Expression of an antigen specific for trunk lateral cells in quarter embryos of the ascidian, Halocynthia roretzi

Cell-lineage analysis has demonstrated that a pair of the right and left A7.6 cells of a 64-cell embryo of the ascidian Halocynthia roretzi, descendants of A4.1 cells of an 8-cell embryo, give rise to trunk lateral cells (TLCs). In this study, in order to investigate cellular mechanisms involved in the specification of TLCs, we have examined the expression of a TLC-specific antigen in cleavage-arrested embryos and in quarter partial embryos. Although cleavage arrest of embryos by treatment with cytochalasin B at early stages, prior to and including the 16-cell stage, inhibited expression of the TLC-specific antigen, embryos arrested at the 32-cell stage and at later stages developed the antigen. The only blastomeres exhibiting expression of the antigen were the presumptive TLCs, as predicted by cell-lineage assignments. When the developmental potential of quarter embryos that originated from four isolated blastomere-pairs (a4.2, b4.2, A4.1, and B4.1 pairs) of an 8-cell embryo was examined, the A4.1 quarter embryos, which are developmentally fated to give rise to TLCs, rarely showed evidence of expression of the antigen. Expression of the antigen was not observed in a4.2 and b4.2 quarter embryos, which are not associated with the TLC fate. By contrast, expression of the antigen was detected in about a half of the B4.1 quarter embryos which are also not associated with the TLC fate. These results are discussed with reference to the relationship between TLCs and mesenchyme cells.

Studies of an aspect of renal function with the aid of dynamic CT and renogram

Dynamic CT scans were conducted on 94 persons who had been randomly selected among the patients and the volunteers. The test results were used to obtain the time-density curve. A part of the subjects (20 cases) underwent the renogram examination for the comparative studies. The cortico-aortic (CA) ratio derived from the time-density curve demonstrated good correlation between the dynamic CT and the renal function (r = 0.68). When the dynamic CT studies and the renogram were compared, the vascular phase of the renogram showed strong correlation with CA ratio. Consequently the dynamic CT study the CA ratio was believed to demonstrate the renal function.

[A clinical investigation of the laryngeal mask airway]

The size 2, 3 and 4 laryngeal masks (LM) were used in 50 patients having various types of clinical anesthesia. We measured the airway pressure at which gas leak occurred during the use of the LM. We compared the time taken to obtain clear airway, when patients were receiving 4.5 or 6 l.min-1 fresh flow by anesthetic machines. We compared the changes of SpO2, heart rate (HR) and arterial pressure (AP) at the time of insertion of the LM during the tracheal intubation. The LM could be successfully inserted in all the patients. Even if the head position was changed, there was no significant change in the leak pressure on each LM size. In both children and adult, the time interval taken to obtain clear airway by the LM was two-thirds of the time necessary during the tracheal intubation. While the LM or the endotracheal tube was inserted, delta SpO2 and delta HR in children, and delta AP in adult were much smaller in the LM group than in the endotracheal tube group. We conclude that the LM is very useful in the clinical anesthesia, and the LM gives less influence to cardiopulmonary system compared with tracheal intubation while offering clear airway.

Inhibition of monoamine oxidase by two substrate-analogues, with different preferences for 5-hydroxytryptamine neurons

Various intraperitoneal doses of 5-fluoro-alpha-methyltryptamine (5-FMT), given to mice, dose-dependently inhibited only MAOA activity, with similar degrees of inhibition in the striatum, hypothalamus and the rest of the forebrain. The activity inhibited in these regions, completely recovered to control levels within 24 hr after the injection. In contrast, p-chloro-beta-methylphenethylamine (p-CMP), selectively inhibited MAOB activity, with complete recovery within 45 min after the injection. Regardless of the differences in time interval and degree of inhibition of MAOA by 5-FMT or MAOB by p-CMP, both kinds of inhibition were competitive, with respect to oxidation of the respective substrate. 5-Fluoro-alpha-methyltryptamine markedly protected only MAOA against inhibition by phenelzine, without protecting MAOB. Also, 5-FMT greatly increased one kind of animal behaviour, the head-twitch and this behaviour was greatly reduced by treatment with fluoxetine, but increased by reserpine. The results indicate that p-CMP is a short-acting, probably reversible, MAOB-selective inhibitor and 5-FMT has the same characteristics of selectivity for MAOA in central serotonergic neurons.

Molecular cloning and expression of a novel homeobox gene AHox1 of the ascidian, Halocynthia roretzi

We have isolated a novel ascidian homeobox gene, designated AHox1, by screening the genomic DNA of Halocynthia roretzi with the Bombyx mori Antennapedia type homeobox as a probe. The AHox1 gene encodes a protein that consists of 741 amino acids. The homeobox of AHox1 is interrupted by 2 introns each of which is about 300 bp in length and it shows about 70% similarity at a deduced amino acid level to that of Drosophila H2.0. This suggests that AHox1 is one of the most diverged homeobox genes so far characterized. Northern blot hybridization with an AHox1 probe showed the presence of single transcripts approximately 2.8 kb in length in larvae, juveniles and some adult tissues. The expression of AHox1 is scarcely detected during the course of early development but it increases to a moderate level at the larval stage. After metamorphosis, the level of AHox1 expression increases as development proceeds. In situ hybridization to the juvenile 7 days after metamorphosis showed that the site of AHox1 expression is the epithelium of digestive tract. Among the adult tissues examined, digestive tract, digestive gland and coelomic cells were the major sites of the expression of AHox1. In gonad, body wall muscle and pharyngeal epithelium, the expression of AHox1 is relatively weak. These results suggest that AHox1 is primarily expressed in the tissues of endodermal origin and that the gene expression may be associated with differentiation of the endodermal tissues.

Heterogeneity of endothelin receptor

The complex formed between endothelin (ET) and its binding protein was adequately stable to be separated by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) at low temperature. Cross-linking was not necessary. This simple method was applied for both qualitative (determination of molecular weight of ET binding protein) and quantitative (determination of content of ET binding protein) analyses of ET-binding protein for various organs from different mammals. Molecular weights of the major ET binding proteins were around 35 and 55 kDa in several canine organs examined. The distribution of these protein species among organs was quite different. In the case of human placenta, the predominant one showed a molecular weight of 35 kDa. We obtained several monoclonal antibodies that could immunoprecipitate ET binding activity from the solubilized human placenta membrane fraction. One of the monoclonal antibodies recognized approximately 58-kDa protein, as determined by Western blot analysis, when the gel is run in the absence of beta-mercaptoethanol.

Effects of bepridil and lidocaine on the intraventricular conduction in acutely ischaemic and infarcted canine myocardium

Effects of bepridil, an antiarrhythmic and antianginal drug, on intraventricular conduction in acutely ischaemic and infarcted myocardium were examined in anaesthetized dogs, and compared with those of lidocaine. Bepridil at doses of 2 and 5 mg/kg markedly prolonged the conduction time of a premature excitation induced by a ventricular stimulation in the infarcted zone. The effect of bepridil was dependent on a coupling time of the stimulation. Bepridil showed a marked effect at a coupling time of 150 ms, while it showed no significant effect at a prolonged coupling time of 1 s. In other words, the effect of bepridil was interval-dependent. Lidocaine showed a similar interval-dependent effect, but the effect of lidocaine at a longer coupling time was less than that of bepridil. The premature stimulation produced severely delayed conduction which resulted in reentrant beats. Bepridil blocked these conductions, thereby preventing reentrant beats. In contrast to the depressant effect of bepridil in the infarcted myocardium, bepridil prevented the prolongation of conduction time during acute ischaemia. The alternation of the ST-T complex during acute ischaemia which is also an important arrhythmogenic factor was also attenuated by bepridil. Contrary to bepridil, lidocaine significantly enhanced the conduction delay and the alternation in the ST-T complex. In conclusion, bepridil as well as lidocaine showed an interval-dependent depression of the conduction in the infarcted zone of the heart, whereas during acute ischaemia bepridil in contrast to lidocaine attenuated the conduction delay and ST-T alternans.

A novel neutral polysaccharide having activity on the reticuloendothelial system from the root of Glycyrrhiza uralensis

A neutral polysaccharide, named glycyrrhizan UC, was isolated from the root of Glycyrrhiza uralensis Fischer. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 69,000. Glycyrrhizan UC is composed of L-arabinose:D-galactose:D-glucose:L-rhamnose in the molar ratio of 10:30 27:1. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies indicated its structural feature as an arabino-3,6-galacto-glucan type polysaccharide.

[Patient's delay and doctor's delay in the primary treatment cases of pulmonary tuberculosis detected by subjective symptoms]

Delays in case finding were studied for the primary tuberculosis patients who were discharged from our hospital in 1987. Of 321 tuberculosis patients who were released from our hospital in 1987, 171 patients received primary treatment. Eighty one of them had been detected by their symptomatic visits. Patient's and doctor's delays tended to be longer in the cases of males than of females. For both males and females patient's delay tended to be longer in younger age group. Total delay until definite diagnosis by 50% and 80% of all diagnosed were 1.6 months, and 3.5 months respectively. Patients with total delay of more than three months were younger in age and were hospitalized longer than patients with total delay of less than 3 months. All cases with total delay of more than three months were smear positive.

Effect of left ventricular assistance on sympathetic tone

To determine the effect of left ventricular assist device (LVAD) pumping on sympathetic tone, renal sympathetic nerve activity (RSNA) was detected in acute animal experiments. Our TH-7B pneumatically driven, sac-type ventricular assist device was used in 7 adult mongrel dogs. RSNA was detected by the use of bipolar electrodes attached to the left renal sympathetic nerve. RSNA was amplified and integrated by use of an R-C integrator circuit. The area of the integrated nerve discharge per unit time was calculated in the computer system and expressed as RSNA per unit time. During LVAD pumping, RSNA decreased with increase in blood pressure, with an increase in pulmonary artery flow, and with a decrease in left atrial pressure. These data suggest that LVAD has an effect on the sympathetic nervous system which is mediated by the aortic and cardiopulmonary baroreflex system.

Effects of betaxolol on cardiohemodynamics and coronary circulation in anesthetized dogs: comparison with atenolol and propranolol

Effects of betaxolol, a cardioselective beta-adrenoceptor antagonist, on cardiohemodynamics and coronary circulation were investigated in two kinds of anesthetized open-chest dog preparations in comparison with those of atenolol and propranolol. When administered intravenously, betaxolol, atenolol and propranolol produced dose-dependent decreases in the heart rate (HR), maximum left ventricular dP/dt [+)dP/dt), cardiac output (CO) and mean arterial pressure (MAP). Although all three drugs were almost equipotent in decreasing HR, betaxolol was much less potent than atenolol and propranolol in decreasing (+)dP/dt. Betaxolol decreased the total peripheral resistance (TPR), whereas atenolol and propranolol increased it. In another series of experiments, when administered intravenously, betaxolol, atenolol and propranolol all produced a decrease in the myocardial oxygen consumption (MVO2) and an increase in the atrioventricular conduction time (AVCT). All three drugs were nearly equipotent in decreasing MVO2, although betaxolol was less potent than the other two drugs at higher doses (greater than 300 micrograms/kg). Prolongation of AVCT with propranolol was stronger than those with betaxolol and atenolol. These results suggest that, unlike atenolol and propranolol, the decrease in TPR as well as beta 1-adrenoceptor blockade may be responsible for both the hypotensive effect of betaxolol and the decrease in MVO2 with betaxolol. The result that the cardiodepressant effect of betaxolol was much less potent than those of atenolol and propranolol suggests that betaxolol would be more beneficial than the others in the treatment of ischemic heart disease.

Inhibition of brain type A monoamine oxidase and 5-hydroxytryptamine uptake by two amphetamine metabolites, p-hydroxyamphetamine and p-hydroxynorephedrine

Two amphetamine metabolites, p-hydroxyamphetamine (p-OHA) and p-hydroxynorephedrine (p-OHN), selectively inhibited the A form of monoamine oxidase (MAO) in rat and mouse forebrain homogenates. Of these two metabolites, p-OHA inhibited MAO-A more strongly than p-OHN. This MAO-A-selective inhibition by p-OHA or p-OHN was found to be competitive with respect to deamination of its substrate, 5-hydroxytryptamine (5-HT). The degree of MAO-A inhibition was not changed by 90 min of preincubation of the enzyme preparations with either metabolite, and the activity inhibited by p-OHA after the preincubation recovered completely to the control level after repeated washing. Uptake of 5-HT or dopamine into mouse forebrain synaptosomes was highly reduced by both p-OHA and p-OHN. Both metabolites were more potent in reducing dopamine uptake than in reducing 5-HT uptake. In reduction of 5-HT and of dopamine uptake, p-OHA was more potent than p-OHN. These results indicate that p-OHA is a more selective inhibitor of brain MAO-A activity and 5-HT uptake than its subsequent metabolite, p-OHN. These two actions of p-OHA might, together with possible 5-HT efflux into the synaptic cleft, greatly contribute to head twitch, a brain 5-HT-mediated animal behavior induced by p-OHA.

[A latent form of essential thrombocythemia presented as portal hypertension and associated with acquired von Willebrand syndrome]

A 32 year-old male patient was admitted to our hospital because of abdominal tumor. The examination on admission showed massive splenomegaly and esophageal varices although peripheral blood cell counts were within normal limits. Exploratory laparotomy was performed with the diagnosis of portal hypertension and revealed the multiple thrombus formations in the splenic vein and the extramedullary hematopoietic findings in the spleen by the microscopic examination. In vitro colony forming assay showed the formation of spontaneous erythroid colonies in cultures of progenitor cells (from peripheral blood mononuclear cells) in erythropoietin-poor medium. Increasing thrombocytosis was observed immediately after splenectomy, and hemorrhagic diathesis of nasal bleeding and gastrointestinal bleeding were also detected. The analysis of plasma von Willebrand factor (vWF) revealed the decrease of ristocetin cofactor activity and the lack of large multimeric components of vWF. These abnormal findings observed after splenectomy led to recovery through the administration of busulfan with the improvement of thrombocytosis. Accordingly, the course of the disease clearly indicated it to be the essential thrombocythemia represented as portal vein thrombosis and in latent form with normal cell counts in peripheral blood at the time of diagnosis, and subsequently, to develop into a full-blown form associated with acquired von Willebrand syndrome following splenectomy.

Effects of an aldose reductase inhibitor, ONO-2235, insulin and their combination on the altered responsiveness to the nerve stimulation and agonists of the isolated atria of diabetic rats

To determine the effects of an aldose reductase inhibitor (ARI) on diabetes-induced cardiac autonomic nerves disturbance, we examined the effects of ONO-2235, an ARI, as well as insulin on the responsiveness to the nerve stimulation and agonists of the isolated atria of the streptozotocin-induced diabetic rats. Insulin, 4 U/animal/day, was administered s.c. for 4 weeks before the experiment and ARI (ONO-2235), 40 mg/kg/day, was administered p.o. 3 weeks before the experiment. The transmural nerve stimulation (TNS) of sympathetic nerves and parasympathetic nerve was performed in the presence of atropine and metoprolol plus prazocin, respectively. The positive chronotropic and the inotropic responses of the atria to sympathetic TNS and to norepinephrine decreased in the rats diabetic for 8 and 12 weeks. In the rats diabetic for 8 weeks, the insulin treatment restored completely both the positive chronotropic and the inotropic responses to sympathetic TNS, whereas the ARI treatment partially improved the positive chronotropic response and did not improve the positive inotropic response. In the rats diabetic for 12 weeks, the insulin treatment partially improved the positive chronotropic and the inotropic responses to sympathetic TNS, whereas the ARI treatment only slightly improved the positive chronotropic response and did not improve the positive inotropic response to TNS. The combination treatment with insulin and ARI restored completely both the positive chronotropic and the inotropic responses in the rats diabetic for 12 weeks. In rats diabetic for both 8 and 12 weeks, the decreased positive chronotropic and the inotropic responses to norepinephrine recovered completely with the insulin treatment, but did not with the ARI treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Specification of notochord cells in the ascidian embryo analysed with a specific monoclonal antibody

Among 40 notochord cells of an ascidian tadpole larva, 32 notochord cells originate from the anterior-vegetal blastomeres (the A4.1 pair) of an 8-cell embryo and eight cells originate from the posterior-vegetal blastomeres (the B4.1 pair), but the animal blastomeres (the a4.2 and b4.2 pairs) are not engaged in the formation of the notochord. If four pairs of cells, separated from an 8-cell embryo, were allowed to develop into quarter embryos, expression of the notochord-specific antigen was evident in the A4.1 and B4.1 quarter embryos. Embryos, in which cytokinesis had been permanently blocked at the 8-cell and later stages with cytochalasin B, were found to develop the notochord-specific antigen only in the presumptive notochord cells. These findings suggest the developmental autonomy of presumptive notochord cells in the ascidian embryo.

Studies on the castability of Co-Cr alloy for cast plates. Part 2: Effect of form of sprue attachment to the wax pattern

Co-Cr alloy is used more frequently than Ni-Cr alloy as a non-precious alloy for cast plates in Japan. However, since the melting point of Co-Cr alloy is very high, about 1300 degrees C, and since it oxidizes easily, a vacuum-pressure casting machine capable of melting this alloy in a reducing atmosphere has recently been developed. Using this vacuum-pressure casting machine, the authors studied the effects on the castability of Co-Cr alloy due to the form of sprue attachment to the wax pattern. The results clarified that in the vacuum-pressure casting method, the form of sprue attachment to the wax pattern has a significant effect (p less than 0.01) on the castability of Co-Cr alloy.

Effects of MCI-154, a novel cardiotonic agent, on mean circulatory filling pressure in anesthetized dogs

The effects of MCI-154, a novel cardiotonic agent, on mean circulatory filling pressure (an index of total body venous tone), total peripheral resistance and the heart were examined in anesthetized dogs. The bolus injection of MCI-154 (10-100 micrograms/kg i.v.) caused a dose-dependent decrease in mean circulatory filling pressure and resistance to venous return. MCI-154 also decreased the mean blood pressure and total peripheral resistance, and increased cardiac output and heart rate. Right atrial pressure was reduced only by the lowest dose (10 micrograms/kg i.v.) of MCI-154. These hemodynamic effects of MCI-154, except those on mean circulatory pressure and resistance to venous return, reached a maximum with 30 micrograms/kg of the drug. Nitroglycerin (50 micrograms/kg i.v.), a venodilator, decreased mean circulatory filling pressure, resistance to venous return, mean blood pressure and total peripheral resistance, and increased heart rate. However, unlike MCI-154, nitroglycerin did not alter cardiac output and right atrial pressure. These results suggest that the venodilator effect of MCI-154, as well as the positive inotropic and vasodilator effects, could potentially benefit patients with congestive heart failure.

[A case of major dehiscence of a prosthetic aortic valve]

A case, 48-year-old man, was presented of dehiscence of an aortic Björk-Shiley prosthesis, which was diagnosed by pendular movement of prosthetic mount in cineangiographic finding. Emergent operation of Re-AVR was performed successfully. Valve dehiscence should be confirmed by cineangiographic examination, in case of progressive congestive heart failure combined with traumatic hemolytic anemia and high grade fever suggestive of prosthetic valve endocarditis.

[Pulmonary Tuberculosis in foreigners]

We studied the background and social problems of pulmonary tuberculosis in foreigners which we recently encountered at the National Chiba- Higashi Hospital and the Chiba Anti-tuberculosis Association. 1) The number of foreigners with pulmonary tuberculosis has been increasing year by year, one in 1983, none in 1984 and 1985, one in 1986, two in 1987 and four in 1988. 2) Most of these patients had been already infected or had some symptoms before their arrival to Japan. 3) Their background includes some serious social problems such as troubles in daily life coming from linguistic and cultural differences and economic difficulties, legal problems such as illegality of their stay in Japan, etc. 4) Most of the above cases could not be treated sufficiently because they are foreigners or because of their illegal stay.

[The effects of intravenous infused magnesium on hemodynamics and renal water-sodium metabolism in patients with essential hypertension]

Mean arterial pressure (MAP), heart rate (HR), urine volume (UV), urinary excretion of sodium (UNaV), endogenous creatinine clearance (Ccr), fractional excretion of sodium (FENa) were measured before and after intravenous infusion of 10% magnesium sulfate (an initial dose: Mg 13.5 mg/m2.BSA/15 min; a maintenance dose: Mg 2.7 mg/m2.BSA/105 min) in 6 normotensive subjects (NT) and 12 mild-to-moderate essential hypertensives (EHT). Following magnesium infusion, serum magnesium concentration (s-Mg) increased and reached the level of about 1.8 times basal value. Significant increases of UV, UNaV and FENa in both NT and EHT, and a similar tendency of Ccr in EHT were observed, while no significant change in MAP nor HR was found in the two groups. The changes in UNaV (delta UNaV) were positively correlated with those in FENa (delta FENa) and a similar tendency was shown between delta UNaV and change in Ccr (delta Ccr) in all subjects. While there was no significant percentage change of s-Mg (% delta s-Mg) nor of Ccr (% delta Ccr), those of UNaV (% delta UNaV) and FENa (% delta FENa) were significantly greater in EHT. It is concluded from these findings that magnesium infusion produces diuresis and the natriuresis which might result from suppression of renal tubular reabsorption of sodium, without any change in systemic hemodynamics in NT and EHT. The pronounced natriuretic response to magnesium in EHT might contribute to the hypotensive mechanism of magnesium loading in EHT.

[Long-term results of intra-arterial infusion therapy using cis-DDP (CDDP) in thoracic esophageal cancer]

The effects of intra arterial infusion therapy using CDDP for patients with thoracic esophageal cancer were investigated. From June 1984 to December 1988, 25 of 146 resected patients with thoracic esophageal cancer underwent preoperative therapy in our institute. All of these patients it was suspected preoperatively that their chief lesion had invaded to the aorta, trachea or main bronchi. Preoperative radio-chemotherapy with intra arterial infusion therapy was given to 10 of 25 patients (A group), and without intra arterial infusion therapy to 15 of 25 patients (B group). CDDP 75 mg was infused into the proper esophageal artery. In A group, 7 of 10 (70%) showed moderately or marked effects in histologic study, although in B group, only 4 of 15 (27%) did so. As for long-term results, the 2-year survival rates were 50% in A group and 13% in B group (Kaplan-Meier method. Preoperative intra arterial infusion therapy using CDDP with radio-chemotherapy showed markedly better effects in histologic study and survival rates than preoperative radio-chemotherapy without intra arterial infusion therapy. We consider that this therapy is very useful for controlling the local lesion in advanced esophageal cancer.

[Distribution of pulsed intra arterial infusion chemotherapy in hepatic carcinomas]

Evaluation of "Gianturco-Wallace chemotherapy pulser," which was developed to produce a more homogeneous drug distribution of the tumors in intra-arterial infusion chemotherapy, was assessed by comparative study of pulsed and nonpulsed arterial radionuclide infusion using Tc-99m pertechnetate for 18 cases of hepatic carcinomas (11 cases of hepatocellular carcinomas and 7 cases of metastatic hepatic carcinomas). Tc-99m pertechnetate, 740 MBq (20 mCi) diluted with saline (30 mL) was infused with or without pulse through the catheter into the hepatic artery at a rate of 1mL per minute. The intrahepatic dynamic radionuclide distribution was analyzed by the time activity curves of ROIs in the tumor and nontumor areas. Pulsed infusion interrupted laminar flow and produced more homogeneous radionuclide distribution in the liver, and combination of pulsed and nonpulsed infusion also produced better radionuclide distribution in the areas of the tumors. This method using Tc-99m pertechnetate was very useful as a simulation to determine the dynamic drug distribution of the tumor and non-tumor region in intraarterial infusion methods.

Potentiation of para-hydroxyamphetamine-induced head-twitch response by inhibition of monoamine oxidase type A in the brain

After pretreatment with either clorgyline, a monoamine oxidase (MAO)-A-selective inhibitor, or pargyline, an MAO-B-selective inhibitor with less selectivity than l-deprenyl, i.c.v. administration of para-hydroxyamphetamine (p-OHA) significantly increased both the frequency and total number of head-twitches in mice. A typical MAO-B-selective inhibitor, l-deprenyl, however, did not change the total count of the p-OHA-induced head-twitch response (HTR). These effects were also found with fixed doses of the selective MAO inhibitors when p-OHA was varied. Administration of clorgyline (1 mg/kg) or pargyline (5 mg/kg) almost inhibited completely MAO-A in the mouse forebrain, and pargyline also almost inhibited completely MAO-B. l-Deprenyl, in contrast, almost inhibited completely MAO-B without affecting MAO-A activity. Systemic administration of l-5-hydroxytryptophan also induced HTR and the total number of twitches was enhanced by clorgyline, but not by pargyline or l-deprenyl. Chlorimipramine or cocaine significantly reduced p-OHA-induced HTR, suggesting an intraneuronal site of action. Together with the presence of considerable MAO-A in 5-hydroxytryptamine (5-HT) neurons of various animal species, and possible accumulation and subsequent monoamine-releasing properties of p-OHA, the present results indicate that p-OHA might induce the HTR by interaction with intraneuronally increased 5-HT. This mechanism probably results in 5-HT release onto the postsynaptic 5-HT2 receptors. Taken together, different roles of MAO-B in "the hyperactivity syndrome" and the HTR are discussed.

[The role of the Na, K-ATPase inhibitor in renal sodium handling in patients with essential hypertension]

The present study aimed to elucidate the role of Na, K-ATPase inhibitor in renal sodium metabolism in essential hypertension. Mean arterial pressure (MAP), heart rate(HR), urine volume (UV), urinary excretion of sodium (UNaV), endogenous creatinine clearance (Ccr), fractional excretion of sodium (FENa), plasma renin activity(PRA) plasma aldosterone concentration(PAC), plasma noradrenaline concentration (PNA) and urinary excretion of noradrenaline(UNA) were measured before and after intravenous injection of ouabain (0.1 mg/m2.BSA) in 12 normotensive(NT) and 22 mild-to-moderate essential hypertensive subjects(EHT). Following ouabain injection, UV, UNaV FENa significantly increased, but PRA decreased, in both NT and EHT. MAP, HR, Ccr, PNA, and UNA did not change significantly in either group. On the other hand, a significant decrease in PAC was observed in NT, but not in EHT. The changes of UNaV and FENa were significantly attenuated in EHT as compared to NT. No significant difference in change of MAP, HR, UV, Ccr, PNA, UNA, or PRA was demonstrated between NT and EHT. A significantly positive correlation was found between delta UNaV and delta FENa in both NT and EHT, while no significant correlation was observed between delta UNaV and delta MAP, delta UV, delta Ccr, delta PRA, delta PAC, delta PNA and delta UNA in either group. These results suggest that 1) Na, K-ATPase inhibitor clearly augments natriuresis by suppression of sodium reabsorption in renal tubules, 2) since this augmentation was attenuated, there is an elevation of endogenous Na, K-ATPase inhibitor(s) should be considered in EHT, and 3) an increase of the inhibitor might participate to the hypertensive mechanism in EHT.

[Studies of diagnosis of rectal cancer using MRI, CT and intrarectal ultrasonography]

Examination using MRI, CT and Intrarectal Ultrasonography (US) were performed in 186 patients with primary rectal cancer and 127 postoperative cases, in order to diagnose the depth of invasion, lymph node metastases and local recurrence. In the diagnosis of depth of invasion, intrarectal US was superior to MRI and CT for detailed diagnosis, and MRI was the best examination modality for detecting infiltration of other organs. Also, these were available for the diagnosis of lymph node metastases, and intrarectal US was superior to MRI and CT for detecting small lymph nodes. In the detection of local recurrence, MRI, CT guided biopsy and intrarectal US were useful, especially MRI was the best examination for the decision of re-resection.

Determination and regulation in the pigment cell lineage of the ascidian embryo

The brain of the ascidian larva comprises two pigment cells, termed the ocellus melanocyte and the otolith melanocyte. Cell lineage analysis has shown that the two bilateral pigment lineage cells (a-line blastomeres) in the animal hemisphere give rise to these melanocytes in a complementary manner. The results of the present investigation suggest that the specification of the fate of pigment cells proceeds in two distinct steps. First, the determination of pigment lineage cells requires an inductive interaction from the vegetal blastomeres of the A-line. Cell dissociation experiments demonstrated that the inductive interaction is completed by the midgastrula stage. However, the two bilaterally positioned cells destined to become the pigment cells in the first step are still equipotent at this stage in that they can give rise to either the ocellus or otolith. Thus, they constitute what is termed an "equivalence group." In the second step, the individual fates of the two cells that compose the equivalence group are determined. Namely, one cell develops into an ocellus and the other cell develops into an otolith. Photoablation of one of the pigment precursor cells at various stages indicated that the second step of determination occurs at the midtailbud stage. It is suggested that the cue to choose one of the alternative developmental pathways may be positional information that exists along the anteroposterior axis. The second step of determination is thought to be mediated by a hierarchical interaction. In the absence of this interaction, melanocyte specification proceeds along the dominant pathway that results in the differentiation of an ocellus.

[Clinical evaluation of CA-50 in cases with colorectal cancer]

Serum CA-50 has been evaluated in 67 healthy donors and in 46 patients with a colorectal cancer by an enzyme immunoassay (EIA Kit, Mitsui pharmaceuticals, Inc.). The mean value of the healthy donors (n = 67) was 10.6 +/- 6.1 U/ml and for patients with a colorectal cancer 31.7 +/- 55.2 U/ml. Both in healthy donors and in patients, the mean value was found to be higher in females than males. The overall sensitivity in the colorectal cancer patients was 26.1 percent, the percentages for those in stage I, 20, II, 9.1, III, 40, IV, 20, and V, 50% respectively. In a correlation between serum CA-50 and CA 19-9, the correlation coefficient was 0.82 (p less than 0.01), and in between CA-50 and CEA, 0.51 (p less than 0.01). Thus a combination assay among CA-50, CA 19-9, and CEA has proved to be of significant value in cases of a colorectal cancer.

Reversal effect of thyroxine on altered vascular reactivity in diabetic rats

The influence of thyroxine treatment on the altered reactivity of the isolated perfused mesenteric vasculature from streptozocin-induced diabetic rats was examined and compared with that of insulin. After 8 weeks of diabetes, the time when the decreased response to isoproterenol appeared, treatment with thyroxine reversed this decreased response to control levels. However, thyroxine replacement did not reverse the decreased responsiveness to norepinephrine, 5-hydroxytryptamine, acetylcholine, and isoproterenol after 12 weeks of diabetes. On the other hand, insulin replacement improved the vascular responsiveness to these agonists at 8 and 12 weeks. Insulin treatment also reversed the attenuated response to nerve stimulation found in diabetic rats, whereas thyroxine treatment did not improve it. Insulin treatment reversed the decreased plasma thyroid hormone levels similarly as thyroxine treatment. These results suggest that thyroid hormone deficiency is likely to be involved partly in the altered reactivity of the rat mesenteric vasculature at the early period of diabetes. On the other hand, adrenergic neuropathy is not induced by hypothyroidism.

In vitro characterization of the effects of MCI-154, a novel cardiotonic agent, on cardiac tissues

In vitro cardiac effects of a cardiotonic drug, MCI-154, for which the main action mechanism was proposed to be the enhancement of Ca2+ sensitivity of cardiac contractile proteins, were investigated. MCI-154 (3 x 10(-8)-3 x 10(-4) M) increased the developed tension in isolated ventricular muscles from cats, dogs, guinea pigs and rats and increased that of isolated left atrial muscles of guinea pigs and rats. However, species differences were observed in the responses to MCI-154. The positive inotropic potency of MCI-154 was stronger than those of amrinone and milrinone. In the isolated right atria from guinea pigs and rats, properties of the chronotropic effect of MCI-154 were different from those of amrinone and milrinone. The positive inotropic action of MCI-154 was not affected by phentolamine, propranolol, cimetidine and tetrodotoxin. MCI-154 did not inhibit cardiac Na+,K+-ATPase. MCI-154 moderately stimulated Ca2+-uptake of isolated cardiac sarcoplasmic reticulum (SR), but induced no release of Ca2+ from the SR. These results support the view that the main mechanism for the action of MCI-154 is the enhancement of Ca2+ sensitivity of cardiac contractile proteins.

[Emergent surgical management of aortic dissecting aneurysm, type A Stanford, complicated with acute cardiac tamponade; report of a case]

A 52-year-old woman, who had been treated medically for 31 days with the diagnosis of type A aortic dissection, suddenly fell in shock because of acute cardiac tamponade. Emergent operation was performed two hours after the onset of shock. Entry and perforation were located in the ascending aorta. Ascending aorta was opened without cross-clamping under profound hypothermic low flow perfusion through femoral artery, and intraluminal grafting with a double ringed graft was completed. Combined technique of open distal anastomosis and ringed graft is useful in such an emergent case as cardiac tamponade of aortic dissection.

The effect of hepatic artery ligation for irresectable cavernous hemangioma of the liver

During the past 19 years, 52 cases of hepatic cavernous hemangioma have been treated at our institution. Thirty patients underwent hepatic resection. In six patients, the extensive tumor mass invaded multiple segments or both lobes of the liver and complete resection was deemed hazardous. Therefore, hepatic artery ligation was carried out. In all six cases the hemangioma occupied more than two segments. Right hepatic artery ligation was done in five patients and left hepatic artery ligation in one. All are doing well without complication. The longest follow-up is 19 years and the shortest 2 years and 2 months following operation. Four patients have been followed for more than 4 years and in all patients there are no residual complaints. Computerized tomography (CT) revealed the reduction of the tumor size after arterial ligation. One patient suffered from cholecystolithiasis 9 years after hepatic artery ligation, and at the time of cholecystectomy, a biopsy and microscopic examination of the lesion revealed evidence of fibrotic degeneration of the hemangioma. These findings indicate the effectiveness of hepatic artery ligation for treatment of hepatic cavernous hemangioma that are judged hazardous to resect.

[Clinical evaluation of a combination assay of CEA, CA-19-9 and TPA in patients with colorectal cancer]

The effectiveness of serum CEA (56 cases), CA-19-9 (53 cases) and TPA (48 cases) in patients with colorectal cancer has been evaluated. The preoperative sensitivity and specificity of CEA and CA 19-9 were found to be almost the same in level but the level of TPA was low. In 20 cases recurrent, the sensitivity of the marker was 66.7% in the liver, 60% in the lung, and 66.7% in the local recurrence of primary foci. In these recurrent cases, serum CEA in initially elevated to 65%, CA 19-9 to 25%, and TPA to only 10%. In diagnostic rate imaging or in our clinical findings, however, the frequency was almost the same as tumor markers.

Changes in vascular reactivity in experimental diabetic rats: comparison with hypothyroid rats

The responsiveness to vasoactive agents in the perfused mesenteric vascular bed of streptozocin-induced diabetic rats was examined and compared with that of propylthiouracil-induced hypothyroid rats. Diabetic rats at 4 and 8 weeks after the induction of diabetes showed a significant decrease in isoproterenol-induced vasodilatation. In addition, the contractile responses to norepinephrine and 5-hydroxytryptamine and the vasodilative response to acetylcholine were significantly decreased in 12-week-diabetic rats. The contractile response to nerve stimulation was markedly decreased at 8 and 12 weeks. On the other hand, hypothyroid rats showed a decreased response to isoproterenol, but they did not show any change in the response to nerve stimulation. A decrease in plasma thyroid hormone levels in diabetic rats at any time period was similar in extent to that in hypothyroid rats. The data indicate that the progressive changes in vascular reactivity in diabetic rats may be divided into two stages. In the early stage, the altered reactivity of vasculature is likely to be mediated by hypothyroidism, whereas in the later stage, it is induced by other factors, e.g. hyperglycemia and hypoinsulinemia. Adrenergic neuropathy is not caused by hypothyroidism.

[Effects of RU38486, an antiprogesterone agent, on endometrium, fertilized ovum and serum sex steroid levels in rats]

Effects of antiprogesterone RU38486 were studied in rats. The synthetic compound effectively (100%) inhibited implantation when administered on day 2 as well as on day 4 postconception (2.5mg/kg, in glycerol). This treatment, however, did not alter circulating estradiol and progesterone levels. Fertilized ovum yielded on day 4 from the uterine cavity showed normal morphology including adequate progress in cell division. A light microscopic study of the endometrium showed decreased cytoplasmic vacuole formation but estrogenic effects were apparently preserved. These data suggest that administration of RU38486 immediately after conception could successfully prevent implantation without altering early luteotropic functions in rats. Also the high dose of the compound was found to have no significant toxic effects on fertilized ovum, indicating that the anticonceptional action of RU38486 mainly functions at the uterine endometrial level.

Acute effects of a parkinsonism-inducing neurotoxin, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on mouse body temperature

The parkinsonism-inducing neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) given in single systemic doses (i.p.) to mice produced marked hyperthermia, and subsequent long-lasting hypothermia. Administration of MPTP or its oxidized product, 1-methyl-4-phenylpyridinium ion, MPP+, via i.c.v. resulted in only hypothermia. In contrast, i.p. MPP+ administration resulted in only hyperthermia. The MPTP-induced hyperthermia (i.p.) was blocked by quaternary derivatives of anti-cholinergic agents, atropine and scopolamine, but not by the tertiary-derivative of atropine. Duration of this hyperthermic effect was potentiated by neostigmine. Pretreatment with 1-deprenyl did not prevent hypothermia, but nomifensine partially or clorgyline completely prevented the effect without preventing MPTP-induced hyperthermia. The thermic effects by MPTP, unlike its neurotoxicity for the nigrostriatal DA system, may not require metabolism to MPP+. These results indicate that peripheral cholinergic functions are responsible for the MPTP-induced hyperthermia, whereas its hypothermic effect may be centrally mediated via dysregulation of the various neuron systems.

Central hypothermic effects of some analogues of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 1-methyl-4-phenylpyridinium ion (MPP+)

Effects of some MPTP or MPP+ analogues on mouse body temperature were studied. Of the analogues tested, 4-phenylpyridine (PPY) and 4-phenyl-1,2,3,6-tetrahydropyridine (PTP) given in single i.p. doses to mice caused marked hypothermia. Intracerebroventricular (i.c.v.) injection of PPY or PTP caused similar hypothermia. Pretreatment with clorgyline or (-)-deprenyl greatly prevented hypothermia induced by i.c.v. PPY, but hypothermia by i.c.v. PTP was prevented only by (-)-deprenyl. These results indicate that, in order to cause central hypothermia, PTP does not seem to require metabolism to PPY and both analogues per se may cause hypothermia.

Antibody to platelet activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine; PAF)

Specific antibodies to platelet activating factor (PAF) were prepared by immunizing rabbits with a hapten-bovine serum albumin (BSA) conjugate. As the hapten we used the synthetic PAF derivative which is resistant against enzymatic inactivation by plasma or tissues and which can bind to BSA through covalent bonding. Antibody activity was determined by an enzyme-linked immunosorbent assay (ELISA). Anti-PAF IgG reacted strongly with PAF. By means of the ELISA inhibition assay, we found that the antibody did not cross-react with phosphocholine, glycerophosphocholine, dilaurylglycerophosphocholine or PAF analogues which have ethanolamine-type polar head groups instead of choline group.

Monoclonal antibodies against components of the myoplasm of eggs of the ascidian Ciona intestinalis partially block the development of muscle-specific acetylcholinesterase

The myoplasm of Ciona intestinalis eggs, believed to contain cytoplasmic determinants responsible for muscle cell differentiation in ascidian embryos, emits weak pale-blue autonomous fluorescence. Utilizing this feature as a marker, the cytoplasm was isolated according to the method described by Jeffery (1985b). Electron microscopy showed that the isolated cytoplasm contained mitochondria, pigment granules, yolk particles and fine granular materials; these are ultrastructural components of the myoplasm of the intact egg. Monoclonal antibodies were prepared against the isolated cytoplasm. Twelve monoclonal antibodies, identified by indirect immunofluorescence, stained the myoplasmic region. When unfertilized eggs were centrifuged, stratifying their mitochondria and some other cytoplasmic components, components identified by several antibodies, for example IIG6B2, remained at the peripheral cytoplasm of the egg. Other antibodies recognized components stratified as the mitochondrial layer. Four representative antibodies were microinjected into fertilized eggs in order to examine their inhibitory effects on the muscle differentiation; the IIG6B2 antibody blocked the development of muscle-specific acetylcholinesterase in more than 80% of the embryos tested.

Expression of epidermis-specific antigens during embryogenesis of the ascidian, Halocynthia roretzi

We have produced two monoclonal antibodies (Epi-1 and Epi-2) which specifically recognize epidermal cells and their derivative, the larval tunic, of developing embryos of the ascidian Halocynthia roretzi. The antigens, examined by indirect immunofluorescence staining, first appear at the early tailbud stage and are present until at least the swimming larval stage. There were distinct and separate puromycin and actinomycin D sensitivity periods for each antigen. Aphidicolin, a specific inhibitor of DNA synthesis, prevented the appearance of each antigen when embryos were exposed to the drug continuously from cleavage stages. These results suggest that the antigens are synthesized during embryogenesis by developing epidermal cells and that several rounds of DNA replication are required for the antigen expression. Early cleavage stage embryos, including fertilized but unsegmented eggs, in which cytokinesis had been blocked with cytochalasin B expressed the antigens, and blastomeres exhibiting the antigens were always of the epidermis lineage. In partial embryos produced by four separated blastomere pairs of the 8-cell embryos, the expression of antigens was seen only in those developed from the animal blastomere pairs, which are progenitors of epidermal cells. These observations indicate that differentiation of epidermal cells in ascidian embryos takes place in a typical "mosaic" fashion.

Cardiovascular pharmacology of 6-[4-(4'-pyridyl)aminophenyl]-4,5-dihydro-3(2H)-pyridazinone hydrochloride, a novel and potent cardiotonic agent with vasodilator properties

The cardiovascular profile of 6-[4-(4'-pyridyl)aminophenyl]-4,5-dihydro-3(2H)-pyridazinone hydrochloride (MCI-154), a novel cardiotonic agent structurally different from cardiac glycosides and beta-adrenoceptor agonists, was investigated in vivo. In anesthetized, open-chest dogs, MCI-154 (0.3-100 micrograms/kg i.v., bolus injection) produced dose-dependent increases in dP/dtmax and cardiac output, and decreases in arterial blood pressure and total peripheral resistance with a relatively small increase in heart rate. The positive inotropic effect of MCI-154 was more potent than those of amrinone and milrinone. In anesthetized, intact-chest dogs, infusion of MCI-154 (0.3-3 micrograms/kg/min i.v.) also exerted a positive inotropic effect. P.o. administrations of MCI-154 (10-300 micrograms/kg) increased dP/dtmax in conscious beagle dogs. The cardiotonic effect of MCI-154 was not attenuated by blockade of autonomic receptors, catecholamine depletion and prostaglandin synthesis inhibition. MCI-154 (0.3-30 micrograms i.a.) produced a direct vasodilator effect in the canine hind-limb. MCI-154 (3 and 30 micrograms/kg i.v.) was effective in heart failure models induced with high doses of propranolol or verapamil. The potent cardiotonic and vasodilator activities of MCI-154 revealed by the present study suggest that this agent would be an effective remedy for the treatment of heart failure.