Male offspring production by asexual Potamopyrgus antipodarum, a New Zealand snail.

As only females contribute directly to population growth, sexual females investing equally in sons and daughters experience a two-fold cost relative to asexuals producing only daughters. Typically, researchers have focused on benefits of sex that can counter this 'cost of males' and thus explain its predominance. Here, we instead ask whether asexuals might also pay a cost of males by quantifying the rate of son production in 45 experimental populations ('lineages') founded by obligately asexual female Potamopyrgus antipodarum. This New Zealand snail is a powerful model for studying sex because phenotypically similar sexual and asexual forms often coexist, allowing direct comparisons between sexuals and asexuals. After 2 years of culture, 23 of the 45 lineages had produced males, demonstrating that asexual P. antipodarum can make sons. We used maximum-likelihood analysis of a model of male production in which only some lineages can produce males to estimate that ~50% of lineages have the ability to produce males and that ~5% of the offspring of male-producing lineages are male. Lineages producing males in the first year of the experiment were more likely to make males in the second, suggesting that some asexual lineages might pay a cost of males relative to other asexual lineages. Finally, we used a simple deterministic model of population dynamics to evaluate how male production affects the rate of invasion of an asexual lineage into a sexual population, and found that the estimated rate of male production by asexual P. antipodarum is too low to influence invasion dynamics.

Knowledge of Australian primary education providers towards dental avulsion injuries: a cross-sectional study.

BACKGROUND/AIM: The aim of this study was to evaluate the knowledge of school professionals regarding the emergency management of dental avulsion. METHODS: This cross-sectional study utilised a self-administered, pilot-tested questionnaire for school staff from primary schools. Descriptive statistics were used for the analysis - the prevalence and univariate associations between a categorical outcome and the variables under consideration, were evaluated using Pearson's Chi-squared test. RESULTS: This survey yielded a response rate of 43.5% (n = 313). Approximately 60% of participants held valid first-aid certificates and 23% had received avulsion advice previously. Over 80% of participants expressed an unwillingness to replant an avulsed tooth, and over 90% believed that there should be greater awareness in this area. This unwillingness to replant was influenced by respondents' age (x2 = 8.13 df = 3, P = 0.043) and receiving advice previously (x2 = 13.15, df = 1, P < 0.001). Under-preparedness was related to years of experience (x2 = 15.03, df = 5, P = 0.010), first-aid training (x2 = 6.41, df = 1, P = 0.011) and receiving advice previously (x2 = 43.47, df = 1, P < 0.001). It was also evident that first-aid training positively influenced appropriate dental referral in the management pathway (x2 = 10.49, df = 1, P = 0.001). CONCLUSION: This study suggests that there is an inadequate level of knowledge on the appropriate management of dental avulsion injuries amongst primary school professionals in Australia.

Detecting white coat and reverse white coat effects in clinic settings using measures of blood pressure habituation in the clinic and patient self-monitoring of blood pressure.

To examine the utility of blood pressure (BP) habituation within and across multiple clinic visits and patient-determined home BP monitoring for detecting white coat (WCE) and reverse white coat effects (RWCE) commonly observed in medical settings, 54 patients undergoing evaluation for hypertension in an internal medicine group practice were categorized according to the magnitude of differences between systolic BP (SBP) and diastolic BP (DBP) obtained in the clinic and through ambulatory BP monitoring. BPs were measured four times during three separate clinic visits, during a 1-week home BP monitoring period, and during a single 24-h ambulatory monitoring period. Patients whose mean clinic and average daytime BPs were within +/-5 mm Hg were categorized as having stable BP; patients whose clinic BPs were >5 mm Hg of their daytime BPs were categorized as showing a WCE and patients whose average daytime BPs were >5 mm Hg of their clinic BPs were categorized as showing a RWCE. Results revealed that degree of habituation occurring between the first and third clinic visits significantly predicted magnitude of both the WCE and RWCE for SBP, with greater habituation being associated with the WCE and lesser habituation associated with the RWCE. Greater SBP habituation within clinic visits was associated with the WCE for SBP and greater DBP habituation within clinic visits was associated with the WCE for DBP. Lesser DBP habituation within clinic visits was associated with the RWCE for both SBP and DBP. Home BP monitoring did not contribute to predicting either WCE or RWCE.

In vivo co-localisation of MBNL protein with DMPK expanded-repeat transcripts.

Myotonic dystrophy (DM1) is the most common form of adult muscular dystrophy and is inherited as an autosomal dominant trait. The genetic basis of DM1 is the expansion of a CTG repeat in the 3' untranslated region of a protein kinase gene (DMPK). The molecular mechanism by which this expanded repeat produces the pathophysiology of DM1 remains unknown. Transcripts from the expanded allele accumulate as foci in the nucleus of DM1 cells and it has been suggested that these transcript foci sequester cellular proteins that are required for normal nuclear function. We have investigated the role of three RNA-binding proteins, CUG-BP, hnRNP C and MBNL, as possible sequestered factors. Using a combination of indirect immunofluorescence to detect endogenous proteins and overexpression of proteins with green fluorescent protein (GFP) tags we have shown that CUG-BP and hnRNP C do not co-localise with expanded repeat foci in DM1 cell lines. However, GFP-tagged MBNL does itself form foci in DM1 cell lines and co-localises with the foci of expanded repeat transcripts. GFP-tagged MBNL does not appear as foci in non-DM1 cell lines. This work provides further support for the involvement of MBNL in DM1.

Interaction between the two ubiquitously expressed transcription factors NF-Y and Sp1.

The regulation of the rat fatty acid synthase gene by mediators such as diet, hormones, cAMP, sterols or retinoic acid is controlled by three NF-Y binding sites. All three sites have a neighbouring Sp1-binding GC-box. This NF-Y/Sp1 motif is conserved in the FAS promoters of rat, human, goose and chicken. We have previously shown cooperative binding of NF-Y and Sp1 to the promoter region at -500 coincident with a diet-induced DNAse I-hypersensitive site. Here, we show an in-vivo interaction of NF-YA with Sp1 using the yeast two-hybrid system. The interacting domains are located between amino acids 55 and 139 of the NF-Y subunit NF-YA and between amino acids 139 and 344 of Sp1. In addition, we show by co-immunoprecipitation direct interaction of NF-Y subunit NF-YA with Sp1 in extracts of rat hepatoma cells H4IIE. Furthermore, we demonstrate by the GST pull-down assay that NF-YA interacts physically with Sp1 in-vitro in the absence of DNA. Therefore, NF-Y can be added to the list of transcription factors interacting with Sp1.

A self-calibrating phase-shifting algorithm based on the natural demodulation of two-dimensional fringe patterns.

A new method of estimating the phase-shift between interferograms is introduced. The method is based on a recently introduced two-dimensional Fourier-Hilbert demodulation technique. Three or more interferogram frames in an arbitrary sequence are required. The first stage of the algorithm calculates frame differences to remove the fringe pattern offset; allowing increased fringe modulation. The second stage is spatial demodulation to estimate the analytic image for each frame difference. The third stage robustly estimates the inter-frame phase-shifts and then uses the generalised phase-shifting algorithm of Lai and Yatagai to extract the offset, the modulation and the phase exactly. Initial simulations of the method indicate that high accuracy phase estimates are obtainable even in the presence of closed or discontinuous fringe patterns.

Development of a yeast-based assay system for monitoring microsatellite instability.

Simple sequence repeats (microsatellites) are found in all eukaryotic genomes. Instabilities within these sequences have been associated with several human disorders including Huntington's chorea and myotonic dystrophy. Further studies have identified links between microsatellite instability, faulty mismatch repair and certain human cancers, in particular a form of hereditary colorectal cancer. The assay system described here consists of a congenic set of yeast strains mutated in DNA replication and mismatch repair genes and assay plasmids with which it is possible to measure differences in microsatellite stability in the range of 5-850-fold. The development of this technology will allow monitoring of environmental and dietary influences on the genomic stability in the context of human disease.

Behavioral and cardiovascular responses to interpersonal challenges among male offspring of essential hypertensives.

Behavioral, cardiovascular, and self-report of cognitive and affective responses to 2 interpersonal challenges were examined among 20 men with a positive (FH+) and 20 with a negative (FH-) family history of hypertension. Heart rate (HR) and blood pressure (BP) were measured throughout the laboratory session; Ss were requested to self-report positive and negative cognitions, state anger, and state anxiety that occurred during interactions with a male and female confederate. Behavioral responses to interpersonal tasks were videotaped, coded, and categorized into 4 major groupings (positive verbal, positive nonverbal, negative verbal, and negative nonverbal). FH+ individuals exhibited significantly higher resting HR and systolic BP (SBP) reactivity to both interactions than FH- counterparts. Analyses of behavioral responses for both interactions revealed significantly more negative verbal and nonverbal behavior and less positive nonverbal behavior among FH+ as compared with FH-Ss.

Psychophysiological arousal in older adults: a critical review.

In spite of the relatively high prevalence rates of anxiety disorders (AD) and related symptoms, very little is known about the experience, presentation, and assessment of anxiety in later life. Because the physiology of the autonomic nervous system changes with age, an enhanced understanding of how these developmental changes affect the somatic-physiological response patterns to anxiety-evoking stimuli among older adults may help explain whether we can generalize current assessment and treatment practices and procedures for AD from younger to older adults. In this paper, we describe and critically evaluate studies that have employed psychophysiological recording of autonomic arousal to anxiety-arousing or stressful stimuli among samples of younger and older adults. The conclusions one can draw from the review are quite limited by both the paucity of relevant literature and the methodological limitations of the published studies.

Myotonic dystrophy--a multigene disorder.

Myotonic dystrophy (DM1) is the most common form of adult muscular dystrophy with an estimated incidence of 1/8000 births. The mutation responsible for this condition is an expanded CTG repeat within the 3' untranslated region of the protein kinase gene DMPK. Strong nucleosome positioning signals created by this expanded repeat cause a reduction in gene expression within the region. This "field effect" is further confounded by the retention of DMPK expansion containing transcripts, which acquire a toxic gain of function. Thus, the various manifestations exhibited by DM1 patients can be explained as a result of gene silencing, nuclear retention and sequestration of nuclear factors by the CUG containing transcript.

Assessment of cardiovascular reactivity across laboratory and natural settings.

The purpose of this investigation was to examine the stability of heart rate and blood pressure reactions of individuals across laboratory challenges and a challenge in the natural environment. Undergraduate musicians' heart rates and blood pressures were measured during anticipation and in response to a mental arithmetic challenge and a visual-verbal concepts challenge in the laboratory and anticipation of a musical performance jury in the natural environment. Results revealed that systolic blood pressure reactivity measured in anticipation of laboratory challenges, but not during these tasks, was related to systolic blood pressure levels measured in anticipation to the musical performance jury. Generalization of heart rate and diastolic blood pressure reactivity across settings was not supported. Systolic blood pressure, diastolic blood pressure, and heart rate reactions were stable across laboratory tasks.

Cognitive response to a cold pressor challenge in high and low blood pressure reactive subjects.

To examine the relationship between cognitive and cardiovascular reactions to a cold pressor challenge, 20 high and 20 low blood-pressure-reactive males were identified. Subjects were trained using a think-aloud procedure and asked to report their thoughts aloud during task presentation. In comparison to low-reactors, high-reactive subjects exhibited greater increases in systolic and diastolic blood pressure, but not heart rate, in response to the task. High-reactive subjects reported fewer distracting self-statements than low-reactors during the task. No group differences in positive, neutral, or negative self-statements were observed. These findings corroborate the importance of distraction strategies in mediating acute cardiovascular reactions to stress.

The effect of social support and physical touch on cardiovascular reactions to mental stress.

To examine the effects of social support on cardiovascular reactions to behavioral stress, the present study tested the relative contribution of three elements of social support: the presence of another person in the laboratory; the presence of a person considered to be a friend; and physical touch. Sixty undergraduate females were assigned to one of the following groups: alone (A); friend present-touch (FT); friend present-no touch (FNT); stranger present-touch (ST); and stranger present-no touch (SNT). Heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) measures were obtained across baseline phases and during presentation of two behavioral challenges (mental arithmetic, mirror-tracing). The findings suggest that neither the presence of a stranger nor physical touch are related to attenuated cardiovascular reactions to stress; rather, if the extent of cardiovascular reactivity is related to social support, the presence of a friend may be the important mediating variable.

Women, anger, and cardiovascular responses to stress.

Cardiovascular reactivity (CVR) to stressful stimuli is predictive of future development of cardiovascular disease (CVD). Anger appears to be an important mediator of this relationship. Unfortunately, the majority of research in this area has utilized predominantly male subjects, leaving the relationship between CVD and anger in females largely unexplored. To address the dearth of research among females, the present study examined the relationship between Anger-In, as well as Anger-Out, and CVR to stressors among women. Females reporting moderate levels of Anger-Out exhibited lower blood pressure reactions to a mental arithmetic stressor than females reporting high and low levels of Anger-Out. Females reporting moderate levels of Anger-Out also exhibited lower heart rate reactions than individuals reporting high levels of Anger-Out. Anger-In was not related to CVR in the present study.

Effects of gender of observer and fear of negative evaluation on cardiovascular reactivity to mental stress in college men.

This study investigated the relation between mere observation, the gender of a confederate observer and cardiovascular reactivity to two laboratory challenges, a math task and verbal anagrams, in both individuals with high and low social fear (e.g. fear of negative evaluation). Forty-eight undergraduate males completed the Fear of Negative Evaluation Scale and were categorized as either high or low social fear based on a median split. Sixteen subjects were tested alone, 16 subjects were observed by a male confederate during task performance and 16 subjects were observed by a female confederate during task performance. Cardiovascular measures of heart rate and blood pressure were measured during both tasks and intervening rest periods. Results revealed subjects with high social fear exhibited higher heart rate reactions to the math task and higher diastolic blood pressure reactions to the anagram challenge than low social fear participants, but only when observed by a female confederate. In addition, participants in the male and female observation conditions exhibited greater SBP responses to the anagram task than participants in the alone condition. No group differences on task performance were observed. Cardiovascular reactivity to the two tasks used in this study was impacted by both contextual laboratory factors (i.e. gender of observer) and dispositional attributes of the participant (i.e. social fear).

Intrathecal fentanyl-induced pruritus is more severe in combination with procaine than with lidocaine or bupivacaine.

BACKGROUND AND OBJECTIVES: Fentanyl is used as an additive to prolong intrathecal anesthesia with both lidocaine and low-dose bupivacaine in the outpatient setting to minimize voiding or discharge delays. Pruritus is the most common side effect. When using procaine as a substitute for lidocaine, we perceived an increased frequency and severity of pruritus. We compared prospectively the frequency and severity of itching with combinations of fentanyl with lidocaine, bupivacaine, and procaine. METHODS: After institutional review board approval, 135 patients requesting neuraxial anesthesia were asked to evaluate the presence and severity (using a 100 point verbal pruritus score [VPS]) of itching 30 minutes after injection of their spinal anesthetic, on arrival to the postanesthesia care unit (PACU), and at the time of resolution of their block. Choice of anesthetic drug and dose and the use of intravenous sedation was left to the discretion of the attending and resident anesthesiologist. RESULTS: Thirty-three patients received lidocaine and fentanyl, 47 received bupivacaine and fentanyl, and 55 received procaine and fentanyl. In the lidocaine group, 21% of patients experienced pruritus compared with 55% of the bupivacaine group and 55% of the procaine group (P =.003). The average VPS at 30 minutes postblock was 18.4 in the procaine group compared with 0 and 5.5 in the lidocaine and bupivacaine groups (P =.06). On admission to the PACU, it was 37 compared with 16 and 20 for lidocaine and bupivacaine, respectively (P =.006). CONCLUSION: Procaine produces a higher frequency of pruritus than that seen with lidocaine-fentanyl combinations and a greater severity of pruritus than seen with lidocaine-fentanyl and bupivacaine-fentanyl spinal anesthesia. Reg Anesth Pain Med 2001;26:252-256.

Femoral nerve block with 0.25% or 0.5% bupivacaine improves postoperative analgesia following outpatient arthroscopic anterior cruciate ligament repair.

BACKGROUND AND OBJECTIVES: Femoral nerve block is effective in reducing postoperative pain after inpatient knee surgery. We studied its efficacy compared with standard analgesia following outpatient anterior cruciate ligament repair, including the duration of analgesia and the effect of different concentrations of bupivacaine. METHODS: After Institutional Review Board approval and informed consent, we prospectively randomized patients to receive, in a blinded fashion, either a sham block, a femoral nerve block with 25 mL 0.25% bupivacaine, or with 25 mL 0.5% bupivacaine after anterior cruciate ligament repair under epidural anesthesia. Verbal analog pain scores were evaluated by a blinded observer at 20 and 40 minutes after injection. Patients with pain >4 (out of 10) were assessed for the presence of a block and offered a supplemental block if no anesthesia was present at either evaluation. By prospective agreement, any study group with 6 failures was excluded from further recruitment. After discharge, patients recorded pain scores and analgesic consumption in a diary, and estimated the time at which they perceived that analgesia and sensory block from the femoral nerve block resolved, based on an increase in pain, sensation, and strength in the leg. RESULTS: In the sham block group, 6 of 12 patients reported inadequate analgesia in the postanesthesia care unit (4 at 20 minutes, 2 at 40 minutes; greater than other groups, P <.003) and were excluded from further study. Patients with sham blocks had higher pain scores 20 minutes after the block, and requested intravenous analgesia more often. Bupivacaine 0.25% and 0.5% provided 23.2 +/- 7 and 25.7 +/- 11 hours of analgesia, respectively. CONCLUSIONS: Femoral nerve block with 0.25% bupivacaine contributes significantly to multimodal postoperative analgesia in the immediate postoperative period following outpatient anterior cruciate ligament repair. Both doses of bupivacaine studied provided analgesia for the first night after surgery.

Three-dimensional Analysis of Laser Scanning Confocal Microscope Sections Reveals an Array of Microtubules in the Cleavage Furrow of Sea Urchin Eggs.

Our recent observation that microtubules (MTs) are required for completion of division (abscission) led us to analyze MT organization during cytokinesis. Although many studies of MTs in sea urchin eggs have been done, computer-aided analysis of optical sections described herein reveals a new MT assemblage, which we call furrow MTs. This assemblage comprises bundles of MTs that lie in the cleavage furrow. Furrow MTs become apparent when the furrow has progressed approximately one-third of the way through the egg and persist to abscission. Furrow MTs are 8-24-&mgr;m long and arc across the base of the cleavage furrow. Acetylated tubulin is localized primarily in the furrow suggesting a distinct MT population. Three-dimensional analysis of optical sections suggests that furrow MTs are spatially distinct from midbody and astral MTs.

Treatment of paruresis with in vivo desensitization: a case report.

In vivo desensitization was employed with a patient exhibiting chronic paruresis. Measures of urination delay, and subjective units of distress were obtained at pre-training, during training, at a generalization trial, and at a follow-up assessment. Urine volume was also measured at pre- and post-training. There was shorter delay in urination, greater urine output, and less subjective anxiety following treatment. These effects were also demonstrated during a generalization post-test in which the patient was exposed to an unknown observer. A follow-up trial involving exposure to a second unknown observer indicated that treatment effects were maintained at 7.5 months following treatment.

Reducing heart rate reactivity to stress with feedback. Generalization across task and time.

Heart rate (HR) reactions to two behavioral stressors (videogame and mental arithmetic) were measured in 8 experimental subjects who received biofeedback training and 8 matched control subjects during three assessment periods: pretraining, posttraining, and one-week follow-up. Experimental subjects exhibited significant reductions in HR following a training session in which they received ongoing HR feedback while playing a videogame. Control subjects, who played the same number of videogames without HR feedback, showed smaller HR reductions. During the training session, all subjects were instructed to reduce HR while maximizing game performance. In comparison to controls, experimental subjects (a) maintained lower HRs during videogame presentations after a one-week period and (b) generalized these HR reductions to the mental arithmetic challenge at follow-up. Performance on the videogame declined from posttraining to follow-up for experimental subjects but not for control subjects. No group difference in mental arithmetic performance was observed.