Functional Divergence of the Tribolium castaneum engrailed and invected Paralogs.

Engrailed (en) and invected (inv) encode paralogous transcription factors found as a closely linked tandem duplication within holometabolous insects. Drosophila en mutants segment normally, then fail to maintain their segments. Loss of Drosophila inv is viable, while loss of both genes results in asegmental larvae. Surprisingly, the knockdown of Oncopeltus inv can result in the loss or fusion of the entire abdomen and en knockdowns in Tribolium show variable degrees of segmental loss. The consequence of losing or knocking down both paralogs on embryogenesis has not been studied beyond Drosophila. To further investigate the relative functions of each paralog and the mechanism behind the segmental loss, Tribolium double and single knockdowns of en and inv were analyzed. The most common cuticular phenotype of the double knockdowns was small, limbless, and open dorsally, with all but a single, segmentally iterated row of bristles. Less severe knockdowns had fused segments and reduced appendages. The Tribolium paralogs appear to act synergistically: the knockdown of either Tribolium gene alone was typically less severe, with all limbs present, whereas the most extreme single knockdowns mimic the most severe double knockdown phenotype. Morphological abnormalities unique to either single gene knockdown were not found. inv expression was not affected in the Tribolium en knockdowns, but hh expression was unexpectedly increased midway through development. Thus, while the segmental expression of en/inv is broadly conserved within insects, the functions of en and inv are evolving independently in different lineages.

Development of Retroperitoneal Abscess Following Routine Injection of Triamcinolone for Musculoskeletal Pain.

Glucocorticoid intramuscular injections are a quick, routine procedure done in an outpatient setting to relieve musculoskeletal pain quickly. However, despite being a low-risk procedure it can lead to local infections, including abscess and skin necrosis, and even more rarely, bacteraemia and multi-organ failure. In this case, we present a healthy, immunocompetent woman in her 40s diagnosed with a retroperitoneal abscess due to methicillin-resistant Staphylococcus aureus after an intramuscular injection of triamcinolone. LEARNING POINTS: Injections of glucocorticoids are commonly used in medical practice to alleviate musculoskeletal pain in addition to oral non-steroidal anti-inflammatory agents.Complications of injections include abscess formation, skin necrosis and sepsis, typically from Staphylococcus aureus or other skin colonisers.It should be understood that there are risks associated with injections regardless of age or co-morbidities, so these risks should be discussed with the patient in depth before administration.

Empyema necessitans complicating a mild COVID-19 infection in a young immunocompetent patient.

COVID-19 infection can be complicated by secondary bacterial infections including pneumonia and empyema resulting in worse outcomes. Empyema management includes empirical antibiotic therapy and drainage with a favorable prognosis in most cases. Abstract: Empyema necessitans is a rare complication of poorly or uncontrolled empyema thoracis resulting in the dissection of pus through the soft tissues and skin of the chest wall resulting in a fistula between the pleural cavity and the skin. Previous reports indicate that secondary bacterial pneumonia can complicate the course of a COVID-19 infection even in immunocompetent patients resulting in worse outcomes. Management of empyema includes empirical antibiotic therapy and drainage with a favorable prognosis in most cases.

Acute Onset of Bullous Skin Rash and Acute Kidney Injury after Exposure to Radiocontrast: Sweet's Syndrome.

Sweet's syndrome or acute febrile neutrophilic dermatosis is characterized by an acute inflammatory skin eruption of oedematous and erythematous papules, plaques or nodules, accompanied by fever, and leucocytosis with possible extracutaneous involvement. Aetiologies include infections, inflammatory bowel disease, pregnancy or malignancy, or the syndrome may be drug-induced by many classes of medications or very rarely, radiocontrast exposure. Herein, the authors report a case of radiocontrast-induced bullous Sweet's syndrome and contrast-induced acute kidney injury in a woman in her 60s with a complex medical history. LEARNING POINTS: Patients with Sweet's syndrome (SS) typically present with acute-onset fever, leucocytosis, and erythematous, tender plaques with dense neutrophilic infiltration in the dermis. The condition is classified into three subtypes: classic SS, malignancy-associated SS, and drug-induced SS.Drug-induced SS is characterized by an abrupt onset of a painful erythematous rash, dense neutrophilic dermal infiltrate without vasculitis, a temporal relationship between exposure and onset, and resolution of symptoms after drug discontinuation and/or corticosteroid therapy.Treatment options include systemic corticosteroids as first-line therapy, while colchicine, dapsone, indomethacin, naproxen, clofazimine, ciclosporin, α-interferon, and potassium iodide may be considered as second-line therapies in cases resistant to corticosteroids.

Transient Leukopenia Induced by Combination Therapy for Severe SARS-CoV-2 Pneumonia.

Treatment strategies for patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to be heavily researched and ever-changing. Recent data has suggested that combination therapy with dexamethasone, remdesivir and baricitinib could decrease the severity and length of illness in patients with severe SARS-CoV-2. However; the data regarding the safety and side effects related to this combination therapy are limited to case reports. The purpose of this case report is to highlight a potentially life-threatening side effect of one or all medications mentioned above. LEARNING POINTS: Current National Institutes of Health treatment guidelines recommend remdesivir for patients with a high risk of progression. In patients requiring minimal supplemental oxygen, remdesivir or dexamethasone monotherapy is recommended, while in patients requiring high-flow oxygen or non-invasive ventilation, dexamethasone monotherapy or dexamethasone plus remdesivir is recommended. Baricitinib or tocilizumab can be added in patients requiring oxygen supplementation.Clinicians should be aware of transient leukocytopenia that can be induced with combination therapy of dexamethasone, remdesivir and baricitinib during the early phase of treatment of SARS-CoV-2 patients.The evaluation approach for leukopenia should consider autoimmune disorders, inflammatory diseases, infections, malignancy, and medication and toxin exposure.