An Amberlite IRA-400 Cl− ion-exchange resin modified with Prosopis juliflora seeds as an efficient Pb2+ adsorbent: adsorption,kinetics, thermodynamics,and computational modeling studies by density functional theory

A Prosopis juliflora-seed-modified Amberlite IRA-400 Cl⁻ ion-exchange resin (hereafter denoted as SMA resin) is used for the removal of Pb²⁺ from wastewater. SEM, EDX, FT-IR, BET, XRD, and XPS analyses were used to characterize the SMA resin. Parameters such as Pb²⁺ concentration, pH, temperature, and time are optimized. The obtained results show that the SMA resin has high efficiency for the removal of Pb²⁺ (73.45%) at a concentration of 100 mg L⁻¹ and a dosage of 0.01 g at pH 6. Thermodynamic studies indicate that the adsorption was spontaneous with negative ΔH° and ΔS° values at all temperatures; pseudo-second-order kinetics and the Langmuir adsorption isotherm provided the best fit (q_max = 106 mg g⁻¹ and R² = 0.99) from 298 to 338 K. In addition, a diffusion-controlled mechanism at 298 K was observed from intra-particle studies. A desorption and recovery process has been applied successfully to the SMA adsorbent. The obtained results showed desorption of 90.7% at pH 2.5 with 86.3% recovery over six cycles. Furthermore, the DFT results suggest that all the functional groups of the SMA resin possibly bind with Pb²⁺ and, of these, the –C O group shows the highest binding energy towards Pb²⁺. Moreover, the high-efficiency removal of Pb²⁺ from synthetic wastewater using the proposed SMA resin was demonstrated to show the real-life application potential.

We have demonstrated a high Pb²⁺ removal efficiency (73.45%) from wastewater using a Prosopis juliflora-seed-modified Amberlite IRA-400 Cl⁻ ion-exchange resin (SMA resin).     

Association of Blastocystis hominis with colorectal cancer: A systematic review of in vitro and in vivo evidences

BACKGROUNDRecently, there have been several findings that showed intestinal colonisation of Blastocystis hominis (Blastocystis) as a risk factor to the worsening of colorectal cancer (CRC). However, studies have shown controversial results in the pathogenicity of Blastocystis.AIMTo review systematically the evidence available on the association between CRC and Blastocystis and the prevalence of Blastocystis in CRC patients and to investigate cytopathic and immunological effects of Blastocystis in in vitro and in vivo studies.METHODSPRISMA guidelines were utilised in conducting this systematic review. Original articles published before February 2, 2020 were included. PubMed, Science Direct, Scopus and Google scholar databases were searched. Manual searching was carried out to find articles missed during the online search.RESULTSOut of 12 studies selected for this systematic review, seven studies confirmed the prevalence of Blastocystis and found it to be between 2%-28% in CRC patients, whereby subtype 1 and subtype 3 were predominantly seen. A total of four studies employing in vitro human colorectal carcinoma cell line study models showed significant cytopathic and immunological effects of Blastocystis. In addition, one in vivo experimental animal model study showed that there was a significant effect of infection with Blastocystis on exacerbation of colorectal carcinogenesis.CONCLUSION Blastocystis is a commonly identified microorganism in CRC patients. These studies have provided supportive data that Blastocystis could exacerbate existing CRC via alteration in host immune response and increased oxidative damage. Future studies of CRC and Blastocystis should attempt to determine the various stages of CRC that are most likely to be associated with Blastocystis and its relationship with other intestinal bacteria.     

Virtual screening of phenylsulfonamido-3-morpholinopropan-2-yl dihydrogen phosphate derivatives as novel inhibitors of MurC–MurF ligases from Mycobacterium leprae

Multi-drug resistance capacity for Mycobacterium leprae demands the profound need for developing new multi-targeted anti-leprosy drugs. Mur ligases (MurC, MurD, MurE, and MurF) involved in biosynthesis of bacterial cell wall peptidoglycan are the best known and validated targets for antibacterial therapy. Transition-state analogs, such as phosphonates, phosphinates, and sulfonamides have good inhibitory activity toward any one or two of these Mur ligases. With an objective of designing a better inhibitor targeting all of these four Mur ligases, we developed phenylsulfonamido-3-morpholinopropan-2-yl dihydrogen phosphate derivatives as multi-targeted small molecule inhibitors for Mur ligases and evaluated using virtual screening studies. The results suggested the 1-(3-acetyl phenyl sulfonamide)-3-morpholino propan-2-yl dihydrogen phosphate as a novel multiple inhibitor for M. leprae MurC–MurF ligases.     

Diphenyl furans and aza analogs: effects of structural modification on in vitro activity, DNA binding, and accumulation and distribution in trypanosomes

Human African trypanosomiasis is a devastating disease with only a few treatment options, including pentamidine. Diamidine compounds such as pentamidine, DB75, and DB820 are potent antitrypanosomal compounds. Previous investigations have shown that diamidines accumulate to high concentrations in trypanosomes. However, the mechanism of action of this class of compounds remains unknown. A long-hypothesized mechanism of action has been binding to DNA and interference with DNA-associated enzymes. The fluorescent diamidines, DB75 and DB820, have been shown to localize not only in the DNA-containing nucleus and kinetoplast of trypanosomes but also to the acidocalcisomes. Here we investigate two series of analogs of DB75 and DB820 with various levels of in vitro antitrypanosomal activity to determine whether any correlation exists between trypanosome accumulation, distribution, and in vitro activity. Despite wide ranges of in vitro antitrypanosomal activity, all of the compounds investigated accumulated to millimolar concentrations in trypanosomes over a period of 8 h. Interestingly, some of the less potent compounds accumulated to concentrations much higher than those of more potent compounds. All of the compounds were localized to the DNA-containing nucleus and/or kinetoplast, and many were also found in the acidocalcisomes. Accumulation in the nucleus and kinetoplast should be important to the mechanism of action of these compounds. The acidocalcisomes may also play a role in the mechanism of action of these compounds. This investigation suggests that the extent of accumulation alone is not responsible for killing trypanosomes and that organelle-specific accumulation may not predict in vitro activity.     

Functional genomics, gene arrays, and the future of pathology.

The human genome project has attracted a great deal of attention in recent years among the general public as well as the scientific community. Although it is likely to be a number of years before many of the expected benefits of the genomics revolution are realized, the impact of these scientific breakthroughs on diagnostic pathology is likely to become apparent relatively quickly. In particular, gene array technology, which allows gene expression measurements of thousands of genes in parallel, provides a powerful tool for pathologists seeking new markers for diagnosis. Several recent studies demonstrate how the gene array approach can not only recognize markers for known categories of neoplasia but also lead to recognition of different categories not previously appreciated. Although this approach shows great potential, the successful application of gene arrays to diagnostic problems will require thoughtful interpretation, just as immunochemical technologies require careful planning and analysis.     

Allelic loss of chromosomal arm 8p in breast cancer progression.

Loss of heterozygosity (LOH) of chromosomal arm 8p has been reported to occur at high frequency for a number of common forms of human cancer, including breast cancer. The objectives of this study were to define the regions on this chromosomal arm that are likely to contain breast cancer tumor suppressor genes and to determine when loss of chromosomal arm 8p occurs during breast cancer progression. For mapping the tumor suppressor gene loci, we evaluated 60 cases of infiltrating ductal cancer for allelic loss using 14 microsatellite markers mapped to this chromosomal arm and found LOH of 8p in 36 (60%) of the tumors. Whereas most of these tumors had allelic loss at all informative markers, five tumors had partial loss of 8p affecting two nonoverlapping regions. LOH for all but one of the tumors with 8p loss involved the region between markers D8S560 and D8S518 at 8p21.3-p23.3, suggesting that this is the locus of a breast cancer tumor suppressor gene. We then studied LOH of 8p in 38 cases of ductal carcinoma in situ (DCIS) with multiple individually microdissected tumor foci evaluated for each case. LOH of 8p was found in 14 of the DCIS cases (36%), including 6 of 16 cases of low histological grade and 8 of 22 cases of intermediate or high histological grade. In four of these DCIS cases, 8p LOH was seen in some but not all of the multiple tumor foci examined. These data suggest that during the evolution of these tumors, LOH of 8p occurred after loss of other chromosomal arms that were lost in all tumor foci. Thus, LOH of 8p, particularly 8p21.3-p23, is a common genetic alteration in infiltrating and in situ breast cancer. Although 8p LOH is common even in low histological grade DCIS, this allelic loss often appears to be preceded by loss of other alleles in the evolution of breast cancer.