Establishment of CD1b-restricted immunity to lipid antigens in the pulmonary response to Mycobacterium tuberculosis infection.

CD1 is an antigen-presenting glycoprotein homologous to MHC I; however, CD1 proteins present lipid rather than peptide antigens. CD1 proteins are well established to present lipid antigens of Mycobacterium tuberculosis (Mtb) to T cells, but understanding the role of CD1-restricted immunity in vivo in response to Mtb infection has been limited by the availability of animal models naturally expressing the CD1 proteins implicated in human response: CD1a, CD1b, and CD1c. Guinea pigs, in contrast to other rodent models, express four CD1b orthologs, and here we utilize the guinea pig to establish the kinetics of gene and protein expression of CD1b orthologs, as well as the Mtb lipid-antigen and CD1b-restricted immune response at the tissue level over the course of Mtb infection. Our results indicate transient upregulation of CD1b expression during the effector phase of adaptive immunity that wanes with disease chronicity. Gene expression indicates that the upregulation of CD1b is the result of transcriptional induction across all CD1b orthologs. We show high CD1b3 expression on B cells, and identify CD1b3 as the predominant CD1b ortholog in pulmonary granuloma lesions. We identify ex vivo cytotoxic activity directed against CD1b that parallels the kinetic changes in CD1b expression in Mtb-infected lungs and spleen. This study confirms that CD1b expression is modulated by Mtb infection in lung and spleen, leading to pulmonary and extrapulmonary CD1b-restricted immunity as a component of the antigen-specific response to Mtb infection.

Genomic and Acoustic Biogeography of the Iconic Sulphur-Crested Cockatoo Clarifies Species Limits and Patterns of Intraspecific Diversity.

Many highly recognisable species lack genetic data important for conservation due to neglect over their hyperabundance. This likely applies to the Sulphur-crested Cockatoo (Cacatua galerita), one of the world's most iconic parrots. The species is native to Australia, New Guinea and some surrounding Melanesian islands. Four subspecies are currently recognised based on morphology. Australian subspecies and populations are abundant, but several factors threaten those in New Guinea and Melanesia. Genetic data from natural populations are scarce - information that is vital to identifying evolutionarily significant units (ESUs) important for modern conservation planning. We used whole-genome resequencing to investigate patterns of differentiation, evolutionary affinities and demographic history across C. galerita's range to assess whether currently recognised subspecies represent ESUs. We complement this with an assessment of bioacoustic variation across the species' distribution range. Our results point to C. galerita sensu lato (s.l.) comprising two species. We restrict C. galerita sensu stricto (s.s.) to populations in Australia and the Trans-Fly ecodomain of southern New Guinea. The second species, recognised here as Cacatua triton, likely occurs over much of the rest of New Guinea. Restricting further discussion of intraspecific diversity in C. triton, we show that within C. galerita s.s. two ESUs exist, which align to Cacatua galerita galerita in eastern Australia and southern New Guinea and Cacatua galerita fitzroyi in northern and north-western Australia. We suggest that the evolution of these species and ESUs are linked to Middle and Late Pleistocene glacial cycles and their effects on sea level and preferential habitats. We argue that conservation assessments need updating, protection of preferential forest and woodland habitats are important and reintroductions require careful management to avoid possible negative hybridization effects of non-complementary lineages.

Assessing Pubic Symphysis Evolution in Guinea Pigs (Cavia procellus): Insights From Computer Tomography on Primiparous and Non-Breeding Females.

In guinea pigs (Cavia porcellus), dystocia is a common occurrence. Several factors have been identified in the literature, including the ossification of the pubic symphysis following failure to breed before 9-12 months of age. The objective of this study was to investigate the ossification of pubic symphysis and its evolution during growth in two groups of females. The first group consisted of non-breeding females, while the second group comprised females introduced to breeding at 4-6 months of age. Twelve pairs of sows were selected for comparison, with one non-breeding and one breeding sow in each pair. Symphysis width and tissue density were assessed using micro-computed tomography. Measurements included the distance between the acetabula, width and bone density of the pubic symphysis. Serial computed tomography scans were performed on each sow over several months, both before and after parturition. The results revealed a significantly higher symphysis width in females that had bred. In addition, symphysis ossification was absent in both breeding and non-breeding sows, contrary to previous descriptions of this species. Therefore, dystocia in guinea pigs may not be attributable to ossification of the pubic symphysis.

Leukotriene B4 is elevated in diabetes and promotes ventricular arrhythmogenesis in guinea pig.

Diabetes (DM) patients have an increased risk (~50%) for sudden cardiac death (SCD), mostly as a result of ventricular arrhythmias. The molecular mechanisms involved remain partially defined. The potent proinflammatory lipid mediator leukotriene (LT) B4, is pathologically elevated in DM compared to nondiabetic patients, resulting in increased LTB4 accumulation in heart, leading to an increased risk for life-threatening proarrhythmic signatures. We used electrophysiology, immunofluorescence, and confocal microscopy approaches to evaluate LTB4 cellular effects in guinea pig heart and ventricular myocytes. We have observed that LTB4 is increased in multiple mouse models (C57BL/6 J/Lepob/ob and PANIC-ATTAC) of DM, promotes profound cellular arrhythmogenesis (spontaneous beats and early after depolarizations, EADs), and severely depresses the rapidly activating delayed rectifier K current (hERG1/IKr) density in HEK293 cells and guinea pig ventricular myocytes. We have further found that guinea pigs challenged with LTB4 displayed a significantly prolonged QT interval, and that this can be prevented with LTB4R inhibition, suggesting that preventing such LTB4R effects may be therapeutically beneficial in DM. Our data suggests that a further elucidation of LTB4 vulnerable substrates, and how this leads to ventricular arrhythmias, is likely to lead to continued improvements in management options, and the development of new therapies for prevention of SCD in DM patients.

Adrenal Disease in Small Mammals.

Adrenal gland disease has been described as a rare disease in pet rabbits and rodents. Hyperadrenocorticism with excessive secretion of corticosteroids is most commonly observed in guinea pigs and hamsters, with dermatologic signs similar to those seen in dogs. Diagnosis is based on clinical signs, diagnostic imaging such as abdominal ultrasound, and determination of the blood hormone concentrations. In guinea pigs, an adrenocorticotrophic hormone stimulation test with the measurement of salivary cortisol or corticosterone concentrations is recommended. The recommended treatment of adrenal disease in guinea pigs and hamsters is oral administration of trilostane or ketoconazole; surgical treatment is also possible.

Body composition analysis using bioelectric impedance in Bissau: reproducibility and level of agreement between two available devices.

Introduction: the need to correctly measure and follow body composition as a simple disease prevention metric is important, especially where the healthcare infrastructures are poor. The variety of inexpensive devices available for this purpose is large. However, it is imperative to validate them in relation to the gold standard method, dual-energy absorptiometry X-ray (DEXA). In low-income countries, DEXA measurements aren't available. Thus, easy-to-use, and accurate devices are indispensable. In Guinea-Bissau, two relatively inexpensive, bioelectrical impedance scales, simple to use, are available. However, their accuracy has not been assessed in this setting. The study compares the level of agreement in measurements between, the Tanita® BC-545 and the Omron Karada Scan BF511, in adult volunteers. Methods: volunteers grouped for athletic and sports modalities at stadiums and sports facilities in Bissau were included. All anthropometric measurements were done in both devices. For statistical analysis, we created Bland-Altman plots to assess their level of agreement. Results: the study included 274 participants, mean age 27.4 years, 214 (78%) males. For body fat, the median between the Omron and Tanita measures was 2.6 and the interquartile was 5.2. The Omron measured median body mass index, -0.3 kg/m2 and 0.8 kg/m2 of interquartile below that of the Tanita. For visceral fat, the Omron measured 1% of median and an interquartile of 2% above that of the Tanita. For skeletal muscle, the Omron median measured 11.3% and 11.4 % of interquartile below that of the Tanita. The intra-class correlation coefficient (ICC) for body fat (BF), body mass index (BMI) and skeletal muscle (SM) was 0.99 and for VF it was 1.00 on both devices. Conclusion: the results indicate a good level of agreement between the two devices. In resource-limited settings, the Omron is likely a reasonable substitute for more expensive body composition devices.

Neoplasia in pet guinea pigs: a retrospective analysis of 2,474 autopsy examinations.

Neoplasia is a common disease in guinea pigs (Cavia porcellus); however, few studies have evaluated the prevalence of neoplasia in all organ systems. We retrospectively analyzed the tumor prevalence in pet guinea pigs and the frequency of metastasis in a multi-institutional study population of 2,474 autopsy cases. Tumors were found in 508 guinea pigs (prevalence: 20.5%), of which 95 cases had >1 tumor, resulting in a total of 627 tumors. The tumor prevalence increased from 1.4% in animals <0.5-y-old to 53.6% for guinea pigs >5-y-old. The most common tumor type was lymphoma or leukemia, affecting 174 guinea pigs (tumor prevalence: 7.0%). Lymphomas or leukemias were disseminated to various organs and/or lymph nodes in 146 (83.9%) cases and localized to 1 organ or 1 lymph node in 28 (16.1%) cases. Primary non-lymphoid tumors were most frequent in the female genital tract (62 of 1,235 cases, mostly uterus), respiratory system (116 of 2,474), skin including mammary gland (81 of 2,474), endocrine system (66 of 2,474, mostly thyroid gland), and alimentary tract (35 of 2,474). Tumors of the alimentary tract were dominated by gastrointestinal stromal tumors. Metastasis was detected in 42 of 453 non-lymphoid tumors (9.3%), with a surprisingly low frequency for pulmonary carcinoma and splenic hemangiosarcoma compared to other species. Our postmortem study demonstrates a high prevalence of disseminated lymphoma or leukemia in pet guinea pigs at the time of death or euthanasia. Additional studies are needed to further characterize these tumors.

Effect of integrated pest management practices on the occurrence of pesticide residue in okra cultivated by farmers in Kwara state.

Integrated pest management (IPM) is a sustainable approach for minimizing the negative impacts of pests on crops while reducing reliance on synthetic pesticides. This study was conducted in Kwara State Nigeria in 2023, to investigate the effects of implementation of IPM practices on the occurrence of pesticide residues in okra cultivated by the farmers in Kwara State, Nigeria, and identify the factors affecting the use of IPM practices for pest control in okra production. A sample of 245 okra farmers was selected across 4 agricultural zones of Kwara State using a multistage sampling technique. Additionally, okra samples were collected from the farmers of each community of the local government areas. The data collected from the farmers were analyzed using descriptive and inferential statistics including frequency count, percentage, mean, standard deviation, and Pearson product moment correlation (PPMC). The collected okra samples were taken to the laboratory for pesticide residue extraction and analysis was performed using gas chromatography (GC)-mass spectrometer (MS). The results showed that most okra producers in Kwara State were smallholder farmers who, despite practicing IPM, had limited knowledge of the technology. Some pesticide residues were detected in okra, out of which two were present in quantities above the maximum residue limit, while others were below the maximum residue limit. Therefore, this study recommends that the government should improve extension services in the State by providing adequate funds and training extension agents who can provide comprehensive training to farmers on the types and application of IPM as an eco-friendly technology for preventing pesticide residue in okra.

Frequency and Factors Associated with Disabilities among Leprosy Patients Admitted to the Kindia Disability Prevention and Physical Rehabilitation Centre (Pirp) in Guinea from 2017 to 2021.

This study aims to estimate the prevalence and analyze the factors associated with leprosy-related disabilities at the Kindia Disability Prevention and Physical Rehabilitation Centre (PIRP) in Guinea. It is a cross-sectional study using routine data from the centre from 2017 to 2021. Of 115 patients, 76% had a disability, 49% of which were grade II and 27% grade I. The age range of 15 to 30 years was the most represented (43.5%), with the average age (standard deviation) being 38 (16.5) years. Children under 14 years of age represented 3.5% of the total. Most (89%) patients had newly diagnosed leprosy. The majority (66.1%) had never come in contact with people with leprosy symptoms. Almost all (99.1%) patients had type 1 reactions on admission. Patients with multibacillary leprosy were in the majority (83.5%), and those with symptoms lasting 7-12 months represented 56.5% of the sample. In total, 79.1% of the patients received corticosteroid therapy, and 92.1% were reported cured at discharge. This neglected tropical disease continues to be a challenge in Guinea, even though leprosy care is free.

Determinants of Low Coverage of the Free Surgical Care Programme for Trachomatous Trichiasis in Rural Guinea in 2022.

This study aimed to describe the experiences of healthcare personnel and patients in the organization of free surgical campaigns and care for trachomatous trichiasis in the health district of Siguiri in Guinea, including challenges experienced in providing surgical care. This was an explanatory qualitative study conducted in 2022 in the health district of Siguiri. A total of 20 participants were interviewed including patients (n = 7; 35%), community health workers (n = 4; 20%), health services managers, and healthcare providers (n = 8; 40%). Two main data collection technics were used: documentary review and in-depth individual interviews. All interviews were transcribed and manually coded using an Excel extraction spreadsheet. Data were analysed using inductive and deductive approaches. The results showed several organizational, structural, and community challenges that underlined the low surgical coverage of trachomatous trichiasis in the health district of Siguiri. Organizational challenges included the low involvement of local actors in planning activities, the limited timeframe of the campaigns, and the lack of logistics for activities supervision and patients' transportation to surgery sites. Structural challenges included the inadequacy of health centres to provide surgical services, poor health infrastructures, and sanitation conditions in some areas. Individual challenges included remoteness of surgical sites and costs associated with services provision including medicines. Community challenges included fear of surgery and the coincidence of the campaigns with agricultural and mining activities. The results of the study call on the national neglected tropical disease program and its partners to adopt and promote micro-planning of trachomatous trichiasis surgical activities, with the effective participation of local stakeholders in endemic health districts. They should also envision integrating the management of surgical treatment including costs associated with care (transportation, food, rehabilitation support for patients who have undergone surgery) and complications of surgical procedures for an expansion of the trachomatous trichiasis free surgical care coverage in endemic health districts in Guinea.

Frequency, Clinical Characteristics, and Management of Snakebite Patients Admitted at the Envenomation Treatment Center of the Applied Biology Research Institute of Guinea.

The aim of this study was to describe the frequency, clinical signs, management, and outcomes of snakebite patients admitted to the envenomation treatment center of the Institut de Recherche en Biologie Appliquée de Guinée (IRBAG). This was a retrospective review combining aggregated annual statistics (2011-2015) and routine data (from January to October 2021) from the IRBAG treatment center. There were 1345 (57.2%) snakebite victims out of a total of 2352 consultations at the center during the study period. Males (67.7%), persons aged ≥45 years (29%) and ≤14 years (27.7%), farmers/housewives (44.5%), workers (23.9%), and those residing in the Kindia Prefecture (53.5%) were the most commonly affected. The majority of victims (84.5%) were admitted three hours after snakebite, with bites mainly occurring in rural areas (86.5%) and during the rainy season (83.2%). Pain (100%), edema (76.8%), and bleeding (65.2%) were the most common clinical presentations. Almost all victims received antivenom serum (98%), antibiotics (87.7%), and analgesics or anti-inflammatory drugs (88.4%). Six out of the one hundred and fifty-five patients died. Snakebites are a frequent public health problem in rural Guinea. The majority of victims seek medical attention too late. There is an urgent need to include snakebite in the country's list of priority NTDs in order to promote access to antivenom serum.

Experience with HCV Detection and Molecular Genetic Characterization among Otherwise Healthy Pregnant Women and Their Partners in the Republic of Guinea.

According to recent data, there are currently 170 to 200 million people infected with HCV worldwide, and the number of new cases annually is approximately 40,000. Thus, the overall prevalence of the pathogen in the world is about 1.8-3%. The dynamic monitoring of circulating viral variants in specific groups that reflect the situation in the wider population, including potential pathogen spread, is of high importance for predicting the epidemiologic situation. Pregnant women are such a group. The Republic of Guinea is one of the poorest countries in the world, in which medicine receives little finance from the state. Among other conditions, HCV infection is not monitored in the country. This work used blood plasma from pregnant women living in the Republic of Guinea and their partners (1810 and 481). ELISA diagnostic kits were used to detect serologic markers, and PCR diagnostic kits were used to detect molecular biologic markers. Sanger sequencing, followed by phylogenetic analysis, was used for genotyping. The present study shows that HCV antibodies were detected in 3.2% of the pregnant women examined and in 3.33% of their male partners. HCV RNA was detected in 0.5% of cases in women and in all anti-HCV-positive male partners (3.33%). HCV RNA was more common in the men than in the pregnant women (χ2 = 25.6, df 1, p < 0.0001, RR = 6.69 with 95% CI: 2.97-15.04). The HCV viral load was determined for all the RNA-HCV-positive samples. The HCV viral load exceeded 1000 IU/mL in all nine women and only in two cases in men. The HCV genes NS5A and NS5B and the NS3 gene fragment were sequenced for 11 samples. Subtype 2q was determined for three isolates and 2j for another three isolates. Another five isolates could not be confidently assigned a subtype because different results were obtained with different methods of analyzing the three viral regions. It can be assumed that these isolates belong to new viral subtypes or to recombinant forms between genotype 2 subtypes. No drug resistance mutations were identified, but a large number of natural polymorphisms in the analyzed genomic regions of the HCV isolates were shown. These results may serve as baseline data for the future planning of a nationwide estimate of the prevalence of bloodborne infections among pregnant women.

Successful formation of sperm cells from transplanted primordial germ cells in sterile interspecific avian recipients.

Primordial germ cells (PGCs) are stem cells, from which only gametes develop. In birds, the female sex is heterogametic, thus female gene conservation necessitates preservation of PGCs. PGC transplantation can generate germline chimeras in a host organism and develop into gametes. However, competition between host and transplanted PGCs hinder efficiency of germline chimera generation. We hypothezised that in sterile hybrid recipients with no germ cells of its own, transplanted donor PGCs may exclusively form gametes. Advantages of sterile hybrids as host for PGCs is compliant with many national regulations on genetically modified organisms and technically simpler procedure than the use of busulphan. Therefore, we investigated whether sterile interspecific hybrids may be suitable as recipients for supporting donor PGCs by injecting green fluorescent protein-labelled chicken PGCs into 3-day-old Guinea fowl and domestic fowl hybrid embryos and monitoring PGC development. The injected PGCs colonized almost 100% of the recipient gonads and produced mature spermatozoa after 44 weeks. However, gamete production in these hybrids was initiated much slower than in domestic fowls. This delay may be caused by suboptimal hormonal regulation of gametogenesis in the hybrids. Our results suggest that sterile interspecific hybrids may be suitable hosts for PGCs for efficient gamete production.

Unconventional Animal Species Participation in Animal-Assisted Interventions and Methods for Measuring Their Experienced Stress.

The participation of animals during complementary therapy for humans is a developing area. Dogs and horses are the most frequent partner species in animal-assisted services, but several unconventional species have also been involved, although there is a lack of information about the stress they experience caused by AAS. We conducted a comprehensive literature search, analyzing 135 articles with the purpose of investigating the effects of AAS on unconventional species such as guinea pigs, rabbits, farm animals, alpacas, donkeys, reptiles, aquarium fishes, and dolphins. We found that the relevant articles emphasize investigating the impact of animal-assisted interventions on humans, and they generally report positive outcomes. Limited data is available concerning the potential consequences the interventions may have on the animals. Therefore, it is our conclusion that more extensive studies should be conducted to get adequate information on stress experienced by animals during AAS, such as the measurement of biochemical parameters such as cortisol. Hence, meeting animal welfare considerations in addition to human interests could serve as a basis for the recommended methodology for therapies.

Radiographic and ultrasonographic findings of seminal vesiculitis with nonmineral stones in a guinea pig: Case report.

This case report refers to a 1-year-old Guinea pig showing signs of anorexia and antipain posture. On abdominal radiography, five rounded mineral opaque structures were evident in the mid-caudal abdomen. On ultrasound, a right seminal vesicle with a reduction in diameter was observed, containing less echogenic material than the contralateral one, with five oval structures with a hyperechogenic contour and a central hypoechogenic area, forming acoustic shadowing. The left seminal vesicle presented with the usual characteristics. After bilateral vesiculectomy, the patient recovered well, with no further symptoms. The histopathological result was a suppurative/abscessive inflammatory process with an accumulation of proteinaceous material.

Risk factors, complications, and outcomes of cystotomy in guinea pigs: 25 cases (2010-2023).

OBJECTIVE: To describe the complications, surgical outcome, and prognosis associated with cystotomies in guinea pigs. METHODS: A retrospective review of medical records of guinea pigs undergoing cystotomy for uroliths or urethroliths between 2010 and 2023. RESULTS: 25 guinea pigs were included in the study. Uroliths were confirmed on radiographs in all 25 cases, with 9 patients (36%) having at least 1 stone within the urethra. The cystotomy procedure was associated with an intraoperative complication rate of 24% and a short-term complication rate of 76%. Discomfort was the only presenting clinical sign significantly associated with survival, with a risk of dying prior to discharge that was a sixth of the risk of dying if a patient presented without signs of discomfort (risk ratio = 0.177). For patients with a stone within the urethra, the probability of death prior to discharge was 6 times that of patients with a stone within the bladder (P = .010; risk ratio = 5.966). CONCLUSIONS: Cystotomies were associated with a mortality rate of 40% prior to discharge and 56% within the first month postoperatively. Further studies are needed to determine what specifically may lead to the high mortality rate as well as whether alternative minimally invasive procedures may be helpful in improving outcomes. CLINICAL RELEVANCE: This study is the first to document risk factors, complications, and outcomes of a cohort of guinea pigs specifically undergoing cystotomy for urolithiasis. Given the high risk for complications and mortality, caution and owner preparation must be considered when a cystotomy is recommended for guinea pig patients.

Finite element analysis on the human and guinea pig cochlear vibration patterns under bone conduction stimulations.

To compare the vibrational patterns of human and guinea pig cochleae accurately, we developed and validated a novel finite element model of the guinea pig, leveraging it to analyze vibrational patterns in the cochlea. This approach is mirrored in our examination of the human cochlear model, providing granular insights into the nuances of human bone conduction hearing. The comparative analysis reveals that the guinea pig cochlea mirrors human cochlear vibrational patterns, thus serving as an efficient proxy for exploring human cochlear function. The human mastoid and the upper region of the guinea pig's skull are recommended as the convenient and comparable sites for bone conduction stimulation. The cochlear vibration pattern encompasses a mix of rigid, rotational, and compressive motion. Significantly, the guinea pig model demonstrates robust agreement with existing experimental data and other studies, these findings are confirming the validity of the model. Our study delineates the distinct roles of the three vibration types across various frequency spectrums. At lower frequencies, rigid motion is the dominant mechanism, supplemented by rotational motion. However, at higher frequencies, the influence of rigid motion wanes, ceding prominence to rotational and compressive motions. This trend is consistently observed in both human and guinea pig models.

Cold atmospheric plasma as a promising tool in treatment of Trichophyton rubrum-induced skin infection in a guinea pig model of experimental dermatophytosis.

The emergence of high-resistance strains to known antifungal drugs has highlighted the urgency of developing novel therapies for chronic dermatophytosis as a global health problem. An experimental dermatophytosis model in guinea pigs was developed to investigate the in vivo wound healing effects of cold atmospheric plasma (CAP) on T. rubrum skin invasion. Guinea pigs were experimentally infected with T. rubrum and wound healing was evaluated at 1, 4, 8 and 12 days post infection in the CAP-treated, terbinafine-treated and non-treated controls. Our results showed that CAP strongly inhibited the fungal virulence in vitro in culture media and in vivo on the skin lesions of experimentally infected guinea pigs even more efficient than that of terbinafine, resulting in complete wound healing at 8 days post infection. These results indicate that CAP would be considered as a promising tool comparable to conventional chemical therapies, for the treatment of drug-resistant chronic dermatophytosis caused by T. rubrum.

Seroprevalence of Avian Influenza in Guinea Fowls in Some Districts in the Upper East Region of Ghana.

The guinea fowl (Numida meleagris) holds significant agricultural importance in Ghana, particularly in the Northern, Upper East and Upper West Regions. Despite their economic and cultural significance, guinea fowls face a potential threat from avian influenza, a global concern for its adverse impact on poultry populations. This study assessed the seroprevalence of the virus in mature guinea fowls in the Upper East Region. A cross-sectional survey was conducted in three districts within the Upper East Region from April to June 2023. Blood samples were collected from 397 guinea fowls that are over 4 weeks old, and seroprevalence was determined using ID Screen Influenza A Antibody Competition Enzyme-linked immunosorbent assay (ELISA). The study analysed demographic factors such as sex, age and source of birds, employing statistical methods to establish associations. Among the sampled guinea fowls, 24.7% tested positive for avian influenza antibodies, whereas 75.3% were seronegative. Age did not show statistically significant associations with seroprevalence, but intriguing patterns were observed. Adult guinea fowls exhibited higher seroprevalence (23.7%) compared to growers (1.0%). The source of birds showed no significant association, but birds from slaughter points demonstrated higher seroprevalence (11.6%) compared to households (5.0%) and live bird markets (8.1%). In conclusion, the study underscores the importance of monitoring avian influenza in guinea fowls to implement effective control measures. The presence of antibodies suggests guinea fowls may contribute to virus transmission in the Upper East Region. The study recommends ongoing nationwide surveillance to assess the true prevalence of avian influenza in guinea fowls across Ghana.

Changes in choroidal thickness and blood flow in response to form deprivation-induced myopia and repeated low-level red-light therapy in Guinea pigs.

PURPOSE: To evaluate ocular refractive development, choroidal thickness (ChT) and changes in choroidal blood flow in form-deprived myopia (FDM) Guinea pigs treated with repeated low-level red-light (RLRL) therapy. METHODS: Twenty-eight 3-week-old male tricolour Guinea pigs were randomised into three groups: normal controls (NC, n = 10), form-deprived (FD, n = 10) and red light treated with form-deprivation (RLFD, n = 8). Interocular refraction and axial length (AL) changes were monitored. Optical coherence tomography angiography (OCTA) measured choroidal thickness, vessel area density, vessel skeleton density and blood flow signal intensity (flux) in the choriocapillaris and medium-large vessel layers. The experimental intervention lasted 3 weeks. RESULTS: At week 3, the FD group had higher myopia and longer axial length than the NC group (all p < 0.001). The RLFD group had higher hyperopia and shorter axial length than the FD group (all p < 0.001). At week 1, the NC group had a thicker choroidal thickness than the FD group (p < 0.05). At weeks 2 and 3, the RLFD group had a thicker choroidal thickness than the FD group (p = 0.002, p < 0.001, respectively). Additionally, the NC group had higher vessel area density, vessel skeleton density and flux in the choriocapillaris layer than the FD group at the three follow-up time points (all p < 0.05). At week 3, the vessel skeleton density and flux were higher in the RLFD group than in the FD group (all p < 0.05). Correlation analysis results showed that weekly changes in refraction and choroidal thickness were negatively correlated with changes in axial length (all p < 0.05). Choroidal thickness changes were positively correlated with alterations in the vessel area density, vessel skeleton density and flux in the choriocapillaris layer, as well as vessel skeleton density and flux changes in the medium-large vessel layers (all p < 0.05). CONCLUSIONS: Repeated low-level red-light (RLRL) therapy retards FDM progression in Guinea pigs, potentially through increased choroidal blood flow in the choriocapillaris layer.