bluuebunny/crossref_metadata_2025 huggingface dataset:
Sympatric Speciation: Models and Empirical Evidence
Authors: Bolnick Daniel I. , Fitzpatrick Benjamin M.
Published: August 2007

Sympatric speciation, the evolution of reproductive isolation without geographic barriers, remains highly contentious. As a result of new empirical examples and theory, it is now generally accepted that sympatric speciation has occurred in at least a few instances, and is theoretically plausible. Instead, debate has shifted to whether sympatric speciation is common, and whether models’ assumptions are generally met in nature. The relative frequency of sympatric speciation will be difficult to resolve, because biogeographic changes have obscured geographical patterns underlying many past speciation events. In contrast, progress is being made on evaluating the empirical validity of key theoretical conditions for sympatric speciation. Disruptive selection and direct selection on mating traits, which should facilitate sympatric speciation, are biologically well supported. Conversely, costs to assortative mating are also widely documented, but inhibit speciation. Evaluating the joint incidence of these key factors may illuminate why sympatric speciation appears to be relatively uncommon.
Cyclical mechanical stretch modulates expression of collagen I and collagen III by PKC and tyrosine kinase in cardiac fibroblasts
Authors: Husse Britta , Briest Wilfried , Homagk Lars , Isenberg Gerrit , Gekle Michael
Published: August 2007

Mechanical load and chemical factors as stimuli for the different pattern of the extracellular matrix (ECM) could be responsible for cardiac dysfunction. Since fibroblasts can both synthesize and degrade ECM, ventricular fibroblasts from adult rat hearts underwent cyclical mechanical stretch (CMS; 0.33 Hz) by three different elongations (3%, 6%, 9%) and four different serum concentrations (0%, 0.5%, 5%, 10%) within 24 h. Expression of collagen I and III, as well as matrix metalloproteinase-2 (MMP-2), tissue inhibitor of MMP-2 (TIMP-2), and colligin were analyzed by RNase protection assay. In the absence of serum, 9% CMS increased the mRNA of collagen I by 1.70-fold and collagen III by 1.64-fold. This increase was prevented by the inhibition either of PKC or of tyrosine kinase but not of PKA. Inhibition of PKC or tyrosine kinase itself reduced the expression of collagen I and collagen III mRNA. The mRNA of MMP-2, TIMP-2, and colligin showed the same tendency by stretch. Combined with 10% serum, 6% CMS reduced the mRNA of collagen I (0.62-fold) and collagen III (0.79-fold). Inhibition of PKC or tyrosine kinase, but not of PKA, prevented the reduction of collagen I and collagen III mRNA in 10% serum. The results show that the response of fibroblasts to CMS depends on the serum concentration. At least two signaling pathways are involved in the stretch-induced ECM regulation. Myocardial fibrosis due to ECM remodeling contributes to the dysfunction of the failing heart, which might be attributed to changes in hemodynamic loading.
Renoprotective and antihypertensive effects ofS-allylcysteine in 5/6 nephrectomized rats
Authors: Cruz Cristino , Correa-Rotter Ricardo , Sánchez-González Dolores Javier , Hernández-Pando Rogelio , Maldonado Perla D. , Martínez-Martínez Claudia María , Medina-Campos Omar Noel , Tapia Edilia , Aguilar Diana , Chirino Yolanda I. , Pedraza-Chaverri José
Published: August 2007

Progressive renal damage and hypertension are associated with oxidative and nitrosative stress. On the other hand, S-allylcysteine (SAC), the most abundant organosulfur compound in aged garlic extract (AG), has antioxidant properties. The effects of SAC and AG on blood pressure, renal damage, and oxidative and nitrosative stress were studied in five-sixths nephrectomized rats treated with SAC (200 mg/kg ip) and AG (1.2 ml/kg ip) every other day for 30 days. Proteinuria and serum creatinine and blood urea nitrogen concentrations were measured on days 0, 5, 10, 15, and 30, and systolic blood pressure was recorded on days 0, 15, and 30. The degree of glomerulosclerosis and tubulointerstitial damage, the immunostaining for inducible nitric oxide synthase, 3-nitrotyrosine, poly(ADP-ribose), and the subunits of NADPH oxidase p22phoxand gp91phox, and the activity of SOD were determined on day 30. SAC and AG reduced hypertension, renal damage, and the abundance of inducible nitric oxide synthase, 3-nitrotyrosine, poly(ADP-ribose), p22phox, and gp91phoxand increased SOD activity. Our data suggest that the antihypertensive and renoprotective effects of SAC and AG are associated with their antioxidant properties and that they may be used to ameliorate hypertension and delay the progression of renal damage.
RhoA required for acid-induced stress fiber formation and trafficking and activation of NHE3
Authors: Yang Xiaojing , Huang Hai-Chang , Yin Helen , Alpern Robert J. , Preisig Patricia A.
Published: August 2007

Exposure to an acid load increases apical membrane Na+/H+antiporter (NHE3) activity, a process that involves exocytic trafficking of the transporter to the apical membrane. We have previously shown that an intact microfilament structure is required for this exocytic process (Yang X, Amemiya M, Peng Y, Moe OW, Preisig PA, Alpern RJ. Am J Physiol Cell Physiol 279: C410–C419, 2000). The present studies demonstrate that acid-induced stress fiber formation is required for stimulation of NHE3 activity. Formation of stress fibers is associated with acid-induced tyrosine phosphorylation and increases in protein abundance of two focal adhesion proteins, p125FAKand paxillin. The Rho kinase inhibitor Y27632 completely blocks acid-induced stress fiber formation and the increases in apical membrane NHE3 abundance and activity, but it has no effect on acid-induced tyrosine phosphorylation of p125FAKor paxillin. Herbimycin A completely blocks acid-induced tyrosine phosphorylation of p125FAKand paxillin but only partially blocks stress fiber formation and NHE3 activation. These studies demonstrate that Rho kinase mediates acid-induced stress fiber formation, which is required for NHE3 exocytosis, and increases in NHE3 activity. Acid-induced tyrosine phosphorylation of the focal adhesion proteins p125FAKand paxillin is not Rho kinase dependent. Thus these two acid-mediated effects are associated, yet independent processes.
Organic anion transporter 3 (Oat3/Slc22a8) knockout mice exhibit altered clearance and distribution of penicillin G
Authors: VanWert Adam L. , Bailey Rachel M. , Sweet Douglas H.
Published: August 2007

The interaction of renal basolateral organic anion transporter 3 (Oat3) with commonly used pharmacotherapeutics (e.g., NSAIDs, β-lactams, and methotrexate) has been studied extensively in vitro. However, the in vivo role of Oat3 in drug disposition, in the context of other transporters, glomerular filtration, and metabolism, has not been established. Moreover, recent investigations have identified inactive human OAT3 polymorphisms. Therefore, this investigation was designed to elucidate the in vivo role of Oat3 in the disposition of penicillin G and prototypical substrates using an Oat3 knockout mouse model. Oat3 deletion resulted in a doubling of penicillin's half-life ( P < 0.05) and a reduced volume of distribution ( P < 0.01), together yielding a plasma clearance that was one-half ( P < 0.05, males) to one-third ( P < 0.001, females) of that in wild-type mice. Inhibition of Oat3 abolished the differences in penicillin G elimination between genotypes. Hepatic accumulation of penicillin was 2.3 times higher in male knockouts ( P < 0.05) and 3.7 times higher in female knockouts ( P < 0.001). Female knockouts also exhibited impaired estrone-3-sulfate clearance. Oat3 deletion did not impact p-aminohippurate elimination, providing correlative evidence to studies in Oat1 knockout mice that suggest Oat1 governs tubular uptake of p-aminohippurate. Collectively, these findings are the first to indicate that functional Oat3 is necessary for proper elimination of xenobiotic and endogenous compounds in vivo. Thus Oat3 plays a distinct role in determining the efficacy and toxicity of drugs. Dysfunctional human OAT3 polymorphisms or instances of polypharmacy involving OAT3 substrates may result in altered systemic accumulation of β-lactams and other clinically relevant compounds.
β-Alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters
Authors: Derave Wim , Özdemir Mahir S. , Harris Roger C. , Pottier Andries , Reyngoudt Harmen , Koppo Katrien , Wise John A. , Achten Eric
Published: August 2007

Carnosine (β-alanyl-l-histidine) is present in high concentrations in human skeletal muscle. The ingestion of β-alanine, the rate-limiting precursor of carnosine, has been shown to elevate the muscle carnosine content. We aimed to investigate, using proton magnetic resonance spectroscopy (proton MRS), whether oral supplementation with β-alanine during 4 wk would elevate the calf muscle carnosine content and affect exercise performance in 400-m sprint-trained competitive athletes. Fifteen male athletes participated in a placebo-controlled, double-blind study and were supplemented orally for 4 wk with either 4.8 g/day β-alanine or placebo. Muscle carnosine concentration was quantified in soleus and gastrocnemius by proton MRS. Performance was evaluated by isokinetic testing during five bouts of 30 maximal voluntary knee extensions, by endurance during isometric contraction at 45% maximal voluntary contraction, and by the indoor 400-m running time. β-Alanine supplementation significantly increased the carnosine content in both the soleus (+47%) and gastrocnemius (+37%). In placebo, carnosine remained stable in soleus, while a small and significant increase of +16% occurred in gastrocnemius. Dynamic knee extension torque during the fourth and fifth bout was significantly improved with β-alanine but not with placebo. Isometric endurance and 400-m race time were not affected by treatment. In conclusion, 1) proton MRS can be used to noninvasively quantify human muscle carnosine content; 2) muscle carnosine is increased by oral β-alanine supplementation in sprint-trained athletes; 3) carnosine loading slightly but significantly attenuated fatigue in repeated bouts of exhaustive dynamic contractions; and 4) the increase in muscle carnosine did not improve isometric endurance or 400-m race time.
Body size and human energy requirements: reduced mass-specific resting energy expenditure in tall adults
Authors: Heymsfield Steven B. , Childers Douglas , Beetsch Joel , Allison David B. , Pietrobelli Angelo
Published: August 2007

Two observations favor the presence of a lower mass-specific resting energy expenditure (REE/weight) in taller adult humans: an earlier report of height (H)-related differences in relative body composition; and a combined model based on Quetelet and Kleiber's classic equations suggesting that REE/weight∝H−0.5. This study tested the hypothesis stating that mass-specific REE scales negatively to height with a secondary aim exploration of related associations between height, weight (W), surface area (SA), and REE. Two independent data sets ( n = 344 and 884) were evaluated, both with REE measured by indirect calorimetry and the smaller of the two including fat estimates by dual-energy X-ray absorptiometry. Results support Quetelet's equation (W∝H2), but Kleiber's equation approached the interspecific mammal form (REE∝W0.75) only after adding adiposity measures to weight and age as REE predictors. REE/weight scaled as H∼(−0.5) in support of the hypothesis with P values ranging from 0.17 to <0.001. REE and SA both scaled as H∼1.5, and REE/SA was nonsignificantly correlated with height in all groups. These observations suggest that adiposity needs to be considered when evaluating the intraspecific scaling of REE to weight; that relative to their weight, taller subjects require a lower energy intake for replacing resting heat losses than shorter subjects; that fasting endurance, approximated as fat mass/REE, increases as H0.5; and that thermal balance is maintained independent of stature by evident stable associations between resting heat production and capacity of external heat release. These observations have implications for the modeling of adult human energy requirements and associate with anthropological concepts founded on body size.
Spontaneous Discharge Patterns in Cochlear Spiral Ganglion Cells Before the Onset of Hearing in Cats
Authors: Jones Timothy A. , Leake Patricia A. , Snyder Russell L. , Stakhovskaya Olga , Bonham Ben
Published: August 2007

Spontaneous neural activity has been recorded in the auditory nerve of cats as early as 2 days postnatal (P2), yet individual auditory neurons do not respond to ambient sound levels <90–100 dB SPL until about P10. Significant refinement of the central projections from the spiral ganglion to the cochlear nucleus occurs during this neonatal period. This refinement may be dependent on peripheral spontaneous discharge activity. We recorded from single spiral ganglion cells in kittens aged P3–P9. The spiral ganglion was accessed through the round window through the spiral lamina. A total of 112 ganglion cells were isolated for study in nine animals. Spike rates in neonates were very low, ranging from 0.06 to 56 spikes/s, with a mean of 3.09 ± 8.24 spikes/s. Ganglion cells in neonatal kittens exhibited remarkable repetitive spontaneous bursting discharge patterns. The unusual patterns were evident in the large mean interval CV (CVi = 2.9 ± 1.6) and burst index of 5.2 ± 3.5 across ganglion cells. Spontaneous bursting patterns in these neonatal mammals were similar to those reported for cochlear ganglion cells of the embryonic chicken, suggesting this may be a general phenomenon that is common across animal classes. Rhythmic spontaneous discharge of retinal ganglion cells has been shown to be important in the development of central retinotopic projections and normal binocular vision. Bursting rhythms in cochlear ganglion cells may play a similar role in the auditory system during prehearing periods.
Highly Specific Olfactory Receptor Neurons for Types of Amino Acids in the Channel Catfish
Authors: Nikonov Alexander A. , Caprio John
Published: August 2007

Odorant specificity to l-α-amino acids was determined electrophysiologically for 93 single catfish olfactory receptor neurons (ORNs) selected for their narrow excitatory molecular response range (EMRR) to only one type of amino acid (i.e., Group I units). These units were excited by either a basic amino acid, a neutral amino acid with a long side chain, or a neutral amino acid with a short side chain when tested at 10−7to 10−5M. Stimulus-induced inhibition, likely for contrast enhancement, was primarily observed in response to the types of amino acid stimuli different from that which activated a specific ORN. The high specificity of single Group I ORNs to type of amino acid was also previously observed for single Group I neurons in both the olfactory bulb and forebrain of the same species. These results indicate that for Group I neurons olfactory information concerning specific types of amino acids is processed from receptor neurons through mitral cells of the olfactory bulb to higher forebrain neurons without significant alteration in unit odorant specificity.
Papillary microcarcinoma and papillary cancer of the thyroid ≤1cm
Authors: Marienhagen J. , Agha A. , Rozeboom S. , Bachmeier E. , Schlitt H. , Eilles C. , Schönberger J.
Published: August 2007

Aims: Major controversies exist regarding the treatment of papillary microcarcinoma of the thyroid (PMC). Prior to 2003 PMC was defined by the WHO as a papillary carcinoma of 1cm or less in diameter. In 2004 that definition changed, with the new classification requiring that the tumour also must be found incidentally. Patients, methods: In this study we reviewed the clinical records of 67 patients with papillary tumours of the thyroid ≤1 cm, taking into account the new WHO definition (54 pts. with incidentally found PMC, median age: 53 years, 13 pts. with suspicion of thyroid neoplasm before resection, median age: 38 years). Clinical presentation, surgical treatment, further therapy and follow-up are presented. Results: Median tumour size was 7 mm in both groups (1.10 mm). Multicentric tumours were found in 15 pts. (22%), 8 had more than one PMC on the same side, and 7 displayed PMC bilaterally. Eleven (16%) of the primary tumors had metastatic involvement of regional lymph nodes at the time of initial surgery or during follow-up. Two patients showed distant metastases. No correlation between tumour size and multifocality or the presence of lymph node metastases could be seen. The gender of patients was the only significant independent variable for all patients; age and lymph node involvement was significantly different between incidentally and non-incidentally found PMC. Conclusions: Despite the majority of patients with PMC having an excellent outcome, there are also cases showing an unfavorable course. Currently no predictive parameter exists to anticipate the course and long-term outcome for an individual patient. Until this problem is solved, each patient should have the option to decide for him or herself whether to be treated similarly or differently than for conventional thyroid cancer.
Institutional Development as a Challenge to Democratic Sustenance in Nigeria
Authors: Kaur Sarabjit
Published: August 2007

Certain pre-conditions that can broadly be classified as economic, social and political have been regarded as essential for sustaining democracy. Among these, the political factor in terms of institutional development may be regarded as vital, for these institutions serve as viable channels for ventilating people's expectations and their dissatisfaction through non-violent means. Besides, they also serve as effective means to establish political accountability. However, more than the mere presence of the political institutions that help democratic sustenance, what matters is the fact that they must be nursed and developed to a level that other narrow, exclusivist ties like ethnic loyalties become less important. In other words, within the process of institutional development, there should be a balanced development of these institutions so that no one particular institution becomes powerful at the expense of other institutions. The experience of Nigeria highlights the troubled times the political parties, judiciary, media and other institutions have gone through as a consequence of military takeovers during much of the country's Independence. Faced with eroded institutions, Nigeria could not unfortunately grapple with the emergent challenges in the social or economic spheres.
Occurrence of Surface Defects in TPO Injected Foam Parts
Authors: Guo Ming-Cheng , Santoni Antoine , Heuzey Marie-Claude , Carreau Pierre J.
Published: August 2007

The occurrence of surface defects in TPO injected foam parts has been investigated. Unlike typical flow marks such as tiger stripes that affect the surface quality of injected bulk parts, jetting and silver streaks are the major problems encountered with the TPO foamed parts. Systematic experiments are performed to study the effect of rheological properties and key injection parameters, such as melt temperature, mold cooling, and injection speed on the occurrence of the surface defects. Premature cell nucleation before the injection of the melt into the mold is believed to be the main cause of the surface defects. Therefore, methods that avoid injection of a two-phase mixture into the mold and force cell nucleation to take place strictly in the mold are considered to improve the surface quality of the parts.
Clinical Outcomes of Coracoclavicular Ligament Reconstructions Using Tendon Grafts
Authors: Nicholas Stephen J. , Lee Steven J. , Mullaney Michael J. , Tyler Timothy F. , McHugh Malachy P.
Published: August 2007

Background

Numerous techniques for reconstruction of the coracoclavicular ligaments have been developed to treat acromioclavicular joint separations. A new, stronger method to reconstruct the coracoclavicular ligaments using semitendinosus tendon allografts has been previously described. No outcome studies have been published on this new procedure.

Hypothesis

Reconstruction of the coracoclavicular ligaments using tendon grafts produces excellent functional results.

Study Design

Case series; Level of evidence, 4.

Methods

Nine patients underwent coracoclavicular ligament reconstruction using augmented cadaveric semitendinosus tendon allografts after a grade V acromioclavicular separation. All patients were evaluated for range of motion, strength, closed kinetic chain testing, the American Shoulder and Elbow Surgeons Rating Scale, Pennsylvania Shoulder Score, the Simple Shoulder Test, and the Acromioclavicular Joint Separation Questionnaire. Preoperative and postoperative radiographs were compared.

Results

Range of motion measurements were normal in all motions except a loss of 5° ± 4° (P < .05) in extension. No significant strength deficits were found. Functional closed kinetic chain tests scored comparatively to standardized norms. American Shoulder and Elbow Surgeons Rating scores were 96 ± 5 out of 100; the Pennsylvania Shoulder Scale scores were 97 ± 3 out of 100; the Simple Shoulder Test scores were 11.6 ± 0 out of 12; and Acromioclavicular Joint Separation Questionnaire scores were 28 ± 3 out of 31. Subjects reported an overall subjective satisfaction of 89% ± 7%. Postoperative radiographs showed no loss of reduction of the acromioclavicular joint in any patient.

Conclusion

Outcome for coracoclavicular ligament reconstructions using augmented semitendinosus tendon grafts was excellent with full recovery of strength, minimal range of motion loss, and no clinical or radiographic loss of reduction of the acromioclavicular joint.

Clinical Relevance

This procedure provides an excellent treatment for grade V acromioclavicular separations.
Torsional Failure in Rectangular Composite Plates
Authors: Yeh Hsien-Yang , Kornak Crystal , Yeh Hsien-Liang
Published: August 2007

In this article the failure of rectangular composite plates is studied under torsional loads using multiple failure theories. Lekhnitskii's equations for calculating the stress distribution under torsion are compared to test data and are shown to be unconservative in predicting failure stresses. However, the predicted torque to failure, based on finite element modeling, is within 6% of the actual tested values. The fact that for a state of pure shear (the axial stresses are negligible) the failure theories investigated in this paper reduce to the same equation, regardless of the failure theory, is disscussed.
The Object of Theological Ethics
Authors: O'Donovan Oliver
Published: August 2007

The object of Theological Ethics as presented by Hans Ulrich is immediately the content of the experience of God; reflectively it is God himself turned towards us; doubly reflected on, it is the inversion of our understanding of the good or conversion. The concept of an object may be traced to the discussion of the sciences from Schleiermacher to Barth. Three questions are put to it: (i) Does it assimilate the study too much to descriptive reason, as opposed to practical reason? (ii) Does it narrow the study's range of interests so as to exclude the created world? (iii) Does it result in an idealised `creaturely man', wholly determined by his end and dissociated from the empirical man who may confront us as a neighbour?
A Survey of Psychological Assessment Feedback Practices
Authors: Smith Steven R. , Wiggins Chauntel M. , Gorske Tad T.
Published: August 2007

There have been no previous studies on how often psychologists conduct feedback and whether they view this practice as a useful component of assessment. To explore psychologists' feedback practices and their perception of the effects of feedback on their clients, the authors examined survey data from 719 psychologist members of the International Neuropsychological Society, the National Academy of Neuropsychology, and the Society for Personality Assessment who regularly conducted assessments as part of their professional activities. The results indicated that the majority of respondents (71%) frequently provided in-person assessment feedback to their clients and/or their clients' families. Furthermore, most respondents (72%) indicated that clients found this information to be helpful and positive. Factors contributing to perceived positive feedback effects, including graduate training and feedback session length, were also examined. Last, differences in the feedback practices of psychologists predominantly practicing neuropsychology versus those predominantly practicing personality assessment were sampled and discussed.
Ultimate Failure of Debond Damaged Sandwich Panels Loaded with Lateral Pressure — An Experimental and Fracture Mechanics Study
Authors: Jolma P. , Segercrantz S. , Berggreen C.
Published: August 2007

In this study a tool for assessing residual strength of debond damaged laterally loaded sandwich panels is developed. The analysis tool consists of a parametric finite element model and a fracture mechanics calculation procedure to determine the residual strength. The parametric approach allows variation of all geometric and material entities. The fracture mechanics calculation uses crack flank displacements obtained from the finite element analysis solution and experimentally measured mixed-mode fracture toughness values to determine the ultimate failure load. The analysis tool is validated with a number of different ship type panels. Debond criticality is evaluated by using the developed tool and by comparing the test results from panel experiments. The comparison shows that the analysis tool predicts both failure load and failure mode well. The tool can be used to determine the residual strength of different damage cases and has a considerable potential for further development.
Culture, Self and Identity: Interactivist Contributions to a Metatheory for Cultural Psychology
Authors: Christopher John Chambers , Bickhard Mark H.
Published: August 2007

A complete and thorough grasp of culture eludes psychology because of the pervasive dualism that pervades psychology and Western thought more broadly. Drawing on interactivism, a process model for human phenomena, we make two main points: first, culture cannot be reified, seen as distinct from the self, nor can it be treated as something objective or subjective; and, second, agency and culture are intertwined and distributed across levels of knowing. We explore how interactivism provides powerful resources for modeling the relationship between culture and the person and indicate how interactivism is generally compatible with social practice, hermeneutic, dialogical and narrative insights but situates them within a developmental ontology. We consider implications of interactivism for existing theories like internalization, self-construal theory and individualism—collectivism.
Reducing dementia-related aggression through a staff education intervention
Authors: Chrzescijanski Deirdre , Moyle Wendy , Creedy Debra
Published: August 2007

This article presents findings from a research study that examined the impact of a staff education programme on aggression as displayed by people with dementia living in residential aged care. The staff education programme was designed to change staff attitudes and perceptions towards their care management of the person with dementia. A simple interrupted time series, with the resident acting as his/her own comparison, was used to measure residents' aggressive behaviour both before and after the education intervention — Emotional Responses as Quality Indicators (ERIC). Forty-three residents and 85 staff were involved in the study. Staff attitudes to their work were assessed before and six weeks after the education intervention using the Attitude to Elderly Severely Mentally Infirm Care Scale. Findings indicate that people with dementia display cues about impending physical aggression, but such cues are often ignored by staff, as they may not see or understand anger as a legitimate human emotion within the context of the disease process.
Inter-individual Variability in the Capacity for Motor Recovery After Ischemic Stroke
Authors: Prabhakaran Shyam , Zarahn Eric , Riley Claire , Speizer Allison , Chong Ji Y. , Lazar Ronald M. , Marshall Randolph S. , Krakauer John W.
Published: August 2007

Background. Motor recovery after stroke is predicted only moderately by clinical variables, implying that there is still a substantial amount of unexplained, biologically meaningful variability in recovery. Regression diagnostics can indicate whether this is associated simply with Gaussian error or instead with multiple subpopulations that vary in their relationships to the clinical variables. Objective. To perform regression diagnostics on a linear model for recovery versus clinical predictors. Methods. Forty-one patients with ischemic stroke were studied. Impairment was assessed using the upper extremity Fugl-Meyer Motor Score. Motor recovery was defined as the change in the upper extremity Fugl-Meyer Motor Score from 24 to 72 hours after stroke to 3 or 6 months later. The clinical predictors in the model were age, gender, infarct location (subcortical vs cortical), diffusion weighted imaging infarct volume, time to reassessment, and acute upper extremity Fugl-Meyer Motor Score. Regression diagnostics included a Kolmogorov-Smirnov test for Gaussian errors and a test for outliers using Studentized deleted residuals. Results. In the random sample, clinical variables explained only 47% of the variance in recovery. Among the patients with the most severe initial impairment, there was a set of regression outliers who recovered very poorly. With the outliers removed, explained variance in recovery increased to 89%, and recovery was well approximated by a proportional relationship with initial impairment (recovery ≅ 0.70 × initial impairment). Conclusions. Clinical variables only moderately predict motor recovery. Regression diagnostics demonstrated the existence of a subpopulation of outliers with severe initial impairment who show little recovery. When these outliers were removed, clinical variables were good predictors of recovery among the remaining patients, showing a tight proportional relationship to initial impairment.
C-terminal processing of yeast Spt7 occurs in the absence of functional SAGA complex
Authors: Hoke Stephen MT , Liang Gaoyang , Mutiu A Irina , Genereaux Julie , Brandl Christopher J
Published: August 2007

Background

Spt7 is an integral component of the multi-subunit SAGA complex that is required for the expression of ~10% of yeast genes. Two forms of Spt7 have been identified, the second of which is truncated at its C-terminus and found in the SAGA-like (SLIK) complex.

Results

We have found that C-terminal processing of Spt7 to its SLIK form (Spt7SLIK) and to a distinct third form (Spt7Form3) occurs in the absence of the SAGA complex components Gcn5, Spt8, Ada1 and Spt20, the latter two of which are required for the integrity of the complex. In addition, N-terminally truncated derivatives of Spt7, including a derivative lacking the histone fold, are processed, indicating that the C-terminus of Spt7 is sufficient for processing and that processing does not require functional Spt7. Using galactose inducible Spt7 expression, we show that the three forms of Spt7 appear and disappear at approximately the same rate with full-length Spt7 not being chased into Spt7SLIK or Spt7Form3. Interestingly, reduced levels of Spt7SLIK and Spt7Form3 were observed in a strain lacking the SAGA component Ubp8, suggesting a regulatory role for Ubp8 in the truncation of Spt7.

Conclusion

We conclude that truncation of Spt7 occurs early in the biosynthesis of distinct Spt7 containing complexes rather than being a dynamic process linked to the action of the SAGA complex in transcriptional regulation.
Analysis of KLFtranscription factor family gene variants in type 2 diabetes
Authors: Gutiérrez-Aguilar Ruth , Benmezroua Yamina , Vaillant Emmanuel , Balkau Beverley , Marre Michel , Charpentier Guillaume , Sladek Rob , Froguel Philippe , Neve Bernadette
Published: August 2007

Background

The Krüppel-like factor (KLF) family consists of transcription factors that can activate or repress different genes implicated in processes such as differentiation, development, and cell cycle progression. Moreover, several of these proteins have been implicated in glucose homeostasis, making them candidate genes for involvement in type 2 diabetes (T2D).

Methods

Variants of nine KLF genes were genotyped in T2D cases and controls and analysed in a two-stage study. The first case-control set included 365 T2D patients with a strong family history of T2D and 363 normoglycemic individuals and the second set, 750 T2D patients and 741 normoglycemic individuals, all of French origin. The SNPs of six KLF genes were genotyped by Taqman® SNP Genotyping Assays. The other three KLF genes (KLF2, -15 and -16) were screened and the identified frequent variants of these genes were analysed in the case-control studies.

Results

Three of the 28 SNPs showed a trend to be associated with T2D in our first case-control set (P < 0.10). These SNPs, located in the KLF2, KLF4 and KLF5 gene were then analysed in our second replication set, but analysis of this set and the combined analysis of the three variants in all 2,219 individuals did not show an association with T2D in this French population. As the KLF2, -15 and -16 variants were representative for the genetic variability in these genes, we conclude they do not contribute to genetic susceptibility for T2D.

Conclusion

It is unlikely that variants in different members of the KLF gene family play a major role in T2D in the French population.
Role of cattle treated with deltamethrine in areas with a high population of Anopheles arabiensis in Moshi, Northern Tanzania
Authors: Mahande Aneth M , Mosha Franklin W , Mahande Johnson M , Kweka Eliningaya J
Published: August 2007

Background

Malaria control measures were initiated from in October 2005 to August 2006 in the Lower Moshi irrigation schemes, Tanzania. This manuscript reports on the entomological evaluation of the impact of pyrethroid-treated cattle in reducing the population of the Anopheles arabiensis for selected houses in the Lower Moshi irrigation scheme.

Methods

Cattle were sprayed with the pyrethroid (deltamethrin) acaricide. Grazing and non-grazing cattles were compared and assessed for difference in knockdown resistance (kdr) time using cone or contact bioassay and residual effect (mortality). In experimental huts, mortality was compared between the huts with treated and untreated cattle.

Results

Results from contact bioassays of cattle treated with deltamethrin showed a knockdown effect of 50% within 21 days for grazing cattle and 29 days for non-grazing cattle. Residual effect at 50% was achieved within 17 days for grazing cattle compared to 24 days for inshed cattle. In discussing the results, reference has been made to the exophilic and zoophilic tendencies of An. arabiensis, which are conducive for zooprophylaxis.

Experimental studies in Verandah huts at Mabogini compared An. arabiensis and Culex spp collected from huts with different baits, i e. human, untreated cow and treated cow. Results indicate higher mortality rates in mosquitoes collected from the hut containing the treated cow (mean = 2) compared to huts with untreated cow (mean = 0.3) and human (mean = 0.8). A significantly higher number of Culex spp. was recorded in huts with treated cows compared to the rest.

Conclusion

This study has demonstrated the role of cattle treated with pyrethroid in the control of malaria and reduction of vector density. It showed that, in areas with a predominant An. arabiensis population, cattle should be placed close to dwelling houses in order to maximize the effects of zooprophylaxis. Protective effects of cattle can further be enhanced by regular treatment with pyrethroids at least every three weeks. This paper demonstrates that cattle can be considered as Insecticide-Treated Material (ITM) as long as acaricide treatment is conducted regularly.
Semi-allogeneic vaccine for T-cell lymphoma
Authors: Yu Jin , Kindy Mark S , Gattoni-Celli Sebastiano
Published: August 2007

Background

Experimental results from studies with inbred mice and their syngeneic tumors indicated that the inoculation of semi-allogeneic cell hybrids (derived from the fusion between syngeneic tumor cells and an allogeneic cell line) protects the animal host from a subsequent lethal challenge with unmodified syngeneic tumor cells.

Methods

Semi-allogeneic somatic cell hybrids were generated by the fusion of EL-4 T lymphoma cells (H-2b) and BALB/c-derived renal adenocarcinoma RAG cells (H-2d). Cell hybrids were injected intra-peritoneally (i.p.) in C57BL/6 mice (H-2b) before challenging the mice with a tumorigenic dose of EL-4 cells.

Results

Semi-allogeneic tumor cell hybrids could not form a tumor in the animal host because they expressed allogeneic determinants (H-2d) and were rejected as a transplant. However, they conferred protection against a tumorigenic challenge of EL-4 cells compared to control mice that were mock-vaccinated with i.p.-injected phosphate-buffered saline (PBS) and in which EL-4 lymphomas grew rapidly to a large size in the peritoneal cavity. Screening of spleen-derived RNA by means of focused microarray technology revealed up-regulation of genes involved in the Th-1-type immune response and in the activation of dendritic antigen-presenting cells (APC).

Conclusion

The results of our studies are entirely consistent with the concept that CD80- and CD86-expressing APC play a central role in mediating the immune protection induced by semi-allogeneic vaccines by activating a Th-1 response and instructing T cells responsible for killing autologous tumor cells.
Catabolic cytokine expression in degenerate and herniated human intervertebral discs: IL-1β and TNFα expression profile
Authors: Le Maitre Christine Lyn , Hoyland Judith Alison , Freemont Anthony J
Published: August 2007

Low back pain is a common and debilitating disorder. Current evidence implicates intervertebral disc (IVD) degeneration and herniation as major causes, although the pathogenesis is poorly understood. While several cytokines have been implicated in the process of IVD degeneration and herniation, investigations have predominately focused on Interleukin 1 (IL-1) and tumor necrosis factor alpha (TNFα). However, to date no studies have investigated the expression of these cytokines simultaneously in IVD degeneration or herniation, or determined which may be the predominant cytokine associated with these disease states. Using quantitative real time PCR and immunohistochemistry we investigated gene and protein expression for IL-1β, TNFα and their receptors in non-degenerate, degenerate and herniated human IVDs. IL-1β gene expression was observed in a greater proportion of IVDs than TNFα (79% versus 59%). Degenerate and herniated IVDs displayed higher levels of both cytokines than non-degenerate IVDs, although in degenerate IVDs higher levels of IL-1β gene expression (1,300 copies/100 ng cDNA) were observed compared to those of TNFα (250 copies of TNFα/100 ng cDNA). Degenerate IVDs showed ten-fold higher IL-1 receptor gene expression compared to non-degenerate IVDs. In addition, 80% of degenerate IVD cells displayed IL-1 receptor immunopositivity compared to only 30% of cells in non-degenerate IVDs. However, no increase in TNF receptor I gene or protein expression was observed in degenerate or herniated IVDs compared to non-degenerate IVDs. We have demonstrated that although both cytokines are produced by human IVD cells, IL-1β is expressed at higher levels and in more IVDs, particularly in more degenerate IVDs (grades 4 to 12). Importantly, this study has highlighted an increase in gene and protein production for the IL-1 receptor type I but not the TNF receptor type I in degenerate IVDs. The data thus suggest that although both cytokines may be involved in the pathogenesis of IVD degeneration, IL-1 may have a more significant role than TNFα, and thus may be a better target for therapeutic intervention.
A FRET map of membrane anchors suggests distinct microdomains of heterotrimeric G proteins
Authors: Abankwa Daniel , Vogel Horst
Published: August 2007

The standard model of heterotrimeric G protein signaling postulates a dissociation of Gα and Gβγ subunits after activation. We hypothesized that the different combination of lipid-modifications on Gα and Gαβγ subunits directs them into different microdomains. By characterizing rapidly and at high sensitivity 38 fluorescence resonance energy transfer (FRET) pairs of heterotrimeric-G-protein constructs, we defined their microdomains in relation to each other, free from the constraints of the raft/non-raft dualism. We estimated that in a cell ∼30% of these membrane-anchored proteins are mostly clustered in 3400-16,200 copies of 30-nm microdomains. We found that the membrane anchors of Gα and Gαβγ subunits of both the Gi/o and Gq family co-cluster differently with microdomain markers. Moreover, anchors of the Gαi/o and Gαq subunits co-clustered only weakly, whereas constructs that contained the anchors of the corresponding heterotrimers co-clustered considerably, suggesting the existence of at least three types of microdomain. Finally, FRET experiments with full-length heterotrimeric G proteins confirmed that the inactive, heterotrimerized Gα subunit is in microdomains shared by heterotrimers from different subclasses, from where it displaces upon activation into a membrane-anchor- and subclass-specific microdomain.
Necessity of inositol (1,4,5)-trisphosphate receptor 1 and μ-calpain in NO-induced osteoclast motility
Authors: Yaroslavskiy Beatrice B. , Sharrow Allison C. , Wells Alan , Robinson Lisa J. , Blair Harry C.
Published: August 2007

In skeletal remodeling, osteoclasts degrade bone, detach and move to new locations. Mechanical stretch and estrogen regulate osteoclast motility via nitric oxide (NO). We have found previously that NO stimulates guanylyl cyclase, activating the cGMP-dependent protein kinase 1 (PKG1), reversibly terminating osteoclast matrix degradation and attachment, and initiating motility. The PKG1 substrate vasodilator-stimulated protein (VASP), a membrane-attachment-related protein found in complexes with the integrin αvβ3 in adherent osteoclasts, was also required for motility. Here, we studied downstream mechanisms by which the NO-dependent pathway mediates osteoclast relocation. We found that NO-stimulated motility is dependent on activation of the Ca2+-activated proteinase μ-calpain. RNA interference (RNAi) showed that NO-dependent activation of μ-calpain also requires PKG1 and VASP. Inhibition of Src kinases, which are involved in the regulation of adhesion complexes, also abolished NO-stimulated calpain activity. Pharmacological inhibition and RNAi showed that calpain activation in this process is mediated by the inositol (1,4,5)-trisphosphate receptor 1 [Ins(1,4,5)P3R1] Ca2+ channel. We conclude that NO-induced motility in osteoclasts requires regulated Ca2+ release, which activates μ-calpain. This occurs via the Ins(1,4,5)P3R1.
Effects of stretch on work and efficiency of frog (Rana pipiens)muscle
Authors: Trinh Michelle , Syme Douglas A.
Published: August 2007

Applying a small stretch to active muscle immediately before shortening results in an increase in force and work done during subsequent shortening. The basis of the increase is not fully understood, having important implications for work and efficiency, and how they are influenced through stretch. We used the anterior tibialis muscle of leopard frogs (Rana pipiens complex) to measure the oxygen consumed and work done during shortening contractions that were immediately preceded by either a brief stretch (5% muscle length over 25 ms) or an isometric contraction (25 ms duration). Work done by the muscle while shortening following stretch was about 28% greater than work done following an isometric contraction(P<0.001). However the net work done during the entire contraction(i.e. accounting for the work required to stretch the muscle) was reduced by 13% if stretch preceded the shortening phase (P=0.003). The energy(oxygen) used during a stretch–shorten cycle was the same as for an isometric-shorten contraction (P=0.34). Likewise, the efficiency of net work (net work/energy used) was only marginally different between shortening contractions preceded by stretch or an isometric phase(P=0.07). Thus, under conditions that were intended to mimic what might occur during animal movement, a stretch that immediately preceded shortening enhanced work during shortening but did not impart a net mechanical or energetic benefit to the contraction. These observations could indicate that stretch simply extends compliant elements that recoil subsequently with some loss of mechanical energy in the process and/or that stretch results in an increase in the number of, and hence work done by, cross bridges during muscle shortening accompanied by a proportionate increase in energy consumed.
Temperature influences the coordinated expression of myogenic regulatory factors during embryonic myogenesis in Atlantic salmon (Salmo salarL.)
Authors: Macqueen Daniel J. , Robb David , Johnston Ian A.
Published: August 2007

Potential molecular mechanisms regulating developmental plasticity to temperature were investigated in Atlantic salmon embryos (Salmo salarL.). Six orthologues of the four myogenic regulatory factors (MRFs:individually: smyf5, smyoD1a/1b/1c, smyoG and sMRF4), the master transcription factors regulating vertebrate myogenesis, were characterised at the mRNA/genomic level. In situ hybridisation was performed with specific cRNA probes to determine the expression patterns of each gene during embryonic myogenesis. To place the MRF data in the context of known muscle fibre differentiation events, the expression of slow myosin light chain-1 and Pax7 were also investigated. Adaxial myoblasts expressed smyoD1a prior to and during somitogenesis followed by smyoD1c (20-somite stage, ss),and sMRF4 (25–30 ss), before spreading laterally across the myotome, followed closely by the adaxial cells. Smyf5 was detected prior to somitogenesis, but not in the adaxial cells in contrast to other teleosts studied. The expression domains of smyf5, smyoD1band smyoG were not confined to the s-smlc1 expression field,indicating a role in fast muscle myogenesis. From the end of segmentation,each MRF was expressed to a greater or lesser extent in zones of new muscle fibre production, the precursor cells for which probably originated from the Pax7 expressing cell layer external to the single layer of s-smlc1+ fibres. SmyoD1a and smyoGshowed similar expression patterns with respect to somite stage at three different temperatures investigated (2°C, 5°C and 8°C) in spite of different rates of somite formation (one somite added each 5 h, 8 h and 15 h at 8°C, 5°C and 2°C, respectively). In contrast, the expression of smyf5, sMRF4 and s-smlc1 was retarded with respect to somite stage at 2°C compared to 8°C, potentially resulting in heterochronies in downstream pathways influencing later muscle phenotype.
Nonlinear Analysis of Double-Layer Grids with Compositive Nodes under Symmetric and Unsymmetrical Gravity Loads
Authors: Koushky A.L. , Dehdashti G. , Fiouz A.
Published: August 2007

The general purpose of this paper is to investigate the behaviour of space structures with compositive nodes. Compositive nodes do not need any specific “node piece” or “unit”, and they are not subjected to special requirements for their assembly. Assembly speed in these connections is quite high. Standard member sections and composite action with concrete slabs are some of the special advantages of compositive systems. By focusing on the structure modeling in this paper, closeness of analysis and test results is demonstrated. 3-D modeling, modeling of eccentricity of joints, material nonlinearity and load-deflection diagrams of the structures are among the aspects investigated in this paper.