Mucosal challenge with cell-associated or cell-free feline immunodeficiency virus induces rapid and distinctly different patterns of phenotypic change in the mucosal and systemic immune systems

The majority of human immunodeficiency virus type 1 (HIV-1) infections occur via mucosal transmission through contact with genital secretions containing cell-associated and cell-free virus. However, few studies have assessed whether exposure to cells, HIV-1 infected or uninfected, plays a role in the sexual transmission of HIV-1. This study examined phenotypic changes in mucosal and systemic lymphoid tissue 24 hr after vaginal exposure to in vitro equilibrated infectious doses of cell-associated or cell-free feline immunodeficiency virus, uninfected heterologous cells, or medium alone. We found that even at this early time-point, mucosal exposure to virus induced substantial alterations in the phenotype and distribution of leucocytes, particularly in the tissues of the mucosal immune system. Second, we found that the type of virus inoculum directly influenced the phenotypic changes seen. Vaginal exposure to cell-free virus tended to induce more generalized phenotypic changes, typically in the peripheral immune system (blood and systemic lymph nodes). In contrast, exposure to cell-associated virus was primarily associated with phenotypic shifts in the mucosal immune system (gut and mucosal/draining lymph nodes). In addition, we found that exposure to uninfected heterologous cells also induced alterations in the mucosal immune system. These data suggest that significant immune changes occur within the first 24 hr of virus exposure, well before substantial replication would be anticipated. As the mucosal immune system, and particularly the gut, is an early and persistent target for lentiviral replication, these findings have substantial implications for HIV-1 pathogenesis and vaccine development.     

Feline Morbillivirus Infection in Domestic Cats: What Have We Learned So Far?

Feline morbillivirus (FeMV) was identified for the first time in stray cats in 2012 in Hong Kong and, since its discovery, it was reported in domestic cats worldwide. Although a potential association between FeMV infection and tubulointerstitial nephritis (TIN) has been suggested, this has not been proven, and the subject remains controversial. TIN is the most frequent histopathological finding in the context of feline chronic kidney disease (CKD), which is one of the major clinical pathologies in feline medicine. FeMV research has mainly focused on defining the epidemiology, the role of FeMV in the development of CKD, and its in vitro tropism, but the pathogenicity of FeMV is still not clear, partly due to its distinctive biological characteristics, as well as to a lack of a cell culture system for its rapid isolation. In this review, we summarize the current knowledge of FeMV infection, including genetic diversity of FeMV strains, epidemiology, pathogenicity, and clinicopathological findings observed in naturally infected cats.     

Genetics of feline hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by an abnormal increase in myocardial mass that affects cardiac structure and function. HCM is the most common inherited cardiovascular disease in humans (0.2%) and the most common cardiovascular disease in cats (14.7%). Feline HCM phenotype is very similar to the phenotype found in humans, but the time frame for the development of the disease is significantly shorter. Similar therapeutic agents are used in its treatment and it has the same complications, such as heart failure, thromboembolism and sudden cardiac death. In contrast to humans, in whom thousands of genetic variants have been identified, genetic studies in cats have been limited to fragment analysis of two sarcomeric genes identifying two variants in MYBPC3 and one in MYH7. Two of these variants have also been associated with human disease. The high prevalence of the reported variants in non-affected cats hinders the assumption of their pathogenicity in heterozygotes. An in-depth review of the literature about genetic studies on feline HCM in comparison with the same disease in humans is presented here. The close similarity in the phenotype and genotype between cats and humans makes the cat an excellent model for the pathophysiological study of the disease and future therapeutic agents.     

Clinical Aspects of Feline Retroviruses: A Review

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses with global impact on the health of domestic cats. The two viruses differ in their potential to cause disease. FeLV is more pathogenic, and was long considered to be responsible for more clinical syndromes than any other agent in cats. FeLV can cause tumors (mainly lymphoma), bone marrow suppression syndromes (mainly anemia), and lead to secondary infectious diseases caused by suppressive effects of the virus on bone marrow and the immune system. Today, FeLV is less commonly diagnosed than in the previous 20 years; prevalence has been decreasing in most countries. However, FeLV importance may be underestimated as it has been shown that regressively infected cats (that are negative in routinely used FeLV tests) also can develop clinical signs. FIV can cause an acquired immunodeficiency syndrome that increases the risk of opportunistic infections, neurological diseases, and tumors. In most naturally infected cats, however, FIV itself does not cause severe clinical signs, and FIV-infected cats may live many years without any health problems. This article provides a review of clinical syndromes in progressively and regressively FeLV-infected cats as well as in FIV-infected cats.     

Incidence of Mycobacterial Infections in Cats in Great Britain: Estimate from Feline Tissue Samples Submitted to Diagnostic Laboratories

The aim of this study was to estimate the incidence of mycobacterial infections in cats in Great Britain (GB). This was performed using the proxy measure of feline tissue samples submitted to diagnostic laboratories in GB that were found to have histopathological changes typical of mycobacterial infection (‘MYC’). Sixteen primary diagnostic laboratories were asked for information on the number of feline samples submitted in 2009, the number with MYC, the number undergoing Ziehl–Neelsen (ZN) staining and, for comparison, the number diagnosed with lymphoma. Eight laboratories provided full data for the whole year: 11 782 samples; lymphoma 3.2% (mean, 95% CI: 2.89, 3.5), MYC 1.16% (0.98; 1.37) and ZN‐positive 0.31% (0.22; 0.43). Data on 1569 samples from seven laboratories that provided partial data on samples for the whole year revealed similar results, although all changes were more frequent: lymphoma 5.42% (4.35; 6.66), MYC 2.36% (1.66; 3.23) and ZN‐positive 0.77% (0.40; 1.33). One laboratory only provided data for part of the year (4.5 months), reporting all three types of histopathology less frequently: 18 232 samples; lymphoma 0.2% (0.18; 0.32), MYC 0.07% (0.04; 0.12) and ZN‐positive 0.05% (0.02; 0.09). The reasons for low reporting rates in this high‐throughput laboratory are unclear. In total, 187 samples were reported as having MYC. Five Reference laboratories were also contacted, reporting 174 feline tissue submissions in 2009, with mycobacteria being cultured from 90. The study shows that MYC are frequently reported in tissue samples from cats in GB, being reported in ∼1% of samples, with confirmation as ZN‐positive in ∼0.3%. Lymphoma is recognized as a common disease in cats, being seen in ∼3% of samples in this study. When compared against MYC, lymphoma was reported only twice as frequently. This confirms that far from being rare, clinically significant mycobacterial infections occur commonly in cats in GB.     

Concurrent oral shedding of feline calicivirus and feline herpesvirus 1 in cats with chronic gingivostomatitis

Oral mucosal salivary samples were collected from 25 cats with chronic gingivostomatitis and 24 cats with periodontal disease. Viral culture and isolation of feline calicivirus and feline herpesvirus 1 were performed. Eighty-eight per cent of cats with chronic gingivostomatitis were shedding both viruses, compared to 21% of cats without chronic oral inflammatory disease. Cats with chronic gingivostomatitis are significantly more likely to concurrently shed both feline calicivirus and feline herpesvirus 1 than are cats with classical periodontal disease.     

体外循环低温持续电诱导室颤心脏心肌氧耗量的变化

目的 观察体外循环低温持续电诱导室颤心脏心肌氧耗量的变化.方法 42只健康杂种猫随机分为两组,每组21只,在体外循环120 min基础上分为单纯循环组（对照组）和低温持续电诱导室颤组（室颤组）.在不同时间点测量心肌氧耗量等.结果 室颤组心肌氧耗量较对照组明显降低（P〈0.01）.结论 低温室颤在持续灌注的情况下有利于氧的供需平衡,为避免严重的心肌缺血性损伤和保持相对满意的心肌能量代谢水平创造了有利条件.     

Feline calicivirus subunit vaccine - a prototype

A vaccine was prepared from a subunit component, antigenically similar to the whole feline calicivirus (FCV) particles. Despite the limited number of animals available for this study we were able to demonstrate that the vaccine protected cats when challenged with a virulent strain of the virus while the non-vaccinates kept as controls developed clinical and histopathological symptoms of the calicivirus disease.     

Evaluation of a Point‐of‐Care Influenza Antigen Test for the Detection of Highly Pathogenic Avian Influenza H5N1 Virus in Cats

Quick diagnosis of H5N1 infection in cats is important because of the zoonotic and pandemic potential of this virus. Human rapid influenza antigen tests are also sold commercially to veterinarians for use in cats. The point‐of‐care test actim^™ Influenza A&B (Medix Biochemica, Kauniainen, Finland) was evaluated for the diagnosis of H5N1 infection in cats. The test showed a very low sensitivity and did not detect virus in samples of experimentally infected cats, so that its application cannot be recommended for the diagnosis of H5N1 infection in cats.