Basal expression of c-Fos and Zif268 in the rat basal ganglia: immunohistochemical characterization of striatal Zif268-positive neurons

Basal expression of the protein products of the inducible immediate early genes (IEGs), c-Fos and Zif268, was investigated in five regions of the rat basal ganglia using immunohistochemistry. In particular, high basal levels of Zif268 but very low levels of c-Fos were seen in the caudate-putamen (CPu). Double immunostaining revealed that many of the constitutively expressed Zif268-positive neurons were GABAergic but very few were cholinergic or neuronal nitric oxide synthase (nNOS)-positive, and some of the Zif268-positive neurons were also immunopositive for a glutamate NMDA receptor subunit NR1 or NR2A. No regional difference between the medial and lateral parts of the CPu was observed in the cellular phenotypes of Zif268-positive neurons. Almost no basal levels of Zif268 were seen in the other four regions: the globus pallidus, entopeduncular nucleus, subthalamic nucleus and substantia nigra pars reticulata. As in the CPu, negligible levels of c-Fos were seen in these four regions. Differential expression of these two IEGs may suggest gene-specific and region-specific functions of c-Fos and Zif268 in the basal ganglia. Constitutive expression of Zif268 existing mainly in the GABAergic neurons in the CPu may at least in part be maintained by glutamatergic afferents.

NMR, UV-vis and CD study on the interaction of pradimicin BMY-28864 with divalent cations of alkaline earth metal

In order to clarify the mechanism of the calcium-activated anti-fungal action of pradimicin derivatives, we investigated the compatibility of four divalent metal cations, Ca2+, Mg2+, Sr2+ and Ba2+, when combined with pradimicin BMY-28864 in an aqueous solution. The 1H NMR studies suggest that all the tested cations can induce a chemical exchange between two types of aggregation of BMY-28864 in an aqueous solution. The exchange rate, however, varies according to the cation species. In descending order they are: Ba2+ > Sr2+ > Ca2+ > Mg2+. The differences in the binding ability of BMY-28864 to the cations and the solubility of the chloride salts are explained by the electronegativity of these cations. The UV-Vis and CD spectra of these solutions show isosbestic points that correspond to an exchange process in the cations' binding to BMY-28864. The results provide experimental support for the hypothesis that there is a common mechanism underlying their cations interactions with the antibiotic. The CD study also provided evidence about the stoichiometric relation of the divalent metal ions to the antibiotic, 1:2, which was obtained by NMR analyses.

Potent in vivo antimalarial activity of 3,15-di-O-acetylbruceolide against Plasmodium berghei infection in mice

The antimalarial activity of the O-acylated bruceolide derivative, 3,15-di-O-acetylbruceolide, was evaluated against Plasmodium berghei in vivo. The concentration of 3,15-di-O-acetylbruceolide required for 50% suppression (ED50) of P. berghei in mice was 0.46 +/- 0.06 mg/kg/day, whereas bruceolide was only half as effective as 3,15-di-O-acetylbruceolide. Two antimalarial drugs used clinically, chloroquine and artemisinin, demonstrated only low activity corresponding to 1/4 and 1/12 of the ED50 value of 3,15-di-O-acetylbruceolide, respectively. These results may be helpful in the design of better chemotherapeutic bruceolides against falciparum malaria.

Masseter muscle activity during the whole day in children and young adults

Changes in size and shape of the craniofacial skeleton during growth may be related to the masticatory muscle function in daily life. The purpose of this study was to measure the masseter muscle activity during the whole day in children and to investigate the differences between children and young adults. Fifteen children (7.8-13.0 years of age) and 30 young adults (20.3-34.7 years of age), who had acceptable occlusions without any remarkable skeletal discrepancy or temporomandibular disorder, were used as the subjects. In both children and young adults, most high-amplitude bursts of masseter muscle appeared mainly during mealtime, whereas a substantially larger number of low-amplitude ones were widely distributed throughout the whole day. The number and total duration of bursts of masseter muscle activity during the whole day was greater in children than in young adults, although significant differences were not found between the sexes. During daytime and sleep, both the number and total duration of bursts were greater in children. During mealtime, no significant differences in the number of bursts were found between children and young adults, however, the duration of bursts tended to be longer in children. It is concluded that the masseter muscle activity during the whole day is greater in children than in young adults.

NMR study of pradimicin derivative BMY-28864 and its interaction with calcium ions in D2O

The dynamic structure of the antifungal antibiotic pradimicin BMY-28864 in D2O and its interaction with calcium ions were analyzed using one- and two-dimensional 1H nuclear magnetic resonance (NMR). Spectra indicate extensive self-association of molecules in the solution. Two-component spectra were observed simultaneously in a very dilute solution, suggesting equilibrium of two aggregative states. The addition of CaCl2 caused a number of changes in NMR spectra. Therefore we concluded that pradimicin BMY-28864 could form a complex with the Ca2+ ion, causing a movement of the equilibrium. The position of the bound calcium ion is determined indirectly by observing how the NMR shift affects protons that are close to the binding site. The stoichiometry of Ca2+ ion to the Pradimicin molecule for the Ca(2+)-saturated complex is verified to be 1:2. Signal broadening and changes in chemical shift in the 1H NMR spectroscopy of BMY-28864 are assumed to be related to changes in the molecular aggregate conformation.

Molecular cloning and expression of human neurochondrin-1 and -2

Human neurochondrins have been cloned from a brain cDNA library. The human neurochondrin-1 and -2 predict leucine-rich (15.8 and 15.9%) proteins of 729 and 712 amino acid residues, with molecular weights of 78.9 and 77.2 kDa, respectively. The deduced amino acid sequence indicates 98% identity among human, mouse and rat species. Northern analysis indicates that about 4 kb human neurochondrin mRNAs are abundant in the fetal and the adult brain.

Double-blind test on the efficacy of methylcobalamin on sleep-wake rhythm disorders

The therapeutic effect of methylcobalamin (Met-12) on sleep-wake rhythm disorders was examined in a double-blind test. In the test group which was given a large dosage, a higher percentage of improvement was found compared to the control group with a small dosage, although the difference was not significant. The test group inconsistently showed significant improvement in both the sleep-wake cycle parameters and in clinical symptoms. The tendency was for the results to show a beneficial effect of Met-12 on rhythm disorders. However, because the percentage of improvement was low and significant improvement was inconsistent, Met-12 might be considered to have a low therapeutic potency and possible use as a booster for other treatment methods of the disorders.

Validity of sleep log compared with actigraphic sleep-wake state II

Twenty-five young people (Y group), three elderly people and seven people with various sleep disorders (SD group) kept a sleep log for 2-7 days, and their wrist-activity was monitored simultaneously. The sensitivity and specificity of the sleep log, and the ratio of agreement between the sleep log and actigraphic sleep-wake state were calculated. The sensitivity and specificity in Y group were 87.93+/-6.49% and 96.51+/-2.37%, respectively. The sensitivity in SD group was significantly lower than in Y group. Even in Y group one-hour agreement ratios dropped during the sleep onset period.

Methamphetamine induces fos expression in the striatum and the substantia nigra pars reticulata in a rat model of Parkinson's disease

In rats with a unilateral 6-hydroxydopamine (6-OHDA) lesion in the nigrostriatal pathway, methamphetamine (3 mg/kg, i.p.) induced Fos-like immunoreactivity (FLI) not only in the striatum on the intact side but also in the substantia nigra pars reticulata (SNr) on the lesioned side. The methamphetamine-induced hyperexpression of FLI in the SNr on the lesioned side was suppressed by pretreatment with either dopamine D1 receptor antagonist SCH-23390 (0.5 mg/kg, i.p.), D2 receptor antagonist raclopride (2 mg/kg, i.p.) or N-methyl-d-aspartate receptor antagonist MK-801 (1 mg/kg, i.p.), which was concomitant with inhibition of the methamphetamine-induced rotational behavior of each antagonist. However, the hyperexpression of FLI in the SNr was not suppressed by intrastriatal grafts of fetal ventral mesencephalon which could suppress the methamphetamine-induced rotation completely. These results indicate that opposite hemispheric asymmetries in FLI are induced by methamphetamine in the striatum and the SNr in the 6-OHDA rats. It is suggested that the FLIs in the two discrete sites are activated independently by different mechanisms, and furthermore, different neuronal pathways are involved in the methamphetamine-induced rotation and Fos expression in the SNr of 6-OHDA rats.

Cardiovascular and sympathetic effects of proadrenomedullin NH2-terminal 20 peptide in conscious rats

Proadrenomedullin NH2-terminal 20 peptide (PAMP) and adrenomedullin (AM), which are derived from the same gene, are novel vasodilative peptides and have been shown to exhibit hypotensive action in anesthetized animals. To avoid the modification via anesthesia, we investigated the effects of intravenously administered PAMP on mean arterial pressure, heart rate (HR), and renal sympathetic nerve activity (RSNA) relative to those of AM in conscious unrestrained rats. We also examined whether the arterial baroreceptor reflex was altered with the two peptides. Intravenous injection of rat PAMP (rPAMP) (10, 20 and 50 nmol/kg) and rat AM (rAM) (0.3, 1.0 and 3.0 nmol/kg) similarly elicited dose-related hypotension accompanied by increases in HR and RSNA. However, the responses to rPAMP were less potent in magnitude and shorter in duration than those to rAM. Moreover, rAM facilitated baroreflex control, whereas rPAMP attenuated it. These findings indicate that although PAMP, as well as AM, may play an important role as a circulating hormone in the systemic circulation of conscious rats, the two peptides derived from an identical origin might have different mechanisms responsible for their cardiovascular and RSNA actions.

Peripherally administered tetrahydrobiopterin increases in vivo tryptophan hydroxylase activity in the striatum after transplantation of fetal ventral mesencephalon in six hydroxydopamine lesioned rats

The intraperitoneal administration of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (6R-BH4), a natural cofactor for tyrosine hydroxylase and tryptophan hydroxylase (TRH), dose-dependently increased the extracellular concentration of 6R-BH4 itself in rat striatum. The concentration was investigated by in vivo microdialysis and measured simultaneously with 5-hydroxytryptophan (5-HTP), a precursor of serotonin, by high performance liquid chromatography with electrochemical detection. The 6R-BH4 (50 mg/kg, i.p.) administration increased the accumulation of 5-HTP as an index of in vivo TRH activity under the inhibition of aromatic L-amino acid decarboxylase by NSD-1015 in the striatum of both normal control and 6-hydroxydopamine lesioned rats with intrastriatal transplants of fetal ventral mesencephalon (VM). The results suggest that TRH in the striatum of both control and VM-grafted rats is activated by 6R-BH4 penetrating into the brain from the blood.

[Transformation of myelofibrosis into acute myelogenous leukemia (M0) with multiple tumor emboli]

A 60-year-old woman was admitted in August 1995 complaining of abdominal pain. A diagnosis of essential thrombocythemia had been made in 1987, and myelofibrosis developed in the patient thereafter. Physical examination revealed massive hepatosplenomegaly, and the peripheral blood showed leukoerythroblastosis with chromosomal abnormalities in peripheral blood cells. In May, 1996, blastic transformation occurred. Based on the findings of surface marker analysis, the blasts met the diagnostic criteria for acete myelogenous leukemia because they were negative for peroxidase and positive for CD13. In June, the patient died of multiple organ failure. Postmortem examination revealed multiple tumor emboli.

Relationship between masticatory muscle activity and vertical craniofacial morphology

The purpose of this study was to investigate the relationship between masticatory muscle activity during the day and vertical craniofacial morphology. The sample comprised 30 subjects (20 males and 10 females, age range 15 to 28 years, mean 24 +/- 3.2 years) who had normal anteroposterior skeletal relationships and complete or nearly complete dentition without serious malocclusion or temporomandibular dysfunction. Using a portable electromyographic recording system, activities of the masseter, temporal, and digastric muscles were recorded for 3 hours during the day, excluding time spent eating, sleeping and exercising. A lateral cephalogram was taken of each subject with the teeth in occlusion. Activities of the masseter, temporal, and digastric muscles consisted mainly of low-amplitude bursts. The duration of digastric muscle activity was greater than that of either the masseter or temporal muscles. Masseter and digastric muscle activity was positively correlated. The activities of the masseter, temporal, and digastric muscles during the day consist of low-amplitude bursts and may be related to vertical craniofacial morphology.

Abdominal vagotomy attenuates interleukin-1 beta-induced nitric oxide release in the paraventricular nucleus region in conscious rats

Nitric oxide (NO) has recently been shown to modulate the hypothalamic-pituitary-adrenal axis response to interleukin-1 beta (IL-1 beta). We measured levels of nitrite (NO2-) and nitrate (NO3-) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1 beta produced a significant increase in both NO2- and NO3- levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1 beta-induced NO release in the PVN region.

Validity of sleep log compared with actigraphic sleep-wake state

Seven women and 11 men, mean age 30.1 years, kept a sleep log for 5-7 days, and their wrist activity was monitored each minute. Sleep-wake state in the sleep log and actigraphic sleep-wake state were compared, and the sensitivity and specificity of the sleep log were calculated for each subject. The ratio of agreement between these two parameters was computed for each subject. The sensitivity and specificity of the sleep log were 72.73-97.56% (mean 86.71%) and 92.85-99.68% (mean 97.04%), respectively. The agreement ratio was 87.30-97.85% (93.48%), but 1-h agreement ratios from midnight dropped during the sleep onset period.

Methamphetamine-induced Fos expression in the substantia nigra pars reticulata in rats with a unilateral 6-OHDA lesion of the nigrostriatal fibers

In rats with a unilateral 6-hydroxydopamine (6-OHDA)-induced lesion in the nigrostriatal fibers, methamphetamine (3 mg/kg, i.p.) induced Fos-like immunoreactivity (FLI), which was inhibited by pretreatment with N-methyl-D-aspartate antagonist MK-801 (1 mg/kg, i.p.), not only in the medial striatum contralateral to the lesion but also in the substantia nigra pars reticulata (SNr) ipsilateral to the lesion. Thus, hemispheric asymmetries in FLI were induced by methamphetamine in the medial striatum and the SNr in the 6-OHDA model of turning which may be related to the altered function of glutamatergic transmission.

Serotonergic activity in the rat striatum after intrastriatal transplantation of fetal nigra as measured by microdialysis

In vivo microdialysis was used to examine the effects of dopaminergic transplants on extracellular concentrations of dopamine (DA), serotonin (5-HT), and their precursors and major metabolites in the denervated rat striatum. Dialysis perfusates were collected from intact 6-hydroxydopamine (6-OHDA) lesion plus sham grafted, and lesion plus fetal substantia nigra (SN) grafted striata. The SN transplants ameliorated the reduction of striatal DA and dihydroxyphenylacetic acid (DOPAC) levels in rats with unilateral 6-OHDA lesions of the mesostriatal pathway. The transplants also increased extracellular levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) in the denervated striatum. In response to NSD-1015 (an inhibitor of aromatic L-amino acid decarboxylase, AADC), 5-hydroxytryptophan (5-HTP) levels were substantially elevated in the SN grafted striata as compared with those in the sham grafted controls, which continued even after subsequent administration of L-3,4-dihydroxyphenylalanine (L-DOPA, 100 mg/kg i.p.). Immunohistochemical analysis showed hyperinnervation of 5-HT fibers in the grafted striatum, which was consistent with the results of microdialysis experiments. These results indicated that implantation of SN grafts into the 6-OHDA-lesioned striatum of rats induces hyperactivity of 5-HT synthesis, release and metabolism.

Effects of anesthetics on norepinephrine release in the hypothalamic paraventricular nucleus region of awake rats

The effects of pentobarbital sodium, chloralose and urethane on norepinephrine (NE) release in the hypothalamic paraventricular nucleus (PVN) region were examined in awake rats. An in vivo microdialysis method was used. Extracellular NE concentrations in the PVN region were measured by high performance liquid chromatography with electrochemical detection. Pentobarbital sodium (30 mg/kg, intravenously [i.v.]) and chloralose (50 mg/kg, i.v.) caused a 30-40% decrease in NE release while urethane (800 mg/kg, i.v.) caused a 50% increase. Plasma NE concentration was not altered after pentobarbital sodium and chloralose administrations, except for its increase in chloralose at 5 h, while the concentration increased significantly (P < 0.01) after urethane. These results suggest that, in the rat, these anesthetic agents have different effects on noradrenergic activity in the PVN region as well as on plasma NE.

Difference in water intake but not in renal sympathetic nerve activity in response to central salt-loading or angiotensin II in awake Dahl salt-sensitive and -resistant rats

Experiments were conducted to examine whether renal sympathetic nerve activity (RSNA) and water intake in response to central salt-loading or angiotensin II (A II) differ between freely-moving Dahl salt-sensitive (DS) and -resistant (DR) rats maintained on a low-salt diet. Intracerebroventricular (i.c.v.) administration of hypertonic saline (0.3 M, 1 microl/min, 20 min) or A II (100 ng/1 microl) evoked water intake, pressor response and suppression of RSNA in both strains. The cumulative water intake in DS rats over a 60-min period after i.c.v. infusion of hypertonic saline or A II was significantly attenuated compared with that in DR rats. The RSNA response did not show a significant difference between the strains. These results demonstrate that water intake, but not RSNA response to acute central salt-loading or A II differ between awake DR and DS rats.

Vitamin B12 treatment for delayed sleep phase syndrome: a multi-center double-blind study

The active form of vitamin B12 (methylcobalamin) has been reported to be effective on sleep-wake rhythm disorders. Previous studies, however, were performed under open trial, and the effect of vitamin B12 has not been properly evaluated. The aim of this double-blind study was to investigate the efficacy of methylcobalamin on delayed sleep phase syndrome (DSPS). Methylcobalamin (3 mg/day) or placebo was administered for 4 weeks. The subjects were 50 patients with DSPS aged 13-55 years (26.8 +/- 1.3), 27 of whom received the active drug while 23 received the placebo. No significant differences were observed between the 2 groups in subjective evaluations of mood or drowsiness during the daytime or in night sleep by sleep-log evaluation. These results indicate that 3 mg methylcobalamin administered over 4 weeks is not an effective treatment for DSPS.

[Salivary gland masses: dynamic MR imaging and pathologic correlation]

PURPOSE

To evaluate the efficiency of dynamic contrast-enhanced magnetic resonance imaging (MRI) for the diagnosis of salivary gland masses.

MATERIALS AND METHODS

We retrospectively examined 19 salivary gland masses that were pathologically diagnosed by surgical operation or biopsy. We obtained T1- and T2-weighted images on MRI, performed dynamic studies on each mass and examined the correlation between enhancement patterns and pathological findings.

RESULTS

Four enhancement patterns were recognized on contrast-enhanced MRI: type 1 showed marked, homogeneous enhancement; type 2 slight, homogeneous enhancement; type 3 marginal enhancement; and type 4 poor enhancement of the mass. Most pleomorphic adenomas had a type 1 enhancement pattern, but two had a type 2 pattern. Pathologically, each mass enhancement pattern had different tumor cell and matrix components. Warthin's tumor generally showed the type 4 pattern. Primary malignant tumors of the salivary gland all showed the type 3 pattern, and pathological specimens showed many tumor cells along the marginal portion of the tumor. One inflammatory cyst and one Warthin's tumor also showed the type 3 pattern. Except for metastatic renal cell carcinoma, the enhancement patterns of late phase images and dynamic study images were the same.

CONCLUSIONS

Dynamic MRI added little diagnostic information about salivary gland masses, but the contrast-enhanced MR features correlated well with the pathological findings.

Effects of systemic interleukin-1beta administration on daily drinking and renal excretory function in conscious rats

To elucidate the roles of interleukin-1beta (IL-1beta), a cytokine with several diverse actions, in the control of body fluid balance, its effects on daily drinking behavior and renal excretory function were examined in conscious rats. Administration of IL-1beta (4 microg/kg, I.P.) resulted in the suppression of both daily drinking and food intake and a decrease in daily urinary sodium and potassium excretion, but had no effect on urine volume. The IL-1beta-induced decrease in sodium excretion was abolished in renal-denervated rats. Kainic acid was then injected into the anteroventral third ventricle region, including the organum vasculosum of the lamina terminalis, to examine whether neurons in this region are involved in the IL-1beta-induced responses; the effects on daily drinking and urinary sodium and potassium excretion were abolished, whereas the effects on food intake, although attenuated, were still present. In contrast, electrical lesion of the subfomical organ did not affect the IL-1beta-induced responses. Thus, IL-1beta seems exert its effects on body fluid balance at several distinct sites in the central nervous system.