Search PubMed⌕ Search

Biomedical subjects

M Kuroda

Publications and source records attributed to M Kuroda.

At least 451 records · Page 25Linked to original sources

Pigmented variant of calcifying odontogenic cyst. Report of an additional case and review of the literature.

A case of the pigmented variant of calcifying odontogenic cyst occurring in a 21-year-old Japanese male is reported, and a review of previously reported cases of the lesion is included. In addition to the characteristic histopathologic features of calcifying odontogenic cyst, dendritic cells containing melanin pigment were widely distributed in the epithelial layer and melanin pigment was also found in the epithelial cells including ghost cells in the present case. Although no conclusion could be drawn from the present examination as to the origin of melanin pigment in the calcifying odontogenic cyst, it is thought that the role of racial pigmentation is one of the important factors in occurrence of pigmented odontogenic lesions.

Adult↗

[VM-26 salvage therapy for refractory or recurrent germinal testicular cancers].

Four patients with refractory or recurrent germinal testicular cancers were treated with the combination of VM-26 and cis-platinum, and two of them also in combination with radiation therapy. Two complete responses and two partial responses were observed. One partial response was rendered no evidence of disease by sequential radiation therapy. Three of the patients remained to have no evidence of disease from 16, 21 and 22 months. Toxicity was tolerable. VM-26 is an active drug in germinal testicular cancers and plays an important role in salvage therapy, for refractory or recurrent cases.

Adult↗

Radiation-induced peroxidation of lipid dissolved in organic solvent and its inhibition by alpha-tocopherol and cepharanthine.

Effects of cepharanthine and alpha-tocopherol on radiation-induced peroxidation of lipids dissolved in methanol(MeOH)-chloroform (CHCl3)-H2O(v/v, 2/1/0.8) were examined. alpha-Tocopherol strongly inhibited radiation-induced peroxidation of lipids dissolved in MeOH-CHCl3-H2O. However, cepharanthine exhibited a weak inhibitory action in this system. The change in the absorption spectrum of alpha-tocopherol and cepharanthine by X-irradiation was measured. The reagents were dissolved in 95% EtOH acidified with 20 mM HCl and in MeOH-CHCl3-H2O. alpha-Tocopherol exhibited the change in its absorption spectrum in both systems, and seemed to be oxidized at a high rate by free radicals. However, cepharanthine slightly exhibited the change in its spectrum in MeOH-CHCl3-H2O, but not in acidified EtOH.

Alkaloids↗

Counter-regulation of insulin-stimulated glucose transport by catecholamines in the isolated rat adipose cell.

The interaction between catecholamines and insulin in regulating glucose transport in isolated rat adipose cells has been evaluated. In the absence of insulin, 1 microM isoproterenol stimulates 3-O-methylglucose transport approximately 2-fold. However, isoproterenol in combination with adenosine deaminase inhibits glucose transport activity approximately 60%. N6-Phenylisopropyladenosine, a nonmetabolizable adenosine analogue, substantially reverses this inhibitory effect and actually stimulates glucose transport activity approximately 2-fold in the absence of isoproterenol. Dibutyryl cAMP inhibits glucose transport activity approximately 75% regardless of adenosine deaminase. While none of these agents significantly influences the basal concentration of plasma membrane glucose transporters, as assessed by specific D-glucose-inhibitable cytochalasin B binding, isoproterenol or dibutyryl cAMP in combination with adenosine deaminase reduces that in the low density microsomes 19 and 58%, respectively. In the presence of insulin, both isoproterenol and adenosine deaminase alone inhibit glucose transport activity approximately 25%. However, only the latter is accompanied by a corresponding decrease in the insulin-stimulated concentration of plasma membrane glucose transporters. Together, isoproterenol and adenosine deaminase inhibit insulin-stimulated glucose transport activity approximately 75%, even in the presence of 5 mM glucose to maintain cellular ATP levels. A similar inhibition is observed with dibutyryl cAMP. However, these agents decrease the insulin-stimulated concentration of plasma membrane glucose transporters only approximately 45%. Nevertheless, all of these inhibitory effects occur through decreases in the transport Vmax. In addition, N6-phenylisopropyladenosine partially reverses the inhibitory effects induced by the presence of adenosine deaminase. These results suggest that catecholamines counter-regulate basal and insulin-stimulated glucose transport in rat adipose cells through a cAMP-mediated mechanism, but only in part by modulating the translocation of glucose transporters.

3-O-Methylglucose↗

Image restoration from non-uniform magnetic field influence for direct Fourier NMR imaging.

A new technique is proposed for NMR image restoration from the influence of main magnetic field non-uniformities. This technique is applicable to direct Fourier NMR imaging. The mathematical basis and details of this technique are fully described. Modification to include image restoration from non-linear field gradient influence is also presented. Computer simulation demonstrates the effectiveness of this technique for both Fourier zeugmatography and spin-warp imaging.

Fourier Analysis↗

Adult-type systemic varicella in a female patient in course of treatment of her so-called reactive lymphocytic (T-cell) hyperplasia.

A 31-year-old woman was examined in this case. Biopsy revealed an abnormal nontumorous proliferation of T-cells in the lymph node. Clinically, the patient was treated by C-MOPP and steroid under clinical suspicion of T-cell lymphoma. In the period of observation of the course of illness, the patient contracted varicella from her real child and died on the 8th day of illness. She was examined pathologically, electron microscopically, and by the fluorescent antibody technique. Virus infections foci, which were mostly necrotic ones, were found in the parenchymatous and interstitial cells of skin, lung, adrenal gland, digestive organs, liver, lymph nodes, and genital organs. In the circulatory system, proliferative foci with degeneration of endothelial and adventitial cells were noticed in small veins or venules, but little change was found in the arterial system. Electron microscopic observation suggested a destruction of the so-called limiting basement membrane around blood vessels. This was an important finding indicative of a mechanism of viral transmission to the interstitial cell system.

Adult↗

[A case of vesical malacoplakia].

A 44-year-old woman was admitted to our hospital, complaining of terminal hematuria. On cystoscopy four yellow and soft nodular masses were observed in the bladder, one of which had central ulceration. TUR was performed for these masses. Histological examination revealed that they were vesical malacoplakia. The masses consisted of aggregates of macrophages with abundant cytoplasma in which typical Michaelis-Gutmann bodies were demonstrated by light and electron microscopies.

Adult↗

Glomerular deposition and serum levels of complement control proteins in patients with IgA nephropathy.

We examined complement control proteins focusing on the role of modulating the complement activation in IgA nephropathy. Glomerular C4-binding protein (C4-bp) deposits were found in 60% of patients with IgA nephropathy, while C4 deposits were found in 30%. Glomerular deposits of beta 1H globulin (beta 1H) were found in 85% of patients with IgA nephropathy. The frequency of glomerular deposits of C4-bp tended to be higher in the group with deposits of various immunoglobulin types than in the group with deposits of IgA alone, and it increased parallel with the progression of glomerular histologic changes. The serum C4-bp level was higher in IgA nephropathy patients. No significant correlation was found between the serum level of C4-bp or beta 1H and the extent or distribution of tissue deposits of these complement control proteins. These results suggest that glomerular immune deposits in IgA nephropathy may be attributable to the activation not only of the alternative pathway but also of the classical pathway, the latter of which may take place locally in glomeruli with advanced histologic change or various immunoglobulin deposits in IgA nephropathy.

Beta-Globulins↗

Malignant potential of homozygous and heterozygous complete moles.

There are two main mechanisms of origin for complete hydatidiform mole: (a) fertilization of an empty egg by a haploid sperm followed by duplication (monospermic mole); and (b) fertilization of such an egg by two haploid spermatozoa (dispermic mole). The former is inevitably homozygous (homozygous mole), whereas the latter may be heterozygous for a given genetic marker (heterozygous mole). A recent cytogenetic study showed that three cases of choriocarcinoma were undoubtedly heterozygous, which prompted us to compare the incidence of postmolar sequelae between patients with homozygous moles and those with heterozygous moles. Making use of chromosomal heteromorphisms and human lymphocyte antigen and phosphoglucuromutase 1 polymorphisms, we established the androgenetic origin of a complete mole in 49 of 56 cases. Homozygosity was confirmed in 21 moles, and heterozygosity was confirmed in five. Three of five patients with heterozygous moles developed postmolar trophoblastic disease, whereas none of the 21 patients with homozygous moles suffered postmolar trophoblastic disease except one who showed signs of degenerating residual trophoblasts. Consistent with this observation is the fact that all of the four destructive moles studied here were of dispermic origin. Thus, heterozygous moles seem to have a higher malignant potential than do homozygous moles.

Chromosome Aberrations↗

Combination chemotherapy including adriamycin for advanced transitional cell carcinoma of the urinary tract.

Thirty-three patients with advanced transitional cell carcinoma of the urinary tract (23 bladder cases, 8 ureter cases, and 2 renal pelvis cases) were treated by three-drug combination chemotherapy using two protocols (protocol I: Adriamycin 50 mg/m2, cyclophosphamide 500 mg/m2, and 5-fluorouracil 500 mg/m2, protocol II: Adriamycin 50 mg/m2, cyclophosphamide 500 mg/m2, and cis-platinum 50 mg/m2). Protocol I induced responses in three of 19 patients (16%), (1 complete response, 2 partial responses), and protocol II (I complete response, 4 partial responses) in five of 14 patients (36%). The overall response rate was 24%. The duration of response was relatively short (median duration 5.1 months). The combination therapy was relatively well tolerated except in three patients, including two mortalities. In our study, three-drug combination chemotherapy with Adriamycin, especially that including cis-platinum, was effective against transitional cell carcinoma of the urinary tract, but the results were not completely satisfactory.

Adult↗

Transcription termination in vitro at the tryptophan operon attenuator is controlled by secondary structures in the leader transcript.

The role of alternative RNA secondary structures in regulating transcription termination at the attenuator of the tryptophan (trp) operon of Serratia marcescens was examined in vitro by transcribing mutant DNA templates having deletions of different segments of the trp leader region. Deletions that removed sequences corresponding to successive segments of postulated RNA secondary structures either increased or decreased transcription termination at the attenuator. The results obtained are consistent with the hypothesis that transcription termination results from RNA polymerase recognition of a particular RNA secondary structure, the terminator. This structure forms only in the absence of an alternative, preceding, RNA secondary structure, the antiterminator.

Chromosome Deletion↗