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N Usui

Publications and source records attributed to N Usui.

At least 19 recordsLinked to original sources
PubMed1992

Purification and characterization of a vitelline coat lysin from Ciona intestinalis spermatozoa.

In Ciona intestinalis a chymotrypsin-like activity is involved in sperm penetration of the egg vitelline coat. A chymotrypsin-like enzyme has been purified from spermatozoa by a protocol including ion exchange chromatography, gel filtration, and native polyacrylamide gel electrophoresis. The purified enzyme resulted homogeneous when analyzed by SDS-PAGE. The molecular weight of the chymotrypsin-like enzyme was estimated to be 35 kDa by gel filtration and 24 KDa by SDS-PAGE in nonreducing conditions. The pH optimum of the enzyme is 8.4 and its activity is enhanced by Ca2+. It shows the highest activity towards the synthetic substrate Suc-Ala-Ala-Pro-Phe-AMC. Furthermore, by electron microscopy, the purified enzyme affects the structure of egg vitelline coat, and thus it fulfills one of the criteria of a lysin.

Amino Acid Sequence↗
PubMed1992

Infection of the HTLV-I-harbouring T-lymphoblastoid line MT-2 by Epstein-Barr virus.

Epstein-Barr virus (EBV), a ubiquitous human B-lymphotropic virus, is associated with certain lymphoproliferative diseases of T-cell lineage. To understand the mechanism by which EBV infects T cells, we have tested the susceptibility of various human T-cell lines to the virus. We report here that the HTLV-I-harbouring T-lymphoblastoid line MT-2 carries a high level of CD21/EBV receptors on their surface, adsorbs fluorescein isothiocyanate-labeled EBV, and synthesizes virus latent antigens (EBNA-1 and LMP) following EBV infection. Pretreatment of MT-2 cells with anti-CD21 monoclonal antibody OKB7 inhibited the virus binding as well as the synthesis of virus latent antigen. These data suggest that human T-cells can be infected with EBV via functionally active virus receptors.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1992

Insulin-like growth factor-I supports formation and activation of osteoclasts.

Although the action of insulin-like growth factor-I (IGF-I) on bone formation has been extensively investigated, the effect of the factor on bone resorption is little known. We first examined the effect of IGF-I on bone resorption by preexistent osteoclasts by using unfractionated bone cells cultured on dentin slices. IGF-I had a dose-related effect of stimulating bone resorption by preexistent osteoclasts, whereas IGF-II did not. When IGF-I was added to cultures of bone cells after preexistent osteoclasts had degenerated on the dentin slices, IGF-I increased the number of osteoclastic multinucleate cells (MNCs) with tartrate-resistant acid phosphatase activity. Moreover, IGF-I augmented the area of pits produced by newly formed osteoclasts. These results suggest that IGF-I directly or indirectly stimulates osteoclast recruitment and activation. Therefore, we next examined the direct effect of IGF-I on osteoclastic MNC formation by using hemopoietic blast cells. In the presence of 1,25-dihydroxyvitamin D3, IGF-I, like granulocyte-macrophage colony-stimulating factor (GM-CSF), dose-dependently increased the number of TRAP-positive MNCs. This stimulatory effect of IGF-I was additive with that of GM-CSF. Both IGF-I and GM-CSF supported the survival of the blast cells, indicating that IGF-I as well as GM-CSF are supporting factors for osteoclast differentiation. In addition, the blast cells possessed high affinity binding sites for IGF-I, with a Kd of 0.8 nM. These data, thus, indicate that IGF-I stimulates osteoclastic bone resorption through its direct or indirect action of supporting the generation and activation of osteoclasts.

Animals↗
PubMed1992

[An early detection of the recurrence of serous cystadenocarcinoma of the ovary with the tumor marker CA125 levels].

We studied whether or not, and to what extent, it was possible to predict the recurrence of serous cystadenocarcinoma of the ovary by means of the tumor marker CA125 levels, in 35 treated cases of ovarian serous cystadenocarcinoma. The relationship between the change in CA125 levels and the frequency of recurrence was examined in two groups (recurrent group and non-recurrent group). When CA125 levels over 35U/ml were defined as positive for recurrence, the true positive rate was 22/23 in the recurrent group, and 0 in the non-recurrent group. When this cut-off level was lowered to 30U/ml, and then 25U/ml, the false positive rate in the non-recurrent group was increased to 1/12 and 4/12, respectively. A three-serial increase in CA125 levels was observed at the onset of recurrent cases including two cases with CA125 levels under 35U/ml, while it was not detected in any in the non-recurrent group. Analysis of the CA125 level increase pattern with a non-linear model showed that recurrence could be detected before the CA125 level reached 100U/ml in 13/19 (68.4%) cases if the interval between CA125 measurements was one mouth, and in 17/19 (89.5%) cases if the interval was two weeks. These results suggest that possibility that recurrence can be detected early.

Adolescent↗
PubMed1992

[Production of CA125 in cell lines derived from human ovarian carcinoma: in relation to the cell cycle].

The association of the production of CA125 with the cell cycle was investigated in two cell lines derived from human ovarian cancer, one from a serous cystadenocarcinoma (HTOA) and the other from a mucinous cystadenocarcinoma (RMUG-s). HTOA and RMUG-s cells secreted CA125 at about 50 and 30U/ml/10(5) cell/24hr, respectively, in the logarithmic growth phase and at about 75 and 100U/ml/10(5) cell/24hr in the steady phase. Analysis by FCM revealed that cultures of both cell lines cultured for 7 days contained more cells in the G0/G1 phase and less cells in the S phase than those cultured for 3 days. The positive rate of immunologically stained DNA polymerase alpha was 31% in HTOA cells and 39% in RMUG-s cells after cultivation of the cells for 3 days. The addition of EGF at 0.01, 0.1 or 1.0nM did not affect the production of CA125 in HTOA or RMUG-s cells while the addition of NaBT at 1, 3 and 5mM raised production in both cell lines as the dose rose. With RMUG-s cells, the addition of EGF at 0.01nM to the culture media accelerated both logarithmic and steady phase growth without a significant change in the production of CA125. In contrast, the addition of NaBT at 1mM suppressed growth, but tended to increase the production of CA125 per cell. With the effect of EGF on the cell cycle of both cell lines, cells in the S phase increased by about 20% as compared with the control, 48 hours after its addition at 0.01nM. In contrast, after cultivation for 48 hours in the presence of 1mM NaBT, cells in the S phase were decreased while those in the G0/G1 phase increased. The results presented above suggested the possibility that some factors other than the cell cycle were involved in the production of CA125. There also is close correlation between cells in the G0/G1 phase and the production of CA125 in the culture of human ovarian cancer cells.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

Effects of recombinant transforming growth factor-beta 1 on hematologic recovery after treatment of mice with 5-fluorouracil.

Transforming growth factor beta 1 (TGF-beta 1) has been shown to inhibit bone marrow colony formation after in vitro treatment as well as after in vivo administration to normal mice. These data suggest that TGF-beta might either protect, or further depress, progenitor cell levels in mice exposed to a cell cycle-active drug such as 5-fluorouracil (5FU). rTGF-beta 1 was administered repeatedly by either the i.v. or i.p. routes to mice during the hyperproliferative state of the bone marrow that occurs 7 to 9 days after the i.v. administration of 150 mg/kg 5FU. The formation of both multilineage and the more differentiated (CFU-c) colonies was inhibited by 20 to 40%/culture, and 66 to 93%/mouse. When multiple doses of rTGF-beta 1 were administered systemically immediately before the injection of 5FU, the resulting rebound in the number of CFU-c and multilineage colonies containing granulocyte, erythroid, megakaryocyte, and macrophage lineage colonies per culture was markedly inhibited by 30 to 77%, whereas the total number of CFU per mouse was inhibited up to 93%. This effect was maximal when rTGF-beta 1 was administered at daily doses of greater than or equal to 5 micrograms/mouse for at least 3 days. This inhibition of the recovery of the bone marrow from 5FU treatment induced by rTGF-beta 1 was a delayed transient response because by day 16 the progenitor cell numbers and bone marrow cellularity were identical to the 5FU-treated marrow controls.

Animals↗
PubMed1991

Reversal of drug resistance in a human colon cancer xenograft expressing MDR1 complementary DNA by in vivo administration of MRK-16 monoclonal antibody.

One strategy to overcome multidrug resistance in neoplasia is to inhibit the gp170 glycoprotein (relative molecular mass, 170,000) that functions as a plasma membrane, energy-dependent, drug-efflux pump. The human colon cancer cell line HT-29, which grows as an ascitic tumor in athymic NCr-nu/nu nude mice, was made multidrug resistant by infection with an MDR1 (also known as PGY1) retrovirus. Referred to as HT-29mdr1, it was used to study reversal of drug resistance in vivo by the anti-P-glycoprotein monoclonal antibody MRK-16. Flow cytometry and radioimmunoassay demonstrated a marked increase in MRK-16 reactivity on HT-29mdr1 cells as compared with its reactivity on the parental, uninfected cell line (HT-29par). The 50% inhibitory concentrations (IC50) of vincristine on HT-29par and HT-29mdr1 cells were 2.5 and 15 ng/mL, respectively. The MRK-16 monoclonal antibody did not affect the vincristine sensitivity of the HT-29par cells. Pretreatment of HT-29mdr1 cells with 10 micrograms/mL MRK-16 in tissue culture partially restored the vincristine sensitivity (IC50 = 7 ng/mL). This modulation of vincristine sensitivity by MRK-16 was then tested in vivo. The median survival times of mice given intraperitoneal transplants of 5 x 10(6) HT-29par or HT-29mdr1 were 37 and 39 days, respectively. Treatment of mice with 1 mg/kg vincristine weekly for 3 weeks, beginning 10 days after tumor injection, resulted in a significant increase in the median survival time of the HT-29par tumor-bearing mice (68 days, P less than .0001), but it had no effect on the HT-29mdr1 tumor-bearing mice. However, treatment of mice bearing the HT-29mdr1 tumor with MRK-16 before vincristine therapy reversed the resistance to the drug (median survival time = 64 days, P less than .0001). The MRK-16 monoclonal antibody alone had no effect on the median survival time of mice given an injection of either HT-29par or HT-29mdr1 cells. These results suggest that strategies employing monoclonal antibody against gp170 may be clinically useful to reverse multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

A role for the interleukin 1 receptor in the synergistic antitumor effects of human interleukin 1 alpha and etoposide against human melanoma cells.

To investigate the possibility that anticancer drugs combined with cytokines may show increased activity, human tumor cells were treated with combinations of human recombinant interleukin 1 alpha (rIL-1 alpha) and etoposide (VP-16). The cytotoxicity of these combinations was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay using rIL-1 alpha-sensitive A375-C6 melanoma cells and A375-C5 cells, a clonal variant line that is resistant to IL-1 alpha. Data were analyzed for synergism by the median effect principle of T-C. Chou and P. Talalay (J. Biol. Chem., 252: 6438-6442, 1977). At a dose ratio of VP-16 to rIL-1 alpha of 12 nM:1 unit/ml in either simultaneous or sequential exposure (VP-16 first), the calculated combination index values indicated synergistic cytotoxicity toward both A375-C6 cells and A375-C5 cells. IL-1 alpha treatment 24 h prior to VP-16 exposure had no advantage over simultaneous treatment. Surface IL-1 alpha receptors on both A375-C6 and A375-C5 cells were measured using 125I-radiolabeled rIL-1 alpha binding; A375-C6 cells had 701 +/- 128 (SD) receptor molecules/cell and A375-C5 cells only had 58 +/- 33 receptor molecules/cell. The dissociation constants for IL-1 alpha were similar in both cell types (19 +/- 6 pM for A375-C6 and 17 +/- 2 pM for A375-C5). The specific binding of rIL-1 alpha to the surface IL-1 alpha receptors of both sensitive and resistant cells was significantly increased in a dose-dependent fashion by the prior treatment with VP-16 (1.75-fold on A375-C6 cells and 3.5-fold on A375-C5 cells). VP-16 also enhanced the internalization of receptor-bound rIL-1 alpha, suggesting that a possible mechanism of the synergistic cytotoxicity of rIL-1 alpha and VP-16 might be related to the modulation of rIL-1 alpha receptors by VP-16, resulting in increased internalization of rIL-1 alpha.

Drug Administration Schedule↗
PubMed1991

Two major acrosomal proteins act on different parts of the oocyte vitelline coat in the abalone, Haliotis discus.

Two proteins of molecular weights 20,000 (20K) and 15,500 (15.5K) are the major soluble substances released from the acrosomal vesicle of the abalone, Haliotis discus, spermatozoon. A crude preparation of them has been shown to possess lytic activity on the oocyte vitelline coat (VC). To elucidate the role(s) of each acrosomal protein (AP) in VC lysis, oocytes were examined after treatment with various AP preparations. The VC, which is about 1 micron thick, is composed of thin outer and inner electron-dense layers and a thick main layer of a fine filamentous feltwork. When oocytes were treated with a crude preparation containing both APs, the outer layer disappeared and the feltwork of the main layer loosened extensively. A preparation containing predominantly the 20K AP dissolved the outer layer completely and the main layer to some extent, whereas another preparation containing predominantly the 15.5K AP caused loosening of the main layer without alteration of the outer layer, suggesting that the 20K AP acts on the outer layer, whereas the 15.5K AP acts on the main layer. However, when purified, each AP by itself failed to dissolve the VC, although lysis occurred in a 1:1 mixture of these preparations. Moreover, when the oocytes were pretreated with the 20K AP and thoroughly washed, the 15.5K AP alone could induce lysis. These results suggest that the lysis of the outer layer requires both APs but not simultaneously. The 15.5K AP, which is located posteriorly in the acrosomal vesicle, must be released to act on the VC following the action of the 20K AP.

Acrosome↗
PubMed1991

Focal segmental glomerulosclerosis associated with infantile spasms in five mentally retarded children: a morphological analysis on mesangiolysis.

We report five cases of nephrotic syndrome due to focal segmental glomerulosclerosis (FSGS) in mentally retarded children with severe infantile spasms. Four of the five children diagnosed as West syndrome, Lennox syndrome, or petit mal epilepsy also had cerebral palsy and microcephaly. The other patient had petit mal epilepsy without cerebral palsy and microcephaly. All patients first developed infantile spasms, with the time of onset ranging from 1 week to 2 years of age, and subsequently developed proteinuria, followed by the nephrotic syndrome at 3 to 14 years of age. Four of the five developed terminal renal failure between 7 and 11 years of age. Three subsequently died, but the other underwent kidney transplantation and is still living without further complications. The light, electron microscopic, and immunohistochemical studies performed on the renal biopsies from all the patients and on the autopsy specimens from two cases exhibited FSGS-like lesions. Besides segmental hyalinosis, differing degrees of mesangiolysis were seen, which sometimes developed into dissecting microaneurysms of the glomerular capillary loops. The clinical picture described can be differentiated from congenital nephrotic syndrome (CNS) or infantile nephrotic syndrome (INS) with respect to the age of onset, outcome, and morphological appearance. We reviewed the previous literature and extended earlier observations about an unusual association between the nephrotic syndrome due to FSGS-like lesion, mental retardation, infantile spasms, and/or microcephaly in children.

Adolescent↗
PubMed1991

[Distribution of inhaled aerosol using nasal nebulizer].

In this paper, we examined distribution and deposition of inhaled 99mTc aerosols in human respiratory tract, nebulization equipment and expired aerosols. Jet nebulizers were used and aerosols were inhaled through the nose. Results were as follows: 1. On normal breathing, deposition rate of human respiratory tracts in normal subjects were 22% of total dosage and there was no difference from sinusitis group. But, deposition rate of nasal cavity was higher than in sinusitis group normal in group. 2. In normal subjects, there was no influence of breathing pattern to deposition rate of nasal cavity. 3. Distribution of the lung was significantly increased on deep breathing in both groups. 4. Residual volume of nebulizer bottle were about 50% of total dosage.

Administration, Intranasal↗
PubMed1991

[A case of Günther vena caval filter insertion for recurrent pulmonary embolism].

We report that the Günther vena caval filter was successfully inserted in a case of recurrent pulmonary embolism resulting from ilio-femoral venous thrombosis. A 42-year-old woman was admitted to Osaka City University Medical School Hospital for dyspnea and chest pain on April 19, 1988. Pulmonary perfusion scintigraphy and pulmonary arterial angiography proved pulmonary emboli. The combination therapy of heparin and urokinase was performed, and her condition markedly improved. Then an ilio-femoral venography revealed only iliac vein compression but no thrombi. Therefore she was followed as an out patient with anticoagulant therapy. Nevertheless on April 10, 1989 she was admitted again complaining dyspnea and cyanosis. By venography at this time, some filling defects due to thrombi in right iliac vein were found. Therefore, we decided the insertion of the Günther vena caval filter for recurrent pulmonary embolism using Seldinger method via right internal jugular vein. We expect that the Günther vena caval filter will be useful for preventing pulmonary embolism resulting from ilio-femoral venous thrombosis because its procedure is easy, non-invasive and without significant complications.

Adult↗
PubMed1990

Tyrosinase-induced free radical formation from VP-16,213: relationship to cytotoxicity.

Tyrosinase-dependent activation of hydroxybenzenes forms reactive compounds, including catechols and o-quinones, and some of which show antitumor activity against pigmented melanomas. Since VP-16 is a phenoxy-containing antitumor drug, forms free radicals and reactive o-quinones during peroxidative activation, we evaluated the cytotoxicity of VP-16 to both tyrosinase-containing and non-tyrosinase-containing tumor cells. Our results show that VP-16 is significantly more cytotoxic to B-16/F-10 melanoma cells than human MCF-7 breast tumor cells. Phenylthiocarbamide, an inhibitor of tyrosinase activity, selectively decreased VP-16 toxicity only in melanoma cells. Furthermore, VP-16 was readily activated to its phenoxy free radical intermediate by purified tyrosinase, indicating tyrosinase may play a role in VP-16 toxicity in pigmented melanomas.

Animals↗
PubMed1990

Clinical courses and treatment of splenic artery aneurysms--report of 3 cases and review of literatures in Japan.

We have treated three cases of splenic artery aneurysms recently, so we reported them with a review of 181 cases in Japan. All three cases are women and have characteristic clinical courses and pathogenesis in each to which we performed a reasonable operation so that they could be saved. First one is a ruptured case. So we performed ligation of the splenic artery from inside the aneurysm under 9 min.'s clamp of the aorta. Second one was pointed out the splenic artery aneurysm during admission for cholecystectomy, so we performed splenectomy and aneurysmectomy, and after that we reconstructed the splenic artery with end-to-end anastomosis. Third one suffered from splenomegaly and portal hypertension. We performed splenectomy with the aneurysm. From the clinical and pathological findings, we concluded that an aneurysm in our first case was associated with arterial dysplasia, second with hemodynamic changes in parous women, and third with portal hypertension. Aneurysms of the splenic artery have been rarely reported until recently, when developments in diagnostic procedures made their discovery easier. We have diagnosed splenic artery aneurysm in three patients preoperatively. The clinical symptoms and operative procedure was different in each case, and are reported here. We demonstrated the summary of our three cases of that at Table 1.

Aneurysm↗
PubMed1990

[The possible association of Epstein-Barr virus and uveitis].

The possible association of Epstein-Barr Virus (EBV) with uveitis was investigated in 28 subjects with various types of uveitis. Serum or aqueous humor (AH) EB viral antibodies were measured in 28 uveitis patients and in 28 cataract patients as controls. Significant rises in EBV antibody levels were seen in 3 cases from the uveitis group. There was an 8-fold increase of the serum antibody titer in an infant subject, a 16-fold increase in the AH EB viral antibody titer in an adult subject, and a higher antibody quotient (10.2) compared with the serum and AH antibody titers in another adult case. No antibodies to EBV were detected in the AH in the control group. It appeared that EBV might have been involved in the pathogenesis of these 3 cases of uveitis. The clinical features of these cases were as follows. (1) A common cold-like prodrome was noted. (2) Severe acute anterior uveitis with fibrinous exudate was present at the onset. (3) A transition to chronic granulomatous anterior uveitis was seen in the 2 adult cases. (4) Little vitreous inflammation was present. (5) Marked hyperemia and swelling of the optic discs was noted. (6) At the onset there were no abnormal chorioretinal findings, except slight retinal vasculitis in the infant case. (7) Sunset-glow fundus appeared earlier in comparison with Harada disease in the adults and a retinal pigment epithelium disorder developed in the infant. (8) Bilateral involvement was seen in adults. (9) Good final visual acuity was recognized. (10) No systemic changes occurred in the course of the uveitis. This constellation of clinical features appears to comprise a new entity, i.e., EBV-associated uveitis.

Adolescent↗
PubMed1990

[Comparison by 31P magnetic resonance spectroscopy of effect of simple immersion and continuous perfusion methods on organ viability of preserved rat hearts].

31P magnetic resonance spectroscopy was used to measure high energy phosphates of the heart continuously as an index of the viability of the preserved organ together with the cardiac function after preservation. Results with the simple immersion (SI) and the continuous perfusion (CP) methods were compared. With SI, ATP decreased to 14.8 +/- 4.1% of the base line after 12 hr of preservation, and phosphocreatine decreased to 27.8 +/- 6.2% after 3 hr, remaining at about 30% of the base line thereafter. With CP, ATP and phosphocreatine were unchanged even after 24 hr of preservation; they were 99.1 +/- 2.6% and 119.6 +/- 6.7%, respectively. The ATP/Pi ratio was 5.4 +/- 0.7% after 12 hr with SI and 62.2 +/- 5.8% after 24 hr with CP. LV dP/dt was 96.6 +/- 11.5% after 3 hr of SI (3-SI), which was not significantly different from the control. After 6 hr of SI (6-SI), the value was 122.7 +/- 0.2%, significantly higher (p less than 0.01) than the control. After 9 hr of SI (9-SI) or after 24 hr of CP (24-CP), it was 80.8 +/- 4.6% and 67.8 +/- 8.2%, respectively, both were significantly lower (p less than 0.01) than the control. The rate-pressure product returned to the control level after 3-SI and 6-SI, but after 9-SI or 24-CP, it was 74.2 +/- 3.7% and 53.0 +/- 11.0%, and they were significantly (p less than 0.01) lower than the control.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1990

[Effect of adenosine on recovery of lowered viability of preserved rat hearts measured by 31P magnetic resonance spectroscopy].

The restoration of the viability of rat hearts preserved for 5 hr by 50 microM adenosine (ADN) was evaluated in terms of the cardiac function after preservation and the recovery of myocardial high energy phosphates measured by 31P magnetic resonance spectroscopy. The hearts were perfused with modified Krebs-Ringer's solution (mKRS) with ADN (ADN group) or without AND (non-ADN group) for 1 hour after 5 hr of preservation by the simple immersion method. Control hearts were perfused but not preserved. ATP and phosphocreatine had decreased to 47.2 +/- 6.6% and 28.0 +/- 8.6% of the base line by 5 hr of preservation, but the levels returned to 147.2 +/- 2.3% and 127.4 +/- 5.6% after 1 hr of perfusion with ADN; at the same time, in the non-ADN group, they were 103.8 +/- 2.3% and 115.8 +/- 8.3% respectively. The same hearts were next perfused for 3 hr with standard Krebs-Ringer's solution so as to beat after the perfusion with mKRS. After 3 hr of beating, LV dP/dt was 3330 +/- 116 mmHg/s in the ADN group, which was not significantly different from the control (3034 +/- 60 mmHg/s). However, in the non-ADN group, the value was 2516 +/- 201 mmHg/s and significantly lower (p less than 0.05) than the control. The rate-pressure product was 19350 +/- 1154 in the ADN group, not significantly different from the control (20899 +/- 709), but it was 14559 +/- 1339 in the non-ADN group, which was significantly lower (p less than 0.01) than the control.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗