Ca2+/calmodulin-dependent kinase II and calcineurin play critical roles in endothelin-1-induced cardiomyocyte hypertrophy

Endothelin-1 (ET-1) induces cardiac hypertrophy. Because Ca(2+) is a major second messenger of ET-1, the role of Ca(2+) in ET-1-induced hypertrophic responses in cultured cardiac myocytes of neonatal rats was examined. ET-1 activated the promoter of the beta-type myosin heavy chain gene (beta-MHC) (-354 to +34 base pairs) by about 4-fold. This activation was inhibited by chelation of Ca(2+) and the blocking of protein kinase C activity. Similarly, the beta-MHC promoter was activated by Ca(2+) ionophores and a protein kinase C activator. beta-MHC promoter activation induced by ET-1 was suppressed by pretreatment with the calmodulin inhibitor, W7, the Ca(2+)/calmodulin-dependent kinase II (CaMKII) inhibitor, KN62, and the calcineurin inhibitor, cyclosporin A. beta-MHC promoter activation by ET-1 was also attenuated by overexpression of dominant-negative mutants of CaMKII and calcineurin. ET-1 increased the activity of CaMKII and calcineurin in cardiac myocytes. Pretreatment with KN62 and cyclosporin A strongly suppressed ET-1-induced increases in [(3)H]phenylalanine uptake and in cell size. These results suggest that Ca(2+) plays a critical role in ET-1-induced cardiomyocyte hypertrophy by activating CaMKII- and calcineurin-dependent pathways.

Structural conversion from non-native to native form of recombinant human epidermal growth factor by Brevibacillus choshinensis

Brevibacillus choshinensis (Bacillus brevis) HPD31 is a very efficient producer of recombinant human epidermal growth factor (EGF). The produced EGF is secreted into the medium with high efficiency. However part of the EGF that accumulates in the medium, exists as multimeric forms which are biologically inactive. We found the bacterium has the activity to structurally convert multimeric forms to the monomeric, native ones. Optimal temperature and pH for the conversion were 40 degrees C and pH 9, respectively. The reaction was promoted in the presence of reduced glutathione or cysteine. But the cells which had been sonicated or exposed to moderate heat treatment completely lost the activity. Thus, it was presumed that the activity might be due to the enzyme(s) that catalyze the protein disulfide exchanging reaction, and that they resides on the surface of viable cells.

Removal of cadmium from scallop hepatopancreas by microbial processes

A microbial process for removing cadmium from a homogenate of hepatopancreas, a waste of scallop processing, was devised to use this waste for value-added protein resources. Microorganisms were screened on the basis of the ability to remove cadmium from a medium with the initial concentration of 10 mg/l of cadmium. One soil isolate, identified as Xanthomonas sp. UR No. 2 by its taxonomical characteristics, removed 98% of the cadmium in the medium in 2 d. During cultivation of this strain in the homogenates of hepatopancreas digested by endopeptidases, 90% of cadmium was removed, while this strain had little effect on the simple non-digested homogenates. The mass balance of cadmium during homogenizations of the hepatopancreas tissues and cultivations in the protease-treated homogenate were examined. The content of crude proteins of culture supernatant treated by Xanthomonas sp. UR No. 2 was equivalent to those of various feedstuffs on the market.

Molecular cloning of the dnaK locus, and purification and characterization of a DnaK protein from Bacillus brevis HPD31

Using part of the dnaK gene from Bacillus subtilis as a probe, a 4. 4-kbp SacI-BglII fragment of chromosomal DNA of Bacillus brevis, a protein-hypersecreting bacterium, was cloned. Nucleotide sequencing revealed 3 open reading frames in the order of grpE-dnaK-dnaJ homologues. We purified DnaK protein to homogeneity from B. brevis HPD31 harboring a multi-copy dnaK expression plasmid. Purified DnaK showed ATPase activity which was synergistically stimulated 14-fold by the addition of glutathione S-transferase-DnaJ and glutathione S-transferase-GrpE fusion proteins. DnaK hydrolyzed not only ATP but also CTP, UTP, and GTP at about 40% of the efficiency of ATP. The specific activity of DnaK-ATPase was 7.25x10-3 unit/mg protein (the turnover number against ATP was 0.47 min-1) under our assay conditions. The DnaK dimers dissociated into monomers on addition of ATP, GTP, CTP, UTP and ATPgammaS, but not ADP or AMP. DnaK formed a stable complex with permanently unfolded carboxymethylated alpha-lactalbumin but not with native alpha-lactalbumin, and this complex was dissociated by addition of ATP/Mg. Formation of this complex was inhibited in the presence of inorganic phosphate.

[Analysis of abnormal findings observed on brain MRI T 2 weighted image in a system for the detection of asymptomatic brain disease in 1,200 cases]

In this study we described the significance of asymptomatic cerebral infarction (ACI) and periventricular hyperintensity (PVH) observed on brain MRI in a system for detection of asymptomatic brain disease with 1,200 cases. The risk factors (RF), population in each age bracket of ACI and PVH, among groups with hypertension (HTG) and without RF (no-RFG), were investigated. The RF of ACI were hypertension (HT), diabetes mellitus (DM), and aging. Without DM, those are common RF of PVH. The population of PVH and ACI with PVH increased with aging in no -RFG. On the other hand, only the population of ACI with PVH increased with aging in HTG. The rate of these abnormal findings in HTG was significantly higher than that in no-RFG. In addition, HT accelerated the occurrence of these findings by 10-20 years. When patients were over 60 years old, ACI increased rapidly. Accordingly, we concluded that (1) PVH and ACI had a common background. (2) Long term follow up concerning the incidence of ACI in the group with only PVH was necessary. (3) It was desirable that treatment for RF should be effected before the age of sixty.

Rehabilitation of spinal cord injury in the national rehabilitation center for the disabled of Japan: profile of a spinal service

The National Rehabilitation Center for the Disabled (hereunder abbreviated NRC) in Japan was established in 1979. It consists of four divisions: the hospital, the rehabilitation training center, the research institute, and the information service section. The spinal unit has been functioning and cooperating corelatively with all of these divisions. There were 1047 patients with a spinal cord injury treated in the 15 years from September, 1980 to August, 1994; consisting of 924 males (88.3%), and 123 females (11.7%). The breakdown of causes of injury were traffic accidents 44.9%, having a fall 14.7%, sports accidents 6.7%, and other causes of spinal paralysis 10.5%. The sites of the spinal cord lesions were cervical 372 (35.5%), thoracic 547 (52.5%), and lumbar spinal cord 128 patients (12.3%). The incidence of complete paralysis in those with a cervical spinal cord injury (SCI) was 68.8%, and for thoracic and lumbar SCI 79% each. The time for completion of activities of daily living (ADL) was 12.0 +/- 1.54 months in those with tetraplegia, and 5.6 +/- 1.71 months for those with paraplegia. The rate of employment for reentry into society was 59% in those with a cervical spinal cord injury, and 74% each in those with a thoracic or lumbar spinal cord injury.

Simultaneous alignment of optical axes by monitoring reflected light from core and cladding

We propose a method of aligning optical axes by monitoring reflected light from the core and the cladding at the coupling end. This method enables the simultaneous alignment of optical axes at multiple coupling ends because it is not necessary to monitor the transmitted light through the couplings. Experimental results show that this method can be used for coupling between cleaved single-mode fibers and between fibers with slant ends. The simultaneous alignment of two coupling ends is also achieved, and it is shown to obtain the optical power transmitted through the coupling, which is enough to begin the precise alignment. Moreover, we confirm fundamentally that one can use this method for precise alignment of optical axes by monitoring the optical beam profiles of the reflected light.

Free-space optical module configuration using a guide-frame assembly method

A new assembly method is described for easy construction of optical modules consisting of guide frames, spacer frames, and a housing frame. This method is used to assemble a two-dimensional optical-fiber collimator and a digital discrete correlator, which are fundamental parts of free-space optical computing systems. We show that a multistage optical system can be constructed simply by stacking of several optical functional blocks. Moreover, these compact modules do not need a conventional optical bench, they are compact, and assembly time is reduced. We demonstrated by experiment that the accuracy of optical modules assembled with this method is within the specifications of the optical system.

Relationship between functional levels and movement in tetraplegic patients. A retrospective study

The aim of the present study was to set targets for each spinal lesion level after determining the relationship between the spinal lesion level and movement abilities in patients with tetraplegia following injury to the cervical cord. A total of 109 patients, 96 men and 13 women were included in the study. We mainly examined locomotion and transfer capabilities according to Zancolli's classification. The results of this study showed that 50% of the patients classified as C6A, 75% of C6B1 and 96% of the patients classified C6B2 accomplished bed transfer. The number of patients who could manage toilet transfer was 53% in the group classified as C6B1 and 85% in group C6B2. These results suggest that achievement of those classified as C6B2 is a clue to the assumption that the patient will achieve toilet transfer capability and can perform ADL independently.

[The effects of short and long duration of hypothyroidism on prolactin secretion in rats]

The aim of the present study was to evaluate the time-dependent effect of an experimentally induced hypothyroid state on prolactin (PRL) secretion in rats. Treatment with radioactive iodine and propylthiouracil (PTU) resulted in reduced serum concentrations of total thyroxine and triiodothyronine, and increased serum TSH concentrations in rats one week after the start of the treatment. Basal serum PRL concentrations were not significantly altered in 1-, 2- and 4-week hypothyroid rats, whereas in 8-week hypothyroid rats, serum PRL concentrations were significantly reduced and remained depressed throughout 24 weeks of PTU ingestion. The PRL response to i.p. administration of haloperidol (0.5mg/kg) was significantly reduced after one week of PTU ingestion. When the duration of hypothyroidism was increased, there was a progressive fall in the PRL response to haloperidol that reached the lowest value after 12 weeks of PTU ingestion. The PRL response to an i.v. bolus injection of vasoactive intestinal peptide (VIP, 150 mu g/kg) was markedly reduced in hypothyroid rats after one week of PTU ingestion and reached the lowest value after two weeks. The PRL response to VIP was progressively recovered after treatment for 4 weeks with PTU, and reached the highest value in 24-week hypothyroid rats. However, the PRL response to VIP in 24-week hypothyroid rats was significantly lower than that in euthyroid rats. Serum PRL response to an i.v. bolus injection of beta -endorphin (450 mu g/kg) was significantly reduced in 8-week hypothyroid rats. Dopamine (DA) concentrations in the pituitary and the hypothalamus were not significantly altered in 2-week hypothyroid rats. In contrast, DA concentrations were significantly increased in both the pituitary and hypothalamus in 8- and 24-week hypothyroid rats. These findings observed in hypothyroid rats were reversed by the administration of thyroxine and triiodothyronine for 9 days. The present results support a modulatory role for thyroid status in regulating the concentration of DA in the pituitary and the hypothalamus, and consequently on PRL secretion by the pituitary. This suggests that PRL releasing factors do not appear to play a major role in PRL secretion in hypothyroid rats. These data also indicate that alterations in PRL secretion and DA concentrations in the pituitary and the hypothalamus in the hypothyroid state become more prominent as the duration of hypothyroidism increases.

Movement of intrapancreatic calcium in dogs with experimental pancreatic lithiasis. With special reference to the process of pancreatic calculus formation

This study was performed to clarify the movement of calcium in the pancreas of dogs with chronic pancreatitis, using scanning and transmission electron microscopes (SEM, TEM) equipped with X-ray elemental microanalyzers. Eleven adult mongrel dogs underwent incomplete ligation of the pancreatic duct. After the procedure, the levels of pancreatic enzymes in the serum did not change for 9 mo, but the endocrine function was reduced gradually. Of all dogs, 5 revealed pancreatic sclerosis, and 2 at 9 mo had calculi, 2-4 mm in size, in the small pancreatic duct. SEM examination revealed the intralobular fibrosis and irregularity of the pancreatic duct wall, and TEM examination revealed the intralobular fibrosis and irregularity of the pancreatic duct wall, and TEM examination demonstrated the amorphous or crystalloid substances and secreted granules in the acinar lumen or ductule. In elemental analysis spectra using SEM, a high calcium peak was seen in the pancreatic duct wall. In elemental analysis spectra using TEM, a high calcium peak was observed in the amorphous or crystalloid substances, and a high ratio of Ca/K was seen in these substances. Calcium was also detected in the secreted granules or microvilli. These results suggest that there is a process of calculus formation based on the congregation of the intraductular substances containing a large quantity of calcium.

Identification and characterization of a plaque forming avian rotavirus isolated from a wild bird in Japan

From fresh faeces of a wild bird (Melanitta fusca), a virus that showed granular cytopathic effects (CPE) on chicken kidney cell (CKC) cultures was isolated. By indirect immunofluorescence analyses (IFA), this isolate reacted with an antiserum against a bovine rotavirus. The isolate produced clear plaques on CKC by conventional techniques, without trypsin. Three virus plaques were selected by plaque size (small, medium, and large) and cloned by three successive plaque cloning. In the SDS-PAGE analyses, dsRNA bands showed a typical profile of avian rotavirus and quite different from that of avian reovirus. With dsRNA patterns, IFA results, CPE, and a morphological property, the clones were identified as avian rotaviruses of group A rotavirus. The clones killed chicken embryos, when they were inoculated to yolk sac.

Negative inotropic effects of disopyramide on guinea-pig papillary muscles

1. The inhibitory effects of disopyramide on electromechanical responses were investigated in guinea-pig papillary muscles driven by electrical stimuli. Disopyramide up to 10(-5) M did not cause a negative inotropic effect, while the maximum upstroke velocity of the action potential (dV/dtmax) was significantly decreased. 2. At higher concentrations, this drug dose-dependently inhibited the contraction, and dV/dtmax was further decreased. This inhibition of contraction was accompanied by a depression of the slow action potential in partially depolarized preparations by increasing [K+]0 (26 mM). 3. In preparations pretreated with nifedipine (10(-6) M) and ryanodine (10(-6) M), the contraction was almost completely inhibited. In such preparations, ouabain (2 x 10(-6) M) markedly increased the contraction, probably through the Na(+)-Ca2+ exchange mechanism. This contraction was inhibited by disopyramide above 10(-8) M, and an almost complete inhibition was caused at 3 x 10(-5) M. 4. A similar inhibitory effect was observed on the contraction increased by the lowering of [Na+]0 (36 mM). 5. These results suggest that disopyramide at high concentrations inhibits Ca influx through slow Ca2+ channels and at low concentrations, it reduces the contraction increased through the Na(+)-Ca2+ exchange mechanism. Disopyramide had a greater effect on cardiac contractility mediated by the Na(+)-Ca2+ exchange mechanism.

Anticholinergic action of disopyramide in intestinal smooth muscle of the guinea pig: inhibition of muscarinic receptors (M1 and M2)

Antimuscarinic actions of disopyramide were investigated by measuring the contractile responses of intestinal smooth muscles and ligand binding in cardiac and intestinal membrane preparations. Disopyramide caused a parallel shift of the dose-response curves for acetylcholine, McN-A-343, and carbachol to the right in the guinea pig taenia caeci; pA2 values were 5.4 for acetylcholine, 5.5 for McN-A-343 and 5.9 for carbachol. In the guinea pig ileum, disopyramide competitively antagonized acetylcholine in the contractile responses, having the pA2 value of 6.1. In microsomal fractions of the guinea pig taenia caecum and heart, disopyramide was capable of replacing 3H-QNB; K1 values were 7 x 10(-6) M for the taenia and 2 x 10(-6) M for the heart. These results suggest that disopyramide exerts antimuscarinic action through M1 and M2 receptors with a potency approximately 3 times greater for M2 than M1.

Cloning and sequencing of RNA-1 cDNA from cucumber mosaic virus strain O

The complete nucleotide (nt) sequence (3369 nt) of RNA 1 of cucumber mosaic virus strain O (CMV-O) was determined. One open reading frame (ORF; 993 aa) could be deduced from the nt sequence. The homologies of the ORF between CMV-O and CMV-Q or CMV-Fny were calculated to be 85% or 97%, respectively. For CMV-O and CMV-Q, the first one-third of the ORF showed a higher degree of homology (89%), as compared with the other portions (82-85%); the first 224 aa showed more than 93% homology. A comparative study of the three viruses revealed that CMV-O is more homologous to CMV-Fny (subgroup I) [corrected]) than to CMV-Q (subgroup II) [corrected].

Complete nucleotide sequence of RNA 3 from cucumber mosaic virus (CMV) strain O: comparative study of nucleotide sequences and amino acid sequences among CMV strains O, Q, D and Y

The complete nucleotide sequence (2217 residues) of RNA 3 of cucumber mosaic virus strain O (CMV-O) was determined. Two open reading frames were identified, encoding a 3A protein (279 amino acid residues) in the 5'-proximal region and a coat protein (218 amino acid residues). The amino acid sequence of the coat protein C terminus was determined directly from purified protein, and confirmed the presence of the coat protein open reading frame in CMV-O RNA 3. Comparison of nucleotide sequences and amino acid sequences of CMV strains O, Q, D and Y indicated the close relationship between these strains. A tRNA-like structure could be adopted by the 3' non-coding region, and this resembled a similar structure in CMV-Q in spite of nucleotide substitutions or deletions.