bluuebunny/crossref_metadata_2025_split huggingface dataset:
H+ Excretion in the Marine Teleost Parophrys Vetulus
Authors: McDonald D. G. , Walker R. L. , Wilkes P. R. H. , Wood C. M. 
Published: April 2021

ABSTRACT
This study examined the branchial, renal and blood acid-base responses of a marine teleost to intravascular infusion of mineral acid (HC1 at 1000 μequiv/kg). In all animals the renal response was insignificant for at least 3 days following infusion. Two types of branchial and blood acid-base response were seen. Either the infused load disappeared rapidly from the extracellular into the intracellular compartment and was slowly cleared from the body (+16h following infusion) or, more commonly, remained in the extracellular compartment until rapidly cleared by a pronounced increase in branchial excretion. In the latter the amount excreted exceeded that infused by about twofold on average. These responses are discussed in relation to those of freshwater teleosts.
The neuromuscular basis of rhythmic struggling movements in embryos of Xenopus laevis
Authors: Kahn J. A. , Roberts A. 
Published: April 2021

ABSTRACT
Xenopus embryos struggle when restrained. Struggling involves rhythmic movements of large amplitude, in which waves of bending propagate from the tail to the head.
Underlying this, electrical activity in myotomal muscles occurs in rhythmic bursts that alternate on either side of a segment. Bursts in ipsilateral segments occur in a caudo-rostral sequence.
Curarized embryos can generate motor nerve activity in a struggling pattern in the absence of rhythmic sensory stimulation; the pattern is therefore produced by a central pattern generator.
Differences between directly measured and calculated values for cardiac output in the dogfish: a criticism of the Fick method
Authors: Metcalfe J. D. , Butler P. J. 
Published: April 2021

ABSTRACT
Cardiac output has been measured directly, and calculated by the Fick method, during normoxia and hypoxia in six artificially perfused dogfish (Scyliorhinus canicula) in an attempt to estimate the accuracy of this method in fish. The construction and operation of a simple extra-corporeal cardiac bypass pump is described. This pump closely mimics the flow pulse profiles of the fish’s own heart and allows complete control of both cardiac stroke volume and systolic and diastolic periods.
During normoxia there was no significant difference between directly measured and calculated values for cardiac output. However, some shunting of blood past the respiratory surface of the gills may have been obscured by cutaneous oxygen uptake. In response to hypoxia there is either a decrease in the amount of blood being shunted past the respiratory surface of the gills and/or an increase in cutaneous oxygen uptake such that the Fick calculated value for cardiac output is on average 38% greater than the measured, value. It is proposed that the increase in the levels of circulating catecholamines that is reported to occur in response to hypoxia in this species may play an important role in the observed response to hypoxia. The results are discussed in terms of their implications for the calculation of cardiac output by the Fick principle in fish.
Energetic Cost of Running With Different Muscle Temperatures in Savannah Monitor Lizards
Authors: Rome Lawrence C. 
Published: April 2021

ABSTRACT
The purpose of this study was to determine whether the energetic cost of locomotion was independent of muscle temperature, or if it tripled with a 10 °C increase in temperature, like the cost of generating isometric force in isolated muscle preparations. For a given running speed of Savannah Monitor lizards, the energetic cost of locomotion (the difference between running and resting metabolism) was the same when muscle temperature was 28·5 °C as when it was 38 °C. It was also found that stride frequency and posture did not change with temperature, indicating that the average force exerted by the lizards’ muscles during locomotion at the two temperatures was the same. This suggests that the cost of generating force in vivo is independent of temperature. Several possible explanations of the apparent difference between in vivo and in vitro muscle energetics are discussed.
Electrical Activity and Structure of Retinal Cells of the Aplysia Eye: II. Photoreceptors
Authors: Jacklet Jon W. , Rolerson Celine 
Published: April 2021

ABSTRACT
Photoreceptors of the eye of Aplysia were studied by intracellular recording and Lucifer yellow injection. Two basic photoreceptor types were observed, R and H. Two other types of cells were occasionally encountered: one was neurone-like, giving only a slight depolarization but large action potentials (APs) in response to light ; the other was presumably glial. Type R photoreceptors were found in the pigmented layer of the retina, had large distal (photoreceptor) processes extending toward the lens and an axon in the optic nerve. They are probably the large, microvillous receptor type with vesicle-filled cytoplasm observed previously in electron microscope studies. Action potentials were observed in the axon but not the cell body of the R receptor. The light response was an increasing conductance, 2 component depolarization followed by hyperpolarization. All 3 components were affected by light adaptation. Electrical coupling between R receptors and secondary neurones was apparent and the system produces the synchronous compound action potentials (CAPs) in the optic nerve. Type H photoreceptors gave a slight depolarization to light with APs, followed by a hyperpolarization, followed by a late depolarization and more APs. They were in the pigmented layer of the retina and had smaller cell bodies and distal processes, but larger axons than R receptors. They may correspond to the photoreceptors with short microvilli and occasional cilia described previously in electron microscope studies. Electrical and dye coupling occurred between the receptors. The H receptors do not contribute to the CAP, but produce separate unitary potentials in the optic nerve.
Disturbances in Haematology, Fluid Volume Distribution and Circulatory Function Associated with Low Environmental pH in the Rainbow Trout,Salmo Gairdneri
Authors: Milligan C. Louise , Wood Chris M. 
Published: April 2021

ABSTRACTExposure of adult rainbow trout to low pH (4·0–4·5) for 3 days resulted in progressive increases in heart rate, mean arterial blood pressure and haematocrit. The haematocrit increase resulted from erythrocyte swelling, a reduction in plasma volume and a mobilization of erythrocytes from the spleen. Erythrocyte swelling probably resulted from plasma acidosis and a reduction in plasma ions (McDonald & Wood, 1981). There was an associated redistribution of body water from extracellular to intracellular compartments, but maintenance of total body water content. Erythrocyte mobilization was reflected in an increase in reticulocyte and erythrocyte counts, and a depletion of splenic blood reserves. Haemoconcentration caused large increases in blood viscosity, which contributed to the rise in blood pressure. Pharmacological analysis revealed an adrenergic component to the cardiovascular disturbance. These events are thought to play a key role in the toxic syndrome.
Excretion in Insects: Energetics and Functional Principles
Authors: Florey E. 
Published: April 2021

ABSTRACT
The contention of Maddrell (1981) that the rate of fluid secretion by insect Malpighian tubules is much slower than the rate of primary urine production (glomerular filtration rate) of vertebrates is valid only when the comparison is made with mammals and birds. Fishes and reptiles have filtration rates similar to or even slower than the rates observed in insects.
Calculations of the concentration or dilution work involved in primary urine production show that the (weight-specific) energy requirement of the insect excretory system is similar to or surpasses that reported for reptilian, and even mammalian, kidneys.
Because the energy demand of any excretory system is small when compared to the resting metabolism of the entire organism, it is likely that selection pressures acted less on a reduction of energy expenditure for excretion and ionic regulation than on the adaptations to the demands of specific environments and life styles, leading to diversified specializations of excretory (and regulatory) mechanisms.
The Cockroach DCMD Neurone
Authors: Edwards Donald H. 
Published: April 2021

ABSTRACTThe projections and response properties of a bilateral pair of large visual interneurones in the cockroach Periplaneta are described. The cells are shown to be analogous to the DCMD neurones of locust (Rowell, 1971a). The organization of the afferent input to the cockroach DCMD was explored by examining the response to different types of visual stimuli. The afferent input is organized into an array of parallel channels. Response habitutation occurs within each channel independently of habituation in other channels. The dynamics of habituation and recovery from habituation were examined. A simple model based on these data is proposed that can predict the DCMD response to repetitive stimuli having a wide range of interstimulus intervals. The relation of this model to models of synaptic depression is discussed. Both u.v.-sensitive and green-sensitive photoreceptors in the eye provide input to the DCMD, but this cell remains unable to detect colour.
Primary Anastomosis Versus End-Ostomy in Left-Sided Colonic and Proximal Rectal Cancer Surgery in the Elderly Dutch Population: A Propensity Score Matched Analysis
Authors: van Loon Yu Ting , van Erning Felice N. , Maas Huub A. , Stassen Laurents P. S. , Zimmerman David D. E. 
Published: April 2021

Abstract
Background
Primary anastomosis (PA) in left-sided colorectal cancer (CRC) surgery in elderly patients is disputed. The aim of our study was to evaluate the differences in postoperative outcomes after left-sided CRC surgery in elderly patients in The Netherlands, comparing patients with PA and those who underwent end-ostomy (EO).

Method
Patients aged ≥ 75 years with stage I–III left-sided CRC, diagnosed and surgically treated in 2015–2017 were selected from the Netherlands Cancer Registry (n = 3286). Postoperative outcomes, short-term (30-, 60-, and 90-day) mortality and 3-year overall and relative survival were analyzed, stratified by surgical resection with PA versus EO. Propensity score matching (PSM) and multivariable logistic regression analysis were conducted.

Results
Patients with higher age, higher American Society of Anesthesiologists classification and higher tumor stage, a perforation, ileus or tumor located in the proximal rectum, and after open or converted surgery were more likely to receive EO. No difference in anastomotic leakage was seen in PA patients with or without defunctioning stoma (6.2% vs. 7.0%, p = 0.680). Postoperative hospital stay was longer (7.0 vs. 6.0 days, p < 0.0001) and more often prolonged (19% vs. 13%, p = 0.03) in EO patients. Sixty-day mortality (2.9% vs. 6.4%, p < 0.0001), 90-day mortality (3.4% vs. 7.7%, p < 0.0001), and crude 3-year survival (81.2% vs. 58.7%, p < 0.0001) were significantly higher in EO patients, remaining significant after multivariable and PSM analysis.

Conclusion
There are significant differences between elderly patients after left-sided CRC surgery with PA versus EO in terms of postoperative length of stay, short-term survival, 3-year overall survival, and relative survival at disadvantage of EO patients. This information could be important for decision making regarding surgical treatment in the elderly.
Emotion regulation, optimism and quality of life among Gastric Ulcer Patients
Authors: Muazzam Amina , Ali Nida , Niazi Yasmeen , Hassan Naima 
Published: April 2021

Objective: The study was aimed to investigate the association among emotion regulation, optimism and quality of life among gastric ulcer patients.
Methods: The Cross-sectional study was conducted in public sector hospitals of Lahore, during January-June 2017. Sample of study was comprised of 100 patients diagnosed with gastric ulcer, aged 25-55 years, selected through non-probability purposive sampling technique. Demographic information sheet, Emotion Regulation Scale by John, Gross 2003, Life Orientation Test-Revised by Sheer, Carver 2002, Quality of Life Enjoyment and Satisfaction Questionnaire by Endicott 1993 were used for data collection. SPSS 21 version was used for data analysis.
Results: Out of total 100 participants 41 (41%) were men and 59 (59%) were women, with mean age of (M= 44.89, SD= 7.99). There was significant positive correlation among emotion regulation, optimism and quality of life (p<0.01). Optimism and emotion regulation were observed as significant predictors of quality of life (p<0.01). Significant gender differences were found in emotion regulation (p< 0.01), optimism (p< 0.01) and quality of life (p<0.01), with men scoring higher as compared to women. One way ANOVA showed significant differences between emotion regulation, optimism and quality of life among different age groups of gastric ulcer patients (p< 0.01).
Conclusion: Quality of life of gastric ulcer patients can be greatly improved by effectively using emotion regulation strategies and optimistic approach.
doi: https://doi.org/10.12669/pjms.37.4.3894
How to cite this:Muazzam A, Ali N, Niazi Y, Hassan N. Emotion regulation, optimism and quality of life among Gastric Ulcer Patients. Pak J Med Sci. 2021;37(4):988-992. doi: https://doi.org/10.12669/pjms.37.4.3894
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.
Some, but not all of the premenstrual syndrome symptoms affect the medical exam scores in medical students
Authors: Bilir Filiz , Akdemir Ramazan , Bilir Cemil 
Published: April 2021

Objectives: This research aims to identify the effects of premenstrual syndrome (PMS) symptoms on the school exam scores in medical students.
Methods: This cross-sectional study was designed at Sakarya University School of Medicine The study included medical students who were in the first, second, and third year of class. In this study, there were 193 male and 100 female students. The study investigated how PMS symptoms affected medical student’s exam scores and school success. All exam scores were recorded during the two-consecutive semester so duration of study was one year.
Results: There were 100 female students, and they had five different committee exams for one year. Female student’s exam scores were significantly higher for four committees and an average score of all year. The mean age of female students was 19.9 ±1.5. Acne, nausea/vomiting, sleeping, abdominal bloating, and prurience change had significantly different exam scores compared to the group without these symptoms. Students with acne had substantially higher exam scores than without acne; inversely, the other four symptoms negatively affected exam scores.
Conclusion: Some of the PMS symptoms can be more annoying and should change the quality of life more than the other symptoms, so we should define these symptoms to improve our student’s quality of life and school success.
doi: https://doi.org/10.12669/pjms.37.4.3931
How to cite this:Bilir F, Akdemir R, Bilir C. Some, but not all of the premenstrual syndrome symptoms affect the medical exam scores in medical students. Pak J Med Sci. 2021;37(4):1190-1195. doi: https://doi.org/10.12669/pjms.37.4.3931
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.
Correlations of circulating miR-26b level with left ventricular hypertrophy and cardiac function in elderly patients with hypertension
Authors: Fu Jian , Lin Fang , Pan Zhengxia , Wu Chun 
Published: April 2021

Objectives: To study the correlations of circulating miR-26b level with left ventricular hypertrophy (LVH) and cardiac function in elderly patients with hypertension.
Methods: A total of 132 eligible patients were divided into low and high miR-26b level groups. Their baseline clinical data and biochemical indices were compared. The correlations between miR-26b level and echocardiographic parameters were studied by Pearson’s analysis. Factors affecting LVH were explored by multivariate logistic regression analysis. The role of miR-26b in diagnosing LVH was predicted by receiver operating characteristic curve.
Results: The relative expression level of miR-26b was 4.56-16.93, with a median of 7.62. The two groups had similar baseline clinical data and biochemical indices (P>0.05). Compared with high miR-26b level group, interventricular septal thickness (IVST), left ventricular posterior wall thickness (LVPWT), left ventricular mass index (LVMI) and number of LVH cases in low miR-26b level group significantly increased (P<0.05), and mitral ratio of peak early to late diastolic filling velocity (E/A) decreased (P<0.05). Circulating miR-26b level was negatively correlated with IVST, LVPWT and LVMI (P<0.0001), and positively correlated with E/A (P<0.0001). The proportion of cardiac hypofunction cases in low miR-26b level group significantly exceeded that of high miR-26b level group (P<0.05). Age and increased IVST, LVPWT and LVMI were independent risk factors for LVH (P<0.05), and elevated miR-26b level was a protective factor (P<0.05). AUC was 0.836, and the optimal cutoff value was 8.83, with high sensitivity and specificity.
Conclusions: MiR-26b level is negatively correlated with LVH and positively correlated with left ventricular diastolic function in elderly hypertensive patients. It is a protective factor for LVH complicated with diastolic dysfunction and a potential biomarker for diagnosis.
doi: https://doi.org/10.12669/pjms.37.4.4048
How to cite this:Fu J, Lin F, Pan Z, Wu C. Correlations of circulating miR-26b level with left ventricular hypertrophy and cardiac function in elderly patients with hypertension. Pak J Med Sci. 2021;37(4):966-971. doi: https://doi.org/10.12669/pjms.37.4.4048
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.
Social media and the COVID-19 pandemic: The dilemma of fake news clutter vs. social responsibility
Authors: Ben Messaoud Moez 
Published: April 2021

This article examines the relationship between fake news and social media as increasingly important sources of news, at a time when mainstream media no longer have exclusive control over news production and dissemination. It has been evident that few media outlets and professionals tend to draw conflicting news about COVID-19 from social media feeds, which are largely produced by common citizens with mostly no journalism training. This pervasive use makes social media key sources to scores of media outlets for news, whether it is related to COVID-19 or public affairs issues, even though it is susceptible to torrents of credibility and accuracy issues.
As a result, of the overwhelming spread of fake news on coronavirus, which is contributing to framing events from several angles, media professionals are now obliged to track and vet information circulating on social media. Due to the scale of disinformation spreading on the Web, it has become imperative that the credibility and accuracy of news is thoroughly verified. Media organizations have already been putting in place various mechanisms to monitor false news.
This article will attempt to identify and assess these monitoring efforts in the Arab world. For this purpose, I have put together a list of Arab observatories launched on the internet in order to monitor fake news circulating in relation to COVID-19, and to discuss their methods of monitoring work, in the context of mobilization carried out by governments and many organizations such as the World Health Organization.
This article is pinned down on social responsibility approach which helps pave the way the different propositions to combat fake news and avoid abuses in social media uses. This article proposes an evaluation of the monitoring initiative via-a-vis fake news and proposes a set of guidelines for improving the work of such monitoring bodies. Hence, this research reveals that social media outlets have diversified their goals to match the power of the conventional media in disseminating information and bringing up issues for debate. However, in the light of the framework of social responsibility, social media actors have to constantly develop a set of ethical practices to be observed by users, establish codes of conduct regulating content production, and lay down a code of integrity to assure accuracy in news and information transmission.
Report of 33 Novel AVPR2 Mutations and Analysis of 117 Families with X-Linked Nephrogenic Diabetes Insipidus
Authors: ARTHUS MARIE-FRANC[COMBINING CEDILLA]OISE , LONERGAN MICHE[Combining Grave Accent]LE , CRUMLEY M. JOYCE , NAUMOVA ANNA K. , MORIN DENIS , DE MARCO LUIZ A. , KAPLAN BERNARD S. , ROBERTSON GARY L. , SASAKI SEI , MORGAN KENNETH , BICHET DANIEL G. , FUJIWARA T. MARY 
Published: April 2021

Abstract.
X-linked nephrogenic diabetes insipidus (NDI) is a rare disease caused by mutations in the arginine vasopressin receptor 2 gene (AVPR2). Thirty-three novel AVPR2 mutations were identified in 62 families that were not included in our previous studies. This study describes the diversity of mutations observed in a total of 117 families, the number of affected people at the time of diagnosis, skewed X chromosome inactivation in severely affected females, the inferred parental origin of de novo mutations, and it provides estimates of incidence. Among 117 families, there were 82 different putative disease-causing mutations. Based on haplotype analysis, it can be inferred that when the same AVPR2 mutation is identified in different families that were not known to be related, the mutations most likely arose independently. More than half of the families had only one affected male; two families presented with a severely affected female and no family history of NDI. A de novo mutation arose during oogenesis in the mother in 20% of isolated cases. The estimate of about 8.8 per million male live births of the incidence of X-linked NDI in the province of Quebec, Canada may be representative of the general population except in Nova Scotia and New Brunswick, where the incidence is more than six times higher. Documentation of the diversity of mutations will assist in revealing the full spectrum of clinical variation. Discussion of genetic and population genetic aspects of X-linked NDI may contribute to early diagnosis and treatment.