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Biomedical subjects

A Sugihara

Publications and source records attributed to A Sugihara.

89 records · Page 5Linked to original sources

Induction of apoptosis by castration in epithelium of the mouse seminal vesicles.

Castration on days 0, 5, 10, 20, 40, and 60 caused increases in an apoptotic index (% of apoptotic cells) in seminal vesicle (SV) epithelium, peaking 1-3 days after castration. The peak apoptotic indices after castration on days 0, 5, 10, and 20 were significantly lower than peak apoptotic indices observed after castration on days 40 and 60. DNA extracted from mouse SVs 2 days after castration on days 0, 5, 10, and 60 showed a ladder pattern on agarose gel electrophoresis. The secretion of androgen by testes was confirmed by the growth retardation of the SVs after castration on days 0, 5, 10, and 20. It would appear that a proportion of SV epithelial cells dependent on testicular androgens for survival is smaller before day 20 than after day 20.

Animals↗

Intrathyroid thyroglossal duct cyst simulating a thyroid nodule.

A case of intrathyroid thyroglossal duct cyst is reported. A 50-year-old woman presented with a right lateral neck mass that was clinically indistinguishable from a thyroid nodule. Ultrasound-guided fine-needle aspiration biopsy (US-FNAB) revealed normal-looking squamous cells. Right thyroid lobectomy was performed and microscopic examination revealed a cyst lined by squamous epithelium that was consistent with a thyroglossal duct cyst. The lesion was completely surrounded by normal thyroid tissue. Our experience suggests that intrathyroid thyroglossal duct cyst should be remembered in the differential diagnosis of a thyroid nodule. Detection of benign squamous cells by US-FNAB may be useful for ruling out the possibility of a cystic thyroid tumor.

Biopsy, Needle↗

Expression of cytokines enhancing the osteoclast activity, and parathyroid hormone-related protein in prostatic cancers before and after endocrine therapy: an immunohistochemical study.

Cytokines, interleukin (IL)-1alpha, IL-1beta, IL-3, IL-6, macrophage colony stimulating factor (M-CSF) and tumor necrosis factor-alpha (TNF-alpha) as well as parathyroid hormone-related protein (PTHrP) have been shown to enhance the osteoclast activity. To investigate mechanisms of the development of bone metastasis of prostatic cancers, expression of these cytokines and PTHrP was examined immunohistochemically in prostatic cancers of patients administered no prior therapy or endocrine therapy. All cytokines and PTHrP were stained in the cytoplasm of the epithelium of non-cancerous prostatic glands, and IL-3 and IL-6 were stained in the cytoplasm of smooth muscle cells besides epithelial cells of non-cancerous prostatic glands. Incidences of positivity of staining in prostate cancers of patients administered no prior therapy were 100% for IL-1alpha, IL-1beta, IL-6, M-CSF and TNF-alpha, 20% for IL-3, and 80% for PTHrP. Incidence of prostatic cancers stained positively for IL-1alpha and IL-1beta decreased significantly in patients administered endocrine therapy, but those for IL-3, IL-6, M-CSF, TNF-alpha and PTHrP did not change significantly. The present results suggest that prostatic cancers produce various cytokines, IL-1alpha, IL-1beta, IL-3, IL-6, M-CSF and TNF-alpha, as well as PTHrP, and that expression of these cytokines and PTHrP except IL-1alpha and IL-1beta is not under androgen control. Cytokines and PTHrP produced by prostatic cancers may play a role in the development of bone metastasis of prostatic cancers.

Aged↗

Inhibition by interleukin 18 of osteolytic bone metastasis by human breast cancer cells.

Effects of interleukin (IL)-18 on experimental bone metastasis of human breast cancer cells, MDA-231 cells, in nude mice were investigated. In addition, effects of IL-18 on subcutaneous growth of MDA-231 cells were examined. Bone metastasis was produced by an intracardiac injection of MDA-231 cells. Twenty eight days after the cell injection, severe osteolytic bone metastasis was examined by X-ray radiography, and both non-osteolytic and osteolytic bone metastases were examined microscopically. IL-18 (1 microgram/mouse) was injected intraperitoneally according to protocols A and B. In protocol A, IL-18 was injected daily from day 7 after an intracardiac or subcutaneous injection of cells, and in protocol B, it was injected daily for 7 days each before and after the cell injection. In protocol A, IL-18 injections significantly suppressed both the incidence of osteolytic bone metastasis detected by X-ray radiography (about 80% vs. about 20% for the control group vs. the treatment group) and the number of its foci/mouse (1.6 vs. 1 for the control group vs. the treatment group). However, they did not cause significant effects on either the incidence of bone metastasis detected microscopically or the number of its foci/mouse. In protocol B, IL-18 injections caused no significant effects on either the incidence of osteolytic bone metastasis detected by X-ray radiography or the number of its foci/mouse. They caused no significant effects on the incidence of bone metastasis detected microscopically, but significantly decreased the number of its foci/mouse (about 2.0 vs. about 1 for the control group vs. the treatment group). In both protocols A and B, IL-18 injections produced no significant effect on the tumor take and subsequent growth of tumors after a subcutaneous injection of the cancer cells. Since in protocol A, IL-18 appears to have exerted its action after establishment of metastasis by cancer cells to the bone marrow, the effects of IL-18 found in Protocol A indicate that IL-18 inhibited osteolytic growth at bone metastatic sites of breast cancers. On the other hand, since in protocol B IL-18 is likely to have functioned around the time when lodging of cancer cells and early development of metastasis occur in the bone marrow, the effects of IL-18 found in Protocol B indicate that the cytokine also suppresses an early stage of bone metastasis of breast cancers, although, this effect was less apparent than the effect on osteolytic growth. Therefore, IL-18 may be useful for suppression of osteolytic bone metastasis which is a serious problem in patients of advanced breast cancers.

Animals↗

Comparison of sensitivities of uterine cells in their proliferation responding to epidermal growth factor and estrogen between neonatal and postneonatal mice.

The uteri of mice up to 20 days after birth show estrogen-independent growth, although their growth is accelerated by estrogen, while the growth of the uteri of mice after 20 days completely depends on estrogen. In the present study, we compared the sensitivities of uterine cells in their proliferation responding to epidermal growth factor (EGF) and diethylstilbestrol (DES) between 5-day-old and 25-day-old ovariectomized mice. A single subcutaneous injection of EGF at doses of 0.25 and over 0.25 microgram/g body weight (BW) increased 3H-thymidine uptake by the whole uterus dose-dependently in both 25-day-old and 5-day-old mice, and a maximal increase in the 3H-thymidine uptake was attained at a dose of 1 microgram/g BW of EGF in both mice. A single subcutaneous injection of DES at 0.001 and over 0.001 microgram/g BW increased 3H-thymidine uptake by the whole uterus dose-dependently in both 25-day-old and 5-day-old mice, and a maximal increase was attained at 0.004 microgram/g BW of DES in both mice. EGF and DES increased labeling indices of both the epithelium and stroma in both 25-day-old and 5-day-old mice. The present results suggest that sensitivities of uterine cells of neonatal mice in their proliferation responding to EGF and DES are similar to those of postneonatal mice.

Age Factors↗

Castration induces apoptosis in the male accessory sex organs of Fas-deficient lpr and Fas ligand-deficient gld mutant mice.

The role of the Fas ligand-Fas system in castration-induced apoptosis in the epithelia of the ventral prostate (VP), seminal vesicle (SV), coagulating gland (CG) and epididymis (Ep) was investigated using lpr/lpr, and gld/gld mutant mice which are deficient in Fas and Fas ligand, respectively. The degree of apoptosis in the epithelium was quantitatively estimated by an apoptotic index (a percentage of apoptotic cells). The weights (mg/10 g body weight) of the VP, SV, CG and Ep of lpr/lpr and gld/gld mice were similar to those of normal +/+ mice and castration decreased the weights of the VP, SV, CG and Ep in these three kinds of mice to similar levels. Castration also increased the apoptotic indices in these organs reaching maximum on days 2-6 after castration. There was no significant difference in the apoptotic index of these organs among +/+, lpr/lpr and gld/gld mice on days 0-8 after castration. Agarose gel electrophoresis of DNAs extracted from the VP, SV, CG and Ep of +/+, lpr/lpr and gld/gld mice on day 4 after castration showed a ladder pattern. The present results suggest that the Fas ligand-Fas system plays little role in castration-induced apoptosis in the mouse male accessory sex organs such as the VP, SV, CG and Ep.

Animals↗

Effects of prolactin and estrogen on cell proliferation of the mouse liver induced by partial hepatectomy.

Estrogen or prolactin suppresses mouse hepatocellular tumorigenesis induced by carcinogens through inhibition of the growth of preneoplastic hepatocytes. In the present study, we investigated whether estrogen or prolactin inhibits proliferation of normal hepatocytes as well as preneoplastic hepatocytes in mice. The proliferation of mouse hepatocytes was induced by partial hepatectomy, and DNA synthesis of the liver was evaluated by measurement of 5-[125I]iododeoxyuridine ([125I]IdUrd) uptake/mg liver DNA after an injection of [125I]IdUrd into mice. For acute treatment with estrogen or prolactin, estradiol-17 beta (E2) (1 micrograms) or ovine prolactin (140 micrograms) was injected into ovariectomized mice twice a day from the day of partial hepatectomy. For chronic treatment with estrogen, ovariectomized mice received implants of E2 pellets containing 100 micrograms E2 40 days before partial hepatectomy, and for chronic treatment with prolactin, hyperprolactinemia was induced by pituitary graft under the renal capsule of ovariectomized mice 40 days before partial hepatectomy or by daily injections of perphenazine (150 micrograms/day) beginning 40 days before partial hepatectomy. The acute treatment with either estrogen or prolactin did not affect the hepatocyte proliferation induced by partial hepatectomy. Chronic hyperprolactinemia induced by the pituitary graft or by injections of perphenazine, and the chronic treatment with E2 pellets did not suppress either basal or partial hepatectomy-induced proliferation of hepatocytes. The present results show that acute and chronic treatments with estrogen or prolactin do not inhibit proliferation of mouse normal hepatocytes, and suggest that the effects of estrogen and prolactin on proliferation of mouse hepatocytes are different from those on proliferation of preneoplastic hepatocytes.

Animals↗

Expression of Fas and Fas ligand in the testes and testicular germ cell tumors: an immunohistochemical study.

The Fas-Fas ligand system plays a crucial role in the production of a signal for apoptosis in the immune system. In the present study, expression of Fas and Fas ligand in the testes and testicular germ cell tumors was examined immunohistochemically. Expression of both Fas and Fas ligand was found on Leydig cells, Sertoli cells, and germ cells in the testis, and on epithelial cells in the epidydimal duct. Expression of both Fas and Fas ligand was also found in all 23 seminomas, 8 embryonal carcinomas, and 3 yolk sac tumors which were examined in this study. Western blot analysis after sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis under a reducing condition with tissues of the thymus, the testis, and a seminoma showed a single major band bound to the antibody for Fas or Fas ligand at the position of molecular weight slightly more than 47.5 kilodalton. Since both Fas and Fas ligand are expressed on normal testicular cells, and on cells of testicular germ cell tumors, the Fas-Fas ligand system in these cells seems to play a role other than producing a signal for apoptosis.

Adult↗

The relationship between stapling doughnuts: characteristics and functional results after total gastrectomy.

BACKGROUND/AIMS: The objective of this study was to determine whether the thickness of the esophageal doughnut is related to postoperative results in total gastrectomy. METHODOLOGY: Thirty-eight total gastrectomy patients were studied, including 18 who underwent jejunal pouch reconstruction and 20 who did not have pouch reconstruction. We used the Proximate-ILS circular stapler, with purse-string suturing at the cut end of the esophagus performing only the mucosal layer manually in all cases. We divided the esophageal doughnuts after stapling into two groups: Group A: doughnut involving muscle tissue of 0-25% of the esophageal circumference; Group B: doughnut involved muscle tissue of 25-100% of the esophageal circumference. Reflux scores and the scintigraphic reflux index were determined. RESULTS: No significant difference was found between the two groups in reflux score or scintigraphic reflux index. CONCLUSIONS: These findings indicate that the degree of postoperative reflux esophagitis was not affected by the amount of the muscular layer included in the esophageal doughnut. Continuity, and not variability of the degree of involved muscle in the esophageal doughnut, is an important factor at the time of stapling.

Aged↗