Can backcalculation models unravel complex larval growth histories in a tropical freshwater fish?

This experimental study compared the precision and accuracy of the biological intercept (BI), modified fry (MF) and time-varying growth (TVG) backcalculation models in estimating the early growth of the tropical freshwater purple-spotted gudgeon Mogurnda adspersa. Larvae were reared up to 41 days post hatching under two temperatures and four different feeding regimes. Food and temperature treatments induced complex growth profiles among fish, and although total length (LT ) and otolith radius were related under all conditions, some uncoupling was evident in the otolith-somatic-growth (OSG) relationship of fish subjected to periods of changing food availability. Furthermore, otolith growth was found to be significantly influenced by temperature, but not by food availability. Analysis of backcalculation residuals by linear mixed effects modelling revealed that BI and TVG were equally precise in predicting somatic growth, with the highest accuracy provided by TVG. The performance of all the three models declined as the OSG relationship weakened under low-food conditions, with maximum errors estimated to be 39, 60 and 36% of observed LT for the BI, MF and TVG models, respectively. The need for careful validation of backcalculation models is emphasized when examining fishes subjected to variable environmental conditions, and when exploring the differential influence of temperature and food on fish LT and otolith growth.

Critical research needs for managing coral reef marine protected areas: perspectives of academics and managers.

Marine protected areas (MPAs) are a primary policy instrument for managing and protecting coral reefs. Successful MPAs ultimately depend on knowledge-based decision making, where scientific research is integrated into management actions. Fourteen coral reef MPA managers and sixteen academics from eleven research, state and federal government institutions each outlined at least five pertinent research needs for improving the management of MPAs situated in Australian coral reefs. From this list of 173 key questions, we asked members of each group to rank questions in order of urgency, redundancy and importance, which allowed us to explore the extent of perceptional mismatch and overlap among the two groups. Our results suggest the mismatch among MPA managers and academics is small, with no significant difference among the groups in terms of their respective research interests, or the type of questions they pose. However, managers prioritised spatial management and monitoring as research themes, whilst academics identified climate change, resilience, spatial management, fishing and connectivity as the most important topics. Ranking of the posed questions by the two groups was also similar, although managers were less confident about the achievability of the posed research questions and whether questions represented a knowledge gap. We conclude that improved collaboration and knowledge transfer among management and academic groups can be used to achieve similar objectives and enhance the knowledge-based management of MPAs.

Non-lethal measurement of pectoral fin aspect ratio in coral-reef fishes.

This study describes a novel method for measuring pectoral fin aspect ratio (AR) on live coral-reef fishes and tests the method against traditional measurements taken from a dissected fin. No significant differences were detected among repeated fin measurements, which validates the accuracy (intact v. dissected) and precision (repeatability over several days) of fin AR measurements on live fishes. One exception highlighted issues that may arise when working with species prone to fin damage.

Asymptomatic shedding of HSV-1 in patients undergoing oral surgical procedures and attending for noninvasive treatment.

Oral surgery and stress can trigger and/or increase asymptomatic shedding of herpes simplex virus type-1 (HSV-1) into human saliva. In this investigation we examined the frequency of HSV-1 shedding in 32 patients undergoing an oral surgery procedure compared with 40 control patients attending for noninvasive treatment. Control patients comprised 18 migraine patients and 22 patients with temporomandibular (TMD) joint problems. Nested-PCR was carried out on oral rinses collected from each patient prior to treatment and 7 days post-treatment. Fifty-two of sixty-one seropositive patients were positive for HSV-1 DNA in one or both oral rinses. The frequencies of HSV-1 shedding for the oral surgery and control patients were 84.6% and 85.7% respectively. Seropositive patients who started shedding after treatment were significantly higher in oral surgery patients (46.2%) compared to control patients (34.3%). Shedding of HSV-1 in the oral cavity is not only increased by direct surgical trauma, but also appears to be common in migraine and TMD patients attending for general dental treatment. Thus pain or pain-induced stress as well as anxiety associated with dental treatment may also be a risk factor for asymptomatic shedding in specific seropositive patients attending for dental treatment.

Functional versatility supports coral reef biodiversity.

We explore the role of specialization in supporting species coexistence in high-diversity ecosystems. Using a novel ordination-based method to quantify specialist and generalist feeding structures and diets we examined the relationship between morphology and diet in 120 wrasses and parrotfishes from the Great Barrier Reef. We find that wrasses, despite their morphological diversity, exhibit weak links between morphology and diet and that specialist morphologies do not necessarily equate to specialized diets. The dominant pattern shows extensive overlap in morphology (functional morphospace occupation) among trophic groups; fish with a given morphology may have a number of feeding modes. Such trophic versatility may lay the foundation for both the origins and maintenance of high biodiversity on coral reefs.

Wave energy and swimming performance shape coral reef fish assemblages.

Physical factors often have an overriding influence on the distribution patterns of organisms, and can ultimately shape the long-term structure of communities. Although distribution patterns in sessile marine organisms have frequently been attributed to functional characteristics interacting with wave-induced water motion, similar evidence for mobile organisms is lacking. Links between fin morphology and swimming performance were examined in three diverse coral reef fish families from two major evolutionary lineages. Among-habitat variation in morphology and performance was directly compared with quantitative values of wave-induced water motion from seven coral reef habitats of different depth and wave exposure on the Great Barrier Reef. Fin morphology was strongly correlated with both field and experimental swimming speeds in all three families. The range of observed swimming speeds coincided closely with the magnitude of water velocities commonly found on coral reefs. Distribution patterns in all three families displayed highly congruent relationships between fin morphology and wave-induced water motion. Our findings indicate a general functional relationship between fin morphology and swimming performance in labriform-swimming fishes, and provide quantitative evidence that wave energy may directly influence the assemblage structure of coral reef fishes through interactions with morphology and swimming performance.

Androgen-receptor defect abolishes sex differences in nitric oxide and reactivity to vasopressin in rat aorta.

Contractions of rat thoracic aorta to vasopressin (VP) are threefold higher in females (F) than in males (M), primarily because nitric oxide (NO) attenuation of contraction is greater in M. To determine the role of the androgen receptor (AR) in this mechanism, vascular reactivity to VP was examined in thoracic aorta of the testicular-feminized male (Tfm) rat, which has an X-linked, recessive defect in AR function in affected M. Maximal contraction of normal aortas to VP was fourfold higher in F (4,128 +/- 291 mg/mg ring wt) than in M (971 +/- 133 mg); maximal response of Tfm (3,967 +/- 253 mg) was similar to that of normal F. N(G)-nitro-L-arginine methyl ester increased maximal response to VP threefold in M but had no effect in F or Tfm. In contrast, maximal contraction of normal aortas to phenylephrine was 43% higher in M (4,011 +/- 179 mg) than in F (2,809 +/- 78 mg); maximal response of Tfm (2,716 +/- 126 mg) was similar to that of normal F. N(G)-nitro-L-arginine methyl ester increased maximal response to phenylephrine by >50% in F and Tfm but had no effect in M. Maximal contractile response to 80 mM KCl did not differ among M, F, or Tfm. Thus androgens and normal vascular AR function are important in the greater NO-mediated attenuation of reactivity to VP in M than in F rat aorta, which may involve specific modulation of endothelial VP signal transduction pathways and NO release by androgens. These data also establish the importance of the Tfm rat as a model to study the effects of androgens on cardiovascular function.

The influence of antifungal drugs on virulence properties of Candida albicans in patients with diabetes mellitus.

OBJECTIVE: This study investigated the influence of nystatin and fluconazole on virulence properties of Candida albicans. STUDY DESIGN: A total of 108 diabetic patients participated in the study. Eighty-eight patients had clinical oral candidosis. Drug therapy was given at 6 hourly intervals for nystatin or daily with fluconazole for a maximum of 2 weeks. Adhesion of C albicans to buccal epithelial cells was determined by using an autologous adhesion assay prospectively over 6 months. Phospholipase production was estimated by using an agar plate method. The data analysis included a paired Student t test and calculation of correlation coefficients. RESULTS: Unlike nystatin, treatment with fluconazole reduced the ability of C albicans to colonize the buccal mucosa for up to 8 weeks after the treatment. Patients without clinical signs of oral candidosis had significantly fewer C albicans isolates producing phospholipase than did patients with oral candidosis. Treatment with fluconazole, but not nystatin, reduced the production of phospholipase from C albicans oral isolates in patients with diabetes mellitus. CONCLUSIONS: In addition to being antifungal, fluconazole alters phospholipase production, modifies buccal epithelial cells, and reduces adhesion of C albicans to human buccal epithelial cells for up to 8 weeks posttreatment in diabetic patients with oral candidosis.

Immunolocalization of electroneutral Na-HCO(3)(-) cotransporter in rat kidney.

An electroneutral Na-HCO(3)(-) cotransporter (NBC(N)1) was recently cloned, and Northern blot analyses indicated its expression in rat kidney. In this study, we determined the cellular and subcellular localization of NBC(N)1 in the rat kidney at the light and electron microscopic level. A peptide-derived antibody was raised against the COOH-terminal amino acids of NBC(N)1. The affinity-purified antibody specifically recognized one band, approximately 180 kDa, in rat kidney membranes. Peptide-N-glycosidase F deglycosylation reduced the band to approximately 140 kDa. Immunoblotting of membrane fractions from different kidney regions demonstrated strong signals in the inner stripe of the outer medulla (ISOM), weaker signals in the outer stripe of the outer medulla and inner medulla, and no labeling in cortex. Immunocytochemistry demonstrated that NBC(N)1 immunolabeling was exclusively observed in the basolateral domains of thick ascending limb (TAL) cells in the outer medulla (strongest in ISOM) but not in the cortex. In addition, collecting duct intercalated cells in the ISOM and in the inner medulla also exhibited NBC(N)1 immunolabeling. Immunoelectron microscopy demonstrated that NBC(N)1 labeling was confined to the basolateral plasma membranes of TAL and collecting duct type A intercalated cells. Immunolabeling controls were negative. By using 2, 7-bis-carboxyethyl-5,6-caboxyfluorescein, intracellular pH transients were measured in kidney slices from ISOM and from mid-inner medulla. The results revealed DIDS-sensitive, Na- and HCO(3)(-)-dependent net acid extrusion only in the ISOM but not in mid-inner medulla, which is consistent with the immunolocalization of NBC(N)1. The localization of NBC(N)1 in medullary TAL cells and medullary collecting duct intercalated cells suggests that NBC(N)1 may be important for electroneutral basolateral HCO(3)(-) transport in these cells.

Oral candidal carriage and infection in insulin-treated diabetic patients.

AIM: To evaluate candidal load and carriage of candidal species in 414 insulin-treated diabetes mellitus patients with and without clinical signs of infection. Host factors that could influence candidal load in diabetic patients with oral candidosis were also investigated. METHODS: Candidal species were recovered from 414 insulin-treated diabetes mellitus patients attending two hospital diabetic clinics, using an oral rinse technique. RESULTS: Seventy-seven per cent of diabetic patients carried Candida species in their oral cavity, with C. albicans being the species most frequently isolated. C. dubliniensis was found for the first time in this patient group. Forty per cent of patients colonized with candidal species had no clinical signs of oral candidosis. Where oral candidosis was present, erythematous candidosis was the most common clinical presentation. Candidal load was not associated with age, sex or glycaemic control. However, it was significantly increased in those patients who were tobacco smokers, and non-significantly increased in those patients who wore dentures, or who had clinical signs of oral candidosis. CONCLUSION: The epidemiology of oral candidal carriage and infections in diabetic patients is complex and includes species which have not been previously reported in this group of patients. The development of oral candidosis in insulin-treated diabetes mellitus patients is not the result of a single entity, but rather, a combination of risk factors.

Symptomatic gastro-oesophageal reflux disease: double blind controlled study of intermittent treatment with omeprazole or ranitidine. The European Study Group.

OBJECTIVE: To assess intermittent treatment over 12 months in patients with symptomatic gastro-oesophageal reflux disease. DESIGN: Randomised, multicentre, double blind, controlled study. Patients with heartburn and normal endoscopy results or mild erosive changes received omeprazole 10 mg or 20 mg daily or ranitidine 150 mg twice daily for 2 weeks. Patients remaining symptomatic had omeprazole 10 mg or ranitidine dose doubled for another 2 weeks while omeprazole 20 mg was continued for 2 weeks. Patients who were symptomatic or mildly symptomatic were followed up for 12 months. Recurrences of moderate or severe heartburn during follow up were treated with the dose which was successful for initial symptom control. SETTING: Hospitals and primary care practices between 1994 and 1996. SUBJECTS: 677 patients with gastro-oesophageal reflux disease. MAIN OUTCOME MEASURES: Total time off active treatment, time to failure of intermittent treatment, and outcomes ranked from best to worst. RESULTS: 704 patients were randomised, 677 were eligible for analyses; 318 reached the end of the study with intermittent treatment without recourse to maintenance antisecretory drugs. The median number of days off active treatment during follow up was 142 for the entire study (281 for the 526 patients who reached a treatment related end point). Thus, about half the patients did not require treatment for at least 6 months, and this was similar in all three treatment groups. According to outcome, 378 (72%) patients were in the best outcome ranks (no relapse or one (or more) relapse but in remission until 12 months); 630 (93%) had three or fewer relapses in the intermittent treatment phase. Omeprazole 20 mg provided faster relief of heartburn. The results were similar in patients with erosive and non-erosive disease. CONCLUSIONS: Intermittent treatment is effective in managing symptoms of heartburn in half of patients with uncomplicated gastro-oesophageal reflux disease. It is simple and applicable in general practice, where most patients are seen.

Cost effectiveness of omeprazole and ranitidine in intermittent treatment of symptomatic gastro-oesophageal reflux disease.

OBJECTIVE: This 1-year study compared the cost effectiveness of omeprazole and ranitidine when used as initial therapy in an intermittent treatment strategy for the management of patients with symptomatic gastro-oesophageal reflux disease with or without erosive oesophagitis. DESIGN AND SETTING: A prospective health economic analysis was conducted alongside an international multicentre randomised, double-blind clinical study. The economic analysis was performed from a societal perspective. PATIENTS: A total of 704 patients in the UK, the Republic of Ireland, Germany, France, Italy and Spain were randomised to 1 of the 3 treatment groups. INTERVENTIONS: Patients were randomised to receive either omeprazole 20 mg once daily, omeprazole 10 mg once daily or ranitidine 150 mg twice daily. Initial treatment failure resulted in dose titration and drug switching from ranitidine to omeprazole, and subsequently open maintenance treatment. MAIN OUTCOME MEASURES AND RESULTS: The estimated mean direct medical costs (medication and number of visits and endoscopies) were found to be lower for both dosages of omeprazole than for ranitidine in all countries except Germany. However, none of the differences were statistically significant. The differences between omeprazole 10 mg and omeprazole 20 mg were small and nonsignificant. With regard to numbers of symptom-free days, both omeprazole 20 mg and omeprazole 10 mg were found to be more effective than ranitidine. However, none of the differences were statistically significant. CONCLUSIONS: Following a pragmatic interpretation, incorporating intermediate short term results, the results in this study give no support to the notion that a step-up approach, either as dose titration from omeprazole 10 mg to omeprazole 20 mg or as drug switching from ranitidine to omeprazole, will result in cost savings and thereby be cost effective.

Patients with metastatic breast cancer: their physical and psychological rehabilitation needs.

Few studies have monitored the physical and psychological sequelae of a diagnosis and treatment of metastatic breast cancer and the findings of the present study enables members of the rehabilitation team to understand the range of problems patients encounter, refer patients to other rehabilitation, and plan appropriate treatment. The present study aimed to describe the levels of anxiety and depression; to describe their rehabilitation status; and to ascertain whether any relationship exists between mood disturbance and physical rehabilitation status in a sample of women with metastatic breast cancer. Eighty patients with staging confirmed metastatic breast cancer were interviewed at home every eight weeks from diagnosis of metastases, on eight occasions using the Cancer Rehabilitation Evaluation System--Short Form, the Hospital Anxiety and Depression Scale, and an interview schedule to ascertain demographic and disease details. Results suggested that patients had a range of rehabilitation needs throughout the course of their disease. Mood disturbance was a significant problem in this sample of patients with many patients scoring in the case range for anxiety and depression on the HAD. A positive and strong relationship was found to exist between mood disturbance and physical rehabilitation status. The results of the study are discussed in the context of previous research and future research and clinical implications for the rehabilitation team are discussed.

Intron polymorphism in small subunit rDNA of Nectria galligena.

PCR amplification of the small subunit (SSU) rDNA gene of 40 isolates of Nectria galligena revealed four length polymorphisms. PCR-RFLP analysis of the SSU rDNA gene divided the isolates into four categories similar, but not identical, to categories identified by Southern-RFLP analysis. Nucleotide sequence analysis revealed that isolates in three of the four SSU rDNA (18S) categories possess an intron of 363 bp, 1185 bp or 1423 bp at the NS 7 priming site. Isolates in the fourth category do not possess an intron. The nucleotide sequences of these introns did not contain the core elements characteristic of typical group I introns, nor did they exhibit a group I intron secondary structure. Homology between the introns indicates a common lineage, all three possibly having come from a larger intron and having been formed by subsequent deletions. PCR primers upstream of the SSU rDNA intron region and from within the internal transcribed spacer 1 region amplify a product specific to N. galligena, which will confirm the identity of the pathogen and reveal its 18S category in a single reaction.

Centrin is synthesized and assembled into basal bodies during Naegleria differentiation.

During differentiation of Naegleria from vegetative amoebae to temporary flagellates, the microtubular cytoskeleton, including two basal bodies and flagella, is assembled de novo. Centrin is an integral component of these basal bodies [Levy et al., 1996, Cell Motil. Cytoskeleton 33: 298-323]. In many organisms, centrin appears to be a constitutive protein, but in Naegleria centrin gene expression occurs only during differentiation. Centrin mRNA, which has not been detected in amoebae, appears and disappears earlier in differentiation than a coordinately regulated set of differentiation-specific mRNAs encoding flagellar tubulin and calmodulin. Centrin antigen accumulates during differentiation, and then decreases in abundance as the flagellates mature and revert to amoebae. No localization of centrin has been detected in amoebae. During differentiation, centrin becomes localized to the basal bodies as soon as these structures are detected with anti-tubulin antibodies, first as a single dot and finally as two basal bodies. During reversion of flagellates to amoebae, centrin remains localized to the basal bodies for as long as they are present. When assembly of tubulin-containing structures during differentiation is prevented using oryzalin, centrin localization is prevented as well, yet inhibition of assembly does not affect accumulation of centrin antigen. Apparently in Naegleria, the role of centrin is primarily for a differentiation- or flagellate-specific function. The temporary presence of centrin is concurrent with the presence of centriolar basal bodies, which supports the conjecture that in Naegleria centrin may be needed only when these organelles are present.

Stable intermediates and holdpoints in the rapid differentiation of Naegleria.

The rapidity of the optional 90-min differentiation of Naegleria gruberi from amoebae to flagellates suggests the possibility of a free-running cascade of events from initiating stimulus through gene expression to organelle assembly and cell morphogenesis. Instead our experiments reveal two points early in the differentiation at which the strength of the inducing stimulus is reevaluated by the cells. Two new physical start signals for differentiation, temperature downshift (DeltaT) and mechanical agitation, are shown to regulate differentiation synergistically with each other and with previously defined signals. A DeltaT of -10 degrees C induces complete differentiation directly in the growth environment, whereas smaller DeltaTs initiate differentiation and allow it to progress for a short time, after which the cells "hold" for up to 4 h, awaiting a stimulus to continue differentiation. Our work defines two "holdpoints," optional points in development where progress can stop, awaiting a suitable signal, while cells retain whatever intermediates represent progress. We propose that such holdpoints, which can be detected in this system because of the temporal reproducibility of the differentiation, are likely to be found in other differentiating cells.

Quality of life during acute and intermittent treatment of gastro-oesophageal reflux disease with omeprazole compared with ranitidine. Results from a multicentre clinical trial. The European Study Group.

AIMS: To investigate quality of life in patients with gastro-oesophageal reflux disease. PATIENTS: A series of 704 patients were randomised to treatment with ranitidine 150 mg bd, omeprazole 10 mg om or omeprazole 20 mg om for 2 weeks. Asymptomatic/mildly symptomatic patients were followed for 12 months. METHODS: The Psychological General Well-Being index and the Gastrointestinal Symptom Rating Scale were completed before and during short-term and intermittent treatment. RESULTS: The quality of life response rate was > 80%. The majority of the patients receiving omeprazole 20 mg om (55%) had symptom relief after 2 weeks despite the fact that more patients on ranitidine required 4 weeks' treatment and an increased dose. There was no difference in the reflux dimension of Gastrointestinal Symptom Rating Scale between treatments in the initial treatment phase, but the total Gastrointestinal Symptom Rating Scale score improved significantly more on omeprazole 10 mg om than on ranitidine 150 mg bd (p = 0.006). Both doses of omeprazole improved the total Psychological General Well-Being score more than ranitidine (omeprazole 10 mg om versus ranitidine 150 mg bd, p = 0.005, omeprazole 20 mg om versus ranitidine 150 mg bd, p = 0.031). During follow-up, relapsing patients returned to pre-treatment symptom and well-being scores, but these dimensions were restored after treatment. CONCLUSION: The quality of life is impaired in patients presenting with reflux symptoms. Irrespective of whether the patients presented with endoscopy positive or endoscopy negative reflux disease, treatment on demand improved the quality of life.

The prevalence and detection of psychiatric morbidity in patients with metastatic breast cancer.

This study monitored the prevalence and detection of psychiatric morbidity in 80 women newly diagnosed with metastatic breast cancer from diagnosis of metastatic disease over a 16-month period. Patients were interviewed at home every 8 weeks using the Hospital Anxiety and Depression Scale (HADS) and an interview schedule compiled by the author to monitor contact with members of the multidisciplinary team, demographic details, current treatment and sites of metastatic spread. One way analysis of variance (ANOVA) comparing the mean anxiety and depression scores at each interview demonstrated that there were no statistically significant differences in mood across the eight interviews, though there was a trend over the course of the eight interviews for mean anxiety and depression to decrease. Using the cut off scores suggested by the authors of the HADS, the scores were then categorized into case, borderline and normal. These analyses illustrated the relatively large proportion of patients who fell into the borderline and case ranges for anxiety and/or depression with, for example, 39% of women scoring in the case range for anxiety and 31% for depression at diagnosis of metastatic breast cancer. Detection of these mood problems was extremely low with referral to appropriate services not in evidence. The results of this study are consistent with those of other studies monitoring the psychological needs of women with breast cancer and the detection of mood disturbance. The clinical relevance of the results of the present study are discussed and future research avenues suggested.