A novel differentiation factor for PC12 cells from culture supernatant of mouse hepatocyte cell line MLE-15A2

We have found a factor that induces neurite outgrowth of rat PC12 cells in the culture supernatant of the cell line MLE-15A2. This factor was designated as MDDF. The factor was sensitive to protease, dithiothreitol, and high-temperature treatments. The apparent molecular mass was 80 kDa on Superdex 200 gel filtration. No significant tyrosine phosphorylation was detected after MDDF stimulation in Western blotting analysis with anti-phosphotyrosine antibody, suggesting that the signal transduction may not be mediated by a tyrosine kinase cascade that is involved in signaling of most of the known factors. Activation of MAP kinase was very weak and was seen only 5 min after stimulation, suggesting that prolonged activation of MAP kinase was not required for neurite outgrowth induced by MDDF. Because the biochemical characteristics of MDDF are different from those of any known peptide factors that induce neurite outgrowth of PC12 cells, MDDF may be a novel differentiation factor for PC12 cells.

Molecular and biochemical characterization of three anthocyanin synthetic enzymes from Gentiana triflora

Full length cDNA clones of flavonoid 3',5'-hydroxylase, dihydroflavonol 4-reductase and flavonoid 3-glucosyltransferase were cloned from petals of Gentiana triflora. Their sequences were homologous to counterparts from other plants. Flavonoid 3',5'-hydroxylase and flavonoid 3-glucosyltransferase were enzymatically characterized by expressing cDNAs in heterologous expression systems.

Dominant negative effect of the truncated p110 subunit of phosphatidylinositol-3 kinase

Effects of p110, the catalytic subunit of PI-3 kinase, on induction of TPA response element-driven promoter by EGF was examined. The induction was enhanced by co-expression of the wild type of p110. The truncated p110 mutants containing the binding site for p85 but missing the catalytic activity repressed the induction. A mutant with no binding activity to p85 did not show this effect. These results suggest that PI-3 kinase is involved in signal transduction of EGF and that the truncated p110s capable of binding to p85 serves as a dominant negative reagent for PI-3 kinase.

Species identification by the positional analysis of fatty acid composition in triacylglyceride of adipose and bone tissues

In a new attempt at species identification, the total composition and positional distribution of fatty acid in triacylglyceride (TG) of adipose and bone tissues were analyzed in human, bovine, pig, dog, cat and chicken tissues. Although the total fatty acid compositions of bovine and pig tissues were significantly different from those of human (different in more than half the fatty acids tested), dog, cat and chicken tissues showed a comparatively similar composition to human fatty acids composed of TG in both tissues. The TG in these tissues was also subjected to stereospecific analysis using pancreatic lipase, that is, the fatty acid distribution in positions 1,3 (not distinguished between 1 and 3) and 2 of the TG were determined. The distribution of fatty acids among the positions 1,3 and 2 in the TG of animal adipose and bone tissues was non-random. The distribution between position 2 and positions 1,3 seems to be governed by chain length and unsaturation in each animal. The shorter and more unsaturated fatty acids showed a greater tendency to occupy position 2 of TG. Although this rule appeared in all animals except the pig, the distribution of each fatty acid into position 2 was species-specific. The positional distribution of fatty acid in TG was identical among the same species and in different regions of the same body. Thus, even when species identification is difficult using the pattern of total fatty acid composition, the analysis of the positional distribution of fatty acid makes it possible to determine the species. From the present results, the evaluation of positional distribution of fatty acid in the TG is a useful tool for the identification of human tissues.

Effects of postnatal cocaine on differentiation of the rat corpus callosum

We investigated the effects of cocaine on the development of the corpus callosum. Pregnant Wistar strain rats (Thirteenth day of gestation) were used in this study. On the day following birth, litters were culled to 8 pups (4 males and 4 females), and rats were assigned to either a control or drug treatment group. From postnatal day 1 (P1, at birth = P0) to P5, cocaine (50 mg/kg) was subcutaneously injected to the cocaine-treated pups, and saline in the same volume to the control pups. Animals were sacrificed in 110 days and a mid-sagittal section of the callosum was obtained. From this section the morphometric measurement of the corpus callosum was performed. In the control group the rat corpus callosum has a sex difference with the male corpus callosum being larger than the female's. But this sex difference disappeared in the cocaine group. This was attributed to the fact that cocaine-treated male rats indicated a significant reduction of callosal area. These findings suggest that the early postnatal cocaine can abolish the sexual differentiation of the corpus callosum.

Study of secondary flow in centrifugal blood pumps using a flow visualization method with a high-speed video camera

Four pump models with different vane configurations were evaluated with flow visualization techniques using a high-speed video camera. These models also were evaluated through in vivo hemolysis tests using bovine blood. The impeller having the greatest fluid velocity relative to the impeller, the largest velocity variance, and the most irregular local flow patterns in the flow passage caused the most hemolysis. Even if the pumps were operated at almost the same speed (rpm) at the same output, the impeller showing more irregular flow patterns had a statistically greater rate of hemolysis. This fact confirms that the existence of local irregular flow patterns in a centrifugal blood pump deteriorates its hemolytic performance. Thus, to optimize the design of the pump, it is very important to examine the secondary flow patterns in the centrifugal blood pump in detail using flow visualization with a high-speed video camera.

Purification and characterization of the phosphatidylinositol-3,4,5-trisphosphate phosphatase in bovine thymus

Using phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] prepared from phosphatidylinositol 4,5-bisphosphate and inositolphospholipid 3-kinase, we identified in bovine thymus extracts the enzyme activity which catalyzed dephosphorylation of PtdIns(3,4,5)P3, to produce phosphatidylinositol biphosphate. Since bovine thymus exhibited the highest level of activity among tissues screened, we tried to purify this enzyme PtdINs(3,4,5)P3 phosphatase from bovine thymus. After sequential chromatographies using S-Sepharose, heparin-Sepharose, blue Sepharose, and Toyopearl HW55, the enzyme was purified 1875-fold with a yield of 10%. SDS/PAGE analysis revealed that a 120-kDA protein band copurified with the enzyme activity. The apparent molecular mass of the active protein was 120 kDa on size-exclusion chromatography, suggesting that the 120-kDa band on SDS/PAGE is the PtdIns(3,4,5)P3 phosphatase. Since PtdIns(3,4,5)P3 phosphatase seemed to be the only activity that metabolized PtdIns(3,4,5)P3, and the enzyme did not hydrolyze phosphatidylinositol 4,5-biphosphate, the enzyme may play a critical role in the inositolphospholipid 3-kinase signalling.

Effects of postnatal exposure to cocaine on the development of the rat corpus callosum

We investigated the effects of cocaine on the development of the corpus callosum in rats. From postnatal days 1 (P1) to 10 (birth = P0), cocaine (10 mg/kg) was subcutaneously injected in the pups, and saline, at the same volume, was administered to control pups. The animals were sacrificed at 110 days of age and a midsagittal section of the callosum was obtained. Morphometric measurement of the corpus callosum was performed in this section. In the control group, but not in the cocaine group, males had larger callosa than females. The cocaine treatment significantly decreased the total callosal area in male rats. These findings indicate that early postnatal cocaine abolishes the sexual differentiation of the corpus callosum.

Two phosphorylations specific to the tail region of the 204-kDa heavy chain isoform of porcine aorta smooth muscle myosin

In a porcine aorta extract, we observed two protein kinase activities which specifically phosphorylate the 204-kDa heavy chain isoform of aorta myosin in the absence of conventional kinase activators. We referred to these two protein kinases, eluted at 0.15 and 0.2 M KCl from a DEAE-column, as myosin kinases I (MKI) and II (MKII), respectively. The phosphorylation site for MKI was determined using a purified phosphopeptide derived from porcine aorta myosin phosphorylated with MKI. By comparison with the deduced amino acid sequence for smooth muscle myosins, the site corresponded to a Ser located at 3 amino acids upstream from a Pro, the putative end of the alpha-helical segment of the 204-kDa heavy chain tail. A homologous Ser is only present in smooth muscle myosins, i.e. not in nonmuscle myosins. MKI was purified 130-fold, but not separated from a kinase activity phosphorylating Ser1 or Ser2 in the 20-kDa regulatory light chain of aorta myosin. In contrast, MKII was purified to near homogeneity. MKII phosphorylated the porcine aorta myosin heavy chain at a Ser 19 amino acids downstream from the MKI site. The amino acid sequence around the Ser shared a consensus sequence of the phosphorylation site. The amino acid sequence around the Ser shared a consensus sequence of the phosphorylation site for casein kinase II and was homologous to that reported for bovine aorta myosin [Kelley, C.A. and Adelstein, R.S. (1990) J Biol. Chem. 265, 17876-17882]. MKII was identified as a multifunctional protein kinase, casein kinase II.

Death caused by undiagnosed acute pancreatitis

A fatal case of acute pancreatitis is reported. On account of difficulty in eating caused by persistent dysphagia and heartburn, the clinical condition of a 39-year-old man who had been a heavy drinker deteriorated rapidly. He was taken to a hospital in an ambulance in an unconscious state. Based on the endoscopic examination and blood chemistry data, the diagnosis of hemorrhagic esophagitis and hepatic failure was made. Treatment including fluid infusion was unsuccessful and he died on the second hospital day. Based on a strong suspicion that the pathologic change in the esophagus may have been chemical esophagitis caused by corrosives of some type, the police ordered an administrative autopsy. The postmortem examination revealed marked necrosis in the pancreas and in the abdominal fatty tissue including the omentum and the mesentery. The necrotic areas in the pancreas were accompanied by only a slight degree of hemorrhage. The cause of death was diagnosed as acute pancreatitis. The pathologic change in the esophagus was identified as Candida esophagitis. Alcohol abuse and malnutrition caused by esophagitis were both considered to be factors which lead to the acute fatal pancreatitis.

A comparative study on developmental capacity to blastocysts derived from 1-and 2(3)-cell bovine embryos after in vitro maturation and fertilization

The present study was conducted to compare the developmental capacity of 1-and 2(3)-cell embryos after 18 and 30 h of fertilization, and blastocyst cell number and in vitro survival after freezing and thawing of bovine blastocysts derived from the 1-and 2-cell embryos. Oocytes were matured and fertilized by conventional IVM/IVF methods. After 18 or 30 h of fertilization, 1-cell embryos (18 h-fertilization) or 1- and 2(3)-cell embryos (30 h-fertilization) were cultured for 8 or 10 d in synthetic oviduct fluid medium (SOFM) supplemented with 10% human serum (HS), minimum essential medium (MEM) essential or nonessential amino acids and glutamine. The separate culture of 1- and 2(3)-cell embryos after 30 h of fertilization showed higher (p < 0.01) cleavage, development to expanded and hatched blastocysts than culture of 1-cell embryos after 18 h of fertilization. Two-cell embryos of 30 h-fertilization group had higher developmental capacity to expanded and hatched blastocysts than 1-cell embryos at 18 or 30 h after insemination (Experiment I). However, there was no significant difference in the mean cell number of blastocysts derived from the culture of 1-cell and 2(3)-cell embryos, respectively (Experiment II). The in vitro survival or hatching after freezing and thawing of blastocysts was significantly affected by embryonic quality before freezing, but did not significantly differ with blastocysts derived from 1- and 2(3)-cell embryos after 18 or 30 h of fertilization. The results indicate that the culture of 2(3)-cell embryos after 30 h of fertilization is an effective method to produce more transferable embryos (blastocysts) in bovine IVM, IVF and IVC techniques.

Role of chaos in trial-and-error problem solving by an artificial neural network

One role of chaotic neural activity is illustrated by means of computer simulations of an imaginary agent's goal-oriented behavior. The agent has a simplified neural network with seven neurons and three legs. The neuronal network consists of one photosensory neuron and three pairs of inter- and motor neurons. The three legs whose movements are governed by the three motor neurons allow the agent to walk in six concentric radial directions on a plane. It is intended that the neural network causes the agent to walk in a direction of greater brightness, to reach finally the most brightly lit place on the plane. The presence of only one sensory neuron has an important meaning. That is, no immediate information on directions of greater brightness is sensed by the agent. In other words, random walking in the manner of trial- and error problem solving must be involved in the agent's walking. Chaotic firing of the motor neurons is intended to play a crucial role in generating the random walking. Brief random walking and rapid straight walking in a direction of greater brightness were observed to occur alternately in the computer simulation. Controlled chaos in naturally occurring neural networks may play a similar role.

The basic amino acid transporter (rBAT)-like immunoreactivity in paraventricular and supraoptic magnocellular neurons of the rat hypothalamus

In the rat hypothalamus, the basic amino acid transporter (rBAT)-like immunoreactivity was analyzed by immunohistochemistry using an antibody against the 15-amino acid sequence of the deduced rat rBAT protein. In the supraoptic and the paraventricular nuclei, magnocellular neurons exhibited the marked rBAT-like immunoreactivity in intracellular structures but not in the plasma membrane. The results suggest that the rBAT serves as an intracellular amino acid transport system in magnocellular neurons.

EGF or PDGF receptors activate atypical PKClambda through phosphatidylinositol 3-kinase

Overexpression of a TPA-insensitive PKC member, an atypical protein kinase C (aPKClambda), results in an enhancement of the transcriptional activation of TPA response element (TRE) in cells stimulated with epidermal growth factor (EGF) or platelet-derived growth factor (PDGF). EGF or PDGF also caused a transient increase in the in vivo phosphorylation level and a change in the intracellular localization of aPKClambda from the nucleus to the cytosol, indicating the activation of aPKClambda in response to this growth factor stimulation. These immediate signal-dependent changes in aKPClambda were observed for a PDGF receptor add-back mutant (Y40/51) that possesses only two of the five major autophosphorylation sites and binds PI3-kinase, and were inhibited by wortmannin, an inhibitor of PI3-kinase. Furthermore, an N-terminal fragment of the catalytic subunit of PI3-kinase, p110alpha, inhibited aPKClambda-dependent activation of TRE in Y40/51 cells stimulated with PDGF. Overexpression of p110alpha resulted in an enhancement of TRE expression in response to PDGF and the regulatory domain of aPKClambda inhibited this TRE activation in Y40/51 cells. These results provide the first in vivo evidence supporting the presence of a novel signalling pathway from receptor tyrosine kinases to aPKClambda through PI3-kinase.

Evidence that cytochrome P-4502E1 contributes to ethanol elimination at low doses: effects of diallyl sulfide and 4-methyl pyrazole on ethanol elimination in the perfused rat liver

The roles of cytochrome P-4502E1 and alcohol dehydrogenase (ADH) on ethanol (EtOH) hepatic elimination was examined in the perfused rat liver. EtOH concentration-time curves of outflow after instantaneous administration (0.46 mg) through the portal vein with or without perfusion of diallyl sulfide (DAS), a selective cytochrome P-450E1 inhibitor, and/or 4-methyl pyrazole (4-MP), a classical ADH inhibitor, were analyzed by the statistical moment analysis and the compartment dispersion model. Recovery ratios obtained by moment analysis significantly changed with perfusion of inhibitors (p < 0.01). Values of the hepatic volume of distribution and the relative dispersion were significantly higher by the perfusion of DAS and 4-MP (p < 0.01). In the two-compartment dispersion model, the partition ratio (K') and the first-order elimination constant (K0) were decreased significantly by DAS (p < 0.05). By the addition of 4-MP, the blood volume of distribution (VB) and the backward partition rate constant (k21) were increased significantly (p < 0.05). K sigma values were decreased significantly to 0 (p < 0.001). The decrease of elimination rates by DAS and/or 4-MP shows the inhibition of metabolic pathways. The change of V beta and k21 caused by DAS and 4-MP indicates that EtOH taken into hepatic tissues was not metabolized and flowed out into the perfusates. Inhibition rates calculated from the efficiency number with addition of DAS and DAS + 4-MP were 40.7 and 99.3%. Therefore, cytochrome P-4502E1 and ADH accounted for 40 and 60% of the hepatic EtOH elimination at low doses.

Prenatal diagnosis of abdominal wall defects and their prognosis

To determine whether associated anatomic features may be useful in predicting fetal prognosis, 43 fetuses who had ultrasonographic evaluation for abdominal wall defects during a 13-year period were reviewed. Thirty-one fetuses had omphalocele and were classified into three groups according to fetal ultrasonography results: ruptured omphalocele with exposed liver, giant omphalocele with exposed liver, and small omphalocele without liver herniation. Twelve fetuses had gastroschisis. Ten of the 12 fetuses with gastroschisis survived; one died in utero. Nine of the 12 with a small omphalocele survived. Ten of 12 fetuses with giant omphalocele survived, but six of the seven with ruptured omphalocele died of pulmonary hypoplasia and respiratory insufficiency. Ruptured omphalocele recognized in utero was accompanied by intrauterine growth retardation and liver herniation and frequently was associated with deformity of the spine, diaphragmatic defects, vesicointestinal fissure, and meningocele. These results indicated that, together with the deformity of the spine, rupture and absence of the covering membrane with an exposed liver (noted through fetal ultrasonography) may suggest a poor prognosis because of pulmonary hypoplasia.

Hepatic saturation mechanism of ethanol: application of mathematical models to ethanol outflow profiles in the perfused rat liver

The saturation mechanism of hepatic ethanol (EtOH) elimination was studied in the perfused rat liver. EtOH outflow profiles after the instantaneous administration of 3 (mg/ml) x 0.4(ml), 12 x 0.1, 24 x 0.1, and 3 x 0.1 mg (as a dose concentration x a volume) through the portal vein were analyzed by the statistical moment analysis and mathematical models (i.e., dispersion models). Results for 3 x 0.1 and 12 x 0.1 mg doses by moment analysis were similar. This demonstrated that the elimination exhibits linear kinetics. Recovery ratio and hepatic volume of distribution for 3 x 0.4 and 24 x 0.1 mg were larger than those for 3 x 0.1 and 12 x 0.1 mg doses and were similar. Kinetics after administration of 3 x 0.4 and 24 x 0.1 mg may be nonlinear. A difference in the relative dispersion (CV2) obtained by moment analysis between 3 x 0.4 and 24 x 0.1 mg doses indicated different properties of the nonlinear elimination kinetics. There were no differences in all the parameters in the one-compartment dispersion model between 3 x 0.4 and 24 x 0.1 mg doses. In the two-compartment dispersion model, there were differences in the blood volume (VB) and the forward partition rate constant (k12) between 3 x 0.4 and 24 x 0.1 mg (p < 0.05), whereas the elimination rate constant (k sigma) and the dispersion number values for these doses were similar. These findings demonstrated that there is difference in the no-equilibrium process between 3 x 0.4 and 24 x 0.1 mg doses. Therefore, we suggest that the continuous EtOH input into the liver causes the saturation of enzyme pathways and the change of the nonequilibrium process.

Karyotype of the Sea Anemone Aiptasiomorpha sp. (Anthozoa, Actiniaria) From Japan

In the Anthozoa, only one karyological study has been performed, namely, a study of the coral Goniopora lobata (2n = 28) by a "squash" method (1) and no information about the chromosomes of a sea anemone has been presented apart from a recent preliminary report of the diploid chromosome number and the complement of chromosomes of Haliplanella lineata (= H. luciae) (2n = 32), which were examined by an air-drying method (2). Morphological details of the chromosomes were not provided. The present study is the first attempt at karyotypic analysis in Actiniaria, a poorly studied order of Coelenterata (3-6). The karyotype of Aiptasiomorpha sp. was determined by conventional Giemsa-stained preparations of early embryos. This species has 2n = 32 chromosomes, consisting of 14pairs of biarmed chromosomes and 2 pairs of chromosomes having one arm or with the second arm extremely small. The presence of two large metacentric pairs characterizes the karyotype of Aiptasiomorpha species.

Role of brain cocaethylene levels in combined cocaine-ethanol lethality in mice

The purpose of this study was to examine the lethal effects of combining cocaine with ethanol in mice by assaying for cocaethylene at the time of death. After the voluntary oral ingestion of ethanol in the form of a liquid diet containing 35% ethanol-derived calories for 5 days, intraperitoneal cocaine (60 mg/kg) was administered daily for up to 5 days while the ethanol diet continued (ethanol diet group). The mice in the ethanol diet group were paired with control mice that received a control liquid diet containing equivalent carbohydrate calories in the form of sucrose instead of ethanol (control diet group). In order to analyze the drugs, samples (blood, liver and brain) were collected for both groups from the dead animals that could not tolerate the 5 days of cocaine administration. A higher rate of lethality was observed in the ethanol diet group as compared to the control diet group. Furthermore, various patterns of cocaine lethality were revealed under different conditions of ethanol intake. According to the survival times after the last cocaine administration, observed respiratory and locomotive disorders, and drug concentrations, a total of 5 subgroups in the ethanol diet group (Groups E1-E5) and a total of 3 subgroups in the control diet group (Groups C1-C3) were differentiated. The ratio of the mean cocaethylene concentration relative to the mean cocaine concentration was over 30% in the livers of animals in an earliest lethal subgroup (Group E1). In addition, examination of all of the dead animals in the ethanol diet group revealed the prolonged presence of cocaethylene in the brain of the mice that died within 2 hours. Thus, it was suggested that cocaethylene has strong effects on the brain receptors and influences cocaine lethality.

Platelet-derived growth factor activates protein kinase C epsilon through redundant and independent signaling pathways involving phospholipase C gamma or phosphatidylinositol 3-kinase

Protein kinase C (PKC), a major cellular receptor for tumor-promoting phorbol esters and diacylglycerols (DGs), appears to be involved in a variety of cellular functions, although its activation mechanism in vivo is not yet fully understood. To evaluate the signaling pathways involved in the activation of PKC epsilon upon stimulation by platelet-derived growth factor (PDGF) receptor (PDGFR), we used a series of PDGFR "add-back" mutants. Activation of a PDGFR mutant (Y40/51) that binds and activates phosphatidylinositol 3-kinase (PI 3-kinase) caused translocation of PKC epsilon from the cytosol to the membrane in response to PDGF. A PDGFR mutant (Y1021) that binds and activates phospholipase C gamma (PLC gamma), but not PI 3-kinase, also caused the PDGF-dependent translocation of PKC epsilon. The translocation of PKC epsilon upon stimulation of PDGFR (Y40/51) was inhibited by wortmannin, an inhibitor of PI 3-kinase. Activation of PKC epsilon was further confirmed in terms of PKC epsilon-dependent expression of a phorbol 12-tetradecanoate 13-acetate response element (TRE)-luciferase reporter. Further, purified PKC epsilon was activated in vitro by either DG or synthetic phosphatidylinositol 3,4,5-trisphosphate. These results clearly demonstrate that PKC epsilon is activated through redundant and independent signaling pathways which most likely involve PLC gamma or PI 3-kinase in vivo and that PKC epsilon is one of the downstream mediators of PI 3-kinase whose downstream targets remain to be identified.

In vivo dynamics of myosin II in Dictyostelium by fluorescent analogue cytochemistry

We used fluorescent analogue cytochemistry to study in vivo dynamics of myosin II in Dictyostelium discoideum. We labeled myosin with biotin or tetramethyl-rhodamine iodoacetamide (IATR). The labeled myosin shows normal activities as reversible filament assembly and Ca2+ and actin-activatable Mg(2+)-ATPase. We used the biotin-myosin as a probe examining the effects of microinjection on the amoebae and the ability to associate with endogenous actin cytoskeleton. The biotin-myosin incorporates into certain actin populations and localizes to the cortex with the highest accumulation in the posterior end of polarized amoebae. The dynamics in live amoebae were probed by TR-myosin. We monitored the dynamics for a long period to determined the dynamic reorganization corresponding specific cellular behaviors. The TR-myosin converges into a discrete actin- and myosin-rich structure located at the posterior end ("myosin-organizing center"). The rod-shaped TR-myosin exhibits linear orderly arrays emanating from the organizing center which extend about two-thirds of the cell length. The myosin arrays show a dynamic reorganization when the amoebae move. To examine if the observed myosin dynamics are related to filamentous (F-) actin, we disrupted the F-actin by cytochalasin D. The ratioed image of TR-myosin (vs. FITC-dextran) demonstrates that myosin in these cells accumulates in the cortex but does not form the organizing center. Overall, the results suggest that the filamentous myosin organizes into orderly arrays in the live cytoplasm and its translocation occurs by means of F-actin cables, converging into the organizing center.