[Resection of a right ventricular diverticulum of fibrous type by off-pump cardiac surgery; report of a case].

Right ventricular diverticulum is very rare and we experienced a case of isolated right ventricular diverticulum in an adult patient The patient was an 80-year-old man and a 3-cm-diameter round mass at the apex of the heart was pointed out by screening computed tomography (CT). A small and akinetic diverticulum having a narrow communication with the right ventricle was revealed by right ventriculography. Upon surgery, a 3-cm-diameter diverticulum was found at the acute margin of the right ventricle. The diverticulum was exposed using the off-pump coronary artery bypass grafting (CABG) technique. Two mattress sutures of 4-0 Prolene with Teflon felt strips were used to close the communication between the diverticulum and the right ventricle, then, the diverticulum was resected. His postoperative course was uneventful. Pathological examination revealed the endothelial-lined wall of the diverticulum consisting of internal elastic lamina and discontinuous thin smooth muscle layer with no myocardium. This type of right ventricular diverticulum could be resected by the off-pump CABG technique.

Induction of apoptosis and cellular senescence in mice lacking transcription elongation factor, Elongin A.

Elongin A is a transcription elongation factor that increases the overall rate of mRNA chain elongation by RNA polymerase II. To gain more insight into the physiological functions of Elongin A, we generated Elongin A-deficient mice. Elongin A homozygous mutant (Elongin A(-/-)) embryos demonstrated a severely retarded development and died at between days 10.5 and 12.5 of gestation, most likely due to extensive apoptosis. Moreover, mouse embryonic fibroblasts (MEFs) derived from Elongin A(-/-) embryos exhibited not only increased apoptosis but also senescence-like growth defects accompanied by the activation of p38 MAPK and p53. Knockdown of Elongin A in MEFs by RNA interference also dramatically induced the senescent phenotype. A study using inhibitors of p38 MAPK and p53 and the generation of Elongin A-deficient mice with p53-null background suggests that both the p38 MAPK and p53 pathways are responsible for the induction of senescence-like phenotypes, whereas additional signaling pathways appear to be involved in the mediation of apoptosis in Elongin A(-/-) cells. Taken together, our results suggest that Elongin A is required for the transcription of genes essential for early embryonic development and downregulation of its activity is tightly associated with cellular senescence.

A ubiquitin ligase, skeletrophin, is a negative regulator of melanoma invasion.

Skeletrophin (mindbomb homolog 2 (MIB2)) is a RING (Really Interesting New Gene) finger-dependent ubiquitin ligase, which targets the intracellular region of Notch ligands. A previous immunohistochemical study demonstrated that skeletrophin was downregulated in many melanomas. In the present study, we have identified a promoter region of skeletrophin on a CpG island and detected aberrant methylation of this region in six of 31 invasive melanomas, but in none of 25 benign nevi or five non-invasive superficial spreading melanomas. Subsequently, we found that a zinc-finger transcriptional factor Snail, which is overexpressed in many melanoma cells, repressed the skeletrophin promoter activity via an E-box-related element and was involved in downregulation of skeletrophin. An activator protein-2, which has a tumor suppressor-like role in melanoma, increased skeletrophin expression. Interestingly, exogenously expressed skeletrophin reduced melanoma cell invasion in vitro and in vivo. Colony formation in soft agar was also reduced in a RING motif-dependent manner, without affecting cell growth. We also found that skeletrophin downregulated transcription of the Met oncogene, which encodes the hepatocyte growth factor receptor and plays a role in the determination of the invasive phenotype of many malignant tumors. Finally, exogenously expressed skeletrophin, but not its RING mutant, increased transcription of Hes1 gene, a downstream effector of Notch pathway in melanoma cells. The present findings indicate that skeletrophin might be a novel suppressor factor for melanoma invasion.

Virus-like particles in a case of human prostate carcinoma.

Two morphologically different types of intracisternal virus-like particles were observed electron microscopically in a biopsy specimen of human prostate cancer. Particles of one type were 150-200 nm in diameter and contained either an electron-dense core or two concentric inner layers. Particles of the other type were smaller, 80-100 nm in diameter, and appeared mostly in filamentous or chainlike formation. Both types of particles and budding were observed in endoplasmic cavities of epithelial tumor cells. The particles had ultrastructural characteristics that suggested a viral nature but were different from the known type B, type C, or type H (hamster type R) virus particles. This was the first election microscopic observation in prostate cancer of virus-like particles similar to those previously reported in a case of human breast carcinoma.

Particle--lamella complexes in a case of human benign prostate hyperplasia: brief communication.

Particle--lamella complexes (PLC's), described for the first time, were found in glandular epithelial cells of the hyperplastic prostate tissues from a patient with transitional cell carcinoma of the urinary bladder. PLC's observed in this patient were similar to those seen in human hematopoietic neoplastic cells. They showed cylindroid forms and were composed of concentrically arranged lamellae and particles found in rows between these lamellae. PLC is closely related to rough endoplasmic reticulum (RER), and some PLC's were completely surrounded by RER. Particles approximately 25--30 nm in diameter were similar to ribosomes in size, shape, and electron density; lamellae approximately 10 nm thick appeared circular in cross sections and lamellar in longitudinal sections. Although the nature and function of PLC's are as yet unknown, the present observation indicated that PLC's are not a characteristic structure restricted to malignant tumors of hematopoietic origin.

Electron microscopic studies of intracisternal virus particles in Soehner-Dmochowski murine sarcoma virus-induced bone tumors of New Zealand Black rats.

Soehner-Dmochowski murine sarcoma virus (Moloney)-induced bone tumors of New Zealand Black rats carry two morphologically different types of virus particles, namely, extracellular type C and intracisternal virus particles, which have thus far not been reported. These two types of virus particles have also been observed in the tissue culture cells derived from normal prostate tissues of A/Dm and BALB/c/Dm mice after inoculation of cell-free extracts of these bone tumors. The intracisternal virus particles, 90 to 120 nm in diameter, have always been found in the rough endoplasmic reticulum; they have two inner concentric layers with a relatively electron-lucent center, frequently showing cylindrical, chain-like, or multipolar budding forms. Type C virus particles produced by Soehner-Dmochowski murine sarcoma virus (Moloney)-infected prostate tissue culture cells from A/Dm and BALB/c/Dm mice belong to the murine sarcoma-murine leukemia virus group, as revealed by the fixed immunofluorescence test and by immunoelectron microscopy. The morphological and immunological relationship of intracisternal virus particles and other types of virus particles (such as type C, type H, and intracisternal type A virus particles) and intracisternal virus particles in guinea pig leukemia are defined by routine electron microscopy observations and by immunoelectron microscopy studies.

High-risk human papillomavirus infections and overexpression of p53 protein as prognostic indicators in transitional cell carcinoma of the urinary bladder.

Ninety Japanese patients with transitional cell carcinoma of the urinary bladder were investigated for tumor incorporation of DNA for high-risk human papillomavirus (HPV) types 16, 18, and 33 by in situ hybridization with biotinylated DNA probes. In addition, immunohistochemical analysis of p53 protein expression was performed with an antibody to p53 protein. Twenty-eight tumors were positive for HPV DNA, and multiple HPV infection was detected in 17 cases. Positive nuclear staining of cancer cells by the antibody to p53 protein was detected in 32 cases. DNA for HPV 16, 18, and/or 33 and the overexpression of p53 protein were simultaneously observed in 6 tumors by using a mirror section method. The overexpression of p53 protein was frequently detected in invasive and nonpapillary tumors (P < 0.05) and in high grade tumors (P < 0.05). In contrast, HPV infection was more common in noninvasive and papillary tumors (P < 0.01). The patients with tumors positive for HPV DNA and/or p53 antibody had a significantly worse survival rate (P < 0.05). These results suggest that HPV infection or overexpression of p53 protein may be related to tumor behavior and may indicate a relatively poor prognosis in patients with transitional cell carcinoma.

Novel t(15;19)(q15;p13) chromosome abnormality in a thymic carcinoma.

A 22-year-old female with a thymic carcinoma is reported. The tumor was refractory to both chemotherapy and irradiation. The patient died with an aggressive clinical course. Cytogenetic study showed that the tumor cells had a chromosome translocation, t(15;19)(q15;p13), which was not identified previously in human cancer.

A Ki-1 (CD30)-positive T (E+, CD4+, Ia+)-cell line, DL-40, established from aggressive large cell lymphoma.

A new human lymphoma cell line, designated DL-40, was established from the peripheral blood of a 64-year-old woman with leukemic conversion of aggressive large cell lymphoma. The cell line grew in suspension with or without forming clumps of cells and exhibited large, round, or multiple nuclei in the relatively abundant cytoplasm that was positive for acid phosphatase. The cells expressed a Ki-1 antigen (CD30), E+, CD2+, CD4+, CD45+, Ia+ phenotype and had rearranged T-cell receptor beta chain but were negative for CD15, HTLV-I, and Epstein-Barr virus nuclear antigen. Chromosome analysis of this cell line showed a human female karyotype with complex hyperdiploid abnormalities. DL-40 cells produced tumors histologically similar to the original lymphoma when transplanted into nude mice and immunosuppressed hamsters. The DL-40 cell line could provide a useful tool for the understanding of biology of the Ki-1-positive non-Hodgkin's lymphoma.

Acute megakaryoblastic leukemia: establishment of a new cell line (MKPL-1) in vitro and in vivo.

A megakaryoblastic cell line (MKPL-1) was newly established from the bone marrow of an adult patient with acute megakaryoblastic leukemia. This cell line grew in single cell suspension with a doubling time of 30 h and consisted of large primitive blasts with persistent development of giant cells carrying multilobed nuclei. MKPL-1 cells were positive for platelet GPIIb/IIIa (CD41) and GPIIIa (CD61), and expressed OKM5 (CD36), MY7 (CD13), and MY9 (CD33) antigens in the absence of erythroid and lymphoid markers. The cytochemical and morphologic characteristics of MKPL-1 were also consistent with those of megakaryoblasts. The cells did not, however, express ultrastructural platelet peroxidase which is considered to be another marker of the megakaryocytic lineage. Cytogenetic analysis of MKPL-1 revealed a model chromosome number of 92 with abnormal chromosomes including those found in the patient's bone marrow cells. Furthermore, MKPL-1 cells were serially transplanted into nude mice for nine passages with production of lethal tumors and leukemic manifestation. Thus, our megakaryoblastic cell line which can be maintained both in vitro and in vivo would be useful for further studies of the biology of megakaryopoiesis and megakaryoblastic leukemia.

Determination of the prognostic significance of unscheduled cyclin A overexpression in patients with esophageal squamous cell carcinoma.

The expression of cyclin A protein was retrospectively investigated in 124 patients with human esophageal squamous cell carcinoma with immunohistochemical techniques using antibody to cyclin A protein (BF683). Of 124 tumors, 49 (39.5%) exhibited positive staining in cancer cells with this antibody. Staining was observed predominantly but not exclusively in the nucleus. A significantly higher degree of association of immunoreactivity with this antibody was detected for advanced types of tumors (stages I, II, III, and IV) than for early tumors (stage 0; P < 0.05). Patients with cyclin A immunopositivity had a significantly poorer survival rate than did other patients (P < 0.01). These findings provide the first evidence for frequent and unscheduled overexpression of cyclin A protein in human esophageal cancer and suggest the possibility that alteration of cyclin A overexpression is associated with tumor progression and patient prognosis for esophageal cancers.

Cyclin A overexpression in carcinoma of the renal pelvis and ureter including dysplasia: immunohistochemical findings in relation to prognosis.

Several in vitro studies have shown that cyclin A gene alteration in the cell cycle plays an important role in carcinogenesis. We immunohistochemically examined the expression of cyclin A protein in 120 patients with transitional cell carcinoma (TCC) of the renal pelvis and ureter, including adjacent dysplastic lesions to determine their significance for the tumor behavior and patient prognosis. Cyclin A immunostaining of the nucleus was observed in 29 tumors (24.2%). Furthermore, 17 cyclin A-positive tumors (58.6%) had dysplastic lesions positive for cyclin A antibody. The prevalence of cases exhibiting cyclin A staining was higher in the high grade (P < 0.01) and invasive tumors (P < 0.05) than in the other types of tumors. In the selected 117 cases, patients whose TCCs expressed a high level of cyclin A protein had a significantly poorer prognosis than those without cyclin A expression (P < 0.01). These in vivo findings provide the first evidence for frequent and redundant cyclin A protein overexpression in TCC and suggest that cyclin A overexpression is related to the tumor behavior and patient prognosis. In addition, our observations indicate that overexpression of cyclin A may be one of the early events, at least in some cases, in the carcinogenesis of TCC.

Molecular cloning and expression of a novel human cDNA containing CAG repeats.

A novel human cDNA containing CAG repeats, designated B120, was cloned by PCR amplification. An approximately 300-bp 3' untranslated region in this cDNA was followed by a 3426-bp coding region containing the CAG repeats. A computer search failed to find any significant homology between this cDNA and previously reported genes. The number of CAG trinucleotide repeats appeared to vary from seven to 12 in analyses of genomic DNA from healthy volunteers. An approximately 8-kb band was detected in brain, skeletal muscle and thymus by Northern blot analysis. The deduced amino-acid sequence had a polyglutamine chain encoded by CAG repeats as well as glutamine- and tyrosine-rich repeats, which has also been reported for several RNA binding proteins. We immunized mice with recombinant gene product and established a monoclonal antibody to it. On Western immunoblotting, this antibody detected an approximately 120-kDa protein in human brain tissue. In addition, immunohistochemical staining showed that the cytoplasm of neural cells was stained with this antibody. These findings indicated that B120 is a novel cDNA with a CAG repeat length polymorphism and that its gene product is a cytoplasmic protein with a molecular mass of 120 kDa.

Chromosomal mapping and expression of the human B120 gene.

We previously reported a novel human cDNA, designated B120, containing a CAG repeat length polymorphism and many repeat units, loosely identified as YXQQP which is found in several human RNA binding proteins. In the present study, the B120 gene was mapped to human chromosome 1p35-36.1 by fluorescence in situ hybridization (FISH). Several human disorders, including that of Schnyder crystalline corneal dystrophy, have been mapped to this region by genetic linkage. Schnyder crystalline corneal dystrophy is thought to be a primary abnormality of corneal lipid metabolism, resulting in opacification secondary to lipid accumulation. In order to examine the function of B120, we introduced B120 cDNA with an expression vector into various cell lines including Cos1, C3H/10T1/2 and NIH/3T3 cells. These transfected cells exhibited small cytoplasmic spherical bodies. The cytoplasmic bodies appeared to be fat droplets on electron microscopy and histochemical staining. These findings suggested that B120 gene expression is associated with lipid metabolism, and that overexpression of B120 may result in lipid deposition in various cells, including those of fibroblastic cell lines. Since the cornea is composed of fibroblastic cells, overfunction of B120 could be related to the pathogenesis of Schnyder crystalline corneal dystrophy.

Late pathologic changes in guinea pig kidneys irradiated with conventional fractionation and hyperfractionation.

PURPOSE: The aim of this study was to determine the differences in renal damage particularly associated with the effect of a small dose per fraction with a constant total dose. METHODS AND MATERIALS: Guinea pigs, 12-week-old English Hartley females, were used. The animals were divided into five groups according to irradiation schedule: No irradiation (control group); 2.0 Gy x 1/day, 5 fraction (f)/week (wk), 40 f, total 80 Gy (Group CF-2.0 [CF = conventional fractionation]); 1.0 Gy x 2/day, 10 f/wk, 80 f, total 80 Gy (Group HF-1.0 [HF = hyperfractionation]); 3.0 Gy x 1/day, 5 f/wk, 27 f, total 81 Gy (Group CF-3.0); and 1.5 Gy x 2/day, 10 f/wk, 54 f, total 81 Gy (Group HF-1.5). Only unilateral irradiation was performed. A histologic analysis was performed before irradiation and at 6 and 12 months after the completion of irradiation. The severity and severity ratios of urinary tubule atrophy, the number of large nuclei per unit area in the renal tubules, the average diameter of the glomeruli, and the number of cells composing the glomerulus were used as parameters for evaluating renal damage. RESULTS: In Groups CF-2.0 and CF-3.0 (the conventional fractionation [CF] groups), all the renal tubules showed severe atrophy 12 months after irradiation. On the other hand, only 20% of the renal tubules showed slight atrophy in Group HF-1.0 at 12 months. In Group HF-1.5, 70% of the renal tubules were atrophic at 12 months. The number of large nuclei markedly increased in Groups HF-1.0 and HF-1.5 (the hyperfractionation [HF] groups) at 12 months, whereas the number was very low in the CF groups at 12 months. Only in Group HF-1.0 had the average diameter of glomeruli not shrunk at 12 months. The number of cells composing the glomerulus in the CF groups markedly decreased at 12 months. The number of cells in the HF groups was also reduced, however the reduction was not as severe as that observed in the CF groups. CONCLUSION: 1.0 Gy per fraction delivered by HF greatly reduces renal damage even in the 80 Gy-irradiated kidney, which is one of the most radiosensitive organs.

Hyalinizing trabecular adenoma and papillary carcinoma of the thyroid gland express different cytokeratin patterns.

It has recently been suggested that hyalinizing trabecular adenoma of the thyroid is an encapsulated variant of papillary carcinoma because of certain similarities of their histology, the occasional occurrence of both tumors in the same gland, and their similar pattern of expression of cytokeratins, including staining for cytokeratin 19. To investigate this notion further, we examined immunocytochemically the expression of a series of cytokeratins in 12 hyalinizing trabecular adenomas and six papillary carcinomas. Hyalinizing trabecular adenoma showed no or minimal reactivity for cytokeratin 19, whereas papillary carcinoma was almost always strongly reactive. Also, hyalinizing trabecular adenoma showed no staining for high-molecular-weight (HMW) cytokeratin, whereas papillary carcinoma was strongly positive. Thus, there are different patterns of cytokeratin 19 and HMW cytokeratin expression in hyalinizing trabecular adenoma and papillary carcinoma. The findings do not support the suggestion that hyalinizing trabecular adenoma is an encapsulated variant of papillary carcinoma.

Developmental expression of carbonic anhydrase-related proteins VIII, X, and XI in the human brain.

Three cDNA homologues of carbonic anhydrase with unknown biological functions have been reported: carbonic anhydrase-related proteins (CA-RP) VIII, X, and XI. In the present study, we produced monoclonal antibodies to these CA-RPs and studied their regional and cellular distributions in the human adult and fetal brains by immunohistochemical analysis. In the adult brain, CA-RP VIII was expressed in the neural cell body spreading to most parts of the brain. CA-RP X was expressed in the myelin sheath and its expression was shown in the cytoplasm of cultured tumor cells by immunocytochemical analysis. CA-RP XI was expressed in the neural cell body, neurites, and astrocytes in relatively limited regions of the brain. In the fetal brain, CA-RP VIII and XI were expressed in the neuroprogenitor cells in the subventricular zone as early as the 84th day of gestation and subsequently detected in the neural cells migrating to the cortex. CA-RP X first appeared in the neural cells in the cortex at the 141st day. In the choroid plexus, the epithelial cells gave CA-RP VIII and XI expressions in both adult and fetal brains. From the findings in the present study on the distribution and the developmental expression of CA-RP VIII, X, and XI in the human brain we suggest that these CA-RPs play roles in various biological process of the CNS.

In situ embedding method of cells grown in beem capsules for immunoelectron microscopic studies of oncornaviruses.

A technique of in situ embedding of cells grown in BEEM capsules has been devised for immunoelectron microscopic studies of oncornaviruses. As compared to other immunoelectron microscopic procedures, this technique is less time and reagent-consuming. The quality and specificity of this method were tested on well-characterized mouse mammary tumor virus (type B virus) and murine sarcoma virus (type C virus particles). This method gave good results in labeling of the virus particles with ferritin or peroxidase in the cells of mouse tissue cultures. In an application of this method, peroxidase labeling of type B virus particles was obtained in frozen sections of normal prostatic tissues of C3H/Dm and A/Dm strain mice treated with rabbit antiserum to mouse mammary tumor virus from A/Dm strain mouse milk. These results indicate that this method is useful and reliable for immunoelectron microscopy studies of oncornaviruses in tissue culture cells and also in frozen sections of tissues.

An experimental application of gene therapy for human retinoblastoma.

PURPOSE: The purpose was to determine the potential of gene therapy for retinoblastoma using transfer of the herpes simplex virus thymidine kinase (HSV-TK) gene into retinoblastoma cells (Y79 cell line). METHODS: A retrovirus-packaging cell line PA317 was electroporated with a retroviral vector plasmid bearing HSV-TK and neomycin-resistance genes to produce a PA317-TK cell line releasing a replication-defective vector bearing both genes. Y79 was transduced by exposure to transmissible virus-containing medium from PA317-TK, and new clones of Y79 containing the HSV-TK gene (Y79-TK) were established. Sensitivity to ganciclovir (GCV) and acyclovir (ACV) was investigated in Y79 and Y79-TK and the effect of HSV-TK-positive cells on negative cells ("bystander effect") was determined in vitro. The effect of antitumorigenesis in a nude mouse system was also investigated. RESULTS: There were no differences in the growth pattern or the morphology between Y79 and Y79-TK. Y79-TK was more sensitive to GCV and ACV than was Y79. The cytotoxicity of Y79-TK was dose dependent. An obvious "bystander effect" was present with the addition of GCV. In vivo studies confirmed the ability of GCV to kill Y79-TK. CONCLUSIONS: In this study a model is proposed for the introduction of a drug-sensitivity gene into Y79 and the possibility is raised of treating retinoblastoma with gene therapy. The results suggest that the transfer of the HSV-TK gene into Y79 followed by the administration of GCV could serve as a model for gene therapy for retinoblastoma.

The aberrant p53 protein (review).

According to the current concept of carcinogenesis, neoplastic transformation consists of multistep accumulations of adverse genetic and epigenetic events. Recent advances in molecular genetics have demonstrated aberrations of oncogenes and tumor-suppressor genes in a variety of human cancers. The loss of wild-type p53 gene expression has exceptionally been implicated in the development of a wide variety of human cancers and it is generally accepted that p53 is a component in biochemical pathways central to human carcinogenesis. Although the role of the p53 gene in cancer genesis and development has fueled as many questions, study of p53 has come to the forefront of cancer research and detection of its abnormalities during the development of tumors may have diagnostic, prognostic and therapeutic implications. To be of value in clinical practice, immunohistochemical assessment of p53 protein should provide clinically relevant information. The degree of concordance between p53 gene mutation and the accumulation of p53 protein cannot be perfect, however, the immunohistochemical assay using anti-p53 antibodies is the most widely applicable approach for detection of tumors in routine investigations, particularly with regard to diagnosis or prognosis.