High spatial-density, cladding-pumped 6-mode 7-core fiber amplifier for C-band operation.

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.

A novel transformation suppressor, Pdcd4, inhibits AP-1 transactivation but not NF-kappaB or ODC transactivation.

Pdcd4 is a novel transformation suppressor that is highly expressed in promotion-resistant (P-) mouse epidermal JB6 cells but not in susceptible (P+) cells. Overexpression of pdcd4 cDNA in stably transfected P+ cells rendered cells resistant to tumor promoter-induced transformation, indicating that elevated expression of Pdcd4 protein is sufficient to suppress neoplastic transformation. To determine whether Pdcd4 suppresses neoplastic transformation through inhibiting known transformation required events, we examined the possibility that pdcd4 inhibited the activation of AP-1 or NF-kappaB dependent transcription or of ornithine decarboxylase (ODC) activity. Activation of AP-1-dependent transcriptional activity was inhibited by pdcd4 expression in a concentration dependent manner. In contrast, Pdcd4 slightly increased NF-kappaB-dependent transcription and did not alter ODC enzymatic activity. Previous studies suggested that activation of AP-1 was required for P+ cell transformation as well as for tumor promotion in vivo. These results indicate that Pdcd4 functions as a transformation suppressor, possibly through inhibiting AP-1 activation in combination with other factors such as enhancing NF-kappaB activation. Pdcd4 may thus constitute a useful molecular target for cancer prevention.

Nuclear expression of the Y-box binding protein, YB-1, as a novel marker of disease progression in non-small cell lung cancer.

Transcription factor Y-box binding protein 1 (YB-1) that binds to the inverted CCAAT box is involved not only in transcription of various genes but also in cell proliferation and DNA repair. We determined whether localization of YB-1 in either the nucleus or cytoplasm could serve as a prognostic marker for patients with non-small cell lung cancer (NSCLC). In 196 NSCLC patients, expression of YB-1 protein in the nucleus or cytoplasm was immunohistochemically evaluated. Of the 196 tumors examined, 88 (44.9%) were positive for YB-1 expression in the nucleus. Nuclear YB-1 expression significantly correlated with T factor, lymph node metastasis, and stage of the disease. Patients with a nuclear YB-1 tumor had a poorer prognosis than did those with a cytoplasmic YB-1 tumor in all of the NSCLC patients (P = 0.0494) and in patients with squamous cell carcinoma (P = 0.0313) but not in patients with adenocarcinomas. Nuclear localization of the YB-1 protein may prove to be an important factor of disease progression for patients with NSCLC, in particular, in cases of squamous cell carcinoma.

Expression of interleukin-1 beta converting enzyme gene family and bcl-2 gene family in the rat brain following permanent occlusion of the middle cerebral artery.

Recent investigations have been suggesting that some neuronal subpopulations may die via programmed cell death after focal ischemic injury. To clarify the possible roles of the genes involved in the cell-death program, this study examined the expression of three members of the interleukin-1 beta converting enzyme (Ice) gene family (Ice, Nedd2, and Yama/CPP32) and two members of the bcl-2 gene family (bcl-2 and bcl-x) in the rat brain after permanent occlusion of the middle cerebral artery. Northern blot analysis revealed a transient induction of Nedd2 mRNA 8 h after the ischemic insult (3.8-fold) and an increase in Yama/CPP32 mRNA 16 to 24 h after the insult (5.8-fold at 24 h), whereas the expression of Ice remained constant. The expression of bcl-2 and bcl-x remained constant after the ischemic insult. Taking into account the key role of the Ice gene family in the execution of programmed cell death, the induction of Ice gene family might play a causative role in apoptotic cell death.

Isolation of a novel mouse gene MA-3 that is induced upon programmed cell death.

Typical programmed cell death requires de novo macromolecular synthesis and shares common morphological changes referred to as apoptosis. To elucidate the molecular mechanism of apoptosis, we isolated cDNA clones that are induced in various types of apoptosis by the differential display method. Among such clones, the MA-3 mRNA was induced in all apoptosis-inducible cell lines tested so far, including thymocytes, T cells, B cells and pheochromocytoma. The nucleotide sequence of the MA-3 cDNA predicted an amino acid (aa) sequence of 469 aa, which did not reveal significant similarity to any known proteins and functional aa motifs in databases. The MA-3 mRNA was strongly expressed in the thymus although small amounts of the MA-3 mRNA were ubiquitously expressed in mouse adult tissues. The MA-3 gene was highly conserved during evolution and cross-hybridization bands were found not only in vertebrates but also in Drosophila melanogaster.

Isolation and characterization of a novel secretory protein, stromal cell-derived factor-2 (SDF-2) using the signal sequence trap method.

With use of the signal sequence trap method, we isolated a cDNA encoding a novel secretory protein, SDF-2, from the mouse stromal cell line, ST2. The human homologue of SDF-2 was also isolated. The amino acid (aa) sequences deduced from both the clones were conserved more than 92%. The chromosomal localization of the human SDF-2 gene was mapped to 17q11.2. The aa sequence of SDF-2 shows similarity to those of yeast dolichyl phosphate-D-mannose:protein mannosyltransferases, Pmt1p [Strahl-Bolsinger et al. (1993) Proc. Natl. Acad. Sci. USA 90, 8164-8168] and Pmt2p [Lussier et al. (1995) J. Biol. Chem. 270, 2770-2775], whose activities have not been detected in higher eukaryotes.

Induction of Bip mRNA upon programmed cell death of differentiated PC12 cells as well as rat sympathetic neurons.

We have found that expression of the Bip (immunoglobulin heavy chain binding protein)/GRP78 (glucose regulated protein 78) gene is markedly enhanced specifically among the heat shock protein (HSP) 70 gene family during the neuronal cell death of PC12 (22a) cells, that is induced by removal of nerve growth factor (NGF) and blocked by a transcription inhibitor, actinomycin D. The Bip mRNA induction is suppressed when the NGF-deprivation-dependent cell death of PC12 (22a) cells is inhibited by cAMP, cycloheximide or high K+. The Ca2+ ionophore, A23187, caused neuronal cell death accompanied by up-regulation of Bip, HSP90, and HSP70 mRNAs. In addition, a chelator of intracellular Ca2+ (BAPTA) elevated Bip mRNA and induced cell death in a low Ca2+ medium. Alterations of intracellular calcium homeostasis thus appear to induce Bip mRNA expression as well as apoptosis in PC12 (22a) cells. However, release of Ca2+ from intracellular stores by thapsigargin induced Bip mRNA expression but not cell death, indicating that Bip mRNA induction is not sufficient for neuronal death. Induction of Bip mRNA in association with apoptosis was also observed for NGF-deprived sympathetic ganglion cells in primary culture. These lines of evidence suggest that selective induction of Bip mRNA may play an important role in the programmed cell death of neurons deprived of neurotrophic factors and could be a landmark of the neuronal programmed cell death.

Steroid-refractory severe ulcerative colitis responding to cyclosporine and long-term follow-up.

We report a case of steroid-refractory ulcerative colitis, treated with cyclosporine, in a 38-year-old woman with a 13-year history of ulcerative colitis. No remission was achieved with treatments that included intravenous hyperalimentation, sulfasalazine, and intensive parenteral prednisolone therapy for 4 weeks. Intravenous infusion of cyclosporine was performed because the patient refused to undergo surgery. Her condition improved dramatically and colectomy was avoided. She has been maintained on oral cyclosporine and azathioprine since steroids were discontinued, and she has remained in clinical and endoscopic remission for 2 years. The side effects were not significant, but mild paresthesia in both hands and mild hypertension, which was controlled by anti-hypertensives. Cyclosporine seems to be an effective treatment for patients with steroid-refractory severe active ulcerative colitis in whom colectomy seems inevitable. We believe further clinical trials of the treatment are warranted.

Transforming growth factor-alpha (TGF alpha)-producing gastric carcinoma with acanthosis nigricans: an endocrine effect of TGF alpha in the pathogenesis of cutaneous paraneoplastic syndrome and epithelial hyperplasia of the esophagus.

A case of well-differentiated adenocarcinoma (Borrmann type 3) of the stomach in a 76-year-old man associated with the typical skin manifestations of acanthosis nigricans and with multiple protruding lesions showing epithelial hyperplasia of the esophagus is reported. The advanced tumor was located in the cardiac region of the stomach, and measured approximately 8 cm in diameter, with partial invasion to the esophagus. The associated cutaneous lesions were characterized by hyperpigmentation and by protruding verrucous papules on the torso, head, face, neck, upper extremities, perineum, and inguinal region. Histologically, the protruding skin lesions showed keratinocytes proliferation throughout the epidermis, resulting in diffuse hyperkeratosis, papillomatosis, and acanthosis of the skin. Immunohistological analysis showed coexpression of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) receptors in the tumor from the stomach. It is reasonable to conclude from this evidence that gastric carcinoma cells secrete TGF alpha in an autocrine for auto-stimulation. EGF receptor expression was also noted on the papillomatous hyperplasia of the cutaneous lesion. Serum level of TGF alpha, determined by an enzyme-linked immunosorbent assay, was high (144 pg/ml; normal, 22.0 +/- 16 pg/ml (Mean +/- SD)). Serum TGF alpha abruptly decreased to 49 pg/ml on day 7 after the total gastrectomy, and then gradually increased to 77 pg/ml within 28 days. Amelioration of the cutaneous lesions and the protruding lesions in the esophagus was observed after surgical resection of the gastric carcinoma. This suggests that the TGF alpha stimulates the proliferation of keratinocytes involved with EGF receptor. Large amounts of circulating TGF alpha in the blood over a long period released by the primary tumor seem to act as an endocrine-like mechanism causing epidermal and esophageal epithelial cells to proliferate. There is a possible link in the pathogenesis of the acanthosis nigricans as a cutaneous paraneoplastic syndrome, and epithelial hyperplasia of the esophagus.

Gastric cancer with high telomerase activity shows rapid development and invasiveness.

Telomerase activity was reported to be activated in most immortal cells and cancers. As the clinical significance of telomerase activity in human gastric cancer is controversial, we investigated this activity using a telomeric repeat amplification protocol. The telomerase activity was tentatively defined by strength of activity as follows: 3+, observed with 0.06 microg of protein; 2+, observed with 0.6 microg of protein; 1+, observed with 6 microg of protein; 0, not observed under these three conditions. Telomerase activity was detected in 35 of 39 (89.7%) gastric cancer specimens. Tumors with high telomerase activities (2+/3+) tended to have a deeper invasion, lymphatic and vascular invasion, lymph node metastasis, liver metastasis, and peritoneal dissemination, as compared to findings in case of low telomerase activities (-/1+). Thus, telomerase activity of gastric cancer tissue may reflect the malignant potential of the tumor and intensive postoperative care might be required for such patients.

Heterogeneity and clinical role of thymidine phosphorylase activity in gastric cancer.

We examined the dThdPase activity in primary gastric cancer and metastatic lymph nodes from human subjects. The dThdPase activities were significantly higher in primary tumors than in the normal gastric wall, particularly in the center of the tumor rather than in the periphery (P<0.01). Tumors with a high dThdPase activity often had venous invasion (P<0.01). The dThdPase activities were significantly higher in metastatic lymph nodes than in the nodes without metastasis (P<0.01). The intratumoral heterogeneity of dThdPase activity was identified and cancer cells with high dThdPase activity may indicate that metastasis will likely occur.

Clinical significance of vascular endothelial growth factor expression in gastric cancer.

Vascular endothelial growth factor (VEGF) is an angiogenic factor in human cancer tissue. To clarify the clinical significance of this factor, we investigated the VEGF expression in early and advanced gastric cancer. This study included analysis of data on 243 patients with gastric cancer, including 118 in the early stage and 125 in the advanced stage. VEGF was immunohistochemically stained. Of 243 tumors, 102 (42%) were VEGF-positive. The VEGF-positive gastric cancers were larger, more invasive, and classified in the more advanced stage than VEGF negative ones. Patients with VEGF-positive cancers had significantly lower survival rates than did those with negative ones, both in early and advanced stages (P < 0.05, P < 0.01, respectively). The VEGF-positive isolates had more hematogenous metastases than VEGF-negative ones. Multivariate analysis revealed VEGF to be an independent prognostic factor and independent risk factor for liver metastasis. The VEGF expression in cancer cells can serve as a pertinent prognostic indicator both in early and advanced gastric cancer.

[Intractable pneumothorax for pleuritis carcinomatosis effectively treated with bronchial embolization: report of a case].

A 57-year-old female was admitted with compliant of cough and body weight loss. Chest X-ray and thoracic computed tomography (CT) scan revealed a collapsed lung and pleural effusion. We diagnosed a pleulitis carcinomatosis. After right chest tube drainage was performed, she developed right intractable pneumothorax. It was occluded endobronchially by the placement of vascular embolization coils and histoacryl. This method is thought to be an effective treatment for intractable pneumothorax patients in endstage of lung cancer.

[Angiogenesis and macrophage infiltration in Borrmann type IV gastric cancer].

The clinical significance of angiogenesis was investigated in Borrmann type IV gastric cancer. Tumors with high microvessel density (MVD) often metastasized to the liver and lymph nodes. A significant correlation was recognized between macrophage infiltration and MVD. However, MVD was not a prognostic factor. Peritoneal dissemination was a prognostic factor in Borrmann type IV gastric cancer. Thus, angiogenesis plays an important role in the metastasis, but not prognosis in Borrmann type IV gastric cancer.

Histone variant macroH2A1.2 is mono-ubiquitinated at its histone domain.

Histone macroH2A1.2 (macroH2A) is an unusual histone H2A variant with a large non-histone macrodomain at its carboxyl terminal. MacroH2A1.2 is enriched in facultative heterochromatin, including inactivated X chromosomes in mammalian females and senescence-associated heterochromatin foci. We show here that a small population of macroH2A1.2 is mono-ubiquitinated in human HeLa cells. Mass spectrometry analysis revealed that the specific targeting sites for the mono-ubiquitination are Lys115 and Lys116 of the histone domain. A corresponding Lys119 conserved in histone H2A is also mono-ubiquitinated by Ring protein in the polycomb group complex. We suggest that the mono-ubiquitination of macroH2A1.2 and histone H2A has similar or synergistic implications, but that the multiple ubiquitination sites in macroH2A1.2 might confer a variety of functions upon macroH2A1.2 to modulate chromatin states.

Replication-dependent marking of DNA by PCNA facilitates CAF-1-coupled inheritance of chromatin.

Chromatin assembly factor 1 (CAF-1) is required for inheritance of epigenetically determined chromosomal states in vivo and promotes assembly of chromatin during DNA replication in vitro. Herein, we demonstrate that after DNA replication, replicated, but not unreplicated, DNA is also competent for CAF-1-dependent chromatin assembly. The proliferating cell nuclear antigen (PCNA), a DNA polymerase clamp, is a component of the replication-dependent marking of DNA for chromatin assembly. The clamp loader, replication factor C (RFC), can reverse this mark by unloading PCNA from the replicated DNA. PCNA binds directly to p150, the largest subunit of CAF-1, and the two proteins colocalize at sites of DNA replication in cells. We suggest that PCNA and CAF-1 connect DNA replication to chromatin assembly and the inheritance of epigenetic chromosome states.

The N-terminal domains of histones H3 and H4 are not necessary for chromatin assembly factor-1- mediated nucleosome assembly onto replicated DNA in vitro.

An in vitro reconstitution system for the analysis of replication-coupled nucleosome assembly is described. In this "two-step system," nucleosome assembly is performed in a separate reaction from DNA replication, wherein purified newly replicated DNA remains noncovalently marked for subsequent chromatin assembly factor-1 (CAF-1)-dependent nucleosome assembly. Because the nucleosome assembly is performed separately from the DNA replication step, this system is more versatile and biochemically tractable when compared with nucleosome assembly during simian virus 40 (SV40) DNA replication. The N-terminal domains of histones H3 and H4 play an important but redundant function in nucleosome assembly in the budding yeast, Saccharomyces cerevisiae. It had been proposed that at least one tail of histone H3 or H4 is required for replication-coupled nucleosome assembly. However, we demonstrate that the N-terminal domains of both histone H3 and H4 are dispensable for CAF-1-mediated formation of nucleosome cores onto newly replicated DNA in vitro. CAF-1 and each of its individual subunits stably bound to recombinant (H3.H4)(2) tetramers lacking the N-terminal domains of both H3 and H4. Therefore, the N-terminal tails of histone H3 and H4 that contain the specific acetylation sites are not necessary for CAF-1-dependent nucleosome assembly onto replicated DNA. We suggest that the histone acetylation may be required for a CAF-1 independent pathway or function after deposition, by marking of newly replicated chromatin.

PCNA connects DNA replication to epigenetic inheritance in yeast.

Formation of a heterochromatin-like structure results in transcriptional silencing at the HM mating-type loci and telomeres in Saccharomyces cerevisiae. Once formed, such epigenetically determined structures are inherited for many mitotic divisions. Here we show that mutations in the proliferating cell nuclear antigen (PCNA), an essential component at the DNA replication fork, reduced repression of genes near a telomere and at the silent mating-typelocus, HMR. The pol30-8 mutant displayed coexistence of both repressed (pink) and de-repressed (white) cells within a single colony when assayed with the ADE2 gene inserted at HMR. Unlike pol30-8, the pol30-6 and pol30-79 mutants partially reduced gene silencing at telomeres and the HMR and synergistically decreased silencing in cells lacking chromatin assembly factor 1 (CAF-1). All silencing defective mutants showed reduced binding to CAF-1 in vitro and altered chromatin association of the CAF-1 large subunit in vivo. Thus, PCNA participates in inheritance of both DNA and epigenetic chromatin structures during the S phase of the cell cycle, the latter by at least two mechanisms.

Increased binding activity of measles virus to monkey red blood cells after long-term passage in Vero cell cultures.

Recent field isolates of measles virus (MV) obtained by using B95-8 cells have been reported not to agglutinate African green monkey red blood cells (AGM-RBC). Vero cell-adapted, plaque-forming strains derived from three field isolates at the third passage in Vero cell cultures (T8Ve-3, T11Ve-3 and N13Ve-3) also exhibited markedly decreased binding activity, as determined by infectivity-absorption and haemadsorption tests. On the other hand, binding activity of the respective strains at the twentieth passage (T8Ve-20, T11Ve-20 and N13Ve-20) increased to practically the same level as that of the Edmonston strain, a standard strain of MV passaged long-term. A membrane immunofluorescence test revealed that the decreased binding activity to AGM-RBC of T8Ve-3, T11Ve-3 and N13Ve-3 was not due to decreased expression of the haemagglutinin (H) protein on the cell surface. The deduced amino acid sequence of the H protein synthesized in T11Ve-3-infected cells was identical to that in T11Ve-20-infected cells, although a single amino acid alteration was observed when T8Ve-3 was compared with T8Ve-20. Similarly, approximately half of the N13Ve-20-infected cells synthesized an H protein identical to that produced in N13Ve-3-infected cells, and nevertheless, exhibited markedly increased haemadsorption. The present results suggest that a viral protein(s) other than the H protein contributed to the binding activity of MV to AGM-RBC.

Induced expression of PD-1, a novel member of the immunoglobulin gene superfamily, upon programmed cell death.

The classical type of programmed cell death is characterized by its dependence on de novo RNA and protein synthesis and morphological features of apoptosis. We confirmed that stimulated 2B4.11 (a murine T-cell hybridoma) and interleukin-3 (IL-3)-deprived LyD9 (a murine haematopoietic progenitor cell line) died by the classical type of programmed cell death. Assuming that common biochemical pathways might be involved in the deaths of 2B4.11 and LyD9, we isolated the PD-1 gene, a novel member of the immunoglobulin gene superfamily, by using subtractive hybridization technique. The predicted PD-1 protein has a variant form of the consensus sequence found in cytoplasmic tails of signal transducing polypeptides associated with immune recognition receptors. The PD-1 gene was activated in both stimulated 2B4.11 and IL-3-deprived LyD9 cells, but not in other death-induced cell lines that did not show the characteristic features of the classical programmed cell death. Expression of the PD-1 mRNA in mouse was restricted to the thymus and increased when thymocyte death was augmented by in vivo injection of anti-CD3 antibody. These results suggest that activation of the PD-1 gene may be involved in the classical type of programmed cell death.