Diel Patterns of Pheromone Release by Male Sea Lamprey.

Costs to producing sexual signals can create selective pressures on males to invest signaling effort in particular contexts. When the benefits of signaling vary consistently across time, males can optimize signal investment to specific temporal contexts using biological rhythms. Sea lamprey, Petromyzon marinus, have a semelparous life history, are primarily nocturnal, and rely on pheromone communication for reproduction; however, whether male investment in pheromone transport and release matches increases in spawning activity remains unknown.

A pheromone antagonist liberates female sea lamprey from a sensory trap to enable reliable communication.

The evolution of male signals and female preferences remains a central question in the study of animal communication. The sensory trap model suggests males evolve signals that mimic cues used in nonsexual contexts and thus manipulate female behavior to generate mating opportunities. Much evidence supports the sensory trap model, but how females glean reliable information from both mimetic signals and their model cues remains unknown.

Fatty-acid derivative acts as a sea lamprey migratory pheromone.

Olfactory cues provide critical information for spatial orientation of fish, especially in the context of anadromous migrations. Born in freshwater, juveniles of anadromous fish descend to the ocean where they grow into adults before migrating back into freshwater to spawn. The reproductive migrants, therefore, are under selective pressures to locate streams optimal for offspring survival.

Bile Salt-like Dienones Having a Novel Skeleton or a Rare Substitution Pattern Function as Chemical Cues in Adult Sea Lamprey.

Two novel sulfated bile salt-like dienones, featuring either a unique, rearranged side chain or a rare cis-11,12-diol on the steroidal C-ring, herein named petromyzene A (1) and B (2), respectively, were isolated from water conditioned with spawning male sea lamprey (Petromyzon marinus; a jawless vertebrate animal). The structures of these natural products were elucidated by mass spectrometry and NMR spectroscopy. Petromyzenes A and B exhibited high olfactory potency for adult sea lamprey and strong behavioral attraction for spawning females.

Mixtures of Two Bile Alcohol Sulfates Function as a Proximity Pheromone in Sea Lamprey.

Unique mixtures of pheromone components are commonly identified in insects, and have been shown to increase attractiveness towards conspecifics when reconstructed at the natural ratio released by the signaler. In previous field studies of pheromones that attract female sea lamprey (Petromyzon marinus, L.), putative components of the male-released mating pheromone included the newly described bile alcohol 3,12-diketo-4,6-petromyzonene-24-sulfate (DkPES) and the well characterized 3-keto petromyzonol sulfate (3kPZS).

Chemical cues and pheromones in the sea lamprey (Petromyzon marinus).

Chemical cues and pheromones guide decisions in organisms throughout the animal kingdom. The neurobiology, function, and evolution of olfaction are particularly well described in insects, and resulting concepts have driven novel approaches to pest control. However, aside from several exceptions, the olfactory biology of vertebrates remains poorly understood.

A pheromone outweighs temperature in influencing migration of sea lamprey.

Organisms continuously acquire and process information from surrounding cues. While some cues complement one another in delivering more reliable information, others may provide conflicting information. How organisms extract and use reliable information from a multitude of cues is largely unknown.

Iso-petromyroxols: novel dihydroxylated tetrahydrofuran enantiomers from sea lamprey (Petromyzon marinus).

An enantiomeric pair of new fatty acid-derived hydroxylated tetrahydrofurans, here named iso-petromyroxols, were isolated from sea lamprey larvae-conditioned water. The relative configuration of iso-petromyroxol was elucidated with 1D and 2D NMR spectroscopic analyses. The ratio of enantiomers (er) in the natural sample was measured by chiral-HPLC-MS/MS to be ca.

(+)- and (-)-petromyroxols: antipodal tetrahydrofurandiols from larval sea lamprey (Petromyzon marinus L.) that elicit enantioselective olfactory responses.

(+)- and (-)-petromyroxol [(+)-1 and (-)-1, respectively], two novel tetrahydrofuran (THF)-diol fatty acid enantiomers, were isolated from water conditioned with larval sea lamprey. We herein describe their isolation and subsequent resolution using chiral chromatography. The absolute configuration of each enantiomer was determined by a combination of Mosher ester analysis and comparison with related natural and synthetic products.

A new clarification method to visualize biliary degeneration during liver metamorphosis in Sea Lamprey (Petromyzon marinus).

Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian countries, with a reported frequency of 1 in 5,000 in Taiwan. Although much is known about the management of biliary atresia, its pathogenesis is still elusive. The sea lamprey (Petromyzon marinus) provides a unique opportunity to examine the mechanism and progression of biliary degeneration.

Petromyzonin, a hexahydrophenanthrene sulfate isolated from the larval sea lamprey (Petromyzon marinus L.).

A new hexahydrophenanthrene sulfate was identified from water conditioned with sea lamprey larvae ( Petromyzon marinus ) and named petromyzonin. Its structure was unequivocally elucidated on the basis of spectroscopic analyses including comparison with spectra of known compounds. The absolute configuration was determined by electronic circular dichroism.

Odor-conditioned rheotaxis of the sea lamprey: modeling, analysis and validation.

Mechanisms for orienting toward and locating an odor source are sought in both biology and engineering. Chemical ecology studies have demonstrated that adult female sea lamprey show rheotaxis in response to a male pheromone with dichotomous outcomes: sexually mature females locate the source of the pheromone whereas immature females swim by the source and continue moving upstream. Here we introduce a simple switching mechanism modeled after odor-conditioned rheotaxis for the sea lamprey as they search for the source of a pheromone in a one-dimensional riverine environment.

Biosynthesis and release of pheromonal bile salts in mature male sea lamprey.

Background: In vertebrates, bile salts are primarily synthesized in the liver and secreted into the intestine where they aid in absorption of dietary fats. Small amounts of bile salts that are not reabsorbed into enterohepatic circulation are excreted with waste. In sexually mature male sea lamprey (Petromyzon marinus L.

Characterization of a novel bile alcohol sulfate released by sexually mature male sea lamprey (Petromyzon marinus).

A sulphate-conjugated bile alcohol, 3,12-diketo-4,6-petromyzonene-24-sulfate (DKPES), was identified using bioassay-guided fractionation from water conditioned with sexually mature male sea lamprey (Petromyzon marinus). The structure and relative stereochemistry of DKPES was established using spectroscopic data. The electro-olfactogram (EOG) response threshold of DKPES was 10(-7) Molar (M) and that of 3-keto petromyzonol sulfate (3 KPZS; a known component of the male sea lamprey sex pheromone) was 10(-10) M.

A thermogenic secondary sexual character in male sea lamprey.

Secondary sexual characters in animals are exaggerated ornaments or weapons for intrasexual competition. Unexpectedly, we found that a male secondary sexual character in sea lamprey (Petromyzon marinus) is a thermogenic adipose tissue that instantly increases its heat production during sexual encounters. This secondary sexual character, developed in front of the anterior dorsal fin of mature males, is a swollen dorsal ridge known as the 'rope' tissue.

Isolation and identification of petromyzestrosterol, a polyhydroxysteroid from sexually mature male sea lamprey (Petromyzon marinus L.).

Petromyzestrosterol (1), a novel polyhydroxylated steroid, was identified from water conditioned with sexually mature male sea lamprey (Petromyzon marinus), a jawless vertebrate animal. Along with this novel steroid, two known steroids, 7α,12α,24-trihydroxy-5α-cholan-3-one-24-sulfate (3k PZS) and 7α,12α,24-trihydroxy-5α-cholan-24-sulfate (PZS), were isolated. Structures of these compounds were unequivocally established by spectroscopic analyses and by comparison with spectra of known compounds.

Exploring weight loss services in primary care and staff views on using a web-based programme.

Background: Demand is increasing for primary care to deliver effective weight management services to patients, but research suggests that staff feel inadequately resourced for such a role. Supporting service delivery with a free and effective web-based weight management programme could maximise primary care resource and provide cost-effective support for patients. However, integration of e-health into primary care may face challenges.

Multiplex quantification of lamprey specific bile acid derivatives in environmental water using UHPLC-MS/MS.

Larval and adult sea lampreys (Petromyzon marinus) release bile salts and acids into the surrounding aquatic environment. Some of these bile salts and acids, such as petromyzonol sulfate (PZS), 3-keto petromyzonol sulfate (3k PZS), petromyzonamine disulfate (PADS), petromyzosterol disulfate (PSDS), and 3-keto allocholic acid (3k ACA), may function as pheromones. To examine the release and distribution patterns of these metabolites, which this study has termed bile acid derivatives, we developed a novel UHPLC-MS/MS method that was characterized by simple sample preparation, baseline separation, and short analysis time for all studied compounds.

A prospective study of nutrition education and oral nutritional supplementation in patients with Alzheimer's disease.

Background: Weight loss in patients with Alzheimer's disease (AD) is a common clinical manifestation that may have clinical significance.

Objectives: To evaluate if there is a difference between nutrition education and oral nutritional supplementation on nutritional status in patients with AD.

Methods: A randomized, prospective 6-month study which enrolled 90 subjects with probable AD aged 65 years or older divided into 3 groups: Control Group (CG) [n = 27], Education Group (EG) [n = 25], which participated in an education program and Supplementation Group (SG) [n = 26], which received two daily servings of oral nutritional supplementation.

Quantification of a male sea lamprey pheromone in tributaries of Laurentian Great Lakes by liquid chromatography-tandem mass spectrometry.

We developed an assay for measuring 7α,12α,24-trihydroxy-5a-cholan-3-one-24-sulfate (3kPZS), a mating pheromone released by male sea lampreys (Petromyzon marinus), at low picomolar concentrations in natural waters to assess the presence of invasive populations. 3kPZS was extracted from streamwater at a rate of recovery up to 90% using a single cation-exchange and reversed-phase mixed-mode cartridge, along with [(2)H(5)]3kPZS as an internal standard, and quantified using ultrahigh performance liquid chromatography-tandem mass spectrometry. The limit of detection was below 0.

Role of IL-4 in aversion induced by food allergy in mice.

To ascertain the role of IL-4 in aversion to antigen induced by food allergy, wild type and IL-4 deficient BALB/c mice were sensitized with ovalbumin and challenged orally with egg white. Sensitized wild type mice had increased production of IL-4 by spleen and mesenteric lymph node cells in vitro, higher levels of serum anti-ovalbumin IgE and IgG1, aversion to ingestion of the antigen and loss of body weight after continuous oral challenge. Intestinal changes in wild type sensitized mice included eosinophil infiltration and increased mucus production.

The role of the health-care assistant in general practice.

The role of the health-care assistant (HCA) has developed rapidly in general practice and has occurred on an ad hoc basis across the UK, with the precise role shaped by the requirements and culture of individual practices. Currently, there is no regulation of HCAs and little published material about the remit of the role. This study aimed to describe general practice colleagues' perceptions of the HCA role; identify key areas of inter-professional agreement and disagreement about the role; and describe the likely impact of these on the direction and development of HCAs.

A synthesized pheromone induces upstream movement in female sea lamprey and summons them into traps.

Female insect pheromone blends induce robust tracking responses in males and direct them into traps. In vertebrates, pheromones that induce strong and precise tracking responses in natural habitats have rarely been described. Here, we show in the sea lamprey (Petromyzon marinus), a vertebrate invader of the Laurential Great Lakes, that a synthesized component of the male mating pheromone, 7alpha, 12alpha, 24-trihydroxy-5alpha-cholan-3-one 24-sulfate (3kPZS), when released into a stream to reach concentrations of 10(-14), 10(-13), 10(-12), 10(-11), or 10(-10) M, triggers robust upstream movement in ovulated females drawing approximately 50% into baited traps.

An experimental in-vivo canine model for adult shunt infection.

Background: Detailed human studies of the mechanisms and development of shunt infection in real time are not possible, and we have developed a canine hydrocephalus model to overcome this. The intention of this pilot study was to show that the canine hydrocephalus model could be shunted using conventional "human" shunts, and that a shunt infection could be established so that further studies could then be planned.

Methods: Hydrocephalus was induced in seven dogs (Canis familiaris) by fourth ventricle obstruction.