Response to platelet-derived growth factor by phenotypically different cultured human aortic smooth muscle cells

We investigated the effects of PDGF on DNA synthesis and mitogen-activated protein (MAP) kinase activity, and demonstrated that the adult intimal SMC was concentration-dependently stimulated by all PDGF isoforms in terms of both [3H]thymidine incorporation and MAP kinase activation, with PDGF-BB and -AB being more potent than PDGF-AA. The intimal SMCs and the neonatal SMCs showed a similar response with regard to MAP kinase activation. On the other hand, the intimal SMCs expressed many more PDGF receptors than the adult medial SMCs, which expressed a greater amount of PDGF-A chain mRNA and showed a lesser response to PDGFs. These results suggest that the intimal SMCs have a relatively high potential to react to exogenous PDGFs, whereas the adult medial SMCs depend on endogenous or autocrine secretion of PDGF-AA.

Enhancement of phase-contrast MR angiography with superparamagnetic iron oxide

The effect of superparamagnetic iron oxide particles (AMI-227) was assessed in three-dimensional (3D) phase-contrast (PC) MR angiography (MRA), with various scanning parameters for rats at 1.5 T. The blood T1 and T2 before and after 20 micromol Fe/kg of AMI-227 injection were measured sequentially at .47 T. The visualization of abdominal aorta, renal artery, inferior vena cava, and portal vein was respectively evaluated before and after AMI-227 injection qualitatively by the four confidence levels and quantitatively by analysis of signal-to-noise ratio (SNR) of vessels. The blood T1 and T2 were sufficiently shortened for at least 1 hour after AMI-227 injection. The visualization of each vessel was improved by AMI-227 at various velocity encoding (VENC) value, suggesting the extended application of PC-MRA in various conditions. The optimal flip angle was increased from 20 degrees to 30 degrees in higher VENC after AMI-227 injection, resulting in higher signal from blood flow. Quantitative analyses showed that the optimal flip angle to achieve the maximum SNR seemed to be 20 degrees in unenhanced images, but the optimal flip angle of the high speed flow was increased by contrast enhancement. The postcontrast PC-MRA provides the increased sensitivity of slow flow components, even with a high VENC gradient. AMI-227 can significantly improve SNR to blood vessels during 3D-PC-MRA with various scanning parameters.

Pathological study of splenomegaly associated with cadmium-induced anemia in rats

Splenomegaly was observed both in male and female Sprague-Dawley rats after 1 week of exposure to CdCl2 (0.6 mg Cd/kg/day). Spleen weight reached about double that in controls by 8 weeks of Cd exposure. Histopathological examination of the enlarged spleen revealed that iron- and lipid-laden histiocytes were clustered in the periarterial lymphatic sheath, and the red pulp appeared to be expanded. It is noteworthy that electron microscopy revealed marked poikilocytosis and Heinz body formation in red blood cells (RBCs) in both the sinus and cord. Histiocytes were swollen by a granular substance in the cytoplasm and also many secondary lysosomes. These morphological findings indicate that degradation of damaged RBCs induced by exposure to Cd might be promoted in the spleen and possibly cause splenomegaly. This RBC damage-hemolysis-splenomegaly sequence is also considered to be associated with the etiology of Cd-induced anemia. In addition to the abnormal RBC degradation, nuclei of lymphocytes in the Cd-exposed spleen exhibited high electron density, consistent with a preapoptotic state suggesting the immunosuppressive effect of Cd.

Hepatitis C virus NS5A protein is phosphorylated in vitro by a stably bound protein kinase from HeLa cells and by cAMP-dependent protein kinase A-alpha catalytic subunit

Hepatitis C virus (HCV) has a positive-strand RNA genome that codes for a polyprotein precursor, which is processed co- and post-translationally by cellular and viral proteinases into three structural and at least six non-structural (NS) proteins. The NS5A protein, expressed in mammalian cells, exists in two phosphorylated forms of 56-kDa and 58-kDa. In this study, we provide evidence for a stable association between NS5A and a protein kinase from HeLa cells and hepatocellular carcinoma (HepG2) cells by co-immunoprecipitation and by affinity to immobilized glutathione-S-transferase (GST)-NS5A fusion protein produced in E. coli. This protein kinase could phosphorylate in vitro the native NS5A on serine residues, (GST)-NS5A, histone H1, and casein as substrates. In addition, the GST-NS5A was also phosphorylated in vitro by the cAMP-dependent protein kinase A-alpha catalytic subunit.

Angiomyolipoma: imaging findings in lesions with minimal fat

PURPOSE

To investigate a method of diagnosing angiomyolipoma that contains minimal fat.

MATERIALS AND METHODS

In six cases of angiomyolipoma with minimal fat, the attenuation on contrast material-enhanced and unenhanced computed tomographic (CT) images, the echogenicity on sonograms, the signal intensity on T2-weighted magnetic resonance (MR) images, and the gross configuration of the lesion were retrospectively analyzed. In 100 cases of renal cell carcinoma, the same parameters were analyzed, and results were compared with those of angiomyolipoma.

RESULTS

When compared with the surrounding renal parenchyma, all six angiomyolipomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms. Of the five angiomyolipomas examined with MR imaging, four were hypointense and one was isointense on T2-weighted images. All six angiomyolipomas protruded from the renal margin. None of the 100 renal cell carcinomas showed homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, or homogeneous isoechogenicity on sonograms.

CONCLUSION

In the kidney, homogeneously high attenuation on unenhanced CT images, homogeneous enhancement on contrast-enhanced CT images, and homogeneous isoechogenicity on sonograms are suggestive of angiomyolipoma that contains abundant muscle and minimal fat.

The amino terminal deletion mutants of hepatitis C virus nonstructural protein NS5A function as transcriptional activators in yeast

To investigate the biological function of hepatitis C virus (HCV)-NS5A, the NS5A was fused at its N-terminus with the DNA binding domain (DBD) of yeast transcriptional activator GAL4 (GAL4-DBD). The GAL4-DBD alone had no transcriptional activation function. However, a mutant of the GAL4-DBD/NS5A fusion protein, in which 129 amino acid residues were deleted from the N-terminus of NS5A, exhibited strong transcriptional activation in yeast cells, bearing the Escherichia coli lacZ reporter gene encoding the beta-galactosidase under the transcriptional control of GAL4 promoter and TATA box. Further mutational analysis of NS5A revealed that the region between the amino acid residues 130 to 352 were critical for optimal level of transactivation. This region includes two acidic domains and one proline-rich region which have been shown to be involved in the function of several transcriptional activators.

Liver metastases from colon cancer with intra-bile duct tumor growth: radiologic features

PURPOSE

Our goal was to characterize the radiologic features of liver metastases from colon cancer with intrahepatic bile duct (IHBD) dilatation.

METHOD

Radiologic findings of liver metastases from colon cancer with IHBD dilatation of four patients were compared with pathologic findings.

RESULTS

The cause of bile duct dilatation in all cases was due to papillary tumor growth in the bile duct. In two patients, intra-bile duct tumor growth (IBDTG) was observed on imaging. In the other two patients, IBDTG was not observed, but a nontapered abrupt obstruction of a dilated bile duct was seen, corresponding to the microscopically proven papillary tumor growth in the ductal lumen. In three patients who underwent an extensive hepatic resection, there has been no recurrence. In one patient who had a nonanatomic limited resection, a recurrence was seen 1 year after surgery.

CONCLUSION

When liver tumor with IBDTG is suspected on imaging, liver metastases should be considered in the differential diagnosis besides hepatocellular carcinoma or cholangiocellular carcinoma. Careful preoperative assessment for IBDTG by imaging is essential to determine the extent of surgical resection.

Phenotypes of human esophageal squamous cell carcinoma based on matrix metalloproteinase production

We investigated the effects of epidermal growth factor (EGF) and transforming growth factor-beta (TGF-beta) on cell growth and on regulation of matrix metalloproteinases (MMPs) in four cell lines of human esophageal squamous cell carcinomas (TE8, TE9, TE10, and TE11). EGF stimulated the production of proforms of gelatinase B (MMP-9) by three cell lines that could synthesize EGF by themselves, with TE9 being the exception. Particularly, both the production of MMP-9 and DNA synthesis in TE10 were stimulated significantly by EGF. TGF-beta slightly stimulated DNA synthesis in two cell lines, TE9 and TE11, and TGF-beta secretion by TE9 was detected. The production of proforms of gelatinases A (MMP-2) and MMP-9 was gradually induced by TGF-beta in a concentration-dependent manner in all the cell lines except for TE9. Flow cytometric analysis revealed that all the lines expressed both EGF- and TGF-beta-receptors. In conclusion, our present results indicate that at least there are possibly two distinct phenotypes in human esophageal squamous cell carcinoma: one (TE10) depends on autocrine EGF production that enhances DNA synthesis and MMP-9 production; and the other (TE9) on autocrine TGF-beta that stimulates DNA synthesis but not in relation to gelatinase production.

Performance of Gd-EOB-DTPA and superparamagnetic iron oxide particles in the detection of primary liver cancer: a comparative study by alternative free-response receiver operating characteristic analysis

The performance of gadolinium-ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) and superparamagnetic iron oxide (SPIO) particles in detecting liver cancer was compared using alternative free-response receiver operating characteristic (AFROC) analysis, which allowed observers to indicate both the confidence level and the locations of all perceived abnormalities. Axial T1-weighted MR images (1.5 T) pre/post Gd-EOB-DTPA (25 mumol/kg) injection were obtained for 12 rats with chemically induced liver tumors (64 tumors). T2-weighted images (T2WI) were obtained pre/post SPIO (10 mumol/kg) injection for the same animal. Liver signal-to-noise ratio (SNR), tumor-liver contrast-to-noise ratio (CNR), and histopathologic sections corresponding to MR images were obtained. In AFROC, the location and the confidence level for each tumor were indicated independently on MR images by four radiologists. By plotting true-positive fraction and probability of false-positive per image, the area under the AFROC curve (A1) was estimated and statistically analyzed between each sequence. Either drug significantly improved tumor-liver CNR (P < .001) and tumor detection (diameter < or = 6 mm; P < .05). Gd-EOB-DTPA significantly (P < .05) improved the A1 in T1WI. There was no A1 difference between T2WI + SPIO and T1WI + Gd-EOB-DTPA. Gd-EOB-DTPA-enhanced T1WI showed the same performance as SPIO-enhanced T2WI in detecting liver tumors.

Apoptosis induced by cadmium

Cell death resulting from cadmium (Cd) intoxication has been confirmed to occur through apoptosis by morphological and biochemical studies. However it is still not clear whether Cd itself or metallothionein (MT) induced by Cd is the major factor responsible for the apoptosis. Although apoptosis is inducible by exposure of cells to various stimuli, the common pathway involved is generally accepted to be activation of endonucleases that induce internucleosomal cleavage of DNA, resulting in the 'ladder' formation observed upon agarose gel electrophoresis and the chromatin condensation seen by electron microscopy. Cd does not seem to activate the endonuclease in vitro. However, Cd itself can be associated with apoptosis through indirect oxidative stress by inhibition of antioxidant enzymes and possible interaction with zinc finger protein. In addition to the direct effect of Cd, MT appears to play dual roles in apoptosis induction: one as a Cd carrier by which Cd accumulates in the nucleus, and the other as an inhibitor of zinc finger proteins, which include transcriptional factors related to apoptosis such as the product of the apoptosis resistance gene A20. In this review, we demonstrated that the mode of cell death following Cd exposure is associated with intracellular movement of Cd and MT. A possible mechanism for Cd-induced apoptosis is also discussed.

Syringomyelia associated with Hajdu-Cheney syndrome: case report

OBJECTIVE AND IMPORTANCE

Hajdu-Cheney syndrome is a rare idiopathic bone disease based on a generalized bone dysplasia accompanied by acro-osteolysis. We describe a surgical case of this syndrome that was accompanied by neurological signs associated with cervical syringomyelia.

CLINICAL PRESENTATION

A 41-year-old woman was referred to our hospital with mild quadriparesis and sensory disturbance resulting from a car accident. There was a neck injury. She showed almost all of the major characteristic clinical features and roentgenographic findings of Hajdu-Cheney syndrome with syringomyelia.

INTERVENTION

Surgical treatment was indicated because of the progressive neurological deficits. Foramen magnum decompression and C1 laminectomy were performed, and the dura was exposed. The dura was opened at the area of the foramen magnum and C1. The occipitocervical posterior fusion was carried out with an iliac bone graft and titanium wires.

CONCLUSION

Postoperatively, quadriparesis and sensory disturbance improved and the patient showed improved ambulation. Magnetic resonance imaging disclosed the well-decompressed foramen magnum. The syringomyelia disappeared in the segmental area of C2 and was decreased in the segmental areas of C5-T6. The treatment of this syndrome is symptomatic. In this patient, magnetic resonance imaging disclosed compression of the brain stem by basilar invagination and platybasia, disturbance of cerebrospinal fluid flow at the level of the foramen magnum, and syringomyelia. It was suspected that the obstruction of cerebrospinal fluid flow at the level of foramen magnum caused the cervical syringomyelia. However, the long-term prognosis remains uncertain. Follow-up is necessary to assess the final result of the treatment.

Determination of arsenic in blood and stomach contents by inductively coupled plasma/mass spectrometry (ICP/MS)

Inductively coupled plasma/mass spectrometry (ICP/MS) was used and evaluated for the practical analysis of the arsenic content of body fluid samples without ashing. The calibration curve for arsenic in blood solution was shown to have good sensitivity, linearity and reproducibility. Blood obtained from normal volunteers was determined by ICP/MS, and compared with that determined by atomic absorption spectrometry (AAS). The arsenic contents determined by ICP/MS showed a linear correlation with that determined by AAS. Furthermore, arsenic was determined in the blood and supernatant of stomach contents obtained from a suicide autopsy case resulting from ingestion of an arsenic compound. It was therefore concluded that ICP/MS could be used rapidly and conveniently in the field of forensic toxicology in acute metal poisoning cases.

[Early phase II trial of Gd-BOPTA (E7155) for the MR imaging of liver tumors]

A clinical early phase II trial of Gd-BOPTA (E7155) was performed to assess its safety and usefulness for the detection of the hepatic lesions. Seventy-nine patients were assigned to three groups; a low dose group (0.025 mmol/kg), medium dose group (0.05 mmol/kg) and high dose group (0.1 mmol/kg). In terms of safety, Gd-BOPTA was assessed as "safe" in 76 patients and "somewhat questionable" in three patients including one with nausea and two with obvious changes in laboratory findings. No severe adverse reaction was experienced. In terms of the usefulness of dynamic study, the percentage of more than "useful" in the high dose group, medium dose group and low dose group were 100%, 100% and 76.9%, respectively. The result of "usefulness" of early and delayed post-contrast images showed more than "useful" in over 60% of cases. These results indicated that both dynamic and post-contrast early and delayed images were useful for the evaluation of liver tumors, suggesting that this contrast agent would have characteristics of both extracellular and liver-specific contrast agents.

Endometrial stromal sarcoma of the uterus with rhabdoid features

A case of endometrial stromal sarcoma of the uterus with rhabdoid features, occurring in a 57 year old woman is reported. Electron microscopy and immunohistochemistry revealed that the rhabdoid cells contained intermediate filaments which were positive for vimentin, cytokeratin, alpha-smooth muscle actin, and muscle specific actin, but not for myoglobin and desmin. This indicated that the tumor in this case differed somewhat from the three rhabdoid tumors and an endometrial stromal sarcoma with rhabdoid differentiation previously reported and that, therefore, these tumors were heterogeneous.

Apoptosis of human kidney 293 cells is promoted by polymerized cadmium-metallothionein

Transformed human kidney cells (293 cells) exposed to 12.5 to 37.5 microM CdCl(2) showed apoptosis as confirmed by characteristic electron microscopic features, a ladder on gel electrophoresis of extracted DNA, and fragmentation of nucleosomes as detected by enzyme linked immunosorbent assay (ELISA). Higher concentrations of Cd were less effective in inducing apoptosis. Furthermore, addition of the protein extract from the serum-free medium used for Cd-exposure promoted apoptosis exhibiting the same features as that after Cd-exposure. The apoptosis induced by the protein was dose-dependent. The molecular weight of the protein (Cd-protein) was shown to be 40 kDa by gel filtration. Two-dimensional electrophoresis revealed the Cd-protein as a single spot with a molecular weight of 6 kDa and pI of 4.5. Competitive ELISA showed that the Cd-protein reacted with anti-metallothionein antibody. The present findings suggest that apoptosis is induced not only by Cd itself but also by polymerized metallothionein molecules (MT) released from cells into the medium.

[Methicillin-resistant Staphylococcus aureus forming the fried egg appearance colonies isolated from a patient with septicemia]

Slower growing and peculiar colonies, "fried egg" appearance, of different sizes were temporally grown on a sheep blood agar plate from a clinical blood sample obtained from a patient with mediastinitis due to infection by methicillin-resistant Staphylococcus aureus (MRSA) following the graft replacement of thoracic aorta. The organisms revealed morphologically characteristic "fried egg" appearance, mainly Gram-positive cocci including some Gram-negative cells and cell-debris, catalase test positive and coagulase test positive as well as having the identical profiles for S. aureus on biochemical examination with VITEK Systems. The rough surfaced cell walls with unequal thickness of the organisms were observed in an electronmicroscope. According to these bacteriological studies, the organisms were identified as a mutant of S. aureus which had many similarities to staphylococcal L-form. Being resistant to oxacillin, instead of methicillin susceptibility test, and possessing a mecA gene, the organisms were confirmed to belong to MRSA. It is likely that this mutant of S. aureus was induced by a long term medication of sulfamethoxazole-trimetoprim, since the patient had been receiving the drug during 5 weeks when the colonies were first detected.

Mild emphysema: a novel method using formalin-fixed lungs for computed tomography and pathological analyses

We evaluated a novel method of computed tomography (CT) analysis using formalin-fixed lungs of autopsy cases with mild emphysema. Eight formalin-inflated lungs (FILs) obtained at autopsy were examined using CT after draining off the formalin and air inflation with an air pump, and subjected to pathological study including pathological scoring of emphysema and microscopic image analysis (MIA). Satisfactory CT examination was carried out within 5 h of lung fixation. The mean alveolar area determined by MIA correlated highly with the lung volume (r = 0.845) and CT score (r = 0.722). This method is simple compared with conventional polyethylene glycol fixation for CT and enables CT examination of resected lungs without anxiety about biohazards, Mild emphysema can be detected by MIA.

Establishment and characterization of immortalized human coronary endothelial cells

We established an immortalized cell line from endothelial cells derived from a human coronary artery, isolated at autopsy from 76-year-old male, by transfecting the cells with origin-minus simian virus 40 DNA. These cells showed SV40 T antigen in the nuclei and Ulex europaeus I agglutinin and factor VIII-related antigen, as endothelial cell markers, in their cytoplasm. This cell line synthesized prostacyclin, tissue-type plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) as well as produced the proform of matrix metalloproteinase 1, which was activated by cultivating the cells with plasminogen. These findings reveal that this immortalized endothelial cell line retains characteristics of human coronary endothelial cells, indicating that this cell line is useful for studying atherogenesis of the coronary artery.

Expression of the histamine H1 receptor gene in relation to atherosclerosis

Histamine in serum and arterial tissue contributes to the pathogenesis of atherosclerosis and the formation of coronary artery vasospasm. As the effect of histamine at a given site will be mediated by its specific receptors, we investigated by in situ hybridization and Northern blot analysis the expression and localization of human histamine H1 receptor mRNA in the arterial wall and in cultured human aortic intimal smooth muscle cells (SMC) and immortalized SMC (ISS10) and endothelial cells (SE1). In situ hybridization showed that SMC and endothelial cells expressed H1 receptor mRNA in vivo and that the expression was increased in SMC in the thickened intima of atherosclerotic foci in both the aorta and coronary artery. By Northern blot analysis, we also detected histamine H1 receptor mRNA in cultured SMC, ISS10, and SE1 and found that platelet-derived growth factor stimulated SMC to increase their expression of the mRNA in vitro. These results suggest that up-regulation of histamine H1 receptor expression by platelet-derived growth factor plays an important role in the initiation and progression of cardiovascular diseases.

Ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules

A rare case of ovarian mucinous cystadenocarcinoma with sarcoma-like mural nodules is reported. Macroscopically, nodular or granular lesions were scattered over the inner surface of a huge, multilocular tumor in the left ovary. The histopathological features were consistent with those of previously documented cases, except significant squamous metaplasia in the present case. The pleomorphic sarcoma-like cells showed a positive reaction for vimentin and alpha-antichymotrypsin but were negative for carcinoembryonic antigen and common epithelial membrane antigen by immunohistochemistry. Electron microscopically, the tumor cells had neither desmosomes nor secretory granules, but they possessed abundant intermediate filaments. Both immunostaining and ultrastructure suggested that the sarcoma-like nodules were derived from reactive proliferation of fibrohistiocytic cells. The fibrohistiocytic reaction seemed to occur in response to hemorrhage, because hemorrhage was reported to be associated with the mural nodules in most of the previous cases as well as ours.

Immunopathological mechanisms of human T cell lymphotropic virus type 1 (HTLV-I) uveitis. Detection of HTLV-I-infected T cells in the eye and their constitutive cytokine production

The immunopathology of human T cell lymphotropic virus type 1 (HTLV-I) uveitis was addressed by using T cell clones (TCC) established from the intraocular fluid of patients with HTLV-I uveitis. Proviral DNA of HTLV-I was identified in 55 out of 94 (59%) or 13 out of 36 (36%) TCC from the ocular fluid or the peripheral blood of these patients, respectively. Most of HTLV-I-infected TCC had a CD3+ CD4+ CD8- phenotype. HTLV-I infection on TCC was confirmed by analysis of the viral mRNA, nucleotide sequence, virus-associated proteins, and virus particles. HTLV-I-infected TCC, but not HTLV-I negative TCC, constitutively produced high amounts of IL-6 (1,336 +/- 1,050 pg/ml) and TNF-alpha (289 +/- 237 pg/ml) in the absence of any stimuli. HTLV-I-infected TCC from the ocular lesion also constitutively produced high amounts of IL-1 alpha (12,699 pg/ml), IL-2 (61 pg/ml), IL-3 (428 pg/ml), IL-8 (1,268 pg/ml), IL-10 (28 pg/ml), IFN-gamma (5,095 pg/ml), and GM-CSF (2,886 pg/ml). Hydrocortisone, a drug effective in vivo for the treatment of HTLV-I uveitis, severely depressed cytokine production in vitro in most cases. In summary, the results demonstrated direct evidence of HTLV-I infection of the eye and suggest that cytokines produced by HTLV-I-infected T cells are responsible for the intraocular inflammation in patients with HTLV-I uveitis.

[CT anatomy of the caudate lobe of the liver]

The anatomy of the portal vein branches in the caudate lobe of the liver was studied in 20 patients by double-phase CT arterial portography (DP-CTAP). DP-CTAP provided excellent images of the portal venous system in the first phase and the perfusion defects of intrahepatic tumors in the second phase. From DP-CTAP images of the first phase, a sufficient number of interpolated images were created for a smooth paging display. The ramifying structures of the portal system were traced on the monitor using the tracking ball. This method was found to be very effective and reliable for the anatomical assessment of the caudate lobe. The number and origins of the caudal portal branches were investigated in each case, and the caudate lobe of the liver could be divided into right and left segments.

Ambient pressure stimulates immortalized human aortic endothelial cells to increase DNA synthesis and matrix metalloproteinase 1 (tissue collagenase) production

In the present study, we investigated the effect of ambient pressure on [3H]-thymidine incorporation and on the production of matrix metalloproteinase 1 (tissue collagenase/proMMP-1) using human aortic endothelial cells immortalized with simian virus 40 (SE-1). Incubation of cells at ambient pressures of 50 and 100 mmHg for 24 h slightly increased [3H]-thymidine incorporation when directly compared with normal culture conditions. The amount of [3H]-thymidine incorporated in SE-1 reached a maximum at 150 mmHg, while a further increase in pressure to 200 mmHg decreased incorporation. The same ambient pressure slightly stimulated human aortic intimal smooth muscle cells (SMC) to increase [3H]-thymidine incorporation but not medial SMC. Immunoblot analysis also showed that ambient pressure, ranging from 50 to 200 mmHg, like 12-O-tetradecanoyl-phorbol-13-acetate stimulated SE-1 to produce proMMP-1, an effect not seen with either intimal or medial SMC. The amount of proMMP-1 produced also reached a maximum level at 150 mmHg. We postulate that human endothelial cells are ambient pressure sensitive and that relatively lower ambient pressures play an important role in the growth of endothelial cells, while higher pressures injure endothelial cells, resulting in the initiation of atherosclerosis. This cell line may prove useful in the investigation of both the physiological and pathological roles of blood pressure on endothelial cell function.

Effects of spatial distribution on proton relaxation enhancement by particulate iron oxide

The proton relaxation effect of superparamagnetic iron oxide (SPIO) particles under varying conditions of spatial distribution was investigated with use of phantoms. Agar phantoms containing various concentrations of SPIO or gadopentetate dimeglumine, with and without Sephadex beads, were studied. Phantoms with Sephadex had a heterogeneous spatial distribution of iron oxide, comparable to liver tissue in vivo. Relaxometry at 0.47 T showed decreased T2 relaxivity of SPIO in Sephadex phantoms compared with that in agar phantoms without Sephadex. On T2-weighted images obtained at 1.5 T, the signal intensity of Sephadex phantoms showed less SPIO relaxation effect than that of plain agar phantoms. Unlike SPIO, gadopentetate dimeglumine showed the same relaxivities and signal intensity in plain agar and Sephadex phantoms. The results show that the T2 relaxation effect of iron oxide depends on its spatial distribution. A heterogeneous spatial distribution, as in intact liver tissue, diminishes the T2 relaxivity of iron oxide particles.

The receptor, metabolism and effects of androgen in osteoblastic MC3T3-E1 cells

We investigated the androgen receptor (AR), metabolism and effects of androgens in osteoblastic MC3T3-E1 cells. AR was proved as a transcript of a 10-kb mRNA and as a 110-kDa protein. An immunocytochemical study showed that AR was located mainly in the nuclei. Specific binding of [3H]DHT was observed in both the nuclear and cytosol fractions. MC3T3-E1 cells possessed approximately 1190 binding sites per cell and most of the sites (1150 sites) situated in the nucleus. The apparent Kd value in the nuclear fraction was 1.35 nM for [3H]DHT binding, and it was similar to that for [3H]testosterone. In the competition analysis, there was not much difference in the displacement of the [3H]DHT binding from AR between the addition of radioinert DHT and testosterone. In studies of 5 alpha-reductase activity and aromatase activity of the cells, both activities were lower than the respective values in classical androgen target tissues. Androgens stimulated the incorporation of [3H]thymidine into the cell, and DHT and testosterone had a similar potency on the cell proliferation. Thus, these results suggest testosterone itself acts mainly on the osteoblasts without conversion to DHT.

Time after excision and temperature alter ex vivo tissue relaxation time measurements

Previously unreported effects of tissue storage were recently observed in the authors' experimental magnetic resonance (MR) studies. To evaluate the effect of elapsed time after excision and storage temperature on tissue relaxation time measurements, tissue samples from the liver, pancreas, kidney, testis, spleen, and brain were obtained in rats. T1 and T2 were first measured within 5 minutes of excision, and between subsequent measurements, tubes were kept in a water bath at 40 degrees C, at room temperature (28 degrees C), or in an ice bath (4 degrees C). Cellular and organellar integrity was assessed with electron microscopy and correlated with the MR findings. At 40 degrees C (20-MHz spectrometer), the T1 of liver decreased from 280 msec +/- 8 to 212 msec +/- 10 during the first 60 minutes; the T1 of pancreas decreased from 276 msec +/- 3 to 208 msec +/- 2. Other tissues showed less than a 5% decrease in T1. T2 changes were smaller than T1 changes in all tissues. Electron microscopy of pancreatic acinar cells showed postmortem changes in mitochondria evolving over the first 60 minutes after death. Manganese loading experiments implicated mitochondrial manganese stores in the observed enhanced postmortem decrease in T1. This study calls into question reported relaxation time data for liver and pancreas. MR studies of excised tissues must account for time and temperature to prevent systematic experimental errors.

Foreign-body granuloma mimicking an extrahepatically growing liver tumor: report of a case

We herein describe a 74-year-old woman with a foreign-body granuloma mimicking a liver tumor. Imaging studies revealed a pedunculated left lobe mass in the setting of chronic liver disease. She had a past history of a cholecystectomy as well as a previous gynecological operation. A left lateral segmentectomy was performed because of the possibility of a rupture. The dissected specimen showed a foreign-body granuloma caused by gauze. We believe this case to be a very unique granuloma, which should be kept in mind whenever making a diagnosis of a liver tumor particularly in a patient with chronic liver disease, who has a past history of abdominal surgery.

Contrast-enhanced MR imaging of diffuse and focal splenic disease with use of magnetic starch microspheres

The diagnostic value of magnetic starch microspheres (MSM), a new superparamagnetic contrast agent, was studied in experimental models of diffuse and focal splenic disease in rats by means of ex vivo relaxometry and in vivo magnetic resonance (MR) imaging. Owing to small differences in unenhanced T1 and T2 values between diffuse lymphoma and normal spleen, MR imaging failed to distinguish tumor-bearing animals from control animals by signal-to-noise ratios (SNRs) obtained with T1- and T2-weighted spin-echo sequences. One hour after injection of 20 mumol/kg MSM, lymphomatous spleen showed significantly (P < .001) reduced enhancement relative to normal splenic tissue. As a result, animals with diffuse lymphoma (SNR: 10.3 +/- 1.7) could be easily differentiated from control animals (SNR: 5.5 +/- 0.6) on T2-weighted (TR msec/TE msec = 2,000/45) images. In focal splenic disease, MSM produced normal enhancement of nontumorous splenic tissue, whereas relaxation times of tumors were not different before and after contrast agent injection. On T2-weighted images (2,000/45), the tumor-spleen contrast-to-noise ratio increased from 4.8 +/- 1.6 to 21.8 +/- 1.9 (+354%), improving conspicuity of splenic tumors. The results show that MSM-enhanced MR imaging improves the detection of diffuse and focal splenic disease.

Enhanced tumor detection in the presence of fatty liver disease: cell-specific contrast agents

It is assumed that hepatobiliary, cell-specific contrast agents will be adversely affected by the presence of diffuse liver disease. The diagnostic efficacy for tumor detection in the presence of fatty liver disease was experimentally studied at contrast-enhanced magnetic resonance (MR) imaging with manganese-DPDP (N,N'-dipyridoxylethylenediamine-N,N'-diacetate 5,5'-bis[phosphate]) and gadobenate dimeglumine (Gd-BOPTA/dimeg) and compared with conventional and chemical shift imaging. Carcinosarcoma was implanted into the liver of rats, and fatty liver was induced with L-ethionine. Without contrast agents, the tumor-fatty liver contrast-to-noise ratio (C/N) was increased on T1-weighted and decreased on T2-weighted MR images relative to tumor-bearing control rats without fatty liver. Chemical shift imaging (phase-contrast method) increased the tumor-fatty liver C/N from 2.3 +/- 1.0 to 6.1 +/- 1.7 (P < .001). Mn-DPDP and Gd-BOPTA/dimeg increased the tumor-fatty liver C/N from -5.4 +/- 1.6 to -11.0 +/- 1.9 and -9.8 +/- 3.4, respectively (P < .001). The hepatobiliary, cell-specific contrast agents were equally effective in both fatty and non-fatty liver and outperformed both chemical shift and conventional MR imaging in detecting liver tumors.

Cytopathological changes induced by cadmium-exposure in canine proximal tubular cells: a cytochemical and ultrastructural study

A highly sensitive cytochemical method for demonstrating intracellular Cd using 8-hydroxyquinoline was developed and applied in the cytopathological study of primary-cultured renal tubular cells from beagle kidneys. The Cd-8-hydroxyquinoline emitted a yellowish-green fluorescence which first appeared in the cytoplasm within 30 min and in the nucleus about 60-90 min after exposure to 100 mM CdCl2. It was noteworthy that intranuclear Cd was stained in the nucleolar regions. The sensitivity of the cytochemical method for Cd was estimated to be about 1.0 pg Cd/cell. Ultrastructural features of the dead cells were consistent with those of apoptosis. We conclude that Cd absorbed by proximal tubular cells rapidly reaches to the nuclei and affects nuclear as well as cytoplasmic metabolism.

Evaluation of hepatocyte-specific paramagnetic contrast media for MR imaging of hepatitis

The hepatocyte-specific paramagnetic magnetic resonance (MR) contrast agents manganese-DPDP [N,N'-dipyridoxylethylenediamine-N,N'-diacetate 5,5'bis-(phosphate)] and gadobenate dimeglumine were used for diagnosing chemically induced hepatitis in rats. Ex vivo liver tissue relaxation times and in vivo MR image signal-to-noise ratios were compared before and after contrast agent administration. Ex vivo relaxometry and in vivo MR imaging showed that Mn-DPDP enhanced normal and diseased livers to the same degree at all time points from 5 to 120 minutes. Gadobenate dimeglumine showed reduced T1 and T2 enhancements in hepatitis relative to those of normal liver, in the early phase (5-30 minutes). However, these effects are offsetting, and as a result, MR imaging failed to allow distinction of diseased from normal livers. This surprising result observed in vivo was in fact predicted by applying the Bloch equation to our ex vivo data. Our results show that detection and quantitation of hepatitis with MR imaging enhanced with paramagnetic cell-specific contrast agents will be more difficult than anticipated.

Cell death and regeneration of renal proximal tubular cells in rats with subchronic cadmium intoxication

Male Sprague-Dawley rats were injected subcutaneously with 0.6 mg cadmium (Cd)/kg/day for 8 wk. The subsequent changes in renal proximal tubules were studied histologically, histochemically, and ultrastructurally. The urinary and tissue Cd concentrations were determined by atomic absorption spectrophotometry. After 4 wk of exposure, apoptosis was observed predominantly in segment S3 along with epithelial regeneration in the affected tubules, and these changes gradually became more pronounced as the experimental period was prolonged. The apoptotic cells were shed into the lumen and were found to contain a large quantity of Cd. Apoptotic cells were counted in paraffin sections after various periods of exposure to Cd. Nuclear bromodeoxyuridine uptake, mitotic count, and nuclear density were used as indicators of tubular regeneration. A correlation was found between the numerical increase of apoptotic cells and the rate of urinary Cd excretion, and the rate of increase in the tissue Cd concentration had a tendency to reduce after 4 wk as the rate of urinary Cd increased. These observations suggest that apoptosis might be helpful for the efficient excretion of Cd into urine. Progressive increases in the preceding indicators of regeneration were observed. From our results, it appears that Cd-induced tubular damage, i.e., cell deletion due to apoptosis, is reversible as a result of marked epithelial regeneration. On the basis of these histological changes, the critical concentration of Cd required to produce renal tubular damage was estimated to be 600 micrograms/g dry tissue.

A combined occurrence of neuroendocrine carcinoma of the skin and a benign appendageal neoplasm

A 76-year-old Japanese male presented with a subcutaneous nodule in the dorsal cubital region of the right arm. The center of the nodule showed typical features of neuroendocrine carcinoma of the skin. The peripheral portion showed epithelial islands of squamoid cells with horn cysts suggestive of benign appendageal tumor with pilar differentiation. The coexistence of two skin neoplasms in the same lesion would suggest that both tumors developed from common pluripotential stem cell.

Orally administered manganese chloride: enhanced detection of hepatic tumors in rats

To evaluate its potential as a tissue-specific hepatobiliary magnetic resonance (MR) contrast agent, manganese chloride was orally administered to rats in increasing doses of 100-1,500 mumol/kg MnCl2, and the relaxation times of liver, pancreas, kidney, and heart were measured with ex vivo relaxometry and in vivo MR imaging. Two hours after ingestion of 200 mumol/kg MnCl2, liver T1 was decreased by 48%, whereas tumor T1 decreased by only 9%. On spin-echo MR images, the signal-to-noise ratio in liver increased by 54%; the contrast-to-noise ratio in tumor, by 375%. The T1 of pancreas, kidney, and heart decreased by 8%, 23%, and 13%, respectively. At subjective assessment, the signal intensity of the upper gastrointestinal tract was reduced, likely because of the high concentration of manganese in the lumen, and delineation of the intestine from other abdominal structures was improved. These results indicate that orally administered MnCl2 causes substantial, reproducible, and tissue-specific enhancement of liver. Because enhancement of tumor was minimal, orally administered MnCl2 may potentially be used to improve detection of hepatic tumors.

Enhancement of tumor-liver contrast-to-noise ratio with gadobenate dimeglumine in MR imaging of rats

The efficacy for tumor detection of the hepatocyte-specific contrast agent gadobenate dimeglumine (gadolinium-BOPTA/Dimeg) was evaluated in four different experimental tumor models in rats. Histologic findings were correlated with quantitative data derived from ex vivo relaxometry and in vivo magnetic resonance (MR) imaging. Noninfiltrating tumors showed maximal enhancement of liver parenchyma 5-10 minutes after contrast agent administration, with a plateau over the next 30 minutes. In contrast, infiltrating tumors, which caused hepatocellular injury and inflammatory changes, delayed maximal enhancement of tumor-free parenchyma by 15-20 minutes. Nonspecific tumor enhancement depended on tumor vascularity and occurred in the early phase after contrast agent administration. Despite differences in specific enhancement of tumor-free parenchyma and nonspecific tumor enhancement, tumor-liver contrast-to-noise ratios increased 96%-248% in all tumor models 30 minutes after intravenous administration of 75 mmol/kg Gd-BOPTA/Dimeg. Gd-BOPTA/Dimeg enhanced tumor conspicuity independently of the histologic characteristics of the tumor.

Bladder tumor staging: comparison of conventional and gadolinium-enhanced dynamic MR imaging and CT

With computed tomography (CT) and unenhanced magnetic resonance (MR) imaging, stage pT3b extravesical extension and beyond can be diagnosed, but tumors confined to the bladder wall (stages pT1-pT3a) are poorly delineated. To determine whether visualization of such tumors could be improved with gadolinium-enhanced MR imaging, dynamic breath-hold T1-weighted MR images were obtained after intravenous infusion of 0.1 mmol/kg gadopentetate dimeglumine in 79 patients (86 tumors). Conventional MR images, CT scans, and histologic correlation were available in all cases. With dynamic gadolinium-enhanced MR imaging, the mucosa could be distinguished from the muscular layers of the bladder wall. Staging accuracy with this technique was 85% (73 of 86), which was significantly better than with CT (55%; 47 of 86) (P < .005) or conventional MR imaging (58%; 50 of 86) (P < .05). The accuracy of staging the intramural extent (pT1-pT3a) of bladder tumors was thus improved with gadolinium-enhanced dynamic MR imaging.

Diagnosis of fatty liver with MR imaging

The diagnosis of fatty liver with magnetic resonance (MR) imaging was evaluated in experimental rat models of simple fatty infiltration and fatty liver with hepatocellular injury. T1 and T2 were measured ex vivo and correlated with the histologic degree of fatty infiltration. Enhancement of fatty liver with four different cells-specific contrast agents was studied with ex vivo relaxometry and in vivo MR imaging. Quantitative analysis of conventional and chemical shift MR images was correlated with biochemically determined fat content of the liver. Diet-induced simple fatty infiltration of the liver caused a decrease in T1 of 15%, whereas the T1 of L-ethionine-induced fatty liver with hepatocellular injury increased by 12%. T2 showed a positive correlation with the degree of fatty infiltration in both models. Cell-specific hepatobiliary contrast agents showed the same liver uptake and relaxation enhancement in fatty livers as in normal livers. Conventional T1-weighted images and chemical shift images showed good correlation (r = .83 and .80, respectively) between signal intensity and the degree of fatty infiltration. However, only chemical shift imaging was reliable in the diagnosis of fatty liver.

[Percutaneous transluminal angioplasty for stenotic dialysis arterio-venous fistulas]

From December 1982 to January 1991, we performed fistulography on 40 patients who complained functional failure of arterio-venous dialysis fistula. And percutaneous transluminal angioplasty (PTA) was attempted on 15 patients (19 times) who revealed marked fistula stenosis. Initial successful rate was 78.9% and patency rate was 56.2% in the first 6 months. (75% in the first 6 months when angioplasty was initially successful). We describe the method of fistulography and PTA for stenotic dialysis fistulas, and evaluate the usefulness of PTA. And also we introduce our attempts for improving the initial successful rate and patency rate. In conclusion, when dialysis arterio-venous fistula is stenotic but not occlusive, PTA should be considered first before surgical treatment is done.

Systemic necrotizing vasculitis with renal involvement accompanied by remarkable eosinophilia: a case with overlapping features of polyarteritis nodosa and allergic granulomatous angiitis

A 71-year-old woman was clinically suspected of allergic granulomatous angiitis (AGA) because of preceding allergic diseases including bronchial asthma, remarkable eosinophilia (14,300/mm3), mononeuritis multiplex, positive rheumatoid factor, elevated serum immunoglobulin E, and eosinophilic inflammation of the kidney. Autopsy findings, however, were characterized of polyarteritis nodosa (PAN). Necrotizing angiitis was present in several organs except for the lung; focal and segmental glomerular lesions with crescent formation were observed in the kidney, and granuloma formation was not found. This case may be an intermediate type between PAN and AGA (an overlap syndrome) and provide useful information on the clinical entities of systemic necrotizing vasculitis.

Efficacy of gadolinium-diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging for differentiation between superficial and muscle-invasive tumor of the bladder: a comparative study with computerized tomography and transurethral ultrasonography

Gadolinium-labeled diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) was evaluated in an effort to clarify whether MRI could replace or be proved to be superior to computerized tomography (CT) and/or transurethral ultrasonography. A total of 57 bladder cancer patients was evaluated. MRI was performed with a superconducting magnet operating at 1.5 Tesla. The images acquired were multisections, having a fast spin-echo pulse sequence of less than a 14-second breath holding. Serial scans were performed before and immediately after Gd-DTPA venous injection. The findings on different imaging techniques were compared with the histological stagings. A proper diagnosis was made in 42 of 57 cases (73.7%) by Gd-DTPA-enhanced MRI, in 27 of 57 (47.4%) by CT and in 31 of 57 (54.4%) by transurethral ultrasonography when comparing the histological findings. The sensitivity and specificity for differentiating superficial and muscle-invasive tumor of each imaging method were, respectively, 96.2 and 83.3% in Gd-DTPA-enhanced MRI, 96.0 and 58.3% in CT, and 88.0 and 66.7% in transurethral ultrasonography. These data suggest that the staging of bladder cancer by Gd-DTPA-enhanced MRI appears to be superior and more accurate than the staging obtained by CT and transurethral ultrasonography.

Pathological study on beagles after long-term oral administration of cadmium

Histopathological, histochemical, and electron microscopic examinations were performed on beagles after a long-term oral cadmium (Cd) administration of greater than 8 years. Although renal atrophy was remarkable in groups receiving doses of 50 and 100 mg/kg body weight/day, bone lesions could not be demonstrated by roentgenological and histopathologic examination. It was noticed that concomitant regeneration or recovery and cell death of the epithelium occurred in the proximal convoluted tubules. The cell death was consistent with apoptosis, a special feature of cell death, which was shown to play a major part in the tubular damage of cadmium by electron microscopic examination. Fatty degeneration of the pars recta tubules was seen to show dose-dependence. The intrarenal cadmium was localized predominantly in the cytoplasm of the proximal tubular epithelium by histochemical and ultracentrifugal cell fractionation examinations. Although no remarkable changes were found in the other organs, aggregates of siderophages in the liver and focal hemorrhage in the spleen, known as spontaneous lesions, might be related to Cd intoxication. In conclusion, the present study revealed that no bone lesions occur with Cd administration in adult beagles in spite of long-term administration. An excessive cell death to regeneration or recovery in the proximal tubules might result in the renal cortical atrophy. No remarkable changes were seen in the glomeruli and distal nephrons, which were in good agreement with Cd distribution.

[Imaging diagnosis of genitourinary tract tumors]

Recent advance of imaging technique have brought great advantages for management of genitourinary tract tumors. We described few examples of changes in this field from our experience. Many asymptomatic masses are discovered in the kidney and adrenal gland associated with wide clinical application of CT and US. In the kidney, the greater part of incidental masses are renal cell carcinomas (RCC) and the rate of such cases has been increasing. When small RCC is diagnosed without any clinical symptoms, better survival would be expected. Many adrenal incidental mass are also discovered by routine use of CT for abdominal workup. Since greater part of these masses are benign nonfunctioning adenomas, correct diagnosis should be made in order to avoid inappropriate surgery. Rapid development of MR also resulted in some changes in the diagnosis of urinary tract tumors. However, MR cannot be used as a screening method. For staging of RCC, intravascular or adjacent organ invasion was well determined with MR compared with CT. Differentiation of adrenal carcinomas from nonfunctioning adenomas is suggested by the difference of signal intensity on T2 weighted images. Fast spin echo scan with GD-DTPA enhancement is new MRI technique separating bladder mucosal layer from muscle layer as hyper-intensity area. Using this method, diagnostic accuracy of deep muscle invasion for bladder tumor would be improved.

Multiple primary cancers in a case of chronic arsenic poisoning--an autopsy report

This is an autopsy report of multiple primary cancers observed in a patient who had clinically been diagnosed as chronic arsenic poisoning. An 88-year-old man, non-smoker, had worked in an arsenic mine for 6 years from the age of 47. He had undergone operations for Bowen's disease and gastric cancer at ages 80 and 86, respectively. At autopsy, squamous cell carcinoma of the lung and a polypoid lesion in the piriform recess were found. Furthermore, microscopic examination revealed latent prostatic adenocarcinoma and oncocytoma in the kidney. The polypoid lesion of the piriform recess appeared to originate from the duct of the minor salivary gland in the pharynx, showing an adenoid cystic carcinoma-like pattern with squamous cell carcinoma in part. The cause of death was thought to be respiratory failure due to bronchopneumonia and pulmonary edema as well as hydrothorax, and chronic heart failure following ischemic heart disease. Bowen's disease was followed by four internal malignant tumors, even though the etiological relation between these cancers and arsenic is not clear.

[Magnetic resonance imaging of bladder tumors: superiority of serial "Fast SE" assisted by Gd-DTPA in tumor staging]

Eighteen cases with bladder tumors were examined by means of superconducting MRI. Sequences used were spin echo (TR/TE (msec) = 500/20 as T1WI (weighted image) and 1500/80 as T2WI) and serial "fast spin echo (fast SE)" pre/post Gd-DTPA administration. "Fast SE" was a new technique offering a distinct T1WI (TR/TE = 100/14, utilizing a 14 second breath hold). Slice thickness of "fast SE" was 10 mm and slice plane was selected perpendicular to the tumor base to detect the extent of invasion. Serial scan of "fast SE" was performed before and immediately after 0.1 mmol/kg Gd administration. Scanning was completed before the bladder was opacified by Gd. Tumor and normal mucosa were both markedly enhanced whereas the surrounding muscle layer remained hypointense. On delayed scan, the elevated character of the tumor was outlined by opacified urine but the distinction between the mucosa and the muscle layer became unclear. Total cystectomy (TC) was performed in 6 of 18 cases and pathological tumor extension was correlated with MR findings. Transurethral resection (TUR) was performed in the remaining 12 patients, and the tumor extension was assessed by follow-up biopsy after TUR. Intact liner hypointensity indicated superficial lesions (= less than pT2), while disruption of the linear hypointensity corresponded pathologically to deep muscle invasion (= greater than pT3a). Accuracy of serial "fast SE" in tumor staging was 94% (17/18). Serial "fast SE" allowed the distinction of superficial from invasive tumors more accurately than conventional studies, and therefore assisted in choosing the correct operative method.

Diffuse pleural rhabdomyosarcoma with persistent pleural effusion

A unique case of embryonal rhabdomyosarcoma arising at the left pleura of a 7-year-old Japanese girl is reported. The present case was characterized by persistent pleural effusion, and the malignant cells incidentally found in it were the first diagnostic clue. The tumor showed a rare growth pattern involving diffuse thickening of the parietal pleura. Biopsy of the thickened parietal pleura upon thoracotomy revealed embryonal rhabdomyosarcoma largely composed of immature mesenchymal cells. Immunohistochemical demonstration of creatinine phosphokinase-MM was most helpful among several types of immunostain for the histopathological diagnosis. Ultrastructurally, thin filaments with primitive Z bands could be seen in some tumor cells. Intensive clinical examination revealed only diffuse thickening of the parietal pleura, which was reduced by chemotherapy. This is the first documented case of rhabdomyosarcoma arising at the pleura. Previous reports of rhabdomyosarcoma arising at unusual sites are reviewed and the histogenesis of this tumor is briefly discussed.