Asymptomatic small-bowel varices.
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Humans↗
Biomedical subjects
T Komatsuda
Publications and source records attributed to T Komatsuda.
Isolated splenic metastases.
We analyzed the primary tumors, sonographic findings, clinical manifestations, and prognosis in five cases of isolated splenic metastases to determine in what situations these rare metastases should be suspected. The metastases were detected by ultrasonography in all five patients, and the primary tumors were colonic cancer in four patients and renal cancer in one patient. Splenectomy was performed and the postoperative course was uneventful in all patients. We conclude that preoperative and follow-up examinations must be performed with special attention given to the spleen in colonic or renal cancer patients.
Adult↗
Fluid shear stress enhanced DNA synthesis in cultured endothelial cells during repair of mechanical denudation.
We have previously observed a stimulatory effect of fluid shear stress on the regeneration of cultured endothelial cell layers after mechanical denudation. In this study we examined how fluid shear stress affects endothelial cell DNA synthesis during regeneration. Following mechanical denudation of narrow linear areas, monolayers of bovine aortic endothelial cells cultured on plastic dishes were subjected to shear stress of 1.3-4.1 dynes/cm2 for 24-48 hours in a specially designed apparatus. After the application of shear stress, cells were stained with propidium iodide, and its fluorescence intensity, reflecting cellular DNA content, was measured using photometric fluorescence microscopy. The DNA content of cells exposed to shear stress increased significantly more than that of paired, static control cells (p less than 0.005 to p less than 0.001). The DNA histogram showed that cells exposed to shear stress contained a relatively high proportion of cells located in the S, G2, and M phases of the cell cycle as compared with the static control. These data suggest that fluid shear stress enhances endothelial cell DNA synthesis during the repair of mechanical denudation.
Animals↗
Cytoplasmic calcium response to fluid shear stress in cultured vascular endothelial cells.
Vascular endothelial cells modulate their structure and functions in response to changes in hemodynamic forces such as fluid shear stress. We have studied how endothelial cells perceive the shearing force generated by blood flow and the substance(s) that may mediate such a response. We identify cytoplasmic-free calcium ion (Ca++), a major component of an internal signaling system, as a mediator of the cellular response to fluid shear stress. Cultured monolayers of bovine aortic endothelial cells loaded with the highly fluorescent Ca++-sensitive dye Fura 2 were exposed to different levels of fluid shear stress in a specially designed flow chamber, and simultaneous changes in fluorescence intensity, reflecting the intracellular-free calcium concentration [( Ca++]i), were monitored by photometric fluorescence microscopy. Application of shear stress to cells by fluid perfusion led to an immediate severalfold increase in fluorescence within 1 min, followed by a rapid decline for about 5 min, and finally a plateau somewhat higher than control levels during the entire period of the stress application. Repeated application of the stress induced similar peak and plateau levels of [Ca++]i but at reduced magnitudes of response. These responses were observed even in Ca++-free medium. Thus, a shear stress transducer might exist in endothelial cells, which perceives the shearing force on the membrane as a stimulus and mediates the signal to increase cytosolic free Ca++.
Animals↗
A disk-type apparatus for applying fluid shear stress on cultured endothelial cell.
To study the effect of fluid shear stress on cultured endothelial cells, we have developed an apparatus for the stress creation, which consists of a stainless steel disk driven by an electric DC motor and a stage to place a culture dish and to adjust the distance between the disk and the dish. When the disk is rotated, a concentric fluid movement occurs in the culture medium in the dish and exerts the shear stress on the endothelial cells cultured on the bottom of the dish. A theoretical analyses concerning the induced concentric flow velocity predicted that when the angular velocity of the disk rotation (omega) is slow enough to maintain a Reynolds' number of the order of 10, the exerted wall shear stress tau w on the endothelial cell monolayer is given for a constant as tau w = mu r omega/d where mu is the viscosity of the medium, d the distance from the plate to the monolayer and r the radial distance from the center of the dish. When omega is varied in a sinusoidal mode tau w also becomes sinusoidal, thus allowing to apply a pulsatile stress. In vitro experiments carried out to examine the validity of the theoretical results, using a suspension of polystyrene as a tracer with the ordinary culture medium and 99% ethanol, revealed excellent agreement of the measured velocity profiles with the predicted ones. The results demonstrated that the present apparatus can create both the steady and pulsatile wall shear stress on the culture cell layer as expected, unless Reynolds' number greatly exceeds the level of 10.
Cells, Cultured↗
Color Doppler findings in Castleman's disease of the mesentery.
Castleman's disease is a relatively rare lymphoproliferative disease. We report an asymptomatic case of Castleman's disease isolated to the mesentery and detected incidentally by sonography. In this case, color Doppler sonography demonstrated an artery penetrating the mass's hilum, suggesting a lymphatic origin of the lesion, as well as fine accessory peripheral arteries, suggesting malignancy. To our knowledge, there has been no previous report of detailed color Doppler findings in Castleman's disease.
Aged↗
Liver tumors in fatty liver: difficulty in ultrasonographic interpretation.
BACKGROUND: Fatty liver and liver tumors are very frequent diseases. Sonography (US) currently is the initial diagnostic tool for hepatic exploration. However, there is a marked paucity of US findings of tumors in fatty liver. METHODS: We studied the US findings of 41 lesions (31 patients) with this combination, with special attention paid to internal echoes, marginal echoes, and especially the mode of back echoes, and compared them with the US results of 64 lesions (38 patients) without fatty liver. RESULTS: Comparing the group having liver tumor without fatty liver with the group having liver tumor with fatty liver showed that (a) the number of hypoechoic lesions increased (29 of 41, 70.7%, vs. 16 of 64, 25.0.%), (2) the tumor margin appeared indistinct (32 of 41, 78.0%, vs. nine of 64, 14.1%), and (c) the lesions showing posterior echo enhancement increased (34 of 41, 82.9%, vs. eight of 64, 12.5%). CONCLUSION: Liver tumors in fatty liver are expected to show unusual patterns on US, so we should consider this difficulty when interpreting these US findings and we should not make a conclusion without including other imaging modalities.
Adult↗
Splenic lymphoma: differentiation from splenic cyst with ultrasonography.
BACKGROUND AND METHODS: Lymphoma can be nearly anechoic and mimic a cyst on ultrasonography (US). To investigate whether this phenomenon occurs at the level of the spleen, we analyzed the US findings of 38 cases of splenic lymphoma and 16 cases of splenic cyst. RESULTS: (1) With regard to shape, echogenicity of the lesion, and mode of posterior echo, there was no difference between splenic lymphomas and splenic cysts. However, the boundaries of the lesions were indistinct in splenic lymphomas and distinct in splenic cysts. (2) Blood flow signals and vascular penetration were seen exclusively in splenic lymphomas. CONCLUSION: The mode of boundary echo (distinct or indistinct) distinguishes splenic lymphomas from splenic cysts. Color Doppler US increases the diagnostic confidence of US.
Cysts↗
Localized gallbladder carcinoma: sonographic findings.
Our study of color (seven cases) and contrast (three cases) Doppler results of seven cases with gallbladder carcinoma localized in the gallbladder wall (TNM stage T1) showed that the presence or absence of blood flow signals distinguishes gallbladder carcinoma in stage T1b (muscular involvement) from tumefactive biliary sludge and that injection of contrast medium markedly increased diagnostic confidence. Thus, when color Doppler sonography is ambiguous, contrast-enhanced Doppler sonography is the next line of investigation. However, actual color Doppler sonography is still not fully capable of displaying fine blood flow signals from gallbladder carcinoma in stage T1a (mucosal involvement), and greater Doppler sensitivity is mandatory for this purpose.
Carcinoma↗
Renal arteriovenous malformation: sonographic findings.
BACKGROUND AND METHODS: Renal arteriovenous malformation (RAVM) is a relatively rare congenital disease. Although sonography (US) currently is the first diagnostic tool for examining the kidney, its US and color Doppler findings have seldom been reported. We reviewed the clinical manifestations and US results of five cases of RAVM to clarify the role and limitations of US in the diagnosis. RESULTS: The lesions were solitary in all cases, and the affected side was the right in four cases and the left in one case. In four cases, the patients complained of hematuria, but the remaining case had no symptoms. US did not detect the lesion, but in all cases color Doppler US showed a focal vascular lesion with posterior color spots. US reexamination with knowledge of the Doppler results did not show any focal lesion. CONCLUSION: US was not diagnostic for RAVM, and color Doppler US should be performed immediately in patients with hematuria.
Arteriovenous Malformations↗
Segmental chronic cholecystitis: sonographic findings and clinical manifestations.
BACKGROUND: In chronic cholecystitis, the gallbladder (GB) wall is usually evenly involved, whereas marked segmental thickening of the GB wall (segmental cholecystitis) seldom is reported. We wanted to define its clinical manifestations and sonographic (US) findings. METHODS: We reviewed the clinical and US data of 13 cases and compared these results with those of 30 patients with chronic cholecystitis with evenly thickened GB walls (usual-cholecystitis group). RESULTS: (a) All cases of segmental cholecystitis showed the portion distal to the kinking to be markedly thickened. (b) The thickened portion corresponded to the fundus in three cases, the body and fundus in seven cases, and the fundus, body, and infundibulum in three cases; and the thickened distal portion contained many stones in 11 cases. (c) There was no difference in the maximal diameters of the GB walls between the segmental-cholecystitis group and the usual-cholecystitis group. However, there was a significant difference in the minimal diameters of the GB walls between groups. CONCLUSION: Knowledge of the US findings and clinical presentations of segmental cholecystitis can help in the development of appropriate diagnostic and therapeutic strategies.
Adult↗
Emphysematous cholecystitis: sonographic findings.
BACKGROUND: Emphysematous cholecystitis (EC) is a rare but life-threatening complication of acute cholecystitis, and an early diagnosis is required to prevent delay in patient management. Because sonography (US) is the first choice for diagnosing gallbladder diseases, US findings of EC should be understood more precisely. METHODS: We reviewed US findings of 11 surgically proven cases of EC (with small amounts of gas in three cases and large amounts in eight cases) and compared those with patients' clinical data. RESULTS: (1) In cases with small amounts of gas, US showed an echogenic line with a distinct ring-down artifact or a "powder snow-like" speckled posterior echo. (2) In cases with large amounts of gas, US showed a wide spiculated echogenic band with a powder snow-like speckled posterior echo or a speckled acoustic shadowing. In all cases, the presence of gas prevented visualization of the gallbladder wall. (3) US did not differentiate gas localized to the gallbladder wall and gas extending to the surrounding hepatic tissue. (4) Two diabetic cases showed gas throughout the intrahepatic bile ducts. In those cases, the time from diagnosis to recovery was relatively long. CONCLUSION: Our series showed some characteristic US patterns of EC. A good understanding of its US findings and appropriate emergent management will reduce the serious morbidity and mortality rates caused by EC.
Aged↗
Accessory hepatic duct: sonographic findings.
Accessory hepatic ducts are relatively rare biliary anomalies. They have been reported only sporadically, and very few reports have described their sonographic (US) findings. Our experience with two such cases suggested that a diagnosis of an accessory hepatic duct should be considered when US shows a fine tubular structure or an anechoic or hypoechoic oval mass with acoustic shadowing at the level between the hepatic hilus and the common bile duct. A good knowledge of the US findings will determine the diagnostic and therapeutic strategies.
Aged↗
Abdominal lymphoma: differentiation from pancreatic carcinoma with Doppler US.
BACKGROUND: Marked lymphadenopathy around the pancreas due to lymphoma (abdominal lymphoma) occasionally can mimic a total pancreatic carcinoma on ultrasonography (US). We investigated whether US and color Doppler US allowed differentiation between those pathologies. METHODS: We analyzed the US and color Doppler results of 12 cases of abdominal peripancreatic lymphoma and 21 cases of total pancreatic carcinoma. RESULTS: With regard to shape, echogenicity of the lesion, and mode of vascular involvement, there was no difference between groups. With regard to maximal velocities and resistive indices of the involved vessels, there was no difference between groups. However, the presence of turbulent flows in the involved vessels was seen exclusively in the pancreatic carcinoma group. CONCLUSION: The presence or absence of turbulent flow in the involved vessels is a very important finding for differentiating abdominal lymphomas from total pancreatic carcinomas.
Abdominal Neoplasms↗
Retroperitoneal cyst: sonographic findings.
BACKGROUND: Retroperitoneal cyst (RC) is a relatively rare disease, and its sonographic (US) findings have not been analyzed sufficiently. METHODS: We studied US findings of five patients with RC, with special attention to location, size, shape, internal echoes, the presence or absence of lateral shadowing, and the mode of back echoes. RESULTS: In all cases, the cyst was situated behind (four cases) or lateral to (one case) the pancreas: behind or lateral to the pancreatic head in two cases, behind the pancreatic body in one case, and behind the pancreatic tail in two cases. Four cases showed a round mass (three cases) or multiple round mass (one case). Internal echoes were present in those cases and showed a "pseudo-solid" pattern. In those cases, M-mode US confirmed the movement of those internal echoes. In the remaining case, the lesion was imaged as an irregularly shaped multilocular mass. No case showed posterior echo enhancement, and no case showed lateral shadowing. No blood flow signals from the lesion were seen. CONCLUSION: Unlike ordinary cysts, RC usually is imaged as a round mass behind the pancreas, with dense internal echoes without lateral shadowing or posterior echo enhancement, which presents a "pseudo-solid" pattern. A diagnosis of RC should be considered when encountering a mass with such US findings.
Child, Preschool↗
Dilatation of the cystic duct in patients with obstructive jaundice.
BACKGROUND: It is well known that obstructive jaundice causes biliary dilatation, but sonographic (US) findings of the cystic duct in patients with obstructive jaundice are rarely reported. METHODS: We reviewed US findings in 25 such patients. RESULTS: US findings of dilated cystic duct could be divided roughly into two patterns: tortuous and tubular. The former pattern was a tortuously dilated cystic duct arising from the gallbladder neck, running predominantly deeply, turning anteromedially, and then joining the posterior face of the common hepatic duct. The latter pattern was a straight dilated cystic duct running parallel with the common hepatic duct, giving the appearance of a septated bile duct. CONCLUSION: A better understanding of the US findings of dilated cystic duct translates into improved biliary US diagnosis.
Adult↗
Appendiceal mucocele: sonographic findings.
BACKGROUND: Appendiceal mucocele (AM) is a relatively rare disease, and its sonograms (US) have not been sufficiently analyzed. METHODS: We studied the US findings of five patients with AM, with special attention to AM size, shape, internal echoes, and the mode of back echoes. RESULTS: All five cases showed an elongated mass in the lower right abdomen. Internal echoes were present in all cases and M-mode US confirmed the movement of those echoes. The echogenecity of the lesion changed according to the frequency of the transducer used. Only one case showed posterior echo enhancement, and no case showed lateral shadowing. CONCLUSION: AM appears as an elongated echo-poor mass without posterior echo enhancement. The cyst wall is less distinct than what one would expect for a cyst. When encountering such a mass in the lower right abdomen, one should strongly suspect an AM. In such cases, appropriate diagnostic and therapeutic strategies are especially necessary to prevent rupture that results in development of pseudomyxoma peritonei.
Aged↗
Differentiation of exudate from transudate ascites by Doppler sonography.
BACKGROUND: We investigated whether the addition of Doppler sonography (US) increases the diagnostic confidence of US for estimating the nature of ascites. METHODS: Of the 127 cases reviewed in this study, there were 42 cases of transudate and 85 of exudate ascites. We reviewed the US, power Doppler, and pulsed Doppler images of these cases. RESULTS: With US, the transudate ascites was imaged as free of echo in 38 of 42 cases (90.5%). The exudate ascites was imaged as free of echo in 22 of 85 cases (25.9%) and with internal echo spots in 63 of 85 cases (74.1%). With Doppler US, we obtained distinct pulsed signals from the transudate ascites in only two of 36 cases (5.6%). In contrast, we obtained distinct Doppler signals from the exudate ascites in 66 of 79 cases (83.5%). Those 66 cases included 16 of the 22 cases with echo-free ascites. CONCLUSION: The presence or absence of echo spots within the ascites helped differentiate transudate from exudate ascites, as reported in the literature. However, the addition of Doppler US contributed to the differentiation of echo-free exudate (Doppler signals present) from echo-free transudate (Doppler signals absent) ascites.
Abdomen↗