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Biomedical subjects

K Satoh

Publications and source records attributed to K Satoh.

At least 505 records · Page 28Linked to original sources
PubMed1996

Pan-nephritis (glomerulonephritis, arteriolitis, and tubulointerstitial nephritis) associated with predominant mesangial C1q deposition and hypocomplementemia: a variant type of C1q nephropathy?

A 35-year-old man showed acute nephritic syndrome manifested as proteinuria, hematuria, and hypocomplementemia after upper respiratory infection. A renal biopsy showed mild to moderate mesangial proliferative glomerulonephritis with an accumulation of mononuclear cells in the capillary loop and with the deposition of C1q (graded as 3+), immunoglobulin (Ig) G, C3 (2+), IgA, IgM, and fibrinogen (weak to 1+), and mononuclear cell infiltration of the glomerular hilus, arterioles, and proximal tubules, which was a peculiar form of renal lesion. The mesangial deposition of C1q has been well documented in lupus nephritis, membranoproliferative glomerulonephritis, and endocapillary glomerulonephritis. The clinical signs and laboratory data in our patient ruled out these diseases. Although an immunofluorescence study showed these similarities to Clq nephropathy, the histopathological features of the peculiar arteriolitis and tubulointerstitial nephritis and laboratory findings of hypocomplementemia, as well as the good response to oral steroid therapy, differed from typical C1q nephropathy. The current patient appears to be a very rare phenotype of nephritis, being the only 1 case in almost 2,800 renal biopsies.

Adult↗
PubMed1996

The distribution of noradrenaline, serotonin and gamma-aminobutyric acid in the monkey nucleus accumbens.

1. The recent histochemical studies have shown that the primate nucleus accumbens (NAC) can be subdivided into at least three subdivisions, the medial, ventral and dorsolateral subdivisions. 2. The medical subdivision possesses dense peptide- and dopamine-immunoreactive (IR) fibers. 3. In order to further investigate the neurochemical characteristics of the primate NAC, the distribution of structures that contain noradrenaline (NA), serotonin (5-HT) and gamma-aminobutyric acid (GABA) were examined in the macaque monkey by using transmitter-immunohistochemical methods. 4. Many NA-IR fibers were observed in the dorsal part of the NAC, corresponding to the medial subdivision. Fine varicose 5-HT-IR fibers were evenly distributed in the NAC. GABA-IR cell bodies and puncta were observed throughout the NAC as well as in the caudate nucleus and putamen. 5. The monkey rostral NAC displays a highly homogeneous distribution of all neuropeptides and neurotransmitters studied so far and we propose that this region be termed the rostral subdivision of the NAC.

Animals↗
PubMed1996

Regular and irregular dichotomies of bronchial branching in the human lung.

RATIONALE AND OBJECTIVES: Typical models of the human bronchial tree depict regular branching. However, some anatomic studies also have revealed irregular dichotomies in the human lung. We therefore studied the patterns of bronchial branching in the human lung. METHODS: We examined a normal right lung. Bronchial branchings were traced up to terminal bronchioles (TBs) in both regular and irregular dichotomies. RESULTS: In 256 TBs in peripheral regions, the number of branchings varied from 11 to 23; the largest number was found in the S10c of the basal segment, and the average was 15. In 354 TBs in hilar regions supplied by irregular dichotomies, the number of branchings ranged from 9 to 15, with the average being 10. In secondary pulmonary lobules, bronchioles supplying the secondary pulmonary lobules reached TBs in two or three divisions. CONCLUSION: Irregular dichotomies are too frequent to be neglected in the interpretation of radiologic and physiologic findings.

Aged↗
PubMed1996

Septal structure of incomplete interlobar fissures of the lung.

RATIONALE AND OBJECTIVES: Some septal structures have been observed in the areas of incomplete interlobar fissures (IIFs) in resected lungs. We describe the anatomy of IIFs with or without the presence of septal structures. METHODS: Twenty fused areas from 16 autopsy cases were examined histologically. Other septal structures outside the areas of IIFs also were examined. RESULTS: In 10 of the 20 fused areas, there was a mixture of septal structures with and without defects. In the remaining 10, there were no septal structures. The septal structures consisted of two inner layers from both lobes. Other septal structures examined were the same as ones observed in the IIFs. CONCLUSION: Linear shadows seen at interlobar fissures and on computed tomography scans do not necessarily depict the presence of complete interlobar fissures. The absence of linear shadows does not necessarily imply the absence of septal structures.

Bronchi↗
PubMed1996

Expression of the recombinase-activating gene (RAG-1) in murine early embryogenesis.

The recombinase activation genes, RAG-1 and RAG-2, are expressed together in immature T or B lymphocytes and possess activity to induce V(D)J rearrangement in T cell receptor (TCR) and Ig genes. In vertebrates, only Ig and TCR molecules are reported to have recombination in their development using multiple V, D, J component gene segments. Thus, expression of RAG genes are localized only in lymphoid organs and sites of extrathymic T cell differentiation. In this study, we have used RAG-1 and RAG-2 genes as markers of possible genetic recombination in developing murine preimplantation embryos, using the highly sensitive reverse transcriptase polymerase chain reaction (RT-PCR) technique and in situ hybridization. From 40 preimplantation embryos of various developmental stages we extracted RNA, reverse-transcribed it into cDNA and used it in RT-PCR studies. A PCR of 35 cycles disclosed expression of RAG-1 but not RAG-2 in morulae and blastocysts. Southern blot hybridization using a specific synthetic oligonucleotide probe for RAG-1 and RT-PCR with another primer pair identified RAG-1 expression in developing embryos. In situ hybridization using a cooled CCD camera also revealed localization of RAG-1 mRNA in blastocysts. We propose possible genetic recombination during late preimplantation murine embryogenesis which may contribute to the loss of totipotency and differentiation of inner cell mass and trophoectoderm.

Animals↗
PubMed1996

Using the proportional odds model to assess the relationship between a multi-item and a global item efficacy scale in a psychiatric clinical trial.

The proportional odds model is illustrated in the analysis of two efficacy scales used in a phase II clinical trial involving 81 schizophrenic patients. The proportional odds model preserves the discrete, ordinal nature of one of the scales. The analysis of this data suggested that the relationship between the two scales is not captured by a linear proportional odds model. A linear model and a piecewise linear model for the explanatory variable were therefore compared using likelihood-based analyses. Residuals from both models were compared. Predicted probabilities for the ordinal categories were constructed from the estimated model. Extensions and limitations of the model for interpretation of other trials and for the planning of future trials are discussed.

Antipsychotic Agents↗
PubMed1996

Genetic engineering of the processing site of D1 precursor protein of photosystem II reaction center in Chlamydomonas reinhardtii.

The D1 protein (D1) of photosystem II (PSII) reaction center is synthesized as a precursor (pD1) and then processed at its carboxyl terminus to establish the function of water cleavage. The amino acid sequence of the carboxyl terminal extension excised by this process is poorly conserved except for a residue after the cleavage site at position of 345. We have constructed a vector for site-directed mutagenesis of the chloroplast psbA gene encoding D1 of the green alga, Chlamydomonas reinhardtii. The vector enables one to transform the chloroplasts of a psbA deletion mutant (Fud7) and directly select transformants for resistance to spectinomycin. Using this transforming vector, we have substituted Ser345 to Gly, Cys, Val and Phe in order to investigate effects of the amino acid side chain at this position on the processing rate. All of the resulting transformants exhibited the PSII activity as wild type and grew normally under photoautotrophic conditions even under strong light where rapid turnover of D1 protein is expected to occur. Western blotting analysis demonstrated that mature D1 accumulates in these transformants at wild type level. Pulse and chase labeling of chloroplast-encoded proteins using [35S] sulfate revealed that the processing of D1 precursor protein occurs in all four transformants as efficiently as in wild type, at least under the experimental conditions examined. The results suggest that either the amino acid side chain at position of 345 (+1 position) is not crucial to the enzymatic cleavage of pD1 in vivo or the apparent rate of processing in vivo is not limited by the enzymatic cleavage.

Animals↗
PubMed1996

Intracellular levels of cyclic AMP and cyclic GMP differentially modify platelet aggregate size in human platelets activated with epinephrine or ADP.

We investigated the effects on human platelet aggregation of several agents that increase either intracellular cyclic AMP or cyclic GMP, using a platelet aggregometer that allows quantification of the size and number of platelet aggregates. During the initial phase of aggregation induced by epinephrine and ADP, small aggregates consisting of < 100 cells predominated; large aggregates formed later. Prostaglandin I2 (PGI2), which increases intracellular cyclic AMP, suppressed the formation of small as well as large aggregates induced by epinephrine, with ID50 values of 10.7 +/- 2.8 and 3.8 +/- 0.5 nM, respectively. ADP-induced formation of small and large aggregates was also inhibited by PGI2, with similar ID50 values. Dibutyryl cyclic AMP (db cyclic AMP), a cell-permeant form of cyclic AMP, also inhibited small and large aggregate formation induced by epinephrine or ADP, with ID50 values of 420-560 microM for small aggregates and 139-166 microM for large aggregates, respectively. On the other hand, nitroprusside, which increases intracellular cyclic GMP, inhibited only the formation of large aggregates, with an ID50 value of 454 +/- 191 nM for epinephrine-induced activation and of 2.1 +/- 0.6 microM for ADP-induced activation. Nitroprusside at 1 mM did not affect the formation of small aggregates induced by epinephrine, whereas that of large aggregates was completely blocked at 10 microM. 8-Bromo cyclic GMP (8-br cyclic GMP) also inhibited only the formation of large aggregates, with ID50 values of 140-170 microM, but not that of small aggregates induced by epinephrine and ADP. Milrinone, which increases the intracellular level of both cyclic AMP and cyclic GMP, suppressed the formation of small and large aggregates induced by epinephrine and ADP. These findings suggest that cyclic AMP and cyclic GMP differentially modify the size of aggregates formed during epinephrine or ADP activation.

Adenosine Diphosphate↗
PubMed1996

Effects of adenine nucleotide analogues on myocardial dysfunction during reperfusion after ischemia in dogs.

We examined effects of adenine nucleotide on ischemic myocardial stunning in dogs. Pentobarbitalanesthetized open-chest dogs were subjected to 20-min ligation of the left anterior descending coronary artery (LAD), followed by reperfusion for 30 min. Either saline, 5 mM 8-bromo-5'-AMP (tributyryl-AMP), or 30 mM N6, 2', 3'-tributyryl-5'-AMP (tributyryl-AMP), 5 mM 5-amino-4-imidazole carboxamide riboside (AICAr) as a positive reference, was infused at 0.1 ml/kg/min in the left femoral vein throughout the experiment. The myocardial contractile function was measured by ultrasonometry. The tissue levels of high-energy phosphates in the reperfused heart were determined. Myocardial contractile function assessed by % segment shortening (%SS) in the saline-infused group decreased during ischemia and returned toward the preischemic level during reperfusion but incompletely. A significant improvement in the %SS during reperfusion was observed in the 8-bromo-AMP- and AICAr-infused groups but not in the tributyryl-AMP-infused group. The magnitude of the protective effect of the drugs on myocardial contractility during reperfusion was 8-bromo-AMP > AICAr > tributyryl-AMP = saline. Only in the 8-bromo-AMP-infused group were the levels of ATP, ADP, and total adenine nucleotides in the reperfused heart significantly higher than those in the saline-infused group. The present result indicates that 8-bromo-AMP improves the ability of the heart to recover from ischemia and reperfusion associated with a significant restoration of ATP.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1996

Simplified procedure for aesthetic improvement of facial contour by maxillary augmentation using a porous hydroxyapatite graft for maxillofacial deformity.

A simplified procedure of maxillary augmentation with a porous hydroxyapatite block graft in the anterior aspect of the maxillary parapiriformis area is described. This procedure is an alternative for maxillary advancement osteotomy and is simple to perform for maxillofacial deformity of cleft lip and palate and other deformities. It is effective for facial aesthetics in association with mandibular surgery, such as mandibular setback by sagittal splitting osteotomy, mandibular segmental osteotomy with premolar extraction, bimaxillary osteotomy, and/or genioplasty. We used this procedure on 21 patients (15 for cleft lip and palate jaw deformity and 6 for aesthetic reasons). Although postoperative infection requiring removal of the hydroxyapatite block occurred in one cleft deformity patient, satisfactory results were obtained in all patients.

Adult↗
PubMed1996

Consideration of a thin flap as an entity and clinical applications of the thin anterolateral thigh flap.

A defatted (thinned) anterolateral thigh flap was designed to reconstruct skin defects requiring thin flap coverage. We used this flap as a free flap for five cases of skin defects, and the outcomes of the reconstructions were all successful. The vascular pedicle of this flap, the cutaneous perforator of the lateral circumflex femoral artery, is about 8 cm long and 2 mm in diameter, and it is ideal for microvascular anastomosis. Thinning is performed in about 3 to 4 mm of thickness almost uniformly except for the vascular pedicle. It was ascertained as one of the useful donor sites of the free thin flap. The virtue of the thin anterolateral thigh flap is its uniform thinness compared with other thin flaps reported previously--the thin groin flap and the thin rectus abdominis musculocutaneous flap. We considered thin flaps as an entity, and they are classified into three types.

Adult↗
PubMed1996

Surgical refinement of the operative procedure for a minor degree of mandibular prognathism.

Although sagittal splitting ramus osteotomy is used widely for mandibular prognathism and even for that of a minor degree, a long duration of preoperative and postoperative orthodontic treatment is required. Conversely, mandibular segmental osteotomy has often been used to correct a minor degree of mandibular prognathism without specific orthodontic treatment. Here we describe a surgical refinement accomplishing mandibular segmental osteotomy, reduction genioplasty by double horizontal osteotomies, and decortication of the middle portion of the osteotomies for a minor degree of mandibular prognathism. The amount of setback is limited to 4 to 5 mm, no intermaxillary fixation is required, and no orthodontic treatment, in principle, is needed. This procedure can obtain a rapid aesthetic improvement. We used this procedure in 11 patients (7 females and 4 males) with a minor degree of mandibular prognathism. The amount of setback of the mandibular anterior portion was 4 to 5 mm, and satisfactory results were obtained in all patients.

Adolescent↗
PubMed1996

K-ras mutation and p53 protein accumulation in intraductal mucin-hypersecreting neoplasms of the pancreas.

Intraductal mucin-hypersecreting neoplasm of the pancreas (IMHN) is a unique tumor that is composed of tumor cells with different cell atypia. K-ras and p53 alterations have been shown to occur in pancreatic duct cell carcinoma (PDC), but they have not been well documented in the individual lesion of IMHN. The aim of this study was to examine the relation of the genetic alterations of K-ras and p53 in IMHN to the tumorigenesis of the pancreas. In 32 microscopically dissected lesions of seven cases of IMHN, the K-ras mutation was investigated by primer-mediated, mutant-enriched, polymerase chain reaction-restriction fragment length polymorphism. Mutant p53 expression was examined in the adjacent serial sections by immunohistochemistry. In IMHN, alterations of K-ras and p53 were frequently observed (71.9 and 50%, respectively). The frequency became higher as the grade of cell atypia increased. Simultaneous alterations of the two genes were detected in carcinoma and its accompanying hyperplastic and dysplastic lesions. It is suggested that alterations of K-ras and p53 may be early events in the tumorigenesis of IMHN and may cooperate to produce neoplastic transformation of the pancreatic duct epithelium.

Adenoma↗
PubMed1996

Chemopreventive effect of a xanthine oxidase inhibitor, 1'-acetoxychavicol acetate, on rat oral carcinogenesis.

The effect of a xanthine oxidase inhibitor, 1'-acetoxychavicol acetate (ACA), on 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis was investigated in male F344 rats. All rats except those in the ACA-alone and untreated groups were given 4-NQO (20 ppm) In the drinking water for 8 weeks to induce oral cancer. Starting 1 week before the 4-NQO exposure, animals were fed diet containing 100 ppm or 500 ppm ACA for 10 weeks, followed by the basal diet without ACA for 22 weeks. Other groups were fed the diet containing ACA at 100 ppm or 500 ppm for 22 weeks, starting 1 week after the cessation of 4-NQO exposure. The remaining groups consisted of rats given 500 ppm ACA alone or untreated rats. At the termination of the experiment (32 weeks), the incidences of tongue neoplasms and preneoplastic lesions, polyamine levels in the tongue tissue, and cell proliferation activity estimated in terms of 5-bromodeoxyuridine (BrdU)-labeling index and by morphometric analysis of silver-stained nucleolar organizer regions' protein (AgNORs) were compared among the groups. Feeding of ACA at the two doses during initiation or postinitiation significantly decreased the development of tongue carcinoma (93-100% reduction, P < 0.001) and preneoplasia (43-50% reduction for hyperplasia and 34-48% reduction for dysplasia, P < 0.05). There were no such lesions in rats fed ACA alone or those in the untreated control group. The number of AgNORs per cell nucleus was significantly decreased by feeding of ACA at a high dose (500 ppm) (29% inhibition, P < 0.05). The BrdU-labeling index was also reduced by dietary administration of ACA (23-32% inhibition, P < 0.01). In addition, ACA feeding reduced tongue polyamine levels (35-40% inhibition, P < 0.05). These results indicate that ACA inhibited rat oral carcinogenesis, and such inhibition might be related to suppression of cell proliferation in the oral mucosa by the xanthine oxidase inhibitor.

4-Nitroquinoline-1-oxide↗
PubMed1996

Suppressing effects of 6-(2,5-dichlorophenyl)-2,4-diamino-1,3,5-triazine and related synthetic compounds on azoxymethane-induced aberrant crypt foci in rat colon.

The modifying effects of dietary administration of 6-(2,5-dichlorophenyl)-2,4-diamino-1,3,5-triazine and 5 related compounds on the occurrence of azoxymethane (AOM)-induced colonic aberrant crypt foci (ACF) were investigated in rats. Male F344 rats were given s.c. injections of AOM (15 mg/kg body weight) once a week for 3 weeks to induce ACF. They also received the diet containing 200 ppm test compound for 5 weeks, starting one week before the first dosing of AOM. At the termination of experiment, all of the compounds had caused a significant reduction in ACF frequency, which might be associated with suppression of the expression of proliferation biomarkers. The apoptotic index in the colonic mucosal epithelium of rats killed at 6 h after the first AOM exposure revealed no blocking activity of the compounds.

Animals↗
PubMed1996

Lentinan enhances sensitivity of mouse colon 26 tumor to cis-diamminedichloroplatinum (II) and decreases glutathione transferase expression.

We investigated the influence of a combination of lentinan, a biological response modifier, and cis-diamminedichloroplatinum(II) (CDDP) on the growth and glutathione S-transferase (GST) content of colon 26 tumor to examine whether lentinan represses GST expression and enhances the therapeutic effects of CDDP. Female CDF1 mice inoculated subcutaneously with transplantable colon 26 adenocarcinoma cells (1 X 10(6)/mouse) received intraperitoneal administrations of lentinan, CDDP, or the two drugs in combination, on days 10, 14, 17 and 21 after the inoculation. On day 24, tumor weights (estimated from their length and width) were significantly lower in the CDDP+ lentinan group (2.7+/-1.3 g) than in the CDDP alone group (4.3+/-0.7 g, P<0.05), both values being less than in the nontreated control group (7.2+/-1.5 g). The major GST form of colon 26 tumor was identified as GST-II, the Pi class form, and a minor form as GST-III belonging to the Mu class. Both GST-II and GST-III values on day 24 were significantly decreased in the lentinan alone (0.90+/-0.29 and 0.26 +/-0.11 microg/mg protein, respectively) and lentinan + CDDP groups (0.98+/-0.22 and 0.29+/-0.07 microg/mg protein), as compared with the control levels (1.39+/-0.20 and 0.52+/-0.11 microg/mg protein). However, these values were not different between the CDDP alone and lentinan + CDDP groups. Neither tissue interleukin (IL)-6, glutathione nor platinum values were different between the two groups. IL-6 values were elevated in about half of the samples treated with lentinan or CDDP and exhibited a modest inverse correlation with GST-II levels (r= -0.46). A GST inhibitor, ethacrynic acid, enhanced the sensitivity of cultured colon 26 cells to CDDP, suggesting the possible involvement of GST in modulating the cytotoxicity of CDDP to this cell line. These results indicated that lentinan administration decreases tissue GST-II and GST-III contents and enhances the sensitivity of colon 26 tumor to CDDP.

Adenocarcinoma↗