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Biomedical subjects

T Shoji

Publications and source records attributed to T Shoji.

At least 163 records · Page 9Linked to original sources
PubMed1994

Clinical evaluation of a new type of centrifugal pump.

The major problems with existing centrifugal pumps are leakage, mechanical trauma, and thrombus formation. In consideration of these problems, a new compact centrifugal pump system was developed. The purpose of this study was to evaluate the new centrifugal pump system clinically. Ten patients underwent open heart surgery with a centrifugal pump or a roller pump. During surgery, hemodynamic and hematological data were obtained. A pulsatile assist device in the pump circuit was used in patients with severe heart disease. There was neither operative death nor hospital mortality, and there was no difference with regard to hemodynamic data between the two groups. The centrifugal pump groups, however, had significantly lower hemolysis, especially during prolonged cardiopulmonary bypass. This centrifugal pump could also create sufficient pulsatile flow with a pulsatile assist device. Postoperative macroscopic and microscopic findings demonstrated the smooth surface of the pump without thrombus formation. This centrifugal pump system might be useful for prolonged cardiopulmonary bypass.

Adolescent↗
PubMed1994

Synthetic approaches to 3-amino-1,4-naphthoquinone-2-carboxylic acid derivatives and photochemical synthesis of novel 1,4,5,10-tetrahydro-5,10-dioxo-2H-naphth[2,3-d][1,3]oxazine derivatives.

Synthesis of 3-alkylamino-1,4-naphthoquinone-2-carboxylic acid (2) was attempted. Although 3-(1-piperidinyl)-1,4-naphthoquinone-2-carboxylic acid (2a) was not obtained, probably because of its instability, the esters (18a, b) of 2a could be prepared. 2-Alkylamino-3-hydroxymethyl-1,4-naphthoquinones (9a-g) were photochemically cyclized to the 1,4,5,10-tetrahydro-5,10-2H-naphth[2,3-d][1,3]oxazines (19a-g), containing a novel heterocyclic ring system in moderate yields. Anti-bacterial activity of the prepared compounds was weak or insignificant.

Anti-Bacterial Agents↗
PubMed1994

Streptomyces ATP nucleotide 3'-pyrophosphokinase-gene cloning and sequence analysis.

Streptomyces ATP nucleotide 3'-pyrophosphokinase is an extracellular enzyme that transfers 5'-beta, gamma-pyrophosphoryl groups of ATP to a variety of nucleotides at the 3'-OH site. The enzyme gene was cloned from partially Sau3AI-digested chromosomal DNA of S. morookaensis in S. lividans TK24/pIJ699 and then in E. coli JM83/pUC12. Some transformants produced the active enzyme. The gene was sequenced by the dideoxynucleotide termination procedure. Its GC content was 72%. Its putative promoter regions, showing little homology to that of the Streptomyces consensus type, were pointed out. No sequence homology was found between the pyrophosphokinase and any other known genes including those of the most mechanistically similar bacterial stringent factor and related proteins. Northern hybridization analysis showed that the gene is constitutionally polycistronic and expressed under transcriptional control. Nuclease S1 mapping indicated that the gene transcription starts from its translation initiation site.

Amino Acid Sequence↗
PubMed1994

Amplification of N-myc gene and increase of urinary VMA and HVA in patients with neuroblastic tumors.

Neuroblastic tumor cases in our departments were evaluated in terms of the stage of the tumor, N-myc amplification, urinary vanillylamndelic acid (VMA)/homovanillic acid (HVA) and survival rate. Two asymptomatic cases, diagnosed when under a year old by mass screening, had no amplifications of N-myc but showed more than one value of urinary VMA/HVA ratio. The patients are now doing well eight years after complete excision of the neuroblastoma which had originated in the sympathetic ganglion. On the other hand, two other symptomatic cases, operated on at the ages of 3 and 5 years, showed remarkable amplifications with less than one value of urinary VMA/HVA, and died from the tumor soon after partial resection of the neuroblastoma and ganglioneuroblastoma which had originated in the adrenal gland and the sympathetic ganglion, respectively. The present monograph reports our cases and discusses prognostic factors.

Child, Preschool↗
PubMed1994

A new technique for performing total thymectomy on rabbits.

Sixty-one Japanese white rabbits underwent total thymectomies. Eight of the animals died of intraoperative hemorrhage or respiratory failure, and twelve died of postoperative hypovolemia, dehydration, malnutrition or wound infections. Forty-one rabbits survived and were used as a total thymectomy model. The whole procedure of our technique is described in detail so that even those with no experience of performing thymectomies can follow it. Some tactics especially how to deal with the thymic vessels and the pleurae, are key points. Our technique permits safe and perfect total thymectomies to be carried out on rabbits.

Animals↗
PubMed1994

[An experimental study on a chemosensitivity test with alginate microcapsule. Feasibility of in vivo succinic dehydrogenase inhibition test].

A new chemosensitivity test was evaluated by the MTT colorimetric asay with human tumor cell lines encapsulated in alginate microcapsules with semipermeable membranes. The proliferation of KATOIII in the microcapsules rapidly increased on the 4th day after the encapsulation. The change expressed on the proliferation curve of the encapsulated KATOIII was approximately 2 days behind the proliferation of the suspension culture. The encapsulated cell number reversed and further proliferation was recognized after the 12th day. After the incubation for 5 hours of encapsulated KATOIII with the medium supplemented with 0.5% MTT, a blue formazan crystal formation was observed radiating around the cells in the capsules. MTT assay depends on the cellular reduction of the absorbance spectra at 540 nm (OD540nm), for complete solubilization of the formazan by DMSO. The formazan formation was observed more significantly in serum medium culture than in serum free medium. In MIT assay when 0.1 mol succinic acid was added, OD540nm of encapsulated KATOIII increased by approximately 50% and its sensitivity also increased greatly. In comparison the results of MTT assay for encapsulated KATOIII and MKN28 with suspended cells under the same conditions (0.1, 1, 10 micrograms/ml of MMC and ADR, 0.5, 5, 50 micrograms/ml of 5FU, 10, 30, 50 micrograms/ml of CDDP), the calculated inhibition index (%) with encapsulated cells were similar to the percentages obtained in the former MTT assay. In this study with microcapsules, the formazan formation in the capsules and the absorbance were macroscopically inhibited when the drug concentration was increased. The encapsulated KATOIII, which was implanted intraperitoneally into rat with a 16-gauge needle, was recovered at a rate of 70.8% on the 8th day and at a rate of 54.5% on the 16th day. The recovered encapsulated KATOIII proliferated remarkably forming cell clots on the 8th day after implantation. Incubation with MTT promoted formazan formation and sufficient cell viability was recognized. The Tegafur concentration in the intraperitoneal microcapsules and the microcapsules containing KATOIII after the intravenous administration of Tegafur was similar to the intrahepatic level. The 5FU level in the microcapsules containing KATOIII was higher than that in the capsules alone. In an attempt to conduct an in vivo chemosensitivity test, encapsulated KATOIII and MKN28 were intraperitoneally implanted, 4 mg/kg of MMC, ADR and CDDP, and 75mg/kg of 5FU were intravenously administered on the 2nd and 4th days after the implantation. On the 6th day, MTT assay was performed on the recovered microcapsules containing cells and the inhibition index was calculated.(ABSTRACT TRUNCATED AT 400 WORDS)

Alginates↗
PubMed1994

[Morphological atypism and clinicopathological factors in colorectal adenoma and cancer using nuclear DNA content, p53 and PCNA].

Cytofluorometric analysis of DNA content and immunohistochemical examination of p53 and PCNA were performed in colorectal adenomas, mainly borderline lesions, and cancers. Nuclear DNA content revealed aneuploidy and polyploid cells in severely atypical adenomas and cancers. Mutated p53 protein was also observed in severely atypical adenomas, especially tortuous and villous lesions and cancers. PCNA labeling index (P-I) was significantly increased in proportion to cell atypism and P-I over 50% was noted in half of severely atypical adenomas. Among infiltrating cancers, poorly differentiated adenocarcinoma showed high P-I. However, well differentiated adenocarcinoma infiltrating beyond the tunica muscularis propria showed various P-I values depending on the presence of metastasis to lymph node or blood vessel invasion. Furthermore, P-I in the metastatic lesion was significantly higher than that of primary lesion. These results suggest that severely atypical adenomas showing morphological features such as an increased N/C ratio, loss of polarity, roundish nucleus, tortuous and villous change of gland have malignant potentiality. So severely atypical adenomas have the clinical indication for polypectomy. In addition, poorly differentiated adenocarcinoma shows high proliferative ability and metastatic lesions or poorly differentiated components existing in infiltrating cancers may affect cancer development as productive clones.

Adenocarcinoma↗
PubMed1994

[Effect of low calcium diet on blood pressure and pressure natriuresis response in rats: role of the renin-angiotensin system].

Dietary Ca is an important modulator of arterial blood pressure in humans and rats. Since the kidney plays a key role in the pathogenesis of hypertension, the effect of a low Ca diet (0.01%Ca) on blood pressure and pressure natriuresis response was studied in Sprague-Dawley rats. In addition, a possible role of the renin-angiotensin system in the development of hypertension and an altered pressure natriuresis response resulting from low dietary Ca intake was investigated. In the low Ca diet group, systolic blood pressure determined by the tail-cuff method was significantly higher than in the normal Ca diet group (1.1%Ca) 1 week after the diet (113.0 +/- 7.1 vs. 105.0 +/- 9.5 mmHg, p < 0.05). Furthermore, low dietary Ca treatment significantly inhibited the water and sodium excretory responses to acute elevation of renal perfusion pressure. Treatment with an inhibitor of angiotensin converting enzyme, captopril (30 mg/kg/day), attenuated both the development of hypertension and the reduced pressure natriuresis response observed in Ca-deficient rats. Although plasma renin activity was not different between the low and normal Ca diet groups after the 2-week dietary regimen, the pressor response to angiotensin II injection was significantly greater in the low Ca diet group. These results indicate a possible involvement of the renin-angiotensin system in the development of hypertension and the inhibitory effects of the pressure natriuresis response caused by low dietary Ca intake, via enhanced sensitivity to angiotensin II.

Animals↗
PubMed1994

[Assessment of the distribution of renal cortical blood flow by contrast ultrasonography].

The importance of the distribution of intrarenal blood flow in the regulation of various renal functions, such as urine concentration and sodium excretion, has been well recognized. However, there have been no reliable methods to measure local flow in the kidney in vivo. The present study demonstrated the usefulness of contrast ultrasonography combined with injection of sonicated 5% albumin for assessment of the distribution of renal cortical blood flow in eleven mongrel dogs. The left kidney was displayed by tomographic echography, and microbubbles of sonicated albumin were injected into the abdominal aorta above the left renal artery. Video density time curves were generated and fitted to a time-intensity curve. Intrarenal infusion of acetylcholine (4.0 micrograms/kg/min) increased renal blood flow (RBF) from 2.5 +/- 0.3 to 4.6 +/- 1.0 ml/min/g kwt (p < 0.01), and norepinephrine (0.5 microgram/kg/min) decreased RBF from 2.5 +/- 0.3 to 1.2 +/- 0.5 ml/min/g kwt (p < 0.01). There were significant positive correlations between percent change in RBF and peak intensity and area under the curve, which were calculated with a time-intensity curve. Furthermore, the inner/outer renal cortex ratio of peak intensity significantly increased during acetylcholine infusion (0.72 +/- 0.11 vs 0.86 +/- 0.09; p < 0.01), whereas no significant change was observed during norepinephrine infusion. These results suggest that renal contrast ultrasonography may be useful for real-time assessment of the distribution of renal cortical blood flow in vivo.

Acetylcholine↗
PubMed1994

[Pharmacokinetic study of ofloxacin using saliva concentration in chronic renal failure].

We evaluated saliva concentration as a parameter of therapeutic drug monitoring (TDM) of Ofloxacin (OFLX) in patients with severe renal failure (CRF). Saliva OFLX concentration correlated closely with serum OFLX concentration as shown in healthy subjects, although it was significantly lower (about three-quarters), indicating that OFLX had less penetration into saliva in patients with renal failure. Saliva concentration was almost equal to serum concentration during hemodialysis, which might have been due to the constant dialysis of OFLX. In conclusion, saliva concentration was useful for TDM of OFLX in patients with CRF, as it is in healthy subjects.

Adolescent↗
PubMed1994

[A case of partial anomalous pulmonary venous return to inferior vena cava and left atrium (Scimitar syndrome)].

Scimitar syndrome is relatively uncommon syndrome. A 14-year-old female referred to our hospital for abnormal shadow of chest fluoroscopic examination. She had no symptom except cough due to bronchial asthma. Chest X-ray film showed Scimitar sign. Cardiac catheterization revealed 30% left to right shunt without atrial septal defect. Pulmonary angiography showed anomalous pulmonary vein was drained to inferior vena cava and left atrium. Surgical correction was attempted monitoring the pulmonary arterial pressure. Anomalous pulmonary vein and systemic arteries were ligated and divided at the level of diaphragm. Postoperative course was smooth. We have found 4 similar operated cases previously reported in the world.

Adolescent↗
PubMed1994

[Cryopreservation of thyroid pieces--optimal freezing condition and recovery].

We have studied the cryopreservation of thyroid pieces for the purpose of autotransplantation. In this paper, the optimal freezing condition was investigated by comparing the survival cells of the cryopreserved thyroid pieces under various freezing conditions, including cooling rate, freezing medium, cryoprotectant, size of pieces and prefreezing incubation. The recovery regarded as survival rate was also evaluated. Based on the results, the optimal freezing condition was that 1 mm 3 of the thyroid pieces in the freezing medium, consisted of culture medium supplemented with 10% of fetal bovine serum and 10% of dimethylsulfoxide, were cooled slowly until -80 degrees C with prefreezing incubation at 4 degrees C for 1 hour and kept in liquid nitrogen for preservation. The number of survival cells under the optimal condition was 1.24-2.03 (1.71 +/- 0.40) x 10(6)/0.1 g tissue, and recovery was 25.2-58.0 (45.5 +/- 14.6)%. This high survival rate suggests the possibility that the cryopreserved thyroid pieces are utilized as the autografts maintaining the intact follicles.

Adolescent↗
PubMed1994

A multicenter study with once a week or once every two weeks high-dose subcutaneous administration of recombinant human erythropoietin in continuous ambulatory peritoneal dialysis.

OBJECTIVE: To investigate the effectiveness of administering relatively high doses of r-HuEPO subcutaneously once a week or once every 2 weeks in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Multicenter prospective analysis. The trial was divided into two phases: an initial 8-week phase (once a week dosing) followed by a 12-week maintenance phase (once every 2 weeks dosing). A response was defined as a change in hematocrit (Ht) of 3% or more. Results were analyzed using Sheffe's test, Mantel-Haenszel's test, and Dunnett's test. SETTING: Eleven renal units in Japan providing a CAPD program. PATIENTS: Forty-one CAPD patients with a Ht of 28% or less. RESULTS: After the initial 8 weeks, 13 (81.3%) of 16 patients showed a response to 6000 U (106.9 +/- 20.0 U/kg) subcutaneously (sc), once a week. Eleven (84.6%) of 13 in the 9000 U (166.5 +/- 27.7 U/kg) group and all 12 (100%) in the 12,000 U (210.7 +/- 42.1% U/kg) group also showed responses. At the end of both phases, that is, at 20 weeks, 7 (53.8%) of 13 patients in the 6000 U group with once every 2 weeks dosing, 7 (63.6%) of 11 in the 9000 U group, and 10 (90.9%) of 11 in the 12,000 U group maintained responses with the same dosing interval. There were no significant changes in mean blood pressure during the study period, and only 2 patients developed treatable hypertension with mild headache. CONCLUSION: Administration of relatively high doses of r-HuEPO to CAPD patients once a week or once every 2 weeks is safe and potentially an effective regimen for the correction of renal anemia.

Adult↗
PubMed1993

[Cases of Graves' disease with falsely high TSH values due to interfering substances which cross-link with mouse monoclonal antibodies in the TSH assay kits].

It has been reported that highly sensitive two-site immunometric assays occasionally indicate falsely high serum TSH values. A possible reason for this is that heterophilic antibodies interfere with these assays. Recently we had a patient in whom the Delfia TSH kit falsely indicated an elevated serum TSH value. A 29-year-old female was diagnosed as having Graves' disease and was referred to Ito Hospital for surgical treatment. Her thyroid hormone values were distinctly high two months before admission (FT3: 20.7pmol/L, FT4: 42.3pmol/L), but her serum TSH level was normal (1.1mU/l). She was clinically hyperthyroid, and T3 and T4 values determined after ethanol extraction and T3 or T4 analog binding rates did not indicate the presence of T3 or T4 antibodies. Her TSH value became undetectable when mouse IgG was added to the assay. These results suggested that the "normal" serum TSH value was caused by interfering substances such as anti-mouse IgG antibodies which had cross-linked with mouse monoclonal antibodies in the Delfia TSH kit. Another 12 patients who were suspected of having the interfering substances were examined because of the discordance between TSH values and thyroid hormone values. All of the serum TSH values measured using the DELFIA TSH kit decreased when mouse IgG was added. In another case, the presence of serum TSH could not be detected using the Delfia TSH kit but could be measured using the RIABEAD II TSH kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Radiosensitization by a new potent nucleoside analog: 1-(1',3',4'-trihydroxy-2'-butoxy)methyl-2-nitroimidazole(RP-343).

PURPOSE: A new hypoxic cell sensitizer has been synthesized; this is a 2-nitroimidazole nucleoside analog having erythritol as a sugar moiety at the N-1 position of the imidazole ring (RP-343). Its possibility as a potent hypoxic cell sensitizer was compared with those of RP-170 and etanidazole. METHODS AND MATERIALS: Radiosensitization was tested in two murine tumors, EMT6 using in vitro and in vivo-in vitro assays and SCCVII using growth delay and TCD50 assays. Pharmacokinetic study was performed in Balb/c mice bearing EMT6 tumors and in Beagle dogs. LD50 of each sensitizer was obtained with ICR mice. RESULTS: As might be expected from the almost identical electron affinities of the three sensitizers, they were equally effective against hypoxic EMT6 cells in vitro. While having the lowest partition coefficient (0.035), RP-343 exhibited almost equally effective distribution to tumors and sensitizing radiation activity. An intravenous (i.v.) injection of 100 mg/kg of RP-343, RP-170 and etanidazole showed an almost equal sensitizer enhancement ratio (SER) of about 1.4 to solid EMT6 tumor under in vivo-in vitro assay and a virtually equal SER of 1.33-1.44 to solid SCCVII tumor under both tumor growth delay assay and TCD50 assay. A great advantage of RP-343 over RP-170 and etanidazole is its very much lower toxicity; their LD50 in mice were > 6.0, 4.3 and 4.8 g/kg, respectively, on i.v. injection. The lower toxicity of RP-343 was supported by its lower concentrations in the brain; the RP-343 AUC for brain was 0.43 times that of RP-170. Three indices were selected to compare the three nitroimidazoles. SER at 5% LD50 doses of RP-343, RP-170 and etanidazole was 1.66, 1.59 and 1.56. At the same toxicity levels, RP-343 was found to have better sensitization of solid tumors over both etanidazole and RP-170. The maximum tumor concentration/AUC for brain (Cmax,tumor/AUCbrain) ratios for RP-343 and RP-170 were 9.62 and 3.98. CONCLUSIONS: This extremely high ratio of RP-343 could explain its lower toxicity than RP-170 or etanidazole. The therapeutic risk index defined as D1.5/LD50 (D1.5 is the sensitizer dose to obtain the SER of 1.5 in vivo) for RP-343, RP-170 and etanidazole were 0.022, 0.033 and 0.036, respectively. Especially, the effectively lower therapeutic risk index for RP-343 presents the possibility of clinical advantage over etanidazole.

Animals↗