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T Shirahama

Publications and source records attributed to T Shirahama.

At least 55 records · Page 3Linked to original sources
PubMed1991

[In-vivo 19F-MRS study of 5-fluorouracil (5-FU) metabolism on tumors].

5-Fluorouracil (5-FU) metabolism on tumors was studied by in-vivo 19F-MRS (magnetic resonance spectroscopy). In this study, two kinds of tumors were used, i.e., Yoshida sarcoma implanted subcutaneously to the abdomen of rats and drug-induced tumors in the rats livers. Sequential 19F spectra were obtained just after 150 mg/kg 5-FU injected intravenously. In Yoshida sarcoma, the accumulation of 5-FU was observed and disappearance of 5-FU was slower compared to the normal tissue. However, synthesis of fluoronucleotides (Fnct) could not be detected. In drug-induced liver tumors, the peak of fluoro-beta-alanine (FBAL) was observed. Disappearance of 5-FU and catabolism to FBAL in the liver tumors group were slower compared to the normal liver. Synthesis of Fnct did not increase in the liver tumor group. The results in the liver tumor group are considered to be the confined result of the hepatocytes and tumors cells. It was considered that the delayed catabolism to FBAL in the liver tumor group showed metabolic dysfunction of the liver. Also the synthesis of Fnct in tumors could not be detected by in-vivo 19F-MRS. 19F-MRS method could not detect Fnct in tumors in-vivo. However, the accumulation of 5-FU could be assessed by this method. It is expected that the evaluation of 5-FU pooling in tumors could be used for the index of chemotherapeutic effect.

Animals↗
PubMed1990

Generation and use of site-specific antibodies to serum amyloid A for probing amyloid A development.

Serum amyloid A (SAA) is an acute phase reactant and the putative precursor of an amyloid fibril protein (AA). During amyloidogenesis in mice, the C-terminal portion of SAA that consists of 28 amino acids is cleaved off to produce the 75 amino acid AA. Of three known isotypes of SAA, SAA2 has been identified as amyloidogenic. For differential immunologic recognition of SAA and AA, antisera were generated in rabbits against AA protein and a synthetic peptide corresponding to the C-terminal (amino acids 84 to 103) of murine SAA2. The anti-AA antiserum reacted with AA and SAA, but the anti-peptide antiserum reacted with SAA only. Immunohistochemically anti-peptide antiserum predominantly stained the rims of murine amyloid deposits. In contrast, anti-AA antiserum generated an overall homogeneous staining of amyloid deposits. The data lend support to a view that SAA are concentrated in the vicinity of the surrounding cells (mostly macrophages) where they are processed to AA, or that SAA are deposited initially as components of the amyloid fibrils onto the outside margin of amyloid deposits and the C-terminus is cleaved off as maturation of the amyloid fibril progresses.

Animals↗
PubMed1990

Amyloid enhancing factor-loaded macrophages in amyloid fibril formation.

Amyloid enhancing factor (AEF) is believed to be a key agent that triggers the second (deposition) phase of amyloidogenesis. However, the target cells of AEF activation and their function after the activation have not yet been clearly identified. We found that peritoneal resident cells from amyloidotic mice contained very high AEF activity. With a simultaneous subcutaneous injection of 1.0 ml of the casein-adjuvant emulsion, an intravenous injection of 10,000 cells was consistently capable of inducing amyloidosis in a recipient mouse in 72 hours. After 2-hour cultures, the major AEF activity was found in the adherent cells (macrophages). An intravenous injection of 5 to 10 million of the live macrophages with the casein-adjuvant injection caused amyloid deposits in the recipient not only in the spleen and the liver but also in the lung (an extremely rare site of AA amyloid deposition). We have interpreted this finding to indicate that the injected AEF-loaded macrophages, while still residing in the lung and exposed to the blood stream, processed SAA to form amyloid. We further tested this postulate in an in vitro system. In a 4-day culture of the AEF-loaded macrophages in a medium containing SAA-rich mouse serum, small masses (less than 15 microns in diameter) of Congo red positive substance were observed scattered adjacent to or surrounded by the macrophages. The present observations lend strong credence to the conclusion that AEF-loaded macrophages are fully capable of processing SAA to AA and further to amyloid fibrils, and that they indeed play a role in the second phase of amyloidogenesis in vivo.

Amyloid↗
PubMed1989

Murine tissue macrophages synthesize and secrete amyloid proteins different to amyloid A (AA).

We recently demonstrated that serum amyloid A (SAA) gene expression can be induced in extrahepatic sites with exception of the brain. Furthermore we demonstrated that tissue macrophages express SAA-gene constitutively and that SAA-gene expression can be increased by endotoxin. Until now the protein corresponding to the SAA-specific mRNA contained in macrophages has not been identified. We compared proteins precipitated from endogenously labelled samples by three antisera against amyloid A (AA) raised in different laboratories. Radiolabelled samples were derived from murine hepatocyte cultures, from cell-free translation of acute phase liver RNA or hepatocytes RNA and from peritoneal macrophages as well as Kupffer cells. All three antisera recognize a protein of 12.5 kDa Mr produced by hepatocytes (SAA), and a major protein of 14.3 kDa Mr contained in the cell-free translation products; this is the precursor of the mature SAA as demonstrated by cleavage experiments with canine pancreas microsomal enzymes. The antisera also recognize two proteins--a major one of 14.5 kDa Mr and a second of 12.5 kDa Mr contained in the supernatants and cell lysates of liver and peritoneal macrophages. New antisera raised against the two proteins do not recognize any protein, either of hepatocyte or of cell-free translation samples; they specifically precipitate two proteins from macrophage samples with the same molecular mass as that of the proteins precipitated by the anti SAA antisera. Murine acute phase sera do not react with the new antisera. However, amyloid deposits of amyloidotic mice specifically react with the new antisera. We describe two new components of murine amyloid produced by tissue macrophages.

Acute-Phase Proteins↗
PubMed1989

Serum amyloid A gene expression and AA amyloid formation in A/J and SJL/J mice.

Serum amyloid A (SAA) gene expression and AA amyloid fibril formation were studied in A/J and SJL/J mice, two strains which have been reported to possess defects in AA fibril formation. Four types of inflammatory stimulation were employed: acute inflammation stimulated with lipopolysaccharide (LPS), chronic inflammation with casein in complete Freund's adjuvant, amyloidosis with injection of amyloid enhancing factor (AEF) together with casein in complete Freund's adjuvant, and non-amyloidogenic inflammation in the presence of AEF with injection of AEF together with LPS. Both A/J and SJL/J mice developed splenic amyloidosis 1 day after initiation of chronic inflammation in the presence of AEF. No amyloid deposits were detected during any of the other types of inflammation. Amyloidotic mice exhibited decreased amounts of SAA mRNA in liver and spleen concomitant with decreased amounts of SAA in serum. Alpha-I-acid glycoprotein mRNA was present in liver throughout the course of AEF accelerated amyloidosis, indicating that decreased SAA gene expression and AA fibril formation is not part of a general inhibitory effect of AEF on protein synthesis.

Animals↗
PubMed1988

Utility of subcutaneous fat aspiration for the diagnosis of systemic amyloidosis (immunoglobulin light chain).

To our knowledge, this is the first blind and controlled analysis of subcutaneous fat aspiration for the diagnosis of primary systemic amyloidosis. The procedure was performed on 82 patients with biopsy-proved systemic amyloidosis and 72 normal adult volunteers. Slides from 71 of the 72 controls were read as negative. Slides from 59 (72%) of the 82 patients with amyloidosis were read as positive or weakly positive after staining with alkaline Congo red. Subcutaneous fat aspiration was as sensitive as rectal biopsy and substantially more sensitive than bone marrow biopsy in diagnosing amyloidosis. In six instances fat aspiration would have obviated the need for a more invasive diagnostic biopsy. Subcutaneous fat aspiration is sensitive (72%) and specific (99%) for amyloidosis. It is technically simpler and less expensive than rectal biopsy and permits immediate assessment of specimen adequacy. The concordance rate for two independent pathologists was 95%. Equivocally positive stains should be interpreted with caution because weak nonspecific staining may be seen.

Adipose Tissue↗
PubMed1988

[Antitumor activity of UFT and interferon-alpha against human renal cell carcinoma in athymic nude mice].

We examined whether a combined use of UFT with interferon against human KDR-1 strain cells was effective or not. KDR-1 strain derived from the patient with renal cell carcinoma was transplanted into nude mice. When the tumor grew large enough, the mice were divided into 4 groups. The group consisted of 1) oral use of 5% Acasia as a control, 2) oral administration of UFT, 3) combined use of UFT and IFN-alpha, 4) intraperitoneal injection of IFN. Each group was treated continuously for 16 days. Antitumor effect was not observed in group 2 and 4, but observed in group 3. The concentration of UFT in the tumor tissue did not show any differences between combination and UFT groups. Therefore, there is no evidence to prove that IFN-alpha makes UFT level higher. Antitumor effect was observed histopathologically in the combined regimen group, although a mechanism of synergistic effect is still unknown.

Animals↗
PubMed1987

Differential expression of the amyloid SAA 3 gene in liver and peritoneal macrophages of mice undergoing dissimilar inflammatory episodes.

The three active serum amyloid A (SAA) genes of mice, SAA 1, SAA 2, and SAA 3, are coordinately expressed in liver during acute and chronic inflammatory stimulation and experimental amyloidosis. The genes, primarily SAA 3, are also expressed extrahepatically. The apoprotein SAA 2 is the precursor of the amyloid A (AA) fibril protein that is deposited as insoluble fibrils extracellularly in spleen and other organs when amyloidosis occurs secondarily to inflammation. The exact cause of AA fibril formation is unknown. Amyloid enhancing factor is a high m.w. glycoprotein extracted from amyloidotic organs. Administration of amyloid enhancing factor alters experimental inflammation to bring about accelerated deposition of amyloid A fibrils first in spleen and later in other organs. In this study, hepatic and extrahepatic expression of the SAA genes were compared during accelerated amyloidosis relative to inflammation uncomplicated by amyloidosis. Differences in kinetics and pattern of SAA gene expression by resident peritoneal macrophages and liver were detected during four dissimilar inflammatory episodes. Macrophages expressed the SAA 3 gene solely, and to a greater extent in chronic than in acute inflammation. In accelerated amyloid induction, macrophage SAA 3 expression increased as SAA 1 and SAA 2 expression in liver decreased. However, alpha-1-acid glycoprotein expression remained elevated throughout the course of amyloid induction. The greatly increased expression of the SAA 3 gene by macrophages and decreased expression of the SAA 1 and SAA 2 genes in liver during amyloidosis, suggests that altered SAA gene expression may play a pathogenetic role in experimental amyloid deposition.

Amyloidosis↗
PubMed1987

Diagnosis of amyloidosis by abdominal fat aspiration. Analysis of four years' experience.

Abdominal fat aspiration samples from 443 consecutive patients were examined for amyloid after Congo red and hematoxylin staining. Of the aspirates from 83 patients known to have systemic amyloid disease prior to the biopsy, 70 (84 percent) were found to yield positive results. The results for four aspirates from patients with localized amyloid disease were negative. Of the aspirates from 356 patients of unknown clinical status referred for analysis by outside physicians, 26 (7 percent) yielded positive results for amyloid. On review of the clinical records of these 26 patients, 11 had proved systemic amyloidosis demonstrated on biopsy of another site; all had a clinical course consistent with amyloid disease. In no case was amyloid found in a fat aspiration sample from a patient without clinical evidence suggestive of systemic amyloid disease. This study supports the proposal that abdominal fat aspiration is the diagnostic procedure of choice in the evaluation of amyloidosis since it requires no specialty consultation or technical expertise, causes minimal patient discomfort, and is accompanied by virtually no risk of morbid complication. A positive result has a high predictive value of amyloid disease in patients of unknown clinical status.

Abdomen↗
PubMed1987

Hemodialysis-associated amyloidosis and beta-2 microglobulin. Clinical and immunohistochemical study.

The beta-2 microglobulin type of amyloidosis was identified in articular and para-articular tissues of 14 patients with non-amyloid nephropathies undergoing long-term hemodialysis. Ten patients had carpal tunnel syndrome, 13 had juxta-articular radiolucent cysts (complicated by spontaneous fractures of the femoral neck in three), and six had destructive arthropathies of the large joints of the limbs. Massive amyloid deposits were found in the synovium, capsule, ligaments, articular cartilage, and/or bone. They were characterized by Congo red-induced green birefringence that was sensitive to potassium permanganate treatment. They reacted with anti-beta-2 microglobulin antiserum, whereas they did not react with antibodies directed against AA protein, prealbumin, or immunoglobulins. These data suggest that the potentially disabling arthropathy of hemodialysis is due to amyloid lesions. The persistently elevated plasma beta-2 microglobulin levels may play a role in the pathogenesis of this recently recognized complication, and if so, this complication should be preventable.

Aged↗
PubMed1987

Production of an amino acid sequence-specific antiserum against human amyloid A (AA) and serum amyloid A (SAA) protein.

The hydrophilic nonapeptide Ser-Asp-Ala-Arg-Glu-Asn-Ile-Gln-Arg, identical with residues 59-67 of human amyloid protein A (AA) and serum amyloid protein A (SAA), was covalently bound via its carboxyl-terminal end to the carrier-protein keyhole limpet haemocyanin. The complex was injected subcutaneously into ten rabbits. All rabbits produced antisera which, unabsorbed, were specific for AA and SAA. The antisera and their isolated peptide specific antibodies were performance-tested and found to be excellent for demonstration of AA and SAA in immunoblotting and immunohistochemical techniques but unsuitable for immunoprecipitation. Since it is difficult to produce AA- and SAA-specific antisera by procedures earlier described and commercial supplies of good such reagents are unavailable, the easy production of sequence-specific such antisera will facilitate more extended studies of the corresponding antigens for diagnostic and scientific purposes.

Amino Acid Sequence↗