Bloqueio do plexo braquial em bugio (Alouatta caraya): relato de caso / Brachial plexus block in Black howler (Alouatta caraya): Case report

Relata-se o emprego da técnica de bloqueio de plexo braquial em um bugio (Alouatta 16 caraya), macho, com aproximadamente 1 ano de idade. O animal apresentava queimadura extensa, abrangendo o terço distal do antebraço e mão direita em consequência de choque elétrico. Após avaliação clínico-cirúrgico, recomendou-se a amputação do membro. O protocolo anestésico constituiu de contenção química com a associação de cetamina, midazolan e clorpromazina, seguido da indução e manutenção da anestesia com isofluorano. O bloqueio do plexo braquial, com lidocaína, teve como referência a palpação do pulso da artéria axilar. Durante o procedimento cirúrgico o animal permaneceu com as frequências cardíaca e respiratória estáveis e teve boa recuperação pós-anestésica. A associação da anestesia geral inalatória com bloqueio locorregional com anestésico local assegurou a estabilidade transoperatória e conforto pós-anestésico imediato.

This is a report of the use of brachial plexus block technique on a black howler (Alouatta caraya), male, approximately 1 year. The animal had extensive burn, covering the distal third of the right forearm and hand due to electric shock result. After clinical and surgical evaluation, it is recommended limb amputation. The anesthetic protocol included a chemical restraint with ketamine, midazolam and chlorpromazine, followed by induction and maintenance of anesthesia with isoflurane. The brachial plexus block was performed with lidocaine, and had reference the pulse palpation of the axillary artery. During the surgical procedure, the animal remained with heart and respiratory rates stable and had good post-anesthetic recovery. The association of inhalation anesthesia with regional blockade with local anesthetic provide intraoperative stability and comfort post anesthetic immediately

Evaluation of endoscopic salpingectomy for sterilization of female Formosan macaques (Macaca cyclopis).

We evaluated the safety and postsurgical outcomes of endoscopic salpingectomy for sterilization of female Formosan macaques (Macaca cyclopis) as a method of population control. Nineteen adult female Formosan macaques were included in our study. The fallopian tubes of each anesthetized macaque were cauterized and excised endoscopically using a 2.7-mm rigid endoscope system. We recorded the complications encountered, and objectively scored the amount of hemorrhage throughout the procedure. Postoperative ovarian function was evaluated by monitoring the serum levels of sex hormones in ten of the macaques for two ovarian cycles following the salpingectomy. Two to 13 months later, eight of the 19 macaques underwent laparoscopy for the objective evaluation of inflammation at the surgical sites on the fallopian tubes. No major anesthetic- or surgical-associated complications were observed in any of the macaques. The hormonal evaluation showed cyclic ovarian function after salpingectomy in all of the ten macaques examined, and the parameters were comparable to those of other macaque species. The long-term postoperative level of inflammation at the surgical site was minimal to low, and was lower than that reported for other tubal occlusion techniques used in macaques. The use of a 2.7-mm rigid endoscope for salpingectomy in macaques is safe and efficient, with fewer postoperative complications than comparable sterilization techniques.

Reversible femtosecond laser-assisted myopia correction: a non-human primate study of lenticule re-implantation after refractive lenticule extraction.

LASIK (laser-assisted in situ keratomileusis) is a common laser refractive procedure for myopia and astigmatism, involving permanent removal of anterior corneal stromal tissue by excimer ablation beneath a hinged flap. Correction of refractive error is achieved by the resulting change in the curvature of the cornea and is limited by central corneal thickness, as a thin residual stromal bed may result in biomechanical instability of the cornea. A recently developed alternative to LASIK called Refractive Lenticule Extraction (ReLEx) utilizes solely a femtosecond laser (FSL) to incise an intrastromal refractive lenticule (RL), which results in reshaping the corneal curvature and correcting the myopia and/or astigmatism. As the RL is extracted intact in the ReLEx, we hypothesized that it could be cryopreserved and re-implanted at a later date to restore corneal stromal volume, in the event of keratectasia, making ReLEx a potentially reversible procedure, unlike LASIK. In this study, we re-implanted cryopreserved RLs in a non-human primate model of ReLEx. Mild intrastromal haze, noted during the first 2 weeks after re-implantation, subsided after 8 weeks. Refractive parameters including corneal thickness, anterior curvature and refractive error indices were restored to near pre-operative values after the re-implantation. Immunohistochemistry revealed no myofibroblast formation or abnormal collagen type I expression after 8 weeks, and a significant attenuation of fibronectin and tenascin expression from week 8 to 16 after re-implantation. In addition, keratocyte re-population could be found along the implanted RL interfaces. Our findings suggest that RL cryopreservation and re-implantation after ReLEx appears feasible, suggesting the possibility of potential reversibility of the procedure, and possible future uses of RLs in treating other corneal disorders and refractive errors.

[Progress on nonhuman primate models of diabetes mellitus].

Diabetes is the third most severely chronic disease after cardiovascular disease and cancer. World Health Organization (WHO) estimated 220 million diabetes patients worldwide in 2009. The rational animal models of diabetes are necessary for understanding the mechanisms of diabetes, diagnosis and prevention of diabetes as well as screen and evaluation of new drugs for diabetes treatment. Compared to other animal models of diabetes, the causes and symptoms of diabetes of nonhuman primates is more like human diabetes. We here reviewed the reported nonhuman primate models of diabetes based on the sources they were generated; especially focused on three models, Macaca mullata, M. fascicularis, Tupaia belangeri. Furthermore, we discussed the perspective development of nonhuman primate models of diabetes mellitus.

Nonhuman primate infections after organ transplantation.

Nonhuman primates, primarily rhesus macaques (Macaca mulatta), cynomolgus macaques (Macaca fascicularis), and baboons (Papio spp.), have been used extensively in research models of solid organ transplantation, mainly because the nonhuman primate (NHP) immune system closely resembles that of the human. Nonhuman primates are also frequently the model of choice for preclinical testing of new immunosuppressive strategies. But the management of post-transplant nonhuman primates is complex, because it often involves multiple immunosuppressive agents, many of which are new and have unknown effects. Additionally, the resulting immunosuppression carries a risk of infectious complications, which are challenging to diagnose. Last, because of the natural tendency of animals to hide signs of weakness, infectious complications may not be obvious until the animal becomes severely ill. For these reasons the diagnosis of infectious complications is difficult among post-transplant NHPs. Because most nonhuman primate studies in organ transplantation are quite small, there are only a few published reports concerning infections after transplantation in nonhuman primates. Based on our survey of these reports, the incidence of infection in NHP transplant models is 14%. The majority of reports suggest that many of these infections are due to reactivation of viruses endemic to the primate species, such as cytomegalovirus (CMV), polyomavirus, and Epstein-Barr virus (EBV)-related infections. In this review, we address the epidemiology, pathogenesis, role of prophylaxis, clinical presentation, and treatment of infectious complications after solid organ transplantation in nonhuman primates.

Prolonged diabetes reversal after intraportal xenotransplantation of wild-type porcine islets in immunosuppressed nonhuman primates.

Cell-based diabetes therapy requires an abundant cell source. Here, we report reversal of diabetes for more than 100 d in cynomolgus macaques after intraportal transplantation of cultured islets from genetically unmodified pigs without Gal-specific antibody manipulation. Immunotherapy with CD25-specific and CD154-specific monoclonal antibodies, FTY720 (or tacrolimus), everolimus and leflunomide suppressed indirect activation of T cells, elicitation of non-Gal pig-specific IgG antibody, intragraft expression of proinflammatory cytokines and invasion of infiltrating mononuclear cells into islets.

Post-transplant upregulation of chemokine messenger RNA in non-human primate recipients of intraportal pig islet xenografts.

BACKGROUND: We have previously shown that pig-to-primate intraportal islet xenografts reverse diabetes, escape hyperacute rejection, and undergo acute cellular rejection in non-immunosuppressed recipients. To gain a better understanding of mechanisms contributing to xenoislet rejection in non-human primates we examined gene expression in livers bearing islet xenografts in the first 72 h after transplantation. METHODS: Liver specimens were collected at sacrifice from seven non-immunosuppressed rhesus macaques at 12, 24, 48 and 72 h after intraportal porcine islet transplantation. Following total RNA extraction, mRNA was quantified using SYBR green real-time reverse transcription polymerase chain reaction (RT-PCR) for species-specific immune response genes. Data were analyzed using comparative cycle threshold (Ct) analysis, adjusted for specific primer-efficiencies and normalized to cyclophilin expression. RESULTS: Porcine insulin mRNA was detected in all liver samples. Cluster analysis revealed differential gene expression patterns at 12 and 24 h (early) compared with at 48 and 72 h (late) post-transplant. Gene expression patterns were associated with histological findings of predominantly neutrophils and only a few lymphocytes at 12 and 24 h and an increasing number of lymphocytes and macrophages at 48 and 72 h. Transcript levels of CXCR3 and its ligands, interferon-inducible protein 10 (IP-10) and monokine induced by IFN-gamma (Mig), significantly increased between early and late time points together with expression of MIP-1alpha, regulated on activation normal T expressed and secreted protein (RANTES) and MCP-1. CCR5 showed only a marginal, non-significant increase. Fas ligand, perforin and granzyme B transcripts were all elevated at 48 and 72 h post-transplant. CONCLUSIONS: Our data suggest that CXCR3, with ligands IP-10 and Mig, is involved in T cell recruitment in acute islet xenograft rejection in non-human primates. Upregulation of RANTES and MIP-1alpha transcripts in the absence of a significant CCR5 increase suggests a possible involvement of other chemokine receptors. MCP-1 expression is associated with T cell and macrophage infiltration. Elevated cytotoxic effector molecule expression (Fas ligand, perforin, granzyme B) indicates T-cell mediated graft destruction by cytotoxic and cytolytic mechanisms within 48 to 72 h after transplantation. These results identify the CXCR3-mediated chemoattractant pathway as an immunosuppressive target in pig-to-primate islet xenotransplantation.

An improved method with a long-shanked glass micropipette and ultrasonography for drug injection into deep brain structure of the monkey.

We describe an improved method to inject drug into deep brain structure of the macaque monkey. A Teflon-coated tungsten wire for extracellular recording was passed through a long-shanked (4-5 cm) glass micropipette, which was then attached to a microsyringe with dental impression material. The surface of the micropippete was coated with Teflon to reduce acoustic artifact in ultrasound imaging. Thereby, it was possible to identify the micropipette in the brain with B-mode ultrasonography. Extracellular recording combined with electrical stimulation in the input source of the target nucleus was also helpful to determine the location of the micropipette. Here, we demonstrate injection of a neuronal tracer, wheat germ agglutinin conjugated to horseradish peroxidase, into the medial mammillary nucleus of the Japanese monkey.

The use of titanium implants and prosthodontic techniques in the preparation of non-human primates for long-term neuronal recording studies.

Investigators that require the chronic implantation of hardware on the non-human primate skull are often challenged with the possible failure of head implants. To improve the success rate of our head implants, titanium anchor screws, referred to as titanium endosseous implants, were implanted in the skulls of six macaques. Techniques adapted from the processing of dentures were utilized to pre-fabricate an acrylic "skull cap", which provided the mechanical support structure for our study-specific hardware. A two-stage procedure adapted from dentistry (Brånemark et al., 1977) was employed for the placement of titanium endosseous implants in the skull. This two-stage technique incorporates the principles of osseointegration and a healing period. Of the six skull-anchored implants prepared implementing the methods described in this paper, we have not experienced any failures. Additionally, all of the titanium endosseous implants examined post mortem were functionally successful (n=30). Histology results confirmed that there was healthy bone in direct contact with the titanium endosseous implants. The dense cortical bone of the macaque skull is ideal for the implantation of titanium endosseous implants. Titanium endosseous implants have provided secure, functional anchor points for the attachment of hardware to the macaque skull and have resulted in healthy, stable head implants that can remain on the skull for extended periods of time.

Functional plasticity in primate somatosensory thalamus following chronic lesion of the ventral lateral spinal cord.

The long-term consequences of thoracic spinothalamic tract lesion on the physiological properties of neurons in the ventral posterior lateral nucleus of the thalamus in monkeys were assessed. Neurons responding to both compressive and phasic brush stimuli (multireceptive neurons), but not brush-specific (low-threshold) neurons, in the partially deafferented thalamus showed increased spontaneous activity, increased responses evoked by cutaneous stimuli and larger mean receptive field size than the same types of cells in the thalamus with intact innervation. The spike train properties of both the spontaneous and evoked discharges of cells were also altered so that there was an increased incidence of spike-bursts in cells of deafferented thalamus. These changes were widespread in the thalamus, and included cells in both the fully innervated forelimb representation and the partially denervated hindlimb representation ipsilateral to the lesion. The spontaneous and evoked spike trains in the ipsilateral thalamus also show increased frequency of both spike-burst and non-burst events compared to the intact thalamus. These results indicate that chronic spinothalamic tract lesion produces widespread changes in the physiological properties of a discrete cell population of the thalamus.The findings in this study indicate that the thalamic processing of somatosensory information conveyed by the lemniscal system is altered by transection of the spinothalamic tract. This change in sensory processing in the thalamus would result in altered cortical processing of innocuous somatosensory inputs following deafferentation and so possibly contribute to the generation of the central pain syndrome.

Striatal tissue transplantation in non-human primates.

The caudate nucleus and putamen form part of a complex but topographically connected circuitry that links the cortex, the basal ganglia and the thalamus. Within this complex system lie a series of functionally and anatomically segregated loops that allow the concurrent processing of a wide range of cognitive and motor information (Alexander et al., 1986; Alexander and Crutcher, 1990). As a constituent of these loops it has been shown that the striatum is involved in movement initiation, response selection and attentional processes (Robbins and Brown, 1990; Alexander, 1994; Lawrence et al., 1998). Although it is the medium spiny GABAergic projection neurones that are primarily lost in HD, it is not sufficient merely to replace the GABA. Instead it is crucial for striatal tissue transplants to integrate with the host tissue in such a way that the cortico-striatal-thalamic circuitry is restored and is functional. Rodent studies have progressed a long way in establishing the principle that striatal grafts can, at least partially, restore function and integrate appropriately with the host (Dunnett and Svendsen, 1993; Björklund et al., 1994; Sanberg et al., 1998) but the limited behavioural repertoire and the undifferentiated striatum meant that it was inevitable that studies should progress into primate models. Anatomical tracing studies have demonstrated that motor, premotor and somatosensory cortical areas send corticostriatal projections primarily to the putamen region in primates, whereas the head and body of the caudate nucleus mostly receive efferent input from associative cortical areas (Kemp and Powell, 1970; Kunzle, 1975, 1977, 1978; Selemon and Goldman-Rakic, 1985). Based on such anatomical, and functional, studies Alexander and colleagues have proposed the existence of at least five cortico-striatal-thalamic loops including a motor, a dorsolateral-prefrontal and an orbito-frontal loop (Alexander et al., 1986). The concentration of motor inputs to the putamen region suggests a particular involvement of this structure in the motor loop. Indeed, unilateral lesions of the putamen disrupt motor performance in the marmoset and generate apomorphine-induced dyskinesias in larger primates (Burns et al., 1995; Kendall et al., 2000). The implantation of striatal grafts into marmosets that had previously received unilateral putamen lesions ameliorated some of the motor impairments, which suggested at least partial restoration of the motor loop. In support of this we found direct evidence of host-graft cortico-striatal connectivity using an anterograde tracer injected in the primary motor cortical region (Kendall et al., 1998a). In larger primates, with lesions of the caudate and putamen, striatal [figure: see text] allografts and xenografts have been shown to reduce apomorphine-induced dyskinesias (Isacson et al., 1989; Hantraye et al., 1992; Palfi et al., 1998). The mechanism by which dyskinesias are elicited is not fully understood but alterations in firing patterns within both segments of the globus pallidus have been identified during dyskinetic movements (Matsumura et al., 1995). It seems likely that it would actually require re-establishment of afferent connections between the implanted putamen and the globus pallidus as well as of functioning dopamine receptors within the graft for the reduction in the dyskinetic profile to be observed. Certainly there is evidence, from rodent studies and the marmoset study described here, that close proximity of the graft to the globus pallidus yields better functional recovery (Isacson et al., 1986). In addition, anatomical tracing studies in rats have demonstrated connections between the implanted tissue and the host globus pallidus (Wictorin et al., 1989b, 1990) However, the relationship between graft placement and functional recovery remains to be fully substantiated.

Respiration rate, heart rate, and body temperature values in cynomolgus monkeys (Macaca fascicularis) during barbiturate anesthesia.

Respiration rate, heart rate, and body temperature values were obtained from 14 cynomolgus monkeys (Macaca fascicularis) during neurosurgery under barbiturate anesthesia. Vital sign values markedly declined below baseline during the early stages of surgery, steadily increased as surgery progressed and neared completion, and finally returned to baseline by the end of the postsurgical recovery period. There was considerable variability among the 14 monkeys, but the ranking of each monkey relative to the others remained constant across the period of observation. The findings suggested that the cynomolgus monkey may be more sensitive to barbiturates than the rhesus monkey, and cynomolgus monkeys may exhibit considerable individual differences in their sensitivity to barbiturates.

Functional properties of palmaris longus muscles of rhesus monkeys transplanted as index finger flexors.

This experiment with skeletal muscle autografts in monkeys was designed to retest previous findings that transplanted skeletal muscle can regenerate to a functional degree in primates without predenervation and to test a new hypothesis that increased functional demands on regenerated muscle grafts in monkeys may result in improved functional capacity of the grafts. Rhesus monkey index flexors were replaced with free palmaris longus muscle autografts with microneural anastomoses between the graft motor nerve and the severed profundus motor nerve. One monkey was taught selective index flexion before grafting and continued with this program after grafting to test the effect of training on the graft. Mature grafts were evaluated for in vivo contractile properties and by histology and histochemistry and were compared with a group of normal Rhesus palmaris longus muscles. The results reconfirm the capacity of nonpredenervated monkey skeletal muscle grafts to regenerate and to achieve some contractile ability and suggest that training of free muscle grafts may enhance recovery of their functional and structural properties.

Percutaneous trephine biopsy of the vertebral body in the rhesus monkey (Macaca mulatta).

Two methods of percutaneous vertebral body biopsy were performed in the Rhesus monkey, using a 3-mm diameter trephine and a pneumatic driver placed at a 30 degrees angle of approach to the transverse plane of the spine. The freehand method involved placing needle landmarks in the spine, followed by examination of a lateral radiograph of the lumbar region to verify landmark positioning and to estimate placement of the trephine. In the 2nd method, a pneumatic trephine guide was oriented according to a trigonometric calculation based on radiographic data. The pneumatic trephine guide allowed precise placement of the driver and steadied the trephine as it passed through the bone.

Technique for primate heterotopic cardiac xenotransplantation.

Heterotopic cardiac transplantation in the primate is a valuable method for the evaluation of immuno-suppressive regimens. This report describes our technique for heterotopic transplantation of cardiac grafts into the neck of baboons. Preliminary experience with cross-genus cardiac transplantation in the nonhuman primate is discussed.

The cynomolgus monkey as a model for orbital research. II. Anatomic effects of lateral orbitotomy.

In order to assess the anatomic consequences of lateral orbitotomy in a disease-free muscle cone, a technique of microsurgical exposure of the ciliary ganglion in the cynomolgus monkey was formulated. Animals were sacrificed at 2 and 6 months following surgery, and microscopic sections of the whole orbit prepared and compared to sections taken from the non-operated contralateral orbits. Findings at two months were: periorbital thickening and hypercellularity along with osteoneogenesis at sites remote from the surgery, particularly the superior-lateral orbit, and lack of appreciable scar formation in the fat of the muscle cone itself. The thickened periorbita persisted at six months, although remodeling of the bone had largely restored the normal appearance of the orbital walls. These findings may possibly explain the restrictive myopathy sometimes seen following surgical and traumatic disruption of the bony orbit.

The cynomolgus monkey as a model for orbital research. III. Effects on ocular physiology of lateral orbitotomy and isolation of the ciliary ganglion.

Five cynomolgus monkeys underwent unilateral lateral orbitotomy and isolation but not removal of the ciliary ganglion. Orbitotomized eyes were compared with untouched contralateral eyes with respect to intraocular pressure, aqueous humor formation rate, pupillary diameter and light reflex, corneal reflex, entry of intravenously administered fluorescein into the anterior chamber, anterior chamber volume, pharmacologically (pilocarpine, carbachol, echothiophate) induced accommodation, electroretinogram (ERG), visually evoked cortical response (VER), and clinical biomicroscopy, ophthalmoscopy, and fluorescein fundus angiography. Orbitotomized eyes accommodated significantly less than contralateral normal eyes in response to topical echothiophate one to two weeks after surgery. This difference was no longer present 15 to 20 weeks after orbitotomy. The implicit time on the light adapted ERG in the orbitotomized eyes was slightly but significantly shorter than in the normal eyes two to six weeks after orbitotomy; all the other ERG and VER parameters were the same in both eyes. Long-term ERG data were not obtained. There were no significant differences between normal and orbitotomized eyes with respect to any of the other parameters.

Primate models in surgical orthodontics.

Between 1969 and 1980, 22 studies using nonhuman primates for experimental research in surgical orthodontics were published in the American Journal of Orthodontics, Angle Orthodontist, Journal of Oral Surgery, or International Journal of Oral Surgery. The most common species used was the rhesus monkey, Macaca mulatta. As laboratory animals, monkeys are relatively expensive and difficult to obtain. These problems have limited the design of experimental studies. Sample sizes are often too small for statistical analysis, control groups are small or omitted, and it has frequently been necessary to pool animals of different ages and sexes. These compromises might be appropriate if monkeys are the best available experimental model for humans, but there is little evidence that this is the case. Monkeys do not fill the usual role of good experimental models, which is to simplify a complex system. The monkeys used for craniofacial surgery have normal craniofacial function and morphology for their species, unlike human clinical patients. Cephalometric radiographs and skull measurements taken on monkeys of the five most common experimental species indicate that all experimental animals are much more prognathic than humans, and sex differences in prognathism are small. However, because many species have a large sex difference in canine size, females are a better experimental model than males for some questions. Considering recent federal legislative interest in animal research and the decreasing financial support for research, it is essential that the choice of experimental animals be justifiable and cost-effective. It would be worthwhile to consider alternatives to primates as the species of choice for experimental research in surgical orthodontics.