PubMed Health⌕ Search

Biomedical subjects

K Tsuchida

Publications and source records attributed to K Tsuchida.

At least 91 records · Page 5Linked to original sources
PubMed1997

Alpha-fetoprotein (AFP) levels in normal children.

Alpha-fetoprotein (AFP) is an important tumor marker for yolk sac tumor and hepatoblastoma in childhood. We have been using the graph of the normal range of serum AFP made by Tsuchida et al, when we evaluate the serum AFP levels in early infancy. We measured the serum AFP levels by an immunoradiometric assay in 163 normal infants under 2 years of age, in order to make a more precise graph. Our normal range was a little wider than that of Tsuchida et al. According to our graph, false-positive cases would be fewer. Referring to the half-lives of serum AFP levels in normal infancy is also useful, when it is difficult to evaluate the AFP level.

Age Factors↗
PubMed1997

Potassium currents in ventricular myocytes from genetically diabetic rats.

Our previous study demonstrated the longer duration of action potential in ventricular myocytes from genetically diabetic WBN/Kob rats without change in calcium channel density compared with age-matched controls [Tsuchida, K., H. Watajima, and S. Otamo. Am. J. Physiol. 267 (Heart Circ. Physiol. 36): H2280-H2289, 1994]. In the present study we examined the alteration of potassium currents, especially transient outward current, in ventricular myocytes of genetically diabetic WBN/Kob rats. WBN/Kob rats gradually develop hyperglycemia with aging and show some similarity to non-insulin-dependent diabetes mellitus models, which differ from the insulin-dependent streptozotocin-treated rat model. The density of the intracellular calcium ion-independent transient outward current (I(to)) from 17- to 19-mo diabetic rat myocytes was significantly smaller than that from age-matched control rat myocytes. In addition, the density of I(to) from 17- to 19-mo rat myocytes was significantly less than that from 2-mo rat myocytes, suggesting that aging-induced alteration of I(to) was accelerated by the diabetic state. The steady-state inactivation curves of I(to), the recovery from I(to) inactivation, and the other outward currents were not significantly altered between diabetic myocytes and age-matched control myocytes. In conclusion, the prolonged duration of action potential from genetically diabetic rat myocytes is mainly due to the depressed I(to).

Aging↗
PubMed1997

Detection of peptidoglycan and endotoxin in dialysate, using silkworm larvae plasma and limulus amebocyte lysate methods.

Silkworm larvae plasma (SLP) reagent is activated by peptidoglycan (PG), a fragment of both the gram-positive and gram-negative bacterial cell wall, as well as beta-glucan (BG), a component of fungi. It is possible to measure contamination of gram-positive bacteria quantitatively by combining the conventional limulus amebocyte lysate (LAL) and PG measurement methods. Therefore, a more highly accurate analysis of dialysate can be made using both SLP and LAL methods to detect endotoxin (ET) and/or PG contamination. We studied the effects of contaminated dialysate on human peripheral blood mononuclear cells (PBMC) by producing various cytokines in vitro. Muramyl dipeptide (MDP) was used as the biologically active minimum constituent of PG. A total of 54 dialysate samples were obtained under sterile conditions from 4 sites: (1) reverse osmosis water unit; (2) proportioning unit; (3) multiple dialysate preparation console, and (4) personal dialysate preparation console, at 9 dialysis facilities. To detect bacterial contamination, the samples were measured with LAL(C), LAL(G) and SLP methods. PBMC were collected from 10 healthy controls and from 10 hemodialysis patients and cultured for 24 h with ET, MDP, ET + MDP and contaminated dialysate. IL-1 receptor antagonist (IL-1Ra), IL-1 beta and TNF-alpha in the culture medium supernatants were measured using the ELISA method. PG was not detected in dialysate from sites 1 or 2. However, dialysate from the inlet of the dialyzer at the bedside monitor of the central supply and personal console showed 4.1 +/- 6.1 ng/ml for site 3 (in 7 of 18 samples) and 3.3 +/- 4.6 ng/ml for site 4 (in 3 of 18 samples). Contamination by PG alone and complex contamination by PG and ET were also detected. Furthermore, IL-1Ra, IL-1 beta and TNF-alpha production by PBMC increased in accordance with the concentrations of MDP. Cytokine production was enhanced 5-10 times more where MDP and ET coexisted than where either MDP or ET existed alone, showing the synergic effects of MDP and ET. Based on these results, there is a high possibility that PG may also be a pyrogen in the dialysate prior to this study. ET had been considered the only pyrogen in dialysate. Therefore, it is essential to recognize the existence of both ET and PG in investigating dialysate contamination.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1997

Effect of GK-128 [2-[(2-methylimidazol-1-yl)methyl]-benzo[f]thiochromen-1-one monohydrochloride hemihydrate], a selective 5-hydroxytryptamine3 receptor antagonist, on colonic function in rats.

We investigated the effects of various selective 5-hydroxytryptamine (5-HT)3 receptor antagonists, including GK-128 [2-[(2-methylimidazol-1-yl)methyl]benzo[f]thiochromen-1-one monohydrochloride hemihydrate], on colonic function. In conscious rats, 5-HT and a 5-HT3 receptor agonist, 2-methyl-5-HT, dose-dependently increased fecal pellet output, but another 5-HT3 receptor agonist, m-chlorophenylbiguanide, did not affect output. The selective 5-HT3 receptor antagonists GK-128, granisetron, ramosetron, azasetron and ondansetron depressed the increase in fecal pellet output caused by 2-methyl-5-HT and by wrap-restraint stress. However, the rank order of potency of antagonists in the two defecation models was not consistent with that for the von Bezold-Jarisch reflex. Although granisetron and ramosetron dose-dependently reduced the spontaneous excretion of fecal pellets, GK-128 did not affect it. These results suggest that GK-128 may be used for the treatment of stress-induced gastrointestinal dysfunction. Furthermore, the present results suggest that the 5-HT3 receptor involved in colonic motility may be different from the classically defined 5-HT3 receptor and/or that the regulation of colonic motility mediated by 5-HT3 receptors during stress may be different from normal physiological conditions.

Animals↗
PubMed1997

In vitro analysis of potency restriction during epiblast differentiation.

During mammalian gastrulation, posterior part of primitive ectoderm differentiates into subsets of mesoderm cells, the most proximal portion of which subsequently gives rise to vascular endothelial cells and hematopoietic cells. To analyze this process in which the potency of multipotent epiblast cells is restricted progressively into hematopoietic cell lineages, we have established a culture system that allows differentiation of epiblast cells as well as embryonic stem cells into hematopoietic cells. Using this culture system, we showed that all parts of epiblast tissues at early streak and late bud stages preserved hematogenic potency, while it was lost from anterior region at early head fold stages. However, this loss of hematogenic potency in the anterior region of the head fold stage embryo was reinduced by addition of activin in the culture. Moreover, in order to detect transitory stages of mesoderm cells that are the direct progeny of multipotent epiblast cells, we developed three monoclonal antibodies that are able to define distinct subsets of mesoderm cells in the gastrulating embryo. These results are discussed from a view of cell-mass based commitment.

Animals↗
PubMed1997

[A case report of sudden death after Bentall's operation (Piehler's modification) due to left coronary occlusion].

We encountered a rare complication after Bentall's operation (Piehler's modification) with the left coronary artery occlusion. A 56-year-old man admitted to our hospital to get the aortic reconstruction operation for the chronic dissecting aortic aneurysm (DeBakey type I) with 7 cm in diameter. We performed Piehler's modification procedure using a 26 mm and 8 mm woven Dacron tubes coated with gelatin, and 23 mm prosthetic valve (St. Jude Medical). He got well after 6-day intubation until he complained anterior chest pain suddenly on 22 postoperative day. He showed ventricular fibrillation on the second attack requiring resuscitation procedures. Emergent angiogram showed total occlusion of the left coronary artery. The percutaneous transluminal coronary angioplasty was performed only with temporal success. Autopsy revealed no thrombus in the grafts and no kinking of the tubes. We might have to use more anticoagulants during the respirator assisted period when the APTT was naturally prolonged from 120 to 160 seconds.

Aortic Dissection↗
PubMed1997

[An experiment in a new method of nursing education--the problem-based learning for prenatal nursing].

At the opening of lectures in 1995 on the Science of maternity Nursing in the Special Subjects of Nursing, a problem-based learning was tried as a new educating method in the unit of "Prenatal Nursing." In the present paper, reviewing the introduction/implementation of the method, subjects in the future are described. This process contained two major flows, one was the training of tutors in problem-based learning, including participating the workshop held at McMaster University, and the other was the preparation for the class at the introduction of the new educational method, such as the overall subject composition and the development of teaching materials of prenatal nursing and resources, etc. according to the procedures of the problem-based learning. As the results of the actual implementation, various different reactions in comparison with the lecture method were observed both in tutors and students. As the subjects hereafter, the following three points have been clearly elucidated, that is, in order to proceed the problem-based learning under the present condition that it is not in the comprehensive curriculum, to prevent the overload and conflict in the student learning, considering and adjusting the relationship with contents and methods of concurrent subjects and units, to establish the system for tutorial assessment and evaluation, and to insure tutors and fulfill their training system.

Curriculum↗
PubMed1996

Selective reduction of V alpha 14+ NK T cells associated with disease development in autoimmune-prone mice.

A novel peripheral T cell subset characterized by the expression of a NK marker and invariant TCR encoded by V alpha 14 J alpha 281 gene segments with a 1-base N-region was investigated in relation to autoimmune disease development. First, we observed that invariant V alpha 14+ NK T cells are specifically reduced with aging in C57BL/6 lpr/lpr or MRL lpr/lpr mice, whereas no change was observed in age-matched control C57BL/6 or MRL +/+ mice as determined by FACS analysis and RNase protection assay. This reduction precedes the disease development and could also be detected in other autoimmune disease-prone mice, such as C3H gld/gld and (NZB x NZW)F1 mice. These results suggest that the specific decrease in invariant V alpha 14+ NK T cells correlates strongly with the development of autoimmunity. Second, injection of MRL lpr/lpr mice with anti-V alpha 14 mAb resulted in the early onset and exacerbation of lymphosplenomegaly due to the accumulation of abnormal CD3+ B220+ CD4-CD8- T cells as well as an increase in the titers of anti-dsDNA autoantibodies. These results indicate that V alpha 14+ NK T cells regulate autoimmune responses and play a crucial role in controlling the development of autoimmune diseases.

Age Factors↗
PubMed1996

Molecular cloning of a novel type I receptor serine/threonine kinase for the TGF beta superfamily from rat brain.

Growth factors belonging to the TGF beta superfamily bind to and signal through a receptor complex comprising two transmembrane serine/threonine kinases, called type I and type II. Each receptor is responsible for the signaling of the individual TGF beta superfamily members. So far, five type II and six type I receptors have been cloned from mammalian sources. We report here the molecular cloning of a novel type I receptor serine/threonine kinase, ALK7 (activin receptor-like kinase 7), from rat brain. ALK7 shows a significant sequence similarity with TGF beta RI and ActRIB in the intracellular kinase domain and is quite distinct from other type I receptors in the extracellular domain. ALK7 mRNA is expressed in embryonic and in adult rat brain, where it was localized in superficial layers of the forebrain, the CA3 pyramidal subfield of hippocampus, the basal ganglia, the thalamus, and the cerebellar cortex. The functionality of the receptor was demonstrated by the identification of a constitutively active point mutant of ALK7 that activates the TGF beta/activin-responsive reporter without any ligand stimulation. Although the endogenous ligand for ALK7 has yet to be identified, its extensive anatomic distribution in brain, gut, spleen, and lung suggests important roles for this orphan receptor.

Activin Receptors↗
PubMed1996

Utilization of a mass-infusion system in the management of ruptured abdominal aortic aneurysms: an alternative application for devices employed in cardiopulmonary bypass.

To stabilize the hemodynamics before and during ruptured abdominal aortic aneurysmal repair, a mass-infusion system was developed and successfully employed in the treatment of two patients. The system consists of a combination of devices used in cardiopulmonary bypass, namely: suction, a reservoir, a heat exchanger, a bubble trap, and an intracaval large-sized venous femoral cannula for infusion. It proved extremely useful to tide the patients over hypovolemic shock before cross-clamping of the proximal aorta, preventing intraoperative hypothermia, which is known to cause multiple physiologic derangement associated with an adverse outcome. Moreover, the employment of a large-sized cannula allowed for a temporary switch from the preceding venous infusion support to the hypothermic circulatory assist with central aortic cannulation, using the caval cannula for drainage. This system provides an optional advantage for patients requiring an open proximal anastomosis.

Aneurysm, Ruptured↗
PubMed1996

A comparative study of the polymerase chain reaction and local antibody production in acute retinal necrosis syndrome and cytomegalovirus retinitis.

BACKGROUND: It has been thought that herpes viruses may play an important role in acute retinal necrosis syndrome (herpes simplex and varicella-zoster viruses) as well as in cytomegalovirus retinitis and it would be useful to know the specificity of the methods for detecting the viruses. METHODS: Amplification of the herpetic viral genome DNA by polymerase chain reaction (PCR) in aqueous and vitreous humor was compared with Goldmann-Witmer coefficients against herpetic antigens in five patients with acute retinal necrosis syndrome and in two patients with cytomegalovirus retinitis, using vitreous samples to determine the specificity of these diagnostic methods. RESULTS: The varicella-zoster virus genome DNA was amplified by PCR in four of the five patients with acute retinal necrosis syndrome, and cytomegalovirus genome DNA was enhanced in both patients with cytomegalovirus retinitis. Four patients who exhibited the varicella-zoster viral genome showed marked increase of the Goldmann-Witmer coefficient against varicella-zoster virus. Conversely, the two patients with cytomegalovirus retinitis showed no remarkable changes among the antigens. CONCLUSION: Our results showed that the amplification of the viral genome DNA in the samples by PCR is specific in both diseases, and that the increased level of local antibody production also is specific in varicella-zoster retinitis. In cytomegalovirus retinitis, however, antibody production against cytomegalovirus does not show increase of the Goldmann-Witmer coefficient.

Aged↗
PubMed1996

Ontogeny of striatal dopamine release in rats after acute administration of methamphetamine.

In the present study, we examined the effects of acute MAP administration on striatal extracellular levels of dopamine (DA) and its metabolites in groups of rats on postnatal days (PNDs) 14, 21, 28, and 56. A single injection of 4 mg/kg MAP (IP) induced increase in extracellular DA and decrease in extracellular 3,4-dihydroxyphenylacetic acid (DOPAC) in the striatal perfusates of rats on all PNDs examined. The magnitude of increase in DA concentrations at 20 min after the MAP injection was significantly smaller on PND 14 than PNDs 21, 28, and 56, whereas the magnitude of decrease in DOPAC concentrations after the MAP injection was significantly smaller on PND 14 than PNDs 21, 28, and 56. After the MAP injection, homovanillic acid levels decreased on PNDs 21, 28, and 56, but increased on PND 14. These results suggest that rats on PND 14 differ from those thereafter in MAP-induced DA release and changes in its metabolites, and that such developmental effect on MAP-induced DA release may be involved in the ontogeny of MAP-induced behavioral sensitization.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

Injection-incision--assisted snare resection of large sessile colorectal polyps.

BACKGROUND: It can be difficult, even for experienced endoscopists, to completely remove large sessile colorectal polyps. We attempted to remove large sessile colorectal polyps without complication and residual tumors. METHOD: Our new technique is characterized by submucosal pre-injection with a large volume of saline solution and then circumferential incision outside the lesion before resection using a special needle-tipped snare. The mean size of 33 polyps (including 9 elevated sessile, 20 flat nodular [villous], and 4 flat sessile polyps), was 4.0 cm (range, 3.0-8.5 cm). RESULTS: Twenty-five (76%) were resected piecemeal and the remainder as a single specimen. Mild to moderate bleeding occurred in 3 (9.1%), but there was no clinically significant bleeding or perforation. No residual or recurrent tumors were recognized. Invasive carcinoma was revealed most frequently (44%) in elevated sessile polyps; none occurred in flat nodular polyps. CONCLUSION: Our removal technique appears to be safe and effective. Flat nodular polyps of any size are a particularly good indication for removal by this technique.

Adult↗
PubMed1996

A new and efficient method for gene transfer into mouse FM3A cells using metaphase chromosomes by electroporation.

We introduced chromosome-mediated genes into mouse thymidine kinase-deficient FM3A (FM3Atk-) cells, by electroporation. The effects of some parameters on the electric shock-mediated transfection of FM3Atk- cells were investigated. Gene transfer of mouse L929 metaphase chromosome DNA into FM3Atk- resulted in a maximum frequency of (3.0 +/- 0.3) x 10(-5) at a cell density of 2.0 x 10(8)/ml and chromosome dosage of 5.0 x 10(7) cell equivalents/ml in a buffer containing 0.25 M mannitol, 0.5 mM MgCl2, 0.1mM CaCl2, and 1 mM Tris-HCl (pH 7.1). The highest yield of the transformants was obtained at an electric field strength of 1 kV/cm and a capacitance of 35 microF, with a single exponentially decaying pulse at 0 degrees C was optimal for post-shock incubation after electroporation. The tk gene was detected in the transformants by in situ hybridization analysis.

Animals↗
PubMed1996

Total obliteration of colonic lumen by localized giant inflammatory polyposis in ulcerative colitis: report of a Japanese case.

Although inflammatory polyposis of the colon is a recognized local complication of ulcerative colitis, giant inflammatory polyposis that totally obliterates the colonic lumen is uncommon, and most of the patients have been from Western countries. We report a Japanese man who had localized giant inflammatory polyposis that obstructed the retrograde flow of barium in a double-contrast barium enema study at the splenic flexure in ulcerative colitis. After resection by total proctocolectomy and ileostomy, pathological examination of the specimen confirmed localized giant inflammatory polyposis in the descending colon and spelnic flexure without malignancy.

Barium Sulfate↗
PubMed1996

[Hemodynamic plus series of St. Jude medical valve prosthesis in aortic position: early clinical outcome and reconsideration of its application].

St. Jude Medical Hemodynamic plus bileaflet valve prosthesis (HP) was employed in 7 cases undergoing aortic valve replacement since December 1993. Echocardiographic evaluation of left ventricular dimension and transvalvular pressure gradient was performed in 5 cases with 19 HP before and after operation. Each data was compared with those of 21 cases having undergone aortic valve replacement with 19 mm Standard model (19 SD). There was no significant postoperative change in left ventricular end-diastolic dimension (50 +/- 4 mm to 44 +/- 8 mm; p = NS) and left ventricular end-systolic dimension (34 +/- 4 mm to 34 +/- 9 mm; p = NS) in 19 HP cases. However, left ventricular end-diastolic dimension (51 +/- 11 mm to 41 +/- 8 mm; p < 0.05) and left ventricular end-systolic dimension (35 +/- 12 mm to 28 +/- 9 mm; p < 0.05) decreased in 19 SD cases. Transvalvular systolic peak pressure gradient was reduced significantly in both groups (19 HP: 94 +/- 38 mmHg to 43 +/- 19 mmHg; p < 0.05, 19 SD: 73 +/- 49 mmHg to 33 +/- 14 mmHg; p < 0.05). Poor reduction of left ventricular volume and high residual systolic pressure gradient in patients with 19 HP might be due to relatively high incidence of stenotic lesion in original aortic valve disease. In some cases with these critical aortic stenosis, radical annular enlargement procedure would provide more fundamental release of left ventricular outflow tract stenosis rather than one size increase of effective orifice area by employing HPs. Structural examination demonstrated that 19 HP had the same outer diameter of sewing flange with identical orifice ring as 21 SD (24 mm) did, and 17 HP had that of 19 SD (22 mm). Therefore, precise attention is needed for application of SJM-19 HP in patients with small aortic annuli.

Adolescent↗
PubMed1996

[Three-dimensional images of the cystic duct obtained with helical DIC CT].

Before laparoscopic cholecystectomy, it is important to clarify the anatomy of the cystic duct. This study assessed three-dimensional CT images (3D images) of the cystic duct obtained non-invasively using helical DIC CT and these images were compared with those obtained with ERCP and DIC. The three-dimensional technique using Helical DIC-CT was applied in 168 patients for laparoscopic cholecystectomy. The cystic duct detected by 3D imaging was evaluated for patency, length and bifurcation. Three-dimensional images showed the cystic duct in 157 of 168 cases (93.5%) and in 81 of 89 cases (91%) in which the cystic duct was not clearly visualized on DIC. Among the 23 cases in which were both 3D images and ERCP undergone, 3D images were equal to those of ERCP in detection of the cystic duct in 20 cases, superior to ERCP in two cases, and inferior to ERCP in one. The technique of 3D images proved useful in demonstrating the patency, length and variations in bifurcation of the cystic duct for surgeons performing laparoscopic cholecystectomy and might be substitute ERCP in preoperative assessment.

Cholangiopancreatography, Endoscopic Retrograde↗