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Biomedical subjects

Y Takeda

Publications and source records attributed to Y Takeda.

At least 433 records · Page 24Linked to original sources
PubMed1997

Secondary acute monocytic leukemia occurring during the treatment of a testicular germ cell tumor. A case report and review of the literature.

Secondary leukemia following chemotherapy or radiotherapy for mediastinal germ cell tumors is a well-described entity. It also may occur in patients with testicular germ cell tumors. We report a case of acute monocytic leukemia occurring in a 44-year-old man who received etoposide-based chemotherapy and radiotherapy for a recurrent, metastatic testicular germ cell tumor. The patient received 14 cycles of systemic chemotherapy for pulmonary and para-aortic lymph node metastases following his initial orchiectomy. The total amount of etoposide this patient received was 6,400 mg/m2. Leukemia occurred 11 years after orchiectomy. A literature review revealed 25 other reported cases of secondary leukemias after treatment for testicular carcinoma. It is not clear whether chemotherapy, radiotherapy or both are responsible for the secondary leukemias seen in these patients.

Adult↗
PubMed1997

Vascular aldosterone in genetically hypertensive rats.

We have reported that aldosterone is synthesized and cytochrome P450aldo mRNA exists in the vasculature. To clarify the pathophysiological role of vascular aldosterone in hypertension, we compared aldosterone production in the mesenteric arteries of stroke-prone spontaneously hypertensive rats (SHRSP) with that in Wistar-Kyoto rats (WKY). The expressions of mRNA of cytochrome P450aldo, mineralocorticoid receptor, and alpha 1, Na,K-ATPase in the mesenteric arteries were compared between the two groups. Aldosterone concentration in the perfusate of the vasculature was measured by radioimmunoassay after purification with high-performance liquid chromatography. Cytochrome P450aldo and mineralocorticoid receptor mRNA levels were quantified by Southern blot analysis of the products of reverse-transcribed polymerase chain reaction. Levels of alpha 1 Na,K-ATPase mRNA were measured by Northern blot analysis. Vascular aldosterone and cytochrome P450aldo mRNA levels of 2-week-old SHRSP were significantly increased compared with those of age-matched WKY. However, vascular aldosterone in 4- and 9-week-old SHRSP did not differ from that in age-matched WKY. Expression levels of mineralocorticoid receptor mRNA in the vasculature of 4- and 9-week-old SHRSP were significantly increased compared with those in age-matched WKY. Concentrations of vascular alpha 1 Na,K-ATPase mRNA of 2-, 4-, and 9-week-old SHRSP also were significantly higher than those in age-matched WKY. These results suggest that vascular aldosterone contributes to the pathophysiology of hypertension in SHRSP in the early stage.

Aldosterone↗
PubMed1997

Brain nitric oxide synthase messenger RNA in central mineralocorticoid hypertension.

The mechanism underlying the central hypertensinogenic effects of mineralocorticoids remains unclear. Given that nitric oxide (NO) is thought to act at autonomic sites in the brain to regulate arterial blood pressure, the effects of the potent mineralocorticoids aldosterone and 19-noraldosterone on the abundance of neuronal NO synthase (nNOS) mRNA in the brain were investigated. Wistar-Kyoto rats received a continuous intracerebroventricular infusion of aldosterone or 19-noraldosterone (5 ng/h) from an implanted osmotic minipump for 4 weeks. Total RNA was purified from microdissected tissue blocks containing the hypothalamus, dorsal medulla, rostral ventrolateral medulla, or caudal ventrolateral medulla, and changes in the abundance of nNOS mRNA were determined with a semiquantitative competitive polymerase chain reaction method. Blood pressure was significantly increased in rats 2, 3, and 4 weeks after the onset of intracerebroventricular aldosterone or 19-noraldosterone infusion compared with that in animals receiving vehicle. Subcutaneous infusion of either mineralocorticoid had no effect on blood pressure. Compared with controls, rats treated with aldosterone or 19-noraldosterone for 4 weeks showed significant decreases in the amount of nNOS mRNA in the hypothalamus and rostral and caudal ventrolateral medulla. These data suggest that reduced nNOS activity may contribute to the increase in blood pressure in rats with central mineralocorticoid-induced hypertension.

Aldosterone↗
PubMed1997

Three-dimensional spiral computed tomography angiography as an alternative imaging modality for a silent dissecting aortic aneurysm--a case report.

The authors report a patient with silent dissecting aortic aneurysm in whom three-dimensional spiral computed tomography (CT) angiography (3D-CTA) provided important imaging data. Images obtained by 3D-CTA were compared with the results of both conventional angiography and CT. They conclude that 3D-CTA was a powerful diagnostic modality for this patient, in addition to conventional CT and angiography.

Aortic Dissection↗
PubMed1997

Immunosuppressive properties of MX-68, a novel unpolyglutamatable antifolate.

MX-68 is a novel unpolyglutamatable antifolate. We here reported the in vitro and in vivo immunosuppressive properties of MX-68 compared with a polyglutamatable antifolate, methotrexate (MTX). MX-68 showed potent suppressive effects on mitogen-induced mouse splenic lymphocyte proliferation as well as immunoglobulin production from LPS-stimulated mouse splenic B cells. In in vivo studies, MX-68 significantly suppressed antigen-specific antibody production of both T cell-dependent antigen and T cell-independent antigen. Moreover, MX-68 inhibited a sheep red blood cell (SRBC)-induced delayed-type hypersensitivity (DTH) reaction by administration starting from the day of antigen immunization, but did not suppress the effector phase of the DTH reaction. MTX showed suppressive activities similar to MX-68 in all experiments. Interestingly, although MX-68 demonstrated somewhat stronger suppressive effects than MTX in vivo, the results from in vitro studies were reversed. These results suggest that polyglutamation is not always required to suppress immune responses and that MX-68 is a slightly stronger immunosuppressive drug than MTX in mice.

2-Aminoadipic Acid↗
PubMed1997

Antirheumatic agents. III. Novel methotrexate derivatives bearing an indoline ring and a modified ornithine or glutamic acid.

The synthesis, biological profile and structure-activity relationship of various methotrexate (MTX) derivatives bearing an indoline ring are described. In particular, Nb-(3-carboxyphenyl)-N alpha-[1-[(2,4-diaminopteridin-6-yl)-methyl] indoline-5-ylcarbonyl]-L-glutamine (3d), compared to MTX, exhibited an enhanced anti-proliferative effect on human peripheral blood mononuclear cells obtained from healthy volunteers.

Antirheumatic Agents↗
PubMed1997

Profiles of insulin-like growth factor binding proteins and the protease activity in the maternal circulation and its local regulation between placenta and decidua.

Insulin-like growth factors (IGF) and their specific binding proteins (IGFBPs) are believed to be important regulators of fetal growth. IGFBP protease which proteolyzes IGFBPs and changes the biochemical properties of IGFBPs is also presumed to be involved in fetal growth. The aim of this study is to elucidate the physiological significance of IGFBP protease in fetal growth and regulators of protease in placenta and decidua. The intact IGFBP-3 was proteolyzed into fragments when pregnant serum was incubated with 125I-IGFBP-3. IGFBP-3 protease activity showed a marked increase at 5 weeks of gestation and reached a plateau in maternal circulation at 15 weeks of gestation. These changes in protease activity correlated with the profiles of IGFBPs in the maternal circulation analyzed by Western ligand blot, where the IGFBP-1 is only the dominant IGFBP. The intact IGFBP-3 was proteolyzed when culture media of decidual cells were incubated with 125I-IGFBP-3, but was not proteolyzed when culture media of trophoblast cells were incubated with 125I-IGFBP-3. Decidual protease activity was slightly increased by IGF-I and completely inhibited by progesterone. The protease activity was more increased in the mothers with growth retarded infant than in those in the mothers with normal growth infants, suggesting that the protease activity is elevated in compensation for the impaired fetal growth. These results suggest that increased protease activity in maternal blood may be involved in the fetal growth indirectly by reducing the binding activity of IGFBP-3 to IGF-I, and that protease activity in maternal blood may be derived from decidua that is regulated by placental hormones.

Adult↗
PubMed1997

Vomiting induction by ipecac syrup in dogs and ferrets.

The dog has been used as an experimental animal in emesis research. In this study, we analyzed the emetic effects of ipecac syrup using a smaller animal, the ferret, and compared its response to that of the dog. Dogs and ferrets were divided into 4 groups (n = 4, each). Each group was given either 0.1, 0.25, 0.5, or 1.0 ml/kg of ipecac syrup, and the latency and numbers of retching and vomiting were recorded. Animals given an equal volume of saline served as controls. The numbers of vomiting and retching increased dose-dependently in both dogs and ferrets, and there was no difference in latency and numbers of vomiting between them. The numbers of retching were greater in ferrets than in dogs at > or = 0.25 ml/kg. Taking these results into consideration, the ferret seems to be as useful as the dog in studies on emetic effects of ipecac syrup.

Animals↗
PubMed1997

DNA-dependent protein phosphorylation activity in Xenopus is coupled to a Ku-like protein.

DNA-dependent protein kinase (DNA-PK) is a nuclear enzyme and functions as a serine/threonine kinase that has been well characterized in both the human and the mouse. The regulatory subunit of DNA-PK is the Ku autoantigen. To demonstrate that a Ku-like protein is present in Xenopus oocytes, we used immunoprecipitation analysis with a monoclonal antibody raised against human Ku antigen and autoimmune serum containing anti-Ku antibodies. Metabolic labeling studies indicate that the Ku-like protein is synthesized mainly in late vitellogenic oocytes. By using a specific peptide substrate for DNA-PK, we demonstrate the activity of a DNA-dependent protein kinase in oocyte extracts. The kinase activity requires the Ku-like protein, since extracts depleted of Ku protein by immunoadsorption with human anti-Ku antibodies fail to demonstrate the DNA-dependent phosphorylation activity. The increased enzyme activity in vitellogenic oocytes may be correlated to the increased levels of Ku protein observed in these oocytes compared to the pre- and early vitellogenic oocytes.

Amino Acid Sequence↗
PubMed1997

Epithelial hyperplasia of the extra-glandular excretory ducts of human minor salivary glands: a histopathologic study.

The histologic features of normal and hyperplastic epithelia of the extra-glandular excretory ducts of human minor salivary glands were studied, and their pathologic significance evaluated. Normal duct epithelium consisted of two layers: inner columnar cells, and basal cubical or squamous cells. A few goblet cells were present among the inner cells. Hyperplasia of the duct epithelia occurred focally or entirely, and was classified into the following histologic types: (1) simple hyperplasia, and (2) metaplastic hyperplasia, which were divided into (a) mucous cell hyperplasia, (b) oncocytic hyperplasia and (c) squamous cell hyperplasia. Squamous cell hyperplasia was subdivided into (i) acanthotic type and (ii) reserve cell-like type with or without dysplasia. Simple or metaplastic epithelial hyperplasia of the extra-glandular excretory ducts of minor salivary glands may be induced by chronic inflammation or other types of irritation, and proliferating cells of such regenerating tissue sometimes exhibit features reminiscent of a neoplastic process. Furthermore, it is suggested that metaplastic epithelial hyperplasia of the excretory minor salivary gland ducts could be the site of origin of tumor development, i.e., some oral squamous cell carcinomas may arise from primary lesions in the hyperplastic epithelium of the extraglandular excretory minor salivary gland ducts.

Carcinoma, Squamous Cell↗
PubMed1997

A central tubercle on the lingual surface of the upper lateral incisor: report of a case.

A case of a central tubercle on the lingual surface of the upper lateral incisor in a 61-year-old Japanese male is reported. The morphologic form of the central tubercle was similar to that of dens evaginatus frequently found in premolars. It was completely distinguishable from a talon cusp, which is a protrusion of the lingual cingulum. Radiographically, the present case was also complicated by dens invaginatus. We also review the Japanese literature on central tubercles of the incisal region.

Dens in Dente↗
PubMed1997

Primary biliary cirrhosis an epithelitis: evidence of abnormal salivary gland immunohistochemistry.

Primary biliary cirrhosis (PBC) is an autoimmune liver disease of unknown etiology. Nearly 93% of patients with PBC exhibit evidence of focal sialoadenitis. In an earlier study, we reported evidence of aberrant expression of PDC-E2, or a mimeotope, in the salivary glands of patients with PBC that had Sjogren's syndrome. At the time of the previous study, data was not yet available regarding patients with PBC without sicca complaints. Therefore, to investigate the extent of salivary gland involvement in PBC, we collected lip biopsy sections from 9 PBC patients diagnosed as PBC by liver biopsy, without clinical or histologic features of Sjogren's syndrome and 9 PBC patients with established Sjogren's syndrome. Using immunohistochemical staining with both a murine monoclonal antibody. C355.1, and a human combinatorial antibody, SP4, we examined the ducts of these salivary glands for the presence of the characteristic aberrant staining pattern found in patients with PBC. We report that 6/9 PBC patients fulfilling established Sjogren's syndrome criteria and 6/9 PBC patients lacking features of Sjogren's syndrome showed intense staining of the ductal epithelial cells of the salivary gland. These data suggest that the PBC-specific antigen recognized by C355.1 and SP4 in bile duct epithelial cells is expressed aberrantly in the salivary gland in 66% of patients with PBC, independent of Sjogren's syndrome. This finding suggests a common disease process in these two tissues. Further, expression of this molecule may be an early marker of salivary gland involvement in patients with PBC.

Animals↗
PubMed1997

Genetic evidence supporting the fecal-perineal-urethral hypothesis in cystitis caused by Escherichia coli.

PURPOSE: The fecal-perineal-urethral hypothesis to explain the cause of urinary tract infections (UTI) by enteric bacteria has been supported by longitudinal studies using methods of serotyping and detecting urovirulence factors such as P fimbriae. However, genetic techniques to more accurately characterize Escherichia coli strains have not been exploited. MATERIALS AND METHODS: A total of 2,700 E. coli colonies isolated from the urine and rectal swabs of 9 female subjects with acute uncomplicated cystitis and from the rectal swabs of 30 healthy women were serotyped and examined for genes encoding various urovirulence factors by colony hybridization test. The clonality of the urine and fecal isolates of E. coli from the cystitis subjects was further evaluated by pulsed-field gel electrophoresis (PFGE). RESULTS: E. coli strains causing cystitis dominated the rectal flora of 7 of 9 patients. In the remaining 2 patients, similar clones comprised at least 20% of the fecal flora. Carriage of E. coli strains with a variety of urovirulence factors was quite common among healthy women. PFGE demonstrated that most of the isolates sharing the same serotypic characteristics and virulence factors in the urine and rectal swab samples from each subject were identical. CONCLUSIONS: Based upon precise genetic techniques, our results clearly support the fecal-perineal-urethral hypothesis, indicating that E. coli strains residing in the rectal flora serve as a reservoir for urinary tract infections, e.g., cystitis.

Acute Disease↗
PubMed1997

[Bacteriological detection methods of enterohemorrhagic Escherichia coli].

A rapid identification of enterohemorrhagic Escherichia coli is critical to diagnose and treat its infection due to a possible development of hemorrhagic colitis, hemolytic uremic syndrome and cerebral symptom. For that, several bacteriological detection methods are developed and some of them have been used in clinical microbiology laboratories. In this article, classical bacteriological methods, immunological methods and PCR for identification of enterohemorrhagic E. coli are reviewed and advantages as well as disadvantages of various methods are discussed.

Bacterial Toxins↗
PubMed1997

[Role of neutrophil elastase in allergen-induced airway microvascular leakage in sensitized guinea pigs].

To determine the role of neutrophil elastase in allergen-induced airway microvascular leakage, we assessed vascular permeability of guinea pig trachea by measuring the extravasation of Evans blue dye in the circulating blood. Inhalation of ovalbumin (OA) to guinea pigs sensitized with OA caused Evans blue extravasation, indicating an increased microvascular permeability. Pretreatment with ONO-5046 a specific inhibitor of neutrophil elastase, inhibited OA-induced vascular leakage in a dose-dependent manner. Tracheal instillation of human neutrophil elastase likewise increased microvascular permeability, and this effect was almost completely abolished by ONO-5046. Challenge with OA increased the number of neutrophils and neutrophil elastase activity in the bronchoalveolar lavage fluid, and these effects were inhibited by ONO-5046. These results suggest that neutrophil accumulation into the airway and the subsequent release of neutrophil elastase may play a role in the airway microvascular leakage produced by antigen challenge.

Animals↗
PubMed1997

Enterohaemorrhagic Escherichia coli.

Enterohaemorrhagic Escherichia coli produces Verotoxins (Shiga-like toxins) and causes diarrhoea, haemorrhagic colitis and haemorrhagic uraemic syndrome. The mode of action of the Shiga toxin family has been well characterized in numerous studies which have demonstrated that the toxin has RNA N-glycosidase activity, which inhibits the binding of EF-1-dependent aminoacyl-tRNA to the 60S ribosomal subunit of eukaryotic cells, thus resulting in an inhibition of protein synthesis of the cells. In 1996, an unexpectedly large number of outbreaks of food poisoning due to E. coli O157:H7 occurred in Japan. In addition, many sporadic cases of E. coli O157:H7 were also reported and a total of about 8400 patients were recorded during that year. In most of these cases, the food vectors could not be identified. The possibility of developing a candidate vaccine is also discussed in this article.

Bacterial Toxins↗