Odontoclasts in the Chinook salmon differ from mammalian odontoclasts by exhibiting a great proportion of cells with high nuclei number

Odontoclasts resorbing teeth are multinucleated cells. Previously, the authors have investigated the distribution of number of nuclei per human odontoclast and showed that the mean number of nuclei per cell is 5.3, the median is 4, and 93.8% of cells have 10 or fewer nuclei. Teleost odontoclasts have features similar to those of mammals; however, the distribution of number of nuclei per cell remains unknown. The present study aimed to examine the distribution of number of nuclei per odontoclast in a teleost fish, Chinook salmon, Oncorhynchus tshawytscha (Walbaum), and to clarify the difference of number of nuclei in odontoclasts between Chinook salmon and humans. The maxillae and mandibles of Chinook salmon were fixed, decalcified, and embedded in Epon 812. Specimens were serially sectioned into 0.5-µm semithin sections and examined by light microscopy. Cells possessing a brush border adjacent to a resorptive lacuna were identified as odontoclasts, and 246 odontoclasts were investigated to determine the distribution of nuclei per cell. The mean number of nuclei per cell was 21.8 and the median was 17; only 24.4% of odontoclasts had 10 or fewer nuclei, and 95.5% had 50 or fewer nuclei. These results suggest that the range for the number of nuclei per odontoclast in Chinook salmon is greater than that in humans.     

Mixed gonadal dysgenesis

Testicular dysgenesis derives from abnormal gonadal differentiation caused by sex chromosome abnormality. Individuals with sex chromosomal mosaicism manifest diverse phenotypes from phenotypic females and individuals with mixed gonadal dysgenesis (MGD) to males. Gonadal asymmetry in MGD is cytogenetically due to local prevalence of cell lines carrying different karyotypes; XO in the streak gonad and XY in the dysgenetic testis while sex chromosome abnormalities in blood do not always reflect the genital abnormalities. Gender assignment should be based on the potential for normal function of the external genitalia under the parents agreement. Laparoscopic and microscopic surgery facilitates the diagnosis and treatment in infants with MGD and its variants. Close follow-up is mandatory for detecting the highly prevalent gonadal tumor in male subjects.     

Effects of hepatocyte growth factor on urokinase-type plasminogen activator (uPA) and uPA receptor in DU145 prostate cancer cells

Urokinase-type plasminogen activator (uPA) and the uPA receptor (uPAR) are involved in a proteolytic cascade resulting of extracellular matrix degradation. Upstream, uPA and uPAR are regulated by various factors including hepatocyte growth factor (HGF), which stimulates the uPA/uPAR proteolytic system and increases invasion of cancers. We recently demonstrated that HGF induces invasion of DU145 prostate cancer cells into collagen gel matrix. We therefore examined effects of HGF on uPA and uPAR expression in DU145 cells. Effects of HGF on uPA expression in culture medium were determined by Western blotting and fibrin zymography, effects on uPAR expression in cell-associated protein were examined by Western blotting. HGF increased uPA and uPAR production in a dose-dependent manner up to 10 ng/mL, while effects of 20 ng/mL were approximately equal to those of 10 ng/mL. HGF stimulated uPA production beyond that in control cultures from 8 h until 48 h after HGF addition. HGF stimulated a uPA/uPAR proteolytic network in DU145 cells, which may be important for acquisition invasive potential by prostate cancer.     

Neuropathological features of a case with schizophrenia and prion protein gene P102L mutation before onset of Gerstmann-Sträussler-Scheinker disease

Gerstmann-Sträussler-Scheinker disease (GSS) is a hereditary transmissible spongiform encephalopathy associated with prion protein gene mutation P102L. The age of onset is roughly restricted to around the sixth decade; however, it is unclear whether the disease-specific pathology of GSS is already evident in the pre-clinical stage. We had a chance to examine an autopsy case with PRNP P102L mutation. The patient had died at 50 years of age before the clinical symptoms of GSS had appeared; neither neuronal loss, gliosis nor spongiform change was found anywhere in the brain. Immunohistochemistry failed to detect any deposition of prion protein. It is thus considered that amyloid plaque formation in GSS probably develops in a relatively rapid fashion compared with Alzheimer's disease. Although the patient suffered from schizophrenia, no significant pathological changes were detected except for astrocytic inclusion bodies in the cerebral cortex. The nature and significance of the inclusion bodies, which are not observed in patients with GSS, remain unclear.     

Acute human T-lymphotropic virus type 1-associated myelopathy: a clinicopathologic study

BACKGROUND: Recently, acute human T-lymphotropic virus type 1-associated myelopathy (HAM) was reported clinically without pathologic information. We report an autopsy case of acute HAM. OBJECTIVE: To report the case of a 52-year-old man with acute-onset gait disturbance followed by rapidly progressive paraplegia, who died 9 months later. RESULTS: The postmortem study showed swelling of the thoracic spinal cord. Histologically, there was inflammation and vacuolation in the white matter. CONCLUSION: We propose that these pathologic findings, mimicking tropical spastic paraparesis, may represent the characteristic pathologic features of acute HAM.     

Detection of hepatocellular carcinoma: comparison of dynamic MR imaging with dynamic double arterial phase helical CT

OBJECTIVE: Three-dimensional (3D) Fourier transformation-enhanced fast gradient-echo sequences with a special spectral inversion recovery pulse and fat suppression developed for abdominal imaging, including MR angiography, can show enhanced areas clearly. The purpose of this study was to evaluate the efficacy of dynamic MR imaging with the pulse sequences for the detection of hypervascular hepatocellular carcinoma by comparing it with that of dynamic helical CT with double arterial phase imaging. SUBJECTS AND METHODS: Fifty-three patients with 103 hypervascular hepatocellular carcinoma nodules who underwent both dynamic MR imaging with 3D Fourier transformation-enhanced fast gradient-echo sequences with a special spectral inversion recovery pulse and dynamic helical CT with double arterial phase imaging were enrolled in the study. For dynamic MR imaging, unenhanced, arterial, portal venous, and equilibrium phase images were obtained before and approximately 19, 60, and 120 sec, respectively, after injection of gadopentetate dimeglumine. Three observers independently interpreted the images obtained with each technique in a blinded manner and in random order. RESULTS: Mean sensitivity and positive predictive values of CT for hypervascular hepatocellular carcinoma (66% and 97%, respectively) were higher than those of MR imaging (63% and 96%, respectively), but there was no significant difference in detecting sensitivity among the observers (p < 0.05). CT and MR imaging were complementary, with some tumors undetected by CT but revealed on MR imaging. There was also no significant difference in A(z) values between CT (0.74) and MR imaging (0.71) (p < 0.05). CONCLUSION: Dynamic MR imaging with 3D Fourier transformation-enhanced fast gradient-echo sequences with a special spectral inversion recovery pulse is recommended to improve the detection of hypervascular hepatocellular carcinoma nodules in addition to the use of dynamic helical CT with double arterial phase imaging.     

A tetrazolium-based colorimetric assay for metabolic activity of stored blood platelets

Introduction: Much work has been carried out in an attempt to establish the optimum cryopreservation of platelets. To estimate the surviving numbers of stored platelets, the metabolic redox activity of resting platelets was measured and compared with the aggregation response. Materials and methods: The activity was determined using a simple colorimetric assay based on reduction of a tetrazolium salt, WST-8 (4-[3-(2-methoxy-4-nitrophenyl)-2-[4-nitrophenyl]-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt), to water-soluble formazan and its quantification with a spectrophotometer. The aggregation response of the platelets was measured at 37 °C with an aggregometer. Results: Colored WST-8 formazan was produced in proportion to the number of intact fresh platelets, but only a little or none was produced by dead platelets lysed by sodium dodecyl sulfate (SDS), by platelets in which glycolysis had been blocked by the inhibitor monoiodoacetic acid (MIA), and by frozen platelets. The assay in conjunction with platelet aggregometry could distinguish between platelets which had lost only the aggregation response and those which had lost both aggregation response and redox activity. Freezing platelets in the presence of cryoprotectant Banbanker resulted in approximately 70% fresh platelets with redox activity and aggregation response. Conclusions: These results indicate that the WST-8 assay can be useful for identifying viable platelets independent of the aggregation response and may contribute to clarifying the mechanism of the loss of function of stored platelets.