Panclicins, novel pancreatic lipase inhibitors. I. Taxonomy, fermentation, isolation and biological activity

Panclicins A, B, C, D, and E are novel pancreatic lipase inhibitors isolated from Streptomyces sp. NR 0619. Structurally, panclicins A, B, C, D, and E are analogues of tetrahydrolipstatin (THL), which contains a beta-lactone and a N-formyl leucine ester, and the IC50s of panclicins A, B, C, D, and E for porcine pancreatic lipase are 2.9, 2.6, 0.62, 0.66, and 0.89 microM, respectively. The potency of the inhibitory activity of each compound is attributed to the amino acid moiety of each structure. The panclicins are either glycine-type compounds such as panclicins C, D, E, which are two to threefold more potent than THL, or they are alanine-type compounds such as panclicins A and B, which are less potent than the glycine compounds. The inhibitory profiles of the panclicins for other lipases such as post-heparin plasma lipases and bacterial lipases are similar to those for pancreatic lipase. Panclicins A, B, C, D, and E, in a manner similar to THL, irreversibly inhibit pancreatic lipase. However, the compounds don't irreversibly inhibit the enzyme as strongly as THL does.

The effect of interleukin-2 on the release of gonadotropin and prolactin in vivo and in vitro

To evaluate a possible physiological role of Interleukin-2 (IL-2) in the control of Luteinizing hormone (LH), Follicle stimulating hormone (FSH) and Prolactin (PRL) release, conscious, ovariectomized (OVX) rats were given injections of IL-2 into the third ventricle. The third ventricular injection of IL-2 induced a significant decrease in plasma LH levels when compared to values in control animals (P < 0.05). Plasma LH concentrations were significantly decreased within 5 min after the injection of IL-2 and remained decreased for 1 h. In contrast, injections of IL-2 had no effect on plasma FSH or PRL levels. To evaluate a possible direct action of IL-2 on LH, FSH and PRL release from the anterior pituitary gland, the cytokine was incubated with dispersed anterior pituitary cells for 4 h. IL-2 in the dose range between 10(-1) and 10(-3) unit stimulated the release of LH and FSH into the culture medium (P < 0.05, P < 0.025 vs. control, respectively). The release of PRL from incubated anterior pituitary cells was not affected at any dose of IL-2 tested. These results indicate that IL-2 possibly plays an inhibitory role in the control of gonadotropin secretion, via hypothalamic action, although it acts directly to stimulate the release of the gonadotropins at the level of the anterior pituitary gland.

Mechanism of inhibition of DNA gyrase by cyclothialidine, a novel DNA gyrase inhibitor

We investigated how cyclothialidine (Ro 09-1437), a novel DNA gyrase inhibitor belonging to a new chemical class of compounds, acts to inhibit Escherichia coli DNA gyrase. Cyclothialidine up to 100 micrograms/ml showed no effect on DNA gyrase when linear DNA was used as a substrate. Under the same conditions, quinolones, which inhibit the resealing reaction of DNA gyrase, caused a decrease in the amount of linear DNA used. No effect of cyclothialidine was observed on the accumulation of the covalent complex of DNA and the A subunit of DNA gyrase induced by ofloxacin in the absence of ATP. The effect of cyclothialidine on the DNA supercoiling reaction was antagonized by ATP, reducing the inhibitory activity 11-fold as the ATP concentration was increased from 0.5 to 5 mM. Cyclothialidine competitively inhibited the ATPase activity of DNA gyrase (Ki = 6 nM). The binding of [14C]benzoyl-cyclothialidine to E. coli gyrase was inhibited by ATP and novobiocin, but not by ofloxacin. These results suggest that cyclothialidine acts by interfering with the ATPase activity of the B subunit of DNA gyrase. Cyclothialidine was active against a DNA gyrase resistant to novobiocin, suggesting that its precise site of action might be different from that of novobiocin.

A new methionine antagonist that has antifungal activity: mode of action

A new antifungal, azoxybacilin (an unusual amino acid with an azoxy moiety) was identified from Bacillus cereus, and its in vitro antifungal activity and mode of action were investigated. Azoxybacilin was active against a broad spectrum of fungi. It was especially active against mycelial fungi, such as Aspergillus, and did not show antibacterial activity. No cross-resistance with antifungals currently on the market was observed. The IC50 values of azoxybacilin antifungal activity against Saccharomyces cerevisiae were significantly greater when amino acids containing sulfur were added to the growth medium, whereas other amino acids were not effective at all. We, therefore, tested the effect of the intermediates involved in the synthetic pathway of these amino acids. The activity markedly diminished when one of the following four intermediates was present in the medium:homocysteine, cysteine, cystathionine or methionine. These four intermediates were the same as those required for the growth of the O-acetylhomoserine sulfhydrylase mutant, S. cerevisiae ONO726, indicating that azoxybacilin would inhibit a step or steps in the sulfur-fixation pathway.

Successful percutaneous transluminal angioplasty of the intracranial vertebral artery 1 month after total occlusion--case report

A 51-year-old male suffering from recurrent cerebral ischemia due to total occlusion of the bilateral intracranial vertebral arteries more than 1 month old was successfully treated by percutaneous transluminal angioplasty (PTA). The totally occluded portion from the right intracranial vertebral artery to the basilar artery was adequately dilated. Follow-up angiography approximately 3 months after angioplasty demonstrated no evidence of restenosis. His symptoms have not recurred. PTA is potentially a much less invasive and safer reconstruction than bypass surgery for total occlusions of the intracranial vertebral arteries less than 3 months old.

Antitumor-promoting activity of mallotojaponin, a major constituent of pericarps of Mallotus japonicus

Mallotojaponin, a major constituent of the pericarps of Mallotus japonicus (Euphorbiaceae), inhibited the action of tumor promoter in vitro and in vivo; it inhibited tumor promoter-enhanced phospholipid metabolism in cultured cells, and also suppressed the promoting effect of 12-O-tetradecanoylphorbol-13-acetate on skin tumor formation in mice initiated with 7,12-dimethylbenz-[a]anthracene.

Polyamino acids that inhibit the interaction of yeast translational elongation factor-3 (EF-3) with ribosomes

EF-3 is a translational elongation factor specific to yeasts and fungi. Its carboxy-terminal region contains three lysine-clusters and is very basic. The region has been reported to be responsible for the interaction with ribosomes [Ishiyama, A., Ogawa, K., & Miyazaki, M. (1992) in Abstracts of the 15th Annual Meeting of the Molecular Biology Society of Japan, p.190]. To find specific inhibitors for the interaction of EF-3 with ribosomes, the effects of two basic polyamino acids, poly-L-(Lys) and poly-L-(Arg), and two acidic polyamino acids, poly-L-(Asp) and poly-L-(Glu), were examined using two assay systems for ATPase of EF-3. One was for the ribosome-activated ATPase and the other for the intrinsic (ribosome-independent) ATPase of EF-3. Basic polyamino acids were expected to act as analogues of the carboxy-terminal region of EF-3, and acidic ones to interact with EF-3. The basic polyamino acids inhibited the ribosome-activated ATPase, but they also inhibited the intrinsic one more effectively. Acidic polyamino acids, poly-L-(Asp) and poly-L-(Glu), inhibited the ribosome-activated ATPase but not the intrinsic one. Thus, acidic polyamino acids could be specific inhibitors of the interaction between EF-3 and ribosomes. Furthermore, a system for detecting the binding of EF-3 to ribosomes was constructed. That is, ribosome-bound EF-3 was detected by measuring the ATPase on precipitated ribosomes after a mixture of EF-3 and ribosomes had been ultracentrifuged. Using this system, poly-L-(Asp) was shown to inhibit the binding of EF-3 to ribosomes directly.

Increased feline cerebral blood flow induced by dehydroevodiamine hydrochloride from Evodia rutaecarpa

Dehydroevodiamine hydrochloride (0.1-0.3 mg/kg iv), which was isolated from the leaves of Evodia rutaecarpa, increased the cerebral blood flow recorded from the surface of the supra-sylvian gyrus in anesthetized cats. This action reached a maximum 1-4 min after injection and continued for 10 min. However, the compound had negligible effects on other cardiorespiratory functions at the doses examined. These results suggest that the compound selectively increases cerebral blood flow.

Cyclothialidine, a novel DNA gyrase inhibitor. I. Screening, taxonomy, fermentation and biological activity

Streptomyces filipinensis NR 0484 produced a new DNA gyrase inhibitor, cyclothialidine. It showed potent activity against DNA gyrases from Escherichia coli and Micrococcus luteus.

Ro 09-1470 is a selective inhibitor of P-450 lanosterol C-14 demethylase of fungi

Ro 09-1470 is a new antifungal agent that belongs to a series of compounds characterized by a tetrahydropyran skeleton with glycine and alkenyl side chains and that inhibits P-450 lanosterol C-14 demethylase (P-450(14DM)) of fungi (Y. Aoki, T. Yamazaki, M. Kondoh, Y. Sudoh, N. Nakayama, Y. Sekine, H. Shimada, and M. Arisawa, J. Antibiot. 45:160-170, 1992; S. Matsukuma, T. Ohtsuka, H. Kotaki, H. Sawairi, T. Sano, K. Watanabe, N. Nakayama, Y. Itezono, M. Fujiu, N. Shimma, K. Yokose, and T. Okuda, J. Antibiot. 45:151-159, 1992). We have studied the compound's mode of interaction with fungal P-450(14DM) and its selectivity for the fungal versus mammalian P-450 enzymes. Ro 09-1470 bound to the Saccharomyces cerevisiae P-450(14DM) by coordinating to the heme with one-to-one stoichiometry. Unlike the azole compounds, it interacted with both ferric and ferrous heme. It was active also against the P-450(14DM) of Candida albicans. Ro 09-1470 preferentially inhibited the yeast P-450(14DM), showing a 50% inhibitory concentration (IC50) of 0.47 to approximately 1.1 microM, which is much lower than the IC50s for rat hepatic P-450s catalyzing cholesterol biosynthesis (IC50 = 341 microM), p-nitroanisol O-demethylation (> 1,000 microM), aniline hydroxylation (> 1,000 microM), and aminopyrine N-demethylation (920 microM). The degree of selectivity for yeast P-450 was higher than that of ketoconazole.

Tetrafibricin: a nonpeptidic fibrinogen receptor inhibitor from Streptomyces neyagawaensis. (II). Its antiplatelet activities

Tetrafibricin; a nonpeptidic fibrinogen inhibitor from microbial origin, showed potent antiaggregation activities on human platelet aggregation induced by either ADP, thrombin or collagen (IC50s = 5.6, 7.6 and 11 microM, respectively) in platelet rich plasma. The ability to inhibit aggregation in platelets treated with chymotrypsin confirmed the GPIIb/IIIa blockage of tetrafibricin. Tetrafibricin blocked the release of serotonin induced by ADP but it did not block the release reaction induced by thrombin. When added to platelets formerly aggregated with ADP, tetrafibricin caused rapid and complete deaggregation. As for the selectivity among other Arg-Gly-Asp -dependent integrins, tetrafibricin seems to be more specific for glycoprotein (GP) IIb/IIIa than RGDS is. This is because it had no effect on adhesion of bovine aortic endothelial cells to RGD-containing proteins. Tetrafibricin is the first nonpeptidic fibrinogen receptor inhibitor that may be valuable for the study on platelet aggregation inhibitors.

Biological characterization of cyclothialidine, a new DNA gyrase inhibitor

Cyclothialidine is a new DNA gyrase inhibitor isolated from Streptomyces filipinensis NR0484. Structurally, it belongs to a new class of natural products containing a unique 12-membered lactone ring that is partly integrated into a pentapeptide chain. Cyclothialidine was found to be one of the most active of all the DNA gyrase inhibitors tested in the DNA supercoiling reaction of Escherichia coli DNA gyrase; 50% inhibitory concentrations (in micrograms per milliliter) of 0.03 (cyclothialidine), 0.06 (novobiocin), 0.06 (coumermycin A1), 0.66 (norfloxacin), 0.88 (ciprofloxacin), and 26 (nalidixic acid) were found. In addition, DNA gyrases from gram-positive species were inhibited equally as well as DNA gyrase from E. coli. Cyclothialidine also inhibited the in vitro DNA replication directed from oriC of E. coli. Among the bacterial species tested, only Eubacterium spp. were inhibited by cyclothialidine, suggesting that it can enter the cells of Eubacterium and exert antibacterial activity through interference with the DNA gyrase within the cells, although its penetration into most bacterial cells appears to be poor. These results provide a basis for cyclothialidine to be a lead structure for novel antibacterial agents with DNA gyrase inhibitory activities.

Tetrafibricin: a nonpeptidic fibrinogen receptor inhibitor from Streptomyces neyagawaensis (I). Its GPIIb/IIIa blockage on solid phase binding assay

Tetrafibricin is a novel nonpeptidic fibrinogen receptor inhibitor isolated from Streptomyces neyagawaensis NR0577. Its competitive and selective fibrinogen receptor blockage was demonstrated in this study. Tetrafibricin competitively inhibited (Ki = 9.9 nM) the binding of biotinylated fibrinogen to purified active glycoprotein (GP) IIb/IIIa immobilized on plastic plate. When RGDS and tetrafibricin were added in combination, the inhibition was additive. The binding of other RGD-containing proteins, fibronectin and von Willebrand factor, to active GPIIb/IIIa were also completely inhibited by tetrafibricin. The fact that tetrafibricin did not inhibit the binding of von Willebrand factor to GPIb/IX indicates the specific blockage of tetrafibricin for GPIIb/IIIa. Fibrinogen receptor inhibition of tetrafibricin was also confirmed by its ability to inhibit 125I-fibrinogen binding to platelets stimulated with ADP. Because of its competitiveness and specificity, tetrafibricin can be used in a new structural model for the design of fibrinogen receptor inhibitors.

Cloning of the chitin synthase 3 gene from Candida albicans and its expression during yeast-hyphal transition

The chitin synthase 3 gene (CACHS3) has been cloned from Candida albicans. The yeast CAL1 gene encoding the chitin synthase 3 of Saccharomyces cerevisiae was used as a probe for the isolation of the gene from C. albicans. The CAL1 homolog was identified in Southern blots of C. albicans genomic DNA and cloned from a C. albicans genomic DNA library. The nucleotide sequences of two partial clones were determined and combined giving a total length of 4610 bp. A continuous open reading frame of 3525 bp encoding a predicted protein of 1175 amino acids and molecular mass of 131 850 daltons was identified. A comparison of the deduced amino acid sequences of CAL1 and the Candida chitin synthase 3 protein showed 59.3% identity. Southern blot analysis indicates that the CACHS3 gene is present in a single copy in the genome and maps to chromosome I. Northern blot analysis shows that expression of chitin synthase 3 gene is dramatically increased during the transition from the yeast to the hyphal form of C. albicans. This change in transcription level strongly suggests that CACHS3 may play a role in Candida morphogenesis.

Management of a broken atrial catheter migrated into the heart: a rare complication of ventriculoatrial shunt--case report

A 21-year-old male, who had undergone a ventriculoatrial shunt for hydrocephalus 5 years previously, became stuporous. A roentgenogram revealed that the distal segment of the broken atrial catheter had migrated and become lodged in the heart. Because the fragment had not adhered to the myocardium, it was easily retrieved by the transvenous approach with a retriever catheter. If the migrated catheter does not adhere to the myocardium, transvenous catheter retrieval is absolutely necessary. If, however, the migrated catheter adheres to the myocardium, an open thoracotomy would be required for retrieval, or the alternative of warfarin administration without retrieval may be the treatment of choice, as long as other problems do not occur.

Species specificity of pharmacological characteristics of CCK-B receptors

Novel CCK-B receptor antagonists, tetronothiodin and L-156,586, showed different affinities for CCK-B receptors in brain membranes from human, rat, guinea pig and mouse. [125I]CCK-8 bound to these membranes with a similar affinity. However, tetronothiodin was most potent in rat (IC50 = 3.6 nM), followed by guinea pig (96 nM), human (210 nM) and mouse (280 nM). L-156,586 bound with highest affinity to membranes from guinea pig (11 nM), and with lowest affinity to membranes from mouse (220 nM). These results suggest the existence of species specificity of CCK-B receptors, and that these two compounds are useful tools for discrimination between these receptors.

[Application of intravascular ultrasound imaging to carotid artery]

Although conventional angiography is utilized to assess the extent and severity of carotid artery disease, it yields only a silhouette of the vessel lumen. Intravascular ultrasound imaging (IUI), which has been developed for imaging the coronary artery, can supplement angiography by providing a tomographic perspective of the vessel wall structure. Therefore, we applied IUI (4.3F, 30MHz) to the carotid artery to evaluate the extent of arteriosclerosis, and we were successful in imaging the perspective of the carotid artery. Our results suggest that IUI is a useful device to evaluate the extent of atherosclerosis of the carotid artery.

Activation of CCK-B receptors elevates cytosolic Ca2+ levels in a pituitary cell line

Cytosolic Ca2+ levels ([Ca2+]i) in GH3 cells, a rat anterior pituitary tumor cell line, were monitored with fura-2 by fluorescence measurements. Cholecystokinin octapeptide (CCK-8) produced a transient elevation of [Ca2+]i. The elevation of [Ca2+]i by CCK-8 was inhibited by L-365,260, but not by devazepide. It was still observed when extracellular Ca2+ was eliminated, indicating that CCK-8 mobilizes Ca2+ from intracellular storage sites after interaction with CCK-B receptors. Cholecystokinin octapeptide increased the turnover of phosphatidylinositol, but it did not affect cyclic AMP levels. A possible involvement of phosphatidylinositol breakdown and calcium mobilization in the transduction system of CCK-B receptors in GH3 cells is suggested.

Percutaneous transluminal angioplasty of supra-aortic arterial stenoses in patients with concomitant cerebrovascular and coronary artery diseases--report of two cases

Percutaneous transluminal angioplasty (PTA) was performed on supra-aortic arterial stenoses in two patients with concomitant cerebrovascular disease (CVD) and coronary artery disease (CAD). One patient had suffered small cerebral infarctions in the left frontal and temporo-occipital regions, and the other a lacunar stroke in the left pontine region. The former had stenosis of the left internal carotid artery as well as severe triple-vessel CAD. The latter had stenosis of the left subclavian artery as well as severe single-vessel CAD of the left circumflex artery. The PTA procedure successfully dilated the cervical arterial stenosis in both patients, while no cardiac complications occurred. In patients with concomitant CAD and CVD, PTA may be safer than endarterectomy or bypass grafts for supraaortic arterial stenoses.

[Predictive factors for in-hospital mortality and delayed mortality following aneurysmal subarachnoid hemorrhage]

It is important to detect predictive factors for in-hospital and delayed mortality of patients with subarachnoid hemorrhage (SAH) due to ruptured aneurysm. Forty-eight patients with initial bleeding of aneurysmal SAH were referred to our hospital from January 1982 to December 1985. In-hospital mortality was 16.7% (8 to 48), and 15% (6) of forty patients died later during the follow-up period. Using the Kaplan-Meier method we were able to conclude that, cumulatively, there was 70.8% probability that much patients would survive for 10 years. We analysed predictive factors of in-hospital and delayed mortality retrospectively. The most significant predictive factor for in-hospital mortality was SAH grading on admission, and for delayed mortality (29.2%) age on admission was the best predictive factor. In fact, two patients died with cardiac event during the follow-up period. This result suggests that, although the SAH grading on admission was the second most significant factor for delayed mortality, patients who survived in the acute phase had a survival probability similar to those in a normal control group.

GH3 cells, an anterior pituitary cell line, express CCK-B receptors

We found that GH3 cells, a rat anterior pituitary tumor cell line, expressed a single class of high-affinity binding sites for radiolabeled cholecystokinin octapeptide (CCK-8) with a Kd of 48 pM. The binding sites had high affinity for CCK-8, CCK-4, gastrin I, and L-365,260 (CCK-B antagonist), and had low affinity for devazepide (CCK-A antagonist), indicating that the binding sites are CCK-B receptors. GTP and its stable analogues inhibited radiolabeled CCK-8 binding to GH3 cell membranes, suggesting a coupling of CCK-B receptors to a G-protein.

Antitumor-promoting activity of scopadulcic acid B, isolated from the medicinal plant Scoparia dulcis L

Scopadulcic acid B (SDB), a tetracyclic diterpenoid isolated from a medicinal plant, Scoparia dulcis L., inhibited the effects of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) in vitro and in vivo; SDB inhibited TPA-enhanced phospholipid synthesis in cultured cells, and also suppressed the promoting effect of TPA on skin tumor formation in mice initiated with 7,12-dimethylbenz[a]anthracene. The potency of SDB proved to be stronger than that of other natural antitumor-promoting terpenoids, such as glycyrrhetinic acid.

[Three months angiographic follow-up after successful percutaneous transluminal angioplasty]

Percutaneous Transluminal Angioplasty (PTA) is applied to supra-aortic arteries. Although first follow-up angiography after coronary angioplasty is usually undergone three or four months later, there are few reports of follow-up angiography after PTA of supraaortic arteries. Because of this, we performed follow-up angiography three months after successful PTA on eight cases of stenosis in seven patients. Although no symptom due to restenosis occurred, it was shown to have occurred in one of four cases of internal carotid arterial stenosis. It was a case of ostial stenosis of a left common carotid artery. Restenosis occurred in neither two cases of subclavian arterial stenosis, nor in a case of left middle cerebral arterial stenosis. The overall restenosis rate was 25%. We suspect that it is important to perform a follow-up angiography after angioplasty of supra-aortic arteries, and our result suggests that the restenosis might occur before three months after PTA as well as after coronary angioplasty.

Successful combination chemotherapy (cisplatin, vinblastine, and bleomycin) with small-dose irradiation in the treatment of pineoblastoma metastasized into spinal cord: case report

A case of successful combination chemotherapy using cisplatin, vinblastine, and bleomycin (PVB) therapy with small-dose irradiation (25 Gy) to treat a pineoblastoma that metastasized into the lumbar region through the cerebrospinal fluid is presented. Pain in the lower extremities and urinary incontinence with paraplegia improved during irradiation of the spinal cord after two courses of PVB therapy administered during a period of 6 weeks. The patient is presently attending school normally and has a score of 100% on the Karnofsky performance scale 4 years after therapy. These results suggest that combination chemotherapy with small-dose back-up radiotherapy may be one of the treatments of choice for recurrent or disseminated pineoblastoma.

Tetronothiodin, a novel cholecystokinin type-B receptor antagonist produced by Streptomyces sp. NR0489. II. Isolation, characterization and biological activities

A novel cholecystokinin type-B receptor antagonist named tetronothiodin has been isolated by column chromatography and preparative HPLC from the fermentation broth of Streptomyces sp. NR0489. Tetronothiodin inhibited the binding of CCK8 (C-terminal octapeptide of cholecystokinin) to rat cerebral cortex membranes (CCK type-B receptors) with an IC50 of 3.6 nM, whereas it did not inhibit CCK8 binding to rat pancreatic membranes (CCK type-A receptors). It also inhibited CCK8 induced Ca2+ mobilization in GH3 cells, a rat anterior pituitary cell line, but was without effect on the basal cytosolic Ca2+ concentration. This finding indicated tetronothiodin was an antagonist of CCK type-B receptors.