Ammocidin, a new apoptosis inducer in Ras-dependent cells from Saccharothrix sp. I. Production, isolation and biological activity.

A new apoptosis inducer, ammocidin, was isolated from the culture broth of Saccharothrix sp. AJ9571. Ammocidin induced apoptotic cell death in Ras-dependent Ba/F3-V12 cells with an IC50 of 66 ng/ml. No cell death was observed in IL-3-dependent Ba/F3-V12 cells at less than 100 microg/ml of ammocidin. Ammocidin significantly reduced the phosphorylation level of MAPK and S6K that mediate the anti-apoptotic function of Ras.

Ammocidin, a new apoptosis inducer in ras-dependent cells from Saccharothrix sp. II. Physico-chemical properties and structure elucidation.

The structure of ammocidin, a new apoptosis inducer in Ras-dependent cells from Saccharothrix sp. AJ9571, was elucidated to be as shown in Fig. 1 by NMR and degradation studies. Ammocidin consists of a 20-membered macrolide ring and three deoxy sugars identified as 6-deoxy-L-glucose, D-digitoxose and D-olivomycose.

Signal transduction inhibitors, hibarimicins, A, B, C, D and G produced by Microbispora. I. Taxonomy, fermentation, isolation and physico-chemical and biological properties.

Strain TP-AO121 which produces a complex of novel tyrosine kinase inhibitors designated hibarimicins A, B, C, D and G was considered to be a new subspecies of Microbispora rosea, and the name, Microbispora rosea subsp. hibaria, was proposed. Hibarimicins A, B, C and D specifically inhibited the src tyrosine kinase activity without affecting protein kinase A or protein kinase C. They also showed in vitro anti-Gram-positive bacterial and antitumor activities. The molecular formulae of hibarimicins A, B, C, D and G were assigned to be C85H112O37, C85H112O37, C83H110O36, C85H112O38, and C85H112O39 respectively.

Signal transduction inhibitors, hibarimicins A, B, C, D and G produced by Microbispora. II. Structural studies.

The structure of hibarimicins A, B, C, D and G which are inhibitors for tyrosine specific protein kinase are determined using spectroscopic techniques. Hibarimicins described in this report consist of a common aglycon and six deoxyhexoses. The aglycon contains a highly oxidized naphtylnaphthoquinone as a chromophore. Among them, hibarimicin B was identical with angelmicin B.

Glucosylquestiomycin, a novel antibiotic from Microbispora sp. TP-A0184: fermentation, isolation, structure determination, synthesis and biological activities.

Glucosylquestiomycin, a novel N-glucopyranoside of questiomycin A, was isolated from the culture broth of Microbispora sp. TP-A0184. The absolute configuration of the sugar was determined as D-configuration by chemical synthesis. The new antibiotic showed antibacterial activity against gram-positive and -negative bacteria and yeasts and cytotoxic activity against U937 cells.

Asymptomatic cor triatrium in an elderly patient--observation by biplanar transesophageal Doppler echocardiography.

We present a case of asymptomatic cor triatrium in a 78-year-old man, in whom the condition was diagnosed and the severity of the lesion was accurately assessed by biplanar transesophageal echocardiography. To our knowledge, our patient is the oldest living person with cor triatrium.

[Bronchial hyperresponsiveness in patients with vasospastic angina pectoris (VSAP)].

To determine the relationship between airway and coronary artery spasmogenesity in patients with vasospastic angina pectoris (VSAP), we measured the bronchial responsiveness to inhaled methacholine in 21 VSAP patients (V-group) and compared it to that of 17 chest pain syndrome patients with normal coronary (N-group). In the V-group, logarithmic values of the minimum cumulative dose required to decrease respiratory conductance from the baseline (Log Dmin) was significantly lower than that in N-group (0.47 +/- 0.60 log units vs. 0.98 +/- 0.60 log units respectively, p < 0.05). Log Dmin was significantly correlated with the dose of acetylcholine which induced a greater than 90% stenosis of the coronary artery (r = 0.383, p < 0.05). We concluded that both the coronary artery and the airway show hyperresponsiveness to cholinergic agonists in patients with VSAP.

[Effects of ATP on cerebral circulation--morphological observation of cerebral circulation and cerebral vasculature].

Review was made on the effect of adenosine triphosphate, 1.0-3.0 mg/kg intravenously, on the cerebral circulation and the presence of the dilating action on the cerebral blood-vessels in cats. 1. The group of the normal intra-cranial pressure showed, as reported previously, the transient hypotension and its complicated decrease of cerebral blood-circulation at the initial period for 30-100 check, then demonstrating the increase of cerebral blood-flow for 200-1000 check. Its increased volume and duration were dose-dependent. 2. The group of the loaded intracranial pressure of 20-30 mmHg (slightly elevated group) showed the increase of cerebral blood-flow, like the group of the normal intracranial pressure. However, the effect of ATP showed the decrease or disappearance in accordance with the elevation of the loaded pressure. 3. Cerebral vasodilating effect of ATP was promptly observed after the administration, and its degree was 30-50% in photographical observation. 4. Increasing effect on cerebral blood-flow and cerebral vasodilating action of ATP were similar in the pattern to that of vasodilators such as papaverine hydrochloride.

Raman spectrum of a transfer RNA.

Raman spectrum of purified formylmethionine transfer RNA from Escherichia coli has been observed in its aqueous solution. In the 1800 to 200 cm(-l) range, about 30 Raman lines are found, each of which can be assigned to one of the constituent nucleotide residues. From the positions and intensities of the lines, information on the intramolecular environments of these base residues can be obtained.