Preparation of hydroxyapatite-granule- implanted titanium alloy composites with a cylindrical shape.

For uniformly implanting hydroxyapatite (HA) granules into curved surfaces of titanium alloy implants such as dental roots, a new superplastic forming system was developed. By fixing PVA films with HA granules on a die's curved inner surface, HA granules are uniformly scattered and hold on the surface. The pressing system has a couple of wedges that enable press load to act on the both sides of a cylindrical titanium alloy sample arranged with its long axis perpendicular to the direction of the load in the die, and thereby the sample to expand in its radius direction. This technique could uniformly press HA granules into all the curved surface of titanium alloy. As a result, HA-granule-implanted titanium alloy composites with a cylindrical shape were formed under the conditions of 1023 K, 1 h, 1960 N in vacuo.

Tongue and jaw muscle activities during chewing and swallowing in freely behaving rabbits.

To study the function of the tongue and the coordination among jaw, tongue, and hyoid muscles during chewing and swallowing, we recorded the electromyographic activities from the masseter (Mas), digastric (Dig), mylohyoid (Myl), thyrohyoid (Thy), genioglossus (Gg) and styloglossus (Sg) muscles as well as jaw movement trajectories in the freely behaving rabbit. Three phases were identified in the chewing cycle (fast- and slow-closing and opening phases). The Gg (main tongue protruder) was active synchronously with the Dig during opening. The Sg (tongue retractor) showed two peaks in each cycle, one in the opening phase and the other in the closing phase. The latter may have a role in retracting the tongue during jaw closing. The co-contraction of the antagonists (i.e. Gg and Sg) during opening may contribute to shape the tongue to be appropriate to gather the foodstuff. In the swallowing cycle, five phases were identified, two in the closing phase and three in the opening phase. Regression analysis revealed that swallowing cycles had a longer cycle duration than that of the chewing cycles due to an extra phase (a pause) inserted in the opening phase, where there was a small co-activation in the jaw opening and closing muscles. The findings suggest that the swallowing center affects masticatory center in the central nervous system, and may also support the view that the masticatory burst timing begins with the Dig activities in the middle of the opening phase.

Effect of Helicobacter pylori eradication on gastric mucosal phospholipid content and its fatty acid composition.

BACKGROUND AND AIMS: Whether Helicobacter pylori eradication alters gastric mucosal phospholipid contents and their fatty acid composition remains unclear. The aim of the present study was to clarify the effect of H. pylori eradication on gastric mucosal phosphatidylcholine (PC) content and its fatty acid composition. METHODS: Endoscopic biopsy specimens were taken from the antrum and body of each of 19 asymtomatic male volunteers for detection of H. pylori, histopathological assessment of gastritis, phospholipid determination and fatty acid analysis. All the subjects with H. pylori infection were treated with eradication therapy. Endoscopy and tissue sampling were repeated again 1 and 6 months after all treatment. RESULTS: In eight subjects, H. pylori infection was evident and was successfully eradicated. Pretreatment degrees of lymphocytes and plasma cells (inflammation) and polymorphonuclear neutrophils (activity) were greater in H. pylori-positive subjects compared with H. pylori-negative subjects (P<0.001), whereas the degree of inflammation decreased (P<0.001), and neutrophils had completely disappeared at 6 months after eradication. Moreover, the gastric mucosal PC contents at the antrum and body were unchanged within 1 month after cessation of treatment, but increased at 6 months after eradication (P<0.05). At 6 months after cessation of treatment, H. pylori-eradicated subjects had an increase (+30% at antrum, +18% at body) in linoleic acid composition and a decrease (-37%, -43%) in arachidonic acid composition of PC at the antrum and body, respectively. CONCLUSIONS: These findings suggest that H. pylori eradication reduces the production of various eicosanoids, resulting in the normalization of gastric mucosal PC content and its fatty acid composition, which may consequently cause the gastric mucosal hydrophobicity to be normalized.

Helicobacter pylori alters n-6 fatty acid metabolism and prostaglandin E2 synthesis in rat gastric mucosal cells.

BACKGROUND AND AIMS: Little is known about whether Helicobacter pylori infection alters fatty acid metabolism in gastric mucosal cells. By using cultured rat gastric mucosal cells (RGM-1), we investigated the effect of H. pylori broth culture filtrates on this point. Furthermore, our study aimed to find out whether n-6 long chain polyunsaturated fatty acids from linoleic acid are formed in RGM-1 cells. METHODS: Rat gastric mucosal cells were incubated with 10, 20 and 40 microg/mL of linoleic acid or medium alone. Phosphatidylcholine content extracted from whole RGM-1 cells was quantitated by using a densitometer, and its fatty acid composition was analyzed by using gas chromatography. Prostaglandin E2 concentration in the culture medium was measured by using radioimmunoassay. The expression of cyclooxygenase (COX)-1 and COX-2 was examined by using reverse transcription-polymerase chain reaction. In addition, after incubation with [1-14C] linoleic acid, radioactivities of both linoleic acid and arachidonic acid components of the PC fraction were counted. The effects of H. pylori broth culture filtrates on PC content, its fatty acid composition and prostaglandin (PG)E2 synthesis were also assessed. RESULTS: Linoleic acid addition caused an increase in the composition of arachidonic acid, as well as linoleic acid, and also in PGE2 concentration. Cyclo-oxygenase-2 expression was induced in RGM-1 cells by the addition of linoleic acid. In addition, [1-14C] linoleic acid added to the culture medium was converted to [1-14C] arachidonic acid in RGM-1 cells. Helicobacter pylori broth culture filtrates decreased linoleic acid composition and increased arachidonic acid composition. Moreover, after incubation with H. pylori broth culture filtrates, PGE2 concentrations were higher than that of the controls. CONCLUSIONS: These findings suggest the presence of fatty acid elongase and Delta5- and Delta6-desaturases synthesize arachidonic acid from linoleic acid in RGM-1 cells. Thus, H. pylori infection may enhance PGE2 synthesis and accelerate n-6 fatty acid metabolism in gastric mucosal cells, which could make the gastric mucosal barrier more fragile.

Role of transcriptional factor activation protein-1 in endogenous expression of the interleukin-1 beta gene involved in Porphyromonas gingivalis fimbria-stimulated bone resorption in the mouse calvarial system.

We previously suggested that endogenous interleukin-1 beta (IL-1 beta) produced by Porphyromonas gingivalis fimbriae stimulation in calvarial bone cell cultures plays a role in bone resorption as a major cytokine. Therefore, in the present study, we initiated experiments to clarify the stimulatory mechanism of IL-1 beta gene expression in fimbria-stimulated bone resorption. Fimbria-stimulated bone resorption was dramatically inhibited by curcumin, a potent inhibitor of activation protein-1 (AP-1). In fact, the fimbriae induced markedly both the expression of c-fos and c-jun genes and their protein production in the calvarial cells. In addition, a mixture of antisense oligonucleotides against c-fos and c-jun significantly inhibited not only the fimbria-induced expression of the IL-1 beta gene but also the fimbria-induced bone resorption. Therefore, the present study demonstrates that transcriptional factor AP-1 plays a functional role in P. gingivalis fimbria-stimulated bone resorption via endogenous IL-1 beta in the mouse calvarial system.

A new approach for brachial plexus block under fluoroscopic guidance.

UNLABELLED: We performed the subclavian perivascular approach to the brachial plexus using contrast medium to confirm the location of the tip of the needle and the spread of the injected solution to obtain a high success rate and to minimize the risk of pneumothorax. Review of the cases led to the hypothesis that the solution injected inside the costal attachment of the middle scalene muscle spreads into the interscalene space. Because of the difference in the placement of the tip of the needle using our technique and the supraclavicular approach, including the subclavian perivascular approach, we termed our technique the supracostal approach. We conducted the present study to establish the supracostal approach by proving this hypothesis. A total of 173 blocks in 149 adult patients were studied. Eighty-four blocks in 74 patients were achieved by using the supracostal approach with contrast medium. The needle was inserted 1 cm lateral to the palpated subclavian artery and 1-2 cm above to the clavicle to touch a specific part of the first rib, which we believed to correspond to the inside of the costal attachment of the middle scalene muscle. After injecting the anesthetic solution with contrast medium, radiographs were obtained for each block, while computed tomographic (CT) studies were performed for five blocks. Five blocks in five patients were achieved by using the subclavian perivascular approach with contrast medium and both radiographs and CT studies. In addition, the anatomical difference between the two approaches was evaluated in five adult cadavers. Based on these studies, we determined the proper part of the first rib that corresponded to the inside of the costal attachment of the middle scalene muscle. Eighty-four blocks in the remaining 70 patients were performed with the supracostal approach without contrast medium. Of the 84 blocks with contrast medium, 80 (95%) produced successful blockade defined by sensory and motor examination. The radiological studies showed that, with the supracostal approach, the injected solution, which spread from the middle scalene muscle into the interscalene space, did not spread below the first rib. However, with the subclavian perivascular approach, the solution was confined within the perineural sheath and spread below the first rib to the axilla. The anatomical studies could explain this difference, revealing that the perineural space of the brachial plexus is not identical to the interscalene space. There was no failure in the 84 blocks performed with the supracostal approach without contrast medium after we determined the proper part of the first rib. We conclude that the supracostal approach to the brachial plexus is reliable, easy to perform, and associated with a low complication rate. IMPLICATIONS: A new fluoroscopically guided approach for brachial plexus block has been established on the basis of anatomical and radiological studies to be reliable, easy to perform, and associated with a low complication rate.

Four cases of bleeding diathesis in children due to congenital plasminogen activator inhibitor-1 deficiency.

Congenital plasminogen activator inhibitor-1 (PAI-1) deficiency is an extremely rare disorder characterized by a bleeding diathesis that begins in childhood due to hyperfibrinolysis as a result of decreased PAI-1 activity. We now present 4 unrelated pediatric cases of congenital PAI-1 deficiency. All 4 patients had a history of recurrent episodes of subcutaneous bleeding beginning in early childhood. These episodes were characterized by abnormal prolonged bleeding after trauma, tooth extraction, and surgical procedures, as well as by rebleeding following initial hemostasis. The 2 female patients both had symptoms compatible with hypermenorrhea. The family history was positive in 2 of the 4 patients. Hemostatic screening studies in all 4 patients revealed no abnormalities. Testing for factor XIII antigen, von Willebrand factor antigen, ristocetin cofactor activity, alpha(2)-plasmin inhibitor (alpha2PI) activity, and plasminogen activity was normal. The euglobulin lysis times were shortened in all cases as compared with those in normal control subjects. None of the patients had elevated tissue plasminogen activator (tPA) antigen levels, but PAI activity was markedly decreased in all cases. Three of the patients also had reduced levels of PAI-1 antigen. There tended to be a reduction in tPA-PAI-1 complex in all cases. In addition, 2 patients had elevated PIC (plasmin-alpha2PI complex). Tourniquet tests were performed in 2 patients, with no appreciable rise in PAI-1 activity or PAI-1 antigen levels. The administration of tranexamic acid clearly improved hemorrhagic symptoms in these patients. We considered PAI-1 deficiency to be the likely etiology of the congenital bleeding diatheses in these 4 cases.

[Operation for left renal cell carcinoma complicated with acute pulmonary tumor embolism and cocurrent removal of tumor].

The prognosis of pulmonary tumor embolism is said to be poor and only a limited number of patients with this disease have survived. The patient was a 64-year-old male suffering from left renal cell carcinoma complicated with tumor extending from the left renal vein to the inferior vena cava. The patient underwent an operation for left renal cell carcinoma during which he developed tumor embolus to the pulmonary artery. The occurrence of the acute embolism was promptly detected and the removal of tumor was performed under cardiopulmonary bypass. The patient made good postoperative progress.

[A basic study of photodynamic therapy of experimental hepatoma with ME 2906].

We have studied effects of photodynamic diagnosis (PDD) and photodynamic therapy (PDT) in hepatoma as confirmed by the existence of hepatoma when using a new photosensitizer mono-L-aspartyl chlorin e6. Japanese white rabbits were selected to perform abdominal incision under intravenous anesthesia and transplant VX2 tumor cells into the liver left lobe for the hepatoma model. Hepatoma of 1 cm in diameter (at one week after transplantation) was used experimentally to radiate a semiconductor laser (664 nm, 200 J/cm2) for treatment.

Cardiac tamponade due to systemic lupus erythematosus in a 7-year-old boy with selective IgG subclass deficiency.

UNLABELLED: Systemic lupus erythematosus (SLE) was observed in a 7-year-old boy with IgG2 and IgG4 subclass deficiencies who had been treated with immunoglobulin (100-200 mg/kg/4 weeks) since 2 years of age. The mother and the half-brother displayed the same deficiency. Serum IgG mainly consisted of IgG1 (98.9%) during the acute phase of SLE due to transient IgG3 deficiency. While he had no common manifestations of SLE such as arthritis or nephropathy, he developed cardiac tamponade due to massive pericardial effusion. CONCLUSION: The clinical features of SLE in the present case such as the development of cardiac tamponade and the absence of renal involvement may result from the markedly imbalanced IgG subclass distribution among auto-antibodies.

Preparation of hydroxyapatite-granule-implanted superplastic titanium-alloy.

In order to obtain a biomaterial that has both biological affinity and high mechanical strength, hydroxyapatite (HAp) granules were implanted into the surface of superplastic titanium-alloy. HAp granules (32-38 microm diameter) were spread over a superplastic titanium-alloy substrate and pressed to implant the granules into the substrate. This was achieved at 17 MPa, 750 degrees C for 10 min. Only the tops of the granules, which were surrounded by the alloy, remained exposed and they were firmly stuck in the substrate. The granules were enclosed in titanium-alloy and a reaction layer was formed at their interface. The HAp-implanted titanium-alloy composites are expected to be useful as biomaterials, such as artificial bones and dental roots.

Interactions of amphiphilic peptides derived from alpha s2-casein with calmodulin.

Calmodulin-binding peptides, which had previously been isolated from a pepsin digest of alpha-CN, were synthesized and then examined for their inhibitory effects on the activation of cyclic nucleotide phosphodiesterase that was induced by calmodulin. The concentrations of the synthetic peptides corresponding to 164-179, LKKISQRYQKFALPQY; 183-206, VYQHQKAMKPWIQPKTKVIPYVRY; and 183-207, VYQHQKAMKPWIQPKTKVIPYVRYL, of alpha s2-CN that gave half-maximal inhibition were 65, 7.0, and 2.6 microM, respectively. These inhibitory effects were reversed by increasing the amount of calmodulin. Fragments and analogs were prepared to study the interactions of the peptides with calmodulin in more detail. The results indicated that modification of the carboxyl terminus enhanced the affinities of the three peptides for calmodulin, and a region involved in the inhibition by alpha s2-CN (f183-207) was located at the carboxyl terminus 191-207. Two predicted calmodulin-binding sequences, 164-179 and 191-207 of alpha s2-CN, despite rather divergent primary structures, shared the structural motif common to the calmodulin-binding domains of the target proteins in the previously proposed complex model.

Prostaglandin E2 stimulates osteoclast formation via endogenous IL-1 beta expressed through protein kinase A.

The present study was conducted to determine whether endogenous IL-1 is involved as a potent mediator of PGE2-stimulated osteoclast formation in 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25-(OH)2D3)-primed calvarial cells from mouse embryos. PGE2 induced IL-1 beta gene expression in the primed calvarial cells. IL-1 beta gene expression was also induced in a dose-dependent manner by forskolin and dibutyryl cAMP. PGE2-induced IL-1 beta gene expression was markedly inhibited by H-89, a potent inhibitor of protein kinase A. On the other hand, osteoclast formation in 1 alpha,25-(OH)2D3-primed calvarial cells was also stimulated by forskolin and dibutyryl cAMP, and their stimulatory effects were dose dependent. H-89 also inhibited PGE2-stimulated osteoclast formation. The presence of the IL-1 beta gene product in the conditioned medium of 1 alpha,25-(OH)2D3-primed calvarial cells treated with PGE2 was proved by the results of an immunoprecipitation assay using anti-mouse IL-1 beta Ab. The addition of anti-mouse IL-1 beta Ab to 1 alpha,25-(OH)2D3 primed calvarial cell cultures markedly inhibited PGE2-stimulated osteoclast formation. The stimulatory effect of conditioned medium of primed calvarial cells treated with PGE2 on osteoclast formation was also inhibited by anti-IL-1 beta Ab pretreatment. Furthermore, we found that endogenous IL-6 is partially involved in PGE2-stimulated osteoclast formation.

Compact diode-pumped all-solid-state femtosecond Cr(4+):YAG laser.

We have developed a compact, all-solid-state self-mode-locked Cr(4+):YAG laser. The laser is pumped by a cw laser-diode-pumped Nd:YVO(4) laser and produces highly stable femtosecond pulses near 1.50 microm. Measurements of noise power spectra for frequencies below 10 kHz show that the diode-pumped laser system greatly improves the output energy fluctuation and pulse timing jitter compared with a laser system that uses a conventional arc-lamp-pumped cw Nd:YAG laser.

Optical parametric oscillator incoherent spectroscopy.

A new incoherent Kerr shutter is demonstrated. It utilizes nanosecond optical pulses from an optical parametric oscillator (OPO) that has a broad bandwidth. Through the use of abeta-BaB(2)O(4) crystal, the OPO has a coherence time of 60-800 fs and shows wide wavelength tunability from 410 to 2600 nm. Kerr relaxation time constants for CS(2) and nitrobenzene are the same as those cited in previous works. We also show, for the first time to our knowledge, a 100-fs response for a nitrobenzene solution of 4-(N,N-diethylamino)-beta-nitrostyrene at a 740-nm idler wavelength.

Calmodulin-binding peptides isolated from alpha-casein peptone.

Peptides that inhibit calmodulin-dependent cyclic nucleotide phosphodiesterase were isolated from a pepsin digest of alpha-casein. Analysis of these peptides showed that they corresponded to the alpha S2-casein sequences 164-179 (Leu-Lys-Lys-Ile-Ser-Gln-Arg-Tyr-Gln-Lys-Phe-Ala-Leu-Pro-Gln-Tyr). 183-206 (Val-Tyr-Gln-His-Gln-Lys-Ala-Met-Lys-Pro-Trp-Ile-Gln-Pro-Lys-Thr-Lys-Val -Ile- Pro-Tyr-Val-Arg-Tyr) and 183-207 (C-terminus, Val-Tyr-Gln-His-Gln-Lys-Ala-Met-Lys-Pro-Trp-Ile- Gln-Pro-Lys-Thr-Lys-Val-Ile-Pro-Tyr-Val-Arg-Tyr-Leu). These peptides inhibited calmodulin-induced cyclic nucleotide phosphodiesterase activity over the range 1-50 microM without affecting the basal enzyme activity. These results demonstrated that the affinities of these peptides for calmodulin are comparable to the affinities of certain endogenous neurohormones and proteins that interact with calmodulin.

Porphyromonas gingivalis fimbria-stimulated bone resorption in vitro is inhibited by a tyrosine kinase inhibitor.

Our previous study (Y. Kawata, S. Hanazawa, S. Amano, Y. Murakami, T. Matsumoto, K. Nishida, and S. Kitano, Infect. Immun. 62:3012-3016, 1994) showed that Porphyromonas gingivalis fimbriae stimulate bone resorption in vitro. Since it has recently been demonstrated that tyrosine kinase encoded by the c-src gene plays an important role in osteoclastic bone resorption, in the present study we examined the effect of a tyrosine kinase inhibitor on the fimbria-stimulated bone resorption. Genistein, a potent inhibitor of tyrosine kinase, markedly inhibited bone resorption stimulated by the fimbriae. Genistein also inhibited induction of several tyrosine-phosphorylated proteins in the fimbria-treated calvarial bone cells from mouse embryos.

Porphyromonas gingivalis fimbriae induce a 68-kilodalton phosphorylated protein in macrophages.

The present study was performed to examine whether Porphyromonas gingivalis fimbriae induce specifically a protein kinase-mediated phosphorylated protein that is involved in the mechanism of signal transduction. The fimbriae induced a 68-kDa phosphorylated protein (pp68) in a dose-dependent manner in mouse peritoneal macrophages. A marked appearance of pp68 was observed 20 min after the initiation of fimbrial treatment. The fimbria-induced pp68 was inhibited dramatically by staurosporine, a potent inhibitor of protein kinase C. pp68 induction was also inhibited by H-7, a potent inhibitor of several types of protein kinase. However, the induction was not inhibited by HA-1004 and H-8, relatively high-affinity inhibitors of protein kinase A. Phorbol myristate acetate and 1-oleoyl-2-acetyl-sn-glycerol, activators of protein kinase C, were able to induce pp68 in mouse peritoneal macrophages. This protein was localized in the cytosolic fraction of fimbria-treated macrophages. pp68 also was induced in fimbria-treated human monocyte-like cells. Finally, we observed that gene expression of the fimbria-induced neutrophil chemoattractant KC was inhibited markedly by staurosporine.

Interferometric measurement of wavelength dispersion on femtosecond laser cavities.

Cavity Fourier-transformed cross correlation measures the wavelength dispersion from the cross-correlation signal taken on spontaneous emission emerging from a cavity under test. This method provides a universal and quick way to detect femtosecond group delay. However, test cavity-length fluctuations have been hindering its application to femtosecond laser cavities. We introduce a dual-interferometer scheme in which one of the interferometers is dedicated to detecting length change in the test cavity, thereby enabling the influence of fluctuations to be nullified. This method is demonstrated on a Ti:Al(2)O(3) laser as well as on a NaCl color-center laser.