bluuebunny/crossref_metadata_2025 huggingface dataset:
Student Misconceptions and the Conservation of Energy
Authors: Froehle Peter , Miller Charles H.
Published: August 2012

An interesting, quick, and inexpensive lab that we do with our students is to tape one end of a string just less than halfway around the back side of a uniform solid cylinder m1 and attach the other end of the string to a mass m2 that is below a pulley (Fig. 1). Data can be collected using either an Ultra Pulley (Fig. 2) or a motion detector with a protective cage designed to stop the falling mass (Fig. 3). We found that each measuring device worked equally well. When experimenting, let m2 hang freely and release the cylinder. The mass m2 is allowed to fall a defined distance h. Note that many motion detectors do not measure accurately within 15 cm of the detector.
Magnetic field sensor
Authors: Silva Nicolas
Published: August 2012

Earlier papers1–3 in this journal have described experiments on measuring the magnetic fields of current-carrying wires and permanent magnets using magnetic field probes of various kinds. This paper explains how to use an iPad and the free app MagnetMeter-3D Vector Magnetometer and Accelerometer4 (compass HD) to measure the magnetic fields.
Atypical transformation in sacral drop metastasis from posterior fossa choroid plexus papilloma: Figure 1
Authors: Stuivenvolt Mischa , Mandl Ellen , Verheul Jeroen , Fleischeuer Ruth , Tijssen Cees C
Published: August 2012

Choroid plexus papillomas (CPP) are rare tumours and spinal metastases of CPP are even less common. We report a 50-year-old woman with spinal drop metastases at Th9 and S1–2 6 years after total resection of a posterior fossa CPP. The metastasis at S1–2 was resected and histological examination showed transformation to an atypical CPP. Atypical transformation in a metastasis years after resection of a benign posterior fossa CPP has been described once. We would like to advocate craniospinal MRI at the time of initial diagnosis as well as periodic follow-up after total and subtotal resection of a posterior fossa CPP in adults at least once in 1 or 2 years, depending on the histological grading of the primary CPP. In our case report, this could have resulted in earlier diagnosis of the locoregional recurrence or of the spinal drop metastasis.
An unusual case of POEMS syndrome
Authors: Gupta Mani , Verma Rajesh , Garg Ravindra Kumar , Singh Maneesh
Published: August 2012

We report a 48-year-old man, a farmer, presenting with chronic sensori-motor polyneuropathy. Electrophysiology revealed demyelinating type of neuropathy. Immunoelectrophoresis for monoclonal protein was negative; however, plasmacytoma was discovered on spine imaging. After receiving radiotherapy and chemotherapy over past 9 months there has been a considerable improvement in patient's disability. This case highlights the role of skeletal survey in evaluation of chronic demyelinating neuropathy.
Infected complex odontoma: an unusual presentation
Authors: Agrawal Bhavana , Gharote Harshkant , Nair Preeti , Shrivastav Saurabh
Published: August 2012

Odontomas represent a hamartomatous malformation. They are usually asymptomatic and are diagnosed on routine radiological examination .The eruption and infection of odontoma are uncommon. Till now, only 20 cases of erupted odontoma are reported in the literature. We report an unusual case of infected complex odontoma with eruption of odontoma in the oral cavity and perforation of the cheeks with a tooth impacted upon which makes the presentation unusual that has not been reported earlier. The dentist should be familiar with common and unusual appearance of odontoma for proper diagnosis and management.
Kawasaki disease: always straight to the heart?
Authors: Clausen Henning , Howarth Claire , Giardini Alessandro
Published: August 2012

Kawasaki disease is an important differential diagnosis when evaluating prolonged fever in childhood. Although the aetiology of this vasculitic disease process remains obscure, prompt recognition and treatment significantly reduces vascular complications such as coronary artery aneurysms. Patients presenting with atypical or incomplete diagnostic features remain a challenge. Here the authors describe the atypical features of Kawasaki disease that led to profound acute hearing loss in a 6-year-old boy with complex congenital heart disease. Coronary changes were not seen on early follow-up, but the patient required bilateral hearing aids. Considering Kawasaki disease early, even in the possibly confusing context of complex congenital heart disease and atypical symptomatology, is crucial to avoid long-term sequelae.
Skin lesion in axilla: an unusual presentation of invasive lobular carcinoma of breast
Authors: Dhebri Alhad , Shah Nigam , Sripadam Raj , Arora Pardeep K
Published: August 2012

Invasive lobular carcinoma (ILC) of breast is known to present with atypical clinical findings in the breast, making it difficult to diagnose. It is also known to have unusual sites of metastases arising de novo or in patients treated for known ILC. Skin lesion in axilla could be a cutaneous metastasis from ILC or ILC in ectopic breast tissue (EBT). We present two cases with skin lesion in axillas which after excision were surprisingly reported as ILC. On further investigations these were found to be primary in EBT. Though such cases are reported, carcinoma arising from EBT is a very rare presentation and one should be aware of this, when dealing with a skin lesion
Hypoxic cardiac arrest in pregnancy due to pulmonary haemorrhage
Authors: Grimme Ina , Winter Ralf , Kluge Stefan , Petzoldt Martin
Published: August 2012

A 23-year-old woman developed massive pulmonary haemorrhage in the 19th week of pregnancy. Essential invasive ventilation was seriously impaired by the mechanical properties of the blood-filled lungs. Consecutive severe respiratory failure (pO210 mm Hg, pCO2320 mm Hg, pH 6.73) induced a cardiac arrest. Bronchoscopy could not identify the source of bleeding. During 45 min of cardiopulmonary resuscitation, veno-venous extracorporeal membrane oxygenation (ECMO) was installed. Subsequently, neither a high-resolution CT (HRCT) scan nor pulmonary angiography could identify the origin of the haemorrhage. Finally, the excessive pulmonary bleeding was controlled by placing an endobronchial blocker in the middle lobe bronchus. However, pulmonary haemorrhage reoccurred and this time HRCT revealed an isolated bronchiectasis in the middle lobe. Based on this finding, surgical lobectomy was performed. The patient recovered fully without any neurological sequelae. A solitary bronchiectasis has not previously been described as a cause of massive pulmonary haemorrhage in pregnancy.
Congenital skull indentation: a case report and review of the literature
Authors: Shamsian Negin , Robertson Andrew Tristan , Anslow Philip
Published: August 2012

Congenital depressions of the skull are rare in Western countries. The majority relate to obstetric trauma at delivery. We present a case of a congenital depression of a neonate's skull not relating to obstetric trauma. The child had an ovoid indentation behind the right coronal suture in the temperoparietal region. This skull depression was thought to relate to the position of her right hand in utero. We report her management, neuro-imaging and outcome on follow-up. A literature review is given in brief.
Coding OSICS sports injury diagnoses in epidemiological studies: does the background of the coder matter?
Authors: Finch Caroline F , Orchard John W , Twomey Dara M , Saad Saleem Muhammad , Ekegren Christina L , Lloyd David G , Elliott Bruce C
Published: August 2012

Objective

To compare Orchard Sports Injury Classification System (OSICS-10) sports medicine diagnoses assigned by a clinical and non-clinical coder.

Design

Assessment of intercoder agreement.

Setting

Community Australian football.

Participants

1082 standardised injury surveillance records.

Main outcome measurements

Direct comparison of the four-character hierarchical OSICS-10 codes assigned by two independent coders (a sports physician and an epidemiologist). Adjudication by a third coder (biomechanist).

Results

The coders agreed on the first character 95% of the time and on the first two characters 86% of the time. They assigned the same four-digit OSICS-10 code for only 46% of the 1082 injuries. The majority of disagreements occurred for the third character; 85% were because one coder assigned a non-specific ‘X’ code. The sports physician code was deemed correct in 53% of cases and the epidemiologist in 44%. Reasons for disagreement included the physician not using all of the collected information and the epidemiologist lacking specific anatomical knowledge.

Conclusions

Sports injury research requires accurate identification and classification of specific injuries and this study found an overall high level of agreement in coding according to OSICS-10. The fact that the majority of the disagreements occurred for the third OSICS character highlights the fact that increasing complexity and diagnostic specificity in injury coding can result in a loss of reliability and demands a high level of anatomical knowledge. Injury report form details need to reflect this level of complexity and data management teams need to include a broad range of expertise.
Twenty-four-hour effects of bimatoprost 0.01% monotherapy on intraocular pressure and ocular perfusion pressure
Authors: Tung Jonathan D , Tafreshi Ali , Weinreb Robert N , Slight J Rigby , Medeiros Felipe A , Liu John H K
Published: August 2012

Objectives

To investigate the 24 h effects of bimatoprost 0.01% monotherapy on intraocular pressure (IOP) and ocular perfusion pressure (OPP).

Design

Prospective, open-label experimental study.

Setting

Single tertiary ophthalmic clinic.

Participants

Sixteen patients with diagnosed primary open-angle glaucoma (POAG) or ocular hypertension (ages, 49–77 years).

Interventions

Baseline data of 24 h IOP in untreated patients were collected in a sleep laboratory. Measurements of IOP were taken using a pneumatonometer every 2 h in the sitting and supine body positions during the 16 h diurnal/wake period and in the supine position during the 8 h nocturnal/sleep period. After baseline measurements were taken, patients were treated with bimatoprost 0.01% one time per day at bedtime for 4 weeks, and then 24 h IOP data were collected under the same laboratory conditions.

Primary and secondary outcome measures

Diurnal and nocturnal IOP and OPP means under bimatoprost 0.01% treatment were compared with baseline.

Results

The diurnal and nocturnal IOP means were significantly lower under the bimatoprost 0.01% treatment than baseline in both the sitting and supine positions. The diurnal and nocturnal OPP means were significantly higher under treatment than baseline in both the sitting and supine positions.

Conclusion

Bimatoprost 0.01% monotherapy significantly lowered IOP and increased OPP during the 24 h period.
Can patients really make an informed choice? An evaluation of the availability of online information about consultant surgeons in the United Kingdom
Authors: Radha Sarkhell Saadi , Caplan Nick , St Clair Gibson Alan , Shenouda Michael , Konan Sujith , Kader Deiary
Published: August 2012

Objectives

The National Health Service (NHS) ‘Choose and Book’ online scheme, which allows patients to select the location and time of hospital appointments, has now been extended to include the option for patients to select a specific consultant to carry out any necessary treatment. The aim of this study was to determine whether there is sufficient online information about consultants or consultant-led teams for patients to make an informed choice regarding a specific consultant.

Design

A web-based analysis of the availability of information.

Setting

North of England.

Participants

Two hundred websites of orthopaedic surgeons.

Main outcome measures

The websites were analysed using a bespoke template that took into account recommendations of the 2010 UK Government white paper. Each website was scored in relation to the availability of specific content relating to each surgeon.

Results

The majority of websites detailed authorship information (73.2%), level of professional qualification (98.5%) and area of general (73.7%) and specialist (93.3%) interest. However, approximately 50% of websites provided no information in relation to update cycle, involvement in teaching or research and patient satisfaction. Only five (2.6%) of the websites presented death rates, and none indicated morbidity rates.

Conclusions

For patients to be able to make informed choices about their healthcare, surgeons need to ensure that sufficient information is available online, according to the identified limitations of the websites investigated in this study.
Friends are equally important to men and women, but family matters more for men's well-being
Authors: Cable Noriko , Bartley Mel , Chandola Tarani , Sacker Amanda
Published: August 2012

Background

People with larger social networks are known to have better well-being; however, little is known about (1) the association with socio-demographic factors that may predict the size and composition of social networks and (2) whether the association with well-being is independent of pre-existing psychological health or socio-demographic factors.

Methods

The authors used information collected from 3169 men and 3512 women who were born in Great Britain in 1958. First, age on leaving full-time education, partnership and employment status at age 42 were used to predict the size and composition of cohort members' social networks at age 45 using ordered logistic regression. Second, using multiple linear regression, the associations between social network size by composition (relatives and friends) and psychological well-being at age 50 were assessed, adjusting for socio-demographic factors and psychological health at age 42.

Results

Not having a partner and staying in full-time education after age 16 was associated with a smaller kinship network in adults. Having a smaller friendship network at age 45 was associated with poorer psychological well-being among adults at age 50, over and above socio-demographic factors and previous psychological health. Additionally, having a smaller kinship network was associated with poorer psychological well-being among men.

Conclusions

Having a well-integrated friendship network is a source of psychological well-being among middle-aged adults, while kinship networks appear to be more important for men's well-being than for women's. These relationships are independent of education, material status and prior psychological health.
Effectiveness of gentamicin for gonorrhoea treatment: systematic review and meta-analysis
Authors: Dowell Deborah , Kirkcaldy Robert D
Published: August 2012

Objectives

The development of resistance to multiple antimicrobial agents has limited treatment options for gonorrhoea. The potential emergence of cephalosporin resistance inNeisseria gonorrhoeaeand cephalosporin allergy in some patients make it necessary to evaluate the effectiveness of other available antimicrobial agents. Gentamicin is widely available in the USA and is used for gonorrhoea treatment in several countries. We conducted a systematic review of the medical literature to assess the effectiveness of gentamicin for treatment of uncomplicated urogenital gonococcal infections.

Methods

Two reviewers assessed relevant articles and independently selected studies that met prespecified selection criteria (including systematic enrolment and assignment to treatment and culture-confirmed diagnosis and outcome). Summary measures for selected studies were pooled using inverse variance-weighted averages with fixed effects. Heterogeneity was assessed using I2, which estimates proportion (0–100%) of variability attributable to heterogeneity between studies. Pooled percentage with negative follow-up culture was compared with Centers for Disease Control and Prevention (CDC) criteria for selection of recommended therapy (lower 95% CI of efficacy ≥95%).

Results

Twenty-nine potentially relevant studies were identified; three met inclusion criteria. Two studies used 240 mg intramuscular gentamicin and one used 280 mg. Percentages with negative culture after single-dose treatment were 90.7% (n=86), 91.4% (n=220) and 95.0% (n=40). Pooled percentage with negative culture after single-dose treatment was 91.5% (95% CI 88.1% to 94.0%, I2=0%).

Conclusions

Gentamicin does not meet current CDC criteria for recommended treatment of gonorrhoea. However, if cephalosporin resistance emerges, gentamicin may be a useful alternative agent. Evaluation of additional regimens, including combination therapy, is warranted.
Changes in prevalence of progressive feline leukaemia virus infection in cats with lymphoma in Germany
Authors: Meichner K. , Kruse D.B. , Hirschberger J. , Hartmann K.
Published: August 2012

Progressive infection with feline leukaemia virus (FeLV) is considered one of the major risk factors for development of feline lymphoma. The aim of this study was to compare cats with lymphoma between 1980 and 1994 (first period) and between 1995 and 2009 (second period) concerning FeLV antigenaemia and age distribution. In addition, differences between FeLV antigen‐positive and antigen‐negative cats with lymphoma regarding patients' characteristics, tumour location and outcome were evaluated. There was a significant decrease in the percentage of lymphoma cases associated with progressive FeLV infection from the first (59 per cent) to the second (13 per cent) observation period. FeLV antigen‐positive cats were significantly younger (median 3.7 v 11.3 years), and had significantly shorter response duration (median 25 days v 472 days) with therapy. In the cats of the second period, gastrointestinal and extranodal lymphomas were the most common anatomical sites, and the majority of those cats were FeLV antigen‐negative. Thus, other aetiologies than progressive FeLV infection must have a greater impact on cancerogenesis among affected cats with lymphoma to date.
Palynological analysis and taxonomic position of the genusMertensia(Boraginaceae)
Authors: Fukuda Tomoko , Ikeda Hiroshi
Published: August 2012

Palynological analysis of the genus Mertensia Roth, s. lat. (Boraginaceae) was performed. All pollen grains studied were mostly dumbbell shaped and had 6-heteroaperturate pollen type without exception. The type of pollen of Mertensia does not contradict recent classifications that assign Mertensia to Cynoglosseae. Among six sections of Mertensia, pollen grains of section Oreocharis (the Himalayan Mertensia) were different from those of other sections in having granulate sculpturing on the colpus and pseudocolpus membranes. The results, along with other morphological differences, may support Riedl’s treatment of the Himalayan species of Mertensia in the distinct genus Pseudomertensia Riedl. Of the other sections, four monotypic sections (sections Steenhanmera, Neuranthia, Typomertensia, and Mertensianthe) showed pollen structures similar to each other. Pollen grains in section Eumertensia had some variations in size and ornamentation, especially in the species distributed in western North America.
Morphological and germination response variability in seeds of wild yellow gentian (Gentiana lutea L.) accessions from northwest Spain
Authors: Pérez-García Félix , Varela Federico , González-Benito M. Elena
Published: August 2012

Gentiana lutea L. (yellow gentian, Gentianaceae) is an important medicinal plant under protection as endangered species in most European countries. The aim of this work was to evaluate variation in seed mass, seed water content, and seed germination among 56 wild accessions of G. lutea. The effect of gibberellic acid (GA3), putrescine, moist chilling, and level of ripeness of seeds on subsequent germination was also investigated. Seeds of G. lutea showed physiological dormancy (final germination percentages ranged from 0% to 11%, depending on the accession) and GA3 enhanced seed germination drastically in all the accessions. The highest germination (99%) of GA3-treated seeds was reached at 15 °C. Final germination percentage and germination rate (as expressed by mean germination time), as well as seed mass and seed water content, varied significantly among accessions. In general, 1 year moist chilling did not significantly enhance G. lutea seed germination. For most accessions, no significant differences were found between fully ripe seeds and less ripe seeds for seed water content, seed mass, and seed germination. Applications of GA3 were always most effective than those of putrescine for increasing seed germination.
Fidelity and diagnostic species concepts in vegetation classification in the Rocky Mountains, northern Utah, USA
Authors: Kusbach Antonín , Long James N. , Van Miegroet Helga , Shultz Leila M.
Published: August 2012

The concepts of diagnostic species and fidelity have been used frequently in European phytosociology but rarely in North American vegetation classification. We developed a classification of the vegetation of a mountainous area of northern Utah and compared the diagnostic species approach with the indicator-species approach of habitat type classification sensu Daubenmire prevailing in the U.S. Interior West. A total of 157 forest and nonforested plots were described by vascular plants and basic environmental factors. Clustering with RandomForest classification and ordination reduced the original number of plots to 26 meaningful vegetation units. Of these 26 units, 22 were strong, having four or more faithful species. Four units were weak, having less than three faithful species. We identified species diagnostic of particular vegetation units that are potentially useful for recognition of these units in the field. We proposed vegetation types at the level of vegetation alliances and associations, and correlated them with environmental factors. We found our vegetation units to be more strongly associated with the underlying environment than major habitat types sensu Daubenmire. Our approach to classification has the potential to directly link vegetation with the physical environment and could be the basis for a substantial improvement of vegetation classification in the central Rocky Mountains.
New records ofDrosera tokaiensissubsp.hyugaensis(Droseraceae) from Kochi Prefecture, Japan
Authors: Hayakawa Hiroshi , Hamachi Hidenori , Ogawa Kohei , Minaniya Yukio , Yokoyama Jun , Arakawa Ryo , Fukuda Tatsuya
Published: August 2012

Drosera tokaiensis subsp. hyugaensis (3x), a hybrid between Drosera spatulata (4x) and Drosera rotundifolia (2x), was found in Kochi Prefecture, Japan. Results of PCR–RFLP analysis of the internal transcribed spacer (ITS) regions of nuclear DNA showed that the hybrid individuals had the combined patterns of both parental species. Moreover, the chloroplast DNA of all hybrid individuals was identical to that of D. spatulata, suggesting that the hybrids were generated as a result of the transfer of pollen grains from D. rotundifolia to D. spatulata. Drosera tokaiensis subsp. hyugaensis was reported from Miyazaki and Kochi prefectures only. Drosera tokaiensis subsp. tokaiensis (6x), which is an allopolyploid species of D. tokaiensis subsp. hyugaensis, grows mainly in the Tokai and Kinki districts and is not distributed with D. tokaiensis subsp. hyugaensis in Miyazaki and Kochi prefectures. These findings indicate that the hybridization between D. spatulata and D. rotundifolia occurred independently and repeatedly in various areas of Japan.
New Cortinarius species from conifer-dominated forests of North America and Europe
Authors: Niskanen Tuula , Liimatainen Kare , Kytövuori Ilkka , Ammirati Joseph F.
Published: August 2012

Five new Cortinarius species with medium to large basidiomata are described based on morphological and molecular data. Three of them, Cortinarius aavae , Cortinarius brunneocalcarius , and Cortinarius grosmorneënsis , belong to subgenus Telamonia and one, Cortinarius subfloccopus , to clade /Fulvescentes. The relationship of the fifth species, Cortinarius brunneotinctus , was not solved but it resembles species of clade /Anomali. Cortinarius brunneocalcarius and C. aavae do not have close relatives within the subgenus Telamonia; whereas, C. grosmorneënsis belongs to section Brunnei. Cortinarius grosmorneënsis is only known from eastern Canada, but the other four species have a wide distribution: C. brunneocalcarius and C. subfloccopus occur in North America and Europe, and C. brunneotinctus and C. aavae in western and eastern North America. The descriptions of the novel species are presented and comparison to similar species provided.
Maternal fitness consequences of interactions among agents of mortality in early life of salmonids
Authors: Mogensen Stephanie , Hutchings Jeffrey A.
Published: August 2012

Maternal effects can be key determinants of female fitness through their influence on survival in early life. In salmonid fishes, three density-dependent sources of offspring mortality are redd superimposition, predation, and starvation. An individual-based model was developed to explore how these sources of mortality can affect functional relationships among maternal fitness, maternal phenotype (body size), spawner density, and spawning timing. We found that the strength of the relationship between maternal size and fitness was highly context-dependent, differing with the source of offspring mortality and with interactions among the mortality agents. Component Allee effects at low spawner densities were also detected in some simulations. The results reveal unanticipated interactions among offspring mortality sources, maternal body size, and fitness. Given the high probability that these mortality sources differ considerably across variable temporal and spatial scales, there would be considerable value in obtaining field-based empirical data to test the predictions proffered here to better understand the correlates of maternal fitness in salmonid fishes.
Early enrichment effects on brain development in hatchery-reared Atlantic salmon (Salmo salar): no evidence for a critical period
Authors: Näslund Joacim , Aarestrup Kim , Thomassen Søren T. , Johnsson Jörgen I.
Published: August 2012

In hatcheries, fish are normally reared in barren environments, which have been reported to affect their phenotypic development compared with wild conspecifics. In this study, Atlantic salmon ( Salmo salar ) alevins were reared in conventional barren hatchery trays or in either of two types of structurally enriched trays. We show that increased structural complexity during early rearing increased brain size in all investigated brain substructures. However, these effects disappeared over time after transfer to barren tanks for external feeding. Parallel to the hatchery study, a group of salmon parr was released into nature and recaptured at smoltification. These stream-reared smolts developed smaller brains than the hatchery reared smolts, irrespective of initial enrichment treatment. These novel findings do not support the hypothesis that there is a critical early period determining the brain growth trajectory. In contrast, our results indicate that brain growth is plastic in relation to environment. In addition, we show allometric growth in brain substructures over juvenile development, which suggests that comparisons between groups of different body size should be made with caution. These results can aid the development of ecologically sound rearing methods for conservational fish-stocking programs.
Early marine growth of juvenile Fraser River sockeye salmon (Oncorhynchus nerka) in relation to juvenile pink (Oncorhynchus gorbuscha) and sockeye salmon abundance
Authors: McKinnell Skip , Reichardt Maxine
Published: August 2012

Mortality of salmon in the ocean is considered to be greatest during the first few months and that its magnitude is an inverse of growth. First year marine growth (M1) in two Fraser River sockeye salmon ( Oncorhynchus nerka ) populations was positively correlated, reflecting a shared oceanic experience as postsmolts. M1 declined abruptly in both populations after 1977, corresponding to a well-documented change in climate. The reduction in average M1 was not accompanied by a detectable reduction in average survival. In both populations, M1 was significantly greater in even years when juvenile pink salmon ( Oncorhynchus gorbuscha ) are abundant in the Strait of Georgia, suggesting that interspecific competition there has little effect on M1. All correlations of M1 with regional pink salmon or sockeye salmon abundances, lagged to align ocean entry years, were negative, but few (pink) or none (sockeye) were statistically significant. The negative correlations were due to the long-term changes (pink salmon abundance increasing, sockeye M1 smaller). Odd year dominance of juvenile pink salmon in northern British Columbia, Canada, is persistent and corresponds with the biennial pattern of M1 variation in Fraser River sockeye salmon and may be the source of the significant odd–even year line effect on M1.
High microcystin concentrations occur only at low nitrogen-to-phosphorus ratios in nutrient-rich Canadian lakes
Authors: Orihel Diane M. , Bird David F. , Brylinsky Michael , Chen Huirong , Donald Derek B. , Huang Dorothy Y. , Giani Alessandra , Kinniburgh David , Kling Hedy , Kotak Brian G. , Leavitt Peter R. , Nielsen Charlene C. , Reedyk Sharon , Rooney Rebecca C. , Watson Sue B. , Zurawell Ron W. , Vinebrooke Rolf D.
Published: August 2012

Although the cyanobacterial toxin microcystin has been detected in Canadian fresh waters, little is known about its prevalence on a national scale. Here, we report for the first time on microcystin in 246 water bodies across Canada based on 3474 analyses. Over the last 10 years, microcystins were detected in every province, often exceeding maximum guidelines for potable and recreational water quality. Microcystins were virtually absent from unproductive systems and were increasingly common in nutrient-rich waters. The probable risk of microcystin concentrations exceeding water quality guidelines was greatest when the ratio of nitrogen (N) to phosphorus (P) was low and rapidly decreased at higher N:P ratios. Maximum concentrations of microcystins occurred in hypereutrophic lakes at mass ratios of N:P below 23. Our models may prove to be useful screening tools for identifying potentially toxic “hotspots” or “hot times” of unacceptable microcystin levels. A future scientific challenge will be to determine whether there is any causal link between N:P ratios and microcystin concentrations, as this may have important implications for the management of eutrophied lakes and reservoirs.
The effect of total spinal anesthesia on cardiac function in a large animal model of brain death
Authors: Almoustadi Waiel A. , Lee Trevor W.R. , Klein Julianne , Kumar Kanwal , Arora Rakesh C. , Tian Ganghong , Freed Darren H.
Published: August 2012

Brain death (BD) causes cardiac dysfunction in organ donors, attributable to the catecholamine storm that occurs with raised intracerebral pressure (ICP). However the direct contribution of the spinal sympathetics has not been well described. We examined the effect of total spinal anesthesia (TSA) on cardiac function in a large animal model of BD. Eighteen pigs were allocated to 3 experimental groups: Group 1, the saline-treated control group; Group 2, TSA administered prior to BD; and Group 3, TSA administered 30 min after BD. Inflation of an intracerebral balloon-tipped catheter was used to induce BD. Ventricular function was assessed using a pressure–volume loop catheter and magnetic resonance imaging. Serum catecholamine levels were assessed with high performance liquid chromatography. Inflation of the intracerebral balloon-tipped catheter was associated with a dramatic rise in heart rate and blood pressure, along with increased concentrations of serum epinephrine and norepinephrine. This phenomenon was not observed in Group 2. In Group 1, there was a significant decline in contractility, whereas groups 2 and 3 saw no change. Group 2 had greater contractile reserve than groups 1 and 3. Our data demonstrate the central role of spinal sympathetics in the hemodynamic response to raised ICP. Further work is required to determine the utility of TSA in reversing cardiac dysfunction in BD donors.
Promotion and inhibition of cardiac hypertrophy by A-kinase anchor proteins
Authors: Blant Alexandra , Czubryt Michael P.
Published: August 2012

Originally identified as mediators of cyclic adenosine monophosphate (cAMP) and protein kinase A signaling, A-kinase anchor proteins (AKAPs) are now recognized as a diverse family of molecular scaffolds capable of interacting with many other proteins. Members of the AKAP family within the heart can take on either pro- or anti-hypertrophic roles by interacting with a myriad of protein kinases and phosphatases in the process. AKAPs often form the core of large signaling complexes (or signalosomes) that allow multiple pathways to converge and functionally intertwine. Approximately 30% of AKAPs discovered to date are expressed in the heart, but the functions of many of these remain to be discovered. This review focuses on AKAPs that have been demonstrated to play roles in mediating cardiac hypertrophy.
Women and the management of acute coronary syndrome
Authors: Ostadal Petr , Ostadal Bohuslav
Published: August 2012

Coronary heart disease (CHD) is the leading cause of morbidity and mortality in both men and women in the developed countries. Despite this fact, females are still under-represented in the majority of clinical trials. At the present time, only limited evidence is available with respect to the female-specific aspects of pathogenesis, management, and outcomes in acute coronary syndrome (ACS). Women less frequently undergo coronary intervention, and a lower proportion of women receive evidence-based pharmacotherapy, compared with men. It has been shown that women benefit from an invasive approach and coronary intervention in ACS as much as men, despite their advanced age and higher rate of bleeding complications. Also, administration of beta-blockers, ACE-inhibitors, and intensive statin therapy is associated with a comparable reduction of cardiovascular event rates in women and men. On the other hand, women may profit less than men from fibrinolytic or glycoprotein IIb/IIIa inhibitor therapy. Both sexes benefit equally from aspirin therapy, whereas contradictory data are available on the efficacy of clopidogrel in women. There is an urgent need for intensive research in the development of female-specific therapeutic strategy in ACS, even though the detailed mechanisms of sex differences are still unknown.
Role of D-type cyclins in heart development and disease
Authors: Hotchkiss Adam , Robinson Jessica , MacLean Jessica , Feridooni Tiam , Wafa Karim , Pasumarthi Kishore B.S.
Published: August 2012

A defining feature of embryonic cardiomyocytes is their relatively high rates of proliferation. A gradual reduction in proliferative capacity throughout development culminates in permanent cell cycle exit by the vast majority of cardiomyocytes around the perinatal period. Accordingly, the adult heart has severely limited capacity for regeneration in response to injury or disease. The D-type cyclins (cyclin D1, D2, and D3) along with their catalytically active partners, the cyclin dependent kinases, are positive cell cycle regulators that play important roles in regulating proliferation of cardiomyocytes during normal heart development. While expression of D-type cyclins is generally low in the adult heart, expression levels are augmented in association with cardiac hypertrophy, but are uncoupled from myocyte cell division. Accordingly, re-activation of D-type cyclin expression in the adult heart has been implicated in pathophysiological processes via mechanisms distinct from those that drive proliferation during cardiac development. Growth factors and other exogenous agents regulate D-type cyclin production and activity in embryonic and adult cardiomyocytes. Understanding differences in the precise intracellular mediators downstream from these signalling molecules in embryonic versus adult cardiomyocytes could prove valuable for designing strategies to reactivate the cell cycle in cardiomyocytes in the setting of cardiovascular disease in the adult heart.
Attenuation of endothelin-1-induced PKB and ERK1/2 signaling, as well as Egr-1 expression, by curcumin in A-10 vascular smooth muscle cells
Authors: Kapakos Georgia , Youreva Viktoria , Srivastava Ashok K.
Published: August 2012

Endothelin-1 (ET-1) is implicated in the pathogenesis of vascular abnormalities through the hyperactivation of growth promoting pathways, including protein kinase B (PKB) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling. ET-1 has been shown to elicit its responses through the generation of reactive oxygen species (ROS). Curcumin, the main constituent of the spice turmeric, exhibits cardio-protective, anti-proliferative, and antioxidant properties; however, the precise molecular mechanism of its action is unclear. Therefore, in the present study, we investigated the effects of curcumin on ET-1-induced PKB and ERK1/2 signaling, as well as insulin-like growth factor type receptor (IGF-1R) phosphorylation. Curcumin dose-dependently inhibited ET-1-induced phosphorylation of PKB, ERK1/2, c-Raf, and insulin-like growth factor type 1 receptor (IGF-1R), in vascular smooth muscle cells (VSMC). Furthermore, curcumin also attenuated ET-1-induced expression of early growth response (Egr)-1, a transcription factor downstream of ERK1/2 that plays a regulatory role in several cardiovascular pathological processes. In conclusion, these data demonstrate that curcumin is a potent inhibitor of ET-1-induced mitogenic and proliferative signaling events in VSMC and suggest that the ability of curcumin to attenuate these events may contribute as a potential mechanism for its cardiovascular protective response.
Influence of ovariectomy on cardiac oxidative stress in a renovascular hypertension model
Authors: Barp Jaqueline , Sartório Carmem Luiza , Campos Cristina , Llesuy Susana Francisca , Araujo Alex Sander , Belló-Klein Adriane
Published: August 2012

The aim of this study was to evaluate the potential influence of endogenous ovarian hormones on cardiac oxidative stress in renovascular hypertension. Female Wistar rats (N = 10 per group) were divided among 4 groups: (i) normotensive control; (ii) hypertensive control; (iii) normotensive ovariectomized; and (iv) hypertensive ovariectomized rats. To induce hypertension, 2-kidney 1-clip (2K1C) Goldblatt’s method was followed. Blood pressure (BP) was enhanced (25%) in 2K1C and it was not further altered in hypertensive ovariectomized animals. Lipid peroxidation (measured by thiobarbituric acid reactive substances; TBARS) increased in heart homogenates after ovariectomy (253%) and was additionally augmented when associated with hypertension (by 28%). Superoxide dismutase and catalase activities were similar in both hypertensive groups. Hypertension enhanced glutathione peroxidase activity (75%), but the association with ovariectomy prevented this change. Total radical trapping antioxidant potential (TRAP) decreased in hypertensive rats (34%) and was recovered when associated with ovariectomy. However, this adaptation seems not to be sufficient to avoid the increased oxidative damage in ovariectomized hypertensive animals. These results suggest a protective role for physiological ovarian hormones in the cardiac oxidative stress induced by 2K1C hypertension.
Adipose tissue houses different subtypes of stem cells
Authors: Stillwell Chris , Wang Fei , Xiang Bo , Deng Jixian , Kashour Tarek , Liu Hongyu , Freed Darren , Arora Rakesh C. , Tian Ganghong
Published: August 2012

Adipose tissue stromal fraction (ASF) contains multipotent cells capable of differentiation towards several lineages and may be used for the treatment of various degenerative diseases. However, the multipotent cells within ASF have not been fully characterized. In this study we have attempted to characterize stem cells in the ASF obtained through serial dilution. Five single-cell clones were studied. It was found that the single-cell clones exhibited slight but significant differences in proliferative capacity and differentiation potential. We conclude that ASF houses different subtypes of stem cells.
Dual influence of spontaneous hypertension on membrane properties and ATP production in heart and kidney mitochondria in rat: effect of captopril and nifedipine, adaptation and dysadaptation
Authors: Ziegelhöffer A. , Mujkošová J. , Ferko M. , Vrbjar N. , Ravingerová T. , Uličná O. , Waczulíková I. , Ziegelhöffer B.
Published: August 2012

This study deals with changes, induced by hypertension and its treatment, in the function and properties of mitochondria in the heart and kidneys. Male, 16-week-old hypertensive rats were allocated to 3 groups: (i) animals treated daily for 4 weeks with captopril (CAP, 80 mg·(kg body mass)–1, n = 45), (ii) animals treated with CAP + nifedipine (NIF, 10 mg·kg–1, n = 45), or (iii) untreated hypertensive controls (n = 96). Wistar rats (n = 96) were used as normotensive controls. Systolic blood pressure (SBP), heart rate (HR), and heart mass / body mass (HW/BW) ratio were measured at the beginning and end of the experiments; measurements for mitochondrial Mg2+-ATPase activity, O2-consumption (QO2), respiratory control index (RCI), ADP/O, oxidative phosphorylation rate (OPR), conjugated diene content (CD), and membrane fluidity (MF) were also taken at different time intervals. In the heart, elevated SBP, HR, and HW/BW accompanied increased QO2, OPR, and Mg2+-ATPase activity, indicating an adaptive response to hypertension-induced increase in the energy demands of the myocardium. Treatments with CAP or with CAP + NIF were very similar in their prevention of increase in SBP, HR, HW/BW, and the rise in OPR (all p < 0.05–0.01). In the kidneys, hypertension induced a drop in OPR; however, antihypertensive therapy aggravated the resulting energy deficiency, whereby treatment with CAP + NIF was more detrimental than treatment with CAP alone. Heart and kidney mitochondria exhibited negligible changes in CD and moderately increased MF, which was more potentiated by treatment with CAP alone than with CAP + NIF.
Allometry of secondary, primary, and nonsexual traits in the beautiful demoiselle (Calopteryx virgo meridionalis)
Authors: Outomuro D. , Cordero-Rivera A.
Published: August 2012

The static allometry between the size of a trait and the body size results from the net selection forces acting on the evolution of both the trait and the body size. An increased knowledge of the functional significance of traits is necessary to understand observed allometric patterns. We studied several traits of males of the beautiful demoiselle ( Calopteryx virgo meridionalis Sélys, 1873), for which there is a good functional knowledge of the genitalic traits and ornaments. We found positive allometry for the wing spot size (considered a secondary sexual trait) and for the distal width (but not length) of the anal appendages, which are used for grasping the female prior to copulation. Regarding the male secondary genitalia, the length but not the width of the big horns of the aedeagus showed an isometric pattern. The aedeagus shaft length showed a negative allometric pattern, while its distal width did not show a significant regression. The slopes of the regressions were higher when using wing length than when using body length as estimators of body size, with the exception of wing spot length. Results are discussed based on the functional significance of the study traits, as well as the pre- and post-copulatory selective pressures acting on them.
Composition of body storage compounds influences egg quality and reproductive investment in the land snail Cornu aspersum
Authors: Nicolai Annegret , Filser Juliane , Lenz Roman , Valérie Briand , Charrier Maryvonne
Published: August 2012

In invertebrates, resources available for growth and reproduction might influence the composition of body stores and subsequently nutrient allocation to eggs, thereby adjusting energy investment in reproduction. We investigated in the land snail Cornu aspersum (Müller, 1774) the efficiency of growth and the main storage compounds in the body and in eggs with respect to lipid content in food (5.5% versus 2.5%). The high body dry mass density of snails fed on lipid-rich diet underlined the high storage capacity of neutral lipids acquired during growth (high growth efficiency) without changing energy content because of the prevailing carbohydrate storage compounds. Reproductive investment was lower in these snails, and maternal effects decreased clutch size. Triglyceride allocation to eggs might enhance survival probability of offspring and therefore compensate for smaller clutch size. Snails fed on lipid-poor diet maximized their investment in clutch size whatever the amount of body stores, and allocated a higher amount of cholesterol to eggs. Cholesterol could be essential for embryo growth, as it ensures membrane functioning. In conclusion, the availability of resources can differentially affect nutrient allocation and energy investment in reproduction. Thus, the investigation of physiological processes becomes essential to understand population dynamics in fluctuating or changing habitats.
Early Holocene glacial retreat isolated populations of river otters (Lontra canadensis) along the Alaskan coast
Authors: Seymour M.S. , Ott K.E. , Guertin D.A. , Golden H.N. , McDonald D.B. , Ben-David M.
Published: August 2012

Pleistocene climatic oscillations have resulted in high rates of speciation. Lesser known are speciation events related to recent glacial retreats. During the early Holocene many Alaskan coastal glaciers receded, exposing much of the Kodiak Island Archipelago (KOD), the Kenai Peninsula, and Prince William Sound (PWS). Using fecal DNA analyses on samples collected in KOD, PWS, Kenai Fjords National Park (KEFJ), Katmai National Park and Preserve (KATM), and Vancouver Island, British Columbia (BC), we found isolation by distance to be an important mechanism for the divergence of populations of river otters ( Lontra canadensis (Schreber, 1777)) along the Pacific coast. Nonetheless, our results also demonstrated that KOD river otters appear to be more isolated genetically from their mainland conspecifics (approximately 50 km away), as river otters inhabiting PWS are from those in BC (over 2500 km away). In addition, KATM and KOD otters likely differentiated from one ancestral stock that inhabited the southwestern shores of Alaska during the Pleistocene and was isolated from more easterly populations by distance. The low genetic diversity among KOD river otters, compared with similar subpopulations in PWS, is likely the result of a founder effect and limited gene flow among the different islands within the Archipelago. Our observation that glacial retreat, rising sea levels, and formation of the Gulf of Alaska Coastal Current in the early Holocene likely led to divergence of populations of river otters, a highly mobile semiaquatic mammal, highlights the potential for future speciation events related to current climate change and ocean currents in coastal animal populations.