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Biomedical subjects

T Sakurai

Publications and source records attributed to T Sakurai.

At least 685 records · Page 38Linked to original sources

Monocyte-mediated suppression of T lymphocyte blastogenesis and its reversal by deoxyguanosine. Defects in patients with systemic lupus erythematosus.

We investigated monocyte-mediated suppression of T lymphocyte blastogenesis in normals and patients with systemic lupus erythematosus (SLE). When monocytes from normals were cocultured with autologous T lymphocytes with a ratio of 1:1 and stimulated with phytohemagglutinin (PHA), 3H-thymidine incorporation by T lymphocytes was suppressed. This monocyte-mediated suppression was reversed by purine nucleoside phosphorylase substrate, deoxyguanosine. In SLE patients, both monocyte-mediated suppression and its reversal by deoxyguanosine were defective. The defective function was observed both in patients with active and inactive diseases. The defective function was studied sequentially before and after change in the clinical status of patients. The defects remained unaffected regardless of the disease activity. The defects in monocyte-mediated suppression and its reversal by deoxyguanosine in SLE patients as demonstrated in our study suggest the presence of intrinsic monocyte dysfunction in SLE.

Adult↗

Bladder inhibition by electrical stimulation of the perianal skin.

Transcutaneous electrical stimulation was applied to the perianal skin of 25 patients with frequency, urgency or incontinence. Repeated cystometrogram during this stimulation disclosed suppression of detrusor activity, inhibition of detrusor instability in 4 of 8 patients and increase of maximum cystometric capacity in 5 of 25 patients. Electromyographic activity of the anal sphincter muscle increased in all the 25 patients. Poststimulation improvement was observed clinically in 9 of 12 patients.

Anal Canal↗

Flow velocity measurement using digital subtraction angiography for hemodynamic evaluation in arterial occlusive disease.

A method for mean flow velocity measurement using digital subtraction angiography (DSA) was evaluated, along with the results of phantom and animal experiments. The validity of its clinical use was studied by applying this technique in the arteries and bypass grafts in patients with arterial occlusive disease. Mean flow velocity was reliably determined by this method, but it could not be used as a determinant of arterial occlusive disease, because of a considerable overlapping between limbs with and without significant arterial lesions. A low value of mean flow velocity was not itself a reliable prognostic indicator of bypass failure. However, measurement of mean flow velocity was valuable in detecting functional abnormalities of the graft.

Animals↗

Mechanisms of pharmacokinetic interaction between ajmaline and quinidine in rats.

In order to elucidate the mechanism of ajmaline-quinidine interaction previously observed in humans, the effects of quinidine on pharmacokinetics of ajmaline were investigated in rats. Concurrent oral administration of 10 mg/kg of quinidine markedly increased the plasma concentration of ajmaline at a dose of 2 mg/kg. On the other hand, it did not affect the pharmacokinetics of ajmaline after intravenous dose. The availability of ajmaline after oral dose showed an increase from 13% to nearly 100% by the presence of quinidine, which suggests a change in the presystemic clearance of ajmaline. In fact, when ajmaline was administered into the intestinal loop, its concentration in mesenteric venous plasma increased approximately 5-fold by the combination with quinidine. Furthermore, quinidine delayed the elimination rate of ajmaline from the perfused rat liver. These results indicate that quinidine prevents presystemic elimination of ajmaline in the intestine and liver, and increases the systemic availability of ajmaline.

Ajmaline↗

Relapsing process in FAB subtypes of adult acute leukemia and its relationship to treatment regimens.

The relapsing process in the bone marrow was studied in those 77 patients with adult acute leukemia, diagnosed according to the FAB classification who achieved complete remission (CR) and then received intermittent multi-drug intensification treatment. Relapse occurred in most of the patients who exhibited Auer rods or Ph1 chromosomes in the bone marrow, or in whom blasts increased to 8% or more, but some patients remained in CR by subsequent treatment, that is, relapsing process was reversible. With our conventional treatment, the relapse or relapsing process occurred in most of the patients with L1, L2 and M1 subtypes within 6 months and was irreversible. It occurred mainly between 5 and 13 months in those with M2, M3 and M5 and was reversible in some cases. Patients with M4 subtype received intensified treatment due to the difficulty of achieving remission; relapse was seen in only 3 of 7 cases. To prevent relapse and attain a potential cure, the treatment should be intensive before the relapsing process with adequate supporting care. In view of the above-mentioned observations, our new treatment protocols for acute leukemia were designed to be more intensive than those conventionally employed, and to be discontinued within approximately 10 months in lymphoblastic leukemia and approximately 8 months in myeloid leukemia.

Adult↗

The effect of food dye and other environmental substances on the host defense reaction in mice in relation to virus infection.

Environmental substances were examined for their effect on interferon induction and delayed type hypersensitivity (DTH) responses in mice. Amaranth, safrole, phenacetin and nicotine suppressed the DTH response, and suppressed the serum interferon titers induced by virus infection. However, they did not affect the interferon titers which were induced by tilorone, a chemical inducer. The peak of interferon titer was 12 hours after infection with herpes simplex virus type 2 (HSV-2). Therefore, amaranth, safrole, phenacetin and nicotine were given to mice intraperitoneally 24 hours before, and 2 and 18 hours after infection with HSV-2. It was found that safrole and nicotine shortened the mean survival time of HSV-2 infected mice when they were given to mice 2 hours after virus inoculation. Amaranth and phenacetin showed similar effects. However it was not definite statistically. In biochemical and hematological tests, these four substances did not affect the functions of liver, kidney and carbohydrate metabolism in normal mice. These results suggest that substances which may often be taken into the body have the potential to affect the onset of virus infectious diseases as a result of the suppression of the host defense reaction.

Animals↗

Enhanced Fc receptor function of monocytes from patients with clinically active systemic lupus erythematosus: binding and degradation of soluble immune complexes in vitro.

The in vitro Fc receptor function of monocytes as measured by using soluble immune complexes (IC) consisting of ovalbumin and 125I-labeled antibody to ovalbumin was examined in serum-free medium. Adherent monocytes were obtained from peripheral blood of 18 patients with systemic lupus erythematosus (SLE; 6 active, 12 inactive) and 13 normal controls. 5 X 10(5) monocytes were incubated with soluble IC containing 20 ng IgG for 16 hr at 4 degrees C, and for 4 hr and 16 hr at 37 degrees C, and then cell-associated and acid-soluble radioactivities were counted. After 16-hr incubation at 4 degrees C, there was no significant difference in the amount of cell-associated IC between monocytes from SLE patients and those from normal controls. After 4 hr incubation at 37 degrees C, monocytes from patients with active SLE bound and phagocytized more IC than those from patients with inactive SLE or from normal controls (P less than 0.01). After 16 hr incubation at 37 degrees C, degradation of soluble IC by monocytes from patients with active SLE greatly increased (P less than 0.003). These findings were discussed in relation to the possible pathophysiologic role of the mononuclear phagocyte system in SLE.

Adult↗

[Cisplatin, methotrexate and peplomycin in the treatment of esophageal carcinoma].

Sixteen patients with advanced or recurrent squamous cell carcinoma of the esophagus were treated with cisplatin 80 mg/m2 i.v. on day 1, methotrexate 40 mg/m2 i.v. on day 2 and peplomycin 15 mg/day 24 hours continuous subcutaneous infusion from day 2 to day 5. Each course was repeated every 3 weeks. The overall response rate was 56% (9/16) with no complete response. Of 10 patients with no prior therapy, 7 (70%) showed partial response. Toxic effects were acceptable with no fatalities, but severe nausea and vomiting (56%), transient nephrotoxicity (44%), anemia (44%), thrombocytopenia (31%) and leukocytopenia (19%) occurred. No clinical evidence of pulmonary toxicity was seen. The dose-limiting toxic effect of this regimen was myelosuppression.

Adult↗

[Immunological background of patients with dilated cardiomyopathy and myocarditis: clinical and experimental studies].

Immunogenetic mechanism may be involved in the pathogenesis of idiopathic cardiomyopathy. Viral myocarditis is considered a cause of dilated cardiomyopathy. In this study, we examined the major histocompatibility complexes (human leukocyte antigens: HLA) by microdroplet cytotoxicity test, lymphocyte subsets by laser flow cytometry, and the activity of lymphocyte blastoformation induced by phytohemagglutinin (PHA) and concanavalin A (Con A) in patients with cardiomyopathies (DCM) and myocarditis (MC). We also examined the incidence and histopathology of encephalomyocarditis (EMC) virus myocarditis in inbred strains of mice, and serial changes of T- and B-lymphocytes in the peripheral blood of DBA/2 mice inoculated with EMC virus by immunofluorescence techniques. The results were as follows: Major histocompatibility complex (HLA and H-2); HLA-B12 in patients with DCM and HLA-DR8 in patients with MC were more frequent than in controls. In EMC virus infection, differences were found in the frequency of occurrence of MC in inbred strains of A/J (H-2a), C57BL/6 (H-2b), BALB/c (H-2d), DBA/2 (H-2d) and C3H/He (H-2k) mice. Genetic mechanism may play a role heart similar to lesions in patients with DCM were seen in DBA/2 mice in the chronic stage of MC. in susceptibility to virus infection. Lymphocyte population study; OKT 8 (suppressor T-cell) was significantly lower in patients with DCM and hypertrophic cardiomyopathy (HCM) than in controls. There were no significant changes of lymphocyte subsets in patients with MC as compared with the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Cell-mediated amegakaryocytic thrombocytopenia associated with systemic lupus erythematosus.

We studied a patient with a rare complication of amegakaryocytic thrombocytopenia (AMT) associated with systemic lupus erythematosus (SLE). To investigate the underlying pathogenesis of AMT, the effects of peripheral blood T cells and serum on human megakaryocyte progenitor cells were studied using in vitro coculture techniques. Mononuclear bone marrow cells (2 X 10(5) from normal donors produced 33.6 +/- 8.8 (n = 10) colony-forming unit-megakaryocytes (CFU-M) in our plasma clot system. When 2 X 10(5) of the patient's T cells were added to the culture system, the number of CFU-M decreased to only 3.5 +/- 0.6/2 X 10(5) bone marrow cells. No evidence of inhibitory effects was found by the addition of the patient's serum and complement to the culture system. The T cells stored at -80 degrees C on admission were also capable of suppressing autologous CFU-M after recovery from AMT. These results indicate that in vitro suppression of CFU-M from allogenic and autologous bone marrow cells by this patient's T cells provides an explanation for the pathogenesis of AMT associated with SLE.

Bone Marrow↗

[Results of brachytherapy of tongue cancer].

One hundred thirty-two patients with primary cases of squamous cell carcinoma of the tongue treated at National Sapporo Hospital from 1972 to 1982 were reviewed. Most primary sites were treated with interstitial needle implant with or without external beam irradiation. The local control rate by needle implant for the primary tongue lesions was 85.5%. That for the single plane implant was especially notable at 92.5%. The cumulative five-year survival rate was 92.8% in stage, I, 74% in stage II, 53.2% in stage III, 12.5% in stage IV and 64% overall.

Adult↗

[A long ureteral polyp with ureteropelvic junction obstruction: report of a case].

A case of long ureteral polyp with ureteropelvic junction obstruction in a 29-year-old man is reported. He had complained of occasional left flank pain since several years earlier. Excretory urography showed left giant hydronephrosis and no urolithiasis. Retrograde pyelography revealed a mass lesion of the left upper ureter. At exploration, the left ureteropelvic junction was found to be obstructed by an aberrant lower pole renal vessel. At just distal of the junction, a finger-like ureteral polyp, 5 cm in maximal length, was present and accompanied with several little polyps. Partial ureterectomy and pyeloplasty improved the left hydronephrosis. The patient remains symptomless for one year after the operation.

Adult↗

[Results of several combination modalities for maxillary cancer].

Two hundred forty-six patients with the histologically proved squamous cell carcinoma of the maxillary sinus were treated at the Department of Radiology, National Sapporo Hospital, with various combined modes of surgery, irradiation and chemotherapy. Four combination modalities were used from 1966 to 1983. One hundred sixty-three (66.3%) patients were men and 83 (33.7%) were women. Five-year survival was 41.0% in T2 (16 cases), 22.3% in T3 (176 cases) and 15% in T4 (53 cases). In 72 cases treated since 1978 with tumor reduction as completely as possible, five-year survival was 43.5%. We recommand tumor reduction as complete as is possible and 40-50 Gy irradiation.

Adult↗