Pilani Nkomozepi

This study proposes an improved retinal blood vessel segmentation method to enhance the diagnosis of microvascular retinal complications. The proposed method extracts local shape features from retinal images utilizing a fractional Hessian matrix, which models blood vessels as surface structures characterized by ridges and valleys resulting from variations in curvature. The methodology integrates adaptive principal curvature estimation with a new framework leveraging the fractional Hessian matrix with nonsingular and nonlocal kernels. The effectiveness of the suggested method is assessed using publicly accessible datasets, including DRIVE, HRF, STARE, and some real images obtained from a local hospital. The proposed segmentation achieves 96.77% accuracy and 98.82% specificity on the DRIVE database, 96.91% accuracy and 98.69% specificity on STARE, and 95.90% accuracy and 98.36% specificity on the HRF database. Optimal parameters for the fractional order and Gaussian standard deviation were empirically determined by maximizing segmentation accuracy. Our findings show that the proposed approach achieves competitive performance compared to the listed methods, including several deep learning approaches, while maintaining significant computational efficiency. The output of the suggested method can be further utilized with deep learning techniques, which will be applied in the clinical context of diabetic retinopathy and glaucoma to identify abnormalities likely related to disease progression and different stages.

The remarkable rise in antibiotic resistance seen in recent years has significantly reduced the effectiveness of most medications. This study aimed at evaluating the antibacterial and toxicological effects of gold nanoparticles (AuNPs), capped with a synthetic heterocyclic compound, 4-(4'-chlorophenyl)-2-imino-1,3-thiazino [2,3-b] benzimidazole (FDM29), and green-synthesized using a leaf extract from Baissea gracillima (B.gracillima-liana) plant. The synthesized AuNPs were characterized by ultraviolet-visible spectroscopy, dynamic light scattering, Fourier transform infrared, transmission electron microscopy, energy-dispersive and diffraction X-ray spectroscopy, supported by ^1H and ^13C nuclear magnetic resonance analysis of the FDM29 ligand. The antibacterial susceptibility of the AuNPs was investigated against Gram-negative (Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis) and Gram-positive bacteria (Bacillus subtilis, Mycobacterium smegmatis, and Staphylococcus aureus) using the broth microdilution method. The zebrafish embryo development toxicity test (ZFET) was employed to evaluate the toxicity of the synthesized AuNPs. Characterization indicated that AuNPs were successfully synthesized. The AuNPs were stable and spherical, with sizes ranging from 13 to 84 nm, which fall within the nanometer scale. In addition, the AuNPs effectively inhibited the growth of most bacterial strains, excluding P. mirabilis and M. smegmatis. The findings suggest that capping AuNPs enhances their antibacterial efficacy and reduces their toxicity compared to chemically synthesized uncapped AuNPs. The exposure of zebrafish embryos to the synthesized AuNPs revealed that the pristine AuNPs exhibited more significant toxicity at all concentrations compared to AuNPs-FDM29 and AuNPs-B. gracillima-liana. At 24 h post-fertilization, most eggs had coagulated, and by 48 hpf, the majority embryos showed absence of heartbeat and developmental retardation, thus being considered toxic. The mortality rate followed the order pristine AuNPs > AuNP-FDM29 > AuNP-B.gracillima-liana, at 81.6, 61.9, and 14.76%, respectively, at 0.25 mg/mL. These results indicate that biological functionalization of AuNPs significantly improves their biocompatibility and antibacterial properties. Notably, the green synthesis using B. gracillima-liana leaf extract yielded AuNPs with the lowest toxicity and substantial antibacterial efficacy, outperforming chemically synthesized counterparts. This study presents a novel, plant-based green synthesis approach for generating biocompatible AuNPs with dual antibacterial and low-toxicity profiles, offering a sustainable platform for developing next-generation antimicrobial agents with potential applications in nanobiotechnology, biomedicine, and pharmaceutical sciences.

Kola nut is commonly consumed by pregnant women to suppress symptoms of morning sickness. This study investigated the effects of kola nut on the biochemical indices of the hippocampus and its dependent memory. Kola nut extract was fed to pregnant dams from the first day of their pregnancy until parturition. The following behavioral function tests were conducted: surface righting (SR); cliff avoidance (post-natal day [PND] 4, 5, 6 & 7); open field; novel object recognition and location; and radial-arm maze (PND 21 and 56). The levels of brain-derived neurotrophic factor (BDNF), acetylcholine (ACh), and malondialdehyde (MDA) of the matched hippocampal tissues were also checked in the pups. The kola nut-treated pups showed significantly reduced behavioral indices compared to the pups in the control group: lower postural balance, higher risk avoidance memory, and lower frequency in pivoting and rearing compared to that in the control group. However, the frequency of urine and fecal bolus was significantly lower in the pups in the control group than that in the treated pups. The discrimination ratio of the control group pups in novel object recognition (NOR) and novel object location (NOL) was significantly higher than that in the treated pups, and the time taken by the treated pups to complete RAM was significantly higher. The levels of ACh and BDNF in the treated pups were increased compared to that in control pups. A positive correlation was found between MDA and SR (r = 0.7207; p = 0.0437), grooming (r = 0.7707; p = 0.0252), and fecal bolus (r = 0.7606; p = 0.0284), as well as with the BDNF level in those treated with grooming (r = 0.7570; p = 0.0297). However, negative correlations between ACh and rearing (r = -0.8261; p = 0.0115) and fecal bolus (r = -0.8066; p = 0.0156) and a positive correlation with NOL (r = 0.8358; p = 0.0098) were observed. Based on these observations, the study concluded that Kola nut affects both biochemical and hippocampal memory profiles.

The unrelenting increase in the incidence of type 2 diabetes (T2D) necessitates the urgent need for effective animal models to mimic its pathophysiology. Zebrafish possess human-like metabolic traits and share significant genetic similarities, making them valuable candidates for studying metabolic disorders, including T2D. This review emphasizes the critical role of animal models in diabetes research, especially focusing on zebrafish as an alternative model organism. Different approaches to a non-genetic model of T2D in zebrafish, such as the glucose solution, diet-induced, chemical-induced, and combined diet-induced and glucose solution methods, with an emphasis on model validation using indicators of T2D, were highlighted. However, a significant drawback lies in the validation of these models. Some of these models have not extensively demonstrated persistent hyperglycemia or response to insulin resistance and glucose tolerance tests, depicted the morphology of the pancreatic β-cell, or showed their response to antidiabetic drugs. These tools are crucial in T2D pathology. Future research on non-genetic models of T2D in zebrafish must extensively focus on validating the metabolic deficits existing in the model with the same metabolic defects in humans and improve on the existing models for a better understanding of the molecular mechanisms underlying T2D and exploring potential therapeutic interventions.

Diabetes mellitus (DM), one of the most serious non-communicable diseases, has long-term negative effects on the healthcare system due to its microvascular and macrovascular manifestations, which can be fatal if left untreated. Nutraceuticals, on the other hand, are alternative therapy choices of orally consumed natural food ingredients applicable in the management of several diseases, including diabetes mellitus. Through their antioxidant capabilities and bioactive components, nutraceuticals have been clinically demonstrated to be effective in preventing a number of ailments, including cancer, diabetes, heart disease, and kidney problems. Flavonoids, which are categorized as phytochemicals, are present in several of these nutraceuticals. Cocoa, one of the flavanols engaged in the treatment of diabetes mellitus, provides an additional non-pharmaceutical intervention in the management of diabetes mellitus, which, in part, is because of its high antioxidant capacity. Additionally, flavonoids improve insulin resistance and sensitivity, dyslipidemia, endothelial function, and blood pressure, as well as lower oxidative stress and inflammatory processes. As a result, they may be able to stop the progression of long-term vascular consequences of diabetes, such as cardiovascular disease, neuropathy, nephropathy, and retinopathy. Therefore, the effects of nutraceuticals (as an alternative treatment) on diabetic-related micro- and macrovascular problems are the main focus of this review.