Process Development of a Macrocyclic Peptide Inhibitor of PD-L1.

This article outlines the process development leading to the manufacture of 800 g of BMS-986189, a macrocyclic peptide active pharmaceutical ingredient. Multiple N-methylated unnatural amino acids posed challenges to manufacturing due to the lability of the peptide to cleavage during global side chain deprotection and precipitation steps. These issues were exacerbated upon scale-up, resulting in severe yield loss and necessitating careful impurity identification, understanding the root cause of impurity formation, and process optimization to deliver a scalable synthesis. A systematic study of macrocyclization with its dependence on concentration and pH is presented. In addition, a side chain protected peptide synthesis is discussed where the macrocyclic protected peptide is extremely labile to hydrolysis. A computational study explains the root cause of the increased lability of macrocyclic peptide over linear peptide to hydrolysis. A process solution involving the use of labile protecting groups is discussed. Overall, the article highlights the advancements achieved to enable scalable synthesis of an unusually labile macrocyclic peptide by solid-phase peptide synthesis. The sustainability metric indicates the final preparative chromatography drives a significant fraction of a high process mass intensity (PMI).

Clinical manifestations and outcomes of otitis media with effusion in adult patients following Omicron infection in China.

Within the constantly changing landscape of the coronavirus disease 2019 (COVID-19) pandemic, the emergence of new variants introduces novel clinical challenges, necessitating the acquisition of updated insights into their impacts on various health conditions. This study investigates the clinical features and therapeutic outcomes of otitis media with effusion (OME) in adults following infection with the Omicron variant of COVID-19, in the context of China ending its "Zero-COVID-19" policy. Conducted as a multicenter, retrospective analysis at two medical institutions in Eastern China from December 2022 to February 2023, the study included patients with confirmed Omicron infection who were diagnosed with OME within two months, adhering to guidelines from the American Academy of Otolaryngology-Head and Neck Surgery Foundation (AAO-HNSF). Data on demographics, time from infection to OME manifestation, associated symptoms, and treatment outcomes were collected. Among 68 patients (73 affected ears) with OME post-Omicron infection, common symptoms included cough and nasal obstruction (69.1%). All reported ear fullness, with 86.8% experiencing hearing loss. Tympanic bullae were observed in 72.6% during otoscopy, and most tympanometry results showed a B-type tympanogram (80.0%). An integrated treatment strategy led to an 83.6% cure rate, although 8.2% experienced relapse within 2-3 months. Our findings highlight OME as a prevalent ear complication associated with COVID-19 during the Omicron pandemic, underscoring the necessity for further investigation into its complexities. While the integrated treatment approach proved effective, the 8.2% post-treatment recurrence rate underscores the importance of ongoing monitoring and signals an urgent need for more comprehensive research.

The silent reservoir? SARS-CoV-2 detection in the middle ear effusion of patients with Otitis media with effusion after omicron infection.

PURPOSE: This multicenter, prospective study is designed to investigate whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is present in the Middle Ear Effusion (MEE) of patients developing Otitis Media with Effusion (OME) subsequent to an Omicron infection. The objective is to elucidate any potential association between the virus and the condition. METHODS: This study, conducted from January to June 2023, spanned the Otolaryngology departments of two medical institutions in Eastern China. Patients manifesting OME subsequent to Omicron infection from both hospitals were subjected to comprehensive otolaryngological assessments, including pure-tone audiometry (PTA), tympanometry, otoscopic examination, and nasopharyngolaryngoscopy. Subsequently, MEE samples extracted from these patients were analyzed through RT-PCR to detect SARS-CoV-2. RESULTS: In this study, 23 patients (32-84 years; 57.5 ± 14.8 mean age; 47.8 % male) presented OME in 25 ears post-Omicron infection, with 21 (91.3 %) exhibiting unilateral symptoms. The median duration from infection to MEE sampling was 21 days (IQR: 25-46; range: 11-150). Predominantly, 64.0 % exhibited Type B tympanograms, and fluid accumulation was observed in 88.0 % of ears. SARS-CoV-2 was detected in 3 MEE samples (12.0 %), with cycle threshold values ranging between 25.65 and 33.30. CONCLUSIONS: Our study highlights the potential effects of COVID-19 on the middle ear, suggesting a link between SARS-CoV-2 and OME onset. The virus, a significant contributor to OME, is detectable in the MEE nearly a month post-Omicron infection, indicating a potential alteration in OME treatment strategies and a risk of recurrence, emphasizing the necessity for otolaryngologist vigilance.

An Effective CTL Peptide Vaccine for Ebola Zaire Based on Survivors' CD8+ Targeting of a Particular Nucleocapsid Protein Epitope with Potential Implications for COVID-19 Vaccine Design

The 2013-2016 West Africa EBOV epidemic was the biggest EBOV outbreak to date. An analysis of virus-specific CD8+ T-cell immunity in 30 survivors showed that 26 of those individuals had a CD8+ response to at least one EBOV protein. The dominant response (25/26 subjects) was specific to the EBOV nucleocapsid protein (NP). It has been suggested that epitopes on the EBOV NP could form an important part of an effective T-cell vaccine for Ebola Zaire. We show that a 9-amino-acid peptide NP44-52 (YQVNNLEEI) located in a conserved region of EBOV NP provides protection against morbidity and mortality after mouse adapted EBOV challenge. A single vaccination in a C57BL/6 mouse using an adjuvanted microsphere peptide vaccine formulation containing NP44-52 is enough to confer immunity in mice. Our work suggests that a peptide vaccine based on CD8+ T-cell immunity in EBOV survivors is conceptually sound and feasible. Nucleocapsid proteins within SARS-CoV-2 contain multiple class I epitopes with predicted HLA restrictions consistent with broad population coverage. A similar approach to a CTL vaccine design may be possible for that virus.

Effect of low-selenium diet on expressions of CCR7, CD206 and CD163 in the liver and kidney of rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of low-selenium diet on the liver and kidneys of rats and explore the role of macrophage polarization into M1 and M2 phenotypes in liver and kidney injuries.</p><p><b>METHODS</b>Twenty-four rats (12 female and 12 male) were randomly divided into control group and low-selenium group and fed with normal chow (dietary selenium of 0.18 mg/kg) and low-selenium diet (dietary selenium of 0.02 mg/kg) for 109 days. After the feeding, the rats were sacrificed for HE staining to observe liver and kidney pathologies, and immunohistochemistry was performed for analyzing CCR7, CD206, CD163-positive cell numbers in the liver and kidneys.</p><p><b>RESULTS</b>The rats in low-selenium group showed severer fibrosis in the liver and kidney than the control group. In either male or female rats in low-selenium group, CCR7 and CD206 expressions in the liver were comparable with those in control group, but CD163 expression was lower than that in the control group (P<0.05 for both female and male rats). In the kidney, the proximal tubule showed a slightly higher while the distal tubule showed a slightly lower CCR7 expression in low selenium group than in the control group (P>0.05). In low-selenium group, a significantly lower CD163 expression in the distal tubule and a significantly higher CD206 expression in the proximal tubule were noted as compared with the control group (P<0.05 in both female and male rats). Compared with the control rats, the male rats in low-selenium group, but not the female rats, showed a significantly lower CD163 expression in the proximal tubule of the kidney (P<0.05); the female but not the male rats in low-selenium group show a higher CD206 expression in the distal tubule (P<0.05).</p><p><b>CONCLUSION</b>Low-selenium diet can cause liver and kidney fibrosis in rats and may inhibit macrophage activation into the M2 phenotype.</p>