Bartonella spp. DNA in cardiac tissues from dogs in Colorado and Wyoming.

BACKGROUND: Several Bartonella species (spp.) have been identified in dogs diagnosed with infectious endocarditis (IE) or myocarditis. OBJECTIVE: To interrogate cardiac tissues of dogs with suspected IE for the presence of Bartonella spp. DNA of dogs in the Rocky Mountain states. ANIMALS: Nine dogs with a clinical diagnosis of endocarditis from January 1990 to June 2008 were included. METHODS: In this retrospective study, medical records at the Veterinary Teaching Hospital were searched. Animals were excluded if there was no diagnosis of IE in the original necropsy report. Paraffin embedded tissue blocks and medical records were available from 9 dogs. Total DNA was extracted from the cardiac tissues and assessed for Bartonella spp. DNA by 3 polymerase chain reaction (PCR) methods. For positive samples, the Bartonella spp. were determined by genetic sequencing or fluorogenic real-time PCR. RESULTS: Bartonella henselae DNA was amplified from the tissues of 7 dogs; Bartonella vinsonii subsp berkhoffii DNA was amplified concurrently from 3 dogs. Six dogs were from Colorado and 1 was from Wyoming. Flea or tick infestations were reported in 2 dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Bartonella spp. should be on the differential list for dogs in the Rocky Mountain states. The results emphasize the need for routine use of external parasite control products even in regions perceived to have low risk for flea and tick infestations.

Abomasal emptying defect of sheep may be an acquired form of dysautonomia.

Abomasal emptying defect (AED) is a disease syndrome that primarily affects Suffolk sheep and is characterized by distension and impaction of the abomasum. No histologic lesion has been consistently associated with this condition. There is no known etiology. In this study, nine cases of AED were identified by necropsy, including three rams and six ewes between 2 and 6 years of age. Four of the cases occurred sporadically, and five ewes were submitted on the same day from a single flock. Histologic examination of celiacomesenteric ganglia from six of the affected sheep revealed scattered chromatolytic or necrotic neurons, without inflammation. Chromatolytic neurons were observed more frequently in AED-affected sheep than in seven healthy Suffolk sheep (P < 0.08, weak statistical support). Neuronal necrosis was not observed in any of the healthy sheep. Lineage records of the flock that suffered an outbreak were incompatible with the possibility of a simple inheritance pattern for this disease; furthermore, the very occurrence of AED in outbreak form is inconsistent with transmission solely by inheritance. Only one of the six tested sheep showed concurrent immunohistochemical evidence of scrapie. The lesion pattern in celiacomesenteric ganglia is suggestive of a neurotoxicosis. Neuronal lesions of AED resemble dysautonomic diseases of humans and other animals.

Moderate exercise training slows mammary tumour growth in adolescent rats.

Adolescence and young adulthood may be critical windows in establishing risk for breast cancer development in humans. Epidemiological data suggest that exercise during this life stage is associated with decreased breast cancer risk yet few experimental studies to elucidate the mechanism have been performed. The purpose of these studies was to evaluate the effects of moderate exercise training on mammary tumour development in adolescent rats using the 1-methyl 1-nitrosourea (MNU) chemical carcinogen model. Exercise (EX) consisted of moderate-intensity treadmill running 30 min/day, 5 days a week. A total of 274 animals were used: 94 in study 1 and 180 in study 2. Animals were injected with MNU (50 and 25 mg/kg body weight in studies 1 and 2, respectively) at 21 days of age and began training at 28 days of age. Groups of animals (n=10-30 depending on the study and time point) were sacrificed every 2 weeks for 8 weeks to evaluate tumour development. No difference in median tumour-free survival time was observed in the EX versus sham-exercise (SHAM), nor were there any differences in multiplicity at either a high or moderate dose of MNU. Latency to first tumour palpated was increased in both studies by 3-4 days. Consistent across both studies, tumour weights were less and the growth rates of the tumours, defined as tumour weight divided by the number of days elapsed since the tumour was first palpated, were reduced in the EX group. The data suggest that latency is increased and tumour growth is retarded in response to moderate exercise training.

Effects of dietary cholesterol restriction in a feline model of Niemann-Pick type C disease.

A feline model of Niemann-Pick disease type C (NPC) was employed to evaluate the effect of dietary cholesterol restriction on progression of disease. Two NPC-affected treated cats were fed a cholesterol-restricted diet beginning at 8 weeks of age; the cats remained on the diet for 150 and 270 days respectively. The study goal was to lower the amount of low density lipoprotein (LDL) available to cells, hypothetically reducing subsequent lysosomal accumulation of unesterified cholesterol and other lipids. Neurological progression of disease was not altered and dietary cholesterol restriction did not significantly decrease storage in NPC-affected treated cats. One NPC-affected treated cat had decreased serum alkaline phosphatase activity (ALP) and decreased serum cholesterol concentration. Liver lipid concentrations of unesterified cholesterol, cholesterol ester and phospholipids in NPC-affected treated cats were similar to those seen in NPC-affected untreated cats. Ganglioside concentrations in the NPC-affected treated cats and NPC-affected untreated cats were similar. Histological findings in liver sections from NPC-affected treated cats showed a diffuse uniform microvacuolar pattern within hepatocytes and Kupffer cells, in contrast to a heterogeneous macro/microvacuolar pattern and prominent nodular fibrosis in NPC-affected untreated cats. Similar differences in vacuolar patterns were seen in splenic macrophages. Although some hepatic parameters were modified, dietary cholesterol restriction did not appear to alter disease progression in NPC-affected kittens.

Growth factor treatment enhances vestibular hair cell renewal and results in improved vestibular function.

The vestibules of adult guinea pigs were lesioned with gentamicin and then treated with perilymphatic infusion of either of two growth factor mixtures (i.e., GF I or GF II). GF I contained transforming growth factor alpha (TGFalpha), insulin-like growth factor type one (IGF-1), and retinoic acid (RA), whereas GF II contained those three factors and brain-derived neurotrophic factor. Treatment with GF I significantly enhanced vestibular hair cell renewal in ototoxin-damaged utricles and the maturation of stereociliary bundle morphology. The addition of brain-derived neurotrophic factor to the GF II infusion mixture resulted in the return of type 1 vestibular hair cells in ototoxin-damaged cristae, and improved vestibular function. These results suggest that growth factor therapy may be an effective treatment for balance disorders that are the result of hair cell dysfunction and/or loss.

Zinc-responsive dermatosis in dogs: 41 cases and literature review.

Forty-one cases of zinc-responsive dermatosis in the dog are described. The Siberian husky was the predominant breed affected. Periocular crusts were the most common clinical sign and parakeratosis was noted in the skin biopsy specimens of all dogs. Treatment with oral zinc ameliorated the clinical signs in most dogs, but cases necessitating other treatments such as parenteral zinc or retinoids are reported. The authors recommend a starting dose of 2-3 mg kg-1 elemental zinc per day in the treatment of this disorder.

Epizootic malignant catarrhal fever in three bison herds: differences from cattle and association with ovine herpesvirus-2.

Three bison herds in Colorado experienced high mortality from malignant catarrhal fever (MCF). In comparison with cattle, the bison had a more rapidly progressive disease, fewer clinical signs, and milder inflammatory histologic lesions. There was consistent association with ovine herpesvirus-2 (OHV-2). Contact with sheep was not consistent. Of 17 animals in herd A, 15 died of acute MCF; 1 was slaughtered while healthy; and 1 developed clinical signs of MCF, was treated with corticosteroids and antibiotics, and died of fungal abomasitis and rhinitis after 5 months. In herds B and C, approximately 300 of 900 and 18 of 20 died of MCF following brief clinical disease. The nearest sheep were 1 mile away from herd A, but direct contact with sheep could be documented in herds B and C. Complete gross and histologic examinations were conducted on 34 animals, including all animals in herd A, and MCF was diagnosed in 31. In addition, field necropsies were performed on all dead animals in herd B and most in herd C and MCF was diagnosed on the basis of the gross lesions in most animals. Clinical signs of each animal in herd A were recorded. Illness was brief, usually 8-48 hours. Clinical signs were subtle; separation from the herd was often observed. In all 3 herds, hemorrhagic cystitis and multifocal ulceration of the alimentary tract were consistently found at necropsy. Mild lymphocytic vasculitis was present in multiple organs. Ovine herpesvirus-2 was found by polymerase chain reaction (PCR) in 71 of 105 formalin-fixed tissue specimens from 29 of 31 animals with MCF. In herd A, blood samples from 13 animals were collected at 5 time points and tested by PCR for the presence of OHV-2 viral sequences in peripheral blood leukocytes. Nine bison with a positive PCR test and 4 with negative results prior to clinical illness died of MCF.

Malignant catarrhal fever: polymerase chain reaction survey for ovine herpesvirus 2 and other persistent herpesvirus and retrovirus infections of dairy cattle and bison.

Using a polymerase chain reaction (PCR) test for sequences of ovine herpesvirus 2 (OHV2), this virus was shown to be significantly associated with sheep-associated malignant catarrhal fever (SA-MCF) in terminal cases of disease in 34 cattle and 53 bison. Ovine herpesvirus 2 was not detected in cattle (38) and bison (10) that succumbed to other diseases. Other persistent herpesviruses, retroviruses, and pestivirus, some of which have been previously isolated from cases of SA-MCF, were not associated with the disease. These included bovine herpesvirus 4 (BHV4), bovine lymphotrophic herpesvirus (BLHV), bovine syncytial virus (BSV, also known as bovine spumavirus), bovine immunodeficiency virus (BIV), and bovine viral diarrhea virus (BVDV). A PCR survey for OHV2 in DNA from individual cow's peripheral blood lymphocytes in 4 dairies showed that the 1 dairy that was in close contact to sheep had a prevalence of OHV2 of 21.3%, whereas the 3 other dairies had no OHV2. Prevalence of the other herpesviruses and retroviruses in the dairy cows was variable, ranging from 2% to 51% for BHV4, 52% to 78.7% for BLHV, and 10% to 34% for BSV. Bovine lymphotrophic herpesvirus and BSV were also found in a few (1-4 of 21 tested) cases of terminal SA-MCF, but BIV and BVDV were not found in either the dairy cows sampled, or in the cases of SA-MCE No significant correlation was found between the presence of any 2 viruses (OHV2, BHV4, BLHV, BSV) in the dairy cows or terminal cases of SA-MCE

Mucopolysaccharidosis VII in a cat.

Mucopolysaccharidosis VII was diagnosed in a domestic shorthair cat from California. The cat was small and had multiple abnormalities, including a small body disproportionate to the size of the skull, angular deformities of the ribs, abnormally short forelimbs, luxating patellas, generalized epiphyseal dysplasia involving the vertebrae and long bones, cuboidal vertebrae, pectus excavatum, subluxation of both hips, osteosclerosis of the tentorium cerebelli and left petrous temporal bone, tracheal hypoplasia, and corneal clouding. Beta-glucuronidase activity was markedly decreased in peripheral blood leukocytes. The cat died at 21 months of age, and a complete necropsy was performed. Tissues were examined by light and transmission electron microscopy. Large clear, round vacuoles representing distended lysosomes were present in many epithelial and connective tissue cells, including fibrocytes, chondrocytes, smooth muscle cells, hepatocytes, astrocytes, and macrophages.

Biocompatibility of a biodegradable in situ forming implant system in rhesus monkeys.

Formulations of a polymeric delivery system containing a 75/25 poly(DL-lactide-co-caprolactone dissolved in either N-methyl-2-pyrrolidone or dimethyl sulfoxide were injected both subcutaneously (SC) and intramuscularly (IM) into rhesus monkeys. Each monkey received an SC and IM injection of each of the two formulations, for a total injection volume of 4 mL. The monkeys were observed daily for overt signs of toxicity, and after 4 weeks biopsies of each implant site were fixed, stained, and evaluated histologically for tissue reaction to the polymer system. Tissue response was graded upon the presence and level of fibrous connective tissue and inflammatory cell infiltrate. The polymer formulations appeared to be safe, as the animals remained healthy and active throughout the study with no changes in food or water consumption, weight loss, or abnormal behavior observed. Tissue response to both formulations was considered mild and similar to that for other biodegradable polymers, in that the reaction was limited to tissue immediately adjacent to the residual polymer fragments and consisted of a mild fibroplasia with the presence of a few lymphocytes and macrophages. There were no differences between the two formulations in tissue response, and both formulations were considered acceptable for use as injectable implant systems.

Encephalitis induced by bovine herpesvirus 5 and protection by prior vaccination or infection with bovine herpesvirus 1.

Calves were intranasally challenged with bovine herpesvirus 5 (BHV5) and followed for the development of viral infection, clinical encephalitis, histologic lesions in the brain, and viral sequences in the trigeminal ganglia. Calves that were previously vaccinated with bovine herepesvirus 1 (BHV1, n = 4) or previously infected with BHV1 (n = 5) or that had not been exposed to either virus (n = 4) were compared. No calf developed signs of encephalitis, although all calves developed an infection as indicated by nasal secretion of BHV5 and seroconversion to the virus. Histologic lesions of encephalitis consisting of multifocal gliosis and perivascular cuffs of lymphocytes were observed in calves not previously exposed to BHV1. BHV5 sequences were amplified from the trigeminal ganglia of calves previously vaccinated and from calves not previously exposed to BHV1; calves sequentially challenged with BHV1 and later BHV5 had exclusively BHV1 sequences in their trigeminal ganglia. Administration of dexamethasone 28 days after BHV5 challenge did not influence clinical disease or histologic lesions in either previously unexposed calves (n = 2) or previously immunized calves (n = 2), although it did cause recrudescence of BHV5, as detected by nasal virus secretion.

Malignant catarrhal fever in bison, acute and chronic cases.

Acute malignant catarrhal fever (MCF) was diagnosed in 10 bison from 6 herds and ranging from 1 to 6 years of age. The pattern of clinical signs and morphologic lesions differed among bison. Combinations of corneal opacity, lacrimation, nasal discharge, depression, excess salivation, anorexia, diarrhea, melena, and hematuria were observed. Vasculitis characterized by lymphoid infiltrates in the adventia with variable extension into media and intima was found in multiple tissues in each animal. Fibrinoid vascular necrosis was rare. Ulceration in the alimentary tract was found in 9/10 bison, and ulceration or hemorrhage in the urinary bladder was found in 8/10 bison. Lymphoid infiltrates were present in 7 of 9 livers and 9 of 9 kidneys examined histologically. Hyperplasia of lymph nodes was observed in 5 bison. Chronic MCF was diagnosed in 1 bison with an 80-day course of illness that began with lacrimation, corneal opacity, mucoid nasal discharge, depression, and anorexia. These signs ceased after 15 days but circling and blindness developed on day 76. Chronic vascular lesions characterized by endothelial cell hypertrophy, intimal thickening, fragmentation of the internal elastic membrane, smooth muscle hypertrophy, and adventitial infiltrates of lymphocytes and plasma cells were found in many organs. The retinal arteries had chronic inflammation and acute transmural fibrinoid necrosis. The retinas were infarcted. Polymerase chain reaction technique for amplification of ovine herpesvirus 2 sequences was performed on formalin-fixed tissues, and viral sequences were detected in 1-7 tissues from each animal. These viral sequences were not found in tissues of 4 bison not affected by MCF.

Analysis of magnetic material in the human heart, spleen and liver.

Isothermal remanent magnetization (IRM) acquisition and alternating field (A.F.) demagnetization analyses were performed on human heart, spleen and liver samples resected from cadavers. The magnetic properties of the samples were measured both at 77K and at 273K. A.F. demagnetization was performed at 273K. Results from the analyses of the tissue indicate the presence of ferromagnetic, fine-grained, magnetically interacting particles which, due primarily to magnetic properties, are thought to be magnetite and/or maghemite. The presence of superparamagnetic particles can be inferred from the increase in saturation IRM values when measured at 77K compared with measurements at 273K and the decay of remanent magnetization upon warming from 77K. The concentration of magnetic material (assuming it is magnetite or maghemite) in the samples varies from 13.7 ng g-1 to 343 ng g-1, with the heart tissue generally having the highest concentration. The presence of magnetic material in these organs may have implications for the function of biogenic magnetite in the human body.

Specific detection of shedding and latency of bovine herpesvirus 1 and 5 using a nested polymerase chain reaction.

A sensitive method for simultaneously detecting and discriminating between bovine herpesviruses types 1 and 5 (BHV-1 and BHV-5) was developed using a nested polymerase chain reaction (PCR) technique. Following amplification using type-common primers derived from gC sequences, amplification using type-specific nesting primers produced different-sized bands specific to the corresponding types, as demonstrated by blot hybridization. Less than 0.1 plaque-forming units (PFU) of each virus and 75 fg or less of viral DNA were routinely detected. The PCR technique amplified correct product from 4 BHV-5 isolates and from 48 BHV-1 isolates, all from the United States, and did not amplify heterologous herpesviruses. The PCR technique was more sensitive than virus isolation in detection of BHV-1 or BHV-5 in nasal secretions from experimentally and naturally infected calves, and it detected BHV-1 or BHV-5 in trigeminal ganglia from these calves.

Immunohistochemical demonstration of equine herpesvirus-1 antigen in neurons and astrocytes of horses with acute paralysis.

Equine herpesvirus-1 (EHV-1) infection in a few widely scattered neurons and astrocytes plus endothelial cells in brain and spinal cord of two horses with naturally occurring paralytic disease was demonstrated by use of an immunoperoxidase technique. These horses were euthanatized less than 48 hours after the onset of clinical signs. No staining for EHV-1 was demonstrated in brain or spinal cord of three horses that had a longer duration of clinical disease or in two uninfected horses.

NYVAC-Pf7: a poxvirus-vectored, multiantigen, multistage vaccine candidate for Plasmodium falciparum malaria.

The highly attenuated NYVAC vaccinia virus strain has been utilized to develop a multiantigen, multistage vaccine candidate for malaria, a disease that remains a serious global health problem and for which no highly effective vaccine exists. Genes encoding seven Plasmodium falciparum antigens derived from the sporozoite (circumsporozoite protein and sporozoite surface protein 2), liver (liver stage antigen 1), blood (merozoite surface protein 1, serine repeat antigen, and apical membrane antigen 1), and sexual (25-kDa sexual-stage antigen) stages of the parasite life cycle were inserted into a single NYVAC genome to generate NYVAC-Pf7. Each of the seven antigens was expressed in NYVAC-Pf7-infected culture cells, and the genotypic and phenotypic stability of the recombinant virus was demonstrated. When inoculated into rhesus monkeys, NYVAC-Pf7 was safe and well tolerated. Antibodies that recognize sporozoites, liver, blood, and sexual stages of P. falciparum were elicited. Specific antibody responses against four of the P.falciparum antigens (circumsporozoite protein, sporozoite surface protein 2, merozoite surface protein 1, and 25-kDa sexual-stage antigen) were characterized. The results demonstrate that NYVAC-Pf7 is an appropriate candidate vaccine for further evaluation in human clinical trials.

Toxicity of field bindweed (Convolvulus arvensis) to mice.

The effects of feeding high and low doses of field bindweed (Convolvulus arvensis) to mice were investigated. Bindweed contains several alkaloids, including pseudotropine, and lesser amounts of tropine, tropinone, and meso-cuscohygrine. Mice fed bindweed exclusively died or were euthanized after 4-7 d and had severe hepatic necrosis and gastritis with ulceration or erosions. Mice fed low doses of bindweed along with standard laboratory mouse diet for 6 or 8 w had no clinical disease or gross lesions on necropsy examination but did have histologic lesions of mild multifocal hepatitis and gastritis.