Combined immunohistochemical protocols to differentiate macrophages within the mononuclear-phagocyte system.

BACKGROUND: The "mononuclear phagocyte system" (MPS) refers to dispersed mononuclear monocytes and macrophages and is used to distinguish them from polymorphonuclear cells. The term "histiocyte" indicates large cells with voluminous granulated cytoplasm, sometimes containing engulfed particles, recognized as fully differentiated end cells of the MPS. Dendritic cells (DC) represent another diversified population whose inclusion in the MPS is still debated. The diverse cells of the MPS cannot all be characterized by single antigen markers or unique functions expressed at all stages of cell differentiation or activation. Nevertheless, in a diagnostic setting, their reliable identification plays a major role when a specific therapy must be established. Understanding the heterogeneity among MPS cell populations is indeed relevant to define different therapeutic approaches that can range from the use of antibiotics to immunomodulatory agents. For this reason, we attempted to establish a protocol to reliably identify the proportion of macrophages within the mononuclear phagocyte system in a tissue and/or in a given inflammatory population. METHODS: the Tafuri method was used in different double immunofluorescence protocols using an anti-Iba-1, anti-MAC387, and anti-CD11b-CD68-CD163-CD14-CD16 antibody. RESULTS AND DISCUSSION: in normal canine skin the anti-Iba-1 antibody stained an epidermal cell population (i.e. Langerhans cells) and scattered cells within the dermal compartment. MAC387 was unable to stain cells containing Leishmania amastigotes in leishmaniasis-diagnosed samples as the anti-CD11b-CD68-CD163-CD14-CD16 antibody did. By using a combination of staining protocols to differentiate macrophages within the whole histiocytic infiltrate we validated the use of a cocktail of rabbit monoclonal antibodies raised against CD11b, CD68, CD163, CD14, CD16 to stain skin macrophages.

Pulmonary Embolism in COVID-19 Patients Is Not Related to a Deterioration of Tissue Oxygenation.

BACKGROUND: COVID-19 induces robust systemic inflammation. One of the main complications is the increased coagulation due to endotheliitis. There is an increased incidence of pulmonary embolism (PE) in COVID-19 patients. However, clinical characteristics for a strict analysis are yet to be determined. AIM: We evaluated oxygenation and characteristics in patients with COVID-19 PE (CPE). MATERIAL AND METHODS: We evaluated 215 COVID-19 patients from 1 January to 30 April 2021. We found 18 patients affected by PE (CPE, 50.0% males, aged 67.00 ± 10.86 years). As controls, we used data from patients affected by PE evaluated in our ward between 1 January 2015 and 31 December 2019 (64 patients, 53.1% males, aged 70.88 ± 16.44 years). All patients underwent a complete physical examination, pulmonary computerised tomography, laboratory tests, D-dimers and blood gas analysis at the time of diagnosis. RESULTS: There were no differences in laboratory tests nor in D-dimers between the two groups. In the CPE group we found a significantly increased pO2 (92.83 ± 42.52 vs. 76.11 ± 32.58 mmHg; p < 0.05), difference of oxygen between alveoli and arteries (A-aDO2; 169.3 ± 171.9 vs. 52.97 ± 39.65 mmHg; p < 0.05), and oxygen saturation % (97.06 ± 2.59 vs. 93.77 ± 5.53%; p < 0.05) compared to controls. No difference was found in pCO2 and the ratio between pO2 and percentage of inspired oxygen (P/F). Finally, a significantly decreased urate (3.67 ± 1.49 vs. 5.60 ± 2.10; p < 0.05) was found in CPE compared to controls. In CPE, platelets count presents an inverse correlation to P/F (r = -0.389, p = 0.02) but a direct correlation to A-aDO2 (r = 0.699, p = 0.001). No similar findings were present in controls. DISCUSSION: COVID-19 PE appears to have a different clinical setting. Reduced oxygenation described in PE may not to be considered as a sign of disease. The increased A-aDO2 may indicate that COVID-19 PE involved smaller vessels compared to classical PE. A possible diffuse capillary thrombosis could explain these results.

Prevalence and genotypic characterization of Clostridium difficile from ruminants in Switzerland.

Clostridium difficile is an emerging enteric pathogen of humans and animals with a known main reservoir in the intestinal tract of various warm-blooded animals. This study was carried out to evaluate the prevalence of C. difficile in 150 rectal swab samples collected from cattle and goats in Switzerland. The overall prevalence of C. difficile was 6.6%. The isolates belonged to the PCR ribotypes 033, 066, 070, 003, 001 and 137. In addition, the occurrence of C. difficile in faecal samples collected from farm ground was also evaluated and C. difficile was detected in 21% (7/30) of these samples. These isolates belonged to ribotypes 033, 066, 014 and 137. Several isolates pertained to ribotypes known to cause Clostridium difficile infections in humans.

Antibiotic treatments of a methicillin-resistant Staphylococcus pseudintermedius infection in a dog: a case presentation.

We report the antibiotic treatments administered to a female dog with mastitis and successive pyoderma. Microbiological investigations allowed the identification of Staphylococcus pseudintermedius after 54 days of various antibiotic treatments. The isolate carried the mecA gene and was resistant to 9 of 15 tested antibiotics. Consistent antibiotic treatment of the infection was possible only after accurate microbiological diagnosis.

Association between waste management and cancer in companion animals.

BACKGROUND: Increased cancer rates have been documented in people residing in areas around Naples characterized by illegal dumping and incineration of waste. HYPOTHESIS: Risk of cancer in dogs and cats is associated with waste management. ANIMALS: Four hundred and fifty-three dogs and cats with cancer and 1,554 cancer-free animals. METHODS: Hospital-based case-control study in Naples (low danger) and nearby cities having a history of illegal waste dumping (high danger). Odds ratio (OR) between high- and low-danger areas was calculated for all tumors and various malignancies in dogs and cats. RESULTS: An increased risk for cancer development was identified in dogs but not in cats residing in high-danger areas (OR: 1.55; 95% confidence interval: 1.18-2.03; P < .01). A 2.39-fold increased risk of lymphoma (P < .01) accounted for the greater tumor frequency in dogs residing in high-danger areas. The risk of mast cell tumor and mammary cancer did not differ in dogs residing in high- or low-danger areas. CONCLUSIONS AND CLINICAL IMPORTANCE: Waste emission from illegal dumping sites increases cancer risk in dogs residing in high-danger areas. An increased prevalence of lymphoma has been previously recognized in humans living close to illegal waste dumps. Thus, epidemiological studies of spontaneous tumors in dogs might suggest a role for environmental factors in canine and human carcinogenesis and can predict health hazards for humans.

Extragenital transmissible venereal tumour associated with circulating neoplastic cells in an immunologically compromised dog.

An adult male intact boxer was presented because of diffuse cutaneous nodules. Fine-needle aspirate revealed transmissible venereal tumour (TVT) cells. Neoplastic cells were also observed in the peripheral blood. Associated simultaneous diseases included leishmaniosis, demodicosis, papillomatosis and coccidiosis. Immunosuppression may have aggravated disease and triggered widespread metastases. The dog was hospitalized and administered oral amoxicillin/clavulanate, subcutaneous meglumine antimonite to treat leishmaniosis and oral chlortetracycline to treat coccidiosis. Intravenous injection of vincristine at weekly interval was used to treat TVT. A rapid regression of cutaneous nodules was noted; however, intractable diarrhoea developed, eventually leading to death after 18 days. This is the first report describing an unusual case of extragenital TVT associated with circulating neoplastic cells in an immunosuppressed dog presenting with multiple cutaneous nodules.