A cDNA that encodes a novel Na⁺-independent neutral amino acid transporter was isolated from FLC4 human hepatocarcinoma cells by expression cloning. When expressed in Xenopus oocytes, the encoded protein designated LAT3 (L-type amino acid transporter 3) transported neutral amino acids such as l-leucine, l-isoleucine, l-valine, and l-phenylalanine. The LAT3-mediated transport was Na⁺-independent and inhibited by 2-aminobicyclo[2.2.1]heptane-2-carboxylic acid, consistent with the properties of system L. Distinct from already known system L transporters LAT1 and LAT2, which form heterodimeric complex with 4F2 heavy chain, LAT3 was functional by itself in Xenopus oocytes. The deduced amino acid sequence of LAT3 was identical to the gene product of POV1 reported as a prostate cancer-up-regulated gene whose function was not determined, whereas it did not exhibit significant similarity to already identified transporters. The Eadie-Hofstee plots of LAT3-mediated transport were curvilinear, whereas the low affinity component is predominant at physiological plasma amino acid concentration. In addition to amino acid substrates, LAT3 recognized amino acid alcohols. The transport of l-leucine was electroneutral and mediated by a facilitated diffusion. In contrast, l-leucinol, l-valinol, and l-phenylalaninol, which have a net positive charge induced inward currents under voltage clamp, suggesting these compounds are transported by LAT3. LAT3-mediated transport was inhibited by the pretreatment with N-ethylmaleimide, consistent with the property of system L2 originally characterized in hepatocyte primary culture. Based on the substrate selectivity, affinity, and N-ethylmaleimide sensitivity, LAT3 is proposed to be a transporter subserving system L2. LAT3 should denote a new family of organic solute transporters.

Background: Ticks and fleas are considered amongst the most important arthropod vectors of medical and veterinary concern due to their ability to transmit pathogens to a range of animal species including dogs, cats and humans. By sharing a common environment with humans, companion animal-associated parasitic arthropods may potentially transmit zoonotic vector-borne pathogens (VBPs). This study aimed to molecularly detect pathogens from ticks and fleas from companion dogs and cats in East and Southeast Asia.Methods: A total of 392 ticks and 248 fleas were collected from 401 infested animals (i.e. 271 dogs and 130 cats) from China, Taiwan, Indonesia, Malaysia, Singapore, Thailand, the Philippines and Vietnam, and molecularly screened for the presence of pathogens. Ticks were tested forRickettsiaspp.,Anaplasmaspp.,Ehrlichiaspp.,Babesiaspp. andHepatozoonspp. while fleas were screened for the presence ofRickettsiaspp. andBartonellaspp.Result: Of the 392 ticks tested, 37 (9.4%) scored positive for at least one pathogen withHepatozoon canisbeing the most prevalent (5.4%), followed byEhrlichia canis(1.8%),Babesia vogeli(1%),Anaplasma platys(0.8%) andRickettsiaspp. (1%) [includingRickettsiasp. (0.5%),Rickettsia asembonensis(0.3%) andRickettsia felis(0.3%)]. Out of 248 fleas tested, 106 (42.7%) were harboring at least one pathogen withR. felisbeing the most common (19.4%), followed byBartonellaspp. (16.5%),Rickettsia asembonensis(10.9%) and “CandidatusRickettsia senegalensis” (0.4%). Furthermore, 35Rhipicephalus sanguineusticks were subjected to phylogenetic analysis, of which 34 ticks belonged to the tropical and only one belonged to the temperate lineage (Rh. sanguineus(sensu stricto)).Conclusion: Our data reveals the circulation of different VBPs in ticks and fleas of dogs and cats from Asia, including zoonotic agents, which may represent a potential risk to animal and human health.

Feline lower urinary tract disease (FLUTD) is a common problem in cats. The objectives of the study were to determine the prevalence, clinical signs, and causes of FLUTD and the risk factors for FLUTD. The medical records of 3486 cats visiting Chiang Mai University Small Animal Veterinary Teaching Hospital (VTH) between November 2016 and October 2017 were reviewed. An age-matched case-control study was performed to determine the risk factors for FLUTD by comparing 78 cats with FLUTD and 78 clinically normal age-matched cats. For each animal, potential risk data were obtained from medical records and cat owner interviews; these were analysed for associations with FLUTD. Multivariable logistic regression analysis was performed to estimate the odds ratios and to adjust for expected confounding factors. The prevalence of FLUTD in cats visiting the Chiang Mai University Veterinary Teaching Hospital was 2.2%. The most common clinical signs identified were urethral obstruction (55.1%) and haematuria (23.1%). The most common diagnoses were feline idiopathic cystitis (FIC) (57.7%) and urolithiasis (struvite) (18%). The multivariable logistic regression analysis results indicated that FLUTD was most likely to be diagnosed in castrated male cats. FIC and urolithiasis were the most common diagnoses in cats with FLUTD, and male sex and castration increased the risk of FLUTD.