RESUMO

Venezuelan and eastern equine encephalitis viruses (VEEV and EEEV, respectively) are mosquito-borne, neuroinvasive human pathogens for which no FDA-approved therapeutic exists. Besides the biothreat posed by these viruses when aerosolized, arthropod transmission presents serious health risks to humans, as demonstrated by the 2019 outbreak of EEE disease in the United States that resulted in 38 confirmed cases, 19 deaths, and neurological effects in survivors. Here, we describe the discovery of a 2-pyrrolidinoquinazolinone scaffold, efficiently synthesized in two to five steps, whose structural optimization resulted in profound antiviral activity. The lead quinazolinone, BDGR-49, potently reduced cellular VEEV and EEEV titers by >7 log at 1 µM and exhibited suitable intravenous and oral pharmacokinetic profiles in BALB/c mice to achieve excellent brain exposure. Outstanding in vivo efficacy was observed in several lethal, subcutaneous infection mouse models using an 8-day dosing regimen. Prophylactically administered BDGR-49 at 25 mg kg-1 per day fully protected against a 10× LD50 VEEV Trinidad donkey (TrD) challenge in BALB/c mice. Similarly, we observed 70% protection when 10× LD50 EEEV FL93-939-infected C57BL/6 mice were treated prophylactically with BDGR-49 at 50 mg kg-1 per day. Last, we observed 100% therapeutic efficacy when mice, challenged with 10× LD50 VEEV TrD, were dosed at 48 hours after infection with BDGR-49 at 25 mg kg-1 per day. Mouse brain viral titers at 96 hours after infection were reduced to values near the limit of detection. Collectively, these results underscore the substantial development potential of a well-tolerated, brain-penetrant lead compound that shows promise in preventing and treating encephalitic alphavirus disease.

Assuntos

RESUMO

Branched chain amino acids (BCAA) are catabolized into various acyl-CoA compounds, which are key precursors used in polyketide productions. Because of that, BCAA catabolism needs fine tuning of flux balances for enhancing the production of polyketide antibiotics. To enhance BCAA catabolism for pikromycin production in Streptomyces venezuelae ATCC 15439, three key enzymes of BCAA catabolism, 3-ketoacyl acyl carrier protein synthase III, acyl-CoA dehydrogenase, and branched chain α-keto acid dehydrogenase (BCDH) were manipulated. BCDH overexpression in the wild type strain resulted in 1.3 fold increase in pikromycin production compared to that of WT, resulting in total 25 mg/L of pikromycin. To further increase pikromycin production, methylmalonyl-CoA mutase linked to succinyl-CoA production was overexpressed along with BCDH. Overexpression of the two enzymes resulted in the highest titer of total macrolide production of 43 mg/L, which was about 2.2 fold increase compared to that of the WT. However, it accumulated and produced dehydroxylated forms of pikromycin and methymycin, including their derivatives as well. It indicated that activities of pikC, P450 monooxygenase, newly became a bottleneck in pikromycin synthesis.

Assuntos

RESUMO

CONTEXT: Pheochromocytoma is a catecholamine-producing tumor characterized by hypertension, headache, tachycardia, excessive diaphoresis and angina. The thunderclap headache is so named because the pain strikes suddenly and severely. Although the symptoms of bladder pheochromocytoma are rather evident, the diagnosis of this rare neuroendocrine tumor can be missed. CASE REPORT: This study reports the case of a woman diagnosed with bladder pheochromocytoma who experienced thunderclap headache triggered by micturition and angina as an initial manifestation. CONCLUSION: This case study suggests that thunderclap headache and angina occurring concurrently with sudden blood pressure elevation during or immediately after micturition are important diagnostic clues for bladder pheochromocytoma. .

CONTEXTO: Feocromocitoma é um tumor produtor de catecolaminas, caracterizado por hipertensão, cefaleia, taquicardia, sudorese excessiva e angina. A dor de cabeça trovão é assim chamada porque a dor ataca de repente e intensamente. Embora os sintomas de feocromocitoma de bexiga sejam bastante evidentes, o diagnóstico deste tumor neuroendócrino raro pode ser perdido. RELATO DE CASO: Este estudo relata o caso de uma mulher diagnosticada com feocromocitoma na bexiga que sentiu a dor de cabeça trovão, desencadeada pela micção e angina como manifestação inicial. CONCLUSÃO: Este estudo de caso sugere que a dor de cabeça trovão e angina ocorrendo simultaneamente com a elevação da pressão de sangue repentina durante ou imediatamente após a micção são dicas importantes de diagnósticos de feocromocitoma na bexiga. .

Assuntos

RESUMO

CONTEXT: Pheochromocytoma is a catecholamine-producing tumor characterized by hypertension, headache, tachycardia, excessive diaphoresis and angina. The thunderclap headache is so named because the pain strikes suddenly and severely. Although the symptoms of bladder pheochromocytoma are rather evident, the diagnosis of this rare neuroendocrine tumor can be missed. CASE REPORT: This study reports the case of a woman diagnosed with bladder pheochromocytoma who experienced thunderclap headache triggered by micturition and angina as an initial manifestation. CONCLUSION: This case study suggests that thunderclap headache and angina occurring concurrently with sudden blood pressure elevation during or immediately after micturition are important diagnostic clues for bladder pheochromocytoma.

Assuntos