Biomedical subjects

H Shirasawa

Publications and source records attributed to H Shirasawa.

At least 55 records · Page 3Linked to original sources

PubMed1994

Expression of neuronal src mRNA as a favorable marker and inverse correlation to N-myc gene amplification in human neuroblastomas.

Neuron-specific src mRNA, which is expressed in human brain tissue by alternative splicing, is associated with neural differentiation. Neuronal c-srcNI expression may be associated with the ability of neuroblastomas to mature; furthermore, c-srcN2 mRNA is induced in chemically differentiated neuroblastoma cells in vitro. The prognosis of a patient with a neuroblastoma is strongly affected by the ability of the tumor to differentiate in vivo. In order to clarify the relationship between neuronal src mRNA expression and the clinical outcome of a neuroblastoma, we analyzed the expression of src mRNA in neuroblastoma tissues from 28 patients by SI-nuclease-protection assay. N-myc gene amplification was also examined by Southern blot hybridization. The clinical significance of neuronal src mRNA expression and its relevance to N-myc gene amplification was also investigated. A high ratio (more than 10%) of c-srcN2 mRNA expression was observed in all early-stage tumors and in advanced neuroblastomas with a favorable prognosis. In contrast, in advanced neuroblastomas with an aggressive clinical phenotype, c-srcN2 mRNA expression was found at a low ratio (below 10%). Genomic amplification of the N-myc gene and expression of c-srcN2 mRNAs were inversely correlated. When combined with other prognostic markers such as N-myc gene amplification, the expression of c-srcN2 mRNA may be a new biological marker to predict the prognosis of patients with neuroblastomas.

Blotting, Southern↗

PubMed1994

Cloning and sequencing of the L1 gene of canine oral papillomavirus.

Canine oral papillomavirus (COPV) DNA was isolated from two different sources. One of these DNAs was molecularly cloned and its physical map was determined. Hybridization analyses using subgenomic fragments of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 16 (HPV16) as probes revealed that the cloned COPV shared moderate homology within the E1 and L1 regions of BPV-1 and HPV16, whereas homology in other regions of BPV-1 and HPV16 was low. The putative L1 gene of COPV was sequenced and several conserved regions, including antigenic epitopes which are common in other known papillomaviruses, were analyzed.

Amino Acid Sequence↗

PubMed1994

Transcription-modulatory activity of full-length E6 and E6*I proteins of human papillomavirus type 16.

The E6 gene of human papillomavirus type 16 (HPV16) has the potential to encode full-length as well as truncated E6 proteins (E6*I and E6*II) by alternative splicings. Spliced ORF E6*I is considered to facilitate the translation of the neighboring E7 ORF; however, the putative E6*I protein is suspected to be functionless. In this study, the transcription-modulatory functions of full-length E6 and E6*I proteins were examined using cDNAs from a cervical carcinoma cell line. E6*I cDNA was able to trans-activate the autologous P97 promoter and the heterologous adenovirus E2 promoter. Full-length E6 was found to trans-activate the heterologous promoter, but repress transcription from the autologous P97 promoter. The transcription-modulatory functions of full-length E6 and E6*I proteins suggested that transcriptional regulation of HPVs associated with mucosal malignant lesions is complex.

Adenovirus E2 Proteins↗

PubMed1994

Transformation from SAA2-fibrils to AA-fibrils in amyloid fibrillogenesis: in vivo observations in murine spleen using anti-SAA and anti-AA antibodies.

Early amyloid fibrillogenesis from serum amyloid A protein (SAA) has been observed in the murine spleen after an injection of casein-Freund's complete adjuvant in the presence of amyloid enhancing factor, using anti-SAA C-terminal (anti-SAA) and anti-amyloid A (AA) antibodies. In Western immunoblotting of sera, both SAA1 and SAA2 reached a maximum after 24 h and began to decrease after 48 h. In spleen extracts, SAA2, but not SAA1 or AA, was found from 48 h, when amyloid was first deposited in the marginal zone. Electron microscopic immunohistochemistry of this stage showed reaction products from SAA in the marginal zone as fine granules along the cell membrane of mononuclear cells and focal intercellular aggregates, which contained fine fibrils originating from the cell membrane. Amyloid nodules, surrounded by mononuclear cells, developed from this stage. In the nodules, fibrils were positive for anti-SAA only in the vicinity of the cell membrane, while anti-AA stained fibrils throughout. Our hypothesis for fibrillogenesis is thus as follows: Serum SAA2 is specifically deposited on mononuclear cells in the marginal zone and polymerized extracellularly into fibrils, retaining its antigenicity (SAA2 amyloid fibrils); these fibrils are then processed to AA amyloid fibrils in situ by cleavage of the C-terminal portion of SAA2.

Amyloidosis↗

PubMed1994

Detection of human papillomavirus DNA and state of p53 gene in Japanese penile cancer.

The frequency of integration with human papillomavirus (HPV) and its genotypes in Japanese penile cancer was examined with relation to p53 gene mutations using polymerase chain reaction amplification. Tissues were obtained from 13 patients (eight from freshly frozen and five from paraffin-embedded samples). HPV DNA was detected in seven out of the 13 (54%), and their genotypes were type 16 in four, type 31 in one and type 33 in two cases. Neither HPV-detected nor -undetected tissues showed mutated alterations in exons 4-9 of p53 genes. The results suggest HPV to be, at least to some extent, involved in the oncogenesis of penile cancer, and that p53 gene mutations may not correlate with the development of penile cancer.

Aged↗

PubMed1993

Expression of alternatively spliced src messenger RNAs related to neuronal differentiation in human neuroblastomas.

Neuroblastoma, the most common malignant solid cancer of children, has an ability to differentiate in vitro and in vivo. This biological property has a significant influence upon the prognosis of patients with neuroblastomas. Neuronal cells express three alternatively spliced forms of c-src mRNA (nonneuronal c-src, neuronal c-srcN1, and neuronal c-srcN2), which are found at different levels in adult and fetal human brain tissue. In this study, the transcriptional levels of the three c-src mRNAs were examined in relation to the neural differentiation in eight human neuroblastoma cell lines and two clonal sublines and in seven primary neuroblastoma tissues by S1 nuclease protection assays. Neuronal c-srcN1 mRNA was expressed at high levels in neuroblastoma cell lines with the ability to differentiate but not in the cell lines lacking the capacity to mature in response to chemical inducers irrespective of N-myc gene amplification and overexpression. In terminally differentiated neuroblastoma cells, the expression of neuronal c-srcN2 mRNA, which was barely detectable at a steady-state level in the uninduced cells, increased to significant levels. Infantile neuroblastomas identified by mass screening tests expressed both neuronal c-srcN1 and c-srcN2 mRNAs at levels almost identical to that found in human brain tissue, but terminally differentiated neuroblastoma cells, neuroblastomas from older children identified based on clinical symptoms, did not. These results suggest that neuronal c-src expression and the ability of neuroblastomas to differentiate in vitro and in vivo may be correlated.

Base Sequence↗

PubMed1993

A novel polymorphism of human serum amyloid A protein, SAA1 gamma, is characterized by alanines at both residues 52 and 57.

We have identified a hitherto unknown polymorphism of serum amyloid A protein (SAA) in the pooled serum of nonamyloidotic inflammatory patients. The molecular weight of the novel SAA determined by ion-spray mass spectrometry appeared 28 amu lower in mass than the known SAA1 subsets, indicating that the substitution of a valine residue by an alanine was present. Further analyses by the combination of liquid chromatography/fast atom bombardment mass spectrometry, collision-activated dissociation mass spectrometry, and amino acid analysis revealed that this novel SAA, designated SAA1 gamma, has alanines at both residues 52 and 57 while the two known SAA1 subsets have a valine at either residue 52 or 57. Furthermore, des-1 Arg and des-1 Arg-2Ser forms of SAA1 gamma as well as those of the known SAA1 subsets were identified. This indicated that the common modification must have occurred at the N-termini of all SAA1 subsets. The existence of this SAA1 gamma had been suggested from one of the two novel AA proteins that we recently found (Baba, S. et al., 1992, Biochim. Biophys. Acta, 1180, 195-200).

Alanine↗

PubMed1993

Paratesticular neuroblastoma with N-myc activation.

The authors describe a case of disseminated neuroblastoma discovered as a paratesticular tumor in a 7-month-old boy. The ectopic adrenal tissues adjacent to the paratesticular tumor and multiple lesions in the adrenal gland and skin suggested the possibility of multifocal primary tumors. Although infantile neuroblastoma diagnosed at less than 1 year of age generally responds well to treatment irrespective of distant metastases, metastases developed, and the boy died of disease within 7 months. All multiple lesions had amplification and overexpression of the N-myc protooncogene, which might explain the aggressive phenotype of this rare case.

Blotting, Northern↗

PubMed1993

Lambda III subgroup immunoglobulin light chains are precursor proteins of nodular pulmonary amyloidosis.

To investigate the selectivity of amyloid deposits in lungs, the authors determined the amino-terminal sequence of two amyloid proteins of two nodular pulmonary cases--a case of systemic amyloidosis without myeloma and a localized case--and produced a specific antibody to the amyloid protein of the systemic case to stain other amyloid lung specimens. Moreover, the authors extracted immunoglobulins (Igs) from the amyloidotic spleen of the systemic case to assess their affinity with the lung specimens. Both nodular pulmonary amyloid proteins had an amino-terminal structure similar to that of the lambda III subgroup Ig light chain and reacted with the same antibody. In other cases, nodular forms also stained positively with the same antibody, but interstitial forms were unstained. Extracted Igs containing amyloidogenic lambda III light chains reacted with pulmonary amyloid deposits on sections of both nodular cases. These results suggest that the lambda III subgroup Ig light chains are precursor proteins of nodular pulmonary amyloidosis and that their affinity for pulmonary tissue may be a main determinant of pulmonary localization in nodular amyloidosis.

Aged↗

PubMed1993

Malignant nerve sheath tumor with rhabdomyoblastic differentiation arising from the acoustic nerve.

A case of a malignant nerve sheath tumor with rhabdomyoblastic differentiation arising from the acoustic nerve in a 38 year old man is reported. At autopsy, the tumor was found to be extensively involved in the right cerebellopontine angle of the brain stem. Histologically, the tumor was composed mainly of spindle-shaped tumor cells proliferating in hypercellular fascicles scattered with pleomorphic cells. The tumor cells were characterized by high mitotic activity and invasive growth. Occasional tumor cells had eosinophilic cytoplasm, which in a few cases was cross-striated. Cytoplasmic interdigitations and a thick basal lamina were confirmed ultrastructurally. Immunohistochemical analysis revealed that some tumor cells were positive for myoglobin and desmin, but weakly positive or negative for S-100 protein. The patient did not have von Recklinghausen's disease.

Adult↗

PubMed1993

Two cases of recurrent hepatic injury associated with early pregnancy: hCG on hepatocytes is a suspected target antigen for lymphocyte attack.

Two cases of recurrent hepatic injury which appeared in the first trimester of pregnancy were studied. Case 1 was a 35 year old woman, gravida 4, para 0, who suffered repeatedly from hepatic injury requiring induced abortions. The patient was healthy before the pregnancies and the plasma aminotransferases increased after 8 weeks gestation and promptly returned to normal after the abortions. No fluctuation of aminotransferases was observed in the menstrual cycle. A liver biopsy immediately after abortion showed spotty necrosis of hepatocytes with mononuclear cell infiltration. Most of the infiltrating cells were cytotoxic T cells that were directly in contact with hepatocytes. Numerous lymphocytic infiltrations were also found in the decidua of the uterine curettage material. The patient's lymphocytes showed conspicuous blast transformation in culture with human chorionic gonadotropin (hCG). The hCG was detected in close vicinity to the injured hepatocytes by immunostaining. Case 2 was a 23 year old woman, gravida 2, para 0, who underwent an induced abortion due to hepatic dysfunction in the first pregnancy. Although hepatic dysfunction reappeared from 10 weeks gestation during the second pregnancy, her health gradually improved with conservative therapy and resulted in a full-term delivery. She lacked allergies to drugs or foods and was healthy when she was not pregnant. These two cases suggest that some hepatotoxic materials appeared transiently in the first trimester. The results of Case 1 suggest strongly that hCG on the hepatocytes was recognized as an antigen and evoked lymphocytic attack.

Adult↗

PubMed1993

Defect of Fc receptors and phenotypical changes in sinusoidal endothelial cells in human liver cirrhosis.

To analyze the pathological changes occurring in Fc receptors (FcRs) in sinusoidal endothelial cells (SECs) in chronic liver diseases, we first characterized immunohistochemically the SEC FcRs by using monoclonal antibodies (MAbs) to FcRs and then investigated the distribution of the SEC FcRs by using peroxidase-antiperoxidase IgG complexes as a ligand on frozen sections. MAb 2E1 to FcRII reacted with SECs in a similar manner to peroxidase-antiperoxidase IgG and blocked the peroxidase-antiperoxidase IgG binding to SECs, whereas MAbs 3G8 and Leu-11b to FcRIII did not. FcRs in normal liver were found along the sinusoidal walls, except for those in the outer periportal zones, but FcRs in chronic active hepatitis and cirrhosis were intermittently or focally absent. The lengths of the FcR-positive portion of sinusoids in unit areas were respectively about 54% and 76% of the normal values in active and inactive cirrhosis. Where FcRs were absent, the MAbs CD36, CD31, and EN4 revealed the presence of sinusoids and, in active cirrhosis, frequently the thickening of liver cell plates. The FcR-negative SECs in the outer periportal zones of normal livers were different from the SECs of other sites in the presence of PAL-E antigen and a rich amount of EN4 antigen, though these sinusoids possessed Kupffer cells and no perisinusoidal deposition of laminin. The FcR-negative SECs in liver diseases occasionally presented the character of ordinary blood vessels, viz., PAL-E antigen, CD34 antigen, and a deficiency of Kupffer cells, regardless of perisinusoidal laminin deposition. However, they preserved the character of normally FcR-possessing SECs, viz., CD36 antigen, and a small amount of EN4 and CD31 antigens. These findings indicate that the outer-periportal SECs in normal livers are phenotypically different from other SECs and that the SECs in diseased livers frequently undergo phenotypical changes, including loss of FcRs, regardless of perisinusoidal laminin deposition, i.e., capillarization of the sinusoids. These phenotypical changes in SECs may reduce the capacity of FcR-mediated IgG-IC metabolism in diseased livers.

Antibodies, Monoclonal↗

PubMed1993

[A case of benign epithelioma of the ciliary body].

A 34-year-old woman showed a partially pigmented, greyish-white mass at a position of 1 o'clock behind the iris of her left eye. The lens equator was compressed and focal opacity had developed. The adjacent ciliary processes and zonules were intact. Photocoagulation was not effective and dense cataract gradually developed, so we performed extracapsular cataract extraction and partial iridocyclectomy. The tumor was nonencapsulated, nodular and myxomatous in appearance, arising from the pars plicata. Histological examinations revealed that the tumor was composed of nonpigmented cells and a small number of pigmented cell clusters. The cells were arranged like cords or gland-like structure with intervening myxomatous, fibrillar, and partially hyalinous interstitium. There was no finding of malignancy. The tumor showed similar microscopic structure and findings of mucous stains of normal ciliary nonpigmented epithelium and internal basement membrane, so a diagnosis of benign epithelioma was made.

Adult↗

PubMed1992

Identification of two novel amyloid A protein subsets coexisting in an individual patient of AA-amyloidosis.

Amyloid A protein (AA), the major fibril protein in AA-amyloidosis, is an N-terminal cleavage product of the precursor protein, serum amyloid A (SAA). Using mass spectrometry and amino-acid sequencing, we identified and characterized two novel AA protein subsets co-deposited as amyloid fibrils in an patient having AA-amyloidosis associated with rheumatoid arthritis. One of the AA proteins corresponded to positions 2-76 (or 75) of SAA2 alpha and the other corresponded to positions 2-76 (or 75) of known SAA1 subsets, except for position 52 or 57, where SAA1 alpha has valine and alanine and SAA1 beta has alanine and valine in position 52 and 57, respectively, whereas the AA protein had alanine at the both positions. Our findings (1), demonstrate that not only one but two SAA subsets could be deposited together as an AA-amyloid in a single individual and (2), support the existence of a novel SAA1 allotype, i.e., SAA152,57Ala.

Alanine↗

PubMed1992

Expression of a human multidrug resistance gene in human ovarian carcinoma cell lines.

To investigate the possible role of the multidrug resistance phenotype to chemoresistance in human ovarian carcinoma, we have analyzed human multidrug resistance gene (mdr 1) expression in 8 human ovarian adenocarcinoma cell lines. An increase in P-glycoprotein level specific to multidrug-resistant tumor cells was not apparently associated with the increase in resistance to vincristine (VCR) or doxorubicin (Adriamycin). Mdr 1 transcripts (4.5 kilobases) were observed in the RNA preparation obtained from only one cell line (SHIN-3) that showed the highest resistance to both drugs in vitro and in vivo. No cell lines showed mdr 1 DNA amplification. These results suggest that the insensitivity of human ovarian carcinoma to chemotherapy could be partly explained by the expression of mdr 1.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1992

Intraperitoneal amyloid formation by amyloid enhancing factor--rich macrophages in ascitic fluid.

Although resident peritoneal cells from amyloidotic mice (amyloidotic peritoneal cells) are capable of processing the precursor protein of secondary amyloidosis, serum amyloid A (SAA) to amyloid fibrils, the peritoneum is a rare site for amyloid deposition. This is considered to be due to a deficiency of SAA in the peritoneum. To increase the supply of SAA to the peritoneum, ascitic fluid containing about the same protein constituents as in the serum was induced in mice. Amyloidotic peritoneal cells were packed in a microchamber which was shielded with filter membranes, and cultured in ascitic fluid supplemented with additional inflammatory factors. On the 7th day, Congo red-positive structures which showed green birefringence under polarized light were found inside and occasionally outside the chamber. By anti-AA or -SAA immunostaining, amyloid deposits and the cell surfaces of macrophages were positive. Immunologic depletion of T- and B-lymphocytes from the amyloidotic peritoneal cells did not adversely effect the amyloid formation in microchambers. These results suggest that either ascitic fluid containing sufficient amounts of SAA, or peritoneal macrophages with a high amyloid enhancing factor (AEF) activity are indispensable for AA amyloid fibrillogenesis in the peritoneum.

Amyloid↗

PubMed1992

Loss of androgen dependency with preservation of functional androgen receptors in androgen-dependent mouse tumor (Shionogi Carcinoma 115).

Shionogi Carcinoma 115 (SC 115) is an androgen-dependent mouse tumor. Chiba Subline 2 (CS 2) is an androgen-independent subline derived from SC 115. CS 2 contains androgen receptors (AR), but is refractory to androgen and does not exhibit androgen-related responses which are observed in SC 115. In the present study the structure and function of AR in SC 115 and CS 2 are examined using cloned cells. There were no gross rearrangements or deletions in the AR genes of these cell lines when compared by Southern blot analysis with the AR gene in the mouse seminal vesicle. SC 115 and CS 2 expressed AR mRNA of normal size. When the cDNA containing DNA- and androgen-binding domains of the AR genes of both cell lines were amplified by polymerase chain reaction, no mutations were found in these regions. SC 115 and CS 2 were transfected with a plasmid containing a long terminal repeat of mouse mammary tumor virus linked to the chloramphenicol acetyltransferase (CAT) gene. Androgen stimulation of these transfectants resulted in equal elevation of CAT activity. These results indicated that the androgen-independent CS 2 contained functionally normal AR which were identical to those in the androgen-dependent parent tumor.

Androgens↗

PubMed1992

Endocytosis of soluble IgG immune complex and its transport to lysosomes in hepatic sinusoidal endothelial cells.

Both Kupffer cells and sinusoidal endothelial cells are engaged in the hepatic uptake of soluble IgG immune complex (IgG-IC) through Fc-receptors on their surface. Hepatocytes have also been reported to take up IgG-IC. It remains unclear, however, whether the endothelial cell degrades IgG-IC and whether the hepatocyte participates in IgG-IC clearance. In this study, normal mice received a single intravenous injection of soluble immune complex preformed in antigen excess, i.e. bovine serum albumin (BSA) anti-BSA-mouse-IgG complex (BABIgG) or BSA anti-BSA-mouse-F(ab')2 complex (BABF(ab')2), or BSA alone. An immunoperoxidase study for BSA showed that from 1 to 120 min after injection only BABIgG was ingested by both endothelial cells and Kupffer cells but not by hepatocytes. The staining intensity of BABIgG was maximal at about 15 min and decreased subsequently. Endocytosis of BABIgG occurred through coated pits in the endothelial cells. Within a few minutes, endocytosed BABIgG was found in tubulovesicular structures and large vesicles. The occasional large vesicles were shown to be lysosomes by simultaneous demonstration of BABIgG with acid phosphatase. BABIgG was not found on either of the endothelial and hepatocellular surfaces facing the space of Disse or in hepatocytes. These results indicate that soluble IgG-IC is endocytosed by sinusoidal endothelial cells and degraded in the lysosomes and that the participation of hepatocytes in the clearance of IgG-IC is improbable.

Acid Phosphatase↗