bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two
Dictyostelium
Orthologs of the Prokaryotic Cell Division Protein FtsZ Localize to Mitochondria and Are Required for the Maintenance of Normal Mitochondrial Morphology
Authors: Gilson Paul R. , Yu Xuan-Chuan , Hereld Dale , Barth Christian , Savage Amelia , Kiefel Ben R. , Lay Sui , Fisher Paul R. , Margolin William , Beech Peter L. 
Published: December 2003

ABSTRACT

In bacteria, the protein FtsZ is the principal component of a ring that constricts the cell at division. Though all mitochondria probably arose through a single, ancient bacterial endosymbiosis, the mitochondria of only certain protists appear to have retained FtsZ, and the protein is absent from the mitochondria of fungi, animals, and higher plants. We have investigated the role that FtsZ plays in mitochondrial division in the genetically tractable protist
Dictyostelium discoideum
, which has two nuclearly encoded FtsZs, FszA and FszB, that are targeted to the inside of mitochondria. In most wild-type amoebae, the mitochondria are spherical or rod-shaped, but in
fsz
-null mutants they become elongated into tubules, indicating that a decrease in mitochondrial division has occurred. In support of this role in organelle division, antibodies to FszA and FszA-green fluorescent protein (GFP) show belts and puncta at multiple places along the mitochondria, which may define future or recent sites of division. FszB-GFP, in contrast, locates to an electron-dense, submitochondrial body usually located at one end of the organelle, but how it functions during division is unclear. This is the first demonstration of two differentially localized FtsZs within the one organelle, and it points to a divergence in the roles of these two proteins.
Functional Characterization of
Candida albicans
ABC Transporter Cdr1p
Authors: Shukla Suneet , Saini Preeti , Smriti  , Jha Sudhakar , Ambudkar Suresh V. , Prasad Rajendra 
Published: December 2003

ABSTRACT

In view of the importance of
Candida
drug resistance protein (Cdr1p) in azole resistance, we have characterized it by overexpressing it as a green fluorescent protein (GFP)-tagged fusion protein (Cdr1p-GFP). The overexpressed Cdr1p-GFP in
Saccharomyces cerevisiae
is shown to be specifically labeled with the photoaffinity analogs iodoarylazidoprazosin (IAAP) and azidopine, which have been used to characterize the drug-binding sites on mammalian drug-transporting P-glycoproteins. While nystatin could compete for the binding of IAAP, miconazole specifically competed for azidopine binding, suggesting that IAAP and azidopine bind to separate sites on Cdr1p. Cdr1p was subjected to site-directed mutational analysis. Among many mutant variants of Cdr1p, the phenotypes of F774A and ΔF774 were particularly interesting. The analysis of GFP-tagged mutant variants of Cdr1p revealed that a conserved F774, in predicted transmembrane segment 6, when changed to alanine showed increased binding of both photoaffinity analogues, while its deletion (ΔF774), as revealed by confocal microscopic analyses, led to mislocalization of the protein. The mislocalized ΔF774 mutant Cdr1p could be rescued to the plasma membrane as a functional transporter by growth in the presence of a Cdr1p substrate, cycloheximide. Our data for the first time show that the drug substrate-binding sites of Cdr1p exhibit striking similarities with those of mammalian drug-transporting P-glycoproteins and despite differences in topological organization, the transmembrane segment 6 in Cdr1p is also a major contributor to drug substrate-binding site(s).
Spatial learning in the restrained American cockroach Periplaneta americana
Authors: Kwon Hyung-Wook , Lent David D. , Strausfeld Nicholas J. 
Published: December 2003

SUMMARY
Spatial learning abilities were tested in restrained cockroaches by observing antennal projection responses towards the positions of a learned visual cue perceived monocularly by one eye in the context of a second stimulus provided to the contralateral eye. Memory of the position of the conditioning stimulus relative to the contralateral reference stimulus was tested by altering the relative positions of the two stimuli. Memory of the conditioning stimulus is retained if the angle between the conditioning stimulus and the contralateral reference stimulus is maintained. The results suggest that during learning the insect recognizes spatial relationships between the conditioning stimulus and the contralateral reference stimulus. Possible mechanisms, such as retinotopic matching versus angular matching, are discussed.
Intrinsic autoregulation of cardiac output in rainbow trout(Oncorhynchus mykiss) at different heart rates
Authors: Altimiras Jordi , Axelsson Michael 
Published: December 2003

SUMMARYIntrinsic regulation of the heart in teleosts is partly driven by central venous pressure, which exerts a modulatory role on stroke volume according to the well-known Frank-Starling mechanism. Although this mechanism is well understood from heart perfusion studies, less is known about how this mechanism operates in vivo, where heart rate varies markedly. We used zatebradine, a bradycardic agent, to attain resting heart rates in surgically instrumented animals. A dose of zatebradine of 2.79±0.47 mg l-1 decreased heart rate by half, from 44.4±4.19 beats min-1 to 22.1±1.9 beats min-1. Zatebradine had no significant effect on the peripheral vasculature and no inotropic effects, so was a suitable pharmacological agent with which to manipulate heart rate. When heart rate halved, cardiac output dropped to 87.5±4.6% of the control value, due to the concomitant increase in stroke volume to 165±13%. In vivo recordings of venous pressure at varying heart rates indicated that the partial compensation in cardiac output was possible through an increase in pressure in the sinus venosus, from -0.06±0.04 kPa at a control heart rate of 58.3±3.5 beats min-1 (N=10)to 0.07±0.05 kPa after injection of zatebradine (4 mg kg-1). The operation of the so-called time-dependent autoregulatory mechanism was further demonstrated in perfused hearts. The positive pressures recorded in the sinus venosus at low heart rates coincident with non-invasive measurements in trout suggest that atrial filling in trout is more dependent on the build-up of pressure in the venous circulation (vis-à-tergofilling) than a suction mechanism during ventricular contraction(vis-à-fronte filling).
In vivomuscle activity in the hindlimb of the arboreal lizard,Chamaeleo calyptratus: general patterns and the effects of incline
Authors: Higham Timothy E. , Jayne Bruce C. 
Published: December 2003

SUMMARYArboreal animals often move on surfaces with variable and steep inclines,but the changes in hindlimb muscle activity in response to incline are poorly understood. Thus, we studied the hindlimb muscle activity in the arboreal specialist, Chamaeleo calyptratus, moving up and down 45°inclines and on a horizontal surface. We quantified electromyograms (EMGs)from nine hindlimb muscles, and correlated EMGs with three-dimensional hindlimb kinematics. Kinematics changed little with incline, but the EMGs changed substantially. Most of the changes in EMGs were for amplitude rather than timing, and the EMGs of the hip and thigh muscles had more conspicuous changes with incline than those of the lower limb muscles. Unlike most other vertebrates, chameleons flexed the knee substantially during the first half of stance while the foot was anchored to the perch, and the amplitude of two large knee flexors increased when moving uphill compared to level and downhill. Thus, knee flexion in early stance probably contributes significantly to propulsion in C. calyptratus. During stance, the caudofemoralis EMGs of C. calyptratus correlated well with femur retraction, knee flexion and posterior femur rotation, and their amplitudes were higher on uphill and level surfaces than on the downhill surface. During the second half of stance, iliotibialis EMGs correlated well with knee extension, and their amplitude was highest on the uphill surface and lowest on the downhill surface. Many of the muscles in the hindlimb of C. calyptratus changed activity with incline in a manner similar to the propulsive limb muscles in mammals. Although muscle strain often increases when animals need more power to move uphill, the minimal changes in the hindlimb kinematics of C. calyptratus with incline imply little change in muscle strain.
Partitioning of evaporative water loss in white-winged doves: plasticity in response to short-term thermal acclimation
Authors: McKechnie Andrew E. , Wolf Blair O. 
Published: December 2003

SUMMARYWe investigated changes in the relative contributions of respiratory evaporative water loss (REWL) and cutaneous evaporative water loss (CEWL) to total evaporative water loss (TEWL) in response to short-term thermal acclimation in western white-winged doves Zenaida asiatica mearnsii. We measured REWL, CEWL, oxygen consumption and carbon dioxide production in a partitioned chamber using flow-through respirometry. In doves housed for 2-4 weeks in a room heated to ca. 43°C during the day, TEWL increased from 5.5±1.3 mg g-1 h-1 at an air temperature(Ta) of 35°C to 19.3±2.5 mg g-1h-1 at Ta=45°C. In doves housed at room temperature for the same period, TEWL increased from 4.6±1.1 mg g-1 h-1 at Ta=35°C to 16.1±4.6 mg g-1 h-1 at Ta=45°C. The CEWL of heat-acclimated doves increased from 3.6±1.2 mg g-1 h-1 (64% of TEWL) at 35°C to 15.0±2.1 mg g-1 h-1 (78% of TEWL) at Ta=45°C. Cool-acclimated doves exhibited more modest increases in CEWL, from 2.7±0.7 mg g-1 h-1 at Ta=35°C to 7.8±3.4 mg g-1h-1 at Ta=45°C, with the contribution of CEWL to TEWL averaging 53% over this Ta range. Cool-acclimated doves became mildly hyperthermic (body temperature Tb=42.9±0.4°C) and expended 35% more energy relative to heat-acclimated doves(Tb=41.9±0.6°C) at Ta=45°C, even though TEWL in the two groups was similar. In each of the two groups, metabolic rate did not vary with Ta, and averaged 7.1±0.5 mW g-1 in cool-acclimated doves and 6.3±0.8 mW g-1 in heat-acclimated doves. The differences in TEWL partitioning we observed between the two experimental groups resulted from a consistently lower skin water vapour diffusion resistance (rv) in the heat-acclimated doves. At Ta=45°C, rv in the cool-acclimated doves was 120±81 s cm-1, whereas rv in the heat-acclimated doves was 38±8 s cm-1. Our data reveal that in Z. a. mearnsii, TEWL partitioning varies in response to short-term thermal acclimation.
Population-based Study of Repeat Laboratory Testing
Authors: van Walraven Carl , Raymond Michael ,   for the Network of Eastern Ontario Medical Laboratories (NEO-MeL)
Published: December 2003

Abstract
Background: Test repetition could be a readily modifiable component of laboratory utilization. Laboratory test repetition has not been rigorously studied at a population-based level. Our objective was to determine the prevalence of, and charges associated with, repetition of eight common laboratory tests.
Methods: We performed a cross-sectional study using high-quality, population-based clinical databases that included adults in Eastern Ontario, Canada, between September 1999 and September 2000 for incidence of repeating eight common laboratory tests (hemoglobin, sodium, creatinine, thyrotropin, total cholesterol, HDL-cholesterol, ferritin, and hemoglobin A1C). Tests were classified as potentially redundant if repeated within the test’s baseline testing interval. For creatinine, sodium, and hemoglobin, only tests repeated in the community were considered. For a sensitivity analysis, we varied the repeat interval by 25%, excluded tests repeated by different physicians, and excluded repeats of normal tests.
Results: Almost 4 million tests were conducted during the study year. Most tests (76%) were conducted on patients in the community. More than one-half of all people in the population had at least one laboratory test, with an overall testing rate of 367 tests per 100 people per year. Repeat testing within 1 month accounted for 30% of all utilization (109 repeat tests per 100 people per year). Repetition was more common in hospitalized patients, varied extensively among tests, and was concentrated in a limited number of people. For the eight tests included in the study, charges of potentially redundant repetition in adults totaled between $13.9 and $35.9 million (Canadian) annually.
Conclusions: Laboratory test repetition is very common, makes up a significant component of overall test utilization, and is costly.
Human Chorionic Gonadotropin Isoforms in the Diagnosis of Ectopic Pregnancy
Authors: Borrelli Paola T A , Butler Stephen A , Docherty Suzanne M , Staite Edyta M , Borrelli Antonio L , Iles Ray K 
Published: December 2003

AbstractBackground: Early diagnosis of ectopic pregnancy uses ultrasound with serial measurements of total human chorionic gonadotropin (hCG). The objective of this study was to explore the possibility that an isolated measurement of hCG isoforms/subunits rather than total hCG could be used as a single test for ectopic pregnancy.Methods: Total and intact hCG, free hCG β- and α-subunits (hCGβ and -α), and hCG β-core fragment were measured by RIA and IRMA in the serum and urine of 76 women presenting at outpatient emergency departments with a positive pregnancy test, lower abdominal pain, and/or vaginal bleeding. Final diagnoses were based on outcomes of pregnancies and tissue histology.Results: Twenty-seven of the 76 women were subsequently diagnosed with viable pregnancies, 37 with spontaneous miscarriage, and 12 with ectopic pregnancy. Concentrations of all forms of hCG were lower in cases of ectopic pregnancy and spontaneous miscarriage than in viable pregnancies. Serum samples gave better results than urine samples. The free hCGβ isoform (P &lt;0.0001) had 100% sensitivity at a specificity of 79% at a 281 pmol/L (6.5 μg/L) cutoff. Total hCG (P = 0.005) had comparable ROC characteristics with a 100% sensitivity and 68% specificity at a cutoff value of 1053 pmol/L (375 IU/L). Neither hCGβ (P = 0.7) nor total hCG (P = 0.4) could distinguish ectopic pregnancies from spontaneous miscarriage.Conclusion: Measurement of serum free hCGβ at the time of presentation can identify women with a high probability of ectopic pregnancy who may benefit from closer surveillance, reducing the risk of tubal rupture.
Assessment of Immunoreactive Synthetic Peptides from the Structural Proteins of Severe Acute Respiratory Syndrome Coronavirus
Authors: Wang Jingqiang , Wen Jie , Li Jingxiang , Yin Jianning , Zhu Qingyu , Wang Hao , Yang Yongkui , Qin E’de , You Bo , Li Wei , Li Xiaolei , Huang Shengyong , Yang Ruifu , Zhang Xumin , Yang Ling , Zhang Ting , Yin Ye , Cui Xiaodai , Tang Xiangjun , Wang Luoping , He Bo , Ma Lianhua , Lei Tingting , Zeng Changqing , Fang Jianqiu , Yu Jun , Wang Jian , Yang Huanming , West Matthew B , Bhatnagar Aruni , Lu Youyong , Xu Ningzhi , Liu Siqi 
Published: December 2003

AbstractBackground: The widespread threat of severe acute respiratory syndrome (SARS) to human life has spawned challenges to develop fast and accurate analytical methods for its early diagnosis and to create a safe antiviral vaccine for preventive use. Consequently, we thoroughly investigated the immunoreactivities with patient sera of a series of synthesized peptides from SARS-coronavirus structural proteins.Methods: We synthesized 41 peptides ranging in size from 16 to 25 amino acid residues of relatively high hydrophilicity. The immunoreactivities of the peptides with SARS patient sera were determined by ELISA.Results: Four epitopic sites, S599, M137, N66, and N371-404, located in the SARS-coronavirus S, M, and N proteins, respectively, were detected by screening synthesized peptides. Notably, N371 and N385, located at the COOH terminus of the N protein, inhibited binding of antibodies to SARS-coronavirus lysate and bound to antibodies in &gt;94% of samples from SARS study patients. N385 had the highest affinity for forming peptide-antibody complexes with SARS serum.Conclusions: Five peptides from SARS structural proteins, especially two from the COOH terminus of the N protein, appear to be highly immunogenic and may be useful for serologic assays. The identification of these antigenic peptides contributes to the understanding of the immunogenicity and persistence of SARS coronavirus.
RETRACTED: Efficacy of Electronic Cigarettes vs Varenicline and Nicotine Chewing Gum as an Aid to Stop Smoking
Authors: Lin Hao-Xiang , Liu Zhao , Hajek Peter , Zhang Wan-Tong , Wu Yuan , Zhu Bao-Chen , Liu Hai-Hua , Xiang Qiu , Zhang Yan , Li Shu-Bin , Pesola Francesca , Wang Ying-Ying 
Published: January 2024

ImportanceElectronic cigarettes (ECs) are often used by smokers as an aid to stopping smoking, but evidence is limited regarding their efficacy compared with nicotine replacement therapy (NRT), and no evidence is available on how their efficacy compares with that of varenicline.ObjectiveTo evaluate whether ECs are superior to NRT and noninferior to varenicline in helping smokers quit.Design, Setting, and ParticipantsThis was a randomized clinical trial conducted at 7 sites in China and including participants who were smoking at least 10 cigarettes per day and motivated to quit, not using stop-smoking medications or EC, and willing to use any of the study products. Participants were first recruited in May 2021, and data analysis was conducted in December 2022.InterventionsA cartridge-based EC (30 mg/mL nicotine salt for 2 weeks and 50 mg/mL after that), varenicline (0.5 mg, once a day for 3 days; 0.5 mg, twice a day for 4 days; and 1 mg, twice a day, after that), and 2 mg (for smokers of ≤20 cigarettes per day) or 4 mg (&amp;gt;20 cigarettes per day) nicotine chewing gum, all provided for 12 weeks and accompanied by minimal behavioral support (an invitation to join a self-help internet forum).Main Outcomes and MeasuresThe primary outcome was sustained abstinence from smoking at 6 months as validated by an expired-air carbon monoxide reading (&amp;lt;8 parts per million). Participants lost to follow-up were included as nonabstainers.ResultsOf 1068 participants, 357 (33.5%) were female, and the mean (SD) age was 33.9 (3.1) years. A total of 409 (38.3%), 409 (38.3%), and 250 (23.4%) participants were randomized to the EC, varenicline, and NRT arms, respectively. The 6-month biochemically validated abstinence rates were 15.7% (n = 64), 14.2% (n = 58), and 8.8% (n = 22) in the EC, varenicline, and NRT study arms, respectively. The quit rate in the EC arm was noninferior to the varenicline arm (absolute risk reduction, 1.47%; 95% CI, −1.41% to 4.34%) and higher than in the NRT arm (odds ratio, 1.92; 95% CI, 1.15-3.21). Treatment adherence was similar in all study arms during the initial 3 months, but 257 participants (62.8%) in the EC arm were still using ECs at 6 months, with no further use in the 2 other study arms. The most common adverse reactions were throat irritation (32 [7.8%]) and mouth irritation (28 [6.9%]) in the EC arm, nausea (36 [8.8%]) in the varenicline arm, and throat irritation (20 [8.0%]) and mouth irritation (22 [8.8%]) in the NRT arm. No serious adverse events were recorded.Conclusions and RelevanceThe results of this randomized clinical trial found that when all treatments were provided with minimal behavior support, the efficacy of EC was noninferior to varenicline and superior to nicotine chewing gum.Trial RegistrationChinese Clinical Trial Registry: ChiCTR2100048156
Wealth Redistribution to Extend Longevity in the US
Authors: Himmelstein Kathryn E. W. , Tsai Alexander C. , Venkataramani Atheendar S. 
Published: January 2024

ImportanceThe US is unique among wealthy countries in its degree of wealth inequality and its poor health outcomes. Wealth is known to be positively associated with longevity, but little is known about whether wealth redistribution might extend longevity.ObjectiveTo examine the association between wealth and longevity and estimate the changes in longevity that could occur with simulated wealth distributions that were perfectly equal, similar to that observed in Japan (among the most equitable of Organisation for Economic Co-operation and Development [OECD] countries), generated by minimum inheritance proposals, and produced by baby bonds proposals.Design, Setting, and ParticipantsThis longitudinal cohort study analyzed the association between wealth and survival among participants in the Health and Retirement Study (1992-2018), a nationally representative panel study of middle-aged and older (≥50 years) community-dwelling, noninstitutionalized US adults. The data analysis was performed between November 15, 2022, and September 24, 2023.ExposureHousehold wealth on study entry, calculated as the sum of all assets minus the value of debts and classified into deciles.Main Outcomes and MeasuresWeibull survival models were used to estimate the association between per-person wealth decile and survival, adjusting for age, sex, marital status, household size, and race and ethnicity. Changes in longevity that might occur under alternative wealth distributions were then estimated.ResultsThe sample included 35 164 participants (mean [SE] age at study entry, 59.1 [0.1] years; 50.1% female and 49.9% male [weighted]). The hazard of death generally decreased with increasing wealth, wherein participants in the highest wealth decile had a hazard ratio of 0.59 for death (95% CI, 0.53-0.66) compared with those in the lowest decile, corresponding to a 13.5-year difference in survival. A simulated wealth distribution of perfect equality would increase populationwide median longevity by 2.2 years (95% CI, 2.2-2.3 years), fully closing the mortality gap between the US and the OECD average. A simulated minimum inheritance proposal would increase populationwide median longevity by 1.7 years; a simulated wealth distribution similar to Japan’s would increase populationwide median longevity by 1.2 years; and a simulated baby bonds proposal would increase populationwide median longevity by 1.0 year.Conclusions and RelevanceThese findings suggest that wealth inequality in the US is associated with significant inequities in survival. Wealth redistribution policies may substantially reduce those inequities and increase population longevity.