Evaluation of the anti-fertility activity of stem bark of Crataeva nurvala buch-hum

The ethanol and aqueous extracts of the dried stem bark of the plant Crataeva nurvala Buch-Hum (Capparidaceae) have been found to possess significant anti-fertility effects in rats. Both ethanol and aqueous extracts exhibited partial and complete resorption of implants at 300 and 600 mg/kg b.wt dose levels, respectively. In estrogenic activity study, both the extracts increased uterine weight and caused opening and cornification of vagina in immature rats. The present work justifies its effectiveness in preventing pregnancy in all rats at dose level

Mosaicism of 50,XX/51,XX in a Murrah buffalo Bubalus bubalis

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Pharmacognostical Standardization and Phytochemical Studies on the leaves of Solanum torvum Sw

A genus of plant belongs to the family Solanaceae well distributed in India more than 26 species which are found naturalised in India. Solanum torvum Sw. is a medium sized flowering plant in the Solanaceae family that is found in India, Malaysia. Transverse section of lamina showed the adaxial part has thick, short hump; the midrib and the adaxial hump have thin, angular epidermal cells. The upper part of adaxial hump has a few layers sclerenchyma cells. The inner layer of the adaxial midrib also has few layers of thick walled cells. The ground tissue consists of wide circular thin walled parenchyma cells with narrow inter cellular spaces. The vascular system of the midrib showed bi-collateral structure. Non glandular, profusely branched, thick walled, lignified epidermal trichome occurs as both on the veins and lamina. Physico-chemical standards such as Foreign Matter, Total Ash, Water Soluble Ash, Sulphated Ash, Loss on Drying, Water Soluble Extractive, Alcohol Soluble Extractive and Crude Fiber Content in percentage were estimated. Preliminary phytochemical screening of appropriate solvent extracts showed the presence of Alkaloids, Amino Acids, Carbohydrates, Cellulose, Lignin, Fats & Fixed Oils, Flavonoids, Glycosides, Tannins, Proteins, Starch, Steroids and Triterpenoids and absence of Volatile Oil, Mucilage and Pectin. Microscopic analysis and other parameters were informative and provide valuable information in the identification, standardization of Solanum torvum leaves. Keywords: Solanum torvum, Solanaceae, leaf, Microscopical evaluation

Berbris aristata DC: Pharmacognostical Standardization and Phytochemical Studies of its Leaves

Berberis aristata DC. (Fam: Berberidaceae) commonly known as Daruharidra, Indian Barberry or tree turmeric. Leaves of this plant are traditionally used in the treatment of inflammation, wound healing, skin disease, menorrhagia, diarrhea, jaundice and infection of eyes etc. Micromorphology and physicochemical analysis of the leaves of B.aristata were performed as per WHO and Pharmacopoeial methods. Leaves (4.9cm × 1.8cm) are deep green on dorsal and light green on ventral side. Leaves are in tufts of 5 to 8, phyllotaxy verticillate, simple spiny, lanceolate, toothed, leathery, sessile, acuminate apex and reticulate pinnate venation. Microscopic evaluation of leaves showed biconvex midrib and thick lamina. The epidermal layers of the midrib are thick with small, less conspicuous cells and thick cuticle. The vascular system consists of three large vascular bundles; the median one is small than the two lateral bundles; the bundles are collateral and wedge shaped.  Lamina is made of epidermal layer on the adaxial side with spindle shaped thick walled cells and papillate cuticle. The abaxial epidermis has squarish or rectangular epidermal cells with prominent spiny cuticular outgrowths. Powder microscopy showed the presence of cuticular papillae, anomocytic stomata and spiny outgrowth. Preliminary phytochemical screening of appropriate solvent extracts showed the presence of alkaloids, sterols, tannins, proteins and amino acids, flavonoids, terpenoids, saponin, carbohydrates and absence of glycosides and volatile and fixed oil. Microscopic analysis and other parameters were informative and provide valuable information in the identification, standardization of B.aristata leaves. Keywords: Berberis aristata, Berberidaceae, leaf, Microscopical evaluation

Stoichiometry of Base Excision Repair Proteins Correlates with Increased Somatic CAG Instability in Striatum over Cerebellum in Huntington's Disease Transgenic Mice

Huntington's disease (HD) is a progressive neurodegenerative disorder caused by expansion of an unstable CAG repeat in the coding sequence of the Huntingtin (HTT) gene. Instability affects both germline and somatic cells. Somatic instability increases with age and is tissue-specific. In particular, the CAG repeat sequence in the striatum, the brain region that preferentially degenerates in HD, is highly unstable, whereas it is rather stable in the disease-spared cerebellum. The mechanisms underlying the age-dependence and tissue-specificity of somatic CAG instability remain obscure. Recent studies have suggested that DNA oxidation and OGG1, a glycosylase involved in the repair of 8-oxoguanine lesions, contribute to this process. We show that in HD mice oxidative DNA damage abnormally accumulates at CAG repeats in a length-dependent, but age- and tissue-independent manner, indicating that oxidative DNA damage alone is not sufficient to trigger somatic instability. Protein levels and activities of major base excision repair (BER) enzymes were compared between striatum and cerebellum of HD mice. Strikingly, 5′-flap endonuclease activity was much lower in the striatum than in the cerebellum of HD mice. Accordingly, Flap Endonuclease-1 (FEN1), the main enzyme responsible for 5′-flap endonuclease activity, and the BER cofactor HMGB1, both of which participate in long-patch BER (LP–BER), were also significantly lower in the striatum compared to the cerebellum. Finally, chromatin immunoprecipitation experiments revealed that POLβ was specifically enriched at CAG expansions in the striatum, but not in the cerebellum of HD mice. These in vivo data fit a model in which POLβ strand displacement activity during LP–BER promotes the formation of stable 5′-flap structures at CAG repeats representing pre-expanded intermediate structures, which are not efficiently removed when FEN1 activity is constitutively low. We propose that the stoichiometry of BER enzymes is one critical factor underlying the tissue selectivity of somatic CAG expansion

On species delimitation: Yet another lemur species or just genetic variation?

<p>Abstract</p> <p>Background</p> <p>Although most taxonomists agree that species are independently evolving metapopulation lineages that should be delimited with several kinds of data, the taxonomic practice in Malagasy primates (Lemuriformes) looks quite different. Several recently described lemur species are based solely on evidence of genetic distance and diagnostic characters of mitochondrial DNA sequences sampled from a few individuals per location. Here we explore the validity of this procedure for species delimitation in lemurs using published sequence data.</p> <p>Results</p> <p>We show that genetic distance estimates and <it>Population Aggregation Analysis </it>(PAA) are inappropriate for species delimitation in this group of primates. Intra- and interspecific genetic distances overlapped in 14 of 17 cases independent of the genetic marker used. A simulation of a fictive taxonomic study indicated that for the mitochondrial D-loop the minimum required number of individuals sampled per location is 10 in order to avoid false positives via PAA.</p> <p>Conclusions</p> <p>Genetic distances estimates and PAA alone should not be used for species delimitation in lemurs. Instead, several nuclear and sex-specific loci should be considered and combined with other data sets from morphology, ecology or behavior. Independent of the data source, sampling should be done in a way to ensure a quantitative comparison of intra- and interspecific variation of the taxa in question. The results of our study also indicate that several of the recently described lemur species should be reevaluated with additional data and that the number of good species among the currently known taxa is probably lower than currently assumed.</p

The wonders of flap endonucleases: structure, function, mechanism and regulation.

Processing of Okazaki fragments to complete lagging strand DNA synthesis requires coordination among several proteins. RNA primers and DNA synthesised by DNA polymerase α are displaced by DNA polymerase δ to create bifurcated nucleic acid structures known as 5'-flaps. These 5'-flaps are removed by Flap Endonuclease 1 (FEN), a structure-specific nuclease whose divalent metal ion-dependent phosphodiesterase activity cleaves 5'-flaps with exquisite specificity. FENs are paradigms for the 5' nuclease superfamily, whose members perform a wide variety of roles in nucleic acid metabolism using a similar nuclease core domain that displays common biochemical properties and structural features. A detailed review of FEN structure is undertaken to show how DNA substrate recognition occurs and how FEN achieves cleavage at a single phosphate diester. A proposed double nucleotide unpairing trap (DoNUT) is discussed with regards to FEN and has relevance to the wider 5' nuclease superfamily. The homotrimeric proliferating cell nuclear antigen protein (PCNA) coordinates the actions of DNA polymerase, FEN and DNA ligase by facilitating the hand-off intermediates between each protein during Okazaki fragment maturation to maximise through-put and minimise consequences of intermediates being released into the wider cellular environment. FEN has numerous partner proteins that modulate and control its action during DNA replication and is also controlled by several post-translational modification events, all acting in concert to maintain precise and appropriate cleavage of Okazaki fragment intermediates during DNA replication