Effect of Biochar Addition on Mechanical Properties,Thermal Stability,and Water Resistance of Hemp-Polylactic Acid (PLA) Composites

The present study investigated the effect of biochar (BC) addition on mechanical, thermal, and water resistance properties of PLA and hemp-PLA-based composites. BC was combined with variable concentration to PLA (5 wt%, 10 wt%, and 20 wt%) and hemp (30 wt%)-PLA (5 wt% and 10 wt%); then, composites were blended and injection molded. Samples were characterized by color measurements, tensile tests, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and water contact angle analysis. Experimental results showed that adding 5 wt% of BC enhanced the composite’s tensile modulus of elasticity and strength. Hence, the use of optimized loading of BC improved the mechanical strength of the composites. However, after BC addition, thermal stability slightly decreased compared with that of neat PLA due to the catalytic effect of BC particles. Moreover, the water-repelling ability decreased as BC content increased due to the specific hydrophilic characteristics of the BC used and its great porosity.     

Molecular Epidemiology of SARS-CoV-2 in Tunisia (North Africa) through Several Successive Waves of COVID-19

Documenting the circulation dynamics of SARS-CoV-2 variants in different regions of the world is crucial for monitoring virus transmission worldwide and contributing to global efforts towards combating the pandemic. Tunisia has experienced several waves of COVID-19 with a significant number of infections and deaths. The present study provides genetic information on the different lineages of SARS-CoV-2 that circulated in Tunisia over 17 months. Lineages were assigned for 1359 samples using whole-genome sequencing, partial S gene sequencing and variant-specific real-time RT-PCR tests. Forty-eight different lineages of SARS-CoV-2 were identified, including variants of concern (VOCs), variants of interest (VOIs) and variants under monitoring (VUMs), particularly Alpha, Beta, Delta, A.27, Zeta and Eta. The first wave, limited to imported and import-related cases, was characterized by a small number of positive samples and lineages. During the second wave, a large number of lineages were detected; the third wave was marked by the predominance of the Alpha VOC, and the fourth wave was characterized by the predominance of the Delta VOC. This study adds new genomic data to the global context of COVID-19, particularly from the North African region, and highlights the importance of the timely molecular characterization of circulating strains.     

Pigmented and polypoid tumor of the pubis

Seborrheic keratosis is a common benign epidermal tumor occurring in patients aged over 50 years. It is located preferentially in the trunk, head and neck. The genital location is rare. We report a case of 59 year‐old‐men presenting a seborrheic keratosis of the pubis.     

Alcohol Use and Associated Environmental Factors Among Middle and High School Students in Sfax (Tunisia)

Our objective was to investigate the prevalence and the environmental determinants of alcohol use among students in the region of Sfax in Tunisia. We carried out a cross-sectional study among 315 middle and high school students. We used the Alcohol Use Disorders Identification Test (AUDIT) to identify risky alcohol consumption, and we used the Parenting Styles and Dimensions Questionnaire (PSDQ) to assess the students’ perceptions of their parents’ parenting styles. The results show that 19.7% reported drinking alcohol at least once in their lifetime. Among them, 21% scored as dependent alcohol users, according to the AUDIT. Those who drank alcohol at least once were more likely to have parents with a permissive parenting style (p < 0.001; Cramer’s V = 0.287), and a father (p < 0.001; Cramer’s V = 0.258), a mother (p = 0.025; Cramer’s V = 0.158), or a friend (p < 0.001; Cramer’s V = 0.341) who drinks. Students perceiving their parents’ parenting style as permissive had the highest AUDIT score (p = 0.005; partial η² = 0.132). The authoritarian style score was significantly higher for students who were current alcohol users (p = 0.028; Cohen’s d = 0.57). Our study highlights the influence of peers, family drinking, and parenting styles on alcohol use among middle and high school students. Therefore, particular attention should be given to students that are at risk of having the abovementioned environmental determinants of alcohol use. And, prevention strategies should involve parents, as well as enhanced guidance and counseling for these students.

     

Association of hyperhomocysteinemia with genetic variants in key enzymes of homocysteine metabolism and methotrexate toxicity in rheumatoid arthritis patients

Objectives

The study investigated the association between plasma homocysteine, folate and vitamin B12 with 5,10 methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), thymidylate synthase (TYMS 2R → 3R) and methionine synthase (MTR A2756G) polymorphisms and methotrexate (MTX) treatment and toxicity in Tunisian Rheumatoid arthritis (RA) patients.

Methods

A total of 185 patients with RA were included. Homocysteine (Hcy) was assessed by fluorescence polarization immunoassay, and folate and vitamin B12 were measured by chemiluminescence immunoassays. The genetic polymorphisms were analyzed by PCR or PCR-RFLP. Hyperhomocysteinemia (HHC) was considered for Hcy?>?15 µmol/L.

Results

MTHFR C677T polymorphism was associated with HHC in RA patients (multi-adjusted OR, 95% CI 2.18, [1.07–4.57]; p?=?0.031). No association was detected with the remaining polymorphisms. Plasma Hcy, folate, and vitamin B12 did not differ according to each polymorphism, or with MTX treatment or toxicity. However, HHC was more prevalent in patients with than those without MTX toxicity (32.7 vs. 16.7%; p?=?0.035).

Conclusions

The MTHFR 677TT genotype is an independent risk factor for HHC in Tunisians RA patients. HHC could be a useful marker of MTX toxicity in RA patients.

     

Uterine leiomyoma with massive lymphoid infiltration: case report

Uterine leiomyoma with massive lymphoid infiltration is a rare and unusual pathological finding; only 20 cases have been reported in the literature. We report a case of this unusual lesion in a 35-year-old woman who underwent a myomectomy. On gross examination, the tumor was of white color and firm consistency. Histological sections showed interlacing bundles of spindle shaped cells of low density with moderate to severe lymphocytic infiltrate associated to lymphoid follicles and few plasma cells. Immunohistochemically, the diffusely infiltrating lymphoid cells were predominantly of T cell phenotype. The interspersed spindle shaped cells were positive with alpha smooth muscle actin, desmin and h-caldesmon. The cause of this unusual lesion is not clear, but the recognition of its distinct histological features is important to avoid possible confusion with differential diagnosis including malignant lymphoma, inflammatory pseudotumor and pyomyoma.     

c.1643_1644delTG XPC mutation is more frequent in Moroccan patients with xeroderma pigmentosum

Xeroderma pigmentosum is a rare autosomal recessive disease characterized by hypersensitivity to UV light which is due to alterations of the nucleotide excision repair pathway. Eight genes (XPA to XPG and XPV) are responsible for the disease. Among them, the XPC gene is known to be the most mutated in Mediterranean patients. The aim of this study was to determine the frequency of the most common XPC mutation and describe the clinical features of Moroccan patients with xeroderma pigmentosum. Twenty four patients belonging to 21 unrelated Moroccan families and 58 healthy subjects were investigated. After clinical examination, the screening for the c.1643_1644delTG (p.Val548AlafsX25) mutation in the XPC gene was performed by PCR and automated sequencing of exon 9 in all patients and controls. The molecular analysis showed that among the 24 patients, 17 were homozygous for the c.1643_1644delTG mutation and all their tested parents were heterozygous, whereas the others (7 patients) did not carry the mutation. The frequency of this mutation was estimated to be 76.19 % (16/21 families). None of the 58 healthy individuals carried this mutation. In addition, clinical investigation showed that the majority of the patients bearing this mutation have the same clinical features. Our results revealed that the p.Val548AlafsX25 mutation is the major cause (76.19 %) of xeroderma pigmentosum in Moroccan families. This would have an important impact on improving management of patients and their relatives.     

SPOP,ZEB-1 and E-cadherin expression in clear cell renal cell carcinoma (cc-RCC): Clinicopathological and prognostic significance

Background

Clear cell renal cell carcinoma (cc-RCC), is a serious cancer regarding; its fatality, liability for metastases and chemoresistance, so identification of recent therapeutic targets to improve the patients prognosis is needed. SPOP is a BTB/POZ domain containing speckle-type POZ protein, has been identified as an E3 ubiquitin ligase component. ZEB1 is an essential epithelial mesenchymal transition (EMT) activator; E-cadherin is a cell adhesion protein that had been detected in normal epithelial cells membrane.