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Abstract Background Hepatitis B virus (HBV) infection is one of the major public health problems worldwide. In pregnant women, there is a risk of mother-to-child transmission (vertical transmission) of the infection. The contaminated newborn will most often remain a chronic carrier. Gabon is part of the highly endemic area for hepatitis B. This study aims to determine the prevalence of hepatitis B in pregnant women at the Estuaire Regional Hospital of Melen, Libreville, Gabon. Material and methods The study was carried out at the Laboratory of the Center Hospitalier Régionale Estuaire Melen (CHREM), over a period of 5 years, from January 2018 to December 2022. It was a retrospective and prospective study ranging from January 2018 to December 2022. For the prospective study, the data was collected in the CHREM Laboratory library, by using registers and filing cabinets. For the prospective study, blood samples were taken and analyzed using Abbott Determine® HBsAg kits and the BioMérieux mini Vidas system. The variables studied were age, HBs status, profession, level of study, and residence. The data collected was entered into an Excel file (Microsoft Office 2016) and analyzed using XLSTAT 2016.4.01 and Epi Info™ 7.2.5 software and expressed as means and percentages. Results A total of 1615 pregnant women seen in the CHREM laboratory department were included in the study. Of which, 315 were diagnosed as HBsAg carriers, representing a prevalence of 8.36%. Depending on the year, the highest prevalence was observed in 2019 with 20 positive cases out of 267 women screened, i.e., 9.38%. Depending on the districts, the highest prevalence was found in the Essassa and Plein Ciel districts with 16.43% and 18.18%, respectively. According to the age groups, the highest prevalence was observed in the age group 26–30 with 10.16% (p = 0.075) out of 492 patients screened. Depending on the profession, the prevalence was higher among female students with 21.97% (p = 0.020). According to marital status, unmarried had the highest prevalence with 8.8% (p = 0.064). And according to nationality, women of Gabonese nationality had a higher prevalence with 9.52%. Conclusion Antenatal transmission of HBV is high in Libreville. The inaccessibility of antiviral therapy for viral hepatitis B makes the immunization of mothers and children a priority in Gabon.

Olawale Razaq Ajuwon,1 Fleury Augustine Nsole-Biteghe,2 Jean Delacroix Ndong,3 Lester Merlin Davids,4 Basiru Olaitan Ajiboye,1 Bartholomew Brai,1 Fisayo Abraham Bamisaye,1 John Adeolu Falode,1 Ikenna Maximillian Odoh,1,5 Kabirat Iyabode Adegbite,6 Bosede Oluwasayo Adegoke,7 Monde Ntwasa,8 Sogolo Lucky Lebelo,8 Ademola Olabode Ayeleso8,9 1Department of Biochemistry, Federal University, Oye-Ekiti, Ekiti State, Nigeria; 2Department of Radiation Oncology and Biomedical Sciences, Cedars-Sinai Medical, Los Angeles, CA, USA; 3School of Arts and Science, Rutgers University, New Brunswick, NJ, 08901, USA; 4Graduate School of Business, University of Cape Town, Cape Town, South Africa; 5Medical Center, Federal University, Oye-Ekiti, Ekiti-State, Nigeria; 6Department of Environmental Health Science, College of Basic Medical and Health Sciences, Fountain University, Osogbo, Osun State, Nigeria; 7Department of Chemical Pathology, Ekiti State University, Ado-Ekiti, Ekiti State, Nigeria; 8Department of Life and Consumer Sciences, University of South Africa, Florida Park 1709, Roodeport, South Africa; 9Biochemistry Programme, Bowen University, Iwo, Osun State, NigeriaCorrespondence: Olawale Razaq Ajuwon, Department of Biochemistry, Federal University OyeEkiti, Ekiti State, Nigeria, Tel +2348054127724, Email olawale.ajuwon@fuoye.edu.ngAbstract: Photodynamic therapy (PDT) is a groundbreaking approach involving the induction of cytotoxic reactive oxygen species (ROS) within tumors through visible light activation of photosensitizers (PS) in the presence of molecular oxygen. This innovative therapy has demonstrated success in treating various cancers. While PDT proves highly effective in most solid tumors, there are indications that certain cancers exhibit resistance, and some initially responsive cancers may develop intrinsic or acquired resistance to PDT. The molecular mechanisms underlying this resistance are not fully understood. Recent evidence suggests that, akin to other traditional cancer treatments, the activation of survival pathways, such as the KEAP1/Nrf2 signaling pathway, is emerging as an important mechanism of post-PDT resistance in many cancers. This article explores the dual role of Nrf2, highlighting evidence linking aberrant Nrf2 expression to treatment resistance across a range of cancers. Additionally, it delves into the specific role of Nrf2 in the context of photodynamic therapy for cancers, emphasizing evidence that suggests Nrf2-mediated upregulation of antioxidant responses and induction of drug efflux transporters are potential mechanisms of resistance to PDT in diverse cancer types. Therefore, understanding the specific role(s) of Nrf2 in PDT resistance may pave the way for the development of more effective cancer treatments using PDT.Keywords: photodynamic therapy, oxidative stress, antioxidant response, tumor resistance, Nrf2

BackgroundInfection with the filarial nematode Loa loa, endemic in Central and Western Africa, has been associated with increased morbidity and mortality. A number of reports described the presence of spleen nodules, originating from degenerating microfilariae, in humans and animals infected with L. loa. The long-term consequences of this process on individuals chronically exposed to infection in terms of spleen function and possible link with excess mortality are unknown. The aim of this study was to evaluate the prevalence of focal spleen lesions, their evolution over time, and markers of spleen function, in individuals with L. loa infection living in highly endemic areas of Gabon.Methodology/principal findingsThis was a cross-sectional study followed by a longitudinal study of the subset of individuals with spleen nodules. Two hundred sixteen participants from Ngounié and Moyen-Ogooué provinces of Gabon, reporting a history of eyeworm migration and/or Calabar swelling, were included. Participants were categorized into infected microfilaraemic with low (N = 74) and high (N = 10) microfilaraemia, and symptomatic amicrofilaraemic (N = 132), based on blood microscopy. Howell-Jolly bodies in erythrocytes, as indirect marker of spleen functional impairment, were within normal ranges. On ultrasound, no evident signs of spleen fibrosis or hypotrophy were observed. Multiple spleen hypoechoic centimetric macronodules were observed in 3/216 participants (1.4%), all with microfilaraemic L. loa infection (3.4% of microfilaraemics); macrondules disappeared at the 6-months follow-up examination in 2/3 individuals. Spleen hypoechoic micronodules, persisting at the 6-months follow-up, were detected in 3/216 participants (1.4%), who were all amicrofilaraemic.Conclusions/significanceTransitory spleen macronodules are present in a small but consistent proportion of individuals with microfilaraemic loiasis, appearing a rather benign phenomenon in terms of impact on spleen morphology and function. Their occurrence should be taken into consideration to avoid misdiagnosis and mistreatment. Prevalence and significance of spleen micronodular ultrasound patterns in the general population would be also worth evaluating.

Fitz-Hugh-Curtis (FHCS) is characterized by an inflammation of the hepatic capsule concomitant or following pelvic infection due to Chlamydia trachomatis or Neisseria gonorrhea. It is a rare condition occurring most often in a woman of childbearing age and very rare in male patients. Splenic involvement is also a rare form of abdominal tuberculosis. The association of these two conditions is very uncommon. We report the exceptional case of a 58- year-old HIV-positive male patient, with whom abdominal ultrasound helped diagnose FHCS associated with abdominal tuberculosis invovlving the spleen.

Introduction: Aucoumea klaineana, Canarium schweinfurthii, Cymbopogon nardus, Dacryodes edulis, and Eucalyptus citriodora are of Gabonese origin, believed to have insecticidal activity. This study contributes to vector control by the insecticidal activities (larvicidal and ovicidal) of five essential oils from these plants against Anopheles gambiae, a major vector of malaria in Gabon. Methods: The essential oils were extracted by hydrodistillation. Larvicidal and ovicidal effects of essential oils were performed using different concentrations on third and fourth instar larvae and eggs of A. gambiae vectors. The effects of these oils were examined on the mortality rate of larvae and eggs. Results: The essential oils of A. klaineana, C. schweinfurthii, C. nardus, A. edulis, and E. citriodora showed greater activity against mosquito larvae (7.33 < LC50 < 107.14) compared to eggs (22.80 < LC50 < 64.63). D. edulis showed the highest activity against Anopheles gambiae eggs and larvae. Of all plants, essential oils from A. klaineana showed the lowest activity of A. gambiae eggs and larvae. Larvae were more sensitive than eggs. All essential oils were toxic to the various aquatic vectors of malaria. Conclusion: The study reveals the potential ovicidal efficacy and larvicidal activity of these plants against A. gambiae.

Abstract A fixed-dose combination of artemether-lumefantrine (AL, Coartem®) has shown high efficacy, good tolerability and cost-effectiveness in adults and children with uncomplicated malaria caused by Plasmodium falciparum. Lumefantrine bioavailability is enhanced by food, particularly fat. As the fat content of sub-Saharan African meals is approximately a third that of Western countries, it raises the question of whether fat consumption by African patients is sufficient for good efficacy. Data from healthy volunteers have indicated that drinking 36 mL soya milk (containing only 1.2 g of fat) results in 90% of the lumefantrine absorption obtained with 500 mL milk (16 g fat). African diets are typically based on a carbohydrate staple (starchy root vegetables, fruit [plantain] or cereals) supplemented by soups, relishes and sauces derived from vegetables, pulses, nuts or fish. The most important sources of dietary fat in African countries are oil crops (e.g. peanuts, soya beans) and cooking oils as red palm, peanut, coconut and sesame oils. Total fat intake in the majority of subSaharan countries is estimated to be in the range 30–60 g/person/day across the whole population (average 43 g/person/day). Breast-feeding of infants up to two years of age is standard, with one study estimating a fat intake of 15–30 g fat/day from breast milk up to the age of 18 months. Weaning foods typically contain low levels of fat, and the transition from breast milk to complete weaning is associated with a marked reduction in dietary fat. Nevertheless, fat intake >10 g/day has been reported in young children post-weaning. A randomized trial in Uganda reported no difference in the efficacy of AL between patients receiving supervised meals with a fixed fat content (~23 g fat) or taking AL unsupervised, suggesting that fat intake at home was sufficient for optimal efficacy. Moreover, randomized trials in African children aged 5–59 months have shown similar high cure rates to those observed in older populations, indicating that food consumption is adequate post-weaning. In conclusion, it appears that only a very small amount of dietary fat is necessary to ensure optimal efficacy with AL and that the fat content of standard meals or breast milk in sub-Saharan Africa is adequate.