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Biomedical subjects

N Kondo

Publications and source records attributed to N Kondo.

At least 505 records · Page 28Linked to original sources
PubMed1987

Role of unique consecutive glutamine repeats in active murine interleukin-2 molecule.

Murine interleukin-2 (MIL-2) cDNA deleted of 11 repeats of a CAG sequence, and that encoded from 33Met to 149Gln were inserted into an expression vector carrying an Escherichia coli tryptophan promoter and were expressed in E. coli, respectively. Recombinant MIL-2 deleted of 11 glutamine repeats (MIL-2(-Gln] supported the growth of murine CTLL-2 cells but recombinant MIL-2 initiated from 34Asp (34Asp-MIL-2) did not. The growth of human T-cell blasts was not supported by MIL-2(-Gln) or 34Asp-MIL-2. MIL-2(-Gln) had identical biological and immunological activities with intact MIL-2, but 34Asp-MIL-2 did not. These results suggest that the consecutive glutamine repeats do not play a role in the biological and immunological activities of MIL-2, but that the peptide sequence around them does, and the species hierarchy that MIL-2 does not act on human lymphocyte is not due to the presence of glutamine repeats in MIL-2.

Animals↗
PubMed1987

The interaction of recombinant IL-2 with human resting lymphocytes: blocking effects of monoclonal antibodies to IL-2 receptors.

Several lines of evidence suggest that subsets of resting lymphocytes naturally express interleukin-2 receptors (IL-2.R). Recombinant IL-2 (rIL-2) induced the enhancement of natural killer (NK) activity, the generation of activated killer (AK) cells, the proliferation of resting lymphocytes, and the production of interferon-gamma (IFN-gamma) in lymphocyte cultures. The subsets of lymphocytes mediating these responses appeared to be heterogeneous, but reside predominantly in nylon wool-passed non-T, non-B cells ("null cells" or T3- cells); in response to rIL-2, only Leu 11+T3- cells showed enhanced NK activity, and both Leu 11+T3- and Leu11-T3- cells showed predominantly AK activity, proliferation and production of IFN-gamma. These findings suggest that the T3- fraction (null cell fraction) contains predominantly cells expressing IL-2.R at the resting state. Unlike the case with activated T cells, however, none of these responses was blocked by any of three monoclonal antibodies to IL-2.R, including anti-Tac antibody at any dilution. These results indicate that IL-2.R on the resting T3- cells possess unique biological features compared to those on activated T or B cells. A most likely explanation is that T3- cells possess higher affinity IL-2.R than activated T or B cells. Other possibilities are also discussed.

Antibodies, Monoclonal↗
PubMed1987

Electrophysiological effects of Ca antagonists, tetrodotoxin, [Ca]o and [Na]o on myocardium of hibernating chipmunks: possible involvement of Na-Ca exchange mechanism.

The electrophysiological performance of myocardium of hibernating chipmunks was investigated in the presence of Ca antagonists and tetrodotoxin, and the effects of high [Ca]o and low [Na]o were examined. The action potential of the preparations was characterized by the low amplitude of the plateau phase (APp). Ca antagonists, nifedipine (10(-6) M) and nitrendipine (2 X 10(-6) M), did not significantly inhibit this APp or the contraction. These nifedipine-insensitive electromechanical responses were completely abolished by an internal Ca release inhibitor, ryanodine. Both increasing [Ca]o and lowering [Na]o, by replacing Na by lithium or choline, also inhibited APp. Tetrodotoxin (10(-5) M) which markedly inhibited the initial rapid phase of the action potential slightly affected APp. These results suggest that the plateau potential of the present preparations is controlled by a process linked to Ca release from internal stores, most likely the Na-Ca exchange mechanism.

Action Potentials↗
PubMed1987

[A case report of successful immunochemotherapy of metastatic renal cell carcinoma using UFT and PSK].

The authors have monitored a case of renal cell carcinoma metastatic to the supraclavicular cavity over a twenty-year period following surgical removal of a cancerous kidney. The subject was a 67-year-old male who had his right kidney removed in 1963 because of renal cell carcinoma. In September of 1983, complaints of pain and an enlarged tumor in the left supraclavicular cavity during a physical examination led to a pathological diagnosis of clear cell carcinoma. Although chemotherapy using FT-207+ PSK was ineffective, there was a response to UFT+ PSK therapy which was deemed effective according to the criteria of Koyama and Saito. The findings suggested that UFT was effective in this case.

Aged↗
PubMed1987

[Clinical observation of pheochromocytoma].

Eleven cases of pheochromocytoma observed at our department between 1976 and 1985 are presented. There were 5 males and 6 females and they were between 18 and 59 years old. The site of the tumor was in the right adrenal in 4 cases, left adrenal in 3 cases, bilateral adrenals in 2 cases and extra adrenal in 3 cases, 1 of which had multiple lesions and involvement of the right adrenal. Clinical symptoms observed were hypertension in 10 cases, headache in 7 cases, palpitation in 3 cases and nausea in 2 cases. Atypical adrenal pheochromocytoma was seen in 1 case. Definitive diagnosis was established by determination of urinary catecholamine levels in the 24-hour sample. Urinary levels of catecholamine revealed higher adrenaline levels for paroxysmal type and higher nor-adrenaline levels for extra-adrenal cases. For localization of tumors, computed tomography was most useful with a diagnostic rate of 100%, followed by ultrasonography and adrenal scan. As preoperative treatment, blood transfusion and administration of adrenergic blocking agents were performed in 9 cases. In all but 2 cases, hypertension was improved and no recurrence was seen after the operation.

Adolescent↗
PubMed1987

[Surgical treatment of "inflammatory" aneurysms of the abdominal aorta].

Two cases of "Inflammatory" aneurysm of the abdominal aorta and a review of this type of lesion were presented. The incidence of inflammatory aneurysm of the abdominal aorta in the literature is 2.5 to 15%, but there were no detail reports concerning with this in Japan. The pathogenesis is not clear, but it is evident both macroscopically and microscopically that the inflammatory aneurysms are different from athelosclerotic ones. They are characterized by perivascular peel of inflammatory fibrous tissue. It is possible that this type of aneurysms are merely a variant of Takayasu's disease. Until recently, the diagnosis of this type of aneurysm has not been made before surgery. The symptom of abdominal pain, weight loss, elevated ESR in a patient with abdominal aortic aneurysm are highly suggestive an inflammatory aneurysm. Characteristics of CT scan lead to more frequent preoperative diagnosis of inflammatory aneurysms of the aorta. It reveals a thickened often calcified aortic wall surrounded by a soft tissue mantle. Dynamic scanning shows an enhancing perianeurysnal mass. Graft replacement in these patients is often difficult and associated with increase in morbidity and mortality. At surgery, no attempt should be made to mobilize adjacent viscela in order to avoid injury. Arterial control should be obtained with as little as possible dissection. Some reports refer to successful steroid therapy resolving the inflammatory process and alleviating symptoms. Further research may resolve the treatment of choice for this type of lesion and optimize the timing of surgery.

Aneurysm, Infected↗
PubMed1987

[A clinical study on 34 cases of urothelial cancer of upper urinary tract].

Thirty-four cases of tumor of the renal pelvis or ureter or both have been treated in our department during the past decade. The primary tumor was in the renal pelvis in 11 cases, in the ureter in 21 cases and in the ureter and renal pelvis in 2 cases, a co-existent tumor in the bladder was found in 4 cases. Seventeen patients had a tumor on the right side and 17 on the left side. The most frequent symptom was gross hematuria (70.6%) and flank pain was the presenting symptom in 7 cases (20.6%). On the intravenous pyelography, a filling defect in the renal pelvis or ureter (41.2%) and nonvisualization (53.0%) were frequent findings. Twenty-nine cases had undergone total nephroureterectomy with resection of a bladder cuff, 3 had simple nephrectomy and 2 had open biopsy alone. Postoperative radiation therapy was done in 1 case, chemotherapy in 10 cases, and 6 cases of them were treated by CAP therapy (cis-dichlorodiamine platinum, doxorubicin and cyclophosphamide). Actual and relative 5-year survival rates were 53.8% and 63.5%, and no significant difference was found in survival rate between the patients with renal pelvic tumors and those with ureteral tumors.

Aged↗
PubMed1986

Excitation-contraction coupling in the myocardium of hibernating chipmunks.

In the myocardium of nonhibernating chipmunks, replacing external Ca by Sr markedly prolongs the action potential plateau with an increase in contraction, while in preparations from hibernating animals this procedure inhibits both responses. Pretreatment with 4-aminopyridine causes a prolongation of the action potential plateau by Sr in hibernating animals.

Action Potentials↗
PubMed1986

Initial bone-implant interfaces of submergible and supramergible endosseous single-crystal sapphire implants.

Three types of bone-single-crystal sapphire implant interfaces were histologically determined in submergible and supramergible implant: direct bone apposition (type I), thin connective tissue with poor collagen fibers (type II), and dense fibrous connective tissue (type III). Type I interface was predominant and type III interface was sparsely seen in submergible implants. In contrast to these findings, type III interfaces frequently appeared in supramergible implants, primarily at the apical region. These differences were considered to occur by the biomechanical variable of postoperative healing.

Aluminum↗
PubMed1986

Temperature-dependent inotropic action of A23187 on guinea-pig ventricular muscles.

The effects of the Ca2+ ionophore, A23187, on the contraction and membrane action potential of the isolated guinea-pig papillary muscle were examined at various temperatures (30-16 degrees C) and compared to those of isoprenaline and a high calcium medium. A23187 caused a marked positive inotropic effect with a significant prolongation of the action potential duration at an early repolarization phase but not a late repolarization phase at normal temperature (30 degrees C). Such an inotropic effect was completely abolished at low temperature (16 degrees C) where a marked positive inotropic effect of isoprenaline (5 X 10(-8) M) and a high calcium medium (6.2 mM) still remained. These results suggest that the cardiac responsiveness to A23187 was sensitive to a low temperature at which a membrane lipid phase transition may occur.

Action Potentials↗
PubMed1986

Electromechanical effects of A23187 on guinea-pig ventricular muscle: a dual action of A23187.

The effects of A23187 on electromechanical activity of guinea-pig papillary muscles were examined by microelectrode techniques. A23187 (10(-6) M) caused a marked positive inotropic effect (868% of control) on preparations driven at 0.2 Hz. This inotropic effect was accompanied by a significant prolongation of the action potential duration at an early repolarization phase (APD 10), but not at a late repolarization phase (APD 30 and APD 80). Other parameters of action potential were unaffected. In the presence of nifedipine (10(-6) M), Ca2+ channel blocker, A23187 still increased the contractile force (495% of control) but had no effect on APD 10. On the other hand, APD 30 and APD 80 were significantly shortened. In the presence of ryanodine (2 X 10(-6) M), an inhibitor of internal Ca2+ release, A23187 was also able to cause the positive inotropic effect (389% of control). This inotropic effect was accompanied by a prolonged APD 10. These electrical and mechanical effects of A23187 were completely blocked by the combined treatment with nifedipine and ryanodine, suggesting that A23187 has a dual action. In papillary muscles depolarized by 26 mM [K+]0, A23187 augmented the slow action potential. In voltage clamp experiments using a single sucrose-gap method, A23187 caused a marked increase in the slow inward current and the outward current. The effects of A23187 were not antagonized by a beta-adrenoceptor and a histamine (H2) receptor antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Immunopathological studies of an autopsy case with Goodpasture's syndrome and systemic necrotizing angiitis.

A rare autopsy case of Goodpasture's syndrome with systemic necrotizing angiitis is reported. The patient, a 56-year-old male, died of respiratory failure with massive pulmonary hemorrhage and renal failure. The autopsy showed widespread hemorrhage in both lungs, diffuse crescentic glomerulonephritis, and systemic necrotizing angiitis in the small arteries. Immunofluorescence studies demonstrated a linear deposition of IgG along the glomerular basement membrane (GBM) as well as the alveolar basement membrane. A granular deposition of C3 was also found along the GBM. Electron microscopy showed that the GBM was irregularly thickened and wrinkled, but electron-dense deposits were indistinct. Anti-GBM antibody activity was detected in the patient's serum and had cross reactivity with normal alveolar basement membrane. The renal eluates contained IgG antibody activity for normal human GBM. These results suggest that glomerulonephritis and pulmonary hemorrhage in the present case were mediated by anti-basement membrane antibodies. We also discussed whether anti-basement membrane antibody is involved in the pathogenesis of systemic necrotizing angiitis.

Anti-Glomerular Basement Membrane Disease↗
PubMed1986

Electromechanical effects of okadaic acid isolated from black sponge in guinea-pig ventricular muscles.

Okadaic acid is a monocarboxylic acid with a unique molecular structure of C44H66O13. Okadaic acid, at concentrations above 10(-5) M, caused a dose-dependent increase of contractile force in guinea-pig isolated ventricular muscles. The increase of contractile force by okadaic acid (1-4 X 10(-5) M) was accompanied by a prolongation of action potential duration (a.p.d.), while a.p.d. was shortened by okadaic acid at above 10(-4) M. The okadaic-acid-induced changes in contractile force and a.p.d. were abolished by pre-treatment with verapamil (2 X 10(-6 M) or nifedipine (10(-6) M). In a low-Ca2+ medium (0.12 mM), the contractile response to okadaic acid (4 X 10(-5) M) was inhibited, whereas the a.p.d. was more prolonged by the drug than in a control medium (containing 1.2 mM-Ca2+). In a low-Na+ (70 mM) medium or in a low-Na+ (70 mM) and low-Ca2+ (0.12 mM) medium both the contractile force and a.p.d. were unaffected by okadaic acid (4 X 10(-5) M). The positive inotropic effect of okadaic acid (4 X 10(-5) M) was not inhibited by treatment with tetrodotoxin (TTX, 2 X 10(-6) M) or with ryanodine (2 X 10(-6) M). In voltage-clamp experiments using a single sucrose-gap technique, okadaic acid (4 X 10(-5) M), caused a significant increase of slow inward current, while it did not affect the net outward current. These findings suggest that okadaic acid has a positive inotropic effect on the heart, probably due to the enhancement of slow Ca2+ and/or Na+ inward current through the cell membrane.

Action Potentials↗
PubMed1986

Excitation-contraction coupling in myocardium of nonhibernating and hibernating chipmunks: effects of isoprenaline, a high calcium medium, and ryanodine.

The electromechanical responses to isoprenaline and a high calcium medium on cardiac muscles from nonhibernating and hibernating chipmunks were studied in the presence and the absence of ryanodine. In nonhibernating animal preparations, isoprenaline (5 X 10(-8) M) caused a marked positive inotropic effect with an increase in the amplitude of the action potential plateau and augmented the slow action potential in muscle depolarized with 26 mM K+. In hibernating animal preparations, isoprenaline failed to cause a positive inotropic effect in spite of an increase in the amplitude of action potential plateau and slow action potentials. Similar inotropic effects were caused in the two preparations when extracellular calcium was raised to 6 mM, but action potential plateau and slow action potentials of the two preparations were less affected by this procedure; only in nonhibernating animal preparations was the amplitude of the slow action potential slightly increased. Ryanodine (2 X 10(-6) M) partially inhibited the contraction but augmented the action potential plateau and slow action potentials in nonhibernating animal preparations, while in hibernating animal preparations, it eliminated the contraction and severely inhibited the action potential plateau and slow action potentials. The electrical effects of isoprenaline on the two preparations and of a high calcium medium on nonhibernating animal preparations were more pronounced in the presence of ryanodine than in the absence of it. However, the electrical activity on hibernating animal preparations was unaffected by a high calcium medium in either the presence or absence of ryanodine.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗