Fluoride analysis of apatite crystals with a central planar OCP inclusion: concerning the role of F- ions on apatite/OCP/apatite structure formation

To study the roles of F- ions in the formation of apatite crystals embedding octacalcium phosphate (OCP) lamella in the center of apatite (Ap), a range of the Ap/OCP/Ap lamellar-mixed crystals were synthesized under various concentrations of fluoride ion (F-) from 0. 1-1.0 ppm at pH 6.5 and 37 degrees C. The products were analyzed for the F- incorporation, F- distribution, and the amount of OCP and Ap by chemical analysis, X-ray diffraction (XRD), electron probe microanalysis (EPMA), and nuclear magnetic resonance (NMR) techniques. The F- content and the amount of apatite in the crystalline product increased with an increase in the F- concentration in solution, whereas the amount of OCP and the yield of total product decreased. EPMA indicated that F- ions are distributed in the crystals almost homogeneously. The combined analysis suggested that a low-substituted fluoridated hydroxyapatite (FHAp) grew on a small amount of F--containing OCP or on a surface-reaction layer of OCP, which has accumulated a small amount of F-. The roles of F- ions were hypothesized as the reduction of the growth rate and/or the critical thickness in the a*-axis direction of OCP, the enhancement of hydrolysis of OCP, and the activation of the growth of FHAp, resulting in thinner OCP lamella and thicker apatite lamella in the a*-axis direction with an increase in F- concentration.

Characteristic expression of cell adhesion molecules in adhalin deficiency

We have reported the reduction of the B1 subunit of laminin and that of heparan sulfate proteoglycan (HSPG) in two Japanese patients with adhalin deficiency. We here investigated immunohistochemically the expression of cell adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), neural cell adhesion molecule (NCAM), and CD44 (HCAM), in four Japanese patients with adhalin deficiency, compared to other types of muscular dystrophy. We found that NCAM was upregulated in a fair number of muscle fibers, regardless of the type of muscular dystrophy. ICAM-1 was detected on the rare muscle cell membrane in all patients. CD44 was barely detected on the muscle cell membrane in adhalin deficiency, in contrast to the strong expression of CD44 which was observed in other types of muscular dystrophy. These findings suggest that a different degenerative or regenerative process is involved in adhalin deficiency compared to other types of muscular dystrophy.

Bone bonding behavior of titanium and its alloys when coated with titanium oxide (TiO2) and titanium silicate (Ti5Si3)

It has been proposed that the essential requirement for artificial materials to bond to living bone is the formation of bonelike apatite on their surfaces in the body. Recent studies have shown that titanium hydrogel and silica gel induce apatite formation on their surface in a simulated body fluid. In this study, the influence of titanium oxide and titanium silicate on the bonding of titanium alloys to bone was studied. Rectangular implants (15 x 10 x 2.2 mm) of titanium, Ti-6Al-4V, Ti-6Al-2Nb-Ta, Ti-6Al-4V coated with TiO2, and Ti-6Al-4V coated with Ti5Si3 were implanted into the tibial metaphyses of mature rabbits. At 8 and 24 weeks after implantation, the tibiae containing the implants were dissected out and subjected to a detaching testing. The failure load for titanium, Ti-6Al-4V, Ti-6Al-2Nb-Ta, Ti-6Al-4V coated with TiO2, and Ti-6Al-4V coated with Ti5Si3 were, respectively, 0.68 +/- 0.48, 0.22 +/- 0.46, 0.67 +/- 0.59, 2.18 +/- 0.71 and 2.03 +/- 0.41 kgf at 8 weeks, and 2.7 +/- 0.91, 2.58 +/- 1.29, 2.38 +/- 0.41, 3.79 +/- 1.7, and 2.79 +/- 0.87 kgf at 24 weeks after implantation. Histological examination by Giemsa surface staining, CMR, and SEM-EPMA revealed the coated titanium alloy implants directly bonded to bone tissue during early implantation. A Ca-P layer was observed at the interface of the coated implants and the bone. The results of this study indicated that TiO2 and Ti5Si3 can enhance the early bonding of titanium alloys to bone by inducing a Ca-P layer (chemical apatite) on the surface of titanium alloys. It also is suggested that the direct bone contact occurs in relation to the calcium and phosphorus adsorption onto the surface of the titanium passive layer formed during long-term implantation.

Both the paired domain and homeodomain are required for in vivo function of Drosophila Paired

Drosophila paired, a homolog of mammalian Pax-3, is key to the coordinated regulation of segment-polarity genes during embryogenesis. The paired gene and its homologs are unusual in encoding proteins with two DNA-binding domains, a paired domain and a homeodomain. We are using an in vivo assay to dissect the functions of the domains of this type of molecule. In particular, we are interested in determining whether one or both DNA-binding activities are required for individual in vivo functions of Paired. We constructed point mutants in each domain designed to disrupt DNA binding and tested the mutants with ectopic expression assays in Drosophila embryos. Mutations in either domain abolished the normal regulation of the target genes engrailed, hedgehog, gooseberry and even-skipped, suggesting that these in vivo functions of Paired require DNA binding through both domains rather than either domain alone. However, when the two mutant proteins were placed in the same embryo, Paired function was restored, indicating that the two DNA-binding activities need not be present in the same molecule. Quantitation of this effect shows that the paired domain mutant has a dominant-negative effect consistent with the observations that Paired protein can bind DNA as a dimer.

Drosophila Paired regulates late even-skipped expression through a composite binding site for the paired domain and the homeodomain

The even-skipped (eve) pair-rule gene plays a key role in the establishment of the anterior-posterior segmental pattern of the Drosophila embryo. The continuously changing pattern of eve expression can be resolved into two phases. Early expression consists of seven broad stripes in the blastoderm embryo, while late expression, which occurs after cellularization, consists of narrow stripes with sharp anterior borders that coincide with the odd-numbered parasegment boundaries. Previous studies have shown that these two phases are controlled by separate classes of cis elements in the eve promoter. Early stripes are expressed by multiple stripe-specific elements under the control of maternal-effect genes and gap genes, while late stripes are expressed by a single regulatory element, the ‘late element’, under the control of pair-rule genes including eve itself. We report here that paired (prd), a pair-rule gene which had been considered to be below eve in the regulatory hierarchy of pair-rule genes, in fact plays a critical role in the regulation of late eve expression. Transgenic analysis shows that this regulation is largely mediated by an evolutionarily conserved sequence within the late element termed PTE (Paired Target Element). In vitro analysis shows that the Prd protein binds strongly to this sequence. Interestingly, PTE contains juxtaposed binding sites for the two DNA-binding domains of the Prd protein, the paired domain and the homeodomain. Mutagenesis of either binding site leads to significant reduction in the activity of the late element, indicating that both DNA-binding domains in the Paired protein are required for regulation.

High occurrence of primary malignant neoplasms in patients with adult T-cell leukemia/lymphoma, their siblings, and their mothers

BACKGROUND

Attempts were made to clarify the correlation between human T-cell leukemia/lymphoma virus (HTLV)-1 infection and malignant oncogenicity other than adult T-cell leukemia/lymphoma (ATL) in a case-control study.

METHODS

The occurrence of primary malignant neoplasms (MN) in 110 ATL patients, their parents, and 430 siblings was compared with HTLV-1 seronegative non-Hodgkin's lymphoma (NHL) patients, their parents and 867 siblings. The chi-square test, odds ratio (OR), and 95% confidence intervals (CI) were used to determine the statistical significance of differences in the occurrence of the primary MN among ATL patients, HTLV-1 seronegative NHL patients, their siblings, and their parents.

RESULTS

The occurrence of primary MN in the ATL patients was higher than the occurrence in HTLV-1 seronegative NHL patients (P = 0.0036; OR = 2.91; 95% CI: 1.42, 6.02). In siblings of the ATL patients, there was a higher occurrence of primary MN than in siblings of the HTLV-1 seronegative NHL patients (P < 0.0001; OR = 3.35; 95% CI: 2.01, 5.58). In mothers of the ATL patients, there was a higher occurrence of primary MN than in mothers of the HTLV-1 seronegative NHL patients (P = 0.0063; OR = 2.55; 95% CI: 1.30, 5.00), but not in fathers (P = 0.1602; OR = 1.68; 95% CI: 0.81, 3.47).

CONCLUSIONS

There is an increased risk of primary MN in ATL patients, their siblings, and their mothers.

[Surgical repair of a dissecting aortic aneurysm with entry at proximal descending aorta through left thoracotomy--a case report]

A 45-year-old man underwent a distal arch and descending aortic replacement through a left thoracotomy. His chronic type A dissecting aortic aneurysm had the entry at the proximal descending aorta. After 9 years of his first dissection, he suffered from a second dissection. In computerized tomogram (CT), the ascending and descending aorta enlarged to 6.0 cm and 7.0 cm in diameter, respectively and descending aorta showed a three channeled dissection. The open proximal anastomosis technique was used under the deep hypothermic circulatory arrest (HCA) followed by selective cerebral perfusion (SCP). Surgical repair included the obliteration of the proximal false lumen at the level between the left carotid and subclavian artery. A thrombosed retrograde dissection in the ascending aorta was revealed in postoperative evaluation, and decreased in size at follow up CT.

[Synthesis of stable solvates of monosodium 2-[R*s,9S*)-(4-methoxy-6,7,8, 9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)sulfinyl]-1H-benzimidazole]

Monosodium 2-[(R*s,9S*)-(4-methoxy-6,7,8, 9-tetrahydro-5H-cyclohepta-[b]pyridin-9-yl)sulfinyl]-1H-benzimidazole (3A), a novel antiulcer agent previously reported by us, was found to be easily decomposed in weakly acidic solutions. In order to improve the stability of the parent compound, 3A, the preparation of 1-substituted benzimidazoles (4A) was attempted. However, the inhibitory effect of 4A against gastric acid secretion was less potent than that of 3A. Then 3A was solvated by EtOH or H2O to afford 5A or 6A, respectively. On the other hand, an another diastereoisomer, (R*s,9R*)-3B, was not solvated by EtOH or H2O under the same conditions. The thus obtained solvates (5A, 6A) are much more stable than that of 3A. The antiulcer activities of 5A and 6A were found to be similar to that of the parent compound (3A). Consequently, 6A was selected as an antiulcer agent for the development.

Runt domain partner proteins enhance DNA binding and transcriptional repression in cultured Drosophila cells

BACKGROUND

The Drosophila gene runt plays multiple roles during embryogenesis, including one as a pair-rule class segmentation gene. The runt protein (Runt) contains an evolutionarily conserved domain (the Runt domain) that is found in several mammalian proteins including the human protein AML1, which is involved in many chromosome translocations associated with leukaemia. Specific DNA binding activity of a mammalian Runt domain is enhanced by a partner protein called PEBP2beta/CBFbeta. DNA binding activity of Drosophila Runt is also stimulated by this protein, suggesting the existence of a similar Runt partner protein in Drosophila.

RESULTS

We report here the cloning of two closely linked Drosophila genes, runt domain partner (rp) beta1 and beta2, that encode homologues of mouse PEBP2beta/CBFbeta. They are highly homologous to each other and to the mammalian counterpart. Either of the rpb proteins is capable of forming a complex with Runt and stimulating its DNA binding activity, but their temporal and spatial distributions are quite dissimilar, suggesting that functional specificity of Runt may be conferred by the interacting partner. Runt represses transcription dominantly when coexpressed with either partner in cultured cells, a function consistent with a direct role for Runt in regulating expression of the even-skipped gene in Drosophila embryos.

CONCLUSIONS

Drosophila Runt can interact with either of two Runt domain partners, and the resulting complex functions as an active repressor of transcription.

[A successful staged complete repair in a neonate with coarctation of aorta, ventricular septal defect, and left ventricular outflow tract obstruction--a new palliative operation]

An eight day old neonate with coarctation of aorta (CoA), ventricular septal defect (VSD), and severe left ventricular outflow tract obstruction (LVOTO) underwent a successful staged repair following a new palliative operation, which comprised aortic arch reconstruction, PTFE bypass graft between main pulmonary artery and descending thoracic aorta, and pulmonary artery banding (PAB) distal to the graft. Insertion of the bypass graft was aimed to allow enough systemic blood flow and reduces after load of ventricles after PAB. The second staged definitive operation was performed 21 days after the first operation and the procedure comprised partial resection of posterioly deviated infundibular septum via VSD, patch closure of VSD, and division of the graft. No evidence of progression of LVOTO was noted until the second stage operation despite the tight PAB. This new palliative operation, which does not need aid of cardiopulmonary bypass, is particularly effective for those with LVOTO, and can be safely applied even to seriously ill neonate. Thus, for the staged repair in aortic arch obstructive disease with VSD and severe LVOTO, this procedure can be a good alternative for palliative operation.

Ultrastructure and morphogenesis of human immunodeficiency virus

The ultrastructure and morphogenesis of human immunodeficiency virus (HIV) were elucidated by observation with several techniques including immunoelectron microscopy and cryo-microscopy. The virus particle consists of an envelope, a core and matrix. The virus particles were observed extracellularly as having one of three profiles: (1) a centric or an eccentric electron-dense core, (2) rod-shaped electron-dense core, and (3) doughnut-shaped. HIV-1 particles in the hydrated state were observed by high resolution electron cryo-microscopy to be globular, and the lipid membrane was clearly resolved as a bilayer. Many projections around the circumference were seen to be knob-like. The shapes and sizes of the projections, especially head parts, were found to vary in each projection. By isolation with Nonidet P40 and glutaraldehyde, HIV-1 cores were confirmed to consist of p24 protein by immunogold labeling. When the virus enters the cell, two entry modes were found: membrane fusion and endocytosis. No structures resembling virus particles could be seen in the cytoplasm after viral entry. In HIV-1-infected cells, positive reactions by immuno-labeling suggest that HIV-1 Gag may be produced in membrane-bound structures and transported to the cell surface by cytoskeletons. Then a crescent electron-dense layer was first formed underneath the cell membrane. Finally, the virus particle was released from the cell surface. Several cell clones producing defective particles were isolated from MT-4/HIV-1 cells. Among them, doughnut-shaped or teardrop-shaped particles were seen to be produced in the extracellular space. In the doughnut-shaped particles, Gag p17 and p24 proteins faced each other against the inner electron dense ring, suggesting that the inner ring consists of a precursor Gag protein.

Effect of intranasal administration of thyrotropin-releasing hormone on ataxic gait in staggerer mice

The ataxia ameliorating effect of an intranasal administration of thyrotropin-releasing hormone (TRH) was examined using normal and ataxic staggerer mutant mice. In the normal mice, the blood TRH level reached the maximum level 5 min after administration and was gradually eliminated during the following 60 min. The antiataxic effects of TRH in the staggerer mice was examined using an open field method. At lower doses, the intranasal administration of TRH in the staggerer mice was examined using an open field method. At lower doses, the intranasal administration of TRH did not exert any evident effect. However, at 3 mg or 4 mg, the fall index (the ratio of the number of falls to the movement score) was significantly decreased for 20 min after the administration. These results show that an intranasal administration of TRH can ameliorate the ataxia in staggerer mice, and may be promising for clinical use in patients with spinocerebellar degeneration.

Mutational analysis of two zinc finger motifs in HIV type 1 nucleocapsid proteins: effects on proteolytic processing of Gag precursors and particle formation

To clarify the physiological function of two zinc finger motifs in the nucleocapsid (NC) domain of the Gag protein of human immunodeficiency virus type 1 (HIV-1), we changed cysteine to serine in either of the two motifs or both by site-directed mutagenesis. Viral infectivity was lost by any of the mutations, but their effects appeared differently in the respective mutants. Northern blot analysis showed that the first finger mutant was far less efficient (approximately 10% of the wild type) in genomic RNA encapsidation and that the dual mutant of both fingers completely failed to encapsidate the RNA. In contrast, the second finger mutant retained its ability for RNA encapsidation with an efficiency similar to that of the wild type. Immunoblot analysis of the lysates of CD4-positive M8166 cells transfected with the mutant proviral DNAs showed that the processing of Gag precursors was delayed in two mutant viruses having alterations in the first finger sequence, whereas the processing of the second finger mutant appeared to be normal. On the other hand, immunoblot analysis of the virus particles showed that the second finger mutant particles contained some proteins that were thought to be degradation products of p24CA. Electron microscopic observation showed that all particles of these mutant viruses were morphologically alike except that they had a slightly larger diameter than that of the wild type. These results indicate that these finger motifs of HIV-1 NC protein do not function equivalently. Namely, the first finger is primarily responsible for RNA encapsidation and the second is required for stabilization of virus particles.

Effects of LHRH, FSH and activin A on follistatin secretion from cultured rat anterior pituitary cells

We demonstrated the release of follistatin, an activin-binding protein, from cultured rat anterior pituitary cells by measuring immunoreactive (ir-) follistatin in a specific immunoradiometric assay. Ir-follistatin release gradually increased in cultures over 1-18 days and reached its maximal level at 12-15 days of incubation. The basal ir-follistatin levels in the culture media increased about 3- (P < 0.01) and 5-fold (P < 0.001) in 2 and 10% fetal calf serum for 6 days, respectively. LHRH and activin A caused an approximately 2.0- (P < 0.05) and 1.8-fold (P < 0.05) rise in ir-follistatin release, respectively, in contrast to the lack of significant FSH effects. The culture medium condensed on sulfate-cellulofine gel was resolved by polyacrylamide gel electrophoresis and blotted with anti-follistatin polyclonal antibody, resulting in at least three protein bands ranging from 35 to 50 kDa under non-reducing conditions. These results indicated that follistatin is produced in anterior pituitary cells and that its secretion is regulated at least in part by LHRH and activin, implying an autocrine/paracrine role of activin and follistatin in the pituitary.

Volatile anaesthetics antagonize nitrous oxide and morphine-induced analgesia in the rat

We reported previously that nitrous oxide induces pre-emptive analgesia that is partially antagonized by naloxone and totally antagonized by halothane. The aims of this study were to determine if halothane and isoflurane are similar in this respect and to examine if volatile anaesthetics antagonize the analgesic effect of exogenous opioids. We found that 75% nitrous oxide prolonged tail-flick latency by 37% and this analgesia was dose-dependently inhibited by halothane and, less effectively, by isoflurane. In contrast, morphine 1.25 mg kg-1 i.v. also prolonged tail-flick latency by 35% but, unlike nitrous oxide-induced analgesia, this effect was attenuated only by high doses of halothane and was unaffected by isoflurane. Neither halothane nor isoflurane alone altered the tail-flick response. We conclude that both halothane and isoflurane dose-dependently antagonized nitrous oxide analgesia but antagonized morphine-induced analgesia to a lesser extent.

An efficient short-step total synthesis of ganglioside GM3: effective usage of the neighbouring group participation strategy

We have developed an efficient methodology for highly stereoselective sialylation using 3-position substituted sialic acids and have prepared 2a having a 3 beta-phenylthio group as a sialic donor. Glycosylation of suitably protected lactoside 3 with 2a gave only the alpha-sialyl trisaccharide 16 in good yield. Condensation of the azidosphingosine 4 with the acetate 17 using promotors, DMTST or NIS-TfOH, afforded the glycolipid 18, which was directly transformed to 20 by reduction with Bu3P and subsequent acylation with octadecanoic acid in the presence of WSC. Removal of the protecting groups generated ganglioside GM3 (1).

Complete inhibition of human immunodeficiency virus Gag myristoylation is necessary for inhibition of particle budding

Myristoylation of human immunodeficiency virus (HIV) Gag protein is essential for virus particle budding. Two reactions are involved; activation of free myristate to myristoyl-CoA and transfer of the myristoyl residue to the Gag N-terminal glycine. We have investigated the effects of triacsin C, an inhibitor of long chain acyl-CoA synthetase, on release of HIV Gag virus-like particle (VLP) produced using the recombinant baculovirus system. First, inhibition of acyl-CoA formation by triacsin C was confirmed using the membrane fractions of insect Sf9 cells as an enzyme source. Second, when HIV Gag protein was expressed in the presence of triacsin C (0-48 microM), Gag myristoylation was inhibited in a dose-dependent manner. Budding of Gag VLP, however, did not follow similar inhibition kinetics but appeared unaffected up to 24 microM, yet was completely abolished at 48 microM when the myristoylation of Gag protein was also completely inhibited. The "all-or-none" inhibition of Gag VLP budding suggests that although inhibition of acyl-CoA synthetase blocks the production of myristoylated Gag protein, only complete inhibition of Gag myristoylation prevents VLP budding. Thus, relatively few myristoylated Gag molecules are sufficient for plasma membrane targeting and VLP budding.

Characteristics of the insulin resistance syndrome in a Japanese population. The Jichi Medical School Cohort Study

We investigated the relationships between hyperinsulinemia (a major indicator of the insulin resistance syndrome), blood pressure, dyslipidemia, and coagulation factors in 2606 community-dwelling Japanese individuals as part of the Jichi Medical School Cohort Study. An age-related decrease of the fasting insulin level was found in men but not in women. Body mass index, systolic and diastolic blood pressure, triglyceride and fasting glucose levels, and factor VII activity all increased in both sexes as the insulin level became higher, while the HDL cholesterol level decreased. In addition, total cholesterol and LDL cholesterol levels increased as the insulin level became higher and lipoprotein(a) levels decreased in the men. Fibrinogen levels were not related to the insulin level in either sex. Multiple logistic regression analysis revealed that fasting insulin levels were positively correlated with body mass index and fasting glucose and factor VII activity levels, whereas they were negatively correlated with HDL cholesterol in both sexes. In addition, fasting insulin levels were positively correlated with LDL cholesterol levels in men and with triglyceride levels in women. Our results indicate that hyperinsulinemia is associated with high factor VII activity in a general Japanese population as well as with high blood pressure and dyslipidemia. The accumulation of these cardiovascular risk factors in hyperinsulinemic subjects appears to contribute to cardiovascular events in the Japanese as well as in westerners.

Bone-bonding behavior of plasma-sprayed coatings of BioglassR, AW-glass ceramic, and tricalcium phosphate on titanium alloy

The bone-bonding behavior of three kinds of bioactive ceramics coated on titanium alloy by the plasma-spray technique was investigated. Titanium alloy (Ti-6A1-4V) coated with BioglassR (45S5), apatite-wollastonite containing glass ceramic (AW), or beta-tricalcium phosphate (TCP) was prepared, and rectangular specimens were implanted into the tibial bones of mature male rabbits, which were sacrificed 8 or 24 weeks after implantation. The tibiae containing the implants were dissected out and subjected to detachment tests to measure the failure load. The bone-implant interface was investigated by Giemsa surface staining, contact microradiography, and scanning electron microscopy-electron probe microanalysis (SEM-EPMA). Eight weeks after implantation, the failure loads for implants coated with BioglassR, AW, and TCP were 1.04 +/- 0.94, 2.03 +/- 1.17, and 3.91 +/- 1.51 kg, respectively, and 24 weeks after implantation, the respective failure loads were 2.72 +/- 1.33, 2.39 +/- 1.30, and 4.23 +/- 1.34 kg. Failure loads of AW- and TCP-coated implants did not increase significantly with time. After the detachment test, breakage of the coating layer was observed. Bioactive ceramics can act as stimulants that induce bonding between bone and metal implants. However, failure load of metal implants coated with the bioactive ceramics was lower than that of bulk AW or TCP. It appears impossible to obtain a higher failure load using a bioactive-ceramic coating on titanium alloy. Histologically, the coating layer was found to become detached from the metal implant and the bone tissue bonded to the coating layer. SEM-EPMA observation revealed breakage of the coating layer, although bonding between bone and the coating layer was evident. A Ca-P-rich layer was observed at the interface between bone and the AW coating, and a Ca-P-rich and a Si-rich layer were observed at the interface between bone and the BioglassR coating. For clinical application, it would seem better to use coated metal implants for short-term implantation. However, there is a possibility of breakage of the coating layer because of both dissolution of the bioactive ceramic and mechanical weakness at the interface between the coating layer and the metal implant.