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Biomedical subjects

T Katayama

Publications and source records attributed to T Katayama.

At least 343 records · Page 19Linked to original sources
PubMed1990

Inhibition of angiogenesis by bleomycin and its copper complex.

The effects of bleomycin (BLM) and its copper complex on embryonic angiogenesis were studied in the chorioallantoic membranes of 4.5-day-old chick embryos. Copper-free BLM inhibited embryonic angiogenesis in a dose-dependent manner, with activity detectable at 1 ng/egg and maximal at 1000 ng/egg. Also, treatment with copper-BLM complex dose-dependently caused inhibition of embryonic angiogenesis in a lower dose range. Since tumor growth is believed to depend on angiogenesis, the present results may indicate that the antiangiogenic activity of BLM is, at least in part, implicated in the antitumor activity of the drug.

Animals↗
PubMed1990

[Stress analysis of titanium-hydroxyapatite implant. Effect of titanium diameter on reinforcement and calculation of implant diameter].

In order to evaluate the effect of titanium diameter on reinforcement of titanium-hydroxyapatite implant and calculate the diameter of the implant under loading, stress analysis was performed using the finite element method. In finite element model, 100% or 70% of root length was supported by PMMA in place of bone and the implant was loaded 15 kgf at 45 degrees of the implant axis. The results were obtained as follows, 1. In the case of 100% support, the titanium diameter had little effect on the reinforcement of the implant, whereas in the case of 70% support, it had much effect. 2. The diameter of this implant was calculated to be more than 3.7 mm under loading. From these results and the view point of manufacturing techniques, the diameter of this implant was supposed to need 4.0 mm and that of titanium was to be 2.0 mm.

Dental Implants↗
PubMed1990

Effects of dietary excess amino acids on the concentrations of cholesterol, alpha-tocopherol, ascorbic acid, and copper in serum and tissues of rats.

An experiment was conducted with growing rats to investigate the effects of feeding excessive specific L-amino acids for 8 days on serum and tissue cholesterol, alpha-tocopherol, ascorbic acid, and copper, and on liver microsomal cytochrome P-450. To a 10% casein diet were added 4% L-methionine, 5% L-cystine, 5% L-histidine, 5% L-threonine, 5% L-tryptophan, 5% L-phenylalanine, 5% L-tyrosine, 6% L-valine, 7% L-isoleucine, 7% L-lysine, or 8% L-leucine. Excessive cystine and histidine increased serum cholesterol and alpha-tocopherol. Excessive cystine and methionine increased liver and kidney alpha-tocopherol and ascorbic acid. Excessive tyrosine and phenylalanine caused a marked increase in serum copper and ceruloplasmin activity, whereas excessive cystine, methionine, and histidine caused a decrease in the ceruloplasmin activity. Excessive histidine increased liver cytochrome P-450, whereas excessive tyrosine markedly decreased liver cytochrome P-450.

Amino Acids↗
PubMed1990

Clinical application of a static splitting agent for removing the denture from its cast after curing.

A very effective method for removing a denture from its cast after curing has been developed using a static expansive agent for hydration. Three filling hole designs for packing the expansive agent into a stone cast were examined to obtain the most effective method of splitting the cast for clinical application. The dynamic strain in the resin denture base was measured during static splitting one filling hole design was the safest for handling and the most effective for removing the denture. The upper tolerance limits for the maximum strain were estimated to be 2.9 x 10(-3) in the upper denture and 3.4 x 10(-3) in the lower denture. These values were lower than one-third of the critical strain corresponding to the proportional limit of the denture resin.

Calcium↗
PubMed1990

[Study of the effects of dopamine hydrochloride on alpha 1-adrenoceptors in rat kidney].

We studied the number and affinity of catecholamine receptors in SD rat kidney by radioreceptor technique. The following conclusions were obtained: 1) By using 3H-prazosin, the numbers of alpha 1-receptor (Bmax) in rat renal cortex were greater than those in rat kidney medulla. As for affinity (Kd), the significance was not recognized between the two. Bmax of the rat renal cortex to 3H-prazosin binding was 96.1 fmol/mg protein, and Kd was 0.17 nM, and for the rat renal medullar these values were 44.5 fmol/mg protein and 0.13 nM, respectively. 2) By measurement of D1-receptor using 3H-SKF38393 in the rat renal cortex in the Scatchard plot analysis, positive cooperativity was observed under the low concentration of hot ligand which was less than 1 nM. But at the concentration of hot ligand over 1 nM, the plots showed a straight line. Bmax of the rat renal cortex to 3H-SKF38393 was 2.5 pmol/mg protein and Kd was 5.3 nM. 3) Based on displacement by dopamine for 3H-prazosin binding to rat renal cortex, it was surmised that high concentration of dopamine had an affinity to alpha 1-adrenoceptors. 4) There was no change in the Kd and Bmax of alpha 1-receptor in the rat renal cortex after incubation of samples with low concentration of dopamine. However, in the case of high concentration of dopamine, a remarkable decrease of the affinity (Kd) of alpha 1-adrenoceptor was observed.

Animals↗
PubMed1990

Aladapcin, a new microbial metabolite that enhances host resistance against bacterial infection. Production, isolation, physico-chemical properties and biological activities.

We have constructed a new screening system for detecting microbial products that enhance host resistance against bacterial infection. It was found that a new compound with such activity is produced by a soil isolate classified as Nocardia sp. SANK 60484. The compound was isolated from the culture filtrate of the organism and named aladapcin after its amino acid composition. Aladapcin was obtained as an amphoteric white amorphous powder with the molecular formula, C13H25N5O5. It consists of 2 mol of D-alanine and 1 mol of meso-diaminopimelic acid. From the analysis of IR, 1H NMR and FAB-MS spectra, the structure was assigned to be a tripeptide. Aladapcin enhanced host resistance against an experimental Escherichia coli infection in mice at doses ranging between 1 and 100 micrograms/kg.

Adjuvants, Immunologic↗
PubMed1990

[Evaluation of anti-androgen therapy for benign prostatic hypertrophy by using transrectal prostatic ultrasonography].

We evaluated the effect of anti-androgen therapy for benign prostatic hypertrophy on 33 patients who had undergone transrectal prostatic ultrasonography both before and after administration of anti-androgenic drugs in our clinic. Patients treated with chlormadinone acetate (CMA) orally, or TSAA-291 intramuscularly showed a significant reduction in the prostatic weight. However, this reduction was not correlated with the degree of symptomatic improvement. In addition, patients who showed no symptomatic improvement despite a reduction in the prostatic weight often had prostatic stones or small inflammatory cell infiltrations in their prostatic tissue. Therefore, the coexistence of prostatitis or bladder neck obstruction with prostatic hypertrophy may contribute to the lack of symptomatic improvement in such patients.

Administration, Oral↗
PubMed1990

[Clinical study of hypogonadotropic hypogonadism].

Clinical study of eight cases of hypogonadotropic hypogonadism was performed. These cases consisted of five prepubertal cases and three postpubertal cases induced by prolactin-producing hypophyseal tumor. The former five cases had the chief complaints of incomplete development of their external genitalia. The chief complaints in three postpubertal cases were decreased libido in two and infertility in one. The average testicular volumes were 7.8 ml and 20 ml in prepubertal and postpubertal cases, respectively. The basal levels of luteinizing hormone (LH) were within the normal limit in most cases and follicle stimulating hormone (FSH) were low in most cases. There were no differences between the levels of these hormones in prepubertal cases and those in postpubertal cases. The range of basal level of prolactin in blood was 92 mg/ml to 1,070 ng/ml in the postpubertal cases. The basal level of testosterone in blood was low in all cases. Most cases had rather good responses of LH and FSH after the administration of luteinizing hormone releasing hormone. The plasma level of testosterone was elevated after the administration of human chorionic gonadotropin (hCG) in most cases. The appearance of sperm in the semen was observed after the hCG therapy in only one of the prepubertal cases. On the other hand, all the postpubertal cases showed almost normal findings in semen analysis after hormone therapy.

Adult↗
PubMed1990

[Clinical phase I and phase II study on a sustained release formulation of leuprorelin acetate (TAP-144-SR), an LH-RH agonist, in patients with prostatic carcinoma. Collaborative++ Studies on Prostatic Carcinoma by the Study Group for TAP-144-SR].

TAP-144-SR is a sustained release formulation of an LH-RH agonist, leuprorelin acetate (TAP-144), that has been newly developed in Japan. As a phase I study, a single subcutaneous dose of TAP-144-SR was given to 15 patients with prostatic cancer to investigate the safety, endocrinological effects, and serum levels of the drug. The patients were divided into four groups according to the dosage levels of 1.88 mg, 3.75mg, 7.5 mg and 15 mg. No serious side effects were noted in any of the patients treated with any dose. No patients exhibited signs of a local reaction at the site of injection. In two patients transient exacerbation of clinical symptoms owing to "flare up" was observed. Serum testosterone levels decreased to the castration level (less than 1.0 ng/ml) in all of the patients, although the time required to attain the castration level tended to be longer in the patients receiving 1.88 mg. Serum TAP-144 levels increased on the first day and gradually decreased thereafter. In the groups of patients that received 3.75 mg or more of TAP-144-SR, TAP-144 was detected in the serum up to 4 weeks after administration. Based on the results of the phase I study, 3.75 mg and 7.5 mg of TAP-144-SR were selected as the doses for the phase II study. The phase II study was carried out as a multi-center open trial. Patients with stage B-D prostatic cancer received subcutaneously either 3.75 mg (3.75 mg group) or 7.5 mg (7.5 mg group) of TAP-144-SR once every 4 weeks for a total of 3 doses over a period of 12 weeks. TAP-144-SR 3.75 mg was administered to 51 patients and 7.5 mg to 50 patients. Both of these doses were adequate to suppress serum LH and FSH levels. Serum testosterone was decreased to the castration level within 22 days after the first dose, and this suppression was maintained throughout the treatment period. Clinical response rate (CR + PR) was 21% in the 3.75 mg group and 22-24% in the 7.5 mg group according to the Criteria for Evaluating the Direct Response to Chemotherapy in Solid Carcinomas and NPCP criteria. The response rate by the criteria of Japanese Prostatic Cancer Study Group was 51% in the 3.75 mg group and 62% in the 7.5 mg group. Adverse reactions were noted in 26% of patients in the 3.75 mg group and 34% in the 7.5 mg group.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1990

[Colorimetric studies on hiding effect of Cosmotech porcelain for laminate restoration].

The hiding effect on color tone of discolored teeth restored with ceramic laminate veneer crown was examined. Translucent (T1, T2), Enamel (E1, E2, E3), Dentin (DA2, DA3, DB2, DB3), Masking dentin (MDA2, MDA3, MDB2, MDB3) in 13 colors and Modifire (M61, M62, M65, M66, M67, M68, M69, M70, M79) in 7 colors of the ceramic materials (Cosmotech porcelain G C Co., Ltd) were examined in this experiments. The colorimetric examination of the color tone backing with the white or black color was carried out by testing for color difference (delta E*ab), value difference (delta L*), chrom and hue of the samples. The result obtained were as follows; 1. Color difference was higher in order of T2 greater than T1 in Translucent greater than E1 greater than E3 greater than E2 in Enamel greater than DB3 greater than DA2 greater than DA3 greater than DB2 in Dentin greater than MDB3 greater than MDA2 greater than MDB2 greater than MDA3 in Masking dentin, and M69 greater than M79 greater than M70 greater than M68 greater than M66 greater than M61 greater than M62 greater than M67 greater than M65 in Modifire. 2. Value difference was higher in order of T2 greater than T1 in Translucent greater than E1 greater than E3 greater than E2 in Enamel greater than DB3 greater than DA2 greater than DB2 greater than DA3 in Dentin greater than MDA2 greater than MDB3 greater than MDB2 greater than MDA3 in Masking dentin, and M69 greater than M70 greater than M79 greater than M68 greater than M66 greater than M61 greater than M67 greater than M65 greater than M62 in Modifire.(ABSTRACT TRUNCATED AT 250 WORDS)

Adhesives↗
PubMed1990

Study of estimation of color recognition on the dentist. On the ability of subjects to discriminate color in terms of hue, value and chroma.

The tooth crown color space model was manufactured and the improvement of the color representation and communication on the dental clinic have been trying. The study of color discrimination by dentist and student viewing with the use of tooth crown color chips reported here in basic knowledge on the color sensitivity of human eye. The test card were 55 x 90 mm in size and the color chip, 5 x 10 mm. The paired color chips were placed on the test card to have a 2 mm distance between them. Color difference of two tooth crown color chips on the test cards was 3.5 (delta E*ab), the combination of hue, value and chroma was constant of all cards. The subjects were 22 people, 6 dentists and 16 dental school students with normal color sensibility. In proportion of method of comparison for surface color (JIS Z 8723), the subject observed the test card which were different of hue, value and chroma on the their naked-eye, were investigated to evaluate their judgement of the test cards. The following results were obtained. The standard of judgment for the color discrimination was made firstly in terms of hue, secondly in terms of value, and thirdly in terms of chroma.

Adult↗
PubMed1990

[A case of primary aldosteronism due to unilateral multiple adrenal adenomas].

A 64-year-old female with hypertension, hypokalemia visited our hospital. Endocrinological examinations showed a low level of plasma renin activity and high level of plasma aldosterone. Circadian rhythmicity of plasma aldosterone level was recognized. No change in the plasma level of aldosterone was observed after loading of standing and administration of furosemide. Adrenal scintigraphy, adrenal venous aldosterone assay and CT scan revealed two tumors in the left adrenal. The diagnosis of primary aldosteronism by left adrenal tumors was made from the above findings. A left adrenalectomy was performed and pathological findings showed two adenomas, which had no capsule either and were surrounded by normal adrenocortical tissue. Blood pressure normalized after surgery and the plasma levels of aldosterone and plasma renin activity were normalized.

Adenoma↗
PubMed1990

[Ultrasonographic changes in the endometrium during ovulatory cycles--correlation to serum estradiol and progesterone concentrations].

Daily changes in the thickness and texture of the endometrium were assessed by ultrasonography in 15 natural ovulatory cycles. The endometrium in the follicular phase became thicker every day until ovulation [5.8 +/- 1.8 mm (mean +/- SD) on day -8, 10.7 +/- 2.9 mm on day 0, day 0: ovulation], but the thickness did not change during the luteal phase. There was a significant correlation between the thickness of the endometrium and the serum estradiol concentration in the follicular phase (r = 0.64, n = 89, p less than 0.01), but the change in the thickness of the endometrium varied with the individual. The texture of the endometrium changed in the menstrual cycle. The hyperechoic area of the endometrium spread from the basal layer to the lumen during the early-mid luteal phase. The ratio of the thickness of the hyperechoic area to the total thickness of the endometrium (hyperechoic endometrial area ratio, HEA ratio) increased from 34.3 +/- 11.0% on day 0 to 100% on day 9. There was a significant correlation between the HEA ratio and the serum progesterone concentration in the period from day -2 to day 9 (r = 0.68, n = 91, p less than 0.01).

Adult↗
PubMed1990

[Fulminant hepatic failure induced by intermediate dose methotrexate in a case of non-Hodgkin's lymphoma].

Methotrexate (MTX) is frequently used as an antifolics agent in many malignant neoplasms such as leukemia, lymphoma and osteosarcoma. The major side effects of MTX are liver and renal damages, bone marrow suppression and so on. But careful management and citrovorum factor rescue could decrease the incidence and degree of these side effects. In this report, we described a patient with non-Hodgkin's lymphoma who developed and died of fulminant hepatic failure soon after the administration of intermediate dose MTX. Serological tests for HB virus were not changed throughout, and lymphocyte stimulation test for MTX was strongly positive. His autopsy revealed no inflammatory cell infiltration into the liver, but marked biliary congestion which is a distinctive feature of drug induced hepatitis. From above results, it was suggested that nature of this fulminant hepatic failure was an allergic reaction to MTX. There is no previous report which is concerning about MTX and fetal drug related hepatic failure.

Adult↗
PubMed1990

[Treatment of secondary empyema following lung resection complicated with internal fistula].

To clarify the results of treatment of secondary empyema following lung resection complicated with internal fistula, 81 cases treated at 31 different institutions during the 5 years period from 1983 to 1987 were analysed. 1) All cases of thoracic empyema treated surgically and secondary empyema following lung resection complicated with internal fistula did not decreased during the study period, in spite of the remarkable decrease of surgical cases for pulmonary tuberculosis. 2) The highest rate was observed in males over 50 years of age. 3) Bacteriologically positive case in empyema space was occupied about 70%. 4) 196 operations (including drainage) of 17 types were performed on 81 patients. Only 16% of the cases were successfully treated with one stage of operation. 5) Principal surgical procedure applied in cases under this study was drainage followed by closure of fistula with muscle plombage and with or without thoracoplasty. Case of air plombage and omental pedicle flap plombage have increased recently in Japan. 6) Success rate was 55.6%, failure rate was 32.1% and the mortality was 12.3%. These results indicate the difficulty involved in treatment. Therefore, to avoid occurrence of secondary empyema cases, careful selection of surgical indication, sufficient training in surgical technique and good preoperative and postoperative management are crucial.

Adult↗
PubMed1989

A cDNA fragment of hepatitis C virus isolated from an implicated donor of post-transfusion non-A, non-B hepatitis in Japan.

Recently, a cDNA from the hepatitis C virus (HCV) RNA genome has been isolated in the USA from a chronically infected chimpanzee. In order to isolate HCV cDNA derived from human material, RNA was extracted from plasma of a Japanese blood donor implicated in post-transfusion non-A, non-B hepatitis and HCV cDNA was synthesized and amplified by the PCR method using HCV-specific oligonucleotide primers. The cDNA fragment, 583 nucleotides long, showed 79.8% homology at the nucleotide level and 92.2% homology at the amino acid level compared with the prototype HCV cDNA. These results provides further evidence to show that HCV is closely associated with the development of post transfusion non-A, non-B hepatitis.

Amino Acid Sequence↗
PubMed1989

Chromatographic method for the preparation of apo-cellular retinol-binding protein and apo-cellular retinoic acid-binding protein from their holo-types.

A chromatographic method is described for the preparation of apo-cellular retinol-binding protein (CRBP) and apo-cellular retinoic acid-binding protein (CRABP) from their corresponding holoproteins. Elimination of retinoids from either purified CRBP or CRABP holoprotein complex could be performed quantitatively by DEAE-cellulose chromatography without any alteration in the inherent properties of the native proteins. In contrast, the usual methods, involving UV irradiation or acetone precipitation, resulted in some modification of these binding proteins. This chromatographic method was also applicable to the preparation of apo-fatty acid-binding protein (FABP) from FABP-palmitic acid holoprotein complex.

Animals↗