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Biomedical subjects

O Yoshida

Publications and source records attributed to O Yoshida.

At least 397 records · Page 22Linked to original sources

Advantages in combination chemotherapy using cisplatin and its analogues for human testicular tumor xenografts.

The antitumor effects and toxicities of combination chemotherapies using cisplatin (CDDP) and its analogues were compared with those of single drug therapies. Congenitally athymic nude BALB/c (nu/nu) mice were used to estimate antitumor activities of these compounds against human testicular tumor (Ht-14) xenografts and hetero-BALB/c (nu/+) mice were used to evaluate the toxic effects of the drugs. Combination therapy with half dosages of CDDP and carboplatin (JM8) (CDDP: 2, JM8: 20 mg/kg/day for 5 days), or of CDDP and (glycolato-O,O')-diammineplatinum (II) (254S) (CDDP: 2,254S: 4 mg/kg/day for 5 days), resulted in significant tumor regression. The combination of CDDP and JM8 had the highest therapeutic efficacy while the CDDP and 254S combination had a lower antitumor potency. In addition, the toxicities of the combination therapies were lower than what was produced by the highest dosage of CDDP (4 mg/kg/day for 5 days). These results demonstrated that the antitumor activities of these combination chemotherapies were equal or superior to the activity of CDDP or an analogue alone, and that the toxicities produced by these combinations were more manageable than those produced by single drug therapies.

Animals↗

Trace elements and complications in patients undergoing chronic hemodialysis.

Abnormalities of trace elements such as aluminum, silicon, zinc, manganese and nickel were found in chronic hemodialysis (HD) patients. The relationship between serum concentration of trace elements and complications such as anemia bone disease, neurological disorder and nutritional disorder in 100 chronic HD patients was examined. Serum Al and Si levels were very high in these patients, and were negatively correlated with indicators of anemia such as RBC, hemoglobin and hematocrit values. Serum Al and Si levels in the HD patients with peripheral neurological disorder (excluding encephalopathy) and with bone disease were significantly high. The levels of serum Zn, Mn and Ni were low, and were correlated with total serum protein levels. In summary, in order to prevent some complications in chronic HD patients, it is very important to regulate levels of trace elements.

Aluminum↗

Epidemiology of urolithiasis in Japan: a chronological and geographical study.

A nationwide survey on urolithiasis in Japan between 1965 through 1987 was carried out, succeeding the previous 1955 and 1966 studies, in an effort to evaluate chronological and geographical changes in urolithiasis among the Japanese people who are relatively racially homogenous and living with similar customs and habits, which have changed dramatically from the old Japanese to westernized modes in a very short period after the Second World War. Incidence of calcium-containing urinary stones in the upper urinary tract has been increasing in Japan since the Second World War with increasing westernization of life-style and industrialization, with the annual incidence of urolithiasis steadily increasing from 53.8/100,000 general population in 1965 to 92.5 in 1985. According to the data, 5.4% of the population may be expected to develop a urinary calculus at least once in their life time. Analysis of 69,949 stones obtained during the years from 1978 to 1987 with infrared analysis showed that 79.4% were calcium oxalate and/or calcium phosphate stones, 7.4% were struvite with or without carbonate apatite, 5.2% were uric acid or urate, and 1.0% were cystine. In the era of new treatment modalities such as the endourological surgery and the extracorporeal shock wave lithotripsy, open surgical treatments were replaced with new types of treatment in about 75% of the cases in 1985.

Calcium↗

Value of prostate-specific antigen measurements in predicting lymph node involvement in prostatic cancer.

The preoperative serum levels of prostate-specific antigen (PA) were determined in 35 consecutive patients who had clinically localized prostatic cancer and underwent bilateral staging pelvic lymphadenectomy. When 10.0 ng/ml of PA was used as the cutoff value for lymph node staging the specificity of an elevated PA level in revealing lymph node involvement was 77% with a sensitivity of 85% and an accuracy of 80%. Only 1 of 18 (6%) patients with negative PA levels (below 10 ng/ml) and a preoperative Gleason score 2-7 tumor had metastatic lymph node disease. Among the 17 patients with positive PA levels (above 10 ng/ml) or a Gleason score 8-10 tumor, 12 (71%) had lymph node involvement. The preoperative PA level and the extent of local tumor invasion correlated strongly with each other. Our study suggests that the PA level could be a simple and objective parameter with which to predict metastatic lymph node disease if used in conjunction with the Gleason histological grade.

Adenocarcinoma↗

Changes in progesterone levels in pregnancy block caused by the proximity of a strange male and by the injection of PMSG.

Attempts were made to examine progesterone levels during pregnancy block, first initiated by pheromones and then by the injection of pregnant mare serum gonadotropin (PMSG). The proximity of a strange male inhibits the usual increase in progesterone levels, resulting in no activation of the corpora lutea, from the estrous cycle to the pregnancy. Strain differences were observed in the imitation of pregnancy block by the injection of PMSG. The C3H and BALB/c strains required much smaller doses of PMSG for pregnancy block than the C57BL/6 strain did. The changes of progesterone observed in pregnancy block initiated by PMSG were slightly different from that caused by the proximity of the strange male: The progesterone levels temporally increased on the day following the injection of PMSG and then decreased on day 4 in the PMSG-treated group. These results suggest that PMSG imitates the effect of the proximate strange male in the pregnancy block.

Animals↗

Structural characterization of the immunoactive and antiviral water-solubilized lignin in an extract of the culture medium of Lentinus edodes mycelia (LEM).

The active principle of EP3, a fraction from an extract of the culture medium of Lentinus edodes mycelia (LEM), which activates murine macrophages, causes proliferation of bone marrow cells, and inhibit the replication of Human Immunodeficiency Virus in vitro, was characterized as a water-solubilized lignin. The detailed structural feature of this water-solubilized lignin was investigated and shown to be a highly condensed and polycarboxylated lignin which is denatured and solubilized by Lentinus edodes from bagasse. The water-solubilized lignin itself was confirmed to have both immunological activities and the antiviral activity.

Animals↗

[Studies on titanium casting. (1) Influence of the mold temperature on titanium castings].

Pure titanium and titanium alloys have excellent biocompatibility, excellent corrosion tarnish resistance, a quarter of the specific gravity of gold base alloys and suitable mechanical properties for dental clinical use. However, titanium has some undesirable characteristics. For example, it has a high melting temperature and chemical reactivity at high temperatures. The investigate influence of the mold temperature on castability and mechanical properties of the titanium castings was study. The castability was found to be good at various mold temperatures, but the higher the mold temperature during casting, the greater the adhesive phenomenon between titanium surface and the investment. From the EPMA observation of the surface layer on the titanium castings, an Si- rich layer whose thickness increased considerably with increasing temperature was observed. The Vickers hardness in the surface layer was greater than that in the inner part. At a higher mold temperature during casting the thickness of the high Vickers hardness layer was increased. There was a relationship between the Vickers hardness value and the thickness of Si rich layer. In the tensile strength test of titanium castings, elongation values decrease and tensile strength values increased with the rise in mold temperature.

Dental Alloys↗

[Afferent nipple valve malfunction as a late complication of the Kock continent ileal reservoir].

Construction of a continent ileal urinary reservoir (Kock pouch) is associated with a high incidence of late complication because of malfunction of the nipple valve, the efferent limb in particular. We have so far experienced several types of afferent nipple malfunction. We herein report on the unexpected complications of the afferent nipple valve in patients with a post operative observation of 1 year or more. From 1984 through 1989, urinary diversion via a Kock pouch was performed on 47 patients at Kyoto University Hospital and Public Toyooka Hospital. The study group comprises 42 patients with a mean observation of 40 months (range 14 to 60 months). The late complications of the afferent nipple valve were observed in 11 of the 42 (26%) patients. These included erosion of Dacron fabric used as a collar (5 patients), afferent nipple stenosis (3 patients) and afferent nipple obstruction by mucous plug or fungus ball (3 patients). Removal of Dacron collar was performed in 4 of the 5 patients with collar erosion and in 1 of the 3 patients with nipple stenosis. Nipple obstruction was relieved by endoscopic manipulation or diuresis. All of the 11 patients had no problems with their efferent nipples. Our results suggest that the use of nonabsorbable material as a collar and peristaltic direction of the afferent limb are mainly involved in the complications of the afferent nipple. A more reliable and simpler procedure for antireflux anastomosis should be considered.

Adult↗

[Clinical studies on endocrine therapy of prostatic carcinoma (1): Multivariate analyses of prognostic factors in patients with prostatic carcinoma given endocrine therapy].

The general trend on the treatment for prostatic carcinoma has been changing from endocrine therapy alone to an alternative type according to stage. We evaluated clinically the favorable and unfavorable outcome of endocrine therapy in Japan, so that others will be appropriately evaluated. In a cooperative study made by members of five universities, 572 patients with clinically or histologically reconfirmed prostatic carcinoma were entered in this retrospective study. We studied the true influence of prognostic factors on the prognosis of 497 patients with prostatic carcinoma who had received endocrine therapy, employing multivariate analyses, such as quantification method II, multiple regression analysis and Cox's proportional hazard model. Twelve factors were considered in the study; "age", "stage", "histological findings (structural atypism = SAT, nuclear anaplasia = NAN, Gleason's primary and secondary pattern)", "pretreatment level of total acid (ACP) and of alkaline phosphatase (ALP)", "castration performed or not performed", "doses of estrogen", "type of response of local prostatic tumor and of ACP to endocrine therapy". Analysis of the "importance" of a prognostic factor by a partial correlation determined by quantification method II, revealed "stage" to have the greatest "importance" on prognosis throughout the entire period. "Response of local prostatic tumor", "response of ACP" and "Gleason's primary pattern" tended to be important factors for prognosis, in particular, in the first half period, and "age" and "Gleason's secondary pattern" were important in the latter half. Multiple regression analysis revealed the "stage", once again to be the most influential factor on the prognosis for the entire observation period. Also "response of local prostatic tumor", "SAT" and "Gleason's primary pattern" affected the patients' prognosis in the first half of the observation period. In the latter half, "age" became more of an influential factor than "histological findings". Analysis with Cox's proportional hazard model revealed that "response of ACP", "stage", "age", "Gleason's primary and secondary pattern", and "response of local prostatic tumor" were definitely the more influential prognostic factors, of which chi-square values (or t values) were statistically significant. Comparison of the significant factors in each multivariate analysis revealed that common influential prognostic factors, such as "age", "stage", "histological findings (mainly Gleason's primary and secondary pattern)", "response of local prostatic tumor" and "response of ACP" were coincident to the clinical impression. The clarification of these factors would be clinically beneficial when treating patients with endocrine therapy.

Estrogens↗

[Clinical studies on endocrine therapy of prostatic carcinoma (2): Prognosis of patients with prostatic carcinoma given endocrine therapy, and analyses of causes of death and side effects of endocrine therapy].

Of 572 patients with prostatic carcinoma, 497 received endocrine therapy as the initial treatment. These patients were surveyed in a cooperative research study by members from five universities. Prognosis, causes of death and side effects of estrogen therapy were studied. The prognosis of patients who had received endocrine therapy became worse, as the stage progressed. The prognosis of those who had received a combination of estrogen therapy with castration tended to be better than that of those who had received estrogen therapy alone. Similarly, the prognosis of those who had received a combination of progesterone therapy with castration tended to be better than that of those who had had progesterone therapy alone. No relationship was found between estrogen doses (low, medium and high) and prognosis, although a precise comparison among the three could not be made because of the smaller number of patents with low doses. A high dose of estrogen may not always be the indication, rather a medium dose such as 300 mg diethylstilbestrol diphosphate may be clinically appropriate. The cause of death could be identified in 303 patients who had received endocrine therapy. Cancer-related death was the most frequent (63.7%), and cardio- or cerebrovascular death accounted for only 14.2% of the cases. When this analysis was confined to the patients who had received estrogen therapy, estrogen administration seemed to be the cause of cardio- or cerebrovascular death of 16.1% of the patients. Daily dosing of estrogen was not definitely related to the incidence, or the interval to cardio- or cerebrovascular death. However, among the patients who had died of cardio- or cerebrovascular disease, 50% of the patients who had received a medium or high dose of estrogen tended to die within two years after treatment, while 50% of those who had received a low dose died within three years.

Cause of Death↗

[Clinical studies on endocrine therapy of prostatic carcinoma (3): Histopathological features of prostatic carcinoma and its prognosis].

We investigated how histopathological features, such as structural atypism (SAT), nuclear anaplasia (NAN) and Gleason's pattern, influence the prognosis of patients receiving endocrine therapy. Patients with SAT 3 or NAN 3 clearly had a lower survival rate and a shorter survival period than those with other grades of SAT or NAN and this tendency was more prominent in the high stage than low stage. Patients with a higher grade of SAT or NAN had a poorer prognosis as well, when only cancer-related death was considered in the calculation of survival and survival period. The results described above suggest that the grade of SAT and NAN is one of most influential factors for prognosis. In the analysis for the prognosis of patients according to grade of mean value of SAT + NAN, there were differences in prognosis among mean value of SAT + NAN 2-4, 5 and 6. This indicated that the combined grading system would provide more information to the prediction of prognosis. Patients with Gleason's primary (or secondary) pattern 1 and 2, or 3 and 4 had a better survival than those with pattern 5 in the analysis when only cancer-related death was considered. This was coincident with the result that the survival rate for each Gleason's sum 2-3, 4-5, 6, 7-8 and 9-10 was different. Consequently, Gleason's pattern influenced the rate of cancer-related deaths, and this pattern may be another important factor for predicting the prognosis.

Estrogens↗