Biomedical subjects

T Ueda

Publications and source records attributed to T Ueda.

At least 37 records · Page 2Linked to original sources

PubMed1992

An appraisal of patch enlargement of the small aortic annulus in 33 patients undergoing aortic valve replacement.

To avoid the problem of valve prosthesis/patient mismatch in the late postoperative period, we have adopted patch enlargement of the small aortic annulus in 33 patients having undergone aortic valve replacement since 1975, when the aortic annulus could not accept a large enough prosthesis. The mean age was 40 years, including 2 children aged 4. The technique of patch enlargement utilized was Nicks' method wherein the incision does not extend onto the mitral leaflet. In 31 adult patients, the aortic annulus before enlargement ranged in diameter from 18 to 24 mm with an average of 20.8 mm. After enlargement, the diameter of the annulus was 25.0 mm on average. In 2 children, the mean diameter of the annulus was enlarged from 16.5 mm to 20.5 mm. There were 2 early deaths in the initial series and 2 late deaths. Patch enlargement of the small aortic annulus is a simple, safe, and effective adjunct permitting the insertion of a valve one or two sizes larger than that which could be accommodated by the native annulus.

Adolescent↗

PubMed1992

Mutations of the 22- and 27-kD zein promoters affect transactivation by the Opaque-2 protein.

By utilizing a homologous transient expression system, we have demonstrated that the Opaque-2 (O2) gene product O2 confers positive trans-regulation on a 22-kD zein promoter. This trans-acting function of the O2 protein is mediated by its sequence-specific binding to a cis element (the O2 target site) present in the 22-kD zein promoter. A multimer of a 32-bp promoter fragment containing this O2 target site confers transactivation by O2. A single nucleotide substitution in the O2 target sequence not only abolishes O2 binding in vitro, but also its response to transactivation by O2 in vivo. We have also demonstrated that an amino acid domain including the contiguous basic region and the heptameric leucine repeat is essential for the trans-acting function of the O2 protein. Similar but not identical O2 target sequence motifs can be found in the promoters of zein genes of different molecular weight classes. Conversion of such a motif in the 27-kD zein promoter to an exact O2 target sequence by site-directed mutagenesis was sufficient to increase the binding affinity of the O2 protein in vitro and to confer transactivation by O2 in vivo.

Base Sequence↗

PubMed1992

Adenylate cyclase induces intracellular calcium increase in single human epidermal keratinocytes measured by fluorescence microscopy using Fura 2-AM.

Intracellular calcium ([Ca2+]i) is an important second messenger of extracellular signals to induce various cellular responses. Extracellular and intracellular Ca2+ are considered to be important for cellular differentiation and proliferation of epidermal keratinocytes. Several mechanisms which increase [Ca2+]i have been demonstrated in various tissues, but in epidermal keratinocytes these mechanisms are poorly understood. In epidermal keratinocytes the adenylate cyclase-cyclic AMP response is thought to regulate cell proliferation and differentiation. However, the series of reactions which follow the cyclic AMP response remain unknown. Beta-adrenergic agonists increase [Ca2+]i in cultured epidermal keratinocytes, and we have therefore studied whether stimulation of keratinocyte adenylate cyclase could induce [Ca2+]i increase, by using fluorescence microscopy with Fura 2-AM. Adenosine and histamine, which are known to be keratinocyte adenylate cyclase receptor agonists, induced transient [Ca2+]i increase, as did epinephrine. In addition, forskolin, a direct adenylate cyclase activator, and dibutyryl-cyclic AMP also induced an increase in [Ca2+]i. In a calcium-free medium epinephrine, adenosine, histamine and dibutyryl-cyclic AMP induced an increase in [Ca2+]i. These results suggest that cyclic AMP in human epidermal keratinocytes regulates [Ca2+]i, which is released from intracellular stores.

Adenosine↗

PubMed1992

Allergic contact dermatitis in shiitake (Lentinus edodes (Berk) Sing) growers.

A 42-year-old female shiitake grower was investigated to clarify the etiology of skin lesions which developed during the planting of shiitake hyphae into bed logs. She complained of repeated eczematous skin lesions during the planting season, from March to July, for 10 years. She handled 7,000 pieces of small conic blocks made of beech, with shiitake hyphae attached to their surface, per day, and 300,000 pieces altogether per season. She was positive on patch testing with extracts of shiitake hyphae. In contrast, female shiitake growers with skin lesions associated with work other than planting, and without skin lesions, were negative on patch testing to the hyphae. Moderate allergenicity was observed to extracts of shiitake hyphae in a guinea pig maximization test. These findings indicated the etiology of skin lesions in shiitake growers to be allergic contact dermatitis induced by shiitake hyphae.

Adult↗

PubMed1992

Comparative study of cisplatin and carboplatin on pharmacokinetics, nephrotoxicity and effect on renal nuclear DNA synthesis in rats.

To clarify the difference in nephrotoxicity between cisplatin and carboplatin, the pharmacokinetics of platinum, renal function and nuclear DNA synthesis in renal cortical and outer medullary cells were studied in rats which had received cisplatin or carboplatin. Male Sprague-Dawley rats were given either cisplatin or carboplatin intravenously at an equi-toxic dose (LD10 or LD50) and were killed at various times within 7 days after the injection. Cisplatin bound to plasma proteins more avidly than carboplatin. Much more platinum was detectable in the renal nuclei after cisplatin injection than after carboplatin injection. BUN and serum creatinine levels in the rats treated with 8.5 mg/kg of cisplatin were significantly higher than in those treated with 100 mg/kg of carboplatin. Cisplatin markedly suppressed the renal nuclear DNA synthesis both in vivo and in vitro, when compared with carboplatin. It is concluded that the differences in nephrotoxicity between cisplatin and carboplatin are related to their different inhibitory effects on nuclear DNA synthesis in the renal cells.

Animals↗

PubMed1992

Ultrastructural alterations and DNA synthesis of renal cell nuclei following cisplatin or carboplatin injection in rats.

To clarify the difference in nephrotoxicity between cisplatin and carboplatin, ultrastructural alterations and DNA synthesis of renal cell nuclei were studied in Sprague-Dawley rats which had received intravenously either cisplatin or carboplatin at an equitoxic dose. Twelve hours after cisplatin injection, nucleolar segregation accompanied by aggregated nuclear heterochromatin was observed in the third segment of the proximal tubules. Seventy-two hours after cisplatin injection, nuclear damage was more widespread while regenerative cells were also observed. Nuclear damage was not observed in the carboplatin-treated rats. Nuclear DNA synthesis of renal cells was suppressed at 8, 12 and 24 h and was accelerated at 72 h after cisplatin injection. Carboplatin did not suppress nuclear DNA synthesis at any time. The results indicate that cisplatin, but not carboplatin, can affect the renal cell nuclei. Cisplatin-induced nephrotoxicity is related to its effects on renal cell nuclei.

Animals↗

PubMed1992

Gastric polyposis caused by multifocal histiocytosis X.

A rare case of gastric polyposis caused by infiltration of Langerhans' cells is reported. A 53 year old Japanese woman complaining of vague abdominal discomfort, was found at endoscopy to have numerous polyps all over the gastric wall. An endoscopic biopsy specimen showed characteristic infiltration of Langerhans' cells in the lamina propria of the mucosa. Functional abnormalities such as impaired gastric acid secretion or malabsorption were not associated with this lesion and the patient was treated conservatively. During follow up over two years, she had a cutaneous eruption with infiltration of histiocytes and osteolytic lesions in the skull. However, no progressive changes occurred in the stomach. This probably benign self-limiting lesion of gastric histiocytosis X may be one of the manifestations of multifocal histiocytosis X, but its aetiology and appropriate treatment have not yet been determined.

Female↗

PubMed1992

Allergy to laboratory animals: an epidemiological study.

A large cross sectional survey was carried out using a self administered questionnaire to examine the prevalence of laboratory animal allergy (LAA) and the factors associated with its development. Out of 5641 workers who were exposed to animals at 137 laboratory animal facilities in Japan, 23.1% had one or more allergic symptoms related to laboratory animals. The commonest symptom as rhinitis. About 70% of LAA subjects developed symptoms during their first three years of exposure. Atopy (past and family history), the number of animal species handled, and the time spent in handling correlated significantly with the development of LAA as did some types of job. A close relation between nasal symptoms and exposure to rabbits and between skin symptoms and exposure to rats were found. LAA subjects developed symptoms most quickly to rabbits.

Adult↗

PubMed1992

Recent trends in bagassosis in Japan.

The only workers presently exposed to bagasse dust in Japan are the employees of sugar refineries and lacquerware factories. A follow up study of six former cases of bagassosis from among the retired employees of a paper board factory, closed since 1973, showed that none of the subjects still had bagassosis. Examinations of 70 employees of a sugar refinery for allergic reactions also showed no case of bagassosis. Seven cases with suspicious shadows of bagassosis on chest radiographs and four cases with positive serum precipitin to stored bagasse were, however, found among those 70 subjects. The results show the disappearance of a past episode of bagassosis and the possibility of a new occurrence of bagassosis among the employees of sugar refineries and lacquerware factories in the near future in Japan.

Adult↗

PubMed1992

Expression of peroxidase activity in rat tracheal epithelial cells associated with Mycoplasma pulmonis.

Endogenous peroxidase activity has not been localized in the tracheal mucosal epithelial cells of specific pathogen-free (SPF) rats. After natural infection with Mycoplasma pulmonis in SPF rats, peroxidase activity became localized to the endoplasmic reticulum, nuclear envelope, and Golgi apparatus of tracheal ciliated or mucous secretory cells. Some secretory cells occasionally had peroxidase-positive secretory granules. At 1 wk M. pulmonis was found to attach to these epithelial cells, which then showed positive peroxidase activity at 2 wk. Serum antibody titers against M. pulmonis were positive at 5 wk. These results suggest that virulent mycoplasma infection and interaction with the tracheal epithelial cells trigger the de novo expression of peroxidase activity, which seems to play a role in mucosal anti-microbial defense mechanisms.

Animals↗

PubMed1992

Intravesical therapy with adriamycin plus verapamil in patients with superficial bladder cancer: a pilot study.

Nineteen patients with histologically proven superficial bladder cancer (Ta, T1) were treated with intravesical instillation of 30 mg of adriamycin (ADM) dissolved in 24 ml physiological saline plus 15 mg of verapamil (VR) (6 ml) every day for 10 days. In spite of the short period of treatment, 6 of the 18 evaluable patients (33.3%) showed complete response (CR) and a further 5 (27.8%) showed partial response (PR). Five of the 6 patients with CR were recurrent cases who had previously received prophylactic intravesical instillation chemotherapy including ADM. Irritative urinary symptoms were observed in 11 of the 19 patients (57.9%). However, these symptoms were mild in the majority of patients and the treatment was completed without interruption in all but 1 patient. There was no significant absorption of ADM and VR into the systemic circulation. No clinical evidence of systemic toxicity was observed. These results suggest that combination of ADM and VR has a possibility to be a useful prophylactic intravesical instillation chemotherapy after endoscopic resection of not only primary but also recurrent chemoresistant bladder cancers.

Administration, Intravesical↗

PubMed1992

Renal cell carcinoma with unusual metastatic lesions detected by angiography.

The case of a patient with left renal cell carcinoma with two small metastatic lesions in the mesenterium and retroperitoneal fatty tissue is reported. These metastatic lesions were incidentally detected by preoperative routine angiographic examinations. The patient underwent left radical nephrectomy and resection of the metastatic nodules. The usefulness of angiography for detecting metastatic lesions and the possible metastatic pathways of these uncommon lesions are discussed.

Adipose Tissue↗

PubMed1992

Bellini duct carcinoma of the kidney.

Human epithelial cells of the kidney present a wide spectrum of cytological and histological variation. The normal epithelium of the kidneys also includes a number of morphologically and functionally different cell types which are arranged along the nephrons and collecting ducts. Although renal carcinoma can involve any type of renal cell, the most common is renal cell carcinoma of the proximal tubuli. Here, we present the case of a 65-year-old Japanese patient with a renal cell carcinoma arising from Bellini duct epithelial cells. State-of-the-art techniques were used to establish the diagnosis and histogenesis of this renal cell carcinoma.

Aged↗

PubMed1992

Idiopathic pulmonary fibrosis and high prevalence of serum antibodies to hepatitis C virus.

The prevalence of serum antibodies to hepatitis C virus (HCV) was assessed by an enzyme-linked immunosorbent assay (ELISA) in 66 patients (46 male and 20 female; mean age +/- SEM, 61.5 +/- 10.1 yr) with idiopathic pulmonary fibrosis (IPF). Nineteen (28.8%) were positive for this test. The frequency of HCV positiveness was significantly higher in the patients with IPF than in the 9,464 control subjects, whose ages were comparable with those of the patients (3.66%, p less than 0.05). Importantly, 12 of the 19 patients with IPF and positive ELISA results (63.2%) had positive results on the Chiron recombinant immunoblotting assay (RIBA), which is known to be more specific for HCV. We judged the 12 perceptible reactions as eight reactive and four indeterminate. When we examined liver function retrospectively, only two of eight patients who tested positive for the HCV had liver dysfunction, suggesting that anti-HCV positivity in IPF was not observed as a result of liver disease. These results lead us to speculate that HCV infection may play an important role in the pathogenesis of IPF, or that the sera of patients with IPF may contain some antibody against an unknown epitope and cross-react with the anti-HCV assay.

Aged↗

PubMed1992

Hypersensitivity pneumonitis in athymic nude mice. Additional evidence of T cell dependency.

We previously demonstrated that C57 Black/6 mice develop lung lesions similar to human hypersensitivity pneumonitis (HP) by repeated transnasal administration of Thermoactinomyces vulgaris (Tv) antigen. To elucidate the role of T cells in the development of this disease, Tv antigen (90 micrograms/day) was transnasally administered to athymic nude C57 Black/nu/nu (nu) mice and their littermates (+/nu) three times a week for 3 wk. The nude mice developed minimal lung lesions, whereas their thymus-intact littermates (+/nu) showed changes equivalent to those in C57 Black/6. Changes in local inflammatory cell responses were evaluated by bronchoalveolar lavage, and increases in the numbers of lymphocytes and macrophages were significantly less severe in the nude mice than in the +/nu mice. Interestingly, the increase in polymorphonuclear leukocytes 6 h after the last antigen inoculation was equivalently seen in both groups. When spleen-derived T cells (more than 95% Thy-1.2+) from the sensitized +/nu mice were adoptively transferred to nude mice, the HP-like lesions in the recipients were found after Tv antigen challenge. These results suggest that Thy-1.2+ T cell-mediated immunity was necessary for the development of HP in this murine model.

Alveolitis, Extrinsic Allergic↗

PubMed1992

Protective effect of a microtubule stabilizer taxol on caerulein-induced acute pancreatitis in rat.

The effect of taxol, which is a microtubule stabilizer, was examined in a model of acute edematous pancreatitis induced in rat by the administration of caerulein. Prophylactic administration of taxol ameliorated inhibition of pancreatic secretion, increased level of serum amylase, pancreatic edema, and histological alterations in this model. Immunofluorescence studies revealed that taxol stabilized the arrangement of microtubules by the action of promoting tubulin polymerization and prevented inhibition of pancreatic digestive enzyme secretion. In isolated rat pancreatic acini, taxol reversed the inhibition of amylase secretion induced by supramaximal concentrations of cholecystokinin octapeptide and did not affect the binding of cholecystokinin octapeptide to its receptor. The results obtained in this study suggest that microtubule disorganization is the initiating event in caerulein-induced pancreatitis and that the inhibition of pancreatic digestive enzyme secretion by interfering with intracellular vesicular transport due to microtubule disorganization causes caerulein-induced pancreatitis.

Acute Disease↗

PubMed1992

Parental methylation patterns of a transgenic locus in adult somatic tissues are imprinted during gametogenesis.

The methylation status of a mouse metallothionein-I/human transthyretin fusion gene was studied during gametogenesis in transgenic mice. In the adult tissues of this mouse line, the promoter region of the transgene on chromosome 11 is methylated when it is maternally inherited and undermethylated when it is paternally inherited. Germ cells from various developmental stages of gametogenesis were isolated, and their DNAs were assayed using methylation-sensitive restriction endonucleases and the polymerase chain reaction. Only low to nonexistent levels of transgene methylation were detected in germ cells from 14.5-day-old male and female fetuses irrespective of the parental origin of the transgene. This undermethylated state persisted in oocytes from newborn females as well as in testicular spermatogenic cells and sperm. By contrast, the transgene promoter was completely methylated in fully grown oocytes arrested at the first meiotic prophase. The endogenous metallothionein-I gene promoter, located on a different chromosome, remained undermethylated at all stages examined, consistent with previous findings reported for a typical CpG island. Taken together, the results suggest that parental-specific adult patterns of transgene methylation are established during gametogenesis.

Animals↗

PubMed1992

Methylprednisolone reduces the nephrotoxicity caused by cisplatin.

Male Sprague-Dawley rats were given either 6.5 or 8.5 mg/kg of iv cisplatin combined with three injections of sc methylprednisolone in doses of either 50, 100 or 250 mg/kg at -4, 0 and 4 h after the cisplatin injection. Blood urea nitrogen and serum creatinine levels were determined on day 5 following the cisplatin injection. The protective effects of methylprednisolone on cisplatin-induced nephrotoxicity were clearly demonstrated. Our preliminary results suggest that a much higher dose of cisplatin could be injected in cancer chemotherapy, if it was combined with methylprednisolone.

Animals↗