Effect of chitosan on the electrophoretic motility of thymocytes

An increase of contact interaction between macrophages and thymocytes in the presence of polysaccharide chitosan was suggested to be due to the change of surface charge of interacting cells. It was found that incubation of thymocytes in the presence of chitosan leads to the change of their charge in the positive direction. The measurement of electrophoretic mobility of the cells was carried out on " Parmoquant 2" (Carl Zeiss Jena, DDR). The change of electrophoretic mobility increases with decrease of pH, increase of chitosan concentration and decrease of the cell concentration in the medium. This phenomenon is probably due to absorption of positively charged molecules of chitosan on negatively charged cell surface.     

The effect of scoliotic deformity on spine kinematics in adolescents

Background

While adolescent idiopathic scoliosis (AIS) produces well characterized deformation in spinal form, the effect on spinal function, namely mobility, is not well known. Better understanding of scoliotic spinal mobility could yield better treatment targets and diagnoses. The purpose of this study was to characterize the spinal mobility differences due to AIS. It was hypothesized that the AIS group would exhibit reduced mobility compared to the typical adolescent (TA) group.

Methods

Eleven adolescents with right thoracic AIS, apices T6-T10, and eleven age- and gender-matched TAs moved to their maximum bent position in sagittal and coronal plane bending tasks. A Trakstar (Ascension Technologies Burlington, VT) was used to collect position data. The study was approved by the local IRB. Using MATLAB (MathWorks, Natick, MA) normalized segmental angles were calculated for upper thoracic (UT) from T1-T3, mid thoracic (MT) from T3-T6, lower thoracic (LT) from T6-T10, thoracolumbar (TL) from T10-L1, upper lumbar (UL) from L1-L3, and thoracic from T1-L1 by subtracting the standing position from the maximum bent position and dividing by number of motion units in each segment. Mann Whitney tests (α?=?0.05) were used to determine mobility differences.

Results

The findings indicated that the AIS group had comparatively increased mobility in the periapical regions of the spine. The AIS group had an increase of 1.2° in the mid thoracic region (p?=?0.01) during flexion, an increase of 1.0° in the mid thoracic region (p?=?0.01), 1.5° in the thoracolumbar region (p?=?0.02), and 0.7° in thoracic region (p?=?0.04) during left anterior-lateral flexion, an increase of 6.0° in the upper lumbar region (p?=?0.02) during right anterior-lateral flexion, and an increase of 2.2° in the upper lumbar region during left lateral bending (p?<?0.01).

Conclusions

Participants with AIS did not have reduced mobility in sagittal or coronal motion. Contrarily, the AIS group often had a greater mobility, especially in segments directly above and below the apex. This indicates the scoliotic spine is flexible and may compensate near the apex.

     

Quality of life after stroke in Croatian patients

In order to evaluate the microsocial factors affecting quality of life in stroke victims, 100 survivors of ischemic stroke and the same number of their relevant family members (key persons, controls) were interviewed using Stroke Specific Quality of Life Scale (SS-QOL) questionnaire. Total SS-QOL score did not differ significantly between post-stroke patients and key persons (z=0.64, P=0.524). Relevant family members ranked the patients' family (P=0.022) and social role (P=0.08), and their mobility (P=0.09) slightly higher than the patients themselves. However, male patients rated their "family role" (z=-2.82, P=0.005), "mobility" (z=-2.28, P=0.023) and "social role" (z=-1.86, P=0.063) higher than their female peers. Recent (< or =33 months) and remote (>33 months after the ischemic accident) stroke patients did not differ substantially in total SS-QOL score, social role and hand function assessment but in mobility (z=-1.90, P=0.057) and family role estimation (z=-2.47, P=0.014) the difference was in favor of recent stroke patients. The domain scores and total SS-QOL score did not differ by gender between recent stroke patients and their controls either. It is concluded that assessment of general functioning and global quality of life among post-stroke patients provided by relevant patients'family members could be accepted with confidence. Male patients slightly overestimate their mobility and social role. No significant impact of post-stroke time span on quality of life estimation was observed.     

Ion mobility-mass spectrometry analysis of large protein complexes

Here we describe a detailed protocol for both data collection and interpretation with respect to ion mobility-mass spectrometry analysis of large protein assemblies. Ion mobility is a technique that can separate gaseous ions based on their size and shape. Specifically, within this protocol, we cover general approaches to data interpretation, methods of predicting whether specific model structures for a given protein assembly can be separated by ion mobility, and generalized strategies for data normalization and modeling. The protocol also covers basic instrument settings and best practices for both observation and detection of large noncovalent protein complexes by ion mobility-mass spectrometry.     

The nuclear-bound form of the progesterone receptor is generated through a hormone-dependent phosphorylation

The solubilized ("cytosolic") receptor present in the rabbit uterus in the absence of hormone and the chromatin-bound ("nuclear") receptor obtained after injection of a progestin were compared. Crude cellular extracts were analyzed by immunoblotting and receptors were purified by immunoaffinity chromatography. With both methods it was observed that the electrophoretic mobility of the "nuclear" receptor was slower than that of the "cytosolic" receptor. This difference in mobility appeared to be due to the existence of variably phosphorylated forms of receptor. The phosphorylation reaction was examined in uterine slices. In the absence of hormone the cytosolic receptor was phosphorylated. When hormone was added the phosphorylation of receptor was markedly enhanced and the electrophoretic mobility of the "nuclear" receptor was decreased. These experiments thus show that the receptor in its "cytosolic" form is a phosphoprotein. Under the effect of the hormone the receptor is further phosphorylated on some supplementary site(s). This polyphosphoprotein is the chromatin-bound, putatively active, form of the receptor. In this respect the intracellular progesterone receptor is similar to various membrane receptors for hormones and growth factors which are phosphorylated upon binding of their ligand.     

Biomechanics of the finger with anatomical restrictions--the significance for the exercising hand of the musician.

Exercise and teaching of musicians presupposes in the individual the constitutive ability to freely execute the finger movements required in the playing of the instrument. However, in the hand anatomical restrictions may exist that limit the mobility of the fingers and, thereby, the possibility to determine their movements voluntarily. In this article we investigate the kinematics of a monodigital system in which restrictions are present.     

Outer membrane of Pseudomonas aeruginosa: heat- 2-mercaptoethanol-modifiable proteins.

A number of polyacrylamide gel systems and solubilization procedures were studied to define the number and nature of "major" polypeptide bands in the outer membrane of Pseudomonas aeruginosa. It was shown that five of the eight major outer membrane proteins were "heat modifiable" in that their mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was determined by the solubilization temperature. Four of these heat-modifiable proteins had characteristics similar to protein II of the Escherichia coli outer membrane. Addition of lipopolysaccharide subsequent to solubilization caused reversal of the heat modification. The other heat-modifiable protein, the porin protein F, was unusually stable to sodium dodecyl sulfate. Long periods of boiling in sodium dodecyl sulfate were required to cause conversion to the heat-modified form. This was demonstrated both with outer membrane-associated and purified lipopolysaccharide-depleted protein F. Furthermore, lipopolysaccharide treatment had no effect on the mobility of heat-modified protein F. Thus it is concluded that protein F represents a new class of heat-modifiable protein. It was further demonstrated that the electrophoretic mobility of protein F was modified by 2-mercaptoethanol and that the 2-mercaptoethanol and heat modification of mobility were independent of one another. The optimal conditions for the examination of the outer membrane proteins of P. aeruginosa by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis are discussed.     

Going Where the Grass Is Greener: On the Study of Pastoral Mobility in Ferlo, Senegal

Based on a case study from Ferlo in Senegal, this paper discusses how pastoral mobility can be studied and understood with special emphasis on the use of GPS data. It has a dual objective: first, to investigate the methodological potential of using GPS data; second, to discuss the analytical use of GPS data for understanding mobility. The methodological potential for using GPS data is related to quantifying mobility and characterizing mobility patterns in space and time. Analytically, GPS data can be used in combination with qualitative information to make method triangulation. The GPS data can be used both prior to qualitative interviews to make informed questions about mobility and they can be used after qualitative investigations to illustrate points made or to reveal inconsistencies. The study shows that cattle walk about 5000 km per year (excluding night grazing) and different mobility patterns occur depending on the season. Issues such as the cattle complex and the notion of the independent, nomadic pastoralist are discussed in relation to pastoral mobility. Although cattle are of major importance to the Fulani, it is not important for them to walk with their animals, which are left to roam freely or supervised by paid herders. It is necessary to take into account all these issues if we want to go beyond the simple understanding of mobility as a means to find pasture and water.     

Comparative Studies on the Two Components in Human Chorionic Somatomammotropin

A small amount of the component accompanied with human chorionic somatomammotropin has been separated on Sephadex ion exchanger. When polyacrylamide disc gel electrophoresis was performed at pH 9.3, the two bands were very close each other in electrophoretic mobility. They possess lacogenic activity for the pigeon crop sac test. A comparison of their physicochemical properties was made. The major component was in excellent agreement with the minor more acidic component in amino acid analyses, n-terminal amino acid analyses and circular dichroism studies. Immunological studies indicated some common properties between them, whereas they differed significantly in the electrophoretic mobility of precipitin arc.     

不同能量供需下雌性棕色田鼠胃运动的变化

用PowerLab/8sp生理信号采集分析系统记录哺乳雌鼠、禁食1d和3d雌鼠及正常对照雌鼠胃内压、胃收缩幅值及收缩频率,以研究在不同能量需求与供应状态下,棕色田鼠(Lasiopodomys mandarinus)胃运动的适应性变化。结果显示,禁食组和哺乳期雌鼠的胃内压及胃收缩幅值均显著高于正常对照雌鼠组(P0.05),禁食组胃内压、胃收缩幅值较哺乳组有所下降,且禁食3d组胃内压明显下降(P0.05)。说明在不同生理状态下,能量需求与供应不同,消化道活动发生适应性变化,且消化道生理功能变化与能量胁迫程度相关。     

An instrument for assessment of videotapes of general practitioners' performance.

OBJECTIVES--To identify those important characteristics of doctors'' and patients'' behaviour that distinguish between "good" and "bad" consultations when viewed on videotape; to use these characteristics to develop a reliable instrument for assessing general practitioners'' performance in their own consultations. DESIGN--Questionnaires completed by patients, general practitioner trainers, and general practitioner trainees. Reliability of draft instrument tested by general practitioner trainers. SETTING--All vocational training schemes for general practice in the Northern region of England. SUBJECTS--First stage: 76 patients in seven groups, 108 general practice trainers in 12 groups, and 122 general practice trainees in 10 groups. Second stage: 85 general practice trainers in 12 groups. MAIN OUTCOME MEASURES--Trainers'' ratings of importance; alpha coefficients of draft instrument by trainee, group, and consultation. RESULTS--6890 characteristics of good and bad consultations were consolidated into a draft assessment instrument consisting of 46 pairs of definitions separated by six point bipolar scales. Nine statement pairs given low importance ratings by trainers were eliminated, reducing the instrument to 37 statement pairs. To test reliability, general practitioner trainers used the instrument to assess three consultations. With the exception of one group of trainers, all alpha coefficients exceeded the acceptable level of 0.80. CONCLUSION--The instrument produced is reliable for assessing general practitioners'' performance in their own consultations.     

Impairment of proprioception after whiplash injury

Whiplash injury usually occurs in traffic accidents. Persons experienced this injury might have an impairment of proprioception clinically expressed as inability to determine the exact position of their heads. The aim of this study was to examine the loss of proprioception in people who had a whiplash injury. The study included 60 subjects with cervical spine injury, aged 20 to 50 years and 60 healthy volunteers matched by sex and age. The instrument used for cervical spine mobility assessment was the Cervical Measurement System (CMS), which determines the ability of subjects to return their head in the exact position as it was before they turned it 30 degrees left or right. Patients with cervical spine injury showed significant impairment of proprioception in comparison with healthy subjects (P < 0.001). The results support the hypothesis that subject with recent cervical spine injury have incorrect perception of their head position. Therefore, their rehabilitation should include the correction of proprioception and head coordination.     

Analysis of electrophoretic mobility histograms of mouse splenocytes and thymocytes during tumor growth and after combined chemotherapy and immunotherapy

Changes in electrophoretic mobility histograms of splenocytes and thymocytes were studied in plasmacytoma X5563-bearing mice as an indicator of response to treatment with mitomycin C (MMC) alone or combined with the immunomodulator Krestin (PSK). Tumor growth was inhibited by 80-90% in the MMC-treated and was further inhibited in the MMC and PSK-treated group. Electrophoretic mobility histograms of splenocytes were used to determine the fraction of cells having intermediate mobility between high mobility (T cells) and low mobility (B cells). This fraction of intermediate-mobility cells increased in tumor-bearing mice, but a normal electrophoretic mobility pattern was obtained following successful antitumor treatment. In the electrophoretic mobility histogram of thymocytes, on the other hand, the low-mobility cells (cortical thymocytes) decreased in number during tumor growth and were further reduced in the MMC-treated group. This reduction was less in the MMC and PSK-treated group. These results suggest that combined therapy with MMC and PSK prevents damage of the host defence mechanism and allows more efficient antitumor treatment. Analysis of electrophoretic mobility histograms of splenocytes and thymocytes using a fully automated cell electrophoretic instrument makes possible the rapid evaluation of the immunological effects of drug therapy of tumor-bearing mice.     

Surface potential and surface charge density of the cerebral-cortex synaptic vesicle and stability of vesicle suspension

Using a microelectrophoresis instrument employing the Lazer-Zee system, the electrophoretic mobility of synaptic vesicles isolated from Guinea-pig brain cortex was measured under several conditions. The mobility was found to depend on both pH and ionic concentration of the solution. The surface of the synaptic vesicle was shown to be negatively charged under physiological conditions. The isoelectric point was observed at pH 4.0 in 0.01 M NaCl solution. Effects of divalent cations were examined and reversal of surface charge was observed in 0.1 M CaCl₂ solution. Interaction of vesicles was also considered on the basis of the DLVO theory of colloid stability by using calculated values of surface charge density and surface potential of the synaptic vesicle.     

Micro- and macroscale electrophoretic study of the constituent proteins of cerebral structures

A comparative study of the protein composition of the brain structures of rats (premotor area of the cortex, the CA3 region of the hyppocampus, the caudate nucleus, the frontal area of the cerebellum) was carried out by the method of disc electrophoresis in the micro- and macroscale. Protein zones were identified by their relative electrophoretic mobility calculated according to the mobility of the "marker" protein (trypsin inhibitor from soya beans). Both methods revealed no significant differences in the composition of the electrophoretic separation of the brain proteins pointed to the greater resolving capacity of the micromethod.     

海马Glu与抑郁症的关系及其对胃运动的影响

目的：探讨抑郁症的发生与海马谷氨酸（Glu）的关系及其对胃运动的影响。方法：运用慢性不可预见性温和应激（GUMS）建立抑郁动物模型,采用海马定位微量注射,通过体重变化率、糖水偏爱、敞箱、强迫游泳实验观察大鼠行为表现,用PowerLab／8sp生理信号采集分析系统记录胃内压,观察胃运动的变化。结果：慢性不可预见性温和应激21d,可显著降低大鼠的体重增长率,糖水偏爱率和敞箱实验的水平运动和垂直运动得分,增加了大鼠的游泳不动时间,与正常对照组相比,差异显著。同时大鼠平均胃内压和胃的收缩幅值也显著降低。海马微量注射Glu与慢性不可预见性温和应激引起的动物行为表现一致,而胃运动减弱的程度小于应激组,但与正常时照组比较,差异明显。海马微量注射NMDA受体阻断剂MK-801,可消除应激所引起的抑郁样行为,减弱应激对胃内压的抑制作用,并明显增大胃的收缩幅值。结论：海马Glu和NMDA受体与应激性抑郁发生密切相关,既参与了应激引起的行为变化。又参与了应激引起的胃活动变化,只是对行为影响和胃活动影响有所不同。     

A Self-Reported Screening Tool for Detecting Community-Dwelling Older Persons with Frailty Syndrome in the Absence of Mobility Disability: The FiND Questionnaire

Background

The “frailty syndrome” (a geriatric multidimensional condition characterized by decreased reserve and diminished resistance to stressors) represents a promising target of preventive interventions against disability in elders. Available screening tools for the identification of frailty in the absence of disability present major limitations. In particular, they have to be administered by a trained assessor, require special equipment, and/or do not discriminate between frail and disabled individuals. Aim of this study is to verify the agreement of a novel self-reported questionnaire (the “Frail Non-Disabled” [FiND] instrument) designed for detecting non-mobility disabled frail older persons with results from reference tools.

Methodology/Principal Findings

Data are from 45 community-dwelling individuals aged ≥60 years. Participants were asked to complete the FiND questionnaire separately exploring the frailty and disability domains. Then, a blinded assessor objectively measured the frailty status (using the phenotype proposed by Fried and colleagues) and mobility disability (using the 400-meter walk test). Cohen''s kappa coefficients were calculated to determine the agreement between the FiND questionnaire with the reference instruments. Mean age of participants (women 62.2%) was 72.5 (standard deviation 8.2) years. Seven (15.6%) participants presented mobility disability as being unable to complete the 400-meter walk test. According to the frailty phenotype criteria, 25 (55.6%) participants were pre-frail or frail, and 13 (28.9%) were robust. Overall, a substantial agreement of the instrument with the reference tools (kappa = 0.748, quadratic weighted kappa = 0.836, both p values<0.001) was reported with only 7 (15.6%) participants incorrectly categorized. The agreement between results of the FiND disability domain and the 400-meter walk test was excellent (kappa = 0.920, p<0.001).

Conclusions/Significance

The FiND questionnaire presents a very good capacity to correctly identify frail older persons without mobility disability living in the community. This screening tool may represent an opportunity for diffusing awareness about frailty and disability and supporting specific preventive campaigns.     

Developing a theory-based instrument to assess the impact of continuing professional development activities on clinical practice: a study protocol

Background

Continuing professional development (CPD) is one of the principal means by which health professionals (i.e. primary care physicians and specialists) maintain, improve, and broaden the knowledge and skills required for optimal patient care and safety. However, the lack of a widely accepted instrument to assess the impact of CPD activities on clinical practice thwarts researchers' comparisons of the effectiveness of CPD activities. Using an integrated model for the study of healthcare professionals' behaviour, our objective is to develop a theory-based, valid, reliable global instrument to assess the impact of accredited CPD activities on clinical practice.

Methods

Phase 1: We will analyze the instruments identified in a systematic review of factors influencing health professionals' behaviours using criteria that reflect the literature on measurement development and CPD decision makers' priorities. The outcome of this phase will be an inventory of instruments based on social cognitive theories. Phase 2: Working from this inventory, the most relevant instruments and their related items for assessing the concepts listed in the integrated model will be selected. Through an e-Delphi process, we will verify whether these instruments are acceptable, what aspects need revision, and whether important items are missing and should be added. The outcome of this phase will be a new global instrument integrating the most relevant tools to fit our integrated model of healthcare professionals' behaviour. Phase 3: Two data collections are planned: (1) a test-retest of the new instrument, including item analysis, to assess its reliability and (2) a study using the instrument before and after CPD activities with a randomly selected control group to explore the instrument's mere-measurement effect. Phase 4: We will conduct individual interviews and focus groups with key stakeholders to identify anticipated barriers and enablers for implementing the new instrument in CPD practice. Phase 5: Drawing on the results from the previous phases, we will use consensus-building methods to develop with the decision makers a plan to implement the new instrument.

Discussion

This project proposes to give stakeholders a theory-based global instrument to validly and reliably measure the impacts of CPD activities on clinical practice, thus laying the groundwork for more targeted and effective knowledge-translation interventions in the future.

     

Freeze-fracture studies of the developing cell surface. II. Particle-free membrane blisters on glutaraldehyde-fixed corneal fibroblasts are artefacts.

We describe, in sections and by freeze-fracture, four classes of intramembrane particle (IMP)-free membrane blebs or "blisters" associated with glutaraldehyde-fixed embryonic corneal fibroblasts: (a) Single blisters attached to the cell membrane; (b) free (detached) vesicles; (c) myelin figures; (d) multivesicular protrusions which resemble the "mounds" described by others on nerve growth cones. The IMP-free, membrane-bounded blisters contain no ground cytoplasm or organelles, in contrast to blebs on trypsin-isolated fibroblasts, which we show here do contain cytoplasm and IMP-rich membranes. That the IMP-free membrane blisters in embryonic corneas are artefacts of fixation is demonstrated by (a) their absence in replicas of fibroblasts frozen and fractured without prior aldehyde fixation and (b) their absence in sections of fibroblasts fixed in a combination of glutaraldehyde and osmium tetroxide. We suggest that the addition of osmium prevents postfixation movement of membrane lipids, especially the negatively charged "fluid" lipids which others have shown are capable of considerable mobility after aldehyde fixation alone. Recent literature has implicated membrane blistering in secretory processes and in growth of nerves, but before the functional significance of such IMP-free blisters is assessed, membrane mobility of the type shown here should be taken into consideration.