Sequences of cDNAs for human salivary and pancreatic α-amylases

The nucleotide sequences of the cloned human salivary and pancreatic α-amylase cDNAs correspond to the continuous mRNA sequences of 1768 and 1566 nucleotides, respectively. These include all of the amino acid coding regions. Salivary cDNA contains 200 bp in the 5′-noncoding region and 32 in the 3′-noncoding region. Pancreatic cDNA contains 3 and 27 bp of 5′- and 3′-noncoding regions, respectively. The nucleotide sequence humology of the two cDNAs is 96% in the coding region, and the predicted amino acid sequences are 94% homologous.Comparison of the sequences of human α-amylase cDNAs with those previously obtained for mouse α-amylase genes (Hagenbuchle et al., 1980; Schibler et al., 1982) showed the possibility of gene conversion between the two genes of human α-amylase.     

Effects of fat content in the diet on hepatic peroxisomes of the rat

Effects of fat content in the diet on rat liver peroxisomes was examined. In the livers of rats fed for one week on the high-fat diet containing 30% fat, the cyanide-insensitive palmitoyl-CoA oxidation was accelerated to eight times that of control and the enzymic activities of catalase, carnitine acetyltransferase and carnitine palmitoyltransferase were elevated by the factors of 1.3, 5 and 2, respectively. In contrast, the activities of D-amino acid oxidase in addition to the three enzymes mentioned above were all lowered by 20% when the animals were maintained on a fat-free diet for the same period of time. It appears that the high-fat diet-induced increase in the activity of carnitine palmitoyltransferase is a result of the raised activity of this enzyme in mitochondria only while the apparent high activity reflects stimulation of carnitine acetyltransferase in all the subcellular fractions. Another notable effect of the high-fat diet was a remarkable increase in the quantity of a peroxisome-associated polypeptide which was separable by sodium dodecyl sulfate polyacrylamide gel electrophoresis. It is noteworthy that this effect of the high-fat diet resemble that of clofibrate. If the diet was deprived of fat, however, this polypeptide species, with an estimated molecular weight of 80 000, decreased to a level slightly lower than normal. On the basis of the electron micrographic criteria, the high-fat diet provoked a marked proliferation of hepatic peroxisomes.     

Participation of peroxisomes in lipid biosynthesis in the harderian gland of guinea pig.

Peroxisomal enzyme activities in the guinea-pig harderian gland, which has a unique lipid composition, were studied. Activities of catalase, acyl-CoA oxidase and the cyanide-insensitive acyl-CoA beta-oxidation system in this tissue were comparable with those in rat liver. The activities of dihydroxyacetone phosphate acyltransferase (DHAPAT, EC 2.3.1.42) and alkyl-DHAP synthase (EC 2.5.1.26) were appreciable, and the distributions of both activities were consistent with that of sedimentable catalase activity. Glycerol-3-phosphate acyltransferase (GPAT, EC 2.3.1.15), which is localized in both microsomes (microsomal fractions) and mitochondria in the rat liver, was a peroxisomal enzyme in the harderian gland, though the activity was only about one-tenth of the DHAPAT activity. These enzymes had different pH profiles and substrate specificity. The existence of high activities of enzymes of the acyl-DHAP pathway in peroxisomes suggests the physiological significance of peroxisomes in the biosynthesis of glycerol ether phospholipid and 1-alkyl-2,3-diacylglycerol in the guinea-pig harderian gland.     

An algorithmic approach to constructing the on-line estimation system for the specific growth rate

The objective of this article is to propose an algorithm for the on-line estimation of the specific growth rate in a batch or a fed-batch fermentation process. The algorithm shows the practical procedure for the estimation method utilizing the macroscopic balance and the extended Kalman filter. A number of studies of the on line estimation have been presented. However, there are few studies discussing about the selection of the observed variables and for the tuning of some parameters of the extended Kalman filter, such as covariance matrix and initial values of the state.The beginning of this article is devoted to explain the selection of the observed variable. This information is very important in terms of the practical know-how for using technique. It is discovered that the condition number is a practically useful and valid criterion for number is a practically useful and valid criterion for choosing the variable to be observed.Next, when the extended Kalman filter in applied to the online estimation of the specific growth rate, which is directly unmeasurable, criteria for judging the validity of the estimated value from the observed data are proposed. Based on the proposed criterial, the system equation of the specific growth rate is selected and initial value of the state variable and covariance matrix of the system noises are adjusted. From many experiments, it is certified that the specific growth rate in the batch or fed -batch fermentation can be estimated accurately by means of the algorithm proposed here. In these experiments, that is, when the cell concentration is measured directly, the extended Kalman filter using the convariance matrix with a constant element can estimate more accurately values of the specific growth rate than the adaptive extended Kalman filter does.     

Occurrence of a novel cardiac natriuretic peptide in rats

We established a specific radioimmunoassay for the ring structure of "iso-ANP" and detected iso-ANP[23-46]-like immunoreactivity (-LI) in the rat atrium (2.76 +/- 0.5 micrograms/g) and ventricle (13.9 +/- 5.7 ng/g). High performance-gel permeation chromatography revealed that iso-ANP[23-46]-LI in the rat heart was composed of two components with molecular weights of 10K and 5K. In reverse phase-high performance liquid chromatography, the retention times of these components were clearly different from that of synthetic iso-ANP. The 5K peptide was demonstrated to be present in the perfusate from isolated rat hearts and possessed binding ability to ANP receptors. This natriuretic peptide was, however, not detectable in other tissues including the brain. We conclude that the novel cardiac natriuretic peptide distinct from iso-ANP and ANP occurs in the rat heart and is secreted from the heart.     

Isolation and sequence determination of rat cardiac natriuretic peptide

We have isolated a cardiac natriuretic peptide of 5K daltons from the rat atrium and determined its amino acid sequence. The 5K cardiac natriuretic peptide was elucidated to be a 45-amino acid peptide with the sequence of S-Q-D-S-A-F-R-I-Q-E-R-L-R-N-S-K-M-A-H-S-S-S-C-F-G-Q-K-I-D-R-I-G-A-V-S-R- L-G-C-D - G-L-R-L-F by sequencing the native peptide and its lysyl endopeptidase digests. The sequence of this peptide was identical to the amino acid sequence [51-95] of the rat brain natriuretic peptide (BNP) precursor deduced from the cDNA sequence. The 5K cardiac natriuretic peptide, or BNP[51-95], was identified as the major storage and secretory form derived from the BNP precursor in the rat heart.     

Endothelin in human plasma and culture medium of aortic endothelial cells--detection and characterization with radioimmunoassay using monoclonal antibody

We have developed monoclonal (KY-ET-1-I) and polyclonal (ET-F5) antibodies against endothelin-1 (ET-1) and established sensitive radioimmunoassays (RIAs) with different specificities. The RIA with KY-ET-1-I detected ET-1, ET-2 and ET-3, while the RIA with ET-F5 recognized ET-3 very weakly. Using these RIAs, we have investigated the concentration and molecular forms of ET-1-like immunoreactivity (-LI) in culture medium of bovine aortic endothelial cells and human plasma. Culture medium of endothelial cells contained two major components compatible with big ET and ET-1. ET-1-LI was also detected in human plasma. ET-1-LI in human plasma consisted of apparent two components, the small molecular form emerging at the position of ET-1 and the large form with the peak eluting at the preceding fraction of the elution position of big ET. The concentration of the small form of ET in human plasma was about 5 pg/ml.     

Detection and characterization of endothelin-1-like immunoreactivity in rat plasma

Using two radioimmunoassays (RIAs) for endothelin-1 (ET-1) with and without a substantial cross-reactivity with ET-3, we have measured the plasma ET-1-like immunoreactivity (-LI) level in rat plasma. ET-1-LI was detected in plasma from male Wistar rats. ET-1-LI in rat plasma consisted of three components with molecular weights of 6K, 4K and 2.5K daltons by gel permeation chromatography. Two of the components were eluted at positions of big ET (4K) and synthetic ET-1 (2.5K). The remaining component was eluted at the preceding fraction (6K). No difference was observed in ET-1-LI of the small molecular form of ET (2.5K) between the two RIAs. Thus, there is little or no ET-3 in rat plasma, which has the sequence found originally in the rat genome. The concentration of the small molecular form of ET, presumably ET-1, in rat plasma was about 4 pg/ml.     

Maternal care in the red-headed spruce web-spinning sawfly,Cephalcia isshikii (Hymenoptera: Pamphiliidae)

We describe oviposition and maternal behavior in the sawfly Cephalcia isshikiiand examine the adaptive significance of this behavior. Females deposited eggs in a single but loose cluster on needles of terminal twigs of spruces, Piceaspp., and remained with the eggs usually on the underside of the twig facing toward the tip. The female attended her eggs until death without taking food but did not follow the first-instar larvae that moved from natal needles even if she survived until then. When the female was disturbed, she usually moved toward the source and attempted to bite it. Though at much lower frequencies, this aggressive behavior was also observed in gravid females and even in males. Field observations and female removal experiments indicated that the female enhanced the survival of the eggs through the reduction of arthropod prédation.     

Acute pulmonary alveolar hypoxia increases lung and plasma endothelin-1 levels in conscious rats.

To investigate the effect of pulmonary alveolar hypoxia on the synthesis and release of endothelin (ET)-1, ET-1-like immunoreactivity (-LI) levels of the lung and plasma were measured in conscious unrestrained rats under hypoxic conditions. Sixty-min exposure to alveolar hypoxia (10% O2 or 5% O2) increased the ET-1-LI level in the lung. The plasma ET-1-LI level in hypoxic rats also increased significantly. The increase of plasma and lung ET-1-LI levels were parallel to the severity of hypoxia. These results demonstrates that acute pulmonary alveolar hypoxia increases lung and plasma ET-1-LI levels in conscious unrestrained rats, suggesting a possible physiological or pathophysiological significance of ET in alveolar hypoxia.