bluuebunny/crossref_metadata_2025 huggingface dataset:
Acid–base regulations a comparison of quantitative methods
Authors: Kowalchuk John M. , Scheuermann Barry W.
Published: April 2011

The [H+] and [HCO3−] of biological solutions is determined by the [Formula: see text], the concentration of strong ions (mainly Na+, K+, Ca2+, Cl−, lactate−), and the concentration of weak acids (mainly proteins, phosphates). Two mathematical models are available that use a quantitative approach to describe the acid–base behaviour of plasma, but which differ in their treatment of the weak acid component: Stewart model (using [Formula: see text], strong ion difference (SID = [Na+ + K+ + Ca2+] − [Cl− + lactate−]) and [protein]TOT); Fencl model (using [Formula: see text], SID, [albumin], and [Pi]TOT). The present study compared measured and estimated [H+] and [HCO3−] in whole-blood samples collected from eight subjects during two double-ramp exercise protocols to the limit of tolerance to assess the accuracy with which each of the quantitative models predicts measured values. Arterialized-venous blood was analyzed for [H+], [Formula: see text], [protein]TOT, [albumin], [Pi]TOT, and SID (= [Na+ + K+ + Ca2+] − [Cl− + lactate−]), and these independent variables were then substituted into the appropriate mathematical model to estimate [H+] and [HCO3−]. Analysis showed that the [H+] and [HCO3−] estimated using either model provided a good estimate of the [H+] (Stewart model, r = 0.81; Fencl model, r = 0.81) and [HCO3−] (Stewart model, r = 0.93; Fencl model, r = 0.93) measured in plasma; linear regression analysis demonstrated that the slopes and intercepts for each of die relationships were not different (p > 0.05) from the line of identity. Differences between estimated and measured values were small, averaging < 3 nmol∙L−1 for [H+] and < 2 mmol∙L−1 for [HCO3−]. However, in the case of plasma [H+], the difference between estimated and measured values became skewed (i.e., [H+]M < [H+]Est) above [H+]M ≈ 55 nmol∙L−1, or at [SID] ≤ 35 mequiv.∙L−1. Reasons for the difference between measured and estimated values are discussed, with attention given to the [SID] and weak acid components.Key words: quantitative acid–base chemistry, strong ion difference, weak acids, strong ions, lactate, hydrogen ion, bicarbonate.
Activation of spinal cord serotonergic neurons accompanies cold-induced sympathoexcitation
Authors: Passerin Alicia M. , Henley William N.
Published: April 2011

These studies examined the hypothesis that serotonergic neurons located in central sites known to be involved with autonomic regulation are activated by cold exposure, a potent stimulator of the sympathetic nervous system. In all experiments, rats were exposed to either 3 °C or 22 °C for 24 h. Significant increases (p < 0.05) in urinary norepinephrine excretion, depletions of myocardial norepinephrine, and enhanced myocardial L-DOPA accumulation following decarboxylase inhibition provided evidence of sympathoexcitation at 3 °C. Accumulations of the serotonin metabolite 5-hydroxyindoleacetic acid, in saline-injected rats, and 5-hydroxytryptophan in decarboxylase-inhibited rats were increased in spinal cord and brainstem regions of cold-exposed rats. Two hours after injection of the serotonin synthesis inhibitor p-chlorophenylalanine, significantly greater depletions of serotonin in spinal cord and 5-hydroxyindoleacetic acid in spinal cord and brainstem of cold-exposed rats were noted; synthesis inhibition also caused a larger drop in body temperature in cold-exposed rats. Microdissections of raphe nuclei and thoracic spinal cord sites indicated that the principal sites of serotonergic activation were the dorsal and intermediate spinal regions, and the raphe magnus. Thus, cold-induced sympathoexcitation was accompanied by activation of serotonergic neurons in spinal cord and brainstem regions known to be involved in autonomic regulation.Key words: serotonin, cold, stress, sympathetic nervous system, spinal cord.
Fish oil, essential fatty acids, and hypertension
Authors: Lee R. M. K. W.
Published: April 2011

A proper balance between the n−3 and n−6 series of essential fatty acids (EFAs) is essential for homeostasis and normal growth in humans. Dietary supplement with fish oil and related n−3 EFAs has been used to study their antihypertensive property in animals and humans with borderline and essential hypertension. In the animal models, chronic treatment of young animals generally only attenuated the development of hypertension. In animals with hypercholesterolemia, n−3 EFA supplement increased the incidence of atherosclerosis. In humans, chronic treatment with fish oil only produced a small reduction in blood pressure. The concerns are that the high dose of fish oil may interfere with the control of blood glucose in diabetic patients, and may cause prolonged bleeding in surgical patients. Studies on the animal models of hypertension showed that n−6 EFAs are more effective than n−3 EFAs in lowering and normalizing the blood pressure of these animals, probably through the production of tissue prostaglandins, which favour vasodilation. The antihypertensive effect of the n−6 EFAs in humans is not well known, because mere are only a few studies, usually involving a very small number of patients. A possible side effect of n−6 EFAs for concern is that they might stimulate tumour development. A careful examination of these risk factors is needed before any recommendation can be made concerning the use of EFAs for the control of hypertension for humans.Key words: fish oil, essential fatty acid, hypertension, γ-linolenic acid.
The role of stomachal digestion on the pharmacological activity of plant extracts, using as an example extracts of Harpagophytum procumbens
Authors: Soulimani R. , Younos C. , Mortier F. , Derrieu C.
Published: April 2011

Various researchers have described anti-inflammatory activity of aqueous extracts of devil's-claw (Harpagophytum procumbens DC.). In this study the extent of the anti-inflammatory activity of an aqueous extract prepared from cryoground fresh plant and administered intraperitoneally, per os (by gavage), and intraduodenally was determined in rats. The anti-inflammatory properties were assessed by applying the carrageenan-induced edema test. The results obtained indicated that intraperitoneal pretreatment with an aqueous extract of H. procumbens significantly reduced the carrageenan-induced edema at 400 and 800 mg/kg 4 h after carrageenan injection (45 and 65% inhibition, respectively). When administered orally (by gavage), the extracts were inefficient. This result could be attributed to the time in transition in the stomach, where the pH is acidic, causing a decrease of the activity of the extract. This inference is consistent with the results obtained by other authors, showing the absence of extract activity when it was treated in an environment of pH 1 and 37 °C (similar to the physicochemical conditions found in the stomach) and then administered intraperitoneally. Intraduodenal pretreatment with the aqueous extract significantly reduced the carrageenan-induced edema at 200, 400, and 1600 mg/kg 6–9 h after carrageenan injection (43, 60, and 41% inhibition, respectively). The presence of extract activity after intraduodenal administration supports the assumption that transition of the extract through the stomach leads to loss of activity.Key words: Harpagophytum procumbens DC., harpagoside, anti-inflammatory properties, carrageenan, edema, intraduodenal.
Role of extracellular Ca2+ in the selective enhancement of contractile responses of arteries from diabetic rats to noradrenaline
Authors: Abebe Worku , Harris Kim Howard , MacLeod Kathleen M.
Published: April 2011

Maximum contractile responses of diabetic aortas incubated in the absence of extracellular Ca2+ to increasing Ca2+ (0.01–10 mM) in the presence of 1 μM noradrenaline, but not 40 mM KCl, were significantly increased compared with those of age-matched control rats. Maximum contractile responses of both aortas and mesenteric arteries from diabetic rats to noradrenaline, but not KCl, in the presence of extracellular Ca2+ (2.5 mM) were also significantly enhanced. The Ca2+ channel antagonists verapamil and nifedipine and the Ca2+ channel agonist BAY K8644 produced a similar percentage change in the magnitude of the noradrenaline response in arteries from both control and diabetic rats. These data confirm the selective nature of the enhancement of contractile responses of arteries from diabetic rats to noradrenaline and suggest that this may be mediated in part through enhanced noradrenaline-induced influx of extracellular Ca2+ through channels sensitive to the Ca2+ channel ligands. However, this does not appear to be the only explanation for the enhanced contractile responses of diabetic arteries to noradrenaline, since in the presence of maximum concentrations of nifedipine (3 μM) and verapamil (10μM), responses of diabetic arteries to noradrenaline were still greater than those of control arteries.Key words: diabetes, arteries, contractility, noradrenaline, extracellular Ca2+.
Gender effects of tall oil versus soybean phytosterols as cholesterol-lowering agents in hamsters
Authors: Ntanios Fady Y , MacDougall Diane E , Jones Peter JH
Published: April 2011

To examine the effect of gender on the mechanisms of action of phytosterols extracted from tall oil (TO) and soybean (SB) on cholesterol and phytosterol metabolism, male and female hamsters were fed cholesterol-enriched diets containing 0.5 or 1% (w/w) TO or SB phytosterols for 90 days. Plasma lipoprotein cholesterol profile and tissue phytosterol and cholesterol biosynthesis levels were determined. Mean plasma total-cholesterol level in females fed 1% (w/w) SB was reduced (p < 0.05) by 44%, while in males it was lowered (p < 0.05) by 25% compared with their respective controls. Moreover, mean plasma total-cholesterol level was reduced (p < 0.05) in male hamsters by -31% and female hamsters by -32% when fed 1% (w/w) TO. Cholesterol biosynthesis was higher (p < 0.05) by twofold in groups fed TO at 0.5 and 1% (w/w) concentrations, compared with SB. Hamsters fed TO at 0.5 and 1% (w/w) levels also had higher (p < 0.05) hepatic and enterocytic campesterol contents than SB-fed animals. These findings demonstrate gender differences in cholesterol metabolism in TO- and SB-fed hamsters. The results suggest that TO, conversely to SB phytosterol, is a more effective cholesterol-lowering agent in male, but not as much in female, hamsters, over a feeding period of 90 days.Key words: phytosterols, cholesterol, sitosterol, sitostanol, gender, hamster.
Evidence for presence of ATP-sensitive K+ channels in rat colonic smooth muscle cells
Authors: Plujà Lídia , Yokoshiki Hisashi , Sperelakis Nicholas
Published: April 2011

Coexpression of sulfonylurea receptor (SUR) and inward-rectifying K+ channel (Kir6.1 or 6.2) subunit yields ATP-sensitive K+ (KATP) channels. Three subtypes of SUR have been cloned: pancreatic (SUR1), cardiac (SUR2A), and vascular smooth muscle (SUR2B). The distinct responses to K+ channel openers (KCOs) produced in different tissues may depend on the SUR isoform of KATP channel. Therefore, we investigated the effects of pinacidil and diazoxide, two KCOs, on KATP currents in intestinal smooth muscle cells of the rat colon (circular layer) using whole-cell voltage clamp. Pinacidil stimulated a time-independent K+ current evoked by various test potentials from a holding potential of -70 mV. The reversal potential of the stimulated current was about -75 mV, which is close to the equilibrium potential for K+ (EK). Both pinacidil and diazoxide dose-dependently stimulated K+ currents (evoked by ramp pulses), with EC50 values of 1.3 and 34.2 µM, respectively. The stimulated current was completely reversed by glybenclamide (3 µM). Since the EC50 values are close to those reported for vascular smooth muscle (VSM) cells, the SUR subtype may be similar to that in VSM cells, and could form the functional KATP channel in rat colonic smooth muscle cells.Key words: ATP-sensitive K+ channels, rat colonic smooth muscle cells, pinacidil, diazoxide, patch-clamp technique.
Characterization of the isoform-specific differences in the gating of neuronal and muscle sodium channels
Authors: O'Leary Michael E
Published: April 2011

Human heart (hH1), human skeletal muscle (hSkM1), and rat brain (rIIA) Na channels were expressed in cultured cells and the activation and inactivation of the whole-cell Na currents measured using the patch clamp technique. hH1 Na channels were found to activate and inactivate at more hyperpolarized voltages than hSkM1 and rIIA. The conductance versus voltage and steady state inactivation relationships have midpoints of -48 and -92 mV (hH1), -28 and -72 mV (hSkM1), and -22 and -61 mV (rIIA). At depolarized voltages, where Na channels predominately inactivate from the open state, the inactivation of hH1 is 2-fold slower than that of hSkM1 and rIIA. The recovery from fast inactivation of all three isoforms is well described by a single rapid component with time constants at -100 mV of 44 ms (hH1), 4.7 ms (hSkM1), and 7.6 ms (rIIA). After accounting for differences in voltage dependence, the kinetics of activation, inactivation, and recovery of hH1 were found to be generally slower than those of hSkM1 and rIIA. Modeling of Na channel gating at hyperpolarized voltages where the channel does not open suggests that the slow rate of recovery from inactivation of hH1 accounts for most of the differences in the steady-state inactivation of these Na channels.Key words: cardiac, neuronal, skeletal muscle, sodium channel.
Whole-body plethysmography, does it measure tidal volume of small animals?
Authors: Enhorning Goran , Schaik Sandrijn van , Lundgren Claes , Vargas Ida
Published: April 2011

A whole-body plethysmograph was used for mice. The increase in pressure caused by each inhalation was equivalent to the increase that could be calculated to result from heating and humidification of the inhaled air. However, comprehending that a drop in temperature and humidity would cause an abrupt pressure decline during exhalation was difficult. Pressure changes in the plethysmograph were also studied with an artificial chest, modeling the respiratory mechanics, but without the "inhaled" air being heated or humidified. The "chest" consisted of a metal bellows oscillated by a stepper motor 25 to 175 times per minute. Hereby air (0.05 to 0.20 mL) moved in and out of the bellows. The air passed through a polyethylene tube, the length of which was proportional to "airway resistance" and varied from 5 to 35 cm. It was found that the pressure oscillation was affected not only by "tidal volume" of the mechanical chest but also by "respiratory rate" and by "airway resistance." We concur with previous investigators that the plethysmograph pressure reflects alveolar pressure and that fluctuations cannot be explained by changes in temperature and humidity. Accordingly, tidal volume can only be qualitatively and not quantitatively assessed.Key words: tidal volume, airway resistance, respiratory rate, chest model.
Territorial fidelity of catbirds
Authors: Darley J. A. , Scott D. M. , Taylor N. K.
Published: April 2011

The fidelity, within three breeding seasons, of 109 catbirds, Dumetella carolinensis, to their mates and breeding territories was studied. About one-third of the birds abandoned their territories, usually after a nesting failure. Most deserted as pairs and established new territories up to 450 m distant from the original. The causes of desertion could not usually be determined: neither the number of nest losses preceding desertion nor the period in the nesting cycle when desertion occurred was clearly influential. Excluding those pairs in which one member of a pair died, only one bird was known to change mates after a nesting failure. The pair-bond remained intact in 15 of 16 pairs that attempted second broods. The reproductive success of pairs faithful to their territory was greater, but not significantly so (P =.143), than that of pairs that deserted.Patterns of desertion in passerines and the advantages of desertion are discussed.
Comparative morphology of the cottid genus Myoxocephalus based on meristic, morphometric, and other anatomical characters
Authors: Cowan Garry I. McT.
Published: April 2011

Specimens representing 15 nominal species of the genus Myoxocephalus were subjected to detailed comparative morphological study to determine some of the more important species characteristics and also those indicating potential for expressing phylogenetic progression.Analysis of seven meristic characters revealed that none of them is consistently sexually dependent. Geographic variation within the species indicated the presence of both latitudinal and longitudinal clines. No evolutionary group affinities were evident.The morphology of the cephalic lateral line system, lateral line ossicles, squamation, and olfactory rosettes were found to exhibit a high degree of specificity, especially the first three systems. With the exception of the lateral line ossicles all evidenced some potential as indicators of phylogeny.Analysis of 23 morphometric characters was accomplished by cluster analysis. The resultant clusters indicated heterogenous unnatural groupings.On the basis of these analyses well-defined species differences exist in most of the major morphological features. The nominal species M. scorpius (Linnaeus) includes three distinct species (Gulf of Alaska, Arctic–East coast, and European). In addition, the data indicate that the genus is probably composed of three basic evolutionary lines: the Holarctic–Atlantic, Bering Sea–Transpacific, and Asiatic.
Responsiveness to noradrenaline of melanophores associated with cryptic patterning in winter flounder, Pleuronectes americanus, in vitro
Authors: Vokey J E , Burton D
Published: April 2011

The cryptic patterning processes of flatfish raise interesting questions about the regulatory mechanisms involved. Winter flounder, Pleuronectes americanus, can display cryptic patterns that have dark band, general background, and white spot components with different responsiveness in vivo to background and stress. In vitro the white spot melanophores display a concentration threshold to noradrenaline approximately 50 times higher than that for the other two pattern components. Completion of melanosome aggregation in response to 10-5 M noradrenaline is fastest for white spot melanophores and slowest for those from the dark bands. This difference is related to melanophore size and is in the same relative order as in vivo. Short-term (44-48 h) denervation with 6-hydroxydopamine and longer term (9-10 days) degeneration of nerve terminals in HAM F-12 medium affect melanophore responses differently according to the pattern component. These results demonstrate that differential activity associated with flatfish patterning includes a peripheral neuroeffector component, part of which is directly associated with the melanophores.
Elevated urinary cortisol in a timber wolf (Canis lupus): a result of social behaviour or adrenal pathology?
Authors: Moger William H , Ferns Lyn E , Wright, Jr. James R , Gadbois Simon , McLeod Peter J
Published: April 2011

In a previously published report, a male timber wolf (Canis lupus) was identified as having significantly elevated urinary cortisol to creatinine ratios relative to other males in the pack. This second-ranking animal, whose social status was being challenged, was involved in far more aggressive interactions than any other pack member. The wolf died 3 years later from gastric and splenic torsion. Necropsy revealed a unilateral adrenal tumour identified by histology and electron microscopy to be a cortical adenoma. This finding is based on the presence of abundant lipid and no evidence of neurosecretory granules. Whether the increased cortisol levels in this wolf were the result of social stress, as originally suggested, the tumour, or both is uncertain.
Nutritional condition and fertility of white-tailed deer (Odocoileus virginianus) from areas with contrasting histories of hunting
Authors: Swihart Robert K , Weeks, Jr. Harmon P , Easter-Pilcher Andrea L , DeNicola Anthony J
Published: April 2011

We evaluated the nutritional condition and pregnancy rates of 58 female white-tailed deer (Odocoileus virginianus) from five areas in Indiana, U.S.A., with differing herd densities and histories of hunting. We found significant differences among sites for five external measures of body size, six physiological indicators of nutritional restriction, and five internal postmortem measures of body size and fat reserves. Multivariate assessment of nutritional condition provided an appreciable increase in classification of deer to their site of origin relative to reliance on any single variable. In addition, postmortem variables and physiological indicators contributed significantly to our ability to correctly classify deer. Nearly all measures of nutrition or stress indicated that deer from sites hunted annually were in better nutritional condition than deer from sites hunted only once in the past several decades. Fertility rates differed significantly among the sites and varied inversely with density. Comparison with other studies within the central and northern hardwood regions suggests that weak density dependence in fertility rates occurs among adult does, although substantial reproduction still occurs when densities exceed 50 deer/km2. Density effects become progressively stronger for first-year and yearling females, with reproduction in the former age group virtually ceasing when densities exceed 30 deer/km2.
Vessel Wall Inflammation in Spontaneous Cervical Artery Dissection
Authors: Pfefferkorn Thomas , Saam Tobias , Rominger Axel , Habs Maximilian , Gerdes Lisa-Ann , Schmidt Caroline , Cyran Clemens , Straube Andreas , Linn Jennifer , Nikolaou Konstantin , Bartenstein Peter , Reiser Maximilian , Hacker Marcus , Dichgans Martin
Published: April 2011

Background and Purpose—

Vessel wall inflammation (VWI) may be a pathogenetic factor in cervical artery dissection (CAD). We used contrast-enhanced high-resolution MRI (hrMRI) and positron emission tomography CT (PET-CT) to systematically investigate VWI in spontaneous CAD.

Methods—

In this monocentric, prospective, observational study, all consecutive patients with acute, MRI-confirmed, spontaneous CAD admitted to our center between August 2007 and August 2009 were included. VWI was defined as perivascular contrast enhancement in hrMRI and increased perivascular [18F]-fluorodesoxyglucose uptake in PET-CT. VWI was further differentiated between local (restricted to the site of dissection) and generalized (exceeding the site of dissection).

Results—

A total of 37 patients were included. Multiple dissections were seen in 10 patients (27%). Twenty-five patients received both modalities as planned, 8 received only PET-CT, and 4 received only hrMRI. A subset of patients showed signs of a generalized VWI in hrMRI (4/29 patients, 14%) and PET-CT (8/33 patients, 24%). In patients who received both modalities, all with hrMRI signs of generalized VWI were PET-CT positive (3/3), whereas some PET-CT–positive patients were hrMRI-negative (4/7). If present, generalized VWI in hrMRI completely resolved within 6 months. The presence of >2 simultaneous dissections (seen in 2 patients) was significantly associated with generalized VWI in hrMRI (
P
=0.015) but marginally not in PET-CT (
P
=0.053).

Conclusions—

A subset of patients with spontaneous CAD showed signs of a generalized transient inflammatory arteriopathy in contrast-enhanced hrMRI and PET-CT. This subset of patients may be more prone to multiple dissections.
Dietary Intakes of Antioxidant Vitamins and Mortality From Cardiovascular Disease
Authors: Kubota Yoshimi , Iso Hiroyasu , Date Chigusa , Kikuchi Shogo , Watanabe Yoshiyuki , Wada Yasuhiko , Inaba Yutaka , Tamakoshi Akiko ,   the JACC Study Group
Published: April 2011

Background and Purpose—

Only a few reports have dealt with the association of antioxidant vitamin intakes with mortality or morbidity from cardiovascular disease in Asia. We investigated the relation of dietary vitamins A, E, and C intake with mortality from cardiovascular disease for Japanese men and women.

Methods—

The subjects were 23 119 men and 35 611 women aged 40 to 79 years without a history of cardiovascular disease or cancer who responded to the food frequency questionnaire as part of the Japan Collaborative Cohort Study for Cancer Risk (JACC) Study. They were followed up for a median period of 16.5 years. Hazard ratios were calculated per quintile of dietary vitamins A, E, and C intake by using Cox proportional hazard model.

Results—

During the 859 962 person-year follow-up, there were 2690 deaths (1343 men and 1347 women) from cardiovascular disease, comprising 1227 (607 men and 620 women) from stroke and 557 (311 men and 246 women) from coronary heart disease. The multivariable hazard ratios (95% CI) associated with the highest versus lowest quintiles of vitamin C intake were 0.70 (0.54 to 0.92) for total stroke, 0.63 (0.41 to 0.97) for coronary heart disease, and 0.79 (0.66 to 0.94) for total cardiovascular disease for women, but the inverse associations observed were weak and did not reach statistical significance for men. No significant association was observed between vitamins A or E intake and risk of mortality for either men or women.

Conclusions—

Vitamin C intake is inversely associated with mortality from cardiovascular disease for Japanese women.
Association With Serum Gamma-Glutamyltransferase Levels and Alcohol Consumption on Stroke and Coronary Artery Disease
Authors: Higashiyama Aya , Wakabayashi Ichiro , Ono Yuu , Watanabe Makoto , Kokubo Yoshihiro , Okayama Akira , Miyamoto Yoshihiro , Okamura Tomonori
Published: April 2011

Background and Purpose—

Light-to-moderate alcohol consumption is associated with reduced risk for cardiovascular disease, whereas high serum γ-glutamyltransferase (GGT) level is associated with cardiovascular disease. However, whether light-to-moderate alcohol drinking is still related to reduced risk of cardiovascular disease irrespective of GGT level is uncertain.

Methods—

We performed a 12.5-year cohort study of 2336 men (excluding exdrinkers) who were free from cardiovascular disease. They were classified into 4 groups according to alcohol consumption: never, and current light, moderate, or heavy drinker. The multivariate-adjusted hazard ratios of alcohol consumption for incidence of coronary artery disease, total stroke, and ischemic stroke compared with those of never drinkers were assessed with stratification by GGT median (32 IU/L).

Results—

In participants with GGT >32 IU/L, the hazard ratios of all current drinkers for total and ischemic stroke were higher than those of never drinkers. However, in all current drinkers with GGT ≤32 IU/L, the multivariate-adjusted hazard ratios for total and ischemic stroke were lower than in never drinkers.

Conclusions—

In men with above GGT median, alcohol drinking even with light-to-moderate consumption could be a risk factor for ischemic stroke.
Examining Parallelism of Sets of Psychometric Measures Using Latent Variable Modeling
Authors: Raykov Tenko , Patelis Thanos , Marcoulides George A.
Published: April 2011

A latent variable modeling approach that can be used to examine whether several psychometric tests are parallel is discussed. The method consists of sequentially testing the properties of parallel measures via a corresponding relaxation of parameter constraints in a saturated model or an appropriately constructed latent variable model. The underlying procedure is readily used in cases with at least three single measures studied for parallelism and is directly extended to the setting of multiple-component measuring instruments. The methodological limitations concerning intended attempts to test if two given measures are parallel are also explicated. The proposed modeling approach is illustrated with an example.
“It’s a Wild Thing, Waiting to Get Me”: Stance Analysis of African Americans With Diabetes
Authors: Davis Boyd H. , Pope Charlene , Mason Peyton R. , Magwood Gayenell , Jenkins Carolyn M.
Published: April 2011

Purpose

This mixed methods study uses a unique approach from social science and linguistics methodologies, a combination of positioning theory and stance analysis, to examine how 20 African Americans with type 2 diabetes make sense of the practices that led to recurrent emergency department visits to identify needs for more effective intervention.

Methods

In a purposive sample of postemergency department visit interviews with a same-race interviewer, people responded to open-ended questions reflecting on the decision to seek emergency department care. As applied to diabetes education, positioning theory explains that people use their language to position themselves toward their disease, their medications, and the changes in their lives. Transcriptions were coded using discourse analysis to categorize themes. As a form of triangulation, stance analysis measured language patterns using factor analysis to see when and how speakers revealed affect, attitude, and agentive choices for action.

Conclusion

Final analysis revealed that one third of the sample exhibited high scores for positive agency or capacity for decision-making and self-management, while the rest expressed less control and more negative emotions and fears that may preclude self-management. This approach suggests a means to tailor diabetes education considering alternative approaches focused on communication for those facing barriers.
The “Ligamentization” Process in Anterior Cruciate Ligament Reconstruction
Authors: Claes Steven , Verdonk Peter , Forsyth Ramses , Bellemans Johan
Published: April 2011

Background: Surgical anterior cruciate ligament reconstruction using tendon grafts has become the standard to treat the functionally unstable anterior cruciate ligament–deficient knee. Although tendons clearly differ biologically from ligaments, multiple animal studies have shown that the implanted tendons indeed seem to remodel into a ligamentous “anterior cruciate ligament–like” structure.

Purpose: The goal of this study was to systematically review the current literature on the “ligamentization” process in human anterior cruciate ligament reconstruction.

Study Design: Systematic review.

Methods: A computerized search using relevant search terms was performed in the PubMed, MEDLINE, EMBASE, and Cochrane Library databases, as well as a manual search of reference lists. Searches were limited to studies examining the healing of the intra-articular portion of the tendon graft based on biopsies of this graft obtained from a living human.

Results: Four studies were determined to be appropriate for systematic review, none of them reaching a level of evidence higher than 3. All reports considered autografts. Biopsy specimens were evaluated by light or electron microscopy and analyzed for vascularization, cellular aspects, and appearance of extracellular matrix. All authors universally agreed that the tendon grafts survive in the intra-articular environment. Based on changes observed in the healing grafts with regard to vascularization, cellular aspects, and properties of the extracellular matrix, different chronologic stages in the ligamentization process were discerned.

Conclusion: The key finding of this systematic review is that a free tendon graft replacing a ruptured human anterior cruciate ligament undergoes a series of biologic processes termed “ligamentization.” The graft seems to remain viable at any time during this course. Histologically, the mature grafts may resemble the normal human anterior cruciate ligament, but ultrastructural differences regarding collagen fibril distribution do persist. Different stages of the ligamentization process are described, but no agreement exists on their time frame. Problematic direct transmission of animal data to the human situation, the limited number of reports considering the ligamentization process in humans, and the potential biopsy sampling error attributable to superficial graft biopsies necessitate further human studies on anterior cruciate ligament graft ligamentization.
Mechanisms of Anterior Cruciate Ligament Injury in World Cup Alpine Skiing
Authors: Bere Tone , Flørenes Tonje Wåle , Krosshaug Tron , Koga Hideyuki , Nordsletten Lars , Irving Christopher , Muller Erich , Reid Robert Cortas , Senner Veit , Bahr Roald
Published: April 2011

Background: There is limited insight into the mechanisms of anterior cruciate ligament injuries in alpine skiing, particularly among professional ski racers.

Purpose: This study was undertaken to qualitatively describe the mechanisms of anterior cruciate ligament injury in World Cup alpine skiing.

Study Design: Case series; Level of evidence, 4.

Methods: Twenty cases of anterior cruciate ligament injuries reported through the International Ski Federation Injury Surveillance System for 3 consecutive World Cup seasons (2006-2009) were obtained on video. Seven international experts in the field of skiing biomechanics and sports medicine related to alpine skiing performed visual analyses of each case to describe the injury mechanisms in detail (skiing situation, skier behavior, biomechanical characteristics).

Results: Three main categories of injury mechanisms were identified: slip-catch, landing back-weighted, and dynamic snowplow. The slip-catch mechanism accounted for half of the cases (n = 10), and all these injuries occurred during turning, without or before falling. The skier lost pressure on the outer ski, and while extending the outer knee to regain grip, the inside edge of the outer ski caught abruptly in the snow, forcing the knee into internal rotation and valgus. The same loading pattern was observed for the dynamic snowplow (n = 3). The landing back-weighted category included cases (n = 4) where the skier was out of balance backward in flight after a jump and landed on the ski tails with nearly extended knees. The suggested loading mechanism was a combination of tibiofemoral compression, boot-induced anterior drawer, and quadriceps anterior drawer.

Conclusion: Based on this video analysis of 20 injury situations, the main mechanism of anterior cruciate ligament injury in World Cup alpine skiing appeared to be a slip-catch situation where the outer ski catches the inside edge, forcing the outer knee into internal rotation and valgus. A similar loading pattern was observed for the dynamic snowplow. Injury prevention efforts should focus on the slip-catch mechanism and the dynamic snowplow.
Etiquette and Effort
Authors: Santamaria Joseph P. , Rosenbaum David A.
Published: April 2011

Etiquette, the customary code of polite behavior among members of a group, provides a means of conveying respect for others, but what is the basis for etiquette’s unwritten rules? Here we show that one form of etiquette, holding a door open for another person, reflects the door holder’s expectation that the person for whom he or she holds the door shares the belief that the total effort expended by the two of them will be less than the summed efforts of the two individuals acting on their own. Our observations extend recent work on effort reduction in motor control to the management of social interactions.
Read-Out of Emotional Information From Iconic Memory
Authors: Kuhbandner Christof , Spitzer Bernhard , Pekrun Reinhard
Published: April 2011

Previous research has shown that emotional stimuli are more likely than neutral stimuli to be selected by attention, indicating that the processing of emotional information is prioritized. In this study, we examined whether the emotional significance of stimuli influences visual processing already at the level of transient storage of incoming information in iconic memory, before attentional selection takes place. We used a typical iconic memory task in which the delay of a poststimulus cue, indicating which of several visual stimuli has to be reported, was varied. Performance decreased rapidly with increasing cue delay, reflecting the fast decay of information stored in iconic memory. However, although neutral stimulus information and emotional stimulus information were initially equally likely to enter iconic memory, the subsequent decay of the initially stored information was slowed for threatening stimuli, a result indicating that fear-relevant information has prolonged availability for read-out from iconic memory. This finding provides the first evidence that emotional significance already facilitates stimulus processing at the stage of iconic memory.
Understanding Infidelity: An Interview With Gerald Weeks
Authors: Smith Travis
Published: April 2011

In this interview, Gerald Weeks shares his expertise on the topic of infidelity and couples counseling. Dr. Weeks defines infidelity, presents assessment strategies for treating the issue of infidelity, and discusses an intersystemic model for infidelity treatment when counseling couples. Dr. Weeks also provides insight into common mistakes made by clinicians when counseling couples in treatment for infidelity. He is the author of 22 books and hundreds of journal articles and a leader in the field of marriage and family therapy and a highly respected educator and clinician.
Mexican American Family’s Perceptions of the Multirelational Influences on Their Adolescent’s Engagement in Substance Use Treatment
Authors: Both Gragg Janee , Wilson Colwick M.
Published: April 2011

Adolescent substance use is a significant challenge for adolescents, their families, and the larger society. Clinicians and researchers continue to explore ways to effectively engage both families and substance using adolescents in an effort to improve treatment outcome. Therapeutic engagement can be especially difficult for immigrant families facing a variety of systemic and contextual factors that impact both treatment-seeking and engagement behaviors. This study explored the perceptions Mexican American families had about the processes that they feel hindered or contributed to their engagement in therapy. Major findings include identification of a multirelational engagement process linking specific relational dynamics to engagement outcomes including breaking cultural rules, sharing stories, managing fear of criticism, and building relational bridges.
Distribution and characterization of ampicillin- and tetracycline-resistant Escherichia colifrom feedlot cattle fed subtherapeutic antimicrobials
Authors: Mirzaagha Parasto , Louie Marie , Sharma Ranjana , Yanke L Jay , Topp Ed , McAllister Tim A
Published: April 2011

Background

Feedlot cattle in North America are routinely fed subtherapeutic levels of antimicrobials to prevent disease and improve the efficiency of growth. This practice has been shown to promote antimicrobial resistance (AMR) in subpopulations of intestinal microflora including Escherichia coli. To date, studies of AMR in feedlot production settings have rarely employed selective isolation, therefore yielding too few AMR isolates to enable characterization of the emergence and nature of AMR in E. coli as an indicator bacterium. E. coli isolates (n = 531) were recovered from 140 cattle that were housed (10 animals/pen) in 14 pens and received no dietary antimicrobials (control - 5 pens, CON), or were intermittently administered subtherapeutic levels of chlortetracycline (5 pens-T), chlortetracycline + sulfamethazine (4 pens-TS), or virginiamycin (5 pens-V) for two separate periods over a 9-month feeding period. Phenotype and genotype of the isolates were determined by susceptibility testing and pulsed field gel electrophoresis and distribution of characterized isolates among housed cattle reported. It was hypothesized that the feeding of subtherapeutic antibiotics would increase the isolation of distinct genotypes of AMR E. coli from cattle.

Results

Overall, patterns of antimicrobial resistance expressed by E. coli isolates did not change among diet groups (CON vs. antibiotic treatments), however; isolates obtained on selective plates (i.e., MA,MT), exhibited multi-resistance to sulfamethoxazole and chloramphenicol more frequently when obtained from TS-fed steers than from other treatments. Antibiograms and PFGE patterns suggested that AMR E. coli were readily transferred among steers within pens. Most MT isolates possessed the tet(B) efflux gene (58.2, 53.5, 40.8, and 50.6% of isolates from CON, T, TS, and V steers, respectively) whereas among the MA (ampicillin-resistant) isolates, the tem1-like determinant was predominant (occurring in 50, 66.7, 80.3, and 100% of isolates from CON, T, TS, and V steers, respectively).

Conclusions

Factors other than, or in addition to subtherapeutic administration of antibiotics influence the establishment and transmission of AMR E. coli among feedlot cattle.
Mycobacterium tuberculosis septum site determining protein, Ssd encoded by rv3660c, promotes filamentation and elicits an alternative metabolic and dormancy stress response
Authors: England Kathleen , Crew Rebecca , Slayden Richard A
Published: April 2011

Background

Proteins that are involved in regulation of cell division and cell cycle progression remain undefined in Mycobacterium tuberculosis. In addition, there is a growing appreciation that regulation of cell replication at the point of division is important in establishing a non-replicating persistent state. Accordingly, the objective of this study was to use a systematic approach consisting of consensus-modeling bioinformatics, ultrastructural analysis, and transcriptional mapping to identify septum regulatory proteins that participate in adaptive metabolic responses in M. tuberculosis.

Results

Septum site determining protein (Ssd), encoded by rv3660c was discovered to be an ortholog of septum site regulating proteins in actinobacteria by bioinformatics analysis. Increased expression of ssd in M. smegmatis and M. tuberculosis inhibited septum formation resulting in elongated cells devoid of septa. Transcriptional mapping in M. tuberculosis showed that increased ssd expression elicited a unique response including the dormancy regulon and alternative sigma factors that are thought to play a role in adaptive metabolism. Disruption of rv3660c by transposon insertion negated the unique transcriptional response and led to a reduced bacterial length.

Conclusions

This study establishes the first connection between a septum regulatory protein and induction of alternative metabolism consisting of alternative sigma factors and the dormancy regulon that is associated with establishing a non-replicating persistent intracellular lifestyle. The identification of a regulatory component involved in cell cycle regulation linked to the dormancy response, whether directly or indirectly, provides a foundation for additional studies and furthers our understanding of the complex mechanisms involved in establishing a non-replicating state and resumption of growth.
Improved antiretroviral treatment outcome in a rural African setting is associated with cART initiation at higher CD4 cell counts and better general health condition
Authors: Mossdorf Erik , Stoeckle Marcel , Mwaigomole Emmanuel G , Chiweka Evarist , Kibatala Patience L , Geubbels Eveline , Urassa Honoraty , Abdulla Salim , Elzi Luigia , Tanner Marcel , Furrer Hansjakob , Hatz Christoph , Battegay Manuel
Published: April 2011

Background

Data on combination antiretroviral therapy (cART) in remote rural African regions is increasing.

Methods

We assessed prospectively initial cART in HIV-infected adults treated from 2005 to 2008 at St. Francis Designated District Hospital, Ifakara, Tanzania. Adherence was assisted by personal adherence supporters. We estimated risk factors of death or loss to follow-up by Cox regression during the first 12 months of cART.

Results

Overall, 1,463 individuals initiated cART, which was nevirapine-based in 84.6%. The median age was 40 years (IQR 34-47), 35.4% were males, 7.6% had proven tuberculosis. Median CD4 cell count was 131 cells/μl and 24.8% had WHO stage 4. Median CD4 cell count increased by 61 and 130 cells/μl after 6 and 12 months, respectively. 215 (14.7%) patients modified their treatment, mostly due to toxicity (56%), in particular polyneuropathy and anemia. Overall, 129 patients died (8.8%) and 189 (12.9%) were lost to follow-up. In a multivariate analysis, low CD4 cells at starting cART were associated with poorer survival and loss to follow-up (HR 1.77, 95% CI 1.15-2.75, p = 0.009; for CD4 <50 compared to >100 cells/μl). Higher weight was strongly associated with better survival (HR 0.63, 95% CI 0.51-0.76, p < 0.001 per 10 kg increase).

Conclusions

cART initiation at higher CD4 cell counts and better general health condition reduces HIV related mortality in a rural African setting. Efforts must be made to promote earlier HIV diagnosis to start cART timely. More research is needed to evaluate effective strategies to follow cART at a peripheral level with limited technical possibilities.
Clinical symptoms and performance on the continuous performance test in children with attention deficit hyperactivity disorder between subtypes: a natural follow-up study for 6 months
Authors: Wang Liang-Jen , Huang Yu-Shu , Chiang Yuan-Lin , Hsiao Chen-Cheng , Shang Zong-Yi , Chen Chih-Ken
Published: April 2011

Background

The aims of this study were to determine the time course of improvements in attention deficit hyperactivity disorder (ADHD) clinical symptoms and neurocognitive function in a realistic clinical setting, and the differences in ADHD symptom improvement using different classifications of ADHD subtypes.

Methods

The Child Behavior Checklist (CBCL) was completed by parents of ADHD children at the initial visit. The computerized Continuous Performance Test (CPT), Swanson, Nolan, and Pelham, and Version IV Scale for ADHD (SNAP-IV), and ADHD Rating Scale (ADHD-RS) were performed at baseline, one month, three months, and six months later, respectively. Patient care including drug therapy was performed at the discretion of the psychiatrist. The ADHD patients were divided into DSM-IV subtypes (Inattentive, Hyperactive-impulsive and Combined type), and were additionally categorized into aggressive and non-aggressive subtypes by aggression scale in CBCL for comparisons.

Results

There were 50 ADHD patients with a mean age of 7.84 ± 1.64 years; 15 of them were inattentive type, 11 were hyperactive-impulsive type, and 24 were combined type. In addition, 28 of the ADHD patients were grouped into aggressive and 22 into non-aggressive subtypes. There were significant improvements in clinical symptoms of hyperactivity and inattention, and impulsivity performance in CPT during the 6-month treatment. The clinical hyperactive symptoms were significantly different between ADHD patients sub-grouping both by DSM-IV and aggression. Non-aggressive patients had significantly greater changes in distraction and impulsivity performances in CPT from baseline to month 6 than aggressive patients.

Conclusions

We found that ADHD symptoms, which included impulsive performances in CPT and clinical inattention and hyperactivity dimensions, had improved significantly over 6 months under pragmatic treatments. The non-aggressive ADHD patients might have a higher potential for improving in CPT performance than aggressive ones. However, it warrant further investigation whether the different classifications of ADHD patients could be valid for predicting the improvements in ADHD patients' clinical symptoms and neurocognitive performance.