DTI of the Olfactory Bulb in COVID-19-Related Anosmia: A Pilot Study

This study aimed to assess the utility of DTI in the detection of olfactory bulb dysfunction in COVID-19-related anosmia. It was performed in 62 patients with COVID-19-related anosmia and 23 controls. The mean diffusivity and fractional anisotropy were calculated by 2 readers. The difference between the fractional anisotropy and mean diffusivity values of anosmic and control olfactory bulbs was statistically significant (P = .001). The threshold of fractional anisotropy and mean diffusivity to differentiate a diseased from normal olfactory bulb were 0.22 and 1.5, with sensitivities of 84.4% and 96.8%, respectively, and a specificity of 100%.

Multitarget in silico studies of Ocimum menthiifolium, family Lamiaceae against SARS-CoV-2 supported by molecular dynamics simulation

The novel strain of human coronavirus, emerged in December 2019, which has been designated as SARS-CoV-2, causes a severe acute respiratory syndrome. Since then, it has arisen as a serious threat to the world public health. Since no approved vaccines or drugs has been found to efficiently stop the virulent spread of the virus, progressive inquiries targeting these viruses are urgently needed, especially those from plant sources. Metabolic profiling using LC-HR-ESI-MS of the butanol extract of Ocimum menthiifolium (Lamiaceae) aerial parts yielded 10 compounds including flavonoids, iridoids and phenolics. As it has been previously reported that some flavonoids can be used as anti-SARS drugs by targeting SARS-CoV-1 3CLpro, we chose to examine 14 flavonoids (detected by metabolomics and other compounds isolated via several chromatographic techniques). We investigated their potential binding interactions with the 4 main SARS-CoV-2 targets: Mpro, nsp16/nsp10 complex, ACE2-PD and RBD-S-protein via molecular docking. Docking results indicated that the nsp16/nsp10 complex has the best binding affinities where the strongest binding was detected with apigenin-7-O-rutinoside, prunin and acaciin with -9.4, -9.3 and -9.3 kcal/mol binding energy, respectively, compared to the control (SAM) with -8.2 kcal/mol. Furthermore, the stability of these complexes was studied using molecular dynamics of 150 ns, which were then compared to their complexes in the other three targets. MM-PBSA calculations suggested the high stability of acaciin-nsp16 complex with binding energy of -110 kJ/mol. This study sheds light on the structure-based design of natural flavonoids as anti-SARS-CoV-2 drugs targeting the nsp16/10 complex.Communicated by Ramaswamy H. Sarma.

Non-ulcerogenic pyrazolyl 2-hydroxychalcones and pyrazolylpyrazolines derived from naturally existing furochromone (khellin): semi-synthesis, docking study and anti-inflammatory activity

Novel pyrazolyl 2-hydroxychalcone derivatives 3a-e and pyrazolylpyrazoline derivatives 4a-e and 5a-j derived from the naturally existing furochromone (Khellin) were synthesized and evaluated for their in vivo anti-inflammatory activity. Most of the synthesized compounds showed better or comparable activity to that of Diclofenac as reference drug. Twelve compounds were evaluated for their ulcerogenic potential and exhibited no ulcerogenic effect. In addition compounds 3c, 5c and 5h as examples showed PGE₂ inhibition % 88.86, 65.87 and 44.06, respectively and TNFα inhibition % 48.62, 31.11 and 16.02, respectively in rat serum samples. Compounds 3c, 5c, 5h and Celecoxib were subjected to in vitro COX-1 and COX-2 inhibition assay, showed selectivity index 45.04, 102.04, 131.58 and 185.18, respectively. The computational finding supported those of in vitro, where the pyrazolylpyrazolines interacted with the COX-2 enzyme in a similar orientation to that of Celecoxib, while chlacones were found to exhibit similar orientation to that of Diclofenac.

Chemical and biological studies on the soft coral Nephthea sp

Soft corals belonging to the family Nephtheidae have been appreciated as marine sources of diverse metabolites with promising anticancer potential. In view of that, the current work investigates the anti-proliferative potential of the crude extract, different fractions, and green synthesized silver nanoparticles (AgNPs) of the Red Sea soft coral, Nephthea sp. against a panel of tumor cell lines. The metabolic pool of the soft coral under study was also explored via an LC-HR-ESI-MS metabolomics approach, followed by molecular docking analysis of the characterized metabolites against the target proteins, EGFR, VEGFR, and HER2 (erbB2) that are known to be involved in cancer cell proliferation, growth, and survival. Overall, the n-butanol fraction of Nephthea sp. exhibited the highest inhibitory activities against MCF7 (breast cancer) and A549 (lung cancer) cell lines, with interesting IC₅₀ values of 2.30 ± 0.07 and 3.12 ± 0.10 μg ml⁻¹, respectively, whereas the maximum growth inhibition of HL60 (leukemia) cells was recorded by the total extract (IC₅₀ = 2.78 ± 0.09 μg ml⁻¹). More interestingly, the anti-proliferative potential of the total soft coral extract was evidently improved when packaged in the form of biogenic AgNPs, particularly against A549 and MCF7 tumor cells, showing IC₅₀ values of 0.72 ± 0.06 and 9.32 ± 0.57 μg ml⁻¹, respectively. On the other hand, metabolic profiling of Nephthea sp. resulted in the annotation of structurally diverse terpenoids, some of which displayed considerable binding affinities and molecular interactions with the studied target proteins, suggesting their possible contribution to the anti-proliferative properties of Nephthea sp. via inhibition of tyrosine kinases, especially the EGFR type. Taken together, the present findings highlighted the relevance of Nephthea sp. to future anticancer drug discovery and provided a base for further work on the green synthesis of a range of bioactive NPs from marine soft corals.

The cytotoxic potential of the crude extract, different fractions, and green synthesized nanoparticles of the soft coral Nephthea sp. was studied, supported by LC-HR-ESI-MS metabolomics analysis and molecular docking of the dereplicated compounds.

A multi-stage virtual screening of FDA-approved drugs reveals potential inhibitors of SARS-CoV-2 main protease

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an ongoing global health emergency. Repurposing of approved pharmaceutical drugs for COVID-19 treatment represents an attractive approach to quickly identify promising drug candidates. SARS-CoV-2 main protease (M^pro) is responsible for the maturation of viral functional proteins making it a key antiviral target. Based on the recently revealed crystal structures of SARS-CoV-2 M^pro, we herein describe a multi-stage virtual screening protocol including pharmacophore screening, molecular docking and protein-ligand interaction fingerprints (PLIF) post-docking filtration for efficient enrichment of potent SARS-CoV-2 M^pro inhibitors. Potential hits, along with a cocrystallized control were further studied via molecular dynamics. A 150-ns production trajectory was followed by RMSD, free energy calculation, and H-bond analysis for each compound. The applied virtual screening protocol led to identification of five FDA-approved drugs with promising binding modes to key subsites of the substrate-binding pocket of SARS-CoV-2 M^pro. The identified compounds belong to different pharmaceutical classes, including several protease inhibitors, antineoplastic agents and a natural flavonoid. The drug candidates discovered in this study present a potential extension of the recently reported SARS-CoV-2 M^pro inhibitors that have been identified using other virtual screening protocols and may be repurposed for COVID-19 treatment.

Anti-epileptic potential, metabolic profiling and in silico studies of the aqueous fraction from Ocimum menthiifolium benth, family Lamiaceae

The current study aimed to investigate the anti-epileptic potential of the ethanol extract and its different fractions from the Lamiaceous plant, Ocimum menthiifolium. The results revealed that the aqueous fraction with the latest onset of myoclonic convulsions (1095 ± 45**** s) was the most biologically active one. This was followed by LC-HR-MS-coupled metabolic profiling which led to dereplication of 8 compounds from that fraction. A molecular docking study was performed on the dereplicated compounds to discover the main responsible ones for the activity. The results highlighted Apigenin-7,4'-di-O-glucoside as the top scoring ligand with a possible mechanism of action involving the modulation of the voltage-gated sodium channel.

Brain-targeting by optimized 99mTc-olanzapine: in vivo and in silico studies

Purpose: Olanzapine (OLZ) is an atypical antipsychotic agent that is characterized by low brain porousness. The present work aimed to develop radiolabeled olanzapine (OLZ) without colloidal impurities and evaluate its biodistribution following intravenous (I.V.) and intranasal (I.N.) administration as a potential agent for brain diagnosis. Materials and methods: OLZ was radiolabeled with technetium-99m by using sodium dithionite as the reducing agent. Biodistribution of ^99mTc-OLZ complex in mice following I.V. and I.N. administrations was examined. Furthermore, a molecular docking study was performed.Results: Sodium dithionite labeling procedure resulted in highest radiochemical yield (96.30 ± 0.09%) and in vitro stability in serum up to 8 h. Biodistribution study of ^99mTc-OLZ complex showed high brain uptake following I.N. (6.2 ± 0.12% ID/g) and I.V. (5.5 ± 0.09% ID/g) at 0.5 and 1 h post administration (P.I.), respectively. Docking into two brain targets predicts higher affinity of ^99mTc-OLZ than free OLZ. Additionally, docking to P-glycoproteins shows less affinity for the radiolabelled OLZ and hence it is expected to be associated with better brain exposure than free OLZ.Conclusion: These chemical and preliminary biological merits strongly suggest that the ^99mTc-OLZ complex with new reducing agent could be used as a potential diagnostic agent for brain.

Local anaesthetic potential, metabolic profiling, molecular docking and in silico ADME studies of Ocimum forskolei, family Lamiaceae

The present study aimed to detect the bioactive metabolites from Ocimum forskolei aerial parts which are responsible for the local anaesthetic activity of the ethyl acetate fraction. Following a bioassay-guided fractionation, twelve compounds were dereplicated from the ethyl acetate fraction which was the most potent one with a mean onset of action (1.43 ± 0.07****) min compared to tetracaine as a positive control (1.37 ± 0.07****) min. These compounds, along with seven other compounds (isolated by diverse chromatographic techniques) were subjected to a molecular docking study to declare the top scoring compounds predicted to be responsible for such activity. The results highlighted Rabdosiin and Apigenin-7-O-rutinoside as the main bioactive leaders of the local anaesthesia via forming multiple H- bonding with the sodium ion channels leading to their blockade and loss of pain sensation, which strongly supports the use of O. forskolei as a local anaesthetic agent.

Anti-Alzheimer potential, metabolomic profiling and molecular docking of green synthesized silver nanoparticles of Lampranthus coccineus and Malephora lutea aqueous extracts

The green synthesis of silver nanoparticles (SNPs) using plant extracts is an eco-friendly method. It is a single step and offers several advantages such as time reducing, cost-effective and environmental non-toxic. Silver nanoparticles are a type of Noble metal nanoparticles and it has tremendous applications in the field of diagnostics, therapeutics, antimicrobial activity, anticancer and neurodegenerative diseases. In the present work, the aqueous extracts of aerial parts of Lampranthus coccineus and Malephora lutea F. Aizoaceae were successfully used for the synthesis of silver nanoparticles. The formation of silver nanoparticles was early detected by a color change from pale yellow to reddish-brown color and was further confirmed by transmission electron microscope (TEM), UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and energy-dispersive X-ray diffraction (EDX). The TEM analysis of showed spherical nanoparticles with a mean size between 12.86 nm and 28.19 nm and the UV- visible spectroscopy showed λmax of 417 nm, which confirms the presence of nanoparticles. The neuroprotective potential of SNPs was evaluated by assessing the antioxidant and cholinesterase inhibitory activity. Metabolomic profiling was performed on methanolic extracts of L. coccineus and M. lutea and resulted in the identification of 12 compounds, then docking was performed to investigate the possible interaction between the identified compounds and human acetylcholinesterase, butyrylcholinesterase, and glutathione transferase receptor, which are associated with the progress of Alzheimer's disease. Overall our SNPs highlighted its promising potential in terms of anticholinesterase and antioxidant activity as plant-based anti-Alzheimer drug and against oxidative stress.

Antiulcer potential and molecular docking of flavonoids from Ocimum forskolei Benth., family Lamiaceae

The present study aimed to detect the bioactive metabolites from Ocimum forskolei aerial parts which are responsible for the antiulcer activity of the total ethanol extract (TEE) as well as different fractions (petroleum ether, dichloromethane, ethyl acetate and aqueous). Six flavonoids were isolated from the dichloromethane fraction which was the most potent; with an ulcer index value of 2.67 ± 2.18*** and % inhibition of ulcer of 97.7%; following a bioassay-guided fractionation. The isolated flavonoids were subjected to molecular docking analysis in an attempt to explain their significant antiulcer potential, and the results revealed that salvitin followed by sideritiflavone were the main active ones acting against M3 and H-2 receptors, respectively. Moreover, a molecular dynamics simulation illustrated the formation of two persistent H-bonds between salvitin and the two amino acids of the active site (Asn507 and Asp147) formed in 42 and 65% of the frames, respectively.

New pyrazole derivatives: Synthesis, anti-inflammatory activity, cycloxygenase inhibition assay and evaluation of mPGES

New pyrazole derivatives 2-5 were synthesized and evaluated for their COX-1 and COX-2 inhibitory activity in vitro. All compounds showed good inhibitory activity at a nanomolar level and most compounds exhibited selectivity towards COX-2 inhibition. Compounds 2a, 3b, 4a, 5b and 5e exhibited IC₅₀ towards COX-2 enzyme of 19.87, 39.43, 61.24, 38.73 and 39.14 nM, respectively. Furthermore, compounds 3b, 4a, 5b and 5e exhibited a selectivity index of 22.21, 14.35, 17.47 and 13.10, respectively. The most active compounds were further subjected to in vivo anti-inflammatory assay. The tested compounds showed better or comparable activity to celecoxib as positive control. In order to explore their binding mode and selectivity behaviour, molecular docking in the active site of COX-2 was carried out for these derivatives. Analysis of the docked poses of the compounds showed that they adopt similar conformations to the highly selective COX-2 inhibitor, SC-558. The docking pose of compound 3b was confirmed by molecular dynamics. All the tested compounds exhibited potent inhibitory effect on the production of PGE₂, in addition to their inhibition of COX-2 enzyme.

A Tandem Green-Red Heterodimeric Fluorescent Protein with High FRET Efficiency

The tetrameric red fluorescent protein from Discosoma sp. coral (DsRed) has previously been engineered to produce dimeric and monomeric fluorescent variants with excitation and emission profiles that span the visible spectrum. The brightest of the effectively monomeric DsRed variants is tdTomato-a tandem fusion of a dimeric DsRed variant. Here we describe the engineering of brighter red (RRvT), green (GGvT), and green-red heterodimeric (GRvT) tdTomato variants. GRvT exhibited 99 % intramolecular FRET efficiency, resulting in long Stokes shift red fluorescence. These new variants could prove useful for multicolor live-cell imaging applications.

Prediction of two-photon absorption enhancement in red fluorescent protein chromophores made from non-canonical amino acids

Two-photon spectroscopy of fluorescent proteins is a powerful bio-imaging tool known for deep tissue penetration and little cellular damage. Being less sensitive than the one-photon microscopy alternatives, a protein with a large two-photon absorption (TPA) cross-section is needed. Here, we use time-dependent density functional theory (TD-DFT) at the B3LYP and CAM-B3LYP/6-31+G(d,p) levels of theory to screen twenty-two possible chromophores that can be formed upon replacing the amino-acid Tyr66 that forms the red fluorescent protein (RFP) chromophore with a non-canonical amino acid. The two-level model for TPA was used to assess the properties (i.e., transition dipole moment, permanent dipole moment difference, and the angle between them) leading to the TPA cross-sections determined via response theory. Computing TPA cross-sections with B3LYP and CAM-B3LYP yields similar overall trends. Results using both functionals agree that the RFP-derived model of the Gold Fluorescent Protein chromophore (Model 20) has the largest intrinsic TPA cross-section at the optimized geometry. TPA was further computed for selected chromophores following conformational changes: variation of both the dihedral angle of the acylimine moiety and the tilt and twist angles between the rings of the chromophore. The TPA cross-section assumed an oscillatory trend with the rotation of the acylimine dihedral, and the TPA is maximized in the planar conformation for almost all models. Model 21 (a hydroxyquinoline derivative) is shown to be comparable to Model 20 in terms of TPA cross-section. The conformational study on Model 21 shows that the acylimine angle has a much stronger effect on the TPA than its tilt and twist angles. Having an intrinsic TPA ability that is more than 7 times that of the native RFP chromophore, Models 20 and 21 appear to be very promising for future experimental investigation.

Two-photon absorption of fluorescent protein chromophores incorporating non-canonical amino acids: TD-DFT screening and classical dynamics

Two-photon spectroscopy of fluorescent proteins is a powerful bio-imaging tool characterized by deep tissue penetration and little damage. However, two-photon spectroscopy has lower sensitivity than one-photon microscopy alternatives and hence a protein with a large two-photon absorption cross-section is needed. We use time-dependent density functional theory (TD-DFT) at the B3LYP/6-31+G(d,p) level of theory to screen twenty-two possible chromophores that can be formed upon replacing the amino-acid Tyr66 that forms the green fluorescent protein (GFP) chromophore with a non-canonical amino acid. A proposed chromophore with a nitro substituent was found to have a large two-photon absorption cross-section (29 GM) compared to other fluorescent protein chromophores as determined at the same level of theory. Classical molecular dynamics are then performed on a nitro-modified fluorescent protein to test its stability and study the effect of the conformational flexibility of the chromophore on its two-photon absorption cross-section. The theoretical results show that the large cross-section is primarily due to the difference between the permanent dipole moments of the excited and ground states of the nitro-modified chromophore. This large difference is maintained through the various conformations assumed by the chromophore in the protein cavity. The nitro-derived protein appears to be very promising as a two-photon absorption probe.

Design, synthesis, characterization, quantum-chemical calculations and anti-inflammatory activity of novel series of thiophene derivatives

Interaction of 1-(4-morpholinophenyl)ethanone 1 with either malononitrile or ethyl cyanoacetate 2 afforded Knoevenagel-Cope product 3. In subsequent treatment of 3 with sulfur, the 2-aminothiophene derivatives (4a, 4b) are formed under basic conditions. The solvent-free reaction of thiophene derivative 4a with ethyl cyanoacetate afforded thieno[2,3-d][1,3]oxazine derivative 6. The base catalyzed condensation of 2-aminothiophene derivative (4a) with ethyl cyanoacetate afforded N-(thieno-2-yl) cyanoacetamide derivative 7. The latter was used to synthesize different heterocyclic derivatives comprising, pyridine and coumarin rings. Also, several substituted thieno[2,3-d]pyrimidines have been prepared from reaction of 2-aminothiophene-3-carbonitrile 4b with some electrophilic reagents. The structure of the newly compounds were confirmed on the basis of elemental analysis and spectral data. The molecular modeling of the synthesized compounds has been drawn and their molecular parameters were calculated. Also, valuable information is obtained from calculation of the molecular parameters including electronegativity, net dipole moment of the compounds, total energy, electronic energy, binding energy, HOMO and LUMO energy. Evaluation of anti-inflammatory activity of the tested compounds was performed in albino rats by producing carrageenan induced paw oedema and measuring the zone of inflammation at different time intervals i.e. 1, 2, 3 and 4h after carrageenan injection. Results indicated that most of the tested compounds showed moderate to good activity comparable to indomethacin. Also, compound 16 with additional morpholine ring beside the thiophene ring inhibits carrageenan induced paw oedema more than the standard indomethacin drug at all the time scales studied. Thus, compound 16 is considered as a promising compound for further modification to obtain clinically useful anti-inflammatory agent.

Synthesis, biological evaluation and molecular modeling of novel series of pyridine derivatives as anticancer, anti-inflammatory and analgesic agents

This paper presents a combined synthesis; characterization, computational and biological activity studies of novel series of pyridines heterocyclic compounds. The compounds have been characterized by elemental analyses and spectral like IR, (1)H NMR, (13)C NMR and MS studies. Michael addition of substituted-2-methoxycarbonylacetanilide 2a,b on the α-substituted cinnamonitriles 3a-d gave the corresponding 2-pyridone derivatives 5-10. Structures of the titled compounds cited in this article were elucidated by spectrometric data (IR, (1)H NMR, (13)C NMR and MS). The molecular modeling of the synthesized compounds has been drawn and their molecular parameters were calculated. Also, valuable information is obtained from the calculation of molecular parameters including electronegativity, net dipole moment of the compounds, total energy, electronic energy, binding energy, HOMO and LUMO energy. Various in vitro antitumor as well as in vivo anti-inflammatory and analgesic activities of the synthesized compounds were investigated. Evaluation of anti-inflammatory activity of test compounds was performed using carrageenan induced paw edema in rats. All the tested compounds showed moderate to good activity. The SAR results indicate that all compounds showed moderate to good activity, among these 7 and 10 compounds having -N(CH3)2 group are most effective.

Two-Photon Absorption in Fluorescent Protein Chromophores: TDDFT and CC2 Results

Two-photon spectroscopy of fluorescent proteins is a powerful bioimaging tool. Considerable effort has been made to measure absolute two-photon absorption (TPA) for the available fluorescent proteins. Being a technically involved procedure, there is significant variation in the published experimental measurements even for the same protein. In this work, we present a time-dependent density functional theory (TDDFT) study on isolated chromophores comparing the ability of four functionals (PBE0, B3LYP, CAM-B3LYP, and LC-BLYP) combined with the 6-31+G(d,p) basis set to reproduce averaged experimental TPA energies and cross sections. The TDDFT energies and TPA cross sections are also compared to corresponding CC2/6-31+G(d,p) results for excitation to S1 for the five smallest chromophores. In general, the computed TPA energies are less functional dependent than the TPA cross sections. The variation between functionals is more pronounced when higher-energy transitions are studied. Changes to the conformation of a chromophore are shown to change the TPA cross-section considerably. This adds to the difficulty of comparing an isolated chromophore to the one embedded in the protein environment. All functionals considered give moderate agreement with the corresponding CC2 results; in general, the TPA cross sections determined by TDDFT are 1.5-10 times smaller than the corresponding CC2 values for excitation to S1. LC-BLYP and CAM-B3LYP give erroneously large TPA cross sections in the higher-energy regions. On the other hand, B3LYP and PBE0 yield values that are of the same order of magnitude and in some cases very close to the averaged experimental data. Thus, based on the results reported here, B3LYP and PBE0 are the preferred functionals for screening chromphores for TPA. However, at best, TDDFT can be used to semiquantitatively scan chromophores for potential TPA probes and highlight spectroscopic peaks that could be present in the mature protein.

Fibre analysis in 3D materials and process validation on artificial data

The physical properties of fibrous materials are closely linked to their microstructure. In order to characterize their microstructures as effectively as possible, all fibres in a sample should be individualized. This work mainly aims at developing a new fibre analysis method that segments a 3D greyscale tomography image into a background and a set of connected components, each representing a single fibre. Properly completed fibre analyses may provide input data for generative or synthetic models, which can in turn be used to estimate various characteristics of the material. In this paper, we introduce an original method based on the skeletonization of the fibre mass, followed by a geometrical analysis of the obtained skeleton. Based on this procedure, several measurements can be computed (e.g. length, orientation, number of contacts). Furthermore, we validate the reliability of our fibre analysis process using various comparisons between our results and artificial ground-truth data.

Outcome of young age at diagnosis of breast cancer in South Egypt

BACKGROUND

Incidence of breast cancer in patients <40 years old accounts for 20% of the total breast cancer patients in Egypt which is quite higher than the incidence reported worldwide. This study was conducted to evaluate the differences in survival between age groups below and above the age of 40.

METHOD

170 patients <40 years and 500 patients ≥40 years were evaluated retrospectively to assess the differences in disease free survival (DFS) and overall survival (OS) between age groups after adjustment of other risk factors like stage, lymph node status, tumor size, and hormonal positivity.

RESULTS

After median follow up of 49 months, there was no significant difference between the 2 age groups with regards to DFS p= 0.6 and OS P=0.7 and there was no significant difference between the 2 groups when we stratified the patients according to stages, hormonal status and number of metastatic lymph nodes. However, we found significant increase in local recurrence after breast conserving surgery in patients <40 years compared to patients ≥40 years.

CONCLUSION

Patients <40 years exhibited more often at advanced stage and large tumors size compared to patients ≥ 40 years; However, there was no significant difference in DFS and OS when we adjusted other risk factors. Furthermore, our analysis revealed that age <40 years can be considered as an adverse prognostic factor for the locoregional failure after breast conserving surgery.

KEYWORDS

breast cancer, young age, <40 years old, locoregional failure, DFS.

Synthesis and biological evaluation of some novel thiazole compounds as potential anti-inflammatory agents

In the present investigation, furo[2,3-d]thiazol-5(2H)-one 5 was obtained from reaction of thiosemicarbazone derivative 2 with diethyl acetylene dicarboxylate. A series of newly synthesized 2-(hydrazinyl)thiazol-4(5H)-one 6, 7 &8 and 2-(4-(substituted)-thiazol-2-yl)hydrazono derivatives 9a, b &10 were synthesized from treatment of thiosemicarbazone derivative 2 with appropriate α-halogenated compounds. Also, a one pot synthesis of thiazole derivatives 13 &15 was achieved from three components reaction of hydrazone derivative 11 with phenyl isothiocyanate and α-halogenated compounds catalyzed by DMF/KOH. 4-(4-Morpholino phenyl) thiazol-2-amino 17 was obtained via the reaction of acetophenone derivative 1 with thiourea in presence of iodine. The reactivity of 2-aminothiazole 17 toward some electrophilic reagents was investigated. The structure of the newly compounds was confirmed on the basis of elemental analysis and spectral data. The antibacterial activity towards two Gram negative (Proteus mirabilis &Serratia marcesens) and two Gram positive (Staphylococcus aureus &Bacillus cereus) bacteria was investigated. The anti-inflammatory activity was also investigated and the inhibition of the carrageenin-induced oedema by these compounds was established.

Analysis of 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-(3-iodo-E-allyl)nortropane in rat plasma. II. Pharmacokinetic profile in male and female Sprague-Dawley rats evaluated by capillary electrophoresis

This paper describes a pharmacokinetic study performed in Sprague-Dawley rats after i.v. administration of a single 6-mg/kg dose of 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-(3-iodo-E-allyl)nortropane (Altropane). Plasma samples were collected from the retro-orbital sinus at times up to 3 h after drug administration, extracted by solid-phase extraction, and the drug levels determined by capillary electrophoresis (CE). Pharmacokinetic parameters were determined by a standard noncompartmental model using WinNonlin version 1.5. The maximum plasma concentrations, clearances of the drug, and areas under the curve for male and female rats were 5.74 and 7.26 microg/ml, 135.7 and 98.5 ml/kg x min, and 44.23 and 60.92 microg x min/ml, respectively. The drug was cleared very rapidly from the systemic circulation, with a terminal t(1/2) of 7 to 10 min and a mean residence time of about 11 min for both sexes. The volume of distribution was approximately 1 l/kg. No metabolites were detected when the samples were analyzed individually. However, after samples were pooled and concentrated, traces of two unknown peaks that may represent metabolites were detected in concentrates from the last two timepoints. Part I of this work [J. Chromatogr. A, 895 (2000) 87] describes validation of CE methods for the analysis of aqueous and plasma samples of Altropane, including its solid-phase extraction from rat plasma.

Analysis of 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-(3-iodo-E-allyl)nortropane in rat plasma. I. Method development and validation by capillary electrophoresis

Altropane, 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-(3-iodo-E-allyl)nor tropane, is an imaging agent that was developed recently for early detection of Parkinson's disease. Its promise as a useful radiopharmaceutical for single-photon emission computed tomography or positron emission tomography imaging of the brain has been well demonstrated, and it is currently undergoing clinical trials. This paper presents methods development and validation of capillary electrophoresis (CE) techniques to analyze Altropane in aqueous environments as well as in rat plasma, using an internal standard, nicotinamide. N-Allylaltropane, 2beta-carbomethoxy-3beta-(4-fluorophenyl)-N-allylnortropane, which is a known degradation product of the Altropane precursor (tributyltinaltropane), was used to verify the method's specificity. A solid-phase extraction method for extraction of Altropane from rat plasma is also described. The results presented in this paper demonstrate the applicability of CE methods to study the pharmacokinetic properties of Altropane in animal models. The results of the pharmacokinetic study will be published later, as Part II.

3-nitropropionic acid oxidase from horseshoe vetch (Hippocrepis comosa): a novel plant enzyme

A novel enzyme that catalyses the oxygen-dependent oxidation of 3-nitropropionic acid (3NPA) to malonate semialdehyde, nitrate, nitrite and H2O2 has been purified from leaf extracts of the horseshoe vetch, Hippocrepis comosa, and named 3NPA oxidase. The enzyme is a flavoprotein with a subunit molecular mass of 36 kDa containing 1 molecule of FMN and exhibits little specificity for all nitroalkanes tested other than 3NPA (apparent Km 620 microM). The maximum enzyme activity in vitro was expressed at pH4.8 and was inhibited strongly by the products nitrate and nitrite. 3NPA oxidase activity was detected in green shoots, which also contain high concentrations of 3NPA, from plants grown with nitrate, ammonium or N2 as sources of nitrogen. Enzyme activity was absent from roots and cell cultures, neither of which accumulate high levels of 3NPA.

Embryonic development of the inner ear and otolith of the rainbow trout Oncorhynchus mykiss

The embryonic development of the inner ear, especially the sensory epithelia and otoliths in the rainbow trout Oncorhynchus mykiss, was studied by light and electron microscopy. Light microscopically, the auditory vesicle, saccular otolith and statoacoustic ganglion were first observed by 12 days after fertilization, while the utricular otolith appeared at 15 days after fertilization. Both the saccular and utricular maculae were more developed at 22 days after fertilization, and well developed by 27 days. The crista ampullaris of the horizontal canal was also developed at 27 days after fertilization, while the other cristae were not yet distinguished. Electron microscopically, vesicular structures and short microvilli were found on the sensory epithelia of the maculae by 15 days after fertilization. At 22 days after fertilization, the saccular otolith possessed 7 incremental layers, and developing cilia, microvilli, and aggregates of secretory materials also appeared on the apical surface of the sensory epithelia. At 27 days after fertilization, the apical surface of each hair cell was covered with a hair bundle consisting of a single kinocilium and a bundle of stereocilia. These findings are discussed with special regard to the environmental factors on early development in fishes.

Bioequivalency studies on tablet formulation of tetroxoprim and sulphadiazine

The paper describes a comparative bioavailability study on two tablet formulations containing 100 mg of tetroxoprim and 250 mg of sulphadiazine. The comparison was based on the estimated pharmacokinetic parameters from time--serum concentration profiles obtained following the administration of the tablets to 12 healthy volunteers. Statistical analysis performed on the parameters showed that the differences are statistically insignificant and the formulations are bioequivalent.

A recombinant-DNA-derived modification of human growth hormone (hGH44-191) with enhanced diabetogenic activity

A modified human growth hormone (hGH) that lacks the first 43 residues of the intact hormone was prepared by recombinant-DNA technology. For preparative purposes an additional alanine was made the amino terminal residue. Sequence analysis and tryptic peptide mapping combined with amino acid analyses confirmed the structure of the polypeptide. Less than 2% N-terminal methionine was detected. The hGH44-191 was estimated to be at least 10 times more active than hGH in producing glucose intolerance in obese yellow mice (Avy/A) and was equipotent to hGH in increasing serum free fatty acids in fasted, hypophysectomized rats. The peptide did not promote growth in hypophysectomized rats nor did it exhibit early (1h) insulin-like activity in fasted, hypophysectomized rats, as indicated by its failure to lower blood glucose and fatty acids. The modified hGH was inactive in the Nb-2 cell assay but was about one-third as active as hGH in stimulating the pigeon crop sac. In radioimmunoassays using 125I-labeled hGH and polyclonal antibodies to intact hGH, cross-reactivity of hGH44-191 was less than 1%. We conclude that removal of the amino terminal portion of hGH enhances its diabetogenic properties, and that this activity does not depend upon the ability to promote growth. Furthermore, the insulin-like activity can be separated from its diabetogenic action by deletion of the first 43 amino terminal residues. This is the first report of a modified hGH that has anti-insulin effects greater than hGH itself.

High-performance liquid chromatographic determination of methotrexate in plasma

A procedure for the determination of methotrexate in human plasma is reported. The analysis involved extraction of methotrexate as an ion pair in ethyl acetate. Reconstituted residue was analyzed using reverse phase C-18 column and a mobile phase consisting of acetate buffer (87%), methanol (6.5%), and acetonitrile (6.5%). The methotrexate recovery range was 95-97%. Theophylline was used as internal standard with a recovery of 96%. The intraday coefficient of variation for the assay ranged from 1.8-3.0%, while interday variation coefficient range was 3.5-3.7%. The method is selective, reproducible, and covers a wide range of methotrexate concentrations in patient's plasma.

Effects of hypophysectomy and the insulin-like and anti-insulin pituitary peptides on carbohydrate metabolism in yellow Avy/A (BALB/c x VY)F1 hybrid mice

The amino-terminal portion of human growth hormone, residues 1-43 (hGH1-43), has insulin-potentiating action, while a hyperglycemic pituitary peptide (HP), which co-purifies with human growth hormone (hGH), is antagonistic to the action of insulin. The effects of hGH, hGH1-43, and HP on glucose metabolism were assessed in young (4-5 weeks) and adult (6-8 months) hypophysectomized yellow Avy/A mice which lacked any interfering endogenous pituitary hormones, and compared with age-matched intact obese yellow Avy/A and lean agouti A/a mice. Treatment with hGH1-43 or HP did not promote body growth in hypophysectomized yellow mice; but after 2 weeks of treatment with hGH, there was a significant increase in body weight (P less than 0.05). Treatment with HP raised blood glucose and lowered insulin concentrations in obese yellow mice, but not in agouti or hypophysectomized yellow mice. The severely impaired glucose tolerance of the hypophysectomized yellow mice was improved by acute (60 min) and chronic (3 days) treatment with hGH1-43 as well as by 2 weeks of treatment with hGH; in contrast, HP had no effect. Glucose oxidation in adipose tissue from obese yellow mice was low and showed essentially no response to stimulation by insulin at doses lower than 1000 microunits/ml. Basal glucose oxidation rates in adipose tissue taken from agouti and hypophysectomized yellow mice were significantly higher (P less than 0.001) than those in tissue from obese yellow mice, and the rates responded significantly (P less than 0.05) to 100 microunits/ml insulin. The insulin binding affinities in liver membranes from agouti mice were higher than those from either obese or hypophysectomized yellow mice. The insulin receptor densities were similar in both agouti and obese yellow mice, but higher in hypophysectomized yellow mice (P less than 0.05). Treatment with hGH1-43 slightly increased, although not significantly, the insulin receptor density in yellow obese mice while hGH showed essentially no change. Therefore, hypophysectomy appeared to increase tissue response and decrease insulin resistance by increasing receptor numbers and lowering the circulating insulin levels. Furthermore, the insulin-like action of hGH was elicited directly in vivo by hGH1-43 in hypophysectomized yellow mice.

Potentiation of response to insulin and anti-insulin action by two human pituitary peptides in lean agouti A/a, obese yellow Avy/A, and C57BL/6J-ob/ob mice

Insulin-like and anti-insulin effects of human growth hormone (hGH) were examined by determining the effects of two peptides representing portions of the hGH molecule in lean agouti A/a and obese yellow Avy/A and ob/ob mice. The peptides were the amino terminal segment, residue 1-43 (hGH1-43), which has been shown to potentiate the response to insulin and another peptide, hyperglycemic peptide (HP), with unknown structure, which has anti-insulin activity. The anti-insulin component is an acidic low molecular weight peptide which co-purifies with hGH but was not recognized by antibodies to intact hGH and did not cross-react with anti-hGH1-43 antiserum. The purpose of these studies was to further understand the multiple actions of hGH and its acute and chronic effects on response to insulin. Injections of hGH1-43 dramatically enhanced the effect of insulin on glucose clearance of obese yellow Avy/A and ob/ob mice and increased the insulin-stimulated glucose oxidation in adipose tissue of yellow mice, but had no direct effect on blood glucose or insulin levels of either genotype. Administration of HP to obese yellow mice produced hyperglycemia and suppressed serum insulin concentrations. Tissues from lean agouti and obese yellow mice treated with HP in vitro showed decreased basal and insulin-stimulated glucose oxidation as well as decreased 14C incorporation into lipids. Chronic treatment of obese yellow and ob/ob mice with HP increased fasting blood glucose and impaired glucose tolerance. The effect of HP was more pronounced in obese yellow mice and the ob/ob mice were more sensitive to the diabetogenic actions of intact hGH. These data provide further evidence for the existence of two opposing biologic activities derived from disparate amino acid sequences in hGH. Additionally, the data indicate that assays using obese yellow Avy/A mice can distinguish the effects of hGH from those of the individual peptides to a greater degree than assays using obese ob/ob mice.

The growth factor from plerocercoid larvae of the tapeworm, Spirometra mansonoides, stimulates growth but is not diabetogenic

A factor produced by plerocercoids of the tapeworm Spirometra mansonoides is similar to human growth hormone (hGH) in that it stimulates body growth, binds to hGH receptors, cross-reacts with anti-hGH antibodies, and has lactogenic and insulin-like activities. The purpose of this study was to determine whether plerocercoid growth factor (PGF) is similar to hGH in expressing diabetogenic activity in the genetically obese (ob/ob) mouse. To determine an effective dose for use in the obese mice, the ability of daily injections of PGF to stimulate growth of phenotypically normal mice of the same strain was assessed in a 10-day weight gain assay. Injections of PGF stimulated a dose-dependent weight gain (r = 0.83) and 25 ng eq/day of PGF stimulated a response not significantly different from that produced by 100 micrograms of bovine growth hormone/day. Diabetogenicity was assessed using fasting blood glucose and glucose tolerance tests in obese mice that had been injected for 3 days with saline, hGH, or PGF. Human growth hormone caused a significant increase (P less than 0.005) in fasting blood glucose and glucose tolerance of the obese mice was impaired (P less than 0.01). All of the doses of PGF used to test diabetogenicity in the obese mice were at least twice that required to stimulate a maximal growth response in normal mice, yet none of the doses of PGF increased fasting blood glucose or decreased glucose tolerance. These results show that PGF was a potent growth stimulant but was not diabetogenic.

Bioequivalency of ranitidine tablets

The bioavailability of two brands of ranitidine tablets was studied in 10 healthy volunteers. Formulation factors were compared by performing disintegration, dissolution and content uniformity tests. Plasma concentrations of ranitidine were measured using a sensitive and precise high pressure liquid chromatographic (HPLC) procedure. Pharmacokinetic parameters were determined for both formulations and included: Cmax, AUCt, AUC infinity, tmax, t1/2 and the terminal rate of elimination (k). Statistical analysis revealed that differences between the brands were not significant. The two formulations can be considered to be bioequivalent.

In vitro insulin-like actions of the growth factor from the tapeworm, Spirometra mansonoides

In vitro actions of purified plerocercoid growth factor (PGF) were compared with those of insulin and human growth hormone (hGH) in adipose tissue from normal male rats. Insulin-like effects were measured by the ability of PGF, insulin, or hGH to stimulate oxidation of [U-14C]glucose to 14CO2, to stimulate lipogenesis, and to inhibit epinephrine-induced lipolysis. PGF and insulin stimulated significant increases in glucose oxidation and lipogenesis in adipose tissue that had not been preincubated as well as in tissue that had been preincubated. hGH stimulated insulin-like effects only in tissue that had been preincubated for 3 hr. Insulin, hGH, and PGF inhibited epinephrine-induced lipolysis of preincubated (3 hr) adipose tissue. hGH produced a dramatic lipolytic response in tissue freshly removed from normal rats but no dose of PGF was lipolytic. PGF did not displace 125I-insulin from its receptors on adipocytes but did competitively inhibit 125I-hGH binding to adipocytes. These results suggest that PGF has direct insulin-like actions which are initiated by binding a GH receptor, but PGF had no anti-insulin action and the insulin-like activity of PGF was unaffected by refractoriness of adipose tissue to GH.

Effects of the amino-terminal portion of human growth hormone on glucose clearance and metabolism in normal, diabetic, hypophysectomized, and diabetic-hypophysectomized rats

A naturally occurring pituitary peptide, human (h) GH-(1-43) potentiates insulin action. The present study has compared the effects of acute (30-60 min) and chronic (3-6 days) injections of synthetic hGH-(1-43), hGH, and insulin in normal, diabetic, hypophysectomized, and diabetic-hypophysectomized rats. Male rats (150-250 g) received injections of saline, insulin (50-200 mU), hGH (200 micrograms), or hGH-(1-43) (200-400 micrograms) with or without insulin. Hormone and glucose were injected simultaneously for glucose tolerance tests. Basal and insulin-stimulated [U-14C]glucose oxidation to 14CO2 in adipose tissue were measured in vitro after in vivo treatments; insulin release by isolated pancreatic islets was determined in vitro. Acute injections of hGH-(1-43) with insulin dramatically increased glucose clearance in diabetic (P less than 0.05) and hypophysectomized (P less than 0.01) rats. In diabetic-hypophysectomized rats acute injections of hGH-(1-43) significantly lowered the elevated basal blood glucose level (P less than 0.025) and stimulated [U-14C]glucose oxidation to 14CO2 in adipose tissue (P less than 0.05); it did not increase the glucose clearance rate during glucose administration. Chronic treatment of diabetic rats with hGH-(1-43) did not lower the elevated blood glucose level significantly, but it stimulated [U-14C]glucose oxidation to 14CO2 in adipose tissue; the oxidation was further stimulated by treatment with insulin. Chronic injections of hGH-(1-43) slightly lowered blood glucose levels in hypophysectomized rats (P less than 0.025) despite a diminished release in vitro of insulin from pancreatic islets (P less than 0.05). Therefore, these experiments show hGH-(1-43) to be an insulin potentiator that increases insulin-stimulated glucose clearance and glucose oxidation without an increase in insulin secretion, and they suggest that the peptide may have a physiological role in regulating carbohydrate metabolism.

Insulin-like effects in the rat of the purified growth factor from Spirometra mansonoides plerocercoids

The acute effects of injections of the human growth hormone-like factor purified from plerocercoids of the tapeworm Spirometra mansonoides on carbohydrate, lipid, and protein metabolisms were determined in intact rats. Male rats were injected ip with saline, insulin, or various doses of partially purified PGF. The rats injected with insulin had significantly reduced serum glucose concentrations but no dose of PGF caused a change in serum glucose levels. Insulin and PGF stimulated [14C]glucose and [14C]leucine oxidation to 14CO2 in adipose tissue and muscle and increased incorporation of both [14C]glucose carbons into lipids and [14C]leucine into protein in fat and muscle. The responses to PGF were dose-dependent and persisted after 3 hr of incubation in vitro. Injections of naloxone prior to injecting PGF to block the stress response did not prevent the stimulation of insulin-like responses by PGF. Therefore, PGF has intrinsic insulin-like activities in normal male rats.

Some biochemical effects of the growth hormone analogue produced by plerocercoids of the tapeworm Spirometra mansonoides on carbohydrate metabolism of adipose tissue from normal, diabetic, and hypophysectomized rats

Plerocercoids of Spirometra mansonoides produce a functional analogue of mammalian growth hormone (GH). Plerocercoid growth factor (PGF) mimics the growth-promoting actions of GH, but has not been shown to duplicate all of the actions reported for GH. The purpose of this study was to determine the effects of plerocercoid infection (chronic PGF treatment) on glucose metabolism of adipose tissue and to compare the effects to those elicited by insulin and GH in intact, diabetic, and hypophysectomized male rats. Groups of rats were constantly exposed to PGF (via plerocercoid infection) or injected twice daily with bovine GH, insulin, or saline for 10 days. Basal oxidation rates of [U-14C]glucose to 14CO2 in adipose tissue segments were measured in vitro immediately after tissue removal. Other aliquots of adipose tissue were preincubated in hormone-free medium for 3 hr prior to testing the ability of the tissue to respond to insulin or human GH (hGH) added in vitro. Adipose tissue from PGF-treated intact and hypophysectomized rats had significantly elevated basal glucose oxidation rates, and the tissue was sensitive to further stimulation by insulin or hGH. The results obtained with intact and hypophysectomized rats were essentially the same, indicating that the effects of PGF were not due to suppression of endogenous GH. The basal glucose oxidation rate in adipose tissue from diabetic rats was stimulated (P less than 0.01) by PGF, but the tissue was not sensitive to insulin added in vitro. Furthermore, PGF had no effect on body growth or blood glucose concentrations of diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)