In vitro prediction of clinical signs of respiratory toxicity in rats following inhalation exposure

The protective efficacy of the antimuscarinic agent scopolamine was evaluated against soman (o-pinacolyl methylphosphonofluoridate [GD])-induced respiratory toxicity in guinea pigs. Anesthetized animals were exposed to GD (841 mg/m3) by microinstillation inhalation exposure and treated 30 seconds later with endotracheally aerosolized scopolamine (0.25 mg/kg) and allowed to recover for 24 hours. Treatment with scopolamine significantly increased survival and reduced clinical signs of toxicity and body weight loss in GD-exposed animals. Analysis of bronchoalveolar lavage (BAL) fluid showed normalization of GD-induced increased cell death, total cell count, and protein following scopolamine treatment. The BAL fluid acetylcholinesterase and butyrylcholinesterase levels were also increased by scopolamine treatment. Respiratory dynamics parameters were normalized at 4 and 24 hours post–GD exposure in scopolamine-treated animals. Lung histology showed that scopolamine treatment reduced bronchial epithelial and subepithelial inflammation and multifocal alveolar septal edema. These results suggest that aerosolized scopolamine considerably protects against GD-induced respiratory toxicity.

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1,1,1,2,3,4,4,5,5,5-Decafluoropentane (HFC-4310mee)

Toxicology and Industrial Health ◽

10.1177/07482337211019860 ◽

2021 ◽

pp. 074823372110198

Keyword(s):

Reproductive Toxicity ◽

Inhalation Exposure ◽

Clinical Signs ◽

Inhalation Toxicity ◽

Acute Response ◽

Abnormal Gait ◽

Volatile Liquid ◽

Skin Sensitizer

HFC-43-10mee is a volatile liquid at room temperature and used as a cleaning agent, aerosol, etc. HFC-43-10mee has low acute inhalation toxicity; 4-hour LC50 in rats of approximately 11,000 ppm. The compound was not a skin or eye irritant and was not a skin sensitizer. A cardiac sensitization response was not observed at 5000 ppm. Inhalation exposure resulted in neurotoxicity consisting of tremors, convulsions, jerking, ataxia, abnormal gait, etc. at exposure concentrations of 2000 ppm and above. Within approximately 30 min of exposure the clinical signs appeared and resolved within 1–2 h during exposure; the rats appeared to adapt such that these clinical signs were no longer observed. The neurotoxicity observed was considered an acute response to HFC-43-10mee. In a 90-day study, rats exposed to 2000 ppm resulted in sporadic clinical signs of neurotoxicity. At 3500 ppm, the clinical signs were evident on most exposure days although as the study progressed the apparent incidence declined likely reflecting adaptation. The NOAEL was 500 ppm. Based on the occurrence of the clinical signs in this and other studies, an acute threshold for neurotoxicity was evident at approximately 2000 ppm and above. No developmental or reproductive toxicity were evident at 2000 ppm, although clinical signs of neurotoxicity occurred in maternal or parental rats at 2000 ppm. No effects on offspring were observed. HFC-43-10mee was not genotoxic in vitro or in vivo. Based on the data, the 8-h TWA WEEL value is 225 ppm (2320 mg/m3). The 15-min STEL is 700 ppm (7217 mg/m3).

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Importance and Antimicrobial Resistance of Mycoplasma bovis in Clinical Respiratory Disease in Feedlot Calves

Animals ◽

10.3390/ani11051470 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1470

Author(s):

Ana García-Galán ◽

Juan Seva ◽

Ángel Gómez-Martín ◽

Joaquín Ortega ◽

Francisco Rodríguez ◽

...

Keyword(s):

Respiratory Disease ◽

Clinical Signs ◽

Antimicrobial Treatment ◽

Mycoplasma Bovis ◽

Bacterial Disease ◽

Feedlot Calves ◽

Fixed Panel

Bovine respiratory disease (BRD) is an important viral and/or bacterial disease that mainly affects feedlot calves. The involvement of Mycoplasma bovis in BRD can lead to chronic pneumonia poorly responsive to antimicrobial treatment. Caseonecrotic bronchopneumonia is a pulmonary lesion typically associated with M. bovis. In Spain, M. bovis is widely distributed in the feedlots and circulating isolates are resistant to most antimicrobials in vitro. However, the role of this species in clinical respiratory disease of feedlot calves remains unknown. Furthermore, available data are relative to a fixed panel of antimicrobials commonly used to treat BRD, but not to the specific set of antimicrobials that have been used for treating each animal. This study examined 23 feedlot calves raised in southeast Spain (2016–2019) with clinical signs of respiratory disease unresponsive to treatment. The presence of M. bovis was investigated through bacteriology (culture and subsequent PCR), histopathology and immunohistochemistry. The pathogen was found in 86.9% (20/23) of the calves, mainly in the lungs (78.26%; 18/23). Immunohistochemistry revealed M. bovis antigens in 73.9% (17/23) of the calves in which caseonecrotic bronchopneumonia was the most frequent lesion (16/17). Minimum inhibitory concentration assays confirmed the resistance of a selection of 12 isolates to most of the antimicrobials specifically used for treating the animals in vivo. These results stress the importance of M. bovis in the BRD affecting feedlot calves in Spain.

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Cytologic detection of Toxoplasma gondii in the cerebrospinal fluid of a dog and in vitro isolation of a unique mouse-virulent recombinant strain

Journal of Veterinary Diagnostic Investigation ◽

10.1177/1040638721996685 ◽

2021 ◽

pp. 104063872199668

Author(s):

Waléria Borges-Silva ◽

Mariana M. Rezende-Gondim ◽

Gideão S. Galvão ◽

Daniele S. Rocha ◽

George R. Albuquerque ◽

...

Keyword(s):

Cerebrospinal Fluid ◽

Toxoplasma Gondii ◽

Recombinant Strain ◽

Neospora Caninum ◽

Clinical Signs ◽

Species Identity ◽

Cytologic Examination ◽

Pcr Rflp ◽

Tissue Homogenates

Parasites resembling Neospora caninum or Toxoplasma gondii were detected by cytologic examination of cerebrospinal fluid (CSF) from a dog with neurologic disease. The dog became severely ill and was euthanized. Canine tissue homogenates were used for direct parasite isolation in cell culture, bioassay in 2 mouse lineages, and PCR. T. gondii was isolated in monkey kidney cells, and species identity was confirmed by PCR. Inoculated parasites were highly virulent for mice, which developed clinical signs and were euthanized immediately. PCR-RFLP for T. gondii using the cultured isolate (TgDgBA22) was conducted with 12 genetic markers, and a unique recombinant strain was identified. Detection of T. gondii by CSF cytology, although described in humans, had not been reported previously in dogs, to our knowledge, and was crucial for the diagnosis of toxoplasmosis in the examined dog.

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CRYAB modulates the activation of CD4+ T cells from relapsing–remitting multiple sclerosis patients

Multiple Sclerosis Journal ◽

10.1177/1352458513489853 ◽

2013 ◽

Vol 19 (14) ◽

pp. 1867-1877 ◽

Cited By ~ 10

Author(s):

Que Lan Quach ◽

Luanne M Metz ◽

Jenna C Thomas ◽

Jonathan B Rothbard ◽

Lawrence Steinman ◽

...

Keyword(s):

Multiple Sclerosis ◽

T Cells ◽

Cytokine Production ◽

Clinical Signs ◽

Healthy Controls ◽

Relapsing Remitting ◽

Remitting Multiple Sclerosis ◽

Multiple Sclerosis Patients ◽

Relapsing Remitting Multiple Sclerosis

Background: Suppression of activation of pathogenic CD4+ T cells is a potential therapeutic intervention in multiple sclerosis (MS). We previously showed that a small heat shock protein, CRYAB, reduced T cell proliferation, pro-inflammatory cytokine production and clinical signs of experimental allergic encephalomyelitis, a model of MS. Objective: We assessed whether the ability of CRYAB to reduce the activation of T cells translated to the human disease. Methods: CD4+ T cells from healthy controls and volunteers with MS were activated in vitro in the presence or absence of a CRYAB peptide (residues 73–92). Parameters of activation (proliferation rate, cytokine secretion) and tolerance (anergy, activation-induced cell death, microRNAs) were evaluated. Results: The secretion of pro-inflammatory cytokines by CD4+ T cells was decreased in the presence of CRYAB in a subset of relapsing–remitting multiple sclerosis (RRMS) participants with mild disease severity while no changes were observed in healthy controls. Further, there was a correlation for higher levels of miR181a microRNA, a marker upregulated in tolerant CD8+ T cells, in CD4+ T cells of MS patients that displayed suppressed cytokine production (responders). Conclusion: CRYAB may be capable of suppressing the activation of CD4+ T cells from a subset of RRMS patients who appear to have less disability but similar age and disease duration.

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Deletion of the L7L-L11L Genes Attenuates ASFV and Induces Protection against Homologous Challenge

Viruses ◽

10.3390/v13020255 ◽

2021 ◽

Vol 13 (2) ◽

pp. 255

Author(s):

Jingyuan Zhang ◽

Yanyan Zhang ◽

Teng Chen ◽

Jinjin Yang ◽

Huixian Yue ◽

...

Keyword(s):

African Swine Fever Virus ◽

Clinical Signs ◽

African Swine Fever ◽

Biological Properties ◽

High Dose ◽

Swine Industry ◽

Epidemic Disease ◽

Intramuscular Inoculation ◽

Homologous Challenge

African swine fever (ASF), caused by the African swine fever virus (ASFV), is a major epidemic disease endangering the swine industry. Although a number of vaccine candidates have been reported, none are commercially available yet. To explore the effect of unknown genes on the biological characteristics of ASFV and the possibility of a gene-deleted isolate as a vaccine candidate, the strain SY18ΔL7-11, with deletions of L7L–L11L genes from ASFV SY18, was constructed, and its biological properties were analyzed. The results show that deletion of genes L7L-L11L did not affect replication of the virus in vitro. Virulence of SY18△L7-11 was significantly reduced, as 11 of the 12 pigs survived for 28 days after intramuscular inoculation with a low dose (103 TCID50) or a high dose (106 TCID50) of SY18ΔL7-11. All 11 surviving pigs were completely protected against challenge with the parental ASFV SY18 on 28 days postinoculation (dpi). Transient fever and/or irregularly low levels of genomic DNA in the blood were monitored in some pigs after inoculation. No ASF clinical signs or viremia were monitored after challenge. Antibodies to ASFV were induced in all pigs from 14 to 21 days postinoculation. IFN-γ was detected in most of the inoculated pigs, which is usually inhibited in ASFV-infected pigs. Overall, the results demonstrate that SY18ΔL7-11 is a candidate for further constructing safer vaccine(s), with better joint deletions of other gene(s) related to virulence.

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PrP P102L and Nearby Lysine Mutations Promote Spontaneous In Vitro Formation of Transmissible Prions

Journal of Virology ◽

10.1128/jvi.01276-17 ◽

2017 ◽

Vol 91 (21) ◽

Cited By ~ 6

Author(s):

Allison Kraus ◽

Gregory J. Raymond ◽

Brent Race ◽

Katrina J. Campbell ◽

Andrew G. Hughson ◽

...

Keyword(s):

Prion Protein ◽

Prion Diseases ◽

Transmissible Spongiform Encephalopathy ◽

Clinical Signs ◽

Protein Aggregates ◽

Structural Features ◽

Spongiform Encephalopathy ◽

Specific Sequence

ABSTRACT Accumulation of fibrillar protein aggregates is a hallmark of many diseases. While numerous proteins form fibrils by prion-like seeded polymerization in vitro, only some are transmissible and pathogenic in vivo. To probe the structural features that confer transmissibility to prion protein (PrP) fibrils, we have analyzed synthetic PrP amyloids with or without the human prion disease-associated P102L mutation. The formation of infectious prions from PrP molecules in vitro has required cofactors and/or unphysiological denaturing conditions. Here, we demonstrate that, under physiologically compatible conditions without cofactors, the P102L mutation in recombinant hamster PrP promoted prion formation when seeded by minute amounts of scrapie prions in vitro. Surprisingly, combination of the P102L mutation with charge-neutralizing substitutions of four nearby lysines promoted spontaneous prion formation. When inoculated into hamsters, both of these types of synthetic prions initiated substantial accumulation of prion seeding activity and protease-resistant PrP without transmissible spongiform encephalopathy (TSE) clinical signs or notable glial activation. Our evidence suggests that PrP's centrally located proline and lysine residues act as conformational switches in the in vitro formation of transmissible PrP amyloids. IMPORTANCE Many diseases involve the damaging accumulation of specific misfolded proteins in thread-like aggregates. These threads (fibrils) are capable of growing on the ends by seeding the refolding and incorporation of the normal form of the given protein. In many cases such aggregates can be infectious and propagate like prions when transmitted from one individual host to another. Some transmitted aggregates can cause fatal disease, as with human iatrogenic prion diseases, while other aggregates appear to be relatively innocuous. The factors that distinguish infectious and pathogenic protein aggregates from more innocuous ones are poorly understood. Here we have compared the combined effects of prion seeding and mutations of prion protein (PrP) on the structure and transmission properties of synthetic PrP aggregates. Our results highlight the influence of specific sequence features in the normally unstructured region of PrP that influence the infectious and neuropathogenic properties of PrP-derived aggregates.

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Miltefosine Administration in Cats with Refractory Sporotrichosis

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.83639 ◽

2018 ◽

Vol 46 (1) ◽

pp. 7

Author(s):

Francina Dos Santos Silva ◽

Simone Carvalho dos Santos Cunha ◽

Andrea Regina de Souza Baptista ◽

Vivian Dos Santos Baptista ◽

Kássia Valéria Gomes Coelho da Silva ◽

...

Keyword(s):

Weight Loss ◽

Sporothrix Schenckii ◽

Clinical Signs ◽

Public Health Problem ◽

Parasite Load ◽

Small Population ◽

Fungal Culture ◽

Cutaneous Lesions

Background: Sporotrichosis is a zoonosis caused by fungi of the Sporothrix schenckii complex. Cats have important zoonotic potential due to the high parasite load found in the cutaneous lesions. Refractory cases to antifungal therapy are increasing, becoming a public health problem. Miltefosine is a drug with high in vitro activity against Sporothrix brasiliensis. However, this efficacy has not been confirmed in vivo yet and administration has not been studied in the feline species. This study aimed to evaluate the effectiveness and safety of miltefosine administration in cats with resistant sporotrichosis.Materials, Methods & Results: Ten cats with refractory sporotrichosis were included in this study. Inclusion criteria were previous diagnosis for sporotrichosis associated with therapy with oral antifungals (itraconazole and/or potassium iodide) for more than one year, followed by one of these conditions: incomplete clinical remission, worsening of disease during treatment or recurrence after conventional treatment. Cats underwent clinical and dermatological examinations. Data on lifestyle and previous treatments were provided by the owners. Fungal culture and histochemical techniques were performed in all cats before miltefosine treatment. Blood samples were collected before and during the study for laboratory tests, such as blood count, blood urea nitrogen (BUN), serum creatinine, alanine aminotransferase (ALT) and alkaline phosphatase, as well as serology for Feline Immunodeficiency (FIV) and Feline Leukemia (FeLV). Miltefosine was prescribed at a dosage of 2 mg/kg orally every 24 h. The animals were monitored by phone during the whole process and reassessed on days 0, 15, 30 and 45 of the treatment. Out of 10 cats, lesions were present on the nose in nine, ears in four, periocular areas in one and limbs in four. One cat received treatment for 45 days, six for 30 days, one for 21 days, one for 15 days and one for 3 days. One cat showed no response to the treatment and nine showed disease progression. Hyporexia and weight loss were the most frequent clinical signs related to miltefosine treatment, followed by sialorrhea, vomiting and diarrhea. Few adverse effects on hematology and biochemistry (mainly renal and hepatic parameters) were observed during the study. Hematocrit decrease was observed in four animals. However, only one cat had hematocrit decrease below normal values (anemia), which was already present before miltefosine administration. Other cats had a decrease of five points. Three cats showed elevation in leucometria and four in plasma protein. In relation to renal and hepatic biochemistry, one animal showed a BUN increase and another one showed a transient increase in ALT. Two animals started the treatment with increased ALT but had no problems during the study and values decreased even during the miltefosine administration.Discussion: Although two cats showed sialorrhea, most owners did not report difficulty in administering the drug orally, representing an advantage of this medication. Weight loss, secondary to gastrointestinal changes, was the most clinically relevant alteration. The most frequent hematological alteration was hematocrit decrease and only the animal that started the study with 20% hematocrit ended the study with anemia. Renal and hepatic parameters were not significant in the cats of this study. Miltefosine did not lead to sporotrichosis remission in this small population of cats, which reveals that, despite its in vitro efficacy against Sporothrix spp., the drug is not effective in vivo in the feline species. Further studies are needed to investigate the efficacy of this drug in a larger number of cats, and possible reasons for its in vivo ineffectiveness.

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Florfenicol - pharmacodynamic, pharmacokinetics and clinical efficacy of oral formulations in domestic animals: A systematic review

Veterinarski glasnik ◽

10.2298/vetgl0506635s ◽

2005 ◽

Vol 59 (5-6) ◽

pp. 635-654 ◽

Cited By ~ 1

Author(s):

Leon Scuka

Keyword(s):

Systematic Review ◽

Clinical Efficacy ◽

Meta Analysis ◽

Clinical Signs ◽

Domestic Animals ◽

Oral Solution ◽

Favorable Effect ◽

Respiratory Pathogens ◽

Oral Formulations

Porcine respiratory disease complex (PRDC) is a major economic problem for swine producers world-wide. Pharmacodynamic, pharmacokinetics and clinical efficacy of florfenicol oral formulations in domestic animals were evaluated. For this purpose the systematic review and meta-analysis were done. In vitro efficacy of florfenicol showed that this drug is highly effective against most important respiratory pathogens. All these facts are shown in our survey. Three studies in pigs were relevant to include in the meta-analysis, which showed that results in the florfenicol group were better than in comparative control groups in all observed parameters: clinical signs, lung lesions and resolution of Actinobacillus pleuropneumoniae (P<0,001). A second meta-analysis with 7 studies showed that the usage of florfenicol reduces mortality in pig herds with PRDC (P<0.05). Other field trials in pigs using florfenicol oral forms where reviewed. After treatment with florfenicol oral solution there was a significant drop of mortality in both groups of pigs (P<0.01); eg. one using florfenicol oral solution in treating PRDC (n=85) and another mixed pneumoenteric infection (n=54). Analysis of data when using premix in pigs (n=118) also suggests that a medicated premix has a favorable anti-infectious effect on pigs, irrespective of the group of animals or the evolution stage of the disease. Finally, favorable effect of florfenicol in treating swine ileitis was also presented. Regarding their pharmacokinetics, in vitro and clinical efficacy of florfenicol oral forms, they should be considered as a powerful tool for combating complex infections that are frequently met in intensive animal production.

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Comparative Cancer Cell Signaling in Muscle-Invasive Urothelial Carcinoma of the Bladder in Dogs and Humans

Biomedicines ◽

10.3390/biomedicines9101472 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1472

Author(s):

Maria Malvina Tsamouri ◽

Thomas M. Steele ◽

Maria Mudryj ◽

Michael S. Kent ◽

Paramita M. Ghosh

Keyword(s):

Urothelial Carcinoma ◽

Human Cancer ◽

Clinical Signs ◽

Common Type ◽

Diagnostic Biomarkers ◽

Naturally Occurring ◽

Carcinoma Of The Bladder ◽

Muscle Invasive ◽

Cancer Cell Signaling

Muscle-invasive urothelial carcinoma (MIUC) is the most common type of bladder malignancy in humans, but also in dogs that represent a naturally occurring model for this disease. Dogs are immunocompetent animals that share risk factors, pathophysiological features, clinical signs and response to chemotherapeutics with human cancer patients. This review summarizes the fundamental pathways for canine MIUC initiation, progression, and metastasis, emerging therapeutic targets and mechanisms of drug resistance, and proposes new opportunities for potential prognostic and diagnostic biomarkers and therapeutics. Identifying similarities and differences between cancer signaling in dogs and humans is of utmost importance for the efficient translation of in vitro research to successful clinical trials for both species.

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