Cellular and Molecular Characterization of a Feline Insulinoma

Background: Insulinoma is an autonomous insulin-secreting islet cell neoplasm that is rarely diagnosed in cats. The clinical and pathological aspects of feline insulinoma have been described previously, but the molecular characteristics of these tumors have not been investigated.
Objectives: The study objectives were to characterize peptide hormone production and determine expression of selected genes involved in glucose metabolism and insulin secretion in a feline insulinoma.
Methods: Immunohistochemistry and RT-PCR were used to examine hormone and gene expression, respectively, by insulinoma cells.
Results: Immunohistochemistry examination indicated that the tumor cells expressed insulin, chromogranin A, and somatostatin but not glucagon or pancreatic polypeptide. The tumor expressed several genes characteristic of pancreatic beta cells (β cells) including insulin ( INS ), glucose transporter 2 ( GLUT2 ), and glucokinase ( GCK ). The tumor also expressed hexokinase 1 ( HK1 ), a glycolytic enzyme not normally expressed in β cells. GCK expression was higher in the insulinoma than in normal pancreas from the same cat. The GCK  :  HK1 ratio was >20-fold higher in insulinoma tissue than in normal pancreas.
Conclusions and Clinical Importance: The feline insulinoma produced several peptide hormones and expressed genes consistent with a β-cell phenotype. The pattern of hexokinase gene expression in tumor cells differed from that of normal pancreas. These findings suggest insulinoma cells may have an increased sensitivity to glucose that could contribute to the abnormal insulin secretory response observed at low serum glucose concentrations.     

Chondrodysplasia in Australian Dexter cattle

Objective To describe the occurrence of chondrodysplasia in Australian Dexter cattle.
Design A pathological and genetic case report.
Procedure Congenital lethal chondrodysplasia was studied in two female Dexter foetuses aborted mid to late gestation. Clinicopathological findings including histological changes in limb bones, and analysis of pedigree information were evaluated.
Results Characteristic features of congenital lethal chon-drodysplasia (Dexter bulldog) include abortion, disproportionate dwarfism, a short vertebral column, marked micromelia, a relatively large head with retruded muzzle, cleft palate and protruding tongue and a large abdominal hernia. Histological changes in limb bones are consistent with failure of endochondral ossification. Dexter chondrodysplasia is considered to be inherited in an incompletely dominant manner with the homozygous form producing the congenital lethal condition. A preliminary minimum estimate of heterozy-gote frequency is 19% within the registered Australian Dexter herd, based on analysis of the contribution of three obligate heterozygotes whose semen has been widely used by artificial insemination in Australia.
Conclusion Dexter chondrodysplasia is present in Australian cattle and further cases of the homozygous form, congenital lethal chondrodysplasia, are likely to occur.
Recommendation It is requested that spleen and liver tissue from bulldog foetuses and blood from their parents be collected to assist research into Dexter chondrodysplasia.     

Sheep‐Associated Malignant Catarrhal Fever Involving 3–5‐Week‐Old Calves in Saudi Arabia

Between late December 1999 and late April 2000, three locally bred Friesian calves (ageing 25, 28 and 35 days) in a dairy farm, at Al‐Ahsa locality of the eastern region of Saudi Arabia showed dullness and inappetence. Their rectal temperatures ranged between 41 and 41.5°C. One to 2 days later and onwards, the calves showed lacrimation, nasal discharge, salivation, oedema of the head, conjunctivitis, exo‐ophthalmia and corneal opacity. One calf showed diarrhoea. The superficial lymph nodes were oedematous and swollen. The calves died after 7, 5 and 8 days, respectively, following the onset of the disease. Calves and rabbits were experimentally infected with materials from the naturally infected calves. The rabbits showed fever, mild conjunctivitis and one rabbit showed wet faeces. The experimentally inoculated calves showed rise in temperature and mild symptoms but none of them died. The virus from the naturally infected calves and from the experimentally infected rabbits was identified as malignant catarrhal fever (MCF) virus using both the complement fixation test and the fluorescent antibody test, employing a reference anti‐serum against the WC 11 strain of MCF virus. Serological survey for MCF antibodies in cattle, sheep and goats from the affected farm revealed that 54% of the examined animals were positive. The situation of MCF in Saudi Arabia was discussed in relation to sheep and wild game. This paper constitutes the first report of MCF in Saudi Arabia and the Gulf region.     

牛眼球石蜡切片制作方法的探索

为探索一种牛眼球的石蜡切片制作方法,本试验比较了常规石蜡切片制作方法和改良的石蜡切片制作方法．结果表明,试验组标本固定后肉眼可见视网膜与脉络膜紧密相连,仅有小部分视网膜出现脱离的现象;切片显示小梁网连续性未被破坏;眼球壁全层组织连续性未破坏,各层未出现分离现象;视网膜无脱离,各层组织细胞无收缩现象。说明试验组大大改进了眼球固定、脱水、透明技术方法,解决了较大眼球无法制作石蜡切片的难题,为眼球基础研究和相应病理研究提供了基础：     

Localized cowpox infection in a 5‐month‐old Rottweiler

Cowpox virus (CPXV) infections are a sporadic cause of localized or disseminated skin disease in domestic animals and humans in Europe. Rodents are considered the primary reservoir host for CPXV. Cats can become infected by close contact with rodents and are the most important source of human infections. Recently, public awareness has also been drawn to CPXV infections by an outbreak of rat to human infections in central Europe. In dogs, CPXV infections are rare. Here we report a case of a 5‐month‐old Rottweiler with a focal nodule on the muzzle. The lesion was fully excised, and recovery was uneventful. The preliminary diagnosis of a CPXV infection was established by the characteristic inclusion bodies on histopathological examination. The diagnosis was confirmed by electron microscopy and polymerase chain reaction (PCR). Sequencing of the PCR product led to a 231 bp sequence of the orthopoxvirus HA gene that was identical to a CPXV strain previously isolated from a cat. This is the third documented case of a canine CPXV infection.     

Surgical repair of a mandibular degloving injury in a 5‐month‐old colt

A 5‐month‐old colt sustained a mandibular degloving injury and penetrating cheek wound after catching his cheek on a metal hook. Avulsion of the lower left lip and cheek exposed parts of the underlying labial surface, interalveolar margin and body of the mandible. The injury prevented the colt from closing his mouth completely and food accumulated between the degloved mandible and avulsed soft tissues. Surgical repair included 7 stented, transmandibular mattress sutures placed over the length of the interalveolar margin, closing the dead space and repositioning the avulsed soft tissues. The horse recovered without complications and functional as well as cosmetic outcome were excellent.     

Mandibular squamous cell carcinoma in a 5‐year‐old Tennessee Walking Horse

Squamous cell carcinoma (SCC) is the second most common neoplasm reported in the horse, but occurs rarely in the oral cavity. Clinical signs may be insidious in onset and mimic other non‐neoplastic processes, thus delaying appropriate treatment. Timely evaluation and advanced diagnostic imaging may offer the opportunity to initiate definitive treatment. This report describes a young gelding with mandibular SCC that was evaluated for mandibular swelling failing to respond to symptomatic therapy.     

Intralesional 5‐fluorouracil (5‐FU) for the treatment of eyelid squamous cell carcinoma in 5 horses

Eyelid squamous cell carcinoma in equine patients often presents a therapeutic challenge to practitioners due to the generally large area affected upon presentation. Surgical excision can be curative if wide enough margins are achieved, but this is not often attainable without enucleation. Other alternatives have been examined including cryotherapy, radiotherapy, brachytherapy, intralesional chemotherapy and photodynamic therapy. Intralesional chemotherapy using cisplatin, mitomycin‐C and bleomycin have been shown to be successful in treating eyelid squamous cell carcinomas but may be prohibitive to some owners due to the cost of therapy. To the authors' knowledge, this is the first case series to illustrate the effectiveness of intralesional 5‐fluoruracil in treating large equine eyelid squamous cell carcinomas. Macroscopic reduction in the size of the affected areas was noted in each case together with regression of clinical signs associated with the mass. This, coupled with the relative inexpensive nature of the procedure, makes this technique an attractive therapy for either primary treatment of eyelid squamous cell carcinoma or as a cytoreductive technique prior to surgical excision.     

Growth hormone stimulation of serum insulin concentration in cattle: Nutritional dependency and potential mechanisms

Previous studies on the effect of growth hormone (GH) on serum insulin concentration in cattle had generated seemingly conflicting results, and little was known about the mechanism by which GH affects serum insulin concentration in cattle, if it does. In this study, we determined whether the effect of GH on serum insulin concentration in cattle could be affected by the nutritional levels of the animal and whether GH increased serum insulin concentration in cattle by directly stimulating insulin release or insulin gene expression in the pancreatic islets. Administration of recombinant bovine GH increased serum insulin concentration in nonlactating, nonpregnant beef cows fed a daily concentrate meal in addition to ad libitum hay, but it had no effect in those cows fed hay only. Both GH treatments for 1 and 24 h increased insulin concentrations in cultures of pancreatic islets isolated from growing cattle. Growth hormone treatment for 24 h increased insulin mRNA expression in cultured bovine pancreatic islets. Growth hormone treatment for 16 h increased reporter gene expression directed by a ∼1,500-bp bovine insulin gene promoter in a rat insulin-producing β cell line. Taken together, these results suggest that exogenous GH can increase serum insulin concentration in cattle, but this effect depends on the nutritional levels of fed cattle, and that GH increases serum insulin concentration in cattle by stimulating both insulin release and insulin gene expression in the pancreatic islets.