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Biomedical subjects

J Yamaguchi

Publications and source records attributed to J Yamaguchi.

At least 145 records · Page 8Linked to original sources
PubMed1986

Immunocytochemical Analysis Shows that Glyoxysomes Are Directly Transformed to Leaf Peroxisomes during Greening of Pumpkin Cotyledons.

The functional transition of glyoxysomes to leaf peroxisomes occurs during greening of germinating pumpkin cotyledons (Cucurbita sp. Amakuri Nankin). The immunocytochemical protein A-gold method was employed in the analysis of the transition using glyoxysomal specific citrate synthase immunoglobulin G and leaf peroxisomal specific glycolate oxidase immunoglobulin G. The labeling density of citrate synthase was decreased in the microbodies during the greening, whereas that of glycolate oxidase was dramatically increased. Double labeling experiments using different sizes of protein A-gold particles show that both the glyoxysomal and the leaf peroxisomal enzymes coexist in the microbody of the transitional stage indicating that glyoxysomes are directly transformed to leaf peroxisomes during greening.

Journal Article↗
PubMed1986

Immunopathological studies of an autopsy case with Goodpasture's syndrome and systemic necrotizing angiitis.

A rare autopsy case of Goodpasture's syndrome with systemic necrotizing angiitis is reported. The patient, a 56-year-old male, died of respiratory failure with massive pulmonary hemorrhage and renal failure. The autopsy showed widespread hemorrhage in both lungs, diffuse crescentic glomerulonephritis, and systemic necrotizing angiitis in the small arteries. Immunofluorescence studies demonstrated a linear deposition of IgG along the glomerular basement membrane (GBM) as well as the alveolar basement membrane. A granular deposition of C3 was also found along the GBM. Electron microscopy showed that the GBM was irregularly thickened and wrinkled, but electron-dense deposits were indistinct. Anti-GBM antibody activity was detected in the patient's serum and had cross reactivity with normal alveolar basement membrane. The renal eluates contained IgG antibody activity for normal human GBM. These results suggest that glomerulonephritis and pulmonary hemorrhage in the present case were mediated by anti-basement membrane antibodies. We also discussed whether anti-basement membrane antibody is involved in the pathogenesis of systemic necrotizing angiitis.

Anti-Glomerular Basement Membrane Disease↗
PubMed1986

Inhibitory effects of antithyroid drugs on oxygen radical formation in human neutrophils.

The effects of antithyroid drugs and related agents on human neutrophil function were studied. Neutrophil function was mainly assessed through oxygen radical formation as determined by chemiluminescence (CL) response, superoxide anion (O-2) generation and hydrogen peroxide production. Propylthiouracil (PTU) at a therapeutic concentration (10 micrograms/ml) inhibited CL response evoked by phorbol myristate acetate (PMA) and other stimulators. The inhibitory effect was not enhanced by pre-incubation of neutrophils with PTU and not exerted through a direct cytotoxic effect of the drug. It was not related to the kind of stimulators to evoke CL response in neutrophils either. However, the inhibitory effect disappeared when PTU was removed from the reaction mixture for CL response. PTU did not inhibit O-2 generation but markedly inhibited hydrogen peroxide production in neutrophils or activity of hydrogen peroxide in vitro. Morphologically, the unique change of cellular configuration of chemotactic neutrophils caused by N-formyl-methionyl-leucyl-phenylalanine (FMLP) was not influenced with PTU. Since hydrogen peroxide is mainly derived from O-2, these observations suggest that PTU may have a scavenger effect on hydrogen peroxide activity. Inhibition of CL response in neutrophils was also demonstrated with methimazole (MMI), thiouracil and thiourea, but not with imidazole and uracil, which suggests that their inhibitory effect on CL response in neutrophils may be closely related to the antithyroid activity.

Antithyroid Agents↗
PubMed1986

[A case of rectal cancer with malacoplakia].

A 59-year-old man was hospitalized for rectal bleeding. Barium enema and proctoscopy revealed an elevated tumor, completely stenosing the rectum. The microscopic features of the specimens obtained by proctoscopic biopsy of the tumor comprised aggregations of histiocytes with intracytoplasmic inclusions (von Hansemann cells and Michaelis-Gutmann bodies). Rectal malacoplakia was diagnosed. In the course of laparotomy, the tumor was found to be strongly infiltrated to the pelvis. Thus, radical surgery was not performed, and an artificial anus was made. Excisional biopsy from the tumor tissue revealed the features of well-differentiated adenocarcinoma and malacoplakia. Forty-three cases of malacoplakia of the gastrointestinal tract from a review of the literature including ours were collected and discussed.

Adenocarcinoma↗
PubMed1985

Reversion to bacillary forms of Serratia marcescens spheroplasts induced by carbenicillin. Scanning electron microscopic study.

Bacterial cells of Serratia marcescens were easily induced to form spheroplasts in liquid medium by the addition of carbenicillin. The spheroplasts were unable to divide, but they were able to revert to the bacillary forms in liquid medium not containing carbenicillin. Four phases of the reversion sequence could be differentiated by scanning electron microscopy. (1) After 3 hr of incubation in carbenicillin-free medium, some projections arose out of the spheroplasts, and grew and elongated. (2) Their elongation resulted in a morphological change in the spheroplasts from spherical bodies to long irregular bacillary forms. (3) Further incubation caused several constricted areas in the bacillary form. (4) The long bacillary forms split along the constricted areas to become the parent bacillary forms of S. marcescens. When the long bacillary form that developed during the reversion was retreated with carbenicillin, it was immediately induced to become a spheroplast again.

Carbenicillin↗
PubMed1985

2-Chloroadenosine: a selective lethal effect to mouse macrophages and its mechanism.

In our studies on the effects of purine compounds on immune responses in vitro, we found that 2-chloroadenosine (2-Cl Ado) exhibited a potent lethal effect on a viability of mouse adherent cells derived from the peritoneal cavity. The lethal effect was specific for adherent peritoneal cells (PC) (macrophages) and was prevented by exogenous addition of adenosine (Ado) or coformycin, a potent inhibitor of adenosine deaminase. A rapid decrease of intracellular ATP content (26% of control) in adherent PC was observed soon after 1 hr exposure to 2-Cl Ado (0.1 mM), and this decrease of ATP was comparable with that of monoiodoacetate (MIA, 0.1 mM)- or NaN3 (5 mM)-treated adherent PC. The ATP decrease by 2-Cl Ado was restored to 88 or 90% of control value by 1 hr addition of Ado or coformycin, respectively. Polymorphonuclear cells and lymphocytes to which 2-Cl Ado did not exhibit the lethal effect did not cause a significant ATP decrease of the cells. Therefore, the data suggested that the reason for the lethal effect on adherent PC treated with 2-Cl Ado could be attributed to a rapid decrease of ATP content at an early time. We assume that 2-Cl Ado competes with intracellular Ado in macrophages and then causes the adenosine starvation resulting in the ATP decrease.

2-Chloroadenosine↗
PubMed1984

Maturation of catalase precursor proceeds to a different extent in glyoxysomes and leaf peroxisomes of pumpkin cotyledons.

As an approach to study the mechanism of the microbody transition (glyoxysomes to leaf peroxisomes) in greening pumpkin cotyledons, catalase molecules were purified from the two different types of microbody and their structural properties were compared. The purified glyoxysomal catalase was found to consist of four identical subunits (55 kDa), whereas the leaf peroxisomal catalase contains two different forms of monomeric subunit (55 and 59 kDa). These different catalase species cross-reacted with the rabbit antibody raised against the glyoxysomal enzyme. During gel filtration on an Ultrogel AcA 34 column, the leaf peroxisomal 55-kDa polypeptide eluted slightly faster than the leaf peroxisomal 59-kDa polypeptide. The profile of catalase activities exactly paralleled the elution pattern of the 55-kDa molecules, which indicated that the 59-kDa polypeptide was enzymically inactive. Peptide mapping analysis using Staphylococcus aureus protease V8 showed that the glyoxysomal 55-kDa polypeptide was identical to the leaf peroxisomal 55-kDa species, whereas the leaf peroxisomal 59-kDa polypeptide had a different primary structure from the 55-kDa polypeptide. In an in vitro translation system directed by mRNA isolated from etiolated and green cotyledons, glyoxysomal and leaf peroxisomal catalases were synthesized as the identical 59-kDa polypeptide. From peptide mapping analysis, the in vitro-translated 59-kDa polypeptide was found to have a nearly identical primary structure to that of the leaf peroxisomal 59-kDa species. In vivo pulse-chase labeling experiments using etiolated cotyledons showed the conversion of the 59-kDa polypeptide to the 55-kDa molecular species. The overall results strongly indicate that the 59-kDa polypeptide is a precursor form of catalase in pumpkin cotyledons.

Journal Article↗
PubMed1984

Purification of glyoxysomal catalase and immunochemical comparison of glyoxysomal and leaf peroxisomal catalase in germinating pumpkin cotyledons.

As a step to study the mechanism of the microbody transition (glyoxysomes to leaf peroxisomes) in pumpkin (Cucurbita sp. Amakuri Nankin) cotyledons, catalase was purified from glyoxysomes. The molecular weight of the purified catalase was determined to be 230,000 to 250,000 daltons. The enzyme was judged to consist of four identical pieces of the monomeric subunit with molecular weight of 55,000 daltons. Absorption spectrum of the catalase molecule gave two major peaks at 280 and 405 nanometers, showing that the pumpkin enzyme contains heme. The ratio of absorption at 405 and 280 nanometers was 1.0, the value being lower than that obtained for catalase from other plant sources. These results indicate that the pumpkin glyoxysomal catalase contains the higher content of heme in comparison with other plant catalase.The immunochemical resemblance between glyoxysomal and leaf peroxisomal catalase was examined by using the antiserum specific against the purified enzyme preparation from pumpkin glyoxysomes. Ouchterlony double diffusion and immunoelectrophoretic analysis demonstrated that catalase from both types of microbodies cross-reacted completely whereas the immunotitration analysis showed that the specific activity of the glyoxysomal catalase was 2.5-fold higher than that of leaf peroxisomal catalase. Single radial immunodiffusion analysis showed that the specific activity of catalase decreased during the greening of pumpkin cotyledons.

Journal Article↗
PubMed1984

Characteristics of chromosomal DNA isolated from Escherichia coli spheroplasts.

The chromosomal DNA of Escherichia coli spheroplasts induced by penicillin G was studied biochemically and electron microscopically. Although the spheroplasts were unable to divide, they continued to synthesize chromosomal DNA for several hours even in the presence of penicillin G. Some differences were observed between the chromosomal DNA of the parent cells and that of the spheroplasts in sucrose gradient centrifugation and electron microscopy; two types of chromosomal DNA, a slower sedimenting form and a faster sedimenting form, were released from the gently lysed parent cells. The former was membrane-free folded chromosome and the latter was membrane-associated chromosome. In contrast, the chromosome from the spheroplast showed a single intermediate value of sedimentation coefficient between those of the chromosomal DNA from the parent cell. Cytochrome spreading for electron microscopy showed that the spheroplast chromosomal DNA formed an aggregated mass consisting of several chromosome-molecules of the parent cell.

Chromosomes, Bacterial↗
PubMed1984

Lupus nephritis. Clinicopathology and immunopathology of 80 biopsy cases.

The clinicopathology and immunopathology of 80 cases of lupus nephritis in a total of 1,187 biopsies were presented. Histologically, they consisted of 11 cases of mesangial lupus nephritis (13.8%), 51 cases of diffuse proliferative lupus nephritis (63.7%), and 18 cases of membranous lupus nephritis (22.5%). No cases of focal proliferative type, minimal changes or end-stage kidneys were included. Ten cases were male and they had no qualitative and quantitative differences with female ones in any respects. The microtubular structures were found in glomerular endothelial cells with a 70% frequency and in the interstitial endothelial cells with a 46% frequency. In the latter case, microtubular structures tended to be localized in the perinuclear space as well as in the endoplasmic reticulum. Spherical microparticles were found in 46% of all cases and the incidences were significantly higher in the membranous type. Organized deposits with straight parallel microfilaments were found only in a single case. Electron-dense deposits with fingerprint pattern were not seen. Immunohistochemically, various immunoglobulins, complement components, and fibrinogen were found deposited more frequently in diffuse proliferative lupus nephritis. IgG was the predominant immunoglobulin deposited in capillary loops in membranous types, and IgA in the mesangium in mesangial types. Extraglomerular deposition of immunoglobulins and complements were found in 26.3% of all cases.

Complement Activating Enzymes↗
PubMed1983

SV40 deletion mutants lacking the 21-bp repeated sequences are viable, but have noncomplementable deficiencies.

We have constructed deletion mutants of simian virus 40 (SV40) lacking the two tandemly repeated copies or all three copies of the 21-bp repeated sequence located in the origin region. The mutants were viable, but had lower infectivities compared to the wild type. The mutant lacking two copies of the 21-bp repeat grew fairly well indicating that the one copy of the 21-bp repeat it contains is adequate. The other mutant lacking all the three copies of the 21-bp repeat was also viable but grew poorly. The viability of this mutant suggests that the upstream 72-bp repeated sequence compensates, though only partially, for the absence of the 21-bp repeat. The growth deficiencies of the deletion mutants could not be overcome by complementation with temperature-sensitive helper mutants providing either the early or the late functions of the virus, suggesting that the deficiencies lie in both early and late gene expression and/or in replication.

Animals↗
PubMed1983

Separation of human X- and Y-bearing sperm using percoll density gradient centrifugation.

Human X- and Y-bearing sperm, which were detected by the quinacrine mustard fluorescent staining method, were separated in density gradient centrifugation using Percoll (Pharmacia Fine Chemicals, Uppsala, Sweden). The apparent percentages of Y-bearing sperm in normo- and oligospermia were 46.7% +/- 3.4% (n = 13) and 46.6% +/- 1.2% (n = 10), respectively. The separation was observed to some extent in Ficoll Paque (Pharmacia Fine Chemicals); then it was further achieved using Percoll. After centrifugation, sperm were distributed widely on various interfaces of the discontinuous Percoll density gradient (1.06 to 1.11 gm/ml). The content of Y-bearing sperm in the fraction lighter than 1.06 gm/ml was 73.1% +/- 3.3% and was reduced gradually along the density increment. Finally, it was found to be 27.4% +/- 3.4% in the sediment (more than 1.11 gm/ml).

Adult↗
PubMed1983

Definition of the simian virus 40 early promoter region and demonstration of a host range bias in the enhancement effect of the simian virus 40 72-base-pair repeat.

The simian virus 40 (SV40) origin region includes the viral replication origin and the early and late promoters and consists of a few palindromes, a 17-base-pair (bp) A + T-rich sequence, three copies of a G + C-rich 21-bp repeat, and two copies of a 72-bp repeat. We have made sequential deletions in the SV40 origin region and determined the early promoter efficiencies of these truncated DNA segments by connecting them in the correct orientation with the coding regions of selectable marker genes and assaying the expression of the chimeric marker genes in vivo in different host cell lines. A truncated SV40 early promoter segment containing only the TATA box and the major in vivo mRNA initiation sites has essentially no promoter efficiency. We have located the major component of the SV40 early promoter within the 21-bp repeated sequences, which consist of an alternating and mutually overlapping array of two C-rich oligonucleotides having the consensus sequences Y-Y-C-C-G-C-C-C (Y = pyrimidine nucleoside) and G-C-C-C-(C)-TA-AT-A(T)-C-T. Between one and two copies of the 21-bp repeat were adequate for gene expression under conditions in which the enhancement effect of the 72-bp repeat was minimal. We also find that the SV40 72-bp repeat exhibits a pronounced host range in its enhancement of gene expression; the enhancement is only 2-fold in the nonpermissive mouse cells but amounts to 10- or 20-fold in the permissive monkey cells or the semipermissive human cells, respectively.

Animals↗