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Y Adachi

Publications and source records attributed to Y Adachi.

At least 325 records · Page 18Linked to original sources
PubMed1999

Convenient murine pneumoperitoneal model for the study of laparoscopic cancer surgery.

To investigate the effects of laparoscopic surgery on the progression of cancers, it is necessary to establish a reliable and economical animal model. We describe a convenient murine pneumoperitoneal model for the study of laparoscopic cancer surgery. Under anesthesia using diethyl ether, peritoneal cavity was insufflated with gas through an intravenous catheter placed in the left lower quadrant. Syringe pump was used for continuous gas insufflation, and intraperitoneal pressure was measured. Intraperitoneal pressure increased and reached 10 cm H2O when 15 mL of CO2 gas was injected, but fell to 1 cm H2O 5 min after stopping the injection. When the continuous flow was adjusted by syringe pump between 20 and 160 mL/hour, intraperitoneal pressure was easily maintained at 8 cm H2O for >60 min. We believe that this murine model for pneumoperitoneum may be useful for the study of laparoscopic cancer surgery.

Animals↗
PubMed1999

A disposable sealing device (Dispo-sand) for conversion between pneumoperitoneum and minilaparotomy.

During laparoscopic procedures, minilaparotomy is a safe technique for removal of large specimens and for the performance of complicated procedures. However, it is time consuming and troublesome to close the minilaparotomy to recreate the pneumoperitoneum. We describe a new device (Dispo-sand) that enables instant conversion between pneumoperitoneum and minilaparotomy.

Disposable Equipment↗
PubMed1998

Applicability of Fractals to the Analysis of the Projection of Small Flocs.

The validity of the concept of fractal structure for the analysis of the projection of small flocs was examined using the data obtained from a table-tennis-ball simulation and a coagulation experiment with polystyrene latex particles. Two methods defining a fractal dimension, the box-counting technique and the enumeration of primary particles in an enclosing circle as a function of the radius, were tested for the result of numerical simulations. Comparison of the two results revealed their qualitative tendencies and the limits of their applicability. The projection of flocs was also examined using the relation between the maximum distance in the projected floc, Dm, and the number of primary particles composing the floc, i. The decrease of fractal dimension, D, in the lower limit of i was demonstrated both numerically and experimentally. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Molecular characterization of a newly identified heme-binding protein induced during differentiation of urine erythroleukemia cells.

A heme-binding protein with a molecular mass of 22 kDa, termed p22 HBP, was purified from mouse liver cytosol, using blue Sepharose CL-6B. We identified a cDNA encoding p22 HBP, and sequence analysis revealed that p22 HBP comprises 190 amino acid residues (Mr 21,063) and has no homology to any other known heme-binding protein. The p22 HBP mRNA (approximately 1.0 kilobases) is ubiquitously expressed in various tissues and is extremely abundant in the liver. cDNA allows for expression of active p22 HBP, with a high affinity for 55Fe-hemin, with a Kd of 26 +/-1.8 nM. The Bmax of hemin binding to p22 HBP was 0.55 +/- 0.021 mol/mol of protein, a value consistent with one heme molecule binding per molecule of protein. The order of potency of different ligands to compete against 55Fe-hemin binding to p22 HBP was hemin = protoporphyrin IX > coproporphyrin III > bilirubin > palmitic acid > all-trans-retinoic acid. Treatment of mouse erythroleukemia (MEL) cells with dimethyl sulfoxide or hemin resulted in an increase in p22 HBP mRNA. The immunoblot analysis showed that p22 HBP increased with time in dimethyl sulfoxide- and hemin-induced MEL cells. Conversely, transfer of antisense oligonucleotides to p22 HBP cDNA resulted in a decrease of p22 HBP in dimethyl sulfoxide-treated MEL cells, and the heme content in these cells decreased to 66-71% of sense oligonucleotides-transferred cells. Thus, this newly identified heme-binding protein, p22 HBP, may be involved in heme utilization for hemoprotein synthesis and even be coupled to hemoglobin synthesis during erythroid differentiation.

Amino Acid Sequence↗
PubMed1998

Effect of Ionic Strength on the Initial Dynamics of Flocculation of Polystyrene Latex with Polyelectrolyte.

The effect of ionic strength on the kinetics of flocculation of polystyrene latex (PSL) particles induced by addition of excess polyelectrolyte was studied. The flocculation experiment was performed in the standardized mixing flow generated by using an end-over-end rotation apparatus and by changing the ionic strength and polyelectrolyte concentration. We focused our attention on the initial process of flocculation, which is characterized by a remarkably high rate of flocculation (the first stage) followed by an abrupt decrease in the flocculation rate (the second stage). The combined measurements of the rate of flocculation and the electrophoretic mobility as a function of mixing steps revealed a transient state of polyelectrolyte adsorbing on the bare surface of PSL particles. Under the conditions of low ionic strength, the picture is consistent with that of kinetically controlled adsorption of polyelectrolyte, while, under high ionic strength, the evidence of kinetically controlled adsorption disappeared. However, even in the latter, the rate of flocculation in the first stage was a function of polyelectrolyte concentration. This is consistent with a picture of nonequilibrium flocculation. A crossover with respect to ionic strength can be ascribed to an increase in flexibility of polyelectrolytes at colloidal surfaces with an increase in ionic strength. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Decreased expression of the metastasis suppressor gene KAI1 in gastric cancer.

KAI1 was immunohistochemically detected in the lower part of fundic glands and intestinal metaplasia in non-cancerous gastric tissues, while only 11.0% (8/73) of cancerous tissues were shown to be positive. The relationship between various clinicopathological characteristics of patients with gastric cancer and KAI1 expression in their tumors was then analyzed to reveal that the incidence of positivity was 16.6% (8/48) of patients with stage Ia-IIIa and 0% (0/25) of patients with stage IIIb-IVb (P < 0.05) and that the incidence of peritoneal or hepatic metastasis tended to be lower in KAI1-positive tumors than in negative ones. These results suggest that decreased KAI1 expression may be related to the progression of gastric cancer.

Adenocarcinoma↗
PubMed1998

A strategy for organ allografts without using immunosuppressants or irradiation.

A strategy to achieve regular and long lasting organ and tissue allografts without using immunosuppressants and/or irradiation has been established for mice. One hundred percent of skin allografts can be induced to survive >350 days after transplantation if spleen cells from the same donors are first injected into the portal vein of the recipients. The mechanisms underlying this long-term tolerance induction can be described as follows: (i) donor T cells from the spleen of the donor facilitate the acceptance of the allogeneic engraftment, (ii) donor-specific anergy is induced in the cytotoxic T-lymphocytes of the recipients, (iii) T helper type 2 cells become the dominant T cells in the recipients that are accepting the skin transplants, and (iv) a lasting chimerism (microchimerism) is established in these recipients. This strategy, perhaps with minor modifications, might permit one also to overcome major barriers to organ allografting in humans. If this were the case, it could represent production of long lasting immunologic tolerance without need for irradiation or cytotoxic chemo-preparative regimen and as such could greatly facilitate allotransplantation free of episodes of chronic or acute rejection or toxic and damaging preparatory regimens.

Adoptive Transfer↗
PubMed1998

Paget's Disease of the Breast: Report of Five Cases and Review of the Japanese Literature.

Five cases of Paget's disease of the breast are presented, and 76 cases reported in the Japanese literature are analyzed. Paget's disease of the breast is often confined to the nipple-areolar complex(68%), and the duration of symptoms issometimes more than 5 years(25%). Paget's disease without palpable tumor in theunderlying breast is characterized by a low incidence of invasive ductal carcinoma(8%), lymph node metastasis(8%), and stage II or greater disease(0%). These cases indicate that Paget's disease without palpable breast tumor has less aggressive behavior and more benign course than that with palpable breast tumor, and local excision and/or radiation therapy may be an alternative to mastectomy as the initial treatment.

Journal Article↗
PubMed1998

Contribution of CR3 to nitric oxide production from macrophages stimulated with high-dose of LPS.

The contribution of the complement receptor type 3 (CR3) to nitric oxide (NO) production from macrophages stimulated by LPS was investigated. When thioglycollate-elicited mouse peritoneal macrophages were stimulated with a high dose of LPS (10 micrograms/ml) in both the presence and absence of fetal calf serum, a source of LPS binding protein (LBP) necessary for the binding of LPS to CD14, NO production was observed. These findings suggest that CD14-dependent and CD14-independent signaling pathways for NO production are present in macrophages. Because binding and phagocytosis of bacteria by macrophages through the CR3 has been previously reported, we investigated whether the CR3 acts in CD14-independent signaling pathway for NO production. By flow cytometric analysis, the binding of FITC-labeled anti-CR3 monoclonal antibody (anti-CR3 mAb) to macrophages was inhibited by LPS. Anti-CR3 mAb induced iNOS protein and produced NO in a dose dependent manner. Further, NO production induced by anti-CR3 mAb was also inhibited by zymocel, beta-glucan with a high affinity to CR3. These results suggest that the CR3 molecule acts in a CD14-independent signaling pathway, and contributes to NO production by macrophages stimulated with high doses of LPS.

Animals↗
PubMed1998

CP-060S interacts with three principal binding sites on the L-type Ca2+ channel.

CP-060S, (-)-(S)-2-[3,5-bis(1,1-dimethylethyl)-4-hydroxypheny1]-3-[3-[N-met hyl-N-[2-(3,4-methylenedioxyphenoxy)ethyl]amino]propyl]-1,3-thi azolidin-4-one hydrogen fumarate is a novel cardioprotective drug, which is able to prevent Na+-, Ca2+-overload and also has Ca2+ channel blocking activity. The latter action of CP-060S was characterized by radioligand binding experiments with rat cardiac membranes in terms of the interaction with the three principal binding sites on the L-type Ca2+ channel, which bind such drugs as the 1,4-dihydropyridines, phenylalkylamines and benzothiazepines. CP-060S exhibited complete and concentration-dependent inhibition of [3H](+)-PN200-110, [3H](-)-desmethoxyverapamil and [3H]cis-(+)-diltiazem binding to their specific binding sites. Saturation studies showed that CP-060S increased the Kd of [3H](+)-PN200-110 and [3H](-)-desmethoxyverapamil without causing a significant change in the maximum binding density. The dissociation kinetics of the three radioligands were accelerated by CP-060S. These results suggest that CP-060S interacts with a novel binding site on the L-type Ca2+ channel and has a negative allosteric interaction with the three principal binding sites for the 1,4-dihydropyridines, phenylalkylamines and benzothiazepines.

Animals↗
PubMed1998

A nitric oxide donor NOC 7 suppresses renal responses induced by norepinephrine and angiotensin II in the NO-depleted denevated rabbit kidney.

Intrarenal arterial infusion of norepinephrine (30 ng/kg per min) or of angiotensin II (4 ng/kg per min) reduced the glomerular filtration rate and urinary Na+ excretion in denervated kidneys of anesthetized rabbits pretreated intrarenally with a nitric oxide (NO) synthase inhibitor N(omega)-nitro-L-arginine methyl ester (50 microg/kg per min). Angiotensin II but not norepinephrine reduced fractional Na+ excretion. Intrarenal administration of a spontaneous NO donor 1-hydroxy-2-oxo-3-(N-methyl-3-aminopropyl)-3-methyl-1-triazene (NOC 7, 30 ng/kg per min) in L-NAME pretreated kidneys did not affect basal values, but attenuated the reduction in urinary Na+ excretion induced by these agonists without affecting the angiotensin II-induced reduction in glomerular filtration rate. The results suggest that NOC 7 can suppress the norepinephrine-induced hypofiltration and the angiotensin II-evoked tubular reabsorption and thereby attenuates the agonist-induced antinatriuresis in the denervated and endogenous NO-depleted rabbit kidney.

Angiotensin II↗
PubMed1998

Stimulatory effects of hepatocyte growth factor on hemopoiesis of SCF/c-kit system-deficient mice.

In this study, we report that W/W mutant mice, which have severe macrocytic anemia caused by a deficit of extracellular domain in c-kit molecules and therefore die perinatally, have hemopoietic stem cells (HSCs) and mature hematolymphoid cells in the bone marrow (BM), thymus, and spleen, although there are significant decreases in cell counts. Moreover, the mitogen-induced proliferative response, mixed lymphocyte reaction, and anti-SRBC plaque formation of spleen cells in W/W mice are similar to those in age-matched +/? littermates and normal mice, suggesting that the SCF/c-kit system is necessary for cell proliferation but not essential for HSCs to differentiate. We next examine the stimulatory effects of hepatocyte growth factor (HGF) on hemopoiesis in W/W mice. HGF has a stimulatory effect on the colony formation (CFU-C) of W/W BM cells when cultured using either a methylcellulose assay (containing cytokines) or a long-term culture (LTC) assay. A similar stimulatory effect of HGF is observed in the other W or SI locus-mutant mice (W/Wv and SI/SId mice), which show less severe anemia than W/W. The numbers of nonadherent cells and cobblestone colonies significantly increase in the LTCs using their BM cells. In addition, in vivo administration of HGF shows a transient increase in the CFU-C counts in BM cells and peripheral blood cells. RBC, WBC, and platelet counts also increased. These results suggest that the SCF/c-kit system is not essential to hemopoiesis but that a compensatory system such as the HGF/c-met system functions in the SCF/c-kit system-deficient mice.

Anemia, Macrocytic↗
PubMed1998

Gliosarcoma with angiosarcomatous features: a case report.

A surgical case of gliosarcoma in which the mesenchymal component showed angiosarcomatous features is reported. The neoplasm was extirpated from the right cerebral hemisphere of a 76-year-old man who presented with left hemiparesis and headache, and it was composed of both anaplastic astrocytomatous and sarcomatous elements. The sarcomatous element was composed of a proliferation of atypical endothelial cells that had pleomorphic, mitotically active nuclei and formed vascular lumina of irregular shapes or solid cellular sheets, and was accompanied by the deposition of collagenous matrix. The cytoplasm of some of the atypical endothelial cells was immunohistochemically positive for vimentin, factor VIII-related antigen, CD 34, and thrombomodulin. The MIB-1 labeling index of the sarcomatous component was higher than that of the astrocytomatous component.

Aged↗
PubMed1998

Primary brain tumors in children under age 3 years.

During the period from 1966 to 1996 the authors analyzed the clinicopathological characteristics of 46 cases of histologically verified primary brain tumors with symptomatic onset during the first 3 years of life. The patient group included 27 males and 19 females. There were 14 patients during the first year, 13 during the second year, and 19 during the third year. Supratentorial tumors (60.9%) were more common than infratentorial tumors. Histologically, neuroepithelial tumors predominated. The incidence of ependymal tumors, particularly malignant ones, and of neuronal/mixed neuronal-glial tumors was higher than in previous reports. Congenital brain tumors, those occurring within 2 months after birth, or tumors of dysplastic origin comprised 42.9% of the tumors that developed within 1 year of birth. At the onset, macrocephaly, failure to thrive, and seizures were prominent symptoms or signs in the younger patients. Focal neurological deficits and increased intracranial pressure predominated in the older patients. All but one patient underwent surgical treatment, and 17 patients received adjuvant therapy after surgery. The prognosis was mainly related to the histology of the malignancy. The outcome of medulloblastomas was poor. The quality of life of surviving patients was relatively good, 77.8% having better performance status (PS) than the Eastern Cooperative Oncology Group PS 2.

Brain Neoplasms↗
PubMed1998

Spontaneous rupture of the stomach in preschool age children: a report of two cases.

The cases of two preschool-age children who suffered spontaneous gastric ruptures are reported herein. The first was a 2-year-old girl with tetralogy of Fallot, transferred to our hospital due to shock. A laparotomy was performed under the diagnosis of gastrointestinal perforation, and two perforations of the posterior wall of the gastric fundus were found. The second case, a 4-year-old girl who had previously experienced an episode of gastric dilatation, was admitted to our department with abdominal distention and vomiting. An abdominal X-ray film revealed a pneumoperitoneum, and an emergency laparotomy was performed, confirming a round rupture in the posterior wall of the stomach. Both patients had a satisfactory postoperative course.

Child, Preschool↗
PubMed1998

Effect of exercise-induced activation of sympathetic nerve activity on clearance of 123I-MIBG from the myocardium.

The effect of exercise on the cardiac kinetics of 123I-MIBG was investigated in the present study. 123I-MIBG was administered intravenously at rest in 6 healthy male volunteers, and anterior planar and SPECT images were obtained 15 minutes, and 2 and 4 hours after administration (protocol A). After 4 weeks, 123I-MIBG was again administered intravenously at rest, and images were obtained 15 minutes later. After imaging, the subjects ran 10 km in approximately 1 hour, and anterior planar and SPECT images were obtained 2 and 4 hours after administration of 123I-MIBG (protocol B). The heart-to-mediastinum uptake ratio (H/M) was calculated from each anterior planar image, and the mean 123I-MIBG clearance from 15 minutes to 2 hours, and from 2 hours to 4 hours was calculated with a bull's eye display. The H/M was much lower after exercise. The mean clearance rate between 15 minutes and 2 hours in protocol B was significantly higher than that between 2 hours and 4 hours, and that between 15 minutes and 2 hours in protocol A. It was concluded that the clearance rate of 123I-MIBG may be a useful index of cardiac sympathetic nerve activity.

3-Iodobenzylguanidine↗
PubMed1998

Early and delayed Tc-99m-tetrofosmin myocardial SPECT in patients with left bundle branch block.

UNLABELLED: To determine the utility of the myocardial tracer Tc-99m-tetrofosmin in the examination of patients with left bundle branch block (LBBB) and to investigate Tc-99m-tetrofosmin uptake and retention in the myocardium, early and delayed Tc-99m-tetrofosmin SPECT was performed in 10 patients having LBBB without coronary stenosis. METHODS: After 740 MBq of Tc-99m-tetrofosmin injection in the resting state, the early and delayed SPECT imaging was done at 30 min and 180 min, respectively. RESULTS: Decreased Tc-99m-tetrofosmin uptake in the septal segments was observed in 4 patients (40%) at 30 min and in 9 (90%) at 180 min. Reverse redistribution was seen in 9 of 10 patients. In patients with LBBB, the septal-to-lateral uptake ratio was lower in the delayed images than in the early images (0.80 +/- 0.09 vs. 0.89 +/- 0.09, p < 0.001). In patients with LBBB, the washout rate of Tc-99m-tetrofosmin was higher in the septal segments than in the lateral segments (28.3 +/- 4.3% vs. 22.8 +/- 3.3%, p < 0.001). CONCLUSION: The SPECT data indicate that in LBBB without coronary stenosis, the uptake of Tc-99m-tetrofosmin is decreased in the septal wall, and that reverse redistribution occurs frequently. Our results contribute to the elucidation of both the cellular biokinetics of Tc-99m-tetrofosmin in the myocardium and the hemodynamics of the septum in LBBB, and indicate the possible clinical utility of Tc-99m-tetrofosmin.

Adult↗