Search PubMed⌕ Search

Biomedical subjects

K Iwabuchi

Publications and source records attributed to K Iwabuchi.

At least 181 records · Page 10Linked to original sources
PubMed1992

Differential expression of the platelet-derived growth factor-A and -B genes during maturation of monocytes to macrophages.

1. Regulation of platelet-derived growth factor (PDGF)-A and -B gene expression was studied using resting monocytes, in vitro matured monocytes and alveolar macrophages. 2. Resting monocytes constitutively transcribed both PDGF-A and -B genes. When monocytes matured to macrophages in vitro, the transcription rates of both genes increased markedly. 3. Consistent with the transcription rates, resting monocytes constitutively expressed both PDGF-A and -B mRNAs. Interestingly, the PDGF-B mRNA levels increased markedly after the maturation, whereas the PDGF-A mRNA did not change. 4. Alveolar macrophages constitutively transcribed both PDGF-A and -B genes at almost the same rates. However, these cells contained 5-fold more PDGF-B mRNA than PDGF-A mRNA. 5. Immunohistochemical study using anti-PDGF-AA and anti-PDGF-BB antibodies suggested that PDGF-BB homodimers were more abundant than -AA homodimers or -AB heterodimers in alveolar macrophages and in vitro matured monocytes. 6. Together these observations indicate that in vitro matured monocytes and alveolar macrophages preferentially express PDGF-B mRNA and produce PDGF-BB homodimers, despite the equal transcription rates for both PDGF-A and -B genes.

Cell Differentiation↗
PubMed1992

A case report of inflammatory pseudosarcoma of the urinary bladder.

A case of inflammatory pseudosarcoma of the urinary bladder in a 35-year-old Japanese male is presented. This benign lesion can easily be mistaken for spindle cell sarcoma since it consists of rhabdomyoblast-like elongated strap cells showing infiltrative growth, and whether it is benign or malignant is difficult to determine by microscopic examination. In this case, spindle cell proliferation extended among bundles of the superficial muscle layer. However, no abnormal mitoses, severe nuclear atypia or cellular pleomorphism could be seen, thus indicating inflammatory pseudosarcoma. Although the lesion was not completely resected, no recurrent disease has been clinically observed for two years following transurethral resection. Urologists and surgical pathologists must be able to detect this lesion in order to avoid unnecessary surgical procedures.

Adult↗
PubMed1992

Immunohistochemical studies of Merkel cell carcinoma of the eyelid.

Merkel cell carcinoma of the eyelid is a rare malignant tumor. Immunohistochemical studies can be helpful in establishing the diagnosis of this tumor. We encountered a case of Merkel cell carcinoma of the eyelid and conducted an immunohistochemical analysis for clarification of its cell properties. The patient in this study was a 78-year-old man who noted a small mass on his right upper eyelid, which was subsequently removed. However, the lesion recurred and progressively enlarged. The results of a biopsy indicated the possibility of a highly malignant tumor. The lesion was removed by orbital exenteration. Merkel cell carcinoma was finally diagnosed by using light and electron microscopy. In immunohistochemical studies, the tumor cells showed both neuron-specific enolase and cytokeratin. Most of the cells were also labeled with antibodies against the protein gene product 9.5, endocrine granule constituent and chromogranin A. However, no neuropeptides were labeled. The properties of the tumor cells appeared virtually the same as those of normal human Merkel cells.

Aged↗
PubMed1992

[Reticular degeneration of retinal pigment epithelium].

Reticular degeneration of the retinal pigment epithelium (RDRPE) was found in 33 out of 3114 files (1.06%) of fluorescein angiography. The age distribution of the cases with RDRPE showed a peak in the 8th decade, and the average age was 73 years. No statistically significant sexual tendency was observed. Eighty five percent of cases had bilateral RDRPE. The linear, incomplete polygon type was found on the nasal quadrants in patients aged 50-70 years old. The complete polygon type was found in both nasal and temporal quadrants in patients over 70 years old. RDRPE and pigment epithelium degeneration at the posterior pole were found to be concomitant manifestations. It was concluded that RDRPE initially appears on nasal quadrants as a lineal, incomplete polygon pattern and in advanced cases complete polygon pattern appears on all quadrants of the peripheral retina.

Aged↗
PubMed1992

[Retroperitoneal malignant lymphoma showing follicular type: report of a case].

We report a case of retroperitoneal follicular malignant lymphoma. A 59-year-old man visited the hospital with the chief complaint of a loss of body weight and left epigastric tumor. CT revealed a tumor, 9 x 6 cm, with non-homogeneous density in the left retroperitoneum. Since no clinical metastasis was identified, the tumor and the left kidney were resected en bloc with para-aortic lymph node dissection. Pathological diagnosis was non-Hodgkin follicular lymphoma of mixed small cleaved and large cell type with lymph node metastasis (2/23). The CHOP adjuvant chemotherapy (cyclophosphamide, adriamycin vincristine, Prednisolone) and the radiation therapy were performed after the operation. Recurrence in the mediastinal lymph node occurred 7 months after operation and radiation and the same adjuvant chemotherapy were performed and resulted in complete remission. The patient remained free of the tumor for 27 months at present.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

[A case of transitional cell carcinoma of renal pelvis with an extremely high serum carcinoembryonic antigen (CEA) level].

A case of urothelial tumor with extremely high serum carcinoembryonic antigen (CEA) levels is described. A 68-year-old female presented with macroscopic hematuria and left flank pain. Laboratory examination revealed an extremely high serum level of CEA (194 ng/ml) and elevated levels of serum CA 19-9 (235 U/ml) and squamous cell carcinoma (SCC)-Antigen (10.7 ng/ml), while urine CEA remained within normal limits. No abnormal findings were recognized in gastrointestinal and respiratory systems, but left renal pelvic tumor (T4N2M0) was discovered. Nephroureterectomy with regional lymph node dissection was done. The pathologic anatomy was infiltrating non-papillary transitional cell carcinoma (TCC, G2 = G3, pT4N2M0). More than 30% of the tumor cells were positive for CEA by ABC-peroxidase staining. Levels of tumor markers remained higher than normal after the operation and were normalized after M-VAC (methotrexate, vinblastine, adriamycin and cisplatin) chemotherapy. However, 6 months after the operation, levels of tumor markers rose again and lung metastases appeared. She died 10 months after the operation.

Aged↗
PubMed1991

Characterization of cDNA clones encoding guinea pig neutrophil cationic peptides.

cDNA clones encoding antimicrobial guinea pig neutrophil cationic peptides GNCP-1 and GNCP-2 were isolated from a bone marrow cell cDNA library. Analysis of these clones indicated that both GNCPs were produced as precursor proteins comprising 93 amino acid residues, which were composed of signal sequences (N-terminal 19 residues), pro-peptide sequences (43 residues) and mature GNCP sequences (31 residues). The deduced amino acid sequences showed that there were only two amino acid differences between GNCP-1 and GNCP-2, one in the pro-peptide region and one in the mature peptide region. Interestingly, Northern blot analysis and transcription run-off assay revealed that the expression of GNCP mRNA and the transcription of GNCP gene was observed in bone marrow cells but not in mature neutrophils. These observations suggest that mature neutrophils, despite their abundant content of GNCPs, lose the capacity to synthesize GNCPs.

Amino Acid Sequence↗
PubMed1991

Expression of insulin-like growth factor-IA and factor-IB mRNA in human liver, hepatoma cells, macrophage-like cells and fibroblasts.

The human insulin-like growth factor-I (IGF-I) gene codes for two transcripts, IGF-IA and IGF-IB mRNAs, formed by alternative splicing. In this study, the expression of these IGF-I mRNA transcripts was examined using human liver, hepatoma cells, macrophage-like cells and fibroblasts. The reverse transcription-polymerase chain reaction revealed that these cells contained both IGF-IA mRNA (representing exons I, II, III and V) and IGF-IB mRNA (representing exons I, II, III and IV). Interestingly, an RNase protection assay using 32P-labeled IGF-IA and IGF-IB exon-specific cRNA probes demonstrated that IGF-IA mRNA was 10-fold more abundant than IGF-IB mRNA in these cells. However, there was no difference in the stabilities of IGF-IA and IGF-IB mRNAs. These observations indicate that IGF-IA mRNA is more expressed than IGF-IB mRNA in these cells independent of their stabilities.

Base Sequence↗
PubMed1991

Deficiency in early development of the thymus-dependent cells in irradiation chimeras attributable to recipient's environment.

Allogeneic bone marrow chimeras were prepared using reciprocal combinations of AKR and C3H mice. When C3H mice were recipients, the number of thymocytes recoverable from such chimeras (C3H recipient chimeras) was small as compared with that from chimeras for which AKR mice were used as recipients (AKR recipient chimeras) regardless of donor strain. The thymocytes from C3H recipient chimeras showed a profound deficiency in generating proliferative responses to stimulation by anti-CD3 mAb (2C11) or anti-TCR (alpha, beta) mAb (H57-597), even though the expression of CD3 and TCR molecules fell within the same range as that in AKR recipient chimeras. Furthermore, after stimulation with immobilized 2C11, the proportion of IL-2R+ cells in the thymocytes from C3H recipient chimeras was much less than that in AKR recipient chimeras. However, no significant difference in proliferative responses to 2C11 plus PMA, in influx of Ca2+ after stimulation with 2C11 or IL-2 production in response to 2C11 plus PMA or PMA plus A23187 was demonstrated between C3H and AKR recipient chimeras. These findings suggest that the thymocytes from C3H recipient chimeras have a deficiency in the signal transduction system as compared with chimeras for which AKR mice are the recipients. The thymic stromal component involved in this difference in the C3H recipient chimeras is discussed.

Animals↗
PubMed1991

Degeneration of the corticopontine tract in olivopontocerebellar atrophy.

Nine cases of sporadic olivopontocerebellar atrophy [Déjérine-Thomas type, multisystemic atrophy (MSA)] were examined histologically and electron microscopically with special reference to the corticopontine tract. Five of nine cases showed degeneration of the myelinated nerve fibres in this tract. More severe degeneration of the fibres at the level of the pons than the crus cerebri indicates that degeneration of the fibres may start axodistally. Electron microscopy revealed selective involvement of large fibres in olivopontocerebellar atrophy, in contrast to unselective axonal atrophy in dentatorubropallidoluysian atrophy. The problem whether the degeneration of the tract is primary or secondary due to the loss of the pontine neurons remains open. We believe the former to be most likely. Degeneration of the corticopontine fibres should be added to the list of neuropathological findings in sporadic olivopontocerebellar atrophy.

Adult↗
PubMed1991

H-2K molecules positively select V beta 17a+ CD4(-)8+ T cells in bone marrow and thymic chimeras.

Population size of V beta 17a brightly positive cells among CD4(-)8+ thymocytes was analyzed in thymic chimeras as well as bone marrow (BM) chimeras in which SWR/J mice were used as BM donors and various strains of mice including H-2Kb mutant (bm) mice as recipients. It was shown that the proportion of V beta 17a+ CD4(-)8+ thymocytes was determined by H-2K molecules expressed on thymic epithelial cells. The highest proportion was observed in Ks and Kb thymuses, the intermediate proportion in Ks/q and Kk, and the lowest in Kq thymuses. Fine analysis of the H-2Kbm molecules involved in the positive selection revealed that the region important to the selection was located on the beta-pleated floor of antigen recognition site. According to the three-dimensional class I structure, this site appears not to be directly accessible to the T cell antigen receptor. Thus, the present finding suggests that the substitutions of amino acids at this site alter the shape and charge of the peptide binding site and eventually influence the positive selection of the V beta 17a+ T cell repertoire during differentiation.

Animals↗
PubMed1991

Comparison of O2(-)-producing activity of guinea-pig eosinophils and neutrophils in a cell-free system.

1. The NADPH-dependent superoxide (O2-) production in a cell-free system of guinea-pig eosinophils was studied, comparing the eosinophils with neutrophils. 2. Eosinophils produced 2.2-fold more O2- than neutrophils in sonicated and intact cells. 3. The subcellular fractionation experiments showed that the O2- production was dependent on the cooperation between the membrane and cytosol fractions. 4. The cross-mixing experiments indicated that the NADPH oxidase-activating activity of the eosinophil cytosol was about 2-fold greater than that of the neutrophil cytosol. 5. These results suggest that the difference in the O2(-)-producing activity between eosinophils and neutrophils is associated with the difference in cytosolic factors necessary for the activation of NADPH oxidase.

Animals↗
PubMed1991

Comparative studies on the platelet-derived growth factor-A and -B gene expression in human monocytes.

1. Platelet-derived growth factor (PDGF)-A and -B gene expression was studied in human monocytes. 2. Resting monocytes constitutively transcribed both PDGF-A and -B genes. When monocytes were stimulated by lipopolysaccharide (LPS), transcription rates of both genes were increased in a similar fashion. 3. Consistent with the transcription rates, resting monocytes constitutively expressed both PDGF-A and -B mRNAs. After LPS stimulation, the PDGF-A mRNA level increased gradually, while the PDGF-B mRNA level increased markedly and then decreased rapidly. 4. Reverse transcription-polymerase chain reaction showed that resting monocytes expressed only short PDGF-A mRNA species (representing exons I-V + VII), but LPS-stimulated monocytes expressed long PDGF-A mRNA species (representing exons I-VII) as well. Both resting and LPS-stimulated monocytes expressed only one PDGF-B mRNA species (representing exons I-VII). 5. Together these observations indicate that expression of PDGF-A and -B genes is differentially regulated at the levels of mRNA splicing and mRNA accumulation in monocytes, while transcription of both genes seems to be similarly controlled.

Blotting, Northern↗
PubMed1991

Distribution of MEL-14+ cells in various lymphoid tissues.

The distribution of MEL-14+ lymphocytes was investigated by both fluorocytometric analysis and complement-dependent-cellular-cytotoxicity (CDCC) tests in which rabbit anti-rat Ig was added with complement at a secondary step. When CDCC was employed to detect MEL-14+ cells, almost half of the thymocytes were found to be MEL-14+ in various strains of mice. This high proportion of MEL-14+ cells stands in striking contrast to prior reports. Furthermore, when determined by fluorocytometric analysis, MEL-14+ cells were found to comprise more than 80% of the cells in the thymus. The MEL-14+ thymocytes comprised both immature subsets (CD4-8-, CD4+8+) and mature subsets (CD+8-, CD4-8+). MEL-14 brightly positive (MEL-14high) cells, however, were located mainly in mature T cell subpopulations within the thymus. The MEL-14high thymocytes appeared to be susceptible to the CDCC method. Most of MEL-14+ cells present in spleens and lymph nodes were shown to be included in the MEL-14high population. The MEL-14+ cells susceptible to treatment with MEL-14, rabbit anti-rat Ig plus complement in the spleen and lymph node were restricted to cells of the T-lineage. These data suggest that T cells may change from cells with low expression of the MEL-14 antigens at their surface to cells with high MEL-14 antigens in the process of differentiation. Furthermore, these findings indicate that MEL-14 molecules may be used as a surface marker to characterize an important T cell subpopulation.

Animals↗
PubMed1991

Changes of lung surfactant and pressure-volume curve in bleomycin-induced pulmonary fibrosis.

We investigated whether alveolar surface force increased and participated in the lung pressure-volume relationship in bleomycin-induced pulmonary fibrosis in hamsters and, if so, whether lung surfactant was hampered in the lungs. On the air-filled pressure-volume curve, decreases of lung volume from control level were significantly higher at 3-8 cmH2O pressure on day 10 than on day 30. Because the change of lung tissue elasticity evaluated from the saline-filled pressure-volume curve was equal for the 2 days, the higher decrease of air volume on day 10 was due primarily to contribution of alveolar surface force. Pressure differences between deflation limbs of air-filled and saline-filled pressure-volume curves, which represented net alveolar surface force, were significantly higher at any lung volume between 50 and 90% total lung capacity on day 10, but almost no significance was observed on day 30. Phospholipid concentration in bronchoalveolar lavage fluid significantly decreased on day 10 but had improved by day 30. Analysis of phospholipid species in purified lung surfactant showed decreased fractions of disaturated phosphatidylcholine and phosphatidylglycerol on day 10. Surface-active properties of the surfactant, measured by a modified Wilhelmy balance, were remarkably hampered on day 10, but most of them had improved by day 30. We consider that the quantitative and functional abnormalities of lung surfactant have a part in the aggravation of lung mechanics in the acute phase of pulmonary fibrosis.

Animals↗
PubMed1991

[Study on argyrophilic inclusions of multisystem atrophy (Oppenheimer)].

UNLABELLED: Non-hereditary olivo-ponto-cerebellar atrophy (OPCA) and striato-nigral degeneration (SND) have been looked upon as a single disease entity called multisystem atrophy (MSA) by Oppenheimer. This study revealed that both intracytoplasmic argyrophilic inclusions (AI) in pontine neurons and glial (argyrophilic) cytoplasmic inclusions (GCIs) widely distributed in the CNS are characteristics of MSA. MATERIALS: a) 12 cases with MSA, b) 16 cases with autosomal dominant (AD) form of spinocerebellar degeneration (SCD): AD form of OPCA 5 cases, Joseph disease 4 cases, AD-dentatorubropallidoluysian atrophy (Naitoh & Oyanagi's form) 6 cases, AD-spastic ataxia (Brown) 1 case, c) 4 cases with autosomal recessive (AR) form of SCD: AR form of OPCA 1 case, myoclonic epilepsy with ragged-red fibers (MERRF) 1 case, complicated form of spastic paraplegia 2 cases, d) 6 cases with non-hereditary SCD including intoxications: late cortical cerebellar atrophy 1 case, alcoholic cerebellar degeneration 2 cases, phenytoin-induced cerebellar degeneration 1 case, neuroleptic malignant syndrome 1 case, and e) 27 cases with other neuropsychiatric diseases: Alzheimer disease 20 cases, progressive supranuclear palsy 5 cases, schizophrenia 2 cases. METHOD: We examined 10 mu-thick paraffin sections stained with HE, Klüver-Barrera, Bodian, Holzer, Gallyas, and Bielschowski methods. RESULTS: AI in pontine neurons were found only in two cases of MSA. Interestingly no AI could be detected even in cases with AD form of OPCA showing mild degeneration in the pontocerebellar system. On the other hand, GCIs were found in all cases with MSA irrespective of the degree of degeneration in the olivo-ponto-cerebellar or striato-nigral system. However, there was no GCIs in cases with other form of SCD and other neuropsychiatric diseases. Gallyas stain was the best method for detecting GCIs. GCIs were widely distributed in the CNS except for superficial layers of the cerebral cortex, the cerebellar cortex, and the dorsal column of the spinal cord. There were also many GCIs in the putamen, pontine base, and cerebellar white matter, even though these sites were well preserved.

Alzheimer Disease↗