Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

Abnormal asymmetries in subcortical brain volume in schizophrenia

Subcortical structures, which include the basal ganglia and parts of the limbic system, have key roles in learning, motor control and emotion, but also contribute to higher-order executive functions. Prior studies have reported volumetric alterations in subcortical regions in schizophrenia. Reported results have sometimes been heterogeneous, and few large-scale investigations have been conducted. Moreover, few large-scale studies have assessed asymmetries of subcortical volumes in schizophrenia. Here, as a work completely independent of a study performed by the ENIGMA consortium, we conducted a large-scale multisite study of subcortical volumetric differences between patients with schizophrenia and controls. We also explored the laterality of subcortical regions to identify characteristic similarities and differences between them. T1-weighted images from 1680 healthy individuals and 884 patients with schizophrenia, obtained with 15 imaging protocols at 11 sites, were processed with FreeSurfer. Group differences were calculated for each protocol and meta-analyzed. Compared with controls, patients with schizophrenia demonstrated smaller bilateral hippocampus, amygdala, thalamus and accumbens volumes as well as intracranial volume, but larger bilateral caudate, putamen, pallidum and lateral ventricle volumes. We replicated the rank order of effect sizes for subcortical volumetric changes in schizophrenia reported by the ENIGMA consortium. Further, we revealed leftward asymmetry for thalamus, lateral ventricle, caudate and putamen volumes, and rightward asymmetry for amygdala and hippocampal volumes in both controls and patients with schizophrenia. Also, we demonstrated a schizophrenia-specific leftward asymmetry for pallidum volume. These findings suggest the possibility of aberrant laterality in neural pathways and connectivity patterns related to the pallidum in schizophrenia.

Structural alterations of the superior temporal gyrus in schizophrenia: Detailed subregional differences

BACKGROUND

Reduced gray matter volumes in the superior temporal gyrus (STG) have been reported in patients with schizophrenia. Such volumetric abnormalities might denote alterations in cortical thickness, surface area, local gyrification or all of these factors. The STG can be anatomically divided into five subregions using automatic parcellation in FreeSurfer: lateral aspect of the STG, anterior transverse temporal gyrus of Heschl gyrus (HG), planum polare (PP) of the STG, planum temporale (PT) of the STG and transverse temporal sulcus.

METHODS

We acquired magnetic resonance imaging (MRI) 3T scans from 40 age- and sex-matched patients with schizophrenia and 40 healthy subjects, and the scans were automatically processed using FreeSurfer. General linear models were used to assess group differences in regional volumes and detailed thickness, surface area and local gyrification.

RESULTS

As expected, patients with schizophrenia had significantly smaller bilateral STG volumes than healthy subjects. Of the five subregions in the STG, patients with schizophrenia showed significantly and marginally reduced volumes in the lateral aspect of the STG and PT of the STG bilaterally compared with healthy subjects. The volumetric alteration in bilateral lateral STG was derived from both the cortical thickness and surface area but not local gyrification. There was no significant laterality of the alteration in the lateral STG between patients and controls and no correlation among the structures and clinical characteristics.

CONCLUSIONS

These findings suggest that of five anatomical subregions in the STG, the lateral STG is one of the most meaningful regions for brain pathophysiology in schizophrenia.

The Piccolo Intronic Single Nucleotide Polymorphism rs13438494 Regulates Dopamine and Serotonin Uptake and Shows Associations with Dependence-Like Behavior in Genomic Association Study

Piccolo (PCLO) inhibits methamphetamine-induced neuropharmacological effects via modulation of dopamine (DA) uptake and regulation of the transport of synaptic vesicles in neuronal cells. Clinical studies have recently suggested that the single nucleotide polymorphism (SNP) rs13438494 in the intron 24 of the PCLO gene is associated with psychiatric disorder, in the meta-analysis of GWAS. Therefore, in this study, we attempted to evaluate the possible role of the PCLO SNP in the mechanisms of uptake of monoamines. To characterize rs13438494 in the PCLO gene, we constructed plasmids carrying either the C or A allele of the SNP and transiently transfected them into SH-SY5Y cells to analyze genetic effects on the splicing of PCLO mRNA. The C and A allele constructs produced different composition of the transcripts, indicating that the intronic SNP does affect the splicing pattern. We also transfected DA and serotonin (5-hydroxytryptamine; 5- HT) transporters into cells and analyzed their uptakes to elucidate the association to psychiatric disorders. In the cells transfected with the C allele, both the DA and 5-HT uptake were enhanced compared to the A allele. We also conducted a clinical study, in order to clarify the genetic associations. PCLO rs13438494 exhibits a relationship with the symptoms of drug dependence or related parameters, such as the age of first exposure to methamphetamine, eating disorders, tobacco dependence and fentanyl requirement. Our findings suggest that rs13438494 is associated with drug abuse and contributes to the pathogenesis of psychiatric disorders via modulation of neurotransmitter turnover.

Imaging genetics and psychiatric disorders

Imaging genetics is an integrated research method that uses neuroimaging and genetics to assess the impact of genetic variation on brain function and structure. Imaging genetics is both a tool for the discovery of risk genes for psychiatric disorders and a strategy for characterizing the neural systems affected by risk gene variants to elucidate quantitative and mechanistic aspects of brain function implicated in psychiatric disease. Early studies of imaging genetics included association analyses between brain morphology and single nucleotide polymorphisms whose function is well known, such as catechol-Omethyltransferase (COMT) and brain-derived neurotrophic factor (BDNF). GWAS of psychiatric disorders have identified genes with unknown functions, such as ZNF804A, and imaging genetics has been used to investigate clues of the biological function of these genes. The difficulty in replicating the findings of studies with small sample sizes has motivated the creation of largescale collaborative consortiums, such as ENIGMA, CHARGE and IMAGEN, to collect thousands of images. In a genome-wide association study, the ENIGMA consortium successfully identified common variants in the genome associated with hippocampal volume at 12q24, and the CHARGE consortium replicated this finding. The new era of imaging genetics has just begun, and the next challenge we face is the discovery of small effect size signals from large data sets obtained from genetics and neuroimaging. New methods and technologies for data reduction with appropriate statistical thresholds, such as polygenic analysis and parallel independent component analysis (ICA), are warranted. Future advances in imaging genetics will aid in the discovery of genes and provide mechanistic insight into psychiatric disorders.

DEGS2 polymorphism associated with cognition in schizophrenia is associated with gene expression in brain

A genome-wide association study of cognitive deficits in patients with schizophrenia in Japan found association with a missense genetic variant (rs7157599, Asn8Ser) in the delta(4)-desaturase, sphingolipid 2 (DEGS2) gene. A replication analysis using Caucasian samples showed a directionally consistent trend for cognitive association of a proxy single-nucleotide polymorphism (SNP), rs3783332. Although the DEGS2 gene is expressed in human brain, it is unknown how DEGS2 expression varies during human life and whether it is affected by psychiatric disorders and genetic variants. To address these questions, we examined DEGS2 messenger RNA using next-generation sequencing in postmortem dorsolateral prefrontal cortical tissue from a total of 418 Caucasian samples including patients with schizophrenia, bipolar disorder and major depressive disorder. DEGS2 is expressed at very low levels prenatally and increases gradually from birth to adolescence and consistently expressed across adulthood. Rs3783332 genotype was significantly associated with the expression across all subjects (F3,348=10.79, P=1.12 × 10(-)(3)), particularly in control subjects (F1,87=13.14, P=4.86 × 10(-4)). Similar results were found with rs715799 genotype. The carriers of the risk-associated minor allele at both loci showed significantly lower expression compared with subjects homozygous for the non-risk major allele and this was a consistent finding across all diagnostic groups. DEGS2 expression showed no association with diagnostic status after correcting for multiple testing (P>0.05). Our findings demonstrate that a SNP showing genome-wide association study significant association with cognition in schizophrenia is also associated with regulation of DEGS2 expression, implicating a molecular mechanism for the clinical association.

Common variants at 1p36 are associated with superior frontal gyrus volume

The superior frontal gyrus (SFG), an area of the brain frequently found to have reduced gray matter in patients with schizophrenia, is involved in self-awareness and emotion, which are impaired in schizophrenia. However, no genome-wide association studies of SFG volume have investigated in patients with schizophrenia. To identify single-nucleotide polymorphisms (SNPs) associated with SFG volumes, we demonstrated a genome-wide association study (GWAS) of gray matter volumes in the right or left SFG of 158 patients with schizophrenia and 378 healthy subjects. We attempted to bioinformatically ascertain the potential effects of the top hit polymorphism on the expression levels of genes at the genome-wide region. We found associations between five variants on 1p36.12 and the right SFG volume at a widely used benchmark for genome-wide significance (P<5.0 × 10(-8)). The strongest association was observed at rs4654899, an intronic SNP in the eukaryotic translation initiation factor 4 gamma, 3 (EIF4G3) gene on 1p36.12 (P=7.5 × 10(-9)). No SNP with genome-wide significance was found in the volume of the left SFG (P>5.0 × 10(-8)); however, the rs4654899 polymorphism was identified as the locus with the second strongest association with the volume of the left SFG (P=1.5 × 10(-6)). In silico analyses revealed a proxy SNP of rs4654899 had effect on gene expression of two genes, HP1BP3 lying 3' to EIF4G3 (P=7.8 × 10(-6)) and CAPN14 at 2p (P=6.3 × 10(-6)), which are expressed in moderate-to-high levels throughout the adult human SFG. These results contribute to understand genetic architecture of a brain structure possibly linked to the pathophysiology of schizophrenia.

Comparison of the symptoms of menopause and symptoms of thyroid disease in Japanese women aged 35-59 years

OBJECTIVE

In this study, we surveyed thyroid function abnormalities and menopausal symptoms in young as well as in menopausal women.

METHODS

We conducted a random survey among outpatients at our facility from September 2008 to June 2011. The study included 853 women aged 35-59 years. We assessed the subjects according to the Simplified Menopause Index, menstrual status, thyroid hormone measurements (thyroid stimulating hormone, free thyroxine, free triiodothyronine), the presence of Hashimoto's disease antibodies (anti-thyroid peroxidase antibody or anti-thyroglobulin antibody), the presence of Grave's disease (anti-TSH receptor antibody), markers of thyroid tumor (high thyroglobulin), and thyroid ultrasonography studies. The data were analyzed by means of the statistical program JMP version 8.0.

RESULTS

'Facial flushing', 'sweating', and 'thyroid tumor' were all positively related with age and menstrual status. 'Breathlessness and palpitations' were positively related to Grave's disease. Moreover, 'sweating', 'irritability', and 'stiff shoulders, low back pain, and joint pain' were related to thyroid tumors. 'Insomnia' decreased with age. Patients with Hashimoto's disease were very rare because they were usually treated at other hospitals that specialize in thyroid disease.

CONCLUSION

The symptoms of thyroid function abnormalities were shown to be very similar to menopausal symptoms and were found to occur in younger women before the onset of menopause. This study shows the need to differentiate menopausal symptoms from those of thyroid diseases.

Four-point correlation function of a passive scalar field in rapidly fluctuating turbulence: Numerical analysis of an exact closure equation

A numerical analysis is made on the four-point correlation function in a similarity range of a model of two-dimensional passive scalar field ψ advected by a turbulent velocity field with infinitely small correlation time. The model yields an exact closure equation for the four-point correlation Ψ{4} of ψ, which may be casted into the form of an eigenvalue problem in the similarity range. The analysis of the eigenvalue problem gives not only the scale dependence of Ψ{4} , but also the dependence on the configuration of the four points. The numerical analysis gives S4(R)∝R{ζ{4}} in the similarity range in which S2(R)∝R{ζ{2}} , where S_{N} is the structure function defined by S{N}(R)≡⟨[ψ(x+R)-ψ(x)]{N} and ζ{4}≠2ζ{2} . The estimate of ζ_{4} by the numerical analysis of the eigenvalue problem is in good agreement with numerical simulations so far reported. The agreement supports the idea of universality of the exponent ζ{4} in the sense that ζ_{4} is insensitive to conditions of ψ outside the similarity range. The numerical analysis also shows that the correlation C(R,r)≡[ψ(x+R)-ψ(x)]{2}[ψ(x+r)-ψ(x)]{2}> is stronger than that given by the joint-normal approximation, and scales like C(R,r)∝(r/R){χ} for r/R<<1 with R and r in the similarity range, where χ is a constant depending on the angle between R and r .

Differences in the pharmacokinetics of Cyp3a substrates in TSOD and streptozotocin-induced diabetic mice

The pharmacokinetics of drugs can change in diabetes mellitus and even among diabetics. They may differ between type I diabetes (T1DM) and type 2 diabetes (T2DM). As triazolam was administered orally to Tsumura, Suzuki, obese, diabetes (TSOD) mice and streptozotocin (STZ) mice, clearance per body (CL/F) in TSOD mice did not differ compared with Tsumura, Suzuki, non-obesity (TSNO) mice. In STZ mice, CL/F was greater than in control mice. Small intestinal cytochrome P450 (Cyp) 3a expression in TSOD mice was significantly lower than in TSNO mice. No significant difference existed in small intestinal Cyp3a expression between STZ mice and control mice. In insulin-treated mice, small intestinal Cyp3a expression was significantly lower than in control mice. These results suggested that the differences in changes in small intestinal Cyp3a expression between T1DM and T2DM may be due to differences in plasma insulin concentrations. This may be a factor in the difference in the drug pharmacokinetics between T2DM and T1DM patients.

Increased digitalis-like immunoreactive substances in neonatal plasma measured using fluorescence polarization immunoassay

OBJECTIVE

To better define the reported increased digitalis-like immunoreactive substances (DLIS) in neonatal plasma, we studied the relation among plasma DLIS level, blank intensity (BLK-I) value at FPIA measurement and plasma total bilirubin level.

METHODS

The DLIS levels were measured in 10 neonates with or without jaundice and 10 infants in good health, using fluorescence polarization immunoassay (FPIA) and microparticle enzyme immunoassay (MEIA). BLK-I value and plasma total bilirubin level were also measured simultaneously.

RESULTS

In neonates with jaundice, DLIS using FPIA, BLK-I and total bilirubin level were 0.58 +/-0.13 ng/mL, 2598 +/- 408, and 17.98 +/- 1.13 mg/dL, respectively, before phototherapy, and 0.33 +/-0.06 ng/mL, 1886 +/- 237, and 15.16 +/- 2.07 mg/dL after phototherapy. Corresponding values in neonates without jaundice were (DLIS: 0.34 +/-0.04 ng/mL; BLK-I: 1,764 +/- 278; total bilirubin: 10.37 +/- 4.54 mg/dL); in healthy infants (0.12 +/-0.06 ng/mL, 400.7 +/- 4.6 and 0.42 +/- 0.13 mg/dL, respectively) and in healthy volunteers (0.10 +/-0.07 ng/mL, 403.1 +/- 8.4, and 0.58 +/- 0.30 mg/dL, respectively). Using MEIA, DLIS was not detected in 10 neonates, 10 infants and 20 healthy volunteers.

CONCLUSIONS

A fluorescent compound related to bilirubin increased the BLK-I value in the measurement of neonatal plasma using FPIA. The fluorescence was not the result of endogenous digitalis-like factors.

Features of bacterial cellulose synthesis in a mutant generated by disruption of the diguanylate cyclase 1 gene of Acetobacter xylinum BPR 2001

The diguanylate cyclase 1 (DGC1) (dgc1) gene in Acetobacter xylinum BPR 2001--a bacterial cellulose (BC) producer--was cloned and sequenced, and a DGC1 gene-disrupted mutant, strain DD, was constructed. The production and structural characteristics of the BC formed by DD were compared with those of the parental strain BPR 2001. BC production by DD was almost the same as that by BPR 2001 in static cultivation and in shake flask cultivation. However, in a jar fermentor DD produced about 36% more BC than the parental strain. DD produced suspended particle materials that cannot aggregate owing to their random structural characteristics in static cultivation; more uniformly dispersed BC pellicles and smaller BC pellets are produced on average in a jar fermentor, as reflected by the higher BC production by DD than by the parental strain in a jar fermentor. Micrographs of BC produced by DD revealed that the width of cellulose ribbons assemblies decreased as a result of differences in the ultrastructure and mechanism of formation of BC between the two strains. These results reveal that disruption of the dgc1 gene, which catalyzes synthesis of c-di-GMP (an effector of BC synthase), is not fatal for BC synthesis, although it affects BC structure.

Purification, characterization, and relation to bikunin of rat urinary trypsin inhibitors

Two forms of urinary trypsin inhibitor (UTI-1 and UTI-2) were purified from pooled urine of normal male rats to apparent homogeneity by salting out, affinity chromatography, gel filtration, and reverse-phase HPLC. UTIs-1 and 2 were shown to be thermostable glycoproteins with the respective molecular weights of 22,000 and 18,000 estimated by SDS-PAGE. These inhibitors combined with bovine trypsin in a 1:1 molar ratio: the Kd values were 2.5 x 10(-10) and 2.3 x 10(-10) M, respectively. Amino acid composition and sequence analysis indicated that UTI-1 corresponded to rat bikunin of which the amino acid sequence was deduced from a rat liver cDNA clone encoding alpha1-microglobulin [Lindqvist et al. (1992), Biochim. Biophys. Acta 1130, 63-67] except that the protein sequence seemed to lack C-terminal serine, and UTI-2 corresponded to UTI-1 lacking N-terminal 21 amino acid residues.

Effects of test H-reflex size on reciprocal inhibition in forearm muscles

We studied effects of test H-reflex size on reciprocal Ia inhibition in forearm muscles. In both healthy control subjects and hemiplegic patients, the amount of Ia inhibition decreased as the test H-reflex size increased. It is possible that forearm reciprocal Ia inhibition in hemiplegics reported previously might be underestimated due to larger test H-reflexes used in the hemiplegics than in the controls.

[A case of chronic, motor, axonal polyneuropathy successfully treated by immunoadsorption]

We reported a 61-year-old male with chronic, motor, axonal polyneuropathy. Neurological examination revealed severe muscle weakness in the proximal parts of the four limbs. Sensory examination was normal. The cerebrospinal fluid protein was elevated to 74 mg/dl, and the cell count was normal. The serum antibodies to GM1, GD1a, GD1b, and GQ1b were all negative. Electrophysiological studies showed reduced compound muscle action potentials (CMAPs) suggesting axonal neuropathy, and the nerve conduction velocity was only mildly reduced. After treatment with plasmapheresis (PP) by the immunoadsorption method, his symptoms significantly improved in three weeks, and the cerebrospinal fluid protein, and CMAPs also improved. Only a few studies have been reported regarding patients with chronic, motor dominant, axonal polyneuropathy that responded to immunosuppressive therapies or PP. It remains to be determined whether chronic, dominantly motor, axonal polyneuropathy as seen in the present case is a subtype of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) or a primary axonal immune-mediated neuropathy that is different from CIDP. At present we are not able to answ what kind of clinical or laboratory markers other than an elevated cerebrospinal fluid protein level may help to predict a positive response to immunosuppressive therapy or PP.

[Effects of a rehabilitation program for alcoholic inpatients based on the MMPI]

The Minnesota Multiphasic Personality Inventory (MMPI) was administered to 53 male inpatients of alcohol dependence syndrome (ICD-10) at the time of their admission to the Alcoholism Rehabilitation Program (ARP) of Shiga Mental Health Center Hospital and again at the time of their discharge. The pretreatment profile had high peaks above 60 on the scale F, Hs, D, Hy, Pd, Pa, Pt, Sc and MAS. The 20 scales in the 27 examined scales changed significantly after the 84 days' treatment in the direction of reduced symptoms (Table 3). The changes in scores between pre and post treatment objectively showed that the ARP was effective as the treatment of alcoholism. It might be the base of all the recovery that the subjects regained their intelligence through the sobriety. Their changes in scores failed to predict their prognoses.

[Estimation of left ventricular wall motion and viability by SPAMM tagging cine MRI]

To estimate the endocardial and epicardial myocardial function separately in patients with myocardial infarction patients with or without reperfusion therapy, the magnetic resonance imaging with tagging by spatial modulation of magnetization (SPAMM) was utilized and the endocardial and epicardial early diastolic strains were evaluated separately. The strain changes were correlated with the thallium-201 uptake and a good correlation between epicardial stain change and the thallium-201 uptake was observed. These results indicate the specific usefulness of SPAMM tagging in estimating the regional myocardial function and viability in reperfused myocardium.

[Expression of epidermal growth factor receptor in squamous cell carcinoma of the head and neck]

Localization of epidermal growth factor receptor (EGFR) was investigated immunohistologically in 68 untreated patients with squamous cell carcinoma of the head and neck regions. These patients consisted of 16 with cancer of the lips and mouth, seven with mesopharyngeal cancer, six with epipharyngeal cancer, 15 with hypopharyngeal cancer, 10 with laryngeal cancer, 12 with maxillary cancer and two with other tumors (cancer of the auricle and cancer of the eyelid in one patient each). The patients consisted of 57 men and 11 women, with a mean age of 60 years. In cases with a normal oral mucosa, marked expression of EGFR was observed in the epithelial cell membrane, while expression decreased toward the luminal surface. Cancer cells also showed positive staining of EGFR in all patients, but the intensity of staining was inconsistent among them. Among the 32 patients in whom the staining intensity of EGFR was equal to or weaker than that in basal cells of the normal oral mucosa, 12 patients had lymph node metastasis. Twenty-eight of the 36 patients in whom the staining was stronger than that in the normal cells had lymph node metastasis, suggesting that overexpression of EGFR in carcinoma cells is a risk factor for lymph node metastasis of head and neck cancers (P < 0.005). On the other hand, there were no obvious relationships between either the size or the degree of keratinization of the primary lesion and EGFR expression.

[Three patients with gas gangrene of the head and neck]

Three patients with non-clostridial gas gangrene of the neck are reported. Patient 1 was a 57-year-old man, patient 2 a 63-year-old woman, and patient 3 a 44-year-old man. All three were treated by thorough debridement and precise administration of antibiotics. We also discuss 26 cases (including our 3) of gas gangrene of the head and neck, reported in Japan from 1975 to 1992, from which the following data were obtained: 1. The 26 patients consisted of 17 males and 9 females. 2. They ranged in age from 2 to 88 years, with a mean 56.5 years. 3. Causes included acute pharyngolaryngeal inflammation (46%), dental disease (27%), trauma (8%) and unknown etiology (19%). 4. As a result of bacteriological assessment, the condition was found to be attributable to Clostridium in only 2 patients, and in the remainder the condition was non-clostridial. 5. The mortality rate was 15%. The patients who died were at least 80 years old, and their prognosis had been poor. 6. CT was useful for diagnosis and treatment.

Facilitation of agonist motoneurons upon initiation of rapid and slow voluntary movements in man

The time course of facilitation of the agonist motoneurons upon initiation of voluntary ankle dorsiflexion was investigated in eight healthy subjects. The H-reflex and visually guided tracking methods were used for testing the excitability of the motoneuron pool and for controlling the initiation of movement as well as speed and force. Since the onset of voluntary EMG activity (EMG reaction time: EMGvRT) was delayed and/or obscured by test H-reflexes which were evoked very close to the behavioral responses, the subject was instructed to make response movements bilaterally, and EMGvRT was measured on the side without stimulation. In every subject, the EMGvRT was invariably longer in the ramp movement than in the step movement. The onset of H-reflex facilitation prior to EMG onset, which was regarded as indicating the arrival time of the descending motor command to the motoneuron pool, always started earlier in the ramp movement than in the step movement. The difference in facilitation onset between the two tasks was smaller than that in EMGvRT. Since the amplitude of the H-reflex at the onset of the voluntary EMG was equivalent in both movements, the development of H-reflex towards the behavioral EMG onset was more gradual in the ramp movement than in the step movement. The present results demonstrate that the longer reaction time in the slow ramp task depends on 2 factors: delay in the arrival of descending facilitatory impulses to the agonist motoneuron pool, and its slow recruitment thereafter.

N-methyl-D-aspartate receptor participates in neuronal transmission of photic information through the retinohypothalamic tract

In order to assess the hypothesis that excitatory amino acids (EAA) are involved in the transmission of light information from retina to suprachiasmatic nucleus (SCN) and pineal via the retinohypothalamic tract (RHT), we have determined whether injections of EAA agonist into SCN could mimic the suppressive effects of light pulse on pineal melatonin production, and whether pretreatment with antagonists could block effects of light pulse in the intact rat. Injection of the EAA agonist N-methyl-D-aspartate (NMDA: 1.0 mM; 0.5 microliter) into the SCN suppressed plasma melatonin level and pineal N-acetyltransferase activity. The pretreatment with D-aminophosphonovalerate (D-APV: 2.5 or 10 mM; 2.0 microliters) or N-[1-(2-thienyl)-cyclohexyl]-piperidine (10 mM; 2.0 microliters) which are NMDA type receptor antagonists blocked the suppressive effect of the light pulse (3.0 Ix for 2 min), while the pretreatment with neither vehicle nor L-APV (optic isomer APV: 10 mM; 2.0 microliters) could block the effect of light. Alpha-D-glutamyl-amino-methylsulfonate (10 mM; 2.0 microliters or 25 mM; 2.0 microliters), which is a relative antagonist for non-NMDA type receptor, had no effect, either. These results suggest that EAA is involved in the transmission of light information through RHT and that in rat SCN EAA operates at the NMDA type receptor on the SCN.

Antitumor activity of T-2 toxin-conjugated monoclonal antibody to murine thymoma

T-2 toxin (T-2(4)), one of the trichothecene mycotoxins produced by various gerera of Fusarium spp., is a potent inhibitor to the syntheses of protein and DNA in mammalian cells. The selective cytotoxicity of T-2 toxin-conjugated anti-EL-4 monoclonal antibodies (T-2-mAb) was investigated against murine thymoma EL-4 cells in vitro and in vivo systems. At first T-2 was converted to T-2 hemiglutarate by glutaric anhydride. Then T-2 hemiglutarate was activated to 3-[4-(N-succinimidoxycarbonyl)-butyryl]-T-2 (T-2-G-OSu) by N-hydroxysuccinimide. Thus obtained T-2-G-OSu was conjugated with mAb specific for EL-4 cells. The T-2-mAb markedly inhibited the proliferation of cultured EL-4 cells, but no such cytotoxic effect was observed against irrelevant SP2/0 cells. The cytotoxicity of T-2-conjugated normal gamma globulin (T-2-nGG) against EL-4 cells was far less than that of the above T-2-mAb. Ammonium chloride and monensin, inhibitors of lysosomal enzymes, enhanced the cytotoxicity of T-2-mAb. The presence of both 2-deoxyglucose together with sodium azide, inhibitors of energy-dependent reaction, reduced the cytotoxicity of T-2-mAb. Therefore, the selective binding to the target cells followed by an energy-dependent endocytosis and an intracellular liberation of T-2 by hydrolysis may account for the cytotoxicity of the T-2-mAb. In mice pre-transplanted with EL-4 cells, T-2-mAb increased the mean survival time (MST) with a direct dosage dependence.(ABSTRACT TRUNCATED AT 250 WORDS)

Stress adaptation and hypersensitivity in 5-HT neuronal systems after repeated foot shock

The relationship between adaptation to stress and change in sensitivity of the 5-hydroxytryptamine (5-HT) neuronal system was studied in rats exposed to repeated foot shock stress for up to 10 days. Although hypolocomotion, freezing behavior and loss of weight were observed after in the initial stress, relief from these behavioral changes developed by the 3rd and persisted for another 7 days, indicating the development of stress adaptation. Following an IP injection of 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), rats exposed to the stress for 10 days, but not for 5 days, displayed enhanced forepaw treading, tremor and Straub tail compared to control rats. These results suggest that the hypersensitivity of the 5-HT system after repeated stress may be in part related to the neuronal mechanism of stress adaptation. However, since hypersensitivity was not observed after exposure for 5 days, when adaptation was maximal, it is proposed that the 5-HT system may participate in the maintenance of adaptation rather than its development. On the other hand, no change in 5-HT1, 5-HT1a and 5-HT2 receptor binding assays was found after chronic stress, suggesting that the hypersensitivity of 5-HT system may not be accompanied with changes in the numbers of 5-HT receptor binding sites. The results of beta-adrenergic receptor binding determined simultaneously were also discussed with reference to previous reports of stress-induced reduction in beta-adrenergic receptor density.

Circadian fluctuations in pain responsiveness and brain Met-enkephalin-like immunoreactivity in the rat

The 24-hour patterns of pain responsiveness and brain Met-enkephalin-like immunoreactivity (MLI) were determined in male Wistar rats housed under a 12-hour light and dark cycle (lights on from 0700 hr to 1900 hr). A circadian rhythm was observed in latencies to hot plate test (55 degrees C), showing the peak level near the onset of the dark phase (2000 hr). Pretreatment with naloxone (5 mg/kg, subcutaneously) decreased the highest latency (2000 hr), but did not change the lowest latency (1100 hr). In the mesolimbic area and the striatum, MLI had a negative correlation with the circadian fluctuation in pain sensitivity. MLI at 2000 hr was reduced significantly compared to that at 1100 hr in the basal ganglia, the frontal cortex and the substantia nigra. These results suggest that the circadian variation in hot plate latencies follows a circadian change in the activity of the endogenous opioid peptides system, and that Met-enkephalin may participate in the enhancement of the opioid system in the brain.

Development of circadian rhythms in rats with lesions of serotonergic system

In order to assess the role of the serotonergic system in the development of overt circadian rhythms in the rat, serotonin neurons in the brain were destroyed either by thermocoagulation of the median raphe (MRL) or by an intracerebroventricular injection of the neurotoxin, 5,7-dihydroxytryptamine (DHT). The reductions in serotonin content induced by two manipulations with MRL and DHT were 41% and 100% in the striatum, 40% and 66% in the hypothalamus, and 62% and 88% in the hippocampus, respectively. Neither manipulation eliminated the expression of circadian rhythms in corticosterone (CS) secretion, locomotor activity and drinking behavior, and changed the phase relationship in the overt CS rhythm. Also, 5,7-DHT treatments did not significantly affect the free-running period in locomotor activity. However, the emergence of CS circadian rhythm was delayed for one week in both MRL and DHT groups compared to the intact control ones. These results suggested that a serotonergic system would not be essential for the generation of the endogenous rhythm and the photoentrainment of overt circadian rhythms, but seems to participate in the only development of CS rhythms during the early stage of life.

Chronic administration of tricyclic antidepressants suppresses hypothalamo-pituitary-adrenocortical activity in male rats

The effect of chronic administration of the clinically effective antidepressants, imipramine, clomipramine and desipramine, on corticosterone (CS) release in male rats was investigated. Chronic administration of imipramine, clomipramine and desipramine at a dose of 20 mg/kg b.w./day, but not at a dose of 2 mg/kg b.w./day, suppressed blood CS concentration at 2000h and abolished its circadian rhythm. The normal circadian rhythm of CS release resumed seven days after the termination of imipramine injection. The acute administration of imipramine (20 mg/kg b.w./day) at 0800h but not at 2000h elevated CS concentrations. Chronic administration of imipramine (20 mg/kg b.w./day) tended to increase the inhibitory effect of dexamethasone on CS release. Adrenocortical sensitivity to exogenous adrenocorticotropic hormone tended to be decreased by chronic administration of imipramine (20 mg/kg b.w./day). These results indicate that antidepressants have effects on the hypothalamo-pituitary-adrenocortical axis which may confound psychoneuroendocrinological tests, such as the dexamethasone suppression test, for the diagnosis of affective disorders.

Free-access to a running wheel shortens the period of free-running rhythm in blinded rats

The period of free-running rhythm was measured with two different devices, Automex and running wheel, in blinded female rats. The period was significantly shorter when measured with a running wheel than with an Automex. After transfer between the two devices, all 13 rats examined showed the same direction of change in the free-running period and that transfer from the Automex to running wheel shortened the period, while transfer from the running wheel to Automex elongated it, with the exception of two rats who did not show any significant change in the period even when they were transferred twice. These results indicate that free access to a running wheel shortens the free-running period in female blinded rats.

Determination of beta-phenylethylamine concentrations in human plasma, platelets, and urine and in animal tissues by high-performance liquid chromatography with fluorometric detection

A highly sensitive method for the determination of beta-phenylethylamine in human plasma, platelets, and urine and in mouse tissue is described. The method is based on a two-step isolation using cation-exchange columns followed by reverse phase high-performance liquid chromatography with fluorometric detection. The recovery of the amine through the whole procedure was almost complete, ranging from 99 to 101%. The calibration graph appeared linear over the range of 50 to 5000 pg/injection. Urinary excretion of beta-phenylethylamine in humans ranged from 0.93 to 51.20 ng/mg creatinine. The amine was also detectable in plasma and platelets. Of the various mouse tissues examined, the highest concentrations were found in the small intestine, followed by the blood and liver. Concentrations of about 5 ng/g wet wt were detected in brain tissue, which increased remarkably after inhibition of monoamine oxidase by pargyline.

[Studies on the reverse tolerance phenomenon after repeated methamphetamine treatment in rats]

Male rats of the Wistar strain were divided into three groups, to which three different doses of methamphetamine (MAP), 0.5 mg, 2 mg, and 4 mg/kg/day, respectively, were intraperitoneally administered 5 times per week for 36 days. Stereotyped behaviors were scored according to the method of Ellinwood & Balster. During the period of repeated MAP treatment, these behaviors increased in a dose dependent manner. Group I treated with 0.5 mg/kg of MAP demonstrated more prominently an increased sensitivity to MAP than the other two, Group II with 2 mg/kg and Group III with 4 mg/kg. Following the withdrawal period of 4 weeks, the rats were reinjected with 0.5 mg/kg of MAP. They showed higher scores of stereotypies than those treated acutely with MAP, that is, reverse tolerance for MAP was observed, although this phenomenon was not necessarily observed in a dose dependent manner for each variable of the behaviors. Lethal autonomic response was observed in Group I and II, in which animals appeared to have reverse tolerance for autonomic response to MAP reinjection in contrast to in Group III. It can be concluded that repeated administration of MAP induces stereotyped behaviors in a dose dependent manner, while autonomic response is not likely to form tolerance.