Resolving trabecular metaphyseal bone profiles downstream of the growth plate adds value to bone histomorphometry in mouse models.

Introduction: Histomorphometry of rodent metaphyseal trabecular bone, by histology or microCT, is generally restricted to the mature secondary spongiosa, excluding the primary spongiosa nearest the growth plate by imposing an 'offset'. This analyses the bulk static properties of a defined segment of secondary spongiosa, usually regardless of proximity to the growth plate. Here we assess the value of trabecular morphometry that is spatially resolved according to the distance 'downstream' of-and thus time since formation at-the growth plate. Pursuant to this, we also investigate the validity of including mixed primary-secondary spongiosal trabecular bone, extending the analysed volume 'upstream' by reducing the offset. Both the addition of spatiotemporal resolution and the extension of the analysed volume have potential to enhance the sensitivity of detection of trabecular changes and to resolve changes occurring at different times and locations. Method: Two experimental mouse studies of trabecular bone are used as examples of different factors influencing metaphyseal trabecular bone: (1) ovariectomy (OVX) and pharmacological prevention of osteopenia and (2) limb disuse induced by sciatic neurectomy (SN). In a third study into offset rescaling, we also examine the relationship between age, tibia length, and primary spongiosal thickness. Results: Bone changes induced by either OVX or SN that were early or weak and marginal were more pronounced in the mixed primary-secondary upstream spongiosal region than in the downstream secondary spongiosa. A spatially resolved evaluation of the entire trabecular region found that significant differences between experimental and control bones remained undiminished either right up to or to within 100 µm from the growth plate. Intriguingly, our data revealed a remarkably linear downstream profile for fractal dimension in trabecular bone, arguing for an underlying homogeneity of the (re)modelling process throughout the entire metaphysis and against strict anatomical categorization into primary and secondary spongiosal regions. Finally, we find that a correlation between tibia length and primary spongiosal depth is well conserved except in very early and late life. Conclusions: These data indicate that the spatially resolved analysis of metaphyseal trabecular bone at different distances from the growth plate and/or times since formation adds a valuable dimension to histomorphometric analysis. They also question any rationale for rejecting primary spongiosal bone, in principle, from metaphyseal trabecular morphometry.

The plate-to-rod transition in trabecular bone loss is elusive.

Changes in trabecular micro-architecture are key to our understanding of osteoporosis. Previous work focusing on structure model index (SMI) measurements have concluded that disease progression entails a shift from plates to rods in trabecular bone, but SMI is heavily biased by bone volume fraction. As an alternative to SMI, we proposed the ellipsoid factor (EF) as a continuous measure of local trabecular shape between plate-like and rod-like extremes. We investigated the relationship between EF distributions, SMI and bone volume fraction of the trabecular geometry in a murine model of disuse osteoporosis as well as from human vertebrae of differing bone volume fraction. We observed a moderate shift in EF median (at later disease stages in mouse tibia) and EF mode (in the vertebral samples with low bone volume fraction) towards a more rod-like geometry, but not in EF maximum and minimum. These results support the notion that the plate to rod transition does not coincide with the onset of bone loss and is considerably more moderate, when it does occur, than SMI suggests. A variety of local shapes not straightforward to categorize as rod or plate exist in all our trabecular bone samples.

Recuperação anestésica e analgesia residual da infusão continua intravenosa de fantanil, lidocaína, cetamina e fentanyl-lidocaína-cetamina associados à anesthesia total intravenosa com Propofol em cadelas submetidas à ovariossalpingo-histerectomia eletiva / Anesthetic recovery and residual analgesia of constant rate infusion intraoperative of fentanyl, lidocaine, ketamine or fentanyl-lidocaine-ketamine associated with total intravenous anesthesia with propofol in bitches submitted to elective ovariohysterectomy

Avaliou-se a recuperação anestésica e a analgesia residual da infusão contínua (IC) de fentanil (F), lidocaína (L), cetamina (K) e fentanil-lidocaína-cetamina (FLK), associados à anestesia total intravenosa com o propofol, em cadelas submetidas à ovariossalpingo-histerectomia. Foram utilizados 32 animais pré-medicados com acepromazina, distribuídos em quatro grupos de acordo com o tratamento analgésico: F: bolus de 0,0036mg/kg de fentanil e IC de 0,0036mg mg/kg/h; L: bolus de 3mg/kg de lidocaína e IC de 3mg/kg/h; K: bolus de 0,6mg/kg de cetamina e IC de 0,6mg/kg/h; e FLK: bolus e IC dos três fármacos nas doses supracitadas. Após o bolus do tratamento analgésico, foi realizada a indução e o início da IC do tratamento analgésico e do propofol. Para avaliação da recuperação anestésica, foram considerados os tempos de extubação, decúbito esternal, posição quadrupedal e os efeitos adversos. A avaliação da analgesia foi realizada por meio da escala visual analógica e modificada de Glasgow, durante seis horas. Os efeitos adversos observados foram vômito, sialorreia e tremor muscular. Receberam analgesia de resgate 100% dos animais do grupo F, 87,5% do K, 50% do L e 12,5% do FLK. O FLK demonstrou maior analgesia, e a recuperação anestésica foi semelhante em todos os grupos.(AU)

The anesthetic recovery and residual analgesia of continuous rate infusion (CRI) of fentanyl (F), lidocaine (L), ketamine (K) and fentanyl-lidocaine-ketamine (FLK) associated with total intravenous anesthesia with propofol in bitches submitted to ovariohysterectomy were evaluated. 32 animals were used, pre-medicated with acepromazine and distributed into four groups according to analgesic treatment: F loading dose (LD) of 0.0036mg/kg fentanyl, and CRI of 0.0036mg/kg/h, L: LD of 3mg/kg lidocaine, and CRI of 3mg/kg/h; K: LD of 0.6mg/kg ketamine, and CRI of 0.6mg/kg/h and FLK: LD and CRI of the three drugs in the above mentioned doses. After the LD of analgesic treatment, the induction was performed and the CRI of the analgesic treatment and propofol started. To evaluate the anesthetic recovery, the time of extubation, sternal decubitus, quadrupedal position and adverse effects were considered. The analgesia evaluation was performed using the visual scale and modified Glasgow for six hours. The adverse effects observed were vomiting, sialorrhea and muscle tremor. 100% of the animals in group F, 87.5% of K, 50% of L and 12.5% of FLK received rescue analgesia. FLK demonstrated greater analgesia, and anesthesia recovery was similar in all groups.(AU)

Autotransfusão imediata em cão - relato de caso / Instant autotransfusion in dog - case report

As hemorragias podem levar à morte, em caso de não interrupção e recuperação da volemia. A substituição do sangue pode ser realizada por transfusão homóloga ou autóloga. Na transfusão homóloga, o sangue é obtido de um doador, na autotransfusão ou transfusão autóloga, o sangue é coletado do próprio paciente. Objetivou-se relatar a autotransfusão em um cão como um método simples, rápido e barato, e discutir esse procedimento como uma alternativa emergencial para clínicas e hospitais que não possuem bancos de sangue ou animais doadores. Foi atendido um cão Rottweiler fêmea, 42,8kg, 10 anos de idade, com queixa principal de tumor mamário e para realização de castração. Após o procedimento, a paciente apresentou hemoperitônio, sendo encaminhada para novo procedimento cirúrgico, durante o qual se observou grande quantidade de sangue livre na cavidade abdominal. Foi realizada a autotransfusão de emergência, pela técnica das duas seringas, devido à indi1111sponibilidade de sangue ou animal doador no momento do procedimento cirúrgico emergencial, demonstrando ser uma opção eficiente, econômica, de fácil acesso e segura, por ser uma transfusão normotérmica, apresentar diminuição do risco de sobrecarga circulatória e por ser o sangue compatível, devendo ser mais explorada, pois existem poucos dados descritos na literatura.(AU)

Hemorrhages can lead to death in case of non-interruption and recovery of blood volume. Blood replacement may be performed by homologous or autologous transfusion. In homologous transfusion, blood is obtained from a donor, in autotransfusion or autologous transfusion, blood is collected from the patient himself. We aimed to report autotransfusion in a dog as a simple, quick, and inexpensive method, and discuss it as an emergency alternative for clinics and hospitals that do not have blood banks or animal donors. A female Rottweiler dog, 42.8kg, 10 years of age, was treated with a primary complaint of mammary tumor and for castration. After the procedure the patient presented hemoperitoneum, being referred to a new surgical procedure, where a large amount of free blood was observed in the abdominal cavity. The emergency autotransfusion was performed by the two syringes technique, due to the unavailability of blood or donor animal at the time of the emergency surgical procedure, proving to be an efficient, economical, easily accessible and safe option because it is a normothermic transfusion, risk of circulatory overload and blood is compatible. It should be more exploited because there are few data described in the literature.(AU)