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Biomedical subjects

R Sasaki

Publications and source records attributed to R Sasaki.

At least 109 records · Page 6Linked to original sources
PubMed1997

Developmental characteristics of temporal control of movement in preschool and school children of different ages.

The purpose of this study was to investigate the temporal control of repetitive tapping in children, ages 3 to 11 (N = 99). The subjects tapped in synchrony with an auditory pulse (synchronizing phase) at nine different tempos (interpulse intervals of 370, 420, 500, 540, 620, 720, 850, 1000, and 1300 msec.) and were then asked to maintain the same tapping tempo without the aid of an auditory pulse (continuing phase). The time difference between the onset of the pulse and the tap in the synchronizing phase and intertap interval in the continuing phase were measured. Both the time difference between the timing pulse and the tap, and variation of intertap intervals were smallest at the tempo of 500 msec. for all age groups. The variation of the intertap interval at slower tempos was greater than that at fast tempos in all age groups. This suggests that the accurate interval (tempo) of all the subjects was around 500 to 600 msec. At slower tempos, the intertap interval had a tendency to become slightly shorter with time and converged at intertap interval 500 to 600 msec. It is suggested that the preferred tempo was superior to the prescribed tempo in the continuing phase for younger subjects. Differing patterns of response in the movement sequence were observed between younger and older subjects in the movement sequence. The changes in temporal control over the age groups are thought to appear at between 5 and 7 years of age.

Age Factors↗
PubMed1997

[Experience in treatment of patients with locally advanced or recurrent breast cancer: intraarterial infusion chemotherapy combined with radiotherapy].

For the purpose of local control and breast conservation, intraarterial infusion chemotherapy combined with radiotherapy has been indicated in patients with locally advanced breast cancer both in primary and recurrent cases. The present series, evaluated during the past 4 years, consisted of 15 patients 35-83 years of age, with invasive ductal carcinoma, including 10 with primary breast cancer (stage IIIb: 1; IV: 9) and 5 with postoperative recurrence (stage IIIb: 2, IV: 3). Intraarterial chemotherapy is started, basically infusing ADM 50 mg, MMC 10 mg and CDDP 50 mg into the internal thoracic and/or subclavian artery 1-3 times, followed by reduction surgery (quadrantectomy: 4, wide resection: 2) and radiotherapy to the breast, supraclavicular, parasternal and cervical regions according to tumor extent. Local response after arterial infusion was CR: 2, PR: 10, NC: 3 (response rate: 73%). The response rate of distant metastases after arterial infusion was 73%. Of 10 patients with primary breast cancer, recurrence was noted in 1. Breast conservation was successful in 8 of 10 patients. One of them, in stage IIIb, has survived for 4.5 years with no evidence of disease and with breast conservation. Five patients with postoperative recurrence showed CR with no recurrence after intraarterial chemotherapy and radiotherapy. Acute skin reaction occurred in 6 patients, and was especially frequent in patients with postoperative recurrence (4 of 5). According to these results, combined therapy affords breast conservation even in patients with locally advanced breast cancer, and improves patient's QOL in stage IV.

Adult↗
PubMed1997

Chronic exertional compartment syndrome in lower legs: localization and follow-up with thallium-201 SPECT imaging.

UNLABELLED: The purpose of this study was to ascertain whether 201Tl SPECT imaging of the leg is useful in precise localization of the ischemic compartment involved in chronic exertional compartment syndrome (CECS). METHODS: Imaging and quantitative analyses of postexercise 201Tl SPECT leg examinations were retrospectively performed in nine patients with clinically diagnosed CECS and eight control subjects. Imaging and quantitative criteria for the ischemic compartment were decreased 201Tl perfusion less than the lower limits of normal, which were defined as 2 s.d. below the mean percentage uptake of the control subjects. The SPECT imaging results were compared with those of quantitative analysis, postoperative SPECT images and clinical diagnoses. RESULTS: Postexercise normal legs had nonuniform 201Tl distribution in both legs and in the four compartments. Lower limits of normal mean percentage 201Tl uptake were about 60% for the anterior compartment and about 50% for the other three compartments. Redistribution was observed in 67% of normal compartments in the control subjects. The SPECT images demonstrated 16 ischemic compartments in eight of the nine patients. The SPECT results were consistent with those of quantitative analysis. There were discrepancies between the clinical and SPECT diagnoses in six legs (33% of the 18 legs) of five patients. Postoperative SPECT demonstrated 201Tl perfusion was improved in all involved compartments for that fasciotomy was performed. CONCLUSION: Thallium-201 SPECT imaging of the legs can easily provide precise localization of the ischemic compartment, which is demonstrated as decreased 201Tl distribution on the stress image. This technique is promising for the screening and follow-up of CECS.

Adult↗
PubMed1997

Chloroquine induces basophilic differentiation of HL-60 cells.

Many agents have been known to induce the differentiation of HL-60 cells. However, only a small number of reports on the basophilic differentiation of this cell line are known. In this study we show that the exposure of HL-60 cells to chloroquine induces to differentiate into basophils. This chloroquine-induced change suggests that the increase in intracellular pH and the upregulation of p21 with subsequent downregulation of cdc2 kinase are triggers for basophilic differentiation of this cell line.

Basophils↗
PubMed1997

B cell malignancy and hepatitis C virus infection.

Italian authors report that hepatitis C virus (HCV) infection may be one of the causes of lymphoid malignancy such as non-Hodgkin's lymphoma (NHL) and Waldenström's macroglobulinemia (WM). To assess the relationship between HCV infection and B cell malignancy (BCM) in Japan, we analyzed HCV-RNA in 50 patients with BCM [25 cases of NHL, 4 of WM and 21 of multiple myeloma (MM)] and determined genotype of infected HCV(Okamoto's classification) using reverse transcription-polymerase chain reaction assay. Eight (16.0%) of 50 patients with BCM were HCV-RNA positive [HCV(+)], while no patients were HCV(+) in control group (18 patients of non-B cell NHL). Numbers of HCV(+) cases in each group examined were as follows; four (16.0%) in B cell NHL (genotype II/III/IV were 3/1/0, respectively), one (25.0%) in WM (genotype III) and three (14.3%) in MM (genotype II/III/IV were 1/1/1, respectively). All patients examined had no symptoms and signs suggesting vasculitis. The incidence of HCV infection in the patients with BCM was markedly higher than that (approximately 1%) of healthy blood donors in Japan. We also experienced four B cell NHL cases with splenic or hepatic origin in the course of chronic hepatitis C. These results implicate the association between persistent HCV infection and the occurrence of BCM.

Genotype↗
PubMed1997

[Influence of fluid replacement on serum magnesium concentration and proper magnesium supplementation during general anesthesia].

We have studied the influence of fluid replacement on serum magnesium (Mg2+) concentrations, and studied proper Mg2+ supplementation during general anesthesia. Thirty eight patients undergoing elective surgery randomly received: Mg(2+)-free acetated Ringer solution (Group I, n = 15), acetated Ringer solution containing 0.5 mmol.l-1 of Mg2+ (Group II, n = 6), 1.0 mmol.l-1 of Mg2+ (Group III, n = 7), 2.0 mmol.l-1 of Mg2+ (Group IV, n = 6), or 4.0 mmol.l-1 of Mg2+ (Group V, n = 4). Measurements were made on serum and urine Mg2+ concentrations during anesthesia. In Group I, the serum Mg2+ concentrations decreased in correspondence with the water balance. It is suggested that dilution due to the fluid replacement induced the reduction in serum Mg2+ concentrations since the observed urine Mg2+ concentrations were negligible. In Group II-V, the reduction in serum Mg2+ concentrations was inhibited by Mg2+ supplementation, and the serum Mg2+ concentrations remained unchanged in Group IV. We conclude the Mg2+ supplementation is required during anesthesia when a large amount of fluid is infused.

Adolescent↗
PubMed1997

[Evaluation of intra-arterial infusion chemotherapy for liver metastasis from gastric cancer].

We evaluated the result of intra-arterial infusion chemotherapy on liver metastasis from gastric cancer. Of 92 cases of metastatic liver tumor, 17 cases received intra-arterial infusion chemotherapy after primary resection. For comparison, we assigned the 17 cases to two groups according to the infused agents. One group was treated with the combination therapy of 5-FU, epirubicin and MMC (FEM group: n = 7), and another with other antineoplastic agents (non-FEM group: n = 10). In the FEM group, the response rate, 1-year survival rate and 50% survival period were 33.3%, 51.4%, 430 days, respectively, while those of the non-FEM group were 10.0%, 10.0%. 147 days. Although there was no significant difference (p = 0.0951), improvements in survival rate and survival period were observed. This implies the possibility that intra-arterial infusion chemotherapy, especially the combination therapy of FEM, is an effective treatment for liver metastasis from gastric cancer.

Aged↗
PubMed1997

[Complication due to arterial infusion chemotherapy for liver metastasis from colorectal cancer].

OBJECTIVES: Arterial infusion chemotherapy is considered to be an extremely effective treatment for liver metastasis from colorectal cancer in terms of its tumor reduction and preventing recurrence in residual liver after resection. However, there still remain some unclear points as to the influence on hepatic artery and bile duct when this treatment is used over the long term. We report some conclusions obtained by examining cases of hepatic arterial occlusion (stenosis) and biliary complication who received this treatment. MATERIALS AND METHODS: Thirty-six cases who received this treatment over 3 months were the objects of this study, with the aim of direct effect against metastatic focus (21 cases) and prevention of recurrence in residual liver (15 cases). The ages were from 27 to 81; 22 cases were male and 14 were female. Indwelling routes of catheter were gastroduodenal artery (GDA) in 28 cases and femoral artery (FA) in 8 cases. Intermittent high-dose infusion (WHF: 5-FU 1,000 mg/m2/5 hrs qw) was adopted as the method. RESULTS: Hepatic arterial occlusion or stenosis was observed in 12 cases (GDA: 10; FA: 2). There seemed to be no correlation with the total dosage of 5-FU or the number of administrations. Even when hepatic arterial occlusion or stenosis occurred, no change was observed in liver function, and there no death was caused by this. However, CT showed a low-density area followed by atrophy in the right lobe in one case with right hepatic arterial stenosis, despite normal portal blood flow. Of the 6 cases which developed obstructive jaundice, 4 were due to the increase of metastatic focus or lymph nodes, and 1 case without dilatation of bile duct died from suspected sclerosing cholangitis. In this case, ALP had been increasing since 1 month before the onset of jaundice. Another case which developed biloma accompanied by the increase of serum bilirubin improved by discontinuance of chemotherapy. CONCLUSION: Since arterial infusion chemotherapy for liver metastasis from colorectal cancer causes hepatic arterial occlusion (stenosis) at a high rate, early detection of abnormalities by liver function test and imaging diagnosis which leads to early treatment is important.

Adult↗
PubMed1996

Anti-erythropoietin receptor monoclonal antibody: epitope mapping, quantification of the soluble receptor, and detection of the solubilized transmembrane receptor and the receptor-expressing cells.

A hybridoma cell line producing the monoclonal antibody against erythropoietin receptor (EpoR) was established using the soluble ectodomain of mouse erythropoietin receptor (sEpoR) as an antigen. The monoclonal antibody termed 1G3 bound to the denatured sEpoR. Epitope mapping with peptide library revealed that 1G3 recognized the amino terminal region including the hexapeptide (positions 6 to 11; LeuProAspProLysPhe). The amino acid sequence in this hexapeptide was identical in mice, rats, and humans, and therefore 1G3 bound to EpoR from all of these sources. Using 1G3, we evaluated sEpoR by a sandwich enzyme-linked immunoassay, and EpoR in the solubilized membrane preparation was detected by Western blotting. The cells expressing EpoR were identified with immunochemical staining. We confirmed the presence of EpoR in a neuronal cell line and PC12 cells, and EpoR was expressed in primary cultured hippocampal neurons.

Amino Acid Sequence↗
PubMed1996

Erythropoietin in mouse avascular yolk sacs is increased by retinoic acid.

Erythropoiesis begins first in the visceral yolk sac (VYS) of the embryo; however, the involvement of erythropoietin (EPO) in yolk-sac erythropoiesis has not been studied adequately. This study reports the expression of EPO in normal and hypoxic VYSs and alterations in yolk sac components induced by retinoic acid (RA) in mice. Gravid mice (plug day = day 0 of gestation) were given one oral dose of 60 mg/kg of RA in olive oil on days 6, 6.5, 7, 7.5, or 8 of gestation and were sacrificed 2.5, 3, or 3.5 days later. Control mice received olive oil without RA. None of the dams developed anemia, but more than 80% of the embryos of the dams that received RA on day 6, 6.5, or 7 of gestation had avascular yolk sacs (AVYs) and anemia. In these AVYs, the adenosine triphosphate (ATP) level was as low as 18-59% of that in the control VYSs. Reverse transcription-polymerase chain reaction and Southern analysis of products demonstrated that mRNA for EPO receptor (EPR) was expressed in both VYSs and AVYs on days 9-11 of gestation, and EPO mRNA was present in VYSs and AVYs on days 9 and 10 of gestation and in vehicle-exposed VYSs on day 11 of gestation. Furthermore, enzyme immunoassay of EPO indicated that AVYs contained more EPO protein than control VYSs. Light microscopy revealed that, in AVYs, in addition to the defective hemopoietic cells, the endodermal layer was exclusively altered: The presence of focal proliferated regions and the separation from the mesenchyme led to a single layer from which some immature cells seemed to be migrating. Immunolocalization of EPO showed its presence in all components of VYSs with a characteristic distribution pattern: In the endodermal layer, cells with positive EPO staining decreased as gestation advanced, and erythroid precursor cells showed positive staining. In AVYs, the proliferated endodermal cells had EPO in abundance; in the separated regions, the distinction between positive and negative EPO staining became clearer than that in the control VYSs, and the immature cells in the lumens also had EPO. EPR was seen on the cell surface of the corresponding cells that reacted to EPO. These findings suggest that VYSs not only produce EPO temporarily but also respond to the oxygen content in situ. EPO and EPR appear to be synthesized in the endodermal cells of the VYSs that are likely to respond to the circumstances induced by RA.

Adenosine Triphosphate↗
PubMed1996

Targeted cancer chemotherapy with arterial microcapsule chemoembolization: review of 1013 patients.

To evaluate the feasibility of intraarterial infusion of microencapsulated anticancer drugs (chemoembolization), collective data on 1013 cancer patients were reviewed. Ethylcellulose microcapsules containing mitomycin C (median total dose 20 mg), cisplatin (60 mg) or peplomycin (40 mg) were given to tumor-feeding arteries by bolus infusion in 79% of the patients and by fractionated infusion in the others, as a palliative (71%) or preoperative measure (29%). The target sites were the liver (42%), kidney (24%), intrapelvic organs (18%), lung (4%), head and neck (3%), bone (1%) and others (9%), excluding the central nervous system and gastrointestinal tract. The incidence of overall adverse effects ranged from 0.2 to 54.9%, but grade 2-3 hematological, renal and hepatic toxicities, local pain, abdominal discomfort, cutaneous reaction, remote embolization and infection were < 10%. Nine patients (0.9%) in the early stages of trials suffered serious complications including treatment-related death in two with critical underlying diseases of the target organs. The remaining patients recovered from the adverse effects, except for grade 2 cutaneous reactions, within 2 months by routine palliative measures. A > or = 50% tumor reduction was seen in 28% of 427 evaluable tumors (42% for < 25-cm2 tumors and 20% for > or = 25-cm2 tumors) with a median treatment number of one. The response rate depended on both the tumor size and the treatment number (P < 0.05), but it was not affected by prior therapies. Mitomycin C microcapsules produced a higher response rate. Complete or partial remission of intractable pain and genitourinary gross hemorrhage was found in two-thirds of eligible patients. The results indicate that this treatment modality, though restricted by catheter technique, can be applied to various tumor lesions with an acceptable morbidity and prospective trials are justified to evaluate the potential role of such a targeted chemotherapy.

Adolescent↗
PubMed1996

Studies on the ileum-contracting mechanisms and identification as a complement C3a receptor agonist of oryzatensin, a bioactive peptide derived from rice albumin.

Oryzatensin (Gly-Tyr-Pro-Met-Tyr-Pro-Leu-Pro-Arg) is an ileum-contracting and immunostimulating peptide derived from rice albumin. The mechanisms for the ileal contraction that it induces, consisting of rapid and slow components, were examined. The rapid contraction was mediated by histamine release and the slow contraction by a prostaglandin E2-like substance, judging from the effects of various pharmacological inhibitors and antagonists on ileal contraction and titration of histamine release. The contractile profile was very similar to that of human complement C3a(70-77), which is the COOH-terminal octapeptide of C3a and has, although less potent, qualitatively the same biological activities as C3a. Oryzatensin showed homology with C3a(70-77) and affinity for C3a receptors (IC50 = 44 microM) by radioreceptor assay. This is the first report of a food-derived bioactive peptide acting through complement C3a receptors.

Amino Acid Sequence↗
PubMed1996

Vasorelaxation by casomokinin L, a derivative of beta-casomorphin and casoxin D, is mediated by NK1 receptor.

Casomokinin L (Tyr-Pro-Phe-Pro-Pro-Leu), a derivative of beta-casomorphin and casoxin D, showed endothelium-dependent vasorelaxing activity on the canine mesenteric artery (EC50 = 7 x 10(-8) M). This relaxing activity was partly blocked by 10(-5) M NAME (nitric oxide synthase inhibitor), and the inhibition by NAME was restored by addition of 10(-4) M arginine, suggesting the involvement of nitric oxide as an endothelium-dependent relaxing factor. The relaxing activity was blocked by 10(-8) M CP-99994 and 10(-7) M FK888 (NK1 antagonists), but not by 10(-6) M SR-48968 (NK2 antagonist). Casomokinin L binds to neurokinin NK1 receptors (Ki = 5.8 x 10(-5) M), and lowered blood pressure in SHR (0.1 mg/kg, i.v. and 3 mg/kg, PO). Thus, despite its only three residues in common with substance P, casomokinin L binds to NK1 receptors, relaxes the artery, and exerts an antihypertensive effect.

Amino Acid Sequence↗