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Biomedical subjects

T Sawada

Publications and source records attributed to T Sawada.

At least 19 recordsLinked to original sources
PubMed1992

Transplantation of embryonic mesencephalic and medullary raphe neurons to the neostriatum of rats with unilateral 6-hydroxydopamine lesions.

The implantation of dopamine-rich mesencephalic grafts into the 6-hydroxydopamine (6-OHDA)-lesioned neostriatum of rats was accompanied by marked hyperinnervation by serotonin (5-HT) fibers. The purpose of this study was to examine the possibility that the graft-derived 5-HT hyperinnervation is governed by target-related effects present in the host neostriatum and the question of whether grafts rich in 5-HT cells can ameliorate the drug-induced motor asymmetry resulting from unilateral 6-OHDA lesions. Rats were allocated to one of two groups: lesion plus mesencephalic raphe grafts (group R5-HT/L); and lesion plus medullary raphe grafts (group C5-HT/L). A third group, sham-lesion plus mesencephalic raphe grafts (group R5-HT/S) was included. Complete recovery of (+)-amphetamine-induced rotation was observed only in rats which received 5-HT grafts derived from medullary raphe neurons. There was no marked recovery of apomorphine-induced rotation in either of the R5-HT/L and C5-HT/L groups. Immunohistochemistry showed that the R5-HT/L and C5-HT/L groups had 5-HT hyperinnervation in the neostriatum of the lesioned side. There was no target-related effect of the 6-OHDA-lesioned neostriatum specific for the different types of 5-HT tissue. It seems likely that the 5-HT tissue derived from the medullary raphe may contain additional neurotransmitters which contribute to the behavioral recovery.

Amphetamine↗
PubMed1992

Influence of electro-acupuncture on the release of substance P and the potential evoked by tooth pulp stimulation in the trigeminal nucleus caudalis of the rabbit.

The effects of electro-acupuncture (EAP) on the release of substance P (SP) and the responses evoked by tooth pulp stimulation (ST) in superficial layers of the trigeminal nucleus caudalis (Vc-I,II) were studied in rabbits. ST evoked increase in release of immunoreactive SP (iSP). This increase was inhibited by EAP in 9 of 13 animals. The potentials evoked by ST were composed of two main components with latency times of ca 4.3 msec and ca. 9.4 msec. The latter component, reflecting the excitation of A delta fibers, was significantly inhibited by CP-96,345 (3 mg/kg, i.v.), an SP antagonist. EAP also inhibited the latter component in 8 of 11 animals. These results suggest that one of the mechanisms of analgesia induced by EAP is inhibition of stimulus-evoked SP release in the Vc-I,II.

Animals↗
PubMed1992

Differential expression of myogenic regulatory genes, MyoD1 and myogenin, in human rhabdomyosarcoma sublines.

A cell line (SCMC-MM-1) was established from a human abdominal tumor that was initially diagnosed as a malignant mesenchymoma by histological, immunohistochemical and clinical criteria. The cell line was composed of 2 morphologically and immunohistochemically distinct cell types, one with a small polygonal phenotype (P-type), characterized by the immunostaining of vimentin and the presence of a few electron-microscopically visible organelles, and the other with a giant tubular phenotype (T-type), characterized by the immunostaining of desmin, alpha-sarcomeric actin and skeletal-muscle myosin, and the presence of thick and thin myofilaments and Z-line materials. The parental cell line was cloned into 2 sublines, a P-type clone (SCMC-MM-1-19P) and a T-type clone (SCMC-MM-1-1T), which shared both 2q37 and 11p15 translocations, the characteristic chromosomal aberrations for rhabdomyosarcoma, with the parental SCMC-MM-1 cell line. Northern-blot analyses of the myogenic regulatory genes, including MyoD1 and myogenin, demonstrated the expression of MyoD1 in both of these sublines. Myogenin was very weakly expressed in the SCMC-MM-1-19P subline, but strongly expressed in the SCMC-MM-1-1T subline. Chromosomal and myogenic-regulatory-gene analyses revealed that both of these sublines were rhabdomyosarcoma cell lines. Furthermore, the regulatory-gene analyses indicated that these 2 sublines represented 2 distinct differentiation stages of myoblasts, and that MyoD1 and myogenin could serve as the lineage marker and the differentiation marker, respectively, of human rhabdomyosarcoma.

Blotting, Northern↗
PubMed1992

Developmental expression of macronuclear specific antigen in Paramecium caudatum.

We obtained a monoclonal antibody (MA-1) specific for macronuclei of the ciliate Paramecium caudatum and P. dubosqui. Immunoblotting showed that the antigen was a polypeptide of 50 kilodalton (kDa). During the process of nuclear differentiation in P. caudatum, the MA-1 antigens appeared in the macronuclear anlagen immediately after four out of eight post zygotic nuclei differentiated morphologically into the macronuclear anlagen. Afterwards, the antigens could be detected in the macronucleus through the cell cycle, and disappeared when the macronucleus began to degenerate in exconjugant cells. These results suggest that the antigens may play a role in the differentiation and function of the macronucleus.

Animals↗
PubMed1992

Sequential changes of sodium magnetic resonance images after cerebral hemorrhage.

Four patients with cerebral hemorrhage were examined serially from the acute to chronic phase by 1H magnetic resonance imaging (MRI), 23Na MRI and computed tomography (CT). At 1-2 days after bleeding, the 23Na image revealed no visible signal change in the area of hemorrhage, although CT and 1H images clearly demonstrated the existence of a hematoma in the thalamus or putamen. At 4-7 days after the hemorrhage, the 23Na images began to exhibit a small increase in signal intensity at the hematoma site, while at 2-3 weeks, a marked increase in 23Na signal intensity was observed. These findings suggest that the hematoma consisted mainly of a corpuscular component, with a low Na+ concentration, with little serum component. Lack of signal from the corpuscular component on the 23Na image was confirmed by an in vitro study. In the late acute phase, Na+ accumulation may occur in the corpuscular component due to failure of the Na+ pump. The intracellular 23Na appears to be totally visible to MRI, resulting in an increase in signal intensity. In the subacute or chronic phase, the corpuscular component may be destroyed, leaving fluid in its place. A high Na+ concentration in this fluid may give markedly increased 23Na signal intensity on MRI. 23Na MRI appears to provide important information for understanding the evolution of cerebral hemorrhage and for estimating the viability of cells, although its value for diagnosis may not be great.

Aged↗
PubMed1992

Correction of methylmalonyl-CoA mutase deficiency in Mut0 fibroblasts and constitution of gene expression in primary human hepatocytes by retroviral-mediated gene transfer.

Methylmalonic acidemia is an often fatal inborn error of organic acid metabolism due to deficiency of methylmalonyl-CoA mutase. The cloning of genes encoding this enzyme and the advent of technologies for gene transfer have introduced the possibility of somatic gene therapy for this disorder. Gene therapy may require replacement of the defective enzyme in hepatocytes, which have a greater capacity for propionate metabolism than other somatic cells and represent the principle physiological site of propionate metabolism. We describe construction of an amphotropic retroviral vector containing the human methylmalonyl-CoA mutase cDNA. This vector is shown to transduce primary MCM-deficient fibroblasts and restore levels of [14C]propionate metabolism by cultures of nonselected cells to normal. This vector will transduce primary human hepatocytes and direct transcription of recombinant human MCM from the integrated provirus. This work demonstrates the feasibility of retroviral-mediated gene transfer of methylmalonyl-CoA mutase into primary human cells, including hepatocytes which represent a difficult, but potentially necessary, target for gene therapy of methylmalonic acidemia.

3T3 Cells↗
PubMed1992

Distribution and quantification of somatostatin in inflammatory disease.

To study the possible alteration of mucosal-submucosal somatostatin-containing cells in inflammatory bowel diseases (IBD), the total numbers of somatostatin-containing endocrine cells (SCEC) and submucosal ganglion cells (SGC) were counted in Crohn's disease (CD) and ulcerative colitis (UC). Tissue specimens from 25 CD and 25 UC patients were fixed in Hollande's fixative immediately after resection and were investigated by immunohistochemical staining. A single specimen was collected from 25 colorectal cancer patients, the control group. There was a significant difference in the number of SCEC between the tissues taken from the proximal colon (ascending and transverse colon) and the distal colon (descending and sigmoid colon). The distal colon tended to contain more somatostatin-immunoreactive cells than did the proximal colon. In IBD, SCEC were decreased in number compared with the controls. This decrease was related to the degree of inflammation in CD; the higher the grade of inflammation, the lower the number of SCEC. The number of SGC was decreased in IBD: however, a significant decrease was noticed only in CD. The anatomic origin and the degree of inflammation did not affect the number of SGC. In the present study, the decrease of somatostatin-containing cells was noticed in both CD and UC, but there was no significant difference between CD and UC. Therefore, it was assumed that this decrease was secondary to inflammation. However, the decrease of somatostatin, which works as an inhibitory peptide for inflammation, might have some role in the pathogenesis of IBD.

Analysis of Variance↗
PubMed1992

Local immunity and metastasis of colorectal carcinoma.

The subsets of tumor-infiltrating lymphocytes (TIL) and prostaglandin (PG) E2 were measured in the resected tissues of 32 colorectal cancers without metastasis and 14 with metastasis in order to investigate the local immunity in metastasis of colorectal carcinoma. Subsets of TIL (Leu 1, Leu 2a, Leu 3a, Leu 10, Leu 11b, IL-2 receptor) were detected by immunohistochemical staining of frozen tissues. The number of positive cells was counted and expressed as number positive per 250 x 250 microns 2. The numbers of T cells (Leu 1) and natural killer cells (Leu 11b) were larger in early cancers and decreased in parallel with the presence of metastasis (control [n = 9]: 89 +/- 28, 6 +/- 4; early cancers [n = 9]: 269 +/- 112*, 76 +/- 56*; advanced cancers without metastasis [n = 11]: 182 +/- 80*, 56 +/- 59*; advanced cancers with metastasis [n = 11]: 76 +/- 42*, 26 +/- 21; values are mean +/- SD; * P less than 0.05, ANOVA). The level of PG E2 from the draining vein (V) measured by radioimmunoassay was higher than that from the feeding artery (A) (119.1 +/- 14.3 vs. 15.4 +/- 1.9 pg/ml; P less than 0.001). The PG E2 V/A ratio of cancers with metastasis was significantly higher than that of those without metastasis (13.2 +/- 2.4 vs. 5.6 +/- 0.8; P less than 0.001). TIL was decreased in parallel with the increase of PG E2 V/A ratio. We conclude that TIL and PG E2 may play an important role in metastasis of colorectal carcinoma and that PG E2 has an adverse effect in suppressing local immunity and enhancing metastasis.

Analysis of Variance↗
PubMed1992

Analysis of major histocompatibility complex (MHC) class I antigen in the rat salivary gland.

This antigen was examined in rats of different ages (new-born, 3, 5, 7, 10, 12 and 14 days after birth and adult) by immunofluorescence and immunoelectron microscopy. Changes in each kind of salivary gland when graft versus host disease was induced in recipient rats were also investigated. Monoclonal antibodies (HAM 2 or OX 18) specific to rat MHC class I antigen were used and these were detected by FITC-conjugated anti-mouse immunoglobulin. With HAM 2, MHC class I antigen in the submandibular gland was mostly located in the secretory duct cells; this expression was first found 10 days after birth. The antigen was found on the cell surfaces of the secretory duct cells by immunoelectron microscopy. With OX 18, MHC class I antigen was mainly found in the secretory duct cells, but weak expression was also found in the acinar cells. Localization of the antigen, by HAM 2 and OX 18 was less evident in the secretory duct cells of parotid and sublingual glands. When graft versus host disease was induced, MHC class I antigen (HAM 2) was observed in both acinar and secretory duct cells of the submandibular gland.

Aging↗
PubMed1992

Distribution of the surface antigen HAM-4 and cytoskeleton during reformation of bile-canalicular structures in rat primary cultured hepatocytes.

The distribution of rat bile-canalicular surface antigen (HAM-4 antigen) and cytoskeletal elements (microtubules, actin filaments, and cytokeratin filaments) was examined during the reformation of bile-canalicular structures (BC-structures) in primary cultures of dissociated hepatocytes obtained following collagenase perfusion. HAM-4 antigen, which initially dispersed after cell dissociation, became focused into regions of cell-to-cell contact even before formation of BC-structures. Typical bile-canalicular microvilli also appeared in these regions before the intercellular spaces were completely closed. Finally, after in vitro reformation of BC, HAM-4 antigen was localized specifically at the BC-surface. The process of BC-reformation and the intracellular organization of actin and cytokeratin filaments were not significantly affected by microtubule inhibitors (nocodazole, colcemid, and colchicine). However, the localization of HAM-4 antigen molecules at the surface of BC was disrupted by these inhibitors, suggesting that the distribution of HAM-4 antigen, which represents a marker for the reconstruction of surface polarity, is dependent on microtubule function.

Animals↗
PubMed1992

Serial measurement of urinary VMA and HVA levels from one infant: a study for neuroblastoma mass screening.

Urinary vanillylmandelic acid (VMA), homovanillic acid (HVA), and creatinine in 188 samples from one infant during the ages of 1 to 12 months were measured serially by high-performance liquid chromatography (HPLC). The mean VMA and HVA levels of the total 188 samples in this study were 11.9 +/- 1.39 and 22.9 +/- 2.92 micrograms/mg creatinine with coefficients of variation (CVs) 11.7% and 12.8%, respectively; and of 76 samples from 5 to 12 months of age, 12.3 +/- 0.84 and 23.1 +/- 2.03 micrograms/mg creatinine with CVs 6.8% and 8.8%. The CVs of VMA and HVA levels expressed in microgram per milligram of creatinine had decreased after 6 months of age (VMA, 5.0% to 8.3%, HVA, 5.3% to 8.4%). Chromatograms demonstrated the similar pattern from 1 to 12 months of age, although the infant had been fed foods typical in Japan, which included breast milk, seasonal fruits, vegetables, fish, chicken, and meat. Diurnal fluctuations of VMA and HVA levels in urine were not significant. When HPLC is used for measurement of VMA, HVA, and creatinine, it is not necessary to restrict foods that cause false-positive results in the qualitative VMA test from the infant's diet. Furthermore, random urine samples obtained throughout the 12 months could be effectively used for the measurement of these substances.

Chromatography, High Pressure Liquid↗
PubMed1992

Antibody titers to HTLV-I-p40tax protein and gag-env hybrid protein in HTLV-I-associated myelopathy/tropical spastic paraparesis: correlation with increased HTLV-I proviral DNA load.

We studied the relationship between antibody titers to recombinant HTLV-I p40tax protein and gag-env hybrid protein in serum (by an enzyme-linked immunosorbent assay) and HTLV-I proviral DNA load in peripheral blood mononuclear cells (by a quantitative polymerase chain reaction method) in 18 patients with HTLV-I-associated myelopathy (HAM)/tropical spastic paraparesis (TSP), 17 HTLV-I carriers without HAM/TSP and 16 HTLV-I uninfected controls. The IgG and IgA antibody titers to either of the proteins correlated significantly with the HTLV-I pX (coding p40tax protein) and pol DNA amounts in HTLV-I infected subjects. HAM/TSP patients had significantly higher titers of IgG and IgA antibodies to the HTLV-I proteins than did the HTLV-I carriers without HAM/TSP. While the IgM antibodies to the HTLV-I proteins were found in only 6% of HTLV-I carriers without HAM/TSP, they were found in 40% of HAM/TSP patients, especially those having both a high HTLV-I proviral DNA load and high titers of the IgG and IgA antibodies. HAM/TSP patients with the IgM antibodies had a tendency to deteriorate more frequently on the Kurtzke's disability status scale and magnetic resonance imaging of the brain (leukoencephalopathy) than did those without in the two-year follow-up. Thus, the presence of IgM antibody and high titers of IgG and IgA antibodies to the HTLV-I proteins, together with the increased HTLV-I proviral DNA load, appears to distinguish HAM/TSP patients from HTLV-I carriers without HAM/TSP.

Adult↗