Search Results (31)

Deforestation driven by plantations, such as Pinus patula Schiede ex Schltdl. et Cham., is a major cause of biodiversity and functional loss in tropical ecosystems. We assessed the diversity and composition of lichens and bryophytes in four size categories of pine cones, small (3–5 cm), medium (5.1–8 cm), large (8.1–10 cm), and very large (10.1–13 cm), with a total of 150 pine cones examined, where the occurrence and cover of lichen and bryophyte species were recorded. Identification keys based on morpho-anatomical features were used to identify lichens and bryophytes. In addition, for lichens, secondary metabolites were tested using spot reactions with potassium hydroxide, commercial bleach, and Lugol’s solution, and by examining the specimens under ultraviolet light. To evaluate the effect of pine cone size on species richness, the Kruskal–Wallis test was conducted, and species composition among cones sizes was compared using multivariate analysis. A total of 48 taxa were recorded on cones, including 41 lichens and 7 bryophytes. A total of 39 species were found on very large cones, 37 species on large cones, 35 species on medium cones, and 24 species on small cones. This is comparable to the diversity found in epiphytic communities of pine plantations. Species composition was influenced by pine cone size, differing from small in comparison with very large ones. The PERMANOVA analyses revealed that lichen and bryophyte composition varied significantly among the pine cone categories, explaining 21% of the variance. Very large cones with specific characteristics harbored different communities than those on small pine cones. The presence of lichen and bryophyte species on the pine cones from managed Ecuadorian P. patula plantations may serve as refugia for the conservation of biodiversity. Pine cones and their scales (which range from 102 to 210 per cone) may facilitate colonization of new areas by dispersal agents such as birds and rodents. The scales often harbor lichen and bryophyte propagules as well as intact thalli, which can be effectively dispersed, when the cones are moved. The prolonged presence of pine cones in the environment further enhances their role as possible dispersal substrates over extended periods. To our knowledge, this is the first study worldwide to examine pine cones as substrates for lichens and bryophytes, providing novel insights into their potential role as microhabitats within P. patula plantations and forest landscapes across both temperate and tropical zones. Full article

4-Aminodiphenylamine (4-ADPA) is a common additive in rubber tires, known for its antioxidant properties. It plays a crucial role in enhancing tire durability by preventing issues such as drying, cracking, and degradation from prolonged exposure to environmental factors like heat, oxygen, and ozone. However, despite its advantages in extending tire lifespan, the use of 4-ADPA raises significant environmental concerns. As tires wear down, microscopic tire wear particles (TWPs) containing 4-ADPA are released into the environment with substantial leaching, contaminating the waterways. The 4-ADPA leachates pollute and pose a threat to aquatic ecosystems, affecting various forms of marine life. The current study investigates the ecotoxicological effects of 4-ADPA on the aquatic plant Lemna minor (L. minor), focusing on its impact on relative growth and physiological biomarkers. Several parameters were assessed to evaluate ecotoxicity, including frond morphology, fresh biomass, total frond number, chlorophyll content, and starch accumulation. L. minor was grown for 7 and 14 days under controlled laboratory conditions using Hoagland media with varying concentrations of 4-ADPA (10–100 μg/L), while a control group was maintained in media without 4-ADPA. The results indicate that exposure to 4-ADPA led to a dose-dependent reduction in fresh biomass, total frond number, and chlorophyll levels. Lugol’s staining revealed increased starch accumulation in the fronds after exposure to 4-ADPA. The biological effects observed in L. minor following exposure to 4-ADPA, even at environmentally relevant concentrations, demonstrate a significant ecotoxicological impact on aquatic ecosystems. Further research involving additional species and investigating the mechanisms behind 4-ADPA toxicity is recommended to better understand its long-term consequences. Full article

The endemic Patagonian conifer, Austrocedrus chilensis, is threatened by the pathogen Phytophthora austrocedri. This study presents the first histological and histochemical analysis of A. chilensis affected by this pathogen. We examined the stem tissues of naturally infected adult trees (over 30 years old) and artificially inoculated saplings (8–12 years old) to identify the pathogen’s colonization strategies and the tree’s histological responses. Using light and scanning electronic microscopy along with several histochemical techniques (Lugol, toluidine blue, vanillin-HCl, Phloroglucinol, Calcofluor white, and aniline blue), we found that P. austrocedri can grow in all active tissues, leading to cambium and parenchyma necrosis. The pathogen spreads through sieve cells and tracheids, moving to the adjacent cells via sieve plates and bordered pits and colonizing nearby parenchyma cells. We observed loss of starch in necrotic tissues. In contrast, starch accumulation and an increase in the number of polyphenolic cells occur in the healthy areas adjacent to the margins of the lesion, indicating a tree’s induced defense mechanisms. The tree’s responses include cambium reprogramming, which leads to the formation of traumatic resin ducts, alterations in cell shape and size, and the deposition of phenolic compounds. We analyze the tree responses and discuss their potential relationship with a methyl jasmonate-induced defense and a hypersensitive-like response. Full article

Poor sanitation, improper food handling, limited access to safe drinking water sources, and limited access to healthcare services contribute to a high prevalence of infections caused by soil-transmitted helminths (STHs) among the BaAka Pygmies, an indigenous community living in Central Africa. The aim of this study was to determine the rates of STH infections in the BaAka people inhabiting the rain forests of the south-western parts of the Central African Republic (CAR) as well as to examine the validity of biannual deworming with a single dose of albendazole 400 mg in high-risk communities exposed to extreme environmental conditions. The study was conducted in August 2021 and involved a sample of 49 BaAka Pygmies inhabiting the rain forest of the Sangha-Mbaéré Prefecture, CAR. The study consisted of collecting single stool samples from each participant and examining the samples for intestinal parasites by light microscopy methods. The collected samples were fixed in SAF fixative and next transported from Africa to Europe, where they were analyzed by light microscopy using three different diagnostic methods (direct smear in Lugol’s solution, the Fülleborn’s flotation, the Kato–Katz thick smear) at the Department of Epidemiology and Tropical Medicine in Gdynia, Poland. Microscopic examination found that 61.2% of the study group were infected with at least one helminthic species. The parasitological screening found invasions with four different species of nematodes, of which hookworm invasions were the most prevalent. The study results demonstrated that although the WHO-recommended mass deworming, which is provided to the BaAka Pygmies in healthcare centers set up on the premises of catholic missions, can effectively reduce the number of infections with soil-transmitted helminths, the prevalence of STH infections remains high in the region. The study findings suggest that in order to contain the spread of STHs in the local community, it will be necessary to implement additional preventive measures, apart from only conducting mass deworming programs. Full article

Identifying the detailed anatomies of the coronary microvasculature remains an area of research; one needs to develop methods for non-destructive, high-resolution, three-dimensional imaging of these vessels for computational modeling. Currently employed Micro-Computed Tomography (Micro-CT) protocols for vasa vasorum analyses require organ dissection and, in most cases, non-clearable contrast agents. Here, we describe a method developed for a non-destructive, economical means to achieve high-resolution images of the human coronary microvasculature without organ dissection. Formalin-fixed human hearts were cannulated using venogram balloon catheters, which were then fixed into the specimen’s aortic root. The canulated hearts, protected by a polyethylene bag, were placed in radiolucent containers filled with insulating polyurethane foam to reduce movement. For vasculature staining, iodine potassium iodide (IKI, Lugol’s solution; 6.3% Potassium Iodide, 4.1% Iodide) was injected. Contrast distributions were monitored using a North Star Imaging X3000 micro-CT scanner with low-radiation settings, followed by high-radiation scanning (3600 rad, 60 kV, 900 mA) for the final high-resolution imaging. We successfully imaged four intact human hearts presenting with chronic total coronary occlusions of the right coronary artery. This imaging enabled detailed analyses of the vasa vasorum surrounding stenosed and occluded segments. After imaging, the hearts were cleared of iodine and excess polyurethane foam and returned to their initial formalin-fixed state for indefinite storage. Conclusions: the described methodologies allow for the non-destructive, high-resolution micro-CT imaging of coronary microvasculature in intact human hearts, paving the way for detailed computational 3D microvascular reconstructions with a macrovascular context. Full article

Background: Human beings consume different chemical forms of iodine in their diet. These are transported by different mechanisms in the cell. The forms of iodine can be part of thyroid hormones, bind to lipids, be an antioxidant, or be an oxidant, depending on their chemical form. The excessive consumption of iodine has been associated with pancreatic damage and diabetes mellitus type 2, but the association between disease and the chemical form consumed in the diet is unknown. This research analyzes the effect of excessive iodine consumption as Lugol (molecular iodine/potassium iodide solution) and iodate on parameters of pancreatic function, thyroid and lipid profiles, antioxidant and oxidant status, the expression of IR/Akt/P-Akt/GLUT4, and transcription factors PPAR-γ and CEBP-β. Methods: Three groups of Wistar rats were treated with 300 μg/L of iodine in drinking water: (1) control, (2) KIO₃, and (3) Lugol. Results: Lugol and KIO₃ consumption increased total iodine levels. Only KIO₃ increased TSH levels. Both induced high serum glucose levels and increased oxidative stress and pancreatic alpha-amylase activity. Insulin levels and antioxidant status decreased significantly. PPAR-γ and C/EBP-β mRNA expression increased. Conclusion: The pancreatic damage, hypertriglyceridemia, and oxidative stress were independent of the chemical form of iodine consumed. These effects depended on PPAR-γ, C/EBP-β, GLUT-4, and IR. Full article

High-resolution anoscopy (HRA) plays a central role in the detection and treatment of precursors of anal squamous cell carcinoma (ASCC). Artificial intelligence (AI) algorithms have shown high levels of efficiency in detecting and differentiating HSIL from low-grade squamous intraepithelial lesions (LSIL) in HRA images. Our aim was to develop a deep learning system for the automatic detection and differentiation of HSIL versus LSIL using HRA images from both conventional and digital proctoscopes. A convolutional neural network (CNN) was developed based on 151 HRA exams performed at two volume centers using conventional and digital HRA systems. A total of 57,822 images were included, 28,874 images containing HSIL and 28,948 LSIL. Partial subanalyses were performed to evaluate the performance of the CNN in the subset of images acetic acid and lugol iodine staining and after treatment of the anal canal. The overall accuracy of the CNN in distinguishing HSIL from LSIL during the testing stage was 94.6%. The algorithm had an overall sensitivity and specificity of 93.6% and 95.7%, respectively (AUC 0.97). For staining with acetic acid, HSIL was differentiated from LSIL with an overall accuracy of 96.4%, while for lugol and after therapeutic manipulation, these values were 96.6% and 99.3%, respectively. The introduction of AI algorithms to HRA may enhance the early diagnosis of ASCC precursors, and this system was shown to perform adequately across conventional and digital HRA interfaces. Full article

Background: Female sex workers (FSWs) are at high risk for sexually transmitted infections (STIs), including infection with human papillomavirus (HPV) and cervical cancer due to occupational exposure. The objective of this study was to estimate the prevalence of HPV, HPV types, and precancerous lesions of the cervix among FSWs in Cameroon. Material and Methods: In this cross-sectional study, FSWs in Cameroon aged 30 years and above were screened for cervical cancer using high-risk HPV testing and genotyping and visual inspection with acetic acid and Lugol’s iodine (VIA/VILI) enhanced using digital cervicography (DC) simultaneously. Those who were positive for VIA/VILI-DC were provided treatment with thermal ablation (TA) immediately for cryotherapy/TA-eligible lesions while lesions meeting the criteria for large loop excision of the transformation zone (LLETZ) were scheduled at an appropriate facility for the LLETZ procedure. HPV-positive FSWs without any visible lesion on VIA/VILI-DC were administered TA. Bivariate analyses were conducted to compare demographic and clinical characteristics. Crude and adjusted logistic regression models were computed for HPV infection status and treatment uptake as outcomes in separate models and their ORs and 95% confidence intervals (95% CI) were reported. Results: Among the 599 FSWs aged 30 years and older that were screened for HPV and VIA/VILI-DC, 62.1% (95% CI: (0.58–0.66)) were positive for one or more HPV types. HPV type 51 had the highest prevalence (14%), followed by types 53 (12.4%) and 52 (12.2%). Type 18 had the lowest prevalence of 2.8% followed by type 16 with 5.2%. In the multivariable model, HIV-positive FSWs were 1.65 times more likely to be infected with HPV compared to their HIV-negative counterparts (AOR: 1.65, CI: 1.11–2.45). A total of 9.9% of the 599 FSWs were positive for VIA/VILI-DC. Conclusion: The prevalence of HPV infection among FSWs in Cameroon is higher than the worldwide pooled FSW prevalence. HPV types 51 and 53 were the most prevalent, while types 18 and 16 were the least prevalent. HIV status was the only variable that was significantly associated with infection with HPV. Full article

Background: Epidemiological clinical reports have shown an association between iodine excess with diabetes mellitus type 2 and higher blood glucose. However, the relationship between iodine, the pancreas, adipose tissue, and glucose transport is unclear. The goal of this study was to analyze the effect of iodine concentrations (in Lugol solution) on glucose transport, insulin secretion, and its cytotoxic effects in mature 3T3-L1 adipocytes and pancreatic beta-TC-6 cells. Methods: Fibroblast 3T3-L1, mature adipocytes, and pancreatic beta-TC-6 cells were treated with 1 to 1000 µM of Lugol (molecular iodine dissolved in potassium iodide) for 30 min to 24 h for an MTT proliferation assay. Then, glucose uptake was measured with the fluorescent analog 2-NBDG, insulin receptor, Akt protein, p-Akt (ser-473), PPAR-gamma, and Glut4 by immunoblot; furthermore, insulin, alpha-amylase, oxidative stress, and caspase-3 activation were measured by colorimetric methods and the expression of markers of the apoptotic pathway at the RNAm level by real-time PCR. Results: Low concentrations of Lugol significantly induce insulin secretion and glucose uptake in pancreatic beta-TC-6 cells, and in adipose cells, iodine-induced glucose uptake depends on the serine-473 phosphorylation of Akt (p-Akt) and Glut4. Higher doses of Lugol lead to cell growth inhibition, oxidative stress, and cellular apoptosis dependent on PPAR-gamma, Bax mRNA expression, and caspase-3 activation in pancreatic beta-TC-6 cells. Conclusions: Iodine could influence glucose metabolism in mature adipocytes and insulin secretion in pancreatic beta cells, but excessive levels may cause cytotoxic damage to pancreatic beta cells. Full article

Micro-computed tomography (microCT) is a common tool for the visualization of the internal composition of organic tissues. Collagen comprises approximately 25–35% of the whole-body protein content in mammals, and the structure and arrangement of collagen fibers contribute significantly to the integrity of tissues. Collagen type I is also frequently used as a key structural component in tissue-engineered and bioprinted tissues. However, the imaging of collagenous tissues is limited by their inherently low X-ray attenuation, which makes them indistinguishable from most other soft tissues. An imaging contrast agent that selectively alters X-ray attenuation is thus essential to properly visualize collagenous tissue using a standard X-ray tube microCT scanner. This review compares various contrast-enhanced techniques reported in the literature for MicroCT visualization of collagen-based tissues. An ideal microCT contrast agent would meet the following criteria: (1) it diffuses through the tissue quickly; (2) it does not deform or impair the object being imaged; and (3) it provides sufficient image contrast for reliable visualization of the orientation of individual fibers within the collagen network. The relative benefits and disadvantages of each method are discussed. Lugol’s solution (I₃K), phosphotungstic acid (H₃PW₁₂O₄₀), mercury(II) chloride (HgCl₂), and Wells–Dawson polyoxometalates came closest to fitting the criteria. While none of the contrast agents discussed in the literature met all criteria, each one has advantages to consider in the context of specific lab capabilities and imaging priorities. Full article

Commercially, leguminous crops (Fabaceae) are the second most important group of cultivated plants, just after grasses (Poaceae). This study focuses on the analysis of pollen development and stainability in two species belonging to the Fabaceae family: Vicia faba L. and Lupinus angustifolius L. Morphological analysis of the anthers at various stages of flower development allowed us to trace the processes of microsporogenesis and microgametogenesis. Nine different cell staining protocols with diverse mechanisms of action, including acetocarmine, Alexander’s dye, aniline blue in lactophenol, Calcein AM, FDA, MTT, TTC, Lugol’s iodine, and aceto-orcein, were tested for their suitability in assessing the viability of microspores as well as pollen grains in both species. Among the applied dyes, four allowed for the discrimination between viable and nonviable microspores in V. faba, and six dyes allowed for this in L. angustifolius. For mature pollen grains, all dyes enabled differentiation between viable and nonviable cells in both species. The highest viability indications for V. faba microspores were obtained with acetocarmine (94.6%), while for mature pollen, aniline blue in lactophenol, MTT, and aceto-orcein yielded the highest viability indications (90.8–96.3%). In L. angustifolius, the highest percentages of viable microspores (64.9–66.5%) were obtained with the acetocarmine, aniline blue in lactophenol, and TTC dyes. For mature pollen, the highest viability indications (83.4%–92.9%) were obtained with acetocarmine, aniline blue in lactophenol, Lugol’s iodine, and aceto-orcein. The viability of V. faba pollen grains in an in vitro germination test showed that the highest pollen germination (61.3%) was observed on the BK medium (rich in minerals with 10% sucrose). In L. angustifolius, the highest pollen germination was observed on the media containing boric acid and 5% sucrose (70.5%) and on the medium containing 10% sucrose only (74.2%). Full article

X-ray contrast techniques were tested on the chick embryos in early periods of embryogenesis. For contrast stain, reagents with radiopacity in various concentrations were used: silver proteinate, eosin, Lugol’s solution (I2KI), phosphomolybdic acid and phosphotungstic acid under heating at 25 °C and 40 °C and exposure for 24 and 48 h. The use of silver proteinate, eosin and I2KI in various concentrations in the contrast of the chick embryo in the early period of embryogenesis did not make it possible to obtain microtomographic results that provide reliable microstructural analysis. The most optimal and effective method of embryo staining at the HH22–HH34 embryonic stages reliably determined the staining of 1% phosphotungstic acid at 40 °C heating and exposure for 24 h. Taking into account the size of the chick embryos and their structures at the HH22–HH34 embryonic stages, the features of the development, location of organs, and the minimum permissible parameters of microtomography for obtaining high-quality and reliable results were determined by the isometric spatial resolution of 8.87 μm, X-ray voltage 50 kV, X-ray current 500 μA, and the use of filters started from Al 0.5 mm. Microtomographic results were obtained, characterized by the appearance of the chick embryo at the HH22–HH34 embryonic stages, and they visualized the locations and structures of the chick embryo organs and provided calculation of their volume and X-ray density. The results of the work open up significant prospects for using the chick embryo at the early embryonic period of embryogenesis as an alternative model for screening teratogenicity. Full article

Histological and naked-eye dissections are frequently used to investigate human anatomy. However, limitations of conventional methods include tissue damage and difficulty in observing structures, rendering findings limited. Micro-computed tomography (micro-CT) allows for a three-dimensional observation with whole-mount staining for contrast enhancement. A precise anatomical understanding of the larynx is essential for both the medical and surgical fields; however, the larynx is difficult to dissect because of its minuscule and complex structures. Therefore, we aimed to clarify the detailed anatomy of the larynx using micro-CT. The study was conducted on twelve specimens of cadavers using Lugol-based-contrast micro-CT. Using Lugol-micro-CT, relevant information on human structures was obtained. Consequently, we successfully employed the Lugol-micro-CT technique in the analysis of specific human soft tissue structures that are challenging to analyze using conventional methods. Full article

Bacillus thuringiensis (Bt) produces, during its vegetative growth, some insecticidal proteins that are secreted and diluted into the culture medium. These proteins are commonly known as vegetative insecticidal proteins (Vips), and include binary Vpb/Vpa proteins (formerly known as Vip1/Vip2) with coleopteran activity; Vip (formerly Vip3) with activity against lepidopterans; and Vpb4 proteins (formerly Vip4), also with coleopteran activity. Vip proteins are highly toxic to different species of lepidopteran pests; however, the difficulty in producing them in a concentrated form has not allowed their development as formulated biopesticides, and they are relegated to only being produced in transgenic crops. In this work, we demonstrated that the gene encoding the Vip protein Vip3Ag4 could be successfully expressed in an asporogenic strain of Bacillus megaterium using (D)-xylose as a low-cost inductor. Under certain conditions (37 °C and induction with 0.5% w/v xylose), active Vip3Ag4 protein was primarily produced in soluble form, remaining encapsulated within the cell wall of B. megaterium. After treatment with lugol (1% for 4 h), induced cells were completely killed (fixed) but maintained the functional Vip3Ag4 protein, which resulted in above 95% mortality against first-instar larvae of Chrysodeixis chalcites, Helicoverpa armigera, Spodoptera exigua, S. frugiperda, S. littoralis and Trichoplusia ni. The fact that the recombinant Vip3Ag4 protein was successfully produced in a soluble and an active form in this bacterium (with a low-cost inductor) suggests that B. megaterium is one of the hosts of choice for the production of sprayable formulations in “killed-microbial pesticides”, based on Vip3 proteins from Bt. Full article

α-amylases are one of the most common and important industrial enzymes widely used in various industries. The present study was conducted with the aim of isolating and identifying symbiotic α-amylase enzyme-producing bacteria in the intestine of Silago Sihama and Rasterliger Canagorta fish living in Qeshm Island, Hormozgan. The intestinal symbiotic bacteria of these species were isolated using nutrient agar culture medium; then, α-amylase producing bacteria were screened using a special culture medium containing starch and the Lugol’s solution test. The α-amylase enzyme activity of enzyme-producing bacteria was measured using the starch substrate. Finally, bacteria with the highest enzyme activity were selected and identified by the 16S rRNA gene sequence analysis. The results showed that out of 22 isolated bacteria, 10 were able to grow in a special culture medium, and 5 strains of these 10 bacteria had the ability to produce relatively stronger halos. The four bacterial strains belonging to the genus Bacillus that had the highest α-amylase enzyme activity were identified and registered in the NCBI gene database as B. subtilis strains HR13, HR14, HR15, and HR16. Among these four strains, two strains of B. subtilis, HR13 and HR16, displayed high enzyme activity and maximum activity at 60 °C at pH values of 5 and 7, respectively. α-Amylase enzymes isolated from marine symbiotic bacteria of Bacillus species can be considered potential candidates for application in various industries. Full article