Epidemiological and clinical characteristics of 66 Tunisian Sickle cell syndrome patients

Introduction

Sickle cell syndrome (SCS) represent a real health problem. In this work, we propose to study the epidemiological and clinical features of 66 patients with SCS.

Methods

This is a retrospective descriptive cross-sectional study carried out on a population of 66 patients with SCS, (36 S/S, 18 S/β-thalassemia, seven S/C and five S/OArab), over a period of two years.

Results

The average age of our population is 15.5 years ± 8.4. 36 patients (55%) were born to a consanguineous marriage and 35 (53%) had siblings with SCS. The average baseline hemoglobin in our patients is 9.1g/dL±1.51. S/C patients have significantly higher baseline hemoglobin than S/S, S/β-thalassemia and S/OArab with p <0.05. Jaundice, mucosal skin pallor and hepatomegaly have been observed only in S/S, S/β-thalassemia and S/OArab patients. The persistence of splenomegaly is more frequent in S/C than in S/S, and in S/-thalassemia than in S/S. The most common acute complications were vaso-occlusive attacks (69.7%) and worsening of anemia (54.54%). The most common chronic complication was cholelithiasis (36.36%).

Conclusion

S/C patients present the best tolerated form and were the least affected by chronic complications and therefore can lead an almost normal life.

Decomposition mechanism of hydroxychloroquine in aqueous solution by gamma irradiation

One of the advanced oxidative processes is gamma irradiation, an efficient technique for removing pesticides and pharmaceutical products. Radiolytic degradation leads to free radical’s formation, which facilitates molecular lesion and breaks the chemical bonds. The use of pharmaceutical compounds, such as hydroxychloroquine (HCQ), is increasing nowadays due to the Covid 19 pandemic situation. This study focused on gamma radiation-induced degradation of HCQ in aqueous solution. The degradation was monitored by High-Performance Liquid Chromatography (HPLC) using an Eclipse XDB-C18 column (150 × 3.0 mm, 3.5 µm) and a mobile phase composed of 94% water (phosphate buffer at pH = 3.6) and 6% acetonitrile, with a DAD detection at λ = 343 nm. The effect of different gamma radiation doses (from 0.05 to 3 kGy) was investigated. Chromatographic analysis shows that 1 kGy dose is effective to degrade completely HCQ at 20 ppm and following a first-pseudo-kinetic order with a dose constant corresponding to 4.2 kGy⁻¹. A comparison was done between gamma degradation and other methods. LC-QToF-MS/MS identified the intermediate products, and their kinetic constants were determined. A mechanism pathway was proposed for HCQ degradation under gamma irradiation.

Arsenite and chromate sequestration onto ferrihydrite, siderite and goethite nanostructured minerals: Isotherms from flow-through reactor experiments and XAS measurements

Sorption isotherms remain a major tool to describe and predict the mobility of pollutants in natural and anthropogenic environments, but they are typically determined by independent batch experiments. In the present study, the sequestration of As(III), Cr(VI) and competitive As(III)-Cr(VI) on/in 6L-ferrihydrite, siderite and goethite nanostructured minerals was reinvestigated using stirred flow-through reactor experiments. Herein, sorption isotherms were particularly determined from breakthrough curves for inert and reactive tracers monitored simultaneously in a single percolation experiment. In complement, X-ray absorption spectroscopy (XAS) was used to identify As sorption sites on 6L-ferrihydrite and goethite. As expected, the minerals have high potential to remove As and Cr from water (siderite = ferrihydrite (about 60 mg/g) > goethite (20 mg/g)). As and Cr sorption isotherms were modelled with a Langmuir model, and with a sigmoidal Hill model in the case of the competitive sorption. XAS measurements have revealed that As(III) was partially oxidized (up to 22%) in the competitive system with chromate oxyanion Cr(VI). As(III) sorbed on ferrihydrite and goethite adopted edge-sharing and corner sharing complex geometries. Nowadays, a new class of adsorbing phases is being developed for wastewater treatment, including engineered nanostructured materials and nanocomposites. The use of flow through reactor experiments as a high throughput method, combined with XAS, should be considered as efficient screening methods to test their sorbing properties on various contaminants.

Organotin speciation in Bizerte lagoon (Tunisia)

For the first time, organotins have been assessed in samples collected from Bizerte lagoon, in Tunisia, during two seasons (summer and winter). The organotin distribution was studied in marine sediments and mussels tissues of this lagoon. Butyl-, phenyl- and octyltins were determined using a rapid speciation analytical method based on one-step ethylation/extraction with sodium tetraethylborate in aqueous phase. Simultaneously to the ethylation, the extraction was performed by either liquid/liquid extraction (LLE) or head-space solid phase microextraction (HS-SPME). Gas chromatography with pulsed flame photometric detection (GC-PFPD) was used to perform quantitative determination. The technique has been validated using biological and sediment reference materials. The different samples from Bizerte lagoon were found to be moderately contaminated, especially by butyltins. This pollution was attributed to industrial activities, which are very important in this area. Organotins appeared accumulated in both sediments and mussels, while significant degradations of triorganotins to monosubstituted ones was observed in water.