Hepatobiliary and pancreatic: cystic liver lesion in a man with abdominal pain.
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Publications and source records attributed to J K Han.
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We have utilized the differential display PCR method to isolate transcripts expressed during early embryogenesis of Xenopus laevis. Among many transcripts that have been found to be expressed differentially during the development, one transcript which was expressed predominantly in the unfertilized egg, was isolated as a full-length cDNA and the sequence was determined. This cDNA contained a predicted size of 198 amino acids. A search of the GenBank database revealed that the predicted amino acid sequence of the cDNA is highly homologous-87.8% identical-to the recently identified human protein, HsYKT6, a prenylated vesicle associated-SNARE ((soluble NSF (N-ethylmaleimide-sensitive fusion protein) attachment protein receptor)). Thus we have named the gene as Xsnare1. RT-PCR analysis showed that the Xsnare1 mRNA expressed throughout the oogenesis, in egg and in the early phase of embryogenesis and the level of expression declined after gastrulation. These results suggest that the Xsnare1, a maternally active, putative Xenopus homologue of prenylated v-SNARE, is a developmentally regulatory gene and may be play a role in the process of the early development of Xenopus laevis.
The identification of the initial signaling events induced by progesterone in Xenopus oocyte maturation was approached by expressing serotonin receptors and by using pharmacological agents. Suppression of phospholipase C (PLC) activity in oocytes by U-73122 or stimulation of oocyte adenylyl cyclase (ACase) by forskolin inhibited progesterone-induced reinitiation of meiotic cell division. Microinjection of cAMP-dependent protein kinase (PKA) pseudosubstrate, PKI, into oocytes--or pretreatment of oocytes with PKA inhibitor, H-89--did not induce oocyte maturation, but both treatments potentiated the rate of progesterone-induced germinal vesicle breakdown (GVBD). In addition, reduced PKA activity by H-89 reversed the inhibition of GVBD caused by U-73122. Expression and activation of the serotonin receptor type 1a or type 2c lowered intracellular cAMP level or mobilized Ins(1,4,5)P3, respectively. These oocytes, however, did not undergo maturation upon serotonin stimulation. Co-expression of these receptors also did not trigger maturation, but it significantly accelerated the rate of GVBD induced by progesterone. From these data, we conclude that (1) changes in levels of these second messengers may well be coupled with progesterone signaling; (2) an initial decrease in cAMP and production of Ins(1,4,5)P3/DG may not be absolute requisites for progesterone-induced meiotic maturation: (3) cross-talk mechanisms between adenylyl cyclase and phosphoinositide signal transduction pathways may exist in the process of progesterone-induced reinitiation of meiotic cell cycle.
In Xenopus oocytes, both sphingosine-1-phosphate (S1P) and lysophosphatidic acid (LPA) activate Ca2+-dependent oscillatory Cl- currents by acting through membrane-bound receptors. External application of 50 microM S1P elicited a long-lasting oscillatory current that continued over 30 min from the beginning of oscillation, with 300 nA (n = 11) as a usual maximum peak of current, whereas 1-microM LPA treatment showed only transiently oscillating but more vigorous current responses, with 2,800 nA (n = 18) as a maximum peak amplitude. Both phospholipid-induced Ca2+-dependent Cl- currents were observed in the absence of extracellular Ca2+, were blocked by intracellular injection of the Ca2+ chelator, EGTA, and could not be elicited by treatment with thapsigargin, an inhibitor of endoplasmic reticulum (ER) Ca2+ ATPase. Intracellular Ca2+ release appeared to be from inositol 1,4,5-trisphosphate (IP3)-sensitive Ca2+ store, because Cl- currents were blocked by heparin injection. Pretreatment with the aminosteroid, U-73122, an inhibitor of G protein-mediated phospholipase C (PLC) activation, to oocytes inhibited the current responses evoked both by S1P and LPA. However, when they were injected with 10 ng of antisense oligonucleotide (AS-ODN) against Xenopus phospholipase C (PLC-xbeta), oocytes could not respond to S1P application, whereas they responded normally to LPA, indicating that the S1P signaling pathway goes through PLC-xbeta, whereas LPA signaling goes through another unknown PLC. To determine the types of G proteins involved, we introduced AS-ODNs against four types of G-protein alpha subunits that were identified in Xenopus laevis; G(q)alpha, G11alpha, G0alpha, and G(i1)alpha. Among AS-ODNs against the G alphas tested, AS-G(q)alpha and AS-G(i1)alpha to S1P and AS-G(q)alpha and AS-G11alpha to LPA specifically reduced current responses, respectively, to about 20-30% of controls. These results demonstrate that LPA and S1P, although they have similar structural features, release intracellular Ca2+ from the IP3-sensitive pool, use different components in their signal transduction pathways in Xenopus oocytes.
RATIONALE AND OBJECTIVES: Tumor vascularity is useful for characterizing tumors and determining tumor management. The recent development of power Doppler sonography has enhanced the sensitivity of color Doppler imaging in the detection of blood flow because of low power noise and less angle dependence. The purpose of this study was to compare the capability of color and power Doppler sonography with that of microangiography for showing tumor vascularity of VX2 carcinoma. METHODS: Color and power Doppler sonography was performed on VX2 carcinomas in the rabbit thighs, and their findings were correlated with those of microangiography. For qualitative analysis, tumor vascularity was categorized into four items including distribution of tumor vessels, crowdedness of vessels, small vessels, (> or = 0.1 mm), and micro-vessels (< 0.1 mm). Tumor blood flow signals of color Doppler sonography and power Doppler sonography were graded as 3, 2, 1, and 0 and were compared with tumor vascularity on microangiography. For quantitative analysis, percentages of tumor vascular area per tumor area on each study were compared. RESULTS: The mean scores of tumor vascularity on power Doppler sonography were 2.87, 2.73, 2.93, and 2.73 in tumor vascular distribution, crowdedness of vessels, small vessels, and micro-vessels, respectively. Those on color Doppler sonography were 2.4, 2.2, 2.8, and 1.67, respectively. Power Doppler sonography was statistically superior to color Doppler sonography in displaying tumor vascular distribution (P < 0.05) and micro-vessels (P < 0.01). The means and medians of percentages of tumor vascular area per tumor area were 22.7% and 23.5% on microangiography, 17.9% and 21.4% on color Doppler sonography, and 36.4% and 34.7 % on power Doppler sonography, respectively. Percentages of tumor vascular area per tumor area on both color Doppler sonography (r = 0.70) and power Doppler sonography (r = 0.84) were well correlated with those on microangiography. CONCLUSIONS: Power Doppler sonography can demonstrate the tumor vascularity on microangiography relatively well, however, it tends to overestimate the blood flow signals. Color Doppler sonography may have some limitations in imaging tumor vascular distribution and micro-vessels and tends to underestimate tumor vascularity, but can display the blood flow direction. Therefore, power Doppler and color Doppler sonography could complement each other in demonstrating the tumor vascularity.
PURPOSE: To determine if a tiny enhancing dot is characteristic of small hemangiomas with low attenuation during the hepatic arterial phase (HAP) and portal venous phase (PVP) of two-phase spiral computed tomography (CT). MATERIALS AND METHODS: Among 249 consecutive patients with 377 hemangiomas who underwent two-phase spiral CT (performed 30 and 65 seconds after the start of injection), 34 hemangiomas in 20 patients were less than 2 cm in diameter, had low attenuation during the HAP and PVP, and showed characteristic findings on dynamic contrast material-enhanced magnetic resonance (MR) images. The CT scans were retrospectively reviewed for tiny enhancing dots and correlated with the MR images. RESULTS: Tiny enhancing dots were found in 26 of 34 hemangiomas (76%). The dots were seen during the HAP and PVP in 15 lesions (58%) and during the PVP alone in 11 lesions (42%). The lesions showed a tendency toward slow fill-in at MR imaging (only four lesions completely filled with contrast material within 5 minutes). The dots seen at CT corresponded to the initial enhancing area at MR imaging. CONCLUSION: Small hemangiomas with persistent low attenuation at two-phase spiral CT can be diagnosed with the "bright dot" sign.
PURPOSE: To determine the two-phase (hepatic arterial phase [HAP] and portal venous phase [PVP]) spiral computed tomographic (CT) findings of a nontumorous arterioportal shunt in the cirrhotic liver that can mimic a hypervascular tumor. MATERIALS AND METHODS: For 14 months, 803 patients with known or suspected hepatocellular carcinoma were referred for initial or repeated transcatheter arterial chemoembolization (TACE). Twenty-nine hyperattenuating lesions on HAP CT images obtained in 25 patients (23 men, two women; age range, 39-70 years) were regarded as nontumorous arterioportal shunts and were included in this study. The diagnosis of nontumorous arterioportal shunt was established by four radiologists who reviewed the two-phase spiral CT images and hepatic angiograms. RESULTS: The longest dimension of the lesion was 1.0-7.9 cm (mean dimension, 2.9 cm). The morphology at HAP CT was wedge-shaped in 25 (86%), geographic (ie, focal area with irregular outline) in two (7%), and nodular in two (7%) lesions. All lesions were homogeneous in attenuation. Hyperattenuating linear branching structures that represented early opacification of portal veins were demonstrated during the HAP in nine (31%) lesions. PVP CT images showed these lesions as isoattenuating (n = 20 [69%]) or slightly hyperattenuating (n = 9 [31%]). Iodized oil CT images showed faint or no accumulation of iodized oil in all lesions. CONCLUSION: In cirrhotic liver, nontumorous arterioportal shunts can be a cause of pseudolesions that mimic hypervascular tumors at two-phase spiral CT. Lesions that have the typical wedge-shaped and homogeneous appearance with or without internal linear branching structures during the HAP and that are isoattenuating or slightly hyperattenuating during the PVP can suggest this unusual condition.
PURPOSE: To investigate the value of contrast material-enhanced power Doppler ultrasonography (US) in the demonstration and characterization of tumor vascularity in hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty patients with HCC were prospectively evaluated with power Doppler US before and after injection of the contrast agent SH U 508 A. The grade and pattern of tumor vascularity at power Doppler US were analyzed, along with the degree of tumor staining at angiography. RESULTS: Intra- and peritumoral flow signals were detected in 19 HCCs (95%) at unenhanced power Doppler US. After injection of contrast agent, flow signals increased in 19 lesions (95%). At contrast-enhanced power Doppler US, two tumors demonstrated grade 1 vascularity; four, grade 2; three, grade 3; and 11, grade 4. At angiography, two tumors demonstrated grade 1 staining; four, grade 2; eight, grade 3; and six, grade 4. The correlation between vascularity grades at contrast-enhanced power Doppler US and at angiography was statistically significant (P < .0001). Seventeen HCCs (85%) showed the intratumoral or basket pattern of vascularity at unenhanced power Doppler US; after injection of contrast material, 15 HCCs (75%) showed the mixed pattern. CONCLUSION: Contrast-enhanced power Doppler US is superior to unenhanced power Doppler US in the demonstration and characterization of tumor vascularity in HCC.
OBJECTIVE: The risk of hepatocellular carcinoma is increased with benign obstruction of the hepatic inferior vena cava (IVC). The purpose of this study was to assess the usefulness of combined interventional treatment for benign obstruction of the hepatic IVC associated with hepatocellular carcinoma. MATERIALS AND METHODS: In a retrospective review of 51 patients with benign obstruction of the hepatic IVC, hepatocellular carcinoma was detected in 15 patients coincidentally or during the follow-up period. Obstruction of the IVC was treated with percutaneous transluminal balloon angioplasty in five patients and metallic stent placement in two patients. Immediate postprocedural and follow-up venacavography was performed to evaluate the effectiveness of this interventional management. Hepatocellular carcinomas were managed with transcatheter chemoembolization in all 15 patients using an emulsion of 3-12 ml of an iodized oil and 20-50 mg of doxorubicin hydrochloride. Gelfoam embolization was performed in three patients. Transcatheter chemoembolizations were repeated in seven patients. Initial response and long-term response to treatment were evaluated by monitoring the level of serum alpha-fetoprotein and by follow-up CT and angiography. RESULTS: During the follow-up period (1-8 years), the IVC was widely open except in one patient who developed moderate stenosis. Clinical symptoms of vena caval obstruction disappeared in all patients. After initial transcatheter chemoembolization, complete remission of the tumor occurred in six patients and partial remission occurred in seven patients. Five of the seven patients who underwent further chemoembolizations remained unchanged or in remission. CONCLUSION: Radiologic interventional treatment plays a significant role in managing both kinds of lesions in patients with benign obstruction of the hepatic IVC complicated by, hepatocellular carcinoma. A follow-up regimen should be designed to detect small hepatocellular carcinoma as early as possible after obstruction of the hepatic IVC is diagnosed.
In this report, we have carried out mRNA in situ hybridization analysis to study the pattern of expression of the fibroblast growth factor-2 (FGF-2) gene during chick development. The expression pattern of FGF-2 was compared to that of the fibroblast growth factor-1 (FGF-1) gene to further assess a possible role of the FGF-2 during chick embryogenesis. The whole embryos of various stages were examined with 35S-labeled riboprobes transcribed from the coding regions of chick FGF-2 and FGF-1 cDNAs. We show that the distribution pattern of FGF-2 mRNA was highly specific. The FGF-2 transcripts were localized to limb mesenchymes, pharyngeal regions, and embryonic kidneys in day 3 to day 6 chick embryos. However, no FGF-1 mRNA was detected in these structures indicating a unique role of FGF-2 in chick development. These results support the hypothesis that FGF-2 may be a crucial signaling molecule during chick embryogenesis.
A cDNA clone encoding a WD-40 repeat protein (BGB1) was characterized in Brassica napus L. The clone contained an open reading frame of 327 amino acid residues almost entirely composed of seven segments of WD-40 repeats. Among the WD-40 repeat proteins, BGB1 showed high similarity (63% identity) to a rat intracellular receptor for protein kinase C (RACK1) that functions in the translocation of activated protein kinase C (PKC) from the cytosolic fraction to the membrane fraction. BGB1 also had two sequence motifs involved in binding of RACK1 to PKC. The cDNA clone, when carried in a Xenopus oocyte expression vector and injected into Xenopus laevis oocytes, inhibited insulin-induced maturation of the oocytes, a PKC-mediated pathway, and this inhibition was accompanied by reduction of PKC in the membrane fraction, as in the case of mammalian RACKs. The data show that BGB1 shares some common functional characteristics with the mammalian RACK1 along with the structural similarity, suggesting that a mammalian RACK1-related cellular process might be operating in plants. Southern blot analyses of the genome of B. napus and Arabidopsis thaliana (L.) Heynh. revealed that BGB1-related genes constitute a small multigene family in both species. An approximately 1.4-kb transcript was constitutively expressed in all organs examined.
PURPOSE: The purpose of this study was to evaluate the usefulness of dynamic spiral CT, including multidimensional reformation, in the detection and localization of islet cell tumors of the pancreas. MATERIAL AND METHODS: Seven patients with histopathologically proven functioning islet cell tumors of the pancreas were studied with 2-phase contrast-enhanced spiral CT. Scanning of the arterial phase and late phase was started 30 s and 180 s, respectively, after injection of 100 ml of contrast medium at a rate of 3 ml/s. RESULTS: Axial images in the arterial phase depicted the lesions in 5 patients, but in the late phase in only one patient. Multiplanar reformatted images of the arterial phase depicted the lesions in all 7 patients. Maximal intensity projection images demonstrated all lesions with information of their relationship to the vascular structure. CONCLUSION: Dynamic spiral CT with scanning during the arterial phase and retrospective multidimensional reformation is useful for preoperative detection and localization of small islet cell tumors of the pancreas.
PURPOSE: To compare conventional spin-echo (SE) sequences with T2-weighted turbo SE and serial gadolinium-enhanced T1-weighted FLASH sequences in the detection and characterization of hepatic hemangiomas, and to describe the enhancement characteristics of the lesions on dynamic MR imaging. MATERIAL AND METHODS: Forty-two patients with 66 hemangiomas were studied at 1.0 T or 1.5 T by using conventional SE sequences (T1-weighted, T2-weighted, and heavily T2-weighted), T2-weighted turbo SE sequences, and breath-hold T1-weighted FLASH sequences acquired before, immediately after, and 1, 2, 3, 5, and 10 min after injection of a bolus of gadopentetate dimeglumine. Images were quantitatively analyzed for lesion-to-liver contrast-to-noise (C/N) ratios, and qualitatively analyzed for lesion conspicuity. The enhancement pattern and the rapidity of enhancement were analyzed in small (<15 mm), medium (15-39 mm), and large (>39 mm) hemangiomas. RESULTS: In T2-weighted images, T2-weighted turbo SE and heavily T2-weighted SE images had higher C/N ratios than T2-weighted SE images (p=0.003). Lesion conspicuity was not significantly different in these 3 sequences (p=0.307). In T1-weighted images, T1-weighted FLASH images had higher C/N (p<0.001) and also better lesion conspicuity (p<0.001) than T1-weighted SE images. Immediate uniform enhancement was seen in 43% of small hemangiomas (9 of 21 lesions), and persistent central hypointensity was seen in 73% of large hemangiomas (11 of 15 lesions). Rapid enhancement was seen in 62% of small hemangiomas (13 of 21 lesions) and in 31% of medium or large hemangiomas (14 of 45 lesions). CONCLUSION: Further clinical study is needed for evaluating the differential diagnostic advantages of turbo SE T2-weighted imaging compared to the calculation of T2-values by means of a SE T2-weighted sequence. However, the results of the present study suggest that T2-weighted turbo SE imaging and precontrast and serial gadolinium-enhanced FLASH imaging have the potential to replace conventional SE imaging in the evaluation of hepatic hemangiomas.
PURPOSE: To determine characteristic features of peripheral cholangiocarcinoma on two-phase spiral computed tomographic (CT) scans. MATERIALS AND METHODS: Thirty-four patients with peripheral cholangiocarcinoma underwent two-phase spiral CT. Hepatic arterial phase and portal venous phase images were obtained 30 and 65 seconds, respectively, after the start of contrast material infusion. RESULTS: Thin, mild, incomplete rimlike contrast enhancement at the tumor periphery was seen on CT scans from both phases in 23 patients. Thick, continuous rimlike contrast enhancement and marked homogeneous contrast enhancement were present on scans in four patients and one patient, respectively. No definite contrast enhancement pattern was seen on scans in six patients. Other findings included increased lobar or segmental hepatic attenuation in adjacent normal liver during the arterial phase (n = 10), markedly low attenuation with amorphous areas of slightly high attenuation in the tumor during both phases (n = 33), internal septumlike linear structures (n = 8), narrowing or obstruction of the portal vein as it traversed the tumor (n = 16), and a patent hepatic vein (n = 4). CONCLUSION: Thin, mild, incomplete rimlike contrast enhancement at the tumor periphery and markedly low intratumoral attenuation with amorphous areas of slightly high attenuation during both scanning phases are typical findings of peripheral cholangiocarcinoma.
OBJECTIVE: The objective of this study was to compare the capability of arterial, portal venous, and delayed phases of helical CT with that of iodized-oil CT for revealing nodular hepatocellular carcinomas. MATERIALS AND METHODS: Forty-eight patients with nodular hepatocellular carcinomas underwent triphasic helical CT examination with 10-mm collimation at 10-mm/sec table speed. We injected 120 ml of contrast material (36 g of iodine) at the rate of 3 ml/sec. Arterial-phase, portal venous-phase, and delayed-phase images were obtained with 30-sec, 65-sec, and 360-sec delays, respectively. All 48 patients also underwent angiography and intraarterial infusion of iodized oil after helical CT; iodized-oil CT was performed about 2 weeks after infusion of iodized oil. Helical CT images were compared with iodized-oil CT images for revealing hepatic nodules. RESULTS: In 48 patients, 79 hepatocellular carcinomas were seen with iodized-oil CT. Using helical CT, the arterial phase revealed 68 lesions (86%), the portal venous phase revealed 53 lesions (67%), and the delayed phase revealed 57 lesions (72%). The arterial phase proved superior to the portal venous and delayed phases for revealing lesions (p = .0025). The portal venous phase showed no significant difference for revealing lesions compared with the delayed phase. When combined, helical CT of the arterial and portal venous phases revealed 73 lesions (92%); a combination of the arterial and delayed phases revealed 72 lesions (91%); and a combination of the portal venous and delayed phases revealed 63 lesions (80%). Any combination of two phases that included the arterial phase proved superior to the combination of the portal venous and delayed phases (p = .0033). Overall, the combination of the arterial and portal venous phases (92%) or the combination of all three phases (92%) proved best at revealing lesions. CONCLUSION: The arterial phase of helical CT is better for revealing nodular hypervascular hepatocellular carcinoma than are the portal venous and delayed phases. The combination of the arterial and portal venous phases is superior to the arterial phase alone. Also, the combination of the arterial and portal venous phases is equal to the combination of the three phases for revealing hypervascular hepatocellular carcinomas.
OBJECTIVES: We compared the ability of preoperative abdominal computed tomography (CT) with that of preoperative abdominal ultrasonography (US) in predicting the extent of tumor growth and the curative resectability of gastric cancer. METHODS: Abdominal CT and US were done in 95 patients with gastric adeno-carcinoma. The radiologic findings were prospectively compared with surgical and pathologic findings. RESULTS: The sensitivities of abdominal CT and US in detecting the perigastric lymph node involvement were 26.6% and 20%, respectively. The sensitivity of abdominal CT in predicting the pancreatic invasion (60%) was better than that of abdominal US (20%). However, there were 6 false positive diagnosis of pancreatic invasion by abdominal CT; in contrast, there was no false positive diagnosis of pancreatic invasion by abdominal US. Of 95 patients who underwent surgical exploration, 14 were found to have unresectable tumors because of extragastric organ involvement and distant metastases. Abdominal CT falsely predicted 8 of 14 cases in which curative gastric resection was impossible as resectable. Moreover, abdominal CT falsely predicted 5 of 81 cases in which curative gastric resection was possible as unresectable. Abdominal US falsely predicted 12 of 14 cases in which curative surgery was impossible as resectable. CONCLUSION: Preoperative abdominal Ct and US did not accurately predict the tumor extent and the curative resectability of the gastric cancer. Especially, abdominal CT finding of pancreatic invasion by gastric cancer should not be a contraindication for surgical exploration.
PURPOSE: This study was undertaken to elucidate characteristic findings of tuberculous (TB) colitis at double-contrast barium enema examination (DCBE). MATERIALS AND METHODS: Twenty-five patients with TB colitis diagnosed by biopsy (n = 13) or therapeutic trial (n = 12) were included. DCBE findings were retrospectively analyzed, with special emphasis on distribution of lesions and mucosal changes. RESULTS: Involvement was asymmetric in 12. The lesion was noted more commonly in the ascending colon (n = 23), cecum (n = 21), and terminal ileum (n = 19) compared with the transverse colon (n = 15) and descending and sigmoid colon (n = 9). Skipped lesions were seen in 13 patients. Sixteen patients had multiple ulcers that were mostly transverse or circumferential in alignment (n = 11). Depth of ulcers was superficial (< 2 mm) in 9 patients and deep in 13. Two patients had fistulas. Twelve patients had inflammatory polyposis. Three patients presented with mass, and misdiagnosis of malignant tumor was made in two. Thickening, deformity, and incompetence of the ileocecal valve were frequently noted (5, 6, and 8, respectively). CONCLUSION: DCBE revealed detailed mucosal changes of TB colitis. Ulcers aligned in transverse or circumferential pattern, involvement of the right side colon, and deformity of the ileocecal valve suggest diagnosis of TB colitis.
Fasciola hepatica is a trematode of herbivorous mammals, and man is infected by accidental ingestion of contaminated raw aquatic vegetables or water. There have been many reports on computed tomographic and cholangiographic features of human fascioliasis. However, findings of magnetic resonance (MR) imaging have not been reported. Hepatic fascioliasis produces three types of lesions in MR images arranged in tract-like fashion. The outermost area presents as an iso-signal area in T1WI, with slightly higher signal intensity in T2WI and diffuse enhancement after i.v. contrast. The second type presents as a well defined low signal area in T1WI, not enhanced, and also shows low signal intensity in T2WI. The third type has low signal intensity in T1WI, is not enhanced, and has high signal intensity in T2WI which is similar to fluid-containing inflammatory lesions such as pyogenic abscess. These findings suggest various changes associated with traumatic hepatitis caused by the migration of the worm in the liver. This diverse signal intensity can be a suggestive finding of fascioliasis.