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Solute carrier family 26 (Slc26) is a family of anion exchangers with 11 members in mammals (named Slc26a1-a11). Here, we identified a novel member of the slc26 family, slc26a12, located in tandem with slc26a2 in the genomes of several vertebrate lineages. BLAST and synteny analyses of various jawed vertebrate genome databases revealed that slc26a12 is present in coelacanths, amphibians, reptiles, and birds but not in cartilaginous fishes, lungfish, mammals, or ray-finned fishes. In some avian and reptilian lineages such as owls, penguins, egrets, and ducks, and most turtles examined, slc26a12 was lost or pseudogenized. Phylogenetic analysis showed that Slc26a12 formed an independent branch with the other Slc26 members and Slc26a12, Slc26a1 and Slc26a2 formed a single branch, suggesting that these three members formed a subfamily in Slc26. In jawless fish, hagfish have two genes homologous to slc26a2 and slc26a12, whereas lamprey has a single gene homologous to slc26a2. African clawed frogs express slc26a12 in larval gills, skin, and fins. These results show that slc26a12 was present at least before the separation of lobe-finned fish and tetrapods; the name slc26a12 is appropriate because the gene duplication occurred in the distant past.
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Evolução Molecular , Filogenia , Transportadores de Sulfato , Animais , Anfíbios/genética , Anfíbios/metabolismo , Aves/genética , Répteis/genética , Transportadores de Sulfato/genética , Transportadores de Sulfato/metabolismoRESUMO
Na+/Cl- cotransporter 2 (Ncc2 or Slc12a10) is a membrane transport protein that belongs to the electroneutral cation-chloride cotransporter family. The Slc12a10 gene (slc12a10) is widely present in bony vertebrates but is deleted or pseudogenized in birds, some bony fishes, and most mammals. Slc12a10 is highly homologous to Ncc (Slc12a3 or Ncc1); however, there are only a few reports measuring the activity of Slc12a10. In this study, we focused on zebrafish Slc12a10.1 (zSlc12a10.1) and analyzed its activity using Xenopus oocyte electrophysiology. Analysis using Na+-selective microelectrodes showed that intracellular sodium activity (aNai) in zSlc12a10.1 oocytes was significantly decreased in Na+- or Cl--free medium and recovered when Na+ or Cl- was readded to the medium. Similar analysis using a Cl--selective microelectrode showed that intracellular chloride activity (aCli) in zSlc12a10.1 oocytes significantly decreased in Na+- or Cl--free medium and recovered when Na+ or Cl- was readded to the medium. When a similar experiment was performed with a voltage clamp, the membrane current did not change when aNai of zSlc12a10.1 oocytes was decreased in Na+-free medium. Molecular phylogenetic and synteny analyses suggest that gene duplication between slc12a10.2 and slc12a10.3 in zebrafish is a relatively recent event, whereas gene duplication between slc12a10.1 and the ancestral gene of slc12a10.2/slc12a10.3 occurred at least about 2 million years ago. slc12a10 deficiency was observed in species belonging to Ictaluridae, Salmoniformes, Osmeriformes, Batrachoididae, Syngnathiformes, Gobiesociformes, Labriformes, and Tetraodontiformes. These results indicate that zebrafish Slc12a10.1 is an electroneutral Na+/Cl-cotransporter and establish its evolutionary position among various teleost slc12a10 paralogs.NEW & NOTEWORTHY Na+/Cl- cotransporter 2 (Slc12a10; Ncc2) is a protein highly homologous to Ncc (Slc12a3; Ncc1); however, there are only a few reports measuring the activity of Slc12a10. Electrophysiological analysis of Xenopus oocytes expressing zebrafish Slc12a10.1 showed that Slc12a10.1 acts as an electroneutral Na+/Cl-cotransporter. This is the third report on the activity of Slc12a10, following previous reports on Slc12a10 in eels.
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Oócitos , Simportadores de Cloreto de Sódio , Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Oócitos/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , Simportadores de Cloreto de Sódio/metabolismo , Simportadores de Cloreto de Sódio/genética , Sódio/metabolismo , Xenopus laevis , Cloretos/metabolismo , Filogenia , Potenciais da Membrana , FemininoRESUMO
Farnesoid X receptor (FXR) regulates bile acid synthesis, lipid metabolism, and glucose homeostasis in metabolic organs. FXR-knockout (FXR-KO) mice lacking the last exon of the FXR gene develop normally and display no prenatal and early postnatal lethality, whereas human patients with mutations in the DNA-binding domain of the FXR gene develop severe hepatic dysfunction. In this study, we generated novel FXR-KO mice lacking the DNA-binding domain of the FXR gene using CRISPR-Cas9 technology and evaluated their phenotypes. Similar to the aforementioned FXR-KO mice, our novel mice showed elevated serum levels of total bile acids and total cholesterol. However, they were obviously short-lived, showing severe liver and renal pathologies at an early age. These results indicate that FXR, including its unknown isoforms, has more significant functions in multiple organs than previously reported. Thus, the novel FXR-KO mice could lead to a new aspect that requires reworking of previous knowledge of FXR in the liver and renal function.
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Fígado , Camundongos Knockout , Receptores Citoplasmáticos e Nucleares , Animais , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Camundongos , Fígado/metabolismo , Fígado/patologia , Rim/metabolismo , Rim/patologia , Camundongos Endogâmicos C57BL , Domínios Proteicos , DNA/metabolismo , DNA/genética , Masculino , Ácidos e Sais Biliares/metabolismo , Nefropatias/genética , Nefropatias/metabolismo , Nefropatias/patologia , Hepatopatias/genética , Hepatopatias/metabolismo , Sistemas CRISPR-CasRESUMO
The regressive evolution of independent lineages often results in convergent phenotypes. Several teleost groups display secondary loss of the stomach, and four gastric genes, atp4a, atp4b, pgc, and pga2 have been co-deleted in agastric (stomachless) fish. Analyses of genotypic convergence among agastric fishes showed that four genes, slc26a9, kcne2, cldn18a, and vsig1, were co-deleted or pseudogenized in most agastric fishes of the four major groups. kcne2 and vsig1 were also deleted or pseudogenized in the agastric monotreme echidna and platypus, respectively. In the stomachs of sticklebacks, these genes are expressed in gastric gland cells or surface epithelial cells. An ohnolog of cldn18 was retained in some agastric teleosts but exhibited an increased non-synonymous substitution when compared with gastric species. These results revealed novel convergent gene losses at multiple loci among the four major groups of agastric fish, as well as a single gene loss in the echidna and platypus.
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Ornitorrinco , Tachyglossidae , Animais , Filogenia , Ornitorrinco/genética , Tachyglossidae/genética , Estômago , Peixes/genéticaRESUMO
In this study, we examined the pharmacokinetics of nifedipine and investigated the maternal and foetal background factors that prolong pregnancy in pregnant women undergoing long-term tocolysis. This prospective observational study included 38 pregnant women hospitalised for threatened preterm labour and treated with nifedipine extended-release tablets in combination with an intravenous ritodrine infusion. Maternal plasma nifedipine concentrations were determined using high-performance liquid chromatography. All patients were administered 20 or 40 mg/dose of nifedipine every 6 h at the time of blood sampling. The plasma trough concentration (Ctrough ) was 22.6 ± 17.3 ng/mL, the maximum plasma concentration (Cmax ) was 30.9 ± 15.3 ng/mL and the time to maximum concentration (Tmax ) was 1.70 ± 1.10 h, as determined using noncompartmental analysis (NCA). The area under the curve for drug concentration (AUCtau ) was 152.3 ± 91.8 mg/Lã»h, and oral clearance (CL/F) was 0.17 ± 0.08 L/h. Using logistic regression analyses, we identified the factors that predicted term delivery from 37 weeks to <42 weeks of gestation. Gestational age at admission and the AUCtau of nifedipine can predict term delivery. The AUCtau of nifedipine is a valuable regulatory predictor of term delivery in pregnant women undergoing long-term tocolysis.
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Trabalho de Parto Prematuro , Ritodrina , Tocolíticos , Feminino , Humanos , Recém-Nascido , Gravidez , Nifedipino , Trabalho de Parto Prematuro/tratamento farmacológico , Trabalho de Parto Prematuro/prevenção & controle , Ritodrina/uso terapêutico , Tocólise/métodos , Tocolíticos/efeitos adversos , Estudos ProspectivosRESUMO
Solute carrier 12 (Slc12) is a family of electroneutral cation-coupled chloride (Cl-) cotransporters. Na+/K+/2Cl- (Nkcc) and Na+/Cl- cotransporters (Ncc) belong to the Nkcc/Ncc subfamily. Human and mouse possess one gene for the Na+/Cl- cotransporter (ncc gene: slc12a3), whereas teleost fishes possess multiple ncc genes, slc12a3 (ncc1) and slc12a10 (ncc2), in addition to their species-specific paralogs. Amphibians and squamates have two ncc genes: slc12a3 (ncc1) and ncc3. However, the evolutionary relationship between slc12a10 and ncc3 remains unresolved, and the presence of slc12a10 (ncc2) in mammals has not been clarified. Synteny and phylogenetic analyses of vertebrate genome databases showed that ncc3 is the ortholog of slc12a10, and slc12a10 is present in most ray-finned fishes, coelacanths, amphibians, reptiles, and a few mammals (e.g., platypus and horse) but pseudogenized or deleted in birds, most mammals, and some ray-finned fishes (pufferfishes). This shows that slc12a10 is widely present among bony vertebrates and pseudogenized or deleted independently in multiple lineages. Notably, as compared with some fish that show varied slc12a10 tissue expression profile, spotted gar, African clawed frog, red-eared slider turtle, and horse express slc12a10 in the ovaries or premature gonads. In horse tissues, an unexpectedly large number of splicing variants for Slc12a10 have been cloned, many of which encode truncated forms of Slc12a10, suggesting that the functional constraints of horse slc12a10 are weakened, which may be in the process of becoming a pseudogene. Our results elaborate on the evolution of Nkcc/Ncc subfamily of Slc12 in vertebrates.NEW & NOTEWORTHY slc12a10 is not a fish-specific gene and is present in a few mammals (e.g., platypus and horse), non-avian reptiles, amphibians, but was pseudogenized or deleted in most mammals (e.g., human, mouse, cat, cow, and rhinoceros), birds, and some ray-finned fishes (pufferfishes).
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Ornitorrinco , Feminino , Bovinos , Animais , Humanos , Cavalos , Camundongos , Membro 3 da Família 12 de Carreador de Soluto , Filogenia , Peixes/genética , Répteis/genética , Aves , Anfíbios/genéticaRESUMO
The application of proton transfer ionization reaction mass spectrometry (PTR MS) combined with microscale supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) aiming to quantitate single-cell fatty acid analysis levels was investigated. Using a microscale extraction vessel, the obtained low limits of quantitation (LLOQs) of arachidonic acid and arachidic acid were 1.2 and 2.7 fmol, respectively, by using less than 1 µL of sample on stainless steel frit. A series of phthalate, vitamin K1, and α-tocopherol were also tested, and the LLOQ was less than one femtomole for phthalate and 35 and 13 fmol for vitamin K1 and α-tocopherol, respectively. A microliter portion of SFE extracts was introduced into the SFC column by split injection, improving the reproducibility of the chromatography and separation efficiency. The method in the present study has great potential to quantitate lipophilic molecules on the nanogram scale of a sample without complex preparation procedures.
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Cromatografia com Fluido Supercrítico , Ácido Araquidônico , Cromatografia com Fluido Supercrítico/métodos , Espectrometria de Massas , Ácidos Ftálicos , Extratos Vegetais/química , Prótons , Reprodutibilidade dos Testes , Aço Inoxidável , Vitamina K , alfa-TocoferolRESUMO
Proton-transfer-reaction (PTR) mass spectrometry (MS), a widely used method for detecting trace-levels of volatile organic compounds in gaseous samples, can also be used for the analysis of small non-volatile molecules by using supercritical fluid as a transporter for the molecules. Supercritical fluid extraction (SFE) is a method that permits lipophilic compounds to be rapidly and selectively extracted from complex matrices. The combination of the high sensitivity of PTR MS with the SFE is a potentially novel method for analyzing small molecules in a single cell, particularly for the analysis of lipophilic compounds. We preliminarily evaluated this method for analyzing the components of a single HeLa cell that is fixed on a stainless steel frit and is then directly introduces the SFE extracts into the PTR MS. A total of 200/91 ions were observed in positive/negative ion mode time-of-flight mass spectra, and the masses of 11/10 ions could be matched to chemical formulae obtained from the LipidMaps lipids structure database. Using various authentic lipophilic samples, the method could be used to detect free fatty acids in the sub-femtomole to femtomole order in the negative ion mode, the femtomole to sub-picomole order for fat-soluble vitamins, and the picomole order for poly aromatic hydrocarbons in both the positive and negative ion mode.
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We have developed a rapid and sensitive analytical method for α-tocopherol and its oxidative products by combining online hyphenation of supercritical fluid extraction-supercritical fluid chromatography (SFC) with proton transfer reaction (PTR) ionization mass spectrometry (MS). α-Tocopherol is a well-known antioxidant that plays a vital role in the antioxidant defense system in plant cells. However, studies on the cellular mechanisms of α-tocopherol have been limited owing to the lack of a rapid analytical method, which limits the comparison of plant cells incubated in various conditions. Additionally, complex sample preparation and long chromatography separation times are required. Moreover, the majority of the involved molecules are a combination of isomers, which must be separated before applying tandem MS. α-Tocopherol produces the α-tocopheroxyl radical in the first step of its antioxidant function; another ion with the same mass may also be generated from the source. SFC separation effectively distinguished the observed ions from their oxidative products in the sample and those produced during the ionization reaction process. This method enabled the measurement of α-tocopherol and its oxidative products such as α-tocopheroxyl radical and α-tocopheryl quinone in approximately 3 min per sample, including the time required for sample preparation.
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BACKGROUND: Recent advancements in a 3-dimensional mapping system allow for the assessment of detailed conduction properties during sinus rhythm and thus the establishment of a strategy targeting functionally abnormal regions in scar-related ventricular tachycardia (VT). We hypothesized that a rotational activation pattern (RAP) observed in maps during baseline rhythm was associated with the critical location of VT. METHODS: We retrospectively examined the pattern of wavefront propagation during sinus rhythm in patients with scar-related VT. The prevalence and features of the RAP on critical VT circuits were analyzed. RAP was defined as >90° of inward curvature directly above or at the edge of the slow conductive areas. RESULTS: Forty-five VTs in 37 patients (66±15 years old, 89% male, 27% ischemic heart disease) were evaluated. High-density substrate mapping during sinus rhythm (median, 2524 points) was performed using the CARTO3 system before VT induction. Critical sites for reentry were identified by direct termination by radiofrequency catheter ablation in 21 VTs or by pace mapping in 12 VTs. Among them, RAP was present in 70% of the 33 VTs. Four VTs had no RAP at the critical sites during sinus rhythm, but it became visible in the mappings with different wavefront directions. Six VTs, in which intramural or epicardial isthmus was suspected, were rendered noninducible by radiofrequency catheter ablation to the endocardial surface without RAP. RAP had a sensitivity and specificity of 70% and 89%, respectively, for predicting the elements in the critical zone for VT. CONCLUSIONS: The critical zone of VT appears to correspond to an area characterized by the RAP with slow conduction during sinus rhythm, which facilitates targeting areas specific for reentry. However, this may not be applicable to intramural VT substrates and might be affected by the direction of wavefront propagation to the scar during mapping. Graphic Abstract: A graphic abstract is available for this article.
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Potenciais de Ação , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Frequência Cardíaca , Ventrículos do Coração/cirurgia , Taquicardia Ventricular/cirurgia , Remodelação Ventricular , Idoso , Idoso de 80 Anos ou mais , Ablação por Cateter/efeitos adversos , Feminino , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Taquicardia Ventricular/patologia , Taquicardia Ventricular/fisiopatologia , Resultado do TratamentoRESUMO
Radiofrequency catheter ablation (RFCA) is the primary choice for treating patients with an accessory pathway and atrioventricular re-entrant tachycardia. However, using RFCA to treat a right-sided accessory pathway in a patient with Ebstein anomaly can be difficult owing to challenges in locating the electrophysiological atrioventricular groove. We report a case of atrioventricular re-entrant tachycardia in a patient with Ebstein anomaly and a right-sided accessory pathway that was successfully treated using RFCA and 3-dimensional (3D) high-density mapping. RFCA and 3D mapping may be useful in the management of such cases and may aid in improving prognoses of patients.
L'ablation par radiofréquence (ARF) est le premier choix de traitement chez les patients qui ont une voie accessoire et une tachycardie atrioventriculaire par réentrée. Toutefois, l'utilisation de l'ARF pour traiter une voie accessoire du côté droit d'un patient qui a une anomalie d'Ebstein peut être difficile en raison des défis de la loca-lisation du sillon atrioventriculaire à l'exploration électrophysiologique. Nous rapportons un cas de tachycardie atrioventriculaire par réentrée chez un patient qui a une anomalie d'Ebstein et une voie accessoire du côté droit, dont le traitement au moyen de l'ARF et de la cartographie tridimensionnelle (3D) haute définition a connu une réussite. L'ARF et la cartographie 3D peuvent être utiles dans la prise en charge de ces cas et aider à améliorer le pronostic des patients.
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Proton-transfer-reaction (PTR) mass spectrometry (MS) is capable of detecting trace-level volatile organic compounds (VOCs) in gaseous samples in real time. Therefore, PTR-MS has become a popular method in many different study areas. Most of the currently reported PTR-MS applications are designed to determine volatile compounds. However, the method might be applicable for nonvolatile organic compound detection. Supercritical fluid chromatography (SFC) has been studied in the last 5 decades. This approach has high separation efficiency and predictable retention behavior, making separation optimization easy. Atmospheric ionization techniques, such as atmospheric chemical ionization (APCI) and electrospray ionization (ESI), are the most studied SFC-MS interfaces. These processes require the addition of makeup solvents to prevent precipitation or crystallization of the solute while depressurizing the mobile phase. In contrast, the PTR process is carried out in a vacuum; supercritical carbon dioxide may release solute into the PTR flow tube without a phase transition as long as it is maintained above a critical temperature. Therefore, this might constitute yet another use for the SFC-MS interface. Caffeine and a few other nonpolar compounds in supercritical carbon dioxide were successfully detected with time-of-flight MS without adding solvent by using preliminarily assembled supercritical flow injection and supercritical fluid extraction (SFE)-PTR interfaces.
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Cromatografia com Fluido Supercrítico , Prótons , Dióxido de Carbono , Espectrometria de Massas , SolventesRESUMO
Background: The existence of atypical fast-slow (F/S) atrioventricular (AV) nodal reentrant tachycardias (NRT) using slow pathway (SP) variants connected to the right atrial (RA) inferolateral (inf) free wall (FW) along the tricuspid annulus (TA), has been neither confirmed nor precisely characterized. MethodsâandâResults: We studied 7 patients (mean age, 48±16 years; 5 men) with F/S-AVNRT with long RP intervals and an earliest atrial activation at the RA inf-FW along the TA (inf-F/S-AVNRT). AV reentrant tachycardia was excluded on observation of the transition zone criteria in all 7 patients. Atrial tachycardia was excluded on the observation of a V-A-V activation sequence after the induction or entrainment of the tachycardia from the right ventricle in all. During the tachycardia, low-frequency, fractionated potentials (LP) preceding the local atrial electrogram were recorded near the site of the earliest atrial activation in 6 patients. Observations of conduction delay and block of the LP during ventricular entrainment or ablation of the tachycardia indicated that LP reflect retrograde activation via the inf-SP. Retrograde SP conduction was interrupted at the site of earliest atrial activation in 3 patients, and in the right posterior septum in 4 patients. Conclusions: inf-F/S-AVNRT are distinct supraventricular tachycardia incorporating an SP variant connected to the RA inf-FW along the TA in the retrograde direction, which were eliminated by ablation.
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OBJECTIVES: To characterise the tackler's head position during one-on-one tackling in rugby and to determine the incidence of head, neck and shoulder injuries through analysis of game videos, injury records and a questionnaire completed by the tacklers themselves. METHODS: We randomly selected 28 game videos featuring two university teams in competitions held in 2015 and 2016. Tackles were categorised according to tackler's head position. The 'pre-contact phase' was defined; its duration and the number of steps taken by the ball carrier prior to a tackle were evaluated. RESULTS: In total, 3970 tackles, including 317 (8.0%) with the tackler's head incorrectly positioned (ie, in front of the ball carrier) were examined. Thirty-two head, neck or shoulder injuries occurred for an injury incidence of 0.8% (32/3970). The incidence of injury in tackles with incorrect head positioning was 69.4/1000 tackles; the injury incidence with correct head positioning (ie, behind or to one side of the ball carrier) was 2.7/1000 tackles. Concussions, neck injuries, 'stingers' and nasal fractures occurred significantly more often during tackles with incorrect head positioning than during tackles with correct head positioning. Significantly fewer steps were taken before tackles with incorrect head positioning that resulted in injury than before tackles that did not result in injury. CONCLUSION: Tackling with incorrect head position relative to the ball carrier resulted in a significantly higher incidence of concussions, neck injuries, stingers and nasal fractures than tackling with correct head position. Tackles with shorter duration and distance before contact resulted in more injuries.
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Traumatismos em Atletas/etiologia , Futebol Americano/lesões , Cabeça , Postura , Adolescente , Traumatismos Craniocerebrais/etiologia , Estudos Transversais , Humanos , Incidência , Masculino , Lesões do Pescoço/etiologia , Lesões do Ombro/etiologia , Adulto JovemRESUMO
AIMS: Radiofrequency catheter ablation (RFCA) has become widely used for drug-refractory atrial fibrillation (AF). However, there is a paucity of data on the long-term clinical outcomes after RFCA for AF. The aim of the present study was to investigate the very long-term outcomes after RFCA for AF in a large number of consecutive patients. METHODS AND RESULTS: In this retrospective single-center study, we evaluated very long-term follow-up results in 1206 consecutive patients undergoing first RFCA for AF. The primary outcomes were adverse outcomes at 30-day as a safety outcome measure and event-free rates from recurrent atrial tachyarrhythmias as efficacy outcome measures. Final follow-up rate reached 99.3% with a mean follow-up duration of 5.0±2.5years. The incidence of overall 30-day adverse outcomes was 3.6% without death. The 10-year event-free rates from recurrent atrial tachyarrhythmias after the initial and last procedures were 46.9% and 76.4%, respectively. Arrhythmia recurrence occurred most commonly during the first year and decreased beyond 3-year, although it continued to occur at an annual rate of 2.0% and 1.3%, respectively, throughout the 10-year follow-up period. The cumulative 10-year incidences of stroke and major bleeding were 4.2% and 3.5%, respectively, with annual rates of 0.3%. Discontinuation rate of oral anticoagulation at 1-, 3-, and 10-year was 34.6%, 53.4%, 58.0% and 61.9%. CONCLUSIONS: RFCA for AF provided favorable very long-term arrhythmia-free survival without much safety concerns. The 10-year rates of stroke and major bleeding were low even with discontinuation of oral anticoagulation in a large proportion of patients.
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Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Ablação por Cateter/tendências , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/mortalidade , Ablação por Cateter/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Characteristics of rugby tackles that lead to primary anterior shoulder dislocation remain unclear. PURPOSE: To clarify the characteristics of tackling that lead to shoulder dislocation and to assess the correlation between the mechanism of injury and morphological damage of the glenoid. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Eleven elite rugby players who sustained primary anterior shoulder dislocation due to one-on-one tackling between 2001 and 2014 were included. Using an assessment system, the tackler's movement, posture, and shoulder and head position were evaluated in each phase of tackling. Based on 3-dimensional computed tomography, the glenoid of the affected shoulder was classified into 3 types: intact, erosion, and bone defect. Orientation of the glenoid defect and presence of Hill-Sachs lesion were also evaluated. RESULTS: Eleven tackles that led to primary shoulder dislocation were divided into hand, arm, and shoulder tackle types based on the site at which the tackler contacted the ball carrier initially. In hand and arm tackles, the tackler's shoulder joint was forcibly moved to horizontal abduction by the impact of his upper limb, which appeared to result from an inappropriate approach to the ball carrier. In shoulder tackles, the tackler's head was lowered and was in front of the ball carrier at impact. There was no significant correlation between tackle types and the characteristics of bony lesions of the shoulder. CONCLUSION: Although the precise mechanism of primary anterior shoulder dislocation could not be estimated from this single-view analysis, failure of individual tackling leading to injury is not uniform and can be caused by 2 main factors: failure of approach followed by an extended arm position or inappropriate posture of the tackler at impact, such as a lowered head in front of the opponent. These findings indicate that injury mechanisms should be assessed for each type of tackle, as it is unknown whether external force to the glenoid is different in each mechanism during shoulder dislocation.
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BACKGROUND: A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. PURPOSE: To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. STUDY DESIGN: Descriptive epidemiology study. METHODS: A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. RESULTS: The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. CONCLUSION: Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for injuries and for lasting symptoms. This information may be useful for planning the proper treatment for stingers in young rugby players.
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Traumatismos em Atletas/epidemiologia , Futebol Americano/lesões , Traumatismos dos Nervos Periféricos/epidemiologia , Adolescente , Plexo Braquial/lesões , Estudos de Coortes , Humanos , Incidência , Masculino , Prevalência , Estudos Prospectivos , Fatores de Risco , Instituições Acadêmicas , Universidades , Extremidade Superior/lesões , Adulto JovemRESUMO
Brown spot is a devastating rice disease. Quantitative resistance has been observed in local varieties (e.g., 'Tadukan'), but no economically useful resistant variety has been bred. Using quantitative trait locus (QTL) analysis of recombinant inbred lines (RILs) from 'Tadukan' (resistant) × 'Hinohikari' (susceptible), we previously found three QTLs (qBS2, qBS9, and qBS11) that conferred resistance in seedlings in a greenhouse. To confirm their effect, the parents and later generations of RILs were transplanted into paddy fields where brown spot severely occurred. Three new resistance QTLs (qBSfR1, qBSfR4, and qBSfR11) were detected on chromosomes 1, 4, and 11, respectively. The 'Tadukan' alleles at qBSfR1 and qBSfR11 and the 'Hinohikari' allele at qBSfR4 increased resistance. The major QTL qBSfR11 coincided with qBS11 from the previous study, whereas qBSfR1 and qBSfR4 were new but neither qBS2 nor qBS9 were detected. To verify the qBSfR1 and qBSfR11 'Tadukan' resistance alleles, near-isogenic lines (NILs) with one or both QTLs in a susceptible background ('Koshihikari') were evaluated under field conditions. NILs with qBSfR11 acquired significant field resistance; those with qBSfR1 did not. This confirms the effectiveness of qBSfR11. Genetic markers flanking qBSfR11 will be powerful tools for marker-assisted selection to improve brown spot resistance.
RESUMO
BACKGROUND: The incidence of reinjuries due to glenohumeral instability and the major risk factors for primary anterior shoulder dislocation in youth rugby players have been unclear. PURPOSE: The purpose of this study was to investigate the incidence, mechanisms, and intrinsic risk factors of shoulder dislocation in elite high-school rugby union teams during the 2012 season. METHODS: A total of 378 male rugby players from 7 high-school teams were investigated by use of self-administered preseason and postseason questionnaires. RESULTS: The prevalence of a history of shoulder dislocation was 14.8%, and there were 21 events of primary shoulder dislocation of the 74 overall shoulder injuries that were sustained during the season (3.2 events per 1000 player-hours of match exposure). During the season, 54.3% of the shoulders with at least one episode of shoulder dislocation had reinjury. This study also indicated that the persistence of glenohumeral instability might affect the player's self-assessed condition, regardless of the incidence during the current season. By a multivariate logistic regression method, a history of shoulder dislocation on the opposite side before the season was found to be a risk factor for contralateral primary shoulder dislocation (odds ratio, 3.56; 95% confidence interval, 1.27-9.97; P = .02). CONCLUSIONS: High-school rugby players with a history of shoulder dislocation are not playing at full capacity and also have a significant rate of reinjury as well as a high risk of dislocating the other shoulder. These findings may be helpful in deciding on the proper treatment of primary anterior shoulder dislocation in young rugby players.