Sultan Qaboos University Journal for Science [SQUJS]

Effects of Microplastic on the Gastrointestinal Tract and Gut microbiome of Sprague Dawley Rats

Taher Baomar — 2024-09-16

ABSTRACT

Nowadays there is evidence that animals are exposed to microplastics (MPs) via food, however there is not much known about their effect on tissue of gastrointestinal tract and on gut microbiome. In this study, adult male rats were fed with polyethylene MPs, mixed with standard pellet food for 24 days at different concentrations ranging from 0 to 1000 μg/day. At the end of experiment, rats were euthanized and histopathological investigation using light and electron microscopy and the gut microbiome was analyzed using MiSeq 16S rRNA amplicon sequencing. Microscopic analysis revealed significant impact of MPs on the intestine, including visible changes to the crypt area as well as reduction in mucus secretion. Autophagic vacuoles were observed in the livers of the rats fed with MPs at 100 µg/day. Oxidative stress was evident in rats fed with 1000 µg/day of MPs, as indicated by the presence of myeloid bodies in both intestinal and hepatic cells. The gut microbiome was also affected by MPs. Although, no distinct clusters were formed when the bacterial communities in the different treatments were ordinated by multidimensional scaling (NMDS), the diversity indices including operational taxonomic unit (OTU) richness and Chao1 exhibited an increasing trend with increasing MPs concentration. Pearson correlations revealed a linear increase in the relative sequence abundance of Clostridia (R=0.036, P=0.003) with increasing MPs concentration, but not in the case of other bacterial groups,. Lactobacillus faecis was the most abundant OTU in the entire dataset, and its relative abundance decreased significantly with increasing MPs concentration. We conclude that exposure to MPs can disrupt cellular function and disturb microbiome balance, and in the event of prolonged exposure, organisms might experience unpredictable effects.

A Census of Lakes in Gandaki Province based on Remote Sensing

Anup Gurung — 2024-09-16

Lakes in Nepal play a crucial role in supporting biodiversity conservation, regulating ecosystems, and providing livelihood opportunities for local communities. Many lakes in Nepal hold immense religious and cultural significance for the local community, serving as sacred pilgrimage sites and embodying spiritual entities that are integral to the traditions, beliefs, and practices of the people, making them important cultural landmarks of the country. Despite their significance and importance, lakes in Nepal have faced degradation and challenges. Due to inappropriate infrastructure development, encroachment, and anthropogenic activities, lakes are degraded in Nepal. In recent years, Gandaki Province also witnessed the degradation of lakes. Therefore, this study aimed to assess the status of lake degradation as well as find out the total number of lakes in the Gandaki Province. The study was conducted utilizing both Remote Sensing (RS) techniques and conducting field visits. First of all, the Normalized Difference Water Index (NDWI) was calculated with the help of Google Earth Engine with Sentinal 2A/B satellite. That gives the water area, and then polygons of water bodies were created throughout the province in an identified area. These polygons were uploaded in ArcGIS and a base map was added. In the ArcGIS platform, polygons were further edited for the precise area using very high-resolution imagery. These edited polygons were further verified in Google Earth. Field visits, personal phone inquiries, and group discussions were conducted for further verification. Data were also collected from municipality/rural municipality, elected representatives, and key informants. Altogether 290 lakes (including ponds, lakes, and glacier lakes) were mapped and identified in the Gandaki Province. These lakes cover about 0.1045% of the total surface area of the Gandaki Province. Approximately 60% of the lakes were identified above 3000 m above sea level (asl). Lakes identified below 3000 m asl were mostly mapped from the Kaski, Parbat, and Nawalparasi Districts. The highest number of lakes discovered in Mustang (a total of 73 lakes), encompasses both lakes situated below 3000 m asl and those above 4500 m asl. Many of the wetland areas, most of which are located below 3000 m are currently facing the threat of extinction. Numerous lakes have already been transformed into playgrounds and residential areas, leading to the loss of valuable wetland ecosystems in the Gandaki Province.

The Allelopathic Effects of Persicaria salicifolia on the Growth and Antioxidant Enzymes of Synechocystis pevalekii and Tetradesmus bernardii

Mustafa A. Fawzy — 2024-09-16

In recent years, there has been an increasing focus on the prospect of exploiting macrophytes as an alternative strategy to control undesired algal growth. The present research was conducted to study the effect of different concentrations of an aqueous stem extract of Persicaria salicifolia on the growth, some metabolites and antioxidant enzymes of the green microalgae Synechocystis pevalekii and Tetradesmus bernardii. Chlorophyll a, dry weight, total protein, total carbohydrate and proline contents of the tested algae decreased with increasing the crude extract concentrations of P. salicifolia. In general, catalase, superoxide dismutase and lipoxygenase activity of T. bernardii increased with increasing the aqueous extract of P. salicifolia. The identification of phytochemical components of the plant extract by gas chromatograph-mass spectrometry (GC-MS) revealed the presence of various biologically active compounds such as 11-Octadecenoic acid, methyl ester (18.03%) and 9,12-Octadecadienoic acid methyl ester (15.03%) that are capable of inhibiting the growth of S. pevalekii and T. bernardii. Therefore, P. salicifolia may provide a cheap and environmentally friendly alternative for controlling microalgae in aquatic ecosystems.

Cutting-Edge Approach to Targeted Therapy: Repositioning of Old Drugs in Combination with Standard Clinical Chemotherapeutics Potentiates a Propitious Novel Targeted Therapy for Human Pancreatic Cancer

Rashelle Aldbai — 2024-09-16

Metastatic pancreatic cancer leads to a fatal outcome, with a median progression-free survival of approximately six months when utilizing the most successful combination of chemotherapeutic regimens. When drug resistance develops, it facilitates an increase in primary tumor growth and new and growing metastases. Patients inevitably and quickly succumb to their disease and die. Notably, chemotherapy has an unintended impact on the development of drug resistance through the enhancement of EMT development and the enrichment of cancer stem cells (CSC). Recent report discovered that neuraminidase-1 (Neu-1) regulates EMT induction, angiogenesis, and cellular proliferation by the activation of several receptor tyrosine kinases. Here, the continual therapeutic inhibition of Neu-1 through intravenous administration of oseltamivir phosphate (OP) and aspirin (ASA) alongside GEM treatment significantly inhibits tumor progression, crucial compensatory signaling pathways, EMT program, CSC, and metastasis progression in a preclinical RAG2xCy double mutant BALB/c mouse model of human PANC-1 pancreatic cancer. The tumorigenic and metastatic potential of the xenotumors from the animals treated with the experimental protocols were significantly ablated when transferred into the mammary fat pads of NSG (NOD SCID gamma) branded mice.

Keywords: pancreatic cancer; chemoresistance; drug repurposing; EMT.

Preventive effects of dill oil on potassium bromated-induced oxidative DNA damage in garlic root tips

Hoda khatab — 2024-09-16

In this study, the potential antimutagenic/cytoprotective effect of the oil extract (2.5µg/ml) from Anethum graveolens L. (Dill) on oxidative DNA damage was tested. The experiments were carried out to inhibit mutagenicity induced by potassium bromated (KBrO₃-9g/l) in Allium assay using mitotic activities and nuclear DNA contents. Result showed a clear reduction in radical length in all KBrO₃-treated groups compared to control plants. Mitotic activity, measured by mitotic index (MI) and mitotic stages, were significantly decreased in meristematic cells after KBrO₃ application, The results showed that mitotic index (MI) was decreased to reach about 0.8 at 24 hrs compared with 23.9% in untreated plants. The analysis of potential cyto and genoprotective of dill extract on nuclear DNA contents showed a statistically significant increase in the nuclear DNA content compared to KBrO₃-treated roots was observed. Clearly, dill oil showed highly performance in protecting the mitotic cells against mutagenic KBrO₃ effects by increasing the MI and decreasing the abnormal chromosomes. Also, the percentage of damage reduction was observed in the pre- (28.9, 57.9 and 46.4 %), simultaneous (53.0, 70.6 and 35.7 %) and post- (37.3, 61.8 and 50 %) treatment. The results of the qualitative study showed that this dill extracts were rich in chemical compounds belonging to several phytochemical classes. GC-MS analysis detected 29 chemical compounds with different concentrations. The predominant ones were Octadecanoic acid (31.75%) and 2-pentanone, 4-hydroxy-4-methyl (16.77). So that these experiments will help to understand and uncover the mechanism of action dill oil against the mutagenic effects of KBrO₃ (i.e whether they have a prophylactic or treatment activity).

Perception of Nurses Toward Working at High Reliability Healthcare Organizations: The Association to Nurses' Psychological Safety and Intention to Stay

Safia Samir Darwish — 2024-09-16

Background: High-reliability organizations (HROs) of healthcare are facing tough challenges to improve nurses’ psychological safety and intent to stay through maintaining organizational resources, work flexibility, environmental safety, and effectively managing stress and anxieties the nurses face in the workplace. Aim: This study aims to identify the relation between perception of working at HRO, psychological safety and intent to stay among Dar Al-Fouad Hospital nurses. Design: A correlational ex-post facto research. Setting: The study was conducted at Dar Al Fouad Hospital. Study subjects: A simple random sample of nurses who are working in Dar Al Fouad Hospital n=225. Tools: Three instruments were used in this study: the instrument one Part (1) - personnel data, Part (2) - Safety Organizing Scale; instrument two - team psychological safety scale, and instrument three - nurses’ intent to stay scale. Results: The total perception levels of HRO was moderate 64.5%, psychological safety was moderate 75.6%, and intent to stay was moderate 89.3% among the studied sample. Conclusion: There was negative statistical significance relation between staff nurses’ total perception level regarding HRO, and psychological safety and intent to stay. Recommendation: Health care managers at HRO work to improve nurses’ psychological safety and intent to stay through providing personal and professional support, encouraging to report mistakes, ask questions, receive effective feedback, and see mistakes as opportunities to learn.

Keywords: High reliability organization; Intent to stay; Psychological safety.

The Continued Presence of Antibiotic-resistant Bacteria and Heavy Metals at one of the World’s Most Important Green Turtles’ Nesting Location, Ras al-Jinz Reserve, Oman

Al-Musharafi S.K — 2024-09-16

Environmental contamination of marine habitats is a global concern, especially in areas that are crucial for endangered species’ life cycles. To gain a comprehensive understanding of environmental contamination, analyzing various biotic and abiotic components of ecosystems is necessary. Situated in the Arabian Peninsula, Ras al-Jinz Reserve serves as an invaluable nesting site for green sea turtles (Chelonia mydas). There, the prevalence of antibiotic-resistant microbial strains and heavy metals was assessed by collecting samples from diverse components of this ecosystem, including sand from turtle nests, dead turtle hatchlings, fresh turtle eggs, oviductal fluids from nestling turtles, turtle carapace smears, live crabs, and seawater. Microbial fauna was identified using a MALDI-TOF Biotyper. The concentration of heavy metals was measured by an inductively-coupled plasma mass spectrometry. Among the isolated bacterial strains, 70 heterotrophic species belonging to eleven genera were identified, with over 46% of isolates belonging to the Pseudomonas species. More than 85% of isolates displayed antibiotic resistance but had negligible resistance to chloride. Of the 23 heavy metals assessed, Titanium and, in lesser measure Vanadium, were found in the highest concentrations, reaching up to 12 µg g^-1. While such concentrations might not be immediately alarming, they are significant enough to warrant attention due to the potential health and environmental impacts. These results obtained over a decade after the last monitoring in the Reserve provide compelling evidence of the persistent presence of antibiotic-resistant bacteria. Additionally, the study confirms the prevalence of heavy metals, the sources of which remain unknown but are likely from anthropogenic sources. It is crucial to implement measures that mitigate sea turtles’ exposure to contaminants in Ras al-Jinz Reserve. Regular monitoring efforts are required to assess the emergence of discernible contamination trends in this critically important area.

Keywords: Chelonian conservation; Environmental contamination assessment; Microbial contamination; Biological reserve; Coastal pollution.

Biosystematic studies on the genus Crepis L. (Asteraceae: Cichorieae) in Egypt

Mona Hassan — 2024-09-16

The taxonomy of the genus Crepis L. in Egypt is critically discussed. The genus is represented in Egypt by seven species with four infra-specific taxa. One new record (C. aspera var. inermis (Cass.) Boiss.) is reported here for the first time for the flora of Egypt. The macro- and micro-morphological characteristics of the studied Crepis taxa, including the capitula, phyllaries, achenes, trichomes, and stomata, were investigated. Multivariate (cluster and PCA) analyses based on macro- and micro-morphological characteristics elucidate the phenetic relationships among the investigated taxa at the sectional level. A key, full descriptions, an updated nomenclature, and a revised type citation to the Crepis taxa are provided.

Keywords: Achenes; Asteraceae; Cichorieae; Crepis; Stomatal index; Trichomes.

Identification of Two Species of the Family Sparidae for eDNA Sequences using a Representative 16SrRNA Reference Library for Omani Fish

Aliya Alansari — 2024-09-16

Identification of fish species accurately is required to support efforts for conserving fishery biodiversity assessment and sustainable management. Recently, environmental DNA (eDNA) was suggested for regular monitoring of species for effective management of biodiversity. In Oman, molecular reference library representing fish species from the Omani coastline can support such potential approaches. In this communication, we used a local mtDNA-16SrRNA reference library representing Sparidae fish species from the Omani coastlines to identify two Sparidae eDNA sequences (zotu24 and zotu85, from Muscat and Dhofar, respectively) from Acanthopagrus and Diplodus genera reported by a recent eDNA study from Oman. The two species are found to be Acanthopagrus berda and Diplodus cervinus and their sampling sites matches the locations range of the reference specimens. The results indicate the utility and importance for DNA markers’ reference library representing fish species from the Omani coastline to effectively sustain the marine resources using emerging technologies.

Keywords: Sparidae, eDNA; 16SrRNA; Acanthopagrus berda; Diplodus cervinus; Oman.