Plasma orexin-A is lower in patients with narcolepsy

Recently identified hypothalamic peptides called orexins (or hypocretins) have been implicated in the sleep-wake cycle and in sleep disorder narcolepsy. Neuropathological studies have shown that in patients with narcolepsy, global reduction in the expression of orexins occurs due to the loss of orexin neurons in the hypothalamus. Cerebrospinal fluid analysis has confirmed a reduced or undetectable level of orexin-A in most narcolepsy patients. In this study, measurement of plasma orexin showed significantly lower concentrations in patients with narcolepsy than in age- and gender-matched normal controls. These data suggest that low levels of orexin-A in plasma could serve as a biological marker for narcolepsy.

[Tumor ablation with MRI navigation--a novel method of microwave coagulation therapy for hepatic tumor]

Fifty-eight patients with hepatic tumor which consisted of 22 hepatocellular carcinomas and 36 metastatic liver tumors were treated by microwave coagulation therapy with MRI navigation. The tumors were located in all segments of liver except S1. In 24 cases among them, the abdominal approach was difficult, because the tumors were located just below the diaphragm. These cases were selected for thoracoscope-assisted microwave ablation under MR-guidance across the diaphragm. All MR data were collected on a vertically oriented open MRI system (0.5 T SIGNA SP/i system: GE Medical Systems). The microwave electrode was introduced into the liver through a 14G needle via a percutaneous puncture with real-time MR image navigation. Microwave ablations at 60 W for 60 seconds were repeated several times depending on the tumor size. MR imaging may be employed as a reliable guide for percutaneous puncture. Moreover, sufficient safety margin could be obtained for hepatic tumor ablation. MR-guided microwave thermoablation therapy is a feasible method of treatment for hepatic tumors.

Cardiovascular changes induced by central hypertonic saline are accompanied by glutamate release in awake rats

To elucidate neurochemical mechanisms responsible for cardiovascular responses induced by central salt loading, we directly perfused the paraventricular nucleus (PVN) of the hypothalamus region with hypertonic saline (0.3 or 0.45 M) by using an in vivo brain microdialysis technique. We then measured the extracellular concentrations of glutamate in the PVN region in conscious rats along with the blood pressure and heart rate. Blood pressure, heart rate, and glutamate levels were increased by perfusion of 0.45 M saline; however, they did not change by perfusion of 0.3 M saline. Next, we examined the possible involvement of glutamate in the cardiovascular responses induced by hypertonic saline. Dizocilpine, a noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, attenuated the increases of blood pressure and heart rate, although 6-cyano-7-nitroquinoxaline-2,3-dione, an antagonist of the non-NMDA receptor, did not affect the blood pressure and heart rate. Our results show that local perfusion of the hypothalamic PVN region with hypertonic saline elicits a local release of glutamate, which may act via NMDA-type glutamate receptors to produce cardiovascular responses.

A homologue of N-ethylmaleimide-sensitive factor in the malaria parasite Plasmodium falciparum is exported and localized in vesicular structures in the cytoplasm of infected erythrocytes in the brefeldin A-sensitive pathway

N-Ethylmaleimide-sensitive factor (NSF) and its homologues play a central role in vesicular trafficking in eukaryotic cells. We have identified a NSF homologue in Plasmodium falciparum (PfNSF). The reported PfNSF gene sequence (GenBank accession number CAB10575) indicated that PfNSF comprises 783 amino acids with a calculated molecular weight of 89,133. The overall identities of its gene and amino acid sequences with those of rat NSF are 50.9 and 48.8%, respectively. Reverse transcription-polymerase chain reaction analysis and Northern blotting with total P. falciparum RNA indicated expression of the PfNSF gene. Polyclonal antibodies against a conserved region of NSF specifically recognized an 89-kDa polypeptide in the parasite cells. After homogenization of the parasite cells, approximately 90% of an 89-kDa polypeptide is associated with particulate fraction, suggesting membrane-bound nature of PfNSF. PfNSF was present within both the parasite cells and the vesicular structure outside of the parasite cells. The export of PfNSF outside of the parasite cells appears to occur at the early trophozoite stage and to terminate at the merozoite stage. The export of PfNSF is inhibited by brefeldin A, with 9 microM causing 50% inhibition. Immunoelectromicroscopy indicated that intracellular PfNSF was associated with organelles such as food vacuoles and that extracellular PfNSF was associated with vesicular structures in the erythrocyte cytoplasm. These results indicate that PfNSF expressed in the malaria parasite is exported to the extracellular space and then localized in intraerythrocytic vesicles in a brefeldin A-sensitive manner. It is suggested that a vesicular transport mechanism is involved in protein export targeted to erythrocyte membranes during intraerythrocytic development of the malaria parasite.

[Transient nephrotic syndrome after allogeneic bone marrow transplantation for chronic myelogenous leukemia]

A 42-year-old man with chronic myelogenous leukemia underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) from an unrelated donor in January 1998. About 100 days later, he developed skin eruption and a diagnosis of chronic graft-versus-host disease (cGVHD) was made by skin biopsy. The eruption improved with steroid therapy, and the dose of steroid was gradually tapered. On day 151, the patient developed nephrotic syndrome with proteinuria up to 20 g/day. A renal biopsy carried out on day 160 showed minimal change in the glomeruli. The proteinuria disappeared 19 days after the onset of nephrotic syndrome without any additional therapy, and no recurrence was observed upon re-tapering of the steroid. In this case, cGVHD might have been related to development of the nephrotic syndrome. Nephrotic syndrome after allo-HSCT is a rare complication, and only ten cases have been reported. The histological findings were mainly membranous nephropathy, and immunosuppressive therapy was effective. As seen in this case, transient nephrotic syndrome with cGVHD may occur after allo-HSCT, and care is necessary to ensure that treatment of cGVHD is sufficient.

Micromere descendants at the blastula stage are involved in normal archenteron formation in sea urchin embryos

Several lines of evidence suggest that micromere signaling plays a key role in endo-mesoderm differentiation along the animal-vegetal (A-V) axis in sea urchin embryos. A recent study has suggested that the activity of micromeres of inducing endoderm differentiation of mesomere descendants is, unexpectedly, maximal at the hatching blastula stage in the echinoids Scaphechinus mirabiris and Hemicentrotus pulcherrimus. In the present study, to confirm the inductive capacity of the micromere descendants in normal development, the timing of initiation of gastrulation and the elongation rate of the archenteron were examined in both micromereless embryos and in micromereless embryos cultured until the hatching blastula stage and then recombined with micromere descendants of the same age. The micromereless embryos consistently exhibited a delay in the initiation of gastrulation and a decrease in elongation rate of the archenteron, as compared with those in controls. In contrast, when the micromereless embryos cultured until the hatching blastula stage were recombined with micromere descendants of the same age, the recombinant embryos exhibited rescue of both the delay in initiation of gastrulation and a decrease in elongation rate of the archenteron. The delayed expression of alkaline phosphatase activity, an endoderm-specific marker, in the micromereless embryos was also rescued in the recombinant embryos. The recombined micromere descendants formed the larval spicules in the same schedule as that observed in the controls. These results indicate that at the hatching blastula stage, micromere descendants emanate a signal(s) required for normal gastrulation of the presumptive endo-mesodermal region.

Fos expression in neurons immunoreactive for neuronal nitric oxide synthase in the rat paraventricular nucleus after intraperitoneal injection of interleukin-1 beta

Double immunostaining for Fos and neuronal nitric oxide synthase (nNOS) was used to examine whether nNOS-immunoreactive neurons in the paraventricular hypothalamic nucleus (PVN) are activated to express Fos immunoreactivity by intraperitoneal injection of interleukin-1 beta (IL-1 beta) in the rat. Quantitative analysis revealed that some nNOS-positive PVN neurons are activated by IL-1 beta (4 microg/kg, i.p.) administration, but the majority of the IL-1 beta-activated PVN neurons do not express nNOS and are distributed mainly in the parvocellular part of the PVN.

Identification of cDNAs encoding two novel nuclear proteins, IMUP-1 and IMUP-2, upregulated in SV40-immortalized human fibroblasts

Using a model system of young, senescent and SV40-immortalized WI-38 fibroblasts, we identified two mRNAs upregulated in immortalized cells (imup-1, immortalization-upregulated protein 1, and imup-2). Compared to normal tissues, both genes were more frequently expressed in cancer cells. The open reading frame of imup-1 spans 321bp, coding for a 10.9 kDa protein of 106 amino acids, while an insertion of 59bp in the otherwise identical mRNA of imup-2 leads to a frameshift, resulting in an 8.5 kDa protein of 85 amino acids. Database searches identified these genes on chromosome 19, which could account for the cloned imup-1 and imup-2 transcripts by alternative splicing. Southern blot analysis of digested genomic DNA confirmed that both transcripts are derived from a single locus. The expressed proteins IMUP-1 and IMUP-2 share 46 identical N-terminal amino acids, whereas the C-termini are unrelated. Green fluorescent protein-fusions of both IMUP-1 and IMUP-2 accumulated in the nucleus of HeLa cells. The C-terminus of IMUP-1 contains a bipartite nuclear localization signal, the deletion of which impaired nuclear translocation. In-vitro translated proteins bound to poly(rG), but did not interact with single-stranded DNA or double-stranded DNA. The nuclear localization of IMUP-1 and IMUP-2 as well as the upregulation of both underlying mRNAs in immortalized cells suggest a function in immortalization.

Increase in norepinephrine but not nitric oxide metabolite levels in the hypothalamic paraventricular nucleus region in response to air jet and swing rotation in freely moving conscious rats

Chronically instrumented, conscious rats were used to examine whether mild exteroceptive stress produces differential neurochemical changes in the hypothalamic paraventricular nucleus (PVN) region. We constructed systems for stress experiment of air jet and swing rotation that were conducted on freely moving conscious rats in a computer-controlled home cage. Concentration of extracellular norepinephrine (NE) and nitric oxide metabolites (NO(X)(-)), nitrite (NO(2)(-)) and nitrate (NO(3)(-)), in the PVN region was then measured by high-performance liquid chromatography with the respective detector; blood pressure (BP) and heart rate (HR) were also measured. Both stressors increased NE concentration in the PVN region as well as BP and HR. Neither stressor altered NO(X)(-) in the PVN region. Cardiovascular and NE changes showed reproducibility in intensity-dependent manner in response to repeated stressors. This finding demonstrated that exteroceptive stress produced different effects on the neurochemical mediators, NE and NO, in the PVN region.

Repeated administration of high dose levodopa enhances hydroxyl radical production in the rat striatum denervated with 6-hydroxydopamine

We examined whether levodopa (L-DOPA) might increase production of hydroxyl radicals in intact and dopamine-denervated rat striatum. Salicylate trapping combined with in vivo microdialysis provided measurements of 2,3-dihydroxybenzoic acid (2,3-DHBA) as a marker of hydroxyl radical production. Acute administration of high-dose L-DOPA (200, 500 mg/kg, i.p.) did not alter 2,3-DHBA levels in intact striatum or in striatum denervated with 6-hydroxydopamine. On the other hand, L-DOPA administration (200 mg/kg, i.p.) transiently increased 2,3-DHBA in dopamine-denervated striatum of rats after repeated administration of L-DOPA (200 mg/kg, i.p., once daily for 16 days). The results indicated that repeated administration of high dose L-DOPA increased production of hydroxyl radicals in dopamine-denervated striatum.

GABA(A) and GABA(B) receptors modulating basal and footshock-induced nitric oxide releases in rat prefrontal cortex

Using an in vivo brain microdialysis technique, we measured extracellular levels of nitric oxide (NO) metabolites (NO(x)(-)) in the medial prefrontal cortex (mPFC) upon perfusion of gamma-aminobutyric acid (GABA) receptor antagonists as well as agonists, and also examined the effects of GABA receptor agonists on mild intermittent footshock-induced NO releases in the mPFC in conscious rats. Perfusion of either bicuculline methiodide, a GABA(A) receptor antagonist, or saclofen, a GABA(B) receptor antagonist, through a microdialysis probe resulted in dose-dependent increases in NO(x)(-) levels. Higher-dose perfusion of either muscimol (50 microM), a GABA(A) receptor agonist, or baclofen (250 microM), a GABA(B) receptor agonist resulted in a significant decrease in NO(x)(-) levels. The elevated levels of NO(x)(-) after mild intermittent footshock were attenuated by perfusion of either muscimol (10 microM) or baclofen (50 microM), either of which alone did not affect basal NO(x)(-) levels. These findings are likely to provide helpful clues to our understanding of the inhibitory modulation of basal and footshock-induced NO metabolites releases by GABA(A) and GABA(B) receptors in the mPFC.

Masticatory muscle activity in children and adults with different facial types

The purpose of this study was to examine the relationship between the duration of masticatory muscle activity during daytime and vertical craniofacial morphology in children and adults. Thirty children (12 boys and 18 girls) and 30 adults (20 men and 10 women) with normal anteroposterior skeletal relations, acceptable occlusions, and without any temporomandibular joint disorders, were selected as subjects. Activities of the masseter, temporal, and digastric muscles were recorded for 3 hours during daytime, excluding the periods for meals, sleep, and hard-exercise, using a portable electromyogram recording system. A lateral cephalogram was taken of each subject at the intercuspal position to divide the subjects into 3 different facial types, ie, low, average, and high angle groups. Masseter, temporal, and digastric muscle activities mainly consisted of low-amplitude bursts during daytime. Children exhibited longer duration of temporal muscle activity, whereas the masseter muscle presented longer duration of activity in adults. The activities of masseter and digastric muscles were significantly related with the vertical facial type in both children and adults, although temporal muscle activity presented no significant relationship with the craniofacial morphology. The duration of masticatory muscle activity during daytime showed a significant difference between children and adults, indicating a close association with vertical craniofacial morphology in children and adults.

Bright light treatment for night-time insomnia and daytime sleepiness in elderly people: comparison with a short-acting hypnotic

Night-time bright light (BL) treatment and triazolam (0.125 mg/day) were given to three healthy elderly people in a cross-over design. They kept a daytime sleepiness test and a sleep log, and their wrist-activity was monitored simultaneously. Subjectively, BL increased daytime sleepiness and naps, and decreased night-time sleep. Triazolam decreased daytime sleepiness and naps, and increased night-time sleep. Actigraphic night-time sleep and naps on the first day were similar to these results. However, on the fourth day night-time insomnia induced by BL had recovered, and naps were shorter than the baseline. Triazolam increased actigraphic naps as the days passed.

Seasonal changes in human sleep-wake rhythm in Antarctica and Japan

The subjects were eight men of the Japanese Antarctic Research Expedition (average age 35.8 years), and 10 healthy people living around Kofu, Japan (28.9 years). They completed a sleep log for 12 to 18 months, and the sleep-wake state was scored in 10-min epochs. Q24 values calculated by chi2 periodgram were low in the Antarctic midwinter. This means that there was difficulty in synchronizing to a 24-h period in the Antarctic midwinter. In Antarctica, sleep onset and offset times were delayed mostly in the midwinter. In Japan, sleep offset time was delayed mostly around the winter solstice.

Interaction of three pradimicin derivatives with divalent cations in aqueous solution

This study focused on further analysis of the aggregation behavior of pradimicin derivatives and their interaction with cations in aqueous solution. BMY was compared with two other pradimicin antibiotics (T2 and FB) with the same aglycone moiety but consisting of different substitute groups. The surface tension measurement showed a clear critical micelle concentration at 1-2 mM of the BMY aqueous solution. The role of Zn2+ in replacing the Ca2+ was examined using 1H nuclear magnetic resonance (NMR) method. From changes in the NMR spectrum and precipitability, it was concluded that zinc ion has lower affinity and higher precipitating ability to BMY than the divalent cations of alkaline earth metal. The aggregation behavior of T2 and FB in aqueous solution was also studied using NMR method. The results suggest that the supramolecular behavior of T2 is similar to BMY whether or not Ca2+ ions are present in solution and that there are two binding sites for calcium ions in a T2 molecule. Unlike BMY and T2, the NMR spectrum of FB does not show distinct change upon Ca2+ addition. The interaction of pradimicin antibiotics with divalent metal ions was thought to be related to ionic electronegativity and to the amphoteric property of the antibiotics.

Differential profiles of nitric oxide and norepinephrine releases in the paraventricular nucleus region in response to mild footshock in rats

The purpose of this study was to determine whether the application of mild intermittent footshock stress can cause changes in the nitric oxide (NO) and norepinephrine (NE) releases in the hypothalamic paraventricular nucleus (PVN) region and medial prefrontal cortex (mPFC). Extracellular levels of NO metabolites and NE in the PVN region and mPFC were determined using an in vivo brain microdialysis technique in conscious rats. In the PVN region, we demonstrated that perfusion of N-methyl-D-aspartate through a microdialysis probe resulted in a dose-dependent increase in NO metabolite levels, whereas intraperitoneal administration of N(G)-nitro-L-arginine methyl ester produced a dose-dependent reduction in the levels of NO metabolites. The levels of NO metabolites in the PVN region increased after intraperitoneal administration of interleukin-1beta in a dose-dependent manner, as we previously reported. This increase in NO metabolite levels was abolished 60 min after systemic administration of N(G)-nitro-L-arginine methyl ester compared to the vehicle-treated control group. Twenty minutes of intermittent footshock induced NE release but did not induce NO release in the PVN region. On the contrary, in the mPFC, 20 min of intermittent footshock induced both NO and NE releases. The present results reveal different patterns and time courses in NO and NE releases between the PVN region and the mPFC in response to mild intermittent footshock stress. These findings are likely to have helpful suggestions for our understanding of the hypothalamic-pituitary-adrenal axis and the limbic forebrain system response to different kinds of stress.

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.