Cyclic and linear trajectories of ecosystem evolution on sand dunes in Siberian taiga: A comprehensive analysis

Extensive unforested sandy areas on the margins of floodplains and riverbeds, formed by dunes, barchans, and accumulation berms, are a ubiquitous feature across northern Eurasia and Alaska. These dynamic landscapes, which bear witness to the complex Holocene and modern climatic fluctuations, provide a unique opportunity to study ecosystem evolution. Within this heterogeneous assemblage, active dunes, characterized by their very sparse plant communities, contrast sharply with the surrounding taiga (boreal) forests common for the stabilized dunes. This juxtaposition makes these regions to natural laboratories to study vegetation succession and soil development. Through a comprehensive analysis of climate, geomorphology, vegetation, soil properties, and microbiome composition, we elucidate the intricacies of cyclic and linear ecosystem evolution within a representative sandy area located along the lower Nadym River in Siberia, approximately 100 km south of the Arctic Circle. The shift in the Holocene wind regime and the slow development of vegetation under harsh climatic conditions promoted cyclical ecosystem dynamics that precluded the attainment of a steady state. This cyclical trajectory is exemplified by Arenosols, characterized by extremely sparse vegetation and undifferentiated horizons. Conversely, accelerated vegetation growth within wind-protected enclaves on marginally stabilized soils facilitated sand stabilization and subsequent pedogenesis towards Podzols. Based on soil acidification due to litter input (mainly needles, lichens, and mosses) and the succession of microbial communities, we investigated constraints on carbon and nutrient availability during the initial stages of pedogenesis. In summary, the comprehensive study of initial ecosystem development on sand dunes within taiga forests has facilitated the elucidation of both common phases and spatiotemporal dynamics of vegetation and soil succession. This analysis has further clarified the existence of both cyclic and linear trajectories within the successional processes of ecosystem evolution.

Carbon footprint of maize-wheat cropping system after 40-year fertilization

Two main challenges which human society faces for sustainable development goals are the maintenance of food security and mitigation of greenhouse gas (GHG) emissions. Here, we examined the impacts of six fertilization treatments including unfertilized control (CK), mineral nitrogen (N, 90 kg N ha-1), mineral N plus 30 kg P ha-1 phosphorus (NP), NP combined with 3.75 Mg ha-1 straw (NP + Str), farmyard manure (Man, 75 Mg ha-1), and NP combined with manure (NP + Man) on crop productivity and carbon emissions (soil GHG emission; GHGI, yield-based GHG intensity; NGHGB, net GHG balance; carbon footprint, CF) in a maize-wheat cropping system during two years (April 2018-June 2020) in a semi-arid continental climate after 40 years of fertilization in the Northwest China. Manure and straw increased total GHG by 38-60 % compared to the mineral fertilizers alone, which was mainly due to the 49-80 % higher direct emissions of carbon dioxide (CO2) rather than nitrous oxide (N2O). Compared to the N fertilizer alone, organic amendments and NP increased cumulative energy yield by 134-202 % but decreased GHGI by 38-55 %, indicating that organic fertilizers increased crop productivity at the cost of higher GHG emissions. When the soil organic carbon changes (ΔSOC) were accounted for in the C emission balance, manure application acted as a net C sink due to the NGHGB recorded with -123 kg CO2-eq ha-1 year-1. When producing the same yield and economic benefits, the manure and straw addition decreased the CF by 59-85 % compared to N fertilization alone. Overall, the transition from mineral to organic fertilization in the semi-arid regions is a two-way independent solution to increase agricultural productivity along with the reduction of C emissions.

Halogens engineering-based design of agonists for boosting expression of frataxin protein in Friedreich's ataxia

OBJECTIVE

Decreased expression of the mitochondrial protein frataxin is the cause of the neurodegenerative disorder Friedreich's ataxia. In patients with cardiac disorders, the death rate of this disease is very high, up to 66%. In order to combat Friedreich ataxia, which is a potentially toxic disorder, de novo drug discovery and design have been created utilizing the approach of compound engineering with halogens. This study aimed to investigate the potential for effective treatment of Friedreich ataxia.

MATERIALS AND METHODS

The screening of twenty different agonist compounds was carried out in order to find the most promising agonist compound that may be used for molecular docking prediction against the Frataxin Protein. The compound with the lowest binding energies is then optimized by halogens. The final candidate's drug-like properties are identified through Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) profiling. Lipinski's rule of five was checked. Molecular dynamic stimulations were evaluated.

RESULTS

The most potent agonist compound was identified out of twenty different compounds utilizing a docking approach against the Frataxin Protein. The compound with the lowest binding energies was next subjected to optimization by halogens. The optimized agonist 9-[1-[(1S, 5R)-8, 8-dimethyl-8-azoniabicyclo[3.2.1]octan-3-yl]triazol-4-yl]fluoren-9-ol  has higher binding energy of -10.4Kcal/mol with molecular weight of 705.63 g/mol. Drug-like properties are identified through ADMET profiling, having water solubility of about -7.59, skin permeation -7.08 cm/s, bioavailability score 0.17, and high GI absorption. The candidate fulfills the Lipinski rule of five and portrays efficient molecular dynamic stimulations.

CONCLUSIONS

The selected agonist is one of the most potent compounds in increasing Frataxin protein expression. Furthermore, optimization with halogens can be a productive approach to improve the candidate's drug efficacy. The development of effective medications for the treatment of Friedreich ataxia would be aided by the results of these computational investigations.

The cytological pattern of cervical smears of a series of Saudi women in one gynecologic center

OBJECTIVE

Cervical intraepithelial neoplasia (CIN) is a type of abnormal cervical epithelial development that can lead to cervical malignancy. Thus, the purpose of this study was to examine the cytological pattern of cervical smears from a group of Saudi women who visited a single gynecologic center.

PATIENTS AND METHODS

From May 2020 to May 2021, 300 women were referred to the cytopathology laboratory and their cytological materials were collected. Because of gynecologic concerns, the women in the study were referred for Pap smears. As part of the obligatory investigations in conjunction with the clinical assessment, a Pap smear is requested.

RESULTS

CIN of various grades was found in 11% of the women. High-grade Squamous Intraepithelial Lesions (HSIL) were the most detected modifications, followed by Atypical Squamous Cells of Undetermined Significance (ASUS) and Low-grade Squamous Intraepithelial Lesions (LSIL), accounting for 36.4%, 33.3%, and 30.3%, respectively. In 23.7% of the women, inflammatory cell infiltrations were found. Infection with Candida Albicans was identified in 2.3% of the women. In 15.8% of the patients, cytological evidence of bacterial infection was found.

CONCLUSIONS

The prevalence of CIN has been growing in Saudi Arabia in recent years, implying a probable involvement in the spread of HPV. Most CIN cases associated with middle age point to HPV infection at a younger age. There is no link between estrogen and/or progesterone levels and CIN.

Plant-soil-microbial interactions mediate vegetation succession in retreating glacial forefields

Global warming is accelerating glacial retreat and leaving open areas for vegetation succession on young developing soils. Soil microbial communities interact with plants affecting vegetation succession, but the specific microbial groups controlling these interactions are unclear. We tested whether plant-soil-microbial interactions explain plant primary succession in the Gongga Mountain glacial retreat chronosequence. The direction and intensity of plant-soil-microbial interactions were quantified by comparing the biomass of one early-, two mid- and two late-succession plant species under sterilized vs. live, and inter- vs. intra-specific competition. The performance of most plant species was negatively affected by soil biota from early habitats (5-10 yr), but positively by soil biota from mid- (30-40) and late-succession (80-100) habitats. Two species of Salicaceae from middle habitats, which are strong competitors, developed well on the soils of all successional stages and limited the establishment of later serial plant species. The strongest microbial drivers of plant-microbial interactions changed from i) saprophytic fungal specialists during the early stage, to ii) generalists bacteria and arbuscular mycorrhizal fungi in the middle stage, and finally to iii) ectomycorrhizal fungal specialists in the late stage. Microbial turnover intensified plant-soil-microbial interactions and accelerated primary succession in the young soils of the glacial retreat area.

Human Papillomavirus genotypes associated with cervical intraepithelial lesions among Saudi women

OBJECTIVE

HPV is responsible for over 90% of cervical cancer worldwide. HPV has numerous subtypes with great variety distribution in different geographical regions. Thus, the present study aimed at assessing Human Papillomavirus (HPV) genotypes associated with cervical intraepithelial lesions among Saudi women.

PATIENTS AND METHODS

The current study collected cervical smears from 300 women transferred to a cytopathology laboratory between May 2020 and May 2021. The studied women were referred to do Pap smear because of gynecologic complaints.

RESULTS

Positive HPV testing was established in 4.7%. Most positive cases were identified in the age range of 14-50 years, followed by 51-60 years, representing 50% and 35.7%, respectively. The risk of HPV infection was significantly high in the age between 40-50 years, the odds ratio (OR), 95% confidence interval (95% CI), OR (95% CI) = 3.0137 (1.0228 to 8.8797), p = 0.0454, z statistic = 2.001. About 57% of the cases of HPV were found with cytological atypia. The risk of HPV in inducing cytological atypia, the OR (95%CI) = 1.8546 (2.9386 to 27.0952), p = 0.0001, z statistic = 3.862. Inflammatory cells infiltrate was identified in 43% of HPV-positive cases. The risk of HPV in inducing inflammatory changes, the OR (95% CI) = 2.6423 (0.8850 to 7.8887), p = 0.0817, z statistic = 1.741.

CONCLUSIONS

The prevalence of High-risk human papillomavirus is relatively low in the AL-Madinah area, Saudi Arabia. Cervical cytological atypia corresponds to the positive HR-HPV findings. HR-HPV infection or cervical cytological atypical changes induce inflammatory cell infiltrates. HR-HPV infection is more common among elderly Saudi women.

Polypharmacy and inappropriate prescribing in elderly patients: a retrospective study at Buriadah Central Hospital, Saudi Arabia

OBJECTIVE

An increase in life expectancy has been attributed to better access to health care and viable treatment options for diseases where there were none before. However, a multiple-drug regimen increases the risk of inappropriate prescription and drug-related problems. This study aimed to investigate polypharmacy and inappropriate prescription among elderly patients in the Qassim region of Saudi Arabia.

PATIENTS AND METHODS

This was a retrospective study wherein the electronic files of patients aged ≥ 60 years were reviewed and investigated for polypharmacy and inappropriate drug prescription using Beer's criteria 2019.

RESULTS

The 1123 patients who met the eligibility criteria were between 60-102 years of age (mean age: 71.9 years). 387 patients (34.46%) used five medications, while the remaining patients used more than five medications. The prevalence of potentially inappropriate medications (PIMs) was 66.25%. The most commonly prescribed PIMs were non-steroidal anti-inflammatory drugs, baclofen, proton pump inhibitors, diuretics, and aspirin (11.3%, 10.6%, 10.1%, 8.46%, and 5.6%, respectively).

CONCLUSIONS

This study showed a high prevalence of polypharmacy, which consequently led to a high prevalence of PIMs. This is a serious health problem in the elderly population and should be prevented or tackled with caution.

Kaempferol Induces Cell Death in A2780 Ovarian Cancer Cells and Increases Their Sensitivity to Cisplatin by Activation of Cytotoxic Endoplasmic Reticulum-Mediated Autophagy and Inhibition of Protein Kinase B

This study investigated whether kaempferol could inhibit ovarian cancer (OC) by activation of endoplasmic reticulum (ER) stress and autophagy, and tested its effect on the sensitivity of OC cells to cisplatin (cis-diamminedichloroplatinum, DPP). To study the effect of kaempferol on activation of ER stress and autophagy and find out whether its mechanism of action involves calcium (Ca2+), A2780 OC cells were cultured in DMEM/F12 for 24 h with or without kaempferol (40 μmol/l) in the presence or absence of autophagy or ER stress inhibitors or a calcium chelator. To study the effect of kaempferol on the sensitivity of OC cells to DPP and the potential involvement of modulation of protein kinase B (Akt) expression, A2780 OC were incubated with kaempferol and increasing concentrations of DPP (0-20 μmol/l) and then with kaempferol at its predetermined IC50 (6.8 μmol/l). Compared to control cells, kaempferol increased cell apoptosis (158 %) and decreased viability (53.17 %) and proliferation (49.17 %) of A2780 OC cells. Concomitantly, it increased the protein levels of GRP78, PERK, ATF6, IRE-1, LC3II, beclin 1, and caspase 4, thus suggesting activation of cytotoxic autophagy. This was mediated by increasing intracellular Ca+2 levels. In addition, kaempferol increased the sensitivity of A2780 cells to DPP (IC50 from 6.867 ± 0.99 to 3.73 ± 0.59 μmol/l) by decreasing the protein levels of p-Akt (0.31 ± 0.09 vs 0.12 ± 0.005). In conclusion, the findings of this study encourage the use of kaempferol alone or in combination with DPP to inhibit tumorigenesis of ovarian cells.

Gene Microarray Analyses of Daboia russelli russelli Daboiatoxin Treatment of THP-1 Human Macrophages Infected with Burkholderia pseudomallei

Burkholderia pseudomallei is the causative agent of melioidosis and represents a potential bioterrorism threat. In this study, the transcriptomic responses of B. pseudomallei infection of a human macrophage cell model were investigated using whole-genome microarrays. Gene expression profiles were compared between infected THP-1 human monocytic leukemia cells with or without treatment with Daboia russelli russelli daboiatoxin (DRRDbTx) or ceftazidime (antibiotic control). Microarray analyses of infected and treated cells revealed differential upregulation of various inflammatory genes such as interleukin-1 (IL-1), IL-6, tumor necrosis factor-alpha (TNF-α), cyclooxygenase (COX-2), vascular endothelial growth factor (VEGF), chemokine C-X-C motif ligand 4 (CXCL4), transcription factor p65 (NF-kB); and several genes involved in immune and stress responses, cell cycle, and lipid metabolism. Moreover, following DRR-DbTx treatment of infected cells, there was enhanced expression of the tolllike receptor 2 (TLR-2) mediated signaling pathway involved in recognition and initiation of acute inflammatory responses. Importantly, we observed that highly inflammatory cytokine gene responses were similar in infected cells exposed to DRR-DbTx or ceftazidime after 24 h. Additionally, there were increased transcripts associated with cell death by caspase activation that can promote host tissue injury. In summary, the transcriptional responses during B. pseudomallei infection of macrophages highlight a broad range of innate immune mechanisms that are activated within 24 h post-infection. These data provide insights into the transcriptomic kinetics following DRR-DbTx treatment of human macrophages infected with B. pseudomallei.

Isolation and distribution of mosquito-larvicidal cry genes in Bacillus thuringiensis strains native to Saudi Arabia

A total of 157 environmental samples were collected from 11 ecological regions across Saudi Arabia to isolate native Bacillus thuringiensis (Bt) strains. Bt isolates (n=103) were recovered by the 50% (v/v) ethanol treatment method with Bt index range of 0.01 to 0.4. Most of Bt isolates showed spherical crystals (54%), while, irregular, bi-pyramidal, and spore-attached crystal constituted 27, 16 and 3% respectively. PCR analysis with eight general and specific dipteran primers of Cry and Cyt genes, revealed positive amplification for cry4 & cyt1, and cry4A, cry4B and cyt2, and cry 10 and cry 11 genes in 28%, 26%, 22%, and 25% of tested strains respectively; whereas cry2 gene was not detected except with the reference Bt kurstaki HD-1 strain. Bioassays against Aedes caspuis and Culex pipiens larvae indicated that 11 strains displayed better larvicidal activity compared with Bacillus thuringiensis H14 (Bti) reference (LC50 0.6 μg/ml) strain against Ae. caspuis, but only two strains (620A & 633R1, LC50 of 0.09 μg/ml & 0.064 μg/ml) that gave significant enhancement. Additionally, one strain (633R1) showed LC50 similar to that of Bti H14 (LC50 0.064 μg/ml) against Cx. pipiens. With the exception of cyt primers, sequenced DNA of all positive primers amplicons revealed 95 to 99% identity in GenBank with Bacillus thuringiensis subsp. israelensis plasmid pBtoxis and also correlated with its SDS-PAGE expressed protein profiles analysis. It is hoped that our wild bio-insecticide Bt strains can be explored in future in the control of mosquito-vector borne diseases in Saudi Arabia.

Association of MHC class I with spondyloarthropathies in Kuwait

This study is the first to assess the prevalence of HLA B27 in Kuwaiti patients with ankylosing spondylitis (AS) or related spondyloarthropathies compared to healthy controls. Positive HLA B27 was found in nine (25.7%) of 35 patients, but only in 22 (4%) of 544 controls (P = 0.000). A significant difference in Cw2 and Cw6 between patients and controls was also found (P < 0.01 and 0.000, respectively), suggesting a linkage disequilibrium between B27 and Cw2 (P < 0.000) in the Kuwaiti population. These findings suggest that B27-positive Kuwaitis are at high risk of developing AS and spondyloarthropathies, especially if they carry Cw2 and Cw6: The importance of HLA Cw loci is becoming increasingly apparent in disease association studies.

Changes in mitogen responsiveness lymphocyte subsets after traumatic injury: relation to development of sepsis

Head injury and multiple trauma patients were evaluated for mitogen responsiveness and lymphocyte subset frequencies within the first few days after injury. The profile obtained was compared to the patient's clinical course to see if there was a relation between early immune abnormalities and the subsequent development of unanticipated sepsis. Lymphocytes from multiple trauma patients were generally hyporesponsive to in vitro stimulation with a suboptimal dose of the mitogen phytohemagglutinin (PHA). In contrast, the response of head injured patients was comparable to that of the control group. There was a significant decrease in the relative number of multiple trauma patient's T4 (29.3 vs 48.6%) and T11 (48.9 vs 74.7%) positive populations (P less than 0.01). There was no change in the percentage of T8-positive cells (19.0 vs 20.5%). Patients with head injuries also had a decrease in T4-positive cells (35.9%). The percentage of cells with B cell and natural killer (NK) markers remained normal. Thus trauma patients appeared to have an increase in null cells. Six patients whose PHA responses were among the lowest developed sepsis early after trauma. The changes in subset distributions although possibly contributing to a decreased responsiveness did not predict the ability to respond to PHA or the development of sepsis.