Olanzapine increases hepatic glucose production through the activation of hypothalamic adenosine 5'-monophosphate-activated protein kinase.

AIMS: To investigate the mechanism of the metabolic disturbance induced by the atypical antipsychotic olanzapine, we examined whether adenosine 5'-monophosphate-activated protein kinase (AMPK) in the hypothalamus and hepatic glucose production are involved in the effect of olanzapine. METHODS: Male 6-week-old ICR mice were used. Blood glucose levels were determined by the glucose oxidase method. The mRNA levels of gluconeogenic or glycolytic enzymes were measured by reverse transcription polymerase chain reaction (RT-PCR). AMPK expression was measured by Western blotting. RESULTS: Systemic injection of olanzapine increased blood glucose levels in both unfasted and fasted mice. However, the increase in fasted mice was less than that in unfasted mice. Central administration of olanzapine also increased the blood glucose levels in unfasted mice, but not in fasted mice. In a pyruvate tolerance test, olanzapine significantly increased blood glucose levels. In addition, olanzapine increased the mRNA levels of glucose-6-phosphatase (G6Pase), a gluconeogenic enzyme, in the liver. Furthermore, olanzapine increased phosphorylated AMPK in the hypothalamus of unfasted mice, and olanzapine-induced hyperglycaemia was inhibited by the AMPK inhibitor compound C. Central administration of the AMPK activator AICAR significantly increased G6Pase mRNA levels in the liver and blood glucose levels. Moreover, both olanzapine- and AICAR-induced hyperglycaemia were attenuated by the ß-adrenergic receptor antagonist propranolol, suggesting that olanzapine and AICAR induce hepatic glucose production through the sympathetic nervous system. CONCLUSIONS: Our results indicate that olanzapine activates AMPK in the hypothalamus, which increases hepatic glucose production via the sympathetic nervous system.

Human visual cortical function during photic stimulation monitoring by means of near-infrared spectroscopy.

Near-infrared spectroscopy (NIRS) was used to monitor human visual cortical function during and after photic stimulation (PS) in five adult volunteers. Cerebral blood volume (CBV) increased on the occipital surface during PS, but NIRS parameters did not change on the frontal surface. The increase in CBV was caused by a rapid increase in oxyhemoglobin with but a small increase in deoxyhemoglobin, suggesting cerebral vascular dilatation with decreased oxygen consumption. After PS stopped, CBV promptly decreased and then slightly increased again. Cytochrome aa3 did not show any change during and after PS. These phenomena reappeared following repeated PS in all five subjects. These results may represent the first step in the development of NIRS imaging.

Characterization of genes encoding multi-domain proteins in the genome of the filamentous nitrogen-fixing Cyanobacterium anabaena sp. strain PCC 7120.

Computational analysis of gene structures in the genome of Anabaena sp. PCC 7120 revealed the presence of a large number of genes encoding proteins with multiple functional domains. This was most evident in the genes for signal transduction pathway and the related systems. Comparison of the putative amino acid sequences of the gene products with those in the Pfam database indicated that and PAS domains which may be involved in signal recognition were extremely abundant in Anabaena: 87 GAF domains in 62 ORFs and 140 PAS domains in 59 ORFs. As for the two-component signal transduction system, 73, 53, and 77 genes for simple sensory His kinases, hybrid His kinases and simple response regulators, respectively, many of which contained additional domains of diverse functions, were presumptively assigned. A total of 52 ORFs encoding putative Hanks-type Ser/Thr protein kinases with various domains such as WD-repeat, GAF and His kinase domains, as well as genes for presumptive protein phosphatases, were also identified. In addition, genes for putative transcription factors and for proteins in the cAMP signal transduction system harbored complex gene structures with multiple domains.

Structure of extracellular polysaccharides of Escherichia coli strains 36M, 72M, and 29M isolated from coligranuloma of chick intestine. I. Polysaccharide from E. coli 36M.

An extracellular polysaccharide was isolated from culture broth of Escherichia coli 36M, and fractionated on a column of Sephadex G-150 into two fractions; the high molecular weight portion (85% of the total polysaccharide) contained pyruvic acid, and showed a positive immune reaction with anti-Ps-I-serum obtained from a rabbit. The low molecular weight portion (15% of the total polysaccharide) showed a negative immune reaction. The methylation, Smith's degradation, partial acid hydrolysis and methanolysis of the higher molecular weight polysaccharide revealed a repeating structure as follows: (see article).

Prostaglandin synthesis in human cancer cells: influence of fatty acids and butyrate.

Previous research has suggested that prostaglandins (PGs) may play a role in the development of colon cancer since tumor cells produce more PGs than normal cells. However, the exact mechanism by which PGs play a role in the development of cancer is not known. In addition, factors that influence PG synthesis are not known since they are complicated by the presence of homeostatic mechanisms. To avoid the homeostatic mechanisms, the present research was designed to examine factors that may influence PG synthesis in an in vitro system, i.e., a tissue culture. We have chosen two human colon cancer cell lines that differ in their ability to metabolize long-chain fatty acids (LCFAs), LS174T cells and HT-29 cells. We examined the effect of LCFAs on their membrane fatty acid composition, growth, and ability to release the main PGs (PGE2 and PGI). The LCFAs used were those most common in the colonic lumen [18:0, 18:2 (n-6), and 18:3 (n-3)]. In addition, we examined the effect of butyrate on the above mentioned parameters. Butyrate is produced in the colon through fermentation of dietary fibers. The data obtained suggest that although both of these tumor cell lines are of human colonic origin, they differ in their response to LCFAs and butyrate in some of the characteristics studied, such as growth, composition of membranes, and the relationship between membrane FA composition and PG synthesis. Polyunsaturated fatty acid supplementation stimulated the growth of HT-29 cells but not of LS174T cells when compared with growth in media supplemented with 18:0.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of chemoembolization therapy for primary liver cancer using a stabilized adriamycin-lipiodol suspension.

We formulated a new lipiodol-Adriamycin suspension (ADM/lipiodol, 50 mg/10 ml) that remained stable for 48 h (half-life, 25 +/- 3 days). In five cases of hepatocellular carcinoma (HCC) resected after intra-arterial infusion of this agent, the ADM concentration in the tumor was quite high and the tumor necrosis rate was more than 80% on histological examination. Over a 5-year period, 180 patients with unresectable HCC underwent transcatheter arterial embolization therapy (TAE) in the presence or absence of this agent. The regimens consisted of suspension injection alone (A, n = 54), suspension injection + TAE using gelatin sponge (B, n = 29), TAE followed by suspension injection (C, n = 34), and TAE alone (D, n = 63). The estimated 1-year survival values determined for patients treated with these regimens were 70%, 73%, 43%, and 39% respectively, and the corresponding 3-year survival values were 27%, 31%, 15%, and 10%. The survival achieved using suspension injection was thus superior to that obtained using conventional TAE, and combined therapy with suspension injection followed by TAE seemed to enhance survival, although there were some biases in tumor size and in the stage of tumor progression. For patients with tumors measuring 5 cm or more in diameter, the survival obtained using regimen A was lower than that achieved using regimen D, but the combination of TAE and suspension injection improved the 1-year survival value obtained using regimen D from 34% to 52%. For patients with tumors measuring less than 5 cm in diameter, the survival achieved using regimen A was markedly better than that obtained using regimen D, although no difference was found between the survival value achieved using regimen A and that obtained using regimens B and C. On the basis of these results, our newly formulated ADM-lipiodol suspension was surmised to be effective by itself against relatively small HCC tumors, whereas it enhanced the efficacy of conventional TAE in large lesions.

Developmental immunohistochemistry of bifunctional protein in human brain.

Immunohistochemical studies of a peroxisomal enzyme, bifunctional protein, were performed on human brains (occipital cortex, cerebellum, pons) from fetus to young adult. Bifunctional protein-positive neurons appeared at 23-25 weeks of gestation in the facial nuclei of pons, at 27-28 weeks in the occipital cortex and Purkinje cells of vermis, and at 36-38 weeks in the Purkinje cells of the cerebellar hemisphere and pontine nuclei. They then increased in number with gestational age. However, bifunctional protein-positive glia appeared early in the occipital deep white matter at 17-20 weeks of gestation, their appearance shifting from the deep to the superficial white matter with increasing age. These results suggest that bifunctional protein is closely related to neuronal maturation and gliogenesis of premyelination in the human brain during development as other peroxisomal enzymes.

Effect of bongkrekic acid, a product of Pseudomonas cocovenenans, on thiol proteases.

The in vitro effect of bongkrekic acid on stem bromelain, papain and ficin was studied. The hydrolysis of casein by these enzymes was inhibited by bongkrekic acid, but the inhibition was always incomplete even with a large excess of the effector. Using a fully activated specimen of stem bromelain, purified on an organomercurial agarose affinity column, the inhibition by bongkrekic acid was not stoichiometric. The SH group of cysteine remained intact after incubation with an excess of bongkrekic acid at 24 degrees C for 20 min. However, partial inhibition of stem bromelain by bongkrekic acid was reversed by incubation at 37 degrees C for 5 min with 5mM cysteine or 2-mercaptoethanol. Ethylene glycol and glycerol had no such restorative effect. These results indicate that molecules of bongkrekic acid are non-covalently bound to a thiol protease, only partially and reversibly shielding its essential SH group.

Responses of cerebral blood volume and oxygenation to carotid ligation and hypoxia in young rabbits: near-infrared spectroscopy study.

After ligation of the bilateral common carotid arteries with exposure to hypoxia in young rabbits, cerebral blood oxyhemoglobin, deoxyhemoglobin, and total hemoglobin were measured by near-infrared spectroscopy. Ligation of common carotid arteries decreased oxyhemoglobin, increased deoxyhemoglobin, and slightly decreased total hemoglobin. Exposure to hypoxia with bilateral carotid ligation more remarkably decreased oxyhemoglobin and increased deoxyhemoglobin than that without carotid ligation. However, the total cerebral blood volume did not change very much. This marked reduction in the cerebral oxygenation may cause brain damage and may be an important monitoring marker for the prevention of hypoxic-ischemic encephalopathy.

A case of infantile spasms: epileptic apnea as partial seizures at onset.

We report a 2-month-old boy who presented with apneic attacks as a manifestation of epileptic seizures at onset and eventually progressed to infantile spasms. At onset, at 2 months of age, apneic attacks were the sole symptom of epileptic fits. Although these seizures were accompanied by cyanosis, bradycardia was not noted. An ictal electroencephalogram showed focal paroxysmal discharges in the temporal area. Treatment with sodium valproate was not effective to control his seizures. By 6 months of age, he progressed to infantile spasms. Although his seizures could be completely controlled with the use of zonisamide, vitamin B6 or high-dose immunoglobulin, his mental and behavioral development was retarded severely. There have been no previously published cases with infantile spasms that evolved from epileptic apnea as partial seizures.

Olivocerebellar retrograde trans-synaptic degeneration from the lateral cerebellar hemisphere to the medial inferior olivary nucleus in an infant.

The neuropathological study of an infant with severe perinatal asphyxia showed specific neuronal loss in the medial part of the inferior olivary nucleus and the lateral part of the cerebellar hemisphere. This distribution suggests that the partial loss of olivary neurons is due to trans-synaptic degeneration from contralateral cerebellar hemispheric lesions, immunohistochemistrically demonstrated by axonal loss and swelling of neurofilaments.

Successful control with bromide of two patients with malignant migrating partial seizures in infancy.

A 3-month-old male and a 4-month-old female infant with intractable seizures were diagnosed as having malignant migrating partial seizures in infancy (MMPSI) with developmental arrest on the basis of characteristics of symptoms, clinical courses and EEGs. We treated these two patients with potassium bromide (80 mg/kg) after conventional antiepileptic drugs failed to adequately control the seizures. The potassium bromide therapy resulted in complete control of seizures in one patient, and more than 95% reduction in seizure frequency in the other.

Siblings of Schwartz-Jampel syndrome with abnormal muscle computed tomographic findings.

Schwartz-Jampel syndrome (SJS) is a disorder characterized by myotonia, joint contractures, skeletal abnormalities, facial dysmorphism and growth retardation. We present two boys of ages 4 and 8 years with SJS. Their clinical, electromyographic and histopathological findings were similar to those described, except for computed tomography (CT) images that revealed diffuse high attenuation in sternocleidomastoid muscles and low attenuation in the paraspinal, quadriceps, sartorius, soleus and gastrocnemius muscles. This is the first report describing abnormal muscle CT findings associated with SJS. Additional studies of muscle CT might help to improve understanding of the pathogenesis of SJS.

Abnormal dendritic development in maple syrup urine disease.

The neuropathology of a 6-year-old boy with maple syrup urine disease revealed spongy appearance of the white matter and marked edema of the brainstem. Golgi studies demonstrated aberrant orientation of neurons together with abnormalities of dendrites and dendritic spines. Similar changes were observed in a patient with dihydropteridine reductase deficiency. Disorders of amino acid metabolism may be associated with alterations in the terminal stages of neuronal migration and maturation.

Clinicopathologic studies on leptomeningeal glioneuronal heterotopia in congenital anomalies.

Leptomeningeal glioneuronal heterotopia was observed in 40 of 129 autopsied infants (31%). It was present in 49% of patients who had congenital anomalies in general and in 65% of patients who had central nervous system malformations. Most of the leptomeningeal glioneuronal heterotopias appeared in the base of the brain (62.5%), midbrain (40%), frontal lobe (37%), and pons (35%). Leptomeningeal glioneuronal heterotopia is closely related to migration disorders on the basis of frequent association with polymicrogyria or neuronal heterotopias.

Developmental change in type VI collagen in human cerebral vessels.

Vascular development in the human brain was studied by immunohistochemistry using an anti-type VI collagen antibody. Positive vessels were evident from an early gestational age in the meninges, from 21 weeks gestation in the basal ganglia and deep white matter, and from 38 weeks gestation in the cerebral cortex and superficial white matter; however, type VI collagen never appeared in the subependymal germinal layer. The absent or scarce type VI collagen in the subependymal germinal layer may be one of the important factors of subependymal/intraventricular/periventricular hemorrhage in premature neonates. The earlier appearance of positive vessels in the deep white matter than in the cortex and superficial white matter suggests that the medullary vein develops earlier than the cortical and subcortical veins and arteries. These characteristics of the developing vascular structure may be one cause of perinatal brain damage.

Immunohistochemistry for a bifunctional protein in patients with peroxisomal disorders.

Immunohistochemical studies using antisera against bifunctional protein, a beta-oxidation enzyme, were performed on liver, kidney, and brain tissue specimens from patients with peroxisomal disorders and from controls to investigate the distribution and development of peroxisomes. Bifunctional protein-positive granules were not found in patients with Zellweger syndrome or neonatal adrenoleukodystrophy, whereas positive immunoreactivity was observed from 8 and 6 weeks gestation in the liver and kidney, respectively, and in the brain, from 23-25 weeks in the brainstem neurons and from 12-14 weeks in the white matter glia, in controls. Bifunctional protein immunoreactivity then increased with gestation in the brain. These results suggest that bifunctional protein immunohistochemistry is useful for the detection of peroxisomes, which are closely related to neuronal maturation and gliogenesis in premyelination in human brain development.

Vitamin B2 activity of 7,8-dimethyl-10-(2,3,4-trihydroxy-4-formylbutyl)isoalloxazine in Lactobacillus casei.

The microbial activities of vitamin B2-aldehyde and vitamin B2-acid, produced by Schizophyllum commune, a Basidiomycete, were studied. Lactobacillus casei ATCC No. 7469 was used as a test microorganism. B2-aldehyde exhibited a good response curve in the growth of L. casei. B2-acid had neither a stimulatory nor an inhibitory effect on the growth. When B2-aldehyde was incubated with the homogenate of L. casei, it was converted to riboflavin. The flavin formed from B2-aldehyde by the homogenate not only exhibited an equivalent response curve to authentic riboflavin in the growth of L. casei, but also showed the same Rf value as authentic riboflavin in any paper chromatogram, as far as tested. Hence, the microbial activity of B2-aldehyde for L. casei seems to be ascribable to riboflavin which is a reduction product of B2-aldehyde.

Characterization of water-insoluble proteins in normal and cataractous human lens.

The mechanism of lens protein aggregation with age and/or cataract formation was investigated using the peptides resolubilized from the insoluble protein fraction of normal and cataractous human lenses. The insoluble fraction was treated with reductants for cleaving disulfide bonds, or with chelating agents for removing calcium ions from the aggregates. This study demonstrates that the insoluble protein aggregates consist of an approximately 400 Kd complex, which is formed by the peptides with lower molecular weight. Protein aggregation in the cataractous lens might be caused by disulfide bonds whereas, in aging, the aggregate might be preferentially formed by calcium ion bridges rather than by disulfide bonds. It was observed that the aggregate from the cataractous lenses involved a peptide with a molecular mass lower by 1 Kd or 2 Kd than the peptides found in the normal lens. The composition of crystallins in aggregating proteins and their secondary structures were also different in the normal and the cataractous lenses. Such changes of molecular weight, conformation, and/or crystallin species in the lens may lead to the disintegration of the orderly arrangement of crystallins, resulting in the diffused reflection and lens opacities which are seen in senile cataract.

Characterization of peptide inducing cataractogenesis in lens of hereditary cataractous rat (ICR/f RAT).

A material with inhibitory action to Na+/K+ ATPase was found in the lens of the ICR/f rat, a recessive hereditary cataractous rat. The material also induced lens opacification in vitro. From the results of amino acid analysis and by secondary ion mass spectroscopy, it was suggested that the material might contain approximately equimolar amounts of four amino acids, ie, aspartic acid, serine, glutamic acid and glycine, and that the molecular weight was 444. These facts suggested that this material with Na+/K+ ATPase inhibitory action might be a peptide. However, there is not yet any corroborating evidence to show whether this peptide is only a single material or not. The peptide significantly increased with aging in the lens of the ICR/f rat until approximately 90 days, when cataract became manifest, but its content decreased thereafter. This study suggests that one of the causes of cataractogenesis in the ICR/f rat might be this peptide, which is transformed in the lens with aging, and also that the peptide might accelerate lens opacification after cataractogenesis.