Comparison of spatial scale variability of shoot density and epiphytic leaf assemblages of Halophila stipulacea and Cymodocea nodosa on the Eastern Coast of Tunisia

Abstract

A study was undertaken to compare the patterns of spatial variability, epiphytic percentage cover, and distribution of epiphytic fauna and flora between the two adjacent seagrasses Cymodocea nodosa and the invasive species Halophila stipulucea. Samples were taken at six stations separated by 600?m and exposed to different current conditions. The stations G2 and G5 were affected by a high current tide, while G4 was directly exposed to the northern marine currents. The station G3 was situated in the middle of a Posidonia oceanica bed and was less exposed to hydrodynamism, whereas the other stations were relatively protected. Results indicate that for both H. stipulacea and C. nodosa, shoot density and epiphytic cover biomass decreased when exposed to high levels of hydrodynamic activity. In terms of epiphytic leaf assemblages, our results showed significant differences for the two host plants in their mean cover and for the six stations at the largest and smallest spatial scale. Our observations highlight the dominance of Rhodophyta and the low number of epiphytic species and the epiphytic cover on H. stipulacea compared to C. nodosa. In addition, results indicate the absence of two taxa Hydrozoans and Annelida in the epiphytic assemblage of H. stipulacea leaves.     

Nonsuicidal Self-Injury and Suicidal Behavior: A Latent Class Analysis among Young Adults

Although there is a general consensus among researchers that engagement in nonsuicidal self-injury (NSSI) is associated with increased risk for suicidal behavior, little attention has been given to whether suicidal risk varies among individuals engaging in NSSI. To identify individuals with a history of NSSI who are most at risk for suicidal behavior, we examined individual variability in both NSSI and suicidal behavior among a sample of young adults with a history of NSSI (N = 439, Mage = 19.1). Participants completed self-report measures assessing NSSI, suicidal behavior, and psychosocial adjustment (e.g., depressive symptoms, daily hassles). We conducted a latent class analysis using several characteristics of NSSI and suicidal behaviors as class indicators. Three subgroups of individuals were identified: 1) an infrequent NSSI/not high risk for suicidal behavior group, 2) a frequent NSSI/not high risk for suicidal behavior group, and 3) a frequent NSSI/high risk for suicidal behavior group. Follow-up analyses indicated that individuals in the ‘frequent NSSI/high risk for suicidal behavior’ group met the clinical-cut off score for high suicidal risk and reported significantly greater levels of suicidal ideation, attempts, and risk for future suicidal behavior as compared to the other two classes. Thus, this study is the first to identity variability in suicidal risk among individuals engaging in frequent and multiple methods of NSSI. Class 3 was also differentiated by higher levels of psychosocial impairment relative to the other two classes, as well as a comparison group of non-injuring young adults. Results underscore the importance of assessing individual differences in NSSI characteristics, as well as psychosocial impairment, when assessing risk for suicidal behavior.     

Effect of Sodium Selenite and Vitamin E on the Renal Cortex in Rats: An Ultrastructure Study

This study examined the use of vitamin E to alleviate toxic effects of sodium selenite. Adult male albino rats (n = 50) was divided into five groups. Group 1 was control, Groups 2 and 4 were treated with sodium selenite (2 mg/kg) for 2 and 4 weeks, respectively, Groups 3 and 5 were treated with sodium selenite (2 mg/kg) and vitamin E (100 mg/kg) for 2 and 4 weeks, respectively. Renal tissues were studied using anti-BCL2 and examined ultrastructurally. Positive Bax immunoreactivity was detected after 2 and more positive after 4 weeks and nearly all groups improved with co-administration of vitamin E. Ultrastructural study revealed lesions in Bowman's capsule and proximal convoluted tubules. The submicroscopic study revealed damage and necrosis of cortical structures after 2 and 4 weeks, respectively. After 4 weeks, cellular changes were seen, such as vacuolation and moderate degeneration of cells, widening of the urinary space scattered through the cortex with loss of cellular details, formation of apical buds, degeneration, and cellular rupture. Present findings disclosed an ameliorative effect of adding vitamin E to sodium selenite-induced changes in cortical tissues. Clinically, it is advised to add vitamin E to avoid selenium overdose hazards.     

The Role of Calcium in Differentiation of Human Adipose-Derived Stem Cells to Adipocytes

Differentiation process of mesenchymal stem cells (MSCs) into adipocyte is involved in obesity. Multiple factors such as Ca²⁺ play important roles in different stages of this process. Because of the complicated roles of Ca²⁺ in adipogenesis, the aim of present investigation was to study the influx and efflux of Ca²⁺ into and out of the cells during adipogenesis. Adipose-derived MSCs were used to differentiate into adipocytes. MSCs were exposed to 2.5 mM Ca²⁺ or 1.8 mM Ca²⁺ plus calcium ionophore, A23187, for 3 days. Lipid staining, triglycerides (TG) content, and glyceraldehyde phosphate dehydrogenase (GAPDH) activity were evaluated to confirm the efficiency of the differentiation. Gene expression of GLUT4, PPARγ2, RAR-α, and calreticulin, as well as the protein levels of GLUT4 and PPARγ2 were determined. Ca²⁺ and in particular Ca²⁺ plus A23187 significantly lowered the efficiency of differentiation accompanied by decrease in intracellular TG deposits, GAPDH activity and alleviation of gene, and protein levels of GLUT4 and PPARγ2. While calreticulin and RAR-α were remarkably upregulated in A23187 group. This study showed the inhibitory effects of calcium in adipogenesis. Additionally, it indicated the greater inhibitory effect of calreticulin and RAR-α in controlling adipogenesis by higher levels of calcium.     

Synthesis,antitumour activities and molecular docking of thiocarboxylic acid ester-based NSAID scaffolds: COX-2 inhibition and mechanistic studies

A new series of NSAID thioesters were synthesized and evaluated for their in vitro antitumor effects against a panel of four human tumor cell lines, namely: HepG2, MCF-7, HCT-116 and Caco-2, using the MTT assay. Compared to the reference drugs 5-FU, afatinib and celecoxib, compounds 2b, 3b, 6a, 7a, 7b and 8a showed potent broad-spectrum antitumor activity against the selected tumour cell lines. Accordingly, these compounds were selected for mechanistic studies about COX inhibition and kinase assays. In vitro COX-1/COX-2 enzyme inhibition assay results indicated that compounds 2b, 3b, 6a, 7a, 7b, 8a and 8?b selectively inhibited the COX-2 enzyme (IC₅₀?=?～0.20–0.69?μM), with SI values of (>72.5–250) compared with celecoxib (IC₅₀?=?0.16?μM, COX-2 SI:?>?312.5); however, all the tested compounds did not inhibit the COX-1 enzyme (IC₅₀?>?50?μM). On the other hand, EGFR, HER2, HER4 and cSrc kinase inhibition assays were evaluated at a 10?μM concentration. The selected candidates displayed limited activities against the various tested kinases; the compounds 2a, 3b, 6a, 7a, 7b and 8a showed no activity to weak activity (% inhibition?=?～0–10%). The molecular docking study revealed the importance of the thioester moiety for the interaction of the drugs with the amino acids in the active sites of COX-2. The aforementioned results indicated that thioester based on NSAID scaffolds derivatives may serve as new antitumor compounds.     

Age patterns of Cryptosporidium species and Giardia duodenalis in dairy calves in Egypt

Little is known of the occurrence and age patterns of species/genotypes and subtypes of Cryptosporidium spp. and Giardia duodenalis in calves in Egypt. In this study, 248 fecal specimens were collected from dairy calves aged 1?day to 6?months on eight farms in three provinces during March 2015 to April 2016. Cryptosporidium spp. were detected and genotyped by using PCR-RFLP analysis of the small subunit rRNA (SSU rRNA) gene, while G. duodenalis was detected and genotyped by using PCR and sequence analyses of the triose phosphate isomerase (tpi), glutamate dehydrogenase (gdh) and β-giardin (bg) genes. The overall infection rates of Cryptosporidium spp. and G. duodenalis were 9.7 and 13.3%, respectively. The highest Cryptosporidium infection rate (26.7%) was in calves of age?≤?1?month while the highest G. duodenalis infection rate (44.4%) was in calves of 2?months. Three Cryptosporidium spp. were identified, including C. parvum (n?=?16), C. bovis (n?=?5) and C. ryanae (n?=?3), with the former being almost exclusively found in calves of ≤3?months of age and the latter two being only found in calves of over 3?months. Subtyping of C. parvum by PCR-sequence analysis of the 60?kDa glycoprotein gene identified subtypes IIaA15G1R1 (n?=?15) and IIaA15G2R1 (n?=?1). The G. duodenalis identified included both assemblages E (n?=?32) and A (n?=?1), with the latter belonging to the anthroponotic subtype A2. These data provide new insights into the genetic diversity and age patterns of Cryptosporidium spp. and G. duodenalis in calves in Egypt.