Properties and function of KCNQ1 K+ channels isolated from the rectal gland of Squalus acanthias

KCNQ1 (K(V)LQT1) K+ channels play an important role during electrolyte secretion in airways and colon. KCNQ1 was cloned recently from NaCl-secreting shark rectal glands. Here we study. the properties and regulation of the cloned sK(V)LQT1 expressed in Xenopus oocytes and Chinese hamster ovary (CHO) cells and compare the results with those obtained from in vitro perfused rectal gland tubules (RGT). The expression of sKCNQ1 induced voltage-dependent, delayed activated K+ currents, which were augmented by an increase in intracellular cAMP and Ca2+. The chromanol derivatives 293B and 526B potently inhibited sKCNQ1 expressed in oocytes and CHO cells, but had little effect on RGT electrolyte transport. Short-circuit currents in RGT were activated by alkalinization and were decreased by acidification. In CHO cells an alkaline pH activated and an acidic pH inhibited 293B-sensitive KCNQ1 currents. Noise analysis of the cell-attached basolateral membrane of RGT indicated the presence of low-conductance (

Primary Bartholin gland carcinoma: a report of seven cases

This study reviews our experience with 7 patients with primary Bartholin gland cancer (BGC) treated at the Queensland Gynaecological Cancer Centre (QCGC) and compares this with previously published data. A retrospective clinicopathologic review of all patients with primary BGC treated at QCGC from 1988 to 2000 was performed. Of the 7 patients treated, all underwent primary surgery and 5 of the 7 patients received radiotherapy postoperatively. All patients presented with a local swelling or a lump. Two had associated discharge and 2 had associated pain. Of the 7 patients, 2, 3 and 2 respectively were classified as having Stage IB, II or III disease. Five of the 7 patients had squamous cell carcinoma (SCC), one had adenoid-cystic carcinoma and 1 had a small-cell neuroendocrine cancer of the Bartholin gland. None of the patients with SCC developed recurrent disease. The patient with adenoid-cystic carcinoma experienced local recurrences at 4 years and again at 5 years and 3 months. Nine years after primary treatment she was diagnosed with pulmonary metastases. The patient with small-cell neuroendocrine cancer of the Bartholin gland was considered tumour-free after operation. Thorough imaging, including a CT scan of her chest, abdomen and pelvis showed no evidence of disease. She died 1 year and three months after diagnosis from disseminated pulmonary disease. We present the first report, of small cell neuroendocrine cancer of the Bartholin gland. Therapeutic principles in the management of vulval cancer at other sites appear to be appropriate for management of BGC.

Submandibular gland aplasia and progressive dental caries: A case report

When severe caries occurs in mandibular permanent incisor teeth, the clinician should consider the possibility of associated submandibular gland aplasia or salivary hypofunction. Early diagnosis of submandibular gland disease is essential, as operative problems involving restoration of mandibular incisor teeth are considerable. Furthermore, progressive severe dental caries can present a dilemma for the clinician in affected individuals, despite intensive preventive and restorative therapy. A case report describing severe progressive dental caries and enamel demineralization of the permanent mandibular incisor teeth in a young girl is presented. Further investigation revealed absence of functional bilateral submandibular salivary glands contributing to the rapid breakdown of the teeth despite intensive preventive measures.

Hand-assisted laparoscopic adrenalectomy: An alternative minimal invasive surgical technique for the adrenal gland

Background: Presently the surgical approach to the adrenal gland is in a state of flux. While the traditional approach to the adrenal gland has been the open transabdominal technique, more recently laparoscopic approaches, particularly via the transabdominal route, have increasingly been utilized. However, laparoscopic intervention for the adrenal gland can be problematic in certain circumstances, particularly for large adrenal masses and in instances of adrenal malignancies. Methods: In this report we describe the use of hand-assisted laparoscopic adrenalectomy as an alternative minimal invasive surgical approach to the adrenal gland. Hand-assisted laparoscopic adrenalectomy using the HandPort system (Smith & Nephew, Sydney, Australia) was undertaken in three patients requiring adrenalectomy for mass lesions including one patient with Conn's syndrome. Results: In all three cases, surgery proceeded promptly and uneventfully. In the present paper, the details of the technique of hand-assisted adrenalectomy are described. This is the first report in the world literature of this new technique for the adrenal gland. Conclusions: Hand-assisted laparoscopic adrenalectomy is an easily performed technique, which can be completed within a short operative time span and which has the advantage of providing intraoperative tactile localization for the adrenal gland. It may be particularly applicable for large adrenal tumours, yet only involves the performance of a small abdominal incision. Postoperative recovery is comparable with that reported for the laparoscopic-only technique. Hand-assisted adrenalectomy is a new technique which has great potential and which warrants further evaluation.

Secondary structure of the third extracellular loop responsible for ligand selectivity of a mammalian gonadotropin-releasing hormone receptor

The extracellular loop 3 (ECL3) of the mammalian gonadotropin-releasing hormone receptor (GnRH-R) contains an acidic amino acid (Glu(301) in the mouse GnRH-R,) that confers agonist selectivity for Are in mammalian GnRH. It is proposed that a specific conformation of ECL3 is necessary to orientate the carboxyl side chain of the acidic residue for interaction with Arg(8) of GnRH, which is supported by decreased affinity for Arg(8) GnRH but not Gln(8) GnRH when an adjacent Pro is mutated to Ala. To probe the structural contribution of the loop domain to the proposed presentation of the carboxyl side chain, we synthesized a model peptide (CGPEMLNRVSEPGC) representing residues 293-302 of mouse ECL3, where Cys and Gly residues are added symmetrically at the N and C termini, respectively, allowing the introduction of a disulfide bridge to simulate the distances at which the ECL3 is tethered to the transmembrane domains 6 and 7 of the receptor. The ability of the ECL3 peptide to bind GnRH with low affinity was demonstrated by its inhibition of GnRH stimulation of inositol phosphate production in cells expressing the GnRH-R. The CD bands of the ECL3 peptides exhibited a superposition of predominantly unordered structure and partial contributions from beta-sheet structure. Likewise, the analysis of the amide I and amide III bands from micro-Raman and FT Raman experiments revealed mainly unordered conformations of the cyclic and of the linear peptide. NMR data demonstrated the presence of a beta-hairpin among an ensemble of largely disordered structures in the cyclic peptide. The location of the turn linking the two strands of the hairpin was assigned to the three central residues L-296, N-297, and R-298. A small population of structured species among an ensemble of predominantly random coil conformation suggests that the unliganded receptor represents a variety of structural conformers, some of which have the potential to make contacts with the ligand. We propose a mechanism of receptor activation whereby binding of the agonist to the inactive receptor state induces and stabilizes a particular structural state of the loop domain, leading to further conformational rearrangements across the transmembrane domain and signal propagating interaction with G proteins. Interaction of the Glu(301) of the receptor with Arg(8) of GnRH induces a folded configuration of the ligand. Our proposal thus suggests that conformational changes of both ligand and receptor result from this interaction.

Enhancement or modulation of the vector competence of ochlerotatus vigilax (Diptera : Culicidae) for Ross River virus by temperature

Two different doses of Ross River virus (1111) were fed to Ochlerotatus vigilax (Skuse), the primary coastal vector in Australia; and blood engorged females were held at different temperatures up to 35 d. After ingesting 10(4.3) CCID50/Mosquito, mosquitoes reared at 18 and 25degreesC (and held at the same temperature) had higher body remnant and head and salivary gland titers than those held at 32degreesC, although infection rates were comparable. At 18, 25, and 32degreesC, respectively, virus was first detected in the salivary glands on days 3, 2, and 3. Based on a previously demonstrated 98.7% concordance between salivary gland infection and transmission, the extrinsic incubation periods were estimated as 5, 4, and 3 d, respectively, for these three temperatures. When Oc. vigilax reared at 18, 25, or 32degreesC were fed a lower dosage of 10(3.3) CCID50 RR/mosquito, and assayed after 7 d extrinsic incubation at these (or combinations of these) temperatures, infection rates and titers were similar. However, by 14 d, infection rates and titers of those reared and held at 18 and 32degreesC were significantly higher and lower, respectively. However, this process was reversible when the moderate 25degreesC was involved, and intermediate infection rates and titers resulted. These data indicate that for the strains of RR and Oc. vigilax used, rearing temperature is unimportant to vector competence in the field, and that ambient temperature variations will modulate or enhance detectable infection rates only after 7 d: extrinsic incubation. Because of the short duration of extrinsic incubation, however, this will do little to influence RR epidemiology, because by this time some Oc. vigilax could be seeking their third blood meal, the latter two being infectious.

Media Convergence's Third Wave Content Streaming

Movies, pieces of music, books, or newspapers can all be expressed in the same binary code. Discrete forms of analogue media are just different dialects of the language of computerese. Content is becoming a very liquid asset. To take Marshall McLuhan's famed dictum a step further: The message is now independent of the medium

Anaphoric choices in Japanese fictional novels: the discourse arrangement of noun phrases, zero and third person pronouns

By examining Japanese fictional novels, this article will discuss how anaphoric devices (noun phrases (NPs), third person pronouns (TPPs), and zero anaphors) are selected and arranged in a given discourse. The traditional view of anaphora considers the co-referential relationship between anaphoric devices to be syntagmatic; that is, a pronoun, for example, refers back to its antecedent. It also declares the hierarchical order of information values between anaphoric devices; NPs are semantically the most informative, indicating an episode boundary, and pronouns less informative. Furthermore, zero anaphora is the most referentially transparent, showing the most accessibility of a topic. However, real text shows the contrary. NPs occur frequently while there is no apparent discourse boundary, and the same episode is continuous. This is because zero anaphors and TPPs (if they occur) break down readily due to the nature of a forthcoming sentence and the NP is reinstated, in order to continue the same topic in a given discourse. Therefore, the article opposes the traditional view of anaphora. Based on the concept of text processing, using ‘mental representations’, this article will determine certain occurrence patterns of the three anaphoric devices.