Profile of patients with HPV infection at the regional hospital of Saint-Louis, Senegal

Background: Objectives of current study was to define the sociodemographic characteristics of patients, to determine the frequency of HPV infection at the CHRSL and to describe factors associated with HPV infection. Methods: This was a prospective cross-sectional study conducted in the gynecology-obstetrics department of the Saint Louis Regional Hospital Center from November 11, 2019 to November 11, 2021, a period of 24 months. We studied sociodemographic, clinical and test results characteristics. Samples were taken from patients in the gynaecological position using a dedicated kit (cytobrush and tube). Viral research was carried out using the Atila Biosystems device for amplification and detection of viral DNA. This test genotypes HPV 16, 18 and 45, and detects 12 other HR HPVs (31, 33, 35, 39, 51, 52, 56, 58, 59, 66 and 68) simultaneously using three probes labelled with different fluorophores. Analysis was performed using Epi-Info software and Excel 2010. Results: The study population comprised 128 patients. The mean age of the patients was 41.95 years, with extremes of 23 and 70 years. They were married (92.97%) and housewives (46.88%). Almost all patients (77.34%) were genitally active. The average age at marriage was 21.78 years, and polygamous households predominated (53.91%). The average age at first intercourse was 20.05 years. The average age at first pregnancy was 21.78. Over (57.81%) of patients had at least two partners. Incense was used in 97.66% of cases. The viral HPV test was positive in (38.28%) of patients. High-risk papillomaviruses were the most common, at 63.27%. Colposcopy was performed in 17.19%; normal and satisfactory in (63.64%) of patients, with 22.27% of cervical biopsies, and histology showed one CIN2 and two CIN3. Therapeutically, one thermoablation and two hysterectomies were performed. Conclusions: HPV viral typing in primary screening for cervical cancer offers opportunities and remains realistic and feasible in less developed countries such as Senegal, despite modest resources

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Lamination and spherulite-like compaction of a hormone's native amyloid-like nanofibrils: spectroscopic insights into key interactions

The native hierarchical self-assembly process of natural somatostatin-14, a highly aromatic and charged peptide hormone involved in various inhibitory functions, was investigated mainly using vibrational spectroscopy (ATR-FTIR and Raman scattering) combined with electron microscopy. Generic kinetic features of amyloid fibrillogenesis were confirmed for the somatostatin-14 case, together with new insights into key interactions involved in the further hierarchical assembly of the somatostatin-14 nanofibrils into i) laterally associated nanofibers and ii) spherulite-like amyloid droplets resulting from the compaction of the nanofibers. In particular, the key role of aromatic side-chains in both fibrillogenesis and the association of the nanofibrils into higher order structures could be followed. It is proposed that the compaction propensity of the somatostatin-14 nanofibrils is relevant to the current hypothesis of the biological function of hormone self-assembly processes: hormone storage inside secretory granules

Self-Association Process of a Peptide in Solution: From β-Sheet Filaments to Large Embedded Nanotubes

Lanreotide is a synthetic octapeptide used in the therapy against acromegaly. When mixed with pure water at 10% (w/w), Lanreotide (acetate salt) forms liquid crystalline and monodisperse nanotubes with a radius of 120 Å. The molecular and supramolecular organization of these structures has been determined in a previous work as relying on the lateral association of 26 β-sheet filaments made of peptide noncovalent dimers, the basic building blocks. The work presented here has been devoted to the corresponding self-association mechanisms, through the characterization of the Lanreotide structures formed in water, as a function of peptide (acetate salt) concentration (from 2% to 70% (w/w)) and temperature (from 15°C to 70°C). The corresponding states of water were also identified and quantified from the thermal behavior of water in the Lanreotide mixtures. At room temperature and below 3% (w/w) Lanreotide acetate in water, soluble aggregates were detected. From 3% to 20% (w/w) long individual and monodisperse nanotubes crystallized in a hexagonal lattice were evidenced. Their molecular and supramolecular organizations are identical to the ones characterized for the 10% (w/w) sample. Heating induces the dissolution of the nanotubes into soluble aggregates of the same structural characteristics as the room temperature ones. The solubilization temperature increases from 20°C to 70°C with the peptide concentration and reaches a plateau between 15% and 25% (w/w) in peptide. These aggregates are proposed to be the β-sheet filaments that self-associate to build the walls of the nanotubes. Above 20% (w/w) of Lanreotide acetate in water, polydisperse embedded nanotubes are formed and the hexagonal lattice is lost. These embedded nanotubes exhibit the same molecular and supramolecular organizations as the individual monodisperse nanotubes formed at lower peptide concentration. The embedded nanotubes do not melt in the range of temperature studied indicating a higher thermodynamic stability than individual nanotubes. In parallel, the thermal behaviors of water in mixtures containing 2–80% (w/w) in peptide have been studied by differential scanning calorimetry, and three different types of water were characterized: 1), bulk water melting at 0°C, 2), nonfreezing water, and 3), interfacial water melting below 0°C. The domains of existence and coexistence of these different water states are related to the different Lanreotide supramolecular structures. All these results were compiled into a binary Lanreotide-water phase diagram and allowed to propose a self-association mechanism of Lanreotide filaments into monodisperse individual nanotubes and embedded nanotubes

Biomimetic organization: Octapeptide self-assembly into nanotubes of viral capsid-like dimension

The controlled self-assembly of complex molecules into well defined hierarchical structures is a promising route for fabricating nanostructures. These nanoscale structures can be realized by naturally occurring proteins such as tobacco mosaic virus, capsid proteins, tubulin, actin, etc. Here, we report a simple alternative method based on self-assembling nanotubes formed by a synthetic therapeutic octapeptide, Lanreotide in water. We used a multidisciplinary approach involving optical and electron microscopies, vibrational spectroscopies, and small and wide angle x-ray scattering to elucidate the hierarchy of structures exhibited by this system. The results revealed the hexagonal packing of nanotubes, and high degree of monodispersity in the tube diameter (244 Å) and wall thickness (≈18 Å). Moreover, the diameter is tunable by suitable modifications in the molecular structure. The self-assembly of the nanotubes occurs through the association of β-sheets driven by amphiphilicity and a systematic aromatic/aliphatic side chain segregation. This original and simple system is a unique example for the study of complex self-assembling processes generated by de novo molecules or amyloid peptides