Students' self-reported fears and the perceived origins thereof.

The objective of this study was to explore the five most frequently reported fears in a sample of university students, and investigate the origins of these fears. The study employed a cross-sectional design with convenience sampling. Data were collected using a self-report questionnaire and analysed using a combination of descriptive statistics and content analysis. Participants consisted of 544 first-year psychology students. This study identified academic failure, animals, general failure, losing loved ones to death, and violence/crime as the top five fears among a sample of university students. 'Conditioning experiences' was one of the most prominent pathways in the acquisition of all these fears. 'Negative information transmission' was also a dominant pathway relating to the origin of fear such as academic failure and violence/crime. However, 'modelling experiences' was not identified as a prominent pathway in the present study. These findings contribute to identifying the origins of first-year students' self-reported fears by using the three pathways theory. These findings may contribute meaningfully to the development and implementation of prevention and intervention programmes at higher education institutions.

Systematic review of a marine nutriceutical supplement in clinical trials for arthritis: the effectiveness of the New Zealand green-lipped mussel Perna canaliculus.

BACKGROUND: Nutritional supplements, such as Seatone, which contain freeze-dried tissue from the New Zealand green-lipped mussel Perna canaliculus, are sold in many countries to relieve arthritic symptoms and to aid in the regeneration of arthritic and injured joints. METHODS: Searches for all published controlled trials on the clinical effectiveness of green-lipped mussel, as a nutritional supplement with potential health benefits for arthritis, were carried out from four independent databases. No language restrictions were imposed, and the review was undertaken from extracted data and was assessed critically according to predefined criteria by the authors. RESULTS: Reports of clinical studies, using freeze-dried mussel powder, show mixed outcome measures and are not conclusive, with only two of five randomized controlled trials attesting benefits for rheumatoid and osteoarthritis patients. Similarly, animal studies have likewise yielded mixed findings. In both these cases possibly due to the lack of stabilization of the omega-3 polyunsaturated fatty acids, now known to be the basis of anti-inflammatory activity. CONCLUSION: There is little consistent and compelling evidence, to date, in the therapeutic use of freeze-dried green-lipped mussel powder products for rheumatoid or osteoarthritis treatment, particularly in comparison to other cheaper alternative nutriceutical supplements of proven efficacy. However, further investigations are necessary to determine whether green-lipped mussel supplements, such as Seatone, are therapeutic options in the management of arthritis.

Activation of the newly discovered cyclostome renin-angiotensin system in the river lamprey Lampetra fluviatilis.

This study describes the first investigations of the physiological signals involved in activating the newly discovered cyclostome renin-angiotensin system (RAS) and its role in the river lamprey Lampetra fluviatilis. Experimental manipulation showed that volume depletion (removal of 40% blood volume) rapidly activated the RAS of lampreys acclimated to water at 576 mOsm kg(-1) (21 p.p.t.), significantly increasing plasma angiotensin concentrations after 30 min and 60 min. In agreement with these results, a rapid change in environmental salinity (758 mOsm kg(-1) to freshwater (FW) and FW to 605 mOsm kg(-1)), resulted in a rapid decrease and increase in plasma [angiotensin], respectively. Intraperitoneal (i.p.) injection of FW-acclimated river lampreys with 1% body mass by volume of nominally isosmotic saline (120 mmol l(-1) NaCl; 233 mOsm kg(-1)) resulted in a significant decrease in the plasma angiotensin concentration within 15 min. In contrast, i.p. injection of hyperosmotic saline (4 mol l(-1) NaCl) at 1% body mass by volume, which significantly increased plasma osmolality, had no significant effect on plasma [angiotensin], suggesting that volume/pressure receptors and osmoreceptors interact in regulating the lamprey RAS. These results indicate an important role for volume/pressor receptors, as in teleosts, but with an additional osmoreceptor mechanism, such that circulatory [angiotensin] is determined by interaction of volume/pressure and osmoreceptors and their relative sensitivities. The volume/pressure sensitivity is in keeping with the recent evidence of a vasoconstrictor action of homologous lamprey angiotensin and provides evidence that the fundamental role of the RAS in maintaining volume and pressure is an ancient function conserved over 500 million years of vertebrate evolution.

Angiotensin I-converting enzyme-like activity in tissues from the Atlantic hagfish (Myxine glutinosa) and detection of immunoreactive plasma angiotensins.

Using a highly sensitive fluorimetric assay, significant levels of angiotensin I -converting enzyme-like activity (ACELA) were detected in a range of tissues (branchial heart, gill, kidney with associated vasculature and archinephric duct, liver, whole brain and gut) from the Atlantic hagfish (Myxine glutinosa). The highest ACELA occurred in heart and gill (1.8 and 1.5 nmol His-Leu min(-1) mg protein(-1), respectively). The mammalian angiotensin I-converting enzyme (ACE) inhibitor, captopril, at 10(-5) M was a potent inhibitor of the ACELA found in all hagfish tissues. Radioimmunoassay showed that immunoreactive angiotensins (251.8+/-11.8 pM) were detectable in hagfish plasma. The validity of the assay for measurement of hagfish angiotensins was indicated by the parallelism of the angiotensin II standard curve against serially diluted hagfish plasma. Measurement of immunoreactive plasma angiotensins and detection of significant levels of ACELA in a wide range of tissues gives indirect evidence for the presence of a renin-angiotensin system in hagfishes, the earliest evolved group of craniates.

Angiotensin converting enzyme-like activity in tissues from the river lamprey or lampern, Lampetra fluviatilis, acclimated to freshwater and seawater.

Angiotensin converting enzyme (ACE) or kininase II is a dipeptidyl-carboxypeptidase that converts angiotensin I (Ang I) to angiotensin II (Ang II) in the renin-angiotensin system (RAS) and inactivates bradykinin in the kallikrein-kinin system (KKS). Angiotensin converting enzyme-like activity (ACELA) has been demonstrated in a wide range of vertebrates, and only in lampreys is a lack of ACELA still suggested. Though long controversial, a lamprey RAS has recently been identified by isolation and sequencing of lamprey Ang I and the measurement of circulating plasma angiotensins. We therefore re-investigated the presence of ACE in tissues from the river lamprey or lampern, Lampetra fluviatilis, using a highly sensitive fluorimetric assay. Significant detection of ACELA was found in a wide range of lamprey tissues (brain, gill, gonad, gut, heart, liver, skeletal muscle, skin, kidney, and plasma). The mammalian ACE inhibitor captopril at 10(-5)M was an effective, but variable inhibitor of the ACELA found in most lamprey tissues. The brain contained the highest ACELA, while kidney (including urinary duct), skin, gonads, and heart only contained very low ACELA. In most tissues, ACELA was similar in lampreys acclimated to freshwater (FW) and seawater (SW). However, gut ACELA was significantly higher in lampreys acclimated to SW than in FW-acclimated lampreys. Liver, skin, and gonad ACELA was significantly lower in lampreys acclimated to SW than in FW lampreys. Male and female lampreys acclimated to FW showed similar ACELA in all tissues except the kidney (including the urinary duct), where ACELA was significantly higher in male than in female lampreys. These results indicate that ACELA, a component of the RAS and KKS, is present in tissues from one of the earliest evolved groups of vertebrates.

Melanocyte-stimulating hormone plasma levels and environmental illumination in the cuttlefish, Sepia officinalis: a role for the neurosecretory system of the vena cava in cephalopods.

A melanotropin-like peptide (alpha-melanocyte-stimulating hormone or alpha-MSH) is suggested to be released into the circulatory system of cephalopods via the neurosecretory system of the vena cava or NSV, where neurosecretory vesicles contained within the axons of the NSV-neuropil on the inner surface of the vena cava lie in close contact with the venous circulation. Radioimmunoassay of blood plasma samples taken from the cephalic vein of anaesthetised cuttlefish, Sepia officinalis showed that immunoreactive alpha-MSH (ir alpha-MSH) was detectable within the cuttlefish circulatory system. The validity of the assay for determination of cuttlefish ir alpha-MSH was determined by parallelism of the alpha-MSH standard curve against serially diluted cuttlefish plasma samples. Plasma samples taken during a natural day-night-day illumination cycle showed a significant elevation in ir alpha-MSH concentration to 1.44 +/- 0.26 ng ml(-1) during the middle of the dark phase compared to concentrations of 0.48 +/- 0.13 and 0.35 +/- 0.10 ng ml(-1) in the middle of the light phases of the illumination cycle. So far, indirect evidence suggests Sepia officinalis may modulate chromatophore activity, body patterning, and behaviour via neuroendocrine release and circulating titres of this proopiomelanocortin-derived peptide.