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Biomedical subjects

T Masuda

Publications and source records attributed to T Masuda.

At least 307 records · Page 17Linked to original sources
PubMed1995

[Intravesical instillation of pirarubicin for a patient with bladder cancer and chronic renal failure: a case report].

The patient was a 71-year-old woman. Two years ago right nephrectomy was performed by a general surgeon at the diagnosis of right renal cell carcinoma. However, the pathological report was transitional cell carcinoma (TCC) of the right renal pelvis, Grade II. She developed chronic renal failure and received hemodialysis once a week. The recurrence of bladder tumor was recognized and she was transferred to our hospital. Transurethral resection of bladder tumor (TUR-Bt) and right ureterectomy with a bladder cuff were performed. Also intravesical instillation of pirarubicin was done after the operation. No side effects or elevation of serum pirarubicin level were observed.

Administration, Intravesical↗
PubMed1995

[The effects of low dose clonidine on perioperative hemodynamics and anesthetic requirements in elderly patients].

The effects of clonidine, alpha 2-adrenergic receptor agonist, on perioperative hemodynamics and anesthetic requirements were studied in randomized 20 elderly patients without hypertension (ASA I-II) scheduled for elective abdominal surgery under general anesthesia. The control group (n = 10) was premedicated with oral diazepam 0.1 mg.kg-1 90 min prior to arrival in the operating room. The clonidine group (n = 10), in addition, received clonidine approximately 2.5 micrograms.kg-1 orally at the same time. Anesthesia was induced with fentanyl 2 micrograms.kg-1 and thiamylal 4 mg.kg-1. Vecuronium 0.15 mg.kg-1 following 0.01 mg.kg-1 priming dose was used to facilitate endotracheal intubation. Anesthesia was maintained with isoflurane in 50% nitrous oxide-oxygen and supplementary fentanyl. Clonidine effectively attenuated the cardiovascular response associated with laryngoscopy and tracheal intubation. Intraoperative variability of heart rate was significantly lower in patients receiving clonidine compared with controls. No significant differences in the requirements of either isoflurane or narcotic supplementation were observed between the two groups. We conclude that a low dose clonidine is a useful adjunct in the management of elderly patients without producing side effects.

Abdomen↗
PubMed1995

Breakdown of self-tolerance by intrathymic injection of a T-cell line inducing autoimmune gastritis in mice.

Autoimmune gastritis (AIG) develops spontaneously in BALB/c mice thymectomized 3 days after birth (3d-Tx). We first confirmed our previous observations that CD4+ splenic T cells in AIG mice induced AIG in nu/nu mice, while those in normal mice suppressed the development of the disease. In addition, we found that a quantitative balance between these effector (Te) and suppressor (Ts) T cells determined either onset or prevention of the disease. Peripheralization of Ts seemed to begin around 3 days after birth, since the incidence of AIG in mice that underwent Tx 6 days after birth (6d-Tx) decreased markedly, compared with that of 3d-Tx mice; 12% in the former, while 79% in the latter. Notably, Ts existed in the 6d-Tx mice that escaped AIG. We next examined the target specificity of such Ts using syngeneic parietal cells known as autoantigens and two kinds of T-cell lines established from an AIG mouse; one is gastritis inducible in vivo, termed A-II, while another is not, named AC-II. Intrathymic injection of parietal cells into mice 3 days after birth followed by 6d-Tx completely prevented the development of AIG. In contrast, injection of irradiated A-II, but not AC-II cells resulted in AIG in 67% of the mice. No autoimmune oophoritis (AIO) was induced in female mice, implying that the breakdown of tolerance is organ specific. Taken together, peripheral tolerance for organ-specific autoantigens seems to be maintained by CD4+ Ts responding to Te, which induces the disease.

Animals↗
PubMed1995

Cross-bridge activation rate constant determined from systolic time intervals in patients with systemic lupus erythematosus.

Cardiac adrenergic activity was investigated in 38 patients with systemic lupus erythematosus (SLE) who were not receiving cardiovascular agents using a new index of the adrenergic tone of the working left ventricular (LV) myocardium and using the heart rate to represent sinus node adrenergic tone. According to the active cross-bridge model employed in this study, the cross-bridge activation rate constant (Ka) of the LV myocardium, corresponding to the rate constant for the binding of Ca2+ to troponin C, can be approximately expressed as Ka = 3/electromechanical systole (sec-1). The Ka value corrected for heart rate (Kac) remains nearly constant in normal individuals, but is increased without change of the heart rate by dobutamine infusion. Fifty patients who fulfilled the American Rheumatism Association criteria for SLE underwent echocardiography, as well as simultaneous recording of the electrocardiogram, phonocardiogram, and carotid pulse wave tracing. Kac was calculated from the interval between the onset of the QRS complex to the second heart sound (QS2 interval) and the heart rate (HR) as follows: Kac = 3/QS2 + 0.0249 (66-HR). The 38 SLE patients were divided into a normal Kac group (n = 26, 6.9 < Kac < 8.3 sec-1) and a high Kac group (n = 12, Kac > or = 8.3 sec-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Epilepsia partialis continua with an epileptic focus demonstrated by PET and unique MRI findings: report of a case].

We reported a 31-year-old woman with epilepsia partialis continua (EPC) whose epileptic focus was delineated by PET. Neurologic examination revealed EPC in the face around the corner of her mouth, her thumb and forefinger on the left, slight exaggeration in the left biceps brachii reflex, and the digiti quiniti sign on the left. Laboratory tests showed pancytopenia, positive anti-nuclear and anti-DNA antibodies and decreased levels of serum complements, being consistent with systemic lupus erythematosus (SLE). Electroencephalogram showed paroxysmal discharges over the right frontoparietal region. PET with 2-18F-fluoro-2-deoxy-D glucose (FDG) clearly demonstrated a hypermetabolic area in the right frontoparietal cortex. T2-weighted images in MRI revealed reversible high signal intensity area in the right insula, postcentral gyrus and angular gyrus, while there were no abnormal findings in T1-weighted images with or without Gd-DTPA. There are only a few reports of EPC with the epileptic focus delineated by PET. Since a focal increase in glucose metabolism observed in them as well as in the present patient is a consistent indicator of the epileptic focus, the PET study is likely to provide significant information available not only for the diagnosis but also for the treatment of the condition. Finally, to our knowledge, this is the first patient with SLE presenting EPC. It is important to realize that vasculopathy associated with SLE may cause EPC and brain lesions with reversible high signal intensities shown by MRI.

Adult↗
PubMed1995

Quantification analysis of translation initiation signal sequences in vertebrate mRNAs.

The signal for directing the position of translation initiation in vertebrate mRNAs requires not only ATG initiation codon but also sequences flanking the initiation codon. A consensus sequence, (GCC) GCC (A or G) CCATGG has been proposed for the signal, but actual initiation sequences differ from it in a greater or lesser degree. In the present report, the translation initiation signal sequences of rat preproinsulin mRNA and its mutant mRNAs were analyzed using a quantification method, which demonstrates that strength of the signal plays important role in determining efficiency of initiation reaction.

Animals↗
PubMed1994

Multiple proline substitutions cumulatively thermostabilize Bacillus cereus ATCC7064 oligo-1,6-glucosidase. Irrefragable proof supporting the proline rule.

Nine residues of Bacillus cereus ATCC7064 oligo-1,6-glucosidase were replaced stepwise with proline residues. Of the nine residues, Lys121, Glu208 and Glu290 were at second sites of beta turns; Asn109, Glu175 and Thr261 were at N-caps of alpha helices; Glu216, Glu270 and Glu378 were in coils within loops. The replacements were carried out in the order, Lys121-->Pro, Glu175-->Pro, Glu290-->Pro, Glu208-->Pro, Glu270-->Pro, Glu378-->Pro, Thr261-->Pro, Glu216-->Pro and Asn109-->Pro. The resultant nine active mutant enzymes contained 1-9 more proline residues than B. cereus oligo-1,6-glucosidase. The thermostability of these mutants was additively enhanced with the increase in the number of proline residues introduced. The increase in the thermostability was most remarkable when proline residues were introduced at second sites of beta turns or at N-caps of alpha helices. The above results afforded irrefragable proof for the proline rule as an effective principle for increasing protein thermostability [Suzuki, Y., Oishi, K., Nakano, H. & Nagayama, T. (1987) Appl. Microbiol. Biotechnol. 26, 546-551].

Amino Acid Sequence↗
PubMed1994

Development of intestinal intraepithelial T lymphocytes is independent of Peyer's patches and lymph nodes in aly mutant mice.

We have previously reported a new spontaneous recessive mutation that induces a generalized lack of lymph nodes (LNs) and Peyer's patches (PPs) accompanied by immunodeficiency in mice (gene symbol, aly). In this study, we have analyzed gut-associated lymphatic tissues of the mutant aly/aly mice and have compared the intestinal intraepithelial T lymphocytes (IEL) in aly/aly and normal aly/+ littermate mice. Immunohistochemical studies revealed that colonization of IEL and lamina propria T cells takes place in the absence of PPs and IgA-producing B cells in the lamina propria. Absolute numbers of Thy-1- IEL-alpha beta and -gamma delta are not altered in aly/aly mutant mice, whereas absolute numbers of Thy-1+ IEL-alpha beta and -gamma delta in aly/aly mice are about half of those in aly/+ mice. In IEL-alpha beta from aly/aly mice, the major CD8 alpha alpha+ and CD8 alpha beta+ subsets are maintained, whereas CD4+ and CD4+, CD8+ subsets are reduced. Although the population size of major CD8 alpha alpha+ and CD4-, CD8- IEL-gamma delta subsets is slightly reduced, the use of TCR-gamma- and -delta-chain variable gene segments by IEL-gamma delta remains almost the same in aly/aly mice. The constitutive cytolytic activity of IEL-alpha beta and -gamma delta is attenuated sharply in the aly/aly condition. This activity is, however, augmented significantly after in vitro stimulation with anti-CD3 mAb. These results indicate that most of the IEL subpopulations develop independently of passage through PPs and mesenteric LNs and that the aly mutation interrupts cytotoxic IEL development during relatively late differentiation steps that convert cytotoxic precursors to the constitutively cytolytic state.

Animals↗
PubMed1994

Molecular cloning and characterization of yeast rho GDP dissociation inhibitor.

We have previously isolated rho GDP dissociation inhibitor (rho DGI) from bovine brain and characterized it. Bovine rho GDI is a protein of a M(r) of 23,421 with 204 amino acids. rho GDI inhibits the GDP/GTP exchange reaction of post-translationally lipid-modified small GTP-binding proteins (G proteins) of the rho family, including the rho, rac, and cdc42 subfamilies, and keeps them in the GDP-bound inactive form. In the present study, we first purified rho GDI from the cytosol fraction of the yeast Saccharomyces cerevisiae and isolated its gene. Yeast rho GDI gene had an open reading frame without introns encoding a protein of a M(r) of 23,138 with 202 amino acids. Yeast rho GDI protein was 36% identical with bovine rho GDI. Yeast rho GDI expressed in Escherichia coli was active not only on yeast rho1 but also on mammalian rho family members which were post-translationally modified. Disruption of rho GDI did not induce apparent phenotypes, whereas overexpression of yeast or bovine rho GDI resulted in the inhibition of cell growth. These results indicate that rho GDI exists and regulates the function of the rho family members in yeast.

Amino Acid Sequence↗
PubMed1994

Pharyngoesophageal pressure in patients with swallowing disorders.

We developed and tested a pressure transducer to correctly determine swallowing pressure at different sites in the pharynx. In normal individuals three pressure peaks were obtained in the mesopharynx, hypopharynx and cervical esophagus, respectively. A patient with central dysphagia demonstrated markedly low mesopharyngeal and hypopharyngeal swallowing pressure. One tongue cancer patient who had undergone right hemiglossectomy, including partial resection of the root of the tongue and bilateral superior neck dissection, had markedly low swallowing pressure in the mesopharynx and vallecula area. Another supraglottic cancer patient treated by supraglottic horizontal partial laryngectomy showed extremely low swallowing pressure in the supraglottic area. Based on our findings, we suggest that measurements using a pressure transducer such as the one described here should be used in combination with radiographic study to diagnose swallowing anomalies correctly. Data obtained with the pressure transducer will allow the clinician to identify the site responsible for postoperative dysphagia as well as its severity, and facilitate planning of reconstructive surgery when required.

Adult↗
PubMed1994

Left ventricular motion after bypass operation for coronary artery disease with collaterals.

Left ventricular ejection changes obtained from left ventricle roentgenograms were analyzed before and after coronary artery bypass grafting in 22 consecutive patients with chronic obstructive left anterior descending coronary artery disease receiving collaterals before surgical revascularization. The collateral vessels all disappeared after surgical revascularization. After operation, ejection changes of anterobasal, anterolateral and apical walls supplied by the left anterior descending coronary artery improved from 43.6% +/- 9.7% to 48.5% +/- 8.6% (p < 0.05), from 35.2% +/- 10.9% to 39.4% +/- 9.5% (p < 0.05), and from 46.0% +/- 10.6% to 50.0% +/- 8.7% (p < 0.05), respectively. The improvement in left ventricular wall motion did not appear to be related to the extent of preoperative collateralization. Thus, left ventricular wall motion was impaired in the area supplied by collaterals and was improved by myocardial revascularization. These results suggest that coronary blood flow, even through well-developed collaterals, may not be sufficient, which may produce chronic active ischemia and impaired left ventricular wall motion.

Aged↗
PubMed1994

A conserved epitope on H+,K(+)-adenosine triphosphatase of parietal cells discerned by a murine gastritogenic T-cell clone.

BACKGROUND/AIMS: H+,K(+)-adenosine triphosphatase (H+,K(+)-ATPase) of parietal cells is an organ-specific enzyme recognized by autoantibodies found in human and murine autoimmune gastritis (AIG). Murine AIG can be induced in BALB/c mice by thymectomy 3 days after birth and is a T cell-mediated disease. This study examined the specificity of T cells that cause AIG and the role of H+,K(+)-ATPase in this disease. METHODS: From an AIG mouse, a gastritogenic T-cell clone (II-6) was established, and its reactivity to synthetic peptides of H+,K(+)-ATPase was tested. RESULTS: II-6 cells are CD4+, V beta 14+, and interferon gamma producers. Adoptive transfer of II-6 cells to syngeneic nude mice resulted in AIG without the production of autoantibodies to parietal cells. The II-6 cells were responsive not only to murine but also to human and porcine parietal cells. Their proliferation was also induced by amino acids 891-905 (alpha 891) and 892-906 (alpha 892) of the alpha subunit of porcine and human H+,K(+)-ATPase, respectively. CONCLUSIONS: The T-cell response to a single epitope of H+,K(+)-ATPase, the amino acid sequence of which is conserved among at least three mammals tested, is sufficient to cause AIG. Autoantibodies to parietal cells are not detected in these AIG mice.

Amino Acid Sequence↗
PubMed1994

Electrophysiological and behavioral studies of taste discrimination in the axolotl (Ambystoma mexicanum).

Electrophysiological and behavioral experiments were performed to determine whether the taste system of the aquatic salamander, axolotl, discriminates taste stimuli. Taste responses were recorded extracellularly from the glossopharyngeal nerve bundle. The behavioral responses of axolotls towards various concentrations of NaCl, KCl, citric acid, quinine-hydrochloride, and sucrose were quantified by measuring the ratio of rejection towards gel pellets, each containing either unitary stimuli or binary mixtures of these chemicals. Rejection ratios [rejection/(rejection+swallowing)] towards the unitary stimuli except sucrose increased with concentration, but were not a single function of the magnitude of neural response induced by the stimuli. Degree of rejection was different depending on the quality of taste stimuli, suggesting that information processing of taste quality occurs in axolotls. The potential of NaCl to induce positive feeding behavior (swallowing) was suggested by a reduction in the rejection ratio of quinine-tainted pellets when they were mixed with 100 mM NaCl. Differential behavioral responses to quinine and NaCl show that axolotls have the ability to discriminate the taste quality of these stimuli.

Ambystoma mexicanum↗
PubMed1994

Use of vascularized corticoperiosteal flap from the femur for reconstruction of the orbit.

The reconstruction of small and thin defects in the orbital area using vascularized cortex is described herein. This vascularized cortex is taken from the medial supracondyle area of the femur because a small, thin, and flexible bone can be harvested. We have treated 5 patients with orbital bony defects that would have been difficult to reconstruct using conventional free bone grafts. All flaps took perfectly, the results were satisfactory, and no functional loss occurred in the donor site. The advantages of this bone flap include rich vascularity, a long vascular pedicle of about 7 cm, easy flap elevation, and the ability to include a saphenous flap. The thinness and flexibility of the bone flap make it a suitable vascularized bone donor site for treating small, flat craniofacial bony defects such as in the orbital area.

Adult↗
PubMed1994

Acute febrile neutrophilic dermatosis (Sweet's syndrome) associated with extreme infiltration of eosinophils.

A remarkable infiltration of eosinophils was observed in skin biopsy specimens in two cases of Sweet's syndrome. One patient was a 29-year-old woman, whose clinical and histological features included associated asthma, a prior respiratory tract infection, red plaques, blood eosinophilia, and a dense dermal infiltrate of neutrophils and eosinophils, without evidence of vasculitis. The other patient was a 61-year-old man characterized by a fever, red plaques, erythema nodosum-like lesions, hepatic dysfunction, a dermal infiltrate of neutrophils accompanied by eosinophils, and a subcutaneous prominent infiltrate of eosinophils. Clinical and histological evidence supported the diagnosis of Sweet's syndrome in both of these patients. While the literature describes eosinophil infiltration in this disease, extreme eosinophil infiltration could be misleading in the diagnosis.

Adult↗