bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oscillatory Contraction Activity in Physarum
Authors: Wohlfarth-Bottermann K. E. 
Published: April 2021

ABSTRACT
The plasmodia of Physarum polycephalum show different oscillatory phenomena (time period approximately 1·3 min) in their contraction behaviour and their protoplasmic flow. The force generating system for these phenomena is cytoplasmic actomyosin. The biochemical nature and location(s) of the oscillator(s), i.e. the clock governing these phenomena are unknown.
The following locations are discussed as possible sites of the oscillator: (1) cytoplasmic actomyosin, (2) the energy supply system, (3) inner Ca2+ stores, and (4) the plasmalemma, which must be involved at least in modulating the force generated by the contractile machinery during a chemotactic response.
The following oscillatory phenomena were used to assess the effects of externally and internally applied substances (e.g. calcium antagonistic drugs, caffeine, D2O) on oscillating force output: persistance of longitudinal contractile activity of veins (for external application of test substances),persistance of radial activity of veins (for internal application of the test substances),de novo generation of contractile activity in protoplasmic drops (external application).
The data seem to exclude rhythmical Ca2+, Na+ or K+ transport across the plasmalemma as a triggering function for the oscillation. Contractile activity seems to represent a spontaneous, endogeneous oscillation which can be modulated via the plasmalemma during chemotaxis.
On Exploring The Basis For Slow Potential Oscillations in the Mammalian Stomach and Intestine
Authors: Connor John A. 
Published: April 2021

ABSTRACT
The basic driving unit of oscillatory electrical activity in stomach and intestine is the slow wave, a propagating depolarization of myogenic origin. The slow wave controls contractile activity in the intestine by triggering action potential bursts, while in the stomach there is both action potential and spike-free slow wave activation. This review attempts to summarize recent characterizations of the slow wave and to explore in detail the evidence, which suggests that the mechanisms which generate the electrical oscillations are quite closely coupled to metabolic processes.
An Atlas of Cellular Oscillators
Authors: Rapp P. E. 
Published: April 2021

ABSTRACT
Rapidly accumulating evidence suggests that periodic behaviour is not confined to a limited number of cell types but is a common property of most biological systems. The argument for this proposition is presented by systematically cataloguing an atlas of biological and biochemical oscillators with periods of an hour or less. The listing consists of eight principal sections .and includes oscillations in secretory cells, neural oscillators, oscillations in muscle cells and rhythmic behaviour in growth and development. Each entry states the experimental preparation, the periodic event (the observed oscillatory variable), the period and lists references to the experimental literature. Four hundred and fifty experimental papers are cited.
Oscillatory Membrane Potential Changes in Cells of Mesenchymal Origin: The Role of an Intracellular Calcium Regulating System
Authors: Nelson P. G. , Henkart M. P. 
Published: April 2021

ABSTRACT
A number of mesenchymal cells (fibroblasts, macrophages and megakaryocytes) respond to a variety of stimuli with large hyperpolarizations lasting several seconds (the H.A. response). The H.A. responses can occur as repetitive trains or oscillations. These hyperpolarizations are due to an increase of the surface membrane permeability to potassium ions which is probably mediated by an increase in the cytoplasmic free calcium ion concentration. Evidence is discussed which suggests that the source of this increased calcium is, at least in part, an intracellular sequestering system, probably the endoplasmic reticulum. A model capable of producing oscillatory changes in membrane potential is proposed based on such an intracellular calcium sequestering and releasing system.
Rapid Acetylcholine and Adenosine Triphosphate Oscillations Triggered by Stimulation of the Torpedo Electric Organ
Authors: Israël M. , Dunant Y. , Lesbats B. , Manaranche R. , Marsal J. , Meunier F. 
Published: April 2021

ABSTRACT
When the electric organ of Torpedo is stimulated a large number of synchronized cholinergic synapses are activated. This permits the measurement of changes in the tissue level of ACh associated with the release process, usually recorded as an electrical discharge. At 5 Hz stimulation the output per impulse and the amount of cytoplasmic (free ACh) declines for about 30 s. The output then remains constant while ACh is synthesized for about 90 s. Finally, the output and cytoplasmic ACh are exhausted after 120 s. These ‘slow wave’ changes in ACh represent about 50% of the total. Superimposed on the ‘slow wave’ are rapid oscillations of 5 s period, which represent about 30% of the total ACh. The amount of ATP oscillates in phase with ACh. These oscillations might result from regulation of enzymes involved in the synthesis of transmitter. The amplitude of electrical discharge does not normally oscillate. Transmitter output is therefore not directly related to ACh concentration changes. The mechanism releasing ACh is a saturable process.
The Glycolytic Oscillator
Authors: Hess Benno 
Published: April 2021

ABSTRACT
The glycolytic oscillator, mainly studied in yeast, is described with respect to its overall dynamic and biochemical properties and the kinetics of its master enzyme phosphofructokinase. Biochemical and kinetic analyses are complemented by analysis of mathematical models. In addition to the discussion of structure and function of the glycolytic oscillator under homogeneous spatial conditions, recent theoretical and biochemical experiments demonstrating spatial pattern formation are also discussed, followed by a presentation of physiological viewpoints.
Dynamic Oscillations in the Membrane Potential of Pancreatic Islet Cells
Authors: Matthews E. K. , O’connor M. D. L. 
Published: April 2021

ABSTRACT
Glucose and other metabolizable sugars which elicit insulin release from the β-cell of the pancreatic islet induce repetitive oscillations in the β-cell transmembrane potential. Upon each phasic depolarization are superimposed rapid fluctuations in potential, i.e. ‘action potentials’ or ‘spikes’ which occur as bursts of electrical activity; the duration and frequency of each burst is a function of glucose concentration. These established electrophysiological features of glucose-islet cell interaction are described in detail together with a consideration of their possible molecular and ionic basis. Based on these observations, a dynamic mathematical computer model of the β-cell membrane electrical behaviour is presented which utilizes the Goldman equation extended to include divalent ions. The model illustrates how the ionic mechanisms deduced from experimental observations can account for the electrical patterns produced by the β-cells in the presence of D-glucose; it also allows systematic changes to be made in a number of state variables in order to assess their relative importance and possible contribution to the integrated processes actually observed. Finally, distinction is made between aspects of the model which are well supported by experimental results and those areas which require further analysis.
Effect of Maintained Hypoxic Exposure on the CrayfishOrconectes Rusticus
Authors: Wilkes P. R. H. , McMahon B. R. 
Published: April 2021

ABSTRACTOxygen uptake in the crayfish Orconectes rusticus was maintained at nor-moxic levels throughout 6 days exposure to an ambient oxygen tension of 45–55 torr. This was attributed to compensatory responses of the ventilatory and cardiovascular pumps. The first 72 h of hypoxic exposure were characterized by a transitory 3-fold increase in both scaphognathite rate and cardiac output above initial normoxic values. During the latter 72 h of hypoxic exposure both scaphognathite pumping and cardiac output were significantly below maximum values but were maintained above initial normoxic levels. Thus, as reflected by the increased convection requirements for both water and haemolymph, the increased scaphognathite and heart activity served to increase oxygen delivery to both the branchial chambers and the tissues. Additionally, the increased branchial ventilation and gill perfusion facilitated removal of dissolved carbon dioxide from the haemolymph, effecting a respiratory alkalosis. The increased haemolymph pH elevated the oxygen affinity of the haemocyanin via the Bohr affect, enabling a greater volume of oxygen to be picked up at the gills by the haemocyanin despite the reduced pressure gradient.
Fatigue assessment by FACIT-F scale in Pakistani cohort with Rheumatoid Arthritis (FAF-RA) study
Authors: Wagan Abrar Ahmed , Raheem Abdul , Bhatti Afra , Zafar Taimoor 
Published: April 2021

Objective: To fine out fatigue frequency and severity by FACIT-F scale in Pakistani cohort with rheumatoid arthritis.
Methods: This study was conducted at department of Medicine division of rheumatology CPMC Lahore. After the approval of IRB, 192 patients of RA were recruited. Written, informed consent was taken, demographic details were noted, patients filled the URDU version of FACIT-F (fatigue severity scale). 5-ml of blood was taken for fasting blood sugar, viral markers and ESR by a trained phlebotomist. Each individual’s disease activity was assessed by DAS-28 and FACIT-F score was calculated.
Results: The Mean age (39.9±10.5) years, (71.9%) were females. Fatigue frequency was 62% (n=126), age, education, hypertension, DAS-28, exercise levels and HCV gives significant association with fatigue score. Linear regression analysis, results showed one unit increase in DAS-28 will gives 2.71 unit increases in fatigue scores(P <0.05).
Conclusions: We have very high frequency of fatigue in RA, increases with disease activity & associated conditions.
doi: https://doi.org/10.12669/pjms.37.4.3602
How to cite this:Wagan AA, Raheem A, Bhatti A, Zafar T. Fatigue assessment by FACIT-F scale in Pakistani cohort with Rheumatoid Arthritis (FAF-RA) study. Pak J Med Sci. 2021;37(4):1025-1030. doi: https://doi.org/10.12669/pjms.37.4.3602
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
T- and B-lymphocytes subpopulations in the early and advanced rheumatoid arthritis
Authors: Martynova A. V. , Popkova T. V. , Aleksankin A. P. , Gridneva G. I. , Gerasimova E. V. , Gorbunova Yu. N. , Semashko A. S. , Lila A. M. 
Published: April 2021

Objective: to evaluate changes in T- and B-lymphocyte subpopulations at different stages of rheumatoid arthritis (RA).Patients and methods. The study included 53 patients with a definite RA diagnosis according to the 2010 ACR/EULAR criteria (mean age 54.2 [47; 62] years). Group 1 included 27 patients (25 women and 2 men) without history of synthetic disease modifying anti-rheumatic drugs (sDMARDs) intake, group 2 included 26 patients (22 women and 4 men) receiving sDMARDs (methotrexate or leflunomide). The control group consisted of 29 healthy volunteers (23 women and 6 men), the median age was 58.5 [53; 62] years. In all participants flow cytofluorometry according to the standard technique with immunophenotyping of T- and B-lymphocytes was performed.Results and discussion. Compared to controls, patients in group 1 who had not previously received sDMARDs showed a transient increase in "switched" memory B-cells, transient B-cells, and plasmablasts, which was not observed in patients of group 2 (on sDMARDs therapy). Patients with advanced RA showed a statistically significant decrease in the absolute and relative number of memory B-cells, the absolute and relative number of "switched" B-lymphocytes, as well as the number of plasmablasts and transient cells. In RA patients, a statistically significant rela tionship was established between the number of swollen joints and the level of plasmablasts (r=0.51), memory cells (r=0.54), and "switched" B-cells (r=0.41), p< 0,05 in all cases. There were no statistically significant changes in other subpopulations of B-lymphocytes and the profile of T-lymphocytes.Conclusion. Changes in the B-lymphocyte profile are characteristic of different stages of RA. At an early stage, there is an increase in the number of transient B-lymphocytes, plasmablasts and plasmocytes, and in the advanced stage, a decrease in the level of certain populations of B-lymphocytes, such as memory B-cells and "switched" B-lymphocytes. It can be assumed that the ineffectiveness of sDMARDs is associated with a change in the population composition of B-lymphocytes, which requires further study.
Relationship of genetic polymorphism of the acute phase marker of inflammation rs12218 of the SAA1 gene with clinical phenotypes of juvenile idiopathic arthritis
Authors: Krylov M. Yu. , Fedorov E. S. , Salugina S. O. 
Published: April 2021

Objective: to test the hypothesis of a possible relationship between the rs12218 polymorphism of the SAA1 gene and a predisposition to different clinical phenotypes of juvenile idiopathic arthritis (JIA).Patients and methods. Genetic typing of rs12218 polymorphism was carried out in 142 children: 77 of them were diagnosed with JIA, including 30 patients with oligoarthritis (oJIA), 20 with polyarthritis (pJIA), and 27 with systemic onset (sJIA). Sixty five healthy volunteers were included in the control group. The rs12218 polymorphism of the SAA1 gene was investigated using real-time polymerase chain reaction.Results and discussion. A high risk of developing the clinical phenotype of oJIA in carriers of the C mutant allele of the rs12218 T/C polymorphism of the SAA1 gene was established. Statistically significant differences between the clinical phenotypes of oJIA and sJIA in the frequency distribution of genotypes and alleles of rs12218 T/C polymorphism of the SAA1 gene are shown.Conclusion. The results of the studies have confirmed the important role of the rs12218 T/C polymorphism of the SAA1 gene in the formation of susceptibility to clinical variants of JIA.
Magnetic resonance tomography capabilities and limitations in managing the efficacy of treatment with biological disease modifying anti-rheumatic drugs in ankylosing spondylitis
Authors: Shesternya P. A. , Gritsenko O. D. , Astanin P. A. , Stepanenko A. Yu. , Popov N. V. 
Published: April 2021

Extensive use of magnetic resonance imaging (MRI) in clinical practice revolutionized our understanding of the pathogenesis of axis spondyloarthritis (aSpA) and treatment approaches. The use of MRI to diagnose non-radiographic aSpA is well established. At the same time, the possibility of its use for follow-up and treatment assessment is actively discussed.Objective: To present comparative analysis of clinical and laboratory data, reflecting the activity of the disease, and analysis of MRI results in patients with ankylosing spondylitis (AS) receiving biological disease modifying anti-rheumatic drugs therapy (bDMARDs).Patients and methods. The study included 39 patients with AS, mainly men (74.3%), 24 patients (61.5%) had late and 15 (38.5%) – advanced stage of the disease. The average age was 41.0 [34.0; 48.0] years. All patients were administered bDNARDs; inhibitors of the tumor necrosis factor α or inhibitors of interleukin 17 were drug of choice. The median of treatment duration was 1.5 [1.0; 4,5] year. All patients had sacroiliac (SI) and spinal MRI. The activity of the disease was estimated using BASDAI and ASDAS-CRP/ESR indexes, functional disorders – using the BASFI questionnaire. Results and discussion. There was no significant difference in disease activity between patients with osteitis in the SI/spine or without it: BASDAI – 4.7 [2.7; 5,5] and 4.2 [2.9; 8,1], respectively (p=0.533); ASDAS-ESR – 2.6 [2.2; 3,0] and 2.6 [2.2; 3,2], respectively (p=0.725); ASDAS-CRP – 2.5 [2.1; 3,4] and 3.1 [2.8; 3.9], respectively (p=0.172). There was no significant difference in the number of osteitis foci between group of patients who have achieved the therapeutic target (ASDAS < 2.1) and those who have not (ASDAS ≥2.1) – 1.0 [0.0; 3.5] and 1.0 [1.0; 4.0], respectively, (p=0.376), and no difference in amount of inflammatory changes – 1.0 [0.2; 1.7] and 0.1 [0.0; 1,1] cm3, respectively (p=0.124). Conclusion. The data suggests a limited MRI informative value as a method for managing the efficacy of bDMARDs treatment in patients with the advanced / late stage of the AS.
Capabilities of ultrasonography in the diagnosis of early rheumatoid arthritis and hand osteoarthritis
Authors: Krivotulova I. A. , Chernysheva T. V. , Korochina K. V. 
Published: April 2021

Objective: to compare results of ultrasound examination (US) of the wrist joints (WJ) and small joints of hands with the clinical signs in patients with early rheumatoid arthritis (eRA) and hand osteoarthriti (OAH).Patients and methods. The study included 42 patients with eRA (group 1) and 38 patients with OAH (group 2). The average age of patients with eRA was 48.60±14.86 years, the duration of clinical manifestations was 7.45±1.77 months, of patients with OAH – 54.97±12.45 years and 8.26±1.83 months, respectively. The ratio of men and women in both groups was approximately the same, the majority were women. All patients with eRA had clinical and instrumentally confirmed signs of OA: I, II, and III radiological stages of OA according to Kellgren–Lawrence were detected in 10 (23.80%), 23 (54.76%) and 9 (21.43%) patients respectively. In erosive OA II and III X-ray stage was diagnosed in 16 (42.10%) and 22 (57.90%) patients, respectively. All patients underwent ultrasound of the joints, as well as a general clinical examination, which included an assessment of the number of painful joints, the number of swollen joints, and a general assessment of pain intensity using a visual analogue scale (100 mm). RA activity was determined using the DAS28 index. We also studied laboratory parameters – the levels of CRP, rheumatoid factor and antibodies to cyclic citrullinated peptide in blood serum.Results and discussion. Comparison of the two groups of patients showed that ultrasound in B-mode and power Doppler mode with eRA and OAH showed more pronounced inflammatory and destructive changes in the wrist joints and small joints of the hands, with the exception of the distal interphalangeal joints (DIPJ). In addition, only in patients of the 1st group there was a close correlation between the enhancement of the Doppler signal and levels of inflammatory markers. Conclusion. eRA compared with OAH is characterized by more pronounced ultrasound signs of inflammatory and destructive changes in the wrist joins and small joints of the hands, with the exception of DIPJ.
Contribution of neurogenic mechanisms to the pathogenesis of chronic joint pain
Authors: Filatova E. S. , Lila A. M. 
Published: April 2021

Objective: to study the contribution of neurogenic mechanisms to the pathogenesis of chronic pain in patients with rheumatoid arthritis (RA), knee osteoarthritis (OAk) and ankylosing spondylitis (AS). To evaluate the effectiveness of an anticonvulsants in complex therapy of RA and OAk.Patients and methods. The study included 518 patients, 208 (40.2%) had definite RA, 160 (30.9%) had OAk and 150 (28.9%) had AS. All patients were rheumatologically and neurologically examined to determine the state of the somatosensory system; DN4 and Pain DETECT questionnaires were used to diagnose pain descriptors characteristic of neuropathic and nocyplastic pain; visual analogue scale (VAS) was used for pain intensity at rest assessment; algometry – for detecting secondary hyperalgesia. Functional, affective disorders and quality of life were assessed as well. Moreover, efficacy of the anticonvulsant in the complex therapy of RA and OAk was evaluated.Results and discussion. 49.5% of RA patients had neuropathic pain. It has been statistically significantly shown that older patients with a long history of the disease, advanced X-ray stage and high level of anxiety and depression experience neuropathic pain more frequently. Disease activity and ESR level did not affect the severity of the neuropathic component of pain. In 37.5% of OAk cases, signs of nociplastic pain were observed. Patients in this group were in pain according to VAS, worse functional state and quality of life, as well as a higher level of anxiety, the differences were statistically significant. 12.7% of AS patients had nociplastic pain. There was no association with the age and duration of the disease. Higher levels of disease activity, pain and depression and worse functional abilities were observed when nociplastic pain was present. The effectiveness of anticonvulsant is demonstrated in the complex therapy of chronic articular pain in RA and OAk, which confirms the role of central sensitization in the pathogenesis of pain in these diseases.Conclusion. Chronic pain in RA, OAk and AS patients in some cases has mixed nature, both inflammatory and neurogenic mechanisms (neuropathic and nociplastic) are involved. It is necessary to examine patients to identify the neuropathic component of pain, which will improve pain control and ensure a holistic approach to therapy. In patients with RA and OAk, having a mixed nature of pain, complex treatment, containing a central action drug from a group of anticonvulsants, is more effective compared with standard anti-inflammatory therapy.