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Biomedical subjects

Y Yoshimura

Publications and source records attributed to Y Yoshimura.

At least 433 records · Page 24Linked to original sources
PubMed1990

Phosphate and pepsin adsorptions by a new boehmite compound and aluminum hydroxide.

A new microcrystalline compound of aluminum oxide hydroxide (tentatively named PT-A) was synthesized in the hope of providing a better phosphate adsorbent for future clinical use than the currently marketed aluminum hydroxide gels (ALG). An X-ray diffraction study demonstrated a boehmite structure in PT-A but an amorphous structure in ALG. PT-A was more stable in pH change than ALG; in elution tests in artificial gastric and intestinal solutions, aluminum ion eluted from PT-A was maximally 10% of the amount from ALG at pH 1.2; and was undetectable at pH 6.8, at which point ALG still showed some aluminum elution. Phosphate-adsorbing efficacy of PT-A and ALG in vitro was about the same at pH 1.2; however, it was four times greater in PT-A than in ALG at pH 6.8, indicating that PT-A will be effective in the intestine. PT-A also adsorbed pepsin but the amount was at most the same or much less than that adsorbed by ALG, which depended on pH in solution.

Adsorption↗
PubMed1990

[Effects of 5-hydroxyeicosatetraenoic acid (5-HETE) on progesterone and prostaglandin production by human corpora lutea].

The present study was undertaken to assess the effects of 5-hydroxyeicosatetraenoic acid (5-HETE) on steroidogenesis and prostaglandin (PG) production in cultured luteal cells derived from human corpora lutea in the mid-luteal phase. The luteal cells were cultured with 5-HETE at 10, 100, 500, or 1,000 ng/ml in the absence or presence of hCG at 100 ng/ml for 10 days. The addition of 5-HETE to the culture media did not affect growth curves of cultured luteal cells. 5-HETE significantly inhibited progesterone (P) production by cultured luteal cells in a dose-related fashion on day 2. P production stimulated by exposure to hCG was also reduced significantly in response to 5-HETE. The addition of 5-HETE did not affect estradiol production by cultured luteal cells. The production of 6-keto-PGF1 alpha by cultured luteal cells in the presence of 5-HETE was slightly but not significantly less than that observed in the absence of 5-HETE. However, 5-HETE affects neither PGF2 alpha nor PGE2 production by cultured luteal cells throughout the culture period. The present study demonstrates that 5-HETE inhibits P production in cultured luteal cells by a mechanism(s) other than through PG production. These data suggest the involvement of a lipoxygenase pathway in the synthesis of P and 6-keto-PGF1 alpha of luteal cells.

Adult↗
PubMed1990

[Treatment of leiomyomas with luteinizing hormone-releasing hormone agonist].

Twenty-five premenopausal women, 36-54 years of age, with uterine myomas were treated with 600-1,200 micrograms/day of luteinizing hormone-releasing hormone agonist (LHRHa) for 4 months. Eight patients reached menopause following the treatment with LHRHa (menopause group), while the resumption of menstruation occurred within 12 weeks after cessation of the therapy in 17 patients (menstruation group). Although the mean hemoglobin (Hb) concentration in the menopause group increased during treatment and was maintained within the normal range after cessation of the therapy, the Hb concentration in the menstruation group decreased after the resumption of menstruation. Both estradiol and CA125 in the menopause group were reduced during and after treatment. However, these parameters in the menstruation group increased concomitantly with the resumption of ovarian function. LH and FSH were suppressed during treatment, but these gonadotropins in the menopause group increased significantly to the levels of menopause. About a 50% reduction in uterine volume was observed in the menopause group. Three months after completing therapy, the restoration of uterine volume occurred in the menstruation group. Bone density findings in microdensitometry 12 weeks after cessation of the therapy did not differ significantly from those before the treatment. These results demonstrate that LHRHa therapy significantly reduces the uterine volume in patients with leiomyoma. It may be possible to treat selected patients with leiomyoma, including perimenopausal women and high surgical risk women with LHRHa, thus avoiding the need for surgery.

Adult↗
PubMed1990

[A study of combined chemotherapy with MMC, ADM, CDDP, etoposide (VP-16), 5'DFUR (MAC-VD therapy) in advanced cancer and local relapse of the stomach].

Eighteen patients with progressive/locally recurrent cancer of the stomach were given therapy with MMC, ADM, CDDP, Etoposide (VP-16), and 5'DFUR (MAC-VD therapy). Drugs were administered intravenously with MMC 10 mg/m2, ADM 20 mg/m2, and CDDP 50 mg/m2 on day 1; orally with etoposide 100 mg/day for five consecutive days from day 3; and orally with 5'DFUR 600 mg/day for three weeks from day 3 followed by discontinuation for one subsequent week. This drug regimen was one course of the treatment and repeated as far as possible. There were 16 evaluable cases; the sex distribution was ten males and six females. Patients ranged in age from 43 to 78 years. P.S. 1 was two cases; 2 ten cases; and 3 four cases. The overall response rate, CR + PR, was 1 + 7/16 (50%), while this rate for primary disease was 2 + 5/16 (43.8%). Of the two CR cases, one primary lesion became operable and CR was demonstrated histologically. The overall response rates, CR + PR, for metastatic lesions were 1 + 3/9 (44.4%) for the liver; 0 + 1/4 (25.0%) for the abdominal lymph nodes; 0 + 1/2 (50.0%) for the superficial lymph nodes; 0 + 1/2 (50.0%) for the bones; and 0 + 1/1 (100%) for the lung. The median duration of the response was 3.7 months (range between 1.5 and 8.2+) and the median duration of survival 5.1+ months (range between 2.2+ and 13.3+). At the same time, the hematological side effects of both leukocytopenia and hypohemoglobinemia were seen in 43.8% of the cases. Non-hematological side effects included alopecia in 18.8% and nausea/vomiting in 12.5%. There was no case of discontinuation due to side effects. It was concluded that the therapy with MMC, ADM, CDDP, etoposide and 5'DFUR (MAC-VD therapy) proved to be a very promising drug regimen in the treatment of stomach cancer with high rates of response and is expected to be a step forward in the establishment of interdisciplinary treatment.

Administration, Oral↗
PubMed1990

[The changes in tumor markers such as serum CEA, CA 19-9, TPA and CA 125 in the chemotherapy of patients with advanced gastric cancer].

Twenty-five patients with advanced gastric cancer were treated with a combination chemotherapy. The levels of serum CEA, CA 19-9, TPA and CA 125 were measured before and during chemotherapy (4 and 8 weeks). One complete and 10 partial responses were obtained, and the response rate was 44%. Pretreatment positive rates of these four tumor markers were all more than 60%, and the positive rate of combination assay was 96%. The mean percent changes of these four tumor markers were similar and correlated well with the response to chemotherapy. There was a significant correlation between tumor reduction and decrease of serum CEA in the responders with measurable lesions. These results suggest that the measurement of changes of serum tumor markers may be useful for monitoring the response to chemotherapy in patients with gastric cancer. It also may be useful to determine early the effectiveness of the treatment.

Adolescent↗
PubMed1990

Direct evidence for ATP consumption due to iodide uptake by isolated, uncultured, pig thyroid epithelial cells.

The concept that iodide uptake by thyroid requires a supply of ATP is currently accepted. However, there is little direct evidence that the extents of iodide uptake and ATP consumption are correlated. To demonstrate this correlation, we used isolated, uncultured pig thyroid epithelial cells in basal media containing only glucose and the cations necessary for Na+,K(+)-ATPase, which prevented other possible cellular activities requiring ATP. The isolated cells were sensitive to various metabolic inhibitors of ATP-generating systems, confirming that they were intact. The extents of increase in iodide uptake and decrease in ATP content of the cells were entirely dependent on the presence of the cations, and were closely correlated with each other. Furthermore, the ATP content was not reduced in the absence of NaI, even when all necessary cations for the ATPase were present. These findings provide direct evidence for a correlation between the extents of iodide uptake and ATP consumption. Cells in medium with Mg alone did not show iodide incorporation or ATP consumption, confirming that Mg2(+)-dependent ATPase does not contribute to iodide uptake by the thyroid.

Adenosine Triphosphate↗
PubMed1990

Variations in manganese effect on 6-phosphogluconate dehydrogenases from the thyroid and liver of the mouse and an evidence for non-interchangeability of manganese and magnesium.

Both manganese (Mn) and magnesium (Mg) are known to activate 6-phosphogluconate dehydrogenase (6-PGDH). Yet in the present study none of the metal ions stimulated 6-PGDH from the thyroid of mice, but Mn alone stimulated the enzyme from the liver. Such a stimulatory effect of Mn on the liver enzyme was seen regardless of the presence of Mg, This suggests that the reaction sites for the two ions must be apart from one another or that the affinity of Mn is stronger than that of Mg. The enzyme preparations from livers of those mice which had been administered intraperitoneally with excess of Mn for 1 - 14 days were greatly stimulated by further in vitro addition of Mn, whereas the enzyme sources from the thyroids thus treated were almost insensitive to Mn in vitro. The results indicate that cellular Mn hardly reaches the levels for maximal stimulation of the enzyme in the liver. In addition, some sex difference was observed in the Mn effect on 6-PGDH from the liver.

Animals↗
PubMed1990

[Possible involvement of leukotriene B4 on human luteal function: special reference to determination of leukotriene B4 produced by cultured luteal cells].

The present study was undertaken to determine the production of leukotriene B4 (LTB4) by cultured human luteal cells in the mid-luteal phase using a reverse phase column (C8). The luteal cells were cultured with or without hCG at 100 ng/ml for 8 days. In the preliminary experiment, methods for extracting culture media samples were assessed prior to radioimmunoassay. Reverse phase column C8, but not C18, made possible the determination of LTB4 produced by human luteal cells. Progesterone (P) production by cultured luteal cells reached its maximum on day 4 following exposure to hCG, and then declined gradually. The concentrations of LTB4 produced by luteal cells varied from 100 to 500 pg/10(5) cells/2 days. However, exposure to hCG did not affect LTB4 production by cultured luteal cells. The level of LTB4 in culture medium (115.0 +/- 37.8 pg/10(5) cells/2 days) was reduced on day 4, but increased thereafter. LTB4 production appeared to decrease concomitantly with increased P production of cultured luteal cells. In conclusion, cultured luteal cells produced considerable amounts of LTB4 throughout the entire culture period. These results suggest that lipoxygenase activity of luteal cells may be closely related to steroidogenic potential.

Adult↗
PubMed1990

Progesterone protects oocytes from premature degeneration within the follicle.

The present study was designed to determine the effects of gestrinone (R2323) in the process of follicle rupture and oocyte maturation and degeneration in an in vitro perfused rabbit ovary model. In the first experiment, R2323 at 10(2), 10(3), or 10(4) ng/ml was added to the perfusate of one ovary. The contralateral control ovary was perfused simultaneously with medium alone. Thirty minutes after the onset of perfusion, 50IU of human chorionic gonadotropin (hCG) was added to the perfusate of both ovaries. All ovaries exposed to R2323 plus hCG or hCG alone ovulated. The addition of R2323 to the perfusate did not affect the ovulatory efficiency of ovaries treated with hCG. No significant difference in the percentage of ovulated ova or follicular oocytes demonstrating germinal vesicle breakdown was seen with R2323 treatment. R2323 increased the degeneration rate of ovulated ova in a dose-dependent fashion. In the second experiment, in which experimental ovaries were perfused with R2323 (10(4) ng/ml) plus progesterone (10(3) ng/ml) and the control ovaries with R2323 (10(4) ng/ml) alone ovulation occurred in response to hCG. However, the addition of progesterone to the perfusate reduced the degeneration-inducing effect of R2323 on both ovulated ova and follicular oocytes. In conclusion, R2323 appears to act as an antiprogesterone, thereby promoting the degeneration of oocytes. The increased production of progesterone in the preovulatory follicle following the gonadotropin surge protects oocytes from premature degeneration within the follicles.

Animals↗
PubMed1990

[Intraventricular arachnoid cyst appearing with attacks of orbital pain: case report and review of the literature].

While there have been 5 cases of intraventricular arachnoid cyst published in the literature, the occurrence in the anterior horn of the lateral ventricle has not been reported. We report a case of intraventricular arachnoid cyst of the anterior horn causing attacks of orbital pain. A 30-year-old man was admitted with frequent attacks of orbital pain on his right side. Neurological examination revealed no abnormality. Plain CT showed a cystic dilatation of the anterior horn of the right lateral ventricle, and enhanced CT showed a deviation of the septal veins to the left side. T1-weighted MRI demonstrated a low-intensity mass in the anterior horn of the right lateral ventricle, and T2-weighted image demonstrated the mass as having high intensity. PEG in the sitting position showed no filling of air into the right lateral ventricle due to obstruction of the right foramen of Monro. The patient underwent an operation under a diagnosis of intraventricular benign cyst. The cyst wall was subtotally removed and the right foramen of Monro was opened. Histological examination of the specimen showed an arachnoid membrane with prolific collagen fibers. From an embryological point of view, the arachnoid membrane is derived from the arachnoid cell. We think intraventricular arachnoid cysts to originate from the remnants of the arachnoid cell on the tela choroidea or on the choroid plexus like intraventricular meningiomas.

Adult↗
PubMed1990

[Treatment of paroxysmal nocturnal hemoglobinuria with danazol].

Glucocorticoid and androgen therapy have been used with moderate success in paroxysmal nocturnal hemoglobinuria (PNH). However, both are poorly tolerated, especially in women, although the side effects of glucocorticoid can be diminished by alternate day therapy. We have treated two patients with PNH with danazol. One of patient is man, 64 years old age with stomach cancer, and the other patient is 34-year-old man. Their disease has existed for 6-14 years. They required many blood transfusions, their hemoglobins ranging between 7.1 and 9.9 grams per deciliter. When treated with danazol by mouth, the hemoglobin level increased approximately 2 to 5 grams in each patient within 3 week, and clinical hemoglobinuria improved. None of the patients has had any side effects.

Adult↗
PubMed1990

[Oocyte fertilizability and hormonal environment of human preovulatory follicles in hyperstimulated cycles in an in vitro fertilization program: Are mature preovulatory follicles undergoing atresia?].

Steroid hormones in preovulatory follicular fluid, maturity of the oocyte-corona-cumulus complex (OCCC), and oocyte fertilizability were studied in 55 hyperstimulated cycles in 40 patients who were indicated for in vitro fertilization and embryo transfer due to tubal infertility. Aspirated follicles were categorized into four groups according to the degree of oocyte maturation and fertilizability, i.e. follicle (Fol)-1 (non-fertilized, intermediate maturation), Fol-2 (fertilized, intermediate maturation), Fol-3 (fertilized, full maturation), and Fol-4 (non-fertilized, full maturation). Estradiol (E2), progesterone (P), and delta 4- androstenedione (delta 4A) concentrations were highest in Fol-3, being lower in Fol-2 and Fol-1 sequentially. Fol-3 contained significantly more E2 and P than did Fol-1, showing that the degree of oocyte maturation and fertilizability correlate with concentrations of E2 and P in the follicles. A comparison of Fol-3 and Fol-4 revealed significantly higher concentrations of delta 4A in Fol-4, whereas differences in E2 and P concentrations were not significant although Fol-4 values were lower. This comparison indicated that Fol-4 were already undergoing atresia at the time of oocyte retrieval, containing morphologically mature OCCC which had lost fertilizability. This study shows that steroid hormones in the follicular fluid reflect oocyte viability and fertilizability, and suggests that preovulatory follicles with mature oocytes can also undergo atresia.

Chorionic Gonadotropin↗
PubMed1990

Open treatment with drainage for ingrowing toenail.

As a radical treatment of ingrowing toenail, labiomatricetomy is accepted among plastic surgeons. However, postoperative hematoma or infection, or both, is the problem when sutures are placed between the nail and nail fold. We have added a drainage procedure to the standard labiomatricectomy, which can be done on an outpatient basis. Ninety-eight patients were observed during a six month period. Three patients who had had steroid therapy had suppuration postoperatively, while all of the other patients had an uneventful recovery period. Recurrence was seen in three patients who suffered from onychogryposis, which may require some other method of treatment. Complications were seen in early instances, three inclusion cysts with infection and three nail spikes. Technical error caused these complications, and these have disappeared with the use of this technique.

Drainage↗
PubMed1990

[Transarterial hepatic embolization of metastatic liver cancers with reference to 17 cases of survival for more than 2 years].

The evaluation of TAE was studied for 73 patients with metastatic liver cancers but without metastasis in other organs, who were treated with initial TAE more than 2 years ago. Seventeen patients survived for more than 2 years. The primary lesions consisted of colon cancer in 9 patients, the Langerhans islet cell tumor of the pancreas in 4, gastric cancers in 2, breast cancer in 1 and leiomyosarcoma of the colon in 1. The overall 2-year survival rate calculated by the direct method was 23.3% and mean survival period was 15.8 months. The prognosis was good in H1 and V3. Lp-TAE produced better effects but no statistically significant difference was found between the 2-year survivals by Lp-TAE and by GS-TAE.

Adult↗
PubMed1990

Involvement of plasminogen activator activity in the process of ovulation.

The present study was undertaken to determine the changes in follicular plasminogen activator (PA) activity during ovulation. In the first experiment, hCG (100 IU) administration in vivo enhanced PA activity in mature follicles within 1 hour. PA activity reached its maximum at 4 hours and then declined. A second peak occurred 8 hours after hCG administration. In the second experiment, the effects of an ovulatory dose (50 IU) of hCG on ovulatory efficiency and PA activity were assessed in mature and immature follicles with an in vitro perfused rabbit ovary preparation. Ovulatory efficiency in immature follicles was significantly less (p less than 0.01) (16.7 +/- 4.5%) than that in mature follicles (86.7 +/- 11.0%). During the perfusion, the growth of mature follicles was observed but not that of immature follicles. PA activity in mature follicles derived from unstimulated ovaries was 1.43 +/- 0.17 IU/g tissue. PA activity in mature follicles (28.4 +/- 4.2 IU/g tissue) 4 hours after in vitro exposure to hCG was significantly greater (p less than 0.01) than that found in immature follicles. In conclusion, exposure to gonadotropin stimulates PA activity in preovulatory follicles. Failure to increase PA activity in immature follicles impairs follicular development, resulting in reduced ovulatory efficiency. The increase in PA activity observed in ovulatory follicles implicates the plasmin-generating system in follicle rupture.

Animals↗