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Biomedical subjects

A Yamaguchi

Publications and source records attributed to A Yamaguchi.

At least 451 records · Page 25Linked to original sources
PubMed1992

Purification and characterization of maturation-promoting factor in fish.

Maturation-promoting factor (MPF) activity has been demonstrated for the first time in fish oocytes. We purified MPF from a 100,000g supernatant of crushed, naturally spawned carp oocytes using four chromatography columns: Q-Sepharose Fast-Flow, p13suc1-affinity Sepharose, Mono S, and Superose 12. The final preparation was purified over 1000-fold with a recovery of about 1%. On Superose 12, MPF eluted as a single peak with an apparent molecular weight of 100 kDa. SDS-PAGE analysis of the active fractions after Superose 12 revealed the presence of four proteins of 33, 34, 46, and 48 kDa. A monoclonal antibody against the PSTAIR sequence of cdc2 kinase recognized the 33- and 34-kDa proteins for which the 46- and 48-kDa proteins are endogenous substrates. The 46- and 48-kDa proteins were recognized by a monoclonal antibody against Escherichia coli-produced goldfish cyclin B, but not by an anti-cyclin A antibody. When oocytes were matured in the presence of 32P, the labeling was seen with the 34-kDa protein, but not with the 33-kDa protein. The 34-kDa protein corresponded to the MPF activity, but the 33-kDa protein did not. These findings indicate that carp MPF is a complex of cdc2 kinase and cyclin B, and further that active MPF contains the phosphorylated form of cdc2 kinase.

Animals↗
PubMed1992

Effects of islet amyloid polypeptide (amylin) and calcitonin gene-related peptide (CGRP) on glucose metabolism in the rat.

In this study, we compared the effects of islet amyloid polypeptide (IAPP) and calcitonin gene-related peptide (CGRP) on glucose metabolism both in vivo and in vitro in the rat. Intravenous injection of rat CGRP caused a significant increase in plasma glucose concentration with a simultaneous increase in plasma insulin levels, whereas neither IAPP-NH2 nor IAPP-COOH had any effect. Moreover, intravenous infusion of CGRP decreased tolerance to intragastric administration of glucose (O-GTT) without altering plasma insulin levels, but again IAPPs had no effect. On the other hand, 125I-[Tyr0]rat CGRP specifically bound to the liver plasma membrane, and not only CGRP but also IAPP-NH2 dose-dependently displaced the specific binding of 125I-[Tyr0] CGRP, whereas IAPP-COOH had no effect. Conversely, CGRP as well as IAPP-NH2 but not IAPP-COOH evoked dose-dependent activation of adenylate cyclase in the membranes, and these effects were significantly inhibited by a CGRP receptor antagonist, human CGRP-I(8-37). However, neither CGRP nor IAPP-NH2 had any effect on glucose production in rat isolated hepatocytes. These results suggest that (1) IAPP-NH2 but not IAPP-COOH induces adenylate cyclase activation via CGRP receptors on rat liver plasma membranes, and (2) CGRP might not involve its action on the liver in the changes of glucose metabolism.

Amyloid↗
PubMed1992

DNA polymerase alpha positive-cell rate in colorectal cancer and its relationship to prognosis.

A total of 63 patients with colorectal cancer were studied for proliferative activity by an immunohistochemical technique using a monoclonal antibody against DNA polymerase alpha. The DNA polymerase alpha positive cell rates ranged from 24.0% to 74.6%. There was a correlation between the DNA polymerase alpha positive cell rates of biopsies and resected specimens. There was no significant correlation between DNA polymerase alpha positive cell rates and histological type, tumour size, invasion of bowel wall, lymphatic invasion, venous invasion, lymph node metastasis or peritoneal metastasis. Tumours with a high growth fraction (a DNA polymerase alpha positive cell rate greater than or equal to 42%) were more frequently associated with liver metastasis than those with a low growth fraction (a DNA polymerase alpha positive cell rate less than 42%). Patients with high growth fraction tumours had significantly poorer prognoses than those with low growth fraction tumours. The results of multivariate analysis using the proportional hazard model of Cox indicated that the DNA polymerase alpha positive cell rates, liver metastasis, and peritoneal metastasis were independent prognostic factors. The results indicate that the DNA polymerase alpha positive cell rate may be a useful prognostic marker of colorectal cancers.

Antibodies, Monoclonal↗
PubMed1992

A simple method for gender verification based on PCR detection of Y-chromosomal DNA and its application at the Winter Universiade 1991 in Sapporo City, Japan.

A simple and reliable screening method for gender verification at international sports competitions was developed on the basis of detection of Y-chromosomal DNA which was specifically amplified by polymerase chain reaction (PCR). Total DNA obtained from buccal mucous membrane cells by digestion with proteinase K followed by boiling treatment was directly used for the PCR. The amplified product was electrophoresed on an agarose gel staining with ethidium bromide. We adopted three sets of the PCR primer, identifying different regions of Y-chromosome, of which sensitivity and specificity were preliminary evaluated for 228 (112 male, 116 female) DNA samples from lymphocytes. This new method was first applied for the gender verification test at the Winter Universiade 1991 Sapporo, accompanied by traditional microscopic tests for X- and Y-chromatins. No positive results were obtained for 155 female competitors using both the PCR and the microscopic methods. The superiority of the proposed method was clearly shown in the reliability of the results and also in the saving on instrumental and personnel costs as compared to previous cytologic methods.

DNA↗
PubMed1992

Lack of evidence that a transplanted liver causes acute graft-versus-host disease in rats. A comparison of liver and spleen grafts.

In this study, we used rat transplant models to investigate whether--and, if so, to what extent--transplanted liver had the potential to incite graft-versus-host disease, compared with the disease induced by a spleen graft. Livers from PVG(RT1c) rats were transplanted orthotopically into (DAxPVG)F1 (RT1a/c) rats and vascularized spleen grafts from PVG rats were transplanted heterotopically into (DAxPVG)F1 recipients. The intensity of the GVH disease was assessed by the recipients' morbidity and mortality, recipient-type serum class I (RT1Aa) antigen titer, and histological examination. The recipients of spleen grafts died within 14 and 23 days of transplantation; all animals had lost body weight and showed typical GVH signs, such as ear erythema, diarrhea, and alopecia. However, all the recipients bearing liver grafts survived indefinitely and did not demonstrate weight loss or the typical symptoms associated with GVH disease. The skins, tongues, and intestines of the liver-grafted rats were virtually normal at histological examination, whereas the livers, salivary glands, and skins of spleen-grafted rats were infiltrated by immunoblasts. The recipient-type serum RT1Aa antigen titer increased progressively until death in the spleen graft but not the liver graft recipients. These results provide evidence that suggest that transplanted liver is less likely than transplanted spleen to initiate the GVH disease in rats.

Acute Disease↗
PubMed1992

Hemodynamic evaluation of a new left ventricular assist device: an integrated cardioassist catheter as a pulsatile left ventricle-femoral artery bypass.

We developed a new left ventricular (LV) assist catheter (transaortic valve from LV to femoral artery) that is implemented percutaneously and exerted as a synchronous pulsatile partial LV flow support with conventional intraaortic balloon pump (IABP) driving system and centrifugal pump system. We investigated whether this pulsatile LV-aorta bypass is superior to the IABP from a hemodynamic viewpoint. Ten dogs with profound heart failure were placed on this device, and hemodynamic measurements were performed under on-off study of this system. The results revealed a significant increase of mean aortic pressure, total cardiac output, and myocardial blood flow, and a significant reduction of left atrial (LA) pressure and LV afterload estimated by diastolic pressure-time index/tension-time index (DPTI/TTI) measurement compared with baseline values and also with IABP exertion alone. These findings suggest that this system is of clinical value for supporting an impaired LV that is intractable under IABP counterpulsation.

Animals↗
PubMed1992

Immunohistochemical detection of c-myc products in colorectal cancer and proliferative cell rate.

Expression of c-myc protein was studied immunohistochemically in colorectal cancers using a monoclonal antibody, MYC-1. Immunoblotting assays with cellular lysates demonstrated a band of the gene products at the level of 60 kDa. c-myc-protein-positive tumor cells were observed in 43 (43.4%) of 99 specimens of colorectal cancers. There was no significant correlation between the incidence of MYC-1-positive tumors and clinicopathological findings. The rate of MYC-1 proteins occurring in patients with liver metastasis was significantly higher than that in patients without the metastasis. The rate of occurrence of DNA polymerase-alpha-positive cells in MYC-1 protein-positive tumors was significantly higher than in MYC-1 negative ones. The results suggested that MYC-1 immunoreactivity might possibly be a useful prognostic marker of colorectal cancers.

Adenocarcinoma↗
PubMed1992

Interrelationship between transforming growth factor-alpha and epidermal growth factor receptor in advanced gastric cancer.

An immunohistochemical study for transforming growth factor-alpha (TGF alpha) and epidermal growth factor receptor (EGFR) was made with 167 primary tumors of advanced gastric cancer to demonstrate the potential existence of autocrine mechanism. TGF alpha stained positively in 87 (52%), and EGFR in 68 (41%) of the tumors. The authors classified the tumors into the following three groups: group 1 with neither TGF alpha nor EGFR staining positively (63 tumors); group 2 with either TGF alpha or EGFR staining positively (53 tumors); group 3 with both TGF alpha and EGFR staining positively (51 tumors). The incidence rates of macroscopically infiltrative tumors and large tumor measuring 6 cm or more in diameter were significantly higher for group 3 than for groups 1 and 2. The patients of group 3 had the poorest prognosis, with a 5-year survival rate of only 12%, while the 5-year survival rates were 45 and 36% for groups 1 and 2. There was a significant difference in survival between the patients of group 1 and those of group 3. Bromodeoxyuridine labeling indices were significantly higher in the tumors belonging to group 3 (median 15.8%) than in those of group 1 (median 10.8%). The results suggest that the autocrine mechanism between TGF alpha and EGFR may play an important role in the progression of gastric cancer, and that when such a mechanism becomes operative, prognosis may be poor.

Adenocarcinoma↗
PubMed1992

Correlation of c-erbB-2 protein expression and lymph node status in early gastric cancer.

For the prediction of nodal status of early gastric cancer, sections of formalin-fixed, paraffin-embedded tissue from 220 early gastric cancers were analyzed immunohistochemically, using a polyclonal antibody against erbB-2 protein. The data of erbB-2 protein expression have been correlated with pathologic data, and a logistic regression analysis was made for the estimation of the significant factors responsible for lymph node metastasis. A pattern consistent with cell membrane staining was regarded as most specific for the erbB-2 expression. There were 22 (10%) cancers with evidence of erbB-2 protein expression. Positive staining was associated with only lymph node metastasis. The risk of lymph node metastasis was 3-fold greater in tumors having erbB-2 protein expression than in tumors without the expression. When the erbB-2 tissue status and clinicopathological parameters were entered into the logistic regression analysis, erbB-2 protein expression emerged as one of the independent significant factors for lymph node metastasis. These results indicate that early gastric cancer with erbB-2 protein expression may represent a potential risk of lymph node metastasis.

Biomarkers, Tumor↗
PubMed1992

In situ hybridization of bone matrix proteins in undecalcified adult rat bone sections.

We have developed a method for in situ hybridization of adult bone tissue utilizing undecalcified sections and have used it to histologically examine the mRNA expression of non-collagenous bone matrix proteins such as osteocalcin (bone Gla protein, BGP), matrix Gla protein (MGP), and osteopontin in adult rats. Expression was compared with that in bone tissues of newborn rats. In the adult bone tissue, osteocalcin mRNA was strongly expressed in periosteal and endosteal cuboidal osteoblasts but not in primary spongiosa near the growth plate. Osteopontin mRNA was strongly expressed in cells present on the bone resorption surface, osteocytes, and hypertrophic chondrocytes, but not in cuboidal osteoblasts on the formation surface. Osteopontin and osteocalcin mRNAs were expressed independently and the distribution of cells expressing osteopontin mRNA corresponded with acid phosphatase-positive mononuclear cells and osteoclasts. Expression of MGP mRNA was noted only in hypertrophic chondrocytes. In newborn rat bone tissues, expression of osteocalcin mRNA was much weaker than in adult rat bone tissues. These results clearly indicate the differential expression of mRNAs of non-collagenous bone matrix proteins in adult rat bone tissues.

Animals↗
PubMed1992

1 alpha,25-dihydroxyvitamin D3 regulates in vivo production of the third component of complement (C3) in bone.

We previously reported that 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25-(OH)2D3] specifically stimulates production of the third component of complement (C3) by murine osteoblastic cells and marrow-derived stromal cells (ST2) in vitro. In the present study we examined tissue-specific production of C3 in vivo in vitamin D-deficient mice, some of which received supplemental 1 alpha,25-(OH)2D3. Western blot analysis indicated that the C3 protein band in bone was undetectable in vitamin D-deficient mice, but became distinct 48 h after 1 alpha,25-(OH)2D3 administration. The mRNA expression of C3 in bone was also undetectable in vitamin D-deficient mice and appeared as early as 24 h after 1 alpha,25-(OH)2D3 administration. mRNA expression apparently preceded the appearance of C3 protein. In contrast, there was no significant difference in the expression of hepatic C3 mRNA among normal mice fed laboratory chow and vitamin D-deficient mice with and without 1 alpha,25-(OH)2D3 administration. The serum concentration of C3 in vitamin D-deficient mice was almost identical to that in normal mice and was unchanged after 1 alpha,25-(OH)2D3 administration. 1 alpha,25-(OH)2D3 receptor (VDR) mRNAs were detected in the kidney and intestine, whereas no appreciable mRNA expression of VDR occurred in the liver. Osteopontin mRNA was expressed in response to 1 alpha,25-(OH)2D3 in the kidney, but not in the intestine. Immunohistochemical studies showed that in normal mice, the C3 protein was located mainly in the periosteal regions of calvaria and on the surfaces of bone trabeculae in the tibial metaphyses. These results demonstrate that 1 alpha,25-(OH)2D3 tissue-specifically regulates in vivo production of C3 in bone. The production of bone C3 cannot be attributed to the presence of VDR alone, and we speculate that other tissue-specific factors are required.

Animals↗
PubMed1992

Interaction between polyethylene films and bromhexine HCl in solid dosage form. IV. Prevention of the sorption by addition of magnesium aluminum silicate.

The effects of magnesium aluminum silicate (MAS) addition on the sorption of bromhexine HCl to polyethylene film in tablets were studied. The addition of MAS prevented the sorption of bromhexine HCl to polyethylene film. In order to investigate the mechanism, the interaction between bromhexine HCl and MAS was studied by the powder X-ray diffraction method. It was observed that bromhexine HCl was preferentially adsorbed to the surface of MAS rather than to polyethylene film. The adsorption was accelerated at high temperature and reduced pressure conditions. The sorption of bromhexine base and bromhexine HCl to packaging material were compared using tablet dosage forms. The sorption of bromhexine base to polyethylene film was greater than that of bromhexine HCl.

Aluminum Compounds↗
PubMed1992

Interaction of platelets and blood vessels--vascular injuries induced by platelet activation in vivo.

We have found that vascular injuries are induced by intravascular aggregation of platelets activated by arachidonic acid (AA) or ADP. The characteristic findings are the appearance of vacuoles in endothelial cells and eventual deendothelialization. In deendothelialized regions, formation of platelet thrombi was observed. The platelets in the thrombi were stained with 2T60, a monoclonal antibody that recognizes activated platelets. The change was more remarkable in the AA-injected animals because AA has a stronger platelet activating effect and a detergent effect on the endothelium. The ADP-injection experiments clarified the role of platelets in vascular injury. These findings suggest that activated platelets play a role in the genesis of vascular injuries, and that their role is related to thrombus formation.

Adenosine Diphosphate↗
PubMed1992

[Utricular papillomatosis. A case report].

A case of utricular papillomatosis is reported herein. A 50-year-old male patient consulted our hospital with a complaint of asymptomatic macrohematuria. Endoscopic examination revealed papillomatous tumor tightly growing within the utricle. Transurethral resection of the tumor was performed. Histopathologically, the tumor consisted of numerous villous structures with slender fibrovascular cores and overlying cuboidal cells in 2 to 3 cell layers. Invasive growth or cellular atypia could not be found. Utricular papillomatosis is rare, and only one similar case was reported to my knowledge in the English literature for the last five years. Such rarity and peculiar clinicopathological characteristics prompted us to report this case.

Humans↗
PubMed1992

[Clinical and histological effects of preoperative chemotherapy for squamous cell carcinoma of the tongue].

According to the effect of preoperative chemotherapy for tongue cancer, if the operation method is modified, the modality of treatment for tongue cancer will contribute to preserve the tongue in terms of function and aesthetics as well as improve the quality of life. A clinicopathologic study on 81 patients with tongue cancer was conducted to elucidate the relationship between clinical and histological effects of preoperative chemotherapy with a single agent and multiple-drug regimens, in order to determine the safe surgical margins in the resection of squamous cell carcinoma of the tongue. Fifty patients were treated with bleomycin alone, sixteen with bleomycin and methotrexate and another fifteen with bleomycin, OK-432 and cisplatin. Multiple-drug regimens resulted in greater response rates than the single agent, but there was not always agreement in the relationship between the tumor regression rate and the histological effects of chemotherapy. The histological effects, including the residual aspects of the tumor cell population, were associated with the grade of histological malignancy according to the mode of tumor cell invasion, mitotic index of tumor cell, the tumor differentiation, the degree of stromal lymphocyte infiltration and cellular atypism. These data indicate that special consideration should be also given to the degree of histological malignancy for biopsied specimen, in addition to the tumor regression rate, in determining safe surgical margins and in the modality of treatment of tongue cancer.

Adult↗