Laryngeal rhabdomyoma in a dog

A 4-year-old spayed female Golden Retriever was presented for investigation of progressive loss of bark, continuous panting and increased upper respiratory noise. Examination of the larynx and pharynx under general anaesthesia identified a spherical 5 x 3 cm mass involving the right arytenoid cartilage. Cytological examination of fine needle aspirates from the mass suggested the tumour was a carcinoma, however histological examination in association with immunoperoxidase and histochemical staining identified the mass as a laryngeal rhabdomyoma.     

Lymphosarcoma with conjunctival manifestation in a guinea pig

A guinea pig with multicentric lymphosarcoma and conjunctival manifestation is described. Primary clinical signs were bilateral infiltrative conjunctival masses. Antemortem diagnosis was based on the cytology of biopsies of conjunctival tissue, fine-needle aspirates of peripheral lymph nodes, and peripheral blood smears.     

人附红细胞体感染FMMU白化豚鼠的研究

用附红细胞体分别感染FMMU白化豚鼠和普通花色豚鼠，同时测定两组豚鼠的红细胞免疫功能，探讨FMMU白化豚鼠的免疫学特性与病原体敏感性之间的关系。结果表明，FMMU白化豚鼠对人附红细胞体比普通花色豚鼠敏感。封闭群FMMU白化豚鼠有独特的免疫学特性，红细胞免疫功能低于普通花色豚鼠，对病原体敏感性高于普通花色豚鼠，更适于建立感染性疾病动物模型。     

Spontaneous Ameloblastic Fibroma in a Young Guinea Pig

A spontaneous ameloblastic fibroma was found in a 9-week-old guinea pig. Histopathologically, neoplastic cells consisted of two components: an odontogenic epithelium and odontogenic mesenchyme. The odontogenic epithelium formed strands, nests and islands that were interspersed within the odontogenic mesenchyme. In the marginal region, odontoblasts and scant dysplastic eosinophilic material were seen between these two components. Immunohistochemically, the odontogenic epithelium was positive for cytokeratin AE1/AE3, and the odontogenic mesenchyme and odontoblast were positive for vimentin, in the same manner as in the normal tooth germ (control). We could not obtain conclusive data suggesting that the eosinophilic material was dental hard tissue because the eosinophilic material was not stained specifically by any methods. Based on these histological characteristics, the tumor in the present case was diagnosed as an ameloblastic fibroma. This is the first report of ameloblastic fibroma in guinea pigs.     

Cutaneous vascular malformation in a guinea pig (Cavia porcellus)

Abstract   A skin lesion classified as a vascular malformation is reported in a young-adult, female guinea pig. The physical examination revealed a 3 × 2-cm irregularly shaped violaceous plaque located on the left caudal flank. The surface of the plaque was ulcerated and bled intermittently, resulting in fatal blood loss. On histology the mass consisted of variably sized vascular spaces filled with red blood cells and variable amounts of extramedullary haematopoietic cells, lined by well-differentiated endothelial cells often surrounded by one layer of spindle-shaped cells. Based on immunohistochemistry, the spindle cell population was confirmed to be smooth muscle cells and no proliferation of endothelial cells was found with the Ki67 proliferation marker. Histological and immunohistochemical findings were consistent with a vascular malformation. Classification of vascular malformations and potential treatments are discussed. To the authors' knowledge, this is the first reported case of a cutaneous vascular lesion in a guinea pig.     

Conjunctival swab cytology from a guinea pig: it's elementary!

Three 3-month-old guinea pigs (Cavia porcellus) were evaluated for purulent ocular discharge. Conjunctival swabs were obtained for cytologic evaluation of Wright's-Giemsa-stained preparations. The specimen from the most severely affected guinea pig consisted primarily of karyolytic neutrophils and small lymphocytes. Epithelial cells occasionally were observed that contained intracytoplasmic coccoid basophilic organisms, 0.5-1.5 microm in diameter. The intraepithelial inclusions were most consistent with Chlamydia sp elementary and reticulate bodies. Specimens from the other 2 guinea pigs had a similar inflammatory response, but organisms were not observed. Polymerase chain reaction (PCR) analysis of a conjunctival swab from the most severely affected guinea pig was positive for C psittaci, which also is referred to as Chlamydophila caviae, immunotype 8, formerly known as the guinea pig inclusion conjunctivitis strain of C psittaci. Chlamydial conjunctivitis is a common problem in guinea pig populations, with C caviae being specific for this species. Cytologic identification of elementary or reticulate bodies within epithelial cells is diagnostic for the organism in Giemsa-stained preparations. However, PCR is an important complementary tool when organisms are not observed and for accurate classification of the Chlamydia species.     

FMMU白化豚鼠用作爆震性耳聋动物模型

为了探讨本中心培育的 FMMU白化豚鼠在听力功能损伤中的模型价值 ,利用听性脑干诱发电位 (ABR)、扫描电镜观察等方法 ,比较了爆震前、后 FMMU白化豚鼠和杂色豚鼠听力功能和结构的变化。结果如下 :爆震前 ,FMMU白化豚鼠的 ABR阈值小于杂色豚鼠的 ABR阈值 ;爆震后 ,FMMU白化豚鼠阈移增加比杂色豚鼠快且明显 ,阈移的恢复比杂色豚鼠慢 ;爆震后 2 1d,FMMU白化豚鼠的永久性阈移大于杂色豚鼠的永久性阈移 ;FMMU白化豚鼠耳蜗超微结构和听力功能的损伤比杂色豚鼠严重。由此表明 ,FMMU白化豚鼠听力敏锐 ,适于作听功能研究 ,其耳蜗对爆震的敏感性较高 ,可制作出较理想的爆震性耳聋动物模型     

Ocular disease in the guinea pig (Cavia porcellus): a survey of 1000 animals

Objective Anecdotal evidence has suggested that guinea pigs have a high prevalence of ocular lesions. Here we undertook a survey of 1000 guinea pigs from populations of animals kept as laboratory animals, breeding show cavies, animals kept as pets and those from rescue and rehoming centers. Each animal was examined to assess for ocular abnormalities. Procedures A full ophthalmic examination was performed on each animal with direct and indirect ophthalmoscopy and with slit lamp biomicroscopy. Measurement of tear production using the Schirmer tear test 1 and intraocular pressure using the Tonopen applanation tonometer after topical anesthesia was undertaken in selected animals. Results Forty‐five percent of animals examined had some ocular abnormality. The majority were lens lesions including 17% with cataract and 21% with subclinical lens abnormalities such as nuclear sclerosis. Other abnormalities included conjunctivitis in 4.7% and keratitis in 3.6%. Lipid deposition in conjunctiva was observed in 2.3% of guinea pigs and ciliary body heterotopic bone formation in 0.8% of animals. Conclusions This study shows a high proportion of eyes with some degree of abnormality in animals otherwise considered healthy. Information on diseases of the guinea pig eye is important given the use of the species as a laboratory rodent and also the number kept as pets and show animals.     

Glandular structures in the major interlobular and extrapancreatic ducts in the guinea pig

The morphology of the pancreatic duct system did not receive much attention as compared to the microanatomy of the exocrine and endocrine pancreas. The histological peculiarities of the excretory duct system are of major importance especially in laboratory animals like guinea pigs. The paper describes the histological peculiarities of the major interlobular and extrapancreatic ducts in guinea pigs. The pancreatic tissue samples were collected from five guinea pigs. For histological investigation, several pancreatic fragments underwent fixation in 10% buffered formalin and were later processed by the standard paraffin technique. Subsequentially, tissue sections were stained by Goldner's trichrome staining. The mucous substances were assessed by Alcian blue and Periodic acid–Schiff staining methods. The interlobular and main pancreatic ducts in the guinea pig present a simple columnar epithelium surrounded by a thick layer of dense connective tissue. The aforementioned epithelium of the main pancreatic ducts includes principal cells, goblet cells and basal cells. Additionally, the ductal epithelium presents occasional unicellular multiloculated intraepithelial mucous glands and prominent extraepithelial glands. The latter adopts a simple or compound tubular feature. The mucus elaborated by the three glandular types is mostly neutral in goblet cells, predominantly acidic in extraepithelial ductal glands, and a similar amount of acidic and neutral mucin in intraepithelial glands. In conclusion, the epithelium-associated mucous glands in the interlobular and main pancreatic ducts in the guinea pig are restricted not only to goblet cells. A substantial mucous discharge probably with a protecting role against irritative pancreatic juice derives from the main ductal intraepithelial and extraepithelial glands.     

pH-dependent modulation of intracellular free magnesium ions with ion-selective electrodes in papillary muscle of guinea pig

A change in pH can alter the intracellular concentration of electrolytes such as intracellular Ca²⁺ and Na⁺ ([Na⁺]_i) that are important for the cardiac function. For the determination of the role of pH in the cardiac magnesium homeostasis, the intracellular Mg²⁺ concentration ([Mg²⁺]_i), membrane potential and contraction in the papillary muscle of guinea pigs using ion-selective electrodes changing extracellular pH ([pH]_o) or intracellular pH ([pH]_i) were measured in this study. A high CO₂-induced low [pH]_o causes a significant increase in the [Mg²⁺]_i and [Na⁺]_i, which was accompanied by a decrease in the membrane potential and twitch force. The high [pH]_o had the opposite effect. These effects were reversible in both the beating and quiescent muscles. The low [pH]_o-induced increase in [Mg²⁺]_i occurred in the absence of [Mg²⁺]_o. The [Mg²⁺]_i was increased by the low [pH]_i induced by propionate. The [Mg²⁺]_i was increased by the low [pH]_i induced by NH₄Cl-prepulse and decreased by the recovery of [pH]_i induced by the removal of NH₄Cl. These results suggest that the pH can modulate [Mg²⁺]_i with a reverse relationship in heart, probably by affecting the intracellular Mg²⁺ homeostasis, but not by Mg²⁺ transport across the sarcolemma.     

Comparison of opioid receptor binding in horse, guinea pig, and rat cerebral cortex and cerebellum

OBJECTIVE: To compare the density and binding characteristics of opioid receptor subtypes in horse, rat, and guinea pig cerebral cortex and cerebellum. STUDY DESIGN: Prospective receptor binding study. ANIMALS: Whole brains were obtained from four neurologically normal adult horses during necropsy. Rat and guinea pig brains were obtained commercially. METHODS: The cerebellum and cerebral cortex were dissected from each brain, and tissue homogenates prepared. A radioligand binding technique with the highly selective ligands [(3)H]-DAMGO, [(3)H]-U69593, and [(3)H]-DPDPE was used to identify the mu- (mu), kappa- (kappa) and delta- (delta) opioid receptors, respectively. Competitive binding assays were performed with these ligands and varying concentrations of one of multiple unlabeled ligands. RESULTS: While there were marked species differences in relative densities of opioid receptors, all radioligands interacted with their binding sites with high, nanomolar affinity in both the cerebral cortex and cerebellum. In the horse cerebral cortex, the percentages of total opioid binding sites for the mu-, kappa- and delta-receptors were 71%, 14% and 15%, respectively. In the rat and guinea pig cerebral cortex, the corresponding values were 56% mu-, 4% kappa- and 40% delta-receptors, and 25% mu-, 37% kappa- and 38% delta-receptors, respectively. In horse and guinea pig cerebellum, the binding was 37% mu-, 59% kappa- and 4% delta-receptors, and 15% mu-, 76% kappa- and 10% delta-receptors, respectively. For competitive analysis, all competitors of the mu-, kappa- and delta-receptors completely displaced [(3)H]-DAMGO, [(3)H]-U69593, and [(3)H]-DPDPE and had inhibitory constants in the nanomolar range. CONCLUSION AND CLINICAL RELEVANCE: Horses used in this study had a greater density of mu-receptors in the cerebral cortex compared with rats and guinea pigs but without further characterization of the functional role of these receptors it is impossible to determine the clinical significance of these data.     

Conjunctival dermoid in two guinea pigs: a case report

Clinical and histologic findings of conjunctival dermoids in two unrelated guinea pigs are described. The dermoids were treated surgically by resection with superficial lamellar keratectomy and corneal epithelial debridement. Histologically the dermis underneath a stratified squamous keratinized and variably pigmented epithelium consisted of multiple hair follicles, with clearly visible arrectores pilorum muscles, sebaceous glands and loose vascularized fatty tissue.     

口蹄疫病毒多基因及猪α干扰素共表达载体的构建及其免疫豚鼠效果研究

为探讨口蹄疫病毒多基因及猪α干扰素（IFN-α）基因共表达真核质粒进入临床试验的可行性,本试验用PCR方法扩增了口蹄疫病毒P12A3C及部分2B基因（P12X3C）和猪IFN-α基因,克隆到真核表达载体pBudCE4.1中,经双酶切鉴定后,将重组质粒pBudCE4.1-P12X3C-IFN-α转染BHK-21细胞中,观察目的基因的表达,并将重组质粒免疫豚鼠,检测豚鼠的血清抗体水平、中和抗体滴度及T淋巴细胞增殖情况。结果显示,经酶切鉴定及DNA序列分析成功构建了重组质粒pBudCE4.1-P12X3C-IFN-α,转染BHK-21细胞后,通过Western blotting、间接免疫荧光试验鉴定证实重组质粒能有效表达。ELISA结果显示,重组质粒pBudCE4.1-P12X3C-IFN-α比重组质粒pBudCE4.1-P12X3C能诱导机体产生更高水平的抗口蹄疫病毒的血清抗体,且中和抗体滴度也高于重组质粒pBudCE4.1-P12X3C组。MTT法检测结果表明,重组质粒pBudCE4.1-P12X3C-IFN-α组淋巴细胞增殖可达15%,而重组质粒pBudCE4.1-P12X3C组则为11%。攻毒后重组质粒pBudCE4.1-P12X3C-IFN-α组和灭活疫苗组保护率达100%,高于重组质粒pBudCE4.1-P12X3C组的80%。本试验成功构建了重组质粒pBudCE4.1-P12X3C-IFN-α,猪IFN-α作为佐剂可有效辅助口蹄疫DNA疫苗提高动物体内的免疫反应。     

Anatomical study of blood supply to the cervical spinal cord in the guinea pig

The aim of this study was to describe the arterial arrangement of the cervical spinal cord in the guinea pig. The study was carried out on 20 adult English self guinea pigs using corrosion and dissection technique. Batson's corrosion casting kit no. 17^© was used as a casting medium. The origin of the ventral spinal artery from the left vertebral artery was found on average in 35% of the cases and from the right vertebral artery on average in 40% of the cases. The ventral spinal artery with origin from the anastomosis of two medial branches was found on average in 25% of the cases. The presence of ventral radicular branches of rami spinales entering the ventral spinal artery in the cervical region was observed in 42% of the cases on the right side and in 58% of the cases on the left side. The presence of dorsal radicular branches of rami spinales that reached the spinal cord was observed in 63% of the cases on the left side and in 37% of the cases on the right side. The number of radicular branches supplying the spinal cord is greater in guinea pig than in humans.     

用DNA指纹技术研究Zmu-1:DHP豚鼠的群体遗传结构

为了鉴定Zm u-1∶DHP新品系豚鼠的遗传组成,试验以Jeffreys 33.6和33.15探针,分别与Zm u-1∶DHP和DHP 2个品系豚鼠基因组DNA的H in fⅠ和H aeⅢ酶切限制性片段进行Sou thern杂交,绘制豚鼠DNA指纹图,分析豚鼠基因组DNA限制性片段长度的多态性。结果显示,33.6探针与H in fⅠ酶组合应用,多态性程度较高,制图效果好;Zm u-1∶DHP豚鼠的DNA指纹图中,在6 kb和9 kb标记点出现特征性基因序列片段;Zm u-1∶DHP品系内的相似系数Fm=0.834±0.066,显著高于DHP品系内的Fm=0.653±0.158,也高于2个品系的Fm=0.670±0.115;Zm u-1∶DHP豚鼠2随机个体间遗传组成完全相同的机率Fmn=1.07×10-2,高于DHP豚鼠的Fmn=8.474×10-5。表明该方法用于豚鼠遗传质量检测和品系鉴定是可行的。Zm u-1∶DHP和DHP豚鼠都属远交系动物,但前者的遗传基因纯合性显著高于后者,结合性状可以看出,Zm u-1∶DHP豚鼠遗传分化形成了新的品系。     

Zmu-1:DHP豚鼠部分生物学特性研究

为积累Zmu-1：DHP豚鼠的生物学特性资料,本研究使用肥大细胞抗原攻击、补体溶血CH50、流式细胞仪及病毒感染方法,测定了豚鼠致敏肥大细胞对抗原的敏感性、血清总补体的活性、血液多形核白细胞的吞噬和呼吸爆发功能及对口蹄疫病毒的敏感性.结果显示,Zmu-1：DHP豚鼠致敏肥大细胞的脱颗粒反应明显低于其它品系（P＜0.01）,血清补体含量大于其它品系（P＜0.01）,多形核白细胞的吞噬功能高于其它品系（P＜0.05）,而呼吸爆发功能低于其它品系（P＜0.01）,对口蹄疫病毒呈现100%的敏感性.表明Zmu-1：DHP豚鼠的生物学特征已不同于其它品系,形成独特的遗传组成和生物学性状,具有较高的应用优势及推广价值.     

试验用Hartley豚鼠的饲养及滴鼻剂变应性鼻炎建模

为探索试验用Hartley豚鼠的饲养及建立滴鼻剂变应性鼻炎(AR)模型的有效方法,本试验采用单因素试验,考察了试验动物种类、饲养方式、卵清蛋白(OVA)致敏剂量、时间对滴鼻剂AR建模的影响,观察空白组与模型组Hartley豚鼠过敏反应症状和鼻黏膜病理切片。结果显示,就滴鼻剂的AR试验而言,Hartley豚鼠是较好的试验动物;饲料为普通小鼠饲料+莴苣叶或油麦菜;OVA为致敏剂,基础致敏浓度为0.1~0.3 mg/mL OVA,隔天腹腔注射1次,共7次;激发致敏浓度为2%,两侧鼻腔各10~30 μL,每天1次,6~9 d后与空白组相比,模型组Hartley豚鼠有明显的过敏反应症状和鼻黏膜病变。该建模方法简单经济,重现性好,可作为滴鼻剂AR建模的最佳方法。