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Beilstein Journal of Organic Chemistry 2020A convenient practical approach for the synthesis of 2-(pyridin-2-yl)ethanols by direct benzylic addition of azaarenes and aldehydes under catalyst- and solvent-free...
A convenient practical approach for the synthesis of 2-(pyridin-2-yl)ethanols by direct benzylic addition of azaarenes and aldehydes under catalyst- and solvent-free conditions is reported. This reaction is metal-free, green, and was carried out in a facile operative environment without using any hazardous transition metal catalysts or any other coupling reagents. Different aromatic aldehydes and azaarenes were monitored, and the yields of the resulting products were moderate to excellent. We accomplished several azaarene derivatives under neat conditions through a highly atom-economical pathway. To evaluate the preparative potential of this process, gram-scale reactions were performed up to a 10 g scale.
PubMed: 33425033
DOI: 10.3762/bjoc.16.259 -
Biochemistry and Molecular Biology... Jan 2008We have designed a laboratory curriculum using the green and red fluorescent proteins (GFP and RFP) to visualize the cloning, expression, chromatography purification,...
We have designed a laboratory curriculum using the green and red fluorescent proteins (GFP and RFP) to visualize the cloning, expression, chromatography purification, crystallization, and protease-cleavage experiments of protein science. The EGFP and DsRed monomer (mDsRed)-coding sequences were amplified by PCR and cloned into pMAL (MBP-EGFP) or pT7His (His(10) -mDsRed) prokaryotic expression vectors. Then the fluorescent proteins were expressed in Rosetta (DE3) pLysS by IPTG induction or autoinduction. We purified the fluorescent proteins by affinity chromatography (Amylose and metal ion-chelating column), anion-exchange chromatography (High Q column), size exclusive chromatography (Sephacryl S-200 column), and hydrophobic interaction chromatography (Methyl HIC column) to exhibit the protein-purification techniques. After purification, the fusion protein MBP-EGFP was cleaved by TEV protease. The recombinant mDsRed protein was crystallized by hanging drop vapor diffusion technique to show students the basic operation of crystallization. The whole procedure can be monitored real time by naked eyes when using fluorescent proteins. The demonstration of expression, purification, crystallization, and protease cleavage became much more vivid and interesting, which greatly deepened the students' understanding of modern protein-science techniques.
PubMed: 21591159
DOI: 10.1002/bmb.117 -
Journal of Indian Society of... 2016Apoptosis plays a critical role in the regulation of inflammation and host immune response. It helps in tissue homeostasis and a disturbance in this is often associated...
BACKGROUND
Apoptosis plays a critical role in the regulation of inflammation and host immune response. It helps in tissue homeostasis and a disturbance in this is often associated with disease. The use of histochemical stains like hematoxylin and eosin (H and E) and methyl green-pyronin (MGP) can provide a simple and cost-effective method for the detection of apoptotic cells.
AIM
Study intended to analyze the expression of apoptosis in the gingival epithelium of healthy subjects and in patients with chronic periodontitis, using H and E and MGP. It is also proposed to correlate the apoptotic index (AI) of healthy individuals and those with chronic periodontitis.
MATERIALS AND METHODS
Twenty gingival biopsies were harvested from which ten samples were of healthy subjects and ten subjects who suffered from chronic periodontitis. Apoptotic cells were analyzed using MGP and H and E under light microscopy.
RESULTS
Apoptotic cells were identified at ×100 magnification and AI was calculated. Apoptotic cells were easily distinguishable in MGP stained sections when compared to those stained using H and E. Moreover, apoptotic cell count was higher in chronic periodontitis. Statistical analyses were done by Tukey's multiple post hoc procedure.
CONCLUSION
The study reveals that MGP staining can be used in a routine basic laboratory set up as one of the cost-effective methods for the detection of apoptotic cells.
PubMed: 27563203
DOI: 10.4103/0972-124X.182601 -
ACS Omega Mar 2020A straightforward green synthesis of 4-methyl-1,2,5,6-tetraazafluoranthen-3(2)-one is reported from ninhydrin via condensation with ethyl acetoacetate, followed by...
A straightforward green synthesis of 4-methyl-1,2,5,6-tetraazafluoranthen-3(2)-one is reported from ninhydrin via condensation with ethyl acetoacetate, followed by cyclization with hydrazine hydrate in water as a benign solvent. Tetraazafluoranthen-3-thione was obtained using Lawesson's reagent. N-alkylated tetraazafluoranthen-3-one and S-alkylated analogues were synthesized via alkylation. The investigation of the unique reactivity of 4-methyl-1,2,5,6-tetraazafluoranthen-3(2)-one/thione toward the alkylation and aza-Michael additions was explored.
PubMed: 32201835
DOI: 10.1021/acsomega.0c00045 -
PloS One 2023Health workers' failure to adhere to guidelines for screening, diagnosis and management of HIV-associated cryptococcal meningitis (CM) remains a significant public...
INTRODUCTION
Health workers' failure to adhere to guidelines for screening, diagnosis and management of HIV-associated cryptococcal meningitis (CM) remains a significant public health concern. We aimed to assess adherence to the standards of care and management of HIV patients at risk of CM per the MoH guidelines and assess stock management of CM supplies in the period of January to June 2021 at selected public health facilities (HFs) in Uganda.
METHODS
The study employed an observational cross-sectional design to assess the level of adherence of health workers to standards of clinical care and management of HIV positive patients at risk of CM as per the clinical guidelines for Uganda, and stock management of CM supplies in the period of January to June 2021in selected public health facilities. The study team used a survey guide designed by MoH to assess and score the screening, diagnosis and management practices of Health Facilities towards CM. Scoring was categorized as red (< 80%), light green (80%-95%), and dark green (˃95%) in the order from worst to best adherence. The data was transcribed into a spread sheet and analysed using STATA-v15.
RESULTS
The study team visited a total of 15 public health facilities including 5 general hospitals, 9 regional referral hospitals (RRHs) and 1 National Referral hospital (NRH). The mean score for adherence to screening and management of CM for all the combined facilities was 15 (64.7%) classified as red. 10 (66.7%) HFs had not performed a baseline CD4 test for eligible patients within 2 weeks of ART initiation. With regards to treatment, 9 (60%) of the HFs were scored as light green on knowledge of the procedure for reconstituting intravenous Liposomal Amphotericin B. None of the HFs visited had potassium chloride tablets in stock.
CONCLUSION
Major MoH guidelines are generally not being adhered to by health workers while managing cryptococcal meningitis. It is vital that government and implementing partners regularly support HFs with training, mentorship, and support supervision on CM management to improve adherence to CM screening and treatment guidelines.
Topics: Humans; Meningitis, Cryptococcal; HIV Infections; Uganda; Cross-Sectional Studies; Methyl Green
PubMed: 37036886
DOI: 10.1371/journal.pone.0284165 -
Heliyon Jun 2020Natural and synthetic phenazines are widely used in biomedical sciences. In dehydrogenase histochemistry, phenazine methosulfate (PMS) is applied as a redox reagent for...
Natural and synthetic phenazines are widely used in biomedical sciences. In dehydrogenase histochemistry, phenazine methosulfate (PMS) is applied as a redox reagent for coupling reduced coenzymes to the reduction of tetrazolium salts into colored formazans. PMS is also currently used for cytotoxicity and viability assays of cell cultures using sulfonated tetrazoliums. Under UV (340 nm) excitation, aqueous solutions of the cationic PMS show green fluorescence (λem: 526 nm), whereas the reduced hydrophobic derivative (methyl-phenazine, MPH) shows blue fluorescence (λem: 465 nm). Under UV (365 nm) excitation, cultured cells (LM2, IGROV-1, BGC-1, and 3T3-L1 adipocytes) treated with PMS (5 μg/mL, 30 min) showed cytoplasmic granules with bright blue fluorescence, which correspond to lipid droplets labeled by the lipophilic methyl-phenazine. After formaldehyde fixation blue-fluorescing droplets could be stained with oil red O. Interestingly, PMS-treated 3T3-L1 adipocytes observed under UV excitation 24 h after labeling showed large lipid droplets with a weak green emission within a diffuse pale blue-fluorescing cytoplasm, whereas a strong green emission was observed in small lipid droplets. This fluorescence change from blue to green indicates that reoxidation of methyl-phenazine to PMS can occur. Regarding cell uptake and labeling mechanisms, QSAR models predict that the hydrophilic PMS is not significantly membrane-permeant, so most PMS reduction is expected to be extracellular and associated with a plasma membrane NAD(P)H reductase. Once formed, the lipophilic and blue-fluorescing methyl-phenazine enters live cells and mainly accumulates in lipid droplets. Overall, the results reported here indicate that PMS is an excellent fluorescent probe to investigate labeling and redox dynamics of lipid droplets in cultured cells.
PubMed: 32566788
DOI: 10.1016/j.heliyon.2020.e04182 -
Polymers Dec 2023Targeted drug delivery to visceral organs offers the possibility of not only limiting the required dose, but also minimizing drug toxicity; however, there is no reliable...
Targeted drug delivery to visceral organs offers the possibility of not only limiting the required dose, but also minimizing drug toxicity; however, there is no reliable method for delivering drugs to the surface of visceral organs. Here, we used six color tracers and the chick chorioallantoic membrane (CAM) model to investigate the use of the heteropolysaccharide pectin to facilitate tracer diffusion across the glycocalyceal charge barrier. The color tracers included brilliant blue, Congo red, crystal violet, indocyanine green, methylene blue, and methyl green. The direct application of the tracers to the CAM surface or embedding tracers into linear-chain nanocellulose fiber films resulted in no significant diffusion into the CAM. In contrast, when the tracers were actively loaded into branched-chain pectin films, there was significant detectable diffusion of the tracers into the CAM. The facilitated diffusion was observed in the three cationic tracers but was limited in the three anionic tracers. Diffusion appeared to be dependent on ionic charge, but independent of tracer size or molecular mass. We conclude that dye-loaded pectin films facilitated the diffusion of color tracers across the glycocalyceal charge barrier and may provide a therapeutic path for drug delivery to the surface of visceral organs.
PubMed: 38201668
DOI: 10.3390/polym16010004 -
ZooKeys 2022A new spionid polychaete, , was discovered in the fine sandy sediments of an intertidal habitat from Korean waters. The new species is considered a simultaneous...
A new spionid polychaete, , was discovered in the fine sandy sediments of an intertidal habitat from Korean waters. The new species is considered a simultaneous hermaphrodite, but no brooding embryos were found in any of the specimens collected in this study. This species is unique in the absence of ciliation in the anteriormost chaetigers. is morphologically most similar to Imajima, 1991 from Japan in having an elevation on the prostomium, conspicuously large and foliaceous branchiae, and intersegmental lateral pouches. However, the new species differs from the latter by the following characteristics: (1) large and lanceolate notopodial postchaetal lamellae of chaetiger 1, (2) transverse ciliated bands and ciliation on the inner branchiae absent in anteriormost chaetigers, and (3) pygidium with one pair of ventral cirri and numerous elongated dorsolateral cirri. Detailed description and illustrations of the new species are provided with molecular information on mitochondrial cytochrome c oxidase subunit I (COI), 16S ribosomal DNA (rDNA), nuclear 18S rDNA, and 28S rDNA.
PubMed: 36760395
DOI: 10.3897/zookeys.1100.80077 -
Toxics Oct 2021species-based extracts were used to carry out the synthesis of homogeneous gold nanoparticles. Various techniques were used to determine the characteristics and...
species-based extracts were used to carry out the synthesis of homogeneous gold nanoparticles. Various techniques were used to determine the characteristics and composition of the nanoparticles. The UV-Vis results showed that the 50% water/ethanol extract had the most reducing agents and stabilizers. Therefore, this type of extract was used to synthesize nanoparticles and for their subsequent characterization. Crystallinity and crystal size were evaluated using X-ray diffraction. Size and morphology were analyzed using scanning electron microscopy, showing that the gold nanoparticles were mostly spherical, with a size range of 15-30 nm. The catalytic activity of the gold nanoparticles was evaluated through the degradation of organic dyes: methylene blue, methyl orange, and methyl red. The degradation rates were different, depending on the nature of each dye, the simplest to degrade was methylene blue and methyl red was the most difficult to degrade. The results indicated that the use of spp. for the synthesis of gold nanoparticles has potential in the remediation of water that is contaminated with organic dyes. Moreover, given the recent serious environmental and economic problems caused by the overpopulation of spp. in the Mexican Caribbean, the findings hold promise for their practical and sustainable use in the synthesis of nanomaterials.
PubMed: 34822671
DOI: 10.3390/toxics9110280 -
Biomolecular Detection and... Dec 2018Detection of genomic alterations in diseases can be achieved with current molecular technologies. However, the molecules extracted from formalin-fixed, paraffin-embedded...
OBJECTIVES
Detection of genomic alterations in diseases can be achieved with current molecular technologies. However, the molecules extracted from formalin-fixed, paraffin-embedded (FFPE) bio-samples are often limited possibly due to DNA fragmentation and crosslinking caused by the sample fixation and processing. The study objective was to design a droplet digital PCR (ddPCR) assay to assess the quality and quantity of DNA derived from various DNA extraction conditions on FFPE samples.
METHODS
We used 10 μm-thick sections from 5 FFPE oral tumoral blocks, each consisting of 10-15 sections. The protocol variables tested included: 1) tissue staining; 2) duration and 3) temperature of post-digestion heat treatment; and 4) DNA extraction method. DNA quantity was assessed using the NanoDrop 2000 (Thermo Fisher Scientific, USA), the Qubit fluorometer (Thermo Fisher Scientific, USA), and a ddPCR-based assay. DNA quality was assessed using a ddPCR assay for the degree of fragmentation and the effectiveness of removing crosslinks with varying guanine-cytosine (GC)-content.
RESULTS
Deparaffinization with xylene helped to increase the DNA yield. Tissue staining (methyl green staining, pH 6) prior to microdissection, comparing to no staining, caused additional DNA fragmentation. Compared to column-based method, DNA extracted with phenol chloroform and ethanol precipitation increased the degree of fragmentation and lowered the yield of amplifiable DNA. The cross-linking derived from GC-contents may not be the only factor impacting on the DNA quality.
CONCLUSIONS
Samples undergoing different pre-treatment conditions prior to extraction can impact the yield of amplifiable DNA. Our ddPCR assay can be used to assess for both DNA quantity and quality.
PubMed: 30560062
DOI: 10.1016/j.bdq.2018.10.001