Brain tumors associated with infantile spasms

Two patients with brain tumors associated with infantile spasms are reported. Both infants displayed typical clinical features of infantile spasms, comprising tonic spasms manifesting in series and hypsarrythmia. In Patient 1, magnetic resonance imaging revealed a tumor in the hypothalamic region, suggestive of hypothalamic hamartoma. In Patient 2, cranial computed tomography and magnetic resonance imaging indicated the existence of a primary brain tumor with calcification in the right temporal lobe. Adrenocorticotropic hormone therapy combined with clonazepam relieved seizures in both infants. In Patient 1, resection of the hypothalamic tumor is impossible because the tumor lacks a stalk. In Patient 2, pathologic investigation of removed tumor tissue demonstrated mixed-oligoastrocytoma. It is suggested that focal lesions, like those in our patients, are involved in the development of infantile spasms.

Use of a guanidine extract of demineralized bone in the treatment of osteochondral defects of articular cartilage

In order to evaluate the ability of a guanidine extract of demineralized bone to repair osteochondral defects in articular cartilage, plugs made of this extract were implanted into defects in rabbit knees. The repair tissue was examined macroscopically, histologically, and immunohistochemically at 4, 8, 12, and 30 weeks. Controls (defects that were left empty) showed no cartilage formation. Four weeks after implantation of a guanidine extract plug, histological examination showed a nonhomogeneous metachromatically stained region extending from the surface of the repair tissue down to cancellous bone. This region also was labeled by an anti-type-II collagen antibody, indicating that cartilage-like tissue had been induced. At 8 weeks, the newly formed cartilage in the subchondral and cancellous bone had been partially replaced by bone. At 12 weeks, the thickness of the newly formed cartilage layer had decreased, and most of the newly formed cartilage in the subchondral and cancellous bone had been replaced by bone. In addition, a tidemark was observed. At 30 weeks, the repair tissue was a mixture of cartilage and fibrocartilage, and there was severe degeneration of the cartilage surrounding the repaired defects. These findings indicate that osteochondral defects of articular cartilage can be partially repaired by the implantation of a guanidine extract and that the newly formed cartilage-like tissue is not permanent.

Successful expression in pollen of various plant species of in vitro synthesized mRNA introduced by particle bombardment

Gold particles coated with beta-glucuronidase (GUS) mRNA with a 5' cap structure that had been synthesized in vitro were introduced, by use of a pneumatic particle gun, into pollen grains of lily (Lilium longiflorum), freesia (Freesia refracta) and tulip (Tulipa gesneriana). A fluorometric assay for the GUS activity indicated that in vitro synthesized GUS mRNA introduced into these pollen cells by particle bombardment was successfully expressed. GUS activity in extracts of the bombarded lily pollen became detectable fluorometrically within 30 min after bombardment, peaked at 6 h, then gradually decreased. This activity changed as a function of the developmental stage of the pollen cell of lily.

[Jacksonian seizure model induced by a kainic acid microinjection into unilateral sensori-motor cortex]

Kainic acid microinjection into unilateral sensori-motor cortex induced focal seizure status and secondarily generalized seizure status for about 4 hours. After these seizure status, focal myoclonic jerkings were induced for about 2 days. EEG demonstrated generalized synchronous periodic spikes with these myoclonic jerkings. This phenomenon was very similar to those symptoms of epilepsia partialis continua in man. During focal seizure status, autoradiographic study with 14C-deoxyglucose demonstrated increased local cerebral glucose utilizations in the injected site of the sensori-motor cortex, ipsilateral caudate nucleus, globus pallidus, substantia nigra and thalamic nuclei. The result suggested that subcortical pathways played an important roles in the seizure propagation from the cortical epileptogenic focus.

Cloning of the human alpha 1d-adrenergic receptor and inducible expression of three human subtypes in SK-N-MC cells

We have cloned the human alpha 1d-adrenergic receptor (AR) and compared the pharmacological properties of the three recombinant human alpha 1-AR subtypes in SK-N-MC cells. SK-N-MC cells natively express a mixture of alpha 1-AR subtypes, and the use of an inducible expression system allowed us to directly compare the recombinant and native subtypes without concern for cell-specific processing or microenvironment. The human alpha 1d-AR was expressed from a cDNA/gene fusion construct cloned from human SK-N-MC cell cDNA and human genomic libraries. This receptor is deduced to contain 572 amino acids with 98% identity to the rat alpha 1d-AR in the transmembrane domains and, when expressed in human embryonic kidney 293 cells, has alpha 1-AR binding properties similar to those of the rat alpha 1d-AR. Norepinephrine increased inositol phosphate formation and mobilized intracellular Ca2+ in transfected 293 cells. Reverse transcription-polymerase chain reaction analysis of the three cloned human subtypes (alpha 1a, alpha 1b, and alpha 1d) in mRNA from SK-N-MC cells, which natively express alpha 1A- and alpha 1B-like pharmacology, showed abundant alpha 1a and alpha 1d but fewer alpha 1b transcripts. The three human clones were expressed in SK-N-MC cells using isopropyl-beta-D-thiogalactoside-inducible vectors. Upon induction, alpha 1-AR density was increased with the recombinant subtype comprising 67-80% of total alpha 1-ARs. Inhibition curves for (+)-niguldipine and 5-methylurapidil fit best to a two-site model in uninduced cells, indicating significant receptor heterogeneity. Isopropyl-beta-D-thiogalactoside induction altered the potencies of both compounds, causing most inhibition curves to fit best to a one-site model. (+)-Niguldipine was 100-fold more potent at the alpha 1a-AR than at alpha 1b- or alpha 1d-ARs, whereas 5-methylurapidil had similar potencies at alpha 1a- and alpha 1d-ARs and about 10-fold lower affinity at the alpha 1b-AR. We conclude that the complex alpha 1A- and alpha 1B-like pharmacology observed in native SK-N-MC cells is due to expression of all three subtypes in different proportions, independently of cell-specific processing or environmental factors, and that the alpha 1a-AR cDNA encodes the pharmacologically defined alpha 1A subtype.

Failure of aspirin and diltiazem to prevent the formation of acute coronary thrombi in dogs

The aim of the present study was to determine the efficacy of aspirin and diltiazem in preventing the formation of coronary thrombi in dogs. Canine coronary thrombi were produced by inserting a small catheter filled with collagen powder into the endothelial-injured, partially occluded left anterior descending coronary artery. Neither aspirin (bolus of 30 mg/kg, followed by 100 mg/kg/h by infusion), nor diltiazem (0.1 mg/kg, followed by 0.3 mg/kg/h by infusion) prevented the formation of coronary thrombi. The mortality in aspirin group was significantly higher than that in control and diltiazem groups. These results indicate that aspirin and diltiazem do not inhibit thrombus formation in the canine model of coronary thrombosis.

[Precision and problems in interpretation of acoustic rhinometry in cases of nasal mass lesion]

Precision and problems in interpretation of results obtained by acoustic rhinometry (AR) in cases of mass lesion in the nasal cavity were evaluated with two models, a simple tubal model and a model based on the cast of a cadaver's nasal cavity (cadaver model), and with a human subject. A simple tubal model of 2 cm inside diameter was used. Spherical claies with volumes of 1, 2, 3, and 3.5 cm3, located at same point in the tube, were measured by AR, and a high correlation was found between the clay volume calculated by AR and the real volume of the clay (r = 0.996). But the peak of decrease on the acoustic curve caused by clay was seen a bit posterior to the point where it was actually located. In the entire segment posterior to the peak on the acoustic curve, the value of the area was shown to be smaller than the value of the control. And the large the volume of clay, the greater the degree of decrease in this segment. In the study using the cadaver model, a pill (0.3 cm3) was put at nine sites in the nasal cavity, and AR was performed in each case. The results were compared with the control curve. The decrease in the area on the acoustic curve corresponding to the site of pill placement was recognized, as in the simple tubal model study, and a decrease in the area in the posterior segment of the acoustic curve was also observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Coupling of the endothelin ETA and ETB receptors to Ca2+ mobilization and Ca2+ sensitization in vascular smooth muscle

Effects of endothelins on cytosolic Ca2+ level ([Ca2+]i) and contraction were examined in the swine pulmonary artery and vein. In the artery, endothelin-1 and endothelin-3, but not sarafotoxin S6c and IRL 1620 (300 nM each), induced transient increase followed by sustained increase in [Ca2+]i and sustained contraction. These effects were inhibited by the ETA receptor antagonist, BQ-123. In the vein, endothelin-1 and endothelin-3 (300 nM each) induced sustained increase in [Ca2+]i and sustained contraction whereas sarafotoxin S6c and IRL 1620 (300 nM each) transiently increased both [Ca2+]i and contractile tension. The ETB receptor in the vein was desensitized by pretreatment with sarafotoxin S6c, abolishing the effects of sarafotoxin S6c and IRL 1620 without changing the effects of endothelin-1 and endothelin-3. In contrast, an ETB antagonist, RES-701-1, antagonized the effects of IRL 1620 without changing the effects of other stimulants. In both artery and vein, the maximum contraction induced by these stimulants was greater than that induced by KCl at a given [Ca2+]i. In the absence of external Ca2+, endothelin-1 and endothelin-3 induced transient increase in [Ca2+]i and slow sustained contraction in both artery and vein. In the vein, sarafotoxin S6c induced small sustained contraction without changing [Ca2+]i. In the permeabilized artery and vein, endothelin-1 augmented the contraction induced by Ca2+. These results suggest that the ETA receptors in the artery and vein are coupled to Ca2+ release (which does not seem to trigger contraction), Ca2+ influx and Ca2+ sensitization.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning, functional expression and tissue distribution of human alpha 1c-adrenoceptor splice variants

We report the cloning and characterization of two isoforms of human alpha 1c-adrenoceptor cDNA (alpha 1c-2, alpha 1c-3). These isoforms are generated by alternative splicing and differ from the clone we previously isolated (alpha 1c-1) in their length and sequences of the C-terminal domain. Tissue distribution of mRNAs showed that these variants co-express with alpha 1c-1 in the human heart, liver, cerebellum and cerebrum. Despite the structural differences, functional experiments in transfected CHO cells showed that the three isoforms have similar ligand binding properties, and all couple with phospholipase C/Ca2+ signaling pathway.

Species difference in the binding characteristics of RES-701-1: potent endothelin ETB receptor-selective antagonist

Species-dependency of RES-701-1 (cyclic (Gly1-Asp9)(Gly-Asn-Trp-His-Gly-Thr-Ala-Pro-Asp-Trp-Phe-Phe- Asn-Tyr-Tyr-Trp)) has been shown using 125I-ET-1 binding to membranes from various animal tissues. RES-701-1 selectively inhibited the 125I-ET-1 binding to ETB receptor from canine, rabbit, porcine, and guinea pig lung tissues in a dose-dependent manner with IC50 values of 60 nM, 20, 4 nM and 13 nM, respectively. Though RES-701-1 retained selectivity for ETB receptor even at higher concentrations, RES-701-1 inhibited the 125I-ET-1 binding to ETB receptor from rat lung, heart, and kidney only weakly; IC50 values were calculated to be 1.2 microM, 0.9 microM and 0.6 microM, respectively. These results suggest that RES-701-1 is a potent and specific antagonist for ETB receptor in various species of animal, and would be a powerful tool for understanding the physiological roles of ETB receptor, but care must be taken in use of RES-701-1 in experiments with rat.

Cloning of several species of MLL/MEN chimeric cDNAs in myeloid leukemia with t(11;19)(q23;p13.1) translocation

The t(11;19)(q23;p13.1) translocation is thought to play an important role in pathogenesis of myeloid leukemias in older patients. The MLL gene involved in other 11q23 abnormalities was also rearranged by this translocation. Screening of cDNA libraries of the t(11;19)(q23;p13.1)-carrying leukemic cells resulted in the isolation of several species of fusion cDNAs between the MLL gene and an unknown gene on 19p13.1, named MEN (myeloid eleven-nineteen translocation), which is ubiquitously expressed. Although the MLL gene was alternatively spliced, the fusion protein should contain an N-terminal half of the MLL, including AT hook motifs, that is fused to the MEN protein with a lysine-rich sequence, suggesting that the MLL/MEN fusion protein could be a chimeric transcription factor. The MLL/MEN fusion transcripts of 8.0 kb were detected in leukemic cells of two cases with the translocation. The MLL/MEN fusion was consistent in all three cases of the t(11;19)(q23;p13.1)-carrying leukemia examined by RNA-based polymerase chain reaction. These findings strongly suggest that the t(11;19)(q23;p13.1) results in the fusion formation encoding a new class of potential chimeric transcription factor that contributes to leukemogenesis of myeloid lineage.

An inhibitor of cyclic AMP-dependent protein kinase enhances the superoxide production of human neutrophils stimulated by N-formyl-methionyl-leucyl-phenylalanine

Intact human neutrophils produced superoxide (O2-) by the stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP) even when the extracellular Ca2+ was absent (0.56 +/- 0.13 nmol/min per 10(6) cells). The production by fMLP was enhanced more than twice in the presence of the extracellular Ca2+. Moreover, the O2- production by fMLP in the presence of extracellular Ca2+ was enhanced nearly three times by the treatment of cells with H-89, an inhibitor of cyclic AMP-dependent protein kinase (PKA). The enhancement was not observed when the extracellular Ca2+ was depleted from the reaction mixture. In addition, H-89 did not enhance fMLP-induced O2- production of electropermeabilized neutrophils in which the intracellular Ca2+ concentration was fixed to about 100 nM. These observations suggest that not only Ca2+ influx but the inhibition of PKA is necessary for the maximum O2- production by fMLP and that the O2- production is partially suppressed by the activation of PKA induced by fMLP.

Comparison of the inhibitory effect of the angiogenesis inhibitor, TNP-470, and mitomycin C on the growth and liver metastasis of human colon cancer

Angiogenesis inhibitors have attracted considerable interest. The anti-tumor and anti-metastatic effects of TNP-470, an angiogenesis inhibitor, and mitomycin C (MMC), a representative anti-neoplastic agent, were investigated using a xenotransplanted human colon cancer, TK-4. Suturing of small pieces of TK-4 tumors to the cecal wall in nude mice (orthotopic transplantation) induced liver metastasis. Mice were randomly divided into 3 groups; a control group given saline solution, a group receiving TNP-470 and a group receiving MMC. TNP-470 was given s.c. on alternate days for 5 weeks from day 10 after cecal transplantation and MMC was administered intraperitoneally (i.p.) once a week from day 10 after cecal transplantation. MMC significantly inhibited cecal tumor growth. In the control group, liver metastases developed in 9 out of 10 mice, including 3 with more than 20 metastatic foci. Liver metastasis also developed in 8 out of 10 mice receiving MMC, 2 of which had many metastases. In contrast, liver metastasis developed in only 2 out of 8 mice in the TNP-470 group and neither of these animals had numerous metastases.

CD28 cross-linking augments TCR-mediated signals and costimulates superantigen responses

The CD28 molecule expressed on the surface of T cells plays a pivotal role in transducing costimulatory signals necessary for cell activation. CD28 coligation enhances tyrosine phosphorylation and phosphoinositol 3-kinase association in responsive cells. CD28 cross-linking has also been reported to activate inositol phospholipid turnover and to cause release of intracellular calcium. Here we examine the effects of CD28 cross-linking on early activation of protein kinase C (PKC). We have reported recently that either PMA or CD28 cross-linking synergizes with signals delivered by superantigen and cytokines to induce the proliferation of APC-depleted T cells. Unlike PMA, CD28 cross-linking alone failed to induce an increase in membrane-associated PKC activity. However, PKC activation was seen in resting T cells when CD28 was cross-linked in the presence of superantigen plus APC-derived supernatant, which by themselves had no effect on PKC activity. Inhibition of PKC activity using calphostin C blocked the response of pure T cells to superantigen in the presence of either autologous APC, PMA, or CD28 cross-linking. This effect was specific; it was only seen when calphostin C was added within the first hour of stimulation. Assays of [Ca2+]i levels showed that CD28 cross-linking augmented and prolonged the rise in [Ca2+]i induced in T cells by superantigen and APC-derived cytokines. In the presence of superantigen, the proliferative response of T cells costimulated by CD28 cross-linking was cyclosporin A-sensitive, whereas in the presence of PMA, CD28 cross-linking conferred resistance to cyclosporin A. Both the phosphorylation of phospholipase C gamma 1 at tyrosine and the rise in [Ca2+]i induced by CD28 cross-linking in preactivated T cells were blocked by herbimycin A. Herbimycin A treatment also blocked the ability of CD28 cross-linking to induce a rise in [Ca2+]i in resting T cells. We conclude that CD28 costimulatory signals augment superantigen-induced TCR signals by converging onto common TCR effector pathways involving the activation of phospholipase C gamma 1 and PKC and by generating a cyclosporin A-sensitive pathway.

CD28 cross-linking augments TCR-mediated signals and costimulates superantigen responses

The CD28 molecule expressed on the surface of T cells plays a pivotal role in transducing costimulatory signals necessary for cell activation. CD28 coligation enhances tyrosine phosphorylation and phosphoinositol 3-kinase association in responsive cells. CD28 cross-linking has also been reported to activate inositol phospholipid turnover and to cause release of intracellular calcium. Here we examine the effects of CD28 cross-linking on early activation of protein kinase C (PKC). We have reported recently that either PMA or CD28 cross-linking synergizes with signals delivered by superantigen and cytokines to induce the proliferation of APC-depleted T cells. Unlike PMA, CD28 cross-linking alone failed to induce an increase in membrane-associated PKC activity. However, PKC activation was seen in resting T cells when CD28 was cross-linked in the presence of superantigen plus APC-derived supernatant, which by themselves had no effect on PKC activity. Inhibition of PKC activity using calphostin C blocked the response of pure T cells to superantigen in the presence of either autologous APC, PMA, or CD28 cross-linking. This effect was specific; it was only seen when calphostin C was added within the first hour of stimulation. Assays of [Ca2+]i levels showed that CD28 cross-linking augmented and prolonged the rise in [Ca2+]i induced in T cells by superantigen and APC-derived cytokines. In the presence of superantigen, the proliferative response of T cells costimulated by CD28 cross-linking was cyclosporin A-sensitive, whereas in the presence of PMA, CD28 cross-linking conferred resistance to cyclosporin A. Both the phosphorylation of phospholipase C gamma 1 at tyrosine and the rise in [Ca2+]i induced by CD28 cross-linking in preactivated T cells were blocked by herbimycin A. Herbimycin A treatment also blocked the ability of CD28 cross-linking to induce a rise in [Ca2+]i in resting T cells. We conclude that CD28 costimulatory signals augment superantigen-induced TCR signals by converging onto common TCR effector pathways involving the activation of phospholipase C gamma 1 and PKC and by generating a cyclosporin A-sensitive pathway.

No involvement of Ki-ras or p53 gene mutations in colitis-associated rat colon tumors induced by 1-hydroxyanthraquinone and methylazoxymethanol acetate

1-Hydroxyanthraquinone (1-HA), which is present in some herbs, and methylazoxymethanol (MAM) acetate, a metabolite of azoxymethane, show synergistic carcinogenicity in rat colon, and 1-HA induces ulcerative changes with simultaneous severe inflammation of the entire colon. In this study, mutations in Ki-ras (exons 1 and 2) and p53 (exons 4-7) were studied by polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis. Of 18 adenomas and 38 adenocarcinomas induced in male F344 rats (52 tumors induced by 1-HA plus MAM acetate, three by 1-HA alone, and one by MAM acetate alone), no mutations in Ki-ras or p53 were detected under two conditions of PCR-SSCP analysis. Because human colon carcinomas from patients with ulcerative colitis have a very low incidence of Ki-ras mutation, this experimental system would be a good animal model of human colon carcinomas with ulcerative colitis and of human colon carcinomas without Ki-ras or p53 mutations.

DNA damage induced by tumour necrosis factor-alpha in L929 cells is mediated by mitochondrial oxygen radical formation

Treatment of L929 cells with tumour necrosis factor-alpha (TNF-alpha) plus actinomycin D induced DNA damage (indicated by the appearance of a sub-G1 peak due to extracellular leakage of low molecular weight DNA following DNA fragmentation) before significant cell lysis occurred. The DNA damage occurred in parallel with a decrease of the intracellular total glutathione content and an increase of intracellular reactive oxygen intermediates (ROI), as indicated by increased dihydrorhodamine 123 oxidation. Because the inhibition of mitochondrial respiration suppressed the increase of dihydrorhodamine 123 oxidation and DNA damage as well as the decrease in the total glutathione content, it was suggested that increased mitochondrial formation of ROI was responsible for DNA damage after TNF treatment. Deferoxamine (a ferric iron chelator) and dithiothreitol (a sulfhydryl reagent) both prevented DNA damage and cell killing, indicate that hydroxyl radicals generated from O2- and H2O2 produced by the mitochondria in a process catalysed by iron contributed to DNA damage and that this pathway may be involved in TNF-alpha-induced cytotoxicity. An inhibitor of poly(ADP)-ribose polymerase (3-aminobenzamide), worsened DNA damage, but was protective against cell lysis, suggesting that DNA repair subsequent to injury was more important than DNA damage per se in development of TNF-alpha cytotoxicity.

[Comparison of complement activation between tuberculous and malignant pleuritis]

Complement activation products in pleural effusions were studied to clarify the causes of tuberculous and malignant pleuritis. Pleural SC5b-9, an activation product of complement common pathway, was significantly higher in tuberculous effusions than in malignant ones. In the tuberculous effusions, the levels of SC5b-9 and LDH (a marker of tissue damage) were significantly correlated, but in the malignant effusions these two values were not correlated. In the tuberculous effusions, SC5b-9 and Bb values were significantly correlated, but SC5b-9 and C4d were not, and nor were SC5b-9 and immune complex. In the malignant effusions, SC5b-9 and Bb values were low and were not significantly correlated. These results suggest that complement activation plays a significant role in tuberculous pleuritis, but not in malignant pleuritis.

Effect of cysteine on expression of cystathionine beta-synthase in the rat liver

Hepatic cystathionine beta-synthase activity is decreased by the addition of cysteine to the diet. This effect of cysteine was slightly greater in diets containing 0.25% methionine than in those containing 1% methionine, and was reduced during aging. Similar changes were observed in the level of the mRNA of this enzyme, although the changes in the transcript levels were slightly greater than the changes in enzyme activity. Thus, we conclude that the addition of cysteine to a methionine-containing diet causes a decrease in cystathionine beta-synthase activity mainly by diminishing its mRNA level.

On the conformation of Phe78 of a chromoprotein antibiotic, neocarzinostatin

A structure of neocarzinostatin, an antitumor chromoprotein antibiotic, has been built using X-ray crystallographic data and NMR data, particularly NOE data observed between the apoprotein and the chromophore. Chemical shift changes of protons of the chromophore upon binding to the apoprotein indicated that the aromatic plane of Phe52 has the conformation almost perpendicular to the C-2-C-3 triple bond of the core of the chromophore while Phe78 takes multiple conformations in solution although one of the stable conformations has been assigned for Phe78 in a crystal structure.