Biomedical subjects

S Akimoto

Publications and source records attributed to S Akimoto.

At least 127 records · Page 7Linked to original sources

PubMed1994

[Atheromatous embolization as a cause of postoperative renal dysfunction in infrarenal aortic reconstructive surgery].

Influences of atheromatous changes in the aortic wall at the site of proximal clamping were studied retrospectively on postoperative renal function in an infrarenal aortic reconstruction. Atheromatous lesion was evaluated on CT scan as low density layer in the aortic wall observed in cases with the thickened wall exceeding 3mm, and they were classified into atheromatous group (group II) consisted of 21 patients. In these patients, the postoperative serum creatinine showed significant elevation from preoperative value of 0.89 +/- 0.32 mg/dl to 1.67 +/- 0.90 mg/dl on 1st postoperative day (p < 0.01), 1.25 +/- 0.99 mg/dl on 7th day (p < 0.05) and 1.24 +/- 0.89 mg/dl on discharge (p < 0.05). Correlation between the severity of the postoperative renal dysfunction and the degree of the atheromatous changes evaluated by preoperative CT scan was also defined and 2 patients with severe changes died of acute renal failure. On the contrary, 39 patients without thickened wall (group I) showed no significant elevation of serum creatinine after operation. These results strongly suggest that atheromatous embolization to the kidney plays an important role to cause postoperative renal impairment following infrarenal aortic reconstructive surgery for the patients with atheromatous changes in the aorta near the site of proximal clamping.

Acute Kidney Injury↗

PubMed1994

Alterations of the cadherin-catenin cell adhesion system in cancers.

The E-cadherin-mediated cell adhesion system acts as an "invasion suppressor" system, which is widely considered to be inactivated when the expression of E-cadherin is reduced and/or heterogeneous. To further investigate the molecular mechanisms responsible for dysfunction of this system in cancers, we examined human carcinoma cell lines lacking tight cell-cell adhesion. In KATO-III, established from stomach cancer, a point mutation of the E-cadherin gene resulted in a mRNA splicing error and markedly reduced E-cadherin expression. In another stomach cancer cell line, MKN 45, an 18-bp deletion of the E-cadherin gene caused a mRNA splicing error and a 4-amino-acid deletion, which was considered to alter the conformation around the key Ca(2+)-binding motif. In these two cell lines, the wild-type allele of the E-cadherin locus, which was assigned to chromosome 16q, was lost. Also in vivo, we found mutation of E-cadherin in breast cancers, where allele loss on chromosome 16 has frequently been reported. Thus, dysfunction of E-cadherin could be caused by a combination of the loss of one allele and a mutation in the remaining allele. Homologous deletion of part of the alpha-catenin gene, resulting in markedly reduced expression, was observed in a human lung cancer cell line, PC9. Recently, we also found mutations of beta-catenin in human carcinoma cell lines. These findings indicate the possible involvement of genetic abnormalities of various components in inactivation of the E-cadherin-mediated "invasion suppressor system" in cancers.

Binding Sites↗

PubMed1993

Mutagenicity and antimutagenicity of extracts of three spices and a medicinal plant in Thailand.

Three kinds of spices (caraway, coriander and black pepper seeds) and a medicinal plant called 'tong tak' in Thai (Baliospermum axillar, a species of the spurge family) were fractionated into hot water, methanol and hexane extracts. These extracts were not mutagenic for Salmonella typhimurium strains TA98 and TA100 by the Ames assay. However, when the extracts were treated with nitrite, samples of the water and methanol extracts were mutagenic for strain TA100 without metabolic activation. The mutagenicity of the nitrite-treated methanol and hot water extracts of black pepper was highest (8380 and 22,200 His+ per 0.1 g of spice powder, respectively), and that of the nitrite-treated hot water extracts of caraway and tong tak was moderate. The hot water extracts were examined for their antimutagenic activity against mutagenicity induced by various carcinogens by the Ames assay, using the preincubation technique. The tested samples (equivalent to 1-2 mg of spice powder) reduced the mutagenicity induced by 2.7 nmole (397 ng) of N-methyl-N'-nitro-N-nitrosoguanidine by more than 84%, and that induced by dimethylnitrosamine (1.48 mg) or ICR-170 (10 ng) by 30-60%. However, they did not inhibit the mutagenic activity of 1-nitropyrene, 3-nitrofluoranthene, AF-2, methyl methanesulfonate, N-ethyl-N'-nitro-N-nitrosoguanidine, 2-aminoanthracene, 2-acetylaminofluorene, benzo[a]pyrene or IQ.

Antimutagenic Agents↗

PubMed1993

Mutagenicity of the bile of dogs with an experimental model of an anomalous arrangement of the pancreaticobiliary duct.

To learn the reasons for the high incidence of biliary carcinoma in patients with anomalous arrangement of the pancreaticobiliary duct (APBD) mutagenicity of the bile of APBD-modeled dogs that had received a dorsal pancreatico-cholecystostomy was assayed by the Ames Salmonella mutation test. The bile from two out of 18 APBD dogs was mutagenic for Salmonella typhimurium strain TA98 under the condition of metabolic activation by rat liver S9 fraction, while the bile from 17 normal dogs was not mutagenic. Furthermore, the bile from five APBD dogs i.p. administered 1-nitropyrene (1-NP), which is a typical environmental mutagen, was more mutagenic for strain TA98 than that from 1-NP-treated normal dogs. The bile from the APBD dogs had very high amylase activity, indicating that the bile contained pancreatic juice as a result of the pancreatico-cholecystostomy. When pancreatic juice from a normal dog was added to the bile from 1-NP-treated normal dogs, mutagenicity of the bile increased 1.6- to 2.0-fold. Furthermore, sulfatase increased the mutagenic activity of the bile in the presence of the pancreatic juice. HPLC revealed that the bile from a 1-NP-treated APBD dog contained mutagenic 1-nitro-6/8-hydroxypyrene and 1-nitro-3-hydroxypyrene, while bile from a 1-NP-treated normal dog did not contain these deconjugated products. The pancreatic juice from a normal dog had very high gamma-glutamyltransferase (GGT) and aminopeptidase activities and low sulfatase activity, but it had no beta-glucuronidase activity. In addition, the bacteria that easily infect the biliary duct of APBD dogs, Escherichia coli, Klebsiella, Enterobacter and Proteus, had high beta-glucuronidase activity. In particular, Klebsiella showed a very high sulfatase activity. These results suggest that pancreatic juice enzymes and bacteria infecting the biliary duct deconjugate the detoxified mutagens in the bile and induce mutagenicity of the bile from APBD dogs or APBD patients.

Anastomosis, Surgical↗

PubMed1993

Biological activities of the intestinal microflora in mice treated with antibiotics or untreated and the effects of the microflora on absorption and metabolic activation of orally administered glutathione conjugates of K-region epoxides of 1-nitropyrene.

To elucidate the effects of the intestinal microflora on absorption and activation of glutathione conjugates of 4,5-epoxy-4,5-dihydro-1-nitropyrene (1-NP 4,5-oxide) and 9,10-epoxy-9,10-dihydro-1-nitropyrene (1-NP 9,10-oxide), we investigated the biological activities of the microflora in specific-pathogen-free (SPF) mice and SPF mice treated with various antibiotics and established the methodology of antibiotic treatment to eliminate the intestinal microflora. Mice were given various kinds of antibiotics by intragastric gavage twice a day for five days. A mixture of antibiotics bacitracin (BC), neomycin (NM) and streptomycin (SM) was the most effective in reducing the various activities of the intestinal microflora. The treatment decreased the bacterial counts and the activities of enzymes of the intestinal contents cysteine conjugate beta-lyase (beta-lyase), beta-glucuronidase and nitroreductase which were derived from the intestinal microflora, but did not affect the activities of gamma-glutamyltransferase and aminopeptidase which were derived from host tissue cells. Furthermore, the treatment did not affect absorption of glucose from the intestinal tract, body weight or liver enzyme activities. The treatment with only an aminoglycoside antibiotic, kanamycin or NM, decreased neither the number of anaerobes in the intestine nor the beta-lyase or nitroreductase activities from the intestinal contents. Glutathione conjugates of [3H]-1-NP oxides were administered to two groups of ICR mice that had been treated with antibiotics (BC, NM, SM) or saline (control group) orally. The radioactivity in the blood increased and reached the maximum level 2 or 3 h after administration of the conjugates in the control group; however, that in the antibiotic-treated group was only slightly increased if at all. Excretion of [3H]-labeled metabolites into the urine was approximately 20% of the total dose in the control group, but it was < 2% in the antibiotic-treated group during 48 h. After 48 h, DNA in the lower intestinal mucosa was extracted and the DNA adducts were analyzed by the 32P-postlabeling method. Three new DNA adducts were detected in the lower intestinal mucosa of the control group but not of the antibiotic-treated group. These results suggest that the intestinal microflora plays an important role in absorption of the metabolites of glutathione conjugates of 1-NP oxides from the intestinal tract and activation of the metabolites in the intestine.

Animals↗

PubMed1993

An inhibitory effect of TZP-4238 on the growth of androgen-sensitive rat prostatic tumor (Dunning R3327).

An inhibitory effect of TZP-4238, a newly synthesized antiandrogen, on the growth of Dunning R3327 rat prostatic tumor was studied and compared with that of chlormadinone acetate (CMA). TZP-4238 markedly suppressed the growth of R3327 tumor. The inhibitory effect of TZP-4238 on the tumor was more potent than that on the prostate. While the inhibitory effect of TZP-4238 on the weight of the ventral prostate was about 6 times as great as that of CMA, the suppressive effect of TZP-4238 on tumor weight was about 40 times as great as that of CMA. Serum levels of testosterone and dihydrotestosterone showed no obvious changes after the administration of either TZP-4238 or CMA. The inhibitory effect of TZP-4238 on the growth of R3327 tumor indicated the application of the compound to human prostatic cancer.

Administration, Oral↗

PubMed1993

[Measurement of serum PA values by a newly developed enzyme immunoassay].

Serum prostate-specific antigen (PA) values detected by a newly developed enzyme immunoassay (EIA, MARKIT-M PA) as a successor of MARKIT-F PA, which has been a leading kit in Japan, were evaluated for its role in the diagnosis of cancer of the prostate and follow-up of the patients afflicted with the disease. The system is one-step sandwich type EIA using horseradish peroxidase as a tracer and has 0.50-100 ng/ml of detectable range with small amount of sample volume (25 microliters) and reliable quality control data. Furthermore, serum PA values detected by the assay were almost equivocal to those detected by MARKIT-F PA. Serum PA values in prostate cancer patients (n = 122) were statistically higher than those in normal males (n = 90), urological malignancies other than prostate cancer (n = 48) or benign prostatic hypertrophy (BPH, n = 73). Even in the patients with stage A and B prostate cancer, serum PA values were observed to be statistically higher than those in BPH cases. If 3.6 ng/ml was used, which is normal value in MARKIT-F PA, as a cut-off value and BPH cases as a control, the sensitivity, specificity and efficacy for diagnosis of prostate cancer were 77.9, 91.8 and 83.1%, respectively, which showed the best results during the range examined. Serially determined serum PA values in following up the patients with prostate cancer were confirmed to be highly effective to evaluate treatment responses. These results suggest that MARKIT-M PA is thought to be one of the best tool for determination of serum PA values.

Humans↗

PubMed1993

[Determination of tumor marker doubling time in the patients with prostate cancer relapsed from endocrine therapy].

Twenty seven patients with endocrine therapy relapsed prostate cancer were studied by measuring their prostatic acid phosphatase (PAP), prostate specific antigen (PSA), gamma-semino-protein (gamma-Sm) and alkaline phosphatase (ALP) serially before change of the treatment, and tumor marker doubling time was calculated. The exponential increase in PAP, PSA and gamma-Sm was observed in all patients and ALP showed a similar pattern in some. The values of PAP doubling time were the same as those of PSA, but gamma-Sm doubling time was slightly longer than the former ones. Tumor marker doubling time correlated with survival after the increase in markers, and also with time between the start of endocrine therapy and the increase in markers. Patients who showed either NC or PR to chemotherapy had a longer tumor marker doubling time than those with PD. In cases showing progression of bone metastasis, patients with exponential increase in ALP showed worse prognosis when compared with those showing other patterns. From these results, it was demonstrated that determination of tumor marker doubling time in patients with endocrine therapy relapsed prostate cancer was a valuable method to measure rate of regrowth, and to assess the prognosis after relapse.

Acid Phosphatase↗

PubMed1993

[Clinical evaluation of a new kit (IMX PA Dainapack) for detection of serum prostate specific antigen].

A study of the clinical utility of the IMx PA Dainapack, a new kit for detection of serum prostate specific antigen (PSA) by a fully automated enzyme immunoassay (EIA) system, was conducted. Results concerning reproducibility, dilution linearity and sensitivity were good. The excellent assay performance of this kit, particularly in terms of its high sensitivity (0.1 ng/ml), was confirmed. The upper limit of normal was determined to be 4.0 ng/ml from the mean +/- 3 S.D. (3.79 ng/ml) in healthy male controls (n = 244). Using 4.0 ng/ml as the upper limit of normal, 6 of 244 healthy male controls (2%) were positive. In various urinary diseases, 173 of 192 prostatic cancer (90%) and 46 of 112 benign prostatic hypertrophy (BPH) (41%) cases were positive. In prostatic cancer, the positive rates increased with the advance in clinical stage and in stage A the positive rate was especially high (8 of 12 (67%) were positive). On the other hand, using the BPH group as a negative control, the maximum accuracy rate for prostatic cancer had a cut-off value of 8.0 ng/ml. Thus, 8.0 ng/ml is an appropriate cut-off value differentiating prostatic cancer from BPH while 4.0 ng/ml is the cut-off value between the normal group and those with prostatic cancer (including stage A) and BPH. In the follow-up patients with prostatic cancer, serum PSA values measured by this kit reflected the effectiveness of treatment. The correlations between values obtained with the IMx PA Dainapack and 6 current kits were good (r = 0.93 to 0.99) but the values differed with the kit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

[A case report of spontaneous rupture of bilateral lumbar artery in a patient with von Recklinghausen disease].

Vascular complications in von Recklinghausen disease are rare, especially spontaneous rupture of a major artery. A 50-year-old man with previously diagnosed neurofibromatosis was admitted because of spontaneous rt-sided lumbago, paresthesia in rt-lower limb and severe anemia. Angiographic studies, CT and MRI revealed pseudo-aneurysm of bilateral lumbar arteries, which ruptured into the psoas muscle. Both arteries were ligated and hematoma was removed. The pathogenesis of the spontaneous rupture is discussed.

Aneurysm, Ruptured↗

PubMed1992

[Assessment of a coaxial system accommodated to a 0.035 inch guide wire in superselective hepatic angiography and embolization].

A special coaxial catheter system accommodated to a 0.035 inch guide wire was recently developed. The four-part coaxial system is composed of a central 0.035 inch flexible guide wire, a 4-French inner catheter (straight, 90 cm in length), a 6-French outer catheter (fork-shaped, 60 cm in length), and a hemostatic valve. The 4 French inner catheter is large enough in diameter to allow a larger volume of contrast medium and greater amount of embolic material than the earlier coaxial system. Using this coaxial catheter system, we performed successful superselective hepatic arteriography and embolization in 44 patients with malignant hepatic tumors. Catheterization of the celiac and superior mesenteric arteries with the 6 French outer catheter was easy, and the angiogram obtained was very distinct. The 4 French inner catheter was easily and safely advanced into the segmental hepatic artery, and even common hepatic arteriography with this catheter provided clear images on conventional cut films. Therefore, in most cases, both angiography and embolization can be accomplished using this coaxial system alone.

Aged↗

PubMed1992

Mutations in the P53 tumour suppressor gene in primary lung cancer in Japan.

The reverse transcription-polymerase chain reaction-single strand conformation polymorphism (RT-PCR-SSCP) analysis and sequencing were used to examine p53 gene alterations in 18 surgical specimens of primary lung cancers obtained in Japan. Somatic mutations resulting in amino acid changes were found in eight of the 18 cases (44%). Seven missense mutations were located in amino acid-conserved domains or their vicinities (codons 110 to 307). Most mutations were found at G-C pairs, suggesting that specific carcinogens are involved in the etiology of lung cancer. The p53 mutations showed a significant association with a history of smoking (P = 0.0294). We suggest that the p53 mutations may be associated with smoking-induced lung carcinogenesis.

Adenocarcinoma↗

PubMed1992

Argyrophilic nucleolar organizer regions in benign hyperplastic and cancerous human prostates.

Argyrophilic nucleolar organizer regions (AgNORs) were examined histologically in cells of benign hyperplastic and cancerous human prostates. Individual dots of AgNORs inside nucleus that were stained as separate granules or as parts of clusters were counted as one, and the average number of dots per cell was obtained by counting 100 nuclei. The number in epithelial cells was similar to that in stromal cells of hyperplastic prostates. In cancerous prostates, the number was larger than in hyperplastic prostates and increased along with upgrading. The number in incidental cancers was smaller than in clinical cancers as compared with cells of the same Gleason pattern. Number correlated with T factor, but not with N and M factors. Response to treatment and cause-specific survival in stage D2 patients receiving endocrine therapy did not correlate with number, although a relationship between Gleason pattern and survival was shown in these patients. It was concluded that AgNORs might not be an indicator to predict prognosis after endocrine therapy, since a number of AgNORs did not influence response to the therapy.

Humans↗

PubMed1992

Clinical course of bone metastasis from prostatic cancer following endocrine therapy: examination with bone x-ray.

X-ray findings of bone metastatic lesions from 81 cases of stage D2 prostatic cancer were examined before and following endocrine therapy. Untreated lesions were classified into five types; osteoblastic (15%), mixed, but mainly osteoblastic (31%), mixed, but mainly osteolytic (17%), osteolytic (10%), and undetermined with a positive bone scan (27%). Patients with two mixed types had a tendency of widely speeded areas of metastasis and elevated serum prostatic acid phosphatase. Temporal enlargement of sclerotic lesion immediately after the start of therapy did not indicate disease progression. In many cases, changes from osteolytic to osteoblastic patterns were noticed in the same lesion regardless of the effects of endocrine therapy. Remodeling to the sclerotic pattern appeared as curative changes. From these findings, it was concluded that the natural course of bone lesions showed a tendency to change from the osteolytic to osteoblastic type and relapse was often accompanied by an increase of the osteolytic type lesion. Evaluation of therapeutic effects based on remodeling, changes in number and areas of lesions, and the appearance of new lesion correlated well with prognosis.

Aged↗

PubMed1992

Disaccharide analysis of the skin glycosaminoglycans in systemic sclerosis.

The disaccharides constituting chondroitinase-digestible glycosaminoglycan (GAG) in the skin lesions of patients with systemic sclerosis were determined using high-performance liquid chromatography (HPLC). In scleroderma there was an increase in the amount of delta Di-4S(DS), the main disaccharide unit of dermatan sulphate, and a decrease in delta Di-HA, the disaccharide unit of hyaluronic acid, as compared with normal skin from a similar site. The distribution pattern of the main disaccharides constituting chondroitin sulphate and dermatan sulphate in scleroderma differed from that in scars or scleredema.

Adult↗

PubMed1992

Role of intestinal microflora in metabolism of glutathione conjugates of 1-nitropyrene 4,5-oxide and 1-nitropyrene 9,10-oxide.

DNA adduct formation in the liver of B6C3F1 mice after administration of 1-nitropyrene (1-NP) was shown by the 32P-postlabeling technique. The major adduct was not N-(deoxyguanosin-8-yl)-1-aminopyrene, which was easily formed in in vitro nitroreduction of 1-NP in the presence of DNA, but the major spots migrated to the same position as the in vitro DNA adduct spots of K-region epoxides of 1-NP (1-NP 4,5- and 9,10-oxide). 1-NP oxides formed by the oxidative activation of 1-NP in the liver were excreted into the bile as detoxified glutathione conjugates which were changed to cysteine conjugates in the upper intestinal tract. The cysteine conjugates were degraded by cysteine conjugate beta-lyase (beta-lyase) of intestinal microflora in the lower intestinal tract. The mutagenicity of cysteine conjugates of 1-NP oxides for Salmonella typhimurium was enhanced by addition of beta-lyase and was decreased by addition of aminooxyacetic acid, a beta-lyase inhibitor. The in vitro binding of the cysteine conjugates to calf thymus DNA was increased by addition of beta-lyase and xanthine oxidase. We administered glutathione conjugates of 1-NP oxides to two groups of mice that had been treated with antibiotics or saline by gavage and analyzed the DNA adducts in the lower intestinal mucosa. The specific DNA adducts were detected in the saline-treated group but not in the antibiotics-treated group. These results suggest that intestinal microflora play an important role in activation of glutathione conjugates of 1-NP oxides.

Animals↗

PubMed1992

[Relationship between extent of bone metastases and effect of endocrine therapy evaluated with bone scintigraphy in stage D2 prostatic cancer].

Bone scintigraphy of metastatic lesion on 128 patients with prostatic cancer were classified according to the proposal by Soloway et al (Cancer, 61; 195-202, 1988). Since all patients received endocrine therapy, the response to therapy and survival were examined in relation to bone lesion. In extent of disease (EOD) 1, main metastatic lesions were located in the pelvis, lumbar spine, and with increasing number of EOD, metastases in the upper spine, rib, and skull appeared. Longer survival were noticed in EOD 1, followed by EOD 2 and EOD 3, and EOD 4 revealed the shortest survival. The survival of EOD 2 was similar to thus of EOD 3. However, when grades of tumor were considered, moderately differentiated cancer showed longer survival than poorly differentiated cancer in EOD 2 and EOD 3. The response as assessed by bone scintigraphy following 6-month therapy was well correlated with the number of EOD. When individual items for evaluation of response were examined, the results of local response of the prostate and values of PAP showed good correlation with survivals, however, that of bone lesions with bone scintigraphy failed to show such a correlation with prognosis. Therefore, it is concluded that the therapeutic evaluation of bone lesions with bone scintigraphy is difficult to interpret 6 months after initiation of treatment.

Adenocarcinoma↗

PubMed1992

Comparison of various assay systems for prostate-specific antigen standardization.

To avoid confusion between serum prostate-specific antigen (PSA) values among various assay systems, clinical studies on the possibility of conversion among detection values were performed. The assay kits used for the PSA comparisons were MARKIT-F PA, MARKIT-M PA, EIKEN PA, PA test WAKO, Ball ELSA PSA, E-Test Tosoh II PA, PROS-CHECK PSA, DELFIA PSA and TANDEM-R PSA. Using each kit, the standards attached to each assay system were detected, and 142 sera samples from benign hypertrophies or prostate cancers were assayed for serum PSA values. By detecting the standards for each kit, slopes were obtained which were almost identical to those obtained from original assay system. The coefficients of correlation among the PSA detection systems, using patients' sera, were very high, and linear regression lines were also obtained. The results suggest that almost identical serum PSA values may be detected either by multiplying by a coefficient to bring it to the standard or using the conversion formula.

Adenocarcinoma↗