Extracellular N6 -isopentenyladenosine (i6A) addition induces cotranscriptional i6A incorporation into ribosomal RNAs

N⁶ -isopentenyladenosine (i⁶A), a modified adenosine monomer, is known to induce cell death upon its addition to the culture medium. However, the molecular fate of extracellularly added i⁶A has yet to be identified. Here we show that i⁶A addition to cell culture medium results in i⁶A incorporation into cellular RNA in several cell lines, including the 5-fluorouracil (5-FU)-resistant human oral squamous cell carcinoma cell line FR2-SAS and its parental 5-FU-sensitive cell line SAS. i⁶A was predominantly incorporated into 18S and 28S rRNAs, and i⁶A incorporation into total RNA was mostly suppressed by treating these cell lines with an RNA polymerase I (Pol I) inhibitor. i⁶A was incorporated into RNA even upon inactivation of TRIT1, the only cellular i⁶A-modifying enzyme. These results indicate that upon cellular uptake of i⁶A, it is anabolized to be used for Pol I transcription. Interestingly, at lower i⁶A concentrations, the cytotoxic effect of i⁶A was substantially more pronounced in FR2-SAS cells than in SAS cells. Moreover, in FR2-SAS cells, i⁶A treatment decreased the rate of cellular protein synthesis and increased intracellular protein aggregation, and these effects were more pronounced than in SAS cells. Our work provides insights into the molecular fate of extracellularly applied i⁶A in the context of intracellular nucleic acid anabolism and suggests investigation of i⁶A as a candidate for a chemotherapy agent against 5-FU-resistant cancer cells.

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.

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.

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.

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.

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

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.

[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

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.

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.

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.

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.

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.

Characteristics of femtosecond pulses near 1.5 microm in a self-mode-locked Cr(4+):YAG laser

The operating characteristics of a self-mode-locked Cr(4+) :YAG laser that produces sub-100-fs pulses are described. Stable, nearly transform-limited pulses are obtained at a central wavelength longer than 1.50 microm, and the spectrum of the wavelength is extended past 1.60 microm, over the net gain bandwidth of the laser material. The group-velocity dispersion and the third-order dispersion of the Cr-doped YAG rod are measured by a Fourierindicating that the group-velocity dispersion vanishes at a transform interferometric cross-correlation technique, wavelength of 1.59 microm.

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.

Femtosecond pulse generation in a Ti:A1(2)O(3) laser by using second- and third-order intracavity dispersion

We investigate the effects of third-order dispersion on pulse width by using a femtosecond Ti:A1(2)O(3) laser with independently adjustable second- and third-order intracavity dispersion compensation. A novel technique for compensating third-order dispersion is demonstrated using Gires-Tournois interferometers that are fabricated monolithically by using multilayer dielectric films. With the addition of intracavity third-order compensation, pulse-width reduction from 45 to 28 fs is achieved. The dispersion compensation effect produced by the Gires-Tournois interferometers is measured in situ using frequency-domain dispersion measurement techniques.

Characterization of mineral-binding 40-kDa glycoprotein extracted from young adult rabbit alveolar bone

A forty-kilodalton (40-kDa) protein was extracted from alveolar bone of young adult rabbit with 0.5 M EDTA after extraction with 4 M GuHCl, and purified by gel-filtration, anion-exchange and hydroxyapatite columns using a high-pressure liquid chromatography system under denaturing conditions. The purified 40-kDa protein was not susceptible to bacterial collagenase and thrombin, but was cleaved by cyanogen bromide. The protein was stained blue with Stains-all. Among various lectins, concanavalin A and lentil lectin agglutinin bound to this protein, but peanut agglutinin, Ricinus communis agglutinin, phytohemagglutinin-E and wheatgerm lectin agglutinin did not. Lectin binding assays showed that the protein is a glycoprotein containing large amounts of mannose and/or glucose residues, but is not a fragment of proteoglycan. The amino acid composition of the protein shows a characteristically high content of acidic amino acids. Therefore, the mineral-binding 40-kDa glycoprotein is considered to be osteonectin/secreted protein acidic and rich in cysteine (SPARC), in terms of similarities to bovine and porcine osteonectins with regard to molecular weight and contents of glycoses and amino acids.

Requirement of both interleukin 3 and interleukin 6 for the growth of primitive hemopoietic progenitors

Using a serum-free culture system, we studied the interaction of interleukin 3 (IL-3) and interleukin 6 (IL-6) in the development of primitive hemopoietic progenitors. A time-course study showed that total colony formation supported by 200 U/ml of IL-3 alone failed to reach the level obtained by the combination of 40 ng/ml of IL-6 and IL-3 in culture containing bone marrow cells of 5-fluorouracil (5-FU) -treated mice. Extremely high concentrations (1,000 U/ml, 10,000 U/ml) of IL-3 also required the presence of IL-6 for the sufficient development of primitive progenitors. The depletion of phagocytic and T cells from crude bone marrow cells of 5-FU-treated mice did not influence the requirement for both factors. These results suggest the existence of primitive progenitors which require both IL-3 and IL-6 for development. The delayed addition of IL-6 to a culture initiated with IL-3 failed to restore total colony growth to the levels obtained by culture initiated with the two factors simultaneously. The results suggest that some primitive hemopoietic progenitors requiring both IL-3 and IL-6 for the substantial growth may be unable to survive in the presence of IL-3 alone.

50-fs pulse generation directly from a colliding-pulse mode-locked Ti:sapphire laser using an antiresonant ring mirror

50-fs pulses were directly generated from a colliding-pulse mode-locked Ti:sapphire laser. To achieve the collidingpulse mode locking, a miniature antiresonant ring containing an organic saturable dye jet was employed as the end mirror for the linear cavity laser. Based on measured dispersion of intracavity elements, a prism pair was implemented to control the cavity dispersion. The generated pulses have no linear chirp but do exhibit parabolic instantaneous frequency owing to third-order dispersion introduced by the prism pair.

Induction of mixed erythroid-megakaryocyte colonies and bipotential blast cell colonies by recombinant human erythropoietin in serum-free culture

The effects of recombinant human erythropoietin (rEp) on murine hematopoietic progenitors were studied using a serum-free culture. A high concentration of rEp stimulated the formation of mixed erythroid-megakaryocyte colonies (EM colonies) and blast cell colonies, as well as erythroid colonies, erythroid bursts, and megakaryocyte colonies from normal mouse bone marrow cells. Direct effects of rEp on EM colony, megakaryocyte colony, and erythroid burst formation were confirmed by depletion of accessory cells such as T cells, B cells, and macrophages from crude bone marrow cells, and inhibition of the colonies by the addition of rabbit anti-rEp antibody to the culture in a dose-dependent fashion. Replating experiments were performed to confirm the differentiating ability of blast cell colonies grown in the presence of rEp. Most of the blast cell colonies yielded not only secondary erythroid colonies but also megakaryocyte colonies in the presence of 2 IU/mL rEp. Some of the blast cell colonies produced secondary EM colonies in the presence of 16 IU/ml rEp of 2 IU/mL rEp plus interleukin-3, although no granulocyte-macrophage colonies were found in the secondary culture. These results suggest that Ep acts not only as a late-acting factor that is specific for erythroid progenitors, but also as a bipotential EM-stimulating factor for murine hematopoietic cells.

Interleukin-6 enhances murine megakaryocytopoiesis in serum-free culture

We investigated the effect of interleukin-6 (IL-6) on murine megakaryocytopoiesis in a serum-free culture system. The addition of IL-6 to a culture containing interleukin-3 (IL-3) resulted in a significant increase in the number of megakaryocyte colonies by bone marrow cells of normal mice. The megakaryocytic progenitors that survive exposure to 5-fluorouracil (5-FU) exhibited a more significant response to IL-6 and IL-3. Polyclonal anti-IL-6 antibody neutralized the stimulatory effect of IL-6 on megakaryocyte colony growth supported by IL-3. Delayed addition experiments and replating experiments of blast cell colonies showed that megakaryocytic progenitors are supported by IL-3 in the early stage of the development but require IL-6 for their subsequent proliferation and differentiation. In addition, IL-6 increased the size of megakaryocytes in granulocyte-macrophage-megakaryocyte colonies. The combination of granulocyte colony-stimulating factor or granulocyte-macrophage colony stimulating factor with IL-3 resulted in an increase in the granulocyte-macrophage colony growth of bone marrow cells of 5-FU-treated mice or normal mice, respectively, but had little effect on the enhancement of pure and mixed megakaryocyte colony growth. These results suggest that IL-6 plays an important role in murine megakaryocytopoiesis.

Group-delay measurement using the Fourier transform of an interferometric cross correlation generated by white light

A new method and apparatus for measuring the group delay in optical components and laser cavities are described. Cross-correlational fringes are fully recorded with a Michelson interferometer, in one of whose arms the optics to be measured are inserted. The path difference of the interferometer is calibrated to subwavelength accuracy, and the group delay is calculated from the phase of the Fourier transform of the measured fringe. The group delay for the entire visible-wavelength region is evaluated after a single measurement in approximately 10 min, using white light.

Synergistic action of phorbol ester and IL-3 in the induction of "connective tissue-type" mast cell proliferation

12-O-Tetradecanoylphorbol-13-acetate (TPA), a tumor-promoting phorbol ester, induced the proliferation of connective tissue-type mast cells (CTMC) synergistically with IL-3 in a methylcellulose culture, as well as with IL-4. The culture of single CTMC and the serum-free culture of CTMC fractionated by Percoll density gradient centrifugation showed that this synergistic action of IL-3 and TPA required no effects of accessory cells or other humoral factors. Although the populations of CTMC acted on by TPA and IL-4 seemed to be close to each other, the velocity of colony growth induced by the simultaneous stimulation of the combination of TPA and IL-4 was faster than that induced by either TPA or IL-4 in the presence of IL-3. In addition, the addition of anti-IL-4 antibody did not neutralize the effect of TPA on the proliferation of CTMC. These results suggest that TPA and IL-4 act on the proliferation of CTMC synergistically with IL-3 via a different pathway. Beside TPA, other phorbol derivatives capable of activating protein kinase C (PKC) induced the proliferation of CTMC synergistically with IL-3, but phorbol derivatives which were unable to activate PKC did not. These results indicate that the activation of PKC is involved in the process of TPA action on the proliferation of CTMC. Furthermore, the facts that 1-oleoyl-2-acetylglycerol, which activated membrane PKC transiently, and staurosporine, which has been reported to inhibit PKC, did not induce the proliferation of CTMC in the presence of IL-3 and that the effect of TPA was exhibited by the sustained stimulation suggest that the action of TPA on the proliferation of CTMC requires at least two steps. The first one is the primary activation of membrane PKC and the second one is the disappearance of PKC from the cells, "down-regulation."

Synergistic action of phorbol ester and IL-3 in the induction of "connective tissue-type" mast cell proliferation

12-O-Tetradecanoylphorbol-13-acetate (TPA), a tumor-promoting phorbol ester, induced the proliferation of connective tissue-type mast cells (CTMC) synergistically with IL-3 in a methylcellulose culture, as well as with IL-4. The culture of single CTMC and the serum-free culture of CTMC fractionated by Percoll density gradient centrifugation showed that this synergistic action of IL-3 and TPA required no effects of accessory cells or other humoral factors. Although the populations of CTMC acted on by TPA and IL-4 seemed to be close to each other, the velocity of colony growth induced by the simultaneous stimulation of the combination of TPA and IL-4 was faster than that induced by either TPA or IL-4 in the presence of IL-3. In addition, the addition of anti-IL-4 antibody did not neutralize the effect of TPA on the proliferation of CTMC. These results suggest that TPA and IL-4 act on the proliferation of CTMC synergistically with IL-3 via a different pathway. Beside TPA, other phorbol derivatives capable of activating protein kinase C (PKC) induced the proliferation of CTMC synergistically with IL-3, but phorbol derivatives which were unable to activate PKC did not. These results indicate that the activation of PKC is involved in the process of TPA action on the proliferation of CTMC. Furthermore, the facts that 1-oleoyl-2-acetylglycerol, which activated membrane PKC transiently, and staurosporine, which has been reported to inhibit PKC, did not induce the proliferation of CTMC in the presence of IL-3 and that the effect of TPA was exhibited by the sustained stimulation suggest that the action of TPA on the proliferation of CTMC requires at least two steps. The first one is the primary activation of membrane PKC and the second one is the disappearance of PKC from the cells, "down-regulation."

Effects of interleukin-3 and interleukin-4 on the development of "connective tissue-type" mast cells: interleukin-3 supports their survival and interleukin-4 triggers and supports their proliferation synergistically with interleukin-3

We examined the effects of interleukin-3 (IL-3) and interleukin-4 (IL-4) on connective tissue-type mast cells (CTMC) purified from murine peritoneal cells. Although both factors failed to induce extensive proliferation of CTMC, they stimulated CTMC proliferation synergistically in a dose-dependent manner. Pretreatment of CTMC with IL-3 and/or IL-4 indicated that the sustained presence of both factors was required for the development of type 1 mast cell colonies. The delayed addition of IL-3 to cultures of purified CTMC with IL-4 induced no colony formation, while the delayed addition of IL-4 to cultures with IL-3, even on day 28 of culture, induced type 1 colony formation. In replating type 1 colonies induced by IL-3 and IL-4 to secondary cultures with IL-3 alone, few secondary colonies developed. However, the delayed addition of IL-4 to the secondary culture induced many type 1 colonies. The purified CTMC cultured with IL-3 retained the morphological and cytochemical characteristics of CTMC, as well as proliferative ability. These observations indicate that IL-3 supports the survival of CTMC in methylcellulose culture and that IL-4 triggers and supports CTMC proliferation synergistically with IL-3. The serum-free culture of purified CTMC and the culture of single CTMC demonstrated that the synergistic effect of IL-3 and IL-4 on colony growth and the surviving effect of IL-3 on CTMC require no influence from accessory cells or other humoral factors.

[Effect of a protein-bound polysaccharide, PSK, on human hemopoietic progenitors]

Using in vitro clonal culture assays, we investigated the effects of PSK, a protein-bound polysaccharide derived from the cultured mycelium of CM101, Coriolus versicolor (Fr.) Quél in Basidiomycetes, on human hemopoietic progenitors. PSK alone did not stimulate colony formation by human bone marrow progenitors. Although 1-100 micrograms/ml of PSK had no effects on colony formation stimulated by erythropoietin and medium conditioned by phytohemagglutinin-stimulated leukocytes, more than 1 mg/ml of PSK inhibited all types of colony formation. In contrast, medium conditioned by PSK-stimulated leukocytes significantly stimulated formation of various types of colonies including erythroid bursts, granulocyte and/or macrophage colonies, eosinophil colonies, megakaryocyte colonies and mixed hemopoietic colonies. It is speculated that administration of the optimal dose of PSK can reduce the hematological suppression of antitumor drugs.

Synergism of BSF-2/interleukin 6 and interleukin 3 on development of multipotential hemopoietic progenitors in serum-free culture

We investigated the effects of B cell stimulatory factor 2/interleukin 6 (BSF-2/IL-6) on the development of murine hemopoietic progenitors using serum-containing culture and serum-free culture. In serum-containing culture, BSF-2 mainly supported multipotential blast cell colonies from spleen cells of normal and 5-fluorouracil (5-FU)-treated mice. In serum-free culture, no colony growth was seen in the presence of BSF-2. Addition of BSF-2 to the serum-free culture containing IL-3 resulted in a significant increase in the number of colonies formed from multipotential progenitors in spleen cells and bone marrow cells of 5-FU-treated mice, whereas no effects were seen on the number of single or oligolineage colonies formed by the spleen cells of normal mice. These results suggested that BSF-2 and IL-3 act synergistically on the multipotential progenitors but not on the maturer progenitors. When BSF-2 was added to a culture containing low concentrations of IL-3 (1 U/ml, 4 U/ml), which had little effect on colony formation, the number of total colonies formed by the spleen cells and bone marrow cells of 5-FU-treated mice increased significantly. The combination of BSF-2 and 40 U/ml of IL-3 resulted in a significant enlargement of GMM colonies. Thus, BSF-2 appears to enhance the sensitivity of multipotential hemopoietic progenitors to IL-3.

Extensive proliferation of mature connective-tissue type mast cells in vitro

There are two phenotypically distinct subpopulations of mast cells in rodents: connective tissue-type mast cells (CTMC) and mucosal mast cells (MMC). These populations differ in their location, cell size, staining characteristics, ultrastructure, mediator content and T-cell dependency. Several investigators recently reported a further subclass of mast cells which arise when normal mouse haematopoietic cells are cultured with interleukin-3 (IL-3); IL-3 is an activity similar or identical to mast-cell growth factor, histamine-producing factor, or P-cell stimulating factor. These cultured mast cells are in many ways similar to MMC; they stain with Alcian blue but not safranin, contain chondroitin sulphate E proteoglycan rather than heparin proteoglycan and have relatively low histamine content, as do MMC. Although proliferation of MMC is known to be T-cell dependent in vivo and thought to be IL-3-dependent in vitro, the factors on which CTMC proliferation depends remain elusive. Here we show that mature CTMC purified from mouse peritoneal cells can proliferate in vitro in methylcellulose culture and maintain the appearance and function of CTMC. We also present evidence that mature CTMC cannot proliferate in the presence of pure IL-3 alone.

Electrophysiological findings in a family with congenital arteriohepatic dysplasia (Alagille syndrome)

Arteriohepatic dysplasia (Alagille syndrome) is a congenital cholestatic disease associated with ocular abnormalities. Three Japanese siblings, a 14-year-old girl, an 11-year-old boy, and a 9-year-old girl with this syndrome were studied. All three patients showed neonatal jaundice, hepatic dysfunction, characteristic facies, and psychomental retardation. The two sisters had cardiac murmurs. Ophthalmological examinations revealed that they had posterior embryotoxon, refractive error, retinochorodial degeneration, and electrophysiological abnormalities. The two sisters showed retinochoroidal degeneration and unilateral high myopia while the brother showed marked retinochoroidal degeneration with extensive pigment clumps. Visual fields showed moderate concentric contraction in the two sisters and marked concentric contraction in the brother. Amplitudes of the single flash electroretinogram were moderately reduced in the sisters, the test was nonrecordable in one eye and extensively reduced in the other eye of the brother. The electrooculogram was borderline in the elder sister and abnormal in the brother and younger sister. Visual evoked cortical potential (VECP) were abnormal in the high myopic eye in each of the two sisters. Ophthalmological findings including electrophysiological examinations may help to confirm the diagnosis of this multisystem familial disorder.

Establishment of human KB cells resistant to 1-beta-D-arabinofuranosylcytosine, and mechanisms of cellular resistance in isolated clones

A subline of human KB cells that was resistant to 1-beta-D-arabinofuranosylcytosine (ara-C) was established by continuous exposure of the cells to increasing concentrations of ara-C. Thirteen resistant clones were isolated from the resistant subline (KB/ara-C). KB/ara-C showed 1,300-fold higher resistance than the parent KB cells to ara-C; the most resistant clones, clones 7 and 10, showed 1,330-fold higher resistance. In the absence of ara-C, the resistance of the parent KB/ara-C cells was stable for at least 14 weeks, whereas that of clone 7 was stable for 10 weeks, but was slightly less after 14 weeks. The ara-C kinase and ara-C deaminase activities of the 13 clones and the cellular uptake of ara-C by several clones were measured. In general the clones showed decreased deoxycytidine kinase activity and decreased cellular uptake of ara-C. Most clones had higher cytidine deaminase activity than KB cells, but some had activity similar to that of the KB cells. A clear inverse relationship was found between the ara-C sensitivity of the clones and their kinase activity, but not their deaminase activity or their ara-C uptake. These results clearly demonstrate that a major mechanism of ara-C resistance of these human KB cells was a decrease in the activity of the ara-C activating enzyme deoxycytidine kinase. The parent KB/ara-C cells showed no clear cross-resistance to various antitumor agents other than an ara-C derivative, including metabolic inhibitors, alkylating agents, DNA binders and mitotic spindle poisons.