Demonstration by DNA fingerprint analysis of genomic instability in mouse BALB 3T3 cells during cell transformation

We employed DNA fingerprint analysis to monitor DNA rearrangements in BALB 3T3 cells transformed spontaneously or by treatment with 3-methylcholanthrene (MCA) and UV-C. The effect of 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in combination with MCA was also examined. Twenty-three spontaneously transformed cells, 28 induced transformed cells (18 by 1 microgram/ml MCA, six by 5 micrograms/ml MCA, and four by UV-C), and 31 non-transformed subclones were isolated from parental BALB 3T3 A31-1-1 cells. The DNAs were digested with HinfI and subjected to DNA fingerprint analysis with three multi-locus minisatellite probes, Per-6, Core, and Ins. Per-6 was the most effective probe for detecting DNA rearrangements. Rearranged bands detected by the Per-6 probe were observed in 9/31 (29%) of non-transformed subclones, 14/23 (61%) of spontaneously transformed cells, 16/18 (89%) of cells transformed by 1 microgram/ml of MCA, 6/6 (100%) of cells transformed by 5 micrograms/ml MCA, and 4/4 (100%) of UV-C-transformed cells. Higher numbers of DNA rearrangements (> or = 3) occurred most frequently in the induced transformed cells. TPA enhanced the frequency of DNA rearrangements in cells transformed by MCA. These data indicate that (1) genomic DNA in BALB 3T3 cells is unstable and susceptible to rearrangement, (2) its instability is elevated during cell transformation, and (3) MCA and UV-C induce DNA rearrangements, and TPA enhances the effect of the former, probably via the recombination process. DNA fingerprint analysis is valuable for monitoring genomic instability during cell transformation.

[A case of tuberculous pleural effusion diagnosed by polymerase chain reaction (PCR)--with reference to tuberculous pleurisy using polymerase chain reaction]

A 38-year-old man was admitted to hospital because of chest pain and for the evaluation of a right pleural effusion on his chest X-ray film. Pleural effusion was characterized as exudative lymphocyte-predominant fluid with elevation of adenosine deaminase (ADA). Bacteriologic examination of pleural fluid was negative in both smear and culture of the fluid. PPD was positive and ESR was elevated. Mycobacterial DNA was detected in the pleural effusion using polymerase chain reaction (PCR) with primers which amplified a fragment of Is6110. Following treatment (INH, RFP and EB), the right pleural effusion disappeared. We conclude that PCR technique may be very useful in the rapid diagnosis of tuberculous pleurisy.

[Intracavernous internal carotid artery aneurysm associated with persistent trigeminal artery variant: case report]

The authors report a case of an intracavernous internal carotid artery aneurysm associated with a persistent trigeminal artery variant (PTAV). A 47-year-old-woman developed a subarachnoid hemorrhage due to the rupture of aneurysm and underwent direct clipping operation. PTAV is basically an anomalous anastomosis between the internal carotid artery and the anterior inferior cerebellar artery. In this patient, the PTAV originated from the C4 portion of the right internal carotid artery and distributed in the territory of the hemispheric branch of the posterior inferior cerebellar artery. There have been only three reported cases of the internal carotid artery aneurysms arising from the crotch of PTAV. It is also unusual that rupture of such a small aneurysm in the cavernous sinus causes subarachnoid hemorrhage. Embryological development of PTAV and possible mechanism of subarachnoid hemorrhage from the intracavernous aneurysm are discussed.

Statistical analysis of data in mutagenicity assays: rodent micronucleus assay

To evaluate chemical safety, many kinds of short-term mutagenicity assays are performed together with long-term assays in animals. Rationales and methodology for these assays have been well discussed and documented. No statistical method, however, has been singled out as the method of choice for the evaluation of mutagenicity assay data, although a number of reports on statistical methods to evaluate such data have been published. Among the mutagenicity assays, the micronucleus assay using mouse bone marrow erythropoietic cells have been widely used to assess cytogenetic activities of test chemicals. A statistical evaluation procedure for this assay is proposed herein, combining the use of historical control data and dose-response relationships. The probability of type I errors and the power of this method are compared with those of some other conventional methods by Monte Carlo simulation.

A study of electrical promontory stimulation in tinnitus patients

Electrical promontory stimulation relieved tinnitus in 74 (57.4%) of 129 ears (112 patients). There was no significant difference in etiology of tinnitus, age, average audiogram, or tinnitus frequency between patients who responded to electrical stimulation and those who did not. Most patients who did not respond to the initial stimulation trial did not respond to the subsequent trials, suggesting that the initial response to treatment predicts the subsequent response. Patients who did not respond to repetitive treatment were supposed to be under severe stress.

Inhibition of mouse hepatitis virus multiplication by antisense oligonucleotide, antisense RNA, sense RNA and ribozyme

Antisense nucleic acids against specific sequences of mouse hepatitis virus (MHV)-RNAs were tested for their inhibitory effects on viral multiplication in mouse DBT cells. An antisense oligonucleotide containing a sequence complementary to leader RNA was synthesized and shown to induce a significant inhibitory effect on the multiplication of MHV-JHM. A vector which expressed the antisense or sense mRNA7 of MHV was transfected into DBT cells. A decreased multiplication of MHV was observed in both cell lines. The transfected cell line which expressed ribozyme against the 5'-end of the MHV genome was established. The rate of inhibition of MHV-multiplication and the quantity of synthesized virus-specific mRNAs in this transfected cell line were the same for both antisense and sense RNA. These results show that antisense nucleic acids might be eligible for use as antiviral agents against MHV multiplication.

Interleukin 4 downregulates cell growth and prostaglandin release of human mesangial cells

Several clinical studies have proposed that a T cell derived cytokine IL-4 is operative in glomerulonephritis; however, its biological activities on renal cells have not been investigated. To elucidate its possible role in glomerulonephritis, we have examined whether IL-4 has effect on cell growth and prostaglandins synthesis using cultured mesangial cells (MC). IL-4 dose-dependently suppressed DNA synthesis and cell proliferation. IL-4 (10 ng/ml) alone did not affect prostaglandin E2 (PGE2) synthesis by mesangial cells, though, it inhibited IL-1 alpha- and TNF alpha-stimulated PGE2 synthesis by 48% and 81%, respectively. Comparable inhibition was observed on the conversion of exogenous arachidonic acid to PGs by IL-1-stimulated cells, suggesting IL-4 down regulates PG endoperoxide synthase activity. These results demonstrated that IL-4 is antagonistic to inflammatory cytokines upon PG synthesis as well as anti-mitogenic with MC.

Chemotactic response of fibroblasts to root surface components in wound healing following flap surgery

The purpose of this study was two-fold; first to investigate the chemotactic response of periodontal cells to root surface components during wound healing following flap surgery; second, to investigate the chemoattractive effect of the root components on cell migration. Cells were obtained by culturing cells from monkey periodontal tissues and rat calvarial cells. Root surface components were obtained from teeth extracted at 4, 7, 10 and 14 days after flap surgery. The chemotactic response of the isolated cells to root surface components was quantitated by an in vitro assay using a 48 well microchemotaxis chamber. The effect of root components or other growth factors on the cell migration was evaluated using a three-dimensional gel system. Cemental components produced a strong chemotactic response for gingival fibroblasts, alveolar bone cells and rat calvarial cells. Kinetics of the chemotactic potential of cementum was characterized by an initial increase (up to 7 days after surgery), a transient decline (at 10 days after surgery) and a second increase (at 14 days after surgery). Cemental components obtained 7 days after surgery most profoundly facilitated invasion of gingival fibroblasts with comparable effects induced by PDGF and TGF-beta. These results suggest that cemental components influence the chemotactic migration of gingival fibroblasts at the initial stage of wound healing, and therefore, cementum plays an important role in periodontal regeneration.

Selective induction of alpha 1 isoform of (Na+ + K+)-ATPase by insulin/insulin-like growth factor-I in cultured rat astrocytes

Treatment of cultured rat astrocytes with insulin increased (Na+ + K+)-ATPase activity expressed per protein or DNA by 1.6- to 2.1-fold, but did not affect Mg(2+)-ATPase and adenylate cyclase activities. Insulin treatment increased protein and DNA contents under the conditions, while it did not cause morphological differentiation as determined by a microscopic inspection. Insulin-like growth factor-I (IGF-I) had a similar effect on the enzyme activity in astrocytes: the effect of insulin was observed at supraphysiological concentrations, while that of IGF-I was observed at physiological concentrations. Insulin and IGF-I both stimulated DNA synthesis at the concentrations that caused an increase in enzyme activity. The effect was blocked by tyrosine kinase inhibitors such as genistein and herbimycin A and by cycloheximide. Western blot analysis showed that alpha 1 and alpha 2 isoforms of (Na+ + K+)-ATPase were present in cultured astrocytes and that insulin and IGF-I increased the content of the alpha 1 isoform but did not that of the alpha 2 isoform. Two components of ouabain inhibition were observed in the enzyme purified partially from cultured astrocytes, and treatment of the cells with IGF-I increased the ratio of the low-affinity component of the inhibition, indicating a selective increase in the activity of the alpha 1 isoform. These results indicate that insulin increases (Na+ + K+)-ATPase activity through an activation of IGF-I receptors and the increase is due to the selective induction of the alpha 1 isoform in cultured astrocytes.

A new antibiotic, cypemycin. Taxonomy, fermentation, isolation and biological characteristics

A new peptide antibiotic, cypemycin, with a molecular weight of 2,097 (M+H), was isolated from the culture broth of Streptomyces sp. OH-4156. The antibiotic possesses cytocidal activity against P388 leukemia cells in vitro at a concentration of 1.3 microgram/ml (IC50 values), and the antibiotic showed antimicrobial activities against Micrococcus luteus (MIC, 0.2 microgram/ml).

Isoproterenol stimulates Cl- current by a Gs protein-mediated process in beta-intercalated cells isolated from rabbit kidney

To examine the effect of isoproterenol on Cl- current and its signal transduction pathway in beta-intercalated cells (beta-IC cell), peanut agglutinin (PNA) positive cells in culture were studied by the whole-cell clamp technique. We identified these cells as beta-IC cells by PNA-binding, cell alkalinization induced by Cl- free in the superfusate, and an increase in intracellular cAMP concentration by isoproterenol, but not by vasopressin. Application of isoproterenol in the voltage-clamp mode induced an activation of Cl- current in a dose-dependent fashion and its threshold concentration was in the order of 0.01 microM and ED50 was about 0.1 microM. This effect of isoproterenol was inhibited by atenolol, a beta-adrenergic blocker. Either extracellular application of forskolin or intracellular application of cAMP mimicked the action of isoproterenol. In the presence of forskolin or cAMP, isoproterenol caused little further activation of Cl- current. A synthetic inhibitor of protein kinase A (5-24 amide) inhibited the Cl- -channel activation by isoproterenol. Isoproterenol failed to activate the current in the presence of intracellular GDP beta S. By contrast, intracellular application of GTP gamma S rendered irreversible the Cl- -channel activation by brief exposure to isoproterenol. The present studies provide direct evidence that in the PNA-binding cell, probably the beta-IC cell, the stimulation of beta-adrenoceptor activates Cl- current through the signal transduction system involving G-protein, adenylate cyclase, cAMP, and protein kinase A.

[Pharmacological studies on human urinary kallidinogenase (SK-827): cerebral protective effects]

We investigated the cerebral protective effects of human urinary kallidinogenase (SK-827) in rabbits. The following results were obtained: 1) At a dose of 5.0 x 10(-3) to 1.25 x 10(-2) PNA U/kg, SK-827 significantly inhibited the decrease of focal cerebral blood flow and the impairment of electrocorticogram (ECoG) activity in infarcted rabbits. 2) SK-827 at a dose of 2.5 x 10(-3) PNA U/kg inhibited the development of infarction area induced by internal carotid arterial injection of glass beads. 3) SK-827 at a dose of 2.5 x 10(-3) to 5.0 x 10(-3) PNA U/kg inhibited the decrease of cerebral cortical pO2 induced by 5% oxygen inhalation. 4) On subacute phase 7 days after the destruction of internal capsule, SK-827 at a dose of 1.25 x 10(-2) PNA U/kg improved the abnormality of spontaneous ECoG. These findings suggest that SK-827 minimizes the reduction of cerebral function induced by ischemia.

[Pharmacological studies on human urinary kallidinogenase (SK-827): effects on cerebral metabolism]

We investigated the effects of human urinary kallidinogenase (SK-827) on cerebral metabolism in normal and infarcted rabbits. SK-827 did not influence cerebral glucose and oxygen uptake in normal rabbits. In infarcted rabbits, cerebral glucose and oxygen uptake significantly decreased. SK-827 tended to inhibit the decrease of cerebral blood flow, and significantly inhibited the decrease of cerebral glucose and oxygen uptake in infarcted rabbits. Thus, SK-827 improved cerebral glucose metabolism in infarcted rabbits.

General pharmacology of the non-sulfhydryl angiotensin converting enzyme inhibitor N-[8-amino-1(S)-carboxyoctyl]-L-alanyl-L-proline

The effects of N-[8-amino-1(S)-carboxyoctyl]-L-alanyl-L-proline (AB-47, CAS 120008-53-9), an orally active angiotensin converting enzyme inhibitor, on the central nervous, respiratory and cardiovascular, autonomic systems, isolated smooth muscles and other functions were investigated in various experimental animals. AB-47 had no effect on central nervous, autonomic systems and isolated smooth muscles. AB-47 (10 and 30 micrograms/kg i.v.) significantly lowered femoral blood pressure without affecting respiration and heart rate in anesthetized rats. However, AB-47 had no effect on the contractile tension of mammalian isolated atrium and aorta. AB-47 had no effect on gastrointestinal transit in mice. Very slight injury of gastric mucosa was observed 4 h after the oral administration of AB-47 in rats but AB-47 did not damage the small intestinal mucosa. AB-47 had no effect on the contraction of rat phrenic nerve-diaphragm preparation induced by electrical stimulation. AB-47 did not affect the incidence of acetic acid-induces writhings. AB-47 potentiated carrageenan-induced hind paw edema in rats. The potentiation of edema may be due to an accumulation of bradykinin induced by the inhibition of angiotensin converting enzyme (ACE), because ACE is the identical enzyme with kinase II. The pretreatment of AB-47 for 7 days (1, 3, 10 mg/kg/d p.o.) inhibited the cardiac hypertrophy induced by isoproterenol (isoprenaline). This result suggests that the renin-angiotensin-aldosterone system directly or indirectly participates in the cardiac hypertrophy induced by isoproterenol.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of in vivo and in vitro alkali treatment on intracellular pH regulation of OMCDis cells

To examine functional changes of the transporters in the inner stripe of the outer medullary collecting ducts (OMCDis) by the peritubular acid-base status, in vitro microperfusion using the acetoxymethyl ester of 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein was performed. Cell alkalinization systems were assessed by the recovery rate (dpHi/dt) of intracellular pH (pHi) after intracellular acid loading by NH(4+)-NH3 prepulse with bath amiloride. In alkali-loaded rabbits (0.15 M NaHCO3 drinking for 14 days), dpHi/dt showed a significant decrease (1.80 +/- 0.29 pH units/s x 10(3)) compared with either control (3.30 +/- 0.59) or acid-loaded rabbits (0.15 M NH4Cl drinking for 14 days, 3.05 +/- 0.46). The difference of dpHi/dt between control and alkali-loaded rabbits was eliminated by lumen N-ethylmaleimide (NEM), suggesting that H+ pump activity was decreased. The effect of in vitro alkali treatment (50 mM HCO3-, pH 7.7) for 3-4 h was also examined. This incubation significantly decreased the dpHi/dt (1.83 +/- 0.35) compared with the time control experiments (3.18 +/- 0.28), whereas no significant difference was seen in the presence of lumen NEM. Anion exchanger activity, as determined from the pHi changes after Cl- addition to the bath, showed no significant change with in vivo or in vitro alkali treatment. The results indicate that cell function of the OMCDis is regulated in response to the peritubular acid-base environment via changes in the H(+)-adenosinetriphosphatase.

A novel pathway for formation of thiol metabolites and cysteine conjugates from cysteine conjugate sulphoxides

p-Bromothiophenol and S-(p-bromophenyl)-L-cysteine were formed enzymatically from S-(p-bromophenyl)-L-cysteine sulphoxide in the in vitro systems with isolated rat hepatocytes or purified cysteine conjugate beta-lyases. Isotope dilution study with non-radiolabelled carrier of each product suggested the initial liberation of the thiol and subsequent formation of the cysteine conjugate. C-S bond cleavage pathway to liberate sulphenic acid and thiol are postulated to play an important role in in vivo generation of toxic intermediates and products from cysteine conjugates.

Granulocyte-macrophage colony stimulating factor inhibits class II major histocompatibility complex expression and antigen presentation by microglia

Granulocyte-macrophage colony stimulating factor (GM-CSF) modulates various functions of monocytes/macrophages including antigen-presenting capacity. Recently it was found that astrocytes produce GM-CSF in the central nervous system (CNS) and that GM-CSF can induce proliferation and morphological changes of microglia. Here we show that GM-CSF can down regulate the interferon-gamma-mediated induction of major histocompatibility complex (MHC) class II antigens in microglia, but not in astrocytes. GM-CSF pretreatment completely prevents myelin basic protein-specific T cell proliferation induced by microglia not astrocytes. GM-CSF did not affect the cell surface expression on microglia of either MHC class I or cell adhesion molecules. The inhibition of microglial MHC class II expression and antigen-presenting function is specific for GM-CSF, as treatment with a different CSF (interleukin-3) did not modulate microglial phenotype or functional capacity. These data suggest that GM-CSF might be involved in the regulation of immune responses within the central nervous system.

New inhibitors of melanogenesis, OH-3984 K1 and K2. I. Taxonomy, fermentation, isolation and biological characteristics

Melanogenesis inhibitors, OH-3984 K1 and K2 were isolated from fermentation broth of Streptomyces sp. OH-3984. OH-3984 K1 and K2 inhibited the melanogenesis of B16 melanoma cells at concentrations of 7.5 and 3.8 micrograms/ml, respectively, whereas inhibition of tyrosinase activity has not been observed. The microbial metabolites showed no antimicrobiological activities against Gram-positive and Gram-negative bacteria, fungi or yeast at a concentration of 1,000 micrograms/ml.