Demonstration of an ecdysis-triggering compound in the epitracheal gland of the cotton bollworm, Helicoverpa armigera (Hubner) (Lepidoptera : Noctuidae)

The recent report of an ecdysis-triggering hormone (ETH) in the tobacco hornworm Manduca sexta and several other Lepidoptera prompted the search for the homologous hormone in the pest noctuid, Helicoverpa armigera. In M. sexta, ETH is produced in a large cell that forms part of a three-cell epitracheal gland complex found near each of the the larval and pupal spiracles. The homologous glands were found in H. armigera and an ecdysis-triggering function of the gland contents was confirmed by the induction of premature ecdysis after injection of a crude gland extract into pupae.

mRNA differential display of 2-amino-1-methyl-6-phenylinlidazo[4,5-b]pyridine-induced rat mammary gland tumors

The mRNA differential display technique was used to compare mRNAs between normal mammary gland and turner-derived epithelial cells from female Sprague-Dawley rat mammary gland tumors induced by the heterocyclic amine 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and promoted by a high-fat diet (23.5% corn oil). Two genes, beta-casein and transferrin, were identified as differentially expressed. The expression of these genes was examined across a bank of rat mammary gland tumors derived from animals on a low-fat diet (5% corn oil) or the high-fat diet. Carcinomas had over a 10- and 50-fold lower expression of beta-casein and transferrin, respectively than normal mammary gland. In addition, carcinomas from animals on the high-fat diet showed on average a 5-fold higher expression of beta-casein, and transferrin than carcinomas from animals on the low-fat diet. The results indicate the process of mammary gland tumorigenesis alters the expression of certain genes in the mammary gland, and that the level of dietary fat further modulates the expression of these genes.

Characterization of peroxisome proliferator-activated receptor alpha in normal rat mammary gland and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine-induced mammary gland tumors from rats fed high and low fat diets

Normal Sprague-Dau ley rat mammary gland epithelial cells and mammary gland carcinomas induced by 2-amino-1 -methyl-6-phenylimidazo[4,5-b]pyridine, a carcinogen found in the diet, were examined for the expression of peroxisome proliferator-activated receptor alpha (PPAR alpha). PPAR alpha mRNA and protein was detected in normal and tumor tissue by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. By quantitative RT-PCR, carcinomas had a 12-fold higher expression than control mammary glands, a statistically significant difference. PPAR alpha expression was examined in carcinomas and normal tissues from rats on high fat (23.5/% corn oil) and low fat (5% corn oil) diets. Although neither carcinomas, nor control tissues showed statistically significant differences between the two diet groups, PPAR alpha expression was the highest in carcinomas from rats on the high fat diet. The expression of PPAR alpha in normal mammary gland and its significant elevation in mammary gland carcinomas raises the possibility of its involvement in mammary gland physiology and pathophysiology. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.

Semiochemicals and social signaling in the wild European rabbit in Australia: I. Scent profiles of chin gland secretion from the field

The European rabbit (Oryctolagus cuniculus) uses the secretion of the chin gland in the maintenance of social status. Previous work has concentrated on secretion collected directly from the animal. In this study, the analysis was conducted by collecting scent marks made by free-ranging animals. Scent marks were found to be concentrated at the center of the area controlled by a social group, and at the boundaries between two adjacent social groups. Only the mark from dominant animals could be identified. Marks were also collected from the skin of rabbits, where they had been placed by the dominant individual. The mark found on the head of a subordinate animal may, in the future, be used to identify the dominant animal of the social group, who placed the mark.

Semiochemicals and social signaling in the wild European rabbit in Australia: II. Variations in chemical composition of chin gland secretion across sampling sites

The volatile components of the chin gland secretion of the wild European rabbit, Oryctolagus cuniculus (L.), were investigated with the use of gas chromatography. Studies of the chemical nature of this secretion by previous workers demonstrated that it was important in the maintenance of social structure in this species. This study identified 34 different volatile components that consist primarily of aromatic and aliphatic hydrocarbons. Especially common are a series of alkyl-substituted benzene derivatives that provide most of the compound diversity in the secretion. Samples of chin gland secretion collected from animals at three different geographical locations, separated by more than 100 km, showed significant differences in composition. This work suggests that variation among populations needs to be considered when undertaking semiochemical research. Alternate nonparametric methods are also used for the analysis of chromatographic data.

To fix or not to fix: The role of 2-phenoxyethanol in rabbit, Oryctolagus cuniculus, chin gland secretion

The European rabbit (Oryctolagus cuniculus) uses the secretion of the chin gland to maintain dominance hierarchies in the wild. Recent work has investigated changes in the secretion when social status is manipulated in the rabbit. When a rabbit becomes dominant, a new compound appears in his secretion, 2-phenoxyethanol. This compound is used as a fixative in the perfume industry. This study investigates whether the compound performs a similar function in the secretion of the rabbit. 2-Phenoxyethanol is not detected olfactorially by rabbits, and slows the release rate of some of the compounds that occur naturally in rabbit chin gland secretion. We suggest that when a rabbit becomes dominant, he adds a fixative to his secretion so that his scent will persist in the environment and not dissipate. He will thus come to dominate the olfactory environment, in much the same way as he does the physical environment.

Anogenital gland secretions of Lemur catta and Propithecus verreauxi coquereli: A preliminary chemical examination

Although prosimians are greatly olfaction-oriented, little is known about the specifics of how they use scent to communicate. In this preliminary study we attempted to delineate intra- and interspecific differences among the anogenital gland secretions of two lemur species (Lemur catta and Propithecus verreauxi coquereli) using gas chromatography-mass spectrometry (GC-MS). The results indicate that the two species are discernible through scent. Furthermore, we were able to identify reproductive status using this technique. The anogenital secretions of the different sexes in L. catta, though perhaps not P. v. coquereli, are chemically distinguishable. Given this information, it appears that at least some lemur species can use scent marks to determine species, sex, and reproductive status. (C) 2004 Wiley-Liss, Inc.

Executive "brake failure" following deactivation of human frontal lobe

In the course of daily living, humans frequently encounter situations in which a motor activity, once initiated, becomes unnecessary or inappropriate. Under such circumstances, the ability to inhibit motor responses can be of vital importance. Although the nature of response inhibition has been studied in psychology for several decades, its neural basis remains unclear. Using transcranial magnetic stimulation, we found that temporary deactivation of the pars opercularis in the right inferior frontal gyrus selectively impairs the ability to stop an initiated action. Critically, deactivation of the same region did not affect the ability to execute responses, nor did it influence physiological arousal. These findings confirm and extend recent reports that the inferior frontal gyrus is vital for mediating response inhibition.

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.