Endogenous serum insulin concentration in dogs with diabetic ketoacidosis

Objective: To determine endogenous serum insulin concentration in dogs with diabetic ketoacidosis (DKA), and to compare it to endogenous serum insulin concentration in diabetic dogs with ketonuria but no acidosis (KDM), diabetic dogs with uncomplicated diabetes mellitus (DM) that did not have ketonuria or acidosis, and dogs with non‐pancreatic disease (NP). Design: Prospective study. Setting: Veterinary Hospital of the University of Pennsylvania. Animals: Forty‐four client‐owned dogs; 20 dogs with newly diagnosed diabetes mellitus (7 dogs with DKA, 6 dogs with KDM, and 7 dogs with DM) and 24 dogs with non‐pancreatic disease. Interventions: Blood and urine samples were obtained at the time of admission to the hospital. Measurements and main results: Signalment, clinical signs, physical examination findings, and concurrent disease were recorded for all dogs. Blood glucose concentration, venous blood pH, venous blood HCO3^? concentration, urinalysis, and endogenous serum insulin concentration were determined in all dogs. Dogs with DKA have significantly decreased endogenous serum insulin concentrations compared to dogs with DM (P = 0.03) and dogs with non‐pancreatic disease (P = 0.0002), but not compared to dogs with KDM (P = 0.2). Five of 7 dogs with DKA had detectable endogenous serum insulin concentrations, and 2 of these dogs had endogenous serum insulin concentration within the normal range. Conclusions: Diabetic dogs with ketoacidosis have significantly decreased endogenous serum insulin concentration compared to dogs with uncomplicated diabetes mellitus. However, most dogs with DKA have detectable endogenous serum insulin concentrations, and some dogs with DKA have endogenous serum insulin concentrations within the normal range.     

Bartonellosis in cats: a role in uveitis?

Bartonellosis has been widely studied in human and veterinary medicine over the past two decades. Despite this fact, it remains an enigmatic disease in many ways. The causative bacteria, Bartonella spp, are transmitted to cats by fleas and thus the prevalence in cat populations, particularly in temperate climates, is high. Most cats, whether infected naturally or experimentally, remain asymptomatic. Thus, correlating the presence of the organism to clinical disease, including uveitis, in cats has been difficult. This review summarizes what is known of the transmission and pathogenesis of Bartonella spp in cats, the possible role of the organism in feline ocular disease, as well methods of diagnosis and treatment.     

Pathophysiology of abomasal parasitism: is the host or parasite responsible?

Nematode larvae developing within the glands cause local loss of parietal cells and mucous cell hyperplasia whereas reduced acid secretion, increased serum gastrin and pepsinogen concentrations and generalized histological changes are associated with parasites in the abomasal lumen. Parietal cells with dilated canaliculi and/or degenerative changes typical of necrosis are present soon after the transplantation of adult worms, and abomasal secretion is also affected. Anaerobic bacteria survive in greater numbers as the pH rises, with bacterial densities becoming similar to ruminal populations at an abomasal pH of 4 and above. Failure to lyse bacteria may affect adversely the nutrition of the host. The parasites may initiate the pathophysiology through the release of excretory/secretory (ES) products which either act directly on parietal cells or indirectly through enterochromaffin-like (ECL) cells by provoking inflammation or by disrupting the protective mucosal defence system.Parietal cell dysfunction is proposed as a key event which leads to loss of mature chief cells and mucous cell hyperplasia, as well as hypergastrinaemia. Inflammation increases circulating pepsinogen concentrations and may also contribute to increased gastrin secretion. Stimulation of mucosal proliferation and differentiation of parietal cells in the isthmus by the raised serum gastrin levels will be beneficial by generating a new population of active parietal cells and adequate acid secretion.     

Xanthine oxidase activity exerts pro‐oxidative and pro‐inflammatory effects in serum of silver catfish fed with a diet contaminated with aflatoxin B1

Several studies have associated the involvement of xanthine oxidase (XO) activity, a source of uric acid and reactive oxygen species (ROS), to pro‐oxidative and pro‐inflammatory effects during pathological conditions. Considering this, the aim of this study was to evaluate whether upregulation on seric XO activity may be a pathway involved in the oxidative stress in fish exposed to a diet contaminated with aflatoxin B₁ (AFB₁), as well as whether it may be considered a pathway involved in ROS and NOx production. Xanthine oxidase activity, as well as the uric acid, ROS and NOx levels increased in serum of fish fed with a AFB₁‐contaminated diet on days 14 and 21 post‐feeding compared to fish fed with a basal diet. Based on these evidences, upregulation of seric XO activity induces pro‐oxidant and pro‐inflammatory profiles in serum of fish fed with a AFB₁‐contaminated diet due to excessive formation on uric acid. Also, the excessive uric acid induces the release of pro‐oxidant and pro‐inflammatory mediators, as ROS and NOx, also contributing to oxidative and inflammatory profiles. In summary, the upregulation on seric XO activity may be considered a pathway involved in the oxidative stress of fish exposed to a diet contaminated with AFB₁.     

异育银鲫溶血性腹水病的病理生理研究

异育银鲫溶血性腹水病的腹水呈淡黄或红色,透明或混浊,pH 值6.5,多数发生凝固,李凡他氏蛋白质定性试验阳性,是由炎症引起的渗出液,主要是肝性腹水。病鱼血清的钠、氯、葡萄糖、总蛋白、白蛋白都非常显著地低于健康鱼,白蛋白的含量不到健康鱼的1％。病鱼血清肌酐、LDH、GOT、GPT,AMY 均非常显著地高于健康鱼。所有这些都表明病鱼的肝、肾、心、胰等发生了严重病变,肝功能不全,肾功能不全,胰功能不全,最后导致尿毒症及肝昏迷而死。     

基于卓越人才培养计划下动物病理生理学实验教学改革与探讨

实验教学是高校实现人才培养目标的重要环节,随着卓越人才培养计划模式的提出,《动物病理生理学》作为承前启后的桥梁课程,其传统的实验教学模式已经无法满足人才培养目标的要求。因此,进一步加深和完善该课程的实验教学改革具有重要的现实意义。在分析传统实验教学中存在的问题的同时,提出了基于卓越人才计划培养模式下的实验教学改革方案,以期为提高动物病理生理学实验教学效果提供参考与借鉴。     

Diseases of tunas,Thunnus spp

Much is known about those aspects of tuna health which can be studied in wild populations, e.g. helminth parasites. However, because aquaculture of these species is in its infancy, knowledge of microbial, nutritional and environmental diseases is limited. This review is an attempt to bring together the available information on those diseases of Thunnus spp. which cause significant morbidity, mortality or economic loss. In doing so it has become clear that much more research needs to be undertaken on the physiology of the species (southern, northern and Pacific bluefin tuna) currently used in aquaculture in order for the pathogenesis of some conditions to be properly understood. Attempts at hatchery culture of Pacific bluefin tuna has indicated that Thunnus spp. will be problematic to hatch and propagate.     

Ruminal,cardiorespiratory and adrenocortical sequelae of Na2EDTA-induced hypocalcaemia in calves

A study was undertaken to provide further information on the ruminal, cardiorespiratory and hypothalamo-pituitary-adrenocortical (HPAC) physiological sequelae of hypocalcaemia in dairy calves.The functional picture observed in standing calves experiencing Na₂EDTA-induced progressive hypocalcaemia showed a biphasic pattern. During the first phase (Ca²⁺ varying between 1.20±0.09 and 0.64±0.15 mmol/L, mean±SD), the animals became dull and lethargic, shifting their weight from one hind limb to the other, with cool extremities and hypersalivation. Their ventilation was slightly increased but their heart rate, thoracoabdominal pressure, pulmonary mechanics, haemoglobin and temperature remained constant. Conversely, their systemic arterial pressure (SAP) and the amplitude of their ruminal contractions (RCA) were severely decreased. During the second phase (Ca²⁺ <0.64±0.15 mmol/L), there was restlessness, tachycardia, hypertension, polycythaemia and, finally, inability to stay upright. It is suggested that the diminished Ca²⁺ availability caused smooth-muscle and myocardial dysfunctions which could explain the RCA and SAP changes recorded during the first phase, whereas neural and/or humoral sympathetic discharge probably accounted for the reversal in SAP and heart rate when Ca²⁺ was decreased further. Serum cortisol increased regularly and remained significantly correlated with Ca²⁺ in each animal. Moreover, regression of cortisol/Ca²⁺ on Ca²⁺/ Na₂EDTA was significant (p0.001).It was concluded that mild asymptomatic hypocalcaemia severely impairs ruminal function, which will progressively worsen the Ca²⁺ deficit; that the inability to maintain posture in hypocalcaemia is not due to hypotension; and that the higher the HPAC response to hypocalcaemia, the higher the resistance to its effects. An asymptomatic periparturient cow with barely detectable ruminal activity may merit preventive calcium borogluconate therapy. Also, the physiological role of hypotension in explaining the clinical picture may be less important than other processes, such as neuromuscular failure. Finally, the present results imply a possible HPAC exhaustion in cows with periparturient paretic hypocalcaemia.Abbreviations A-aDO₂ alveolar-arterial O₂ difference - AVP arginin vasopressin - C _Ldyn dynamic lung compliance - ECG electrocardiogram - EEZF end expiratory zero flow - Hb_TOT total haemoglobin content - HPAC hypothalamo-pituitary-adrenocortical - HR heart rate - Na₂EDTA disodium ethylenediaminetetraacetate - O_2CT total O₂ content - P _aCO₂ arterial CO₂ tension - P _aO₂ arterial O₂ tension - PH periparturient hypocalcaemia - P _pl pleural pressure - P _ru intraruminal pressure - PTH parathyroid hormone - P_TOT plasma total protein - RCA amplitude of ruminal contraction - RCD duration of ruminal contraction - RCF frequency of ruminal contraction - R _L total pulmonary resistance - RR respiratory rate - SAP systemic arterial pressure - T _E expiratory time - T _I inspiratory time - T _p core temperature - V respiratory airflow - V _E minute volume - V _T tidal volume     

Evidence for a parasite-mediated inhibition of abomasal acid secretion in sheep infected with Ostertagia leptospicularis

The acid secretory capacity of the abomasal mucosa was studied in sheep experimentally infected with Ostertagia leptospicularis. The acidity of the abomasal contents, permanently recorded by a pH probe located inside the abomasum, decreased markedly to mean levels between pH 5 and 6. Subcutaneous administration of histamine or carbachol successfully stimulated acid secretion (pH 3.4). The results indicate that the abomasal mucosa harboured a population of functional parietal cells which were also identified immunohistochemically (H(+)/K(+)-ATPase). Ultrastructural investigation before stimulation revealed that the majority of these cells was in a resting state. Despite high serum gastrin levels, the acid secretion was blocked either at the level of the parietal cell or the enterochromaffin-like cell by an unknown factor, possibly mediated by the parasites. This is the first report of a parietal cell dysfunction associated with a nematode infection in the abomasum. It is suggested that the parasites induce changes in their environment which favour their survival and/or increase their reproduction.     

Transvascular fluid dynamics

Objective To review the pathophysiology of fluid and macromolecular movement between the microvascular, interstitial and lymphatic spaces and provide a basis for logical intravenous colloid therapy. Databases used Medline (1966 – present), Commonwealth Agricultural Bureaux abstracts (1973 – present) and Personal files.