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Biomedical subjects

N Umeda

Publications and source records attributed to N Umeda.

At least 19 recordsLinked to original sources
PubMed2006

Antiparasitic effect of calcium and magnesium ion-free buffer treatments against a common monogenean Neobenedenia girellae.

This study investigated a new effective method for controlling the capsalid monogenean Neobenedenia girellae. We examined in vitro and in vivo the effect on the percentage survival of N. girellae in buffers containing different metallic ions. Decreased survival was observed in buffer solutions lacking two ions. In particular, the percentage survival of N. girellae was significantly decreased after 10 min exposure to buffer containing neither Ca(2+) nor Mg(2+). Transmission electron microscopic observations showed that treatment with this buffer disrupted intercellular junctions. This significant effect on percentage survival of N. girellae using Ca(2+)/Mg(2+)-free buffer was confirmed in an in vivo assay. Ca(2+)/Mg(2+)-free buffer had no effect on the condition of the host, spotted halibut Verasper variegates (Pleuronectidae). These results suggest that treatment with Ca(2+)/Mg(2+)-free buffer is a new effective control method, which could replace existing control methods.

Animals↗
PubMed2005

A small ciliary surface glycoprotein of the monogenean parasite Neobenedenia girellae acts as an agglutination/immobilization antigen and induces an immune response in the Japanese flounder Paralichthys olivaceus.

The capsalid monogenean Neobenedenia girellae, a parasite of seawater fishes, was found to express an antigen that elicits antibodies in rabbits, and these antibodies had agglutination/immobilization activity against N. girellae larvae (oncomiracidia) in vitro. Indirect immunofluorescence staining of N. girellae oncomiracidia showed that this agglutination/immobilization antigen was expressed on the surface of cilia. An intraperitoneal injection of ciliary proteins (either sonicated or intact) with adjuvant also elicited agglutinizing/immobilizing antibodies in sera from Japanese flounder, Paralichthys olivaceus. These antisera showed a clear correlation between anti-ciliary antibody levels (measured by enzyme-linked immunosorbent assays) and their agglutination/immobilization activity. Anti-ciliary antibody levels in Japanese flounder reached a plateau at 39 days after booster immunization and were significantly higher in the two immunized groups (injection of sonicated or intact cilia) as compared with control fish (injection of bovine serum albumin; ANOVA, Tukey's test, P < 0.01). Anti-ciliary antibodies were also found in fish mucus; however, there was no correlation between fish serum anti-ciliary antibody levels and mucus antibody levels. A Triton X-114-soluble 8 kDa glycoprotein of the ciliary integral membrane fraction is a plausible candidate for the agglutination/immobilization antigen based on SDS-polyacrylamide gel electrophoresis and immunoblot analyses with rabbit and fish antisera.

Agglutination↗
PubMed2003

Difference in the heat sensitivity of DNA-dependent protein kinase activity among mouse, hamster and human cells.

PURPOSE: To examine the heat sensitivity of DNA-dependent protein kinase (DNA-PK) activity in a variety of cultured mouse, hamster and human cell lines. MATERIALS AND METHODS: Eight cell lines, which have been routinely used in our laboratory, were examined. Cells were heated at 44.0 +/- 0.05 degrees C and DNA-PK activity was measured by a DNA-pull-down assay followed by gel-electrophoresis. Cellular sensitivity to hyperthermia and/or X-ray was evaluated by a colony formation assay. RESULTS: In mouse FSA1233 and FM3A cells, DNA-PK activity dropped to 15-16% of unheated control after 20 min of heating. In Chinese hamster V79 and CHO-K1 cells, kinase activity did not change appreciably after 20 min treatment but decreased to 60-70 and 22-23% after 40 or 60 min treatment, respectively. However, even after 180 min treatment, DNA-PK activity remained almost intact in human MOLT-4, MKN45 and A7 cells, and decreased only slightly in U937 cells. Hyperthermic radiosensitization was seen even in human cells but, as a trend, it was small compared with rodent cells. CONCLUSIONS: The heat sensitivity of DNA-PK was clearly different among mouse, hamster and human cells. The results suggested a possibility that the role of DNA-PK inactivation in hyperthermic radiosensitization might be variable, depending on cells, and would reinforce the warning that the direct extrapolation of data from rodent cells might lead to overestimation of the effectiveness of hyperthermia on human cancer.

Animals↗
PubMed2002

Phosphorothioate oligonucleotides, suramin and heparin inhibit DNA-dependent protein kinase activity.

Phosphorothioate oligonucleotides and suramin bind to heparin binding proteins including DNA polymerases, and inhibit their functions. In the present study, we report inhibition of DNA-dependent protein kinase activity by phosphorothioate oligonucleotides, suramin and heparin. Inhibitory effect of phosphorothioate oligonucleotides on DNA-dependent protein kinase activity was increased with length and reached a plateau at 36-mer. The base composition of phosphorothioate oligonucleotides did not affect the inhibitory effect. The inhibitory effect by phosphorothioate oligodeoxycytidine 36-mer can be about 200-fold greater than that by the phosphodiester oligodeoxycytidine 36-mer. The inhibitory effect was also observed with purified DNA-dependent protein kinase, which suggests direct interaction between DNA-dependent protein kinase and phosphorothioate oligonucleotides. DNA-dependent protein kinase will have different binding positions for double-stranded DNA and phosphorothioate oligodeoxycytidine 36-mer because they were not competitive in DNA-dependent protein kinase activation. Suramin and heparin inhibited DNA-dependent protein kinase activity with IC(50) of 1.7 microM and 0.27 microg ml(-1) respectively. DNA-dependent protein kinase activities and DNA double-stranded breaks repair in cultured cells were significantly suppressed by the treatment with suramin in vivo. Our present observations suggest that suramin may possibly result in sensitisation of cells to ionising radiation by inactivation of DNA-dependent protein kinase and the impairment of double-stranded breaks repair.

Antineoplastic Agents↗
PubMed2001

Patients with constipation-predominant irritable bowel syndrome (IBS) may have elevated serotonin concentrations in colonic mucosa as compared with diarrhea-predominant patients and subjects with normal bowel habits.

BACKGROUND: Serotonin (5-HT) may play an important role in the regulation of colonic motility in humans. However, it is not known whether alterations in the colonic 5-HT system are involved in the pathophysiology of irritable bowel syndrome (IBS). METHODS: Colonic mucosal specimens ranging from the ascending colon to the rectum were obtained from patients with diarrhea- or constipation-predominant IBS (n = 7 and n = 8, respectively) and from subjects with normal bowel habits (n = 7) by endoscopic biopsy in order to determine whether patients with different clinical manifestations of IBS have different mucosal disposition of 5-HT. The tissue concentrations of 5-HT and its major metabolite, 5-hydroxyindoleacetic acid, were determined by reversed-phase high-performance liquid chromatography with fluorescence detection. RESULTS: In all study groups, the mean mucosal 5-HT concentrations obtained from the rectum were significantly (p < 0.05) higher than those obtained from more cephalic regions of the colon. In addition, the overall mean mucosal 5-HT concentrations obtained from patients with constipation-predominant IBS were significantly (p < 0.05) higher than those obtained from the control subjects and patients with diarrhea-predominant IBS. No significant differences were observed in 5-hydroxyindoleacetic acid concentrations among the three groups. CONCLUSIONS: The mucosal 5-HT concentrations in the colon showed an ascending cephalocaudal gradient in all study groups. Although the mucosal 5-HT concentrations were elevated in patients with constipation-predominant IBS as compared with those with diarrhea-predominant IBS and the control subjects, further studies are necessary to determine whether the elevated mucosal 5-HT is a cause or a result of abnormal colonic motility.

Adult↗
PubMed2000

Cleavage and phosphorylation of XRCC4 protein induced by X-irradiation.

We report the p35 and p60 forms of XRCC4 protein, appearing in human leukemia MOLT-4 or U937 cells following X-irradiation or hyperthermia. p35 appeared in conjunction with the cleavage of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and the fragmentation of internucleosomal DNA, and was suppressed by Ac-DEVD-CHO. p35 was also produced in vitro by treating MOLT-4 cell lysate with recombinant caspases, suggesting that p35 was a caspase-cleaved fragment of XRCC4 in apoptotic cell death. p60 was sensitive to treatment with phosphatase or wortmannin and was undetectable in M059J cells deficient in DNA-PKcs. However, p60 was found in ataxia-telangiectasia cells after irradiation. These results indicated p60 as a phosphorylated form of XRCC4, requiring DNA-PKcs but not ataxia-telangiectasia mutated (ATM).

Androstadienes↗
PubMed2000

Sensitization by wortmannin of heat- or X-ray induced cell death in cultured Chinese hamster V79 cells.

Here we found that wortmannin sensitized Chinese hamster V79 cells to hyperthermic treatment at 44.0 degrees C as determined either by colony formation assay or by dye exclusion assay. Wortmannin enhanced heat-induced cell death accompanying cleavage of poly (ADP-ribose) polymerases (PARP). Additionally, the induction of heat shock protein HSP70 was suppressed and delayed in wortmannin-treated cells. Heat sensitizing effect of wortmannin was obvious at more than 5 or 10 microM of final concentrations, while radiosensitization was apparent at 5 microM. Requirement for high concentration of wortmannin, i.e., order of microM, suggests a possible role of certain protein kinases, such as DNA-PK and/or ATM among PI3-kinase family. The sensitization was minimal when wortmannin was added at the end of heat treatment. This was similar to the case of X-ray. Since heat-induced cell death and PARP cleavage preceded HSP70 induction phenomenon, the sensitization to the hyperthermic treatment was considered mainly caused by enhanced apoptotic cell death rather than secondary to suppression or delay by wortmannin of HSP70 induction. Further, in the present system radiosensitization by wortmannin was also at least partly mediated through enhancement of apoptotic cell death.

Androstadienes↗
PubMed1999

Flow-through thin latissimus dorsi perforator flap for repair of soft-tissue defects in the legs.

Flow-through thin latissimus dorsi perforator flaps were used in six cases with complicated defects of the legs. This flap has a small amount of latissimus dorsi muscle with a considerable amount of fatty tissue removed to make a thin flap. In addition, the flap has several branches of the subscapular vessel, which are interposed to the recipient vessels of the legs. The advantages of this thin flap are: (1) flow-through vascular reconstruction can preserve the main vessels of the damaged legs; (2) the double arterial inflows and venous drainage systems of the flap ensure safe vascularization of the flap; (3) a flow-through venous drainage system from the distal extremities can also be established to prevent congestion of the affected legs; (4) this flap is versatile (it can be either thin or large); and (5) even in emergent ischemic legs, simultaneous elevation of the flap is possible with preparation of the legs. This flow-through flap is indicated for: (1) cases with a large skin defect and obstruction of the main vessels in the leg; (2) cases with a possibility of tumor recurrence in the legs; and (3) young women or girls with a large defect in the legs, rather than the rectus abdominis musculocutaneous flap.

Adult↗
PubMed1999

A gel-electrophoretic analysis for improved sensitivity and specificity of DNA-dependent protein kinase activity.

DNA-dependent protein kinase (DNA-PK) is considered a critical enzyme in the repair and/or signal transduction of DNA double-strand breaks. DNA-PK activity has been mostly measured through "DNA-plus-minus" or "DNA-pull-down" procedures using synthetic peptide as substrate followed by filter-binding analysis, i.e. liquid scintillation counting of acid-insoluble radioactivity bound to phosphocellulose filter. Considering that non-specific phosphorylation of other cellular proteins in filter-bound acid-insoluble count could interfere with the detection of specific phosphorylation of peptide substrate, we examined the specificity and characteristics of these assay procedures by SDS gel-electrophoresis of the reaction mixture. The electrophoretic pattern showed phosphorylation in wide range of non-specific protein bands other than the specific substrate. The very low DNA-PK activity shown by murine L5178Y or FSA1233 cells was unambiguously detectable as the count in substrate band. Even following DNA-pull-down procedure, which would separate DNA-PK from most of other protein kinases, substantial amount of phosphorylation of other cellular proteins were still contaminated. Thus by selectively counting the particular bands, small amount of specific phosphorylation of peptide substrate was reliably quantified. These results indicated that the DNA-PK activity through filter-binding analysis was, as suspected, contaminated by non-specific phosphorylation of other cellular proteins and also that the gel-electrophoretic analysis would improve detectability of specific phosphorylation by DNA-PK of synthetic peptide substrate and, therefore, would improve the kinase assay in both sensitivity and specificity.

Amino Acid Sequence↗
PubMed1998

Failed hip prostheses in hemodialysis patients. Amyloid deposition at the bone-implant interface in 4 cases.

4 hemodialysis patients with failed bipolar hip prostheses underwent 6 revision arthroplasties. Their average age was 55 years, the average duration of hemodialysis was 14 years and the average interval from the primary arthroplasty to revision was 7 years. The interface membranes revealed amyloid deposits in all specimens. There were few polyethylene wear particles, and cement debris or foreign body reactions were rare. It appears that amyloid may cause osteolysis and early prosthetic loosening.

Adult↗
PubMed1997

A double-muscle transfer using a divided rectus femoris muscle for facial-paralysis reconstruction.

There are two types of smiling: without exposure of the teeth (usual smile), and with their exposure (square smile). Performance of the former involves use of the major zygomatic muscle, while the latter is created by the major zygomatic and the depressor labii inferior muscles. The function of the depressor labii inferioris muscle cannot be ignored in facial paralysis reconstruction. A double-muscle transfer using a divided rectus femoris muscle for one-stage reconstruction of both the major zygomatic muscle and the depressor labii inferior muscle is described. The patient suffered facial paralysis caused by an extracranial schwannoma originating from the facial nerve. After the tumor was removed, divided rectus femoris muscle segments were transferred to reconstruct the major zygomatic muscle and the depressor labii inferior muscle. After the pedicle vessel of the muscles was anastomosed to the recipient facial vessel, the long motor nerve of the proximal divided muscle was cross-faced and coapted directly to the prepared contralateral buccal branch. The short motor nerve of the distal muscle segment was sutured to the ipsilateral masseteric nerve. The advantages of divided rectus femoris muscle transfers are that (1) independent muscle contraction can be reconstructed; (2) no tongue or trapezius muscle atrophy occurs because the masseteric nerve is used as the motor source of the labial depressor; (3) only one muscle is sacrificed for muscle grafts; and (4) it is a one-stage reconstruction.

Adult↗
PubMed1997

A full-thickness chondrocutaneous flap from the auricular concha for repair of tracheal defects.

A free full-thickness chondrocutaneous flap from the auricular concha for the repair of large tracheal defects was transferred successfully. The flap is based on the superficial temporal vessels (reversed flow) and the posterior auricular vessels. The advantages of this flap for the repair of tracheal defects are (1) its dissection is easy, (2) thin components of the flap provide a wide postoperative airway, (3) the structure of the reconstructed trachea is made firm by the conchal cartilage with vascularization, (4) the highly vascularized cartilage results in less resorption than a free cartilage graft, (5) the donor site can be repaired easily and is concealed by the remnant auricle, and (6) a long arterial pedicle (reversed flow) can be obtained. The disadvantages are (1) there may be temporary postoperative congestion of the flap, (2) postoperative narrowing of the auriculocephalic sulcus may occur, and (3) a short venous pedicle often requires a vein graft.

Adult↗
PubMed1997

[Clinical features of acute hepatitis G].

Fifty-one patients with acute A, B, C, and non A-C hepatitis were studied. Alcoholic abusers and drug-induced hepatitis were excluded from non A-C hepatitis. Among 10 patients with acute non A-C hepatitis, 3 were positive for HGV-RNA by nested RT-PCR as primer of 5' non-coding region of HGV. Maximal s-ALT values in acute hepatitis G patients were significantly higher than those in acute hepatitis C(p < 0.05), but not different from those in acute hepatitis A and B. Although HGV-RNA was demonstrated after 9 years of onset of hepatitis in one patient, non of three patients took chronic course. In one patient, route of transmission was assumed to be blood transfusion.

Acute Disease↗
PubMed1997

Serum transforming growth factor-alpha level can be a parameter for evaluating liver regeneration after partial hepatectomy in patients with liver cancer.

Sensitive and reliable laboratory parameters are necessary to evaluate the degree of liver regeneration serially in patients after partial hepatectomy for liver cancer. We evaluated the serum levels of transforming growth factor-alpha (TGF-alpha) and hepatocyte growth factor (HGF), both of which are potent mitogens for hepatocytes, in 22 hepatectomized patients with liver cancer: 10 patients with hepatocellular carcinoma and 12 patients with metastatic liver tumors. Ten patients who underwent laparotomy for nonhepatic surgery were also studied as surgical controls. The serum TGF-alpha and HGF levels were measured by sandwich enzyme-linked immunosorbent assay techniques. Both the serum TGF-alpha and HGF levels increased after partial hepatectomy. However, there was no correlation between the levels of TGF-alpha and HGF. The maximal level of TGF-alpha achieved in each case correlated significantly with the resected liver volume and the increased volume of the remaining liver. Hepatocyte growth factor showed no such correlations. After nonhepatic surgery, the HGF level also increased significantly, while the TGF-alpha level did not. These results suggest that the serum TGF-alpha level varies depending on the regenerative stimulus to the liver, and that its increase corresponds with the degree of liver regeneration that occurs in patients after partial hepatectomy for liver cancer. In contrast, it is unlikely that the serum HGF level reflects liver regeneration. In conclusion, the serum TGF-alpha level can be used as a parameter for evaluating liver regeneration in patients who have undergone partial hepatectomy.

Carcinoma, Hepatocellular↗
PubMed1996

Free vascularized deep peroneal nerve grafts.

An ideal donor site for vascularized nerve grafts should have a constant anatomy, minimal functional loss after the nerve has been sacrificed, and a dependable blood supply parallel to the nerve over a relatively long distance. Creating a pedicle for a free vascularized deep peroneal nerve graft with the anterior tibial vessels seems to be a most suitable method for repairing long nerve gaps of over 20 cm and digital nerve defects with severe finger damage. Applications of this nerve graft to digital nerve losses with severely scarred beds created by avulsion injury, and two-stage reconstruction in some partial brachial plexus palsies (free vascularized nerve graft in the first stage and free vascularized muscle graft in the second stage) are well indicated. Advantages of this technique are: (1) A long nerve graft (up to 25 cm) can be obtained, and anomalies are rare (the nerve is absent in only 4 percent of cases). (2) The caliber of the vascular pedicle is large (approximately equal to 3 mm). (3) The nerve has a sufficient blood supply from the collateral blood vessels. (4) The graft can be easily obtained in the supine position. (5) A monitoring skin flap, based on the inferior lateral peroneal artery, can be attached to the nerve graft. (6) Sensory loss resulting from the sacrifice of the nerve covers a minimal area. (7) A donor scar on the anterior aspect of the lower leg is more acceptable than one on the posterior aspect because of less movement in walking. Disadvantages of this technique are: (1) Sacrifice of the large vessels in the lower leg may result in circulatory complications in the donor foot; to avoid this problem, preoperative angiography is recommended. (2) The donor scar is in an exposed area in female patients. (3) There may be temporary postoperative edema and disability in the donor leg.

Adolescent↗
PubMed1996

Epidemiologic analysis of Crohn disease in Japan: increased dietary intake of n-6 polyunsaturated fatty acids and animal protein relates to the increased incidence of Crohn disease in Japan.

We examined the correlation between the incidence of Crohn disease and dietary change in a relatively homogeneous Japanese population. The incidence and daily intake of each dietary component were compared annually from 1966 to 1985. The univariate analysis showed that the increased incidence of Crohn disease was strongly (P < 0.001) correlated with increased dietary intake of total fat (r = 0.919). animal fat (r = 0.880), n-6 polyunsaturated fatty acids (r = 0.883), animal protein (r = 0.908), milk protein (r = 0.924), and the ratio of n-6 to n-3 fatty acid intake (r = 0.792). It was less correlated with intake of total protein (r = 0.482, P < 0.05), was not correlated with intake of fish protein (r = 0.055, P > 0.1), and was inversely correlated with intake of vegetable protein (r = -0.941, P < 0.001). The multivariate analysis showed that increased intake of animal protein was the strongest independent factor with a weaker second factor, an increased ration of n-6 to n-3 polyunsaturated fatty acids. The present study in association with reported clinical studies suggests that increased dietary intake of animal protein and n-6 polyunsaturated fatty acids with less n-3 polyunsaturated fatty acids may contribute to the development of Crohn disease.

Adult↗