Synthesis of 2-imidazolidinylidenepropanedinitrile derivatives as stimulators of gastrointestinal motility

Ranitidine (1), the histamine H2-receptor antagonist, has been previously reported to increase gastric emptying and gastric motility by inhibition of acetylcholinesterase (AChE) and enhancement of acetylcholine (ACh) release. In order to obtain potent gastroprokinetic agents, a new series of ranitidine derivatives (5-32) possessing a nitrogen atom instead of a sulfur atom (B) was synthesized and their AChE inhibitory activity and potentiating action on electrically evoked contractions of guinea pig ileum were evaluated. Modification of substituents R1 and R2 markedly influenced the activities. In particular, compound 19, (1-[2-[[[5-(piperidinomethyl)-2-furanyl]methyl]amino]-ethyl]-2- imidazolidinylidene)propanedinitrile fumarate, showed 20 and 100 times more potent AChE inhibitory activity and potentiating action on the ileal contraction, respectively, than ranitidine. Furthermore, compound 19 (KW-5092) enhanced gastrointestinal motility in anesthetized rabbits along with a negligible histamine H2-receptor blocking activity.

Characterization of thromboxane A2/prostaglandin H2 receptors and histamine H1 receptors in cultured guinea-pig tracheal smooth-muscle cells

We characterized thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors and histamine H1 receptors in Guinea-pig cultured tracheal smooth-muscle cells (TSMC). [3H]SQ 29,548 (a TXA2 antagonist)-binding sites were saturable and a high affinity with a dissociation constant of 6.2 +/- 0.60 nM (mean +/- S.E.) and a receptor density of 46 +/- 4.6 fmol/10(6) cells. [3H]SQ 29548 binding was completely inhibited by TXA2 mimetics or antagonists. Intracellular calcium concentration ([Ca2+]i) in TSMC was increased with U46619 stimulation and the increase was attenuated by TXA2 antagonists, the potencies of which correlated with those inhibiting the activities of the [3H]SQ 29548 binding. [3H]Mepyramine (a H1 antagonist)-binding sites were also present in TSMC. [3H]Mepyramine had a single class of low-affinity-binding sites with a dissociation constant of 2.6 +/- 0.081 microM and a receptor density of 10.6 +/- 0.11 nmol/mg protein. [3H]Mepyramine binding in TSMC membrane was inhibited by H1 antagonists, but not by H2 antagonists. The inhibition constants of mepyramine in TSMC were 910-times lower than those in tracheal membranes. In contrast, the histamine-induced increase in [Ca2+]i in TSMC was inhibited in the presence of low concentrations of H1 antagonists. All these observations provide evidence that TXA2/PGH2 receptors, mepyramine-binding sites and/or H1 receptors are expressed in cultured TSMC.

[Sudden death due to bilateral pulmonary thromboembolism in a patient with multiple myeloma: an autopsy case report]

We encountered a patient with multiple myeloma who died suddenly, in whom bilateral pulmonary artery thrombosis was found at autopsy. The patient was a 50-year-old woman who had received chemotherapy for multiple myeloma at a local clinic for 4 years, and was transferred to our hospital because of recurrence of multiple myeloma in August 1990. Despite chemotherapy performed after admission, serum globulin level increased and her low back pain worsened, and she was generally restricted to bed. On October 21, she developed sudden dyspnea, became markedly cyanotic, lost consciousness, and then suffered a cardiopulmonary arrest. Autopsy revealed bilateral pulmonary artery thrombosis as well as thrombosis in the pelvic veins. Hyperviscosity due to multiple myeloma and long-term recumbency were the probable causes of pelvic venous thrombosis and subsequent pulmonary artery thrombosis. We report a rare case of bilateral pulmonary artery thrombosis which developed during the course of multiple myeloma and led to sudden death.

Adenosine A1 antagonists. 2. Structure-activity relationships on diuretic activities and protective effects against acute renal failure

Diuretic activities of xanthine or nonxanthine adenosine antagonists and their ameliorative effects against glycerol-induced acute renal failure in rats were investigated in order to clarify the physiological and pathological function of adenosine receptors in the kidney. Diuretic and natriuretic activities of a variety of adenosine antagonists clarified systematically for the first time that the blockade of A1 receptors is more important than that of A2 receptors in sodium and water excretion and support the hypothesis that endogenous intrarenal levels of adenosine directly enhance tubular sodium readsorption. Studies of structure-activity relationships of 8-substituted xanthines in the acute renal failure demonstrated that the activation of adenosine A1 receptor was an important factor in developing such a renal failure. A series of 8-(3-noradamantyl)xanthines exhibited the extremely potent diuretic and natriuretic activities (24; 2.5 micrograms/kg, po, the ratio of urinary excretion value in treated rats to urinary excretion value in control rats = 1.69, the ratio of Na+/K+ in treated rats to Na+/K+ in control rats = 1.76) and potent ameliorative effects against glycerol-induced acute renal failure (24; 10 micrograms/kg, ip, 55% inhibition). From our detailed studies of structure-activity relationships, we can speculate that some tissue differences of the adenosine A1 receptor might exist between kidney and brain and sites of action for adenosine antagonists could be different between two renal pharmacological assays. 1,3-Dipropyl-8-(3-noradamantyl)xanthine, KW-3902 (24), was chosen for further studies and is under development as a drug for treating the acute renal failure.

[Basic studies of intra-arterial hyperthermic treatment]

Basic studies on intra-arterial hyperthermic treatment (1AHT) were conducted in rabbits implanted with VX2 tumor inside the thigh. For the purpose of determining the best temperature, saline added Adriamycin (ADM) (2 mg/body) that heated up to a predetermined objective temperature was injected. At 3 days after administration, the intratumor concentration of ADM (ITCA) and blood laboratory data were obtained. ITCA of the 53 degrees C group (1.13 +/- 0.41 micrograms/g) was significantly higher than those in the 23 degrees C group. In the 58 degrees C group, BUN, CPK, and creatinine were elevated. These data suggested that the best temperature of IAHT was about 53 degrees C. The treated rabbits were divided into 4 groups (heated saline added ADM, heated saline, non-heated saline added ADM, control) and the tumor growth rates after IAHT were investigated. The tumor size of the groups treated by heated saline was inhibited compared with that in the other two groups. There was no elevation of intratumor temperature in spite of IAHT. At 2 days after the IAHT, patho logically there were vacuolar degeneration in the arterial endothelial cells near the tumor, and narrowing of involved artery. These results suggest that the antitumor effect by IAHT is related with blood supply without hyperthermic effect.

The ES-242s, novel N-methyl-D-aspartate antagonists of microbial origin, interact with both the neurotransmitter recognition site and the ion channel domain

ES-242-1 approximately 5 are novel microbial bioxanthracenes which do not contain nitrogen. The ES-242s inhibited the binding of [3H]TCP and [3H]CGS19755 to the N-methyl-D-aspartate (NMDA) receptor complex. They had no effect on the binding of the specific ligands for the non-NMDA receptor. The biochemical and pharmacological properties of ES-242-1 were fully examined since it is the most potent of the five compounds. ES-242-1 is highly specific for the NMDA receptor; it has no effect on other receptors. Kinetic analyses indicated that ES-242-1 inhibited the binding of [3H]TCP and [3H]CGS19755 in a competitive manner, respectively, suggesting that ES-242-1 interacts with both the transmitter recognition site and the channel domain. ES-242-1 selectively inhibited NMDA-induced Ca2+ influx in primary cultures of mouse hippocampal neurons. ES-242-1 also specifically blocked the increase in cyclic GMP accumulation induced by NMDA or L-glutamate in rat cerebellar slices. In a concentration range of 0.1-1.0 microM, ES-242-1 was as potent as MK-801 in preventing glutamate-induced neurotoxicity in primary cultures of mouse hippocampal neurons. These results show that ES-242-1 is a potent and specific antagonist for the NMDA receptor. The antagonistic properties of the ES-242s appear to be due to a novel mechanism of action at the NMDA receptor.

Effects of KW-3635, a novel dibenzoxepin derivative of a selective thromboxane A2 antagonist, on human, guinea pig and rat platelets

We examined the binding of [3H]U-46619, a thromboxane A2 agonist, to human and guinea pig platelets and the binding of [3H]SQ 29,548, a thromboxane A2 antagonist, to human, rat and guinea pig platelets. KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1- benzimidazolyl)ethylidene]-6,11-dihydrodibenz[b,e]oxepin-2-c arboxylate monohydrate) concentration-dependently inhibited the [3H]U-46619 binding to human and guinea pig platelets with inhibition constants of 1.2 nM and 2.7 nM, respectively. KW-3635 also potently inhibited the [3H]SQ 29,548 binding to human and guinea pig platelets with inhibition constants of 1.9 nM and 3.2 nM, respectively. In contrast, KW-3635 was less active against thromboxane A2/prostaglandin H2 receptors in rat platelets with an inhibition constant of 97 nM. KW-3635 at 10(-5) M did not antagonize various receptors including prostaglandin E2, prostaglandin I2 and neurotransmitters. In addition, 10(-5) M KW-3635 did not alter the prostaglandin D2-induced cAMP accumulation in EBTr cells. KW-3635 was inactive towards thromboxane synthase, cyclooxygenase and prostaglandin I2 synthase up to 10(-5) M. KW-3635 slightly inhibited 5-lipoxygenase with an IC50 value of 71 microM. These data indicate that KW-3635 is a potent and selective non-prostanoic thromboxane A2 antagonist, and it can recognize the species differences in thromboxane A2/prostaglandin H2 receptors.

8-Polycycloalkyl-1,3-dipropylxanthines as potent and selective antagonists for A1-adenosine receptors

With the aim of characterizing the hydrophobic interactions between xanthines and the A1 receptor site, 1,3-dipropyl-8-substituted xanthines were synthesized. Introduction of a quaternary carbon and the conformationally restricted cyclopentyl moiety into the 8-position of xanthines enhanced the adenosine A1 antagonism. 1,3-Dipropyl-8-(3-noradamantyl)xanthine was identified to be a selective and the most potent A1 receptor antagonist reported to date. Under our structure-activity relationship, the 8-substituent of xanthine antagonists and the N6-substituent of adenosine agonists appears to bind to the same region of the A1 receptor.

Muscarinic receptor subtypes in feline tracheal submucosal gland secretion

To determine what muscarinic receptor subtype regulates [Ca2+]i mediating airway submucosal gland secretion, we examined the effects of atropine (Atr), pirenzepine (PZ), 11([2-(diethylamino)methyl-1-piperidinyl] acetyl)-5,11-dihydro-6H-pyrido (2,3-b)(1,4)-benzo-diazepin-6-one (AF-DX116) and 4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP) on methacholine (MCh)-evoked [Ca2+]i rise in acinar cells, and compared this with mucus glycoprotein (MGP) and electrolyte secretion evoked by MCh from submucosal glands isolated from feline trachea. [Ca2+]i was measured with the Ca(2+)-sensitive fluorescent dye, fura 2. We determined MGP secretion by measuring TCA-precipitable 3H-labeled glycoconjugates and electrolyte secretion by the change in the rate constant of 22Na-efflux from isolated glands. Half-maximal inhibitory concentrations (IC50) of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked [Ca2+]i rise were 10(-7) M, 6 x 10(-6) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. IC50 of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked MGP secretion were 10(-6) M, 2 x 10(-5) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. MCh (10(-5) M)-evoked 22Na efflux was significantly inhibited by 10(-7) M 4-DAMP and 10(-7) M Atr (P less than 0.01, each) but not by 10(-7) M PZ. Receptor binding assays with [3H]quinuclidinyl benzilate showed that the Ki values for PZ, AF-D x 116, 4-DAMP and Atr were 2.2 x 10(-8) M, 6.6 x 10(-7) M, 6.2 x 10(-10) M, and 2.9 x 10(-10) M, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular cloning of the human cDNA for a stimulatory GDP/GTP exchange protein for c-Ki-ras p21 and smg p21

We have previously purified smg GDP dissociation stimulator (GDS) from bovine brain and isolated its cDNA from a bovine brain cDNA library. smg GDS stimulates the GDP/GTP exchange reaction of a group of small GTP-binding proteins (G proteins), including at least c-Ki-ras p21, smg p21A, smg p21B, rhoA p21 and rhoB p21, by stimulating the dissociation of GDP from and the subsequent binding of GTP to each small G protein. In this study, we have isolated and sequenced the cDNA of smg GDS from a human brain cDNA library using the cloned bovine smg GDS cDNA. The cDNA has an open reading frame encoding a protein of 558 amino acids with a calculated Mr value of 61,122. Human smg GDS shares 93% nucleotide and 96% amino acid sequence homologies with bovine smg GDS. The isolated cDNA is expressed in Escherichia coli, and the encoded protein shows the physical and functional properties similar to those of bovine smg GDS.

Effects of dextran sulphate on renal dysfunctions induced by gentamicin as determined by the kidney perfusion technique in rats

The effect of dextran sulphate on accumulation of gentamicin within the renal cortex and on renal functional changes induced by gentamicin has been investigated using the rat renal perfusion technique. Gentamicin accumulation decreased by the coadministration of dextran sulphate, the degree being proportional to dextran sulphate concentration. The filtered load of gentamicin was unaffected by dextran sulphate. The perfusion of kidney with gentamicin brought about a decrease in the reabsorption of Na+ and an increase in the rate of urine flow with no effect on that of glomerular filtration. The addition of dextran sulphate in the perfusate resulted in the resumption of these levels to those of the control. Dextran sulphate thus apparently interacts with gentamicin in the lumen of proximal tubules to inhibit the reabsorption of gentamicin by proximal tubular cells, and prevents the renal dysfunctions induced by gentamicin.

[YAG laser contact therapy of ovarian endometriosis under laparoscopy]

Thirty-six patients with ovarian endometriosis were treated with Nd:YAG laser contact irradiation under laparoscopic control. Indications for laparoscopy were infertility (n = 20) and dysmenorrhea (n = 16). The laparoscopic procedures so far undertaken in our clinic include: Aspiration of chocolate cyst, removal of ovarian endometriosis, adhesion-lysis, uterine nerve ablation, coagulation of peritoneal endometriosis and irrigation. No complications were seen. After undergoing this procedure, eight of 20 patients achieved pregnancy and 15 of 16 patients obtained pain relief. Serum CA125 levels were significantly decreased postoperatively. We confirmed that contact irradiation with a cone-shaped sapphire probe provides adequate incision and lysis at lower power levels, and that this method is an effective treatment for ovarian endometriosis.

Tissue and subcellular distributions of an inhibitory GDP/GTP exchange protein (GDI) for the rho proteins by use of its specific antibody

We have recently purified from bovine brain cytosol to near homogeneity a GDP/GTP exchange protein for the rho proteins, named rho GDI, that inhibits the dissociation of GDP from and the subsequent binding of GTP to the rho proteins. In the present study, we made a monoclonal antibody against rho GDI and studied its tissue distribution in rat and its subcellular distribution in rat cerebrum by use of this antibody. rho GDI was found in most rat tissues as described for the rho proteins. In rat cerebrum, rho GDI was mostly found in the cytosol of neuron body and synaptosome. In synaptosome, it was mainly found in the synaptic cytosol.

Tissue and subcellular distributions of an inhibitory GDP/GTP exchange protein (GDI) for smg p25A by use of its antibody

We have recently purified from bovine brain cytosol to near homogeneity a GDP/GTP exchange protein for smg p25A, named smg p25A GDI, that inhibits the dissociation of GDP from and the subsequent binding of GTP to smg p25A. In the present study, we made an antiserum against smg p25A GDI and studied its tissue distribution in rat and its subcellular distribution in rat cerebrum by use of this antiserum. smg p25A GDI was found in secretory cells with both regulated and constitutive secretion types. Since smg p25A was previously found in only secretory cells with a regulated secretion type, this result suggests that small GTP-binding proteins different from smg p25A but recognized by smg p25A GDI are present in secretory cells with a constitutive secretion type, and that smg p25A GDI is involved in both regulated and constitutive secretory processes. In subcellular fractionation analysis of rat cerebrum, smg p25A GDI was mostly found in the cytosol fraction of neuron body and synaptosome. In synaptosome, it was mainly found in the synaptic cytosol.

[A case of cardiac amyloidosis showing the ischemic change by exercise Tl-201 myocardial scintigraphy]

A case of cardiac amyloidosis, which was recognized as an ischemic change by exercise Tl-201 myocardial scintigraphy, was studied. The case was 41 year-old woman, whose initial symptom was pretibial edema and died of ventricular fibrillation. Ischemic change was ascertained by the treadmill exercise test and exercise Tl-201 myocardial scintigraphy, however, the significant coronary stenotic lesion was not detected by coronary angiography. Our data suggested that ischemic change may be related with the disturbance of microcirculation caused by deposit of amyloid in the vessels and/or around the vessels from the pathological findings.

[Comparison of ciprofloxacin with polymyxin B for infection prophylaxis in neutropenic patients with acute non-lymphocytic leukemia]

Twenty-four neutropenic patients receiving intensive chemotherapy for acute non-lymphocytic leukemia were studied in a randomized trial comparing ciprofloxacin with polymyxin B for prevention of infections. Both groups (12 patients each group) received amphotericin B for antifungal prophylaxis. 20 febrile episodes occurred in 22 courses of oral prophylactic ciprofloxacin and 22 occurred in 24 courses of oral prophylactic polymyxin B. Patients receiving ciprofloxacin had a mean time to the first infection-related febrile episode of 7.2 days, compared with 4.3 days for the polymyxin B group (p less than 0.01). Patients receiving ciprofloxacin also had fewer days of fever (average 6.5 days versus 9.8 days for the polymyxin B group, p less than 0.02). Duration of administration of parental antibiotics were also shorter in the ciprofloxacin group (p less than 0.001). Although modifications of the empiric antibiotic regimen were required more frequent in patients receiving polymyxin B, this did not reach statistical significance. These results suggest that ciprofloxacin is a more efficacious oral antimicrobial agent than polymyxin B for the prevention of infections in neutropenic patients with acute non-lymphocytic leukemia.

Effect of dextran sulfate on renal accumulation of gentamicin

The effect of dextran sulfate of three molecular weights (1000, 5000, and 90,000) on the accumulation of gentamicin in rat kidney was investigated using a continuous infusion technique. During the infusions of both gentamicin and gentamicin-dextran sulfate mixtures, the gentamicin plasma concentration was maintained at 10 microgram/ml. The renal cortical accumulation of gentamicin was significantly lower when dextran sulfate (1000, 5000) was coadministered. The inhibition of cortical gentamicin accumulation increased with increasing dextran sulfate dose, and it was proportional to the amount of dextran sulfate excreted into the urine. Analysis by electrophoresis on cellulose acetate membrane indicated that gentamicin binds to dextran sulfate in rat urine. Therefore, gentamicin-dextran sulfate binding within the lumen of the proximal tubules may reduce the renal reabsorption and possibly the renal toxicity of gentamicin.