bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficacy of Oral, Topical, or Combined Oral and Topical 5-Aminosalicylates, in Ulcerative Colitis: Systematic Review and Network Meta-analysis
Authors: Barberio Brigida , Segal Jonathan P , Quraishi M Nabil , Black Christopher J , Savarino Edoardo V , Ford Alexander C 
Published: January 2021

Abstract

Background
5-Aminosalicylates [5-ASAs] are the mainstay of treatment for ulcerative colitis [UC]. The optimum preparation, dose, and route of administration for UC remain unclear. We conducted a network meta-analysis to examine this issue.

Methods
We searched MEDLINE, EMBASE, EMBASE Classic, and the Cochrane central register of controlled trials from inception to December 2020. We included randomised controlled trials [RCTs] comparing oral, topical, or combined oral and topical 5-ASAs, with each other or placebo for induction of remission or prevention of relapse of UC. Results were reported as pooled relative risks [RRs] with 95% confidence intervals [CIs] to summarise effect of each comparison tested, with treatments ranked according to P-score.

Results
We identified 40 RCTs for induction of remission and 23 for prevention of relapse. Topical mesalazine [P-score 0.99], or oral and topical mesalazine combined [P-score 0.87] ranked first and second for clinical and endoscopic remission combined. Combined therapy ranked first in trials where ≥50% of patients had left-sided/extensive disease, and topical mesalazine first in trials where ≥50% of patients had proctitis/proctosigmoiditis. High-dose [≥3.3 g/day] oral mesalazine ranked third in most analyses, with the most trials and most patients. For relapse of disease activity, combined therapy and high-dose oral mesalazine ranked first and second, with topical mesalazine third. 5-ASAs were safe and well tolerated, regardless of regimen.

Conclusions
Our results support previous evidence; however, higher doses of oral mesalazine had more evidence for induction of remission than combined therapy and were significantly more efficacious than lower doses. Future RCTs should better establish the role of combined therapy for induction of remission, as well as optimal doses of oral 5-ASAs to prevent relapse.
Bloody tricuspid stenosis: case report of an uncommon cause of haemoptysis
Authors: Trombara Filippo , Bergonti Marco , Toscano Olga , Dalla Cia Alessia , Assanelli Emilio M , Polvani Gianluca , Bartorelli Antonio L 
Published: January 2021

Abstract

Background
Haemoptysis is usually caused by pulmonary and infectious diseases. In few cases, it has a cardiac cause, such as pulmonary embolism or mitral valve stenosis. Haemoptysis may be an uncommon symptom of prosthetic valve dysfunction, being related to elevated right heart pressures.

Case summary
A 22-year-old woman from sub-Saharan Africa known for a triple valve replacement was hospitalized for dyspnoea and haemoptysis. A careful clinical evaluation excluded the most common causes of haemoptysis. Transthoracic echocardiogram showed normal biventricular function, normally functioning mechanical prosthetic aortic and mitral valves, and the biological tricuspid prosthesis showed an increased transvalvular gradient. Contrast chest computed tomography scan excluded pulmonary embolism and mechanical valve obstruction, but revealed marked systemic venous hypertension. Right heart catheterization confirmed increased right heart pressures and severe bioprosthetic tricuspid valve stenosis. The patient underwent a successful percutaneous tricuspid valve-in-valve replacement, with complete resolution of symptoms.

Discussion
The increase in venous pressures due to bioprosthetic tricuspid stenosis caused veno-venous shunts: blood from the lower body was drained into the superior vena cava via the azygos vein. Increased pressure in the latter affected pressure in bronchial veins and arteries, leading to haemoptysis. Cardiac surgical reinterventions are associated with worse outcomes and higher mortality rates. Management of a degenerated prosthetic tricuspid valve is challenging and requires a multidisciplinary assessment. Transcatheter tricuspid valve replacement is becoming a feasible option in patients with prosthetic dysfunction. Based on evidence to date, tricuspid valve-in-valve replacement appears to be a safe, feasible, and effective alternative in selected young patients.
Artificial intelligence-assisted auscultation in detecting congenital heart disease
Authors: Lv Jingjing , Dong Bin , Lei Hao , Shi Guocheng , Wang Hansong , Zhu Fang , Wen Chen , Zhang Qian , Fu Lijun , Gu Xiaorong , Yuan Jiajun , Guan Yongmei , Xia Yuxian , Zhao Liebin , Chen Huiwen 
Published: January 2021

Abstract

Aims
Computer-assisted auscultation has become available to assist clinicians with physical examinations to detect congenital heart disease (CHD). However, its accuracy and effectiveness remain to be evaluated. This study seeks to evaluate the accuracy of auscultations of abnormal heart sounds of an artificial intelligence-assisted auscultation (AI-AA) platform we create.

Methods and results
Initially, 1397 patients with CHD were enrolled in the study. The samples of their heart sounds were recorded and uploaded to the platform using a digital stethoscope. By the platform, both remote auscultation by a team of experienced cardiologists from Shanghai Children’s Medical Center and automatic auscultation of the heart sound samples were conducted. Samples of 35 patients were deemed unsuitable for the analysis; therefore, the remaining samples from 1362 patients (mean age—2.4 ± 3.1 years and 46% female) were analysed. Sensitivity, specificity, and accuracy were calculated for remote auscultation compared to experts’ face-to-face auscultation and for artificial intelligence automatic auscultation compared to experts’ face-to-face auscultation. Kappa coefficients were measured. Compared to face-to-face auscultation, remote auscultation detected abnormal heart sound with 98% sensitivity, 91% specificity, 97% accuracy, and kappa coefficient 0.87. AI-AA demonstrated 97% sensitivity, 89% specificity, 96% accuracy, and kappa coefficient 0.84.

Conclusions
The remote auscultations and automatic auscultations, using the AI-AA platform, reported high auscultation accuracy in detecting abnormal heart sound and showed excellent concordance to experts’ face-to-face auscultation. Hence, the platform may provide a feasible way to screen and detect CHD.
Acute safety, efficacy, and advantages of a novel cryoballoon ablation system for pulmonary vein isolation in patients with paroxysmal atrial fibrillation: initial clinical experience
Authors: Anic Ante , Lever Nigel , Martin Andrew , Breskovic Toni , Sulkin Matthew S , Duffy Elizabeth , Saliba Walid I , Niebauer Mark J , Wazni Oussama M , Varma Niraj 
Published: January 2021

Abstract

Aims
Cryoballoon pulmonary vein isolation (PVI) is a safe and effective treatment for atrial fibrillation (AF). Current limitations include incomplete vein occlusion due to balloon rigidity and inconsistent electrogram recording, which impairs identification of isolation. We aimed to evaluate the acute safety and performance of a novel cryoballoon system.

Methods and results
The system includes a steerable sheath, mapping catheter, and a balloon that maintains uniform inflation pressure and size following initiation of ablation. Protocol-directed cryoablation was delivered for 180 s for isolation documented in ≤60 s, otherwise freeze duration was 240 s. Primary endpoints were acute safety and vein isolation. Pulmonary vein isolation was confirmed at ≥30 min post-isolation. Data were compared across vein locations. Thirty patients with paroxysmal AF were enrolled at two centres and underwent PVI. Pulmonary vein isolation was achieved with cryoablation only in 100% of veins (120/120). Nadir temperature was −53.1 ± 5.3°C. The number of applications to achieve PVI was 1.4 ± 0.4 per vein. Of the 120 veins, 89 were isolated with a single cryothermal application (10/30 patients required only 4 total cryoablations). There were no procedural- or device-related serious adverse events at 30 days post-procedure. A subset (24/30) of patients was followed for 1-year and 71% (17/24) remained free of atrial arrhythmias. Six patients with arrhythmia recurrence were remapped and three had durable PVI for all four veins.

Conclusion
In this first human experience, the novel cryoballoon platform was safe, efficacious, and demonstrated a high proportion of successful single ablation isolation.
Genome-wide mapping of Piwi association with specific loci inDrosophilaovaries
Authors: Liu Na , Neuenkirchen Nils , Zhong Mei , Lin Haifan 
Published: January 2021

AbstractSmall noncoding RNA pathways have been implicated in diverse mechanisms of gene regulation. In Drosophila ovaries, Piwi binds to Piwi-interacting RNAs (piRNAs) of mostly 24–28 nucleotides (nt) and plays an important role in germline stem cell maintenance, transposon repression, and epigenetic regulation. To understand the mechanism underlying these functions, we report the application of the DamID-seq method to identify genome-wide binding sites of Piwi in Drosophila ovaries. Piwi localizes to at least 4535 euchromatic regions that are enriched with piRNA target sites. Surprisingly, the density of Piwi binding to euchromatin is much higher than in heterochromatin. Disrupting the piRNA binding of Piwi results in an overall change of the genomic binding profile, which indicates the role of piRNAs in directing Piwi to specific genomic sites. Most Piwi binding sites were either within or in the vicinity of protein-coding genes, particularly enriched near the transcriptional start and termination sites. The methylation signal near the transcriptional termination sites is significantly reduced when Piwi was mutated to become defective in piRNA binding. These observations indicate that Piwi might directly regulate the expression of many protein-coding genes, especially through regulating the 3' ends of targeted transcripts.
THYMIDYLATE SYNTHETASE IN MUTANTS OF DROSOPHILA MELANOGASTER
Authors: Carpenter Nancy J 
Published: January 2021

ABSTRACT
Thymidylate synthetase has been examined with respect to the normal pattern of activity throughout the development of the Oregon-R strain of Drosophila melanogaster. Large amounts of the enzyme are present in both the unfertilized and the fertilized eggs. A comparison of the ovarian thymidylate synthetase activity of the Oregon-R strain and the female sterility mutants, fs(2)B, fu, and fs(1)N, indicates variations in the activity of this enzyme in each strain. At four days of age, the ovarian-specific activity of the female sterility mutants is comparable to or less than that of the Oregon-R strain, but it is reduced at fifteen days of age. The enzyme activity per ovary is low in the fs(2)B strain but is similar in the Oregon-R, fu, and fs(1)N strains. When expressed as activity per organism, thymidylate synthetase declines after six to eight hours of development until the minimal level is reached in the late embryonic stage. Enzyme activity rises throughout the larval instars, reaching a maximum immediately after puparium formation. The activity decreases during pupation, but rises again during the first four days of adult life.
GENE CONVERSION AND TRANSFER OF GENETIC INFORMATION WITHIN THE INVERTED REGION OF INVERSION HETEROZYGOTES
Authors: Chovnick Arthur 
Published: January 2021

ABSTRACT
Prior studies of recombination which monitor exchange events in exceedingly short intervals (i.e., separable sites within a cistron) reveal that the basic event in recombination involves a non-reciprocal transfer of information, termed conversion. As a logical consequence of the model suggested by the work in Drosophila, the present investigation examined recombination between rosy mutant alleles (ry:3-52.0) in Drosophila melanogaster in a paracentric inversion (In(3R)P18) heterozygote, which placed the rosy region approximately at the center of the inverted region. Comparison of the results of this study with experiments carried out in standard chromosome homozygotes reveals a dramatic suppression of classical crossovers between the rosy mutant alleles in the inversion heterozygote. However, conversions continue to occur for all rosy mutant alleles in all heterozygous combinations in the inversion heterozygote. Moreover, the order of magnitude of conversion frequencies seen in the inversion heterozygote does not change from that seen in the standard chromosome homozygote study. The significance of these observations with reference to the role of rearrangements as barriers of information transfer is discussed. Particular attention is directed to the elaborate inversion polymorphisms seen in natural populations, and to notions concerning their role in the evolution of adaptive gene complexes.
SEGMENTAL ANEUPLOIDY AS A PROBE FOR STRUCTURAL GENES IN DROSOPHILA: MITOCHONDRIAL MEMBRANE ENZYMES
Authors: O'Brien Stephen J , Gethmann Richard C 
Published: January 2021

ABSTRACT
A method for detecting possible structural genes in D. melanogaster based on gene dosage dependency is presented. By making thirty crosses between Y-autosome translocations, and an attached-4 cross, it is possible to produce large duplications (approximately 150 salivary gland chromosome bands in length) for every autosomal region with the exception of 83DE. The usefulness of the technique was demonstrated by dosage dependency of three known gene-enzyme systems: α-glycerophosphate dehydrogenase-1, alcohol dehydrogenase and malate dehydrogenase. A screen for genes affecting two enzymes localized on the inner membrane of the mitochondrion, α-glycerophosphate oxidase (αGPO) and succinic dehydrogenase (SHD), produced a dosage-sensitive region in each case. Region 50C-52E affected αGPO activity and region 28D-29F affected SDH activity. The latter region apparently includes the malic dehydrogenase-1 gene. The methodology and limitations of the technique are discussed.
THE CROSSVEINLESS POLYGENES IN AN IOWA POPULATION
Authors: Boyer Bradford J , Parris Deborah L , Milkman Roger 
Published: January 2021

ABSTRACT
A natural population of Drosophila melanogaster was tested for the presence of crossveinless (cve) alleles over the course of a summer. Approximately 8% of the wild-caught females tested carried enough cve alleles to produce true-breeding crossveinless lines. In some cases, different isofemale lines produced identical cve strains. Also, differences were sometimes observed among independently selected cve sublines of a given isofemale line.—The cv-2 allele was found to occur with a frequency of about 1% to 2%.
THE AGE OF A NEUTRAL MUTANT PERSISTING IN A FINITE POPULATION
Authors: Kimura Motoo , Ohta Tomoko 
Published: January 2021

ABSTRACT
Formulae for the mean and the mean square age of a neutral allele which is segregating with frequency x in a population of effective size Ne have been obtained using the diffusion equation method, for the case of 4Nev&lt;1 where v is the mutation rate. It has been shown that the average ages of neutral alleles, even if their frequencies are relatively low, are quite old. For example, a neutral mutant whose current frequency is 10% has the expected age roughly equal to the effective population size Ne and the standard deviation 1.4Ne (in generations), assuming that this mutant has increased by random drift from a very low frequency. Also, formulae for the mean "first arrival time" of a neutral mutant to a certain frequency x have been presented. In addition, a new, approximate method has been developed which enables us to obtain the condition under which frequencies of "rare" polymorphic alleles among local populations are expected to be uniform if the alleles are selectively neutral.—It was concluded that exchange of only a few individuals on the average between adjacent colonies per generation is enough to bring about such a uniformity of frequencies.
LINKAGE DISEQUILIBRIUM IN SUBDIVIDED POPULATIONS
Authors: Nei Masatoshi , Li Wen-Hsiung 
Published: January 2021

ABSTRACT
The linkage disequilibrium in a subdivided populaton is shown to be equal to the sum of the average linkage disequilibrium for all subpopulations and the covariance between gene frequencies of the loci concerned. Thus, in a subdivided population the linkage disequilibrium may not be 0 even if the linkage disequilibrium in each subpopulation is 0. If a population is divided into two subpopulations between which migration occurs, the asymptotic rate of approach to linkage equilibrium is equal to either r or 2(m 1 + m 2) - (m 1 + m 2)2, whichever is smaller, where r is the recombination value and m 1 and m 2 are the proportions of immigrants in subpopulations 1 and 2, respectively. Thus, if migration rate is high compared with recombination value, the change of linkage disequilibrium in subdivided populations is similar to that of a single random mating population. On the other hand, if migration rate is low, the approach to lnkage equilibrium may be retarded in subdivided populations. If isolated populations begin to exchange genes by migration, linkage disequilibrium may increase temporarily even for neutral loci. If overdominant selection operates and the equilibrium gene frequencies are different in the two subpopulations, a permanent linkage disequilibrium may be produced without epistasis in each subpopulation.
REGULATION OF PHOSPHATE METABOLISM IN NEUROSPORA CRASSA. CHARACTERIZATION OF REGULATORY MUTANTS
Authors: Lehman John F , Gleason Mary K , Ahlgren Sandra K , Metzenberg Robert L 
Published: January 2021

ABSTRACT
A mutant of Neurospora crassa, called UW-6, differs from wild type in being partially constitutive for synthesis of a species of alkaline phosphatase, and also for a species of phosphate permease that has a high affinity for phosphate at high pH. UW-6 is possibly allelic with a mutant called nuc-2 that was previously isolated by Ishikawa. nuc-2 has the converse phenotype, in that it cannot be derepressed for either of these two activities. UW-6 is co-dominant with its wild-type allele in heterokaryons and in partial diploids. An unlinked mutant, nuc-1, is like nuc-2 in that it fails to make the alkaline phosphatase or the permease referred to above. nuc-1 is epistatic to UW-6 in the double mutant. The control of phosphorus metabolism is discussed, and is compared with some other control systems in filamentous fungi.
SOMATIC MUTATIONAL TRANSIENTS. III. RESPONSE BY TWO GENES IN A CLONE OF NICOTIANA TO 24 ROENTGENS OF GAMMA RADIATION APPLIED AT VARIOUS INTENSITIES
Authors: Sand Seaward A , Smith Harold H 
Published: January 2021

ABSTRACT
Somatic effects of radiation intensity on the mutable V and stable R genes were detected in plants of a heterozygous clone (vS3/vs, R/r) subjected to the same dose at four rates. The effects were compared by counting speckled and purple sectors in flowers from irradiated and control plants. Response curves were estimated from the mutant sector averages, observed over a period of transient response for successive mature flowers. A structure for integrating the mutational contributions from different flowers was provided by models. The average control mutation rates are 8,110 per 107 cells for the V gene, and 49.45 for R. At a constant intensity of 4320 roentgens/hour, average induced mutation rates per 107 cells per roentgen for V increase from 194 (at 24 r total dose) to 1,116 (at 3 r dose); the corresponding rates for R increase from 7.24 to 27.65. With these responses as standards, both genes at corresponding total doses yield lower rates at lower intensities. For the series of intensities 1.2, 0.6, 0.3 and 0.15 roentgens/hour, the decreases in mutation rate for the V gene are, respectively, 66, 148, 315, and 617 per 107 cells per roentgen. The corresponding decrements for R are 4.86, 8.70, 14.61, and 23.51. These effects are non-linear functions of intensity for both genes, but V is at least 13 times as sensitive as R. Radiation operating to extinguish a buffering system against final mutation can account for the dose and dose-rate effects observed.
THE RELATIONSHIP BETWEEN CHIASMATA AND CROSSING OVER IN TRITICUM AESTIVUM
Authors: Fu T K , Sears E R 
Published: January 2021

ABSTRACT
Telocentrics for the β arm of chromosome 4A and the long arm of 6B were used as cytological markers for the determination of chiasma frequency. In concomitant studies of recombination, terminal segments of rye and T. umbellulatum chromatin carrying Hp (Hairy peduncle) and Lr9 (Leaf-rust resistance), respectively, marked 4A and 6B. Two temperatures, 21° and 32°, were used for both the 4A and 6B experiments.—Only one chiasma was observed in each heteromorphic bivalent. Because there was a substantial reduction in pairing between diakinesis and metaphase I, all determinations of chiasma frequency were made at diakinesis. In the 21° experiments, agreement was good between genetic recombination and cytological prediction on the basis of the partial chiasmatypy hypothesis that each chiasma represents a crossover. At 32° both chiasma frequency and crossing over, but particularly the latter, were strongly reduced. The fewer crossovers than expected are explained in part by stickiness of chromosomes at the high temperature, sometimes resulting in adjacent chromosomes being wrongly scored as having a chiasma, and in part by premetaphase disjunction of some recombined bivalents and subsequent independent behavior of the two resulting univalents.—Male transmission of the 4A telocentric from the heteromorphic bivalent was unusually high: 51% at 21° and 31% at 32°.
CELL CLUSTERING AND PLEIOTROPY IN WHITE-VARIEGATED EYES AND MALPIGHIAN TUBES OF DROSOPHILA HYDEI
Authors: Van Breugel F M A 
Published: January 2021

ABSTRACT
The type of variegation of eyes of white-mottled mutants of D. hydei, either small-spotted or large-spotted, depends on the specific chromosome rearrangement involved. This distinction between mutants, though handsome, is not absolute because very seldomly small-spotted types do show a larger pigment aggregate and some "large-spotted" flies have no large spots at all, but only minor spots. Because of a pleiotropic action of the white gene, we could study the variegation of Malpighian tubules. The quasi-linear array of Malpighian cells enables a thorough statistical analysis. The problem was in how far the variegation of the tubes that is correlated with the variegation of eyes (in as far as numbers of pigmented and unpigmented cells are concerned) is also connected with a cell-lineage type of determination. Statistics now show that in spite of temperature-induced great variation in the percentage of pigmented cells, all types studied show a nearly random distribution of pigmented and unpigmented cells in the Malpighian tubules. This implies that the cell-lineage type of determinatim is not only largely mutant-specific but also organ-specific, i.e., limited to eyes. A basic gradient, however, as characteristic for eyes, was also found in Malpighian tubes.