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Biomedical subjects

M Akimoto

Publications and source records attributed to M Akimoto.

At least 19 recordsLinked to original sources
PubMed1992

Computed tomographic evaluation of bone metastases in prostatic cancer patients.

This report provides new morphological insights, based on diagnostic methods, into metastases to the bone in prostate cancer patients. Lumbar CT examination is available to evaluate whether metastases are truly present or not, especially in aged patients with positive bone scans. The evaluation of response is clearer on CT. Furthermore, CT is useful not only in estimating the presence of metastases, CT also provides definite details on the extent of the metastatic condition.

Aged↗
PubMed1992

Relationship between endothelin and thromboxane A2 in rat liver microcirculation.

In our previous study, we determined changes in hepatic blood flow using a Laser Doppler blood flow meter after i.v. injection of endothelin-1 (ET-1) or endothelin-3 (ET-3) at 2 nmol/kg in rats and found that ET-3 caused greater decreases in blood flow than ET-1. In the present study, we determined how the arachidonic acid cascade, mainly thromboxane A2 (TXA2), is related to ET-1 and ET-3 using indomethacin (INDO), which inhibits the biosynthesis of prostaglandin (PG), and OKY-046, a selective inhibitor of TXA2 synthesis. In the first series of experiments, ET-1 and ET-3 were administered after inhibiting the biosynthesis of PG by s.c. injection of 2 mg/kg of INDO. While INDO failed to inhibit the slight decrease in hepatic blood flow induced by ET-1, it significantly inhibited the marked decrease in hepatic blood flow elicited by ET-3. In the next series of experiments, ET-1 and ET-3 were administered after administration of 20 mg/kg of OKY-046. OKY-046 showed no effects in animals treated with ET-1, as in those pre-treated with INDO, while it significantly inhibited the decreases in hepatic blood flow induced by ET-3. These findings suggest that ET-1 decreases hepatic blood flow due to its direct effects although to a lesser extent than ET-3, while ET-3 does so due not only to its direct effects but also to TXA2-mediated effects. It is therefore likely that in addition to ET family peptides, PG-mediated mechanisms are involved in the regulation of hepatic microcirculation by ETs.

Animals↗
PubMed1992

ET-3 sensitive reduction of tissue blood flow in rat liver.

Changes in gastric mucosal and hepatic tissue blood flow were simultaneously determined using a laser-Doppler blood flow meter in rats given i.v. injection of endothelin-1 (ET-1) and endothelin-3 (ET-3), both at 2 nmol/kg. Gastric mucosal blood flow decreased significantly after administration of ET-1 compared to after administration of ET-3. Decreases in blood flow due to ET-1 were reversed by pre-treatment with 10 mg/kg of BQ-123 (sodium salt), an ETA receptor antagonist, to levels comparable to those induced by ET-3, but BQ-123 had no effects on decreases in blood flow due to ET-3. On the other hand, decreases in hepatic tissue blood flow by ET-3 were significant compared to those by ET-1. Decreases in hepatic tissue blood flow due to ET-1 were slightly inhibited by pre-treatment with 10 mg/kg of BQ-123, but it had no effect at all on decreases due to ET-3. These findings indicate that decreases in gastric mucosal blood flow are mainly caused by ET-1 via ETA receptors inhibited by BQ-123, while decreases in hepatic tissue blood flow are caused mainly by ET-3 via non-ETA receptors not inhibited by BQ-123. The fact that ET-3 decreases blood flow more significantly than ET-1 suggests the involvement of ET-3 selective receptors (ETc). The findings obtained in the present study indicate that complex mechanisms are involved in the regulation of tissue blood flow by ET, with different receptor subtypes and ET family peptides being involved according to the type of tissue.

Animals↗
PubMed1992

Metabolism of L-amino acids in a marine bacterium isolated from mackerel intestines in relation to eicosapentaenoic acid biosynthesis.

Metabolism of glucose and L-amino acids in an obligately aerobic marine bacterium isolated from Pacific mackerel intestines was investigated for the mechanism and pathway of eicosapentaenoic acid (EPA) biosynthesis. This bacterium could not uptake glucose but the cell-free extract of this bacterium had the enzymatic activities of L-alanine oxidase (EC 1.4.3.2), L-alanine dehydrogenase (EC 1.4.1.1). L-serine dehydratase (EC 4.2.1.13), and malate dehydrogenase (EC 1.1.1.40), and of seven enzymes involved in the TCA cycle of the usual aerobes. On the other hand, the carbon-13 concentration in cellular fatty acids of the bacterium, especially that in their methyl carbon atoms in contrast to their carbonyl carbons, increased drastically when the bacterium was grown in the presence of 13CH3COONa. These results indicate that: (i) the TCA cycle works in this bacterium, (ii) glucose is not utilized and pyruvic acid is in vivo synthesized from L-alanine, L-serine, and malic acid, and (iii) EPA and other cellular fatty acids are in vivo synthesized from acetyl coenzyme A by the usual de novo synthesis route.

Amino Acids↗
PubMed1992

[Endothelin levels under water-immersion stress in rats].

Rats with water-immersion stress-induced ulcer were prepared to determine the levels of ET in blood and gastric tissues, and their relationship with the gastric mucosal blood flow, PGs and pathogenesis in the gastric mucosa were evaluated. Pathology in the gastric mucosa appeared an hour after stress loading, while blood flow rate decreased significantly 30 minutes later. PGE2 increased 30 minutes later, then decreased. PGI2 decreased significantly. Blood ET level was 1.22 +/- 0.50 pg/ml for the controls, but this increased remarkably after one hour and significantly peaked after two hours of water immersion. The level of ET in the gastric tissues was 25.87 +/- 1.63 pg/g tissue for the controls, and this increased markedly after two hours of immersion, reaching a significant peak. In the present study, increased in endogenic ET due to stress were confirmed, and the results suggested the possibility of ET being involved in the pathogenesis of ulcer.

Animals↗
PubMed1992

[Operation of female stress incontinence--comparison between Raz procedure and Gittes procedure].

We performed Raz procedure and Gittes procedure for female stress incontinence since October 1986. Raz procedure was performed on 19 patients between October 1986 and February 1990, and Gittes procedure was performed on 18 patients between June 1990 and May 1991. We followed up 17 patients who underwent Raz procedure and all the patients who underwent Gittes procedure at the time August 1991. Disappearance or marked improvement of incontinence was confirmed in 12 patients by Raz procedure, and 16 patients by Gittes Procedure. No serious complications were recognized. The reason why the result of Raz procedure was not sufficient was due to our immature operative technique and incorrect patient selection in our early experience. From this experience, we believe that both procedures can be very useful and minimal invasive operation for female stress incontinence.

Adult↗
PubMed1992

[Clinical studies on Kock continent urinary reservoir and Indiana continent urinary reservoir].

Recently, the continent urinary reservoir which provides the patient with a better quality of life has become popular. Many types of reservoirs have been reported, but the optimal procedure remains to be established. From July 1987 through November 1988, we performed Kock pouch construction on 11 patients (ages 39 to 76 years). Between July 1989 and March 1991, 9 patients (ages 44 to 66 years) underwent Indiana pouch operation. The first 4 patients underwent ileal patch type, and the subsequent 5 underwent Heineke-Mikulicz type procedure. A one-stage radical cystectomy and continent urinary reservoir construction was performed on 19 patients, and bilateral cutaneous ureterostomy was converted to Kock pouch in one patient. There were no perioperative deaths, but reoperation was required for urinary leakage from the reservoir on one patient in each group. As the late complications in the Kock pouch group, one patient required revisional operation of the continent valve mechanism, 2 patients experienced intermittent prolapse of the nipple valve of the efferent limb, and 2 had malfunction of the afferent nipple valve. In the Indiana pouch group unilateral hydronephrosis was noticed in one patient, and 4 had mild difficulty of catheterization. Although 3 patients in both groups had mild urinary leakage, all patients had good quality of life with capacity of reservoir over 500 ml and with good renal function. We changed the type of operative procedure from Kock pouch to Indiana pouch because of the high complication ratio in the former.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Effect of bismuth nitrate given in combination with cis-diamminedichloroplatinum(II) on the antitumor activity and renal toxicity of the latter in nude mice inoculated with human bladder tumor.

The effects of bismuth nitrate pretreatment on the toxicity and antitumor activity of cis-diamminedichloroplatinum (cisplatin, CDDP) were examined in nude mice that had been inoculated with human bladder-tumor tissue. Pretreatment with bismuth nitrate depressed the renal toxicity of CDDP without compromising its activity against a transplantable human bladder tumor. Renal metallothionein (MT) and bismuth (Bi) levels in nude mice were markedly increased by Bi preadministration, but no significant MT induction was observed in inoculated human bladder-tumor tissue in which only a trace amount of Bi was incorporated. Furthermore, it was confirmed that tumor platinum (Pt) concentrations in CDDP-treated mice were not affected by Bi pretreatment. Thus, the administration of Bi compounds prior to chemotherapy with CDDP may provide an effective mode of treatment for advanced bladder tumors.

Animals↗
PubMed1991

Three-dimensional CT system using a personal computer.

A three-dimensional CT display system using a personal computer was developed and used for diagnosis of craniofacial abnormalities. The advantages of this system are that it is inexpensive and easy to operate.

Computer Graphics↗
PubMed1991

The correlation between the immunohistochemical expression of DF3 antigen and serum CA15-3 in breast cancer patients.

The immunohistochemical expression of DF3 antigen and serum concentrations of CA15-3, a breast carcinoma-associated antigen recognized by the monoclonal antibodies (MAbs) 115D8 and DF3, was investigated in breast cancer patients. The levels of serum CA15-3 in 23 primary breast cancer patients did not correlate to the percentage cytoplasmic reactivity of MAb DF3 with the carcinoma cells in tissue specimens from each respective patient. In 17 patients who subsequently developed metastatic breast cancer, however, the serum CA15-3 concentrations generally correlated well to the cytoplasmic reactivity of MAb DF3 with the carcinoma cells in specimens obtained at initial biopsy or mastectomy. Elevated levels of serum CA15-3 were seen in metastatic breast cancer patients when the carcinoma cells in their primary specimens expressed enhanced levels of cytoplasmic DF3 antigen. The results of this study suggest that the immunohistochemical demonstration of DF3 antigen in tissue specimens, together with the periodical measurement of circulating CA15-3 antigen, may be important for monitoring the clinical course of breast cancer patients.

Antibodies, Monoclonal↗
PubMed1991

Clinical application of video image flexible ureteronephroscope for diagnosis of upper urinary tract disorders.

Ureteroscopy has become the diagnostic and therapeutic procedure of choice for many conditions of the upper urinary tract. Technology is progressing rapidly in endourology, facilitating both goals. As reported previously, we developed a 2F video image flexible ureteronephroscope. This instrument is the smallest caliber of all ureteronephroscopes available to date. Because of the small diameter the device can be inserted into the ureter cystoscopically in a manner similar to catheter insertion. The procedure is done with the patient under local anesthesia. We performed ureteronephroscopic procedures on 79 patients using mainly a 6F passively deflecting flexible ureteronephroscope, which consists of the aforementioned 2F video image flexible ureteronephroscope and a 3F working channel. The area to be viewed was accessed successfully in 41 of 43 patients (95%). Over-all, diagnostic maneuvers were successful in 64 of 79 patients (87%). We suggest that the 2F and 6F flexible ureteronephroscopes would be indicated when conclusive diagnosis for upper urinary disease is not obtained by other means.

Endoscopes↗
PubMed1991

Anti-allergic effect of bryonolic acid from Luffa cylindrica cell suspension cultures.

The anti-allergic activity of bryonolic acid (1) isolated from the cultured cells of Luffa cylindrica L. (Cucurbitaceae) was compared with that of glycyrrhetinic acid (2), the aglycone of glycyrrhizin from licorice. Compound 1, when administered to rats intraperitoneally at a dose of 600 mg/kg, inhibited homologous passive cutaneous anaphylaxis more strongly than 2 at the same dose. Compound 1 also significantly inhibited delayed hypersensitivity in mice which could not be inhibited by 2. In contrast to 2, 1 showed not only little toxicity but no visible side effects on mice, without impairing the activity of the hepatic enzyme (4,5 beta-dihydrocortisone:NADP+ delta 4-oxidoreductase) involved in steroid catabolism.

Animals↗
PubMed1991

Study of macrophages in prostatic fluid from nonbacterial prostatitis patients. V. Relation between activation of macrophages and stage of prostatitis.

Relationship between activation of macrophages in prostatic fluid and stage of nonbacterial prostatitis was studied by observing the rate of adherence of leukocytes, percentage of macrophages among adherent leukocytes and presence of spreading of macrophages. As a result, it was found that macrophages in the early stage of NBP were more activated than macrophages in the chronic stage.

Adult↗
PubMed1991

Recombinant interleukin-2-expanded tumor infiltrating lymphocytes from human renal cell cancer do not exhibit autologous tumor cell-specific cytotoxicity.

We studied subsets and cytotoxicity of recombinant interleukin-2 (rIL-2)-expanded tumor-infiltrating lymphocytes (TIL) from renal cell cancer (RCC) patients. TIL were successfully expanded in 13 of 14 RCC cases using anti-CD3 during the initial 48 h of culture. Percentages of CD8-positive cells among rIL-2-expanded TIL at 1-4 week(s) of culture were 56.2 +/- 15.1% (range 26.2-79.8%, n = 13) and not necessarily predominant over CD4-positive cells. Natural killer and lymphokine-activated killer (LAK) activities of TIL at 3-6 weeks of culture were 31.6 +/- 15.8% (range 1.4-57.4%, n = 9) and 16.6 +/- 11.6% (range 3.8-35.6%, n = 6), respectively. Autologous and allogeneic RCC cytotoxicity of TIL at 3-4 weeks of culture were 17.9 +/- 19.7% (range 0-47.6%, n = 4) and 18.9 +/- 14.8% (range 0-47.3%, n = 12), respectively. Since there was no statistical difference between them, autologous specific cytotoxicity was not demonstrated. From these result of the present study, it is unlikely that most of effector cells of rIL-2-expanded TIL in autologous RCC lysis are major histocompatibility complex-restricted cytotoxic T cells. We concluded that it is doubtful whether TIL is significantly superior over LAK cells in immunotherapy of human RCC.

Carcinoma, Renal Cell↗
PubMed1991

Establishment of an estrogen receptor-positive cell line (HMA-1) derived from human breast carcinoma.

We have established a novel human breast carcinoma cell line, HMA-1, derived from ascites of a female breast cancer patient. HMA-1 was shown to be an epithelial cell line with intracytoplasmic duct-like vacuoles, microvilli, desmosomes and tonofibrils in accordance with human breast cancer. The cell line demonstrated a good cell growth ability in monolayer fashion with a doubling time of 46 hr. Based on a whole cell binding assay the cell line contained estrogen receptor (1.45 x 10(-4) sites/cell). Tamoxifen, an anti-estrogen agent induced a dose-dependent decrease in the cell growth rate, but estradiol stimulated the cell growth. HMA-1 could be transplanted subcutaneously into BALB/c nude mice, and was able to cause tumors approximately two months after heteroinoculation. These results indicate that HMA-1 cell line may serve as a new human breast carcinoma cell line which could be utilized in the breast cancer research.

Adenocarcinoma↗