Fate of nascent microtubules organized at the M/G1 interface, as visualized by synchronized tobacco BY-2 cells stably expressing GFP-tubulin: time-sequence observations of the reorganization of cortical microtubules in living plant cells

Transgenic BY-2 cells stably expressing a GFP (green fluorescent protein)-tubulin fusion protein (BY-GT16) were subcultured in a modified Linsmaier and Skoog medium. The BY-GT16 cells could be synchronized by aphidicolin and the dynamics of their microtubules (MTs) were monitored by the confocal laser scanning microscopy (CLSM). We have succeeded in investigating the mode of reorganization of cortical MTs at the M/G1 interface. The cortical MTs were initially organized in the perinuclear regions and then they elongated to reach the cell cortex, forming the bright spots there. Subsequently, the first cortical MTs rapidly elongated from the spots and they were oriented parallel to the long axis towards the distal end of the cells. Around the time when the tips of the parallel MTs reached the distal end, the formation of transverse cortical MTs followed in the cortex near the division site, as we had previously suggested [Hasezawa and Nagata (1991) Bot. Acta 104: 206, Nagata et al. (1994) Planta 193: 567]. It was confirmed in independent observations that the appearance of the parallel MTs was followed by the appearance of the transverse MTs in each cell. We found that the transverse MTs spread through the whole cell cortex within about 20-30 min, while the parallel MTs disappeared. The significance of these observations on the mode of cortical MT organization is discussed.

Morphometry in anatomy: image analysis on fine structure and histochemical reactions with special reference to radioautography

Anatomy now has a step to transfer from qualitative science to quantitative science. The methods of anatomical investigation employ optical instruments. Anatomy initially described qualitative features of the structure of the body, but now it turns to transfer to new fields measuring the number, size, length, area and volume of not only, structure but also the histochemical components of the structure with quantitative analysis. In order to quantify histochemical reactions in various organs, light and electron microscopic radioautograms were prepared from the liver, pancreas, intestines and kidney which were labeled with 3H-thymidine, 3H-uridine, 3H-leucine, 3H-glucosamine and 3H-glycerol, fixed in glutaraldehyde and osmium tetroxide, embedded in Epoxy resin, sectioned either thick or thin, coated with either Konica NR-M2 or -H2 radioautographic emulsions, exposed, developed, stained for either light or electron microscopic radioautographs. The radioautographs were observed with Olympus Vanox AHB-LB or Nikon Optiphot-2 light microscopes or Hitachi H-700, JEOL JEM-4000EX electron microscopes at 200 and 400 kV. The radioautograms were analysed with various image and analysed such as PPA-250, MOP, Digigramer-G, IBAS-II, Quadra 900, Luzex 300 to count the number of silver grains and to measure the size and number of structures. Some electron microscopic radioautographs were analysed in analytical electron microscopes, combined with Hitachi H-700 Horiba EMAX-1800E, JEOL JEM-200CX Kevex 7000-77, and JEOL JEM-4000EX Tracor-Northern TN-5400 to quantify silver grain contents. The results demonstrated that correct data can be obtained by controlling both full-automatic and semi-automatic image analysers by operating them manually.

Microscopic polyangiitis associated with sinobronchial syndrome

A woman with a long history of chronic bronchitis and chronic sinusitis, i.e., sinobronchial syndrome, was admitted with a fever. Radiologically, there were areas of longstanding consolidation in both lungs, with areas of active inflammation demonstrated by gallium-67 scintigraphy. Antineutrophil cytoplasmic antibody specific for myeloperoxidase was highly positive. Pulmonary hemorrhage and hematuria occurred 2 weeks after admission and responded to steroid therapy. However, the patient died of pneumonia. An autopsy revealed systemic necrotizing vasculitis affecting multiple organs, consistent with microscopic polyangiitis. The vasculitis might have been caused by the chronic inflammation in the lungs associated with sinobronchial syndrome.

Propofol inhibits FMLP-stimulated phosphorylation of p42 mitogen-activated protein kinase and chemotaxis in human neutrophils

Propofol is used in the peri-operative setting and may affect some neutrophil functions. The effects of propofol on the function and intracellular signal transduction systems of neutrophils is controversial. Mitogen-activated protein kinase families (MAPKs) are members of the intracellular signal-transducing systems in eukaryotes. MAPKs have been shown to be involved in neutrophil chemotaxis by the use of PD98059, the specific inhibitor of MAPK/ERK kinase (MEK). The effects of propofol in dimethyl sulfoxide on phosphorylation of MAPKs and chemotaxis were investigated in human neutrophils. Isolated neutrophils (2 x 10(7) cells per ml) from healthy volunteers were incubated with propofol (2-500 microM) and stimulated by N-formyl-L-methionyl-phenylalanine (FMLP) (100 nM). The effects of propofol on the phosphorylation of p44/42 MAPK were investigated by immunoblotting. The effects of FMLP (1 microM) on chemotaxis were investigated with the under-agarose method. The phosphorylation of p42 MAPK and chemotaxis stimulated by FMLP were both inhibited by propofol at clinically relevant concentrations (> or = 10 and > or = 20 microM respectively). PD98059 (50 microM) also inhibited chemotaxis stimulated by FMLP, suggesting the involvement of p42 MAPK in the response. Propofol might therefore inhibit human neutrophil chemotaxis, at least in part, by suppressing the p44/42 MAPK pathway.

Characteristics of somatosensory feedback in postural control during standing

In the present study, the function of the somatosensory feedback system in postural control was investigated. For the sake of simplicity, the present study considered only balancing in the anteroposterior direction using the ankle strategy, in which the ankle moment is mainly used to maintain balance. To suppress the vestibular and visual feedback paths, a subject stood on a force-measuring platform with a fixed back support. Because the subject's body was immovable under these conditions, the subject controlled a computer model that simulated the subject's load at the ankles. Information about the sway angle of the model was fed through the somatosensory feedback path. Frequency response functions of the ankle moment in response to the sway angle were calculated. The experimental results suggest that the human somatosensory feedback system has derivative characteristics and, consequently, can maintain an upright posture by itself. The results were compared with those of previous studies on vestibular and visual feedback systems. The comparison reveals that subject-to-subject variance in the somatosensory system is significantly smaller than that in the other systems. This may indicate that the somatosensory feedback is the most automatic of the systems and plays a dominant role when a subject maintains an upright posture using the ankle strategy.

Three-dimensional high voltage electron microscopy of thick biological specimens

The procedures recently developed in our laboratory to observe three-dimensional structures of cell organelles in thick biological specimens by means of high voltage electron microscopy are reviewed. Thick biological specimens such as whole mount cultured cells seeded and grown on grid meshes in culture vessels or thick sections cut from embedded tissues and stained by histochemical reactions can be readily observed three-dimensionally by high voltage transmission electron microscopy at 400-1000kV. Cultured cells used were both primary cultures from animal tissues and established cell lines maintained in our laboratory. The livers of adult Wistar rats were isolated by collagenase perfusion, and hepatocytes were suspended in a Leibovitz medium and seeded on formval coated gold grid meshes in Petri dishes, incubated in a CO(2) incubator in a humidified atmosphere containing 5% CO(2) in air at 37 degrees C for a few days. Established cell lines, CHO-K1 cells, were cultured in Ham's F12 medium, while HeLa cells were cultured in Eagle's MEM under the same condition. Some of the cells were cultured under experimental conditions such as hepatocyte culture in the medium containing peroxisome proliferating agents such as clofibrate or bezafibrate and some of them were labeled with (3)H-thymidine, (3)H-uridine, (3)H-labeled precursors and (14)C-bezafibrate. Also some cells were incubated in medium containing HRP to induce pinocytosis. All the whole mount cultured cells on grid meshes were prefixed in buffered 2.5% glutaraldehyde, stained with various histochemical reactions and postfixed in 1% osmium tetroxide. The histochemical reactions used were glucose-6-phosphatase (G-6-Pase), thiamine pyrophosphatase (TPPase), cytochrome oxidase, acid phosphatase (AcPase), DAB, ZIO, PA-TCH-SP reactions and radioautography was performed after labeling with radiolabeled compounds. The whole mount cultured cells were dried in a critical point dryer and were observed with JEOL JEM-4000EX or Hitachi H-1250M high voltage electron microscopes at 400-1000kV. By tilting the specimens' stereo-pair micrographs were recorded and they were observed with stereoscopes. Rat liver, mouse intestine and pancreas tissues, fixed and stained as above, were embedded in Epoxy resin, thick sectioned at 1-2 microm and were observed as for the whole mount cultured cells at 1000kV. Stereo-pairs were further analyzed with an image analyzer JEOL JIM-5000 (JEOL, Tokyo, Japan), producing two contour lines plotted from the micrographs at a thickness of 0.2 microm and were observed with anaglyph type glasses, demonstrating the depth or heights of respective cell organelles. The results show that whole mount cultured cells and thick sections stained with histochemical reactions reveal cell organelles corresponding to marker enzymes, such as G-6-Pase in endoplasmic reticulum, TPPase and ZIO in Golgi apparatus, cytochrome oxidase in mitochondria, AcPase in lysosomes, DAB in peroxisomes and pinocytotic vesicles, PA-TCH-SP in secretory granules, (3)H-thymidine and (3)H-uridine in nuclei, (3)H-animo acids in endoplasmic reticulum and secretory granules, (14)C-bezafibrate around ER and peroxisomes. The ultrastructure of these cell organelles as well as the structural relationship between them can be demonstrated three-dimensionally with stereo-pair images. Overall, these procedures are useful for analyzing stereologically the ultrastructure of cell organelles in cells and tissues.

Structural analysis of a novel antimutagenic compound, 4-Hydroxypanduratin A, and the antimutagenic activity of flavonoids in a Thai spice, fingerroot (Boesenbergia pandurata Schult.) against mutagenic heterocyclic amines

Six compounds were isolated from fresh rhizomes of fingerroot (Boesenbergia pandurata Schult.) as strong antimutagens toward 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) in Salmonella typhimurium TA98. These compounds were 2',4',6'-trihydroxychalcone (pinocembrin chalcone; 1), 2',4'-dihydroxy-6'-methoxychalcone (cardamonin; 2), 5,7-dihydroxyflavanone (pinocembrin; 3), 5-hydroxy-7-methoxyflavanone (pinostrobin; 4), (2,4,6-trihydroxyphenyl)-[3'-methyl-2'-(3' '-methylbut-2' '-enyl)-6'-phenylcyclohex-3'-enyl]methanone (5), and (2,6-dihydroxy-4-methoxyphenyl)-[3'-methyl-2'-(3' '-methylbut-2' '-enyl)-6'-phenylcyclohex-3'-enyl]methanone (panduratin A; 6). Compound 5 was a novel compound (tentatively termed 4-hydroxypanduratin A), and 1 was not previously reported in this plant, whereas 2-4 and 6 were known compounds. The antimutagenic IC(50) values of compounds 1-6 were 5.2 +/- 0.4, 5.9 +/- 0.7, 6.9 +/- 0.8, 5.3 +/- 1.0, 12.7 +/- 0.7, and 12.1 +/- 0.8 microM in the preincubation mixture, respectively. They also similarly inhibited the mutagenicity of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). All of them strongly inhibited the N-hydroxylation of Trp-P-2. Thus, the antimutagenic effect of compounds 1-6 was mainly due to the inhibition of the first step of enzymatic activation of heterocyclic amines.

Obstructive jaundice facilitates hepatic metastasis of B16F1 mouse melanoma cells: participation of increased VCAM-1 expression in the liver

Obstructive jaundice facilitates experimental liver metastasis in the rat model, but the detailed mechanisms of this facilitation remain unclear. This study aimed to evaluate the contribution of vascular cell adhesive molecules-1 (VCAM-1) to augmented hepatic metastasis in cases of obstructive jaundice. Obstructive jaundice was induced in male C57BL/6 mice by common bile duct obstruction for 5 days using a Surgiclip. For the biliary decompression, obstructive jaundice was induced for 5 days, followed by removal of the Surgiclip. Liver specimens and blood samples were obtained from animals 5 days after biliary obstruction (OJ5) or sham operation and 2, 5, 11, 14 days after biliary decompression. The expression of VCAM-1 mRNA was increased in the livers from the OJ5 group. Western blot analysis demonstrated increased expression of VCAM-1 protein in the livers of the OJ5 group, in contrast with low VCAM-1 expression in the sham group. The expression of VCAM-1 protein was sustained at high levels at 2 days and decreased at 5 days after biliary decompression (BD5). For the induction of experimental hepatic metastasis, male C57BL/6 mice were randomized to three groups (sham, OJ5, BD5) of six animals each. B16F1 melanoma cells were introduced into the animals by an intraportal injection. Metastatic colonies in the livers were investigated 13 days after inoculation. The mean number of metastatic colonies was significantly increased in the OJ5 group (70.5+/-51.2) compared to that of the sham group (7.2+/-7.9) (p<0.05). This augmentation of hepatic metastasis was abrogated in the BD5 group (16.8+/-20.3). In conclusion, our results suggest that augmented hepatic metastasis in cases of obstructive jaundice are partly mediated through VCAM-1/VLA-4 interaction.

Protective cytotoxic T lymphocyte responses induced by DNA immunization against immunodominant and subdominant epitopes of Listeria monocytogenes are noncompetitive

Taking advantage of the fact that plasmid DNA encoding a single cytotoxic T lymphocyte (CTL) epitope can induce CTLs, we examined the influence of T-cell responses to dominant epitopes on those to a subdominant epitope derived from Listeria monocytogenes. Our data suggest that interaction between T cells against dominant and subdominant epitopes does not operate in the generation of the hierarchy. Furthermore, we found that a single dominant epitope is sufficient for the induction of protective immunity.

Functional mutagenesis of AML1/RUNX1 and PEBP2 beta/CBF beta define distinct, non-overlapping sites for DNA recognition and heterodimerization by the Runt domain

The Runt domain family of transcription factors play key roles in transcriptional regulation of definitive hematopoiesis and osteogenesis. This transcription factor family is characterized by a DNA-binding alpha-subunit harboring the Runt domain and a secondary subunit, beta, which binds to the Runt domain and enhances its interaction with DNA. Missense mutations in the Runt domain from either the blood or bone-related gene product are associated with the onset of acute human leukemia as well as a disease of skeletal patterning known as cleidocranial dysplasia. NMR "footprinting" analysis of Runt domain/beta/DNA ternary complexes in solution previously identified the likely residues that form the heterodimerization and DNA-binding surfaces of the Runt domain. Functional mutagenesis at 37 positions in the Runt domain or beta confirms the original identification of these interaction surfaces and reveals that the heterodimerization and DNA-binding surfaces of the Runt domain occur at distinct, non-overlapping sites within the domain. The analysis of an additional 21 disease-related missense mutations identified from patients with either blood or bone disease demonstrates that the primary defect in these patients is a failure in DNA-recognition by the Runt domain. The molecular basis for the DNA-binding defect is analyzed in the context of the three-dimensional structure of the Runt domain in binary and ternary protein/DNA complexes.

Decreased expression of c-myc family genes in thymuses from myasthenia gravis patients

The thymus is a critical organ for the elimination of autoreactive T cells by apoptosis. We studied the expression of apoptosis-associated genes, bcl-xL, bad, caspase-3, and c-myc family genes in myasthenia gravis (MG) thymuses. We observed that the mRNA levels of myc family genes, c-myc and max, were markedly reduced in MG thymuses. These results indicate that c-myc-mediated signaling is abnormal in MG thymuses. The levels of molecules whose expressions are associated with myc, such as STAM, prothymosin-alpha, and NFkappaB, were also analyzed.

[Cytotoxic activity and cytokine gene induction of Asp-hemolysin to vascular endothelial cells]

We examined the effects of Asp-hemolysin from Aspergillus fumigatus Fresenius-Muramatsu strain on the viability and cytokine gene expression of human umbilical vein endothelial cells (HUVEC). The cell viability of HUVEC was reduced to 50% by 100 micrograms/ml of Asp-hemolysin. However, lower concentration of Asp-hemolysin (< 30 micrograms/ml) had no effect on the cell viability. The mRNA expression of such cytokines as tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta, IL-6, IL-8 and granulocyte-macrophage colony stimulating factor (GM-CSF) were also observed in HUVEC cultured with 30 micrograms/ml of Asp-hemolysin.

Effect of round-edged acrylic intraocular lenses on preventing posterior capsule opacification

PURPOSE

To clarify the extent to which the adhesiveness of an acrylic material influences the formation of posterior capsule opacification (PCO).

SETTING

Jinshikai Medical Foundation, Nishi Eye Hospital, Osaka, Japan.

METHODS

Two types of AcrySof(R) intraocular lenses (IOLs) were prepared: round edged and tumbled. The AcrySof with round edges was implanted in 1 eye in a group of 4 rabbits and the tumbled IOL, in 1 eye in a group of 5 rabbits. In both groups, the contralateral eye received a conventional AcrySof with sharp optic edges. A histopathological examination was performed 3 weeks after surgery.

RESULTS

With the round-edged AcrySof IOL, no capsular bend formed at the optic edge and abundant lens epithelial cells (LECs) migrated posteriorly. With the sharp-edged AcrySof lens, a sharp capsular bend formed and LEC migration was significantly inhibited. In eyes with a tumbled IOL, a capsular bend was created, but it was less marked than that created by the sharp-edged lens and there was slightly more LEC migration posteriorly.

CONCLUSIONS

The AcrySof IOL lost its preventive effect on PCO when the optic was rounded. The effect of the AcrySof lens in preventing PCO is mainly a result of its rectangular, sharp-edged optic design. The acrylic material may play a complementary role by helping create a sharp capsular bend. Capsular bend formation is the key to the PCO preventive effect of an IOL.

Immunohistochemical localization of osteopontin in human pulp stones

The organic matrix component of human pulp stones was investigated by immunohistochemistry. Two pulp stones were extracted from the upper molar teeth of two patients suffering from irreversible pulpitis. Both were formed in the center of the pulp cavity and located apart from the dentin walls. After demineralization, serial sections of the stones were prepared and subjected to immunohistochemical procedures using specific antibodies to type I collagen and noncollagenous proteins (osteopontin, osteonectin, and osteocalcin), which are reported to be involved in calcified matrix formation. Type I collagen was localized evenly in the stones, indicating that it is a major matrix component of pulp stones. Strong immunostaining of osteopontin appeared in the peripheral area of the stones, whereas osteonectin and osteocalcin were not detected. We previously reported that dental pulp cells produced osteopontin in vitro. Osteopontin has been commonly found in other pathological calcification, such as urinary stones, atherosclerotic plaques, and dental calculus. Taken together, the present findings suggest that osteopontin produced by dental pulp cells is possibly associated with calcification of the pulp stone matrix.

[Effects of low density lipoprotein and oxidized low density lipoprotein on the cytotoxic activity of Asp-hemolysin to murine macrophages]

We examined the effects of human low density lipoprotein (LDL) and oxidized LDL (Ox-LDL) on the cytotoxic activity of Asp-hemolysin from Aspergillus fumigatus Fresenius-Muramatsu strain to mouse peritoneal macrophages (M phi). The inhibitory effects of LDL and Ox-LDL on the cytotoxic activity of Asp-hemolysin to M phi increased in a dose-dependent manner, and the effect of Ox-LDL was greater than the inhibitory effect of LDL. Furthermore, the binding of Asp-hemolysin to LDL or Ox-LDL was observed by western blot analysis of the culture medium. These results suggest that the inhibition by LDL or Ox-LDL on the cytotoxic activity of Asp-hemolysin to M phi was due to the binding of LDL or Ox-LDL to Asp-hemolysin in the culture medium.

Induction of E-selectin after partial hepatectomy promotes metastases to liver in mice

BACKGROUND

The liver is the most frequent site of tumor metastasis. It has been suggested that partial hepatectomy promotes liver metastasis of malignant disease and that expression of E-selectin, a cell adhesion molecule, plays roles in tumor metastasis. However, no reports are available concerning the expression of E-selectin after hepatectomy.

METHODS

In the present study, we used BALB/c mice subjected to 30% partial hepatectomy after injection of 1 x 10(4) colon 26 cells to determine the effects of partial hepatectomy on tumor metastasis to liver. E-Selectin expression within the liver after partial hepatectomy was evaluated using reverse transcription polymerase chain reaction and Western blotting. In addition, we injected polyclonal antibody to E-selectin into mice in which partial hepatectomy had augmented liver metastasis.

RESULTS

Mice subjected to partial hepatectomy had significantly increased numbers of liver metastases (sham operation, 1.5 +/- 2.0, vs partial hepatectomy, 35.5 +/- 19.3; P < 0.001). Expression of E-selectin mRNA within the liver was markedly increased 4 h after partial hepatectomy, but subsequently decreased at 24 h. E-Selectin protein was detected 8 h after hepatectomy, but subsequently decreased at 24 h as measured by Western blotting. Mice subjected to intraperitoneal injection of neutralizing antibody after operation had significantly decreased numbers of liver metastases (phosphate-buffered saline, 20.6 +/- 9.2, P < 0.05, and normal IgG, 18.0 +/- 8.0, P < 0.05, compared with polyclonal antibody to E-selectin, 5.6 +/- 4.8).

CONCLUSION

Induction of E-selectin by partial hepatectomy promotes hematogenous liver metastasis. Our findings can be applied to surgical treatment of liver tumor to reduce the recurrence of liver metastasis after hepatectomy by inhibiting E-selectin-mediated adhesion using reagents to E-selectin.

Double-blind placebo-controlled administration of fluoxetine in restricting- and restricting-purging-type anorexia nervosa

BACKGROUND

Anorexia nervosa is an often chronic disorder with high morbidity and mortality. Many people relapse after weight restoration. This study was designed to determine whether a selective serotonin reuptake inhibitor would improve outcome and reduce relapse after weight restoration by contributing to maintenance of a healthy normal weight and a reduction of symptoms.

METHODS

We administered a double-blind placebo-controlled trial of fluoxetine to 35 patients with restricting-type anorexia nervosa. Anorexics were randomly assigned to fluoxetine (n = 16) or a placebo (n = 19) after inpatient weight gain and then were observed as outpatients for 1 year.

RESULTS

Ten of 16 (63%) subjects remained on fluoxetine for a year, whereas only three of 19 (16%) remained on the placebo for a year (p =.006). Those subjects remaining on fluoxetine for a year had reduced relapse as determined by a significant increase in weight and reduction in symptoms.

CONCLUSIONS

This study offers preliminary evidence that fluoxetine may be useful in improving outcome and preventing relapse of patients with anorexia nervosa after weight restoration.

Helical CT in the diagnosis of small bowel obstruction

With recent technologic developments, the role of computed tomography (CT) in the diagnosis of bowel obstruction has expanded. CT is recommended when clinical and initial radiographic findings remain indeterminate or strangulation is suspected. This modality clearly demonstrates pathologic processes involving the bowel wall as well as the mesentery, mesenteric vessels, and peritoneal cavity. CT should be performed with intravenous injection of contrast material, and use of thin sections is recommended to evaluate a particular region of interest. CT is reported to have a sensitivity of 78%-100% for the detection of complete or high-grade small bowel obstruction but may not allow accurate diagnosis in cases involving incomplete obstruction. In such cases, the use of adjunct enteroclysis is indicated. Furthermore, multiplanar reformatted imaging may help identify the site, level, and cause of obstruction when axial CT findings are indeterminate. CT can also demonstrate findings that indicate the presence of closed-loop obstruction or strangulation, both of which necessitate emergency exploratory laparotomy. Unfortunately, these pathologic conditions may be missed, and patients with suspected severe obstruction or bowel ischemia in whom CT and clinical findings are widely disparate must also undergo laparotomy. In general, however, CT allows appropriate and timely management of these emergency cases.

Prophylactic chemolipiodolization for postoperative hepatoma patients

BACKGROUND/AIMS

The efficacy of prophylactic chemolipiodolization following hepatic resection in patients with hepatocellular carcinoma was studied.

METHODOLOGY

Forty-four of 67 consecutive patients with hepatocellular carcinoma who underwent hepatectomy between 1980 and 1997 were divided into two groups: group A (n = 21), in which prophylactic chemolipiodolization was performed during postoperative follow-up (2.4 times on average using a 39 mg mean dose of epirubicin or doxorubicin); and group B (n = 23), without prophylactic chemolipiodolization. The clinicopathological background and patient survival were compared retrospectively.

RESULTS

There were no differences in the clinicopathological background between the two groups. Multiple intrahepatic recurrence was frequently observed in group B (P < 0.02). The recurrence-free survival rates in group A (54.4% and 31.1% at 3 and 5 years, respectively) were significantly higher than those in group B (15.7% and 7.9%, respectively). The survival rates of group A (95.2% and 80.4% at 3 and 5 years, respectively) were significantly higher than those in group B (40.1% and 22.9%, respectively).

CONCLUSIONS

Our data suggest that postoperative prophylactic chemolipiodolization can be an effective treatment in reducing intrahepatic recurrence and may prolong survival for hepatocellular carcinoma patients following hepatic resection.

Toxic shock syndrome toxin-1 accelerated collagen-induced arthritis in mice

The aim of this study was to explore the roles of toxic shock syndrome toxin-1 (TSST-1) in collagen-induced arthritis (CIA). DBA/1 mice were immunized with type II collagen (CII) and treated with TSST-1. Intraperitoneal and intravenous injections of TSST-1 aggravated CIA, enhancing its incidence and severity. CIA was accompanied by an increase in anti-CII IgG Ab levels. Intraperitoneal administration with TSST-1 enhanced IFN-gamma, TNF-alpha, and IL-4 production in DBA/1 mice. We discovered the mRNA expressions of IFN-gamma, IL-2, TNF-alpha, IL-1beta, and iNOS in spleen cells stimulated with TSST-1 in vitro. However, IL-12 and IL-4 mRNA expression were seen constitutively without stimulation. Only a little increase of IL-12 and IL-4 mRNA expression was seen at 2-3 h after treatment with TSST-1. Our experiments demonstrated that CIA was aggravated by the treatment with TSST-1, which may have induced various proinflammatory cytokines and the production of both Th1 and Th2 cytokines.

Evaluation of liver regeneration using the L-[1-13C]methionine breath test

BACKGROUND

We examined the relationship between changes in the liver weight/body weight percentage, amount of hepatic tissue total DNA, and the results of the [1-(13)C]methionine ((13)Cmet) breath test during hepatic regeneration in a rat model of 70% hepatectomy, to assess their usefulness for evaluating hepatic regeneration.

MATERIALS AND METHODS

Male Wistar rats (230-290 g) were subjected to 70% hepatectomy under anesthesia with Nembutal. One, 2, 3, 7, and 14 days postoperatively, 40 mg/kg (13)Cmet was intravenously injected into the femoral vein, and the increase in exhaled (13)CO(2) (Delta(13)CO(2)) was measured for 15 min. Simple laparotomy was performed in control rats. Following the breath test, the regenerated liver was removed and weighed. The amount of DNA was determined.

RESULTS

The correlation coefficients (r) between liver weight/body weight (LW/BW) and results of the (13)Cmet breath test, and between DNA and results of the (13)Cmet breath test were 0.892 and 0.800, respectively.

CONCLUSIONS

The (13)Cmet breath test is considered to be very useful for assessing liver regeneration, and total (13)CO(2) output over 15 min in the (13)Cmet breath test graph seems to be an effective indicator for evaluating liver regeneration.

Ghrelin is an appetite-stimulatory signal from stomach with structural resemblance to motilin

BACKGROUND & AIMS

: Ghrelin, an endogenous ligand for growth hormone secretagogue receptor, was recently identified in the rat stomach. We examined the effects of the gastric peptide ghrelin on energy balance in association with leptin and vagal nerve activity.

METHODS

: Food intake, oxygen consumption, gastric emptying, and hypothalamic neuropeptide Y (NPY) messenger RNA expression were measured after intra-third cerebroventricular or intraperitoneal injections of ghrelin in mice. The gastric vagal nerve activity was recorded after intravenous administration in rats. Gastric ghrelin gene expression was assessed by Northern blot analysis. Repeated coadministration of ghrelin and interleukin (IL)-1 beta was continued for 5 days.

RESULTS

: Ghrelin exhibited gastroprokinetic activity with structural resemblance to motilin and potent orexigenic activity through action on the hypothalamic neuropeptide Y (NPY) and Y(1) receptor, which was lost after vagotomy. Ghrelin decreased gastric vagal afferent discharge in contrast to other anorexigenic peptides that increased the activity. Ghrelin gene expression in the stomach was increased by fasting and in ob/ob mice, and was decreased by administration of leptin and IL-1 beta. Peripherally administered ghrelin blocked IL-1 beta-induced anorexia and produced positive energy balance by promoting food intake and decreasing energy expenditure.

CONCLUSIONS

: Ghrelin, which is negatively regulated by leptin and IL-1 beta, is secreted by the stomach and increases arcuate NPY expression, which in turn acts through Y(1) receptors to increase food intake and decrease energy expenditure. Gastric peptide ghrelin may thus function as part of the orexigenic pathway downstream from leptin and is a potential therapeutic target not only for obesity but also for anorexia and cachexia.

Melatonin's gastroprotective and antistress roles involve both central and peripheral effects

Systemic administration of melatonin (5 to 20 mg/kg) has been reported to inhibit the induction of acute gastric mucosal lesions by stress or ischemia-reperfusion in rats. We recently demonstrated that intracisternal (i.c.) melatonin at low doses (1 to 100 ng) dose-dependently decreased acid and pepsin outputs in rats. The aim of the present study was to further investigate the peripheral and central roles of melatonin in gastric mucosal defense. Using a radioimmunoassay, we measured melatonin concentrations in the plasma and cerebrospinal fluid (CSF) of the cisterna magna in rats subjected to water immersion restraint stress and given intraperitoneal (i.p.) or i.c. injection of melatonin. Water immersion restraint stress was followed by a significant duration-related increase in peripheral plasma melatonin levels; the stress similarly produced a time-dependent increase in the extent of gastric mucosal lesions. Administration of melatonin (1 or 10 mg/kg, i.p., or 100 ng/10 microl, i.c.) significantly reduced the extent of stress-induced gastric damage, by 46%, 67%, and 54%, respectively. The effective i.c. dose of melatonin was at least 10,000-fold smaller than the effective i.p. dose. Melatonin levels in plasma and CSF after the i.p. injection of melatonin at 10 mg/kg were dramatically higher than those after the i.c. injection of vehicle or 100 ng of melatonin. Our results suggest that the peripheral gastroprotective action of melatonin should be investigated with due regard to these central effects.

A simple and rapid system for the quantitation of RNA interference in plant cultured cells

The phenomenon known as RNA interference (RNAi) by double-stranded RNA (dsRNA) that was reported recently in the nematode Caenorhabditis elegans has been shown to operate by a mechanism that is widely conserved among species including plant cells. No quantitative analysis of the effects of RNAi on the expression of specific genes in plant cultured cells has been reported. An RNAi effect was observed 24 h after the introduction of dsRNA expression plasmids into tobacco BY-2 cells by electroporation. The simple system for suppression of specific genes in plant cells should be useful in attempts to elucidate the roles of individual genes in plant cells.

Stability and bioavailability of antioxidants in garland (Chrysanthemum coronarium L.)

The stability and bioavailability of the major antioxidants in garland (Chrysanthemum coronarium L.), chlorogenic acid, 3,5-dicaffeoylquinic acid and 4-succinyl-3,5-dicaffeoylquinic acid, were investigated together with caffeic acid. These compounds were stable in artificial digestive juice, but more than 90% of them disappeared from plasma within 30 min after intravenous injection into rats. When they were orally administered, only caffeic acid could be detected.

Effects of polysaccharides (FI0-b) from mycelium of Ganoderma tsugae on proinflammatory cytokine production by THP-1 cells and human PBMC (I)

AIM

To compare the effects of water-soluble polysaccharides, FI0-b, and its formic acid-modified derivative, FI0-b-H, on production of human proinflammatory cytokines.

METHODS

The polysaccharides were modified by formic acid. Cytokine production was quantitated by radioimmunoassay. mRNA for cytokines was measured by semi-quantitative RT-PCR.

RESULTS

FI0-b and FI0-b-H 4, 40, and 400 mg/L significantly downregulated interleukin-1 alpha (IL-1 alpha) production by THP-1 cells induced by lypopolysaccharide (LPS) 1 or 10 mg/L and phorbol myristate acetate (PMA) 200 nmol/L. At lower stimulation with LPS 10 mg/L and PMA 200 nmol/L, both polysaccharides significantly upregulated tumor necrosis factor alpha (TNF alpha) production by THP-1 cells. However, at higher stimulation with LPS 100 mg/L and PMA 200 nmol/L, they downregulated TNF alpha production. FI0-b-H downregulated interleukin-8 (IL-8) production by THP-1 cells at a lower-dose of LPS 1 mg/L and PMA 200 nmol/L, but upregulated IL-8 production at a higher-dose of LPS 10 mg/L and PMA 200 nmol/L. Production of cytokines (IL-1 alpha and TNF alpha) was transcriptionally or post-transcriptionally regulated by FI0-b and FI0-b-H.

CONCLUSION

The water-soluble polysaccharides of Ganoderma tsugae mycelium have bidirectional immunomodulatory effects on cytokine production in different stimulatory conditions in a dose-dependent manner. Compared with FI0-b, FI0-b-H has more marked effects on human proinflammatory cytokine production.

Effects of polysaccharides (FI0-c) from mycelium of Ganoderma tsugae on proinflammatory cytokine production by THP-1 cells and human PBMC (II)

AIM

To study the effects of water-soluble polysaccharides. FI0-c, and its sulfated derivative, FI0-c-S, on production of human proinflammatory cytokines, interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha).

METHODS

The herbal polysaccharides were modified by chlorosulfornic acid in dimethyl sulfoxide (Me2SO). Cytokine production was measured by radioimmunoassay, mRNA for the cytokines was measured by semi-quantitative RT-PCR.

RESULTS

FI0-c 4 mg/L itself induced IL-1 alpha production by THP-1 cells without stimulants, such as lipopolysaccharides (LPS) and phorbol myristate acetate (PMA). On the other hand, FI0-c and FI0-c-S inhibited the IL-1 alpha production by THP-1 cells with these stimulants. FI0-c and FI0-c-S significantly upregulated TNF alpha production by THP-1 cells without stimulants or at a low dose of LPS 10 mg/L and PMA 200 nmol/L, whereas these polysaccharides markedly downregulated the TNF alpha production by a high dose of LPS 100 mg/L and PMA. Human peripheral blood mononuclear cells (PBMC) responded to FI0-c and FI0-c-S in IL-1 alpha and TNF alpha production in a fashion similar to THP-1 cell responses. FI0-c 4 mg/L downregulated high-dose LPS- and PMA-induced IL-1 alpha or TNF alpha mRNA and their protein production by THP-1 cells.

CONCLUSION

The water-soluble polysaccharides of Ganoderma tsugae mycelium have bidirectional immunomodulatory effects on cytokine production in different cell stimulatory conditions. Chemical modification of this polysaccharide changed the intensity of regulatory effect on cytokine production.

Expression of a bioactive bovine interleukin-12 using baculovirus

Recombinant baculoviruses that express recombinant bovine interleukin-12 (rboIL-12) subunits, p35 and p40 subunits were constructed. A recombinant virus containing the p40 subunit gene expressed the p40 subunit as a 40kDa monomer and an 80kDa disulfide-linked homodimer in the infected insect cells and in the culture supernatant. The p35 subunit was expressed in a 30kDa monomer in the infected cells but not in the supernatant. Superinfection of both recombinant viruses into the cells in a spinner flask resulted in the formation of a 70kDa disulfide-bonded heterodimer detected in the supernatant by immunoblotting using anti-p40 and anti-p35 subunits antibodies. The superinfected culture supernatant showed induction of IFNgamma mRNA synthesis and IFNgamma production in bovine peripheral blood mononuclear cells. Thus, the bioactive rboIL-12 was produced in large scale using a baculovirus expression system.

[Bronchial atresia with atelectasis of the left upper lobe]

A 69-year-old woman visited her physician on October 1 complain of dry cough. However, the chest radiograph revealed no abnormalities. She was later admitted to our hospital because a radiograph taken by another physician on November 26 revealed a massive lesion in the right upper mediastinum. Computed tomographic findings showed a massive lesion containing a branching structure with a few calcifications, suggesting a case of atelectasis of the left upper lobe with mucus plug. Bronchoscopic examination revealed complete obstruction of the orifice of the left upper lobe bronchus, and so a diagnosis of bronchial atresia was made. However, since the patient had a history of tuberculous peritonitis and the mass lesion was somewhat calcified, the possibility that this was an acquired case could not be ruled out. After treatment with oral antibiotics, the size of the atelectasis was decreased. Therefore, we considered that the expansion of the atelectasis could have been due to superimposed bacterial infection.

Efficient cloning and engineering of giant DNAs in a novel Bacillus subtilis genome vector

The Genome of Bacillus subtilis 168 was used for cloning and engineering of large-sized DNAs. A mouse genomic DNA of approximately 120 kb was cloned into a locus of the B. subtilis genome by ordered assembly of 20- to 50-kb mouse DNA segments. Cloned mouse DNA, maintained stably, was engineered through B. subtilis transformation and recombination. Creation of an I-PpoI recognition sequence at both ends of the insert facilitated its isolation by pulsed field gel electrophoresis. The basic concept of genome vector technology is suited to the handling of DNAs larger than 100 kb.

Two novel diterpenoids, erinacines H and I from the mycelia of Hericium erinaceum

Novel diterpenoids, erinacines H (1) and I (3), were isolated from the cultured mycelia of Hericium erinaceum. The structures of the compounds were determined by interpretation of the spectral data. Erinacine H showed stimulating activity of nerve growth factor (NGF)-synthesis.

Possible involvement of cyclophilin B and caspase-activated deoxyribonuclease in the induction of chromosomal DNA degradation in TCR-stimulated thymocytes

TCR engagement of immature CD4(+)CD8(+) thymocytes induces clonal maturation (positive selection) as well as clonal deletion (negative selection) in the thymus. However, the cell death execution events of thymocytes during the negative selection process remain obscure. Using a cell-free system, we identified two different DNase activities in the cytosol of in vivo anti-TCR-stimulated murine thymocytes: one that induced chromosomal DNA fragmentation, which was inhibited by an inhibitor of caspase-activated DNase, and another that induced plasmid DNA degradation, which was not inhibited by an inhibitor of caspase-activated DNase. We purified the protein to homogeneity that induced plasmid DNA degradation from the cytosol of anti-CD3-stimulated thymocytes and found that it is identical with cyclophilin B (Cyp B), which was reported to locate in endoplasmic reticulum. Ab against Cyp B specifically inhibited the DNA degradation activity in the cytosol of anti-CD3-stimulated thymocytes. Furthermore, recombinant Cyp B induced DNA degradation of naked nuclei, but did not induce internucleosomal DNA fragmentation. Finally, we demonstrated that TCR engagement of a murine T cell line (EL4) with anti-CD3/CD28 resulted in the release of Cyp B from the microsome fraction to the cytosol/nuclear fraction. Our data strongly suggest that both active caspase-activated DNase and Cyp B may participate in the induction of chromosomal DNA degradation during cell death execution of TCR-stimulated thymocytes.

Expression of OX40 and OX40 ligand (gp34) in the normal and myasthenic thymus

OBJECTIVES

To examine the expression of OX40, an activated memory T-cell marker, and its ligand (OX40L), a set of molecules for T-cell-B-cell interaction, and other lymphocyte activation markers in the thymuses of myasthenia gravis (MG) and controls.

MATERIAL AND METHODS

We studied the expression of OX40, OX40L, IL-2Ralpha and HLA-DR in the thymic tissues of MG and controls using immunocytochemistry and flowcytometry.

RESULTS

In both hyperplastic thymus of MG and control thymus, OX40+ cells were scattered mainly in the medulla with much fewer OX40L+ cells being distributed in the corticomedullary junctions. IL-2Ralpha and HLA-DR were expressed in the medulla at higher frequencies as compared with OX40 in controls as well as MG. In contrast, the numbers of OX40+ cells around the germinal centers (GC) were significantly greater than those of control thymuses, and some mononuclear cells in GC were OX40L+. A considerable number of OX40+ cells were seen in the thymic tissues adjacent to thymomas. OX40+ cells were CD4+ CD8- or CD4+ CD8+ and were mostly HLA-DR-. (The coexpression of OX40 and IL-2Ralpha on activated CD4+ T cells was previously reported.)

CONCLUSION

OX40, expressed in a fraction of activated CD4+ T cells, may be upregulated in thymic tissues adjacent to GC and thymoma in MG, and OX40 may interact with OX40L in GC to enhance anti-acetylcholine receptor antibody production in MG.

High prevalence of spinocerebellar ataxia type 1 (SCA1) in an isolated region of Japan

Autosomal dominant cerebeller ataxias (ADCAs) are a heterogeneous group of neurodegenerative disorders that differ in both the clinical manifestations and modes of inheritance. At present, eight different genes causing ADCAs have been found: spinocerebeller ataxia type 1 (SCA1), SCA2, SCA3/Machado-Joseph disease (MJD), SCA6, SCA7, SCA8, SCA12 and dentatorubropallidoluysian atrophy (DRPLA). The relative prevalence of each mutation varies according to race and native place. We studied 117 unrelated ADCA families that originated from the Tohoku District in the northernmost part of Honshu Island in Japan (mainly Miyagi Prefecture in the central part of Tohoku District). The SCA1 mutation was the most frequent among the known disorders (24.8% of all such families). The relative prevalence of SCA1 in the Tohoku District is very high compared with the values already reported from other regions in the world. Because the population of this area had seldom moved, the alleles with SCA1 mutations (including alleles with an intermediate CAG repeat number) are assumed to have been present in this area for a long time.

Two distinct components of initial glutamate release synchronized with anoxic depolarization in rat global brain ischemia

Numerous reports have suggested that anoxic depolarization is a critical event in the pathogenesis of cerebral ischemia. Extracellular glutamate concentration ([Glu]e) is closely related to the pathogenesis of ischemia. Therefore, these pathogenic mechanisms merit study, especially the relationship between [Glu]e elevation and the ionic basis of early changes in membrane potential after ischemic insult in vivo. It is often presumed from electrophysiological studies that a causal relationship exists between impaired glutamate uptake and/or progressive glutamate increase and anoxic depolarization, but few in vivo reports have found any sign of a progressive increase of [Glu]e elevation preceding anoxic depolarization. Recently, we reported the application of an oxygen-independent real-time technique for monitoring glutamate levels in the extracellular space during in vivo ischemia, and demonstrated that the massive glutamate release during ischemia is biphasic. In the present study, using this real-time monitoring system, we carried out a more detailed analysis of the initial events in the first phase of glutamate release during ischemia-induced anoxic depolarization. The shape of the rising slope that forms the peak of the first phase suggested two components. The second component was approximately 10 times steeper than the first, with two different components of the rise on the way to the peak of the biphasic [Glu]e elevation. This is the first report to demonstrate these components of the initial glutamate peak, and suggests a progressive second component of the [Glu]e increase preceding Ca2+-dependent release from synaptic vesicles with anoxic depolarization, in vivo.

Metabolism of ginsenoside Rg1 by intestinal bacteria. II. Immunological activity of ginsenoside Rg1 and Rh1

AIM

To compare the effect of ginsenoside Rg1 and its metabolite Rh1 on proinflammatory cytokines and their mRNA expression by THP-1 cells.

METHODS

Human peripheral blood mononuclear cells (PBMC) were incubated with Rg1 and Rh1 at concentrations of 0.1, 1, 10, and 100 mg/L, and the cell proliferation was measured 24 h after incubation. Radioimmunoassay (RIA) was used to detect the production of proinflammatory cytokines, TNF alpha, IL-1 alpha, and IL-8. TNF alpha mRNA level was detected by reverse transcription polymerase chain reaction (RT-PCR) after administration of Rg1 and Rh1.

RESULTS

Rg1 and Rh1 (at concentration of 0.1, 1, 10, 100 mg/L) had no effect on PBMC proliferation. Rh1 1 mg/L could upregulate the productions of TNF (and IL-8 induced by lipopolysaccharides (LPS) 10 mg/L plus phorbol myristate acetate (PMA) 200 nmol/L, however, Rg1 showed an inhibitory effect on TNF alpha production induced by LPS 100 mg/L. Rg1 1 mg/L and Rh1 100 mg/L enhanced the production of IL-1 alpha level in THP-1 cells in the presence of LPS 10 mg/L. RT-PCR revealed that Rh1 stimulated TNF alpha mRNA expression in suitable stimulatory conditions.

CONCLUSION

Rg1 and Rh1 have different effects on the production of cytokines produced THP-1 cells stimulated by LPS and PMA.

A case of monoclonal gammopathy associated with acute myelomonocytic leukemia with eosinophilia suggested to be the result of lineage infidelity

Acute myelomonocytic leukemia (AMMoL) accompanied by monoclonal gammopathy is a rare condition, and its pathogenesis and the cytogenetic mechanism of such leukemogenesis have not been determined in detail. A case of AMMoL with eosinophilia accompanied by immunoglobulin G kappa monoclonal gammopathy is described. Immunophenotypic studies of the peripheral blood and bone marrow mononuclear cells revealed no evidence of abnormally proliferating cells of B-lineage. DNA analyses of bone marrow mononuclear cells containing leukemic cells revealed rearrangement of the kappa-light chain (Igkappa) gene and c-myc and c-jun proto-oncogenes. The intensities of the rearranged bands for these genes on Southern blot analysis suggested the existence of a major population of leukemic cells with rearranged Igkappa gene and minor population(s) of leukemic cells with rearranged c-myc and/or c-jun proto-oncogene(s) in the patient's bone marrow and indicated the occurrence of genetic evolutionary changes in leukemic cells in this patient before starting chemotherapy. These results suggest that these leukemic cells are the most likely candidate for immunoglobulin G kappa monoclonal protein production, and structural abnormalities of c-myc and c-jun proto-oncogenes may have contributed to the evolution of leukemic cells in this patient.

Pentadentate terpyridine-catechol linked ligands and their cobalt(III) complexes

A series of novel pentadentate terpyridine-catechol linked ligands were prepared, in which the terpyridine and catechol moieties were linked together by (CH2)n chains of different lengths (n = 4-6). Together with 1-methylimidazole, these ligands formed low-spin, six-coordinate Co(III) complexes. Two of the complexes (n = 4, 5) were characterized by X-ray crystallography [n = 4, monoclinic, P2(1)/c, a = 14.957(7) A, b = 10.585(9) A, c = 23.033(7) A, beta = 106.01(3) degrees, V = 3505(3) A3, Z = 4, R = 0.063; n = 5, monoclinic, P2(1)/c, a = 8.848(7) A, b = 15.78(1) A, c = 25.455(7) A, beta = 93.90(5) degrees, V = 3544(3) A3, Z = 4, R = 0.056], which revealed similar structures around the Co(III) centers but different conformations for the (CH2)n linkers. The (CH2)4 linker showed a straight, symmetric conformation whereas the (CH2)5 linker showed a curved conformation that allowed the accommodation of one extra CH2 unit, suggesting that the (CH2)4 linker presents the "best-fit" length for these complexes.

The high level of hCDC10 gene expression in neuroblastoma may be associated with favorable characteristics of the tumor

BACKGROUND

The biological behavior of neuroblastomas detected through mass screening (MS, </=1 year of age) and that of mass screening-negative later-presenting (MSN, >1 year of age) neuroblastomas have been reported to differ in many studies. To investigate the biological differences between these two groups, we analyzed the differences in mRNA profiles.

MATERIALS AND METHODS

We analyzed the mRNA profiles of MS and MSN neuroblastomas using differential display, and cloned and sequenced the bands differentially expressed between these two groups. Using the RNA analysis by polymerase chain reaction (RNA-PCR) method, the relative amount of mRNA in tumor tissue in each sample was measured. Associations between relative amount of mRNA and clinical and genetic variables related to patient prognosis and the effect of the level of mRNA expression on survival probability were investigated using statistical methods.

RESULTS

Using differential display and RNA-PCR, we found that the mRNA for the human homologue of the yeast cdc10 gene (hCDC10) identified in Saccharomyces cerevisiae was expressed at a higher level in the MS group of patients than in the MSN group of patients (0.554 +/- 0.197 for MS neuroblastoma, n = 24 and 0.244 +/- 0.179 for MSN neuroblastoma, n = 10, P < 0.01), and this difference was suggested to be independent of the histologic subtype of tumor. A high level of hCDC10 mRNA expression in neuroblastomas (relative amount of hCDC10 mRNA > 0.35) was also suggested to be associated with younger age at diagnosis (</=1 year of age, P < 0.01), favorable clinical stage (I, II, and IVs, P < 0. 01), and favorable histology in the Shimada classification (P < 0. 01), whereas a low level of hCDC10 mRNA expression (relative amount of hCDC10 mRNA </=0.35) was suggested to be associated with the progression of clinical stage (P < 0.01) and N-myc gene amplification (>1 copy, P < 0.05). Patients with neuroblastomas with a high level of hCDC10 mRNA expression were suggested to have a better prognosis than those with a low level of hCDC10 mRNA expression (P < 0.01).

CONCLUSIONS

A high level of hCDC10 mRNA expression in neuroblastomas may be associated with favorable clinical and biological characteristics, and the expression of hCDC10 mRNA in neuroblastomas may affect the clinical and biological characteristics of this type of tumor.

Detection of aberrations of 17p and p53 gene in gastrointestinal cancers by dual (two-color) fluorescence in situ hybridization and GeneChip p53 assay

We performed dual (two-color) fluorescence in situ hybridization (FISH) using direct fluorescent labeling probes for p53 and chromosome 17 in six gastrointestinal (3 stomach and 3 colon) cancers. In three of these (1 stomach and 2 colon) the interphase cell nuclei showed an imbalance of signals for the p53 and chromosome 17; that is, the p53 signal count was lower than the chromosome 17 signal count, indicating deletion of the p53 gene. Moreover, metaphase FISH analysis demonstrated that those nuclei actually had a chromosome 17 with deletion of the p53 gene. Interestingly, these three cases had an abnormal chromosome 17 copy number, that is, chromosome 17 aneusomy. Furthermore, to investigate the possibility of p53 mutation in tumors with an imbalance of signals for chromosome 17 and p53 per nucleus, we performed a GeneChip p53 assay which has recently been developed. GeneChip p53 assay demonstrated that a primary tumor sample from one colon cancer case had a heterozygous point mutation of CGT (Arg) to CAT (His) at codon 273 in exon 8. In addition, a sample of metastatic tumor in the liver from the same case revealed two heterozygous point mutations. One of them was the same mutation as that is the primary tumor; the other was GTG (Val) to GGG (Gly) at codon 217 in exon 6. In conclusion, we found that the combination of dual-color FISH and GeneChip p53 assay offered reliable results and important information concerning not only deletion of the p53 gene and chromosome 17 aneusomy but also p53 mutations. Using these techniques, we demonstrated that an imbalance of signals for chromosome 17 and p53 per nucleus, chromosome 17 aneusomy, and accumulation of p53 mutations had occurred during carcinogenesis and development of gastrointestinal cancers.

A dominant negative mutant of sar1 GTPase inhibits protein transport from the endoplasmic reticulum to the Golgi apparatus in tobacco and Arabidopsis cultured cells

Protein secretion plays an important role in plant cells as it does in animal and yeast cells, but the tools to study molecular events of plant secretion are very limited. We have focused on the Sar1 GTPase, which is essential for the vesicle formation from the endoplasmic reticulum (ER) in yeast, and have previously shown that tobacco and Arabidopsis SAR1 complement yeast sar1 mutants. In this study, we have established a transient expression system of GFP-fusion proteins in tobacco and Arabidopsis cultured cells. By utilizing confocal laser scanning microscopy, we demonstrate that a dominant negative mutant of Arabidopsis Sar1 inhibits the ER-to-Golgi transport of Golgi membrane proteins, AtErd2 and AtRer1B, and locates them to the ER. The same mutant Sar1 also blocks the exit from the ER of a vacuolar storage protein, sporamin. These results not only provide the first evidence that the Sar1 GTPase functions in the ER-to-Golgi transport in plant cells, but also prove that conditional expression of dominant mutants of secretory machinery can be a useful tool in manipulating vesicular trafficking.

Endothelin-1 is a potent activator of nonselective cation currents in human bronchial smooth muscle cells

The effects of endothelin (ET)-1 on cultured human bronchial smooth muscle cells (HBSMC) were investigated and compared with those of histamine, using the patch clamp techniques and measurements of intracellular Ca(2+) ([Ca(2+)](i)). Both ET-1 and histamine caused an initial transient elevation of [Ca(2+)](i) by Ca(2+) mobilization, followed by a sustained rise due to Ca(2+) entry. Nicardipine inhibited the sustained phase, but La(3+) abolished it. With low ethyleneglycol-bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid (EGTA) and K(+) internal solutions, both ET-1 and histamine induced a sustained depolarization from approximately -40 to -20 mV. Under voltage clamp conditions, both drugs transiently activated an outward K(+) current at a holding potential of 0 mV. Additionally, with a Cs(+) internal solution, they elicited another transient inward current, frequently followed by current oscillations. These transient currents were blocked by high EGTA or heparin. With high EGTA and Cs(+) internal solutions, both drugs activated a long-lasting inward current. The reversal potential of these agonist-induced currents was approximately 0 mV and was not altered by the replacement of internal or external concentration of Cl(-), suggesting that the inward current was a nonselective cation current (I(cat)). The half-maximal effective concentration to activate I(cat) was 12 nM for ET-1 and 11 microM for histamine. La(3+) and Cd(2+) abolished these agonist-induced I(cat). The effects of ET-1 on [Ca(2+)](i) and I(cat) could be blocked by combined pretreatment with BQ-123 and BQ-788. Sarafotoxin S6c also increased [Ca(2+)](i) and activated I(cat). By polymerase chain reaction of reverse transcribed RNA, we detected both ET-A and ET-B receptor messenger RNA. These results provide the first evidence that ET-1 is a potent activator of I(cat) in HBSMC via ET-A and ET-B receptors, and the activation of I(cat) plays an important role in ET-1-induced Ca(2+) entry in human airways.

Synthesis and receptor sites of endothelin-1 in the rat liver vasculature

Immunocytochemical localization of big endothelin-1 (big ET-1), ET-1, and ET receptor A and B (ET(A) and ET(B)), and gene expression of prepro ET-1 mRNA were examined on the rat liver vasculature. Immunoreactivities for big ET-1 and ET-1 were preferentially seen along the endothelium of interlobular veins (IV) and artery (IA), although the staining intensity was more pronounced in IV. Expression of preproET-1 mRNA was detected in both vascular endothelia and the signal intensity was more prevalent in IV. Immunoelectron microscopy showed that rough endoplasmic cisterns were immunoreactive for big ET-1, while Weibel-Palade (WP) bodies, a storage site for ET-1, were immunoreactive for ET-1 in endothelial cells of IV. These results indicate that endothelial cells of IV are the major site of synthesis of ET-1, which is extracellularly secreted by degranulation and/or exocytosis of WP bodies. Hepatic stellate cells (HSCs), especially of the plasma membrane of perisinusoidal and interhepatocellular processes, were immunoreactive for both ET(A) and ET(B) receptor antibodies. These findings suggest that ET-1 receptor-mediated HSC contraction is involved in the regulation of hepatic sinusoidal blood flow as previously cited in mammalian liver cirrhosis. We also showed that sarcolemma and caveoles in the smooth muscle cells of the media of IV, and its branches before reaching the hepatic sinusoids, were immunoreactive for ET(A) receptor antibody. The results suggest that such vessels, which contains a large amount of hepatic blood inflow, participate in pump mechanism toward hepatic sinusoidal circulation in a receptor-mediated paracrine fashion.

Roles of hydrophobicity, protein binding and the probenecid-sensitive transport system in the cerebrospinal fluid delivery of nucleoside analogues with anti-viral activity

Ten nucleoside analogues with anti-herpes or anti-HIV activity were investigated for their transport into the cerebrospinal fluid (CSF) following intravenous administration in rats. The novel anti-herpes agent 1-beta-D-arabinofuranosyl-2-thio-5-fluorocytosine (5F-araSC) showed the highest CSF/plasma concentration ratio (>20%), while that of acyclovir (ACV) was very low (<5%). A linear relationship was observed between the partition coefficient (chloroform/water) and CSF/unbound plasma concentration in 6 of 9 agents. The exceptions were DDI, AZT and ACV, which showed much lower concentrations in the CSF than expected from their hydrophobicity and protein binding activities. The effects of probenecid treatment on the CSF and plasma concentrations were measured with continuous intravenous administration of ACV, AZT, araC and 5F-araSC. Probenecid markedly increased the CSF concentrations of ACV and AZT, although the effect was minimal in araC and 5F-araSC. These results may provide useful information for molecular design of nucleoside analogues with better transport to the brain.

Multi-impulsivity of Japanese patients with eating disorders: primary and secondary impulsivity

Several studies have noted that multi-impulsive bulimia nervosa tends to be refractory to treatment. However, it is not known whether these impulsivities are an expression of more fundamental psychopathology or simply the consequence of chaotic eating behaviors. Studies of the temporal relationship between the onset of eating disorder and the occurrence of impulsive behaviors will facilitate a better understanding of these issues. Subjects consisted of 60 patients with anorexia nervosa restricting type (AN-R), 62 patients with anorexia nervosa binge-eating/purging type (AN-BP), 114 patients with bulimia nervosa purging type (BN) and 66 control subjects. Impulsive behaviors and childhood traumatic experiences were assessed by self-report questionnaire. Multi-impulsivity (defined by at least three of the following: heavy regular alcohol drinking; suicide attempt; self-mutilation; repeated shoplifting of items other than food; sexual relationships with persons not well known to the subject) was found in 2% of AN-R, 11% of AN-BP, 18% of BN and 2% of control subjects. Eighty percent of BN patients with multi-impulsivity had a history of suicide attempts or self-mutilation history prior to the onset of bulimia nervosa. In BN patients, there tended to be a relationship between childhood parental loss or borderline personality disorder and multi-impulsivity. In conclusion, primary impulsivity (chronological prior occurrence of impulsive behaviors) does exist even in a very different culture, although the number of patients of this type is very limited.

Role of the JAK/STAT pathway in rat carotid artery remodeling after vascular injury

In cultured vascular smooth muscle cells (VSMCs), Janus kinases (JAKs) and signal transducers and activators of transcription (STATs) are expressed constitutively and play a role in angiotensin II (Ang II)-induced intracellular signaling and proliferation. However, little is known regarding the relevance of these proteins to the process of vascular remodeling. The role of JAK and STAT proteins in vascular remodeling and their functional coupling with Ang II were examined in balloon-injured rat carotid artery. Immunoreactive Jak2, Tyk2, Stat1, and Stat3 were not detected in the intact artery. Immunohistostaining showed transient expressions of these JAKs and STATs in medial and neointimal VSMCs at days 2 and 5, respectively, with a peak at day 7 in both layers. The expressions declined to insignificant levels by day 14. Ang II type 1 receptors (AT(1)s) were coexpressed in the medial and neointimal VSMCs expressing Jak2 and Stat3. The Jak2 and Stat3 inductions in the injured artery were accompanied by constitutive Jak2 and Stat3 phosphorylations, which were enhanced by ex vivo Ang II stimulation via AT(1). Additionally, a Jak2 inhibitor, AG490, blocked the Ang II-induced Stat3 phosphorylation. Furthermore, local treatment with AG490 inhibited constitutive Stat3 phosphorylation and neointimal VSMC replication and subsequently reduced neointima formation in the injured artery. In conclusion, JAK and STAT proteins were inducible in medial and neointimal VSMCs after vascular injury and were functionally coupled to AT(1). The inductions of JAKs and STATs would be involved in the mechanisms of neointima formation after vascular injury.