Highly potent PDE4 inhibitors with therapeutic potential

Based on the hypothesis that the dose-limiting side effects of PDE4 inhibitors could be mediated via the central nervous system (CNS), design and synthesis of a hydrophilic analogue is considered to be one approach to improving the side-effect profile of Ariflo 1. Water-soluble piperidine derivatives were found to possess therapeutic potential.     

<Emphasis Type="Italic">Puccinia calystegiae-soldanellae</Emphasis>, a new rust species on <Emphasis Type="Italic">Calystegia soldanella</Emphasis> from Japan

A rust species on Calystegia soldanella in Japan has been treated as Puccinia convolvuli to date. However, morphological characteristics of specimens on C. soldanella collected from Japan are significantly different from those of specimens on other Calystegia and Convolvulus species from different areas of the world. It is proved by inoculation experiment that the rust on C. soldanella is specific to C. soldanella. Based on these results, Puccinia rust on C. soldanella from Japan is described as a new species, Puccinia calystegiae-soldanellae.     

Highly potent PDE4 inhibitors with therapeutic potential

The hypothesis that the dose-limiting side effects of PDE4 inhibitors could be mediated via the central nervous system prompted us to design and synthesize a hydrophilic piperidine analog to improve the side effect profile of Ariflo 1, which is an orally active second-generation PDE4 inhibitor. During evaluation of various water-soluble piperidine analogs, 2a-b, 11b-14b, and 17a showed therapeutic potential in cross-species comparison studies. The following three findings were obtained: (1) The hydroxamic acid group, a well known metal chelator, caused a marked increase of inhibitory activity. (2) Water-soluble piperidine analogs lacked the configurational isomerism of Ariflo 1 without loss of inhibitory activity. (3) Replacement of the 4-methoxy residue with a difluoromethoxy residue led to an increase of in vivo potency. Structure-activity relationships are presented. Single-dose rat pharmacokinetic data for 11b, 12b, and 17a are also presented.     

Effects of fasting on thermoregulatory processes and the daily oscillations in rats

To investigate the mechanism involved in the reduction of body core temperature (T(core)) during fasting in rats, which is selective in the light phase, we measured T(core), surface temperature, and oxygen consumption rate in fed control animals and in fasted animals on day 3 of fasting and day 4 of recovery at an ambient temperature (T(a)) of 23 degrees C by biotelemetry, infrared thermography, and indirect calorimetry, respectively. On the fasting day, 1) T(core) in the light phase decreased (P < 0.05) from the control; however, T(core) in the dark phase was unchanged, 2) tail temperature fell from the control (P < 0.05, from 30.7 +/- 0.1 to 23.9 +/- 0.1 degrees C in the dark phase and from 29.4 +/- 0.1 to 25.2 +/- 0.2 degrees C in the light phase), 3) oxygen consumption rate decreased from the control (P < 0.05, from 24.37 +/- 1.06 to 16.24 +/- 0.69 ml. min(-1). kg body wt(-0.75) in the dark phase and from 18.91 +/- 0.64 to 14.00 +/- 0.41 ml. min(-1). kg body wt(-0.75) in the light phase). All these values returned to the control levels on the recovery day. The results suggest that, in the fasting condition, T(core) in the dark phase was maintained by suppression of the heat loss mechanism, despite the reduction of metabolic heat production. In contrast, the response was weakened in the light phase, decreasing T(core) greatly. Moreover, the change in the regulation of tail blood flow was a likely mechanism to suppress heat loss.     

Structure-activity study of L-amino acid-based N-type calcium channel blockers

Synthesis and structure-activity relationship (SAR) study of L-amino acid-based N-type calcium channel blockers are described. The compounds synthesized were evaluated for inhibitory activity against both N-type and L-type calcium channels focusing on selectivity to reduce cardiovascular side effects due to blocking of L-type calcium channels. In the course of screening of our compound library, N-(t-butoxycarbonyl)-L-aspartic acid derivative 1a was identified as an initial lead compound for a new series of N-type calcium channel blockers, which inhibited calcium influx into IMR-32 human neuroblastoma cells with an IC(50) of 3.4 microM. Compound 1a also exhibited blockade of N-type calcium channel current in electrophysiological experiment using IMR-32 cells (34% inhibition at 10 microM, n=3). As a consequence of conversion of amino acid residue of 1a, compound 12a, that include N-(t-butoxycarbonyl)-L-cysteine, was found to be a potent N-type calcium channel blocker with an IC(50) of 0.61 microM. Thus, L-cysteine was selected as a potential structural motif for further modification. Optimization of C- and N-terminals of L-cysteine using S-cyclohexylmethyl-L-cysteine as a central scaffold led to potent and selective N-type calcium channel blocker 21f, which showed improved inhibitory potency (IC(50) 0.12 microM) and 12-fold selectivity for N-type calcium channels over L-type channels.     

Proteasome activator PA28gamma-dependent nuclear retention and degradation of hepatitis C virus core protein

Hepatitis C virus (HCV) core protein plays an important role in the formation of the viral nucleocapsid and a regulatory protein involved in hepatocarcinogenesis. In this study, we have identified proteasome activator PA28gamma (11S regulator gamma) as an HCV core binding protein by using yeast two-hybrid system. This interaction was demonstrated not only in cell culture but also in the livers of HCV core transgenic mice. These findings are extended to human HCV infection by the observation of this interaction in liver specimens from a patient with chronic HCV infection. Neither the interaction of HCV core protein with other PA28 subtypes nor that of PA28gamma with other Flavivirus core proteins was detected. Deletion of the PA28gamma-binding region from the HCV core protein or knockout of the PA28gamma gene led to the export of the HCV core protein from the nucleus to the cytoplasm. Overexpression of PA28gamma enhanced the proteolysis of the HCV core protein. Thus, the nuclear retention and stability of the HCV core protein is regulated via a PA28gamma-dependent pathway through which HCV pathogenesis may be exerted.     

Cytopathologic and clinicopathologic features of ovarian hepatoid carcinoma. A case report

BACKGROUND: Hepatoid carcinoma is a rare ovarian tumor and is thought to be a different histopathologic subtype from hepatoid-type yolk sac tumor based upon its pathologic features. However, the cytopathologic characteristics of ovarian hepatoid carcinoma (OHC) have not been reported previously. We report the clinicopathologic and cytopathologic features and immunoreactivity of a case of OHC. CASE: A 36-year-old woman presented to our department with lower abdominal pain. A left ovarian tumor was found on pelvic examination, magnetic resonance imaging and computed tomography. The tumor was diagnosed as a hepatoid carcinoma of the left ovary based upon the histopathology of the surgically resected specimen. Cytopathologic specimens from a tumor touch preparation of the tumor exhibited pleomorphic tumor cells with abundant cytoplasm. The nuclei contained rough, granular chromatin and large, prominent nucleoli. Several tumor cells were multinucleated. Tumor cells were immunoreactive for alpha-fetoprotein (AFP). Hematoxylin and eosin staining revealed that the tumor cells were in a sinusoidal pattern resembling hepatocellular carcinoma without any glandular formation. The tumor cells were negative for human chorionic gonadotropin while positive for AFP, alpha-1-antitripsin, CA-125 and carcinoembryonic antigen. CONCLUSION: Cytopathologic examination is of considerable aid in the diagnosis of OHC since cytopathologic preparations highlight the characteristic cell pleomorphism.     

Lipid membrane with low proton permeability

This work reports the production of a liposomal formulation, having a lipidic membrane with known chemical composition and a low proton permeability, as confirmed by physicochemical characterization of the maintenance of a transmembranic pH gradient. These liposomes consist of DSPC, DSPE-PEG, DSPG and cholesterol, with low internal pH. To verify the low proton permeability of these liposomal bilayers, a study of proton migration according to the fluorescence quenching of 9-aminoacridine (9AA), as well as CPT-11 encapsulation, were used to monitor the acidification of the intravesicular space. Both experiments showed that this liposomal formulation is able to maintain a transmembranic proton gradient.     

Larval behavioral,morphological changes,and nematocyte dynamics during settlement of actinulae of Tubularia mesembryanthemum,Allman 1871 (Hydrozoa: Tubulariidae)

The marine colonial hydroid Tubularia mesembryanthemum produces a morphologically unique dispersive stage, the actinula larva. Detailed observations were made on the behaviors and nematocyte dynamics of actinula larvae during attachment and morphogenesis by employing microscopic and time lapse video techniques. These observations produced four primary results. (1) Actinula larvae demonstrated two forms of attachment: temporary attachment by atrichous isorhiza (AI)-nematocysts discharged from the aboral tentacle (AT) tips-and permanent settlement by cement secretion from the columnar gland cells of the basal protrusion. (2) During larval settlement, numerous AIs were discharged from the AT tips with sinuous movement and rubbing of the tentacles onto the substrata, leading to "nematocyte-printing" around the settlement site. (3) Simultaneous with the discharge of the AIs, migration of stenoteles, desmonemes, and microbasic mastigophores occurred, resulting in a dramatic change of nematocyte composition in the ATs after larval settlement. This was in parallel with changes in larval behavior and the tentacle function. (4) Nematocyte-printing behavior during settlement could be recognized as metamorphic behavior responsible for irreversible changes in AT function, from attachment to feeding and defense.     

Structure-activity study and analgesic efficacy of amino acid derivatives as N-type calcium channel blockers

The synthesis and structure-activity relationship (SAR) study of a novel series of N-type calcium channel blockers are described. L-Cysteine derivative 2a was found to be a potent and selective N-type calcium channel blocker with IC(50) 0.63 microM on IMR-32 assay. Compound 2a showed analgesic efficacy in the rat formalin-induced pain model by intrathecal and oral administration.