Transcatheter Aortic Valve Replacement in Bicuspid Aortic Valve: A Case Report.

Among other valvular heart disease Aortic stenosis (AS) is the most common in the developed world. Transcatheter Aortic Valve Replacement (TAVR) is most acceptable treatment option for patient with severely calcified aortic stenosis with high and intermediate risk group. Among several challenges, one of the main challenges is to deal with bicuspid aortic valve (BAV). Non-circular annulus, bulky leaflets leading to perivalvular leaks and risk for rupture and often very severe calcification may contribute to periprocedural strokes leading to poor clinical outcome. This case, a 68-year-old woman with a history of type 2 diabetes mellitus (DM), hypothyroidism, bicuspid aortic valve and severe aortic stenosis, bronchial asthma, who had repeatedly refused any suggestion for open heart surgery, was our volunteer candidate for TAVR. After successful TAVR the peak pressure gradient decreased from 100mmHg to 17mmHg. So, TAVR could be a viable option for highly selected patients with severe aortic stenosis and bicuspid aortic valve who have favourable anatomy.

Understanding the Impact of Obesity on Ageing in the Radiance of DNA Metabolism.

Ageing is a multi-factorial phenomenon which is considered as a major risk factor for the development of neurodegeneration, osteoporosis, cardiovascular disease, dementia, cancer, and other chronic diseases. Phenotypically, ageing is related with a combination of molecular, cellular, and physiological levels like genomic and epi-genomic alterations, loss of proteostasis, deregulation of cellular and subcellular function and mitochondrial dysfunction. Though, no single molecular mechanism accounts for the functional decline of different organ systems in older humans but accumulation of DNA damage or mutations is a dominant theory which contributes largely to the development of ageing and age-related diseases. However, mechanistic, and hierarchical order of these features of ageing has not been clarified yet. Scientific community now focus on the effect of obesity on accelerated ageing process. Obesity is a complex chronic disease that affects multiple organs and tissues. It can not only lead to various health conditions such as diabetes, cancer, and cardiovascular disease but also can decrease life expectancy which shows similar phenotype of ageing. Higher loads of DNA damage were also observed in the genome of obese people. Thus, inability of DNA damage repair may contribute to both ageing and obesity apart from cancer predisposition. The present review emphasizes on the involvement of molecular phenomenon of DNA metabolism in development of obesity and how it accelerates ageing in mammals.

Antibacterial activity of polyphenolic fraction of Kombucha against Vibrio cholerae: targeting cell membrane.

The present study was undertaken to determine the mechanism of antibacterial activity of a polyphenolic fraction, composed of mainly catechin and isorhamnetin, previously isolated from Kombucha, a 14-day fermented beverage of sugared black tea, against the enteropathogen Vibrio cholerae N16961. Bacterial growth was found to be seriously impaired by the polyphenolic fraction in a dose-dependent manner. Scanning Electron Microscopy demonstrated morphological alterations in bacterial cells when exposed to the polyphenolic fraction in a concentration-dependent manner. Permeabilization assays confirmed that the fraction disrupted bacterial membrane integrity in both time- and dose-dependent manners, which were proportional to the production of intracellular reactive oxygen species (ROS). Furthermore, each of the polyphenols catechin and isorhamnetin showed the ability to permeate bacterial cell membranes by generating oxidative stress, thereby suggesting their role in the antibacterial potential of Kombucha. Thus, the basic mechanism of antibacterial activity of the Kombucha polyphenolic fraction against V. cholerae involved bacterial membrane permeabilization and morphological changes, which might be due to the generation of intracellular ROS. To the best of our knowledge, this is the first report on the investigation of antibacterial mechanism of Kombucha, which is mostly attributed to its polyphenolic content. SIGNIFICANCE AND IMPACT OF THE STUDY: The emergence of multidrug-resistant Vibrio cholerae strains has hindered an efficient anti-Vibrio therapy. This study has demonstrated the membrane damage-mediated antibacterial mechanism of Kombucha, a popular fermented beverage of sugared tea, which is mostly attributed to its polyphenolic content. This study also implies the exploitation of Kombucha as a potential new source of bioactive polyphenols against V. cholerae.

A gas-jet transport and catcher technique for on-line production of radioactive ion beams using an electron cyclotron resonance ion-source.

Radioactive ion beams (RIB) have been produced on-line, using a gas-jet recoil transport coupled Electron Cyclotron Resonance (ECR) ion-source at the VECC-RIB facility. Radioactive atoms∕molecules carried through the gas-jet were stopped in a catcher placed inside the ECR plasma chamber. A skimmer has been used to remove bulk of the carrier gas at the ECR entrance. The diffusion of atoms∕molecules through the catcher has been verified off-line using stable isotopes and on-line through transmission of radioactive reaction products. Beams of (14)O (71 s), (42)K (12.4 h), (43)K (22.2 h), and (41)Ar (1.8 h) have been produced by bombarding nitrogen and argon gas targets with proton and alpha particle beams from the K130 cyclotron at VECC. Typical measured intensity of RIB at the separator focal plane is found to be a few times 10(3) particles per second (pps). About 3.2 × 10(3) pps of 1.4 MeV (14)O RIB has been measured after acceleration through a radiofrequency quadrupole linac. The details of the gas-jet coupled ECR ion-source and RIB production experiments are presented along with the plans for the future.

Sudden onset quadriparesis after minor injury to neck in a male with OS odontoideum.

Os odontoideum is a rare anomaly of the second cervical vertebra. Here, a young male patient with quadriparesis secondary to myelopathy associated with os odontoideum is reported. The patient was totally asymptomatic prior to this episode which was precipitated by trivial neck injury. He started recovering with conservative measures and was referred to our neurosurgery department for further evaluation and definitive surgical intervention as there is always a chance of recurrence of symptoms in these patients. There is a role for conservative treatment of an asymptomatic incidentally found, radiologically stable, and noncompressive os odontoideum, however surgery has a definite role in symptomatic cases.

Design and development of a radio frequency quadrupole linac postaccelerator for the Variable Energy Cyclotron Center rare ion beam project.

A four-rod type heavy-ion radio frequency quadrupole (RFQ) linac has been designed, constructed, and tested for the rare ion beam (RIB) facility project at VECC. Designed for cw operation, this RFQ is the first postaccelerator in the RIB beam line. It will accelerate A/q < or = 14 heavy ions coming from the ion source to the energy of around 100 keV/u for subsequent acceleration in a number of Interdigital H-Linac. Operating at a resonance frequency of 37.83 MHz, maximum intervane voltage of around 54 kV will be needed to achieve the final energy over a vane length of 3.12 m for a power loss of 35 kW. In the first beam tests, transmission efficiency of about 90% was measured at the QQ focus after the RFQ for O(5+) beam. In this article the design of the RFQ including the effect of vane modulation on the rf characteristics and results of beam tests will be presented.

Carcinoma of the gall bladder presenting as dermatomyositis.

Dermatomyositis (DM), manifested as paraneoplastic syndrome, is not a very common clinical entity but its association with various internal malignancies is well-documented in literature. We present such a case of DM associated with characteristic skin lesions and subacute onset of proximal muscle weakness, acquired from a very rare malignancy like adenocarcinoma of gall bladder.

Induction of apoptosis by Phenothiazine derivatives in V79 cells.

Phenothiazine derivatives chlorpromazine (cpz) and trifluoperazine (tfp) were found to induce apoptosis, abnormal cell cycle and expression of p53 in Chinese hamster lung fibroblast V79 cells. Both the drugs can induce apoptosis when cells are treated with drug at a concentration of 10 microg/ml within 4 h, as detected by propidium iodide staining and DNA fragmentation analysis. Flow cytometric analysis revealed that the apoptotic response is mediated by a loss of G(1) population of cells. In Western blot analysis, p21 is induced and p53 is accompanied by additional bands. Also indirect immunolabeling of single cells revealed that p21 is accumulated from cytoplasm into nucleus after the drug treatment and the intensities of p53 increased. Our findings demonstrate for the first time that phenothiazine derivatives, in addition to their cytotoxic effects, could induce apoptosis, an observation that has important clinical implications.

Werner syndrome protein interacts with human flap endonuclease 1 and stimulates its cleavage activity.

Werner syndrome (WS) is a human premature aging disorder characterized by chromosomal instability. The cellular defects of WS presumably reflect compromised or aberrant function of a DNA metabolic pathway that under normal circumstances confers stability to the genome. We report a novel interaction of the WRN gene product with the human 5' flap endonuclease/5'-3' exonuclease (FEN-1), a DNA structure-specific nuclease implicated in DNA replication, recombination and repair. WS protein (WRN) dramatically stimulates the rate of FEN-1 cleavage of a 5' flap DNA substrate. The WRN-FEN-1 functional interaction is independent of WRN catalytic function and mediated by a 144 amino acid domain of WRN that shares homology with RecQ DNA helicases. A physical interaction between WRN and FEN-1 is demonstrated by their co-immunoprecipitation from HeLa cell lysate and affinity pull-down experiments using a recombinant C-terminal fragment of WRN. The underlying defect of WS is discussed in light of the evidence for the interaction between WRN and FEN-1.

Sequential assembly of the nucleotide excision repair factors in vivo.

Here, we describe the assembly of the nucleotide excision repair (NER) complex in normal and repair-deficient (xeroderma pigmentosum) human cells, employing a novel technique of local UV irradiation combined with fluorescent antibody labeling. The damage recognition complex XPC-hHR23B appears to be essential for the recruitment of all subsequent NER factors in the preincision complex, including transcription repair factor TFIIH. XPA associates relatively late, is required for anchoring of ERCC1-XPF, and may be essential for activation of the endonuclease activity of XPG. These findings identify XPC as the earliest known NER factor in the reaction mechanism, give insight into the order of subsequent NER components, provide evidence for a dual role of XPA, and support a concept of sequential assembly of repair proteins at the site of the damage rather than a preassembled repairosome.

p53 Modulates the exonuclease activity of Werner syndrome protein.

Werner syndrome (WS) is characterized by the early onset of symptoms of premature aging, cancer, and genomic instability. The molecular basis of the defects is not understood but presumably relates to the DNA helicase and exonuclease activities of the protein encoded by the WRN gene that is mutated in the disease. The attenuation of p53-mediated apoptosis in WS cells and reported physical interaction between WRN and the tumor suppressor p53 suggest that p53 and WRN functionally interact in a pathway necessary for the normal cellular response. In this study, we have demonstrated that p53 inhibits the exonuclease activity of the purified full-length recombinant WRN protein. p53 did not have an effect on a truncated amino-terminal WRN fragment that retains exonuclease activity but lacks the physical interaction domain for p53 located in the carboxyl terminus. Two naturally occurring p53 mutants found in human cancer displayed a reduced ability to inhibit WRN exonuclease activity. In cells arrested in S phase with hydroxyurea, WRN exits the nucleolus and colocalizes with p53 in the nucleoplasm. The regulation of WRN function by p53 is likely to play an important role in the maintenance of genomic integrity and prevention of cancer and other clinical symptoms associated with WS.

Analysis of repair and PCNA complex formation induced by ionizing radiation in human fibroblast cell lines.

Proliferating cell nuclear antigen (PCNA), an auxiliary factor for DNA polymerase delta and epsilon, is involved in both DNA replication and repair. Previous studies in vitro have demonstrated the requirement of PCNA in the resynthesis step of nucleotide excision repair (NER) and base excision repair (BER). Using a native chromatin template isolated under near physiological conditions, we have analysed the involvement of PCNA in the BER pathway in different NER defective human cell lines. The repair sites and PCNA were visualized by indirect immunolabelling followed by fluorescence microscopy. The results indicate that exposure to X-rays triggers the induction of PCNA in all the three human fibroblast cell lines studied, namely normal, xeroderma pigmentosum group A (XP-A) and Cockayne syndrome group B (CS-B). In all the cell lines, induction of PCNA and repair patches occurred in a dose- and time-dependent fashion. Induction of repair patches in NER-deficient XP-A cells suggests that the X-ray-induced lesions are largely repaired via the BER pathway involving PCNA as one of the key components of this pathway. X-ray-induced repair synthesis was greatly inhibited by treatment of cells with DNA polymerase inhibitors aphidicolin and cytosine arabinoside. Interestingly, inhibition of repair resynthesis did not affect the intensity of PCNA staining in X-irradiated cells indicating that the PCNA may be required for the BER pathway at a step preceding the resynthesis step.

Characteristics of UV-induced repair patches relative to the nuclear skeleton in human fibroblasts.

We have tried to characterize the nucleotide excision repair (NER) events associated with the nuclear skeleton in both repair-proficient and repair-deficient human cell lines following UV irradiation. The repair patches were labelled with biotin-16-dUTP and the repair sites were visualized by fluorescence microscopy using fluorescence-conjugated antibodies to biotin. The intensities of repair labelling measured for the three human cell lines of normal, xeroderma pigmentosum group C (XP-C) and Cockayne syndrome group B (CS-B) are in good agreement with their known repair capabilities. Digestion of nuclei with DNase I markedly solubilized the repair patches in normal (3-fold reduction after 1 h post-UV incubation) and transcription-coupled repair (TCR)-defective Cockayne syndrome cells (6-fold reduction after 1 h post-UV incubation). The intensity of repair labelling remained the same in TCR-proficient XP-C cells after DNase I digestion, indicating that the repair events mediated by the TCR pathway are tightly associated with the nuclear skeleton. Treatment with ammonium sulphate after DNase I digestion further reduced the intensity of repair patches in both normal and Cockayne syndrome cells, but not in XP-C cells. The tight association of repair patches generated by the TCR pathway with the nucleoskeleton in XP-C cells reinforces the concept of functional compartmentalization of the nucleus, where NER is highly heterogeneous.

Cytotoxic and genetic effects of X-irradiation of human cells in the presence of chlorpromazine.

Human epidermoid carcinoma cells (Hep-2) were X-irradiated in the presence of 5-10 micrograms/ml of chlorpromazine (CPZ). Survival of the cells decreased with increasing CPZ concentration. Lymphocytes from three normal volunteers exposed to X-irradiation in the presence of CPZ showed an increased frequency of dicentric and ring formation.