Detection of occult metastatic lymph nodes in the neck with gray-scale and power doppler us

Purpose: To determine the most accurate criterion for predicting malignancy of small cervical lymph nodes with gray-scale ultrasound (GSUS) and power Doppler ultrasound (PDUS).

Material and Methods: Findings of 69 pathologically verified cervical nodes (38 benign, 31 malignant) in 57 patients without wide echogenic hilum on GSUS that measured less than 10 mm in minimal axial diameter were prospectively studied. Minimal and maximal axial diameters, ratios of minimal to maximal axial diameters, and presence or absence of calcification or necrosis of the nodes were assessed. On PDUS, vascularity in the node was classified into 4 pattern groups. A logistic model was used to evaluate the significant factors for predicting malignancy.

Results: The logistic model revealed that the minimal axial diameter and vascularity patterns were the only significant factors for malignancy. Using the minimal axial diameter, a node larger than 8 mm showed the highest accuracy (73%) with 45% sensitivity and 93% specificity. Of the vascularity patterns, spotted or peripheral pattern had the highest accuracy (80%) with 61% sensitivity and 93% specificity. A combined criterion of the minimal axial diameter larger than 8 mm and spotted or peripheral pattern increased the accuracy to 82% and sensitivity to 77% but specificity decreased to 86%.

Conclusion: A combined criterion of minimal axial diameter and vascular patterns was most accurate for diagnosing occult metastatic lymph nodes in the neck.

MR imaging of the lingual thyroid: Comparison to other submucosal lesions

Purpose: To study MR findings for clues to the diagnosis of lingual thyroid.

Material and Methods: MR findings and clinical and scintigraphic data of 5 cases of lingual thyroid were reviewed and the MR findings were compared to those of 16 cases of other submucosal lesions in the base of the tongue.

Results: Four of the 5 patients with lingual thyroid were women and all had hypothyroidism. MR imaging depicted lingual thyroid in the midline in the base of the tongue (n=5) and additional ectopic thyroid glands in the floor of the mouth (n=2) or between the right and left sternohyoid muscles (n=1). Ectopic thyroid glands appeared isointense or hyperintense relative to muscle tissue on T1-weighted images and showed slight or fair contrast enhancement. All glands had low to intermediate T2 signal, which was also seen in 1 case of non-Hodgkin's lymphoma and 1 case of adenoid cystic carcinoma. All ectopic thyroid glands had well-defined margins, whereas malignant tumors tended to have ill-defined margins and to invade the surrounding structures. All but the 5 cases of lingual thyroid had an MR-demonstrable thyroid gland in the normal cervical position.

Conclusion: A well-defined mass of low-intermediate T2 signal in the midline base of the tongue, neither with invasive tendency nor with a cervical thyroid gland in the normal site on MR imaging, may strongly indicate lingual thyroid.

Oxidative stress, advanced glycation end product, and coronary artery calcification in hemodialysis patients

Coronary artery calcification is an index of the severity of atherosclerotic vascular disease, and may predict future adverse cardiovascular events in uremic patients undergoing hemodialysis (HD). HD patients are exposed to oxidative stress, and show high plasma levels of advanced glycation end products (AGEs). The association between oxidative stress, AGEs, established cardiovascular risk factors, and coronary artery calcification score (CACS) was studied in 225 HD patients (123 male, 102 female patients). CACS was measured by using multi-detector row computed tomography. Age, systolic blood pressure, calcium, calcium x phosphate, malondialdehyde, lipid peroxides, and pentosidine were significantly and positively correlated with CACS. Duration on HD tended to be positively correlated with CACS. From the independent variables included in the forward stepwise multiple linear regression analysis, only age, systolic blood pressure, lipid peroxides, calcium, and pentosidine were independently associated with CACS. The odds ratios for past history of coronary artery disease and the presence of diabetes mellitus for high CACS (> or =100) were 6.25 (95% confidence interval; 1.83-21.4) and 2.03 (95% confidence interval; 1.02-4.05), respectively. The plasma pentosidine was significantly and positively correlated with indoxyl sulfate. In conclusion, in addition to such traditional cardiovascular risk factors as past history, diabetes mellitus, aging, systolic blood pressure and calcium overload, oxidative stress (lipid peroxides), and AGE (pentosidine) are associated with extensive coronary artery calcification in HD patients. Lipid peroxidation and glycoxidation may be involved in the pathogenesis of coronary artery calcification.

Innervation and functional changes in mesenteric perivascular calcitonin gene-related peptide- and neuropeptide Y-containing nerves following topical phenol treatment

We have previously shown that age-related reduction of innervation and function in mesenteric perivascular calcitonin gene-related peptide-containing vasodilator nerves takes place in spontaneously hypertensive rats. The present study was performed to investigate innervation and functional changes in perivascular calcitonin gene-related peptide- and adrenergic neuropeptide Y-containing nerves after topical treatment with phenol, which damages nerve fibers, around the rat superior mesenteric artery. Under pentobarbital-Na anesthesia, 8-week-old Wistar rats underwent in vivo topical application of phenol (10% phenol in 90% ethanol) or saline (sham rats) to the superior mesenteric artery proximal to the bifurcation of the abdominal aorta. After the treatment, the animals were subjected to immunohistochemistry of the 3rd branch of small arteries proximal to the intestine and to vascular responsiveness testing on day 3 through day 14. The innervation levels of calcitonin gene-related peptide-like immunoreactivity containing fibers and neuropeptide Y-like immunoreactivity containing fibers were markedly reduced on day 3 to day 14 and on day 5 to day 14 after the treatment, compared with those in sham-operated rats, respectively. In perfused mesenteric vascular beds isolated from phenol-treated rats, adrenergic nerve-mediated vasoconstriction and calcitonin gene-related peptide nerve-mediated vasodilation in response to periarterial nerve stimulation (2-12 Hz) were significantly decreased on day 3 and day 7. Neurogenic release of norepinephrine in phenol-treated rats on day 7 was significantly smaller that that in sham-operated rats. Nerve growth factor content in the mesenteric arteries of phenol-treated rats was significantly lower than that in sham-operated rats. Administration of nerve growth factor using osmotic mini-pumps for 7 days after the phenol treatment resulted in greater density of calcitonin gene-related peptide- and neuropeptide Y-like immunoreactivity fibers than in phenol-treated rats and restored decreased vascular responses to periarterial nerve stimulation. These results suggest that topical phenol-treatment of the mesenteric artery effectively induces functional denervation of perivascular nerves, which can be prevented or reversed by nerve growth factor treatment.

Possible link between glycolysis and apoptosis induced by sodium fluoride

Fluoride has been used to prevent caries in the dentition, but the possible underlying mechanisms of cytotoxicity induction by this compound are still unclear. Since fluoride is known as an inhibitor of glycolytic enzymes, we investigated the possible connection between NaF-induced apoptosis and glycolysis in human promyelocytic leukemia HL-60 cells. NaF-induced apoptotic cell death is characterized by caspase activation, internucleosomal DNA fragmentation, loss of mitochondrial membrane potential, and production of apoptotic bodies. Higher activation of caspases-3 and -9, as compared with that of caspase-8, suggested the involvement of an extrinsic pathway. Utilization of glucose was nearly halted by NaF, whereas that of glutamine was rather enhanced. NaF enhanced the expression of Bad protein, but not that of Bcl-2 and Bax proteins, and reduced HIF-1alpha mRNA expression. Analysis of these data suggests a possible link between glycolysis and apoptosis.

MR imaging of primary malignant lymphoma in the larynx

We present MR findings in a patient with primary laryngeal lymphoma. The MR images showed a homogeneous mass in the right supraglottic larynx extending to the true vocal cord through the paraglottic space, of which signal intensity was intermediate both on T1- and T2-weighted images. The tumor was moderately enhanced and preserved mucosal layers were demonstrated as hyperintense bands on gadolinium-enhanced fat-suppressed T1-weighted images. Primary laryngeal lymphoma should be included in the differential diagnosis for a homogeneous solid mass in the supraglottic submucosal area.

Prognostic significance of magnetic resonance findings in advanced papillary thyroid cancer

We assessed the prognostic importance of magnetic resonance (MR) findings in locally advanced papillary thyroid cancer. MR findings, clinical data, and pathologic (and surgical) data for 66 patients, including 51 women and 15 men with a mean age of 57 years, who had primary surgery for papillary thyroid cancers were correlated with prognosis. Mean follow-up was 27.5 months (range, 5-117 months). Recurrence was seen in 18 patients (27%). In univariate analyses, age of 60 years or more (p = 0.0066), male gender (p = 0.0373), six MR findings (tumor size of > or = 4 cm ([p = 0.0002], ill-defined margins ([p < 0.0001], tumor extension of the trachea [p = 0.0337], carotoid artery [p = 0.0028]), esophagus [p < 0.0001], and lymph nodes [p = 0.0005]), and three pathologic findings (tumor extension of soft tissues [p = 0.0288], carotid artery [p = 0.0013], and esophagus [p < 0.0001]) had a significant adverse effect on disease-free survival. In multivariate analyses, tumor size (p = 0.0169) and nodal metastasis (p = 0.0393) determined on MR imaging and pathologic esophageal invasion (p = 0.0016) were the only significant independent variables. Esophageal invasion was accurately diagnosed with MR imaging (94% accuracy). MR findings may contain prognostic importance of locally advanced papillary thyroid cancer.

Tracheal invasion by thyroid carcinoma: prediction using MR imaging

OBJECTIVE

The purpose of this study was to evaluate the accuracy of MR imaging in predicting tracheal invasion by thyroid carcinomas and to determine MR imaging criteria for diagnosing tracheal invasion.

MATERIALS AND METHODS

MR imaging was performed on the normal trachea of one cadaver and 30 healthy subjects as a standard of reference. Then, MR imaging findings in 67 patients with thyroid carcinoma were reviewed and correlated with surgical and pathologic findings. A logistic regression model was used to determine which MR imaging features were significant for predicting tracheal invasion.

RESULTS

Twenty-three (34%) of the 67 patients had tracheal invasion. Logistic regression model analysis revealed that significant MR characteristics for determining tracheal invasion included soft-tissue signal in the tracheal cartilage (p < 0.001), intraluminal mass (p < 0.001), and degree of tumor circumference around the trachea (p = 0.001). The highest accuracy (90%) for determining tracheal invasion was achieved using a combination of findings. A case was considered positive for tracheal invasion if there was soft-tissue signal in the cartilage, an intraluminal mass, or a tumor that abutted a circumference of the trachea of 180 degrees or greater. Using these factors resulted in seven false-positive diagnoses because soft-tissue signal in the cartilage was sometimes seen in healthy trachea. Although intraluminal mass invariably reflected deep tracheal invasion, soft-tissue signal in the cartilage rarely indicated actual cartilage invasion but rather indicated tumor extension between the cartilaginous rings.

CONCLUSION

Tracheal invasion by thyroid carcinomas can be accurately diagnosed with MR imaging, and using a combination of criteria is the most accurate method of predicting this phenomenon.

Sonographic detection of secondary MALT lymphoma of the submandibular gland

This report describes a case of mucosa-associated lymphoid tissue (MALT) lymphoma of the lacrimal glands that recurred in the submandibular salivary glands. Gray-scale sonography showed small hypoechoic nodules, measuring less than 0.5 cm in diameter, in both submandibular glands. The echogenicity and echotexture of the rest of the submandibular glands and of the parotid glands was normal. Power Doppler sonography revealed increased vascularity within the nodules. A sonographically guided aspiration biopsy of the nodules revealed MALT lymphoma. Secondary MALT lymphoma should be considered in the presence of multiple small hypoechoic nodules in the salivary glands in patients with a history of MALT lymphoma at another location.

Head and neck lesions: characterization with diffusion-weighted echo-planar MR imaging

PURPOSE

To evaluate whether apparent diffusion coefficients (ADCs) calculated from diffusion-weighted echo-planar magnetic resonance (MR) images can be used to characterize head and neck lesions.

MATERIALS AND METHODS

Diffusion-weighted echo-planar MR imaging was performed with a 1.5-T MR unit in 97 head and neck lesions in 97 patients. Images were obtained with a diffusion-weighted factor, factor b, of 0, 500, and 1,000 sec/mm(2), and an ADC map was constructed. The ADCs of lesions, cerebrospinal fluid, and spinal cord were calculated.

RESULTS

Acceptable images for ADC measurement were obtained in 81 (84%) patients. The mean ADC of malignant lymphomas, (0.66 +/- 0.17[SD]) x 10(-3) mm(2)/sec (n = 13), was significantly smaller (P <.001) than that of carcinomas. The mean ADC of carcinomas, (1.13 +/- 0.43) x 10(-3) mm(2)/sec (n = 36), was significantly smaller (P =.002) than that of benign solid tumors. The mean ADC of benign solid tumors, (1.56 +/- 0.51) x 10(-3) mm(2)/sec (n = 22), was significantly smaller (P =.035) than that of benign cystic lesions, (2.05 +/- 0.62) x 10(-3) mm(2)/sec (n = 10). No significant differences were seen in the mean ADC of cerebrospinal fluid and of spinal cord among four groups of lesions. When an ADC smaller than 1.22 x 10(-3) mm(2)/sec was used for predicting malignancy, the highest accuracy of 86%, with 84% sensitivity and 91% specificity, was obtained.

CONCLUSION

Measurement of ADCs may be used to characterize head and neck lesions.

Parotid masses: prediction of malignancy using magnetization transfer and MR imaging findings

OBJECTIVE

We determined the most accurate criteria for predicting malignancy of masses in the parotid gland using magnetization transfer ratios.

SUBJECTS AND METHODS

Lesion-to-muscle magnetization transfer ratios obtained with a spoiled gradient-recalled acquisition in a steady state sequence with a 1-kHz off-resonance pulse were measured in 72 parotid masses (52 benign lesions, 20 malignant tumors). Various MR imaging findings and lesion-to-muscle magnetization transfer ratios were simultaneously assessed using a logistic model to determine the useful factors for predicting malignancy. We also studied the clinical usage of magnetization transfer ratios.

RESULTS

Of the MR imaging findings, poorly defined margins showed the highest accuracy, 81%, with 60% sensitivity and 88% specificity. Of the lesion-to-muscle magnetization transfer ratios, a ratio of greater than 0.71 was most accurate (85%), with 90% sensitivity and 83% specificity. All four recurrent tumors and 10 (91%) of 11 secondary tumors were correctly diagnosed using the magnetization transfer ratio analysis. The logistic model revealed that the margin characteristics (p = 0.084) and lesion-to-muscle magnetization transfer ratios (p < 0.001) were statistically significant predictors for malignancy. A combined criteria of poorly defined margins and a lesion-to-muscle magnetization transfer ratio of greater than 0.71 raised the accuracy to 86% and specificity to 96%, but the sensitivity decreased to 60%.

CONCLUSION

A combination of MR imaging findings and lesion-to-muscle magnetization transfer ratios was the most accurate predictor of malignancy.

Effect of endotoxin-induced reactive oxygen species on sperm motility

OBJECTIVE

To define the mechanism of infection-induced damage of sperm.

DESIGN

The effect of lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) on sperm motility and its modification by scavengers were investigated.

SETTING

Research laboratory of a university hospital.

PATIENT(S)

Normozoospermic semen samples were obtained from 37 healthy volunteers.

INTERVENTION(S)

The sperms were incubated in the presence of LPS with or without scavengers.

MAIN OUTCOME MEASURE(S)

Sperm motility was evaluated by a sperm quality analyzer (SQAIIB). ROS formation in semen samples was measured by a Berthold luminometer (LB953).

RESULT(S)

Motility of spermatozoa was decreased in the LPS-treated samples compared with that in the control groups. ROS was significantly higher in the LPS-treated groups than in the control groups. The addition of ROS scavengers restored the motility index and suppressed ROS production in the LPS-treated semen samples.

CONCLUSION(S)

These data suggest that endotoxin-induced excessive production of ROS is responsible for the decrease in sperm motility and that antioxidant therapy may be a therapeutic option for infertile men with bacterial genital tract infection.

Spontaneous extensive necrosis in non-Hodgkin lymphoma: prevalence and clinical significance

PURPOSE

We studied the prevalence of spontaneous extensive necrosis in the nodes of patients with non-Hodgkin lymphomas and assessed the clinical significance of this finding.

METHOD

CT and MRI performed before initiation of radiation or chemotherapy were reviewed in 60 consecutive patients with non-Hodgkin lymphomas to evaluate the presence or absence of spontaneous extensive necrosis in the lymphomatous nodes. The results were correlated with histopathologic grading, stages of lymphomas, maximal axial diameters of the lesions, International Prognostic Index (IPI), age, and serum lactate dehydrogenase (LDH) levels. We then performed Kaplan-Meier analysis of disease-free survival using each factor.

RESULTS

Extensive necrotic nodes that appeared as rim-enhanced masses on enhanced CT or MR images were found in 15 patients (25%), of whom 10 patients had pathologic verification. The patients with necrosis had significantly higher stages (Stage II or higher), greater IPI (IPI of > or = 2), and higher serum LDH levels than those without necrosis (p = 0.001, p = 0.005, and p = 0.005, respectively). With the Kaplan-Meier method, a statistically significant difference was noted for serum LDH levels (p = 0.015) and IPI (p = 0.021) but not for extensive necrosis (p = 0.600).

CONCLUSION

Spontaneous extensive necrosis in lymphomatous nodes is not a rare event. This finding may have a prognostic significance for patients with non-Hodgkin lymphomas.

Singlet oxygen generation from phosphatidylcholine hydroperoxide in the presence of copper

This study pursued whether singlet oxygen ((1)O2) is generated from phosphatidylcholine hydroperoxide (PCOOH), the oxidized modification product of a major constituent of biomembranes and serum lipoproteins. The (1)O2 formation was detected, by utilizing the oxidation of 2,2,6,6-tetramethyl-4-piperidone (TMPD) by (1)O2 to yield 2,2,6,6-tetramethyl-4-piperidone-1-oxyl (TEMPONE), which generates electron spin resonance (ESR) signals. The TEMPONE signal was detected in human plasma with addition of PCOOH by ESR determination after introducing copper(II). The TEMPONE formation was proportional to the amounts of PCOOH added according to moles of active oxygen. The TEMPONE signal intensity was weakened significantly in the presence of beta-carotene and histidine in a concentration-dependent manner, but was not at all decreased by mannitol, Mn-superoxide dismutase and catalase. In addition, HPLC-chemiluminescence analysis demonstrated that incubation with the PCOOH/Cu(II) combination oxidized cholesterol, a relatively oxidation-resistant component, to the cholesterol hydroperoxide. These results reveal that (1)O2 is generated from PCOOH in contact with copper(II). In conclusion, this in-vitro study provides directly the (1)O2 formation in living organisms following the advancement of peroxidation of constitutive lipids.

Cytotoxic activity of saponins from Camassia leichtlinii against human oral tumor cell lines

Five steroidal saponins from Camassia leichtlinii showed higher cytotoxicity against human oral squamous cell carcinoma cells HSC-2, as compared to normal human gingival fibroblasts HGF. The tumor specificity of saponins varied considerably from sample to sample, but was generally higher than that of tannins, flavonoids and prenylated compounds such as geranylgeraniol and vitamin K2 (MK-2). Agarose gel electrophoresis showed that the saponins failed to induce internucleosomal DNA fragmentation, but produced large DNA fragments in HSC-2 cells, whereas two saponin samples (compounds 1 and 5) induced internucleosomal DNA fragmentation in human promyelocytic leukemic HL-60 cells. In contrast to epigallocatechin gallate or gallic acid, the cytotoxic activity of saponins was not significantly affected by metals (Co2+, Cu2+, Fe3+) or by antioxidants (sodium ascorbate, N-acetyl-L-cysteine, catalase). Furthermore, the saponins did not produce radicals (detected by ESR spectroscopy) nor oxidation potential (measured by NO monitor). These data suggest that an oxidation-mediated mechanism is not involved in the cytotoxicity induced by the steroidal saponins.

Protective effect of Ninjin-yoei-to on damage to isolated hepatocytes following transient exposure to tert-butyl hydroperoxide

To establish a simple screening system for estimating efficacy of an agent for an oxidative-related lesion, we investigated the damage in isolated rat hepatocytes exposed to 75 microM tert-butyl hydroperoxide (t-BuOOH) and then subsequently incubated the cells in fresh medium. By electron spin resonance spectroscopy analysis using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), DMPO adducts of tert-butoxyl radicals and carbon center radicals were detected during the t-BuOOH exposure, and DMPO-OH formation was detected after t-BuOOH removal. In t-BuOOH-exposed cells, the level of phosphatidylcholine hydroperoxide (PCOOH), a peroxidative product of biomembranes in the hepatocytes, and the leakage of enzymes into the culture medium were significantly increased. An increase in acid phosphatase (AP) activity representing lysosome destabilization preceded the aspartate oxoglutarate aminotransferase (AST), alanine oxoglutarate aminotransferase (ALT) and lactate dehydrogenase (LDH) leakage. Ninjin-yoei-to added to the culture medium following the t-BuOOH exposure significantly inhibited the PCOOH formation and the leakage of AP, AST, ALT and LDH, concentration-dependently. Ninjin-yoei-to at 1 mg/ml in culture medium completely diminished these increases in enzyme activities down to the background levels found in control experiments and this reduction was greater than the most effective alpha-tocopherol concentration of 20 micromol/ml. Considering all of these results, it is likely Ninjin-yoei-to may exert its protective effect by antioxidative action and membrane stabilization.

[Presence of alpha 5 beta 1 integrin and fibronectin in the anterior subcapsular cataract]

PURPOSE

We investigated whether alpha 5 beta 1 integrin and fibronectin were present in myofibroblast-like lens epithelial cells in anterior subcapsular cataract (ASC).

METHODS

Nine anterior capsule specimens were obtained from the patients during cataract surgery and frozen for cryostat sections. Six specimens were anterior capsule obtained from cataract with ASC. As a control, three specimens were obtained from cataract without ASC. Alpha-smooth muscle actin (alpha-SMA), alpha 5 beta 1 integrin, and fibronectin were detected by immunohistochemical observation.

RESULTS

In all 6 specimens from patients with ASC, the lens epithelial cells around fibrosis tissue included myofibroblast-like lens epithelial cells which were positive for alpha-SMA. alpha 5 beta 1 integrin was detected in these lens epithelial cells. Fibronectin was also detected around these myofibroblast-like lens epithelial cells. Three control specimens showed no immunoreactivity against alpha-SMA, alpha 5 beta 1 integrin, or fibronectin.

CONCLUSIONS

Alpha 5 beta 1 integrin and fibronectin may play an important role in myodifferentiation of lens epithelial cells.

Glutathionyl hemoglobin in uremic patients undergoing hemodialysis and continuous ambulatory peritoneal dialysis

BACKGROUND

To assess the redox state in hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients, we focused on the formation of glutathionyl hemoglobin (Hb) because the ratio of oxidized glutathione disulfide (GSSG) to reduced glutathione (GSH) is increased in uremia, and GSSG is a source of glutathionyl Hb.

METHODS

Glutathionyl Hb levels were measured in 30 HD patients, 10 CAPD patients, and 20 healthy subjects by using liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS).

RESULTS

Hbbeta showed a peak at 15,868 D in a deconvoluted ESI mass spectrum. Glutathionyl Hbbeta was detected at 16,173 D (15,868 + 305). The peak at 16,173 D was identified as glutathionyl Hbbeta based on the following findings: (1) the peak disappeared by reducing the sample with dithiothreitol, and (2) the peak could be detected at a high level by incubating Hb in vitro with GSH in water at 37 degrees C for seven days. Glutathionyl Hb levels expressed as the peak height ratios of glutathionyl Hbbeta to intact Hbbeta were significantly elevated in HD patients (8.0 +/- 3.6%, mean +/- SD, N = 30, P < 0.0001) and CAPD patients (5.9 +/- 2.7%, N = 10, P < 0.05) as compared with normal subjects (3.0 +/- 1.6%, N = 20). However, there were no significant differences in the glutathionyl Hb levels before (8.7 +/- 3.2%, N = 12) and after HD (8.7 +/- 2.8%, N = 12).

CONCLUSION

Glutathionyl Hb levels were increased in HD and CAPD patients, probably because of enhanced oxidative stress. The measurement of glutathionyl Hb may be useful to assess oxidative stress in uremic patients.

Dialysis-related amyloidosis of the heart in long-term hemodialysis patients

BACKGROUND

Dialysis-related amyloidosis (DRA) predominantly occurs in the osteoarticular structures, but it also systemically appears in the extra-articular tissues as well. However, the pathological characteristics of DRA in the hearts of hemodialysis (HD) patients have rarely been reported.

METHODS

We studied the pathological characteristics of DRA in the hearts of 18 HD patients, including its relationship to calcification. Furthermore, we studied the immunohistochemical localization of advanced glycation end products (AGEs) using monoclonal anti-imidazolone and anti-Nepsilon-(carboxymethyl)lysine (CML) antibodies.

RESULTS

beta2-microglobulin (beta2m) amyloid deposits were detected in the hearts of seven patients who had undergone HD for more than 10 years. beta2m amyloid deposits in the left atrium were localized in the endocardium, the myocardium, and the walls of small blood vessels, whereas in the left ventricle, they were localized only in the walls of small blood vessels. The extent and prevalence of DRA in the heart were severe in the patients on HD for more than 15 years. Most calcification areas near mitral valve were dotted with beta2m amyloid deposits, while diffuse fine calcification was localized within the beta2m amyloid tissues in some cases. Imidazolone and CML were localized not only in massive beta2m amyloid deposits, but also in cardiac myocytes.

CONCLUSION

DRAs were localized extensively in the hearts of long-term HD patients. A strong affinity was observed between beta2m amyloid deposits and calcification.

MR imaging of primary leiomyosarcoma of the thyroid gland

Primary leiomyosarcoma of the thyroid gland is extremely rare and radiological information on this tumor is scant. We presented radiological findings on primary thyroid leiomyosarcoma in a 66-year-old woman in which anaplastic carcinoma was suspected based on clinical and cytological features and discussed the radiological clues to distinguish between the two diseases. Ultrasonography showed an ill-defined hypoechoic mass without halo in the left lobe and the isthmus of the thyroid gland. Computed tomography depicted a low-density mass with calcification and necrosis, which invaded the thyroid cartilage. No lymphadenopathy was seen. The tumor was demonstrated as an isointense mass on T1-weighted MR images and a mass of intermediate signal on T2-weighted images. The tumor showed a fair enhancement on gadolinium-enhanced T1-weighted images. Although the radiological picture was nonspecific, primary thyroid leiomyosarcoma appeared less invasive and far less frequent in developing nodal metastasis than anaplastic carcinoma in light of the literature.

Cytotoxic activity of polyprenylalcohols and vitamin K2 derivatives

Cytotoxic activity of 9 polyprenylalcohols and 6 vitamin K2 derivatives (MK-1 to MK-6) with various lengths of prenyl units was investigated. Among these compounds, geranylgeraniol with 4 prenyl units, and MK-2 with 2 prenyl units, showed the highest cytotoxic activity against human oral tumor cell lines (HSC-2, HSG), without induction of internucleosomal DNA fragmentation. Higher molecular weight compounds showed selective cytotoxicity against tumor cell lines than normal human gingival fibroblasts HGF. ESR spectroscopy showed that all polyprenylalcohols did not produce radical, nor scavenged O2- generated by hypoxanthine and xanthine oxidase reaction, and only slightly enhanced the radical intensity of sodium ascorbate. Vitamin K2 derivatives scavenged O2- more efficiently, but did not produce radical (except MK-3) and only slightly modified the ascorbate radical intensity. Cytotoxic activity of these compounds might be affected by the molecular weight, hydrophobicity, van der Waals area and stabilization of hydration of the molecule.

Cytotoxic activity of steroidal saponins against human oral tumor cell lines

Three steroidal saponins showed higher cytotoxicity against human oral squamous cell carcinoma cell lines (HSC-2), as compared with normal human gingival fibroblasts HGF. Tumor specificity of saponins exceeded that of tannins and flavonoids. Agarose gel electrophoresis showed that saponins failed to induce internucleosomal DNA fragmentation, but produced large DNA fragments in both HSC-2 cells and human promyelocytic leukemic HL-60 cells. In contrast to epigallocatechin gallate or gallic acid, cytotoxic activity of saponins was not significantly affected by metals (Co2+, Cu2+, Fe3+) nor by antioxidants (sodium ascorbate, N-acetyl-L-cysteine, catalase). Furthermore, saponins did not produce radicals (detected by ESR spectroscopy) nor oxidation potential (measured by NO monitor). These data suggest that an oxidation-mediated mechanism is not involved in the cytotoxicity induced by steroidal saponins.

Styrene inhibits monoamine oxidase A, but not monoamine oxidase B in monkey brain mitochondria

The effects of styrene on mitochondrial monoamine oxidase (MAO) activity in rat and monkey brains were compared in vitro. After preincubation at 25 degrees C for 20 min with 1 mM styrene monomer MAO-A activity in monkey brain was inhibited potently using 5-HT (for MAO-A substrate), but MAO-B activity in monkey brain and platelets were slightly inhibited using beta-PEA (for MAO-B substrate). Styrene monomer also competitively inhibited MAO-A activity in a dose-dependent manner. MAO-A in monkey brain was inhibited by styrene in ascending order of potency: styrene trimer>styrene dimer>styrene monomer. In contrast styrene monomer slightly inhibited both MAO-A and MAO-B activities in rat brain mitochondria. In the present study styrene monomer potently inhibits MAO-A activity, but not MAO-B activity, in monkey brain mitochondria in vitro. These results indicate the inhibiting action of styrene differs depending on animal species and MAO isoforms.

Effect of antioxidants on radical intensity and cytotoxicity of hydroquinone

Hydroquinone (HQ) dose-dependently reduced the viable cell number of oral tumor cell lines (HSC-2, HSG). HQ induced internucleosomal DNA fragmentation in human promyelocytic leukemic HL-60 cells, but not in HSC-2 nor HSG cells. Cytotoxic activity of HQ was slightly reduced by catalase, but was enhanced by superoxide dismutase, suggesting the possible involvement of hydrogen peroxide in HQ-induced cytotoxicity. This was supported by slight increase or decrease of cytotoxicity of HQ in the presence of Cu2+ and Fe3+, respectively. Lower concentrations of sodium ascorbate, ascorbic acid and ascorbic acid 6-palmitate reduced both the radical intensity and cytotoxic activity of HQ, more efficiently than ascorbic acid 2,6-dipalmitate, in contrast to the cytotoxic action of these ascorbates at higher (millimolar) concentrations. Popular antioxidants such as N-acetyl-L-cysteine and cysteine also reduced the radical intensity and cytotoxic activity of HQ. The present study suggests that cytotoxic activity of HQ is generated by radical-mediated oxidation mechanism.

Day/night variation of 5-hydroxyindole acetic acid concentration in rat cerebrospinal fluid after acute and long-term administration of a selective serotonin reuptake inhibitor, fluvoxamine

When 30 mg/kg, p.o. of fluvoxamine, a selective serotonin reuptake inhibitor, was administered, significant increases of 3-methoxy-4-hydroxyphenylglycol (MHPG) and 5-hydroxy indole-3-acetic acid (5-HIAA) contents in rat cerebrospinal fluid (CSF) were observed from two days after administration of fluvoxamine in both the light and dark periods and in the dark period of the light/dark cycle, respectively. In long-term treatment with 15 mg/kg, p.o. of fluvoxamine, the level of MHPG in CSF exhibited no difference, whereas the levels of 5-HIAA showed a significant increase during the light periods. These results suggest that fluvoxamine enhances the 5-HT system, but only with long-term treatment.

Cytotoxic activity of low molecular weight polyphenols against human oral tumor cell lines

A total of 150 chemically-defined natural and synthetic polyphenols (flavonoids, dibenzoylmethanes, dihydrostilbenes, dihydrophenanthrenes and 3-phenylchromen-4-ones), with molecular weights ranging from 224 to 824, were investigated for cytotoxic activity against normal, tumor and human immunodeficiency virus (HIV)-infected cells. They showed higher cytotoxic activity against human oral squamous cell carcinoma HSC-2 and salivary gland tumor HSG cell lines than against normal human gingival fibroblasts HGF. Many of the active compounds had a hydrophilic group (hydroxyl group) in the vicinity of a hydrophobic group (prenyl, phenyl, methylcyclohexene or methylbenzene moiety), similar to isoprenoid-substituted flavones. Substitution of hydrophobic group (prenyl or geranyl group) did not significantly change the cytotoxic activity of flavanones, isoflavans, chalcones or 5-hydroxy-3-phenoxychromen-4-ones. However, the prenylation(s) of an isoflavone and a 2-arylbenzofuran significantly enhanced the cytotoxic activity. Agarose gel electrophoresis showed that active components induced internucleosomal DNA fragmentation in human promyelocytic leukemic HL-60 cells, but not in HSC-2 cells. Most of the polyphenols failed to reduce the cytophathic effect of HIV infection in MT-4 cells.

Differentiated thyroid carcinomas. Prediction of tumor invasion with MR imaging

PURPOSE

To assess diagnostic accuracy for tumor invasion of surrounding organs by measurement of tumor circumferences on MR images in patients with differentiated thyroid carcinomas.

MATERIAL AND METHODS

Surgical and MR imaging findings in 50 patients with differentiated thyroid carcinoma (43 primary, 7 recurrent lesions) were retrospectively reviewed. The degrees of circumference of tumor encroachment to the organs were measured, and the measurements and morphologic diagnosis of tumor invasion made by a head and neck radiologist were compared with surgical and pathologic findings using receiver operating characteristic curves.

RESULTS

Diagnosis of tumor invasion by the radiologist was superior to the measurements of the carotid artery and cartilage, while the reverse was true for the trachea and esophagus. However, no statistical differences were noted between them for each structure. Optimal thresholds for tumor invasion were 90 degrees or more for the cartilage (94% accuracy) and esophagus (86% accuracy), 135 degrees or more for the trachea (86% accuracy), and 225 degrees or more for the carotid artery (90% accuracy).

CONCLUSION

Tumor invasion was more accurately diagnosed by measurement of tumor circumferences of each organ on MR images.

Radiologic assessment of metastases to the thyroid gland

PURPOSE

We reviewed the radiologic and clinical data in patients with metastatic disease to the thyroid gland and assessed the role of radiologic techniques in this disorder.

METHOD

The findings on US (n = 11), CT (n = 7), MRI (n = 6), palpation or US-guided fine needle aspiration (FNA) biopsy, and clinical records were reviewed in 11 cases of pathologically verified metastatic tumors of the thyroid gland.

RESULTS

Five patients had palpable thyroid nodules and six had nonpalpable nodules discovered incidentally with imaging procedures. Three patients had no known malignancies at the time of diagnosis of thyroid tumors. Correct diagnosis was obtained in 10 of the 11 cases with FNA biopsy. Thyroid metastases were detected in all of the cases with US and MRI and six of the seven cases with CT. Thyroid metastases were solitary (n = 5) or multiple (n = 6), and about half of them measured <2 cm in diameter. These tumors typically had well defined margins and no calcification and sometimes had cystic portions. Multiple nodules within the same patient were radiologically quite similar to each other. On US, metastases appeared as hypoechoic or markedly hypoechoic areas without halo, on CT as low density areas, and on MRI as areas of varying signal intensities. Half of the metastases showed hypointensity on either T2-weighted images or gadolinium-enhanced T1-weighted images. The tumors involved lymph nodes in 10 cases and other remote organs in 5. Level I or II or parotid nodes were involved in six cases.

CONCLUSION

These radiologic features may alert clinicians to a possibility of metastatic thyroid cancer. US combined with US-guided FNA biopsy is suitable for early diagnosis of metastases to the thyroid gland.

Role of carbohydrate moiety in granulocyte colony stimulating factor

Biological activities of two granulocyte-colony stimulating factor (G-CSF) preparations with (Lenograstim) or without (Filgrastim) sugar moiety were compared. Both G-CSF preparations similarly enhanced the N-Formyl-Met-Leu-Phe-induced-migration of human peripheral blood polymorphonuclear cells, but did not significantly affect the proliferation of human oral tumor cell lines (HSC-2, HSG). However, Lenograstim induced cytotoxicity (accompanied by the production of cytoplasmic vacuoles and large DNA fragments) in human promyelocytic leukemic cells HL-60, more potently than Filgrastim. Lenograstim, but not Filgrastim, enhanced the cytotoxic activity of sodium ascorbate. In contrast to Lenograstim, Filgrastim was degraded gradually, but too slowly to explain its lower biological activity. These data suggest that the carbohydrate moiety in G-CSF might confer unique biological activities.

Primary thyroid lymphoma: diagnosis of immunoglobulin heavy chain gene rearrangement with polymerase chain reaction in ultrasound-guided fine-needle aspiration

We present a case of primary thyroid lymphoma coexisting with Hashimoto's thyroiditis in a 75-year-old woman in whom B-cell lymphoma was substantiated based on the findings of immunophenotyping and polymerase chain reaction (PCR) gene rearrangement in specimens that had been obtained by ultrasound (US)-guided fine-needle aspiration biopsy (FNAB). The immunophenotyping technique showed A light chain restriction, and PCR-based assays showed a discrete narrow band, which was diagnostic for clonal B-cell proliferation. Analyses of PCR gene rearrangement in US-guided FNAB may be a useful ancillary technique to pathological findings for diagnosis of primary thyroid lymphoma, especially for differentiation between low-grade B-cell lymphomas and Hashimoto's thyroiditis.

Secondary malignant lymphoma which simulated primary thyroid cancer

A patient with secondary thyroid lymphoma who complained of a neck mass was presented. Multiple nodules were detected in both lobes of the thyroid gland, which appeared as homogeneous hypoechoic masses on ultrasonogarphy (US), low-density masses on computed tomography (CT), and areas of increased uptake on gallium-67 scintigraphy. The residual thyroid gland was normal. Surgery established a diagnosis of secondary thyroid lymphoma with no coexistent Hashimoto's thyroiditis but with cervical node involvement by lymphoma. Radiologic evidence of normal residual thyroid gland in a patient with thyroid lymphoma may be a sign of secondary thyroid lymphoma.

Head and neck lesions: determination of an optimal MT technique for prediction of malignancies

RATIONALE AND OBJECTIVES

To determine an optimal magnetization transfer (MT) technique for diagnosis of malignancies in the head and neck.

METHODS

Lesion magnetization transfer ratios (MTRs) and lesion-to-muscle MTRs were prospectively measured in 52 head and neck lesions of 52 patients at frequency offsets of 0.3, 0.5, and 1 kHz from water resonance. The diagnostic capability for each MT pulse was calculated by using receiver operating characteristic (ROC) curves, and an optimal MT technique was determined for diagnosis of malignancies.

RESULTS

The lesion MTRs and the lesion-to-muscle MTRs in malignant tumors were statistically significantly greater than those in benign lesions at both 0.5- and 1-kHz MT pulses, but no significant differences were noted between them at the 0.3-kHz MT pulse. Diagnosis with the lesion-to-muscle MTRs was better than that with the lesion MTRs at each MT pulse. Among all MTRs, lesion-to-muscle MTRs at the 1-kHz MT pulse showed the highest diagnostic capability for malignancies (area under the ROC curve = 0.82+/-0.06). With a lesion-to-muscle MTR at a 1-kHz MT pulse of 0.61 or greater, the highest accuracy of 85% was attained with 90% sensitivity and 77% specificity.

CONCLUSIONS

Lesion-to-muscle MTRs at a 1-kHz MT pulse were optimal for diagnosis of malignancies in the head and neck.

Antioxidant and hepatoprotective actions of the medicinal herb Artemisia campestris from the Okinawa Islands

The antioxidant action of Artemisia campestris was examined in vitro and in vivo. A water extract of A. campestris showed a strong scavenging action of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals. When the extract was given intraperitoneally to mice prior to carbon tetrachloride (CCl4) treatment, CCl4-induced liver toxicity, as seen by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities, was significantly reduced. Depression of the elevation of serum enzyme levels after CCl4-treatment was also observed by oral administration of the extract. In that case, CCl4-derived lipid peroxidation in the liver was decreased by the extract treatment. These results suggest that the extract of A. campestris scavenges radicals formed by CCl4 treatment resulting in protection against CCl4-induced liver toxicity.

Induction of apoptosis by dopamine in human oral tumor cell lines

Dopamine dose-dependently reduced the viable cell number of both human salivary gland tumor HSG and oral squamous cell carcinoma HSC-2, HSC-4, and NA cells. CoCl2 significantly reduced both the cytotoxic activity and radical intensity of dopamine (determined by ESR spectroscopy). Dopamine produced DNA fragments (demonstrated by TUNEL method) and induced degradation of cytokeratin by activated caspase in HSG cells (detected by an immunocytochemical method, using a specific M30 monoclonal antibody). FACS analysis demonstrated that dopamine induced DNA fragmentation, a biochemical hallmark of apoptosis, in human promyelocytic leukemia HL-60 cells. The addition of catalase did not prevent the apoptosis-inducing activity of dopamine, reducing the possibility of the involvement of H2O2 for dopamine-induced apoptosis. Dopamine transiently induced p38 mitogen-activated protein kinase (MAP kinase) phosphorylation. However, an inhibitor of p38 MAP kinase phosphorylation, SB203680, failed to inhibit the dopamine-induced apoptosis. These data suggest that p38 phosphorylation at an early stage may not be a causative event for apoptosis.

Changes in monoamine metabolites concentrations in rat cerebrospinal fluid after acute and long-term administration of a selective serotonin reuptake inhibitor, trazodone

In order to clarify the mechanism of the antidepressive effects of trazodone, a selective serotonin reuptake inhibitor, we investigated the dynamics of monoamine metabolites in cerebrospinal fluid (CSF) of free-moving conscious rats by acute and long-term treatment with trazodone. When 100 mg kg-1 p.o. of trazodone were administered, a significant increase of 3-methoxy-4-hydroxyphenylglycol (MHPG) concentration was soon observed in the light period of the light/dark cycle, and a significant decrease of dihydroxy phenyl acetic acid (DOPAC) concentration was observed during the 2 days after administration of trazodone; in contrast, the homovanilic acid (HVA) level was increased. However, we detected no significant changes in the 5-hydroxy indole-3-acetic acid (5-HIAA) concentration during the 3 days. In the case of long-term treatment with 50 mg kg-1, p.o. of trazodone, the levels of MHPG, DOPAC and HVA exhibited no difference when compared with values obtained during saline treatment in either the light or dark period, whereas the levels of 5-HIAA showed a significant increase during the light period. These findings suggest that a long-term treatment with trazodone enhances the serotonergic neurons.

The inhibition of monoamine oxidase activity by various antidepressants: differences found in various mammalian species

The effects of the antidepressant drugs zimeldine, imipramine, maprotiline or nomifensine on mitochondrial monoamine oxidase (MAO) activity in mouse, rat, dog and monkey brains were compared in vitro. Mouse, rat, dog and monkey brain MAO-B activities were inhibited by zimeldine more potently than MAO-A activity. Imipramine inhibited MAO-B more potently than MAO-A activity in mouse and rat brains. When dog and monkey brains were investigated, MAO-A activity was inhibited more potently than MAO-B activity at high concentrations of imipramine, while at low concentrations, MAO-B activity was more potently inhibited. Maprotiline and nomifensine inhibited mouse and rat brain MAO-B activity more potently than MAO-A activity, while the inverse was true for dog and monkey brains. All four drugs are competitive inhibitors of MAO-A, but noncompetitive inhibitors of MAO-B in all animal brains. The respective Ki values of these reagents for monkey brain MAO-A and MAO-B were low compared to those of mouse, rat and dog. These results indicate that monkey brain MAOs are more sensitive to antidepressant drugs than those in rodent brain.

Detection of medullary thyroid carcinoma and regional lymph node metastases by magnetic resonance imaging

OBJECTIVES

To evaluate the usefulness of magnetic resonance imaging in detecting primary medullary thyroid carcinoma (MTC) and regional metastasis to the lymph nodes, and to correlate magnetic resonance signal intensity to pathologic changes.

MATERIALS AND METHODS

Magnetic resonance images in 14 patients with MTC (9 with primary disease, 5 with recurrent disease) were reviewed for signal intensities, tumor morphologic characteristics, and tumor invasion with spin-echo T1-weighted images (T1WIs), T2-weighted images (T2WIs), and gadolinium-enhanced T1WIs. Multiple regression analysis was used to examine the correlation between T2-weighted signal intensity and pathologic findings. Lymph nodes were evaluated based on signal and morphologic characteristics.

RESULTS

Magnetic resonance imaging detected tumors in 9 (90%) of the 10 patients who had MTC in the thyroid gland. Extrathyroidal spread of the tumors was correctly predicted using this procedure. Most tumors were hyperintense or markedly hyperintense on T2WI. T2-weighted signal intensity of the tumor was associated with increased amyloid deposition and high tumor cellularity and low level of fibrosis (r = 0.91, P = .01). Lymph node metastasis was present in 38 (23%) of 168 surgically dissected nodes. The combined use of 4 criteria (nodule size, a minimum-maximum diameter ratio of 0.80 or greater, marked hyperintensity on T2WI, and necrosis in the node) yielded a high detection accuracy (93%) for nodal metastasis, with 74% sensitivity and 98% specificity.

CONCLUSIONS

Magnetic resonance imaging is useful for detecting primary and recurrent MTC, and its signal intensity reflects the underlying pathologic changes.

Monitoring of radical scavenging activity of peroral administration of the Kampo medicine Sho-saiko-to in rats

The Kampo medicine Sho-saiko-to scavenged superoxide anion radicals (O2-), hydroxyl radicals (*OH) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent fashion. We attempted to investigate the transition of free radical scavenging activity in plasma after oral administration of Sho-saiko-to in rats. From the response-time profile, kinetic parameters including values for Ka (absorption rate constant), Tmax (peak concentration time), T1/2 (half life) and MRT (mean residence time) of radical scavenging activity in plasma could be calculated for the O2-, *OH and DPPH radicals. These parameters calculated from the dynamics of antioxidation are considered a very meaningful procedure to examine the effects of Sho-saiko-to.

Oral adsorbent ameliorates renal TGF-beta 1 expression in hypercholesterolemic rats

BACKGROUND

A spontaneously hypercholesterolemic Imai rat has recently been reported as a model of focal glomerulosclerosis that causes nephrotic syndrome followed by renal failure. This study was designed to determine if an oral adsorbent, AST-120, ameliorates renal lesions and TGF-beta 1 expression in the rats.

METHODS

AST-120 was given orally to the Imai rats for 32 weeks, and renal function and pathology were compared between the AST-120-administered and control Imai rats.

RESULTS

AST-120-administered rats showed significantly lower level of blood urea nitrogen, serum creatinine, urinary protein, serum total-cholesterol, serum triglyceride, and serum and urinary indoxyl sulfate, and significantly higher levels of serum albumin and creatinine clearance than control rats. AST-120 reduced the glomerular sclerosis index, interstitial fibrosis area, and the extent of glomerular lipid deposition. Immunohistochemistry demonstrated that AST-120 reduced the expression of transforming growth factor (TGF)-beta 1 and tissue inhibitor of metalloproteinase (TIMP)-1 as well as interstitial infiltration of macrophages in the renal cortex of the Imai rats.

CONCLUSIONS

AST-120 prevented the progression of nephrotic syndrome and renal failure in the Imai rats by ameliorating glomerular sclerosis and interstitial fibrosis, accompanied with reduced expression of TGF-beta 1 and TIMP-1, and reduced infiltration of macrophages in the kidneys.

Increased erythrocyte 3-DG and AGEs in diabetic hemodialysis patients: role of the polyol pathway

BACKGROUND

3-Deoxyglucosone (3-DG) accumulating in uremic serum plays an important role in the formation of advanced glycation end products (AGEs). To determine if 3-DG is involved in the formation of intracellular AGEs, we measured the erythrocyte levels of 3-DG and AGEs such as imidazolone and N epsilon-carboxymethyllysine (CML) in hemodialysis (HD) patients with diabetes. Further, to determine if the polyol pathway is involved in the formation of erythrocyte 3-DG and AGEs, an aldose reductase inhibitor (ARI) was administered to these patients.

METHODS

The erythrocyte levels of sorbitol, 3-DG, imidazolone, and CML were measured in ten diabetic HD patients before and after treatment with ARI (epalrestat) for eight weeks, and were compared with those in eleven healthy subjects. 3-DG was incubated in vitro with hemoglobin for two weeks to determine if imidazolone and CML are formed by reacting 3-DG with hemoglobin.

RESULTS

The erythrocyte levels of sorbitol, 3-DG, imidazolone, and CML were significantly elevated in diabetic HD patients as compared with healthy subjects. The erythrocyte levels of 3-DG significantly decreased after HD, but sorbitol, imidazolone or CML did not. The administration of ARI significantly decreased the erythrocyte levels of sorbitol, 3-DG and imidazolone, and tended to decrease the CML level. Imidazolone was rapidly produced in vitro by incubating 3-DG with hemoglobin, and CML was also produced, but less markedly as compared with imidazolone.

CONCLUSION

The erythrocyte levels of 3-DG and AGEs are elevated in diabetic HD patients. The administration of ARI reduces the erythrocyte levels of 3-DG and AGEs, especially imidazolone, as well as sorbitol. Thus, 3-DG and AGEs, especially imidazolone, in the erythrocytes are produced mainly via the polyol pathway. ARI may prevent diabetic and uremic complications associated with AGEs.

NO contribution to lipopolysaccharide-induced hepatic damage in galactosamine-sensitized mice

To investigate the role of nitric oxide (NO) in hepatitis-induced endotoxemia, we injected mice intraperitoneally with 250 mg/kg galactosamine (GalN) and 1 mg/kg lipopolysaccharide (LPS) separately and in combination. NO synthesis increased in a dose-dependent manner with LPS. NO generation at 5 hr after administration of LPS was greater than that at 24 hr. Enhancement of NO generation was demonstrated in mice administered GalN and LPS in combination. A nitrosyl-heme signal in 10,000 g supernatant of liver homogenate, due to cytochrome P450 (P450) combining with NO, NO-P450, was detected at more than ten hr and even more after administration of LPS by electron spin resonance (ESR) measurements at 77 degrees K. The strongest NO-P450 signal and most extreme elevation of aspartate oxoglutarate aminotransferase (AST), alanine oxoglutarate aminotransferase (ALT), and lactate dehydrogenase (LDH) in serum and of lysosomal enzyme activity in plasma were observed in the GalN + LPS group. Their potency was greater than in the 10 mg/kg LPS group, which was even greater than in the LPS 1 mg/kg group. The aniline hydroxylase activity was inversely proportional to NO-P450 signal intensity. It appears that NO might contribute to LPS-induced hepatic damage in GalN-sensitized mice through degeneration and inactivation of liver microsomal enzymes by binding P450 active sites.

Parotid gland lesions: diagnosis of malignancy with MRI and flow cytometric DNA analysis and cytology in fine-needle aspiration biopsy

BACKGROUND

The purpose of this study was to assess the capability of magnetic resonance imaging (MRI) and cytology and flow cytometric (FCM) deoxyribonucleic acid (DNA) analysis in fine-needle aspiration biopsy (FNAB)-derived materials for diagnosing malignancy of the parotid lesions and the efficacy of FCM analysis in FNAB.

METHODS

Magnetic resonance imaging findings and FCM results (ploidy and S + G2 + M phases [S + G2M] fraction) and cytology in FNAB-derived materials in 26 patients with 26 parotid lesions (12 benign lesions, 14 malignancies) were assessed for predicting malignancy. Flow cytometric results in aspirates were compared with those in surgically resected tissues.

RESULTS

When a single predictor was used, cytology (92% accuracy) was most accurate for malignancy, followed by ill-defined margin (88% accuracy) and aneuploidy (88% accuracy). The combination of FCM and cytology raised the rate of sufficient materials from 92% to 100% and accuracy from 92% to 96% compared with cytology alone. The same highest accuracy (96%) was obtained with the combination of the ill-defined margin or other findings such as cytology, aneuploidy, or a high (S + G2M) fraction (6% <). Deoxyribonucleic acid ploidy in the FNAB showed full agreement with that in the surgical specimens. Receiver operating characteristic curves showed that the diagnosis of malignancy with (S + G2M) fraction in FNAB was superior to that in surgical specimens, but no significant difference was noted.

CONCLUSIONS

A combination of MRI findings, cytology, and FCM results is optimal for diagnosing malignancies of the parotid lesions, and FNAB may replace the surgical specimens in FCM analysis.

Urinary indoxyl sulfate is a clinical factor that affects the progression of renal failure

We recently demonstrated that indoxyl sulfate is a stimulating factor for the progression of chronic renal failure (CRF). In this study we determined whether the urine or serum levels of indoxyl sulfate are related to the progression rate of CRF in undialyzed uremic patients. Fifty-five CRF patients with a serum creatinine of >2 mg/dl who had not been treated with an oral sorbent (AST-120) were randomly enrolled in the study. We measured the serum and urine levels of indoxyl sulfate, and estimated the recent progression rate of CRF as the slope of the reciprocal serum creatinine versus time (1/S-Cr-time) plot. The mean urinary amount of indoxyl sulfate in the patients was 60 mg/day. Those with indoxyl sulfate urine levels of >60 mg/day had a significantly faster progression rate of CRF than those with <60 mg/day. Especially, those patients with indoxyl sulfate urine levels of >90 mg/day had the highest CRF progression rate and those with indoxyl sulfate urine levels of <30 mg/day had the slowest CRF progression rate. Urinary indoxyl sulfate had a significantly negative correlation with the slope of the 1/S-Cr-time plot. However, the serum level of indoxyl sulfate or the ratio of serum indoxyl sulfate to creatinine was not significantly correlated with the slope of the 1/S-Cr-time plot. In conclusion, high urine levels of indoxyl sulfate are related with a rapid progression of CRF in undialyzed uremic patients. Thus, urinary indoxyl sulfate is one of the clinical factors that affect CRF progression.

Immunohistochemical detection of imidazolone and N(epsilon)-(carboxymethyl)lysine in aortas of hemodialysis patients

The modification of long-lived proteins with advanced glycation endproducts (AGEs) has been hypothesised to contribute to the development of pathologies associated with uremia. Imidazolone and N(epsilon)-(carboxymethyl)lysine (CML) are common epitopes of AGE-modified proteins. Imidazolone is a reaction product of arginine with 3-deoxyglucosone (3-DG) which is markedly accumulated in uremic serum. CML is produced by glycoxidation, and represents a marker of oxidative stress. The specificity of anti-imidazolone antibody that we had developed was further examined using ELISA. The antibody reacted only with imidazolone derived from 3-DG and arginine, but did not react at all with the other imidazolone-like compounds such as reaction products of glyoxal, methylglyoxal, glucosone with arginine or a reaction product of 3-DG with creatine. Further, to determine if AGEs are involved in the development of atherosclerosis in hemodialysis (HD) patients, we studied the localisation of imidazolone and CML in the aortas obtained from HD patients by immunohistochemistry using the anti-imidazolone and anti-CML antibodies. Imidazolone and CML were localised in all atherosclerotic aortic walls of the HD patients. In conclusion, imidazolone and CML are localised in the characteristic lesions of atherosclerosis in HD patients. These results strongly suggest that imidazolone produced by 3-DG, and CML produced by glycoxidation may contribute to the development of atherosclerosis in uremic patients.

Variation of monoamines and their metabolite contents in the cerebrospinal fluid of conscious rats

To study the circadian rhythm of the monoamine and metabolite contents, cerebrospinal fluid was taken from the cisterna magna through a polyethylene catheter tube every 4 hr in the conscious rat. Norepinephrine and 3-methoxy-4-hydroxy-phenylglycol were found to describe a rhythm with the maximal content occurring during the dark phase and the minimal content occurring during the light phase. Dopamine levels increased significantly during the light phase compared with the dark phase. These results, given that cerebrospinal fluid can be taken chronically from conscious rats, indicate that our present method may be suitable for estimating changes in brain monoamine and metabolite contents.

Thyroid metastasis from rectal carcinoma coexisting with Hashimoto's thyroiditis: gray-scale and power Doppler sonographic findings

We present the gray-scale and power Doppler sonographic findings in a case of rectal carcinoma metastasis to the thyroid that mimicked a primary thyroid neoplasm and coexisted with Hashimoto's thyroiditis in a 67-year-old man. Gray-scale sonography revealed a hypoechoic mass with ill-defined borders in the left lobe of the thyroid; the mass extended through the isthmus to the right lobe. Sonography also showed multiple enlarged cervical lymph nodes. Power Doppler sonography showed increased flow in the nontumorous thyroid gland and decreased flow in the tumor. This contributed to the differentiation between the tumor and the remainder of the thyroid, which was involved with Hashimoto's thyroiditis.

Power Doppler imaging findings in multilocular giant parathyroid adenoma which caused hypercalcaemic crisis

Radiological findings including ultrasonography, computed tomography (CT) and Tc-99m sestamibi scintigraphy of a patient with multilocular giant parathyroid adenoma which caused hypercalcaemic crisis are presented. The location of the tumour by grey scale sonography, CT and Tc-99m sestamibi scintigraphy was not certain because the tumour was uncommon in shape, location, size and internal structure. Whereas, increased flow in the solid portion of the mass was demonstrated on power Doppler sonography, which proved to reflect abundant vessels in the adenoma in pathological findings.