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1.
J Vet Emerg Crit Care (San Antonio) ; 31(5): 629-637, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34330152

RESUMO

OBJECTIVE: To examine the relationship between after-hours (ie, nights and weekends) emergency general surgery and morbidity or mortality in dogs and cats during hospitalization. DESIGN: Cross-sectional study from September 1, 2013 to May 31, 2017. SETTING: University teaching hospital. ANIMALS: Four hundred seventy-four dogs and 66 cats that underwent emergency general surgery (gastrointestinal, hepatobiliary, urogenital, soft tissue traumatic injury, splenectomy/excision of bleeding abdominal tumor, surgical revision, and negative exploratory categories) with the emergency surgery service. All patients were required to have complete medical records. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Study animals were grouped as exposed or not exposed to after-hours emergency surgery. They were further classified as either postoperatively dead or suffering morbidity (yes or no). Additional exposure factors (eg, age, sex, American Society of Anesthesiology [ASA] status) were investigated. Multivariable logistic regression was used to identify and quantify any associations with mortality or morbidity. In dogs, exposure to after-hours emergency general surgery was not associated with mortality or morbidity. In dogs, both mortality and morbidity were associated with ASA status. In cats, mortality was not examined because the number of dead cats was small (n = 5). The odds of morbidity were 3.4 times lower (1/0.29) in cats having emergency surgery after hours, compared to cats admitted during regular hours (odds ratio [OR], 0.29; 95% Confidence Interval (CI), 0.09-0.93; P = 0.03). No other investigated exposure factors were associated with morbidity in study cats. CONCLUSIONS: After-hours emergency surgery in dogs was not associated with increased risk of mortality and morbidity at the study facility. Feline patients having emergency surgery during regular hospital hours had a higher risk of morbidity; further investigation of modifiable risk factors is warranted.


Assuntos
Doenças do Gato , Doenças do Cão , Animais , Doenças do Gato/cirurgia , Gatos , Estudos Transversais , Doenças do Cão/cirurgia , Cães , Hospitalização , Morbidade , Estudos Retrospectivos
2.
Vet Surg ; 49(7): 1406-1411, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32716063

RESUMO

OBJECTIVE: To determine the ability to detect the presence of epithelial remnants after total ear canal ablation (TECA) and lateral bulla osteotomy (LBO) with endoscopy and to identify the most common locations of epithelial remnants after tympanic curettage. STUDY DESIGN: Experimental study. ANIMALS: Five fresh canine cadavers with no gross evidence of middle ear disease. METHODS: Ten TECA-LBO were performed by four surgeons. After tympanic curettage, a 1.9-mm rigid 30° endoscope was inserted into the rostral, caudal, dorsal, ventral, and medial sections of the tympanic cavity. Three observers evaluated otoscopic images for epithelial remnants in each compartment. The median distribution of epithelial remnants was calculated for each section of the tympanic cavity with a three-dimensional tympanic cavity model. RESULTS: Epithelial remnants were identified in at least one of the five areas of the tympanic cavity after each TECA-LBO. The rostral section contained the most epithelial remnants (35.6%), while the medial section contained the least amount (1.8%). CONCLUSION: Use of a 1.9-mm rigid endoscope was an effective method to evaluate all sections of the tympanic cavity after curettage in TECA-LBO. Epithelial remnants were consistently found after TECA-LBO, especially in the rostral compartment. CLINICAL SIGNIFICANCE: Intraoperative endoscopy should be considered to improve removal of epithelium after initial TECA-LBO or revision surgeries.


Assuntos
Técnicas de Ablação/veterinária , Doenças do Cão/cirurgia , Meato Acústico Externo/cirurgia , Orelha Média/diagnóstico por imagem , Osteotomia/veterinária , Otite Externa/veterinária , Otoscopia/veterinária , Animais , Cadáver , Cães , Epitélio/cirurgia , Otite Externa/cirurgia
3.
Vet Surg ; 49(3): 582-589, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31916633

RESUMO

OBJECTIVE: To determine the influence of self-directed learning, peer feedback, or expert feedback on suturing technique of novice veterinary student surgeons. STUDY DESIGN: Prospective, blinded, video feedback study. SAMPLE POPULATION: Three groups of surgery naïve veterinary students, two groups of 37 students and one group with 36 students. METHODS: Each student completed three cruciate sutures in SynDaver skin. Student performance was video recorded and scored with a validated pro forma. Students were randomly divided into three groups: (1) students critically evaluated their own performance, (2) students critically evaluated peer's performance, and (3) students received a peer's evaluation. Each student repeated the surgical task and assessed his or her own performance, guided by the pro forma. Each student received a video with individualized feedback from an expert prior to repeating the task. Scores and times were analyzed. Student and expert evaluations were compared. RESULTS: Task composite score, time to completion, and completion rate did not differ between groups. Student self-assessed scores did not correlate with expert scores. Forty-three percent and 62% of students stated that self-feedback and peer feedback, respectively, were acceptable forms of learning, and 96% of students felt expert feedback was superior to both. CONCLUSION: Video-based self-evaluation and peer-assisted learning were as effective as expert feedback after didactic lecture in teaching suturing technique to novice veterinary surgeons. CLINICAL SIGNIFICANCE: Video-based self-evaluation and peer feedback were viable alternative teaching strategies to didactic lecture and expert feedback alone for instructing novice veterinary surgeons.


Assuntos
Competência Clínica , Educação em Veterinária , Estudantes , Técnicas de Sutura , Gravação em Vídeo , Humanos , Educação em Veterinária/métodos , Estudos Prospectivos , Cirurgia Veterinária , Técnicas de Sutura/educação , Técnicas de Sutura/veterinária , Suturas
4.
J Vet Emerg Crit Care (San Antonio) ; 30(1): 18-27, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31840933

RESUMO

OBJECTIVES: To investigate veterinary technician burnout and associations with frequency of self-reported medical error, resilience, and depression and job-related risk factors. DESIGN: Cross-sectional observational study using an anonymous survey conducted between November 2017 and June 2018. SETTING: Four referral teaching hospitals in the United States and Canada. SUBJECTS: A total of 344 veterinary technicians were invited to participate. Response rate was 95%. Overall 256 surveys were ultimately analyzed. INTERVENTIONS: Burnout, depression, and resilience were measured using validated instruments. Respondents reported perceptions of workload, working environment, and medical error frequency. Associations between burnout and factors related to physical work environment, workload and schedule, compensation package, interpersonal relationships, intellectual enrichment, and exposure to ethical conflicts were analyzed. MEASUREMENTS AND MAIN RESULTS: Burnout, characterized by high emotional exhaustion, depersonalization, and low sense of personal accomplishment was common, and was positively associated with perceived medical errors, desire to change career, and depression. Burnout levels on all 3 burnout subscales were higher in this population than previously reported for a contemporaneous group of trauma nurses working with human patients (P < 0.05). Burnout was negatively associated with resilience. Respondents' feelings of fear or anxiety around supervisor communications, perception that patient load was too high to allow for excellent patient care, and perceived lack of available assistance during sudden workload increases were all associated with burnout. CONCLUSIONS: Burnout in veterinary technicians is common and is associated with numerous undesirable outcomes. Work-related interventions to reduce burnout should focus on improving supervisor relationships and maintaining an appropriate patient:caregiver ratio.


Assuntos
Técnicos em Manejo de Animais/psicologia , Esgotamento Psicológico/psicologia , Hospitais de Ensino , Local de Trabalho , Adulto , Canadá , Estudos Transversais , Feminino , Humanos , Masculino , Fatores de Risco , Inquéritos e Questionários , Estados Unidos
5.
Vet Surg ; 48(6): 975-984, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31017722

RESUMO

OBJECTIVE: To evaluate the usefulness of a high-fidelity model for teaching ovariohysterectomy (OHE) to veterinary students. STUDY DESIGN: Longitudinal survey. SAMPLE POPULATION: Clinicians with ≥2 years postgraduate experience in small animal surgery and a sophomore veterinary student population at 1 institution. METHODS: Twelve clinicians evaluated the high-fidelity model for realism. Questionnaires were distributed to sophomore veterinary students prior to and after OHE training on the high-fidelity model (SynDaver Surgical Canine) and after performing OHE as primary surgeon with a live dog. Time for students to perform OHE (identify the first ovarian pedicle to transecting the uterine body) and number of technical errors (visceral injury, hemorrhage, loose ligatures) were compared between the model and live dog groups. RESULTS: Evaluators rated the high-fidelity model as moderate-to-highly realistic. Students' confidence improved after practicing on the model in all critical steps and additionally improved after performing an OHE on a live dog. Time to complete the OHE on the model (mean ± SD,73.4 ± 27.1 minutes) and live dogs (83.0 ± 24.7 minutes) did not differ (P = .20). Frequency of hemorrhagic events (P = .77) and accidental visceral injury (P = .30) did not differ between the model and live dogs. However, fewer loose ligatures were placed in live dogs (23/64) compared with the model (22/37; P = .02). CONCLUSION: The high-fidelity model improved the confidence of sophomore students. The duration of OHE did not differ between the model and live dogs. CLINICAL IMPACT: The high-fidelity model is valuable for improving confidence in veterinary students prior to live-dog OHE.


Assuntos
Educação em Veterinária , Histerectomia/veterinária , Modelos Anatômicos , Ovariectomia/veterinária , Animais , Competência Clínica , Cães , Feminino , Humanos , Estudantes , Inquéritos e Questionários
6.
Case Rep Vet Med ; 2019: 3696978, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30941228

RESUMO

A 10-week-old sexually intact female golden retriever was evaluated for two functional anal openings and a bipartite vulva. Examination revealed haired skin between two separate anatomically smaller anal openings. On rectal palpation, a soft tissue septum (5 cm) with a mucosal surface between the two anal openings was palpated. In addition, circumferential rectal musculature was not appreciated on the ventral aspect. Urogenital evaluation revealed duplication of the vestibule and vagina with a complete centrally located septum extending dorsoventrally. Computed tomography (CT) of the abdomen and pelvis, vaginocystourethrogram, and colonogram were performed. Complete bifurcation of the urinary bladder with duplication of the urethra, cervix, and vaginal canal was noted. Approximately 2 cm from the rectum, there was a similar bifurcation that converged the colon into two rectal portions and separate anal openings. The owner was counseled on the severity of congenital malformations and a high likelihood of aging-related developmental complications in the future. The owner elected humane euthanasia and a necropsy was performed to confirm the malformations.

7.
Am J Vet Res ; 80(5): 469-479, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31034275

RESUMO

OBJECTIVE: To compare joint stability and ultimate strength among 4 prosthetic ligament constructs for repair of tarsal medial collateral ligament (MCL) injury in dogs. SAMPLE: 13 canine cadavers (26 hind limbs). PROCEDURES: Each limb was stripped of all soft tissues except those associated with the tarsal joint and assigned to 1 of 4 prosthetic ligament constructs. The AN construct consisted of 3 bone anchors connected with monofilament nylon suture. The AU construct consisted of low-profile suture anchors connected with multifilament ultrahigh-molecular-weight polyethylene (UHMWPE) suture. The TN and TU constructs involved the creation of 3 bone tunnels and use of nylon or UHMWPE suture, respectively. Each limb underwent biomechanical testing before and after MCL transection and before and after cyclic range-of-motion testing following completion of the assigned construct. Tarsal joint stability (extent of laxity) was assessed with the joint in each of 3 positions (75°, 135°, and 165°). After completion of biomechanical testing, each limb was tested to failure to determine the ultimate strength of the construct. RESULTS: Relative to intact tarsal joints, joint laxity was significantly increased following completion of all 4 constructs. Construct type was not associated with the magnitude of change in joint laxity. Ultimate strength was greatest for the UHMWPE-suture constructs. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that all 4 constructs effectively stabilized MCL-deficient tarsal joints. Implants used for the TU, TN, and AU constructs had a lower profile than those used for the AN construct, which may be clinically advantageous. In vivo studies are warranted.


Assuntos
Membros Artificiais/veterinária , Ligamentos Colaterais/lesões , Ligamentos Colaterais/cirurgia , Cães/lesões , Cães/cirurgia , Técnicas de Sutura/veterinária , Animais , Fenômenos Biomecânicos , Cadáver , Instabilidade Articular , Polietilenos , Âncoras de Sutura/veterinária , Suturas/veterinária
8.
J Am Vet Med Assoc ; 253(3): 315-321, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30019998

RESUMO

OBJECTIVE To identify risk factors associated with surgical site infection (SSI) in dogs following tibial plateau leveling osteotomy (TPLO). DESIGN Retrospective cohort study. ANIMALS 320 dogs that underwent unilateral or bilateral TPLO (n = 405 procedures) between 2007 and 2015 and were reexamined by a veterinarian at least once ≥ 8 weeks after the procedure. PROCEDURES Data were extracted from medical records regarding signalment, TPLO procedure details, medical history of dermatitis, and SSI status. Logistic regression was performed to identify factors associated with SSI development. RESULTS An SSI developed following 34 (8.4%; 95% confidence interval [CI], 6.1% to 11.5%) procedures. Prophylactic antimicrobial administration was provided following 36.8% (n = 149) of procedures. For 71 (17.5%) procedures, the dog had dermatitis at the time of surgery; 12 of these procedures involved dermatitis at the surgical site. The incidence of SSI following the 12 procedures for dogs with dermatitis at the surgical site was 16.7% (2/12 [95% CI, 3.3% to 54.3%]) and was 10.2% (6/59 [95% CI, 4.5% to 21.3%]) for dogs with dermatitis elsewhere; however, these differences in incidence were not significant. On multivariable analysis, German Shepherd Dogs (vs other breeds), meniscectomy (vs no meniscectomy), and attending surgeon having performed ≤ 20 (vs > 20) procedures during the study period were associated with increased odds of SSI. CONCLUSIONS AND CLINICAL RELEVANCE SSI following TPLO was associated with the German Shepherd breed, meniscectomy, and surgeon. Prospective studies are needed to investigate the mechanisms underlying these associations.


Assuntos
Ligamento Cruzado Anterior/cirurgia , Doenças do Cão/epidemiologia , Cães/lesões , Infecção da Ferida Cirúrgica/veterinária , Tíbia/cirurgia , Animais , Estudos de Coortes , Cães/cirurgia , Feminino , Masculino , New York/epidemiologia , Osteotomia/veterinária , Estudos Retrospectivos , Fatores de Risco , Infecção da Ferida Cirúrgica/epidemiologia
10.
Vet Surg ; 47(4): 543-548, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29570810

RESUMO

OBJECTIVE: To evaluate the ability to assess laryngeal function and to diagnose unilateral laryngeal paralysis (uLP) via airway endoscopy and carbon dioxide (CO2 ) stimulation. STUDY DESIGN: Experimental study. ANIMALS: Six healthy, adult beagles. METHODS: Dogs were anesthetized with sevoflurane and dexmedetomidine. Laryngeal activity was observed via endoscopy placed through a laryngeal mask airway (LMA). The absolute and normalized glottic gap areas (AGGA and NGGA, respectively) and the glottic length (GL) were measured at inspiration and before and after surgically induced uLP. Measurements were obtained at eupnea and during hypercapnic hyperpnea produced by the administration of CO2 . Values for each hemilarynx were also measured. Video recordings were observed by 2 surgeons who scored function as normal or uLP. RESULTS: The AGGA and NGGA increased similarly during CO2 administration in intact dogs and in dogs with uLP; the GL increased in dogs with uLP but not in intact dogs. The AGGA and NGGA of the intact hemilarynx increased more than those of the affected hemilarynx in dogs with uLP. uLP was correctly identified more frequently by observers at hypercapnic hyperpnea than during eupnea. CONCLUSION: The increase in AGGA and NGGA at peak inspiration during CO2 administration was not limited by uLP, but asymmetry in hemilarynx AGGA and NGGA was observed in dogs with uLP. CO2 administration facilitated the identification of uLP. CLINICAL SIGNIFICANCE: Laryngeal endoscopy through an LMA coupled with administration of CO2 in anesthetized dogs facilitates the observation of arytenoid function and may improve the diagnosis of naturally occurring mild laryngeal paralysis.


Assuntos
Cartilagem Aritenoide/cirurgia , Cães , Hipercapnia/veterinária , Máscaras Laríngeas/veterinária , Laringoscopia/veterinária , Paralisia das Pregas Vocais/veterinária , Animais , Dióxido de Carbono/farmacologia , Endoscopia , Feminino , Glote , Laringe , Masculino , Respiração , Paralisia das Pregas Vocais/diagnóstico
11.
J Vet Diagn Invest ; 29(6): 904-909, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28782436

RESUMO

The Charcot-Leyden crystal (CLC) is a major human eosinophil protein that readily crystallizes; these crystals are common in eosinophilic diseases. Although anecdotal existence of these crystals is known in veterinary pathology, definitive reports do not exist, to our knowledge. We identified eosinophilic crystals in a laryngeal myxosarcoma from a 2-y-old, spayed female, Labrador Retriever dog that were tentatively interpreted as CLCs. However, Ziehl-Neelsen acid-fast stain was negative, arguing against CLCs. The crystals stained red with Masson trichrome, precluding collagen. Periodic acid-Schiff and alcian blue were negative. The crystals stained positively with Okajima, and no myoglobin immunoreactivity was detected, supporting their identity as hemoglobin crystals. In the absence of a hematologic abnormality, these crystals were interpreted to be abnormal hemoglobin breakdown products. Protein sequence comparison was pursued to determine whether a protein similar to CLC exists in mammals. Only 3 nonhuman primate species, the Sumatran orangutan ( Pongo abelii), rhesus macaque ( Macaca mulatta), and cynomolgus monkey ( Macaca fascicularis), had a sequence similarity of >80%. Of the crystal-forming residues, 12 of 54 (22%) were different in the Sumatran orangutan and 15 of 54 (28%) were different in the Macaca spp., which may affect the crystallization process. The lack of reports of CLCs in nonhuman species and our results collectively suggest that CLCs are human-specific.


Assuntos
Doenças do Cão/metabolismo , Glicoproteínas/isolamento & purificação , Neoplasias Laríngeas/veterinária , Lisofosfolipase/isolamento & purificação , Mamíferos/metabolismo , Mixossarcoma/veterinária , Animais , Doenças do Cão/etiologia , Cães , Feminino , Neoplasias Laríngeas/etiologia , Neoplasias Laríngeas/metabolismo , Mixossarcoma/etiologia , Mixossarcoma/metabolismo , Primatas/metabolismo , Análise de Sequência de Proteína/veterinária , Coloração e Rotulagem/veterinária
12.
Artigo em Inglês | MEDLINE | ID: mdl-28352471

RESUMO

BACKGROUND: Concentrated breeding effort to produce various body structures and behaviors of dogs to suit human demand has inadvertently produced unwanted traits and diseases that accompany the morphological and behavioral phenotypes. We explored the relationship between pelvic conformation and canine hip dysplasia (HD) because purebred dogs which are predisposed, or not, to HD share common morphologic features, respectively. Thirteen unique bilateral anatomical features of the pelvis were measured on 392 dogs of 51 breeds and 95 mixed breed dogs. Principal components (PCs) were derived to describe pelvic morphology. Dogs were genotyped at ~183,000 single nucleotide polymorphisms and their hip conformation was measured by the Norberg angle and angle of inclination between the femoral neck and diaphysis. RESULTS: No associations reached genome wide significance for the Norberg angle when averaged over both hips. PC1 was negatively correlated with the Norberg angle (r = -0.31; P < 0.05) but not the angle of inclination (r = -0.08; P > 0.05). PC1, 2, 4, and 5 differed significantly between male and female dogs confirming pelvic sexual dimorphism. With sex as a covariate, the eigenvector contribution to PC1 reflected the overall size of the pelvis and was significantly associated with the IGF-1 locus, a known contributor to canine body size. PC3, which represented a tradeoff between ilial length and ischial length in which a longer ischium is associated with a shorter ilium, was significantly associated with a marker on canine chromosome 16:5181388 bp. The closest candidate gene is TPK1, a thiamine-dependent enzyme and part of the PKA complex. Associations with the remaining PCs did not reach genome wide significance. CONCLUSION: IGF-1 was associated with the overall size of the pelvis and sex is related to pelvic size. Ilial/ischial proportion is genetically controlled and the closest candidate gene is thiamine-dependent and affects birth weight and development of the nervous system. Dogs with larger pelves tend to have smaller NAs consistent with increased tendency toward HD in large breed dogs. Based on the current study, pelvic shape alone was not strongly associated with canine hip dysplasia.

13.
Vet Surg ; 45(3): 347-55, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27007191

RESUMO

OBJECTIVE: To determine the effects of the Proximal Abducting Ulnar Osteotomy (PAUL) on contact pressures of congruent and incongruent (short radius) canine elbows. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: Unpaired normal cadaveric canine forelimbs (n=16). METHODS: A servohydraulic testing frame and thin-film sensors were utilized to measure intra-articular contact area (CA), mean contact pressure (mCP), and peak contact pressure (pCP) for medial and lateral elbow compartments. Percent contribution of the medial compartment relative to the whole (%Med) was also examined. Baseline data were collected in 9 congruent elbows and 7 incongruent elbows where the radius was shortened. Both sets of elbows were tested following ulnar osteotomy and sequential placement of 2 and 3 mm PAUL plates and paw repositioning (to account for any medial to lateral shift of transarticular forces). Paired t-tests compared sequential procedural steps. P<.05 was significant. RESULTS: For congruent elbows, the 2 mm PAUL plate decreased CA in both compartments compared to baseline; lateral pCP increased with subsequent paw repositioning. Induction of radio-ulnar incongruity decreased CA and increased mCP medially, decreased pCP laterally, and increased %MedCA and %MedmCP compared to baseline. Both PAUL plates decreased mCP and pCP medially, with no effect laterally. Paw repositioning had no effect. CONCLUSION: The PAUL procedure had no effect on medial compartment pressure in the congruent elbow. It may ameliorate increased medial compartment pressure in the incongruent elbow. This change does not result from a medial to lateral compartmental shift and deserves further investigation.


Assuntos
Placas Ósseas/veterinária , Doenças do Cão/cirurgia , Articulação do Cotovelo/fisiologia , Deformidades Congênitas das Extremidades Superiores/veterinária , Animais , Fenômenos Biomecânicos , Cadáver , Cães/fisiologia , Membro Anterior/fisiologia , Osteotomia/veterinária , Pressão , Amplitude de Movimento Articular , Deformidades Congênitas das Extremidades Superiores/cirurgia
14.
Can Vet J ; 52(11): 1248-50, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22547849

RESUMO

A 4-year-old male castrated English bulldog was referred to the Atlantic Veterinary College for evaluation of exercise intolerance, multiple syncopal episodes, and a grade IV/VI heart murmur. The dog was shown to have 3 congenital cardiac anomalies: atrial septal defect, mitral valve dysplasia, and subaortic stenosis. Medical management consisted of exercise restriction, atenolol, pimobendan, and taurine.


Assuntos
Estenose da Valva Aórtica/veterinária , Doenças do Cão/diagnóstico , Cardiopatias Congênitas/veterinária , Comunicação Interatrial/veterinária , Insuficiência da Valva Mitral/veterinária , Animais , Estenose da Valva Aórtica/congênito , Estenose da Valva Aórtica/diagnóstico , Doenças do Cão/congênito , Cães , Cardiopatias Congênitas/diagnóstico , Comunicação Interatrial/diagnóstico , Masculino , Valva Mitral/anormalidades , Insuficiência da Valva Mitral/congênito , Insuficiência da Valva Mitral/diagnóstico
15.
Exp Physiol ; 93(7): 863-71, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18356556

RESUMO

The Fischer 344 x Brown Norway F1-hybrid (F344BN) rat has become an increasingly popular and useful strain for studying age-related declines in skeletal muscle function because this strain lives long enough to experience significant declines in muscle mass. Since exercise is often considered a mechanism to combat age-related declines in muscle function, determining the utility of this strain of rat for studying the effects of exercise on the ageing process is necessary. The purpose of this study was to evaluate the plasticity of skeletal muscle aerobic function in late middle-aged male rats following 7 weeks of treadmill exercise training. Training consisted of 60 min per day, 5 days per week with velocity gradually increasing over the training period according to the capabilities of individual rats. The final 3 weeks involved 2 min high-intensity intervals to increase the training stimulus. We used in situ skeletal muscle aerobic metabolic responses and in vitro assessment of muscle mitochondrial oxidative capacity to describe the adaptations of aerobic function from the training. Training increased running endurance from 11.3 +/- 0.6 to 15.5 +/- 0.8 min, an improvement of approximately 60%. Similarly, distal hindlimb muscles from trained rats exhibited a higher maximal oxygen consumption in situ (23.2 +/- 1.3 versus 19.7 +/- 0.8 mumol min(-1) for trained versus sedentary rats, respectively) and greater citrate synthase and complex IV enzyme activities in gastrocnemius (29 and 19%, respectively) and plantaris muscles (24 and 28%, respectively) compared with age-matched sedentary control animals. Our results demonstrate that skeletal muscles from late middle-aged rats adapt to treadmill exercise by improving skeletal muscle aerobic function and mitochondrial enzyme activities. This rat strain seems suitable for further investigations using exercise as an intervention to combat ageing-related declines of skeletal muscle aerobic function.


Assuntos
Envelhecimento/fisiologia , Músculo Esquelético/fisiologia , Condicionamento Físico Animal/fisiologia , Adaptação Fisiológica/fisiologia , Animais , Masculino , Consumo de Oxigênio/fisiologia , Resistência Física/fisiologia , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344
16.
Rejuvenation Res ; 9(2): 219-22, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16706647

RESUMO

In skeletal muscles and heart in vitro complex IV activity is lower in young adult caloric restricted (CR) animals despite normal aerobic function in situ and in vivo. On the other hand, whereas markers of oxidative capacity decline 25% to 46% between 8 and 10 months and 35 months in ad libitum fed (AL) animals, in most muscles there is no decline in CR across the same absolute age (35 mo old) or relative age (35% survival rate) span and PGC-1alpha gene expression in gastrocnemius muscle declines more slowly with aging. The present results show that CR largely prevents the age-associated decline in mitochondrial function in heart and skeletal muscles, and suggest that this is secondary to a better-maintained drive on mitochondrial biogenesis.


Assuntos
Envelhecimento/fisiologia , Restrição Calórica , Coração/fisiologia , Músculo Esquelético/fisiopatologia , Animais , Citrato (si)-Sintase/metabolismo , Masculino , Ratos , Ratos Endogâmicos F344 , Fatores de Transcrição/metabolismo
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