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Biomedical subjects

K Shimizu

Publications and source records attributed to K Shimizu.

At least 325 records · Page 18Linked to original sources

[The difference in saccadic parameters among several visually guided tasks].

PURPOSE: The present study was undertaken to establish the effects of the five different paradigms (simultaneous, gap, overlap, delayed-memory and anti-saccade tasks) on saccade dynamics (duration, peak velocity, and amplitude). METHODS: We recorded ocular movements in 7 normal subjects, using infrared oculography with a visual stimulation system. RESULTS: The distribution of saccade accuracy in gap and overlap tasks had about the same steepness as that in simultaneous tasks, but that in delayed-memory and anti-saccade tasks was broader than that in simultaneous tasks. The distribution in anti-saccade tasks had a marked intersubject variability, and the average values of accuracy were hypermetric in four subjects. The peak velocity/amplitude ratio in simultaneous and gap tasks were higher than those of other tasks. The relationship between average of peak velocity of abduction and adduction was different, adduction was higher than abduction in simultaneous and gap tasks, and abduction was lower than adduction in delayed-memory and anti-saccade tasks. CONCLUSIONS: The dynamics in simultaneous tasks had about the same characteristics as in gap tasks, but were different from those in overlap, delayed-memory, and anti-saccade tasks. These results indicated that the marked differences in dynamic properties among different saccade types may reflect processes in the visuomotor system.

Adult↗

Co-transduction of herpes simplex virus thymidine kinase gene and human interleukin-2 gene into mouse ovarian cancer cell line, OVHM.

We studied the thymidine kinase (TK) gene and the interleukin (IL)-2 gene co-transduction into tumor cells for a possible strategy of cancer gene therapy. A murine ovarian cancer cell line, OVHM, was retrovirally transduced with the TK (OVHM/TK) or the IL-2 gene (OVHM/IL-2). The TK or IL-2 expression was permanent in OVHM/TK or OVHM/IL-2. OVHM/TK cells were susceptible to gancyclovir (GCV) in vitro, and their intraperitoneal growth was completely regulated with GCV administration. The bystander effect was not observed in vitro and in vivo in this model, and only the marginal emergence of immune involvement was observed in the OVHM/TK-cured mice with GCV. OVHM/IL-2 cells produced IL-2 biologically active to be immunogenic, but still tumorigenic to kill the mice when inoculated intraperitoneally. Then, OVHM/TK cells were co-transduced with the IL-2 gene to establish OVHM/TK/IL-2 cells. OVHM/TK/IL-2 cells were also susceptible to GCV and transiently produced active IL-2. A significant resistance against the challenge of parental tumor cells was observed in the mice that were inoculated with OVHM/TK/IL-2 cells and cured with GCV administration. It is suggested that tumor cells transduced with both TK and IL-2 genes could be regressed with GCV administration with subsequent generation of immune activation in the host. Since the bystander effect may not always be a common phenomenon in gene therapy using the TK gene, this type of combination may be advantageous in the clinical application of gene therapy for human cancers.

Animals↗

[A case of non-small-cell lung cancer successfully treated using combination chemotherapy with CDDP and vinorelbine].

A 67-year-old woman presented to our hospital with a chief complaint of bloody sputum. A plain chest X-ray a CT scan revealed a tumor shadow 3 cm in size in the middle lobe of the right lung, multiple nodular shadows in the bilateral lung fields and enlarged hilar and mediastinal lymph nodes. A tumor biopsy done under bronchoscopy revealed poorly differentiated adenocarcinoma of the lungs (cT2N3M1). She was given two courses of combination therapy consisting of cisplatin (80 mg/m2) and vinorelbine (20 mg/m2). The primary tumor in the middle lobe of the right lung and the lung metastases were markedly reduced in size, and a complete response was obtained. The only adverse events were grade 4 neutropenia and grade 2 nausea and vomiting.

Aged↗

[A case of Klebsiella pneumoniae infection causing a buccal abscess complicated with multiple lung abscesses].

A 51 year-old man fitted with a dental prosthesis was hospitalized with buccal swelling, fever and chest pain. Laboratory data showed marked inflammatory changes, and chest radiography and CT scanning revealed small nodular shadows within the lung. A diagnosis of multiple lung abscesses secondary to a buccal abscess possibly caused by the prosthesis was made from needle aspiration biopsies of the lung nodules and of a buccal lesion. Klebsiella pneumoniae was isolated from these lesions and from a blood culture. The patient was successfully treated with antibiotics and by surgical drainage of the buccal abscess. It is important to note that the patient was immunodeficient at the time as a result of diabetes and alcohol intoxication.

Abscess↗

Tacrolimus (FK506) treatment of CD34+ hematopoietic progenitor cells promote the development of dendritic cells that drive CD4+ T cells toward Th2 responses.

The macrolide lactone, tacrolimus (FK506), is utilized in bone marrow transplantation (BMT) to prevent graft-versus-host disease (GVHD). In the current study, we evaluated the ability of FK506 to modify the function of dendritic cells (DCs) derived from CD34+ hematopoietic progenitor cells (HPCs). Comparable to DCs obtained in the absence of FK506, DCs cultured in the presence of FK506 (FK-DCs) had higher expression of CD1a+ and formed a greater number of DC colonies. Despite the same expression of costimulatory molecules, FK-DCs displayed a reduced capacity to stimulate an allogeneic T cell response, and showed significantly lower interleukin (IL)-12 production. While normal DCs pulsed with the exogenous antigen, keyhole limpet hemocyanin (KLH) induced specific Th1-like interferon-gamma(IFN-gamma) producing CD4+ T cell line, FK-DCs induced Th2-like interleukin-4 (IL-4) producing CD4+ T cell line. These data demonstrate the ability of FK506 to induce Th2-promoting function in developing DCs.

Antigens, CD34↗

[An effective case of hepatic arterial infusion chemotherapy based on biochemical modulation for hepatic recurrence of non-functioning islet cell carcinoma of the pancreas].

A 55-year-old man had a metastasis in segment 3 of the liver 5 months after surgery for non-functioning islet cell carcinoma of the pancreas. The metastatic lesion increased in size in a short period, and other liver micro-metastases that could not be detected by imaging may exist, so hepatic arterial infusion chemotherapy was scheduled for 3 months. The patient underwent hepatic arterial infusion chemotherapy of 5-fluorouracil (250 mg/day/body for 5 days/week) and adriamycin (10 mg/day/body for 2 days/week) and cisplatin (10 mg/day/body for 5 days/week) and he was put on Leucovorin 30 mg/day as a biochemical modulator of 5-FU and tamoxifen 40 mg/day as a biochemical modulator of ADM. A total 6,000 mg of 5-FU, 100 mg of ADM and 240 mg of CDDP had been administered, until hepatic arterial infusion chemotherapy was discontinued because of complicated gastric ulcer. Three months later, the size of the metastatic liver tumor was reduced remarkably and no other metastasis was detected on CT scan, so he underwent partial hepatectomy of the metastatic lesion. No recurrence was found and he has survived in good physical condition during the follow-up period of 5 months after the second operation.

Administration, Oral↗

[A case of a combined aortectomy with dissection of recurrent paraaortic lymph nodes of sigmoid colon cancer].

A combined aortectomy was performed on a patient with recurrence of sigmoid colon cancer in the paraaortic lymph nodes. The 48-year-old woman was found to have tumor recurrence in the lymph nodes in the area between the aortic bifurcation and the paraaortic area, accompanied by left hydronephrosis, four years after surgery for sigmoid colon cancer (H0, P0, ss, n3, stage IIIb). No metastasis to distant areas was detected at that time. The woman thus underwent a reoperation. Intraoperatively, the aortic bifurcation and the lymph nodes were seen as a mass. The mass involved the left common iliac vein and the left ureter, as well. Therefore, we resected the area from the aortic bifurcation to the bilateral common iliac arteries, the left common iliac vein, the left ureter and the left kidney en bloc, and replaced them with a Y-shaped graft. One year after the reoperation, a tumor metastasis to the liver was detected, and a partial hepatectomy was performed. At present, the patient is being managed at our outpatient clinic. The results suggest that extended resection, involving the aorta as well, is sometimes useful when dealing with tumor recurrence in the paraaortic lymph nodes, unaccompanied by blood-borne metastasis.

Aorta↗

A case of pulmonary arteritis with stenosis of the main pulmonary arteries with positive myeloperoxidase-antineutrophil cytoplasmic autoantibodies.

A 53-year-old woman was referred to our hospital with the main symptoms of productive cough, fever and exertional dyspnoea. Chest X-ray revealed enlargement of the left hilar shadow and cavitary infiltration in the right upper lobe. 99mTechnetium-macroaggregated albumin (99mTc-MAA) perfusion scintigram showed complete hypoperfusion through the entire right lung. A pulmonary angiogram revealed stenotic lesions in the right and left main pulmonary arteries. Right cardiac catheterization showed an elevated right ventricular systolic pressure. There was no evidence of systemic arterial lesions nor vasculitis. The patient was positive for myeloperoxidase (MPO)-antineutrophil cytoplasmic autoantibodies (ANCA) (168 EU). The Mycobacterium avium complex sputum culture was positive. The pulmonary stenotic lesions were surgically resected. The resected pulmonary arterial lesions were pathologically diagnosed as non-specific vasculitis. The cavitary lesion disappeared 6 months after the surgery. Two years after the surgery, although the MPO-ANCA level had decreased to 12 EU, stenosis of the pulmonary arteries reappeared. It is suggested that the patient became positive for MPO-ANCA in association with the Mycobacterium avium complex infection, and that the presence of MPO-ANCA may not be related to the development of pulmonary stenosis of the main pulmonary arteries.

Angiography↗

[MN/CA IX antigen as a potential target for renal cell carcinoma].

MN/CA IX is considered as a carbonic anhydrase isoenzyme expressed in the normal alimentary tract in a tissue-specific manner. This antigen is activated in the majority of renal cell carcinomas (RCC) but not in the normal kidney tissues. Our previous study revealed that increase of malignant potential is related to down-regulation of MN/CA9. To investigate the mechanism of MN activation in RCC, we examined the methylation status of this gene (MN/CA9) in RCC cell lines (SKRC-1, 6, 10, 12, 14, 44, 59). Moreover, we analyzed the circulating blood of patients for the presence of RCC cells by RT-PCR, to determine whether detection of circulating RCC cells could be useful as a biomarker. CpG methylation was investigated at 7 CpG sites in the MN/CA9 5' region. Clear mRNA signals were observed in 5 cell lines (SKRC-1, 6, 10, 44, 59), e.g., MN/CA9 positive. These 5 MN-positive cell lines showed hypomethylation in the 5' region. In contrast, all CpG sites were methylated in the remaining 2 lines and 3 normal kidney tissue samples. These results suggest that hypomethylation in the 5' region may play an important role in the expression of MN/CA9 in RCC. RT-PCR analysis of blood samples from RCC patients revealed the presence of circulating MN-positive cancer cells in the blood. Although a significant correlation with tumor stage and grade was not observed, the analysis of blood samples from patients with metastases resulted in a high detection rate of 82%. These findings suggest the usefulness of MN/CA IX as a potential diagnostic marker for detection of RCC.

Antigens, Neoplasm↗

[Mechanisms of antigenic variation in influenza virus].

Human influenza A viruses evolve rapidly by antigenic shift and antigenic drift. Antigenic shift occurs by genetic reassortment between currently circulating human viruses and influenza viruses of other origin, by re-emergence of a previously circulating virus, and by invasion of animal influenza viruses. The segmental structure of the virus genome enables reassortment in multiply infected cells and also promotes multiple infection because it results in yielding noninfectious particles which randomly lack some genome segment and only become infectious by complementation with others. Antigenic drift is due to an accumulation of nonsynonymous substitutions in the genes encoding the HA and NA proteins. The limited nature of infection to the respiratory epithelium which is the border of the immune system enables the virus to reinfect and grow under the partial immune pressure which results in selecting and expanding antigenic mutants.

Animals↗

Metabolic control analysis for lysine synthesis using Corynebacterium glutamicum and experimental verification.

Metabolic control analysis was carried out for the lysine biosynthetic pathway in Corynebacterium glutamicum ATCC 21253 using mechanism-based kinetic models developed for enzymatic reactions for this pathway. The rate-limiting steps during lysine production were determined with the aid of flux control coefficients, which indicated that the lysine synthesis flux is governed mainly by both aspartokinase and permease activity in the export system. Analyses indicated that an increase in the activity of aspartokinase would significantly alleviate its effect on the overall flux, and the limiting step is expected to shift to permease and other lysine synthetic enzymes. The influences of many participating precursors and cofactors on lysine synthesis flux were also investigated through the calculation of response coefficients for individual parameters. Although most parameters were not found to exert significant influences on lysine flux, extracellular lysine concentration was found to have a substantial effect on lysine production, and detailed analysis indicated that a decrease in the external lysine concentration will enhance the metabolite synthesis considerably and shift the control from export step to other steps. Although a decrease in external pH (pH0) seems to increase lysine flux, consideration of the export carrier concentration in response to external pH confirmed the optimum pH0 to be 7.0. Two types of recombinant strains overexpressing aspartokinase and dihydrodipicolinate synthase were constructed to verify the results obtained from metabolic sensitivity analysis.

Journal Article↗

Inflammatory cytokines induced down-regulation of m-calpain mRNA expression in fibroblastic synoviocytes from patients with osteoarthritis and rheumatoid arthritis.

Our previous reports revealed that calpain has proteoglycanase activity and exists in synovial fluid in osteoarthritis and rheumatoid arthritis. We examined the effects of cytokines on expression of the calpain-calpastatin system in fibroblastic synoviocytes (FLS). Primary cultures of human FLS from osteoarthritis (OA) and rheumatoid arthritis (RA) patients were stimulated with inflammatory cytokines and the amounts of m-calpain and calpastatin mRNAs expressed were determined by Northern blotting. Northern blots were subjected to computerized densitometer and band intensities were determined. Interleukin-1 (IL-1) down-regulated m-calpain and tissue-type calpastatin mRNA expression in OA and RA FLS. In RA FLS, although IL-6 did not alter m-calpain mRNA expression, IL-1 + tumor necrosis factor (TNF) and IL-1 + transforming growth factor (TGF) down-regulated m-calpain mRNA expression. These results provide new information about the effects of inflammatory cytokines on calpain and calpastatin system in OA and RA pathology.

Arthritis, Rheumatoid↗

Effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, on the survival of mice infected with influenza virus.

The antiviral effect of Hochu-ekki-to (TJ-41), a Japanese herbal medicine, was investigated using mice infected with influenza virus. TJ-41 was found to increase the survival rate, prolong the mean survival days, suppress viral growth in bronchoalveolar labage fluid (BALF) and inhibit the lung index (lung consolidation) on day 4 after infection in mice infected with influenza, after the agent had been administered orally once daily from day 7 to 2 before infection and from day 0 to 4 after infection. Administration of TJ-41 decreased the BALF concentrations of IL-1alpha, IL-6 and GM-CSF, but not TNF-alpha or interferon-gamma (IFN-gamma), on day 4 after infection. In addition, TJ-41 elevated the level of IFN-alpha in BALF on day 2 after infection. Yet, TJ-41 did not show any inhibitory effect on the growth of influenza virus in vitro. These results suggest that TJ-41 exerts its inhibitory effect on influenza virus infection via enhancement of the host immune responses in this experimental murine system.

Administration, Oral↗

Roles of dopamine and serotonin in larval attachment of the barnacle, Balanus amphitrite.

In order to clarify the roles of neurotransmitters including serotonin and dopamine in larval settlement (attachment) and metamorphosis of the barnacle Balanus amphitrite, the effects of lisuride, which acts as both a serotonin agonist/antagonist and a dopamine agonist, were examined. Lisuride did not induce larval attachment and metamorphosis; however, it promoted only larval behavior of searching for attachment sites without actual attachment to substrata which lasted for 5 to 6 days in a dose-dependent manner. Further evidence was obtained with a range of agonists/antagonists; serotonin agonists promoted the attachment, while serotonin antagonists inhibited it. Similarly, dopamine agonists inhibited the attachment. Furthermore, mixtures of serotonin and dopamine showed similar effects to those of lisuride. These results suggested that the promotion effect on larval searching behavior was derived from a combination of activities of serotonin and dopamine. Moreover, both serotonin and dopamine were detected in cyprids by HPLC. Thus, larval attachment process is regulated by both serotonin and dopamine neurons in this species. J. Exp. Zool. 284:746-758, 1999. Copyright 1999 Wiley-Liss, Inc.

Journal Article↗

Mouse jagged1 physically interacts with notch2 and other notch receptors. Assessment by quantitative methods.

The Delta/Serrate/LAG-2 (DSL) domain containing proteins are considered to be ligands for Notch receptors. However, the physical interaction between DSL proteins and Notch receptors is poorly understood. In this study, we cloned a cDNA for mouse Jagged1 (mJagged1). To identify the receptor interacting with mJagged1 and to gain insight into its binding characteristics, we established two experimental systems using fusion proteins comprising various extracellular parts of mJagged1, a "cell" binding assay and a "solid-phase" binding assay. mJagged1 physically bound to mouse Notch2 (mNotch2) on the cell surface and to a purified extracellular portion of mNotch2, respectively, in a Ca(2+)-dependent manner. Scatchard analysis of mJagged1 binding to BaF3 cells and to the soluble Notch2 protein demonstrated dissociation constants of 0.4 and 0.7 nM, respectively, and that the number of mJagged1-binding sites on BaF3 is 5,548 per cell. Furthermore, deletion mutant analyses showed that the DSL domain of mJagged1 is a minimal binding unit and is indispensable for binding to mNotch2. The epidermal growth factor-like repeats of mJagged1 modulate the affinity of the interaction, with the first and second repeats playing a major role. Finally, solid-phase binding assay showed that Jagged1 binds to Notch1 and Notch3 in addition to Notch2, suggesting that mJagged1 is a ligand for multiple Notch receptors.

Amino Acid Sequence↗

Chromosome rearrangement at 17q25 and xp11.2 in alveolar soft-part sarcoma: A case report and review of the literature.

BACKGROUND: Despite the characteristic histopathologic appearance of alveolar soft-part sarcoma (ASPS), its histogenesis remains unclear, and cytogenetic analysis of ASPS is limited to eight cases so far because of the extreme rarity of this disease. METHODS: The authors document a cytogenetic study of a primary case of ASPS in which a modern spectral karyotyping technique was used. RESULTS: A standard cytogenetic analysis of the primary tumor cells with G-banding revealed 46,XY, add(17)(q25) in 23 of 25 metaphases analyzed. This structural rearrangement of chromosome 17, involving band q25, was also present in 5 of 8 ASPS cases in the literature. Moreover, with the spectral karyotyping technique, the additional part of the long arm of chromosome 17 in the current case was found to originate from chromosome X, resulting in a final tumor karyotype of 46, XY, add(17)(q25).ish der(17)t(X;17) (p11.2;q25)(wcpX+). CONCLUSIONS: This case report documents a clonal chromosome abnormality of der(17)t(X;17)(p11.2;q25) in ASPS. The results of the current study indicate that further molecular analyses focused on 17q25 and Xp11.2 are of interest and could help to elucidate the pathogenesis of ASPS.

Child↗

SCOP, a novel gene product expressed in a circadian manner in rat suprachiasmatic nucleus.

To elucidate the mechanism of the circadian rhythm, genes differentially expressed during subjective day and night in the rat suprachiasmatic nucleus (SCN), a circadian oscillator in mammals, were surveyed by a differential display method. We isolated a novel gene, scop (SCN circadian oscillatory protein), that was expressed in a circadian manner in the SCN. SCOP protein is predominantly expressed in the brain and has domains including a pleckstrin homology domain, leucine-rich repeats, a protein phosphatase 2C-like domain and a glutamine-rich region. The structural feature of SCOP protein suggests its role in the intracellular signaling in the SCN.

Amino Acid Sequence↗