RESUMO
Atmospheric particulate matter (APM) produced by the steel industry comprises a complex mixture of particles that includes a wide variety of metals and metallic nanoparticles. These particles settle out onto areas surrounding the industries. There is evidence that this 'settleable' APM (SePM) may cause air-to-water cross-contamination with significant effects on aquatic biota. Recent investigations have reported sublethal impacts on the gill structure and blood oxygen-carrying capacity of fishes, which raises the hypothesis that there will be consequences for gas exchange capacity and ability to support aerobic activities. Therefore, we investigated the effects of an environmentally relevant level of SePM contamination on swimming performance and associated aerobic metabolic rates in Nile tilapia, Oreochromis niloticus. Short-term exposure (96 h) to SePM reduced critical swimming speed, energetic efficiency of aerobic swimming, standard metabolic rate, maximum metabolic rate, and aerobic scope. The compromised swimming performance could have adverse ecological effects by limiting foraging ability, predator evasion, territorial protection, and migration. The impairments to aerobic capacity could also affect overall fish performance by influencing long-term energy balance and allocation to growth and reproduction. Thus, despite being sublethal, SePM contamination is considerably debilitating, and if its limiting effects are not compensated for in the longer term, this may reduce the survival and fitness of fish populations.
Assuntos
Ciclídeos , Animais , Natação , Material Particulado/toxicidade , Metabolismo Energético , Consumo de OxigênioRESUMO
Atmospheric particulate matter (APM) emitted by iron ore processing industries has a complex composition, including diverse metallic particles and nanoparticles. Settleable APM (SePM) causes air to water cross-contamination and has recently been demonstrated to have harmful sublethal impacts on fish, eliciting stress responses, affecting the immune system, and reducing blood oxygen-carrying capacity. These findings imply potential consequences for fish aerobic performance and energy allocation, particularly in their ability to tolerate respiratory challenges such as aquatic hypoxia. To assess that potential limitation, we analyzed metabolic, cardiorespiratory, and morphological alterations after exposing tilapia, Oreochromis niloticus, to an environmentally relevant concentration of SePM (96 h) and progressive hypoxia. The contamination initiated detectable gill damage, reducing respiratory efficiency, increasing ventilatory effort, and compromising fish capacity to deal with hypoxia. Even in normoxia, the resting respiratory frequency was elevated and limited respiratory adjustments during hypoxia. SePM increased O2crit from 26 to 34% of O2 (1.84 to 2.76 mg O2·L-1). Such ventilatory inefficacy implies higher ventilatory cost with relevant alterations in energy allocation. Progression in gill damage might be problematic and cause: infection, blood loss, ion imbalance, and limited cardiorespiratory performance. The contamination did not cause immediate lethality but may threaten fish populations due to limitations in physiological performance. This was the first investigation to evaluate the physiological responses of fish to hypoxia after SePM contamination. We suggest that the present level of environmental SePM deserves attention. The present results demonstrate the need for comprehensive studies on SePM effects in aquatic fauna.
Assuntos
Ciclídeos , Animais , Ciclídeos/metabolismo , Brânquias/metabolismo , Hipóxia , Oxigênio/metabolismo , Material Particulado/metabolismo , Material Particulado/toxicidadeRESUMO
Sensory neuropathy is a dose-limiting side effect of oxaliplatin-based cancer treatment. This study investigated the antinociceptive effect of amifostine and its potential neuroprotective mechanisms on the oxaliplatin-related peripheral sensory neuropathy in mice. Oxaliplatin (1 mg/kg) was injected intravenously in Swiss albino male mice twice a week (total of nine injections), while amifostine (1, 5, 25, 50, and 100 mg/kg) was administered subcutaneously 30 min before oxaliplatin. Mechanical and thermal nociceptive tests were performed once a week for 49 days. Additionally, c-Fos, nitrotyrosine, and activating transcription factor 3 (ATF3) immunoexpressions were assessed in the dorsal root ganglia. In all doses, amifostine prevented the development of mechanical hyperalgesia and thermal allodynia induced by oxaliplatin (P<0.05). Amifostine at the dose of 25 mg/kg provided the best protection (P<0.05). Moreover, amifostine protected against neuronal hyperactivation, nitrosative stress, and neuronal damage in the dorsal root ganglia, detected by the reduced expression of c-Fos, nitrotyrosine, and ATF3 (P<0.05 vs the oxaliplatin-treated group). In conclusion, amifostine reduced the nociception induced by oxaliplatin in mice, suggesting the possible use of amifostine for the management of oxaliplatin-induced peripheral sensory neuropathy.
Assuntos
Doenças do Sistema Nervoso Periférico , Amifostina/uso terapêutico , Animais , Antineoplásicos/toxicidade , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Hiperalgesia/prevenção & controle , Masculino , Camundongos , Oxaliplatina , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/prevenção & controleRESUMO
Sensory neuropathy is a dose-limiting side effect of oxaliplatin-based cancer treatment. This study investigated the antinociceptive effect of amifostine and its potential neuroprotective mechanisms on the oxaliplatin-related peripheral sensory neuropathy in mice. Oxaliplatin (1 mg/kg) was injected intravenously in Swiss albino male mice twice a week (total of nine injections), while amifostine (1, 5, 25, 50, and 100 mg/kg) was administered subcutaneously 30 min before oxaliplatin. Mechanical and thermal nociceptive tests were performed once a week for 49 days. Additionally, c-Fos, nitrotyrosine, and activating transcription factor 3 (ATF3) immunoexpressions were assessed in the dorsal root ganglia. In all doses, amifostine prevented the development of mechanical hyperalgesia and thermal allodynia induced by oxaliplatin (P<0.05). Amifostine at the dose of 25 mg/kg provided the best protection (P<0.05). Moreover, amifostine protected against neuronal hyperactivation, nitrosative stress, and neuronal damage in the dorsal root ganglia, detected by the reduced expression of c-Fos, nitrotyrosine, and ATF3 (P<0.05 vs the oxaliplatin-treated group). In conclusion, amifostine reduced the nociception induced by oxaliplatin in mice, suggesting the possible use of amifostine for the management of oxaliplatin-induced peripheral sensory neuropathy.
Assuntos
Animais , Masculino , Coelhos , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/prevenção & controle , Amifostina/uso terapêutico , Oxaliplatina , Hiperalgesia/induzido quimicamente , Hiperalgesia/prevenção & controle , Hiperalgesia/tratamento farmacológico , Antineoplásicos/toxicidadeRESUMO
We evaluated the role of the first pair of gill arches in the control of cardiorespiratory responses to normoxia and hypoxia in the air-breathing catfish, Clarias gariepinus. An intact group (IG) and an experimental group (EG, bilateral excision of first gill arch) were submitted to graded hypoxia, with and without access to air. The first pair of gill arches ablations reduced respiratory surface area and removed innervation by cranial nerve IX. In graded hypoxia without access to air, both groups displayed bradycardia and increased ventilatory stroke volume (VT), and the IG showed a significant increase in breathing frequency (fR). The EG exhibited very high fR in normoxia that did not increase further in hypoxia, this was linked to reduced O2 extraction from the ventilatory current (EO2) and a significantly higher critical O2 tension (PcO2) than the IG. In hypoxia with access to air, only the IG showed increased air-breathing, indicating that the first pair of gill arches excision severely attenuated air-breathing responses. Both groups exhibited bradycardia before and tachycardia after air-breaths. The fH and gill ventilation amplitude (VAMP) in the EG were overall higher than the IG. External and internal NaCN injections revealed that O2 chemoreceptors mediating ventilatory hypoxic responses (fR and VT) are internally oriented. The NaCN injections indicated that fR responses were mediated by receptors predominantly in the first pair of gill arches but VT responses by receptors on all gill arches. Receptors eliciting cardiac responses were both internally and externally oriented and distributed on all gill arches or extra-branchially. Air-breathing responses were predominantly mediated by receptors in the first pair of gill arches. In conclusion, the role of the first pair of gill arches is related to: (a) an elevated EO2 providing an adequate O2 uptake to maintain the aerobic metabolism during normoxia; (b) a significant bradycardia and increased fAB elicited by externally oriented O2 chemoreceptors; (c) increase in the ventilatory variables (fR and VAMP) stimulated by internally oriented O2 chemoreceptors.
Assuntos
Ar , Peixes-Gato/fisiologia , Coração/fisiologia , Hipóxia/fisiopatologia , Respiração , AnimaisRESUMO
O objetivo deste estudo é avaliar os efeitos do extrato de levedura (EPL) em dietas úmidas sobre a microbiota fecal, a produção de gás e a morfologia intestinal de gatos adultos. Foram utilizados 20 gatos adultos, de ambos os sexos, distribuídos ao acaso em quatro tratamentos: 1) dieta comercial úmida (controle); 2) controle + 0,2% de extrato de levedura em matéria seca; 3) controle + 0,4%; e 4) controle + 0,6%. Foram realizadas a microbiologia fecal, a avaliação da morfologia intestinal por meio de exames radiográficos, ultrassonográficos e de colonoscopia, bem como a biópsia para histologia intestinal. Não foram observadas diferenças significativas (p>0,05) para contagem de bactérias do ácido lático e de clostrídio sulfito redutor, área de gás em alças intestinais (avaliação radiográfica), espessura da parede do cólon (ultrassonografia intestinal) e contagem de colonócitos/células caliciformes (histologia). Por meio da colonoscopia, notaram-se alterações em características de mucosa em animais submetidos ao tratamento 4. Conclui-se que a adição de até 0,6% de EPL não teve efeito sobre os parâmetros avaliados, mas novos estudos são necessários para compreender os mecanismos de ação e os efeitos desse aditivo para gatos domésticos.
The aim of this study is to evaluate the effects of yeast extract (EPL) in the moist diet on the fecal microbiotal, gas production and intestinal morphology of adult cats. Twenty adult cats from both sexes were randomly assigned to four treatments: 1) moist commercial diet (control); 2) control + 0,2% yeast extract dry matter; 3) control + 0,4%; and 4) control + 0,6%. Fecal microbiology and intestinal morphology were performed by radiographic, ultrasound, colonoscopy and intestinal biopsy exams for histology. There were no significant differences (P>0,05) for lactic acid bacteria counts and clostridium-reductor, gas area in the bowel (radiographic), wall thickness of the colon (ultrasound) and colonocytes count/globet cells (histology). Through colonoscopy, changes in characteristics of the intestinal mucosa in animals receiving treatment 4 were noticed. It is concluded that the addition of up to 0.6% EPL had no effect on the parameters evaluated, but further studies are needed to understand the action mechanisms and additive effects for domestic cats.
Assuntos
Animais , Gatos , Vazamento de Gases , Intestinos/anatomia & histologia , Microbiota , Gatos , DietaRESUMO
A proposta com este trabalho foi avaliar a hemiarcada superior direita de gatos domésticos por meio de técnicas radiográficas odontológicas do paralelismo, empregando-se filmes intraorais aos posicionadores de Han Shin. As imagens obtidas por essa metodologia foram correlacionadas com as técnicas radiográficas convencionais (extraorais), com o intuito de se estabelecerem vantagens ou desvantagens para detectar possíveis afecções dentais e periodontais. Foram utilizados 30 gatos, sem raça definida, 17 machos e 13 fêmeas, faixa etária entre um e três anos, confinados em gatis do Departamento de Zootecnia da Universidade Federal de Lavras/MG. Com os animais sob anestesia geral, foram realizadas radiografias da hemiarcada superior direita, incluindo três incisivos, um canino, três pré-molares e um molar em radiografias intraorais e extraorais. As imagens radiográficas foram analisadas e efetuaram-se comparações qualitativas entre pares intraorais e convencionais dos mesmos animais. Para se estabelecer a técnica radiográfica dental mais bem adaptada, foram realizadas análises estatísticas pelo teste de McNemar (qui-quadrado modificado). A técnica intraoral mostrou ser superior à extraoral (P<0,05), para achados referentes a espaço periodontal aumentado, canal radicular amplo e arredondamento de ápice, e também para a avaliação mais bem detalhada de dentes caninos, pré-molares e molares em gatos.
The aim of this research was to evaluate the right maxilla hemiarcade of cats through parallel dental radiographic techniques, applying Han Shin intraoral film positioner. Images obtained with this method were correlated with conventional radiographic techniques (extraoral). The goal was to establish the advantages and disadvantages to detect possible dental and periodontal diseases. Thirty mixed breed cats were evaluated, 17 males and 13 females, ages one to three years old, confined in catteries in the Department of Zootecnia of the Federal University of Lavras/MG. Radiographies of the right maxilla were taken with the animals under general anesthesia, and three incisors, one canine, three premolars and one molar teeth were included in the intraoral and extraoral images. The radiographic images were analyzed and a qualitative comparison of pairs of intraoral and conventional images from the same animals was achieved. To establish the dental image procedures that were better adapted for cats, the McNemar Test (Modified Qui-Square) was used for statistical analysis. The intraoral technique was superior than the extra oral (P<0,05), for findings relating to increased periodontal space, broad root canal and rounded apex, and also for a more detailed evaluation of canine, premolar and molar teeth in cats.
Assuntos
Animais , Gatos , Gatos/anatomia & histologia , Odontologia/veterinária , Radiografia , Radiografia/veterináriaRESUMO
Radiography (conventional and contrasted - canalography) and audioelectrophysiologic (impedance audiometry) tests were correlated with otitis media in 12 middle ear affected and 12 healthy dogs. When comparing both diagnostic methods, it was found that the reliability in the detection of otitis media in dogs was 100 percent for the first and 58.3-60.0 percent for the latter. Thus, it was possible to attest that the impedance audiometry was the most accurate method in the identification of otitis media in dogs when compared with radiographic assessments.
RESUMO
Foram avaliadas as técnicas radiográficas dentárias intra (TIB) e extrabucal (TEB) em 50 cães com doença periodontal, no intuito de padronizar os procedimentos de diagnóstico dessa síndrome. A TIB revelou que 16 animais não apresentaram lesões ósseas visíveis, enquanto a TEB apontou que 39 pacientes foram negativos para as mesmas lesões. Em resumo, a TIB foi mais eficaz na detecção de sinais radiográficos, especialmente as chamadas lesões finas, que a TEB, sendo a técnica de escolha na síndrome periodontal.
The intra (IOT) and extraoral (EOT) dental radiographic techniques in 50 dogs with periodontal disease were compared to standardize the most appropriate procedure for accurate diagnosis of abnormalities that occur in this syndrome. For IOT, 16 animals showed no visible radiographic lesions, whereas in EOT, 39 patients were negative for the same radiographic lesions. For incisor and canine teeth, IOT presented the highest sensitivity of lesion detection, while there was no significant difference for the premolar and molar teeth group. It is concluded that IOT is more effective in detecting radiographic signs (especially the so-called thin lesions) than the EOT and should therefore be the technique of choice in the periodontal syndrome.
Assuntos
Animais , Cães , Cães/fisiologia , Doenças Periodontais/diagnóstico , Doenças Periodontais/veterinária , Radiografia Dentária/métodos , Radiografia Dentária/veterinária , Odontologia/veterinária , Periodontia/métodosRESUMO
The African catfish, Clarias gariepinus, possesses a pair of suprabranchial chambers located in the dorsal-posterior part of the branchial cavity having extensions from the upper parts of the second and fourth gill arches, forming the arborescent organs. This structure is an air-breathing organ (ABO) and allows aerial breathing (AB). We evaluated its cardiorespiratory responses to aquatic hypoxia. To determine the mode of air-breathing (obligate or accessory), fish had the respiratory frequency (f (R)) monitored and were subjected to normoxic water (PwO(2) = 140 mmHg) without becoming hyperactive for 30 h. During this period, all fish survived without displaying evidences of hyperactivity and maintained unchanged f (R), confirming that this species is a facultative air-breather. Its aquatic O(2) uptake ([Formula: see text]) was maintained constant down to a critical PO(2) (PcO(2)) of 60 mmHg, below which [Formula: see text] declined linearly with further reductions of inspired O(2) tension (PiO(2)). Just above the PcO(2) the ventilatory tidal volume (V (T)) increased significantly along with gill ventilation ([Formula: see text]), while f (R) changed little. Consequently, the water convection requirement [Formula: see text] increased steeply. This threshold applied to a cardiac response that included reflex bradycardia. AB was initiated at PiO(2) = 140 mmHg (normoxia) and air-breathing episodes increased linearly with more severe hypoxia, being significantly higher at PiO(2) tensions below the PcO(2). Air-breathing episodes were accompanied by bradycardia pre air-breath, to tachycardia post air-breath.
Assuntos
Peixes-Gato , Doenças dos Peixes/metabolismo , Coração/fisiologia , Hipóxia/veterinária , Mecânica Respiratória , Ar , Animais , Doenças dos Peixes/patologia , Brânquias/fisiologia , Frequência Cardíaca/fisiologia , Hipóxia/metabolismo , Hipóxia/patologia , Consumo de Oxigênio , Ventilação Pulmonar/fisiologia , Respiração , Fatores de TempoRESUMO
Avaliaram-se os efeitos da suplementação de dois tipos de probióticos para cães filhotes da raça Beagle, que receberam dois tipos de dieta de alta e baixa qualidade, sobre os achados em exames de diagnóstico por imagem. Foram utilizados 18 cães filhotes da raça Beagle, distribuídos em três tratamentos inteiramente ao acaso: tratamento 1, controle (ração); tratamento 2, ração com probiótico 1 (Bifidobacterium); e tratamento 3, ração com probiótico 2 (Lactobacillus). O experimento foi dividido em duas fases, cada uma caracterizada pela mudança da dieta de qualidades diferentes. Ao exame ultrassonográfico, foi avaliada a espessura da parede gastrintestinal, e ao radiográfico, a presença de gás em alças intestinais e o espessamento da parede. Observou-se aumento da espessura da parede das alças intestinais (P<0,05), nos animais dos grupos tratados com probiótico 1 e 2 (5,74mm e 6,01mm, respectivamente) em relação aos do grupo-controle (5,03mm). O uso de probióticos não influenciou a produção de gás intestinal. Não houve diferença (P>0,05) entre os tratamentos quanto ao escore de gás intestinal. A avaliação quantitativa permitiu a determinação de um escore de gás intestinal, de forma não invasiva, por meio do software Image J®. Concluiu-se que o diagnóstico por imagem sustenta a recomendação dessa metodologia como ferramenta auxiliar na avaliação nutricional de dietas para cães.
The effects of supplementation with types of probiotics for beagle puppies that received high and low quality diets on the findings of imaging techniques were evaluaded. Eighteen animals were distributed in three randomized treatments: 1, control (diet), 2, diet with a probiotic (Bifidobacterium), and 3, diet with another probiotic (Lactobacillus). The experiment was divided into two phases each characterized by a change of diet. By ultrasonography, the thickness of the gastrointestinal wall was evaluated as well the presence of gas in the bowel and thickening of the wall by radiography. There was an increase in the thickness of the intestinal wall (P <0.05) in animals treated with probiotic, groups 1 and 2, ((5,74mm and 6,01mm, respectively) compared to the control group (5,03mm). The use of probiotics did not influence the production of intestinal gas. No significant differences (P>0.05) were observed among treatments for scores of intestinal gas. The quantitative analysis allowed the determination of a score of intestinal gas, noninvasively, using the software Image J ®. It was concluded that the imaging technique supports the recommendation of this method as an auxiliary tool in nutritional assessment of diets for dogs.
Assuntos
Animais , Cães , Diagnóstico por Imagem/veterinária , Intestinos , Intestinos , Avaliação Nutricional , Ração Animal , Suplementos Nutricionais , Cães , ProbióticosRESUMO
Control of the heart rate and cardiorespiratory interactions (CRI) is predominantly parasympathetic in all jawed vertebrates, with the sympathetic nervous system having some influence in tetrapods. Respiratory sinus arrhythmia (RSA) has been described as a solely mammalian phenomenon but respiration-related beat-to-beat control of the heart has been described in fish and reptiles. Though they are both important, the relative roles of feed-forward central control and peripheral reflexes in generating CRI vary between groups of fishes and probably between other vertebrates. CRI may relate to two locations for the vagal preganglionic neurons (VPN) and in particular cardiac VPN in the brainstem. This has been described in representatives from all vertebrate groups, though the proportion in each location is variable. Air-breathing fishes, amphibians and reptiles breathe discontinuously and the onset of a bout of breathing is characteristically accompanied by an immediate increase in heart rate plus, in the latter two groups, a left-right shunting of blood through the pulmonary circuit. Both the increase in heart rate and opening of a sphincter on the pulmonary artery are due to withdrawal of vagal tone. An increase in heart rate following a meal in snakes is related to withdrawal of vagal tone plus a non-adrenergic-non-cholinergic effect that may be due to humoral factors released by the gut. Histamine is one candidate for this role.
Assuntos
Animais , Anfíbios/fisiologia , Sistema Nervoso Autônomo/fisiologia , Peixes/fisiologia , Frequência Cardíaca/fisiologia , Répteis/fisiologia , Sistema Respiratório/inervaçãoRESUMO
Currently, liver transplantation is the only option for patients with end-stage liver disease. In Brazil, the mortality rate on the waiting list is about 25%. Multiple strategies to expand the donor pool are being pursed, however, grafts from poisoned donors are rarely used. This report documents successful liver, kidney and heart transplantations from four female donors who suffered brain death by hypoxia despite cardiopulmonary resuscitation following Aldicarb exposure ([2-methyl-2-(methylthio)propionaldehyde O-(methylcarbamoyl)-oxime]). The success rate of 12 grafts from four donors poisoned by Aldicarb was 91% 6 months after transplantation. Poisoned patients are another pool of organ donors who at present are probably underused by transplantation services. More studies are necessary to confirm the safety for the recipients.
Assuntos
Carbamatos/intoxicação , Transplante de Coração/métodos , Inseticidas/intoxicação , Transplante de Rim/métodos , Transplante de Fígado/métodos , Doadores de Tecidos/provisão & distribuição , Obtenção de Tecidos e Órgãos/métodos , Adolescente , Adulto , Criança , Feminino , Seguimentos , Humanos , Transplante de Fígado/mortalidade , Fatores de Tempo , Resultado do Tratamento , Listas de Espera , Adulto JovemRESUMO
Control of the heart rate and cardiorespiratory interactions (CRI) is predominantly parasympathetic in all jawed vertebrates, with the sympathetic nervous system having some influence in tetrapods. Respiratory sinus arrhythmia (RSA) has been described as a solely mammalian phenomenon but respiration-related beat-to-beat control of the heart has been described in fish and reptiles. Though they are both important, the relative roles of feed-forward central control and peripheral reflexes in generating CRI vary between groups of fishes and probably between other vertebrates. CRI may relate to two locations for the vagal preganglionic neurons (VPN) and in particular cardiac VPN in the brainstem. This has been described in representatives from all vertebrate groups, though the proportion in each location is variable. Air-breathing fishes, amphibians and reptiles breathe discontinuously and the onset of a bout of breathing is characteristically accompanied by an immediate increase in heart rate plus, in the latter two groups, a left-right shunting of blood through the pulmonary circuit. Both the increase in heart rate and opening of a sphincter on the pulmonary artery are due to withdrawal of vagal tone. An increase in heart rate following a meal in snakes is related to withdrawal of vagal tone plus a non-adrenergic-non-cholinergic effect that may be due to humoral factors released by the gut. Histamine is one candidate for this role.
Assuntos
Anfíbios/fisiologia , Sistema Nervoso Autônomo/fisiologia , Peixes/fisiologia , Frequência Cardíaca/fisiologia , Répteis/fisiologia , Sistema Respiratório/inervação , AnimaisRESUMO
Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG) located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.
Assuntos
Animais , Anfíbios/fisiologia , Peixes/fisiologia , Respiração , Répteis/fisiologia , Células Quimiorreceptoras/fisiologia , Mecanorreceptores/fisiologia , Sistema Respiratório/inervaçãoRESUMO
Fish and amphibians utilise a suction/force pump to ventilate gills or lungs, with the respiratory muscles innervated by cranial nerves, while reptiles have a thoracic, aspiratory pump innervated by spinal nerves. However, fish can recruit a hypobranchial pump for active jaw occlusion during hypoxia, using feeding muscles innervated by anterior spinal nerves. This same pump is used to ventilate the air-breathing organ in air-breathing fishes. Some reptiles retain a buccal force pump for use during hypoxia or exercise. All vertebrates have respiratory rhythm generators (RRG) located in the brainstem. In cyclostomes and possibly jawed fishes, this may comprise elements of the trigeminal nucleus, though in the latter group RRG neurons have been located in the reticular formation. In air-breathing fishes and amphibians, there may be separate RRG for gill and lung ventilation. There is some evidence for multiple RRG in reptiles. Both amphibians and reptiles show episodic breathing patterns that may be centrally generated, though they do respond to changes in oxygen supply. Fish and larval amphibians have chemoreceptors sensitive to oxygen partial pressure located on the gills. Hypoxia induces increased ventilation and a reflex bradycardia and may trigger aquatic surface respiration or air-breathing, though these latter activities also respond to behavioural cues. Adult amphibians and reptiles have peripheral chemoreceptors located on the carotid arteries and central chemoreceptors sensitive to blood carbon dioxide levels. Lung perfusion may be regulated by cardiac shunting and lung ventilation stimulates lung stretch receptors.
Assuntos
Anfíbios/fisiologia , Peixes/fisiologia , Répteis/fisiologia , Respiração , Animais , Células Quimiorreceptoras/fisiologia , Mecanorreceptores/fisiologia , Sistema Respiratório/inervaçãoRESUMO
Relata-se a avaliação ultrassonográfica, com auxílio do Doppler em cores, da anomalia vascular portossistêmica em um cão da raça Poodle Toy, que apresentou edema pulmonar e alterações gastrintestinais. Ao exame ultrassonográfico, foram observados vasos portais dilatados e tortuosos. Esses resultados associados aos achados clínicos e laboratoriais permitem identificar a anomalia vascular portossistêmica no paciente.
It was reported the ultrasonographic evaluation, assisted to Doppler color, of the portosystemic vascular anomaly in a Poodle Toy dog. The dog was referred with lung edema and gastrointestinal alterations. At ultrasonographic exam, portal vessels were extended and tortuous. These findings associated to clinical and laboratorial findings, allowed to identify the vascular portosystemic anomaly in the patient.
Assuntos
Animais , Masculino , Cães , Veia Porta , Ultrassonografia Doppler , Doenças VascularesRESUMO
Congenital, hereditary, and developmental diseases are common in small animals radiology. Chondrodystrophy is characterized to osteoarticular angular deformities. The aim of this study is to relate a case of feline chondrodystrophy, alteration uncommon in this species. The animal presented bone alterations in limbs, without healthy commitment at clinical examination. At radiographic evaluation, bone angulation was altered in long bones with articulation enlargement. It was concluded that, even uncommon in felines, chondrodystrophy may be an incidental radiographic finding, but with importance to epidemiologic aspect of this disease.
Assuntos
Animais , Gatos , Osteocondrodisplasias/classificação , Osteocondrodisplasias , Osteocondrodisplasias/veterináriaRESUMO
The role of the parasympathetic nervous system, operating via the vagus nerve, in determining heart rate (f(H)) and cardiorespiratory interactions was investigated in the neotropical fish Piaractus mesopotamicus. Motor nuclei of branches of cranial nerves VII, IX and X, supplying respiratory muscles and the heart, have an overlapping distribution in the brainstem, while the Vth motor nucleus is more rostrally located. Respiration-related efferent activity in the cardiac vagus appeared to entrain the heart to ventilation. Peripheral stimulation of the cardiac vagus with short bursts of electrical stimuli entrained the heart at a ratio of 1:1 over a range of frequencies, both below and sometimes above the intrinsic heart rate. Alternatively, at higher bursting frequencies the induced f(H) was slower than the applied stimulus, being recruited by a whole number fraction (1:2 to 1:6) of the stimulus frequency. These effects indicate that respiration-related changes in f(H) in pacu are under direct, beat-to-beat vagal control. Central burst stimulation of respiratory branches of cranial nerves VII, IX and X also entrained the heart, which implies that cardiorespiratory interactions can be generated reflexly. Central stimulation of the Vth cranial nerve was without effect on heart rate, possibly because its central projections do not overlap with cardiac vagal preganglionic neurons in the brainstem. However, bursts of activity recorded from the cardiac vagus were concurrent with bursts in this nerve, suggesting that cardiorespiratory interactions can arise within the CNS, possibly by irradiation from a central respiratory pattern generator, when respiratory drive is high.
Assuntos
Peixes/fisiologia , Frequência Cardíaca/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Mecânica Respiratória/fisiologia , Nervo Vago/fisiologia , Animais , Vias Eferentes/fisiologia , Estimulação Elétrica , Nervo Vago/anatomia & histologiaRESUMO
Avaliou-se o efeito de dois fosfatos, tripolifosfato de sódio (TPF) e hexametafosfato de sódio (HMF), incorporados à ração seca sob diferentes formas, como cobertura do grânulo da ração e no interior da massa da ração, na prevenção do desenvolvimento de cálculo dentário em 25 cães. O delineamento experimental utilizado foi inteiramente ao acaso, com cinco tratamentos e cinco repetições. Os tratamentos experimentais foram: 1) ração seca; 2) ração seca com TPF incorporado na cobertura do grânulo da ração; 3) ração seca com TPF incorporado na massa da ração; 4) ração seca com HMF incorporado na cobertura do grânulo da ração; 5) ração seca com HMF incorporado na massa da ração. Os animais receberam as dietas por um período experimental de 90 dias e, após esse período, foram submetidos à avaliação da área de cálculo dentário formado. A inclusão do HMF na ração seca, tanto na cobertura dos grânulos como no interior da massa, e do TPF, como cobertura dos grânulos, reduziu o acúmulo de cálculo dentário em cães, comparada à dieta sem adição de fosfatos. O HMF foi o fosfato mais eficiente, ao reduzir o acúmulo de cálculo dentário em até 47 por cento. As formas de inclusão do HMF na ração não influenciaram o acúmulo de cálculo dentário. Houve redução do desenvolvimento de cálculo dentário pela incorporação do TPF como cobertura do grânulo da ração, comparada à inclusão deste fosfato no interior da massa da ração. Conclui-se que os fosfatos incorporados na ração seca reduzem o acúmulo de cálculo dentário em cães.
The effect of dry food treated with sodium tripolyphosphate (TPP) or sodium hexametaphosphate (HMP), as kibble coated or added into the interior of the kibble on the accumulation of dental calculus in 25 dogs was evaluated. The study used a completely randomized design with five treatments and five repetitions. The experimental treatments were: 1) dry food; 2) dry food coated with TPP; 3) dry food with TPP incorporated into the interior of the kibble; 4) dry food coated with HMP; 5) dry food with HMP incorporated into the interior of the kibble. The animals received the diets for a 90-day experimental period, and then, the teeth were clinically examined for the presence of calculus. The inclusion of HMP in the dry food, as kibble coated or added into the interior of the kibble, and the inclusion of TPP as kibble coated reduced the accumulation of dental calculus compared to the control group without anti-calculus agents. HMP was the most efficient phosphate, reducing the accumulation of dental calculus in 47 percent. The forms of HMP inclusion in the dry food exerted no significant effect upon calculus formation. However, there was a reduction of calculus accumulation when TPF was incorporated as coating of the kibble, compared to the inclusion of this phosphate into the interior of the kibble. It was concluded that phosphates incorporated in the dry food reduce the accumulation of dental calculus in dogs.