy and is alive for 87 months. The literature was reviewed and 5-year survival of solitary metachronous metastasis to contralateral adrenal gland was 60%. Follow-up duration of our case was the longest in the literature. It is suggested that the solitary contralateral adrenal gland metastasis of renal cell carcinoma should be resected since there is no effective treatment of metastatic renal cell carcinoma. Good prognosis may be then and the good be expected.

Pilot study on the effect of a mouthrinse containing silver zeolite on plaque formation

A double-blind cross-over study was performed to evaluate the inhibitory activity of silver zeolite (SZ) mouthrinse on plaque formation. Eleven dental students participated in this study. SZ mouthrinse was prepared by suspending SZ powder into phosphate-buffered saline (PBS) at a concentration of 3% (w/w). Type-A zeolite was used as a placebo. Before the experiment, the subjects were rendered plaque-free by professional prophylaxis. They then suspended any oral hygiene for five days, during which time they rinsed with either SZ or type-A zeolite mouthrinse twice a day. SZ significantly reduced plaque formation compared to the placebo (p < 0.05), suggesting that silver ions released from the SZ inhibited plaque formation.

Insulin resistance contributes to carotid arterial wall thickness in patients with non-insulin-dependent-diabetes mellitus

The aim of this study was to clarify whether insulin resistance contributes to atherosclerosis in patients with non-insulin-dependent diabetes mellitus (NIDDM). Fifty-three NIDDM patients (36 males and 17 females, 53+/-10 years old (mean+/-SD)) were studied. As an index of atherosclerosis, we measured the average thickness (IMT) as well as basal thickness excluding the maximum thickness and the height of the maximum thickness of the carotid artery wall. Euglycemic hyperinsulinemic glucose clamp was conducted for 90 min to evaluate average glucose infusion rate (GIR) as an index of insulin sensitivity in the peripheral tissues. For another 180 min after intake of oral glucose load with 0.3 g/kg, the euglycemic hyperinsulinemic clamp was continued to measure ratio of splanchnic glucose uptake (SGU) as an index of insulin sensitivity of the liver. The patients were separated into three activity groups according to the grade of their leisure-time physical activity. GIR (r = -0.32, p < 0.05) but not SGU (r=0.139) showed a significant inverse relationship with IMT. Multivariant regression analysis indicated that age and total cholesterol remain as independent risk factors for basal thickness and GIR as only independent risk factor for the height of the maximum thickness. Paralleling the degrees of habitual exercise (low, moderate, and high active group), GIR was higher (6.19+/-1.02, 6.38+/-1.38, 7.44+/-1.80, respectively) and IMT was lower (1.34+/-0.33 mm, 1.20+/-0.31 mm, and 1.12+/-0.29 mm, respectively) in male NIDDM as well as in female NIDDM. These data suggest that insulin resistance in the peripheral tissues but not the splanchnic tissues may independently contribute to carotid arterial wall thickness and especially to plaque lesion, and that habitual exercise might reduce insulin resistance leading to attenuation of atherosclerosis.

Metabolic suppression of platelet-type 12-lipoxygenase in human uterine cervix with invasive carcinoma

Several types of lipoxygenases with various functions occur in mammalian cells. Although the presence of 12-lipoxygenase activity has been reported in uterine tissues, neither its type nor its biological functions have yet been established. Moreover, the putative role of uterine 12-lipoxygenase in cervical cancer has not been addressed before. Homogenates of uterine tissues from women without cancer and from patients with invasive cervical carcinoma were incubated with (1-(14)C)-arachidonic acid under various conditions and the labelled reaction products were analyzed both by thin-layer chromatography and by high-pressure liquid chromatography. 12-Lipoxygenase protein was estimated by Western blot using anti-serum against recombinant human platelet-type 12-lipoxygenase. Highest concentrations and activities of 12-lipoxygenase were found in the exocervix. The formation of 12S-hydroxy-5Z,8Z,10E, 14Z-eicosatetraenoic acid (12-HETE) was stimulated by micromolar concentrations of 13S-hydroperoxy-9Z,11E-octadecadienoic acid, suggesting metabolic control of the 12-lipoxygenase activity via the hydroperoxide tone. Immunohistochemical investigation revealed that the enzyme is mainly located in the squamous epithelium, and is of platelet-type. Significantly lower values for the 12-HETE formation were found in samples from patients with invasive cervical carcinoma, whereas the amount of immunochemically detectable 12-lipoxygenase protein was unaltered. At the same time the expression levels of the bcl-2 gene were enhanced. Thus, it is concluded that during carcinogenesis the hydroperoxide-reducing capacity of the uterine cervix tissue is enhanced, possibly mediated by bcl-2 protein, and in turn metabolically suppresses the 12-lipoxygenase activity. Furthermore, the data suggest an anti-carcinogenic action of 12-lipoxygenase in human cervix, in contrast to its reported pro-carcinogenic action in breast cancer.

Impaired splanchnic and peripheral glucose uptake in liver cirrhosis

BACKGROUND/AIM

Patients with liver cirrhosis are insulin-resistant and frequently glucose-intolerant. Although peripheral glucose uptake has been shown to be impaired in liver cirrhosis, little is known about the significance of splanchnic (hepatic) glucose uptake after oral glucose load.

METHODS/RESULTS

We performed an oral glucose tolerance test and euglycemic hyperinsulinemic clamp with oral glucose load for eight patients with liver cirrhosis and eight patients with chronic active hepatitis. The patients with liver cirrhosis had higher plasma glucose levels 2 h after glucose load than those with chronic active hepatitis (228+/-22 mg/dl vs. 102+/-9 mg/dl, p<0.01). Using the euglycemic hyperinsulinemic clamp with oral glucose load, we simultaneously measured peripheral and splanchnic glucose uptake. Peripheral glucose uptake in liver cirrhosis was 6.1+/-0.7 mg x kg(-1) x min(-1), which was lower than that in healthy volunteers (10.5+/-0.9 mg x kg(-1) x min(-1), p<0.05) and in chronic active hepatitis (8.4+/-0.3 mg x kg(-1) x min(-1), p<0.05). Furthermore, splanchnic glucose uptake in liver cirrhosis was much lower (20.1+/-3.4%) than in healthy volunteers (36.0+/-4.0%, p<0.05) and in chronic active hepatitis (37.2+/-3.1%, p<0.05).

CONCLUSION

These results suggest that glucose intolerance in patients with liver cirrhosis is caused by a defect of the glucose uptake of both splanchnic and peripheral tissues.

Oxidative stress induces p21 expression in pancreatic islet cells: possible implication in beta-cell dysfunction

AIMS/HYPOTHESIS

Prolonged poor glycaemic control in patients with Type II (non-insulin-dependent) diabetes mellitus often causes pancreatic beta-cell dysfunction accompanied by decreases in insulin biosynthesis and beta-cell proliferation. This is well known as a clinical concept called glucose toxicity. Whereas oxidative stress is provoked under diabetic conditions, we examined the possible implication of cyclin-dependent kinase (Cdk) inhibitor p21 (WAF1/CIP1/Sdi1) in beta-cell dysfunction mediated by oxidative stress.

METHODS

Oxidative stress was induced in isolated rat pancreatic islet cells by treatment with H(2)O(2) and mRNA expression of p21 and insulin was examined by northern blot analyses. Also, the expression of p21 and insulin mRNA was examined in Zucker diabetic fatty rat. In islet cells p21 was overexpressed using adenovirus and its effect on insulin gene transcription was examined.

RESULTS

When oxidative stress was charged on isolated rat pancreatic islet cells, p21 mRNA expression was induced whereas insulin mRNA was decreased. Also, when diabetes developed in Zucker diabetic fatty rats, p21 expression was induced and the insulin mRNA expression was reduced. As support for the implication of p21 in impairment of beta-cell function, the p21 overexpression in the islet cells suppressed the insulin gene transcription.

CONCLUSIONS/INTERPRETATION

The expression of cyclin-dependent kinase inhibitor p21, which can be induced by oxidative stress, increases in pancreatic islet cells upon development of diabetes. By suppressing cell proliferation and insulin biosynthesis, the p21 induction is likely to be implicated in the beta-cell glucose toxicity.

Development of a hepatocyte-specific prostaglandin E(1) polymeric prodrug and its potential for preventing carbon tetrachloride-induced fulminant hepatitis in mice

A polymeric prodrug of prostaglandin E(1) (PGE(1)) was synthesized using galactosylated poly(L-glutamic acid hydrazide) (Gal-HZ-PLGA) as a biodegradable and targetable carrier to hepatocytes. Poly(L-glutamic acid hydrazide) was prepared by reacting poly(gamma-benzyl-L-glutamate) with hydrazine monohydrate, followed by reaction with 2-imino-2-methoxyethyl-1-thiogalactosides to obtain Gal-HZ-PLGA after i.v. injection. (111)In-labeled galactosylated poly(L-glutamic acid hydrazide) ((111)In-Gal-HZ-PLGA) rapidly accumulated in the liver in a dose-dependent manner, whereas (111)In-poly(L-glutamic acid hydrazide) did not, indicating the involvement of a galactose-specific mechanism in the uptake of (111)In-Gal-HZ-PLGA. Fractionation of liver cells revealed that (111)In-Gal-HZ-PLGA was preferentially taken up by liver parenchymal cells. After being taken up by the liver, (111)In-Gal-HZ-PLGA was gradually degraded, and radioactive metabolites with low molecular weight were detected within 10 min after injection. Then, PGE(1) or [(3)H]PGE(1) was coupled to Gal-HZ-PLGA via a hydrazone bond under mild conditions to obtain PGE(1) conjugate. After i.v. injection, [(3)H]PGE(1) conjugate was rapidly taken up by the liver (more than 80% of the dose). After injection of the conjugate, (3)H radioactivity remained in the liver, representing about 70% of the dose, even at 24 h, whereas little radioactivity remained in the organ at 1 h after the injection of free [(3)H]PGE(1). Finally, its pharmacological activity was examined in mice with fulminant hepatitis induced by peritoneal injection of carbon tetrachloride. The i.v. injection of PGE(1) conjugate at a dose of 1 mg (0.074 mg PGE(1))/kg effectively inhibited the increase of plasma glutamic pyruvic transaminase activity, whereas twice this dose (0.15 mg/kg) of free PGE(1) had little effect. These results suggest that the PGE(1) conjugate is an excellent polymeric prodrug of PGE(1) for hepatitis therapy.

Polymorphism in the tumor necrosis factor B gene is associated with Palmoplantar pustulosis

We investigated the allele and genotype distribution of a polymorphism of the tumor necrosis factor (TNF) B gene and the frequency of HLA-DR9 in 49 patients with Palmoplantar pustulosis (PPP) and 51 healthy controls. We found that the frequency of TNFB2 in the PPP patients was significantly higher than that in the controls. Furthermore, the DR9-TNFB2 haplotype was significantly more frequent in the PPP patients (P=0.0045). These results suggest that TNFB2 may confer susceptibility to PPP.

Overexpression of the aldose reductase gene induces apoptosis in pancreatic beta-cells by causing a redox imbalance

To determine the role of the polyol metabolizing pathway under hyperglycemic conditions, the effects of aldose reductase (AR) on the cellular functions of pancreatic beta-cells were examined. Stable transfectants of rat AR cDNA were obtained with a pancreatic beta-cell line, HIT, in which a negligible amount of AR was originally expressed. Overproduction of AR triggered DNA fragmentation, as judged with the TUNEL method and agarose gel electrophoresis. Morphological analysis by electron microscopy also clearly showed apoptosis of the AR-overexpressing HIT cells. Induction by interleukin-1beta of gene expression such as those of an inducible form of nitric oxide synthase (NOS-II) and Mn-superoxide dismutase (Mn-SOD), was much lower in the transfectants than in the control cells, while the expression of constitutively expressed genes such as those for Cu,Zn-superoxide dismutase and insulin was not changed. The susceptibility to interleukin-1beta stimulation of the expression of the NOS II and Mn-SOD genes was due to suppressed NF-kappaB activity, which is essential for the expression of these genes. In addition, the intracellular NADPH/NADP+ ratio was considerably lower in the AR-transfected cells than in control cells. Thus, the overexpression of AR in pancreatic beta-cells induced apoptosis that may be caused by a redox imbalance.

Severe impairment of B cell function in lpr/lpr mice expressing transgenic Fas selectively on B cells

Transgenic lpr/lpr mice expressing functional Fas selectively on B cells were produced in an attempt to elucidate the role of Fas on B cells in the regulation of autoantibody production. The homozygous lpr/lpr mice carrying the transgene did not produce anti-double-stranded DNA antibodies throughout their lives, whereas the development of abnormal lpr T cells (double negative, B220(+)) was not suppressed. Further analyses, however, revealed that the expression of the transgenic Fas on B cells of lpr/lpr homozygous mice resulted in severe impairment of the B cell function. The defect was characterized by a decrease in the number of mature peripheral B cells, a reduction in the serum Ig level and the total failure of B cells to mount antibody responses to stimulations of T-dependent as well as T-independent antigens. Such a defect was prominent only when the transgene was expressed on the lpr/lpr homozygous background. On the contrary, B cells of the transgenic lpr/lpr mice were shown to be capable of producing Ig when stimulated with anti-CD40 in the presence of IL-4 and IL-5. Furthermore, lpr/lpr T cells showed enhanced non-specific cytolytic activity. These observations suggested that the observed B cell defect was probably attributable to the destruction of activated B cells expressing transgenic Fas by aggressive lpr/lpr T cells.

Genetic dissection of "OLETF," a rat model for non-insulin-dependent diabetes mellitus: quantitative trait locus analysis of (OLETF x BN) x OLETF

To identify genetic determinants relevant to non-insulin-dependent diabetes mellitus (NIDDM), we performed a genome-wide analysis for quantitative trait loci (QTLs) using 359 backcross progeny of the Otsuka Long-Evans Tokushima Fatty (OLETF) rat. The OLETF strain is a well-studied animal model of obese NIDDM, with features of hyperinsulinemia, hyperglycemia, insulin resistance, and abundant abdominal fat. Our extensive genomic scanning with 218 markers revealed nine significant QTLs, including a strong determinant of obesity on chromosome 1 (Dmo1: LOD = 13.99, for body weight). Two highly significant QTLs for glucose homeostasis were found, one on chromosome 1 (Dmo4 LOD = 7.16, for postprandial glucose level) and the other on chromosome X (Dmo11/Odb1: LOD = 7.81, for postprandial glucose level). These data are comparable to results of our previous studies of the OLETF rat.

A radiation hybrid map of the rat genome containing 5,255 markers

A whole-genome radiation hybrid (RH) panel was used to construct a high-resolution map of the rat genome based on microsatellite and gene markers. These include 3,019 new microsatellite markers described here for the first time and 1,714 microsatellite markers with known genetic locations, allowing comparison and integration of maps from different sources. A robust RH framework map containing 1,030 positions ordered with odds of at least 1,000:1 has been defined as a tool for mapping these markers, and for future RH mapping in the rat. More than 500 genes which have been mapped in mouse and/or human were localized with respect to the rat RH framework, allowing the construction of detailed rat-mouse and rat-human comparative maps and illustrating the power of the RH approach for comparative mapping.

Clinical significance of mdm2 and p53 expression in bladder cancer. A comparison with cell proliferation and apoptosis

BACKGROUND

Clinical significance of immunohistochemically detectable level of p53 protein has been reported, but with some limitation as a prognosticator of bladder cancer patients. Whether or not simultaneous evaluation of mdm2 and p53 expression in bladder cancer exceed the prognostic significance of conventional histological findings, cell proliferation markers and apoptotic parameters remains unclear.

MATERIALS AND METHODS

The paraffin-embedded materials taken from 84 patients with transitional cell carcinoma of the bladder who were treated with total cystectomy were used in this study. Immunostainings of p53 protein, mdm2 protein and Ki67 antigen were performed using monoclonal antibodies (clone DO7, clone 1B10 and clone MIB1, respectively). In addition, the apoptotic cells were determined using a terminal deoxynucleotidyl transferase (TdT) mediated dUTP biotin nick end labeling (TUNEL) technique. The results were quantitatively evaluated using a CAS 200 Image Analyzer (Cell Analysis System, Elmhurst, Ill., USA) and were compared with histological findings and clinical course.

RESULTS

The mean values of mdm2 expression, p53 immunoreactivity, Ki67 expression and apoptotic index were 19.2, 20.5, 22.4 and 0.96%, respectively. Histological grade and pT category were significantly positively correlated with 53 immunoreactivity (p < 0.05 and p < 0.05, respectively), Ki67 expression (p < 0.005 and p < 0.0001, respectively) and apoptotic index (p < 0.01 and p < 0.0001, respectively), while both were not correlated with mdm2 expression. Using univariate analysis, the prognostic relevance for both survival and disease progression was noted in histological grade, pT category, p53 expression, Ki67 index and apoptotic index, whereas it was not in mdm2 expression. However, when analyzing the simultaneous evaluation of mdm2 and p53 expression (mdm2-p53 category), the relationship of the mdm2-p53 category with Ki67 expression and apoptotic index showed a statistical significance and a borderline significance (p = 0.0085 and p = 0.0652, respectively). In addition, the patients with both mdm2(-) and p53(-) showed a significant better prognosis as compared with either counterpart of mdm2-p53 category (p < 0.05 for both). Multivariate analysis revealed only pT category and mdm2-p53 category as independent factors for both disease progression and survival.

CONCLUSIONS

Clinical significance of simultaneous evaluation of mdm2 and p53 immunostaining proved to be superior over that of cell proliferation and/or apoptotic markers when elucidating the biological characteristics of bladder cancer.

A calculation method for the range of occluding phase at the lower incisal point during chewing movements using the curved mesh diagram of mandibular excursion (CMDME)

The purpose of this study was to develop a method for calculating the range of the occluding phase in chewing movements. In this study, we defined 'range' as the distance of the movement at the lower incisal point while the mandible moves with tooth contact. First, mandibular excursions were measured using an opto-electronic movement analysis system, which can measure mandibular movement with six degrees-of-freedom at a sampling frequency of 100 Hz. With use of this measurement data, the curved mesh diagram of mandibular excursion (CMDME) previously reported was made. Then, chewing movements were measured using the same analysis system. The movements were separated into their component chewing cycles. Finally, we calculated the distance between each cycle and the CMDME. The occluding range of our subject was 0.4 mm at the closing phase and 3.4 mm at the opening phase. These results suggest that tooth contact occurs during chewing movement and demonstrate that the range of the occluding phase for the opening and closing phases of a subject can be calculated without morphological data from a dental cast.

Disposition characteristics of glycosylated poly(amino acids) as liver cell-specific drug carrier

Potentials of glycosylated poly(amino acids) as carriers of drugs and/or polynucleotides to the liver were studied in mice in detail. Poly-L-glutamic acid (PLGA) and poly-L-lysine (PLL) were selected as carrier backbones and modified with 2-imino-2-methoxyethyl 1-thiogalactoside or mannoside to obtain galactosylated and mannosylated derivatives. After intravenous injection in mice at a dose of 1 mg/kg, Gal-PLGA and Man-PLGA were selectively taken up by the liver parenchymal cells (PC) and liver nonparenchymal cells (NPC), respectively. Moreover, the uptake of Gal-PLGA and Man-PLGA by the liver were significantly inhibited by the presence of Gal-BSA and Man-BSA, respectively. On the other hand, PLL was targeted to the liver without glycosylation. However, Gal-PLL and Man-PLL showed higher accumulation in the liver than unmodified PLL. Although Gal-PLL and Man-PLL showed different distribution between PC and NPC from that of PLL, the effect of the modifications was less pronounced than the cases of PLGA derivatives. In addition, these glycosylated poly(amino acids) investigated, regardless of the type of amino acid or the sugar grafted, were rapidly degraded to be eluted in the low molecular weight fractions in a gel filtration chromatography. These results suggest that glycosylated PLGAs can be useful carriers of low molecular drugs to the liver cells through conjugation, while glycosylated PLLs could be targetable carriers to the cells after the reduction of their cationic charge by complex formation with polynucleotides.

[Allogeneic peripheral blood stem cell transplantation in an elderly patient with myelodysplatic syndrome with myelofibrosis]

Allogeneic peripheral blood stem cell transplantation (Allo-PBSCT) has in recent years become an alternative to allogeneic bone marrow transplantation because it facilitates rapid hematopoietic reconstitution without an increase in the incidence of severe graft-versus-host disease (GVHD). We report on a 61-year-old man with myelodysplastic syndrome (MDS) and myelofibrosis who received an allo-PBSCT from his HLA-matched 68-year-old brother. The preparative regimen consisted of busulfan and cyclophosphamide. Cyclosporin A and methotrexate were administered for GVHD prophylaxis. The donor was treated with granulocyte colony-stimulating factor (G-CSF) at a dose of 10 micrograms/kg/day subcutaneously for 4 consecutive days. A preparation of 4.04 x 10(6) CD34+ cells/kg recipient weight was collected in a single apheresis and infused immediately. Engraftment times to a neutrophil count greater than 500/microliter and platelet count greater than 2.0 x 10(4)/microliter were 15 days each. Acute GVHD of grade II developed, but was resolved with methylprednisolone. However, the patient died of thrombotic microangiopathy 97 days after his allo-PBSCT. Administration of G-CSF and apheresis in the donor were feasible and well tolerated. Allo-PBSCT may result in earlier engraftment and be especially beneficial to elderly patients with MDS.

The development of autoimmune inflammatory arthropathy in mice transgenic for the human T cell leukemia virus type-1 env-pX region is not dependent on H-2 haplotypes and modified by the expression levels of Fas antigen

Previously, we reported that human T cell leukemia virus type-1 env-pX region-introduced transgenic (pX-Tg) mice develop an inflammatory polyarthropathy. Although autoimmune pathogenesis was suggested, the detailed mechanisms remain to be elucidated. In this report, we examined effects of the MHC and fas genes on the development of the disease. When pX-Tg mice were backcrossed with different inbred strains, the incidence of arthritis differed among strains; 64% and 72% in BALB/cAn (H-2d), 25% and 46% in C3H/HeN (H-2k), and 0% and 2% in C57BL/6J (H-2b) background at 3 and 6 months of age, respectively. Rheumatoid factor levels in the serum correlated with the susceptibility to the disease, whereas IL-1beta and MHC gene expression were similarly elevated in all of these strains, suggesting involvement of immune regulatory genes in this strain difference. However, introduction of the H-2d locus into C57BL/6J pX-Tg mice did not increase the incidence of arthritis, and substitution of the BALB/cAn H-2 locus with the H-2b did not decrease it. The results indicate that the H-2 locus is not the major determinant of the disease. Then, since previous study indicated a defect in Fas-mediated apoptosis of transgenic T cells, the effects of fas gene modification on the disease were examined. The incidence increased when these pX-Tg mice were crossed with lpr/lpr mice, while it decreased when crossed with fas-transgenic mice. These observations suggest that aberration of Fas-mediated apoptosis of peripheral lymphocytes, rather than negative selection in the thymus, is involved in the development of autoimmune arthropathy in pX-Tg mice.

Mechanism of impaired left ventricular wall motion in the diabetic heart without coronary artery disease

OBJECTIVE

To elucidate whether impairment of the myocardial free fatty acid (FFA) metabolism and small vessel abnormalities in the myocardium are etiologic or contributory factors of myocardial dysfunction in patients with NIDDM without any significant coronary artery disease.

RESEARCH DESIGN AND METHODS

We performed myocardial imaging with 123I-labeled beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a branched analog of FFA, and dipyridamole-infusion 201thallium scintigraphy (Dip) in nine patients who demonstrated left ventricular wall motion abnormalities without any significant coronary artery disease and in fifteen control cases. As an index of myocardial FFA metabolism, the heart-to-mediastinum count ratio (H/M) of BMIPP was calculated from the mean count in the regions of interest at the heart and the upper mediastinum.

RESULTS

Nine patients with reduced wall motion documented by left ventriculography (LVG), (hypokinetic group) demonstrated significantly lower BMIPP uptake (2.1 +/- 0.2, mean +/- SD) than fifteen patients with normal wall motion (normokinetic group) (2.3 +/- 0.2, P < 0.05). Regional ventricular wall motion observed by LVG, regional BMIPP uptake, and regional redistribution phenomenon (RD) were evaluated for five regions of the left ventricle: anterior, septal, apical, lateral, and inferoposterior regions. Wall motion was abnormal in 24 out of 120 regions. Regional BMIPP uptake was reduced in 47 regions. RD in Dip was observed in 23 regions. In regional analysis, the existence of defect in the BMIPP image showed significant correlation with wall motion abnormality (P < 0.01), but there was no significant relationship between the RD in Dip and regional wall motion abnormality (P = 0.16). Myocardial biopsy specimens obtained from the right ventricle of 20 patients showed no pathologic changes, with the exception of two patients.

CONCLUSIONS

Our findings suggest that impairment of myocardial FFA metabolism rather than small vessel abnormalities in the myocardium is responsible for modest left ventricular dysfunction in patients with diabetes.

Effect of troglitazone on microalbuminuria in patients with incipient diabetic nephropathy

OBJECTIVE

Although some studies have suggested a direct action of troglitazone on vascular cells, its effects on diabetic vascular diseases have not been reported. We therefore investigated the effect of troglitazone on microalbuminuria in patients with incipient diabetic nephropathy.

RESEARCH DESIGN AND METHODS

A total of 30 patients with type 2 diabetes associated with microalbuminuria (urinary albumin-to-creatinine ratio [ACR] [milligrams per gram creatinine] ranging from 30 to 300 mg/g creatinine) were studied. They were randomly divided into two groups: patients treated with metformin (500 mg/day, n = 13) or with troglitazone (400 mg/day, n = 17) for 12 weeks. ACR, lipid profile, blood pressure, glycated hemoglobin, and plasma glucose during meal-load tests were measured every 4 weeks.

RESULTS

Anthropometric indices (BMI and percent fat), lipid profile, and blood pressure did not change with either treatment. Fasting and postmeal glucose levels decreased similarly in the two groups. Decrements in glycated hemoglobin were greater in the metformin group at 4 and 8 weeks after the initiation of treatment (P < 0.05). Troglitazone reduced ACR (median [25-75th percentiles]) from 70 (49-195) to 40 (31-90) mg/g creatinine at 4 weeks (P = 0.021) and maintained these reduced levels throughout the treatment period (8 weeks: 35 [26-68], P = 0.007; 12 weeks: 43 [26-103], P = 0.047). Metformin did not change ACR throughout the 12 weeks.

CONCLUSIONS

Troglitazone ameliorated microalbuminuria in diabetic nephropathy. Furthermore, our findings suggest that troglitazone has some effects on vascular cells other than lowering plasma glucose levels. Troglitazone might be useful for diabetic angiopathy, including nephropathy and coronary artery disease.

Service-mix in general dental practice in Japan: a survey in a suburban area

Overseas investigations have reported the amount and variety of dental services provided. An understanding of the current service-mix in private general practice is important in the anticipation of the future practice of dentistry. The main purpose of this study was to describe the service-mix of private general practitioners in Japan, which was recorded using the Australian Dental Association Dental Procedure Code. Some comparisons with previous studies were offered. The youngest age group and adolescents formed only a small percentage of the total patients, while the greatest percentage of patients occurred in the 45-64 year age group. The services provided were mainly restorative, diagnostic advanced restorative and endodontic services. Preventive services represented a minority of dental activity, especially for young patients. Periodontic and orthodontic services were also remarkable for their low percentage in all age groups. In comparison with an Australian study, the percentage of preventive services was considerably lower. Movement toward a preventive emphasis in Japanese dentistry requires a change in the clinical model, de-emphasizing biomedical and aetiological approaches and placing greater emphasis on the patient and factors affecting dental practice.

Chest wall repair with a titanium instrument

We performed chest wall repair with titanium alloy instruments as artificial ribs for prevention of paradoxical respiration and protection of the lung and liver after chest wall resection including the nearly entire length of the right seventh to the eleventh ribs and the costal arch for metastasis of osteosarcoma. The technique of this operation is presented diagrammatically.

[Allogeneic peripheral blood stem cell transplantation in 30 patients with hematologic disorders]

Thirty patients (median age of 32 years; range, 6-61) with hematologic disorders received unmanipulated peripheral blood stem cell transplants from HLA-matched or one-antigen-mismatched related donors following myeloablative therapy for acute lymphoblastic leukemia (7), acute myelogenous leukemia (6), chronic myelogenous leukemia (8), myelodysplastic syndrome (3), or other disorders (6). Granulocyte colony stimulating factor (G-CSF) mobilized peripheral blood stem cells were collected from donors in 1 to 3 aphereses. The apheresis products contained mean counts of 11.3 x 10(8) (range, 3.8-17.2) nucleated cells/kg and 6.7 x 10(6) (range, 1.3-16.7) CD34+ cells/kg. Graft-versus-host-disease (GVHD) prophylaxis consisted of cyclosporin A plus methotrexate, or FK506 plus methotrexate. All patients received G-CSF following their transplant. Although 1 patient died of pneumonia 6 days after transplantation, the others demonstrated rapid engraftment. Median days to recovery to 500/microliter neutrophils and 20,000/microliter platelets were 13 (range, 8-21) and 14 (range, 1-23) days, respectively. The incidence of acute GVHD grade II-IV was 33%; chronic GVHD developed in 57% of the assessable patients. There were no episodes of graft failure or rejection. Nineteen patients (63%) were alive and in complete remission from 147 to 839 days following their transplant (median follow-up of 560 days). Further follow-up study will be required to assess the incidence of chronic GVHD and graft-versus-leukemia (GVL) effects.

Disappearance of AML1-MTG8 transcript by reverse transcriptase polymerase chain reaction in a patient in remission of acute myeloid leukemia (M2) after low-dose cytosine arabinoside

It is well-known that low dose cytosine arabinoside (LDAC) has activity in elderly patients with acute myeloid leukemia (AML). Several studies have shown that AML patients with t(8;21) in long term complete remission (CR) following intensive chemotherapy or allogeneic bone marrow transplantation (BMT) still have persistence of AML1-MTG8 transcripts by reverse transcriptase polymerase chain reaction (RT-PCR) method. We report here a patient who has no evidence of residual disease detectable by RT-PCR after LDAC. A 69-year-old patient did not obtain CR after two courses of intensive chemotherapy with behenoyl-ara-C, daunorubicin, 6-mercaptopurine and prednisolone. He received subcutaneous LDAC 10 mg every 12 h and granulocyte colony-stimulating factor (G-CSF) for 29 days and achieved CR. He continued on a 21 to 28-day course of LDAC without G-CSF every 2 or 3 months and has remained well and in CR for 5 years without chimeric AMLI-MTG8 transcript by RT-PCR. LDAC therapy seems to be effective in eradicating the leukemic clone as post-induction or maintenance therapy in this patient. This is the first case report of the disappearance of AML1-MTG8 transcript by RT-PCR in a patient with t(8;21) in long-term remission after LDAC.

CMDME (curved mesh diagram of mandibular excursion) method for visualization and diagnosis of mandibular movement

The CMDME (curved mesh diagram of mandibular excursion) method was developed for easy visualization and diagnosis of mandibular movement. This method uses measured mandibular movement to produce a diagram of the range, shape, and inclination of mandibular excursion in three dimensions using any arbitrary landmark of the mandible. First, the mandibular movement of a subject was measured by an opto-electronic movement analysis system capable of measuring mandibular movement with six degrees-of-freedom at a sampling frequency of 100 Hz. For the measurement, the subject was initially instructed to perform four repetitions of mandibular excursion at will, with tooth contact, each lasting 30 s. A total of 12 000 positions of the mandible were thus obtained. Secondly, an attempt was made to match these positions to intersection points (0.1 mm apart) of a CMDME (i.e. mesh) for arbitrary mandibular landmarks with intercuspal position at the origin. The CMDME method can visualize mandibular excursion, and can be used to compare several landmarks, different subjects, or different times. This makes this method an effective diagnostic tool for mandibular movement.

Increased hepatic glucose production and decreased hepatic glucose uptake at the prediabetic phase in the Otsuka Long-Evans Tokushima fatty rat model

To investigate the time course of the hepatic glucose metabolism in non-insulin-dependent diabetes (NIDDM), we measured hepatic glucose production (HGP) and first-pass uptake of portal glucose infusion by the liver (HGU) using dual-tracer methods in a NIDDM model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats, and in normal controls, Long-Evans Tokushima Otsuka (LETO) rats, at 8, 14, and 28 weeks of age (n = 5, respectively). The fasting plasma glucose level in OLETF rats was significantly higher than in LETO rats at 28 weeks of age (8.9 +/- 1.7 v 6.3 +/- 0.4 mmol/L, P < .01), while there was no significant difference at 8 and 14 weeks. Hyperinsulinemia in OLETF rats appeared at > or = 8 weeks of age. Basal HGP was significantly higher in OLETF than in LETO rats at 8 and 28 weeks (8 weeks, 12.7 +/- 1.7 v 9.4 +/- 1.8 mg x kg(-1) x min(-1), P < .05; 28 weeks, 10.9 +/- 1.6 v 7.1 +/- 1.3 mg x kg(-1) x min(-1), P < .01). At 14 weeks, basal HGP was not significantly different between OLETF and LETO rats. However, at all study points, HGU during a portal glucose infusion was significantly lower in OLETF than in LETO rats (8 weeks, 0.9 +/- 0.2 v 2.3 +/- 0.5, P < .01; 14 weeks, 0.8 +/- 0.3 v 1.4 +/- 0.3, P < .05; 28 weeks, 0.7 +/- 0.2 v 1.4 +/- 0.3 mg x kg(-1) x min(-1), P < .01). Fasting plasma free fatty acid (FFA) levels were not significantly different between OLETF and LETO, except at 8 weeks. Suppression of plasma FFA levels by endogenous insulin during a portal glucose infusion was impaired in OLETF rats compared with LETO rats. In summary, this study demonstrates that derangement of hepatic glucose handling, such as increased basal HGP and decreased HGU, is observed in obese NIDDM model OLETF rats at the prediabetic phase when hyperglycemia is still not apparent. Furthermore, these derangements may be accompanied by impaired lipid metabolism.

Reduction in brain-derived neurotrophic factor protein level in the hippocampal CA1 dendritic field precedes the delayed neuronal damage in the rat brain

Utilizing a specific polyclonal antibody against a peptide unique for brain-derived neurotrophic factor (BDNF), we investigated the regional and temporal profiles of immunoreactivity of the BDNF protein in the rat hippocampus after transient forebrain ischemia. The pattern of immunoreactivity for the BDNF receptor (TrkB) was also examined and compared with that for BDNF. In the early phase after ischemia, we observed a distinct regional difference in immunoreactivity between the pyramidal cell layer and the stratum radiatum of the CA1 subfield. In the pyramidal cell layer, there was a rapid and transient increase in the positive immunostaining for both BDNF and TrkB. By contrast, in the stratum radiatum there was a marked decrease in BDNF immunoreactivity, but not one in that of TrkB. One week after ischemia, high immunoreactivity for both BDNF and TrkB was observed in the reactive astrocytes in the dendritic field of the CA1 subfield. These findings suggest that a transport of BDNF from the neuronal soma to the dendrites of the stratum radiatum might be ceased after the ischemic insult. Thus, a dysfunctional autocrine mechanism of BDNF within the CA1 neuron may be involved in the pathogenesis of selective neuronal damage after ischemia.

[Correlation between pyrimidine nucleoside phosphorylase (PyNPase)/platelet-derived endothelial cell growth factor and histological prognostic factor, and influences of 5'-deoxy-5-fluorouridine (5'-DFUR) administration on PyNPase levels. 5'-DFUR Joint Research Group in the Osaka Area for Gastric Cancer]

PURPOSE

Pyrimidine nucleoside phosphorylase (PyNPase), among which thymidine phosphorylase (dThdPase) exists mainly in human tumor tissues, is an enzyme to convert 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil. Recently, it was reported that dThdPase was identical to platelet-derived endothelial cell growth factor, angiogenetic factor. Therefore, we expect that there is possibility of dThdPase being a prognostic factor.

METHODS

We investigated for a possible correlation between PyNPase activities in tumor tissues and prognostic factors of histological findings, examined the influences of preoperative oral 5'-DFUR administration to PyNPase levels and investigated for a correlation between HPLC methods and ELISA methods in patients with gastric cancer.

RESULTS

Higher levels of PyNPase were observed in patients with advanced t,n,v, and ly factors. PyNPase levels decreased by 5'-DFUR in patients with differentiated cases. A high correlation was found between HPLC and ELISA methods.

CONCLUSION

This study suggests that we must investigate possibility of PyNPase being a prognostic factor in more detail.

Pioglitazone enhances splanchnic glucose uptake as well as peripheral glucose uptake in non-insulin-dependent diabetes mellitus. AD-4833 Clamp-OGL Study Group

To evaluate the effect of pioglitazone on insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM) patients, a double-blind placebo-controlled trial was carried out with 30 NIDDM patients. Twenty-one subjects, three on diet alone and 18 on sulfonylurea (SU), orally received 30 mg pioglitazone once daily for 12 weeks. Nine subjects, one on diet alone and eight on SU, received a matching placebo once daily for 12 weeks. Euglycemic (5.2 mmol/l) hyperinsulinemic (1200 pmol/l) clamp combined with an oral glucose load (OGL) was performed before and after 3-month treatment with pioglitazone or placebo to determine insulin-stimulated glucose disposal and splanchnic glucose uptake (SGU). No significant differences existed in the patients' characteristics, including age and body mass index, between the two study groups. The pioglitazone treatment increased the mean glucose infusion rate (GIR) prior to OGL from 8.2 +/- 2.2 to 9.2 +/- 2.0 mg/kg.min (mean +/- SD, P = 0.003) and increased the SGU rate from 28.5 +/- 19.4 to 59.4 +/- 27.1% (P = 0.010). The placebo treatment produced no significant changes in either GIR or SGU after treatment. A significant difference (P = 0.042) was observed in change of SGU between the pioglitazone and placebo treatment groups. In conclusion, the results indicate that pioglitazone is effective for ameliorating insulin resistance in NIDDM by enhancing SGU as well as peripheral glucose uptake.

Direct fractionation of proteins in particle-containing feedstocks by a filter paper pieces-based DEAE-cellulose column chromatography. Rapid, robust and low-cost capturing procedure for protein

Filter paper pieces-based (FPB) DEAE-celluloses was prepared for direct fractionation of proteins in particle-containing feedstocks. FPB DEAE-cellulose has a protein binding capacity equivalent to that of commercially available DEAE-cellulose. Crude extracts from porcine intestine and kiwi fruit pulp, which were unmanageable by commercially available chromatographic media due to rapid clothing, could be directly fractionated with FPB DEAE-cellulose column. In addition, effluents from an FPB DEAE-cellulose column were extensively clarified. The present approach can be used as a rapid, robust and low-cost capturing step for protein from particle-containing feedstocks.

TAS-301, an inhibitor of smooth muscle cell migration and proliferation, inhibits intimal thickening after balloon injury to rat carotid arteries

The purpose of this study was to determine the efficacy and the possible mechanism of action of a recently synthesized drug, TAS-301 [3-bis (4-methoxyphenyl)methylene-2-indolinone], on intimal formation in comparison with those of tranilast, the clinical efficacy of which was reported earlier. Rat carotid arteries were injured using a balloon catheter. Neointimal thickening, measured 14 days after injury, was reduced by the oral administration of TAS-301 in a dose-dependent fashion (3-100 mg/kg), and the effect of TAS-301 at a dose of 100 mg/kg was significantly greater than that of tranilast (300 mg/kg). Fewer cells were found on the intima of balloon-injured arteries of TAS-301-treated rats than on arteries of tranilast-treated rats. In an in vitro assay, TAS-301 inhibited the migration of smooth muscle cells (SMCs) stimulated by platelet-derived growth factor-BB, insulin-like growth factor-1 or heparin-binding epidermal growth factor-like growth factor. In addition, TAS-301 and tranilast reduced the proliferation of medial and intimal SMCs at 4 and 8 days, respectively, after the injury. In vitro, TAS-301 inhibited basic fibroblast growth factor-induced proliferation of SMCs dose dependently. These findings indicate that TAS-301 shows a higher inhibitory potency on intimal formation than tranilast due to inhibition of both migration of medial SMCs and proliferation of medial and intimal SMCs. Our results suggest that further evaluation of TAS-301 as an inhibitor of postangioplasty intimal thickening is warranted.

[A successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy by mediastinoscopy]

We reported a successfully treated case of empyema with a large tracheal fistula after subtotal esophagotomy. This 59-year-old male was treated by drainage with mediastinoscopy and repeated wash-out under bronchoscopy, because we could not use the omentum and he was the poor-risk patient. The trancheal fistula was obliterated bronchoscopically, 4 months after the mediastinoscopy. We believe that this method (abscess drainage with mediastinoscope and wash-out repeatedly) is useful for those who has broncheal fistula after esophagectomy.