Biomedical subjects

S Wada

Publications and source records attributed to S Wada.

At least 217 records · Page 12Linked to original sources

PubMed1996

Assessment of the course and variations of the hepatic artery in bile duct cancer by intraductal ultrasonography.

BACKGROUND: We evaluated the course and variations of the hepatic artery in bile duct cancer using intraductal ultrasonography (IDUS). METHODS: IDUS was used to demonstrate the course of the hepatic artery preoperatively in 20 patients with extrahepatic bile duct cancer, and the image was compared with angiographic and surgical findings. RESULTS: IDUS was able to assess tumor invasion to the main branch of the right hepatic artery in all cases. However, it demonstrated only three cases in the left hepatic artery and four cases in the proper hepatic artery. When the hepatic artery indicated re-entry or bifurcation on the IDUS image, the proximal portion of re-entry or bifurcation was established as the proper hepatic artery, but when it showed neither re-entry nor bifurcation it was established as the right hepatic artery. CONCLUSIONS: IDUS demonstrated the main branch of the right hepatic artery in all cases, but was not useful for demonstration of the left and proper hepatic arteries. Correct assessment of re-entry and bifurcation was essential on IDUS images for making the distinction between the right hepatic artery and the proper hepatic artery.

Aged↗

PubMed1996

Hroth an orthodenticle-related homeobox gene of the ascidian, Halocynthia roretzi: its expression and putative roles in the axis formation during embryogenesis.

To obtain insight into the axis-forming mechanism in ascidian embryogenesis, Hroth, an ascidian counterpart of orthodenticle/otx, was isolated from Halocynthia roretzi and its expression in embryogenesis was examined by whole mount in situ hybridization. It was revealed that Hroth is expressed in both involuting mesoendoderm and anterior ectoderm during gastrulation while later expression is restricted to the sensory vesicle and anterior epidermis. Expression pattern of Hroth around gastrulation was compared with that of Hrlim, the ascidian LIM class homeobox gene that is known to be expressed during gastrulation. In the light of the present findings on the expression of Hroth, properties of the axis-forming mechanism in ascidian embryogenesis are discussed.

Amino Acid Sequence↗

PubMed1996

Assessment of pancreatic parenchymal invasion by bile duct cancer using intraductal ultrasonography.

BACKGROUND AND STUDY AIMS: This study was performed to clarify the diagnostic accuracy of intraductal ultrasonography (IDUS) in assessing pancreatic parenchymal invasion by bile duct cancer. PATIENTS AND METHODS: Preoperative assessment of pancreatic parenchymal invasion was carried out by IDUS via a percutaneous tract or a transpapillary route in 18 patients with extrahepatic bile duct cancer. Various probes with diameters of 1.4, 2.0, 2.4, 2.6 and 3.2 mm, and frequencies of 7.5, 15, 20 and 30 MHz were used. All patients underwent angiography and endoscopic ultrasonography (EUS). In the first six cases, IDUS and EUS images were analyzed retrospectively without knowledge of the operative outcome or the results of other imaging tests. In the subsequent 12 cases, the IDUS und EUS images were prospectively reviewed prior to surgery. The diagnostic accuracy of IDUS was compared with angiography and EUS by means of a histopathological examination of the resected specimens. RESULTS: The accuracy of IDUS, EUS, and angiography in assessing pancreatic parenchymal invasion was 100%, 78% and 61%, respectively. However, IDUS could not assess pancreatic capsular invasion. The accuracy of IDUS in assessing horizontal tumor extension to the intrapancreatic bile duct and to the hepatic side was 83% and 72%, respectively. CONCLUSIONS: IDUS proved useful for assessing the extension of cancer invasion to the pancreatic parenchyma, but not to the pancreatic capsule or mucosal surface.

Aged↗

PubMed1996

Modifying influence of swine-serum-induced liver fibrosis on development of preneoplastic lesions in rat liver.

Modifying effects of fibrosis or a cirrhotic state, caused by treatment with swine serum (SS), on the induction of preneoplastic focal lesions were assessed in a rat medium-term liver bioassay model for the detection of environmental carcinogens, in which the test compound is administered during the promotion phase after initiation with diethylnitrosamine. In experiment I, repeated intraperitoneal administration of SS concomitantly with the hepatopromoting agent deoxycholic acid (DCA) or phenobarbital (PB) resulted in a cirrhotic state and a significant increase in the number or size of preneoplastic glutathione S-transferase placental form (GST-P)-positive liver cell foci as compared to the corresponding DCA or PB alone groups. In experiment II, SS was given prior to commencement of the same medium-term bioassay system, in which a known hepatopromoting agent, DCA, 17-alpha-ethynylestradiol, or 2-acetylaminofluorene, was applied. In this case, the liver did not show obvious cirrhotic change and, rather than any enhancement, slight inhibition of promotion occurred. The results indicate that a coexisting, but not a pre-existing, cirrhotic condition acts to increase growth pressure on GST-P+ preneoplastic foci, and suggest that concomitant administration of SS with the promoting agent could be applied to improve the sensitivity of the assay protocol.

2-Acetylaminofluorene↗

PubMed1996

Comparison of proliferative activities and metastases between two subtypes classified at the deeply infiltrating sites of colorectal moderately differentiated adenocarcinomas.

Twenty-eight moderately differentiated adenocarcinomas invading beyond the muscularis propria of the colorectum were subclassified as 13 moderate- and 15 poor-subtype tumors based on the histology at the deeply infiltrating sites. Moderately differentiated cancer cells were correlated with liver metastasis and p53 immunoreactivity. Poorly differentiated cancer cells were correlated with lymph node metastases but not to p53 immunoreactivity. The proliferative cell nuclear antigen (PCNA) labeling index (LI), Ki-67 LI and agyrophilic nuclear organizer regions (AgNOR) values determined for the poorly differentiated cancer cells in the poor-subtype tumors were significantly lower than those of moderately differentiated cancer cells in the moderate-subtype tumors. In cells from tumors classified as poor-subtype, poor differentiation was associated with decreased PCNA LI levels, but with unchanged Ki-67 LI and AgNOR values. These results indicate that colorectal adenocarcinoma cells that are histologically subclassified as moderately differentiated have different proliferative and metastatic activities from cancer cells that are poorly differentiated. Moderately differentiated cancer cells are associated with hematogenous metastasis to liver and high proliferative activity, and loss of tubular formation of cancer cells may be fundamentally related to lymph node metastasis and infiltrative growth.

Adenocarcinoma↗

PubMed1996

Effects of perfluorochemical-based artificial blood compounds in discordant xenotransplantation.

Fluosol-DA and FC43 emulsion were developed as red blood cell substitutes. However, these perfluorochemical (PFC)-based compounds are not very promising because of their immunosuppressive effects. Therefore we used these compounds as immunosuppressive agents in guinea pig-to-rat discordant heart xenotransplantations. In rats treated with these compounds (5 microliters/g body weight), rhythmic beating of the hearts was maintained for 265.7 +/- 50.3 min (Fluosol-DA-treated group) and 424.3 +/- 40.1 min (FC43 emulsion-treated group), respectively whereas the untreated heartbeat lasted for only 15.5 +/- 6.6 min. In the xenografted heart treated with PFC compounds, no pathologic changes, such as multiple coronary thromboses due to hyperacute rejection, had occurred by 3-4 h after reperfusion, and the endothelial cells were well preserved. We conclude that these PFC compounds can prolong the survival time of guinea pig heart xenografts by inhibiting thrombus formation in the xenografted heart.

Analysis of Variance↗

PubMed1996

Physiological levels of calcitonin regulate the mouse osteoclast calcitonin receptor by a protein kinase Alpha-mediated mechanism.

We have reported that calcitonin (CT) treatment induced downregulation of the CT receptor (CTR) in mouse osteoclast-like cells (OCLs). Here, we studied the features of homologous down-regulation of the CTR in mature mouse OCLs. Treatment with salmon CT (sCT) and human CT (hCT) reduced [125I]sCT specific binding. The decreased binding after 24 h of CT treatment was associated with a decrease in the cell surface receptor concentration. The extent of CT-induced down-regulation in 24 h was dose-dependent, and the ED50 value was 3.6 +/- 4.1 (mean +/- SD; n = 3) x 10(-13 M for sCT and 4.9 +/- 3.3 x 10(-11) M for hCT. These values were very similar to those for the CT inhibition of the bone-resorbing activity of OCLs. The data suggest that these two distinct actions of CT may be mediated by a common intracellular pathway. Treatment of OCLs with activators of protein kinase A (PKA) mimicked the effect of CT on CTR downregulation, whereas neither activation of protein kinase C nor elevation of intracellular Ca2+ did so. Attenuation of CT-induced CTR down-regulation by the competitive cAMP antagonist, RpcAMP, and high concentrations of H-7, but not by protein kinase C-specific inhibitors (sphingosine, staurosporine, and a lower concentration of H-7), suggested that the PKA pathway is primarily involved in homologous regulation of the CTR. The changes in CTR messenger RNA confirm the findings in binding studies and demonstrate that CT treatment of OCLs results in decreased CTR synthesis through the PKA pathway. The low concentrations of hCT that result in CTR regulation are very close to the physiological range, providing new insights into a dynamic relationship between circulating levels of CT and CTR expression in osteoclasts.

Animals↗

PubMed1996

Calcitonin receptor down-regulation relates to calcitonin resistance in mature mouse osteoclasts.

We have reported that short calcitonin (CT) treatment of mature mouse osteoclast-like cells (OCLs) in culture induced prolonged down-regulation of the CT receptor (CTR) and desensitization to CT rechallenge, at the level of adenylate cyclase activity. In this study, we have extended those studies to examine the bone resorbing activity of OCLs pretreated with CT. OCLs, which formed on gelled type I collagen, were pretreated with salmon CT (sCT)(10(-9)M, 1 h) and 24 h later were replated onto plastic dishes or dentine slices after removal from the gel by collagenase digestion. The number and population of either mononuclear or multinuclear OCLs that adhere to either surface was not affected by sCT pretreatment. It was found that OCLs pretreated with sCT regained reduced but significant bone resorbing capacity, which was quantitated as the surface area resorbed by OCLs on dentine slices. However, compared with control, the number of resorption pits produced by sCT- pretreated OCLs was slightly reduced, and the total pit area was decreased by approximately 40-50%. The distribution of individual pit sizes was altered by sCT-pretreatment so that the number of larger pits was predominantly reduced, suggesting that short sCT treatment may produce a long lasting decrease in osteoclast mobility. sCT was able to inhibit bone resorption activity of CT-pretreated OCLs (ED50:10(-13)-10(-12)M). Importantly, the ED50 of sCT inhibition of bone resorption in sCT-pretreated OCLs was approximately 100-fold greater than for control, indicating resistance of the OCLs to CT rechallenge. Consistent with these results, treatment of OCLs with sCT greatly decreased the expression of CTR messenger RNA, whereas no significant effect was observed on the tartrate-resistant acid phosphatase messenger RNA expression, a marker of resorptive capacity of osteoclasts. These results indicate, therefore, that an important component of escape of osteoclastic resorption from CT inhibition is CT resistance of mature osteoclasts, which regain bone resorbing function.

Animals↗

PubMed1996

Cellular changes of rat embryonic fibroblasts by an actin-polymerization inhibitor, bistheonellide A, from a marine sponge.

Bistheonellide A, an inhibitor of actin polymerization from the marine sponge Theonella sp., was introduced at a concentration of 100 nM into rat fibroblast of 2.4 x 10(4) cells/ml. Within 1 h, it disrupted stress fibers, accompanied by a marked change of the cell morphology, resulting in the formation of processes from the cell surface. Further incubation for 24 h in the presence of 100 nM bistheonellide A led to binucleation in most cells and subsequent inhibition of cell cycle progression. When bistheonellide A was withdrawn from the culture medium, binuclear cells began to grow again within 20 h and reverted to mononuclear morphology. Flow cytometric analysis fluorescence-activated cell sorting showed that 2C diploid DNA content in G1 phase was changed into 4C content of tetraploid for the bistheonellide A treated-cells in G1 phase and into 8C content during G2 and M phase. Therefore, we suggested that the bistheonellide A treatment inhibited cytokinesis, but not mitosis in M phase, and that treated cells were arrested at the early G1 phase. These effects of bistheonellide A on the cell cycle progression of 3Y1 fibroblast were also observed more prominently in cells synchronized in S phase with hydroxyurea. Cells in G0 phase were then activated by the addition of fetal calf serum in the presence of 100 nM bistheonellide A. Cell cycle progression of the bistheonellide A-treated cells was obviously slowed down or completely inhibited during G1 phase. These results reveal that actin filaments are not only essential to cytokinesis but also for promoting the progression of cell cycle G1 to S phase.

Actins↗

PubMed1996

Pemphigus foliaceus with typical histological and immunohistological findings in a dog.

A seven-year-old female mongrel dog showed incurable skin lesions for about a year. The lesions were at nasal bridge and periocular area, and were composed of crust formation and scaling. Biopsy specimens from the skin lesions possessed with multiple intraepidermal pustules containing many acatholytic keratinocytes. Direct immunoperoxidase stain using paraffin-embedded section showed IgG deposition at the intercellular area of upper epidermis and follicular infundibula. IgG was not detected at basement membrane zone. Clinical and pathological findings of the present case were identical to those of pemphigus foliaceus, an uncommon pustular autoimmune skin disease.

Animals↗

PubMed1996

Homeobox genes exhibit evolutionary conserved regionalization in the central nervous system of an ascidian larva.

Animals in each subgroup of the phylum Chordata exhibit a similar process by which they form a tubular central nervous system (CNS). However, little is known about spatial relationship among the CNSs of chordates; vertebrates, cephalochordates and urochordates (tunicates). Ascidians constitute a major animal group in the subphylum Urochordata. In the present study, we examined the expression patterns of labial and orthodenticle related genes of the ascidian, Halocynthia roretzi, in the developing larval CNS. These homeobox genes exhibited region-specific expression patterns that are strikingly similar to those of murine Hoxb-1 and Otx2. The regionalization as characterized by the expression of these genes supports the division of the ascidian larval CNS suggested by the previous morphological studies. Furthermore, conservation of the expression pattern of the homeobox genes suggests that such regionalization occurred in the CNS of a putative common ancestor of chordates.

Amino Acid Sequence↗

PubMed1996

[A study on the concurrent validity of personality inventory from the view of the Five Factor Model concerning personality traits].

By using the Adjective Check List (ACL) in its Japanese version, the concurrent validity of a personality inventory is investigated through canonical correlation analysis and procrustes factor rotation from the view of the Five Factor Model concerning personality traits. After describing the objective of the present paper, the principles both of canonical correlation analysis and of incomplete orthogonal procrustes factor rotation to be used are explained. And, following the description concerning samples and data for analysis, the results both based on the scales and on the items of the personality inventory are presented. The important role of procrustes type of factor rotation in editing personality inventory is stressed before closing the discussion.

Adult↗

PubMed1996

[The effectiveness of neoadjuvant chemotherapy for invasive bladder cancer].

BACKGROUND: Sixteen patients with invasive bladder cancer were received neoadjuvant methotrexate, vinblastine, pirarubicin and cisplatin chemotherapy on our planning protocol. METHODS: The tumor was evaluated after 1 course of chemotherapy by radiographic examination, urine cytology, cystoscopy and random biopsy. If the response is CR or PR, one more course of chemotherapy was performed, and cystectomy was carried out. If the response is NC or PD, cystectomy was immediately carried out. Twelve of them were underwent cystectomy and four were preserved bladder. Clinical response was evaluated by echo, CT, MRI, urinary cytology, cystoscopy and random biopsy. RESULTS: Clinical CR was observed in 25% and PR was 37.5%. Pathological CR was observed in 31.3% and PR was 37.5%. The different rate between clinical and pathological evaluations was 31.3% and the result suggests that we should find the method of more accurate staging evaluation. Four patients who were evaluated clinical CR were selected bladder-preserving. However, two of them (50%) had recurred; one had grade 3 tumor was treated by total cystectomy and the other had multiple tumors was treated by one course of M-VAC and TUR-Bt. CONCLUSION: We should consider which cases are possible to preserve bladder by investigating the tumor characteristics.

Aged↗

PubMed1996

Utility of endoscopic ultrasonography with color Doppler function for the diagnosis of islet cell tumor.

OBJECTIVE: To evaluate the efficacy of endoscopic ultrasonography with color Doppler function for the diagnosis of islet cell tumor. METHODS: Endoscopic ultrasonography was compared with other modalities such as ultrasonography, computed tomography, and angiography in the evaluation of seven patients with islet cell tumor and 28 patients with duct cell cancer. RESULTS: In cases of islet cell tumor, the tumor detection rates by ultrasonography and endoscopic ultrasonography were 86% and 100%, respectively. Color signals were detected in 14% and 100% of the cases of islet cell tumor by ultrasonography and endoscopic ultrasonography, respectively. The pattern of color signals obtained was rich and abundant, showing pulsatile and/or continuous wave patterns. Angiography and computed tomography showed hypervascularity. However, in cases of duct cell cancer, the tumor detection rates by ultrasonography and endoscopic ultrasonography were 96% and 100%, respectively, whereas color signals were detected in 78% with both ultrasonography and endoscopic ultrasonography. The image of blood flow, which was connected to surrounding vessels, showed a linear pattern and few blood flow signals. In these cases, angiography and computed tomography demonstrated encasement of the artery or portal vein without hypervascularity. CONCLUSIONS: Endoscopic ultrasonography was usefull for the localization and differential diagnosis of islet cell tumor because of its excellent ability to visualize small lesions and tumor vascularity simultaneously.

Adenoma, Islet Cell↗

PubMed1996

Assessment of arterial invasion in pancreatic cancer using color Doppler ultrasonography.

OBJECTIVE: We report the first study on the value of color Doppler ultrasonography (CDUS) in assessing arterial invasion of pancreatic cancer. METHODS: The relationships between tumors and surrounding major splanchnic arteries (celiac, superior mesenteric, common hepatic, splenic, and gastroduodenal arteries) were preoperatively evaluated with CDUS in 33 consecutive patients with pancreatic cancer. When a tumor partially or completely surrounded the artery, the invasion was diagnosed as positive. Imaging results were then compared with angiographic, surgical, and histopathological findings. RESULTS: In 22 nonsurgical patients, the correspondence rate of CDUS with angiography for the presence of invasion, absence of invasion, and overall was 78%, 95%, and 88%, respectively. In 11 surgical patients, a sensitivity of 60%, specificity of 93%, and accuracy of 87% for detection of arterial invasion were obtained in comparing CDUS with surgical and histopathological findings. There was no significant difference between the accuracy of CDUS and that of CT, or that of angiography. However, the accuracy of CDUS was higher than that of CT (72%) and equal to that of angiography (91%). CONCLUSION: Color Doppler ultrasonography is useful for detecting arterial invasion in pancreatic cancer. It may make angiography unnecessary, especially with advanced tumors, if thorough evaluation for the large artery invasion is performed initially.

Adult↗

PubMed1996

Diagnosis of gallbladder carcinoma with color Doppler ultrasonography.

A 65-yr-old woman was referred to our department for evaluation of a gallbladder lesion detected at another institution, where she was diagnosed with chronic cholecystitis. Conventional ultrasonography revealed that the gallbladder lumen was filled with debris-like components, and the gallbladder wall was mildly thickened. Color Doppler ultrasonography revealed color signals in both the lesion and the gallbladder wall. These signals showed a high-speed pulsatile wave, and one of the visualized signals revealed a high-resistance index (1.0) on fast Fourier transform analysis. These findings were highly suggestive of malignancy. Surgery was performed, and histological examination of the resected specimen revealed carcinoma of the gallbladder. We conclude that color Doppler ultrasonography can be useful in the diagnosis of tumefactive gallbladder lesions.

Adenocarcinoma↗

PubMed1996

[The evaluation of three dimensional image distortion of helical scanning CT].

We developed a computer algorithm to simulate distortion in the three-dimensional (3D) displays obtained by helical scanning. The algorithm constitutes calculation of the image profile in the longitudinal direction, which is assumed to be a convolution of the object function with the slice sensitivity profile (SSP) of helical scanning. Experiments were performed to examine the algorithm for its validity with the use of a K2HPO4 phantom. Simulated results and measurements was in a good agreement. The distortion was investigated by the computer simulation. The model simulated was a high density object (Ol) surrounded by low density tissue (Os). The helical interpolation used was 360-degree linear interpolation. Two parameters were defined: delta Lz, which is the difference in length between the 3D image and the actual object Ol in the longitudinal direction, and the cut level index (CLI), which is defined as CLI = (Cut Level CT Number-CT Number of Os)/(CT Number of OI-CT Number of Os). We found that magnitude of delta Lz increased depending on the table feed distance per 360-degree scan (Dt). When Ol was twice as long as Dt, delta Lz directly depended on CLI, but was independent of Ol length. When Ol length was longer than Dt, delta Lz was shown to be 0 at CLI not equal to 0.5 at every Dt. When Ol was shorter than Dt, delta Lz decreased remarkably depending on the length of Ol in higher CLI. The simulations, with the use of a newly developed algorithm, were demonstrated to be useful for evaluating the amount of distortion and for better understanding the characteristics of 3D displays of helical scanning.

Algorithms↗

PubMed1996

A study of antitumor effects of thymosin on rat and mouse urinary bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine.

N-Butyl-N-(4-hydroxybutyl)-nitrosamine (BBN), which induces bladder carcinoma in female Wistar rats and female C3H/HeJ mice, was given as 0.025% (w/v) solution to rats and 0.05% to mice in the drinking water. Thymosin fraction 5 (TF5) or thymosin alpha 1 (T alpha 1) dissolved in normal saline, and normal saline (control) respectively were injected into the right thigh IM twice a week in the experimental rats. At the 30th week of BBN oral administration, weights of urinary bladder were different among the three groups. Bladder weights and incidence of bladder carcinoma were significantly lower in the TF5-treated group as compared with control group. Natural killer cell activity of splenic lymphoid cells was significantly elevated in the TF5-treated group as compared with the control group. However, these parameters were not significantly different between the T alpha 1-treated group and control saline-treated group. On the other hand, bladder weights and incidence of bladder carcinoma were not significantly different among TF5-, T alpha 1- and saline-treated groups at 10, 15, 20, and 25 weeks of BBN administration in mice according to the same protocol as rats.

Animals↗