Structural and chemical characteristics and maturation of the calcium-phosphate crystals formed during the calcification of the organic matrix synthesized by chicken osteoblasts in cell culture

The calcium-phosphate (CA-P) crystals formed in the extracellular organic matrix synthesized by chicken osteoblasts in cell culture were examined after 30, 40, and 60 days of culture by a number of physical and chemical techniques including chemical analyses, X-ray diffraction, transmission electron microscopy of isolated crystals, and resolution-enhanced Fourier transform infrared spectroscopy. The data reveal that the solid inorganic calcium-phosphate phase consists of a very poorly crystalline apatite, having a low carbonate content and containing acid phosphate groups. The chemical and structural characteristics are generally similar to the apatite crystals found in young newly synthesized bone but there were small but significant differences found. The major significant differences noted were the rate at which maturational changes occurred in the crystals formed in cell culture compared with those noted in vivo and in synthetic carbonate apatite crystals equilibrated with the same cell culture medium, and the persistence of labile groups, especially HPO4(-2) ions during a relatively long period of incubation. Despite extensive chemical efforts to degrade the organic constituents and to disperse the individual crystals isolated from the organic matrix constituents, a large proportion of the crystals were found to be organized in both loosely and densely packed relatively large roughly spherical aggregates. A few of the aggregates were organized in the form of fibrils with the crystals oriented with their c-axes roughly parallel to the long axes of the crystal aggregate. With briefer periods of chemical treatment, larger aggregates of crystals were occasionally observed in which there was a distinct axial periodicity of approximately 70 nm. In such collagen-crystal fragments, the crystals were well-oriented with their c-axis roughly parallel to the long axes of the aggregate similar to the organization and relationships between crystals and collagen fibrils in native bone. Isolated crystals were in the shape of thin plates. At the end of 30 days of culture, many of the crystals were clearly larger than those observed in native chick bone, except for those in the very youngest (7- to 8-day-old) embryos. At the end of 40 and 60 days of culture, the crystal habit remained as thin plates but the crystals were predominantly smaller, similar to those found in older embryo and postnatal chicken bone. The marked tendency of the crystals to form relatively large aggregates that resist dispersion by techniques that readily disperse the crystals of bone, and the presence of a significant number of larger crystals has also been observed in studies of calcified cartilage. Resolution enhanced FTIR spectroscopy revealed the presence of a high concentration of labile phosphate groups, especially after 30 days of culture and just after the plateau of mineralization is reached.

Isolation of calcium-phosphate crystals of bone by non-aqueous methods at low temperature

We have developed low temperature nonaqueous solution methods as well as low power plasma ashing for the degradation of the organic matrix of bone power which have permitted us to obtain bone crystals essentially free of organic matrix constituents without any significant change in their composition, overall structure, or internal short-range order. We have also been able to disperse the crystals, which has made it possible to examine the isolated crystals by X-ray diffraction and resolution-enhanced Fourier transform infrared (FTIR) spectroscopy and isolated single crystals by high resolution transmission electron microscopy (TEM) and electron diffraction. TEM of isolated single crystals of fish, chicken, mouse and bovine bone have clearly demonstrated that the crystals are very thin plates. No rod or needle-like crystals were observed in any of the bone samples in the four species studied including the earliest crystals deposited. Although there were variations in the size distribution of the crystals in the different species studied, in general the average crystal dimensions were very similar.

Binary phase spatial modulation using photoinduced anisotropy in amorphous As(2)S(3) thin film

We present a method for binary phase spatial modulation that uses photoinduced anisotropy in a chalcogenide amorphous As(2)S(3) thin film and its application to binary phase-only filters in a VanderLugt optical correlator. The time-dependent light-transmission properties of the photoilluminated As(2)S(3) thin film are analytically examined by use of third-order nonlinear polarization theory. Experimental results on optical correlation are discussed.

Expression of protein kinase C delta gene in germ cells

PURPOSE

To investigate the biological functions of protein kinase C delta (PKC delta) in spermatogenesis.

MATERIALS AND METHODS

We examined PKC delta transcript in mouse testis by means of in situ hybridization and Northern blotting.

RESULTS

In testes of normal mice, signals of PKC delta gene expression were detected specifically at the spermatid stage. The PKC delta gene was weakly expressed in 8-week-old mice and highly expressed by 12 weeks. However, the expression was not detected in testes of germ cell-deficient W/Wv mice even at 12 weeks.

CONCLUSIONS

Protein kinase C delta gene expression may be controlled by specific developmental processes and PKC delta may play a role in spermatogenesis.

Intracellular Ca2+ pool depletion is linked to the induction of nitric oxide synthesis in murine peritoneal macrophages

The ability of putative Ca(2+)-ATPase inhibitor of endoplasmic reticulum (ER), thapsigargin (TG), to induce nitric oxide (NO) synthesis in murine peritoneal macrophages was examined. TG alone had small effect on NO synthesis, whereas TG in combination with LPS markedly increased NO synthesis in a dose dependent manner. This increase in NO synthesis was reflected as increased amount of inducible NO synthase (iNOS) mRNA by Northern blotting. In addition, the ability of TG on NO synthesis could be mimicked by another chemically unrelated inhibitor of Ca(2+)-ATPase, 2,5-DI-(t-butyl)-1, 4-benzohydroquinone (tBuBHQ). Adding EGTA, a calcium chelator, to the incubation medium significantly reduced the ability of macrophages to induce NO synthesis in response to the optimal stimulation of TG or TG plus LPS. These results therefore demonstrate that intracellular Ca2+ pool depletion is linked to the induction of NO synthesis in murine peritoneal macrophages and further suggest that it is also related with interferon-gamma (IFN-gamma)-induced signaling.

Involvement of protein kinase C during taxol-induced activation of murine peritoneal macrophages

Taxol has been known to block cell division by stabilizing microtubules with promising anticancer activity. However, taxol has distinct cell cycle-independent effects. Recently, this novel drug has been shown to provide a second signal for murine macrophage activation to tumoricidal activity via L-arginine-dependent nitric oxide (NO) synthesis. To investigate the mechanism of taxol-induced NO synthesis, we evaluated the ability of protein kinase C (PKC) inhibitors such as staurosporine (STSN) or polymyxin B to block taxol-induced effects. Taxol alone had only a small effect, whereas taxol in combination with rIFN-gamma markedly increased NO synthesis in a dose-dependent manner. STSN and polymyxin B decreased NO synthesis, which had been induced by rIFN-gamma plus taxol. Furthermore, prolonged incubation of the cells with phorbol ester, which down-regulates PKC activity, abolished synergistic cooperative effect of taxol with rIFN-gamma on NO synthesis. Synergy between IFN-gamma and taxol was mainly dependent on taxol-induced TNF-alpha secretion because not only the increase of inducible NO synthase (iNOS) gene expression by rIFN-gamma plus taxol was associated with the increased expression of TNF-alpha gene but also taxol-induced NO production was decreased by the treatment of anti-murine TNF-alpha neutralizing Abs. STSN and polymyxin B potently inhibited taxol-induced TNF-alpha secretion and TNF-alpha gene expression as well as iNOS gene expression by rIFN-gamma plus taxol. However, rIFN-gamma plus TNF-alpha-induced NO synthesis was not blocked by STSN or polymyxin B. This result indicates that TNF-alpha-induced signaling for induction of NO synthesis is not dependent on PKC activation, and further suggests that the point at which TNF-alpha acts on the NO synthesis from rIFN-gamma-primed macrophages lies next to the point of PKC activation. In conclusion, the present results strongly suggest that the capacity of taxol to increase NO synthesis from rIFN-gamma-primed macrophages is the result of taxol-induced TNF-alpha secretion via the signal transduction pathway of PKC activation.

Involvement of protein kinase C during taxol-induced activation of murine peritoneal macrophages

Taxol has been known to block cell division by stabilizing microtubules with promising anticancer activity. However, taxol has distinct cell cycle-independent effects. Recently, this novel drug has been shown to provide a second signal for murine macrophage activation to tumoricidal activity via L-arginine-dependent nitric oxide (NO) synthesis. To investigate the mechanism of taxol-induced NO synthesis, we evaluated the ability of protein kinase C (PKC) inhibitors such as staurosporine (STSN) or polymyxin B to block taxol-induced effects. Taxol alone had only a small effect, whereas taxol in combination with rIFN-gamma markedly increased NO synthesis in a dose-dependent manner. STSN and polymyxin B decreased NO synthesis, which had been induced by rIFN-gamma plus taxol. Furthermore, prolonged incubation of the cells with phorbol ester, which down-regulates PKC activity, abolished synergistic cooperative effect of taxol with rIFN-gamma on NO synthesis. Synergy between IFN-gamma and taxol was mainly dependent on taxol-induced TNF-alpha secretion because not only the increase of inducible NO synthase (iNOS) gene expression by rIFN-gamma plus taxol was associated with the increased expression of TNF-alpha gene but also taxol-induced NO production was decreased by the treatment of anti-murine TNF-alpha neutralizing Abs. STSN and polymyxin B potently inhibited taxol-induced TNF-alpha secretion and TNF-alpha gene expression as well as iNOS gene expression by rIFN-gamma plus taxol. However, rIFN-gamma plus TNF-alpha-induced NO synthesis was not blocked by STSN or polymyxin B. This result indicates that TNF-alpha-induced signaling for induction of NO synthesis is not dependent on PKC activation, and further suggests that the point at which TNF-alpha acts on the NO synthesis from rIFN-gamma-primed macrophages lies next to the point of PKC activation. In conclusion, the present results strongly suggest that the capacity of taxol to increase NO synthesis from rIFN-gamma-primed macrophages is the result of taxol-induced TNF-alpha secretion via the signal transduction pathway of PKC activation.

Multizone Photorefractive Keratectomy for Myopia of 9 to 14 Diopters

We performed photorefractive keratectomy (PRK) using new multizone software of the Summit Omnimed excimer laser (Summit Technology, Inc., Waltham, Mass.) on thirteen highly myopic eyes. Average preoperative myopia was -10.94 diopters (D) (range -8.60 D to -13.50 D). Mean postoperative spherical equivalent refraction was -0.15 D (range +1.50 D to -4.00 D), at 3 months postoperatively. Uncorrected visual acuity of all the eyes improved markedly. There was no serious complication except one eye that lost two lines of spectacle corrected visual acuity possibly due to decentration. Though we need longer follow-up data and a larger sample size, the new multizone software seems to be effective for correcting high myopia.

Administration of dehydroepiandrosterone reverses the immune suppression induced by high dose antigen in mice

Several factors including antigen concentration, the route of antigen administration, hormones and cytokines have shown to affect T cells to produce the distinct patterns of lymphokines which exert regulatory and effector functions of immune response. In this study, we asked whether administration of dehydroepiandrosterone (DHEA) to mice which were tolerized by high dose of antigen could modulate T cell functions to restore the suppressed cellular immune response and to produce the distinct lymphokines. An intravenous injection of high dose of sheep red blood cells induced suppression of delayed type hypersensitivity (DTH) and a single subcutaneous injection of the tolerant mice with DHEA restored the suppressed DTH response. Furthermore, in vitro treatment of spleen cells from tolerant mice with DHEA abolished the transfer of tolerance to naive recipients. Lymphocytes from the DHEA-treated tolerant mice produced more IFN-gamma and less IL-4 and IL-6 than the cells from tolerant animals without DHEA treatment. These findings indicate that DHEA could recover antigen-specific immune suppression by differentially affecting T cells to produce the distinct lymphokines.

Down-regulation of transforming growth factor-beta gene expression by antisense oligodeoxynucleotides increases recombinant interferon-gamma-induced nitric oxide synthesis in murine peritoneal macrophages

Increasing evidence indicates that the production of nitric oxide (NO) by inducible NO synthase (iNOS) is tightly regulated. Transforming growth factor-beta (TGF-beta) is a family of multifunctional peptides secreted during macrophage activation, but several lines of evidence suggest that TGF-beta is selectively suppressive for macrophage NO production. We therefore reasoned that a strategy employing oligodeoxynucleotides (ODN) complementary to TGF-beta mRNA (antisense ODN) might increase NO production in interferon-gamma (IFN-gamma) treated murine peritoneal macrophages. To evaluate this concept, we tested the effects of antisense ODN targeted to TGF-beta mRNA (25-mer ODN complementary to TGF-beta mRNA sequences) by introducing them into the medium of cultured macrophages. Phosphorothioation of ODN was employed to retard their degradation. Antisense ODN had no effect on NO production by itself, whereas IFN-gamma alone had a modest effect. When antisense ODN were used in combination with IFN-gamma, there was a marked cooperative induction of NO production. These effects of antisense ODN were associated with decreased TGF-beta expression in activated macrophages. However, sense ODN had no effect. Adding anti-TGF-beta antibodies to the IFN-gamma-treated macrophages mimicked the positive effect of antisense ODN on NO production. In addition, the effects of either antisense ODN or anti-TGF-beta antibodies were blocked by adding exogenous TGF-beta in cultured macrophages. These results indicate that the generation of TGF-beta by activated macrophages provides a self-regulating mechanism by which the temporal and perhaps spatial production of NO, a reactive and potentially toxic mediator, can be finely regulated.

The Fc gamma RI receptor signals through the activation of hck and MAP kinase

U937 cells differentiated with IFN-gamma (termed U937IF cells) were used to study Fc gamma RI signaling. IFN induces a functional Fc gamma RI receptor signaling pathway in U937 cells, leading to the activation of the respiratory burst. IFN induces the expression of the nonreceptor protein tyrosine kinase, hck, and cross-linking the Fc gamma RI receptor in U937IF cells results in the activation of hck kinase as evidenced by the three- to fivefold increased tyrosine phosphorylation of hck. In vitro kinase assays demonstrate that the specific kinase activity of hck is increased 10-fold after Fc gamma RI stimulation. hck is observed to associate with two prominent tyrosine-phosphorylated proteins, p72 and p95, after Fc gamma RI-activation. Fc gamma RI cross-linking also results in mobility shift in MAP kinase in U937IF cells, suggesting that the Fc gamma RI receptor signals through the activation of MAP kinase. The data suggest that hck, p72, p95, and MAP kinase are involved in signal transduction through the Fc gamma RI receptor.

The Fc gamma RI receptor signals through the activation of hck and MAP kinase

U937 cells differentiated with IFN-gamma (termed U937IF cells) were used to study Fc gamma RI signaling. IFN induces a functional Fc gamma RI receptor signaling pathway in U937 cells, leading to the activation of the respiratory burst. IFN induces the expression of the nonreceptor protein tyrosine kinase, hck, and cross-linking the Fc gamma RI receptor in U937IF cells results in the activation of hck kinase as evidenced by the three- to fivefold increased tyrosine phosphorylation of hck. In vitro kinase assays demonstrate that the specific kinase activity of hck is increased 10-fold after Fc gamma RI stimulation. hck is observed to associate with two prominent tyrosine-phosphorylated proteins, p72 and p95, after Fc gamma RI-activation. Fc gamma RI cross-linking also results in mobility shift in MAP kinase in U937IF cells, suggesting that the Fc gamma RI receptor signals through the activation of MAP kinase. The data suggest that hck, p72, p95, and MAP kinase are involved in signal transduction through the Fc gamma RI receptor.

Fibronectin activates murine peritoneal macrophages for tumor cell destruction in the presence of IFN-gamma

Increasing evidence indicates that interaction of cells with fibronectin (Fn) affects many aspects of cellular responses including growth, morphology, differentiation, and activation. However, it is not known whether Fn could activate macrophages for the tumor cell killing. Here we report that Fn provides a signal for murine macrophage activation to tumoricidal activity. Tumoricidal activity was determined by the release of 51Cr from prelabeled P815 mastocytoma target cells. Fn alone had no effect, whereas recombinant interferon-gamma (rIFN-gamma) weakly induced C57BL/6 murine macrophages to kill P815 mastocytoma cells. However, combination of Fn with rIFN-gamma synergized to activate macrophages to lyse tumor cells in a dose dependent manner. Secretion of nitric oxide (NO) correlated with tumor cell killing, and the activated macrophages failed to kill tumor cell targets in the presence of NG-monomethyl-L-arginine (NGMMA), a competitive inhibitor of NO synthase (NOS). Fn, unlike lipopolysaccharide (LPS), alone had no effect on NO synthesis by itself and did not induce bioactive tumor necrosis factor-alpha (TNF-alpha) secretion from murine peritoneal macrophages. The data illustrate the potential for Fn to activate macrophage-mediated antitumor mechanisms in addition to its better characterized role as a cell adhesion molecule.

Effect of qigong training on proportions of T lymphocyte subsets in human peripheral blood

The effect of Qigong training on proportions of T lymphocyte subsets was investigated in human peripheral blood. We observed that the ratio of CD4+/CD8+ T lymphocytes was increased as much as 50% in a trainee group who practiced Qigong training more than 5 months compared to a normal healthy group who did not practice. The absolute number of CD4+ T lymphocytes was also elevated in trainee group with 100 cells/mm3 more than in normal healthy group. The positive correlation between the ratio of CD4+/CD8+ T lymphocytes and the ratio of CD4+45RA-/CD4+CD45RA+ T lymphocytes was shown in the trainee group. In contrast, there was a negative correlation between the ratio of CD4+/CD8+ T lymphocytes and the ratio of CD8+CD57+/CD8+CD57- T lymphocytes in the trainee group. The data indicate that Qigong training affects the profile of lymphocyte subsets in human peripheral blood, especially the proportion of CD4+ T lymphocytes.

Delayed cutaneous hypersensitivity reactions in Qigong (chun do sun bup) trainees by multitest cell mediated immunity

To determine the difference of cellular immunity between a Qigong trainee group and a normal healthy group, skin tests for delayed cutaneous hypersensitivity (DCH) were carried out with ubiquitous seven antigens. The maximal antigen response time was faster in Qigong trainee group (24 hr) and the response antigen number was also higher in the Qigong trainee group (6 antigens) than in normal healthy person (48 hr and 4 antigens). Qigong trainee also had a larger induration diameter (5.14 mm) than normal healthy person (3.79 mm) at 24 hr. Our results represent the difference in cell mediated immunity (CMI) between Qigong trainees and normal healthy subjects.

Differential expression of protein kinase C genes in cultured mast cells derived from normal and mast-cell-deficient mice and mast cell lines

We investigated the expression of mRNA of protein kinase C (PKC) isozymes (alpha, beta, gamma, delta, epsilon, xi, and eta) in cultured mast cells (CMC) derived from normal (+/+) mice, CMC derived from genetically mast-cell-deficient (W/W, Wv/Wv, and mi/mi) mice, and murine mast cell lines (IC2, MC9, and P-815) by Northern blotting. In +/+ CMC, abundant expression of PKC delta and moderate expression of PKC alpha and beta was observed, while other PKCs (types gamma, epsilon, xi, and eta) were not detected. In vivo expression of PKC delta was demonstrated in the skin by in situ hybridization. In mast cell lines, the expression pattern of PKC isozymes was similar to that of +/+ CMC, except that the expression of PKC eta was detected in the IC2 cell line. The expression levels of PKC delta in CMC derived from c-kit-deficient mutants, W/W, Wv/Wv, and mi/mi, were lower than that of +/+ mice. These results indicate that PKC delta is the main isozyme in various types of murine mast cells and also suggest that the reduced level of PKC delta expression in mutant mice may be caused by a deficit in the signal transduction system through c-kit receptor.

Phorbol ester synergistically increases interferon-gamma-induced nitric oxide synthesis in murine microglial cells

The effect of phorbol ester on the synthesis of nitric oxide (NO) in murine microglial cells was examined. Phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, alone had no effect, whereas PMA with recombinant interferon (rIFN)-gamma synergistically increased NO synthesis in murine microglial cells. The maximal effect of PMA on NO synthesis increase always fitted with the range for full activation of PKC in these cells. The increase of NO synthesis was reflected as increased amount of immunologic NO synthase (iNOS) mRNA detected by Northern blotting. Treatment with PKC inhibitors such as staurosporine or polymyxin B decreased rIFN-gamma-plus-PMA-stimulated NO synthesis. Further, prolonged incubation of the cells with PMA, which down-regulates PKC activity, abolished the synergistic cooperative effect with IFN-gamma. NG-monomethyl-L-arginine monohydrate, an analogue of L-arginine, and arginase inhibited rIFN-gamma-plus-PMA-induced NO production in murine microglial cells. On the basis of these observations, we conclude that PKC might not be involved in the expression of iNOS, but instead, might be involved in the posttranscriptional modification of iNOS mRNA.

Assessing drug compliance using longitudinal marker data, with application to AIDS

The assessment of non-compliance to a study medication is an important issue in the evaluation of clinical trials of self-administered drugs. Traditional methods for evaluating the compliance of subjects include self-reported questionnaires and pharmacologic assays of drug levels in randomly-drawn blood samples, but each of these has important limitations. This paper adapts and extends changepoint methods to assess compliance from longitudinal data on laboratory markers that are affected by the drug. The maximum likelihood estimators for two models are developed and examined. The effect of the drug on the marker process, as well as the spacing of the observations of the marker process relative to the time of non-compliance determine which model parameters are estimable. For the situations examined, the method of maximum likelihood is found to perform well in most cases. However, when non-compliance begins shortly before the last observation of the marker process, these (as well as any other) estimators cannot reliably distinguish non-compliance from compliance. The methods are illustrated with an example from a recent clinical trial of persons infected with HIV.

Synergistic cooperation between phorbol ester and IFN-gamma for induction of nitric oxide synthesis in murine peritoneal macrophages

The role of protein kinase C (PKC) in the induction of nitric oxide (NO) synthesis in murine peritoneal macrophages was examined. Phorbol ester, a PKC activator, had no effect on NO synthesis by itself, whereas IFN-gamma alone had modest activity. When phorbol ester was used in combination with IFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as increased amount of inducible NO synthase (iNOS) mRNA, as determined by Northern blotting. The optimal effect of phorbol ester was shown at 6 h after treatment with IFN-gamma. Phorbol ester also induced the release of NO to the incubation medium by bacillus Calmette-Guerin-infected peritoneal macrophages. Prolonged incubation of cells with phorbol ester, which down-regulates PKC activity, abolished the synergistic cooperative effect on NO production with IFN-gamma. In addition, such PKC inhibitors as staurosporin or polymyxin B reduced NO production induced by IFN-gamma plus phorbol ester. When the cells were treated with both actinomycin D and phorbol ester after IFN-gamma stimulation, more NO was produced and more iNOS mRNA was expressed than in the cells treated with actinomycin D alone. On the basis of these observations, we conclude that PKC might not be directly involved in the expression of NO synthase, but, instead, might be involved in the stabilization of the iNOS mRNA already expressed by the treatment of IFN-gamma.

Synergistic cooperation between phorbol ester and IFN-gamma for induction of nitric oxide synthesis in murine peritoneal macrophages

The role of protein kinase C (PKC) in the induction of nitric oxide (NO) synthesis in murine peritoneal macrophages was examined. Phorbol ester, a PKC activator, had no effect on NO synthesis by itself, whereas IFN-gamma alone had modest activity. When phorbol ester was used in combination with IFN-gamma, there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as increased amount of inducible NO synthase (iNOS) mRNA, as determined by Northern blotting. The optimal effect of phorbol ester was shown at 6 h after treatment with IFN-gamma. Phorbol ester also induced the release of NO to the incubation medium by bacillus Calmette-Guerin-infected peritoneal macrophages. Prolonged incubation of cells with phorbol ester, which down-regulates PKC activity, abolished the synergistic cooperative effect on NO production with IFN-gamma. In addition, such PKC inhibitors as staurosporin or polymyxin B reduced NO production induced by IFN-gamma plus phorbol ester. When the cells were treated with both actinomycin D and phorbol ester after IFN-gamma stimulation, more NO was produced and more iNOS mRNA was expressed than in the cells treated with actinomycin D alone. On the basis of these observations, we conclude that PKC might not be directly involved in the expression of NO synthase, but, instead, might be involved in the stabilization of the iNOS mRNA already expressed by the treatment of IFN-gamma.

Nitric oxide inhibits the expression of protein kinase C delta gene in the murine peritoneal macrophages

Since there is increasing evidence that protein kinase C (PKC) has a crucial role in the production of nitric oxide (NO) from activated macrophages, this study was undertaken to address whether NO could regulate the expression of the gene of this enzyme. Stimulation of the cells with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA) after treatment with recombinant interferon-gamma (rIFN-gamma) resulted in the increased production of NO in the medium. rIFN-gamma in combination with either LPS or PMA showed marked inhibition of the expression of PKC delta gene, whereas rIFN-gamma alone showed modest inhibition. The inhibition of gene expression was correlated with the amount of NO produced by activated macrophages. The inhibitory effect of NO on the expression of PKC delta gene is mimicked by the treatment of NO generating agent, sodium nitroprusside (SNP). On the other hand, a specific inhibitor for NO synthase, NG-monomethyl-L-arginine (NGMMA), blocked the inhibition of the expression of PKC delta gene by blocking the NO production in the rIFN-gamma and LPS-stimulated cells. However, production of NO did not affect the expression of both TNF-alpha and TGF-beta gene which were induced by the stimulation of macrophages, as well as beta-actin gene, which was constitutively expressed in the macrophages. In conclusion, these findings show that NO has a regulatory role for the expression of the gene of PKC delta which is crucially involved in the process of NO synthesis.

Generation of nitric oxide inhibits formation of superoxide in macrophages during activation

We have studied the production of nitric oxide (NO) and superoxide by murine peritoneal macrophages during activation. The production of NO was induced by activation of cells with recombinant interferon-gamma (rIFN-gamma) and lipopolysaccharide (LPS). Phorbol 12-myristate 13-acetate (PMA)-induced formation of superoxide also increased during activation. However, NO released by the activated macrophages exerted the inhibitory effect on the superoxide formation in the same cells. This fact is supported by the increased production of superoxide when the cells were treated with NG-monomethyl-L-arginine (NGMMA) in addition to stimulation with rIFN-gamma and LPS. The production of superoxide was also inhibited by treatment with sodium nitroprusside (SPN), which spontaneously released nitric oxide in vitro, and at the same time there was increased adenosine diphosphate (ADP)-ribosylation of 37 kDa proteins of the cytoplasm. The 3-aminobenzamide (3-AB) treatment, which decreased ADP-ribosylation, partially reversed SNP-induced inhibition of superoxide generation in macrophages. The above data provide evidence that NO decreases superoxide formation possibly via ADP-ribosylation.

Chemical modification of implantable biologic tissue for anti-calcification

Biologic porcine tissue was modified by coupling sulfonated polyethyl-eneoxide (PEO-SO3) and the effect of modification on calcification was evaluated in vitro and in vivo. The modification process involves grafting PEO-SO3 to porcine valve leaflet either by carbodiimide (EDC) activation or by direct coupling using glutaraldehyde. Thermal property, measured by differential scanning calorimetry, showed that the shrinkage temperature of modified tissue increased compared with control tissue and fresh tissue, suggesting increased thermal stability. Resistance to collagenase digestion revealed that modified tissues have greater resistance to enzyme digestion than do control tissues. In vitro calcification showed that modified tissues have less calcium deposition than do control tissues. In vivo calcification, using a rat subcutaneous implantation model, also showed less calcification of modified tissue than that of control. The resistance of modified tissue to collagenase, higher shrinkage temperature, and reduced calcification, when compared with control tissue, attest to the usefulness of this chemical modification for implantable biologic tissue.

Comparative studies of adriamycin and 28-deacetyl sendanin on in vitro growth inhibition of human cancer cell lines

The limonoid compound (28-deacetyl sendanin) isolated from the fruit of Melia toosendan SIEB. et ZUCC. was evaluated on anticancer activity. According to a standard in vitro cytotoxicity assay, eight human cancer cell lines and SRB assay were introduced for present evaluation. As a positive standard, adriamycin was tested in parallel. The cell lines were originated from six different organs. In view of dose-response profiles to 28-deacetyl sendanin, the most sensitive cells were SF-539 and PC-3 which were derived from CNS and prostate, respectively. In contrast, all the cell lines responded similarly to adriamycin to give rise to nearly identical dose-response profiles. By comparison of Gl50 between 28-deacetyl sendanin and adriamycin, six cell lines were more sensitive to 28-deacetyl sendanin and two were more resistant. As a result, 28-deacetyl sendanin had more sensitive and selective inhibitory effects on in vitro growth of human cancer cell lines in a comparison with adriamycin.

Involvement of protein kinase C in the inhibition of nitric oxide production from murine microglial cells by glucocorticoid

The effects of glucocorticoid on the production of nitric oxide (NO) by murine microglial cells were investigated. Stimulation of the cells with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA) after the treatment of recombinant interferon-gamma (rIFN-gamma) resulted in the increased accumulation of nitrite in the medium. Concomitant incubation of the cells with dexamethasone (DEX) markedly inhibited the production of NO in a dose dependent manner. DEX also suppressed both rIFN-gamma and rIFN-gamma plus LPS-induced activity of the enzyme protein kinase C (PKC), a putative regulator of NO synthesis, but had only a modest inhibitory effect on basal activity. In addition, the inhibitory effect of DEX on NO generation was mimicked by the treatment of PKC inhibitors such as staurosporine (STSN) and polymyxin B. Our findings show that glucocorticoids have the potential to modulate central nervous system (CNS) NO production via the inhibition of PKC activity particularly under the conditions of stimulated production of NO, such as inflammatory and demyelinating CNS disorders.

Direct exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases infectivity of human erythrocytes to a malarial parasite

Direct exposure to 10 nM 2,3,7,8-TCDD caused a 75% increase and a 2-fold increase in the infectivity of isolated human erythrocytes to P. falciparum after 48 hours when the parasites were in an unsynchronized or synchronized state of growth, respectively. Treatment of human erythrocytes with 10 microM sodium orthovanadate (NaOV), an inhibitor of plasma membrane Ca-ATPase and phosphotyrosine phosphatase, decreased parasitemia by 30%. Co-treatment of RBCs with TCDD and NaOV completely blocked the TCDD-induced increase in parasitemia. Because erythrocytes are anucleated, these results are discussed as evidence for biochemical changes by TCDD without requiring the activation of gene products.

PKC gamma gene expression is delayed in postnatal central nervous system of mi/mi mice

In the central nervous system (CNS), the expression of protein kinase C (PKC) genes is strictly controlled by the developmental stage. We have examined the expression of PKC genes (cPKC alpha, beta, gamma, and nPKC delta, epsilon) in the process of the postnatal development in normal (+/+) C57BL/6 and microphthalmic (mi/mi) C57BL/6 mouse brains by Northern blotting and in situ hybridization. By Northern blotting, the expression level of cPKC gamma mRNA in mi/mi mice was significantly lower than that in +/+ littermates at d 9, 13, and 17. By in situ hybridization analysis, cPKC gamma mRNA-positive cells were detected in hippocampal and Purkinje cells in +/+ and mi/mi mice, but the magnitude of the signals in mi/mi mice was lower than that of +/+ mice, and the number of positive cells was smaller, whereas other isozymes (cPKC alpha, beta, and nPKC delta, epsilon) showed no significant difference between normal and mi/mi mice. The neuronal morphometric analysis by anti-P400 antibody revealed the same number and expression level of P400 protein in cerebellar Purkinje cells compared with +/+ mice. These results indicate that the deficiency of mi gene product causes the delayed expression of the cPKC gamma gene.

Expression of osteopontin messenger RNA by macrophages in atherosclerotic plaques. A possible association with calcification

Calcification is a common complication in atherosclerosis. As osteopontin (OPN) and osteonectin (ON) are not only involved in the physiological but also the pathological calcification of tissues, we examined the expression of OPN and ON messenger (m)RNAs in normal and atherosclerotic human aortas. By Northern blotting, the OPN mRNA expression was related to the severity of the atherosclerosis. However, ON mRNA expression decreased with the development of atherosclerosis. By a combination of in situ hybridization and immunohistochemistry of serial sections, the macrophages surrounding the atheromatous plaques were identified as the OPN mRNA-expressing cells. The ON mRNA-expressing cells in aortas of a newborn baby and a 3-year-old boy were medial smooth muscle cells, but in aortas of adults, smooth muscle cells that had invaded the intima were found to express ON mRNA. As OPN mRNA-expressing macrophages surrounded the atheromatous plaques, and as the level of OPN mRNA expression increased as atherosclerosis advanced, it is possible that OPN plays a role in the calcification of atheromatous plaques.

In vivo canine studies of a Sinkhole valve and vascular graft coated with biocompatible PU-PEO-SO3

PU-PEO-SO3 was applied as a coating material over a newly designed Sinkhole bileaflet PU heart valve and a porous PU vascular graft. Performance and biocompatibility were evaluated using an in vivo canine shunt system between the right ventricle and pulmonary artery. The survival periods in three implantations were 14, 24, and 39 days, during which no mechanical failure occurred in any Sinkhole valve or vascular graft. Scanning electron microscopy (SEM) studies demonstrated much less platelet adhesion and thrombus formation on PU-PEO-SO3 grafts than on PU vascular grafts. Cracks in the valve leaflet were occasionally observed on PU surfaces, but not on PU-PEO-SO3. After a 39 day implantation, calcium deposition on vascular grafts was decreased as compared with valve leaflets, and calcification on PU-PEO-SO3 was much lower than on PU. These results suggest that Sinkhole valves and vascular grafts are promising, and PU-PEO-SO3 as a coating material is more blood compatible, biostable, and calcification resistant in vivo than in untreated PU.

Absence of immature mast cells in the skin of Ws/Ws rats with a small deletion at tyrosine kinase domain of the c-kit gene

Ws/Ws rats have a small deletion at the tyrosine kinase domain of the c-kit gene, and practically no mast cells were detectable when the tissues were stained with alcian blue. Because alcian blue stains proteoglycans, there is a possibility that immature mast cells that do not contain a sufficient amount of proteoglycans are not detectable by this method. We examined this possibility by using other markers of mast cells. The histamine content in the skin of Ws/Ws rats was 0.3% that of control normal (+/+) rats. Because the number of alcian blue-positive mast cells in the skin of Ws/Ws rats was also 0.3% that of +/+ rats, histamine in the skin seemed to be concentrated to alcian blue-positive mast cells. Mast cells in the skin of +/+ rats express messenger RNA of Fc epsilon RI beta-subunit and c-kit protein. Because c-kit messenger RNA was normally expressed at least in the brain of Ws/Ws rats despite the small deletion, we examined the expression of Fc epsilon RI beta-subunit and c-kit messenger RNA in the skin and stomach of Ws/Ws rats by reverse transcriptase modification of polymerase chain reaction. Expression of either Fc epsilon RI beta-subunit or c-kit messenger RNA in the skin and stomach of Ws/Ws rats was estimated to be less than 1% that of +/+ rats. Moreover no Fc epsilon RI beta-subunit-expressing and no c-kit-expressing cells were detectable in the skin of Ws/Ws rats by in situ hybridization histochemistry. The present result suggests the absence of immature mast cells in tissues of Ws/Ws rats.

Localization and developmental expression of a novel protein kinase C delta gene

The expression and localization of a novel protein kinase C delta (nPKC delta) mRNA were investigated using Northern blotting and in situ hybridization in the developmental process of mouse brain. In adult mice, nPKC delta was abundantly expressed in the thalamus, moderately in the pons and the cerebellum, but faintly in the cerebral cortex and the spinal cord. By in situ hybridization, the signals were observed specifically at the sensory and motor relay nuclei of the thalamus, the dorsal cochlear nuclei of the pons, and the molecular layer of the cerebellum. When developmental changes in the expression of nPKC delta gene were analyzed by in situ hybridization, it was not detectable in embryonic and neonatal brains, very weakly expressed in the thalamus in the first week, and highly expressed at two weeks of age. These results suggest that the gene expression of nPKC delta is strictly controlled by both the cell type and the developmental process.

Immunogenetic and nutritional profile in insulin-using youth-onset diabetics in Korea

There are few reports on the genetic, immunological and nutritional characteristics of insulin-using youth-onset diabetes mellitus, insulin-dependent diabetes mellitus (IDDM) and malnutrition-related diabetes mellitus (MRDM) in Korea. Among 1266 hospitalized Korean diabetics, 29 (2.3%) were IDDM and 84 (6.6%) were MRDM. A diabetes history of first-relatives (28.6%) was more frequently found in the MRDM group than in the IDDM (14.8) and non-insulin-dependent diabetes mellitus (NIDDM) (19.0%) groups. HLA-DR4 was more common among IDDM (54.2%) and MRDM (52.4%) patients than controls (26.3%), and HLA-DR3 was more common among only IDDM patients (29.2%) than controls (10.9%). Conventional islet-cell antibodies were detected in 8 of 15 IDDM patients tested (53.3%) and in 11 of 22 MRDM patients (50.0%). MRDM patients had higher serum basal (1.02 +/- 0.51 ng/ml) and peak (1.44 +/- 0.76 ng/ml) C-peptide concentrations than IDDM patients, but lower concentrations than NIDDM patients. Before the onset of diabetes, the calorie intake of 21 MRDM patients assessed was 63.1% of the daily requirement and the intake of carbohydrate, protein and fat was 71.7%, 55.9% and 39.8%, respectively. In summary, our data suggest that IDDM in Korea is associated with HLA-DR3 or HLA-DR4, indicating a risk for IDDM in Western societies; furthermore, MRDM has a history of undernutrition at the preonset period and is also associated with HLA-DR4. It might be also concluded that MRDM in Korea is another expression of IDDM caused by the shortage of some nutrients for the structural and/or functional maintenance of pancreatic beta-cells.

Spatial expression of genes encoding c-kit receptors and their ligands in mouse cerebellum as revealed by in situ hybridization

Expression of mRNA for c-kit receptors and their ligands was examined in the cerebellum of mice by in situ hybridization technique. The c-kit receptors were expressed in the molecular layer of the cerebellum and the ligands for the c-kit receptors were detected at the boundary of molecular and granular layers. The expression of the c-kit ligands was not detectable in the cerebellum of lurcher (Lc/+) mutant mice that lack Purkinje cells, indicating the cells expressing the c-kit ligands were Purkinje cells. The cells expressing c-kit receptors decreased but were present in the cerebellum of Lc/+ mice. The c-kit mRNA-positive cells appeared to represent basket cells and stellate cells from their appearance and location. Since neurons in the molecular layer construct suppressive neurojunctions with Purkinje cells, the present result suggests that c-kit receptors and their ligands may play an important role for the construction of their junctions.

Characterization of Ws mutant allele of rats: a 12-base deletion in tyrosine kinase domain of c-kit gene

Homozygous mutant rats at the newly found white spotting (Ws) locus were anemic and deficient in mast cells and melanocytes. Because the phenotype of Ws/Ws rats resembled the phenotype of mice possessing a double-gene dose of mutant alleles at the W locus and because the c-kit gene was mapped at the W locus of mice, we characterized the c-kit gene of Ws/Ws rats. The authentic sequence of the rat c-kit cDNA was determined by using a cDNA library prepared from the hippocampus of Sprague-Dawley rats. The c-kit cDNA of Ws/Ws and normal (+/+) control rats was obtained by reverse transcriptase modification of the polymerase chain reaction. When compared with the authentic sequence, a deletion of 12 bases was found in the c-kit cDNA of Ws/Ws rats. This change was shown to be a result of the deletion of the genomic DNA. Four amino acids encoded by the deleted 12 bases (ie, Val-Lys-Gly-Asn) were located at two amino acids downstream from the tyrosine autophosphorylation site in the c-kit kinase and were conserved not only in mouse and human c-kit kinases but also in mouse and human c-fms kinases (ie, receptors of colony-stimulating factor-1). Taken together, the Ws/Ws rat is the first characterized mutant of the c-kit gene in an animal species other than the mouse.

Facial nerve paralysis associated with Kawasaki disease

Kawasaki disease is a multisystem disorder with varying clinical expression. This is a report on one case of Kawasaki disease which during its clinical course developed facial nerve palsy and spontaneous recovery without specific treatment. It is hoped that this report will serve to remind physicians of the association of facial nerve paralysis with Kawasaki disease.

Coxsackie B virus assays in IDDM families: the GAW5 data on antibody prevalence

There is evidence that infection by Coxsackie viruses can serve as an environmental "trigger" for insulin-dependent diabetes mellitus (IDDM). This background information is summarized briefly, and the data in the IDDM component of Genetic Analysis Workshop 5 (GAW5) concerning serum antibodies to Coxsackie B viruses are described.

Presence of hexobarbital in primary cultures of rat hepatocytes maintains cytochrome P-450 levels and drug metabolizing enzyme activities

Addition of hexobarbital (1 mM) to the culture medium of rat hepatocytes protected against the rapid decline in the level of cytochrome P-450 and the activities of various drug metabolizing enzymes. While the hepatocytes cultured for 72 hr without hexobarbital had only 30% of their original level of cytochrome P-450, the cells maintained with hexobarbital had 75% of the initial level of the hemoprotein. After 72 hr in culture, the activities of aminopyrine N-demethylase and biphenyl 4-hydroxylase were 22-24% of the original rate for the nontreated cells and 73-78% for the hexobarbital treated cells. The activities of 7-ethoxycoumarin O-deethylase and aryl hydrocarbon hydroxylase in the cultures of treated cells were even higher than those of the freshly isolated hepatocytes. Additions of other substrates of hepatic mixed function oxidase to the culture medium did not protect against the loss of cytochrome P-450 and enzyme activities.

Human leukocyte antigen (HLA) in Korean patients with autoimmune thyroid diseases

In previous studies, there has been evidence of different allelic associations with a particular disease among various ethnic groups. The present study was done to investigate the associations between HLA and autoimmune thyroid diseases in the Korean. We found no association between Graves’ disease and HLA-B8 or -B35. However, increased frequencies of HLA-A11 and -DRw8, and the decreased frequencies of HLA-A10 and B12 were found in patients with Graves’ disease. In the cases of Hashimoto’s disease, the frequencies of HLA-A2 and -DRw8 were found to be significantly increased and the frequency of HLA-DRw6y decreased. These data indicate that the association between autoimmune thyroid disease and HLA in the Korean would appear to be different from that in most other racial groups, including Caucasians, Japanese and Chinese.

A large pedunculated left ventricular thrombus with recurrent systemic thromboembolism in a young man

We present the case of a young man who has suffered from recurrent systemic thromboembolism since he developed an acute interior wall myocardial infarction at the age of 27. A large elongated, pendunculated left ventricular thrombus was found by two dimensional echocardiography and was successfully removed by open heart surgery.

The effects of diet and exercise in the treatment of non-insulin dependent diabetes mellitus

Diet and exercise could be an essential part of the treatment of non-insulin dependent diabetes mellitus (NIDDM). The effects of a strict dietary restriction (800–1,200 Kcal/day) with exercise (2-hour walk per day) on glycemic control were evaluatedin NIDDM patients. A short-term study was performed on 147 cases In these cases, the duration of hospitalization was 7–14 days. We achieved glycemic control [fasting blood sugar (FBS) less than 140 mg/dl] in 112 cases (76%). Among them, 78 (53%) were controlled with diet and exercise only and in 34 (23%), control was induced with oral gliquidone treatment for about 5 days A long-term study was done on 76 cases who followed our program for from 1 to 12 months (mean : 3.8 months) after discharge. Glycemic control was maintained in 56 (74%) in spite of the insignificance of the amount of weight reduction. Glycemic control was significantly related to the duration of diabetes, diabetic complications and the peak C-peptide level, but was unrelated to the initial body weight, FBS levels and HbA_1c levels. These data indicate that a program of diet and exercise must be an integral part in the treatment of NIDDM. This was true, especially, for patients who have had adequate insulin secretory capacity few diabetic complications, short duration of disease, and no previous history of oral hypoglycemic agents or insulin therapy.

Immunohistochemical localization of keratin in the taste buds of rat vallate papillae

Keratin detected with anti-human whole keratin serum, raised in rabbits by injection of the isolated human whole keratin, was used as a histologic marker to study the origin of the cells in taste buds. Rat vallate papillae, including surrounding tissue, were processed for indirect immunofluorescent staining of ketatin. In the taste buds, most basal cells and some of the elongated cells were immunoreactive with anti-keratin serum, showing that most taste-bud cells, if not all, originate from cells of epithelial origin.

Effects of butylated hydroxytoluene (BHT) on biliary excretion of xenobiotics and bile flow in rats

A significant enhancement in the biliary excretion of iv injected sulfobromophthalein (BSP), phenol- 3,6 -dibromphthalein disulfonate (DBSP), procaine amide ethobromide (PAEB) and ouabain was observed in rats maintained on diets containing 0.25% BHT for periods of 10 days. The enhanced biliary excretion of these drugs in BHT treated rats appears to be correlated with the increase in bile flow produced by BHT. The increased bile flow was due to an increase in canalicular bile production rather than a change in net ductular secretion or reabsorption of fluid since bile to plasma concentration ratios of erythritol were unchanged and no permeability change in the biliary tree was observed when mannitol was administered by retrograde intrabiliary injection. The increase in bile flow was not due to an enhanced excretion of bile salts into bile, because both the biliary bile acid concentration and total biliary excretion of bile acids were lower in BHT-treated rats than in control rats. It appears that the increase in bile flow produced by BHT is due to the osmotic choleresis related to the secretion of BHT and its metabolites into bile.