Vicariance in a generalist fish parasite driven by climate and salinity tolerance of hosts.

Acanthocephalans are parasites with complex lifecycles that are important components of aquatic systems and are often model species for parasite-mediated host manipulation. Genetic characterization has recently resurrected Pomphorhynchus tereticollis as a distinct species from Pomphorhynchus laevis, with potential implications for fisheries management and host manipulation research. Morphological and molecular examinations of parasites from 7 English rivers across 9 fish species revealed that P. tereticollis was the only Pomphorhynchus parasite present in Britain, rather than P. laevis as previously recorded. Molecular analyses included two non-overlapping regions of the mitochondrial gene - cytochrome oxidase and generated 62 sequences for the shorter fragment (295 bp) and 74 for the larger fragment (583 bp). These were combined with 61 and 13 sequences respectively, from Genbank. A phylogenetic analysis using the two genetic regions and all the DNA sequences available for P. tereticollis identified two distinct genetic lineages in Britain. One lineage, possibly associated with cold water tolerant fish, potentially spread to the northern parts of Britain from the Baltic region via a northern route across the estuarine area of what is now the North Sea during the last Glaciation. The other lineage, associated with temperate freshwater fish, may have arrived later via the Rhine/Thames fluvial connection during the last glaciation or early Holocene when sea levels were low. These results raise important questions on this generalist parasite and its variously environmentally adapted hosts, and especially in relation to the consequences for parasite vicariance.

Relationship between European eel Anguilla anguilla infection with non-native parasites and swimming behaviour on encountering accelerating flow.

The effect of Anguillicola crassus, Pseudodactylogyrus bini and Pseudodactylogyrus anguillae infection on the behaviour of downstream migrating adult European eels Anguilla anguilla as they encountered accelerating water velocity, common at engineered structures where flow is constricted (e.g. weirs and bypass systems), was evaluated in an experimental flume. The probability of reacting to, and rejecting, the velocity gradient was positively related to A. crassus larval, adult and total abundance. High abundance of Pseudodactylogyrus spp. reduced this effect, but A. crassus was the strongest parasitic factor associated with fish behaviour, and abundance was positively related to delay in downstream passage. Delayed downstream migration at hydraulic gradients associated with riverine anthropogenic structures could result in additional energetic expenditure for migrating A. anguilla already challenged by A. crassus infection.

Larval gryporhynchid tapeworms (Cestoda: Cyclophyllidea) of British freshwater fish, with a description of the pathology caused by Paradilepis scolecina.

Larvae of the cyclophyllidean tapeworms Paradilepis scolecina (Rudolphi, 1819), Neogryporhynchus cheilancristrotus (Wedl, 1855) and Valipora campylancristrota (Wedl, 1855), are described from British freshwater fish. The morphometrics of the rostellar hooks, infection characteristics and host ranges of these parasites from fisheries in England and Wales are presented. Difficulties in the detection, handling and identification of these tapeworms are highlighted, and may in part explain the paucity of records from Britain. Tissue digestion was shown to be a useful technique for the examination of these parasites, providing clear and consistent preparations of the rostellar hooks for measurement. The pathological changes caused by P. scolecina to the liver of wild tench, Tinca tinca, are detailed for the first time. Tapeworms located in the hepatic parenchyma and pancreatic tissues caused little pathological damage and invoked only mild inflammatory responses. The small size of these tapeworms and their encapsulation within host tissues appear to limit the severity of pathology, compared with parasites that insert their rostellum during attachment.

Introduction and spread of non-native parasites with Silurus glanis L. (Teleostei: Siluridae) in UK fisheries.

Despite growing concern of the ecological risks posed by the European catfish Siluris glanis L. in freshwater fisheries, little information exists on the parasite fauna of this silurid catfish in Britain. Parasitological examinations of released S. glanis from four still-water fisheries in England revealed the presence of Thaparocleidus vistulensis (Siwak, 1932) and Ergasilus sieboldi (Nordmann, 1832), both non-native parasites, the latter known to be an important fish pathogen. This represents the first record of T. vistulensis from British freshwater fish. The human-assisted movement of S. glanis between UK recreational still-water fisheries provides a clear avenue for the introduction and spread of non-native parasites.

Parasite fauna of introduced pumpkinseed fish Lepomis gibbosus: first British record of Onchocleidus dispar (Monogenea).

A survey of pumpkinseed Lepomis gibbosus from a stillwater fishery in southern England revealed infections by the ancyrocephalid monogenean Onchocleidus dispar at 100% prevalence. Host specificity of O. dispar to North American centrarchid fish suggests that it is a non-native parasite, introduced to Britain with L. gibbosus. Mean intensity of O. dispar was significantly higher in male (25.5 parasites) compared to female (15) and immature (7) hosts, but was not influenced by host standard length or sampling time. This sex-biased parasitism is likely to be related to both ecological and physiological factors, such as differential exposure to infective stages during nest building, or higher susceptibility to infection due to enhanced host stress levels. O. dispar significantly dominated the external surfaces and the outer gill arches. Analysis of the spatial distribution of the parasite between the 9 regions of gill surface determined that as density increased, higher numbers of parasites were found on the anterior and central gill regions compared to posterior (distal) regions. Apparent microhabitat selection is discussed in terms O. dispar life cycle, maximising oxygen availability, avoiding unstable areas and increasing intraspecific contact. The absence of O. dispar in the gills of roach, rudd and gudgeon sampled from the same fishery supports the assumption that this parasite is currently of little threat to native fish populations.

Analytic and numerical solutions to the seismic wave equation in continuous media.

This paper presents two approaches to mathematical modelling of a synthetic seismic pulse, and a comparison between them. First, a new analytical model is developed in two-dimensional Cartesian coordinates. Combined with an initial condition of sufficient symmetry, this provides a valuable check for the validity of the numerical method that follows. A particular initial condition is found which allows for a new closed-form solution. A numerical scheme is then presented which combines a spectral (Fourier) representation for displacement components and wave-speed parameters, a fourth-order Runge-Kutta integration method, and an absorbing boundary layer. The resulting large system of differential equations is solved in parallel on suitable enhanced performance desktop hardware in a new software implementation. This provides an alternative approach to forward modelling of waves within isotropic media which is efficient, and tailored to rapid and flexible developments in modelling seismic structure, for example, shallow depth environmental applications. Visual comparisons of the analytic solution and the numerical scheme are presented.

Evidence of micro-continent entrainment during crustal accretion.

Simple models involving the gradual outboard accretion of material along curvilinear subduction zones are often inconsistent with field-based evidence. A recent study using 3-D geodynamic modelling has shown that the entrainment of an exotic continental fragment within a simple subduction system can result in a complex phase of growth. Although kinematic models based on structural mapping and high-resolution gravity and magnetic maps indicate that the pre-Carboniferous Tasmanides in southeastern Australia may have been subjected to this process, to date there has been little corroboration from crustal scale geophysical imaging. Here, we apply Bayesian transdimensional tomography to ambient noise data recorded by the WOMBAT transportable seismic array to constrain a detailed (20 km resolution in some areas) 3-D shear velocity model of the crust beneath southeast Australia. We find that many of the velocity variations that emerge from our inversion support the recently developed geodynamic and kinematic models. In particular, the full thickness of the exotic continental block, responsible for orocline formation and the tectonic escape of the back arc region, is imaged here for the first time. Our seismic results provide the first direct evidence that exotic continental fragments may profoundly affect the development of an accretionary orogen.

The internal structure of the McGill pain questionnaire in dysmenorrhoea patients.

The McGill pain questionnaire (MPQ) was administered to 166 women attending Gynaecology Clinics complaining of dysmenorrhoea. Responses were subjected to factor analysis with 4 dimensions emerging. These reflected sensory qualities of the pain experience and factors related to the reaction component of the pain. These results are considered in relation to factorial analysis of the MPQ among back patients and in terms of treatment implications.

A comparison of primary dysmenorrhoea and intrauterine device related pain.

A pain questionnaire designed to measure sensory, affective, evaluative and temporal components of pain was administered to 119 patients with primary dysmenorrhoea and 75 patients with intrauterine device (IUD) related pain. In addition "self-report" information was obtained on the behavioural effects of pain, global ratings and biographical details of these patients. It was found that dysmenorrhoea and IUD related pain were generally similar in nature. This led to the conclusion that IUD insertion does not in general lead to an exacerbation of presenting dysmenorrhoea, nor does it radically alter the type of sensations experienced by the patient. While no differences between patient groups emerged, the implications of the different pain components did vary. Thus, pain intensity scores were reflected in a larger sensory component with IUD users, whereas with dysmenorrhoea the affective component predominated. The results show sufficient consensus in the two patient groups of word adjectives used to describe their pain, to allow the development and evaluation of a rapid card sort system for pain assessment.

Pain measurement: an overview.

The practice and theoretical basis of pain measurement is reviewed and critically examined in the areas of animal research, human subjects laboratory investigation and clinical study. The advantages and limitations of both physiological and behavioral methods are discussed in each area, and subjective report procedures are evaluated in human laboratory and clinical areas. The need for procedures that bridge these areas is emphasized and specific issues are identified. Progress in the technology of pain measurement over recent decades is reviewed and directions for future work are suggested.

Mood and cognitive style in premenstrual syndrome.

Women with premenstrual syndrome (PMS) report symptoms that resemble those of affective disorder. In depression, there is an alteration in cognitive processing and performance such that dysphoric material is retrieved more readily and the ability to concentrate and sustain attention and motivation is impaired. To determine whether PMS leads to changes in information processing similar to those accompanying depression, ten subjects with PMS and nine controls were subjected to psychological testing, selective and incidental recall tests, and measures of cognitive performance during the follicular and luteal phases of the menstrual cycle. Women with PMS failed to show the characteristic cognitive changes that usually accompany depression. Despite substantial symptomatology, there were no significant differences in cognitive functioning between PMS subjects and controls.

Cognitive functioning in premenstrual syndrome.

OBJECTIVE: To evaluate cognitive functioning in women with premenstrual syndrome (PMS) and controls during the follicular and luteal phases of the menstrual cycle. METHODS: Thirty women with PMS and 31 controls were selected on the basis of psychiatric interview and prospective daily diary recordings. Subjects were tested on two occasions, follicular (days 8-10) and luteal (days 24-26), using complex tasks consisting of measures validated previously for the assessment of "executive" frontal-lobe functions. Tests were counterbalanced for order across subjects. RESULTS: The Beck Depression Inventory scores were significantly different between the groups and across time (P < .001). Women with PMS had a mean luteal phase Beck score of 13.3 consistent with mild-to-moderate premenstrual depression. There were no statistically significant score differences in tests for attention, memory, cognitive flexibility, and overall mental agility. The evaluation of our preliminary data with 30 PMS subjects and 31 controls indicated a very small effect size (.02). To detect an effect size this small (if in fact one exists) with a power of .8 would require a sample of more than 1000 subjects per group. CONCLUSION: Our sample of women with PMS failed to demonstrate objective evidence of diminished cognitive performance, despite subjective feelings of inadequacy.

Whole-blood serotonin in premenstrual syndrome.

Whole-blood serotonin levels in 14 subjects with well documented premenstrual syndrome and 13 age-matched controls were compared. Serotonin levels of premenstrual syndrome subjects were significantly lower during the last ten days of the menstrual cycle. No significant differences were noted in levels of serum estradiol and progesterone. Decreased serotonin is known to be associated with depression in humans, and nonhuman primates have exhibited abnormal behavioral profiles when given serotonin antagonists. The present observation suggests that the physiologic basis of premenstrual syndrome involves an alteration in serotonin metabolism.

Attitudes and anxiety levels in women conceiving through in vitro fertilization and gamete intrafallopian transfer.

Anxiety and attitudes have been examined in a series of women conceiving through in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT). Women were assessed before and after their first ultrasound examination conducted between 6 and 8 weeks' gestation. A comparison group of women attending for genetic counseling for advanced maternal age also was assessed. The results showed the two patient groups to be comparable on psychological testing. The IVF-GIFT group tended to be more concerned about a problem developing but were not more anxious. Attitude ratings showed the IVF-GIFT women to have greater investment in the pregnancy and the fetus. A comparison of scores before and after the ultrasound showed anxiety reduction for women seeing the fetal heartbeat. Attitude ratings were more positive for the women seeing the fetal heartbeat, with change less pronounced in women denied this feedback. These results confirm the effects of diagnostic testing on emotional state. Women with IVF-GIFT pregnancies show both higher concern than documented elsewhere in low-risk pregnancies, as well as greater emotional investment in the fetus.

Psychological changes over the course of pregnancy: a study of attitudes toward the fetus/neonate.

Pregnant women's attitudes towards their fetus over the course of the pregnancy were studied in relation to physiological events of pregnancy, namely seeing the fetus via ultrasound and experiencing fetal movement. A consecutive series of primiparae (n = 129) was randomly assigned, at recruitment between 10 and 14 weeks menstrual age, to conditions of high (n = 67) or low (n = 62) feedback real time ultrasound. Thereafter, women were assessed at 16 and 32 weeks gestation, within 24 hours of delivery and by questionnaire at 3 months postpartum. On each occasion women completed attitude rating scales concerning their pregnancy and their fetus or neonate. These scales were subjected to principal components analysis and two main dimensions were derived for ratings of both attitudes towards the pregnancy and the fetus/neonate. No relationship was found between factor scores and ultrasound feedback condition, although scores on the fetal attachment dimension showed a significant linear increase over the pregnancy. Women reporting fetal movement at 16 weeks displayed significantly higher scores on the fetal-attachment dimension at all three assessment points. Multiple regression analyses were utilized to identify predictors of initial reactions to the neonate and attachment ratings at 3 months postpartum. At delivery, ratings of attachment to the neonate were related to drug requirements in labor and attachment ratings at 32 weeks. Reactions to the neonate at delivery and ratings of postpartum mood emerged as significant predictors of maternal attachment at 3 months postpartum. These results are discussed in the context of research attempting to establish the importance of postpartum bonding.

Quantitative assessment of the effect of 0.05% chlorhexidine on rat articular cartilage metabolism in vitro and in vivo.

Wound infection remains a problem. Syringe and needle jet lavage of chlorhexidine gluconate 0.05% removed or killed 99.8% of contaminating bacteria within 1 minute in a wound model. In clinical use, however, possible toxicity to articular cartilage is a concern. In an established intact rat patella model in vitro, 1 minute of exposure to chlorhexidine 0.05% and chlorhexidine jet lavage did not significantly alter cartilage metabolism. A 1-hour exposure decreased metabolic activity. In vivo, a 30-minute exposure with or without rinsing produced no impairment of metabolic activity 6 weeks later, suggesting that cartilage has the potential for biological recovery. However, injecting and leaving chlorhexidine 0.05% in the joints was detrimental to the metabolic activity of the articular cartilage as assessed 6 weeks later. Thus, chlorhexidine gluconate 0.05% could be used on normal articular cartilage. Any potential damage from prolonged exposure can be avoided by rinsing after 1 minute.

Decreased central opioid activity in premenstrual syndrome: luteinizing hormone response to naloxone.

OBJECTIVE: To evaluate central opioid activity in women with prospectively documented premenstrual syndrome (PMS) and control women in the mid- and late luteal phases of the menstrual cycle. METHODS: Blood was collected every 15 minutes 1 hour before (0800) and 2 hours after treatment (0900-1100). The treatment was administered in a randomized fashion and consisted of naloxone 1 or 4 mg or placebo, and blood was assayed for luteinizing hormone (LH). Baseline estradiol, progesterone, and prolactin were measured at 0800 and 0900 hours. RESULTS: There was a significant increase in LH area under the curve and mean LH in response to naloxone in the midluteal phase in the control (P < .001). The PMS subjects did not display a significant increase in LH concentration in response to naloxone in the midluteal phase. There were no significant LH responses to naloxone in either group in the late luteal phase. There were no significant differences in estradiol, progesterone, or prolactin concentrations or estrogen to progesterone ratios between groups. CONCLUSION: Control women have an enhanced central opioid tone during the midluteal phase that diminishes and becomes minimal in the late luteal phase of the menstrual cycle. In contrast, women with PMS have a loss of central opioid tone during the midluteal phase as indicated by the loss of LH response to naloxone. This attenuated central opioid tone in women with PMS as compared with asymptomatic control women may play a role in the pathophysiology of PMS.

Pain measurement and experience.

Issues and developments in clinical pain assessment will be considered. The focus will be on measuring pain, rather than degree of relief. Three main response channels may be distinguished: subjective, behavioral and physiological, although the latter will not be elaborated upon here. The measurement of subjective report of pain, although an anathema to behaviorists, continues to be one of the most widely used measures. Recent developments in assessing verbal report, of the form of questionnaires and ratings derived from psychophysical scaling methods, will be reviewed. Although behavioral indices at first sight lend themselves to well-established methods of measurement, issues in establishing rather than assuming the reliability and validity of such measures will be considered. Parallel monitoring across response channels, as well as attending to questions concerning the psychometric adequacy of measures employed, will both further our understanding of pain mechanisms and provide sound indications as to treatment efficacy.

A card sort method of pain assessment.

PIP: This paper addresses the problem of measuring the subjective report of clinical pain. In recognition of the multidemensional nature of pain, there was 1st a questionnaire which measured 3 dimensions of pain (sensory, effective, evaluative) and then a rating scale. The content of this test was drawn from the results of a survey of 200 sufferers of pelvic pain. The 1st study consisted of the identification of commonly used adjectives describing pelvic pain and was aided by the cooperation of 221 women. 35 women attended family planning clinics and were then part of a survey to determine the amount of pain indicated by each word (through use of a 5-point scale). The aim of these 2 surveys was to arrive at 3 words describing different amounts of qualitatively similar pain sensation which could then be used in the card sort. The results are included in tabular form. The 2nd study evaluted the card sort method of pain assessment. 2 words on 2 cards which describe pain (1 above the other) are presented to the patient who must then sort the cards according to whether the top or bottom word on each card most closely resembles the pain being experienced. The objectives were: 1) to establish the relevance of words included in the test and the degree of consensus over meaning and 2) to acess the internal structure of the card sort to validate the groupings of triads into sensation, affective, and evaluative dimensions of pain. The card sort was administered 213 times and based on the high degree of consensus, it was taken to have sufficient reliability for purposes of pain assessment. Scores were subjected to factor analysis and 3 emerged. The 1st accounted for 42% of the common variance and it seems that this 1 tapped the overall reaction to the pain experience; the 2nd accounted for 11% of the common variance and represents the sensory qualities of pain; and the 3rd factor accounted for 10% of the common variance and described the temporal quality of pain. There is strong evidence for viewing pain as a multidimensional experience for which commonly used assessment methods are inadequate. High internal consistency was found to exist for the test as a whole although it was somewhat lower for the sensory triads. The validity of the test was also found to be high and there was support for the distinction between sensation and the reaction or evaluation of these. The card sort could be a useful index in clinical research trials for pain; it is a method not limited to gynecological pain and it has demonstrated clinical utility and face validity.^ieng

A survey of patient attitudes towards artificial insemination by donor.

The psychological characteristics of a consecutive series (n = 58) of women attending an AID clinic have been examined. Women were assessed prior to treatment on a number of attitudinal and acceptability measures, as well as required to complete personality and martial adjustment inventories. At the time of each insemination, over 6 successive cycles, state anxiety was assessed. Following an interval of 6 months women were reassessed on an acceptability measure. The results showed generally positive attitudes at the outset. No systematic trends in anxiety were identified, with no differences between women becoming pregnant and those continuing in treatment. At follow-up women acknowledged the strain involved in timing the insemination to coincide with ovulation, with both pregnant and nonpregnant women attributing outcome to their psychological and emotional state at the time. The implications of these results are considered in terms of the characteristics of women requesting AID and the ways in which clinics can attend to the psychological states of the patients.