Prolonged survival of the phosphorylated form of rhodopsin during dark adaptation of Royal College Surgeons rat

AbstractTo study rhodopsin (Rho) phosphorylation and dephosphorylation in Royal College of Surgeons (RCS) rat retina, specific antibodies toward major Rho phosphorylation sites in vivo, 334Ser or 338Ser, were prepared by immunization of authentic phosphorylated peptides in rabbit. Enzyme-linked immunosorbent assay identified that the raised antibodies exclusively recognized either the phosphorylated 334Ser or 338Ser site. In immunofluorescence labeling, both antibodies recognized photoreceptor outer segments in light-adapted retinas from Sprague–Dawley (SD), Brown–Norway (BN) and RCS rat. During dark adaptation, immunoreactivities toward phosphorylated 338Ser and 334Ser sites were diminished within several hours (0.2–2 h) in SD and BN rat retinas. However, those toward phosphorylated 338Ser and 334Ser sites were diminished within 4 to 7 days in RCS rat retinas. In vitro studies demonstrated decreased levels of both Rho phosphorylation and dephosphorylation reactions in RCS retinas. However, the dephosphorylation reaction was much more greatly affected than the phosphorylation reaction. Extremely prolonged survival of phosphorylated forms of Rho may contribute to persistent misregulation of phototransduction processes in retinal degeneration in RCS rat

Elevated Expression of Pyrimidine Nucleoside Phosphorylase (PyNPase) in Renal Cell Carcinoma Tissue

Background: Pyrimidine nucleoside phosphorylase (PyNPase) is an enzyme that converts 5\u27-deoxy-5-fluorouridine to 5- fluorouracil. PyNPase is identical to platelet-derived endothelial cell growth factor (PD-ECGF), and has angiogenic activity. In the present study of PyNPase activity in renal cell carcinoma, we tested for correlation between PyNPase activity and tumor extension, tumor proliferation and clinical characteristics. Methods: Samples of tumor tissue and non-tumor tissue were obtained from 10 renal cell carcinoma patients who underwent radical nephrectomy. These samples were examined, and PyNPase activity of the tissues was assayed. Results: PyNPase activity was significantly higher in renal cancer tissue than in normal tissue (p<0.01), and in immunohistochemical assays PyNPase was strongly stained in the cytoplasm of renal cancer cells. However, there were no significant correlation between PyNPase activity and tumor extension, according to the results of histopathological examination and evaluation of vascularity of renal cancer tumor tissue. Conclusion: In this study, we did not observe correlation between PyNPase activity and renal cancer extension and proliferation. However, the present data suggest that pyrimidine-class drugs may be useful against renal cell carcinoma, because PyNPase activity is significantly higher in renal cancer tissue than in normal tissue

The Possible Role of TASK Channels in Rank-Ordered Recruitment of Motoneurons in the Dorsolateral Part of the Trigeminal Motor Nucleus.

Because a rank-ordered recruitment of motor units occurs during isometric contraction of jaw-closing muscles, jaw-closing motoneurons (MNs) may be recruited in a manner dependent on their soma sizes or input resistances (IRs). In the dorsolateral part of the trigeminal motor nucleus (dl-TMN) in rats, MNs abundantly express TWIK (two-pore domain weak inwardly rectifying K channel)-related acid-sensitive-K(+) channel (TASK)-1 and TASK3 channels, which determine the IR and resting membrane potential. Here we examined how TASK channels are involved in IR-dependent activation/recruitment of MNs in the rat dl-TMN by using multiple methods. The real-time PCR study revealed that single large MNs (&gt;35 μm) expressed TASK1 and TASK3 mRNAs more abundantly compared with single small MNs (15-20 μm). The immunohistochemistry revealed that TASK1 and TASK3 channels were complementarily distributed in somata and dendrites of MNs, respectively. The density of TASK1 channels seemed to increase with a decrease in soma diameter while there were inverse relationships between the soma size of MNs and IR, resting membrane potential, or spike threshold. Dual whole-cell recordings obtained from smaller and larger MNs revealed that the recruitment of MNs depends on their IRs in response to repetitive stimulation of the presumed Ia afferents. 8-Bromoguanosine-cGMP decreased IRs in small MNs, while it hardly changed those in large MNs, and subsequently decreased the difference in spike-onset latency between the smaller and larger MNs, causing a synchronous activation of MNs. These results suggest that TASK channels play critical roles in rank-ordered recruitment of MNs in the dl-TMN

A case of locally advanced adenosquamous carcinoma of the cecum with long-term survival

A 63-year-old woman was admitted to our hospital with a right lower abdominal mass and general fatigue. Preoperative examination suggested a large ovarian tumor or cecal carcinoma. However, her intraoperative diagnosis was colon cancer; we therefore performed an ileocecal resection with oophorectomy. The tumor was pathologically diagnosed as adenosquamous carcinoma T4bN1M-stage IIIa. We administrated CapeOX adjuvant chemotherapy for 6 months. Adenosquamous carcinoma is extremely rare, at around 0.1% of all colorectal cancers, and usually has a poor prognosis. The patient is still alive without recurrence after 84 post-operative months, even with later developments of metachronous early colorectal cancer and breast cancer. We herein report a rare case of cecal ASC with good prognosis