Orbital Variations of Biogenic CaCO3 and Opal Abundance in the Western and Central Equatorial Pacific Ocean During the Late Quaternary

Biogenic CaCO3 and opal abundances were measured in two piston cores (PC313 and PC5101) collected, respectively, along the equator in the western and central Pacific Ocean. The age model for core PC313, which extends to about 750 ka, was developed by comparing the oxygen isotope stratigraphy of planktonic foraminifera (N. dutetrei) to the SPECMAP stack. The age model for core PC5101, which extends to about 600 ka, was developed by stratigraphic correlation of CaCO3 contents to those in the well-dated core RC11-210 (Chuey et al. 1987). Both cores distinctly exhibited a series of CaCO3 and opal variations, which are mainly controlled by the orbital eccentricity cycle of about 100-kyr. The orbital-scale cyclic variations of CaCO3 and opal contents appear to be contrasting in both cores such that high CaCO3 and low opal contents occurred during the glacial periods. In contrast, during the interglacial periods, low CaCO3 and high opal contents occurred. Mostly remarkable is the distinct occurrence of a mid-Bruhnes event (MBE) at around 350 ka. The CaCO3 content was higher in core PC5101 than in core PC313 before the MBE, whereas biogenic opal abundance became higher in core PC5101 after the MBE. Such a characteristic discrepancy of biogenic (CaCO3 and opal) production, i.e., a succession of primary producers from coccolithophore to diatom, between cores PC313 and PC5101 may be attributed to the prevailing dominant hydrographic conditions (i.e., the South Equatorial Current), in the path of which both cores are located. The intensity of westward propagation might have been an important factor in contrasting biogenic production centering around the MBE

Hepatocellular carcinoma with characteristic mucin production: a case report

We present a unique case of hepatocellular carcinoma with mucin-producing gland formation. A 53-year-old man with hepatitis B infection presented with weight loss for the past month. Computed tomography demonstrated a 10 × 9.8 cm mass in the right hepatic lobe accompanied by cirrhotic changes in the hepatic parenchyma. Right hepatectomy was performed, and the tumor cut surface showed a poorly-circumscribed, white to pink tumor with numerous nodules and extensive necrosis. Microscopically, the tumor was composed of thick trabeculae and large, irregularly-shaped islands, both of which were filled with pleomorphic eosinophilic hepatoid cells or gland-forming columnar cells with mucin production. Those cells were immunoreactive for cytokeratin 19 in both the trabeculae and the glands. In some tumor cells, limited immunoreactivity for cytokeratin 7, epithelial membrane antigen and carcinoembryonic antigen was noted. The cells forming thick trabeculae were focally positive for hepatocyte paraffin 1 and alpha-fetoprotein. We suggest that this tumor shows bidirectional differentiation into hepatocytes and cholangiocytes, supporting the concepts that human hepatocarcinogenesis can be based on transformation of progenitor cells which can imply divergent differentiation

Clinical Impact of Prophylactic Antibiotic Treatment for Self-Expandable Metallic Stent Insertion in Patients with Malignant Colorectal Obstruction

Purpose. The aim of this study was to determine the efficacy of prophylactic antibiotics (PA) for reducing the infectious complications and the potential risk factors responsible for the infectious complications after stent insertion for malignant colorectal obstruction. Methods. We performed a retrospective review of 224 patients who underwent self-expandable metallic stent (SEMS) insertion for malignant colorectal obstruction from May 2004 to December 2012. Results. There were 145 patients in the PA group and 79 in non-PA group. The CRP level in PA group was significantly higher than that in non-PA. Abdominal tenderness and mechanical ileus were significantly more frequent in PA group than those in non-PA. The frequency of post-SEMS insertion fever, systemic inflammatory response syndrome (SIRS), and bacteremia was not significantly different between PA and non-PA groups. In multivariate analysis, the CRP level was risk factor related to post-SEMS insertion SIRS. However, in propensity score matching analysis, there was no independent risk factor related to post-SEMS insertion fever, SIRS, and bacteremia. Conclusion. The use of PA in patients with malignant colorectal obstruction may be not effective to prevent the development of infectious complications after SEMS insertion

Clarithromycin Susceptibility Testing of Mycobacterium avium Complex Using 2,3-Diphenyl-5-thienyl-(2)-tetrazolium Chloride Microplate Assay with Middlebrook 7H9 Broth

A series of 119 Mycobacterium avium complex isolates were subjected to clarithromycin susceptibility testing using microplates containing 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC). Among 119 isolates, 114 (95.8%) were susceptible to clarithromycin and 5 were resistant according to the new and the standard method. STC counts the low cost and reduces the number of procedures needed for susceptibility testing

Metronidazole-induced encephalopathy in a patient with liver cirrhosis

Encephalopathy is a disorder characterized by altered brain function, which can be attributed to various causes. Encephalopathy associated with metronidazole administration occurs rarely and depends on the cumulative metronidazole dose, and most patients with this condition recover rapidly after discontinuation of therapy. Because metronidazole is metabolized in the liver and can be transported by the cerebrospinal fluid and cross the blood-brain barrier, it may induce encephalopathy even at a low cumulative dose in patients with hepatic dysfunction. We experienced a patient who showed ataxic gait and dysarthric speech after receiving metronidazole for the treatment of hepatic encephalopathy that was not controlled by the administration of lactulose. The patient was diagnosed as metronidazole-induced encephalopathy, and stopping drug administration resulted in a complete recovery from encephalopathy. This case shows that caution should be exercised when administering metronidazole because even a low dose can induce encephalopathy in patients with liver cirrhosis