The demonstration of rabies antigen in paraffin-embedded tissues using the peroxidase-antiperoxidase method: a comparative study.

Mice experimentally infected with challenge virus standard rabies virus as well as skunks and foxes experimentally infected with street rabies virus were used to demonstrate rabies viral antigen in paraffin-embedded tissue by the peroxidase-antiperoxidase method. Tissues fixed with different fixatives (10% formalin, Bouin's, acetone, ethanol) for various times and fresh frozen tissues were stained by the fluorescent antibody and the peroxidase-antiperoxidase method. Formalin- and Bouin's-fixed tissues were tested with and without use of digestive enzyme (pepsin). The results demonstrated that a procedure using formalin-fixed paraffin-embedded tissue treated with pepsin and stained by peroxidase-antiperoxidase was the best method for both preservation of morphological details and demonstration of antigen.     

A study on the origin of adenocarcinoma in fowls using immunohistological technique

When tumor tissues collected from 12 hens suffering from so-called adenocarcinoma were stained with antisera by the indirect immunofluorescent method, all of the tissues appeared to contain ovalbumin. We suggest that most adenocarcinomas in the thoracoabdomen of mature hens are oviductal in origin.     

A pilot study using synthetic feline facial pheromone for the management of feline idiopathic cystitis

Synthetic feline facial pheromone (FFP) (Feliway; Ceva Animal Health) was assessed for the management of cats with recurrent feline idiopathic cystitis (FIC). Nine of 12 cats completed the randomised, double-blinded, placebo-controlled, crossover pilot study. They had their environment treated daily with either FFP or placebo for 2 months, after which time the treatment groups were reversed. Owners used visual analogue scales to define the severity of their cat's clinical signs and behavioural changes. Five (56%) of the owners stated that their cat's overall health was better when they were using FFP. Four (44%) of the owners noticed no difference between when using the FFP and when using the placebo. While there were no statistical differences between the two treatment groups there was a trend for the cats exposed to FFP to show fewer days with clinical signs of cystitis (FFP total, mean per cat+/-standard deviation, 30, 4.3+/-6.7; placebo 69, 9.9+/-19.1), a lower overall clinical score (1667, 238+/-476; 2009, 287+/-425), a reduced number of episodes of cystitis (9, 1.3+/-2.0; 10, 1.4+/-2.1) and reduced negative behavioural traits (e.g., less aggression and fear) (-128, -18.3+/-65.8; -73, -10.4+/-35.1).     

An ultrastructural study of granulocytic development in feline bone marrow

Granulocyte development in the bone marrow of foetal cats was studied using cytological smears and transmission electron microscopy. The three types of granulocytes could be distinguished at the promyelocyte stage on the basis of granule content. Neutrophilic promyelocytes had numerous primary (azurophilic) granules while the eosinophilic and basophilic promyelocytes had specific granules. Specific granules had developed in the neutrophil by the myelocyte stage. The appearance of the specific granules was compared to findings in other reports on cat granulocytes, in other animals and in man.     

Chlamydia immunoreactivity in birds with psittacosis: localization of chlamydiae by the peroxidase-antiperoxidase method

Diagnosis of psittacosis (infection with Chlamydia psittaci) has traditionally been dependent upon culture or demonstration of chlamydiae in tissues by cytochemical stains such as the Gimenez or Macchiavello's stain. In this study, a peroxidase-antiperoxidase (PAP) technique that employs a commercially available monoclonal antibody directed against Chlamydia is used to demonstrate chlamydiae in the necropsy tissues of nine birds. Chlamydiae were identified in air sacs (83%), liver (78%), spleen (78%), small intestines (67%), large intestines (44%), and kidneys (33%). Usually chlamydiae were associated with microscopic lesions, but in 75% of large intestines examined, organisms were identified within the lumen of histologically normal intestine. PAP studies revealed numerous chlamydiae that were inapparent in hematoxylin-and-eosin-stained sections. These results demonstrate the utility and sensitivity of the PAP method in the identification of chlamydiae in microscopic sections.     

An immunohistochemical study of cyclooxygenase-2 expression in various feline neoplasms

Cyclooxygenase (COX) enzymes catalyze the synthesis of prostaglandins and exist as two isoforms, COX-1 and COX-2. COX-2 is a potent inducible mediator of inflammation. COX-2 is also upregulated in several human tumors and in canine squamous cell, renal cell, and transitional cell carcinomas, prostatic adenocarcinoma, and intestinal neoplasia. The purpose of this study was to determine whether COX-2 is expressed in various feline tumors. Results of this study may help determine whether COX-2 is a potential target for therapeutic and preventive strategies in cats. Immunohistochemical studies were performed on paraffin-embedded tissues using the amplified streptavidin-biotin-horseradish peroxidase system. COX-2 was found in 7 of 19 (37%) feline transitional cell carcinomas and in 2 of 21 (9%) feline oral squamous cell carcinomas. No COX-2 immunoreactivity was detected in cutaneous squamous cell carcinomas (6), adenocarcinomas (nine mammary, eight pulmonary, seven intestinal), lymphomas (six nasal, six intestinal), or 10 vaccine-associated sarcomas. The widespread absence of COX-2 expression in most feline neoplasms might suggest that COX-2 inhibitors would have a low potential as anticancer agents.     

Detection of viral antigens in bluetongue virus-infected ovine tissues, using the peroxidase-antiperoxidase technique

An indirect immunoperoxidase procedure was developed to detect viral antigens in bluetongue virus (BTV)-infected tissues. Embryonating chicken eggs were infected with BTV serotypes 10, 11, 13, or 17, and the chorioallantoic membranes were subsequently fixed in formalin and embedded in paraffin. The peroxidase-antiperoxidase (PAP) system was used to examine the infected membranes for the presence of viral antigens. Sheep antisera raised against BTV serotypes 10, 11, 13, and 17 served as the primary antibodies in the PAP procedure. Specific staining was observed when each of these antisera was applied to membranes expressing antigens of homologous and heterologous BTV serotypes. The PAP method was rapid, reliable, and specific in its detection of BTV.     

Ultrasonographic study of the feline sciatic nerve

This study was conducted to describe the ultrasonographic appearance and technique for the evaluation of sciatic nerve (ScN) in cats. An anatomical study was carried out using six feline cadavers to determine anatomic landmarks. An ultrasonographic 'in vitro' study was performed using eight pelvic limbs from four fresh feline cadavers to assess the ScN in three regions (glutea, femoralis and popliteal) using a 4-13MHz linear transducer. Five healthy adult experimental cats were employed for an 'in vivo' ultrasonographic study of the ScN using the same protocol described for the 'in vitro' study. The ultrasonographic images of the ScN were well correlated with those obtained in the anatomical study. The ScN was easily identified in all the approaches. The ScN was observed as a hypoechoic structure with internal echoes, outlined by hyperechoic lines. This study shows the usefulness of ultrasound to evaluate the entire pathology of the ScN in the cat.     

An epidemiological survey of the feline urological syndrome

An epidemiological survey of the feline urological (or urolithiasis) syndrome (FUS) was carried out from 1 October 1973 to 30 September 1974. Details of 437 FUS cases were recorded by veterinary surgeons in thirty-three practices. An independent market research organisation collected corresponding details, where applicable, of 604 pet cats selected randomly from the pet cat population of the practice areas.
Total incidence of reported cases was estimated at about 0.64% of the domestic cat population in one year. The number of cases of FUS was highest in the autumn and winter of 1973 and then decreased to the end of the survey period.
Comparison of clinical and control surveys showed an association of the disease with several factors. These included age, diet and neutering (especially of male animals). By comparison with the controls, FUS cats tended to drink less, to be fed on dry cat food, to be considered lazy, taking little exercise, to have less freedom to leave the house at will and to be provided with indoor urinating facilities. There was also some evidence of an association with the brand of dry cat food and with the number of cats in the household. These factors were not necessarily either causative agents or additive in effect. A follow-up survey revealed a FUS mortality of 22% (90/403 cats) at 6 months after the survey episode, the majority dying or being put down in the first week. The death-rate was higher in males. Further episodes were noted in 32% of the cats followed up. The rate of recurrence was the same in those cats (68%) whose diet had been changed after the initial episode.     

An improved method for hemagglutinin extraction from feline herpesvirus type 1-infected cell line

Hemagglutination (HA) activity of feline herpesvirus type 1 (FHV-1) propagated in feline lung cell culture and two established feline cell lines, CRFK and fcwf-4, was investigated. Intra- and extracellular crude samples obtained from those infected cell cultures did not show HA activity. However, when treated with tween 80-ether, HA activity appeared. There was no correlation between virus infectivity titers and the HA titers at various harvesting times, and besides, hemagglutinins were found in intracellular samples at the early stage of infection. By ultrasonic destruction of the infected fcwf-4 cells, high titer hemagglutinins were obtained. High titer hemagglutinins were also extracted successfully from infected fcwf-4 cell membranes by solubilization with any of the three detergents: Triton X-100, DOC, and CHAPS. The optimal concentrations of each detergent for solubilizing hemagglutinin were 0.05 (v/v)%, 0.5 (w/v)%, and 0.1-0.2 (w/v)%, respectively. The HA activities of both the ultrasonic-treated hemagglutinin and the detergent-soluble hemagglutinin from infected fcwf-4 cells were inhibited specifically by anti-FHV-1 sera. Therefore, either hemagglutinin could be used as HA antigen for the hemagglutination-inhibition test.     

Histopathological study of feline eosinophilic dermatoses

A retrospective study was conducted on skin specimens from 24 cats with eosinophilic granuloma complex. The specimens were stained with haematoxylin and eosin and Gallego's trichrome stain. In all specimens, flame figures and/or large foci of so-called "collagen degeneration" were detected and histopathological features were not predictive of the clinical picture. Use of the term eosinophilic dermatosis was advocated in diagnostic dermatopathology. On trichrome-stained sections, normally stained collagen fibres were identified in the middle of both flame figures and large foci of "collagen degeneration" and the debris surrounding collagen bundles showed the same tinctorial properties as eosinophil granules. Eosinophil degranulation around collagen bundles seemed to represent the major pathogenetic event in these lesions, analogous with human flame figures. The term flame figures might therefore be more accurately used to designate those foci of eosinophilic to partly basophilic debris commonly referred to as "collagen degeneration".     

An unusual cause of feline urethral obstruction

An air-gun pellet that entered a cat's bladder through the flank carried in sufficient of the cat's own hair to block the penile urethra.
Resumé. Un plomb tiré d'une arme à air cornprimé a pénétré dans la vessie d'un chat à travers le flanc de l'animal; les poils entrainés par le projectile ont suffi pour obstruer I'urètre pénien de l'animal.
Zusammenfassung. Eine Luftgewehrkugel, die in die Blase eines Katers durch die Flanke eindrang, riss genügend Pelzhaare mit, um die Harnröhre zu blockieren.     

An enzyme-linked immunosorbent assay using nuclear antigen for detection of feline herpesvirus 1 antibody.

To detect antibody against feline herpesvirus 1 (FHV-1) in the sera of cats, the sensitivity and specificity of an enzyme-linked immunosorbent assay (ELISA) using nuclear antigen was investigated. The standardized optical density readings (ODs) of the ELISA obtained by the 1-step serum dilution (1:80) method were compared with the serum neutralization test (SNT) results, with a correlation of 0.993, and with the hemagglutination inhibition (HI) test results, with a correlation of 0.851. The ODs for the ELISA titers were obtained using the serial serum dilution method and were compared with the SNT results, with a correlation of 0.933, and with the HI test results, with a correlation of 0.987. In the experimental infection of 4 specific-pathogen-free cats, the results of different serologic tests (SNT and HI) and the ELISA using the serial serum dilution method revealed rapid production of antibodies after inoculation, whereas the ELISA using the one-step serum dilution method indicated that titers increased more slowly. These results indicate that with the present ELISA using nuclear antigen, there are fewer demands on time and labor, making the method convenient for monitoring FHV-1 infection.     

Comparison of feline parvovirus subspecific strains using monoclonal antibodies against a feline panleukopenia virus

Four monoclonal antibodies (mAb) against a feline panleukopenia virus (FPLV) TU 1 strain, one of the host range variants of feline parvovirus (FPV), were produced and applied for antigenic analysis of FPLV, canine parvovirus (CPV) and mink enteritis virus (MEV). All mAbs were considered to be directed at epitopes on the virus capsid surface because they neutralized the infectivity and inhibited the hemagglutination (HA) of the homologous virus as well as other FPV strains. They were of the mouse IgG1 type. High antigenic homogeneity among FPLV strains was confirmed by HA-inhibition (HI) test with the mAbs and polyclonal immune sera against FPLV or CPV. But the TU 11 strain of FPLV was antigenically distinguished from the remaining 14 FPLV strains by both the HI test and the micro-neutralization test with one of the mAbs produced. MEV Abashiri strain was found to be antigenically indistinguishable from FPLV. Most of the CPV strains isolated after 1981 were considered to be antigenically different from earlier CPV isolates when some mAbs were applied in the serological tests, confirming the replacement of CPV by an antigenic variant in Japan. However, antigenically different CPVs were detected at the end of 1984 from unrelated epizootics occurred a month apart in the same area.     

Alkaline phosphatase isoenzymes in feline serum using an agarose gel alkaline phosphatase kit method.

Total serum alkaline phosphatase (ALP) activity is the product of the combined activity of isoenzymes from a number of tissue sources. In this study, a commercially available kit for electrophoretic separation of ALP isoenzymes in an agarose gel was used to separate ALP isoenzymes in feline tissue extracts and serum. Five separate bands of ALP activity were identified. These bands were numbered 1 to 5 with band 1 having the most anodal migration. The tissue of origin corresponding to the migration position of the isoenzymes are as follows: Band 3 was the liver isoenzyme, band 4 was the bone isoenzyme and ALP isoenzymes of both intestine and kidney migrate in the position labelled band 5. Band 1 appears to be related to albumin and does not represent true ALP activity. The tissue source of band 2 (a and b) was not identified. Serum ALP activity of mature, healthy cats is primarily of liver origin. Immature cats (< 1 year of age) have a greater proportion of the bone isoenzyme in the serum.