Bile duct wall metastasis from micropapillary variant transitional cell carcinoma of the urinary bladder mimicking primary hilar cholangiocarcinoma.
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Bile Duct Neoplasms↗
Biomedical subjects
Nam Hoon Cho
Publications and source records attributed to Nam Hoon Cho.
Surgical anatomy of the sphenopalatine artery in lateral nasal wall.
OBJECTIVE: We investigated the surgical anatomy of the sphenopalatine artery. First, the location of the sphenopalatine foramen on the lateral nasal wall and the pattern of the main branches of the sphenopalatine artery from the sphenopalatine artery were studied. Second, the course of the posterior lateral nasal artery with respect to the posterior wall of the maxillary sinus, the perpendicular plate of the palatine bone, and the pattern of distribution of its branches on the fontanelle was determined. Third, the distribution pattern on the inferior turbinate was analyzed. STUDY DESIGN: Fifty midsagittal sections of randomly selected Korean adult cadaver heads with intact sphenoid sinus and surrounding structures were used in the study. METHODS: The mucosa on the sphenopalatine foramen and its surrounding mucosa were removed with a microscissors, a fine forceps, and a pick to expose the sphenopalatine artery under an operating microscope (original magnification x6). RESULTS: The feeding vessels of the superior turbinate were from the septal artery in 36 cases (72%). The feeding vessels to the middle turbinate branch originated from the proximal portion of the posterior lateral nasal artery just after exiting the sphenopalatine foramen in 44 cases (88%). Some portion of the posterior lateral nasal artery ran anterior to the posterior wall of the maxillary sinus in 38%. The major feeding arteries to the fontanelle were from the inferior turbinate branch in 25 cases (50%). In most cases, the inferior turbinate branch was the end artery of the posterior lateral nasal artery (98%). CONCLUSIONS: The study provides detailed information concerning the sphenopalatine artery, which we hope will help explain the arterial bleeding that may occur during ethmoidectomy, middle meatal antrostomy, conchotomy, and endoscopic ligation of the sphenopalatine artery.
Arteries↗
Alteration of cell cycle in cervical tumor associated with human papillomavirus: cyclin-dependent kinase inhibitors.
The ability of viral oncoproteins to subvert cell cycle checkpoints may constitute a mechanism by which viral oncoproteins induce genetic instability. HPV 16 E6 and E7 disrupt cell cycle checkpoints, particularly affecting nearly all cyclin-dependent kinase inhibitors linked to the G1- and G2- checkpoints, in each case by means of a different mechanism. HPV 16 E7 shows homology with the pRb binding sites of cyclin D1, which consequently releases E2F. In addition, E7 directly binds to p21, and releases PCNA and other S-phase promoting genes. In turn, released E2F activates cyclin E, and cyclin E accelerates p27 proteolysis as a function of the antagonistic reaction of its own inhibitor. The induction of p16 expression is assumed to be indirectly associated with E7, which is upregulated only after prolonged inactivation of Rb. HPV 16 E6 decreased the fidelity of multiple checkpoints controlling both entry into and exit from mitosis, with the mechanism of p53 inactivation. In addition, HPV 16 E6 increased the sensitivity to chemically induced S-phase premature mitosis and decreased mitotic spindle assembly checkpoint function. Alongside the impressive advances made in the understanding of the molecular mechanisms, which HPV disrupts, the validity of these conclusions should be evaluated in the diagnostic and prognostic fields.
Cyclin-Dependent Kinase Inhibitor p16↗
Human papillomavirus type 59 identified in a verrucous cyst of the flank.
The verrucous cyst is a non-plantar epidermoid cyst with histopathological features of human papillomavirus (HPV) infection, including papillomatosis and hypergranulosis of the cyst lining. We report the first case of a verrucous cyst demonstrating not only the histopathological and immunohistochemical features of HPV infection, but also homology with HPV type 59 on HPV genotyping. A 28-year-old male developed a palpable mass in his right flank. Histological examination revealed an intradermal cyst lined by an acanthotic and papillomatous squamous epithelium with prominent keratohyaline granules and squamous eddies. The keratinocyte nuclei were positive for papillomavirus antigens on immunohistochemistry and HPV genotyping demonstrated a homology to HPV type 59, a high-risk genital type. Although we only experienced a single case with such a finding, we suggest that it may be necessary to subject patients with verrucous cysts to a closer follow up for better characterization of their clinical behavior.
Adult↗