From LC-MS/MS metabolomics profiling of Kanchanara Guggulu to molecular docking and dynamics simulation of quercetin pentaacetate with aldose reductase

Kanchanara Guggulu (KG) is an important traditional medicine that is prescribed by the Ayurveda physicians for the treatment of swellings in various organs such as the thyroid, and lymph nodes. High-resolution mass-spectrometry-based metabolomics found metabolites in KG. LC-MS/MS-based metabolomics analysis of KG identified 2,579 compounds including quercetin and kaempferol derivatives. The molecular docking and dynamics analysis of quercetin pentaacetate with aldose reductase is documented for further consideration in drug discovery.     

Cloning of the human thiamine transporter, a member of the folate transporter family.

We have isolated a cDNA from human placenta, which, when expressed heterologously in mammalian cells, mediates the transport of the water-soluble vitamin thiamine. The cDNA codes for a protein of 497 amino acids containing 12 putative transmembrane domains. Northern blot analysis indicates that this transporter is widely expressed in human tissues. When expressed in HeLa cells, the cDNA induces the transport of thiamine (K(t) = 2.5 +/- 0.6 microM) in a Na(+)-independent manner. The cDNA-mediated transport of thiamine is stimulated by an outwardly directed H(+) gradient. Substrate specificity assays indicate that the transporter is specific to thiamine. Even though thiamine is an organic cation, the cDNA-induced thiamine transport is not inhibited by other organic cations. Similarly, thiamine is not a substrate for the known members of mammalian organic cation transporter family. The thiamine transporter gene, located on human chromosome 1q24, consists of 6 exons and is most likely the gene defective in the metabolic disorder, thiamine-responsive megaloblastic anemia. At the level of amino acid sequence, the thiamine transporter is most closely related to the reduced-folate transporter and thus represents the second member of the folate transporter family.     

Human Immunodeficiency Virus Type 1-Induced Hematopoietic Inhibition Is Independent of Productive Infection of Progenitor Cells In Vivo

Human immunodeficiency virus (HIV)-infected individuals exhibit a variety of hematopoietic dysfunctions. The SCID-hu mouse (severe combined immunodeficient mouse transplanted with human fetal thymus and liver tissues) can be used to model the loss of human hematopoietic precursor cell function following HIV infection and has a distinct advantage in that data can be obtained in the absence of confounding factors often seen in infected humans. In this study, we establish that HIV type 1 (HIV-1) bearing a reporter gene inserted into the viral vpr gene is highly aggressive in depleting human myeloid and erythroid colony-forming precursor activity in vivo. Human CD34(+) progenitor cells can be efficiently recovered from infected implants yet do not express the viral reporter gene, despite severe functional defects. Our results indicate that HIV-1 infection alone leads to hematopoietic inhibition in vivo; however, this effect is due to indirect mechanisms rather than to direct infection of CD34(+) cells in vivo.     

Purification and characterization of a major zinc binding protein from renal brush border membrane of rat.

In spite of the fact that zinc is an essential trace element, mechanisms that contribute to zinc homeostasis in mammals are poorly understood. An attempt has been made to identify and purify zinc binding components from renal brush border membrane (BBM), which could be involved in the binding of zinc and the subsequent translocation across the BBM. A 40 kDa major zinc binding protein has been identified and purified from renal BBM, which showed a dissociation constant (Kd) of 211 microM and maximal binding (Bmax) of 207 nmol/mg protein. 8 g zinc atoms could interact with 1 mol of protein. Specificity of the protein for zinc was checked by metal displacement and UV-absorption assay. It was found that only Cd2+ could displace the zinc bound to the protein. Other metals tested (Cu2+, Mg2+, Ca2+) did not show any interaction with the protein. These data indicated that purified protein is highly specific and has a high affinity for zinc. The carbohydrate content was found to be 7.85 mg% in the purified protein. Immunofluorescence localization of this protein in kidney sections revealed that this major zinc binding protein is exclusively localized in the proximal convoluted tubules. These results suggested that the 40 kDa major zinc binding transmembrane glycoprotein is highly specific for zinc and has a high affinity for zinc.     

Leopard (Panthera pardus) occupancy in the Chure range of Nepal

Conservation of large carnivores such as leopards requires large and interconnected habitats. Despite the wide geographic range of the leopard globally, only 17% of their habitat is within protected areas. Leopards are widely distributed in Nepal, but their population status and occupancy are poorly understood. We carried out the sign‐based leopard occupancy survey across the entire Chure range (~19,000 km²) to understand the habitat occupancy along with the covariates affecting their occupancy. Leopard signs were obtained from in 70 out of 223 grids surveyed, with a naïve leopard occupancy of 0.31. The model‐averaged leopard occupancy was estimated to be 0.5732 (SE 0.0082) with a replication‐level detection probability of 0.2554 (SE 0.1142). The top model shows the additive effect of wild boar, ruggedness, presence of livestock, and human population density positively affecting the leopard occupancy. The detection probability of leopard was higher outside the protected areas, less in the high NDVI (normalized difference vegetation index) areas, and higher in the areas with livestock presence. The presence of wild boar was strong predictor of leopard occupancy followed by the presence of livestock, ruggedness, and human population density. Leopard occupancy was higher in west Chure (0.70 ± SE 0.047) having five protected areas compared with east Chure (0.46 ± SE 0.043) with no protected areas. Protected areas and prey species had positive influence on leopard occupancy in west Chure range. Similarly in the east Chure, the leopard occupancy increased with prey, NDVI, and terrain ruggedness. Enhanced law enforcement and mass awareness activities are necessary to reduce poaching/killing of wild ungulates and leopards in the Chure range to increase leopard occupancy. In addition, maintaining the sufficient natural prey base can contribute to minimize the livestock depredation and hence decrease the human–leopard conflict in the Chure range.     

Loss of TDP-43 in male germ cells causes meiotic failure and impairs fertility in mice

Meiotic arrest is a common cause of human male infertility, but the causes of this arrest are poorly understood. Transactive response DNA-binding protein of 43 kDa (TDP-43) is highly expressed in spermatocytes in the preleptotene and pachytene stages of meiosis. TDP-43 is linked to several human neurodegenerative disorders wherein its nuclear clearance accompanied by cytoplasmic aggregates underlies neurodegeneration. Exploring the functional requirement for TDP-43 for spermatogenesis for the first time, we show here that conditional KO (cKO) of the Tardbp gene (encoding TDP-43) in male germ cells of mice leads to reduced testis size, depletion of germ cells, vacuole formation within the seminiferous epithelium, and reduced sperm production. Fertility trials also indicated severe subfertility. Spermatocytes of cKO mice showed failure to complete prophase I of meiosis with arrest at the midpachytene stage. Staining of synaptonemal complex protein 3 and γH2AX, markers of the meiotic synaptonemal complex and DNA damage, respectively, and super illumination microscopy revealed nonhomologous pairing and synapsis defects. Quantitative RT–PCR showed reduction in the expression of genes critical for prophase I of meiosis, including Spo11 (initiator of meiotic double-stranded breaks), Rec8 (meiotic recombination protein), and Rad21L (RAD21-like, cohesin complex component), as well as those involved in the retinoic acid pathway critical for entry into meiosis. RNA-Seq showed 1036 upregulated and 1638 downregulated genes (false discovery rate <0.05) in the Tardbp cKO testis, impacting meiosis pathways. Our work reveals a crucial role for TDP-43 in male meiosis and suggests that some forms of meiotic arrest seen in infertile men may result from the loss of function of TDP-43.     

Does Auxin Play a Role in the Release of Apical Dominance by Shoot Inversion in Ipomoea nil?

According to the auxin-inhibition hypothesis of apical dominance,apically produced auxin moves down the stem and inhibits axillarybud outgrowth, either directly or indirectly. This hypothesishas been examined further by monitoring changes in basipetalauxin transport and endogenous auxin concentration in Ipomoeanil caused by shoot inversion, a stimulus that releases apicaldominance. The results indicate that inversion reduces auxintransport in the main stem. In upright shoots of intact plants,a 16-h pretreatment with [³H]IAA 4 cm below the apex resultsin downward movement of label and accumulation in nodes, especiallythe cotyledonary node. Label does not accumulate in the lateralbuds. GC-MS determinations of endogenous free auxin level inthe fourth node, where a lateral bud grows out following inversionof the upper part of the shoot, show no changes at 3 and 8 hafter inversion, the range of times for inversion-induced budrelease, or at 24 h, when bud outgrowth is continuing. However,inversion did cause a just-detectable decrease (approx. 10%)in the IAA level of the shoot's elongation region. Althoughauxin transport in segments of the main stem is partially inhibitedby inversion over a period shorter than the latent time of budrelease, thus providing a means for the expected depletion ofauxin in the fourth node, no depletion could be detected there.These results suggest that either a decrease in IAA level inthe main stem is not causal of bud release or that the decreasedIAA pool responsible for bud release is compartmented and cannotbe measured in whole-tissue extracts.Copyright 1993, 1999 AcademicPress Apical dominance, auxin content, auxin transport, axillary bud release, GC-MS, Ipomoea nil, Pharbitis nil, shoot inversion     

Optical analysis of RE3+ (RE = Eu,Tb):MgLa2V2O9 nano-phosphors

Red and green rare-earth ion (RE³⁺) (RE = Eu, Tb):MgLa₂V₂O₉ micro-powder phosphors were produced utilizing a standard solid-state chemical process. The X-ray diffraction examination performed on the phosphors showed that they were crystalline and had a monoclinic structure. The particles grouped together, as shown in the scanning electron microscopy (SEM) images. Powder phosphors were examined using a variety of spectroscopic techniques, including photoluminescence (PL), Fourier-transform infrared, and energy dispersive X-ray spectroscopy. Brilliant red emission at 615 nm (⁵D₀ → ⁷F₂) having an excitation wavelength (λ_exci) of 396 nm (⁷F₀ → ⁵L₆) and green emission at 545 nm (⁵D₄ → ⁷F₅) having an λ_exci = 316 nm (⁵D₄ → ⁷F₂) have both been seen in the emission spectra of Tb³⁺:MgLa₂V₂O₉ nano-phosphors. The emission mechanism that is raised in Eu³⁺:MgLa₂V₂O₉ and Tb³⁺:MgLa₂V₂O₉ powder phosphors has been explained in an energy level diagram.     

Studies on a novel SrZr2CaLa2O8:Eu3+ phosphor for lighting applications emitting direct white light

Direct white light emitting phosphors play a significant role in the display industry due to their ability to improve the quality, efficiency, and versatility of lighting sources used in most of the displays. The currently investigated phosphor SrZr₂CaLa₂O₈:Eu³⁺ was prepared by a conventional solid-state reaction method. It has been observed that the stoichiometric ratio of all precursors plays an important role in determining the characteristics of the final phosphor. From X-ray diffraction (XRD) analysis, the phosphor was observed to have a hexagonal phase and a crystal size of ~28 nm. Scanning electron microscopy (SEM) observations revealed a cluster of rod-like structures with an average diameter of ~0.2 μm. The excitation peak maximum observed at 280 nm is due to charge transfer between Eu³⁺-O²⁻ ions. The energy transitions ⁷F₀ → ⁵L₆ and ⁷F₀ → ⁵D₂ are responsible for the appearance of other excitation peaks at ultraviolet (UV) (395 nm), blue (~467 nm), green (~540 nm), orange (~590 nm), and red (~627 nm) attributed to ⁵D₀ → ⁷F_J (J = 0–4) transitions of europium ion (Eu³⁺). The Commercial International de I'Eclairage (CIE) chromaticity coordinates were estimated to be (0.37, 0.0.33) and (0.67, 0.33) for the emissions corresponding to 395 and 590 nm, respectively. The characteristic emissions of Eu³⁺ ions allow this novel phosphor to be used to generate direct white light in light-emitting diodes (LEDs), which is otherwise difficult to achieve in single-component systems.