Doppler ultrasound scoring to predict chemotherapeutic response in advanced breast cancer

Background

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited disease. It is relatively recent that type 2C was identified as a separate group solely presenting with pheochromocytomas. As an illustration, an interesting case is presented of a pregnant woman with refractory hypertension. It proved to be the first manifestation of bilateral pheochromocytomas. The family history may indicate the diagnosis, but only identification of a germ line mutation in the DNA of a patient will confirm carriership.

Case presentation

A 27 year pregnant patient with intra uterine growth retardation presented with hypertension and pre-eclampsia. Magnetic resonance imaging revealed bilateral adrenal pheochromocytoma. She underwent laparoscopic adrenelectomy and a missense mutation (Gly93Ser) in exon 1 of the VHL gene on chromosome 3 (p25 - p26) was shown in the patient, her father and her daughter confirming the diagnosis of VHL.

Conclusion

In almost all VHL families molecular genetic analysis of DNA will demonstrate an inherited mutation. Because of the involvement in several organs, periodic clinical evaluation should take place in a well coordinated, multidisciplinary setting. VHL disease can be classified into several subtypes. VHL type 2C patients present with pheochromocytomas without evidence of haemangioblastomas in the central nervous system and/or retina and a low risk of renal cell carcinoma. Therefore, in such families, periodic clinical screening can be focussed on pheochromocytomas.     

Structural and Logical Analysis of a Comprehensive Hedgehog Signaling Pathway to Identify Alternative Drug Targets for Glioma,Colon and Pancreatic Cancer

Hedgehog is an evolutionarily conserved developmental pathway, widely implicated in controlling various cellular responses such as cellular proliferation and stem cell renewal in human and other organisms, through external stimuli. Aberrant activation of this pathway in human adult stem cell line may cause different types of cancers. Hence, targeting this pathway in cancer therapy has become indispensable, but the non availability of detailed molecular interactions, complex regulations by extra- and intra-cellular proteins and cross talks with other pathways pose a serious challenge to get a coherent understanding of this signaling pathway for making therapeutic strategy. This motivated us to perform a computational study of the pathway and to identify probable drug targets. In this work, from available databases and literature, we reconstructed a complete hedgehog pathway which reports the largest number of molecules and interactions to date. Using recently developed computational techniques, we further performed structural and logical analysis of this pathway. In structural analysis, the connectivity and centrality parameters were calculated to identify the important proteins from the network. To capture the regulations of the molecules, we developed a master Boolean model of all the interactions between the proteins and created different cancer scenarios, such as Glioma, Colon and Pancreatic. We performed perturbation analysis on these cancer conditions to identify the important and minimal combinations of proteins that can be used as drug targets. From our study we observed the under expressions of various oncoproteins in Hedgehog pathway while perturbing at a time the combinations of the proteins GLI1, GLI2 and SMO in Glioma; SMO, HFU, ULK3 and RAS in Colon cancer; SMO, HFU, ULK3, RAS and ERK12 in Pancreatic cancer. This reconstructed Hedgehog signaling pathway and the computational analysis for identifying new combinatory drug targets will be useful for future in-vitro and in-vivo analysis to control different cancers.     

Distinct CG and CNG DNA methyltransferases in Pisum sativum

DNA methyltransferase activity, present in low salt extracts of nuclei from young pea shoot apices, has been fractionated into two different species by assaying with model substrates. The CG methyltransferase (an unstable enzyme believed to be of 140 kDa) methylates cytosine only in oligonucleotides with CG and CI dinucleotide targets while an enzyme of 110 kDa (the CNG methyltransferase) methylates the cytosines in 5′-CAG-3′ and 5′-CTG-3′ target sequences, especially when hemimethylated, but not in 5′-CCG-3′ nor in 5′-CGG-3′ target sequences present in oligonucleotides.     

Desynchronized vasomotion and desynchronized fiber activation pattern enhance oxygenation in a model of skeletal muscle

Although the full physiological significance of vasomotion is still debated, it is generally thought to have a role in optimizing tissue oxygenation parameters. We study the effect of vasomotion rhythm in skeletal muscle on oxygen transport using a computational model. The model is used: (i) to test a novel hypothesis that “vasomotors” form a chemical network in which the rhythm adapts to meet oxygen demand in skeletal muscle and (ii) to study the contribution of desynchronized/chaotic vasomotion in optimizing oxygen delivery to skeletal muscle. We formulate a 2D grid model of skeletal muscle consisting of an interleaved arrangement of vessels and muscle fibers fired by a motor neuronal network. The vasomotors too form a network interacting by chemical means. When positive (negative) synapses dominate, the neuronal network exhibits synchronized (desynchronized) activity. Similarly, when positive (negative) chemical interactions dominate, the vessels exhibit synchronized (desynchronized) activity. Optimal oxygenation is observed when both neuronal network and vasomotor network exhibit desynchronous activity. Muscle oxygenation is thought to result by interactions between the fiber/neuron network and the vessel network; optimal oxygenation depends on precise rhythm-related conditions on the two networks. The model provides interesting insights into the phenomenon of muscle fatigue.     

Mechanism of Ca2+ and dipicolinic acid requirement for L-alanine induced germination of Bacillus cereus BIS-59 spores

Spores prepared from different sporulating media containing varying amounts of Ca and dipicolinic acid (DPA), exhibited differential responses to germination in L-alanine (0.25 M). Ca-spores with moderately high Ca and DPA contents could be triggered to germination by L-alanine, whereas P-spores with low contents of Ca and DPA could not be germinated by L-alanine unless Ca2+ or DPA was exogenously added. The initiation of L-alanine induced germination by P-spores in the presence of 45CaCl2 was associated with a marked uptake of 45Ca2+. Experiments involving stepwise extraction of 45Ca from prelabelled spores indicated that a part of the spore calcium may be involved in L-alanine induced germination. Both Ca2+ and DPA seemed to have a stimulatory effect on the incorporation of 14C-L-alanine.     

<Emphasis Type="Italic">In vitro</Emphasis> propagation of <Emphasis Type="Italic">Rhododendron wattii</Emphasis> Cowan—a critically endangered and endemic plant from India

Rhododendron wattii Cowan is a rare and endangered plant found in northeast India. In an effort to boost specimen numbers, experiments of in vitro seed germination, shoot induction on different media supplemented with the cytokinin isopentenyladenine (2iP), and root induction with auxins α-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) in woody plant medium (WPM) were carried out. A maximum mean shoot number of 7.72 per explant were obtained from nodal explants cultured on WPM and 39.36 μM 2iP with a maximum mean shoot length of 2.30 cm per explant. Among the auxins investigated for root induction, IBA at 2.45 μM was found to produce the most and the longest roots, when compared to other treatments. However, WPM supplemented with 0.2% (w/v) activated charcoal also showed 100% root formation with shoots having broader leaves compared to auxin treatments. About 60% of in vitro rooted plantlets transferred from lab to greenhouse conditions survived. Sixty acclimatized plants were reintroduced in the vicinity of their natural habitat at Naga Heritage Village, Kisama, Nagaland, in May 2016 for ex situ conservation. Survival of the reintroduced plants was confirmed during the field visit conducted in November 2016.     

Quantification of photonic localization properties of targeted nuclear mass density variations: Application in cancer‐stage detection

Light localization is a phenomenon which arises due to the interference effects of light waves inside a disordered optical medium. Quantification of degree light localization in optical media is widely used for characterizing degree of structural disorder in that media. Recently, this light localization approach was extended to analyze structural changes in biological cell like heterogeneous optical media, with potential application in cancer diagnostics. Confocal fluorescence microscopy was used to construct “optical lattices,” which represents 2‐dimensional refractive index map corresponding to the spatial mass density distribution of a selected molecule inside the cell. The structural disorder properties of the selected molecules were evaluated numerically using light localization strength in these optical lattices, in a single parameter called “disorder strength.” The method showed a promising potential in differentiating cancerous and non‐cancerous cells. In this paper, we show that by quantifying submicron scale disorder strength in the nuclear DNA mass density distribution, a wide range of control and cancerous breast and prostate cells at different hierarchy levels of tumorigenicity were correctly distinguished. We also discuss how this photonic technique can be used in examining tumorigenicity level in unknown prostate cancer cells, and potential to generalize the method to other cancer cells.      

S-adenosylhomocysteine Hydrolase Participates in DNA Methylation Inheritance

DNA (cytosine-5) methyltransferase 1 (DNMT1) is essential for mammalian development and maintenance of DNA methylation following DNA replication in cells. The DNA methylation process generates S-adenosyl-l-homocysteine, a strong inhibitor of DNMT1. Here we report that S-adenosylhomocysteine hydrolase (SAHH/AHCY), the only mammalian enzyme capable of hydrolyzing S-adenosyl-l-homocysteine binds to DNMT1 during DNA replication. SAHH enhances DNMT1 activity in vitro, and its overexpression in mammalian cells led to hypermethylation of the genome, whereas its inhibition by adenosine periodate or siRNA-mediated knockdown resulted in hypomethylation of the genome. Hypermethylation was consistent in both gene bodies and repetitive DNA elements leading to aberrant gene regulation. Cells overexpressing SAHH specifically up-regulated metabolic pathway genes and down-regulated PPAR and MAPK signaling pathways genes. Therefore, we suggest that alteration of SAHH level affects global DNA methylation levels and gene expression.