Kupffer cell targeting by intraportal injection of the HVJ cationic liposome

The aim of this study was to target Kupffer cells (KCs) selectively and efficiently by the intraportal injection of fusigenic cationic liposomes with hemagglutinating virus of Japan components (HVJ cationic liposomes). Phosphorothioate FITC-oligodeoxynucleotides (FITC-ODNs) encapsulated in either HVJ cationic liposomes, HVJ anionic liposomes or conventional cationic liposomes without HVJ were transferred to the rat. FITC-ODNs in HVJ cationic liposomes administered via portal vein were selectively transfected to KCs for up to 24 h with no apparent cytotoxicity at higher transfection efficiency than FITC-ODNs in conventional cationic liposomes without HVJ administered via portal vein or tail vein. On the other hand, FITC-ODNs in HVJ anionic liposomes were observed mainly in hepatocytes, not KCs. This new method will be useful for the modulation of KCs activity in both basic research and clinical applications.

Evaluation of thermal cycling and mechanical loading on bond strength of a self-etching primer system to dentin

OBJECTIVE

The aim of this study was to evaluate the in vitro durability and fracture modes of the tooth-resin interface following thermal cycling, fatigue load cycling (FLC) and micro-tensile bond strength testing (MTBS).

METHODS

Twenty-four human molars were divided into two groups. In group A, coronal dentin was ground flat with #600-grit SiC paper, Clearfil Linerbond.2V (LB.2V) adhesive was applied and a crown fabricated with Clearfil AP-X resin composite. Samples were loaded in the FLC simulator and thermal cycle device. In group B, Class I cavities were prepared with a diamond bur and the cavity restored with LB.2V/AP-X. Samples were simultaneously subjected to FLC and thermal cycling. After storage of the specimens in water for 1 week, MTBS tests were performed, and fracture modes examined by SEM.

RESULTS

For group A, MTBS were approximately 40 MPa with cohesive failures in the bonding resin of all specimens. Neither thermal nor mechanical stressing altered bond strengths on flat dentin surfaces. In group B, MTBS in the unstressed control group was 21 MPa with cohesive failures in the resin. As both thermal and mechanical stresses increased, there was a significant decrease in bond strength (16 MPa, P<0.05) and the fractures were seen in the resin-dentin interface and hybrid layer.

SIGNIFICANCE

Surface preparation, C-factor, cavity depth, the dentin substrate and character of the smear layer strongly influence the bond strength values after thermal and fatigue loading. The FLC simulator in combination with MTBS testing provides meaningful in vitro evaluation of dentin bonding durability.

Lack of tumorigenesis in the mouse liver after adenovirus-mediated expression of a dominant stable mutant of beta-catenin

Mutations in the glycogen synthase kinase 3beta (GSK3beta) phosphorylation sites of the beta-catenin gene exon 3 are found in 20-30% of human primary hepatocellular carcinoma (HCC), whereas mutations in the APC or AXIN genes are found in other HCC populations. These data strongly suggest that the Wnt signaling pathway is involved in hepatocarcinogenesis. To determine the role of beta-catenin in intestinal tumorigenesis, we earlier constructed a mutant mouse strain Catnb(lox(ex3)), in which exon 3 of the beta-catenin gene was sandwiched by loxP sequences. By genetic crosses of these mice with the Fabpl-cre transgenic mice that express the cre gene controlled by the fatty acid binding protein gene promoter, we introduced the beta-catenin stabilizing mutation into the small intestine and liver. Although numerous polyps were formed in the small intestine, we did not find any neoplastic (i.e., dysplastic) foci in the liver, and the mice died in 5 weeks after birth because of acute liver damage accompanying mitochondrial swelling. When a recombinant adenovirus that expresses the cre gene from a human cytomegalovirus early gene promoter was constructed and inoculated at a high multiplicity (10(9) plaque-forming units/mouse), the Catnb(lox(ex3)) mice showed marked hepatomegaly, with similar mitochondrial swelling in the hepatocytes, and died within 3 weeks after infection. On the other hand, when inoculated at lower multiplicities of infection (10(7) and 10(8) plaque-forming units/mouse, respectively), the Catnb(lox(ex3)) mice survived >6 months without any neoplastic foci in the liver, although the nuclear localization of beta-catenin was found in some hepatocytes even after 6 months. These results suggest that, in contrast to intestinal polyposis, the Wnt pathway activation by stabilized beta-catenin is not sufficient for hepatocarcinogenesis, but additional mutations or epigenetic changes may be required.

An integrated analysis and database system for full-length cDNA

Annotation and database system of full-length cDNA sequences was developed. As the components of the system, ORF annotation system, functional annotation system based on database search results, mapping annotation system, and integrated retrieval and display system were developed. In the ORF annotation system integrated analyses using conventional tools are performed and useful retrieval interface using motif list are introduced. In the functional annotation system based on database search results, a new method that characterizes a given unknown cDNA was developed by using a profile of similarity level over words appearing in sequence database entries. In the mapping annotation system, we linked by similarity searches full-length cDNA sequences with database DNA sequences that are already mapped on chromosomes. By using these links, full-length cDNAs can be retrieved by the retrieval condition of physical mapping information. Genetic disease information mapped on the physical mapping site can also be displayed by this system. Furthermore, we constructed an integrated database system for these analyzed data, and thus enabled annotation and selection of full-length cDNAs from points of both gene function and mapping information.

Facilitation of dopaminergic neural transmission does not affect [(11)C]SCH23390 binding to the striatal D(1) dopamine receptors, but the facilitation enhances phosphodiesterase type-IV activity through D(1) receptors: PET studies in the conscious monkey brain

The present study evaluated the effects of methamphetamine and scopolamine on the striatal dopamine D(1) receptor binding, measured by [(11)C]SCH23390, and D(1) receptor-coupled cAMP messenger system, determined as phosphodiesterase type-IV (PDE-IV) activity, were evaluated in the brains of conscious monkeys using positron emission tomography (PET) with microdialysis. When methamphetamine (0.1, 0.3, and 1 mg/kg) or scopolamine (0.01, 0.03, and 0.1 mg/kg) was systemically administered, [(11)C]SCH23390 binding to D(1) receptors was not affected. With administration of methamphetamine, the striatal PDE-IV activity, as measured with R-[(11)C]rolipram (active form) and S-[(11)C]rolipram (inactive form), was dose-dependently facilitated with enhanced dopamine level in the striatal ECF. Administration of scopolamine also induced facilitated PDE-IV activity without any apparent changes in the ECF dopamine. These facilitations of PDE-IV activity were abolished by preadministration of SCH23390, but not by raclopride. These results demonstrate that, as evaluated by PDE-IV activity, the inhibition of muscarinic cholinergic receptors actually facilitated dopamine neuronal signal transduction through D(1) receptors, as observed previously on D(2) receptors with no apparent increase in the striatal ECF dopamine level, but the enhanced dopamine transmission could not detected by [(11)C]SCH23390.

Congenital glaucoma and Silver-Russell phenotype associated with partial trisomy 7q and monosomy 15q

We report on a 28-year-old man with trisomy 7q34-qter and monosomy 15q26.3-qter caused by a paternal balanced chromosomal translocation, t(7;15)(q34;q26.3). He had bilateral congenital glaucoma (buphthalmos), as well as typical manifestations of partial trisomy 7q. To our knowledge, this is the second description of a possible relation between congenital glaucoma and 7q trisomy. He also had some Silver-Russell syndrome features, such as short stature of prenatal onset, a characteristic triangular face, clinodactyly of the fifth fingers, and body asymmetry. Fluorescence in situ hybridization analysis on his chromosomes revealed that one copy of the insulin-like growth factor 1 receptor gene (IGF1R) at 15q25-q26 was deleted, suggesting a possible role of IGF1R in the SRS phenotype.

Effects of aging on 5-HT(1A) receptors and their functional response to 5-HT(1a) agonist in the living brain: PET study with [carbonyl-(11)C]WAY-100635 in conscious monkeys

Age-related changes in the serotonin 5-HT(1A) receptors in the living brains of conscious young (5.9 +/- 1.8 years old) and aged (19.0 +/- 3.3 years old) monkeys (Macaca mulatta) were evaluated by [carbonyl-(11)C]WAY-100635 and high-resolution positron emission tomography (PET). The regional distribution pattern of [carbonyl-(11)C]WAY-100635 at 60-91 min postinjection was the highest in the cingulate gyrus and hippocampus, high in the frontal and temporal cortices, lower in the occipital cortex, striatum, thalamus, and raphe nuclei, and lowest in the cerebellum in both young and aged monkeys. Graphical Logan plot analysis with metabolite-corrected plasma radioactivity as an input function into the brain was applied to evaluate 5-HT(1A) receptor binding in vivo. Significant age-related decreases in 5-HT(1A) receptor binding were observed only in the frontal and temporal cortices. In the hippocampus, although 5-HT(1A) receptor binding indicated no significant age-related changes, it showed an inverse correlation with individual cortisol levels in plasma. When the 5-HT(1A) receptor agonist 8-OH-DPAT was administered intravenously at a dose of 0.1, 0.3, or 1 mg/kg 30 min after tracer injection, binding of [carbonyl-(11)C]WAY-100635 was displaced in both age groups in a dose-dependent manner. However, the degree of displacement was more marked in young than in aged monkeys. These observations demonstrated the usefulness of [carbonyl-(11)C]WAY-100635 as an indicator of the age-related changes in cortical 5-HT(1A) receptors measured noninvasively by PET. In addition, these observations suggested that the age-related impairment of 5-HT(1A) receptor responses to 8-OH-DPAT might be related to the reduced efficacy of antidepressant therapy in elderly patients with depression.

Ketamine alters the availability of striatal dopamine transporter as measured by [(11)C]beta-CFT and [(11)C]beta-CIT-FE in the monkey brain

The effects of ketamine anesthesia on the binding of [(11)C]-labeled cocaine analogs, [(11)C]beta-CFT (2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane) and [(11)C]beta-CIT-FE (N-(2-fluoroethyl)-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane), to the striatal dopamine transporter (DAT) were evaluated in the monkey brain using positron emission tomography (PET). We sequentially measured the kinetics of these labeled compounds in the brains of five young-adult male rhesus monkeys (Macaca mulatta) in the conscious state, followed by those under ketamine anesthesia with continuous infusion (3 and 10 mg/kg/h). After intravenous injection, [(11)C]beta-CFT and [(11)C]beta-CIT-FE were predominantly accumulated in the striatum in both conscious and ketamine-anesthetized states. In the conscious state, the striatal uptake of [(11)C]beta-CFT and [(11)C]beta-CIT-FE continuously increased with time up to 91 min after injection. Continuous infusion of ketamine-induced higher levels of uptake of [(11)C]beta-CFT and [(11)C]beta-CIT-FE into the brain in a dose-dependent manner as compared with conscious state, and kinetic analysis with metabolite-corrected arterial input function indicated that the binding potentials (BP = k(3)/k(4)) of both compounds were elevated by ketamine. Not only [(11)C]beta-CIT-FE but also [(11)C]beta-CFT reached the equilibrium state of specific binding in the striatum within 40-50 min after injection. The present results demonstrated that ketamine significantly alters the DAT availability as measured with [(11)C]beta-CFT and [(11)C]beta-CIT-FE in the brain.

Detection of Fcgamma binding protein antigen in human sera and its relation with autoimmune diseases

Intestinal goblet cells of patients with ulcerative colitis and Crohn's disease highly express a binding protein of the Fc portion of IgG (FcgammaBP), which is entirely different from the Fcgamma receptors I,II, and III on neutrophils and macrophages. In this study, we proved the qualitative existence of FcgammaBP antigen in the sera of patients with rheumatoid arthritis and systemic lupus erythematosus, and, further, established a highly sensitive and quantitatively reproducible assay for FcgammaBP antigen in order to prevent the cross-reactivity of FcgammaBP with von Willebrand factor which has about 30% homology. This assay revealed a higher level of FcgammaBP antigen in the blood stream of patients with autoimmune diseases, especially progressive systemic sclerosis. This would suggest that abnormal production of autoantibodies reflects increased generation of FcgammaBP in goblet cells and its secretion into the circulation by an unknown mechanism.

Characterization and purification of a protein binding to the cis-acting element for brain-specific exon 1 of the mouse aromatase gene

The functional differences between male and female brains commit to the existence of androgen that the testis secretes during the perinatal period. Androgen exerts its action on the brain after conversion to estrogen by brain aromatase. The aromatase appears in some neural nuclei such as in the hypothalamus and amygdala, and has been indicated to be involved in the expression of sexuality by the results of neurobehavioral analyses involving aromatase-knockout mice. We analyzed the brain-specific promoter in order to clarify the control mechanism for the expression of brain aromatase, which is deeply concerned in the sexual differentiation of the brain. The 202bp upstream region of brain-specific exon 1 contains at least three kinds of cis-acting elements, Arom-Aalpha, -Abeta and -B. In particular, the binding activities as to the Abeta sequence show a tissue-specific pattern. Gel shift analysis revealed that the Abeta binding factor recognizes the TTGGCCCCT sequence. Abeta binding activity is detectable at the perinatal stage, but is undetectable at the adult stage in the brain. Furthermore, a protein which binds to the Abeta sequence was purified from the fetal mouse brain. The molecular mass of the Abeta binding protein was estimated to be 49kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Physiological effects of shift work on hospital nurses

OBJECTIVE

The purpose of this study was to assess the physiological effects of shift work on the urinary excretion rates of norepinephrine, 6-sulfatoxymelatonin and estriol in hospital nurses.

METHOD

Twenty-four hour urine specimens were examined on a daytime/nighttime basis for each work shift of pregnant and non-pregnant subjects. The urinary norepinephrine and 6-sulfatoxymelatonin were measured by enzyme-linked immunosorbent assay and estriol by radio-immunoassay.

RESULTS

Urinary norepinephrine level during the night work was higher than the night levels of the days off and the day shift. Urinary 6-sulfatoxymelatonin level during the night work was lower than the night levels of the days off and the day shift. Urinary estriol level of pregnant subjects showed no differences among work shift and also between daytime and nighttime.

CONCLUSIONS

Urinary excretion rates of norepinephrine and 6-sulfatoxymelatonin were affected by shift work both for non-pregnant and pregnant subjects. It was unlikely that urinary estriol levels in the pregnant subjects were significantly affected by shift work.

Aromatase in atherosclerotic lesions of human aorta

It is well documented that estrogens have atheroprotective effects in humans. Peripheral aromatization of circulating androgens has been demonstrated to exert estrogenic actions in many human tissues, especially in men and post-menopausal women. Recently, production of estrogens mediated by aromatase was detected in cultured smooth muscle cells and aortic endothelial cells and it has been proposed that this in situ produced estrogen may influence the development of atherosclerosis. In this study, we first examined aromatase expression by immunohistochemistry in human aortic tissues obtained from 85 autopsy cases (50 males, 35 females, 49.6 +/- 2.9-year-old) and by mRNA in situ hybridization in 10 cases. We then semi-quantified the level of aromatase mRNA in aortic tissues of 12 men and 12 post-menopausal women by reverse transcriptase-polymerase chain reaction (RT-PCR) to examine whether or not and in which cell types aromatase was expressed. We also studied alternative use of multiple exon 1 of its gene and immunolocalization of 17beta-hydroxysteroid dehydrogenase type I (17beta-HSD I), which converts estrone produced by aromatase to estradiol, a biologically active estrogen. Aromatase immunoreactivity and mRNA hybridization signals and 17beta-HSD I immunoreactivity were all detected in smooth muscle cell (SMC) of the media and thickened intima, especially in SMC adjacent to an atheromatous plaque. The levels of aromatase mRNA were significantly higher in female cases than in male cases (P<0.05). The amount of aromatase mRNA was significantly higher in the specimens with fibroatheroma (P<0.05) than other lesions, and was also significantly higher in the cases utilizing 1c (I.3) or 1d (PII) of exon 1, i.e. gonadal types than those utilizing 1b (I.4), i.e. fibroblasts type as the promoter (P<0.01). These results suggest that estrone and estradiol are produced in SMC of the human aortic wall and that their production is mediated by aromatase and 17beta-HSD I, respectively. Moreover, it was suggested that aromatase overexpression, possibly as a result of alternative splicing, may play some roles in the development of atherosclerosis.

Analysis of transcriptional regulation of human breast aromatase by in vitro and in vivo studies

Aromatase mRNA in normal breast tissues is mainly transcribed from exon 1b (I.4) of the gene. However, in breast cancer tissues, it is often transcribed from exon 1c/1d (I.3/PII). Such a switching from exon 1b to exon 1c/1d has often found concomitantly with elevated levels of aromatase mRNA. To elucidate the molecular mechanism of a switching of multiple exons 1 and enhanced expression of aromatase in the breast tissues, we identified essential elements responsible for transcription from exon 1b. Gel shift assays indicated that there are two essential elements for transcription from exon 1b between -300 and -500 bp in the promoter region. The two unique elements have homologous consensus DNA sequences, and competed for binding of the specific nuclear protein with each other. We next generated transgenic mouse expressing a reporter gene controlled by multiple promoters in the human aromatase gene. The mouse gave tissue-specific expression of the reporter gene and tissue-specific utilization of the alternative promoter regions. These results show that this transgenic mouse is a good model animal for the study of tissue-specific regulation of human aromatase gene.

Molecular characterization of NSD1, a human homologue of the mouse Nsd1 gene

NR-binding SET-domain-containing protein (NSD1) is a mouse nuclear protein containing su(var)3-9, enhancer-of-zeste, trithorax (SET), proline-tryptophan-tryptophan-proline (PWWP) and plant homeodomain protein (PHD)-finger domains (Huang et al., EMBO J. 17 (1998) 3398). This protein also has two other distinct nuclear receptor (NR)-interaction domains, called NID(-L) and NID(+L), and acts as both a NR corepressor and a coactivator by interacting directly with the ligand-binding domain of several NRs. Thus, NSD1 is a bifunctional, transcriptional, intermediary factor. We isolated the human homologue (NSD1) of the mouse NSD1 gene (Nsd1), mapped it to human chromosome 5q35, and characterized its genomic structure. NSD1 consists of at least 23 exons. Its cDNA is 8552 bp long, has an 8088 bp open reading frame, contains at least six functional domains (SET, PWWP-I, PWWP-II, PHD-I, PHD-II, and PHD-III) and ten putative nuclear localization signals, and encodes 2696 amino acids. NSD1 shows 86% identity with the mouse Nsd1 at the nucleotide level, and 83% at the amino acid level. NSD1 is expressed in the fetal/adult brain, kidney, skeletal muscle, spleen, and the thymus, and faintly in the lung. Two different transcripts (9.0 and 10.0 kb) were consistently observed in various fetal and adult tissues examined. These findings favor the character of NSD1 as a nucleus-localized, basic transcriptional factor and also a bifunctional transcriptional regulator, such as that of the mouse Nsd1. It remains to be investigated whether mutations of NSD1 lead to a specific phenotype in man.

Vitamin C inhibits corpus gastritis in Helicobacter pylori-infected patients during acid-suppressive therapy

BACKGROUND

Previous studies have shown that gastric acid suppression worsens corpus gastritis in Helicobacter pylori (H. pylori)-positive patients. We evaluated the effect of acid-suppressive therapy and vitamin C on H. pylori-associated gastritis.

METHODS

Forty patients with reflux esophagitis were divided into three groups by the status of H. pylori and therapy: group A (n=15), H. pylori (+) and omeprazole 20 mg; group B (n=15), H. pylori (+) and omeprazole 20 mg + vitamin C 1200 mg; and group C (n=10), H. pylori (-) and omeprazole 20 mg. In all three groups, the mucosal interleukin (IL)-8 contents, H. pylori colonization density, neutrophil infiltration in the corpus, and serum gastrin were evaluated at entry and 2 weeks after starting therapy; in group B, serum vitamin C levels were also measured.

RESULTS

In group A, the IL-8 contents and the degree of neutrophil infiltration during therapy exceeded those at entry, whereas in groups B and C, these values did not change significantly with treatment. Helicobacter pylori colonization density during therapy was similar to that at entry in all three groups. The serum gastrin (in all groups) and vitamin C levels (in group B) during therapy exceeded those at entry.

CONCLUSIONS

Potent acid suppression worsens H. pylori-associated corpus gastritis, although such worsening gastritis may be inhibited by vitamin C.

Motoneuron pool excitability of hemiplegic patients: assessing recovery stages by using H-reflex and M response

OBJECTIVES

To compare the excitability of the motoneuron pools of both the spastic and the unimpaired sides of patients with hemiplegia with a new method by using H-reflexes and M responses. The method determines the ratio of the developmental slope of the H-reflex (Hslp) to the slope of the M response (Mslp). We also examined the relation between the Brunnstrom stages and the Hslp/Mslp.

DESIGN

Experiment.

SETTING

Electrophysiologic experimental laboratory in a Japanese medical school.

PATIENTS

Fifteen hemiplegic patients (9 men, 6 women; age range, 48-71yr; mean, 60yr) with spasticity caused by a stroke.

INTERVENTIONS

The subject was instructed to relax while seated in a reclining chair with his foot fixed on an immobile pedal. After the soleus H-reflex and M responses on one side were recorded, the same experimental procedures were carried out on the other side.

MAIN OUTCOME MEASURES

Hslp/Mslp Brunnstrom stages.

RESULTS

Hslp/Mslp had better predictive value than conventional indicators of motoneuron pool excitability. Hslp/Mslp appeared to be a better match for the bell-shaped pattern of the Brunnstrom stages.

CONCLUSION

Hslp/Mslp is the preferred index for evaluating the motoneuron pool excitability of the spastic side of hemiplegic patients.

17 beta-Hydroxysteroid dehydrogenase type 2 expression and enzyme activity in the human gastrointestinal tract

The 17 beta-hydroxysteroid dehydrogenases (17 beta HSDs) play an important role in the regulation of intracellular levels of biologically active sex steroid hormones in various human tissues. To date, eight distinctive 17 beta HSD enzymes have been cloned and characterized in humans. Among these isoenzymes, 17 beta HSD type 2 (17 beta HSD2) catalyses the conversion of testosterone into androstenedione and/or oestradiol into oestrone in various tissues, and it has thus been suggested to be involved in the biological inactivation of these sex steroids. The human gastrointestinal tract and liver are considered as the principle sites of inactivation and metabolism of various forms of orally administered sex steroids. We therefore examined 17 beta HSD2 expression and activity in human adult non-pathological gastrointestinal tract in order to clarify further the biological significance of this enzyme. A total of 80 specimens (40 from males and 40 from females) of normal oesophageal, stomach, duodenal, ileal, colonic and rectal tissues were examined for immunohistochemistry. Altogether, 17 tissue specimens were used for enzyme assay, and eight for RNA analysis. 17 beta HSD2 activity was detected in the stomach, duodenum, ileum, colon and rectum. 17 beta HSD2 mRNA was most abundant in the small intestine. 17 beta HSD2 immunoreactivity was localized almost exclusively to the absorptive epithelium, which may be involved in the inactivation of excessive endogenous and exogenous active sex steroids. Results from the present study thus suggest that the human gastrointestinal tract is an important sex steroid metabolizing organ in humans.

Transit endoscopic ultrasound of colorectal cancer using a 12 MHz catheter probe

The objective of this study was to examine the accuracy of a 12 MHz ultrasound catheter probe in the pre-operative staging of colorectal cancer by assessing the depth of tumour infiltration and involvement of pericolonic lymph nodes. 159 patients with colorectal cancer who underwent ultrasound examination with a 12 MHz catheter probe were studied prospectively. The results of this imaging procedure were compared with the histological findings of the resected specimens. The accuracy of the 12 MHz ultrasound catheter probe for depth of invasion (T category) was 85% (131/154) for all tumours, 87% (46/53) for pT1 tumours, 60% (9/15) for pT2 tumours, 89% (74/83) for pT3 tumours and 67% (2/3) for pT4 tumours. The accuracy for tumours of the rectum and colon was 81% and 89%, respectively. The accuracy of the probe for nodal staging (N category) was 67% (76/114) overall. The sensitivity was 70% (33/47), the specificity 64% (43/67), the positive predictive value 58% (33/57) and the negative predictive value 75% (43/57). Endoscopic ultrasound using a 12 MHz catheter probe accurately assessed tumour stage, although nodal staging remained suboptimal. This method may aid in the selection of treatment for patients with colorectal cancer.

Age-specific prevalence of open-angle glaucoma and its relationship to refraction among more than 60,000 asymptomatic Japanese subjects

To clarify the prevalence of open-angle glaucoma (OAG) and its relationship to refraction among a Japanese population with a broad range of ages including children and adolescents, an 1-year epidemiological survey was conducted. The subjects of this study were 64,394 asymptomatic individuals who had attended the glasses and contact lens center in Yokohama, Japan from February 15, 1999 to February 14, 2000 and had been subjected to several optical examinations. The results of this study showed that the overall prevalence of OAG was 1.19% (1.14% for men, and 0.98% for women). Prevalence for children aged 6 to 14 of both sexes was approximately 0.5%. There were significant positive associations between the strength (diopter) of myopic refraction and OAG prevalence among all the examined subjects.

Age-related changes in muscarinic cholinergic receptors in the living brain: a PET study using N-[11C]methyl-4-piperidyl benzilate combined with cerebral blood flow measurement in conscious monkeys

The effects of changes in regional cerebral blood flow (rCBF) with aging on muscarinic cholinergic receptor binding were evaluated with [15O]H(2)O and N-[11C]methyl-4-piperidyl benzilate (4-MPB) in the living brains of young (5.9+/-1.8 years old) and aged (19.0+/-3.3 years old) monkeys (Macaca mulatta) in the conscious state using high-resolution positron emission tomography (PET). For quantitative analysis of receptor binding in vivo with [11C]4-MPB, metabolite-corrected arterial plasma radioactivity curves were obtained as an input function into the brain, and graphical Patlak plot analysis was applied. In addition, two-compartment model analysis using the radioactivity curve in the cerebellum as an input function (reference analysis) was also applied to determine the distribution volume (DV=K(1)/k(2)') for [11C]4-MPB. With metabolite-corrected arterial input, Patlak plot analysis of [11C]4-MPB indicated a regionally specific decrease in muscarinic cholinergic receptor binding in vivo in the frontal and temporal cortices as well as the striatum in aged compared with young animals, showing no correlation with the degree of reduced rCBF. In contrast, on the reference analysis with cerebellar input of [11C]4-MPB, all regions assayed except the pons showed a significant age-related decrease of DV, and the degree of reduction of DV was correlated with that of rCBF. These results demonstrated the usefulness of kinetic analysis of [11C]4-MPB with metabolite-corrected arterial input, not with reference region's input, as an indicator of the aging process of cortical muscarinic cholinergic receptors in vivo measured by PET with less blood flow dependency.

Synthesis and redox behavior of azulene-substituted benzene derivatives and (eta(5)-cyclopentadienyl)[tetra- and di(6-azulenyl)cyclobutadiene]cobalt complexes

1,2-Di(6-azulenyl)tetraphenylbenzenes and (6-azulenyl)pentaphenylbenzenes were synthesized by Diels-Alder reactions of di(6-azulenyl)acetylenes and 6-(phenylethynyl)azulenes with tetraphenylcyclopentadienone. Cobalt-mediated cyclooligomerization of mono- and di(6-azulenyl)acetylenes afforded 1,3,5- and 1,2,4-tri(6-azulenyl)benzene derivatives together with (eta(5)-cyclopentadienyl)[tetra- and di(6-azulenyl)cyclobutadiene]cobalt complexes. The redox behavior of these novel (6-azulenyl)benzene derivatives and [tetra- and di(6-azulenyl)cyclobutadiene]cobalt complexes was examined by cyclic voltammetry (CV). Mono(6-azulenyl)benzenes exhibited a reduction wave upon CV. In contrast, 1,2-di(6-azulenyl)benzenes showed a two-step reduction wave at the similar potential region upon CV, which revealed the formation of a dianion stabilized by 6-azulenyl substituents under electrochemical reduction conditions. Three 6-azulenyl substituents on benzene in a 1,2,4 relationship also increased electron-accepting properties because of the formation of a closed-shell dianionic structure, whereas 1,3,5-tri(6-azulenyl)benzenes were reduced stepwise.

Solid-Phase synthesis of a library constructed of aromatic phosphate, long alkyl chains and tryptophane components, and identification of potent dipeptide telomerase inhibitors

Telomerase inhibitors are expected as a new candidate of therapeutic agents for cancer. Recently, we have found novel inhibitors based on the bisindole skeleton. In this study, solid-phase synthesis was applied to construct a library of inhibitors having aromatic phosphate, long alkyl chain and tryptophane components, from which a D,D-ditryptophane derivative has been identified as a new potent telomerase inhibitor with IC(50) values of 0.3 microM. A hypothetical binding model for the new inhibitors has been proposed based on the structure-activity relationship.

Aberrant intracellular localization of RCAS1 is associated with tumor progression of gastric cancer

A novel tumor-associated antigen, RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) is expressed at a high frequency in human uterine and ovarian cancer cells as well as in other mammalian cancer cells. We investigated a relationship between RCAS1 expression and clinicopathological features in gastric cancer. Immunohistochemically, RCAS1 was detected in 98.4% of gastric carcinomas. However, its expression was also observed in non-cancerous gastric epithelial cells including gastric adenomas (100%), gastric ulcers (66.7%) and normal gastric epithelia (100%). Striking difference was observed in the pattern of RCAS1 expression between benign and malignant cells. In cases of normal gastric mucosae, gastric ulcers and gastric adenomas, RCAS1 was localized only in the perinuclear region of the mucosal epithelial cells (PN pattern), while, in most of gastric cancers (83.9%), it was detected diffusely in the cytoplasm and cell membranes of the tumor cells (DC pattern). In semi-quantitative RT-PCR analysis, RCAS1 mRNA levels in gastric adenocarcinoma tissues were significantly higher than those in non-neoplastic tissues (p=0.038). The PN pattern of RCAS1 expression was more frequently observed in well differentiated adenocarcinoma (25%) than in moderately differentiated adenocarcinoma (0%) (p=0.01). In addition, it is noteworthy that DC pattern of RCAS1 expression was more frequently recognized in carcinomas which invaded beyond the submucosa (100%) compared to intramucosal carcinoma (67.7%) (p=0.0026). These findings suggest that altered intracellular distribution of RCAS1 is strictly associated with tumor progression of gastric cancer and is a useful marker for the diagnosis and prognosis in gastric cancer.

Strict closed-system drainage for treating chronic subdural haematoma

A comparative study chiefly of the recurrence rate of chronic subdural haematoma after two treatment modalities was conducted. Patients were divided into a burr hole strict closed-system drainage group (SCD group; n=56) and a burr hole closed-system drainage with irrigation group (CDI group; n=45). The burr hole strict closed-system drainage involved simply inserting a drainage tube into the haematoma cavity as quickly as possible after minimally incising the haematoma capsule. The introduction of air into the haematoma cavity was prevented, and irrigation was not performed. Symptoms in both groups disappeared soon after surgery, with no postoperative complications. Haematoma recurred in one patient (1.8%) of the SCD group compared with 5 (11.1%) of the CDI group. The rate of recurrence was significantly lower for the SCD than for the CDI group (p<0.05). In 4 of 5 recurrences in the CDI group, the volume of residual intracapsular air was sufficient after initial surgery. These results suggested that postoperative residual intracapsular air is a factor contributing to recurrence. Burr hole strict closed-system drainage is a simple, less invasive procedure with which to treat chronic subdural haematoma and the outcome is excellent. Furthermore, prevention of intracapsular air intrusion during surgery might help prevent recurrence.

Inhibitory action of Oren-gedoku-to extract on enzymatic lipid peroxidation in rat liver microsomes

We examined the inhibitory action of the extract of Oren-gedoku-to, a traditional herbal medicine known to act as an antioxidant, on enzymatic lipid peroxidation in rat liver microsomes. Simultaneous addition of a spray-dried preparation of Oren-gedoku-to extract (Tsumura TJ-15) inhibited enzymatic lipid peroxidation induced by reduced beta-nicotinamide adenine dinucleotide phosphate (NADPH) and ADP/Fe3+ complex in liver microsomes in a dose-dependent manner. When the inhibition by TJ-15 of enzymatic lipid peroxidation in liver microsomes was kinetically analyzed, this medicine showed a competitive inhibition against NADPH or ADP/Fe3+ complex. TJ-15 inhibited the NADPH-driven enzymatic reduction of ADP/Fe3+ complex or cytochrome c in liver microsomes competitively. TJ-15 enhanced NADPH consumption by liver microsomes with ADP/Fe3+ complex. Treatment with TJ-15 after the onset of enzymatic lipid peroxidation in liver microsomes inhibited the progression of lipid peroxidation in a dose-dependent manner. The present results indicate that Oren-gedoku-to extract inhibits enzymatic lipid peroxidation in rat liver microsomes in the initiation and propagation steps in a dose-dependent manner. These results also suggest that Oren-gedoku-to extract inhibits enzymatic lipid peroxidation in rat liver microsomes not only through its antioxidant action but also through reduction of the supply of electrons derived from NADPH to ADP/Fe3+ complex in liver microsomes both in a competitive manner and through stimulation of NADPH oxidation.

Roles of superoxide dismutase in rat mast cell granules

BACKGROUND

It has been suggested that in the granules of rat mast cells there is some kind of superoxide dismutase (SOD), but details of this SOD in mast cells remain unclear. In the present study, we studied the mode of existence of SOD in mast cells and its releasing mechanism from the granules. In addition, we discussed the physiological role of SOD in allergic events.

METHODS

Purified rat mast cells were disrupted with a sonic disrupter and granules (sample I) were separated from supernatant (sample II) by centrifugation. The granules were treated with 1 mM Ca(2+), and the supernatant (sample III) was separated from the pellet (sample IV). Sample III was applied to a heparin column and the eluate was used as sample V. SOD activity was measured in these samples.

RESULTS

SOD existed in mast cell granules as a heparin-binding and an inactive form. However, when granules were released and exposed to high Ca(2+) concentration, SOD was discharged from heparin and shifted to the active form. The expression of macrophage inflammatory protein-1 alpha mRNA was enhanced when hydrogen peroxide (H(2)O(2)) or sample III with the xanthine-xanthine oxidase system were added to the culture media.

CONCLUSIONS

These findings suggest that in stimulated rat mast cells, the released SOD may transform the generated superoxide anion into H(2)O(2), and the generated H(2)O(2) may enhance the expression of chemokine mRNA in the mast cells.

Genetic susceptibility and environmental estrogen-like compounds

Environmental chemicals with estrogenic activities have been suggested to be able to interact with the endocrine system. Endogenous estrogen is synthesized in the ovarian theca cells of premenopausal women or in the stromal adipose cells of the breast of postmenopausal women and minor quantities in peripheral tissue. These cells, as well as breast tissue, express all the necessary enzymes for this synthesis, CYP17, CYP11a, CYP19, 17-beta-hydroxysteroid hydrogenase, steroid sulfatase as well as enzymes further hydroxylating estradiol, such as CYP1A1, CYP3A4, CYP1B1, catechol-o-methyltransferase (COMT). Polymorphisms in these enzymes may have a possible role in the link between environmental estrogens and hormone-like substances and the interindividual risk of breast cancer.

Angiogenesis and metastasis marker of human tumors

Tumor growth and metastasis are dependent on angiogenesis. Therefore, certain angiogenesis markers may be useful as metastasis markers and/or the targets for antiangiogenic therapy. We and others have been studying endoglin(EDG; CD105) for such purposes. EDG is a proliferation-associated antigen of endothelial cells and essential for angiogenesis. In addition, EDG is a component of the transforming growth factor(TGF)-beta receptor complex. Expression of EDG is up-regulated in tumor-associated angiogenic vasculature compared with normal tissue vasculature. Microvessel density detected for EDG expression in breast cancer tissues showed a statistically significant correlation with overall and disease-free survival. In addition, elevated serum EDG was associated with metastasis in patients with colorectal, breast, and other solid tumors. On the other hand, We have been targeting EDG on tumor vasculature to suppress tumor growth and metastasis by systemic(i.v.) administration of anti-EDG monoclonal antibodies(mAbs) and immunoconjugates(IMCs). To thid end, we have been using three animal models, i.e., severe combined immunodeficient(SCID) mouse model of MCF-7 human breast cancer, human skin/SCID mouse chimera model bearing MCF-7 tumor, and syngeneic metastasis model of colon-26 adenocarcinoma cells in BALB/c mice. In addition, antiangiogenic activities of anti-EDG mAbs and IMCs were evaluated in mice using the dorsal air sac assay. The IMCs were prepared by coupling deglycosylated ricin A-chain or 125I to individual anti-EDG mAbs. These anti-EDG IMCs and mAbs showed substantial antitumor efficacy and antimetastatic activities without showing severe toxicity. Recently, we generated a recombinant human/mouse chimeric anti-EDG mAb to facilitate clinical application of the mAb.

Activated protein C prevents endotoxin-induced hypotension in rats by inhibiting excessive production of nitric oxide

BACKGROUND

Excessive production of nitric oxide (NO) by the inducible isoform of NO synthase (iNOS) is critically involved in endotoxin (ET)-induced hypotension. Tumor necrosis factor-alpha (TNF-alpha) plays an important role in induction of iNOS. Because activated protein C (APC), a physiological anticoagulant, inhibits TNF-alpha production, it might prevent hypotension by inhibiting excessive production of NO. In this study, we examined this possibility using a rat model of septic shock.

METHODS AND RESULTS

Intravenous administration of APC prevented both ET-induced hypotension and the increases in plasma levels of NO(2)(-)/NO(3)(-). The hypotension was also inhibited when APC was administered 30 minutes after ET administration. APC inhibited the increases in lung levels of iNOS activity by inhibiting expression of iNOS mRNA in animals given ET. APC significantly inhibited the increases in lung tissue levels of TNF-alpha and expression of TNF-alpha mRNA in animals given ET. Neither DEGR-F.Xa, a selective inhibitor of thrombin generation, nor DIP-APC, an active site-blocked APC, showed any effect on these ET-induced changes. Both inhibition of TNF-alpha production by leukocytopenia and treatment with anti-rat TNF-alpha antibody produced effects similar to those induced by APC. Aminoguanidine, a selective inhibitor of iNOS, inhibited both the hypotension and the increases in plasma levels of NO(2)(-)/NO(3)(-) in this animal model.

CONCLUSIONS

These observations strongly suggest that APC inhibits iNOS induction by decreasing TNF-alpha production, leading to the prevention of ET-induced hypotension. Furthermore, such effects of APC were not dependent on its anticoagulant effects but rather on its serine protease activity.

Immunohistochemical localization of steroidogenic enzymes in the corpus luteum and the placenta of the ribbon seal (Phoca fasciata) and steller sea lion (Eumetopias jubatus)

To study the luteal and placental function of pinnipeds, we analyzed the localization of steroidogenic enzymes (P450scc, 3 beta HSD and P450arom) in the corpus luteum and the placenta of ribbon seals (Phoca fasciata) and Steller sea lions (Eumetopias jubatus) immunohistochemically. P450scc and 3 beta HSD were present in all luteal cells of both species. Almost all of the luteal cells were immunostained for P450arom, while P450scc and 3 beta HSD were negatively immunostained in placentae and P450arom was present in the syncytiotrophoblast of placentae. These findings suggest that 1) corpora lutea of both species synthesize pregnenolone, progesterone and estrogen during the entire pregnancy period, and 2) like other terrestrial carnivores in the suborder Caniformia, placentae of both species do not have the capability for synthesizing progesterone in the latter half of active pregnancy period.

Age differences in muscarinic cholinergic receptors assayed with (+)N-[(11)C]methyl-3-piperidyl benzilate in the brains of conscious monkeys

Age-related changes in muscarinic cholinergic receptors were evaluated with the novel ligand (+)N-[(11)C]methyl-3-piperidyl benzilate ((+)3-MPB) in the living brains of young (5.9 +/- 1.8 years old) and aged (19.0 +/- 3.3 years old) monkeys (Macaca mulatta) in the conscious state using high-resolution positron emission tomography (PET). For quantitative analysis of receptor binding in vivo, metabolite-corrected arterial plasma radioactivity curves were obtained as an input function into the brain, and kinetic analyses using the three-compartment model and graphical Logan plot analysis were applied. Kinetic analyses of [(11)C](+)3-MPB indicated a regionally specific decrease in the receptor binding in vivo determined as binding potential (BP) = k(3)/k(4) in aged animals compared with young animals. Thus, the frontal and temporal cortices as well as the striatum showed age-related reduction of muscarinic cholinergic receptors in vivo, reflecting the reduced receptor density (B(max)) determined by Scatchard plot analysis in vivo. In the hippocampus, although BP of [(11)C](+)3-MPB indicated no significant age-related changes, it showed an inverse correlation with individual cortisol levels in plasma. When the graphical Logan plot analysis was applied, all regions assayed showed significant age-related decrease of [(11)C](+)3-MPB binding. These results demonstrate the usefulness of kinetic three-compartment model analysis of [(11)C](+)3-MPB with metabolite-corrected arterial plasma input as an indicator for the aging process of the cortical muscarinic cholinergic receptors in vivo as measured by PET.

Somatic activation of beta-catenin bypasses pre-TCR signaling and TCR selection in thymocyte development

Mutation or ablation of T cell factor 1 and lymphocyte enhancer factor 1 indicated involvement of the Wnt pathway in thymocyte development. The central effector of the Wnt pathway is beta-catenin, which undergoes stabilization upon binding of Wnt ligands to frizzled receptors. We report here that conditional stabilization of beta-catenin in immature thymocytes resulted in the generation of single positive T cells that lacked the alpha beta TCR and developed in the absence of pre-TCR signaling and TCR selection. Although active beta-catenin induced differentiation in the absence of TCRs, its action was associated with reduced proliferation and survival when compared to developmental changes induced by the pre-TCR or the alpha beta TCR.

Synthesis, absolute configuration, and enantiomeric enrichment of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin, and its oxazoline analog

Stereochemical studies of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin [(-)-4], and its oxazoline analogue, spirooxazoline (11), were carried out. Racemic spirobrassinin [(+/-)-4] was synthesized by SOCl(2)- or MsCl-mediated cyclization of dioxibrassinin [(+/-)-8]. Treatment of (3-hydroxyoxindol-3-yl)methylammonium chloride [(+/-)-9] with CSCl(2) and subsequent methylation of the obtained spirooxazolidinethione (+/-)-10 afforded spirooxazoline [(+/-)-11]. Enantioresolution of (+/-)-4 and (+/-)-11 was achieved by derivatization with (S)-(-)-1-phenylethyl isocyanate (12), chromatographic separation of diastereomeric amides 13, 14 or 15, 16, and their cleavage with CH(3)ONa. Absolute configuration of the stereogenic center in natural (S)-(-)-4 was derived from the exciton, calculated via CD methods, and unequivocally confirmed by X-ray crystallographic analyses of 1-[1'S,4'R-(-)-camphanoyl] derivatives [(-)-19 and (-)-20] of (+)- and (-)-4. Novel enantiomeric enrichment phenomena of 4 and 11 were discovered during their chromatographic separations under achiral HPLC conditions. Screening of antifungal activity against the fungus Bipolaris leersiae revealed no significant dependence of this activity on absolute configuration.

Brain aromatase is neuroprotective

The expression of aromatase, the enzyme that catalyzes the biosynthesis of estrogens from precursor androgens, is increased in the brain after injury, suggesting that aromatase may be involved in neuroprotection. In the present study, the effect of inactivating aromatase has been assessed in a model of neurodegeneration induced by the systemic administration of neurotoxins. Domoic acid, at a dose that is not neurotoxic in intact male mice, induced significant neuronal loss in the hilus of the hippocampal formation of mice with reduced levels of aromatase substrates as a result of gonadectomy. Furthermore, the aromatase substrate testosterone, as well as its metabolite estradiol, the product of aromatase, were able to protect hilar neurons from domoic acid. In contrast, dihydrotestosterone, the 5 alpha-reduced metabolite of testosterone and a nonaromatizable androgen, was not. These findings suggest that aromatization of testosterone to estradiol may be involved in the neuroprotective action of testosterone in this experimental model. In addition, aromatase knock-out mice showed significant neuronal loss after injection of a low dose of domoic acid, while control littermates did not, indicating that aromatase deficiency increases the vulnerability of hilar neurons to neurotoxic degeneration. The effect of aromatase on neuroprotection was also tested in male rats treated systemically with the specific aromatase inhibitor fadrozole and injected with kainic acid, a well characterized neurotoxin for hilar neurons in the rat. Fadrozole enhanced the neurodegenerative effect of kainic acid in intact male rats and this effect was counterbalanced by the administration of estradiol. Furthermore, the neuroprotective effect of testosterone against kainic acid in castrated male rats was blocked by fadrozole. These findings suggest that neuroprotection by aromatase is due to the formation of estradiol from its precursor testosterone. Finally, a role for local cerebral aromatase in neuroprotection is indicated by the fact that intracerebral administration of fadrozole enhanced kainic acid induced neurodegeneration in the hippocampus of intact male rats. These findings indicate that aromatase deficiency decreases the threshold for neurodegeneration and that local cerebral aromatase is neuroprotective. Brain aromatase may therefore represent a new target for therapeutic approaches to neurodegenerative diseases.

Effects of different burs on dentin bond strengths of self-etching primer bonding systems

This study evaluated the effects of cutting dentin with different types of burs on tensile bond strength using three self-etching primer bonding systems (Clearfil Liner Bond 2 [LB2], Clearfil Liner Bond 2V [2V] and Clearfil SE BOND [SE], Kuraray, Co, Ltd, Osaka, Japan). Thirty-six intact extracted human third molars were ground flat to expose occlusal dentin, followed by polishing the dentin surfaces with #600 SiC paper. The teeth were divided into four groups according to bur type and grit: fine cut fissure steel bur (SB600), cross cut fissure steel bur (SB703), regular grit diamond bur (DB). Controls were abraded with #600 grit SiC paper (AP#600). The dentin surfaces of the SB600, SB703 and DB groups were cut under copious air-water spray with the respective burs mounted in a dental handpiece. The teeth were treated with one of three adhesive systems, then composite buildups were created with Clearfil AP-X (Kuraray Co, Ltd, Osaka, Japan). After soaking in water at 37 degrees C for 24 hours, serial vertical sections (0.7 mm thick, 7-8 slices per one tooth) were made, trimmed to form an hour-glass shape with a 1.0 mm2 cross-section and tensile bond strengths were determined at a cross-head speed of 1 mm/min. Statistical analysis was made using one and two-way ANOVA and Fisher's PLSD test (p<0.05). Eight additional molars were prepared. Burs or abrasive paper were used for SEM observations of the dentin surfaces of each group before and after treatment with the self-etching primers. All adhesive systems yielded the same ranking of bond strengths to the surfaces prepared with different abrasives: from highest to lowest, AP#600 > SB600 > SB703 > DB. This ranking reached statistical significance using Clearfil Liner Bond 2V (p<0.05). Therefore, when cutting dentin, selecting the adequate bur type is important for improved bonding of adhesive systems using self-etching primer to dentin.

The analyses of 17beta-hydroxysteroid dehydrogenase isozymes in human endometrial hyperplasia and carcinoma

Intratumoral metabolism and synthesis of estrogens are considered to play very important roles in the pathogenesis and development of human endometrial adenocarcinoma. The 17beta-hydroxysteroid dehydrogenase (17beta-HSD) isozymes catalyze the interconversion of estradiol (E2) and estrone and thereby serve to modulate the tissue levels of bioactive E2. To elucidate the possible involvement of this enzyme in human endometrial carcinoma, we first examined the expression of 17beta-HSD type 1 and type 2 in 20 normal cycling human endometria, 36 endometrial hyperplasia, and 46 endometrial endometrioid adenocarcinoma using immunohistochemistry, and we then studied immunoreactivity of 17beta-HSD type 2 using immunoblotting analyses, the activity of 17beta-HSD type 1 and type 2 using thin-layer chromatography and their expression using RT-PCR in endometrial endometrioid adenocarcinoma. We correlated these findings with various clinicopathological parameters to examine the biological significance of 17beta-HSDs in human endometrial disorders. 17beta-HSD type 2 immunoreactivity in normal endometrium was present in all cases of secretory phase (n = 14), but not in any endometrial mucosa of proliferative phase (n = 6). In addition, 17beta-HSD type 2 immunoreactivity was detected in 27 of 36 (75%) endometrial hyperplasia and 17 of 46 (37%) carcinoma cases. 17beta-HSD type 1 immunoreactivity was not detected in all the cases examined. In both endometrial hyperplasia and carcinoma cases there were significant positive correlations between 17beta-HSD type 2 and progesterone receptor labeling index (LI). In carcinoma cases, a significant inverse correlation was detected between 17beta-HSD type 2 immunoreactivity and age. In addition, 17beta-HSD type 2 immunoreactivity was also correlated with 17beta-HSD type 2 enzymatic activity, and semiquantitative analyses of 17beta-HSD type 2 messenger RNA. No significant correlations were detected between 17beta-HSD type 2 and estrogen receptor LI, Ki67 LI, amount of aromatase messenger RNA or histological grade. These data indicated that the expression of 17beta-HSD type 2 in hyperplastic and/or neoplastic endometrium may represent altered cellular features through hyperplastic and neoplastic transformation. However, 17beta-HSD type 2 may also play some protective and/or suppressive roles toward unopposed estrogenic effects through inactivating E2 in situ, especially in premenopausal patients.

[Genetic polymorphism and variability of steroid hormone metabolism: connection with risk of developing breast neoplasms]

Endogenous estradiol is synthesized in the ovarian theca cells of premenopausal women or in the stromal adipose cells of the breast of postmenopausal women and in minor quantities in peripheral tissue. These cells, as well as breast cancer tissue, express all the necessary enzymes for this synthesis: CYP17, CYP11a, CYP19, hydroxysteroid hydrogenase, steroid sulphatase as well as enzymes further hydroxylating estradiol such as CYP1A1, CYP3A4, CYP1B1. Polymorphisms in these enzymes may have a possible role in the link between environmental estrogens and hormone-like substances and the interindividual risk of breast cancer.

Bond strengths of self-etching primer adhesives to in vitro-demineralized dentin following mineralizing treatment

PURPOSE

The purpose of this study was to determine if treatment of experimentally demineralized dentin with a calcium phosphate precipitating (CPP) solution could restore the bond strength of self-etching adhesives to that of normal mineralized control values.

MATERIALS AND METHODS

The occlusal surfaces of human teeth were exposed for bonding. The teeth were assigned to a mineralized control group or one of three demineralized (40% phosphoric acid for 60 s) experimental groups. One of the experimental groups remained untreated, while the other two were treated with the CPP solutions for either 1 or 10 min. All experimental groups were then chemically dehydrated with ascending acetone concentrations to prevent shrinkage prior to bonding with Clearfil Liner Bond 2 (LB2) or MacBond II (MBII). Composite buildups were made and vertically, serially sectioned into multiple slabs about 0.7 mm thick. Each slab was then trimmed for microtensile bond testing and SEM examination.

RESULTS

Both self-etching adhesives produced high bond strengths to control mineralized dentin (ca 42 and 37 MPa for LB2 and MBII, respectively). Acid etching with 40% phosphoric acid for 60 s followed by chemical dehydration significantly lowered (p < 0.05) bond strength to 26 and 27 MPa for LB2 and MBII, respectively, and created hybrid layers between 7 and 8 microns thick. When the demineralized dentin was treated with the CPP solution for 1 min, the bond strengths increased (p < 0.05) to 39 for LB2 and 42 MPa for MBII, and the hybrid layers were 11 microns thick. Increasing the CPP treatment time to 10 min lowered (p < 0.05) bond strengths but increased the hybrid layer thickness to 16 to 20 microns.

CONCLUSION

The use of calcium phosphate precipitating solutions may permit higher bond strengths of self-etching primers to demineralized (e.g., caries-affected) dentin.

Involvement of adenosine in vascular contractile preconditioning

Measurements of isometric tensions of rat aortic rings revealed the fact that when aortic rings with intact endothelium were precontracted (preconditioned) for 20 min by the alpha1-adrenergic agonist phenylephrine (10 microM), the tonic level of subsequent contraction by the same agonist was depressed and/or declined regardless of the presence or absence of endothelium during the second contraction. The removal of endothelium before preconditioning showed no such phenomenon. With the use of specific blockers, involvements of adenosine or of ATP-sensitive K+ (K(ATP)) channels during preconditioning or second contraction, respectively, were evaluated. Actions of nitric oxide synthase, cyclooxygenase, P(2) ATP purinoceptors, or K(ATP) channels during preconditioning appear not to be involved. Exogenous adenosine (up to 100 microM) without endothelium could mimic the preconditioning; however, contractile preconditioning by phenylephrine, mechanical stretching, or activation of protein kinase C needed to be done. The release of adenosine and adenine nucleotides from aortic rings was augmented by phenylephrine or by mechanical stretching of the rings with intact endothelium. Our results suggest that during vasocontraction, endothelium-derived adenosine acquires an ability to protect vascular tone against subsequent repeated contractions by mediating a delayed, possibly indirect, opening of K(ATP) channels.

Evaluation of PET ligands (+)N-[(11)C]ethyl-3-piperidyl benzilate and (+)N-[(11)C]propyl-3-piperidyl benzilate for muscarinic cholinergic receptors: a PET study with microdialysis in comparison with (+)N-[(11)C]methyl-3-piperidyl benzilate in the conscious monkey brain

We developed PET ligands (+)N-[(11)C]ethyl-3-piperidyl benzilate ([(11)C](+)3-EPB) and (+)N-[(11)C]propyl-3-piperidyl benzilate ([(11)C](+)3-PPB) for cerebral muscarinic cholinergic receptors. The distribution and kinetics of the novel ligands were evaluated for comparison with the previously reported ligand (+)N-[(11)C]methyl-3-piperidyl benzilate ([(11)C](+)3-MPB) in the monkey brain (Macaca mulatta) in the conscious state using high-resolution positron emission tomography (PET). At 60-91 min postinjection, regional distribution patterns of these three ligands were almost identical, and were consistent with the muscarinic receptor density in the brain as previously reported in vitro. However, the time-activity curves of [(11)C](+)3-EPB and [(11)C](+)3-PPB showed earlier peak times of radioactivity and a faster clearance rate than [(11)C](+)3-MPB in cortical regions rich in the receptors. Kinetic analysis using the three-compartment model with time-activity curves of radioactivity in metabolite-corrected arterial plasma as input functions revealed that labeling with longer [(11)C]alkyl chain length induced lower binding potential (BP = k(3)/k(4)), consistent with the rank order of affinity of these ligands obtained by an in vitro assay using rat brain slices and [(3)H]QNB. The cholinesterase inhibitor Aricept administered at doses of 50 and 250 microg/kg increased acetylcholine level in extracellular fluid of the frontal cortex and the binding of [(11)C](+)3-PPB with the lowest affinity to the receptors was displaced by the endogenous acetylcholine induced by cholinesterase inhibition, while [(11)C](+)3-MPB with the highest affinity was not significantly affected. Taken together, these observations indicate that the increase in [(11)C]alkyl chain length could alter the kinetic properties of conventional receptor ligands for PET by reducing the affinity to receptors, which might make it possible to assess the interaction between endogenous neurotransmitters and ligand-receptor binding in vivo as measured by PET.