Bronchopneumonia by Streptococcus equi subsp. zooepidemicus in a horse with inhalation of pine branch of Araucaria angustifolia

ABSTRACT: Respiratory problems due to tracheobronchial foreign bodies (FBs) are unusual in horses; although equines kept in pastures eventually inhale FBs, as conifer twigs of Araucaria angustifolia. A 1,5-year-old Criolle foal was presented with hemoptysis, dyspnea, restlessness and fever (40.9 ºC rectal temperature). Complete blood count showed intense neutropenia, monocytosis, thrombocytopenia and hypoproteinemia. Treatment was carried out but no clinical improvement was observed. At the post-mortem examination, marked amount of dark red liquid was observed in the thoracic cavity (hemothorax). The lung parenchyma was diffusely consolidated, predominantly in the cranioventral area, associated with mild pleural fibrin deposition. The right primary bronchus was obliterated by a Araucaria angustifolia pine branch measuring 18 cm in length, with adjacent darkened areas (lung consolidation). Microscopically, there was diffuse necrosis with severe hemorrhage in the lungs, associated with marked neutrophilic inflammatory infiltrate, numerous coccoid bacterial aggregates, and fibrinous pleuritis. Additionally, there was diffuse alveolar edema and multifocal thrombosis. Lung fragments were submitted for bacterial culture and mixed bacterial growth was observed with a predominance of Streptococcus equi subsp. zooepidemicus. Inhalation of branches is not commonly reported in horses, but it must be included in the differential diagnoses of pneumonia, and attention should be taken when allowing horses to graze in areas where the plant occurs.

Anaphylactic shock with pulmonary eosinophilic infiltration due to honeybee attack in a donkey: case report

ABSTRACT A case of a donkey attacked by Africanized honeybee is reported here with clinical signs of agitation, dehydration, congestion of the ocular mucous membranes, tongue edema, tachycardia and inspiratory dyspnea, and progression to death. At necropsy, diffuse, severe subcutaneous edema at face and cervical regions and severe diffuse pulmonary hyperemia with abundant edema without parenchymal collapse were observed. Microscopically, marked, diffuse deep dermis and panniculus carnosus edema and marked diffuse alveolar edema, with moderate population of eosinophils predominantly around larger caliber vessels were noted. The final diagnosis of anaphylactic shock was supported by history, clinical signs, and anatomic pathology findings. This is the first report of a honeybee attack with pulmonary eosinophilic infiltration in a mammal.

Clinical and pathomorphological analysis of deaths from COVID-19 in 2020

The aim of the work – to conduct clinical and pathomorphological analysis of deaths from COVID-19 in 2020. Materials and methods. We analyzed 41 case histories and results of pathological-anatomical examination of patients who were died of COVID-19 during 2020. Results. The lethal outcome of COVID-19 disease was recorded at day 22 (16; 27) of the disease. Among the dead, there is a high percentage of men (73.2 %), early old age and middle old age patients (75.6 %) with comorbid pathology (92.7 %). Early lung damage with COVID-19 in the deceased was determined by pronounced interstitial and interstitial-alveolar edema, the presence of erythrocyte stasis in the pulmonary microvessels, blood clots and hypoperfusion leukocyte stasis, as well as the presence of erythrocytes in the alveoli. Bilateral polysegmental subtotal viral pneumonia in 90.2 % of dead patients was characterized by significant edema and thickening of the alveolar walls with their moderate infiltration by lymphocytes, focal peribronchial and perivascular inflammatory polymorphonuclear infiltration, multiple and small exfoliated alveolar epithelium (87.8 %), as well as metaplasia of a few alveolocytes preserved on the luminal surface of the alveoli (82.9 %). Every tenth person who died of COVID-19 had signs of secondary bacterial microflora. In 85.4 % of patients who died on day 22–27 of the disease focal or sublobar pneumofibrosis was diagnosed. In those who died due to COVID-19, multiorgan failure was characterized by focal necrosis of the renal tubular epithelium (73.2 %), focal lymphocytic-leukocyte infiltration (12.2 %) and renal microvascular thrombosis (17.1 %), focal centro-lobular necrosis (90.2 %) and focal lymphocytic-leukocyte infiltration of lobes (7.3 %) of the liver. Thrombotic complications were confirmed in 22.0 % of deceased patients: ischemic cerebral infarction, transmural myocardial infarction, pulmonary embolism, deep vein thrombosis of the lower extremities under the pathology. These thrombotic complications were not diagnosed during life in all patients. The majority of deaths due to COVID-19 had morphological signs of chronic cardiovascular pathology. Ischemic heart disease and hypertension during the life of patients were not diagnosed in all cases. Conclusions. Early lung damage in COVID-19 in the deceased was determined by pronounced interstitial-alveolar edema, blood clots and leukocyte stasis in microvessels, less often – the presence of “hyaline membranes”. In 90.2 % of the dead patients bilateral polysegmental subtotal pneumonia with edema and lymphocytic infiltration of the pulmonary interstitium, inflammatory peribronchial and perivascular focal polymorphonuclear infiltrates, foci of atelectasis and dyscryphaseses was found. In 9.7 % of patients bilateral subtotal viral-bacterial fibrinous-purulent bronchopneumonia developed. In those who died on the 22nd–27th day of the disease focal pneumofibrosis was determined. Pathomorphologically, thrombotic complications, which were not diagnosed in all patients during their lifetime, were confirmed in 22.0 % of deceased patients. Most deaths from COVID-19 had morphological signs of chronic cardiovascular disease.

Insights into pathophysiology, immune response and treatment of novel CoVID-19

The beginning of year 2020 has brought with it mass destruction of mankind in form of novel coronavirus, named as CoVID-19. Declared as pandemic by World Health Organization (WHO), CoVID-19 has its origin in bats and pangolin from which it was probably transferred to human. Subsequent human to human transmission has been seen by respiratory droplets, fomites and oral-fecal route. The disease has caused widespread deaths in America, China, France and Italy followed by many European and Asian countries. CoVID-19 targets the human lungs and multiplies in alveoli using host machinery. Interstitial edema and alveolar edema at later stages cause alveoli collapse and difficulty in breathing. Severe cases may pave to systemic inflammatory response that has fatal response in body. Unfortunately, researchers are still struggling for potential vaccine or promising drug to combat the disease. WHO has issued guidelines suggesting regular hand washing, social distancing, wearing masks and quarantination as the best ways to prevent infection. This review gives an overview of the novel CoVID-19, conditions and immune response of human body related with it.

The Role of Alveolar Edema in COVID-19

The coronavirus disease 2019 (COVID-19) has spread over the world for more than one year. COVID-19 often develops life-threateninghypoxemia. Endothelial injury caused by the viral infection leads to intravascular coagulation and ventilation–perfusion mismatch. However, besides above pathogenic mechanisms, the role of alveolar edema in the disease progression has not been discussed comprehensively. Since the exudation of pulmonary edema fluid was extremely serious in COVID-19 patients, we bring out a hypothesis that severity of alveolar edema may determine the size of poorly-ventilated area and the blood oxygen content. Treatments to pulmonary edema (conservative fluid management, exogenous surfactant replacementsand ethanol–oxygen vapor therapyhypothetically) may be greatly helpful for reducingthe occurrences of severe cases. Given that late mechanical ventilation may causemucus (edema fluid) to be blown deep intothe small airways,oxygentherapy should be given at the early stages. Theoptimaltimeand blood oxygen saturation (SpO2) thresholdforoxygentherapy are also discussed.

CLINICAL AND HISTOPATHOLOGICAL FEATURES OFLUNG INJURY IN COVID-19 INFECT

The aim of the study was to evaluate the histopathological changes in the lungs of patients who died of a new coronavirus infection (COVID-19) in relation to the length of hospital stay. We evaluated lung autopsy material, autopsy reports, and death summaries of 39 patients who died of COVID-19. The length of hospital stay ranged from a few hours to 25 days. At all stages of the disease, lung alterations (desquamation of bronchial and alveolar epithelium), circulatory disorders (alveolar edema and hemorrhages, congestion in small blood vessels, thrombosis), compensatory response (fibrosis) were identified. The patients who died during the first week of hospitalization demonstrated predominant signs of circulatory disorders (alveolar edema, hyaline membranes, alveolar hemorrhages, congestion in small blood vessels). Fibrosis, usually not typical for the first week of acute respiratory distress syndrome, was detected in 46% of the deceased during the first week of hospitalization, which may be due to late hospitalization or patterns of fibrosis development in COVID-19. For those who died in the 2nd and 3rd weeks of hospitalization, the compensatory response and progression of fibrosis were noted. By the 3rd week, pulmonary fibrosis was detected in 91% of patients. Thrombotic complications (thrombosis, pulmonary artery thromboembolism) were observed in almost half of fatalities occurring during weeks 2–3. Hemorrhagic infarction was found in 43% (6 patients) who died during week 2 of hospitalization, three of them were diagnosed with pulmonary embolism, indicating progression of pulmonary vascular damage.

The Role of Alveolar Edema in COVID-19

The coronavirus disease 2019 (COVID-19) has spread over the world for more than one year. COVID-19 often develops life-threatening hypoxemia. Endothelial injury caused by the viral infection leads to intravascular coagulation and ventilation-perfusion mismatch. However, besides above pathogenic mechanisms, the role of alveolar edema in the disease progression has not been discussed comprehensively. Since the exudation of pulmonary edema fluid was extremely serious in COVID-19 patients, we bring out a hypothesis that severity of alveolar edema may determine the size of poorly-ventilated area and the blood oxygen content. Treatments to pulmonary edema (alcohol-oxygen vapor therapy and fluid management) may be great helpful for reducing occurrence of severe cases. Given that late mechanical ventilation may cause mucus (edema fluid) to be blown to the deep of the small airways, oxygen therapy should be given at the early stages. The optimal time and SpO2 threshold for oxygen therapy are also discussed.

C-Reactive Protein Triggers Cell Death in Ischemic Cells

C-reactive protein (CRP) is the best-known acute phase protein. In humans, almost every type of inflammation is accompanied by an increase of CRP concentration. Until recently, the only known physiological function of CRP was the marking of cells to initiate their phagocytosis. This triggers the classical complement pathway up to C4, which helps to eliminate pathogens and dead cells. However, vital cells with reduced energy supply are also marked, which is useful in the case of a classical external wound because an important substrate for pathogens is disposed of, but is counterproductive at internal wounds (e.g., heart attack or stroke). This mechanism negatively affects clinical outcomes since it is established that CRP levels correlate with the prognosis of these indications. Here, we summarize what we can learn from a clinical study in which CRP was adsorbed from the bloodstream by CRP-apheresis. Recently, it was shown that CRP can have a direct effect on blood pressure in rabbits. This is interesting in regard to patients with high inflammation, as they often become tachycardic and need catecholamines. These two physiological effects of CRP apparently also occur in COVID-19. Parts of the lung become ischemic due to intra-alveolar edema and hemorrhage and in parallel CRP increases dramatically, hence it is assumed that CRP is also involved in this ischemic condition. It is meanwhile considered that most of the damage in COVID-19 is caused by the immune system. The high amounts of CRP could have an additional influence on blood pressure in severe COVID-19.

Hypercapnia Impairs Na,K-ATPase Function by Inducing Endoplasmic Reticulum Retention of the β-Subunit of the Enzyme in Alveolar Epithelial Cells

Alveolar edema, impaired alveolar fluid clearance, and elevated CO2 levels (hypercapnia) are hallmarks of the acute respiratory distress syndrome (ARDS). This study investigated how hypercapnia affects maturation of the Na,K-ATPase (NKA), a key membrane transporter, and a cell adhesion molecule involved in the resolution of alveolar edema in the endoplasmic reticulum (ER). Exposure of human alveolar epithelial cells to elevated CO2 concentrations caused a significant retention of NKA-β in the ER and, thus, decreased levels of the transporter in the Golgi apparatus. These effects were associated with a marked reduction of the plasma membrane (PM) abundance of the NKA-α/β complex as well as a decreased total and ouabain-sensitive ATPase activity. Furthermore, our study revealed that the ER-retained NKA-β subunits were only partially assembled with NKA α-subunits, which suggests that hypercapnia modifies the ER folding environment. Moreover, we observed that elevated CO2 levels decreased intracellular ATP production and increased ER protein and, particularly, NKA-β oxidation. Treatment with α-ketoglutaric acid (α-KG), which is a metabolite that has been shown to increase ATP levels and rescue mitochondrial function in hypercapnia-exposed cells, attenuated the deleterious effects of elevated CO2 concentrations and restored NKA PM abundance and function. Taken together, our findings provide new insights into the regulation of NKA in alveolar epithelial cells by elevated CO2 levels, which may lead to the development of new therapeutic approaches for patients with ARDS and hypercapnia.

Investigation of Bosentan's Effects on Pulmonary Contusion Created by Blunt Thoracic Trauma in Rats

Introduction Bosentan is an endothelin-1 receptor antagonist with anti-inflammatory, antioxidant, and antiproliferative effects. We aimed to evaluate its effects on lung tissue in a pulmonary contusion (PC) model. Materials and Methods The rats were randomly divided into five groups: PC3: PC evaluated on the 3rd day (n = 8), PC-B3: PC enteral bosentan 100 mg/kg/day, for 3 days (n = 8), PC7: PC evaluated on the 7th day (n = 7), PC-B7: PC 7 days bosentan 100 mg/kg/day, for 7 days (n = 8), C: control (n = 6). Unilateral lung contusion was created by dropping a metal weight onto the chest. The rats were sacrificed on the 3rd or the 7th days. The lung tissue was evaluated histopathologically for alveolar edema, congestion, and leukocyte infiltration, biochemically for malondialdehyde (MDA), superoxide dismutase (SOD), and nitric oxide (NO) levels, and immunohistochemically for inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and apoptosis scores. Results Alveolar edema, congestion, and leukocyte infiltration scores were increased in all groups compared with the control group (p < 0.05) and decreased in bosentan-treated groups compared with the relevant nontreated groups (p < 0.05). Fibrosis was observed only in PC7 and PC-B7 groups. Bosentan did not have any effect on fibrosis development. iNOS and eNOS levels were higher in all groups compared with the control (p < 0.05) without a difference in the nontreated versus treated groups (p > 0.05). Bosentan treatment caused decreased MDA and increased SOD levels in comparison to the nontreated groups (p < 0.05). Tissue NO levels did not show any significant difference among groups. PC groups had higher levels of apoptosis compared with the control group (p < 0.05). The degree of apoptosis decreased in bosentan-treated groups compared with the nontreated groups (p < 0.05). Conclusion PC causes progressive lung tissue damage. Bosentan reduced leukocyte infiltration and alveolar edema and congestion caused by PC. It also decreased MDA levels and increased SOD levels. Bosentan prevents tissue damage by inhibiting acute inflammatory response and reduces oxidative stress secondary to inflammation. It has therapeutic effects on apoptosis.