[CT-guided stereotactic operation for cerebellar abscess by the transtentorial hiatus approach: a case report]

We reported a case of cerebellar vermian abscess, well managed by CT-guided stereotactic aspiration and drainage via the transtentorial hiatus route. A 69-year-old man was admitted to our hospital because of acute deterioration of bronchiectasis. About one month later, he complained of headache and gait unsteadiness. CT scan revealed a multilocular abscess in the cerebellar vermis. Although conservative therapy with antibiotics was applied, the symptoms deteriorated and the lesion continued to grow. Aspiration and drainage were therefore performed for the main lesion by CT-guided stereotactic surgery via the transtentorial hiatus route. This was completed without complications. The postoperative course was good and the lesion had disappeared when enhanced CT was carried out about 2 months after the operation. We consider this stereotactic transtentorial hiatus operation to be an effective treatment for patients such as the present one with a superior vermian lesion and who is at risk due to a poor respiratory condition.

KT-5720 reverses multidrug resistance in variant S49 mouse lymphoma cells transduced with the human MDR1 cDNA and in human multidrug-resistant carcinoma cells

T-25-Adh cells, cell variants derived from S49 mouse lymphoma, were transduced with a retrovirus containing the human MDR1 cDNA. The resultant cells (HU-1) are cross-resistant to colchicine, doxorubicin, vinblastine and actinomycin D, and their resistance to colchicine is reversed by verapamil. HU-1 cells were used to screen several protein kinase modulators for their ability to reverse multidrug resistance. Among the tested indole carbazole (K-252a) family of protein kinase inhibitors, only the antibiotic alkaloid KT-5720 (9-n-hexyl derivative of K-252a) could overcome the multidrug resistance of HU-1 cells and KB-V1 human carcinoma cells. Since other protein kinase A, C and G modulators did not reverse multidrug resistance in the tested multidrug-resistant cells, the chemosensitising activity of KT-5720 on these cells is apparently independent of its kinase inhibitory effects. Since KT-5720 fully reversed multidrug resistance at non-toxic concentrations, it might be a candidate for clinical chemosensitisation in combination chemotherapy.

Effect of particle size of metastable calcium phosphates on mechanical strength of a novel self-setting bioactive calcium phosphate cement

Resistance to compressive strength after setting of the calcium phosphate cement consisting of tetracalcium phosphate (TECP), dicalcium phosphate dihydrate (DCPD), and 40 wt/wt% of a synthetic hydroxyapatite (HAP) was tested. An equimolar mixture of the calcium phosphate powder containing DCPD (particle diameter [D] 0.52-3.33 microns) and TECP (D, 1.1-13.1 microns) transformed into HAP at 37 degrees C, 100% RH after being mixed with 25 mM phosphoric acid. X-ray diffraction suggested that the cement containing fine particles of DCPD and TECP completely transformed to HAP, but that mixtures containing larger particles did not. Because particle size of both DCPD and TECP affected the compressive strength of the cement, the crystal growth of HAP during cement formation depended on the specific surface area (Sw) of the raw materials. The crystallite size of transformed HAP was estimated based on X-ray diffraction peaks at 25.8 and 32.8 degrees attributable to the 002 and 300 planes. The crystalline size attributable to the 300 plane decreased with increasing Sw, but that attributable to the 002 plane showed no significant relationship. The compressive strength of the cement after hardening increased with an increase of its Sw. This suggested that the harder calcium phosphate cement was (derived) from the smaller particle size of the raw materials.

Drug release from a novel self-setting bioactive glass bone cement containing cephalexin and its physicochemical properties

A novel device containing cephalexin as a model drug using a self-setting bioactive cement based on CaO-SiO2-P2O5 glass was investigated. The device consisted of 95 wt/wt% glass powders and 5 wt/wt% cephalexin powder hardened within 5 min after mixing with a phosphate buffer. After setting, in vitro drug release from homogeneous or heterogeneous drug-loaded cement pellets in a simulated body fluid (SBF) at pH 7.25 and 37 degrees C continued for over 4 weeks. The hardened cement gradually formed low-crystallinity hydroxyapatite with high bioactivity in hard bone tissue and reduced in volume by about 5% during dissolution testing in SBF. Consequently, 30% of the loaded drug was squeezed from the cement system at the initial stage of the drug release, and the remainder released more slowly. Because the heterogeneous system consisting of the cement and drug-loaded pellet avoided the drug-squeezing effect, it showed a longer drug release term than the homogeneous drug-loaded cement. The heterogeneous system using the hardened cement after soaking in SBF at 37 degrees C for 10 days showed very slow drug release at the initial stage because it completely avoided the drug-squeezing effect, and the release was a zero-order pattern.

Effects of a novel N-methyl-D-aspartate (NMDA) receptor antagonist, 3,3'-dimethyl-3,4,3',4'-tetrahydro-6,8,6',8'-tetramethoxy-[10,10' -bi-2- oxanthracene]-4,9,9'-(1H,1'H)-triol 4-acetate (ES-242-1), on NMDA-induced increases of intracellular Ca2+ concentration in cultured hippocampal neurons

The effects of a novel N-methyl-D-aspartate (NMDA) receptor antagonist, ES-242-1 (3,3'-dimethyl-3,4,3',4'-tetrahydro-6,8,6',8'-tetramethoxy-[10,10' - bi-2-oxanthracene]-4,9,9'-(1H,1'H)-triol 4-acetate), on NMDA-induced increases of intracellular Ca2+ concentration in cultured hippocampal neurons were examined. ES-242-1 selectively blocked the NMDA-induced increase in intracellular free Ca2+ concentration ([Ca2+]i), but not the [Ca2+]i increase stimulated by quisqualate or kainate. The effect of ES-242-1 appeared in the slow development of a blockade of [Ca2+]i (half blocking time: 90 sec) when 100 microM NMDA was applied with 10 microM ES-242-1, whereas the initial [Ca2+]i rise was attenuated by 10 microM ES-242-1 when the latter was applied with a lower concentration of NMDA (10 microM). This is consistent with a previous observation that ES-242-1 binds to both the transmitter recognition site and the channel domain. The blockade by ES-242-1 was reversed by washing. In contrast, the blockade by MK-801 was not relieved easily by washing. These results suggest that ES-242-1 blocks the NMDA-induced [Ca2+]i increase due to a combination of two well-recognized mechanisms, which are different from that of MK-801, at the NMDA receptor.

In situ demonstration of the HTLV-I genome in the spinal cord of a patient with HTLV-I-associated myelopathy

Using polymerase chain reaction (PCR) and in situ hybridization, we investigated the HTLV-I genome in the CNS of an HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patient with a 20-year disease duration. Neuropathologically, there was severe white matter degeneration throughout the spinal cord, but lymphocytic infiltrates were not evident in any lesion. PCR amplification of the pX region of HTLV-I DNA detected its sequence in the spinal cord and all extra-CNS tissue samples. In situ hybridization using probes complementary to the pX and gag regions detected the HTLV-I genome in the cytoplasm and nucleus of cells in the thoracic cord. The findings indicate a direct involvement of HTLV-I in the neurodegeneration of HAM/TSP.

Spot mapping on the standard profile of restriction landmark genomic scanning (RLGS) of sorted chromosome 20 using methylation-insensitive enzyme

We established the spot mapping system on a restriction landmark genomic scanning (RLGS) profile using sorted chromosome as RLGS material. In this mapping system, we can mapped RLGS spots physically, regardless of their polymorphism, using methylation-insensitive enzymes in all RLGS steps. Here, we report that we identified 28 spots derived from human chromosome 20 on an RLGS profile, and that number was in good agreement with the number predicted from the length of the chromosome 20.

Ca++ mobilization mediated by endothelin ETA receptor in endothelium of rabbit aortic valve

The mechanism of Ca++ mobilization induced by endothelins (ETs) and the receptor subtype responsible for this effect were examined in the endothelium of rabbit aortic valve. In the endothelium loaded with fura-2, ET-1 (1-100 nM) induced large transient increase followed by small sustained increase in cytosolic Ca++ level ([Ca++]i) in a concentration-dependent manner. ET-3 induced only a small increase in [Ca++]i at higher concentrations (100-300 nM) than ET-1, whereas a selective ETB agonist, 100 nM IRL 1620 (succinyl-[Glu9, Ala11,15]ET-1 8-21), was ineffective. A selective ETA antagonist, 3 microM BQ-123, (cyclo [-Asp-Pro-Val-Leu-Trp-]) but not a selective ETB antagonist, 10 microM RES-701-1 [cyclic (Gly1-Asp9) (Gly-Asn-Trp-His-Gly-Thr-Ala-Pro-Asp- Trp-Phe-Phe-Asn-Tyr-Tyr-Trp)], inhibited the effects of ET-1 and ET-3. The sustained increase in [Ca++]i induced by ET-1 was abolished by 30 microM La , although 100 nM nicardipine was ineffective. In the absence of external Ca++ (with 0.5 mM EGTA), ET-1 induced only a transient increase in [Ca++]i, which was inhibited by an inhibitor of Ca+(+)-ATPase in endoplasmic reticulum, 1 microM thapsigargin. However, an inhibitor and an activator of Ca+(+)-induced Ca+(+)-release channel, 10 microM ryanodine and 10 mM caffeine, did not change [Ca++]i. These results suggest that, in the endothelium of rabbit aortic valve, only the ETA receptor mediates the effects of ETs to increase [Ca++]i, which is attributable to the release of Ca++ from thapsigargin-sensitive and ryanodine-insensitive Ca++ stores and also to the Ca++ influx through La (-)sensitive and dihydropyridine-insensitive Ca++ channels.

Augmented receptor-mediated Ca2+ mobilization causes supersensitivity of contractile response to serotonin in atherosclerotic arteries

We have previously reported that atherosclerotic arteries obtained from Watanabe heritable hyperlipidemic (WHHL) rabbits exhibit a marked increase of contractile response to serotonin (5-hydroxytryptamine [5-HT]) and ergonovine and that these augmented contractile responses to specific agonists may play an important role in the pathogenesis of vasospasm. In the present study, we investigated whether supersensitivity to 5-HT in atherlosclerotic arteries was due to an increase in 5-HT receptor-mediated Ca2+ mobilization or to an increase in Ca2+ sensitivity of the contractile elements. We measured simultaneously both isometric tension and [Ca2+]i in fura 2-loaded aortic smooth muscle strips from control and WHHL rabbits. Muscle tension in the high K+ (72.7 mmol/L)-stimulated states and [Ca2+]i in both resting and high K(+)-stimulated states did not differ between control and WHHL rabbits. In atherosclerotic aortas from WHHL rabbits, the dose-response curves of both tension and [Ca2+]i for 5-HT were shifted to the left at lower threshold concentrations and one-half maximally effective dose. The maximum response of contraction produced by 5-HT in WHHL rabbits was augmented compared with that in control rabbits (123 +/- 17% versus 33 +/- 7% of the 72.7 mmol/L K(+)-induced contraction, P < .001). The maximum response of [Ca2+]i produced by 5-HT was also augmented in WHHL rabbits compared with control rabbits (29 +/- 4% versus 10 +/- 0.9% of the 72.7 mmol/L K(+)-induced [Ca2+]i, P < .001). In contrast, the responses of contraction and [Ca2+]i to phenylephrine were similar between control and WHHL rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)

Essential role of myosin light chain kinase in the mechanism for MgATP-dependent priming of exocytosis in adrenal chromaffin cells

Ca(2+)-induced exocytosis in chromaffin cells now seems to consist of at least two distinct steps:MgATP-dependent Ca(2+)-dependent priming of the secretory apparatus, and Ca(2+)-dependent MgATP-independent step that triggers exocytosis (Bittner and Holz, 1992). Recently we found that a specific inhibitor of myosin light chain kinase (MLCK), wortmannin, inhibits Ca(2+)-induced catecholamine release from digitonin-permeabilized chromaffin cells, suggesting an implication of MLCK in the mechanisms of Ca(2+)-induced exocytosis (Imaizumi et al., 1992b). To elucidate further the implication of MLCK in the mechanism of exocytosis, we studied the effects of wortmannin and a peptide inhibitor (SM-1) corresponding to the pseudosubstrate domain of MLCK on MgATP-dependent and MgATP-independent release in digitonin-permeabilized chromaffin cells. Ca(2+)-induced exocytosis from the permeabilized cells in the presence of MgATP was inhibited by both SM-1 and wortmannin. Inhibitory effect of wortmannin on the rate of release induced by 10 microM Ca2+ in the presence of MgATP was much prominent in the later phase (1-10 min), although the initial rate was also decreased. SM-1 strongly inhibited ATP-dependent release without affecting Ca(2+)-dependent ATP-independent release at all. In addition, priming effect of MgATP that underlies Ca(2+)-dependent ATP-independent release was remarkably reduced by both wortmannin and SM-1. These results suggest that MLCK plays an essential role in ATP-dependent priming of Ca(2+)-induced exocytosis in chromaffin cells.

Transposition of Tnr1 in rice genomes to 5'-PuTAPy-3' sites, duplicating the TA sequence

Tnr1 is a repetitive sequence in rice with several features characteristic of a transposable DNA element. Its copy number was estimated to be about 3500 per haploid genome by slot-blot hybridization. We have isolated six members of Tnr1 located at different loci by PCR (polymerase chain reaction) and determined their nucleotide sequences. The Tnr1 elements were similar in size and highly homologous (about 85%) to the Tnr1 sequence identified first in the Waxy gene in Oryza glaberrima. A consensus sequence of 235 bp could be derived from the nucleotide sequences of all the Tnr1 members. The consensus sequence showed that base substitutions occurred frequently in Tnr1 by transition, and that Tnr1 has terminal inverted repeat sequences of 75 bp. Almost all the chromosomal sequences that flank the Tnr1 members were 5'-PuTA-3' and 5'-TAPy-3', indicating that Tnr1 transposed to 5'-PuTAPy-3' sites, duplicating the TA sequence. PCR-amplified fragments from some rice species did not contain the Tnr1 members at corresponding loci. Comparison of nucleotide sequences of the fragments with or without a Tnr1 member confirmed preferential transposition of Tnr1 to 5'-PuTAPy-3' sites, duplicating the TA sequence. One amplified sequence suggested that imprecise excision had occurred to remove a DNA segment containing a Tnr1 member and its neighboring sequences at the Waxy locus of rice species with genome types other than AA. We also present data that may suggest that Tnr1 is a defective form of an autonomous transposable element.

Dissolution behavior of phenytoin-bile salt complexes prepared by co-grinding

The physicochemical properties of phenytoin (PHT)-bile salt complexes comprised of sodium dehydrocholate (DHCNa), sodium deoxycholate (DCNa) or sodium cholate (CNa) prepared by co-grinding were investigated by X-ray diffraction analysis, DSC and dissolution kinetics. All X-ray diffraction peak intensities of the co-ground PHT-bile salt [1 mol: 1 mol] mixtures were decreased by grinding for 3 h, and showed a halo pattern of a noncrystalline solid. The solubility of ground products with DCNa, DHCNa and CNa were 212, 56, 68 times higher, respectively, than those of physical mixtures.

A novel skeletal drug delivery system using self-setting calcium phosphate cement. 7. Effect of biological factors on indomethacin release from the cement loaded on bovine bone

The use of self-setting bioactive calcium phosphate cement containing indomethacin as a model drug in bovine bone was investigated by means of an in vitro drug release test, mercury porosimetry, and scanning electron microscopy (SEM). Calcium phosphate cements containing 2 and 5% indomethacin after being mixed with dilute phosphoric acid were applied to defect sites and the medullary cavity of bovine bone and transformed into hydroxyapatite. The in vitro drug release from the cement loaded on the defect site into a simulated body fluid (SBF) containing 2.5 mM Ca2+ and 1.0 mM HPO4(2+) or 0.1 M phosphate buffer at pH 7.25 and 37 degrees C continued for more than 3 weeks. The release profiles of the drug-loaded cements in phosphate buffer were linear using the Higuchi plot; however, that was not the case for SBF. The drug release in SBF was much lower than that in phosphate buffer. The total pore volume of the cement after the drug release test in SBF was lower than its initial value. However, the pore size of 0.1-0.01 microns after drug release in phosphate buffer was higher than that seen in SBF. The micropore distribution results suggested that hydroxyapatite crystallized from SBF and the pore volume in the cement decreased after drug release. However, in phosphate buffer it appeared to dissolve. The SEM observations for cements loaded on the bone after drug release in phosphate buffer suggested that there was a boundary layer between the cement and natural bone, but this was not the case in SBF, where the cement bonded with the natural bone. The drug release rates from the cement-loaded bone were significantly higher than those from cement loaded on the dissolution holder. The results suggested that cement formation and drug release were affected by the presence of protein from natural bone. The drug release rates from the cement loaded on the defective bone were slower than those from the medullary cavity.

A novel skeletal drug delivery system using a self-setting calcium phosphate cement. 5. Drug release behavior from a heterogeneous drug-loaded cement containing an anticancer drug

A novel drug delivery device based on a self-setting bioactive calcium phosphate cement formed from tetracalcium phosphate and dicalcium phosphate has been developed and tested in vitro using the anticancer agent 6-mercaptopurine (6-MP) as a model compound. X-ray diffraction results suggest that equimolar mixtures of the calcium phosphate salts were transformed into hydroxyapatite after being mixed with a dilute phosphoric acid solution, even in the presence of various amounts of 6-MP powder. The inclusion of 6-MP in the reaction mixture resulted in the formation of a homogeneous drug-containing cement. Alternatively, the drug was loaded after cement formation to produce a heterogeneous drug-containing pellet. In vitro drug release from both the homogeneous and heterogeneous drug-loaded cement pellets into simulated body fluid (pH 7.25, 37.0 degrees C) was measured using the rotating-disk method. Release from the homogeneous 5% drug-loaded cements did not obey the Higuchi equation. The release rate from the heterogeneous drug-loaded cements of different thicknesses (1, 2, and 3 mm) was a function of thickness, indicating that release kinetics could be controlled by the design of the cement formulation.

PS-990, a novel neuritogenic compound from Acremonium sp

A novel compound, PS-990, which induces differentiation of neuroblastoma cells, was isolated from the culture broth of a fungus, Acremonium sp. KY12702. PS-990 inhibited brain calcium calmodulin-dependent cyclic nucleotide phosphodiesterase with an IC50 value of 3 micrograms/ml, and markedly induced neurite extension of mouse neuroblastoma, Neuro2A, at concentrations ranging from 10 to 30 micrograms ml.

Characterization of mouse non-receptor tyrosine kinase gene, HYL

We previously reported a novel human non-receptor tyrosine kinase gene, HYL (hematopoietic consensus tyrosine-lacking kinase) (Sakano et al., 1994), which consists of each of the SH2 (src homology 2), SH3 and tyrosine kinase catalytic domains. HYL has unique structural features shared with CSK (C-terminal Src kinase). Recently it has also been reported that matk (Bennett et al., 1994) and Ctk (Klages et al., 1994) are isolated as novel kinases with structural similarity to CSK. Comparisons of cDNA sequence indicate the HYL, matk and Ctk are the same gene. We further characterized the mouse HYL genomic structure and HYL mRNA expression in mouse brain. The mouse HYL gene is distributed over 5.8 kb and is composed of 12 exons. The exon-intron organization is almost identical with that of human CSK. The mouse HYL gene was assigned to the R-positive C1 band of chromosome 10 by fluorescent in situ hybridization. RNA in situ hybridization demonstrated the broad distribution of HYL mRNA expression in various neuronal cells. Especially, strong signals were detected in Purkinje cells, pyramidal cells in the hippocampus, granule cells in the dentate gyrus, and mitral cells in the olfactory bulb, indicating that mRNA expression of HYL in brain is very similar to that of SRC-family kinases. These findings establish close relationship between the HYL and CSK genes and also suggest that HYL may play an important role in signal transduction through SRC-family kinases in the central nervous system.

Myosin II is involved in transmitter release at synapses formed between rat sympathetic neurons in culture

The presynaptic function of myosin II was studied at cholinergic synapses formed between rat superior cervical ganglion neurons in culture. Immunofluorescent staining showed that myosin II was colocalized with synaptophysin at the presynaptic nerve terminals. Antimyosin II antibody introduced into presynaptic neurons inhibited synaptic transmission. Transmission was also inhibited in a dose-dependent manner by two inhibitors of myosin light chain kinase: a peptide, SM-1, and an organic inhibitor, wortmannin. The inhibition produced by these agents was dependent on presynaptic activity. Extracellularly applied wortmannin also blocked synaptic transmission, but its effects were slower in onset. Wortmannin also decreased postsynaptic potentials and post-tetanic potentiation in intact superior cervical ganglia. These results suggest a model in which myosin light chain kinase phosphorylates myosin, and the resultant change in actin-myosin interactions is involved in neurotransmitter release.

Identification of renal natriuretic peptide receptor subpopulations by use of the non-peptide antagonist, HS-142-1

1. The renal actions of natriuretic peptides are dictated by the distribution of guanylyl cyclase-linked (NPRA and NPRB) and non-guanylyl cyclase-linked (NPRC) receptors. Natriuretic peptide receptors have previously been distinguished on the basis of their differential affinity for peptide fragments and analogues; however, most of the available ligands are not fully selective. We have used the specific guanylyl cyclase-linked receptor antagonist, HS-142-1, to investigate the differential distribution of natriuretic peptide receptor subtypes in the human, bovine and rat kidney. 2. Specific, high affinity 3-([125I]-iodotyrosyl)-rat-ANP-(1-28)([125I]-rANP1-28) binding sites were identified in all three species, localized to glomeruli, inner medulla, intrarenal arteries and regions in the outer medulla corresponding to vasa recta bundles. Binding sites were also identified in the smooth muscle lining of the hilar region in the bovine and rat kidney. 3. In the rat, [125I]-rANP1-28 binding was inhibited by unlabelled peptide sequences with a rank order of potency (rANP1-28 > pCNP1-22 > C-ANP4-23). The glomeruli exhibited a heterogeneous population of binding sites, C-ANP4-23 and pCNP1-22 producing a significantly better fit to a two component inhibition curve compared to the single component curve for rANP1-28. 4. Competitive inhibition experiments with the receptor selective ligands, C-ANP4-23 and HS-142-1, suggested that, like the rat, human and bovine glomeruli possessed a heterogeneous population of binding sites, whilst those in the inner medulla and intrarenal arteries of all three species represented a homogeneous population. Rat glomeruli exhibited a high proportion (>80%) of the NPRc receptor subtype whereas in human and bovine glomeruli this receptor represented less than 20% of the total population, the majority of binding sites being HS-142-1-sensitive.5. C-ANP4-23 exhibited a significantly higher inhibitory potency for binding sites in rat glomeruli compared to those in human and bovine kidney whilst HS-142-1 was significantly more potent in the rat and bovine kidney compared to man. No evidence was found to suggest the presence of a renal NPRBreceptor subtype.6. The relative density, affinity and proportion of natriuretic receptor subtypes in the kidney exhibit significant species differences. HS-142-1 may be a valuable tool in further elucidating the localization and function of these receptors, but heterogeneity between species should be considered when selecting experimental models.

Enhanced suppression of tumor growth by combination of angiogenesis inhibitor O-(chloroacetyl-carbamoyl)fumagillol (TNP-470) and cytotoxic agents in mice

The antitumor effect of the novel angiogenesis inhibitor O-(Chloroacetyl-carbamoyl) fumagillol, TNP-470 (TNP, s.c.), a synthetic analogue of fumagillin, was studied in combination with cytotoxic agents--mitomycin C (MMC, i.p.), Adriamycin (i.p.), cisplatin (i.p.), and 5-fluorouracil (i.p.), using B16BL6 melanoma (B16 M) and Lewis lung carcinoma in C57BL/6 mice. When the mice were treated on days 3 and 5, addition of MMC (total dose, 5 mg/kg) or 5-fluorouracil (140 mg/kg) to TNP (150 mg/kg) maximally reduced s.c. B16 M volume from 60 to 15% or from 68 to 40% of control, respectively, and addition of MMC (5 mg/kg) to TNP (150 mg/kg) reduced s.c. Lewis lung carcinoma volume from 75 to 62% of control (P < 0.02, compared to the corresponding single drug treatments). During treatment on days 3, 5, 7, 9, and 11, addition of MMC (5 mg/kg) to TNP (150 mg/kg) reduced s.c. B16 M volume from 43 to 6% of control and reduced the number of pulmonary metastasis of i.v. B16 M from 26 to 5% of control (P < 0.001). For established tumors (> 5 mm in maximal diameter), addition of MMC (12-14 mg/kg), Adriamycin (15-17.5 mg/kg), or cisplatin (4 mg/kg, by one shot) to TNP (120-140 mg/kg) with a 6-7 fractionated dosing schedule reduced s.c. B16 M volume from 50 to 20, 24, or 31% of control and reduced s.c. Lewis lung carcinoma volume from 52 to 34, 27, or 34% of control, respectively (P < 0.02). The effect of combination therapy was additive and dose-dependent, and the earlier fractionated dosing schedule exerted more enhanced antitumor effects. TNP reduced the body weight by approximately 10% of control at maximum, but this toxicity was reversible and was not affected by addition of the cytotoxic agents. The results suggest that the combination of angiogenesis inhibitor TNP and standard cytotoxic agents can be a beneficial addition to the treatment of solid tumors.

Pregnancy complicated by liver dysfunction: possible pathogenesis of vasospasm

BACKGROUND

Acute fatty liver of pregnancy, the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP), and severe preeclampsia form a disease spectrum. We report a case that showed a vasospastic phenomenon supported angiographically and hematologically.

CASE

A 31-year-old Japanese woman presented at 37 weeks gestation with a 1-week history of nausea, vomiting and general fatigue. She underwent cesarean delivery for fetal distress. Liver dysfunction and disseminated intravascular coagulopathy were detected. The celiac angiogram showed vascular narrowing and irregularity of the vascular wall. Serum endothelin and the ratio of thromboxane B2 to 6-keto-prostaglandin F1 alpha were increased at the same time. The patient experienced rapid resolution of symptoms and laboratory abnormalities in the immediate postoperative period.

CONCLUSION

A pregnancy complicated by liver dysfunction showed a vasospastic phenomenon, which may suggest the presence of a vasospastic syndrome.

Stabilization of Atomic Hydrogen in Both Solution and Crystal at Room Temperature

Atomic hydrogen has been stably encapsulated in both solution and crystal at room temperature. Upon gamma-ray irradiation of [(CH(3))(3)Si](8)Si(8)O(20), which is the trimethylsilylated derivative of the silicate anion with a double four-ring (D4R) cage, electron spin resonance (ESR) spectra revealed that a single hydrogen atom is encapsulated in the center of the D4R cage and is stable for periods of many months. Attack by chemically reactive species such as oxygen was prevented by the D4R cage, but the ESR signal of the hydrogen atom was sensitive to the magnetic interaction caused by the presence of the O(2) molecule near the cage.

Endothelin ETB receptor antagonist, RES-701-1: effects on isolated blood vessels and small intestine

RES-701-1 (cyclic (Gly1-Asp9)(Gly-Asn-Trp-His-Gly-Thr-Ala-Pro-Asp-Trp-Phe- Phe-Asn-Tyr-Tyr-Trp)), a peptide isolated from Streptomyces sp., has been reported to inhibit the endothelin ETB receptor. We examined the effects of this peptide on the blood vessels and the small intestine. In isolated rat aorta without endothelium, 10 microM RES-701-1 did not affect the resting tone, nor did it attenuate the contractions induced by endothelin-1, endothelin-3 or norepinephrine. In the aorta with endothelium, 3 microM RES-701-1 shifted the concentration-response curves for the contractile effects of endothelin-1 and endothelin-3 to the left. Removal of endothelium showed a similar effect to 3 microM RES-701-1. In the norepinephrine-stimulated aorta, endothelium-dependent relaxation induced by endothelin-3 was antagonized by 0.3-10 microM RES-701-1 in a concentration-dependent manner. In the guinea pig ileum stimulated by carbachol, endothelin-3 induced a transient relaxation followed by sustained relaxation. RES-101-1 (3 microM) selectively inhibited the transient relaxation. Since it has been shown that the contractile effects of endothelins in the aorta are mediated by the endothelin ETA receptor whereas the endothelium-dependent relaxation and the ileal relaxation are mediated by the endothelin ETB receptor, it is suggested that RES-701-1 is a selective antagonist against the endothelin ETB receptor.