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Biomedical subjects

S Maki

Publications and source records attributed to S Maki.

At least 127 records · Page 7Linked to original sources
PubMed1987

Ricinus communis agglutinin I blocks the binding of human anti-renal basement membrane antibodies to the kidney.

Whether or not glycosyl moieties of glycoproteins present in human renal basement membranes are related to the sites where anti-basement membrane antibodies bind was examined by blocking experiments using several kinds of lectin. Ricinus communis agglutinin I (RCA I), specific for galactose, blocked the binding of human anti-glomerular basement membrane (GBM) and anti-tubular basement membrane (TBM) antibodies to renal basement membranes. This lectin also diminished the binding of rabbit anti-laminin antibody, but did not inhibit the binding of mouse anti-fibronectin or rabbit anti-human TBM antibodies. These findings suggest that the binding sites of human anti-GBM and anti-TBM antibodies and heteroantibodies to laminin are closely related to the galactose moieties in glycoproteins of human renal basement membranes. Whether the galactose-containing branches are associated with the nephritogenicity of human anti-GBM and anti-TBM antibodies or simply exist adjacently to the antibody binding sites remains to be discerned.

Antibodies↗
PubMed1986

Characterization of tubular basement membrane antigens in human kidney.

Tubular basement membrane (TBM) was prepared from normal human kidneys and solubilized with various enzymes. Collagenase digestion released antigenic moieties from the TBM. All four anti-TBM antibodies we studied, three from patients with idiopathic tubulo-interstitial nephritis (TIN) and one from a renal allograft recipient, distinctively reacted with collagenase-digested (CD) TBM during enzyme-linked immunoassay and could discriminate among sera of normal controls or of other nephritis patients, including anti-glomerular basement membrane (anti-GBM) nephritis. When digested with pronase, trypsin, or pepsin, antigenicity of the TBM decreased. We studied the TBM antigens with immunoprecipitation and immunoblotting. After incubation of radio-iodinated CDTBM with anti-TBM sera, immunoprecipitates were identified by single-dimension SDS polyacrylamide gel electrophoresis or two-dimension gel electrophoresis, followed by autoradiography. All four antibodies had identical results on immunoprecipitation; under nonreducing conditions, they gave two protein bands with m.w. of 54,000 and 48,000 and with pI 7.0 to 8.0 and 6.5 to 7.0. Electrophoresis performed under reducing conditions disclosed only one band at the m.w. of 48,000 and pI of 6.5, suggesting that the 54-kDa component is composed of peptides linked by interchain disulfide bonds. Immunoblot analysis showed that the anti-TBM antibodies were heterogeneous; three antibodies from the idiopathic TIN patients reacted with the 54-kDa band, but the one from the renal allograft recipient reacted with neither band. This finding suggests that there are two antigenic determinants on the 54-kDa component. One such determinant that was resistant to denaturation with SDS was detected by the first three antibodies, and the other that was sensitive to such denaturation bound to the last antibody. The 48-kDa component seemed not to be immunoreactive after incubation with SDS. We studied TBM antigens reactive with anti-GBM antibodies. By immunoblotting, all four sera from patients with anti-GBM nephritis stained TBM proteins of 45 to 50 kDa and 25 to 27 kDa at pH 8.0 to 9.0; this was similar to the staining pattern of CDGBM with the same sera, but the highly cationic (pH greater than 9.0) components were specifically detected in the CDGBM. By inhibition ELISA, the binding of the anti-GBM sera to denatured CDTBM decreased with preincubation of the sera with CDGBM, suggesting that the anti-GBM antibodies recognize the same epitope(s) on the GBM and the TBM.

Adult↗
PubMed1986

Dopaminergic facilitation of recovery from amygdaloid lesions which affect hypothalamic defensive attack in cats.

Influence of dopamine agonists, methamphetamine (MAT, 1 mg/kg, i.p.) and apomorphine (APO, 1 mg/kg, i.p.), on the effects of amygdaloid lesions on thresholds for the defensive attack behavior elicited by electrical stimulation of the ventromedial hypothalamic nucleus was studied in cats. The thresholds were measured in two situations, one with provocation by a human and the other without provocation. Electrolytic lesions of the basolateral part of the amygdala attenuated markedly facilitatory influences of the visual provocation on the thresholds, but subsequent administration of MAT or APO rapidly abolished the effects of the lesions. The effects of MAT lasted for at least 3.5 h while the effects of APO were of shorter duration. The results were discussed from the viewpoint of possible rapid compensation by the remaining intact tissue of the amygdala which was produced by excessive dopaminergic inputs to it.

Aggression↗
PubMed1986

Pseudomembranous colitis in a patient of paraquat intoxication.

A 49 year-old man drank paraquat 7-8 fold of human fatal dose, and died of severe respiratory failure in 24 days in spite of intensive therapy. The autopsy revealed diffuse pulmonary fibrosis caused by prolonged intoxication of paraquat. An interesting finding was many raised plaques from 1 mm to 10 mm in diameter, observed in whole colon. Histologically, these plaques were composed of necrotic mucosa ("pseudomembrane"), disrupted crypts and edematous submucosa with fibrin education, intervening in normal colon tissue with sharp margins, and diagnosed as non-antibiotic-induced pseudomembranous colitis. Since the edematous submucosa of the raised plaque had a stratified fibrin education around a dilated capillary, it was speculated that the vessel injury by paraquat might play a role in the pathogenesis of pseudomembranous colitis.

Administration, Oral↗
PubMed1986

[CT image of the liver cancer after administration of SMANCS/lipiodol].

A new type of anticancer agent with an amphiphilic nature, poly (styrene-co-maleic acid)-conjugated neocarzinostatin [SMANCS], was dissolved in the lipid contrast medium Lipiodol [SMANCS/LPD]. This medium was injected intra-arterially and was found to be an invaluable tool for highly sensitive CT image analysis of tumors. Following administration, CT images revealed high-density areas which corresponded to the location and size of liver cancer, the smallest being 4 mm in diameter. The deposition pattern of SMANCS/LPD in liver cancers by CT was classified into 3 types. In type A, Lipiodol was distributed relatively evenly in the tumor lesion, while in type B it was accumulated predominantly around the tumor periphery, the central portion remaining low in density. A for cases exhibited a type C pattern which was a mixture of types A and B. Type A was found essentially in primary liver cancer, and types B and C in secondary liver cancer. Thus, the CT pattern was found to be useful for differential diagnosis. For a sufficient therapeutic effect, 0.08 ml of SMANCS/LPD per cm2 of the maximal CT cross-section of the tumor area was found to be necessary. As a routine protocol after SMANCS/LPD administration, CT scanning was recommended for primary liver cancer initially at one week and then once every month. Secondary liver cancer required more frequent CT follow-ups after administration, on the 3rd day, after one and two weeks, and every month, due to the relatively rapid disappearance of the stain than in primary liver cancer.

Antibiotics, Antineoplastic↗
PubMed1985

Image enhancement in computerized tomography for sensitive diagnosis of liver cancer and semiquantitation of tumor selective drug targeting with oily contrast medium.

A new type of anticancer agent with an amphiphilic nature, poly(styrene-co-maleic acid)-conjugated neocarzinostatin (Smancs), was dissolved in lipid contrast medium Lipiodol (Smancs/Lpd, Gelbet Co., Paris, France). This medium was injected arterially and found to be an invaluable tool for highly sensitive computerized tomography (CT) image analysis of tumors. After the administration, CT images revealed high-density areas which corresponded to the location and size of liver cancer, the smallest being 4 mm in diameter. The deposition pattern of Smancs/Lpd in liver cancers by CT was classified into three types. In type A, Lipiodol was distributed relatively even in the tumor lesion, whereas in type B it was accumulated predominantly around the tumor's periphery although the central portion remaining low in density. A few cases exhibited type C pattern, which was a mixture of types A and B. Type A was found essentially in primary liver cancer, and types B and C in secondary liver cancer. Thus, the CT pattern was found to be useful for differential diagnosis. For a sufficient therapeutic effect, 0.08 ml of Smancs/Lpd per cm2 of the maximal CT cross-section of the tumor area was found to be necessary. As a routine protocol after Smancs/Lpd administration, CT scanning was recommended for primary liver cancer initially at 1 week and then once every month. Secondary liver cancer required more frequent CT follow-ups after the administration (on the third day, after 1 and 2 weeks, and every month) due to relatively rapid disappearance of the stain than in the primary liver cancer.

Aged↗
PubMed1985

Initiation of replication of the Escherichia coli chromosomal origin reconstituted with purified enzymes.

A mixture of purified proteins has replaced a crude enzyme fraction capable of efficient replication of oriC-containing plasmids. The reconstituted enzyme system contains proteins which provide initiation, replication, and specificity functions required for dnaA-dependent replication specific for an oriC template. Replication can be separated into successive stages of RNA synthesis and DNA replication. Isolation of an intermediate no longer requiring RNA polymerase action requires the presence of dnaA protein, DNA gyrase, dnaB protein and dnaC protein. Intermediate formation likely involves binding of dnaA protein to a 9-bp sequence present 4 times as inverted repeats within the chromosomal origin sequence.

Bacterial Proteins↗
PubMed1985

Effects of dopamine agonists on hypothalamic defensive attack in cats.

The effects of methamphetamine (MAT) and apomorphine (APO), dopamine agonists, were studied in 16 cats to evaluate their effects on threshold for defensive attack behavior elicited by electrical stimulation of the ventromedial hypothalamic nucleus (VMH). Directed attack and hissing were selected from elementary responses as constituting a defensive attack. Hissing threshold was measured in two situations, one with human provocation and the other without provocation. MAT administered systemically lowered the thresholds for all three types of responses in a dose-related manner (0.5, 1.0, and 3.0 mg/kg). The effects of 1.0 mg/kg of APO were almost identical to those observed with 0.5 or 1.0 mg/kg of MAT. These results suggest that MAT-induced aggressive behavior may be mediated by a dopamine-induced increase in the excitability of the VMH.

Aggression↗