ADAM8: a novel osteoclast stimulating factor

We used polymerase chain reaction (PCR)-selective complementary DNA (cDNA) subtraction hybridization with an immortalized murine osteoclast (OCL) precursor cell line to identify genes that are highly expressed in OCLs compared with OCL precursors and which may be involved in the OCL differentiation process. ADAM8 was one of the 50 genes identified. ADAM (a disintegrin and metalloproteinase) peptides are membrane-bound proteins that can act as cell-to-cell and cell-to-matrix adhesion molecules, degrade the extracellular matrix, and play a role in tissue morphogenesis. Addition of antisense (AS) S-oligonucleotides for ADAM8 (1-10 nM) to mouse bone marrow cultures treated with 10(-9) M 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] significantly inhibited OCL formation compared with treatment with the control S-oligonucleotide. Furthermore, conditioned media from 293 cells transiently transfected with a secretable form of the ADAM8 cDNA increased OCL formation in a dose-dependent manner. In addition, treatment of OCLs with soluble ADAM8 conditioned media significantly increased pit formation per dentin slice compared with control OCLs. Time course studies indicated that ADAM8 increased OCL formation only when it was present during days 4-7 of the 7-day culture period. Structural analysis, using truncated constructs of ADAM8, showed that the cysteine-rich/disintegrin domain was responsible for its OCL stimulatory activity. Western blot analysis confirmed that the soluble form of ADAM8 is present in normal marrow cultures. These data suggest that ADAM8 plays an important role in OCL formation and acts primarily at the later stages of OCL differentiation.

Comparative genomic hybridization study of nasal-type NK/T-cell lymphoma

BACKGROUND

Nasal-type NK/T-cell lymphoma is a rare type of non-Hodgkin's lymphoma. The genetic changes associated with pathogenesis have not been well defined. This study investigates the nonrandom genetic alteration of nasal-type NK/T-cell lymphoma.

METHODS

Nine cases were studied. Comparative genomic hybridization (CGH) was carried out using fresh tumor tissues of seven nasal-type NK/T-cell lymphomas. To complement the data by CGH, loss of heterozygosity (LOH) of chromosomes 6q, 1p, and 17p using polymorphic markers and p53 gene mutation by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) were analyzed.

RESULTS

The DNA copy number changes of seven nasal-type NK/T-cell lymphomas were gains on chromosomes 2q(5), 13q(4), 10q(3), 21q(2), 3q(2), 5q(2), and 17q(2), and losses involving chromosomes 1p(4), 17p(4), 12q(3), 13q(2), and 6q(1). One of six cases informative for at least two markers for chromosome 6q showed LOH at D6S300, D6S1639, D6S261, D6S407, and D6S292. Two cases showing loss of 1p and 17q by CGH revealed LOH at D1S214, D1S503, and D17S559. P53 mutation was detected in exon 8 in one of nine cases.

CONCLUSIONS

Frequent DNA losses at 1p, 17p, and 12q and gains at 2q, 13q, and 10q suggested that these regions could be targets for further molecular genetic analysis to investigate tumor suppressor genes or oncogenes associated with tumorigenesis of NK/T-cell lymphoma. Infrequent alteration of 6q contrary to previous studies raises doubt about an implication of 6q loss in the pathogenesis of early-stage NK/T-cell lymphoma. Further studies on more defined cases are required to verify their association.

Lactitol-based poly(ether polyol) hydrogels for controlled release chemical and drug delivery systems

The hydroxyl groups of lactitol were propoxylated to produce poly(ether polyol) (LPEP). The average pK(a) value of hydroxyl groups of the polyol was 1.63. Cross-linked hydrogels were synthesized by esterification with chlorinated poly(ethylene glycol) bis(carboxymethyl) ether (PEGBCOCl). The swelling ratio decreased with increasing cross-linking ratio (PEGBCOCl:LPEP) from 2:1 to 4:1 in the hydrogels and was sensitive to temperature change between 25 and 55 degrees C and concentrations of salt and glucose. The swelling ratio did not change significantly with pH in the range of 4-9. The release profiles of a model active agent, acetylsalicylic acid, from the hydrogels showed that the diffusional release rate had a half-order dependence on time, and the diffusivity decreased with increasing cross-linking ratio. This work demonstrated that LPEP-based hydrogels can be used for controlled delivery of drugs and agrochemicals and the release rates can be controlled with the cross-linking ratio of the hydrogel.

Mechanism and characteristics of protein release from lactitol-based cross-linked hydrogel

Lactitol-based cross-linked hydrogel was synthesized, and model proteins (alpha-chymotrypsin, beta-lactoglobulin, bovine serum albumin (BSA), and gamma-globulin) were incorporated into the cross-linked hydrogel. The larger-molecular-weight proteins have lower diffusivity (D(e)) in the hydrogel. Increasing temperature accelerated the diffusion rate of proteins; however, the diffusion did not follow the Arrhenius equation at temperatures above 37 degrees C. The swelling ratio of the hydrogel was slightly decreased after heating for 2 h at 37 and 45 degrees C, and significantly reduced after 1 h at 60 degrees C. Therefore, diffusion of beta-lactoglobulin and BSA may be decreased by hydrogel shrinking at temperature over 37 degrees C. The model proteins have high affinities to buffer solution compared to the hydrogel network structure, resulting in high partition coefficients (K > 1) which do not affect the calculation of D(e) values. Incorporated protein release follows the theory of hindered diffusion.

Follicular dendritic cell sarcoma presenting as a submucosal tumor of the stomach

Follicular dendritic cell (FDC) sarcomas, especially those of extranodal origin, are extremely rare, and this entity could easily be missed without a high index of suspicion. We report a case of FDC sarcoma presenting as a submucosal tumor of the stomach in a 45-year-old man. The mass was a spindle and epithelioid mesenchymal tumor with many individually scattered and perivascular aggregates of lymphocytes. Immunohistochemical and ultrastructural studies confirmed the diagnosis. Although more than 50 cases of this tumor have been documented in the English literature, to our knowledge the presentation of FDC sarcoma as a submucosal tumor of the stomach has never been recorded. This case highlights the occurrence of FDC sarcoma as a submucosal tumor of the gastrointestinal tract. We believe that FDC sarcoma should be included in the differential diagnosis of spindle or epithelioid cell tumors of the gastrointestinal hollow viscus to prevent this still under-recognized tumor from being overlooked.

Gastrulation defective is a serine protease involved in activating the receptor toll to polarize the Drosophila embryo

The dorsoventral axis of the Drosophila embryo is induced by a ventrally restricted ligand for the receptor Toll. The Toll ligand is generated by a proteolytic processing reaction, which occurs at the end of a proteolytic cascade and requires the gastrulation defective (gd), nudel, pipe, and windbeutel genes. Here we demonstrate that the GD protein is a serine protease and that the three other genes act to restrict GD activity to the ventral side of the embryo. Our data support a model in which the GD protease catalyzes the ventral activation of the proteolytic cascade that produces the Toll ligand.

Protective effect of harmalol and harmaline on MPTP neurotoxicity in the mouse and dopamine-induced damage of brain mitochondria and PC12 cells

The present study elucidated the protective effect of beta-carbolines (harmaline, harmalol, and harmine) on oxidative neuronal damage. MPTP treatment increased activities of total superoxide dismutase, catalase, and glutathione peroxidase and levels of malondialdehyde and carbonyls in the basal ganglia, diencephalon plus midbrain of brain compared with control mouse brain. Coadministration of harmalol (48 mg/kg) attenuated the MPTP effect on the enzyme activities and formation of tissue peroxidation products. Harmaline, harmalol, and harmine attenuated both the 500 microM MPP(+)-induced inhibition of electron flow and membrane potential formation and the 100 microM dopamine-induced thiol oxidation and carbonyl formation in mitochondria. The scavenging action of beta-carbolines on hydroxyl radicals was represented by inhibition of 2-deoxy-D-ribose degradation. Harmaline and harmalol (100 microM) attenuated 200 microM dopamine-induced viability loss in PC12 cells. The beta-carbolines (50 microM) attenuated 50 microM dopamine-induced apoptosis in PC12 cells. The compounds alone did not exhibit significant cytotoxic effects. The results indicate that beta-carbolines attenuate brain damage in mice treated with MPTP and MPP(+)-induced mitochondrial damage. The compounds may prevent dopamine-induced mitochondrial damage and PC12 cell death through a scavenging action on reactive oxygen species and inhibition of monoamine oxidase and thiol oxidation.

Structure of a vortex in the t-J model

We study the single-vortex solution of the t-J model within resonating-valence-bond mean-field theory. We find two types of vortex cores, insulating and metallic, depending on the parameters of the model. The pairing order parameter near both cores have d(x(2)-y(2))+ietad(xy) symmetry. For some range of t/J the calculated tunneling spectrum of the metallic vortex core agrees qualitatively with the STM tunneling data for BSCCO.

Pattern of deposition of stainless steel welding fume particles inhaled into the respiratory systems of Sprague-Dawley rats exposed to a novel welding fume generating system

In order to investigate occupational diseases related to welding fume exposure, such as nasal septum perforation, pneumoconiosis and manganese intoxication, we built a welding fume exposure system that included a welding fume generator, exposure chamber and fume collector. The fume concentrations in the exposure chamber were monitored every 15 min during a 2-h exposure. Fume (mg/m(3)) concentrations of major metals, including Fe, Mn, Cr, and Ni were found to be consistently maintained. An acute inhalation toxicity study was conducted by exposing male Sprague-Dawley rats to the welding fumes generated in this apparatus by stainless steel arc welding. The rats were exposed in the inhalation chamber to a welding fume with a concentration of 62 mg/m(3) total suspended particulates for 4 h. Animals were sacrificed at 4 h and at 1, 3, 7, 10, and 14 days after exposure. Histopathological examinations were conducted on the animals' upper respiratory tracts, including the nasal pathway and the conducting airway, and on the gas exchange region including the alveolar ducts, alveolar sacs, and alveoli. Diameters of fume particles varied from 0.02 to 0.81 microm and were distributed log normally, with a mean diameter of 0.1 microm and geometric standard deviation of 1.42. Rats exposed to the welding fume for 4 h did not show any significant respiratory system toxicity. The mean particle diameter of 0.1 microm resulted in little adsorption of the welding fume particles in the upper respiratory tract. Particle adsorption took place principally in the lower respiratory tracts, including bronchioles, alveolar ducts, alveolar sacs, and alveoli.

Sequence of precursor polyprotein gene (segment A) of infectious bursal disease viruses isolated in Korea

The coding regions of segment A of two recent Korean very virulent (vv) infectious bursal disease virus (IBDV) isolates (KK1 and KSH) and one atypical IBDV isolate (K310) were amplified by reverse transcriptase-polymerase chain reaction, sequenced, and compared with published sequences for IBDV. The overall amino acid sequence similarity of the KK1 and KSH strains compared with foreign vvIBDV strains was between 97.43% and 98.02%. The KK1 and KSH strains, like vvIBDV strains, share unique amino acid residues at positions 222(A), 256(I), 294(I), and 299(S). The sequence of K310 strain was markedly different from other IBDV strains. The K310 strain had 12, 2, and 1 unique amino acid substitutions in the VP2 hypervariable region, VP4, and VP3 gene, respectively, and 3 of 12 substitutions in a VP2 hypervariable region were found in two hydrophilic regions known to be involved in antigenic determination. Also, the K310 strain had 222(S) and 254(S), which were found in variant IBDV strains. The SWSASGS heptapeptide is conserved in all Korean IBDV isolates. By phylogenetic analysis, KK1 and KSH were categorized in one group with foreign vvIBDV isolates, but K310 isolate was categorized in a separate group that was differentiated from the other IBDV strains compared. The K310 strain seemed to be evolved from a separate lineage of IBDV strain.

Inhibitory effect of serotonergic drugs on contractile response of the rat vas deferens to electrical nerve stimulation: in vivo study

PURPOSE

To evaluate, in vivo, the inhibitory effects of certain serotonergic drugs on the contractile response of the rat seminal tract to electrical stimulation of the hypogastric nerve.

MATERIALS AND METHODS

Twenty-five Sprague Dawley rats (250 to 300 gm. each) were equally divided into 5 groups based on experimental agent; normal saline, clomipramine, sertraline, paroxetine, and fluoxetine. The hypogastric nerve was electrically stimulated and the intraluminal pressure of the vas deferens was measured, both pretreatment and 30 minutes after intravenous injection of four different doses (0.1 to 20 x the therapeutic dose) of each agent. Variations of responses relative to the time after administration of each agent (at 10- and 20-fold concentration) were also observed.

RESULTS

All serotonergic drugs caused dose-dependent inhibition of elevation in intraluminal pressure of the vas deferens (p <0.05). The inhibitory effect of clomipramine was significantly better (p <0. 05) than that of fluoxetine at a 1-fold dose, while no significant differences were noted among clomipramine, sertraline and paroxetine. At doses of 10- and 20-fold, clomipramine had the strongest inhibitory effect, followed by sertraline and paroxetine, then fluoxetine (p <0.05). No differences were found in the inhibitory effects of the drugs studied, as a function of the time after injection.

CONCLUSIONS

Clomipramine was the most potent drug for inhibition of elevation in intraluminal pressure of the rat vas deferens induced by electrical stimulation of the rat hypogastric nerve. The stronger inhibitory effect of clomipramine than the selective serotonin reuptake blockers suggests a possible peripheral action of clomipramine in addition to its central serotonergic action.

Serologic responses of Korean soldiers serving in malaria-endemic areas during a recent outbreak of Plasmodium vivax

Anti-Pv200 antibody levels were assessed in samples from endemic areas of Plasmodium vivax malaria in the Republic of Korea (ROK), using an indirect enzyme-linked immunosorbent assay (ELISA) method. Asymptomatic carriers of P. vivax were detected using nested polymerase chain reaction (PCR) of blood samples. Anti-Pv200 antibody levels in 20 vivax malaria patients (optical density +/- standard deviation [OD +/- SD] values 1.85 +/- 0.29 of IgG isotype and 1.33 +/- 1.33 of IgM isotype) were markedly higher than those of uninfected, malaria-naive controls (0.08 +/- 0.16 of IgG isotype and 0.04 +/- 0.04 of IgM isotype). Antibody levels for 7 out of 8 soldiers with a recent malaria infection were sustained above the cut-off values for 4 months after successful treatment. Analysis of serum collected from 40 healthy, asymptomatic soldiers who had a P. vivax malaria attack within 3 months after our sampling, revealed 11 antibody-positive samples (27.5%), compared to 5 positive samples (12.5%) collected from a random selection of 40 soldiers. Among a larger pool of 1,713 soldiers who had served in high-risk areas for P. vivax transmission, 15% were antibody positive. Among 1,000 blood samples from asymptomatic soldiers who had served in the high-risk areas, 4 samples (0.4%) were parasite positive, as determined by nested PCR. Our results show that anti-Pv200 antibody levels can provide useful information in the late diagnosis of P. vivax malaria infection in a previously naive population and also in large seroepidemiologic studies. Furthermore, our results suggest that asymptomatic P. vivax carriers could be important in the current outbreak of malaria in Korea.

Mitochondrial ATPase 6 gene expression in unfertilized oocytes and cleavage-stage embryos

OBJECTIVE

To compare the level of mitochondrial ATPase 6 gene expression in unfertilized oocytes and cleavage-stage embryos.

DESIGN

Reverse transcription polymerase chain reaction was performed in unfertilized oocytes and cleavage-stage embryos derived from tripronucleate embryos to determine ATPase 6 gene expression.

SETTING

Department of Obstetrics and Gynecology, Human Genetics Laboratory, Infertility Medical Center of CHA General Hospital, College of Medicine, Pochon CHA University, Seoul, Korea.

PATIENT(S)

Oocytes were obtained from infertile couples undergoing in vitro fertilization.

INTERVENTION(S)

Unfertilized oocytes collected at 48 hours after retrieval and cleavage-stage embryos derived from tripronucleate embryos were prepared for evaluation of mitochondrial gene expression.

MAIN OUTCOME MEASURE(S)

Comparison of ATPase 6 gene expression by using single-cell reverse transcription polymerase chain reaction.

RESULT(S)

Expression of unfertilized oocytes decreased compared with early cleavage-stage embryos.

CONCLUSION(S)

Our findings of decreased ATPase 6 expression in unfertilized oocytes suggest that there may be a decrease in the mitochondrial functional capacity of oxidative phosphorylation.

The short-term changes of bone mineral metabolism following bone marrow transplantation

Organ transplantation is now the treatment of choice for many patients with life-threatening chronic diseases. A new set of side effects unique to these groups of patients has become recognized, and bone disease is one of these complications. However, little is known about the effects of myeloablative treatment followed by bone marrow transplantation (BMT) on bone mineral metabolism. We have prospectively investigated 31 patients undergoing BMT for hematologic diseases. Serum concentrations of calcium, phosphorus, creatinine, gonadotropins, sex hormones, and the biochemical markers of bone turnover were measured. The samples were collected before BMT and 1, 2, 3, 4, and 12 weeks, 6 months, and 1 year after BMT. Bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry before BMT and 1 year after BMT. The serum carboxy-terminal cross-linked telopeptide of type I collagen increased progressively until 4 weeks after BMT. Thereafter, it began to decrease and reached basal values after 1 year. Serum osteocalcin decreased progressively until 3 weeks after BMT. After that, it increased and reached basal values after 3 months. No distinct differences were observed in the serum biochemical turnover markers between males and females, or between patients who received total body irradiation and those who did not. One year after BMT, lumbar spine BMD had decreased by 2.2%, and total proximal femoral BMD had decreased by 6.2%. Eighty-six percent of the women (12/14) went into a menopausal state immediately after BMT. This was caused by high gonadotropin levels and low estradiol levels. In contrast, gonadotropin levels and testosterone levels did not change significantly in the male patients after BMT. In conclusion, the rapid impairment of bone formation and the increase in bone resorption, as shown by the biochemical markers in this study, might play a role in post-BMT bone loss.

Neural control of the compensatory increase of testosterone in hemicastrated adult male rats

It is unclear why the concentration of testosterone increases in the testicular vein after hemicastration without corresponding alteration in gonadotropins. The present work was undertaken to examine whether the testosterone levels could be modified by denervation of the testis in adult rats. Both systemic and testicular blood samples were collected either immediately before or 6 and 24 hours after hemicastration from the rats two weeks after denervation of either inferior spermatic nerves (ISN) or ISN plus superior spermatic nerves (ISN-SSN). Increase of testicular testosterone induced by hemicastration was significantly (P<0.05) inhibited in these rats, as compared with the sham animals (at 6 and 24 hours, ISN vs sham: 16.00+/-3.35 vs 42.72+/-13.85 and 26.93+/-8.68 vs 71.16+/-13.30 whilst ISN-SSN vs sham: 31.63+/-7.92 vs 60.61+/-18.11 and 27.70+/-8.93 vs 93.92+/-19.73 ng/ml, respectively), whereas no significant change in LH was observed in all the experimental groups. FSH underwent no alteration in all the ISN denervation groups, but a significant elevation was observed in the ISN-SSN denervation groups (P<0.05) before hemicastration. Therefore, it appears that the change in FSH is not the cause of the inhibition of testosterone increase in the hemicastrated rats after testicular denervation and that ISN plays an active role in regulation of testosterone increase induced by hemicastration.

Language supports for children's understanding of numerical fractions: cross-national comparisons

This study examined Croatian, Korean, and U.S. children's knowledge of numerical fractions prior to school instruction. The research is part of an ongoing project examining the influence of language characteristics on mathematical thinking and performance. The part-whole quantitative relation denoted by numerical fractions may be easier to understand in East Asian languages like Korean. In these languages, the concept of fractional parts is embedded in the mathematics terms used for fractions. The results from this study suggest that the Korean vocabulary of fractions may influence the meaning 6- to 7-year-old children ascribe to numerical fractions and that this results in children being able to associate numerical fractions with corresponding pictorial representations prior to formal instruction.

[A novel chiral selector in capillary electrophoresis--beta-cyclodextrin polymer]

Three chiral selectors CM-beta-CD, EP-beta-CD, beta-CD were studied for the enatio-separation of three drugs under optimum conditions respectively. The results demonstrate that the resolving power for the drugs is as follows CM-beta-CD > EP-beta-CD > beta-CD, with the exception of lobeline. This is due to the--CH2COOCH3 group of CM-beta-CD, which will change the combination and improve the recognition on guest molecules. Although EP-beta-CD is inferior to CM-beta-CD for the separation of chlorpheniramine and verapamil, it has excellent recognition on lobeline and it has not been reported previously. In most cases EP-beta-CD is superior to beta-CD. The explanations are: (1) EP-beta-CD has good solubility in water, which enables high concentrations to be used and consequently achieves excellant separation of racemic compounds, (2) the polymerization of beta-CD changes the properties of CD units and the process produces a more rigid and different conformation from CD, (3) we must attribute much merits to the cooperation or synergism of two, three or even more CD moieties of two polymers for inclusion. Complexation with analytes possesses more than one guest part in their structure.

Enhanced hepatocyte uptake and liver targeting of methotrexate using galactosylated albumin as a carrier

Liver targeting of drugs has wide therapeutic implications due to numerous liver-related diseases. Using conjugates of methotrexate (MTX) to variously galactosylated bovine serum albumin (BSA), we studied whether we could enhance the liver targeting of MTX, a model drug, via galactose receptors selectively abundant on the hepatocytes. Here, we report that the galactosylation of the carrier protein BSA significantly enhanced the hepatocyte uptake and liver targetability of MTX. In vitro, the amount of MTX taken up by rat hepatocytes was positively correlated with the galactose content in BSA. MTX conjugates were relatively stable in plasma, but released MTX with time in liver homogenates. These results imply that the conjugates would exert low toxicity in the blood, but have therapeutic activity in the liver by liberating MTX. In vivo, MTX-galactosylated BSA conjugates (MTX-L(24)BSA) showed significantly different pharmacokinetics from free MTX or MTX-BSA conjugates. The plasma level of free MTX rapidly declined in a biexponential fashion with an apparent terminal half-life of 0.35 h. MTX-BSA conjugates showed the slowest decline with an apparent terminal half-life of 6 h, whereas MTX-L(24)BSA showed a biphasic pattern; a rapid distributive phase with a half-life of 0.567 h and a slow terminal phase. MTX-L(24)BSA showed the highest liver targetability, when evaluated in terms of two indices based on the area under the total amount of radioactivity-time curve (AUQ); Te*(liver), % AUQ(liver) to total AUQ, and te*, the ratio of AUQ(liver) to AUQ(kidney). Compared with free MTX and MTX-BSA, MTX-L(24)BSA showed about twofold higher Te*(liver) of 87.5%. The te* of MTX-L(24)BSA was 25- and fourfold higher than those of free MTX and MTX-BSA, respectively. Moreover, MTX-L(24)BSA showed a gradual increase in the therapeutically active intact form of MTX in the liver while showing the lowest level of intact MTX in the kidney. These results suggest that galactosylated BSA has a great potential as an hepatocyte-directed and more effective liver targeting carrier of drugs for liver diseases.

A case of primary transitional cell carcinoma of the fallopian tube

The primary carcinoma of the fallopian tube is the rarest of all gynecologic malignancies and histologically most of them are adenocarcinomas. Primary transitional cell carcinomas are extremely rare in the fallopian tube. A 63-year-old postmenopausal woman presenting with lower abdominal pain was found to have a left adnexal mass. Exploratory laparotomy revealed a mass arising from the fallopian tube with the histologic features of transitional cell carcinoma. Light and electron microscopic studies supported the notion of transitional cell carcinoma. The tumor was extended to the muscle layer and confined to the left fallopian tube without metastasis. The patient received 3 courses of systemic cisplatin-based chemotherapy and has been well with no evidence of recurrence until August, 1998.

Co-administration of toluene and xylene antagonized the testicular toxicity but not the hematopoietic toxicity caused by ethylene glycol monoethyl ether in Sprague-Dawley rats

Occupational painters are exposed to ethylene glycol monoethyl ether (EGEE), a widely used emulsifying solvent known to cause testicular degeneration and bone marrow depression, together with toluene (TOL) and xylene (XYL) as a mixture. In the previous study (Chung et al., Tox. Lett. 104:143, 1999), testicular atrophy caused by EGEE (200 mg/kg) was shown to be antagonized by co-administration of TOL (250 mg/kg) and XYL (500 mg/kg). This study was conducted to provide histological support for the previously observed antagonistic protective effect of TOL + XYL on EGEE inducible testicular toxicity and to determine whether a similar antagonistic effect can be demonstrated against the EGEE derived hematopoietic toxicity. Compared to the extent of seminiferous tubule degeneration caused by EGEE (150 mg/kg, six times per week for 4 weeks), testes of rats given co-administration of TOL (250 mg/kg) + XYL (500 mg/kg) showed dramatically reduced tubular degeneration. Hyperplasia of Leydig cells in the interstitium was observed in both EGEE and EGEE + TOL + XYL-treated rats. Although a minimal dose of EGEE causing testicular atrophy was used, WBC and platelet counts were decreased significantly. In the TOL + XYL-treated control group, the WBC and platelet counts were not decreased. However, the bone marrow depression caused by EGEE was not reversed by the combined administration of TOL + XYL. In all experimental groups (EGEE alone, TOL + XYL, EGEE + TOL + XYL), plasma levels of creatinine and alkaline phosphatase were significantly decreased. In addition to the marked testicular atrophy, EGEE also decreased the weights of adrenal glands and epididymis. In conclusion, while the testicular degeneration caused by EGEE was antagonized by TOL + XYL, the EGEE derived hematopoietic suppression was not reversed.

[Vasoactive intestinal polypeptide induced prolactin release is model dependent in free-moving rats]

Our previous experiments in vitro showed that the stimulating effects of vasoactive intestinal polypeptide (VIP) on pituitary (PRL) depended on the endocrinal status of the animals. The present investigation was to determine whether the effect of VIP varied in vivo with changes of different physiological conditions. For infusion of VIP (5 micrograms/100 g body weight) and collection of blood sample, all the animals were cannulated with silicon tube into jugular vein 2-3 d before the experiments. The results showed that VIP concentration in blood was increased rapidly after the infusion (maximum: 21.32 +/- 2.33 ng/ml at 10 min and lasting more than 30 min). The concentration of PRL in blood of all the animals tested was increased significantly (P < 0.05) after VIP infusion. The increase rate of PRL induced by VIP was higher in male rats (158.04 +/- 37.06), but lower in the female (Diestrus: 50.42 +/- 16.44, Proestrus: 62.67 +/- 21.34) and in Suckling-depended lactating ones (Suckled 90.00 +/- 36.00 vs. Separated 31.05 +/- 4.42). The above observations suggest that the VIP action in vivo depends on the endocrinal and/or neural status of the animals.

A case of Strongyloides stercoralis infection

Strongyloidiasis has been recognized as one of the life-threatening parasitic infections in the immunocompromised patients. We report an intestinal infection case of Strongyloides stercoralis in a 61-year-old man. Rhabditiform larvae were detected in the stool examination and developed to filariform larvae having a notched tail through the Harada-Mori filter paper culture. The patient received five courses of albendazole therapy but not cured of strongyloidiasis.

Expression of a non-inactivating K+ channel driven by a rat heat shock promoter increased the resting potential in Aplysia silent neurons

We assessed the role of a non-inactivating K+ channel (aKv5.1) in the resting potential by overexpressing this channel by heat shock in the neurons. A reporter gene lacZ linked to a promoter region spanning from the -285 to the +88 base of the rat HSP70ib gene was induced 62.5-fold when this DNA construct was microinjected into the neurons of the marine mollusk Aplysia and treated with heat shock at 30 degrees C for 3 h. Using this efficient induction system, we induced the expression of aKv5.1 by heat shock in cultured, electrically silent neurons of Aplysia and examined its effect on the resting potential. The channel expression increased the resting potential by approximately 10 mV. This increase was specific to heat shock induction and abolished by treatment with TEA, a specific K+ channel blocker. These results provide the direct evidence that a low voltage-activated, non-inactivating K+ channel can contribute to the resting potential.

RNA-Stimulated ATPase and RNA helicase activities and RNA binding domain of hepatitis G virus nonstructural protein 3

Hepatitis G virus (HGV) nonstructural protein 3 (NS3) contains amino acid sequence motifs typical of ATPase and RNA helicase proteins. In order to examine the RNA helicase activity of the HGV NS3 protein, the NS3 region (amino acids 904 to 1580) was fused with maltose-binding protein (MBP), and the fusion protein was expressed in Escherichia coli and purified with amylose resin and anion-exchange chromatography. The purified MBP-HGV/NS3 protein possessed RNA-stimulated ATPase and RNA helicase activities. Characterization of the ATPase and RNA helicase activities of MBP-HGV/NS3 showed that the optimal reaction conditions were similar to those of other Flaviviridae viral NS3 proteins. However, the kinetic analysis of NTPase activity showed that the MBP-HGV/NS3 protein had several unique properties compared to the other Flaviviridae NS3 proteins. The HGV NS3 helicase unwinds RNA-RNA duplexes in a 3'-to-5' direction and can unwind RNA-DNA heteroduplexes and DNA-DNA duplexes as well. In a gel retardation assay, the MBP-HGV/NS3 helicase bound to RNA, RNA/DNA, and DNA duplexes with 5' and 3' overhangs but not to blunt-ended RNA duplexes. We also found that the conserved motif VI was important for RNA binding. Further deletion mapping showed that the RNA binding domain was located between residues 1383 and 1395, QRRGRTGRGRSGR. Our data showed that the MBP-HCV/NS3 protein also contains the RNA binding domain in the similar domain.

An inducible gene product for 6-phosphofructo-2-kinase with an AU-rich instability element: role in tumor cell glycolysis and the Warburg effect

Cancer cells maintain a high glycolytic rate even in the presence of oxygen, a phenomenon first described over 70 years ago and known historically as the Warburg effect. Fructose 2,6-bisphosphate is a powerful allosteric regulator of glycolysis that acts to stimulate the activity of 6-phosphofructo-1-kinase (PFK-1), the most important control point in mammalian glycolysis. The steady state concentration of fructose 2,6-bisphosphate in turn depends on the activity of the enzyme 6-phosphofructo-2-kinase (PFK-2)/fructose-2, 6-bisphosphatase, which is expressed in several tissue-specific isoforms. We report herein the identification of a gene product for this enzyme that is induced by proinflammatory stimuli and which is distinguished by the presence of multiple copies of the AUUUA mRNA instability motif in its 3'-untranslated end. This inducible gene for PFK-2 is expressed constitutively in several human cancer cell lines and was found to be required for tumor cell growth in vitro and in vivo. Inhibition of inducible PFK-2 protein expression decreased the intracellular level of 5-phosphoribosyl-1-pyrophosphate, a product of the pentose phosphate pathway and an important precursor for nucleic acid biosynthesis. These studies identify a regulatory isoenzyme that may be essential for tumor growth and provide an explanation for long-standing observations concerning the apparent coupling of enhanced glycolysis and cell proliferation.