Short-term heart rate variability in healthy dogs and dogs in various stages of degenerative mitral valve disease evaluated before pharmacotherapy.

Mitral valve disease (MVD) progression is associated with autonomic nervous system (ANS) imbalance. This study hypothesized that sympathetic and parasympathetic tones would be altered with MVD progression. ANS activity was assessed among different MVD classes in untreated dogs. This cross-sectional retrospective study included 29 healthy control dogs and 71 dogs with MVD divided according to American College of Internal Medicine (ACVIM) guidelines. Heart rate variability (HRV) analyses utilised time and frequency domains and were derived from 5 min, six-lead electrocardiogram recordings of sinus rhythm or respiratory sinus arrhythmia. While all time domain-related HRV parameters decreased with disease severity, only dogs in stage C exhibited significantly lower values (P < 0.05). High frequency (HF) band values decreased more than low frequency (LF) band values as disease severity increased (P < 0.05). The LF/HF ratio also progressively increased with MVD severity. A negative correlation was observed between HRV parameters and La/Ao ratio when the entire MVD case population was pooled (P < 0.05). Both sympathetic and parasympathetic tones were altered in dogs with MVD before clinical signs were observed and prior to the development of cardiomegaly. This is the first HRV study in untreated dogs with MVD. Investigating ANS imbalances preceding subclinical left-sided cardiomegaly in dogs with MVD should be considered in future age-matched, longitudinal studies to determine the potential benefits of early vagal tone augmentation in high-risk canine patients.

The peculiarities of the masticator muscles in rodents / Particularidades da masculatura mastigatória dos roedores

Comparative research concerning masticatory musculature in squirrel, muskrat and rabbit, take into account the emphasizing and morphofunctional interpretation of the osteomuscular particularities involved in the prehension and mastication processes. The development of the coronoid process on the muskrat and squirrel demonstrates the growing of the force when raising the mandible by increasing the action force attached to the temporal muscle, with insertion on the coronoid process. In comparison with that, in the case of rabbits, both the coronoid process and the temporal muscle are reduced. From a philogenetic point of view, it has been found that the species that have the articular condyle lowered at or under the level of the dental tables (carnivores) present a greater pressure force between the dental tables. Analyzing this aspect of the rodents taken into discussion, we noticed the lowering of the articular condyle up to the inferior molars' plane, in the case of squirrels and muskrats, but through obliquity, namely through cranial caudal and dorsoventral movement. This peculiarity is emphasized through the analysis of the angle formed by the axis of the mandible recurved branch (passing through the mandibular condyle) with the axis of the horizontal branch of the mandible, where it was noticed that along with the increase in the angle formed by the two axes, which becomes an obtuse 160 degree angle on the squirrel and 130 degrees on the muskrat, there is also a lowering of the articular condyle up to the molar level, while in the case of carnivores, the lowering of the condyle is done without the modification of the angle between the two axes, which measures approximately 90 degrees.

Investigações comparativas com respeito à musculatura mastigatória do esquilo, do rato-almiscarado e do coelho buscam o realçamento e a interpretação morfo-funcional das particularidades do sistema dos músculos esqueléticos envolvido no processo de agarramento e mastigação. O desenvolvimento do processo coronoide no rato-almiscarado e no esquilo demonstra o aumento da força no levantamento da mandíbula por meio do aumento do braço da força de ação do músculo temporal com inserção sobre o processo coronoide, em comparação com os leporídeos, que têm tanto o processo coronoide como o músculo temporal mais reduzidos. Do ponto de vista filogenético, observa-se que as espécies que apresentam o côndilo articular baixado igual ou inferior ao nível das placas dentárias (carnívoros) apresentam uma força de pressão maior entre as placas dentárias. Em relação aos roedores estudados, nota-se a descida do côndilo articular perto do plano dos molares inferiores no esquilo e no rato-almiscarado, mas por meio da obliquidade, isto é, por meio do movimento do côndilo articular da borda craniana e dorsoventral. Esta particularidade evidencia-se em virtude do ângulo formado pelo eixo do ramo dobrado da mandíbula (que atravessa o côndilo mandibular) junto ao eixo do ramo horizontal da mandíbula, resultando no aumento do valor do ângulo formado pelos dois eixos, que se tornam obtusos a 160º no esquilo e a 130º no rato-almiscarado, em função da descida do côndilo articular quase ao nível do plano dos molares, em comparação com os carnívoros, nos quais a descida do côndilo realiza-se sem a modificação do ângulo formado pelos dois eixos de, aproximadamente, 90 graus.

[Anterior ischemic optic neuropathy. The experience of 71 cases]. / Neuropatia optica ischemica anterioara. Experienta pe 71 cazuri.

The purpose of the study is to point out the characteristic clinical, therapeutical and evolutive features in the acute ischaemic suffering of the optic nerve's preliminary portion. A retrospective study has been performed, on the patients with anterior ischaemic optic neuropathy (AION), hospitalized in the Ophthalmologic Clinic from Cluj-Napoca, between 1986-1994: 71 cases. The main functional (visual field, visual acuity) and ophthalmoscopic aspects are analyzed, as their evolution after treatment. Results are significantly better if corticosteroids are systemically used (43.3% improvement of the visual field) than in their absence (17.07% improvement of the visual field). The high percentage of failures (70%) proves the absence of a therapeutical method to cure or bring a significant visual function's improvement in AOIN.