Induction of midbrain dopaminergic neurons from ES cells by stromal cell-derived inducing activity

We have identified a stromal cell-derived inducing activity (SDIA) that promotes neural differentiation of mouse ES cells. SDIA accumulates on the surface of PA6 stromal cells and induces efficient neuronal differentiation of cocultured ES cells in serum-free conditions without use of either retinoic acid or embryoid bodies. BMP4, which acts as an antineuralizing morphogen in Xenopus, suppresses SDIA-induced neuralization and promotes epidermal differentiation. A high proportion of tyrosine hydroxylase-positive neurons producing dopamine are obtained from SDIA-treated ES cells. When transplanted, SDIA-induced dopaminergic neurons integrate into the mouse striatum and remain positive for tyrosine hydroxylase expression. Neural induction by SDIA provides a new powerful tool for both basic neuroscience research and therapeutic applications.

The woodchuck hepatitis virus X gene is important for establishment of virus infection in woodchucks

All mammalian hepadnaviruses possess a gene, termed X, that encodes a protein capable of transactivating virus gene expression. The X gene overlaps the polymerase and precore genes as well as two newly identified open reading frames (ORFs) termed ORF5 and ORF6. In this investigation, we examined whether ORF5, ORF6, and the X gene were important for the replication of woodchuck hepatitis virus (WHV) in susceptible woodchucks. First, we investigated whether proteins were produced from ORF5 and ORF6 by in vitro translation of appropriate viral transcripts, searched for antibodies against the putative proteins in the sera of animals infected with wild-type virus, and looked for an antisense WHV transcript, necessary for expression of a protein from ORF6, in the livers of acutely or chronically infected woodchucks. All such experiments yielded negative results. Next, we used oligonucleotide-directed mutagenesis to introduce termination codons into ORF5 and ORF6 at two locations within each ORF. Adult woodchucks in groups of three were transfected with one of the four mutant genomes. All of these woodchucks developed WHV infections that were indistinguishable from those of animals transfected with the wild-type WHV recombinant. Polymerase chain reaction amplification and direct DNA sequencing confirmed that reversion of the mutants to a wild-type genotype did not occur. Taken together, these data indicate that ORF5 and ORF6 are not essential for virus replication and are unlikely to represent authentic genes. Finally, we generated five WHV X-gene mutants that either removed the initiation codon for protein synthesis or truncated the carboxyl terminus of the protein by 3, 16, 31, or 52 amino acids. Groups of three adult woodchucks were transfected with one of the five X-gene mutants. Only the mutant that possessed an X gene lacking 3 amino acids from the carboxyl terminus was capable of replication within the 6-month time frame of the experiment. In contrast, all seven woodchucks transfected with wild-type WHV DNA developed markers consistent with viral infection. Thus, it is likely (P < 0.01) that the WHV X gene is important for virus replication in the natural host.

A missense mutation of the Na+ channel alpha II subunit gene Na(v)1.2 in a patient with febrile and afebrile seizures causes channel dysfunction

Generalized epilepsy with febrile seizures plus (GEFS+), a clinical subset of febrile seizures (FS), is characterized by frequent episodes beyond 6 years of age (FS+) and various types of subsequent epilepsy. Mutations in beta1 and alpha(I)-subunit genes of voltage-gated Na(+) channels have been associated with GEFS+1 and 2, respectively. Here, we report a mutation resulting in an amino acid exchange (R188W) [corrected] in the gene encoding the alpha-subunit of neuronal voltage-gated Na(+) channel type II (Na(v)1.2) in a patient with FS associated with afebrile seizures. The mutation R188W [corrected] occurring on Arg(187), a highly conserved residue among voltage-gated Na(+) channels, was not found in 224 alleles of unaffected individuals. Whole-cell patch clamp recordings on human embryonic kidney (HEK) cells expressing a rat wild-type (rNa(v)1.2) and the corresponding mutant channels showed that the mutant channel inactivated more slowly than wild-type whereas the Na(+) channel conductance was not affected. Prolonged residence in the open state of the R188W [corrected] mutant channel may augment Na(+) influx and thereby underlie the neuronal hyperexcitability that induces seizure activity. Even though a small pedigree could not show clear cosegregation with the disease phenotype, these findings strongly suggest the involvement of Na(v)1.2 in a human disease and propose the R188W [corrected] mutation as the genetic defect responsible for febrile seizures associated with afebrile seizures.

Transplantation of human neural stem cells for spinal cord injury in primates

Recent studies have shown that delayed transplantation of neural stem/progenitor cells (NSPCs) into the injured spinal cord can promote functional recovery in adult rats. Preclinical studies using nonhuman primates, however, are necessary before NSPCs can be used in clinical trials to treat human patients with spinal cord injury (SCI). Cervical contusion SCIs were induced in 10 adult common marmosets using a stereotaxic device. Nine days after injury, in vitro-expanded human NSPCs were transplanted into the spinal cord of five randomly selected animals, and the other sham-operated control animals received culture medium alone. Motor functions were evaluated through measurements of bar grip power and spontaneous motor activity, and temporal changes in the intramedullary signals were monitored by magnetic resonance imaging. Eight weeks after transplantation, all animals were sacrificed. Histologic analysis revealed that the grafted human NSPCs survived and differentiated into neurons, astrocytes, and oligodendrocytes, and that the cavities were smaller than those in sham-operated control animals. The bar grip power and the spontaneous motor activity of the transplanted animals were significantly higher than those of sham-operated control animals. These findings show that NSPC transplantation was effective for SCI in primates and suggest that human NSPC transplantation could be a feasible treatment for human SCI.

Metabolic inactivation of retinoic acid by a novel P450 differentially expressed in developing mouse embryos

Retinoic acid (RA) is a physiological agent that has a wide range of biological activity and appears to regulate developmental programs of vertebrates. However, little is known about the molecular basis of its metabolism. Here we have identified a novel cytochrome P450 (P450RA) that specifically metabolizes RA. In vitro, P450RA converts all-trans RA into 5,8-epoxy all-trans RA. P450RA metabolizes other biologically active RAs such as 9-cis RA and 13-cis RA, but fails to metabolize their precursors, retinol and retinal. Overexpression of P450RA in cell culture renders the cells hyposensitive to all-trans RA. These functional tests in vitro and in vivo indicate that P450RA inactivates RA. The P450RA gene is not expressed uniformly but in a stage- and region-specific fashion during mouse development. The major expression domains in developing embryos include the posterior neural plate and neural crest cells for cranial ganglia. The expression of P450RA, however, is not necessarily inducible by excess RA. These results suggest that P450RA regulates the intracellular level of RA and may be involved in setting up the uneven distribution of active RA in mammalian embryos.

Helical polyacetylene synthesized with a chiral nematic reaction field

Helical polyacetylene was synthesized under an asymmetric reaction field consisting of chiral nematic (N*) liquid crystals (LCs). The chiral nematic LC was prepared by adding a chiroptical binaphthol derivative as a chiral dopant to a mixture of two nematic LCs. Acetylene polymerizations were carried out using the catalyst titanium tetra-n-butoxide-triethylaluminum dissolved in the chiral nematic LC solvent. The polyacetylene film was shown by scanning electron microscopy to consist of clockwise or counterclockwise helical structure of fibrils. A Cotton effect was observed in the region of the pi --> pi* transition of the polyacetylene chain in circular dichroism spectra. The high electrical conductivities of approximately 1500 to 1800 siemens per centimeter after iodine doping and the chiral helicity of these films may be exploited in electromagnetic and optical applications.

Congenital malformations due to antiepileptic drugs

To identify the major risk factors for the increased incidence of congenital malformations in offspring of mothers being treated for epilepsy with antiepileptic drugs (AEDs) during pregnancy and, to determine the relative teratogenic risk of AEDs, we prospectively analyzed 983 offspring born in Japan, Italy, and Canada. The incidence of congenital malformations in offspring without drug exposure was 3.1%, versus an incidence with drug exposure of 9.0%. The highest incidence in offspring exposed to a single AED occurred with primidone (PRM; 14.3%), which was followed by valproate (VPA; 11.1%), phenytoin (PHT; 9.1%), carbamazepine (CBZ; 5.7%), and phenobarbital (PB; 5.1%). The VPA dose and level positively correlated with the incidence of malformations. This study first determined a cut-off value of VPA dose and level at 1000 mg/day and 70 microg/ml, respectively, to avoid the occurrence of malformations. The incidence of malformations increases as the number of drugs increases, and as the total daily dose increases. Specific combinations of AEDs such as VPA + CBZ and PHT + PRM + PB produced a higher incidence of congenital malformations. The incidence of malformations was not associated with any background factors studied except for the presence of malformations in siblings. These results indicate that the increased incidence of congenital malformations was caused primarily by AEDs, suggesting that malformations can be prevented by improvements in drug regimen, and by avoiding polypharmacy and high levels of VPA (more than 70 microg/ml) in the treatment of epileptic women of childbearimg age.

Interleukin-6 and interleukin-8 levels in serum and synovial fluid of patients with osteoarthritis

Concentrations of interleukin (IL)-6 and IL-8 in serum and synovial fluid obtained from patients with osteoarthritis (OA) of the knee were determined by the chemiluminescence-ELISA (CL-ELISA) method, the sensitivity of which is 100-1,000 times greater than that of the conventional ELISA method. The results were compared with those obtained from patients with rheumatoid arthritis (RA) and from healthy subjects. The mean IL-6 and IL-8 levels in synovial fluid indicated higher concentrations in RA than in OA. The IL-6 and IL-8 levels in serum were significantly higher in RA and OA relative to controls. Among OA patients in whom remarkable improvement was noted in hydrarthrosis, the synovial fluid IL-6 and IL-8 levels at the initial examination were relatively higher, and were markedly decreased after treatment with sodium hyaluronate (NaHA). Among those in whom no improvement was noted in hydrarthrosis, the synovial fluid IL-6 and IL-8 levels at the time of initial examination were relatively lower, and hydrarthrosis was not significantly improved even after treatment with NaHA. In addition, there was a tendency for the synovial fluid IL-6 and IL-8 levels to decrease as HA levels increased. Evaluation of X-ray findings revealed that the IL-6 levels in synovial fluid at the initial examination in low-grade cases tended to be significantly higher than in high-grade cases. In low-grade cases, as determined by X-ray findings, there was a significant decrease in IL-6 levels in synovial fluid after treatment with NaHA.

The gene encoding a newly discovered protein, chorein, is mutated in chorea-acanthocytosis

Chorea-acanthocytosis is a neurodegenerative disorder with peripheral red cell acanthocytosis. Linkage of chorea-acanthocytosis to chromosome 9q21 has been found. We refined the locus region and identified a previously unknown, full-length cDNA encoding a presumably structural protein, which we called chorein. We found a deletion in the coding region of the cDNA leading to a frame shift resulting in the production of a truncated protein in both alleles of patients and in single alleles of obligate carriers.

Detection of serum hepatitis B virus DNA in patients with chronic hepatitis using the polymerase chain reaction assay

We compared the sensitivity of the polymerase chain-reaction (PCR) assay to that of slot-blot hybridization for detecting hepatitis B virus (HBV) DNA in the serum of 31 patients with chronic hepatitis. Of 14 chronic hepatitis patients positive for both HBV surface and HBV e antigens, 9 were positive for HBV DNA by slot-blot hybridization and all 14 by PCR. Also, of 9 patients positive for HBV surface antigen and antibody against HBV e antigen, 2 were positive for HBV DNA by slot-blot analysis and 8 by PCR. Finally, in 8 patients positive for HBV DNA by slot-blot hybridization, but 4 were positive by PCR. We find that analysis by the PCR technique provides a greater than 10(4)-fold increase in sensitivity over the slot-blot hybridization assay. This result represents an important breakthrough in sensitivity because it is now possible to detect as few as three HBV DNA genomes per sample of serum.

RNA-dependent RNA polymerase activity of the soluble recombinant hepatitis C virus NS5B protein truncated at the C-terminal region

The hepatitis C virus (HCV) NS5B protein encodes an RNA-dependent RNA polymerase (RdRP), which is the central catalytic enzyme of HCV replicase. We established a new method to purify soluble HCV NS5B in the glutathione S-transferase-fused form NS5Bt from Escherichia coli which lacks the C-terminal 21 amino acid residues encompassing a putative anchoring domain (anino acids 2990-3010). The recombinant soluble protein exhibited RdRP activity in vitro which was dependent upon the template and primer, but it did not exhibit the terminal transferase activity that has been reported to be associated with the recombinant NS5B protein from insect cells. The RdRP activity of purified glutathione S-transferase-NS5Bt and thrombin-cleavaged non-fused NS5Bt shares most of the properties. Substitution mutations of NS5Bt at the GDD motif, which is highly conserved among viral RdRPs, and at the clustered basic residues (amino acids 2919-2924 and 2693-2699) abolished the RdRP activity. The C-terminal region of NS5B, which is dispensable for the RdRP activity, dramatically affected the subcellular localization of NS5B retaining it in perinuclear sites in transiently overexpressed mammalian cells. These results may provide some clues to dissecting the molecular mechanism of the HCV replication and also act as a basis for developing new anti-viral drugs.

Ablation of cerebellar Golgi cells disrupts synaptic integration involving GABA inhibition and NMDA receptor activation in motor coordination

The role of inhibitory Golgi cells in cerebellar function was investigated by selectively ablating Golgi cells expressing human interleukin-2 receptor alpha subunit in transgenic mice, using the immunotoxin-mediated cell targeting technique. Golgi cell disruption caused severe acute motor disorders. These mice showed gradual recovery but retained a continuing inability to perform compound movements. Optical and electrical recordings combined with immunocytological analysis indicated that elimination of Golgi cells not only reduces GABA-mediated inhibition but also attenuates functional NMDA receptors in granule cells. These results demonstrate that synaptic integration involving both GABA inhibition and NMDA receptor activation is essential for compound motor coordination. Furthermore, this integration can adapt after Golgi cell elimination so as not to evoke overexcitation by the reduction of NMDA receptors.

Protective effects of 1α,25-(OH)2D3 against the neurotoxicity of glutamate and reactive oxygen species in mesencephalic culture

This study was undertaken to determine whether 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)(2)D(3)], an active metabolite of vitamin D, protects dopaminergic neurons against the neurotoxic effects of glutamate and dopaminergic toxins using rat mesecephalic culture. Brief glutamate exposure elicited cytotoxicity in both dopaminergic and non-dopaminergic neurons. Pretreatment, but not co-administration, of 1 alpha,25-(OH)(2)D(3) protected both types of neurons against the cytotoxicity of glutamate in a concentration- and time-dependent manner. The neuroprotective effect of 1 alpha,25-(OH)(2)D(3) was inhibited by the protein synthesis inhibitor, cycloheximide. To investigate the mechanisms of these neuroprotective effects, we examined the effects of 1 alpha,25-(OH)(2)D(3) on neurotoxicity induced by calcium ionophore and reactive oxygen species (ROS). Pretreatment with 1 alpha,25-(OH)(2)D(3) protected both types of neurons against the cytotoxicity induced by A23187 in a concentration-dependent manner. Furthermore, 24-h pretreatment with 1 alpha,25-(OH)(2)D(3) concentration-dependently protected both types of neurons from ROS-induced cytotoxicity. A 24-h incubation with 1 alpha,25-(OH)(2)D(3) inhibited the increase in intracellular ROS level following H(2)O(2) exposure. A 24-h exposure to 1-methyl-4-phenylpyridium ion (MPP(+)) or 6-hydroxydopamine (6-OHDA) exerted selective neurotoxicity on dopaminergic neurons, and these neurotoxic effects were ameliorated by 1 alpha,25-(OH)(2)D(3). These results suggest that 1 alpha,25-(OH)(2)D(3) provides protection of dopaminergic neurons against cytotoxicity induced by glutamate and dopaminergic toxins by facilitating cellular functions that reduce oxidative stress.

Cloning and expression of a cDNA for the rat kappa-opioid receptor

We cloned a cDNA for the rat kappa-opioid receptor from a rat thalamus cDNA library. The deduced amino acid sequence consists of 380 residues with features shared by members of the G protein-coupled receptor family. The specific binding of [3H]bremazocine to the membrane of COS-7 cells transfected with the cDNA was displaced by kappa-specific opioid ligands, but not by mu- and delta-specific ligands. Xenopus oocytes injected with the in vitro transcribed mRNA responded to opioid ligands with the same subtype specificity. Northern blot analysis demonstrated that kappa-opioid receptor mRNA is expressed in a regionally specific manner in rat brain.

Rapid and sensitive method for the detection of serum hepatitis B virus DNA using the polymerase chain reaction technique

We have developed a rapid procedure for the detection of serum hepatitis B virus (HBV) DNA using the polymerase chain reaction (PCR) technique. HBV DNA is released from virions by incubating serum with 0.1 M NaOH for 60 min at 37 degrees C. The mixture is brought to neutral pH with HCl, and the HBV DNA sequences are detected by agarose gel electrophoresis and ethidium bromide staining after PCR amplification with two successive sets of primer pairs. The detection limit of this method (i.e., 10(-5) pg of HBV DNA) is equivalent to that previously determined by one round of PCR amplification and Southern blot hybridization analysis. The advantages are that the assay can be completed in 1 day, is very sensitive, and does not require the use of radiolabeled reagents.

Noradrenergic inhibition of the release of substance P from the primary afferents in the rabbit spinal dorsal horn

To investigate pre-synaptic influence of the descending noradrenergic system on the primary afferents containing substance P (SP), effects of noradrenergic manipulations on the in situ release of immunoreactive SP (iSP) from the dorsal horn were examined in the thalamic rabbit. Local application of noradrenaline (10 microM) to the dorsal horn produced complete inhibition of the noxious mechanical stimuli-evoked release of iSP. This effect was reversed by yohimbine (the more selective alpha 2-blocker, 10 microM) and partially antagonized by prazosin (the more selective alpha 1-blocker, 10 microM). The resting release of iSP was not affected by noradrenaline. The noxious mechanical stimuli-evoked release of iSP was significantly increased by acute spinal transection and local application of yohimbine (10 microM) alone to the dorsal horn. Prazosin (10 microM) slightly increased the evoked iSP release, and a beta-blocker metoprolol did not affect it. These results suggest that the nociceptive primary afferents containing SP are tonically inhibited by the descending noradrenergic system linked to alpha-adrenoceptors, and that such alpha-adrenoceptors located on the primary afferent terminals may be one of the sites of action of noradrenaline spinal analgesia. In contrast to the evoked iSP release, the resting iSP release was increased only by acute spinal transection and not by yohimbine, prazosin and metoprolol. All these observations suggest that tonic inhibition in propriospinal neurons containing SP is mediated by a non-noradrenergic system.

Nicotine protects cultured cortical neurons against glutamate-induced cytotoxicity via alpha7-neuronal receptors and neuronal CNS receptors

We examined the effects of nicotine on glutamate-induced cytotoxicity using primary cultures of rat cortical neurons. The cell viability decreased significantly when cultures were exposed to glutamate for 10 min and then incubated with glutamate-free medium for 1 h. The exposure of cultures to nicotine (10 microM) for 8-24 h prior to glutamate application ameliorated the glutamate-induced cytotoxicity, with no significant effect of nicotine alone on the cell viability. Neuroprotection by nicotine was dependent on the incubation period. alpha-bungarotoxin (alpha-BTX) and methyllycaconitine (MLA), both of which are alpha7-neuronal receptor antagonists, and dihydro-beta-erythroidine (DHbetaE), a neuronal central nervous system (CNS) receptor antagonist, each significantly antagonized the protection by nicotine against glutamate-induced cytotoxicity. Ionomycin, a calcium ionophore, and S-nitrosocysteine (SNOC), a nitric oxide (NO) donor, also induced cytotoxicity in a manner similar to glutamate. Nicotine protected cultures against ionomycin-induced cytotoxicity, but not against SNOC-induced cytotoxicity. These results suggest that nicotine protects cultured cortical neurons against glutamate-induced cytotoxicity via alpha7-neuronal receptors and neuronal CNS receptors by reducing NO-formation triggered by Ca2+ influx.

Teratogenicity of antiepileptic drugs: analysis of possible risk factors

To determine the primary factors responsible for the increased incidence of malformation in the off-spring of antiepileptic drug (AED)-treated epileptic mothers, special attention was paid to drug combinations in a prospective study of 172 deliveries. Variables used for analysis were eight antiepileptic drugs (AEDs) and total daily dosages (drug score), and seven background factors consisting of maternal age at delivery, gravida, outcome of previous pregnancy, etiology and type of epilepsy, occurrence of seizures in the first trimester of pregnancy, and seizure frequency during pregnancy. The overall rate of malformation was 14.0%. Thirty-one patients were administered a single drug, and the rate of malformation was 6.5%. The remaining 141 patients were treated with multiple AEDs, and the rate of malformation was 15.6%. The drug score of the latter group was significantly higher than the former (p = 0.01). There was no definite dose-dependent increase in the incidence of malformations associated with any individual AEDs. There was no relationship between the type of defect and individual AEDs. Wilcoxon rank-sum test revealed significant association between the drug score, valproate (VPA), and congenital malformation. Carbamazepine (CBZ) also reached an almost significant level. Furthermore, VPA polypharmacy produced the highest incidence of malformation, higher than that produced by any other AED or drug combination. There was no significant association between the presence of malformations and the other putative risk factors. These results suggest that high dose of AEDs reflecting polypharmacy, VPA polypharmacy in particular, are primary factors responsible for the increased incidence of congenital malformation in the offspring of treated epileptic mothers.

A novel mutation of CHRNA4 responsible for autosomal dominant nocturnal frontal lobe epilepsy

OBJECTIVE

To identify the mutation responsible for autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) in a nonwhite family.

BACKGROUND

ADNFLE is newly recognized as an entity of idiopathic partial epilepsy. Recently, two different mutations of the neuronal nicotinic acetylcholine receptor alpha4 subunit (CHRNA4) gene were identified in a white family as a cause of ADNFLE.

METHODS

Four affected and three unaffected individuals in three generations of a Japanese family with ADNFLE, and 100 unrelated healthy Japanese volunteers were studied. Clinical features and EEG findings in affected individuals were consistent with those of ADNFLE reported in white families with ADNFLE. Mutations within the CHRNA4 gene were screened for using single-strand conformation polymorphism analysis (SSCA) and were determined by direct sequencing. The mutation identified was sought in volunteers by the amplification refractory mutation system.

RESULTS

A C-to-T exchange (C755T) was found in exon 5 of the CHRNA4 gene on one allele of affected individuals. C755T segregated in affected individuals and was not found in 200 alleles obtained from the volunteers. C755T replaced serine 252 (Ser252) in the second membrane-spanning domain (M2) of CHRNA4 with a leucine. Ser252 is conserved characteristically in the alpha-subunit of acetylcholine receptor and is considered to play an important role in channel function.

CONCLUSION

C755T is a novel missense mutation of the CHRNA4 gene causing autosomal dominant nocturnal frontal lobe epilepsy in this Japanese family.

Exercise and aspirin increase levels of circulating gliadin peptides in patients with wheat-dependent exercise-induced anaphylaxis

BACKGROUND

Food-dependent exercise-induced anaphylaxis (FDEIA) is an allergic reaction characteristically induced by intense exercise combined with the ingestion of causative food. Recent reports have shown that aspirin intake is a contributing factor in some patients with FDEIA. Wheat is known to be the most frequent causative food, and the IgE-binding epitopes of a major wheat allergen (omega-5 gliadin) in wheat-dependent exercise induced anaphylaxis (WDEIA) have already been clarified. However, the mechanism of eliciting the symptom in WDEIA remains not fully understood.

OBJECTIVES

The aim of this study was to examine the relationship of serum gliadin levels and allergic symptoms induced by exercise or aspirin in patients with WDEIA.

METHODS

Six patients with a history of recurrent anaphylaxis associated with wheat ingestion were diagnosed as having WDEIA by the provocation test, which included wheat ingestion, exercise, aspirin intake and a combination of these challenges. During the tests, serum levels of gliadins were monitored by gliadin-specific sandwich ELISA. The effects of exercise and aspirin on serum gliadin levels were also investigated in four healthy subjects.

RESULTS

Immunoreactive gliadins appeared in the sera of patients during the provocation test with both wheat-exercise and wheat-aspirin challenges in parallel with allergic symptoms. Serum gliadin levels also increased under the two same challenge conditions in the healthy subjects, although they exhibited no allergic symptoms. However, low levels of gliadin were detected in the sera of both patients and healthy subjects when challenged with wheat alone.

CONCLUSION

We demonstrated for the first time that blood gliadin levels correlate with clinical symptoms induced by exercise and aspirin in patients with WDEIA. These findings suggest that exercise and aspirin facilitate allergen absorption from the gastrointestinal tract.

Prognostic value of c-erbB-2 protein expression in human lung adenocarcinoma and squamous cell carcinoma

203 primary human lung tumours, of which 119 were adenocarcinoma and 84 were squamous cell carcinoma, were investigated immunohistochemically for the expression of c-erbB-2 protein. Positive staining was evident in 33 (28%) of adenocarcinomas and 2 (2%) of squamous cell carcinomas. In cases of adenocarcinoma, c-erbB-2 was present in 18% of those with stage I disease. In stage IIIA, stage IIIB and stage IV cases, c-erbB-2 was present in 39%, 50% and 60%, respectively (I vs. IIIA and I vs. IIIB: P less than 0.05, I vs. IV: P less than 0.01). The 5-year survival rates of c-erbB-2 positive patients and those who were negative were 30% and 52%, respectively, with a statistically significant difference (P less than 0.01). These observations suggest that when the expression of c-erbB-2 correlates with invasiveness of the tumour, this correlation may serve as a prognostic indicator, particularly in cases of adenocarcinoma of the lung.

Differential gene expression between chronic hepatitis B and C hepatic lesion

BACKGROUND & AIMS

Complementary DNA (cDNA) microarray technology allows simultaneous expression analysis of hundreds to thousands of genes. We applied the cDNA microarray technique to clarify gene expression profiles in chronic viral hepatitis tissue lesions.

METHODS

We made cDNA microarrays consisting of 1080 human cDNAs and analyzed gene expression using labeled cDNAs prepared from 6 normal, 12 chronic hepatitis B, and 14 chronic hepatitis C liver tissues. Relative expression ratios of individual genes were obtained by comparing hybridization of Cy5-labeled cDNAs from chronic hepatitis lesions and Cy3-labeled cDNA from normal liver tissue.

RESULTS

Hierarchical clustering analysis of the gene expression profiles in 26 patients showed that the patients were clustered into 2 groups with respect to similarities in differentially expressed genes. Hepatitis B and C virus infection, but not age, sex, or histology of hepatitis, were significant factors determining clustering (P < 0.05). In hepatitis B tissue lesions, genes involved in inflammation were predominant, whereas in hepatitis C, expression of anti-inflammatory response genes was relatively dominant.

CONCLUSIONS

These findings shed new light on the possible differential molecular mechanisms in the pathogenesis of hepatitis caused by hepatitis B virus and hepatitis C virus infection, from which hepatocellular carcinoma frequently develops.

Synaptic integration mediated by striatal cholinergic interneurons in basal ganglia function

The physiological role of striatal cholinergic interneurons was investigated with immunotoxin-mediated cell targeting (IMCT). Unilateral cholinergic cell ablation caused an acute abnormal turning behavior. These mice showed gradual recovery but displayed abnormal turning by both excess stimulation and inhibition of dopamine actions. In the acute phase, basal ganglia function was shifted to a hyperactive state by stimulation and suppression of striatonigral and striatopallidal neurons, respectively. D1 and D2 dopamine receptors were then down-regulated, relieving dopamine-predominant synaptic perturbation but leaving a defect in controlling dopamine responses. The acetylcholine-dopamine interaction is concertedly and adaptively regulated for basal ganglia synaptic integration.

Effects of zonisamide on dopaminergic system

Effects of zonisamide (ZNS) on extracellular dopamine (DA), its precursor 3,4-dihydroxyphenylalanine (DOPA), its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) levels in the striatum as well as hippocampus of freely moving rats were studied. Intracellular DA, DOPA, DOPAC and HVA levels, as well as DOPA accumulation as an index of tyrosine hydroxylase activity in the rat brain in vivo, DA re-uptake in the striatum and hippocampus, and monoamine oxidase (MAO) activities were also determined. Acute administrations of therapeutic ZNS doses (20 and 50 mg/kg) increased striatal extracellular DOPA levels, intracellular striatal and hippocampal DOPA levels, and stimulated DOPA accumulation in both brain regions. ZNS also increased striatal and hippocampal intracellular as well as extracellular DA and HVA levels, but decreased those of DOPAC levels. Chronic (3 weeks) administrations of therapeutic ZNS doses (20 and 50 mg/kg/day) increased intracellular DA, DOPA, DOPAC and HVA levels in striatum and hippocampus. ZNS-induced changes were greater in intracellular levels than in extracellular levels. Acute and chronic supratherapeutic ZNS dose (100 mg/kg) administration decreased intracellular levels of all substances detectable in both brain regions, and inhibited DOPA accumulation. Both subtypes of MAO (type A and type B) activities were weakly inhibited by ZNS. ZNS showed no effect on DA re-uptake in striatum nor in hippocampus. These results suggest that therapeutic ZNS doses increase DOPA accumulation as well as both intracellular and extracellular DA, DOPA and HVA levels. However, such doses also decrease extracellular and intracellular DOPAC levels by enhancing DA synthesis and/or by selectively inhibiting MAO-B activities. In addition, chronic therapeutic ZNS dose administration enhances DA synthesis, which results in increased intracellular DA, its precursor and its metabolites levels. On the other hand, both acute and chronic supratherapeutic ZNS dose administrations inhibit DA turnover. These ZNS effects on DA metabolism are at least partly involved in the mechanisms of action of ZNS.