Phytochrome control of some oxido-reductases in germinating Pinus roxburghii Sarg pollen

Germination of Pinus roxburghii pollen was observed to be phytochrome-controlled.The red and far-red light affected the activities of succinatedehydrogenase and glucose-6-phosphate dehydrogenase in a mannercharacteristic of enzyme induction by phytochrome. Activitiesof peroxidase and malate dehydrogenase were not affected byred and far-red lights in this system. ¹This research was supported by the Indian Council of AgriculturalResearch, New Delhi and forms a part of the Ph.D. dissertationsubmitted to the Punjab Agricultural University, Ludhiana byA.K.D. ²Present address: Botany Department, The Australian NationalUniversity, Canberra, ACT 2600, Australia. (Received December 25, 1978; )     

Specific ion effect as a probable cause of growth inhibition under saline conditions

Summary The replacement of carboxy-proton of IAA, plays an important role in the process of growth under saline conditions. Appreciable changes in pH have ben observed in the presence of CO₃ ^–2 and HCO₃ ^–, and increase in pH appears to be caused owing to the formation of unstable complex of IAA, which soon hydrolyzes and gives alkalinity. The pH change thus achieved favours IAA oxidase activity; therefore, suppression of growth is resulted in CO₃ ^–2 and HCO₃ ^– medium. In the presence of SO₄ ^–2 and Cl^– salts slight lowering of pH takes place which does not favour IAA oxidase activity. It is therefore, presumed that anion (CO₃ ^–2, HCO₃ ^–, SO₄ ^–2 and Cl^–) controls the process of growth and development through the alteration of pH of the medium.     

Keratinization of fish skin with special reference to the catfish Bagarius bagarius

Summary Histochemical reactions indicating keratinization have previously been demonstrated in parts of the epidermis of Bagarius bagarius. Fluorescence histochemistry and electron microscopy have now confirmed these results. Elevated areas of the epidermis are capped by a layer of dead cells with altered contents. On the outer aspect of these cells a dense layer, 18 nm thick, beneath the plasma membrane corresponds to the resistant envelope found in keratinized cells in tetrapod vertebrates. In Bagarius this layer does not extend to all faces of the keratinized cells, but a similar envelope has been detected in two other sites of piscine keratinized epidermis investigated, namely in the breeding tubercles of Phoxinus phoxinus and in the teeth of Lampetra fluviatilis. In the elevated areas of Bagarius-epidermis, the epithelial cells undergo progressive changes in cytoplasmic organization as they become more superficial. The second tier from the surface is sealed by tight junctions and is separated from the overlying keratinized cells by a sub-corneal space resembling that found in keratinized amphibian epidermis. Histochemical evidence of a high lipid content in the outer layers of the epidermis correlates with the presence of lipid inclusions and lamellated membranous profiles in the material studied by electron microscopy. Histochemical results show that the fin skin of Blennius pholis is not keratinized, but secretes a cuticle, histochemically reactive for both proteins and glycoproteins.     

“Nutrient-sensing” and self-renewal: O-GlcNAc in a new role

Whether embryonic, hematopoietic or cancer stem cells, this metabolic reprogramming is dependent on the nutrient-status and bioenergetic pathways that is influenced by the micro-environmental niches like hypoxia. Thus, the microenvironment plays a vital role in determining the stem cell fate by inducing metabolic reprogramming. Under the influence of the microenvironment, like hypoxia, the stem cells have increased glucose and glutamine uptake which result in activation of hexosamine biosynthesis pathway (HBP) and increased O-GlcNAc Transferase (OGT). The current review is focused on understanding how HBP, a nutrient-sensing pathway (that leads to increased OGT activity) is instrumental in regulating self-renewal not only in embryonic and hematopoietic stem cells (ESC/HSC) but also in cancer stem cells.     

First mammal evidence from the Late Cretaceous of India for biotic dispersal between India and Africa at the KT transition

The Late Cretaceous record of mammals from India assumes great significance in view of the fact that it is the only Gondwanan landmass that has yielded definitive eutherian mammals. These mammals have variously been assigned to palaeoryctids, archontans or Eutheria incertae sedis. Well preserved lower molars recovered from a new mammal-yielding Deccan intertrappean site near Kisalpuri village, Dindori District, Madhya Pradesh (state), India, are described here under a new species Deccanolestes narmadensis sp. nov. The new fossil material indicates close phylogenetic relationship between Deccanolestes from India and Afrodon (Adapisoriculidae) from the Late Palaeocene of Africa and Europe. In view of older age and more primitive state of Deccanolestes teeth, it is inferred that Deccanolestes represents an ancestral morphotype from which the African/European adapisoriculid Afrodon may have been derived. This is the first compelling terrestrial fossil evidence for an early dispersal between India and Africa. Such a dispersal possibly involved an East African contact with India at the KT transition.     

Altered glycosylation in cancer: A promising target for biomarkers and therapeutics

Glycosylation is a well-regulated cell and microenvironment specific post-translational modification. Several glycosyltransferases and glycosidases orchestrate the addition of defined glycan structures on the proteins and lipids. Recent advances and systemic approaches in glycomics have significantly contributed to a better understanding of instrumental roles of glycans in health and diseases. Emerging research evidence recognized aberrantly glycosylated proteins as the modulators of the malignant phenotype of cancer cells. The Cancer Genome Atlas has identified alterations in the expressions of glycosylation-specific genes that are correlated with cancer progression. However, the mechanistic basis remains poorly explored. Recent researches have shown that specific changes in the glycan structures are associated with 'stemness' and epithelial-to-mesenchymal transition of cancer cells. Moreover, epigenetic changes in the glycosylation pattern make the tumor cells capable of escaping immunosurveillance mechanisms. The deciphering roles of glycans in cancer emphasize that glycans can serve as a source for the development of novel clinical biomarkers. The ability of glycans in intervening various stages of tumor progression and the biosynthetic pathways involved in glycan structures constitute a promising target for cancer therapy. Advances in the knowledge of innovative strategies for identifying the mechanisms of glycan-binding proteins are hoped to hold great potential in cancer therapy. This review discusses the fundamental role of glycans in regulating tumorigenesis and tumor progression and provides insights into the influence of glycans in the current tactics of targeted therapies in the clinical setting.     

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Na?ve Adolescents at High Risk for Psychosis

Growing evidence suggests that movement abnormalities are a core feature of psychosis. One marker of movement abnormality, dyskinesia, is a result of impaired neuromodulation of dopamine in fronto-striatal pathways. The traditional methods for identifying movement abnormalities include observer-based reports and force stability gauges. The drawbacks of these methods are long training times for raters, experimenter bias, large site differences in instrumental apparatus, and suboptimal reliability. Taking these drawbacks into account has guided the development of better standardized and more efficient procedures to examine movement abnormalities through handwriting analysis software and tablet. Individuals at risk for psychosis showed significantly more dysfluent pen movements (a proximal measure for dyskinesia) in a handwriting task. Handwriting kinematics offers a great advance over previous methods of assessing dyskinesia, which could clearly be beneficial for understanding the etiology of psychosis.     

A Multivariate Surface-Based Analysis of the Putamen in Premature Newborns: Regional Differences within the Ventral Striatum

Many children born preterm exhibit frontal executive dysfunction, behavioral problems including attentional deficit/hyperactivity disorder and attention related learning disabilities. Anomalies in regional specificity of cortico-striato-thalamo-cortical circuits may underlie deficits in these disorders. Nonspecific volumetric deficits of striatal structures have been documented in these subjects, but little is known about surface deformation in these structures. For the first time, here we found regional surface morphological differences in the preterm neonatal ventral striatum. We performed regional group comparisons of the surface anatomy of the striatum (putamen and globus pallidus) between 17 preterm and 19 term-born neonates at term-equivalent age. We reconstructed striatal surfaces from manually segmented brain magnetic resonance images and analyzed them using our in-house conformal mapping program. All surfaces were registered to a template with a new surface fluid registration method. Vertex-based statistical comparisons between the two groups were performed via four methods: univariate and multivariate tensor-based morphometry, the commonly used medial axis distance, and a combination of the last two statistics. We found statistically significant differences in regional morphology between the two groups that are consistent across statistics, but more extensive for multivariate measures. Differences were localized to the ventral aspect of the striatum. In particular, we found abnormalities in the preterm anterior/inferior putamen, which is interconnected with the medial orbital/prefrontal cortex and the midline thalamic nuclei including the medial dorsal nucleus and pulvinar. These findings support the hypothesis that the ventral striatum is vulnerable, within the cortico-stiato-thalamo-cortical neural circuitry, which may underlie the risk for long-term development of frontal executive dysfunction, attention deficit hyperactivity disorder and attention-related learning disabilities in preterm neonates.     

Cell Surface Concentrations and Concentration Ranges for Testing In Vitro Autocrine Loops and Small Molecules

A common assumption made when performing in vitro cellular assays is that the concentration of substances in the culture system is uniform. However, since the cells that internalize and secrete substances reside at the bottom of the well, it is conceivable that a concentration gradient could arise across the fluid layer. Importantly, the concentration of a substance in the vicinity of a cell, which is the concentration of interest, cannot be measured via existing methods. In this work a simple strategy for estimating the concentration of a chemical species at the surface of a cell is presented. Finally, this result is used to outline a method for determining the appropriate concentration ranges for testing in vitro autocrine loops and small molecules.