Biomedical subjects

Yukiko Hayashi

Publications and source records attributed to Yukiko Hayashi.

23 records · Page 2Linked to original sources

PubMed2003

Recombinant protein 1/secretoglobin 1A1 participates in the actin polymerization of human platelets.

BACKGROUND: Human protein 1 which was originally isolated from pathological urine is identified with clara cell 10 kDa protein and uteroglobin. It has immunomodulatory and anti-inflammatory effects in many vertebrates. Although there have been thorough studies on the structure, molecular biology and biochemical characteristics, the precise mechanism of its biological activities is unknown. The purpose of this research is to clarify the biochemical mechanism of protein 1 through its effect on the platelet aggregation process. METHODS: Changes in calcium mobilization, actin filament concentrations and functions of integrin alphaIIbbeta3 resulting from platelet stimulation were measured in the presence or absence of recombinant protein 1 (rP1). RESULTS: Recombinant protein 1 inhibited U46619- and thapsigargin-induced platelet aggregation by preventing store mediated calcium entry (SMCE). The binding of rP1 to resting platelets induced an increase in the actin filament that accompanied the structural changes of alphaIIbbeta3. When rP1-pretreated platelets were activated by thrombin or thapsigargin, the alterations in the actin filament and alphaIIbbeta3 resulting from the stimulation decreased. CONCLUSION: These results suggest that rP1 inhibits platelet aggregation by participation in the actin polymerization through which SMCE is mediated.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed2003

Superficial basaloid squamous carcinoma of the esophagus. A clinicopathological and immunohistochemical study of 12 cases.

Basaloid squamous carcinoma (BSC) is a rare variant of squamous cell carcinoma (SCC). In this study, clinicopathological and immunohistochemical characteristics of 12 superficial esophageal BSCs were examined and compared with those of typical superficial SCCs. Eight cases were classified into an elevated type, and the other four into a depressed type. High-grade intraepithelial neoplasia was not observed around the invasive lesions in five cases, and only BSC components were apparent. High-grade intraepithelial neoplasia was demonstrated in seven cases, five of which had both BSC and SCC components in the invasive lesion. A cribriform growth pattern, comedo-type necrosis, and hyaline deposits were conspicuous histological findings. CK14 was positively stained in 90% of the series, but the proportion of positive cells was small in most cases. Type IV collagen was increased or well preserved in the basement membrane in 70% of cases, but heparan sulfate was decreased in the majority. In comparison with SCCs, lymphatic permeation was observed less frequently. However, regarding the frequencies of venous permeation, nodal metastasis, p53 protein expression, and Ki-67 labeling index, no significant differences were noted. Thus, esophageal BSCs demonstrate the pathological features characteristic of an early stage, but pathological parameters related to biological behavior do not significantly vary from those typical of SCCs.

Aged↗

PubMed2003

Expression of ARPP-16/19 in rat denervated skeletal muscle.

It is known that denervation of rat skeletal muscle causes atrophy and this is often adopted as a model for human muscle atrophy. To understand the molecular changes that occur, it is important to identify the profiles of differential gene expression. In the present study, we investigated differentially expressed genes in denervated muscle using DNA microarrays with printed genes preferentially expressed in skeletal muscle. We found that several genes are differentially expressed. Of these genes, ARPP-16/19 (cAMP-regulated phosphoprotein 16/19) is selectively enhanced after denervation. The expression of ARPP-16/19 in denervated muscles starts to increase from two days after denervation surgery. On the other hand, the expression of ARPP-16/19 does not change in hind-limb suspended muscles, such as EDL and soleus muscles. These results suggest that the increase in ARPP-16/19 mRNA expression is regulated by unknown factor(s) secreted from nerves, and not by electrical muscle activity.

Animals↗

PubMed2002

Expression of estrogen receptor (ER) (beta)cx protein in ER(alpha)-positive breast cancer: specific correlation with progesterone receptor.

Estrogen receptor (ER) (beta)cx, a splice variant of ERbeta, is a dominant repressor of ER(alpha) function. In this study we investigated the possibility that because the progesterone receptor (PR) gene is a downstream target of activated ER(alpha), in ER(alpha)-positive breast cancers, expression of ER(beta)cx would result in repression of PR. In ER(alpha)-positive MCF-7 cells, stable transfection of an ER(beta)cx expression vector resulted in reduced expression of PR without affecting ER(alpha) expression. In breast cancers, immunohistochemical evaluation of ER(alpha)-positive foci for the expression of PR and ER(beta)cx revealed a significant correlation between a PR-negative phenotype and the presence of ER(beta)cx within the foci. However, when entire lesions were evaluated by Allred scoring in 115 ER(alpha)-positive breast cancer specimens, the presence of two distinct groups of patients could be discerned. One group expressed ER(beta)cx and had very reduced levels of PR expression, as expected. The second group showed both ER(beta)cx and high levels of PR. To evaluate the role of ER(beta)cx in sensitivity to tamoxifen, 18 core needle biopsies, obtained before preoperative treatment with tamoxifen, were investigated. The results show that expression of ER(beta)cx in primary lesions correlated with a poor response to tamoxifen, especially in cancers with a low PR expression in Allred score. This is the first evidence that evaluation of ER(beta)cx along with PR may contribute to a better characterization of ER(alpha)-positive breast cancers.

Amino Acid Sequence↗

PubMed2002

Ductal and acinar differentiation in pancreatic endocrine tumors.

Rare pancreatic endocrine tumors consisting of both exocrine and endocrine components have been reported sporadically. We investigated the ductal and acinar differentiation in pancreatic endocrine tumors. In immunohistochemical studies of 28 pancreatic endocrine tumors, staining with anti-carcinoembryonic antigen (CEA) or CA19-9 antibody indicated ductal differentiation, while staining with anti-amylase or anti-trypsin antibody indicated acinar differentiation. K-ras gene mutations and p53 gene alterations also were studied. Ten tumors were immunoreactive for CEA or CA19-9. Five tumors diffusely immunoreactive for CEA or CA19-9, in addition to endocrine markers, were diagnosed as duct-endocrine cell tumors of the pancreas. Two tumors diffusely immunoreactive for CEA or CA19-9 and also for pancreaticogut hormones as well as endocrine markers were diagnosed as duct-acinarendocrine cell tumors. These tumors showed uniform histologic features and synchronous ductal, acinar, and endocrine differentiation, distinct from the coexisting different cellular populations seen in collision tumors. All tumors were malignant. These duct-endocrine cell tumors or duct-acinar- endocrine cell tumors of the pancreas may be derived from a stem cell that retains the capability of expressing either an exocrine or endocrine phenotype. Only one K-ras gene mutation and no p53 gene alterations were detected in these tumors, which suggests that they constitute an entity with a different origin than ductal carcinomas.

Adult↗