Thrombopoietin enhances neutrophil production by bone marrow hematopoietic progenitors with the aid of stem cell factor in congenital neutropenia

We examined the effects of granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), and thrombopoietin (TPO), alone or in combination, on the generation of neutrophils by bone marrow (BM) cells from three patients with severe congenital neutropenia (SCN) through the use of a serum-deprived liquid culture system. Synergistic effects of G-CSF and SCF on the neutrophil production by BM CD34+CD38+c-kit+ cells were observed in SCN patients as well as in normal controls. The addition of TPO to the culture containing G-CSF and SCF further augmented the growth of neutrophils in the two groups. Single-cell culture experiments revealed that the three-factor combination caused increases in both the number and size of neutrophil colonies compared with G-CSF + SCF in normal BM cells, whereas only a significant increment in the colony size was observed in SCN patients. Even in the presence of SCF or SCF + TPO, the concentrations of G-CSF necessary for the substantial production of neutrophils by CD34+CD38+c-kit+ cells were higher in two patients compared with the levels obtained by normal control cells. In addition, TPO did not accelerate the maturation of neutrophilic cells supported by G-CSF + SCF. When BM CD34+CD38-c-kit+ cells were targeted, the addition of TPO to the culture containing G-CSF and SCF was required for significant neutrophil colony growth in the two groups. These results suggest that TPO enhances the G-CSF-dependent neutrophil production with the aid of SCF in this disorder.

Primary gastric B cell lymphoma: audit of 82 cases treated with surgery and classified according to the concept of mucosa-associated lymphoid tissue lymphoma

There has been a trend toward stomach conservation during treatment for primary gastric lymphoma, but surgery ensures accurate pathologic diagnosis through the examination of resected specimens. A histopathologic classification for primary gastric lymphoma had been established with the knowledge that the low grade and high grade components occasionally coexist in a single lesion. Efficacy of this classification as an indicator of biologic behavior and prognosis was evaluated. The classification was performed by reexamining surgically resected specimens from 82 patients with stage IE and IIE gastric lymphoma. Clinical characteristics of the low grade and high grade lymphomas were then evaluated and the survival data analyzed. Despite the larger tumor diameter, the depth of invasion for the low grade type was mostly submucosal, and none had serosal invasion. In contrast, 50% of the high grade type had serosal involvement and were also found to have a higher incidence of node metastasis. Prognosis of the low grade type, a 10-year survival rate exceeding 90%, was significantly better than that of the high grade type. Multivariate analysis revealed that curability of the operation followed by the histopathologic grade were significant independent prognostic factors. Some characteristics of the low grade lymphoma were not consistent with what has been reported in the studies involving stomach-conserving strategies. Investigators are advised to note that the histopathologic grade determined with biopsy specimens alone could be misleading.

Differential response to corticosteroid therapy of MRI findings and clinical manifestations in spinal cord sarcoidosis

Spinal cord sarcoidosis is a rare disorder whose natural history and therapeutic outcome are not fully known. We examined four patients with spinal cord sarcoidosis both clinically and radiologically, particularly in relation to corticosteroid treatment. The initial manifestation was cervical myelopathy in three and uveitis in one. All four patients progressed slowly until corticosteroid therapy was initiated. The cervical spine was involved in all patients. Magnetic resonance imaging (MRI) who showed spinal cord swelling with T2-weighted high intensity and linear leptomeningeal and patchy or diffuse intramedullary enhancement with gadolinium diethylene triamine-pentaacetic acid. With corticosteroid therapy, dramatic improvement was seen on MRI, including disappearance or marked reduction of swelling and enhancement. Plasma levels of angiotensin-converting enzyme (ACE) were also markedly improved. In contrast, the clinical symptoms were little improved in one patient, unchanged in two, and rather worsened in one patient. Recurrence was seen on MRI at the maintenance dose in all four patients, without any dramatic change in clinical manifestation. MRI findings and plasma ACE are well correlated with active lesion of the spinal cord sarcoidosis, providing a useful marker for recurrence, but do not parallel the clinical manifestations.

Distribution of dorsal-forming activity in precleavage embryos of the Japanese newt, Cynops pyrrhogaster: effects of deletion of vegetal cytoplasm, UV irradiation, and lithium treatment

Two types of axis-deficient embryos developed after deletion of the vegetal cytoplasm: wasp-shaped embryos and permanent-blastula-type embryos. In situ hybridization revealed that neither type of axis-deficient embryo expressed goosecoid or pax-6. brachyury was expressed in the constricted waist region of the wasp-shaped embryos but was not expressed in the permanent-blastula-type embryos. Further, we examined the effect of UV irradiation on Japanese newt embryos. Surprisingly, UV-irradiated Japanese newt eggs formed hyperdorsalized embryos. These embryos gastrulated in an irregular circular fashion with goosecoid expression in the circular equatorial region. At tailbud stage, these embryos formed a proboscis which is very reminiscent of that formed in hyperdorsalized Xenopus embryos. Transplantation of the marginal region of the UV-irradiated embryos revealed that the entire marginal zone had organizer activity. Thus we conclude that UV hyperdorsalizes Japanese newt embryos. Finally, lithium treatment of normal embryos at the 32-cell stage also resulted in hyperdorsalization. Lithium treatment of vegetally deleted embryos had two distinct results. Lithium treatment of permanent-blastula-type embryos did not result in the formation of dorsal axial structures, while the same treatment reinduced gastrulation and dorsal axis formation in the wasp-shaped embryos. Based on these results, we propose a model for early axis specification in Japanese newt embryos. The model presented here is fundamentally identical to the Xenopus model, with some important modifications. The vegetally located determinants required for dorsal development (dorsal determinants, DDs) are distributed over a wider region at fertilization in Japanese newt embryos than in Xenopus embryos. The marginal region of the Japanese newt embryo at the beginning of development overlaps with the field of the DDs. Gastrulation is very likely to be a dorsal marginal-specific property, while self-constriction is most probably a ventral marginal-specific property in Japanese newt embryos.

Voltage-gated K(+)Channel, Kv4.2, localizes predominantly to the transverse-axial tubular system of the rat myocyte

Kv4.2 subunit, a member of K(+)channel gene family, is considered to play a major role in the formation of depolarization-activated transient outward K(+)current channels in the mammalian heart. We investigated the subcellular localization of Kv4.2 subunit in the rat heart by immunofluorescence and immunoelectron microscopy. In atrial cells, Kv4.2 immunofluorescent staining was intensely observed in the peripheral sarcolemma and the intercalated disks, but seldom found in transverse tubules, which are rare or absent in atrial cells. In ventricular cells, the labeling of Kv4.2 immunofluorescent staining was found throughout the entire cell membrane, and the staining was stronger in the transverse-axial tubular system than in the peripheral sarcolemma. Correlative immunoconfocal and immunoelectron microscopy using FluoroNanogold confirmed that Kv4.2 distributed in the transverse-axial tubular system including the longitudinally oriented axial tubules. Immunogold electron microscopy of ultrathin cryosections revealed that Kv4.2 was distributed on the plasma membranes of the T-tubules. The extensive distribution of Kv4.2 on the entire cell membrane of myocytes would provide rat myocardial cells with a large capability for the transport of K(+)ions through the channels in the repolarization phase.

[A case of superior sagittal sinus thrombosis following long-term medication with carbamazepine]

A 55-year-old man, who had been medicated with carbamazepine, phenobarbital, and sodium valproate for 12 years' duration, presented with severe headache, nausea, and transient diplopia. The neurological examination revealed mild disturbance of consciousness and postural tremor. He also complained of severe continuous headache but no throbbing pain. Enhanced head CT showed empty delta sign and irregular pooling of contrast agent around the superior sagittal sinus. Head MRI did not show the flow void in the superior sagittal sinus. Cerebral angiography demonstrated incomplete occlusion of the superior sagittal sinus and well-developed colateral channels. He was diagnosed having superior sagittal sinus thrombosis, and was placed on anticoagulant and antiplatelet drugs. He did not have any other risk factors such as inflammatory disease, infection, malignancy, and oral contraceptives. However, he had been medicated with some anticonvulsants including carbamazepine, which is known to induce venous thrombosis in the leg. Therefore, the association between superior sagittal sinus thrombosis and long term medication with carbamazepine was suspected. This is the first case report of anticonvulsant-associated cerebral venous thrombosis. It suggests that long-term medication with carbamazepine should be considered to be one of the risk factors for cerebral venous thrombosis.

Novel antiarthritic agents with 1,2-isothiazolidine-1,1-dioxide (gamma-sultam) skeleton: cytokine suppressive dual inhibitors of cyclooxygenase-2 and 5-lipoxygenase

Various 1,2-isothiazolidine-1,1-dioxide (gamma-sultam) derivatives containing an antioxidant moiety, 2,6-di-tert-butylphenol substituent, were prepared. Some compounds, which have a lower alkyl group at the 2-position of the gamma-sultam skeleton, showed potent inhibitory effects on both cyclooxygenase (COX)-2 and 5-lipoxygenase (5-LO), as well as production of interleukin (IL)-1 in in vitro assays. They also proved to be effective in several animal arthritic models without any ulcerogenic activities. Among these compounds, (E)-(5)-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-ethyl-1, 2-isothiazolidine-1,1-dioxide (S-2474) was selected as an antiarthritic drug candidate and is now under clinical trials. The structure-activity relationships (SAR) examined and some pharmacological evaluations are described.

Participation of neuropeptides in antigen-induced contraction of guinea pig bronchi via NK(2) but not NK(1) receptor stimulation

We evaluated the contribution of neuropeptides to antigen-induced contractions of isolated bronchi and tracheae of passively sensitized guinea pigs using CP-96345 and SR 48968, specific antagonists of NK(1) and NK(2) receptors, respectively, in combination with treatment by an antihistaminic and a cysteinyl leukotriene antagonist. SR-48968 but not CP-96345, significantly inhibited the late phase of the bronchial contraction. Phosphoramidon, a neutral endopeptidase inhibitor, tended to potentiate bronchial contraction. Posttreatment with SR-48968 decreased the enhanced contraction induced by the inhibitor as well as the nonenhanced contraction to similar levels of tension. On the other hand, antigen-induced tracheal contraction was not altered by either neuropeptide antagonist. These results suggest that neuropeptides mediate the antigen-induced contractile response of the guinea pig bronchus partly through NK(2) receptor stimulation.

An anterograde and retrograde tract-tracing study on the projections from the thalamic gustatory area in the rat: distribution of neurons projecting to the insular cortex and amygdaloid complex

Projections from the thalamic gustatory nucleus, i.e. the parvicellular part of the posteromedial ventral thalamic nucleus (VPMpc) to the forebrain regions were studied in the rat by the tract-tracing methods with anterograde tracer (biotinylated dextran amine, BDA) and anterograde/retrograde tracer (wheat-germ agglutinin-horseradish peroxidase, WGA-HRP). After BDA injection into the VPMpc, terminal labeling was observed in the insular cortex, amygdaloid complex, and fundus striati. The terminal labeling in the amygdaloid complex was distributed in dorsolateral area of the rostral part of the lateral amygdaloid nucleus and the rostral part of the lateral subdivision of the central amygdaloid nucleus. The terminal labeling in the central amygdaloid nucleus extended to the fundus striati. The retrograde tracing study with WGA-HRP revealed that the projection fibers from the VPMpc to the amygdaloid complex originated from the medial part of the VPMpc and also from the thalamic area medial to the VPMpc. In the rats injected with Fluoro-Gold and WGA-HRP, respectively into the insular cortex and amygdaloid complex, no double-labeled neuronal cell bodies were found in the VPMpc, although neurons labeled singly with Fluoro-Gold were intermingled with those singly labeled with WGA-HRP in the medial part of the VPMpc. The results indicated that VPMpc neurons projecting to the amygdaloid complex constituted a population different from VPMpc neurons projecting to the insular cortex.

Theophylline induces neutrophil apoptosis through adenosine A2A receptor antagonism

This study was designed to determine whether theophylline would augment granulocyte apoptosis via a mechanism of adenosine A2A receptor antagonism. A selective adenosine A2 receptor agonist (CGS-21680, 1 microM) exhibited the most efficient potency for decreasing neutrophil apoptosis for 16 h from 63+/-5 to 19+/-4% (P < 0.001); it exerted poor and adverse effects on eosinophil survival. A selective protein kinase A inhibitor KT-5720 (10 microM) reversed the capacity of dibutyryl cAMP but not CGS-21680 to induce an inhibitory effect on neutrophil apoptosis, suggesting that occupancy of adenosine A2 receptors inhibit neutrophil apoptosis by a cAMP-independent mechanism. Theophylline derivatives show the following pattern of potency for inducing neutrophil apoptosis competing with CGS-21680: 8-phenyltheophylline = 8-p-sulfophenyltheophylline > theophylline >> enprofylline. This pattern is consistent with the affinity established for A2A receptors. Theophylline demonstrated an additive effect to that of anti-Fas antibody (CH11, 1 microg/mL) in inducing neutrophil apoptosis, but not to that of adenosine deaminase or KF-17837 (a selective A2 receptor antagonist; 1 microM), suggesting conflicting effects on the receptor antagonism. These findings suggest that theophylline has an immunomodulatory action on neutrophil apoptosis via a mechanism of A2A antagonism.

Physiological change after local injection of liposomes containing tumor necrosis factor (TNF)

After the local (subcutaneous) administration of tumor necrosis factor-alpha (TNF), two types of physiological change were clearly observed in dogs. One was a systemic change, the other was a local change at the injected site. Solution, negatively charged liposome and positively charged liposome were locally injected in dogs. Even with local administration, the increase of triglyceride in plasma and the decrease of blood pressure were the most serious after administration of the solution. These changes were typical systemic side effects of TNF. Consequently, liposomes suppressed these serious systemic side effects of TNF after a local administration. Another physiological change was irritation at the injected site. However, after administration of positively charged liposome, the lowest irritation at the injected site was observed, along with the highest local concentration of TNF. We reported the superior antitumor effect of positively charged liposomes in solution, as well as the lowest systemic circulation after an intratumor administration. Therefore, it was speculated that a positively charged liposome directly acted on the tumor cells without TNF release. These results exhibited the potency of liposomal delivery of TNF with local administration.

Revealing hepatic metastases from colorectal cancer: value of combined helical CT during arterial portography and CT hepatic arteriography with a unified CT and angiography system

OBJECTIVE

The purpose of our study was to evaluate the use of combined helical CT during arterial portography and CT hepatic arteriography in the preoperative assessment of hepatic metastases from colorectal cancer using a unified CT and angiography system.

MATERIALS AND METHODS

Fifty-four patients with hepatic metastases from colorectal cancer preoperatively underwent combined CT during arterial portography and CT hepatic arteriography using the unified CT and angiography system. Three radiologists independently and retrospectively reviewed the images of CT during arterial portography alone, CT hepatic arteriography alone, and combined CT during arterial portography and CT hepatic arteriography. Image review was conducted on a segment-by-segment basis; a total of 432 hepatic segments with (n = 103) 118 metastatic tumors ranging in size from 2 to 160 mm (mean, 25.8 mm) and without (n = 329) tumor were reviewed.

RESULTS

Relative sensitivity of combined CT during arterial portography and CT hepatic arteriography (87%) was higher than that of CT during arterial portography alone (80%, p < 0.0005) and CT hepatic arteriography alone (83%, p < 0.005). Relative specificity of CT hepatic arteriography alone (95%, p < 0.0005) and combined CT during arterial portography and CT hepatic arteriography (96%, p < 0.0001) was higher than that of CT during arterial portography alone (91%). Diagnostic accuracy, determined by a receiver operating characteristic curve analysis, was greater with combined CT during arterial portography and CT hepatic arteriography than with CT during arterial portography alone (p < 0.05) or CT hepatic arteriography alone (p < 0.01).

CONCLUSION

Using a unified CT and angiography system, we found that combined CT during arterial portography and CT hepatic arteriography significantly raised the detectability of hepatic metastases from colorectal cancer.

Positively charged liposomes containing tumor necrosis factor in solid tumors

The antitumor effects against solid tumors, such as Meth A sarcoma, MH-134 hepatoma and colon 26 adenocarcinoma, were examined after intratumoral administration of liposomes and Tumor Necrosis Factor (TNF) solution. The antitumor effects of liposomes against solid tumors were superior to those of TNF solution. In particular, the antitumor effect of positively charged (decyl amine) liposomes was superior to that of negatively charged liposomes and TNF solution. Further, positively charged liposomes containing a higher dose of TNF than the solution could be administered without killing the mice, because of reduced side-effects. After intratumoral (Meth A sarcoma) administration, the TNF plasma concentration was determined in order to estimate the systemic side-effects of TNF. The area under curve (AUC) after administration of positively charged liposomes containing 6 times dose of TNF was about 1/30 the AUC after the administration of TNF solution. After administration of positively charged liposomes, TNF was mainly retained locally. Positively charged liposomes exhibited a stronger antitumor effect than the solution and had a lower AUC (about 1/180) than the solution. Consequently, some solid tumors could be completely cured by positively charged liposomes, because of their increased antitumor effect and reduced toxicity.

Analysis of capsid formation of human polyomavirus JC (Tokyo-1 strain) by a eukaryotic expression system: splicing of late RNAs, translation and nuclear transport of major capsid protein VP1, and capsid assembly

Human polyomavirus JC (JCV) can encode the three capsid proteins VP1, VP2, and VP3, downstream of the agnoprotein in the late region. JCV virions are identified in the nucleus of infected cells. In this study, we have elucidated unique features of JCV capsid formation by using a eukaryotic expression system. Structures of JCV polycistronic late RNAs (M1 to M4 and possibly M5 and M6) generated by alternative splicing were determined. VP1 would be synthesized from M2 RNA, and VP2 and VP3 would be synthesized from M1 RNA. The presence of the open reading frame of the agnoprotein or the leader sequence (nucleotides 275 to 409) can decrease the expression level of VP1. VP1 was efficiently transported to the nucleus in the presence of VP2 and VP3 but distributed both in the cytoplasm and in the nucleus in their absence. Mutation analysis indicated that inefficiency in nuclear transport of VP1 is due to the unique structure in the N-terminal sequence, KRKGERK. Within the nucleus, VP1 was localized discretely and identified as speckles in the presence of VP2 and VP3 but distributed diffusely in their absence. These results suggest that VP1 was efficiently transported to the nucleus and localized in the discrete subnuclear regions, possibly with VP2 and VP3. By electron microscopy, recombinant virus particles were identified in the nucleus, and their intranuclear distribution was consistent with distribution of speckles. This system provides a useful model with which to understand JCV capsid formation and the structures and functions of the JCV capsid proteins.

High-brightness 138-W green laser based on an intracavity-frequency-doubled diode-side-pumped Q-switched Nd:YAG laser

Green power of 138 W was generated at an estimated beam quality of M(2) = 11 by intracavity frequency doubling of a diode-pumped Nd:YAG laser. The laser employs a diffusive close-coupled diode-pumping design and a bifocusing-compensation resonator design to ensure stable operation.

[In vitro activities of carbapenem antibiotics against the various clinical isolates]

The annual changes of antibacterial activities of beta-lactam antibiotics, mainly carbapenem antibiotics, were investigated against 5 bacterial species, S. aureus (MSSA), methicillin-resistant S. aureus (MRSA), Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa, which had been isolated from the clinical materials at Toho University Omori Hospital during the period of 1995 to 1997. In addition, antibacterial activities against other main bacterial strains isolated from the clinical materials during 1997 were also determined. The five bacterial species on which annual changes of the sensitivity were investigated did not show any remarkable trend to increase in resistance to the carbapenem antibiotics tested. The antibacterial activities of the carbapenem antibiotics against MRSA were weak, and MIC90 values were between 25 and 50 micrograms/ml. In S. marcescens and P. aeruginosa on which high resistance by the production of metallo-beta-lactamase has become a problem in recent years, there were no remarkable changes in annual changes of sensitivities. Especially, MIC90 valuses of the carbapenem antibiotics against P. aeruginosa were between 12.5 and 25 micrograms/ml, 4 to 8 times better than that of PIPC, like the case of CAZ. Furthermore, the carbapenem antibiotics showed strong antibacterial activities against clinically important 16 bacterial species, from Gram-positive to Gram-negative bacteria.

[An autopsy case of bilateral carotid artery occlusion with repetitive epilepsy and brain atrophy in a senile patient]

A 67-year-old man was referred to us for tonic-clonic convulsions. A review of his history revealed that he had been hospitalized for loss of consciousness, hypotension, and suspected apoplexy at age 67. He had experienced prior tonic-clonic convulsions at age 72 and age 74. He had malaria and tuberculosis in his history but had been otherwise generally well. Physical examination was normal, and his blood pressure was 100/80 mmHg. Laboratory findings were normal except alcalinephosphatase (292 U/l) and gamma-glutamyl transpeptidase(60 U/l). Neurological examination showed alert consciousness, mild upper gaze palsy, slight right-side hemiparesis and left Babinski signs was present. Cranial magnetic resonance imaging showed no abnormality, but cerebral angiography revealed bilateral carotid artery occlusion. There were abundant leptomeningeal anastomoses, and the posterior communicating artery was supplied by the left vertebral artery. Electroencephalography showed a spike wave in the temporal lobe and rebuild-up phenomenon in the right hemisphere. Brain atrophy in the anterior and temporal lobes progressed, and the patient experienced gradual disorientation, delirium and hypobulia. He was eventually bedridden. He also demonstrated repetitive tonic-clonic convulsions. After one convulsion, he remained unconscious and died of pneumonia. Autopsy revealed thickening of the intima and internal elastic lamina in the occluded internal carotid artery. The anterior and middle cerebral arteries showed the same pathological changes. Multiple small infarctions restricted to grey matter were present in the cerebral cortex and may have caused the progressive brain atrophy. There was no myelin pallor in the white matter of the cerebrum. Atherosclerotic changes, senile plaque, and neurofibrillary tangles were seen but were within normal limits. These pathological findings were strongly suggestive of moyamoya disease.

20-W ultraviolet-beam generation by fourth-harmonic generation of an all-solid-state laser

We have obtained UV power of 20.5 W with a repetition rate of 10 kHz by the use of a high-brightness high-power all-solid-state green laser and a high-quality CsLiB(6)O(10) crystal. This power is, to our knowledge, the highest UV power achieved so far in all-solid-state lasers.

Left-right asymmetric expression of BbPtx, a Ptx-related gene, in a lancelet species and the developmental left-sidedness in deuterostomes

The long-standing question of how asymmetric development or asymmetric body structures in lancelets (amphioxus) are phylogenetically related to the body plan of other animals is still untouched. Three anterior structures, the preoral pit, club-shaped gland and mouth, are remarkable asymmetric features in developing lancelets that all open on the left side of the body. A Ptx-related gene, BbPtx is the first identified transcription factor gene with an asymmetrical expression pattern in lancelets similar to that in vertebrates, and thus it may provide a clue for the above question. Expression of the BbPtx gene is first detected at the dorsal margin of the blastopore in early mid-gastrulae and then becomes restricted to the left anterodorsal wall of the primitive gut and to the developing left somitocoelomic system. Expression continues on the left side in the developing preoral pit, club-shaped gland and mouth as well as in the mesoderm at the caudal end. Unlike D-Ptx1 in Drosophila, BbPtx is not coexpressed with a fork head gene in lancelets; instead the two genes are expressed in a complementary fashion on the left side of the embryo. The expression pattern of BbPtx is not compatible with the calcichordate hypothesis of Jefferies, in which the proposed ancestor of chordates rotated its tail 90 degrees counterclockwise in relation to the head/trunk. The expression of both BbPtx and vertebrate Pitx2 in tissues derived from the coelom implies that the left-right asymmetric development has a common origin between cephalochordates and vertebrates. Considering the development of the coelom in deuterostomes, however, left-right asymmetric development involving Pitx2-related genes is rather likely to be a primitive character shared among deuterostomes.

All-solid-state 5-kHz 0.2-TW Ti:sapphire laser system

We have developed an all-solid-state 5-kHz Ti:sapphire laser system, which produces 22-fs, 0.2-TW pulses. An average power of 22.2 W is the highest ever obtained in ultrashort laser sources. The serious thermal lensing due to high power pumping in a small area of the Ti:sapphire crystal is controlled successfully by a stable quasi-cavity with two concave mirrors.

A method for detection of a cytokine and its mRNA in the central nervous system of the developing rat

We report here an effective and concise method to determine the localization of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, and its mRNA in the central nervous system of pre- and postnatal rats. This method allows for double staining to demonstrate localization of different molecules on the same tissue specimen at the levels of mRNA and proteins by in situ hybridization and immunohistochemistry, respectively. Additionally, the present method gives results more quickly than the conventional isotopic techniques. By use of this method, we carried out immunohistochemistry with an anti-rat MIF polyclonal antibody and demonstrated positive staining using the avidin-biotin complex method (ABC method). To detect its mRNA, we performed nonradioactive in situ hybridization using a digoxigenin (DIG)-labeled RNA probe prepared from a full length fragment of rat MIF cDNA. MIF was strongly expressed in the telencephalon on embryonic day 16. Non-radioactive in situ hybridization with a DIG-labeled RNA probe as well as the immunohistochemistry described here could be applicable to characterize localization of mRNA and proteins of different molecules on the same tissue specimen.

Adenocarcinoma of the gastroesophageal junction in Japan: relevance of Siewert's classification applied to 177 cases resected at a single institution

BACKGROUND

There had been a lack of international consensus about the definition of cancer of the gastric cardia until Siewert's classification was approved at a consensus conference during the second International Gastric Cancer Congress held in 1997.

STUDY DESIGN

A review of the prospective gastric cancer database at Aichi Cancer Center from 1983 to 1992 identified 1,913 gastric carcinoma patients who underwent gastrectomy. These patients were classified retrospectively according to the Siewert classification, and 177 patients who fell into one of the three types form the basis of this study. Survival analyses were performed after stratifying patients by clinicopathologic variables.

RESULTS

There were 33 patients with type II and 144 with type III, although none had type I, a type frequently observed in the west. No evidence of a change in the frequency of types II or III cancers (approximately 9.3% overall) among gastric carcinoma patients was observed over the 10-year period. Clinical staging of gastric carcinoma by the TNM classification was found to reflect accurately the prognosis of these patients. There were no longterm survivors among the few patients with metastasis to the perigastric nodes of the distal stomach.

CONCLUSIONS

A striking difference in the distribution of types of adenocarcinoma of the gastroesophageal junction was observed in Japan compared with previously reported western data. A subgroup of carcinoma of the proximal stomach identified as types II and III may not require proximal gastrectomy from the viewpoint of sufficient lymphadenectomy.

Induction of apoptosis in metastatic foci from human gastric cancer xenografts in nude mice and reduction of circulating tumor cells in blood by 5-FU and 1-hexylcarbamoyl-5-fluorouracil

Antimetastatic effects of 5-FU and its derivative, 1-hexylcarbamoyl-5-fluorouracil (HCFU) on human gastric cancer micrometastasis and their mode of action were evaluated, using a spontaneous lung metastasis model (HY-1) in nude mice. Metastases were first detected in the lung from 4 weeks after subcutaneous transplantation, growing intravascularly and forming micrometastases at 100% incidence by 6 weeks after implantation. Lung metastasis in mice bearing subcutaneous tumors was significantly inhibited by HCFU at doses of 100-150 mg kg(-1) day(-1) without severe toxic side-effects, when orally administered three times per week either from week 4 or week 6 to 9 weeks after implantation. Spontaneous lung metastasis was also inhibited by the administration of 5-FU, but to lesser extent than with HCFU at equimolar low doses. Apoptosis within primary tumors and lung metastatic foci, as detected by the terminal-deoxynucleotidyltransferase-mediated dUTP nick-end labeling method, was found to be significantly enhanced by HCFU as well as 5-FU administration at doses of more than 100 mg kg(-1) day(-1) and 50 mg kg(-1) day(-1) respectively. However, proliferating activity of the metastatic foci, as evaluated by MIB-1 immunostaining, was not significantly suppressed by HCFU or 5-FU treatment. Furthermore, polymerase chain reaction analysis using human specific primers for the beta-globin gene, which proved to be capable of detecting 10 tumor cells/ml mouse blood, revealed that circulating tumor cells in the peripheral blood of mice bearing primary tumors were reduced by HCFU or 5-FU administration. These results indicate that circulating tumor cells in blood and micrometastases in the lung are sensitive to these chemotherapeutic agents, and suggest that the anti-metastatic effect of these agents is mediated, at least in part, by enhanced apoptosis rather than by inhibition of cell proliferation.

Peritoneal washing cytology: prognostic value of positive findings in patients with gastric carcinoma undergoing a potentially curative resection

BACKGROUND AND OBJECTIVES

Free cancer cells in the abdominal cavity exfoliated from a tumor are considered to be responsible for peritoneal dissemination, the most frequent pattern of failure in gastric carcinoma patients treated with curative surgery.

METHODS

A prospective survival analysis was performed with 91 gastric carcinoma patients treated by potentially curative resection. Cytology was performed for all the patients. The method of Kaplan and Meier was used to construct curves with diagnosis of peritoneal dissemination and cancer death as the end points. Multivariate analysis by Cox's proportional hazards model was performed to identify independent prognostic factors of significance.

RESULTS

Patients with a positive cytology result were confirmed to have a greater risk for recurrence in the pattern of peritoneal carcinomatosis and hence a significantly inferior prognosis. Positive cytology was the only significant independent prognostic factor among the curatively resected patients with advanced gastric carcinoma.

CONCLUSIONS

Peritoneal lavage cytology should be employed for all advanced cancer undergoing potentially curative resection for added accuracy in the stage classification. The results should also reflect the eligibility of the patients for future clinical trials involving perioperative intraperitoneal chemotherapy.

[The cerebral peduncle lesion in multiple system atrophy]

Atrophy of the cerebral peduncle and the pons can be seen on radiologic examination in patients of multiple system atrophy. This radiologic finding is one of the landmarks for the diagnosis of multiple system atrophy, but its detailed pathological background has not been thoroughly assessed. To clarify the pathological features of the cerebral peduncle lesion, samples from 28 autopsied cases (male 16, female 12; age 50-76 yr) were semiquantitatively examined after staining by HE, KB, Holzer, GFAP, Bodian and Gallyas methods. Atrophy of the cerebral peduncle was symmetric in most cases and resulted from the loss of small-sized nerve fibers. The glial cytoplasmic inclusion (GCI) in the cerebral peduncle increased significantly in severe atrophic cases compared with mild atrophic cases. However, in the most severe atrophic cases, in which this tissue was severely damaged, the GCI was decreased. The atrophy of the cerebral peduncle correlated significantly with the degree of degeneration in the olivo-ponto-cerebellar system and tended to correlate with a decrease in brain weight. The duration of disease is significantly longer in severe atrophic cases compared with mild atrophic cases.

Development of a novel mouse model for dengue virus infection

In the present study, we established an animal model for dengue virus infection using severe combined immunodeficient mice transplanted with a human hepatocarcinoma cell line (HepG2). At 7-8 weeks after transplantation, the HepG2-grafted mice were infected intraperitoneally with dengue virus type 2 (DEN-2). A higher titer of the virus was detected in the liver and serum but not in the brain in the early stage of postinfection. When the mice showed paralysis, the highest titer of virus was detected in the serum and brain. DEN-2 antigens were also found in HepG2 cells of the liver in the early stage and some neurons of the brain in the late stage. Upon clinical examination, thrombocytopenia, prolonged partial thromboplastin time, and increased hematocrit, blood urea nitrogen, and tumor necrosis factor alpha were seen in the paralyzed mice. Moreover, mild hemorrhage in the liver and tarry stool in the small intestine were observed in some mice. Our results show some similarities to human DEN infection and this mouse model might be valuable for studying some aspects of pathogenesis of this disease.

Case of intraductal papillary mucinous tumor (noninvasive adenocarcinoma) of the pancreas resected 27 years after onset

A case of intraductal papillary mucinous tumor (IPMT) of the pancreas resected 27 yr after onset is presented. In March of 1997, a 71-yr-old man was admitted to our hospital with a complaint of severe epigastric pain. He had initially undergone endoscopic retrograde pancreatography (ERP) in April 1971 in our hospital and the patient had been followed up for pancreatografic changes for 26 yr. Dilatation of the main pancreatic duct gradually progressed during follow-up, and the filling defect owing to the tumor became demonstrable. On admission, ERP revealed diffuse dilatation of the main pancreatic duct, which was 20 mm in diameter, and the filling defect of 35 mm in diameter. We diagnosed this patient as having an IPMT of the pancreas. Considering his general condition, pancreatic segmentectomy was carried out, and the postoperative course was favorable. Histological findings were compatible with those of noninvasive papillary adenocarcinoma. This is a precious case for studying the natural history of intraductal papillary tumor of the pancreas and to evaluate the application of surgery, because the biologic behavior of this tumor is much less aggressive than that of pancreatic ductal cell carcinoma.

Cytolytic mechanisms involved in non-MHC-restricted cytotoxicity in Chediak-Higashi syndrome

To determine the mechanisms responsible for the impaired lymphocyte-mediated cytotoxicity in Chediak-Higashi syndrome (CHS), we investigated the killing ability of peripheral blood lymphocytes (PBL) from three patients with CHS using several kinds of target cells that were sensitive to perforin, Fas ligand (FasL), and/or tumour necrosis factor-alpha (TNF-alpha). Freshly isolated CHS PBL did not kill K562 target cells, killing of which by normal PBL was perforin-dependent, as demonstrated by complete inhibition by concanamycin A (CMA), an inhibitor of perforin-based cytotoxicity. In contrast, the CHS PBL exhibited substantial cytotoxicity against Jurkat cells, which was only partially inhibited by CMA treatment but not by the addition of neutralizing anti-FasL or anti-TNF-alpha antibodies. IL-2-activated CHS PBL exhibited substantial levels of cytotoxicity against K562 and Jurkat cells, the levels being 74% and 83% of the respective normal control values, respectively. CMA treatment showed that while the cytotoxicity of IL-2-activated CHS PBL against K562 was largely dependent on perforin, that against Jurkat was largely not. IL-2-activated CHS PBL expressed FasL mRNA, and killed Fas transfectants. These findings indicate that CHS PBL have an ability to kill some target cells via a perforin-mediated pathway, especially when they are activated by IL-2. It was also demonstrated that CHS PBL can exert cytotoxicity against certain target cells by utilizing FasL and an undefined effector molecule other than perforin, FasL, or TNF-alpha.

Peritoneal washing cytology: prognostic value of positive findings in patients with gastric carcinoma undergoing a potentially curative resection

BACKGROUND AND OBJECTIVES

Free cancer cells in the abdominal cavity exfoliated from a tumor are considered to be responsible for peritoneal dissemination, the most frequent pattern of failure in gastric carcinoma patients treated with curative surgery.

METHODS

A prospective survival analysis was performed with 91 gastric carcinoma patients treated by potentially curative resection. Cytology was performed for all the patients. The method of Kaplan and Meier was used to construct curves with diagnosis of peritoneal dissemination and cancer death as the end points. Multivariate analysis by Cox's proportional hazards model was performed to identify independent prognostic factors of significance.

RESULTS

Patients with a positive cytology result were confirmed to have a greater risk for recurrence in the pattern of peritoneal carcinomatosis and hence a significantly inferior prognosis. Positive cytology was the only significant independent prognostic factor among the curatively resected patients with advanced gastric carcinoma.

CONCLUSIONS

Peritoneal lavage cytology should be employed for all advanced cancer undergoing potentially curative resection for added accuracy in the stage classification. The results should also reflect the eligibility of the patients for future clinical trials involving perioperative intraperitoneal chemotherapy.

[An adult patient of Reye's syndrome--the possible background mechanism of lesions in claustrum, striatum and limbic system and limbic dementia]

We reported a 35-year-old male patient with Reye's syndrome, who showed temporarily lesions of claustrum, striatum, hippocampus and amygdala on CT, MRI and PET scan. He was previously healthy and affected upper respiratory infection. After taking 4 tablets of aspirin (335 mg x 4), he developed severe headache and status epileptics. The cerebrospinal fluid showed normal cell count and protein. The serum GOT and GPT elevated to 499 IU/l and 221 IU/l respectively. The parainfluenza virus type I titer was 32 times on admission and increased up to 128 times two weeks later. In spite of the anticonvulsant, status epileptics lasted for about one month and he needed mechanical ventilation. On 13-18 days of illness, abnormal lesions appeared in bilateral claustrum and striatum on CT and MRI. On 49 days of illness, abnormal lesions appeared in bilateral hippocampus and amygdala. All these lesions changed into normal on MRI on 111 days of illness. The 18F-FDG PET study on 80 days of illness revealed high uptake on striatum, hippocampus and amygdala bilaterally and changed into normal on 130 days of illness. He has improved markedly but showed long-standing abnormal signs of limbic dementia. We suggested this patient could be suffered from post infectious encephalitis in limbic system after Reye's syndrome.

Hypoxia inhibits the changes in action potentials and ion channels during primary culture of neonatal rat ventricular myocytes

Action potentials of rat ventricular myocytes are progressively shortened after birth within several weeks mainly due to a progressive increase in transient outward potassium current (I(to)). On the supposition that an elevation in blood oxygen after birth may contribute to such developmental change, we studied effects of long-term exposure to hypoxia on changes in cardiac action potentials and I(to). Single ventricular myocytes isolated from day-old neonatal rat hearts were cultured in normoxic condition (21% O(2)) for 15 days and served as control. To test the influence of long-term exposure to hypoxia, O(2)tension was reduced to 7.5% at day 6 during culture. In 15-day cells cultured in normoxia, action potential duration (APD) was shortened by 44% (n=11) compared with 5-day cells (n=10); cell capacitance was increased to 2.0-fold. I(to)density was increased by 189-265% (n=11) at voltage levels from -20 to 50 mV without any changes in the kinetics of current inactivation. In 15-day cells cultured in hypoxia, APD was shortened only by 16% (n=6) from control; the increment of cell capacitance was 2.1-fold (n=6). The I(to)increment was limited to 53% (n=8); both inactivation and its recovery of the current was apparently slowed due to the amplification of the slower component. These results suggest that the developmental augmentation of I(to)expression during culture requires oxygen and the increase in I(to)and cell hypertrophy are likely regulated independently.

Isolation and characterization of temperature-sensitive mutations in the gene (rpb3) for subunit 3 of RNA polymerase II in the fission yeast Schizosaccharomyces pombe

Subunit 3 (Rpb3) of eukaryotic RNA polymerase II is a homologue of the alpha subunit of prokaryotic RNA polymerase, which plays a key role in subunit assembly of this complex enzyme by providing the contact surfaces for both beta and beta' subunits. Previously we demonstrated that the Schizosaccharomyces pombe Rpb3 protein forms a core subassembly together with Rpb2 (the beta homologue) and Rpb11 (the second alpha homologue) subunits, as in the case of the prokaryotic alpha2beta complex. In order to obtain further insight into the physiological role(s) of Rpb3, we subjected the S. pombe rpb3 gene to mutagenesis. A total of nine temperature-sensitive (Ts) and three cold-sensitive (Cs) S. pombe mutants have been isolated, each (with the exception of one double mutant) carrying a single mutation in the rpb3 gene in one of the four regions (A D) that are conserved between the homologues of eukaryotic subunit 3. The three Cs mutations were all located in region A, in agreement with the central role of the corresponding region in the assembly of prokaryotic RNA polymerase; the Ts mutations, in contrast, were found in all four regions. Growth of the Ts mutants was reduced to various extents at non-permissive temperatures. Since the metabolic stability of most Ts mutant Rpb3 proteins was markedly reduced at non-permissive temperature, we predict that these mutant Rpb3 proteins are defective in polymerase assembly or the mutant RNA polymerases containing mutant Rpb3 subunits are unstable. In accordance with this prediction, the Ts phenotype of all the mutants was suppressed to varying extents by overexpression of Rpb11, the pairing partner of Rpb3 in the core subassembly. We conclude that the majority of rpb3 mutations affect the assembly of Rpb3, even though their effects on subunit assembly vary depending on the location of the mutation considered.

Effect of a magnetic field on sonoluminescence

The effect of a magnetic field on single-bubble sonoluminescence in water reported experimentally by Young, Schmiedel, and Kang [Phys. Rev. Lett. 77, 4816 (1996)] is studied theoretically. It is suggested that bubble dynamics is affected by the magnetic field because moving water molecules of the liquid suffer torque due to the Lorentz force acting on their electrical dipole moment, which results in the transformation of some of the kinetic energy into heat. It is shown that the magnetic field acts as if the ambient pressure of the liquid were increased. It is suggested that the effect increases as the amount of the liquid water increases. It is predicted that nonpolar liquid such as dodecane exhibits no effect of the magnetic field.

Mechanism of single-bubble sonoluminescence

The mechanism of the light emission of single-bubble sonoluminescence (SBSL) is studied theoretically based on the quasiadiabatic compression model. It is concluded that SBSL is not the blackbody radiation but the thermal radiation. It is clarified that the shape of the spectrum is determined by the temperature inside the bubble and the intensity is determined by the rates of the microscopic processes of the light emission. For a noble-gas bubble, radiative recombination of electrons and ions and electron-atom bremsstrahlung are the dominant microscopic processes of the light emission, and the intensity is mainly determined by the degree of ionization of the gas inside the bubble. It is also clarified that for a noble-gas bubble the pulse width of the light is nearly independent of wavelength.

Effects of antitumor agents on inducible prostacyclin production in vascular smooth muscle

The effects of various antitumor agents were examined on prostacyclin production induced by interleukin-1beta in rat aortic smooth muscle cells. Stimulation of the cells with interleukin-1beta (2.5 ng/ml) resulted in a great increase of prostacyclin production, which was abolished by indomethacin (1 microM) or cycloheximide (2 microM). Daunorubicin at 0.1-1 microM inhibited the inducible prostacyclin production in a concentration-dependent manner. However, other antitumor agents (cyclophosphamide at 1-100 microM, 5-fluorouracil at 1-100 microM and vincristine at 1-100 nM) tested did not significantly affect it. Protein expression of cyclooxygenase-2 induced by interleukin-1beta was inhibited by daunorubicin at 0.1-1 microM, but was not affected by other antitumor agents. These results suggest that daunorubicin inhibits induction of cyclooxygenase-2 and subsequent prostacyclin production in rat aortic smooth muscle cells.

Presenility of granulocytes in Down syndrome individuals

Neutrophil function defects occur in individuals with Down syndrome (DS). We examined apoptosis of granulocytes (neutrophils and eosinophils) in DS individuals and control healthy subjects. Granulocyte survival was shortened in DS individuals, and the percentage of apoptotic granulocytes from DS during incubation was significantly higher than that from healthy subjects. The difference was time-dependent, and that between DS and healthy subjects was nearly 30% after longer periods of incubation. In control granulocytes, both granulocyte-macrophage colony-stimulating factor (10 ng/ml) and interleukin-5 (5 ng/ml) counteracted the programmed cell death and delayed the apoptosis caused by anti-Fas antibodies, whereas those inflammatory cytokines were not able to completely prevent cellular apoptosis in DS patients. Apoptosis and functional impairment of granulocytes may contribute to the risk of infections underlying pathological conditions of DS, and accelerated apoptosis of granulocytes may be a factor to prevent chronic airway inflammation and bronchial asthma in DS individuals.

Interferon therapy lowers the rate of progression to hepatocellular carcinoma in chronic hepatitis C but not significantly in an advanced stage: a retrospective study in 1148 patients. Viral Hepatitis Therapy Study Group

BACKGROUND/AIM

Hepatocellular carcinoma frequently develops during the advanced stages of chronic hepatitis C. We examined whether interferon prevents the development of hepatocellular carcinoma in chronic hepatitis C patients.

METHODS

Japanese patients with chronic hepatitis C (n = 1.148; 117 with portal fibrous expansion (F1), 636 with bridging fibrosis (F2), 355 with bridging fibrosis and architectural distortion (F3)) and 40 cirrhotic (F4) patients were treated with interferon. These patients were followed from 1 to 7 years after interferon therapy. Blood tests and image analysis were serially performed to assess response to interferon and to detect hepatocellular carcinoma. Fifty-five cirrhotic type C patients (control F4) not receiving interferon were enrolled in this study.

RESULTS

Sustained (SR: 27.5%) and transient (TR: 23.0%) responders totaled 50.5%, while 49.5% did not respond to interferon. SR showed an improvement in disease stage reflected by increased platelet counts. Fifty-two patients (9 F2, 36 F3, and 7 F4) developed hepatocellular carcinoma in the follow-up period; 3 SR, 8 TR, and 41 non-responders (NR). The cumulative incidence of hepatocellular carcinoma in F2 was significantly lower (p = 0.019) in SR compared with NR, but not in SR in F3 and F4 patients. However, the cumulative incidence of hepatocellular carcinoma was significantly decreased in all SR (p = 0.0001) and TR (p = 0.0397) compared with all NR.

CONCLUSION

These results indicate that interferon therapy in chronic hepatitis C patients lowered the rate of progression of hepatocellular carcinoma in sensitive cases but not in patients in an advanced stage.

Age-related morphologic changes of the central canal of the human spinal cord

To elucidate the role of the human central canal on the physiology and pathogenesis of acquired syringomyelia, we analyzed the age-related morphologic changes in the normal human central canal of the spinal cord. The subjects included 158 autopsy cases ranging in age from 1 week postnatally to 116 years of age. Each segment of the whole spinal cords was investigated from the C3 to S3 levels. The microscopic pictures of the central canal were classified as patent or occluded at each level for each age decade. The patency rate under 1 year of age was 100% in almost all the segments, which markedly decreased in the second decade, and the canals were occluded in all the segments with advancing age. According to the longitudinal pattern of the central canal occlusion, 19 of 20 cases where the canals were patent in all segment levels were less than 10 years of age. Cases in which the canals were occluded in all segment levels appeared in the second decade, and their number increased gradually with advancing age. The occlusion of the central canal started at the T6 and L5 to S2 levels. We suggest that the central canal does not function after infancy because of its occlusion, and that it is not involved in the development of syringomyelia in adult patients.

Attenuation changes in periportal region during triple-phasic contrast-enhanced CT

OBJECTIVE

To evaluate attenuation changes in the periportal regions of the liver during triphasic contrast CT.

MATERIALS AND METHODS

The study group consisted of 93 patients, all of whom underwent triphasic contrast-enhanced CT with a helical scanner for survey of liver disease. The three phases included the arterial phase, portal venous phase, and equilibrium phase. Attenuation changes in the periportal area in each phase were evaluated in every patient. Factors surmised to be related with periportal low attenuation, including elevation of venous pressure, presence of ascites, cardiac enlargement, and lymphadenopathy of the porta hepatis and lesser omental region, were also evaluated.

RESULTS

Periportal low attenuation was seen in 65 patients (69.8%) in the portal venous phase where the liver parenchyma showed the largest attenuation value. Among them, periportal low attenuation was continuously observed in every phase in 13 patients (13.9%), while it was confirmed only in the portal venous phase in 28 patients (30.1%), and in 24 patients (32.2%) in the portal venous phase plus either the arterial or equilibrium phase. None of the factors that were investigated could be related to the appearance of periportal low attenuation.

CONCLUSION

Periportal low attenuation was a relatively common finding in the portal venous phase of triphasic contrast CT, whereas it was less usual in the arterial or equilibrium phase.

beta-adrenergic modulation of L-type Ca2+-channel currents in early-stage embryonic mouse heart

Little information is available concerning the modulation of cardiac function by beta-adrenergic agonists in early-stage embryonic mammalian heart. We have examined the effects of isoproterenol (Iso) on the spontaneous beating rate and action potential (AP) configuration in embryonic mouse hearts at 9.5 days postcoitum (dpc), just 1 day after they started to beat. Iso (3 microM) increased the spontaneous beating rate in whole hearts, dissected ventricles, and isolated ventricular myocytes. In ventricular myocytes, Iso also increased the slope of the pacemaker potential and the action potential duration but decreased the maximum upstroke velocity. In whole cell voltage-clamp experiments, the Ca2+-channel currents were measured as Ba2+ currents (IBa). In 9.5-dpc myocytes, IBa was enhanced significantly from -4.7 +/- 0.9 to -6.7 +/- 1.2 pA/pF (by 52.4 +/- 14.8%, n = 10) after the application of Iso. Propranolol (3 microM) reversed the effect of Iso. Forskolin (For, 10 microM) produced an increase in IBa by 95.5 +/- 18.8% (n = 8). In ventricular myocytes at a late embryonic stage (18 dpc), 3 microM Iso caused an appreciably greater increase in IBa from -6.2 +/- 0.5 to -14.5 +/- 2.2 pA/pF (by 137.8 +/- 33.0%, n = 8), whereas the increase in IBa by 10 microM For (by 120.0 +/- 23.0%, n = 7) was comparable to that observed in the early stage (9.5 dpc). These results indicate that the L-type Ca2+-channel currents are modulated by beta-adrenergic receptors in the embryonic mouse heart as early as 9.5 dpc, probably via a cAMP-dependent pathway.

CT and MR findings of splenic angiosarcoma

A surgically confirmed primary splenic angiosarcoma is described. Although angiography showed most of the characteristic findings of the present patient, MR imaging provided a useful information as a supplemental tool. The tumor demonstrated low-signal intensity on both T1- and T2-weighted images, which might differ from hemangioma findings. Subacute hemorrhage within the tumor was revealed by MR imaging, suggesting the way in which the tumor grew during a short period of time. This finding was different from reported angiosarcoma MR findings of siderotic nodules within the tumor. After the administration of Gd-DTPA, MR images clearly demonstrated heterogeneous enhancement within the tumor, which corresponded to the pathologic findings of solid parenchyma with necrotic tissues.

Paracrine hypertrophic factors from cardiac non-myocyte cells downregulate the transient outward current density and Kv4.2 K+ channel expression in cultured rat cardiomyocytes

OBJECTIVES

Cardiac hypertrophy is characterized by a prolongation of action potential duration (APD) and a reduction of outward K+ currents, primarily the transient outward current (Ito). Since the interaction between cardiac non-myocyte cells (NMCs) and cardiomyocytes (MCs) plays a critical role during the process of myocardial hypertrophy, in the present study, we investigated the effects of NMCs on cell growth and K+ channel expression in cultured newborn rat ventricular cells.

METHODS

Single MCs were isolated from day-old Wistar rat ventricles and cultured for a period of five days. The effects of NMCs were examined by MC-NMC co-culture or incubating pure MCs in NMC-conditioned growth medium (NCGM). Whole-cell voltage-clamp recording and Western blot analysis using a polyclonal antibody against rat Kv4.2 channel protein were performed.

RESULTS

A marked increase in surface area and total cell protein concentration of MCs was observed in the MC-NMC co-culture. In the pure MC culture, this hypertrophic effect could be mimicked by a 72-h addition of NCGM, with a significant prolongation of APD25 (APD at 25% repolarization) and a 42% decrease in Ito density (at +30 mV). The rates of inactivation and recovery from inactivation of Ito were unchanged. In the NCGM-treated MC culture, Western blots of MC proteins also showed a 36% reduction of the Kv4.2 K+ channel protein level. In addition, the NCGM-induced MC hypertrophy was partially inhibited by anti-insulin-like growth factor-1 (IGF-1) antibody, while it revealed no effects on Ito density and Kv4.2 channel expression.

CONCLUSIONS

These findings first demonstrate that some paracrine hypertrophic factors released from cardiac NMCs, although unidentified, downregulate cardiac K+ channel expression.

Orientation change of cardiocytes induced by cyclic stretch stimulation: time dependency and involvement of protein kinases

Mechanical stress has been implicated as one of the growth regulators in the heart. We investigated the effect of cyclic stretch stimulation on morphology and orientation of cultured cardiocytes. Embryonic rat (17 days postcoital) cardiomyocytes cultured on silicone dishes were cyclically stretched to 120% in length at a frequency of 30 cycles/min. After 12 h, in the initial stage of cultivation, cardiocytes and intracellular myofibrils oriented parallel to the stretch direction. When the stretch stimulus was prolonged to 24-48 h, myofibrils that oriented perpendicular to the stretch direction emerged. Furthermore, when the cells were stretched only in the later stage (after 24 h of cultivation), both cells and myofibrils tended to orient perpendicular to the stretch direction. Next we examined the effects of chemical compounds on these phase-related changes in myofibril orientation. None of the drugs tested (H-7, HA-1004, staurosporine, herbimycin A, genistein, GdCl3, and EGTA) blocked the parallel orientation of myofibrils induced by the initial-stage stretch. By contrast, H-7, staurosporine, herbimycin A, and genistein did inhibit almost completely the perpendicular orientation of the myofibrils induced by the late-stage stretch, but HA-1004, GdCl3, or EGTA did not. Immunoblotting study using anti-phsophotyrosine antibody indicated that tyrosine phosphorylation of a protein of about 125 kDa was enhanced in a time-dependent manner by the late-stage stretch, but not by the initial-stage stretch.

IN CONCLUSION

the alignment change induced by cyclic stretch depends on the stage of cultivation: with stretch in the initial stage (within 12 h), cells and myofibrils orient parallel to the stretch; with stretch in the later stage (after 24 h), they orient perpendicular to the stretch. The effect of stretch in the later stage is likely mediated by protein kinase C and tyrosine kinase pathways.

CD27/CD70 interaction augments IgE secretion by promoting the differentiation of memory B cells into plasma cells

The induction of IgE switching in B cells requires several signals given by cytokines and cell contact-delivered signals. Here, we investigated the role of CD27/CD70 interaction in B cell IgE synthesis. The addition of CD27 ligand (CD70) transfectants to B cell cultures increased the IgE synthesis synergistically in the presence of IL-4 plus anti-CD40 mAb (anti-CD40). The effect of CD70 transfectants was dose dependent and was completely blocked by anti-CD70 mAb. CD27+ B cells had the ability to produce IgE, which was increased by contact with CD70 transfectants, whereas CD27- B cells did not produce IgE. CD27/CD70 interaction enhanced B cell proliferation in the presence of IL-4 or IL-4 plus anti-CD40. The augmentation of B cell proliferation by CD70 transfectants was apparent in CD27+ B cells, but was mild in CD27- B cells. The helper activity for IgE synthesis by the CD27/CD70 interaction did not contribute to the enhancement of germline epsilon transcripts. Flow cytometric and morphological analyses demonstrated that the addition of CD70 transfectants to B cell cultures remarkably promoted differentiation into plasma cells in the presence of IL-4 and CD40 signaling. Finally, CD27 cross-linking resulted in the up-regulation of positive regulatory domain I-binding factor-1. Taken together, our findings indicate that signaling via CD27 on B cells induces IgE synthesis, in cooperation with IL-4 and CD40 signaling, by promoting the generation of plasma cells through up-regulation of positive regulatory domain I-binding factor-1.

The number of metastatic lymph nodes: a promising prognostic determinant for gastric carcinoma in the latest edition of the TNM classification

BACKGROUND

The number of metastatic regional lymph nodes determines the new pN categories in the 5th edition of the TNM classification.

STUDY DESIGN

Our retrospective study was conducted to compare the new method of defining lymph node status with the conventional classification, consisting of the anatomic extent of lymph node metastases, a well-established prognostic factor. The study was based on clinical data for 493 patients with gastric carcinomas who underwent potentially curative operations and had histologically confirmed nodal metastases. These patients were stratified into 1) n categories according to the Japanese Classification of Gastric Carcinoma, 2) the new pN categories, and 3) the pN categories determined by the number of metastatic perigastric nodes resected by standard D1 gastrectomy. Survival data were analyzed for each group.

RESULTS

The number of metastatic nodes after D2 lymphadenectomy reflected prognosis well and was shown by multivariate analysis to be a strong independent prognostic factor. When the classification was performed limited to the metastatic perigastric nodes, stage migration was evident, but the variable remained competent as a prognostic indicator.

CONCLUSIONS

The number of metastatic nodes is a promising determinant in the new international stage classification.