Ethnic disparities in perioperative management among foreigners residing in Japan.

The objectives of this research were to examine the current status of perioperative treatment among foreigners, to elucidate the health status/outcome disparities that contribute to ethnic differences, and to recommend counter-measures to rectify these ethnic disparities. The authors identified 36 non-Japanese and 111 Japanese females who underwent gynecological surgery from 2004 to 2009 at a single institution. Electronic medical records were reviewed and telephone survey was conducted in order to obtain patient background, preoperative, operative, and postoperative data. The non-Japanese group showed significantly larger number of uninsured, shorter length of stay (LOS), higher rate of emergency surgery, and higher cases of spinal anesthesia. There were significant differences in length of residency in Japan and LOS among four foreign countries. Seventy-nine percent of patients contacted by phone understood informed consent from doctors, 73.7% understood explanation in operating room (OR), and 84.2% understood explanation from anesthesiologists. This research was the first survey of the ethnic disparities in perioperative management among foreign patients treated in Osaka. The authors have demonstrated differences in operative method, emergency surgery, anesthesia, and American Society of Anesthesiologists physical status (ASA-PS) due to the difference in disease structure, language, and culture. It is recommended that the barriers between non-Japanese patients and medical staff are rectified during the perioperative period when mutual understanding is needed the most.

Differential effects of transforming growth factor-beta on the synthesis of extracellular matrix proteins by normal fetal rat calvarial bone cell populations.

To determine the effects of transforming growth factor-beta (TGF-beta) on the different cell types that exist in bone, cell populations (I-IV), progressively enriched in osteoblastic cells relative to fibroblastic cells, were prepared from fetal rat calvaria using timed collagenase digestions. TGF-beta did not induce anchorage-independent growth of these cells, nor was anchorage-dependent growth stimulated in most populations studied, despite a two- to threefold increase in the synthesis of cellular proteins. In all populations the synthesis of secreted proteins increased 2-3.5-fold. In particular, collagen, fibronectin, and plasminogen activator inhibitor synthesis was stimulated. However, different degrees of stimulation of individual proteins were observed both within and between cell populations. A marked preferential stimulation of plasminogen activator inhibitor was observed in each population, together with a slight preferential stimulation of collagen; the effect on collagen expression being directed primarily at type I collagen. In contrast, the synthesis of SPARC (secreted protein acidic rich in cysteine/osteonectin was stimulated approximately two-fold by TGF-beta, but only in fibroblastic populations. Collectively, these results demonstrate that TGF-beta stimulates matrix production by bone cells and, through differential effects on individual matrix components, may also influence the nature of the matrix formed by different bone cell populations. In the presence of TGF-beta, osteoblastic cells lost their polygonal morphology and alkaline phosphatase activity was decreased, reflecting a suppression of osteoblastic features. The differential effects of TGF-beta on bone cell populations are likely to be important in bone remodeling and fracture repair.

Nitric oxide attenuates vascular endothelial cadherin-mediated vascular integrity in human chronic inflammation.

In this study, we examined the role of nitric oxide (NO) in controlling vascular integrity mediated by vascular endothelial (VE)-cadherin in chronic inflammation. Periapical granulomas were analysed for the expression of inducible NO synthase (iNOS) and VE-cadherin, and more iNOS expression than VE-cadherin was shown. Human umbilical vein endothelial cells (HUVECs) were stimulated with proinflammatory cytokines and lipopolysaccharide extracted from Porphyromonas gingivalis and it induced iNOS expression, whereas it reduced VE-cadherin expression, compared with negative controls. On the other hand, pre-incubation with 1400W, an iNOS-specific inhibitor, markedly reduced iNOS expression in stimulated HUVECs and restored VE-cadherin expression to its control level, suggesting that vascular integrity was modulated in conjunction with the reduction of NO. Immunocytochemistry confirmed the functional role of NO in cultured HUVEC monolayers with or without 1400W. These data are consistent with a hypothesis suggesting that NO could attenuate VE-cadherin-mediated vascular integrity in human chronic inflammation.

Function of Platelet-Induced Epithelial Attachment at Titanium Surfaces Inhibits Microbial Colonization.

The aim of this study was to evaluate the barrier function of platelet-induced epithelial sheets on titanium surfaces. The lack of functional peri-implant epithelial sealing with basal lamina (BL) attachment at the interface of the implant and the adjacent epithelium allows for bacterial invasion, which may lead to peri-implantitis. Although various approaches have been reported to combat bacterial infection by surface modifications to titanium, none of these have been successful in a clinical application. In our previous study, surface modification with protease-activated receptor 4-activating peptide (PAR4-AP), which induced platelet activation and aggregation, was successful in demonstrating epithelial attachment via BL and epithelial sheet formation on the titanium surface. We hypothesized that the platelet-induced epithelial sheet on PAR4-AP-modified titanium surfaces would reduce bacterial attachment, penetration, and invasion. Titanium surface was modified with PAR4-AP and incubated with platelet-rich plasma (PRP). The aggregated platelets released collagen IV, a critical BL component, onto the PAR4-AP-modified titanium surface. Then, human gingival epithelial cells were seeded on the modified titanium surface and formed epithelial sheets. Green fluorescent protein (GFP)-expressing Escherichia coli was cultured onto PAR4-AP-modified titanium with and without epithelial sheet formation. While Escherichia coli accumulated densely onto the PAR4-AP titanium lacking epithelial sheet, few Escherichia coli were observed on the epithelial sheet on the PAR4-AP surface. No bacterial invasion into the interface of the epithelial sheet and the titanium surface was observed. These in vitro results indicate the efficacy of a platelet-induced epithelial barrier that functions to prevent bacterial attachment, penetration, and invasion on PAR4-AP-modified titanium.

Expression of an amphibian homolog of the Eph family of receptor tyrosine kinases is developmentally regulated.

In order to study the function of tyrosine kinase receptors during Xenopus development, we have isolated Xek (Xenopus Elk-like kinase), a tyrosine kinase receptor, which shows significant homology to rat Elk and chicken cek5, members of the Eph family. Xek exists as a maternally expressed mRNA which decreases in expression at the mid blastula transition and reappears at late neurulation in Xenopus. Xek mRNA is expressed at higher levels in the anterior and dorsal regions of embryonic stages 16, 24 and 37. In adult Xenopus tissues, Xek appears to be ubiquitously expressed with higher expression observed in brain and ovary. In situ hybridization analysis demonstrates localized mRNA expression in the brain, brachial arches, trigeminal facial ganglion, and the retina of the swimming tadpole stage of development. The similarities in sequence and expression pattern suggest that Xek is an amphibian member of the Eph family and may play a role in the development or function of the central nervous system.

Two-step induction of primitive erythrocytes in Xenopus laevis embryos: signals from the vegetal endoderm and the overlying ectoderm.

Primitive blood cells differentiate from the ventral mesoderm blood islands in Xenopus embryos. In order to determine the tissue interactions that propagate blood formation in early embryogenesis, we used embryos that had the ventral cytoplasm removed. These embryos gastrulated normally, formed a mesodermal layer and lacked axial structures, but displayed a marked enhancement of alpha-globin expression. Early ventral markers, such as msx-1, vent-1 and vent-2 were highly expressed at the gastrula stage, while a dorsal marker, goosecoid, was diminished. Several lines of experimental evidence demonstrate the critical role of animal pole-derived ectoderm in blood cell formation: 1) Mesoderm derived from dorsal blastomeres injected with beta-galactosidase mRNA (as a lineage tracer) expressed alpha-globin when interfaced with an animal pole-derived ectodermal layer; 2) Embryos in which the animal pole tissue had been removed by dissection at the blastula stage failed to express alpha-globin; 3) Exogastrulated embryos that lacked an interaction between the mesodermal and ectodermal layers failed to form blood cells, while muscle cells were observed in these embryos. Using dominant-negative forms of the BMP-4 and ALK-4 receptors, we showed that activin and BMP-4 signaling is necessary for blood cell differentiation in ventral marginal zone explants, while FGF signaling is not essential. In ventralized embryos, inactivation of the BMP-4 signal within a localized area of the ectoderm led to suppression of globin expression in the adjacent mesoderm layer, but inactivation of the activin signal did not have this effect. These observations suggest that mesodermal cells, derived from a default pathway that is induced by the activin signal, need an additional BMP-4-dependent factor from the overlying ectoderm for further differentiation into a blood cell lineage.

Cloning and expression of cDNA encoding Xenopus laevis bone morphogenetic protein-1 during early embryonic development.

The Xenopus laevis DNA fragment encoding a protein homologous with human bone morphogenetic protein-1 (BMP-1) was amplified by polymerase chain reaction (PCR) from cDNA derived from stage 26 (st.26) embryonic RNA. Subsequently this fragment was used as a probe to isolate cDNA clones by screening of a X. laevis st.24 embryonic cDNA library. Two partial clones (22 and 63) were obtained and the missing 5'-end of the clone 22 was extended by the anchored PCR technique. The nucleotide sequence of the resulting clone (22AN) contained an open reading frame coding for a protein with 707 deduced amino acids. Three sizes of mRNA (2.9, 5.2 and 6.6 kb) were detected in blastula (st.9) and early gastrula (st.10) embryos, and in hatched tadpole (st.40), but little or no expression was observed in morula (st.7) and late gastrula (st.12) embryos, suggesting a physiological role(s) of X.laevis BMP-1 in normal embryonic development.

Elicitation of weak immune response in larval and adult Xenopus laevis by allografted pituitary.

To test the claim that tolerance to organ-specific self antigens is established during the ontogenic development of the immune system, pituitary anlagen were removed from early tailbud embryos of Xenopus laevis, and the resulting hypophysectomized tadpoles were grafted with pituitaries after the tadpoles had become immunocompetent. The result was that none of the histocompatible or allogeneic pituitary grafts was rejected throughout an observation period of 100 days. Subsequent experiments revealed that hypophysectomy does not affect the development of immune responsiveness. In addition, allogeneic pituitary grafts were usually not rejected by unoperated, normal tadpoles or froglets, although they suffered lymphoid invasion to various degrees. However, a significant number of allogeneic pituitaries was rejected when they were grafted, either after or at the same time as the grafting of skin from the pituitary donors. We conclude that the pituitary of Xenopus possesses weak transplantation antigens or expresses them in ways that make them less accessible to the immune surveillance system of the allogeneic host.

Analysis of allotolerance in thymectomized Xenopus restored with semiallogeneic thymus grafts.

The triploid J strain Xenopus laevis (MHC haplotype, j/j/j) were thymectomized as early larvae, and in the adult stage each animal was given a pair of thymuses or lymphocytes from semiallogeneic diploid donor frogs (j/k). The alloreactivity of host frogs was restored to third-party donors in terms of skin graft rejection and mixed leukocyte reaction, but there was specific unresponsiveness against the k haplotype. Grafting of heavily irradiated (10,000 rads) thymuses also restored host reactivity with induction of tolerance to the k haplotype. In the latter frogs, all thymic and splenic lymphocytes were of host origin. Injection of splenocytes from the restored frogs into secondary thymectomized J frogs not only restored immunocompetence but also transferred specific tolerance to the k haplotype. Injection of lymphocytes from the restored frogs to normal frogs failed to transfer specific tolerance by both in vivo and in vitro immune tests. The results suggest that a selective deletion of the T cell population reactive to the k haplotype was maintained in the T-cell-restored frogs.

Biochemical and immunocytochemical characterization of mineral binding proteoglycans in rat bone.

We examined biochemically and immunocytochemically the type and distribution of mineral binding proteoglycans (PGs) in rat mid-shaft subperiosteal bone using three monoclonal antibodies (MAb 1-B-5, 9-A-2, and 3-B-3) which specifically recognize unsulfated chondroitin, chondroitin 4-sulfate (C4-S) and dermatan sulfate (DS), and chondroitin 6-sulfate. Bone proteins were extracted from fresh specimens with a three-step technique: 4 M guanidine HCl (GdnCl), aqueous EDTA without GdnCl (E-extract), followed by GdnCl. Western blot analysis of SDS-polyacrylamide gel electrophoresis revealed that E-extract after chondroitinase ABC digestion reacted strongly with MAb 9-A-2 but not with MAb 1-B-5 or 3-B-3. After adehyde fixation, ethanolic trimethylammonium EDTA was used as a demineralizing agent for light and electron immunocytochemistry. This provided good retention of water-soluble PGs in the specimens. After chondroitinase ABC pre-treatment of tissue sections, MAb 9-A-2 specifically stained C4-S and/or DS in the walls of osteocyte lacunae and bone canaliculi in the mineralized matrix as well as in the unmineralized matrix such as pre-bone, vascular canals, and pericellular matrix surrounding osteocytes; the remainder of the mineralized matrix lacked staining. These results indicate that mineral binding PGs contain C4-S and/or DS and are exclusively localized in the walls of the bone lacuna and canaliculus.

Nature and distribution of mineral-binding, keratan sulfate-containing glycoconjugates in rat and rabbit bone.

The presence of keratan sulfate (KS) and KS proteoglycans in bone has been demonstrated in birds and rabbits but comparison with other animal species has not been investigated. The nature and distribution of mineral-binding, KS-containing glycoconjugates in rat and rabbit bone were investigated with a monoclonal antibody (MAb 5D4) specific for KS. Mineral-binding proteins were extracted from the mineralized bone with 0.4 M EDTA without guanidine-HCl (E-extract). On Western blot analysis of SDS-polyacrylamide gel electrophoresis, rat E-extract gave a weak 5D4-reactive band, M(r) 66,000-68,000, whereas rabbit E-extract produced two major reactive populations of small and large molecular size; one population consisted of two closely spaced bands at M(r) 61,000-63,000 and 66,000-68,000, and the other population consisted of one band at approximately M(r) 200,000. The identity of KS chains was further established by the sensitivity of these bands to keratanase II (Bacillus sp. Ks 36) and endo-beta-galactosidase. Immunocytochemistry with MAb 5D4 showed that, in rat bone, staining associated with the mineral phase was limited to the walls of osteocytic lacunae and bone canaliculi, whereas the remainder of the mineralized matrix lacked staining. In contrast, in rabbit bone the staining was distributed over the entire portion of the mineralized matrix with focal accumulation of staining in the wall of the lacunocanalicular system. These results indicate that rat bone contains a mineral-binding, KS-containing glycoconjugate with preferential localization in the wall of the lacunocanalicular system, whereas rabbit bone contains at least two or possibly three types of KS-containing glycoconjugates distributed over the entire portion of the mineralized matrix.

Gadolinium-enhanced magnetic resonance imaging in acute myocardial infarction.

To investigate the clinical application of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) in the management of acute myocardial infarction (AMI), we examined 44 patients with AMI within 1 month after onset. Enhanced images were classified into 4 types: nontransmural (type 1), transmural and homogeneous (type 2), transmural and marginal (type 3), and no enhancement (type 4). Each enhancement pattern was correlated with angiographic and thallium-201 imaging results. The redistribution images of thallium were graded on a 4-point scale from 0 (normal) to 3 (markedly reduced or absent activity). The percentage of the perimeter affected by asynergy was obtained from the left ventriculogram. Peak creatine kinase and the percentage of asynergic perimeter were significantly higher in type 3 than in other type patients. End-diastolic volume index was significantly higher in type 3 than in type 2 patients. Left ventricular ejection fraction was lowest, and end-systolic volume index, thallium-201 score, and incidence of wall thinning on MRI were highest in type 3 patients. Therefore, the transmural and marginal enhancement pattern (type 3) was compatible with extensive myocardial infarction with infarct expansion and less viable myocardium. In the other types, the infarction was small to moderate in size and left ventricular function was well preserved. Thus, Gd-DTPA-enhanced MRI may be useful in the evaluation of left ventricular function and myocardial viability of the infarct region after AMI.

Expression and Function of Xmsx-2B in Dorso-Ventral Axis Formation in Gastrula Embryos.

Msx is a homeodomain-containing transcriptional factor that plays an essential role in pattern formation in vertebrata and invertebrata embryos. In Xenopus laevis, two msx genes have been identified (Xmsx-1 and Xmsx-2). In the present study, we attempted to elucidate the expression and function of Xmsx-2B (formerly designated as Xhox7.1') in early embryogenesis. Whole mount in situ hybridization analyses showed that the expression pattern of Xmsx-2B at gastrula and neurula stages was very similar to that of Xmsx-1: the transcript of Xmsx-2B was observed in ventral and lateral sides of the embryo. At the tailbud stage, however, the expression pattern of Xmsx-2B in neural tissues was distinct from that of Xmsx-1. An RNA injection experiment revealed that, like BMP-4, Xmsx-2B has a strong ventralizing activity. In the Xmsx-2B -injected embryos, differentiation of axial structures such as the notochord, muscle, and neural tissue was completely suppressed, whereas alpha-globin mRNA, a blood cell marker, was highly expressed. Simultaneous injection of Xmsx-1 and Xmsx-2B RNAs showed that they function in an additive manner. It was also shown that coinjection of Xmsx-2B with a dominant-negative BMP-4 receptor (tBR), which can induce formation of secondary axis when injected alone in ventral blastomeres, suppressed secondary axis formation. Furthermore, Xmsx-2B also suppressed secondary axis formation, which was induced by a dominant-negative form of Xmsx-1 (VP16/msx-1). Therefore, like Xmsx-1, Xmsx-2B is a downstream nuclear factor of the BMP-4-derived ventralizing signal, and these two factors probably share the same target molecules. In conclusion, Xmsx-1 and Xmsx-2B function in dorso-ventral axis formation in early Xenopus laevis development.

Attachment of human periodontal ligament cells to enamel matrix-derived protein is mediated via interaction between BSP-like molecules and integrin alpha(v)beta3.

BACKGROUND: Although enamel matrix-derived protein (EMD) can stimulate attachment of human periodontal ligament (HPDL) cells to the root surface, the biological mechanism of this phenomenon is unclear. The purpose of this study was to determine which molecules in EMD are involved in the attachment of HPDL cells, and which types of integrins on the cell surface mediate the interaction between the cells and EMD. METHODS: HPDL explants were obtained from tooth surfaces extracted from 4 individuals, and cells taken from the individual explants were separately harvested and subcultured through as many as 5 passages. Cells were incubated on EMD-coated culture plates with and without neutral antibodies for integrins or RGD-sequence blocking peptides and stained with toluidine blue. Proteins in EMD that were able to induce cell attachment were identified by incubating sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) replicas with HPDL cells; the cell-binding regions were detected by staining the cells with toluidine blue. Characteristics of the cell-binding proteins in the EMD were identified by Western blot analysis. RESULTS: It was shown that anti-alpha(v)beta3 antibody and GRGDSP peptide markedly reduced attachment of HPDL cells to EMD. When the cells were incubated with SDS-PAGE replicas, distinct cell attachment was observed at a molecular mass of approximately 55 kDa. The cell-binding ability of this protein was completely blocked by treatment with anti-alpha(v)beta3 antibody or GRGDSP peptide. In the Western blot analysis, the 55 kDa protein was recognized by anti-bone sialoprotein (BSP) antibody as a single band. CONCLUSIONS: Our study provides the first evidence that the attachment of HPDL cells to EMD can be mediated by interaction between a BSP-like molecule and integrin alpha(v)beta3 on the cell surface.

Xenopus msx-1 regulates dorso-ventral axis formation by suppressing the expression of organizer genes.

We demonstrated previously that Xmsx-1 is involved in mesoderm patterning along the dorso-ventral axis, under the regulation of BMP-4 signaling. When Xmsx-1 RNA was injected into the dorsal blastomeres, a mass of muscle tissue formed instead of notochord. This activity was similar to that of Xwnt-8 reported previously. In this study, we investigated whether the activity of Xmsx-1 is related to the ventralizing signal and myogenesis promoting factor, Xwnt-8. Whole-mount in situ hybridization showed that Xmsx-1, Xwnt-8, and XmyoD were expressed in overlapping areas, including the ventro-lateral marginal zone at mid-gastrula stage. The expression of XmyoD was induced by the ectopic expression of either Xmsx-1 or Xwnt-8 in dorsal blastomeres, and Xwnt-8 was induced by the ectopic expression of Xmsx-1. On the other hand, the expression of Xmsx-1 was not affected by the loading of pCSKA-Xwnt-8 or dominant-negative Xwnt-8 (DN-Xwnt-8) RNA. In addition, Xmsx-1 RNA did not abrogate the formation of notochord if coinjected with DN-Xwnt-8 RNA. These results suggest that Xmsx-1 functions upstream of the Xwnt-8 signal. Furthermore, the antagonistic function of Xmsx-1 to the expression of organizer genes, such as Xlim-1 and goosecoid, was shown by in situ hybridization analysis and luciferase reporter assay using the goosecoid promoter construct. Finally if Xmsx-1/VP-16 fusion RNA, which was expected to function as a dominant-negative Xmsx-1, was injected into ventral blastomeres, a partial secondary axis formed in a significant number of embryos. In such embryos, the activity of luciferase, under the control of goosecoid promoter sequence, was significantly elevated at gastrula stage. These results led us to conclude that Xmsx-1 plays a central role in establishing dorso-ventral axis in gastrulating embryo, by suppressing the expression of organizer genes.

Feasibility of myocardial dual-isotope perfusion imaging combined with gated single photon emission tomography for assessing coronary artery disease.

The clinical feasibility of both dual-isotope single photon emission tomography (SPET) and gated SPET have been described. The present study evaluates the feasibility of combining gated SPET with exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET corrected for scatter. Ninety-one patients with known or suspected coronary artery disease underwent cardiac catheterization and coronary angiography. Twenty-nine of them underwent exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET with a second 201Tl injection 3 h after the initial 201Tl injection (protocol 1). We then segregated a Bull's eye polar map into three coronary artery territories and quantified the relative regional uptake. The remaining 62 patients underwent exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET combined with gated SPET. We visually evaluated exercise and rest images from the three coronary artery territories. Left ventricular (LV) function was assessed globally by means of the LV ejection fraction and regionally by means of visual scoring analysis, compared with left ventriculography (LVG). The correlation between rest 99mTc-tetrofosmin and 201Tl reinjection images in 87 areas of coronary artery territory (r=0.89, P<0.01) and in 13 infarcted areas (r =0.94, P<0.01) was very close in protocol 1. The overall values for vessel-related sensitivity, specificity and accuracy were 88%, 79% and 82%, respectively, in protocol 2. The correlation between gated SPET and LVG was significant and linear with respect to the LV ejection fraction (r=0.77, P<0.01). The wall motion score from visual evaluation in gated SPET revealed a close overall agreement with LVG (concordance rate, 88%; kappa, 0.670). Exercise 201Tl/rest 99mTc-tetrofosmin dual-isotope SPET with scatter correction for assessing the coronary artery disease offers excellent diagnostic accuracy and the additional gated SPET provides useful information about LV function similar to that for LVG. This sequential protocol requires only 2 h to generate much useful clinical information.

Noninvasive identification of left ventricular involvements in arrhythmogenic right ventricular dysplasia: comparison of 123I-MIBG, 201TlCl, magnetic resonance imaging and ultrafast computed tomography.

We examined the feasibility of myocardial 123I-MIBG, 201TlCl, magnetic resonance imaging (MRI) and ultrafast computed tomography (UFCT) for the early detection of left ventricular involvements in 15 patients with arrhythmogenic right ventricular dysplasia (ARVD). Radionuclide ventriculography (RNV) and myocardial imaging with 123I-MIBG, 201TlCl, MRI and UFCT were performed in all 15 patients and in 10 normal subjects. The patients' scans were visually interpreted by two nuclear medicine physicians taking into consideration the extent score (ES) and severity score (SS) calculated by using the bull's-eye view in relation to normal data derived from the normal subjects. The left ventricular ejection fraction (LVEF) was measured by RNV. Fourteen (93%) patients showed regional 123I-MIBG defects, while 12 (80%) patients showed regional 201TlCl defects. The ES and SS were higher in 123I-MIBG than 201TlCl (ES: 31.5 +/- 18.5 vs. 17.5 +/- 18.2, p < 0.01, SS: 34.8 +/- 42.2 vs. 16.9 +/- 37.5, p < 0.01). Abnormal UFCT and MRI findings suggesting fatty involvements of the LV myocardium were demonstrated in 7 patients (Group B), while 7 patients showed regional 123I-MIBG defects without abnormal UFCT and MRI findings (Group A). 123I-MIBG was significantly more sensitive than UFCT and MRI (p < 0.05), although one patient, an exception, showed abnormal UFCT findings for the apex of the LV myocardium without abnormal 123I-MIBG and MRI findings. The LVEF, as a measure of LV systolic function, was better preserved in Group A than in Group B (59.3 +/- 3.6 vs. 45.8 +/- 5.8, p < 0.01). The present findings indicated that myocardial imaging with 123I-MIBG sensitively detects myocardial damage in patients with ARVD in the early stage when cardiac systolic function is still preserved.

Comparative study of pyridoxine-alpha, beta-glucosides, and phosphopyridoxyl-lysine as a vitamin B6 nutrient.

The nutritional effects of pyridoxine-alpha-glucoside (PN-alpha-Glc), pyridoxine-5' beta-glucoside (PN-5' beta-Glc) and epsilon-N-(phosphopyridoxyl)-lysine (PNP-Lys) were examined by means of: 1) transport across the intestinal wall using everted rat intestine, 2) metabolic conversion by liver or kidney homogenate, and 3) oral administration of the compound to B6-deficient rats and the subsequent analysis of B6 derivatives found in plasma. Using everted sacs prepared from rat small intestine, PN-alpha-Glc was transported into the serosal side in its intact form. On the other hand, a part of PN-5' beta-Glc was found as PN on the serosal side (PN-5' beta-Glc: PN = 2:1). When PN-alpha-Glc, PN-5' beta-Glc or PNP-Lys was incubated with liver or kidney homogenate for 3 h at pH 6.0, PN-alpha-Glc was hydrolyzed to PN (6%), while there was no hydrolysis of PN-5' beta-Glc. After 30 min of administration of each B6 derivative to B6-deficient rats, blood was collected from the heart, and the B6-derivatives found in plasma were analyzed. It was ascertained that PN-alpha-Glc served as well as PN as a B6 nutrient, while PN-5' beta-Glc and PNP-Lys were not easily metabolized to the coenzyme form, pyridoxal 5'-phosphate.

Change in blood levels of vitamin B-6 derivatives in pregnant and lactating rats.

By using an HPLC method which we have developed, concentration changes of vitamin B-6 derivatives in blood of pregnant and lactating rats were studied. PLP and PL were the main derivatives in plasma and erythrocytes, and occasionally, PMP was found in the plasma of rats fed a normal solid diet which contained 8.3 mg PN.HCl/kg diet. Upon pregnancy, the plasma PLP concentration decreased significantly (p < 0.01), whereas plasma PL tended to increase (p < 0.05). PLP concentration in erythrocytes tended to increase upon pregnancy. These results suggest that metabolism or utilization of vitamin B-6 is altered upon pregnancy and that plasma PLP concentrations alone may not be a good indicator of nutritional status. Further confirmation was needed for so from erythrocyte samples under our analytical conditions was not so from erythrocyte samples under our analytical conditions was not converted to PIC-P via PLP, after the sample was treated with glyoxylic acid and then with KCN.

Feeding experiments of pyridoxine derivatives as vitamin B6.

In order to compare the nutritional effect of vitamin B6 derivatives, long-term feeding experiments with rats were carried out using pyridoxine-alpha-D-glucoside (PN-alpha-Glc), pyridoxine-beta-D-glucoside (PN-beta-Glc) or epsilon- (N-phosphopyridoxyl)lysine (PNP-Lys) with test diets consisting of basically the AIN-76 composition, except for the addition of 0.1 mg pyridoxine equivalent (PN eq.)/100 g diet. During 21 days of pair-feeding against the vitamin B6-deficient diet group, body weight gain, urinary excretion of xanthurenic acid and pyridoxic acid were measured. After the feeding experiment, rats were killed and examined in terms of liver kynureninase activity (EC 3.7.1.3) with and without adding exogenous pyridoxal 5'-phosphate (PLP), erythrocyte aspartate aminotransferase activity (EC 2.6.1.1), as well as PLP concentration in blood. Rats fed with PN-alpha-Glc grew well, relative to the PN group. On the contrary, PN-beta-Glc poorly served as vitamin B6 source, because average bioavailability was only about 22% in comparison to that of PN (100%). From this long-term feeding experiments, we have shown that PN-alpha-Glc (average bioavailability about 84%) is a good source of vitamin B6 similar to PN.