Fungal metabolites. XV. Primary structures of antibiotic peptides, hypelcins B-I, B-II, B-III, B-IV and B-V, from Hypocrea peltata. Application of electrospray mass spectrometry and electrospray mass spectrometry/mass spectrometry

Hypelcin B is a mixture of antibiotic peptides produced by Hypocrea peltata. Hypelcins B-I, B-II, B-III, B-IV and B-V are components of this mixture purified by reversed-phase high-performance liquid chromatography. The amino acid sequences of these peptides were determined by electrospray mass spectrometry and electrospray mass spectrometry/mass spectrometry. The molecular weights of these peptides were all ca. 2000 and the structures were very similar.     

Leptin receptor of Zucker fatty rat performs reduced signal transduction

Arthroscopy of the first carpometacarpal joint has been developed as a reliable surgical procedure offering an opportunity for direct evaluation of the joint's intra-articular status, with minimal morbidity to the joint capsule. The procedure uses a 1.9-mm short barrel arthroscope with standard supportive electronic equipment. After adequate anesthesia is established, approximately 5 lb. of longitudinal traction is applied to the thumb. Arthroscopic portals are located on the radial side of the abductor pollicis longus tendon (1-R portal) and the ulnar side of the extensor pollicis brevis tendon (1-U portal). Care must be exercised in establishing these portals so that injury to the radial artery and branches of the superficial radial nerve can be avoided.     

Macroscopic and pathohistological investigation of endarterial plaque after intraoperative balloon dilatation of the carotid artery during carotid endarterectomy

Twelve patients associated with stenosis of the extracranial carotid artery underwent intraluminal balloon dilatation during carotid endarterectomy (CEA). There were 11 men and 1 woman, and age ranged from 56 to 73 years old. The rate of stenosis, shown by angiography, in each patient was from 60 to 85% in width. After securing carotid blood flow by a T-shaped shunt tube, a balloon catheter was inserted from the exposed common carotid artery into the internal carotid artery. The balloon was inflated three or four times with 2.5-3.5 atm. for 30-40 seconds. Immediately after balloon dilatation, endoscopic investigation was performed (Wolf; hard type endoscope, 2.7 mm diameter). Then CEA was performed using the usual procedure. The removed endarterial plaque was investigated pathohistologically. In macroscopic and endoscopic findings, there were 6 patients with mural thrombosis, 4 patients with laceration of the intima, and one patient with outflow of atheroma from the intima. Only 3 patients had increase in lumen after balloon dilatation. In pathohistological appearance, all patients had a moderate degree of fibrosis, calcification, and atheroma in the cross section of the plaque. Ten patients had intramural hemorrhage. Three typical patients were revealed by the use of angiographical, ultrasonographical, endoscopic, and pathohistological presentation. Case 10 showed laceration of the intima by balloon dilatation, and had moderate increase in lumen size macroscopically and endoscopically. There were moderate cases of fibrosis, calcification, atheroma, and intramural hemorrhage. Dilatation of the lumen seemed to be accomplished by a decrease in thickness of the atheroma and intramural hemorrhage. Case 8 demonstrated an increase in lumen size, but also laceration of the intima and outflow of atheroma from the arterial wall. There were much atheroma and large intramural hemorrhage in the intima, which might become a source of enbolism. Case 7 revealed no laceration of the intima and no increase in lumen size. Preoperative ultrasonography showed hyperechoic finding and postoperative pathohistological findings showed severe fibrosis and calcification, which were thought to have interrupted balloon dilatation. There have been small numbers of reports about pathohistological presentation after percutaneous transluminal angioplasty (PTA), because it is very difficult to take a specimen after PTA. In this report we were able to present the necessity of preoperative investigations by angiography, ultrasonography, and 3D-CT.     

Coiled-coil interaction of N-terminal 36 residues of cyclase-associated protein with adenylyl cyclase is sufficient for its function in Saccharomyces cerevisiae ras pathway

In the budding yeast Saccharomyces cerevisiae, association with the 70-kDa cyclase-associated protein (CAP) is required for proper response of adenylyl cyclase to Ras proteins. We show here that a small segment comprising the N-terminal 36 amino acid residues of CAP is sufficient for association with adenylyl cyclase as well as for its function in the Ras-adenylyl cyclase pathway as assayed by the ability to confer RAS2(Val-19)-dependent heat shock sensitivity to yeast cells. The CAP-binding site of adenylyl cyclase was mapped to a segment of 119 amino acid residues near its C terminus. Both of these regions contained tandem repetitions of a heptad motif alphaXXalphaXXX (where alpha represents a hydrophobic amino acid and X represents any amino acid), suggesting a coiled-coil interaction. When mutants of CAP defective in associating with adenylyl cyclase were isolated by screening of a pool of randomly mutagenized CAP, they were found to carry substitution mutations in one of the key hydrophobic residues in the heptad repeats. Furthermore, mutations of the key hydrophobic residues in the heptad repeats of adenylyl cyclase also resulted in loss of association with CAP. These results indicate the coiled-coil mechanism as a basis of the CAP-adenylyl cyclase interaction.     

New wear tests of tool materials for metal forming

Tribological phenomena, i.e. friction, tool wear and material pick-up to the tool, in metal forming processes are influenced by various factors. Therefore, in friction tests in the laboratory, these factors should be varied widely and independently and they should be measured easily. A new test method which has these features is described; the test parameters are the tool pressure, sliding speed, enlargement of the workpiece surface, length of contact between the tool and workpiece, sliding distance, contact angle and viscosity of the lubricant. Some results of the tests on tool wear are presented and discussed.     

An improved algorithm for diagnosis of system failures in the chemical process

The detailed techniques for improving the efficiency of a fault-diagnosis algorithm can be based on the signed directed graph. This graph represents the structure of the system, and the pattern on the graph represents a state of the system. The usefulness of the improved algorithm is demonstrated using a model of a chemical process comprising a reactor, a heat exchanger and a distillation tower.