Biomechanical disc culture system: feasibility study using rat intervertebral discs

Ramakrishnan, P S,Hong, J,Martin, J A,Kurriger, G L,Buckwalter, J A,Lim, T-H SAGE Publications 2011 Proceedings of the Institution of Mechanical Engin Vol.225 No.6

Loss of von Hippel-Lindau Protein (VHL) Increases Systemic Cholesterol Levels through Targeting Hypoxia-Inducible Factor 2α and Regulation of Bile Acid Homeostasis

Ramakrishnan, Sadeesh K.,Taylor, Matthew,Qu, Aijuan,Ahn, Sung-Hoon,Suresh, Madathilparambil V.,Raghavendran, Krishnan,Gonzalez, Frank J.,Shah, Yatrik M. American Society for Microbiology 2014 Molecular and cellular biology Vol.34 No.7

<P>Cholesterol synthesis is a highly oxygen-dependent process. Paradoxically, hypoxia is correlated with an increase in cellular and systemic cholesterol levels and risk of cardiovascular diseases. The mechanism for the increase in cholesterol during hypoxia is unclear. Hypoxia signaling is mediated through hypoxia-inducible factor 1α (HIF-1α) and HIF-2α. The present study demonstrates that activation of HIF signaling in the liver increases hepatic and systemic cholesterol levels due to a decrease in the expression of cholesterol hydroxylase CYP7A1 and other enzymes involved in bile acid synthesis. Specifically, activation of hepatic HIF-2α (but not HIF-1α) led to hypercholesterolemia. HIF-2α repressed the circadian expression of Rev-erbα, resulting in increased expression of E4BP4, a negative regulator of <I>Cyp7a1</I>. To understand if HIF-mediated decrease in bile acid synthesis is a physiologically relevant pathway by which hypoxia maintains or increases systemic cholesterol levels, two hypoxic mouse models were assessed, an acute lung injury model and mice exposed to 10% O<SUB>2</SUB> for 3 weeks. In both models, cholesterol levels increased with a concomitant decrease in expression of genes involved in bile acid synthesis. The present study demonstrates that hypoxic activation of hepatic HIF-2α leads to an adaptive increase in cholesterol levels through inhibition of bile acid synthesis.</P>

Trends in the Growth of Literature on Hepatitis(1984-2003): Quantitative Analysis

Babu, B. Ramesh,Ramakrishnan, J. Korean Library and Information Science Society 2007 한국도서관정보학회지 Vol.38 No.2

이 논문에서는 1984년부터 2003년까지 200년에 걸쳐 MEDLINE과 CINAKL. IPA 등 3개 서지데이터베이스에 수록된 간염에 관한 분야의 문헌의 증가추세를 계량과학적으로 분석하였다. 이 기간 동안MEDLINE은 최대인 75,750건의 레코드를 수록하였으며, CINAHL, IPA의 순이었다. 특정지식영역의 연간문헌증가율은 동일하지 않으며, 연간증가율을 측정하기 위해서는 RGR을 적용하는 것이 아주 적합한 것으로 나타났다. RGR은 감소추세를 보였는데, 다만 1985년과 1997년에 성장률에서 약간의 변동이 있었다. 대학과 기업, 연구기관들은 RGR 및 Dt와 관련한 성과에서 성장추세와 감소추세, 변동추세 등의 결과에서 혼재된 양상을 보여주었다. 간염연구는 논문수와 페이지수의 측면에서 연단위로 RGR과 Dt를 산정했을 때는 다양한 양상을 보여주었다. This paper presents a scientometric analysis of the growth of literature output in the field of Hepatitis covered in three bibliographic databases namely MEDLINE, CINAHL and IPA. The literature covered in three databases for the period 1984-2003 was considered. MEDLINE covered the maximum of 75750 records during the study period 1984 to 2003. This is followed by CINAHL and IPA databases. It is found that the annual growth rate of literature in a particular field of knowledge will not be uniform and in order to measure the rate of growth from year after year, the application of RGR is quite appropriate. The RGR has shown a decreasing trend, with a slight fluctuation of growth rate for the years 1985 and 1997. The output by colleges, universities, corporate sector and research institutions with reference to RGR and Dt has shown mixed results such as increasing trend, decreasing trend and fluctuation trend. Hepatitis research indicates a different picture when the RGR and Dt were calculated by year-wise both in terms of number of papers and number of pages.

간염에 관한 문헌의 증가추세(1984-2003): 계량적 분석

B. Ramesh Babu,J. Ramakrishnan 한국도서관·정보학회 2007 한국도서관정보학회지 Vol.38 No.2

이 논문에서는 1984년부터 2003년까지 200년에 걸쳐 MEDLINE과 CINAKL, IPA 등 3개 서지데이터베이스에 수록된 간염에 관한 분야의 문헌의 증가추세를 계량과학적으로 분석하였다. 이 기간 동안 MEDLINE은 최대인 75,750건의 레코드를 수록하였으며, CINAHL, IPA의 순이었다. 특정지식영역의 연간문헌증가율은 동일하지 않으며, 연간증가율을 측정하기 위해서는 RGR을 적용하는 것이 아주 적합한 것으로 나타났다. RGR은 감소추세를 보였는데, 다만 1985년과 1997년에 성장률에서 약간의 변동이 있었다. 대학과 기업, 연구기관들은 RGR 및 Dt와 관련한 성과에서 성장추세와 감소추세, 변동추세 등의 결과에서 혼재된 양상을 보여주었다. 간염연구는 논문수와 페이지수의 측면에서 연단위로 RGR과 Dt를 산정했을 때는 다양한 양상을 보여주었다. This paper presents a scientometric analysis of the growth of literature output in the field of Hepatitis covered in three bibliographic databases namely MEDLINE, CINAHL and IPA. The literature covered in three databases for the period 1984-2003 was considered. MEDLINE covered the maximum of 75750 records during the study period 1984 to 2003. This is followed by CINAHL and IPA databases. It is found that the annual growth rate of literature in a particular field of knowledge will not be uniform and in order to measure the rate of growth from year after year, the application of RGR is quite appropriate. The RGR has shown a decreasing trend, with a slight fluctuation of growth rate for the years 1985 and 1997. The output by colleges, universities, corporate sector and research institutions with reference to RGR and Dt has shown mixed results such as increasing trend, decreasing trend and fluctuation trend. Hepatitis research indicates a different picture when the RGR and Dt were calculated by year-wise both in terms of number of papers and number of pages.

Urinary Incontinence-85: An Expanded Prostate Cancer Composite (EPIC) Score Cutoff Value for Urinary Incontinence Determined Using Long-term Functional Data by Repeated Prospective EPIC-Score Self-assessment After Radical Prostatectomy

Karolin Bossert,Venkat M. Ramakrishnan,Burkhardt Seifert,Kurt Lehmann,Lukas J. Hefermehl 대한배뇨장애요실금학회 2017 International Neurourology Journal Vol.21 No.4

Purpose: To determine an objective cutoff value (COV) for urinary incontinence (UI) using the Expanded Prostate Cancer Composite (EPIC) score after radical prostatectomy (RP). Methods: From 2004–2013, all RP patients at our institution completed the EPIC urinary domain (EPIC-UD) questionnaire preoperatively and 6 weeks; 3, 6, 9, 12, and 18 months postoperatively; and yearly thereafter. The EPIC-UD is composed of several questions, 4 of which address UI qualitatively (EPIC-UI). Furthermore, patients were asked to complete a global quality of life (QoL) questionnaire regarding continence. The EPIC COV was calculated using receiver operating characteristic (ROC) analysis. Correlations between the EPIC-UI and quantitative QoL were evaluated using the Kendall-Tau test. Results: We analyzed 239 patients with a median age of 63 years (interquartile range [IQR], 59–66 years), a median follow-up of 48 months (IQR, 30–78 months) and a median preoperative EPIC-UI score of 100 (IQR, 91.75–100). The ROC analysis for the distinction between EPIC-UI and the use of ≤1 pad/day yielded an EPIC-UI COV of >85, which we termed the UI-85, with an area under the curve of 0.857 (P<0.0001). A stronger correlation was seen between QoL scores and the UI-85 (1 year postoperatively: correlation coefficient [CC], 0.592; P<0.0001) than between QoL and not using a pad (CC, 0.512; P<0.0001). Conclusions: The calculated COV of the EPIC-UI for continence was 85. UI is a multidimensional condition that cannot be adequately characterized by a single piece of information, such as pad usage only. Hence, the UI-85 represents a nuanced and straightforward tool for monitoring and comparing continence between different time points and cohorts in a multidimensional and objective manner.

National Patterns of Research output and Priorities in Hepatitis: a Scientometric Analysis

Babu, B. Ramesh,Ramakrishnan, J. Korea Institute of Science and Technology Informat 2008 Journal of Information Science Theory and Practice Vol.39 No.4

이 연구에서는 MEDLINE과 CINAHL, IPA 등 3개 서지데이터베이스에 수록된 1984년부터 2003년까지 20년간의 문헌을 바탕으로 간염의 하위영역의 국가별 연구패턴과 우선순위에 대한 계량과학적 분석을 시도하였다. 이 연구에서는 연구자들의 간염연구분야의 전반적인 문헌분석에 대한 선행연구를 바탕으로 특히 하위영역에 대한 계량과학적 분석을 시도하였다. 간염분야의 주요 하위영역의 문헌은 23개로 세분되고 있으며, 1984-1993년의 기간중에는 일부 하위영역이 높은 우선순위를 차지하고 있었다. 하위영역의 우선순위가 높은 국가를 분석기간의 전반기와 후반기로 비교해 보면, 전반기(1984-1993)에는 미국(10개하위영역), 영국(9), 독일(8), 캐나다, 러시아, 네덜란드(각각 7) 순이었고, 후반기 (1994-2003)에는 독일(10), 영국(9), 미국(8), 캐나다, 러시아, 네덜란드(각각 7) 순이었다. This paper presents a scientometric analysis of national patterns of research output and priorities in the sub-fields of Hepatitis covered in three bibliographic databases namely MEDLINE, CINAHL and IPA. The literature covered in three databases for the period 1984-2003 was considered. We have already discussed the Trends in the Growth of Literature on Hepatitis in our previous paper. Therefore in this paper only sub-fields analysis is presented. It has been found that the Hepatitis literature output has been grouped in 23 major sub-fields based on databases covered. It was found that there were high priorities for some of the sub-fields of Hepatitis research during 1984-1993. It was found that the research priority profile was more or less homogenous since majority of the sub-fields are showing either below or above average levels of priority profile. In the first phase of the research period covering from 1984-1993, there are high priorities in 10 sub-fields in USA followed by 9 in UK and 8 in Germany, 7 each in Canada, Russia and Netherlands. On the other hand, in the second phase (1994-2003) there are high priorities for 10 sub-fields in Germany, 9 in UK, 8 in USA, 7 each in Canada, Russia and Netherlands. In the productivity of Pediatrics sub-field, India is in the third position.

Ameliorating Effect of Capsaicin on Alterations in Lipid Metabolism during Mice Lung Carcinoma

P. Anandakumar,S. Jagan,S. Kamaraj,G. Ramakrishnan,J. Binu Clara,D. Pathitha,T. Kavitha,T. Devaki 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.2

Spices and vegetables possess antioxidant activity that can be applied for preservation of lipids and lower lipid peroxidation in biological systems. In the present study, we have investigated the effect of capsaicin on lipid metabolism during benzo(a)pyrene induced lung cancer in Swiss albino mice. Benzo(a)pyrene (50 mg/kg wt) induced lung cancer animals showed abnormal changes in the tissue and serum lipids, lipoproteins and lipid metabolizing enzymes. Treatment with capsaicin (10 mg/kg body wt) remarkably attenuated all the above alterations and restored normalcy. These findings reveal the chemomodulatory potential of capsaicin in attenuating the alterations in lipid metabolism during experimental lung carcinogenesis.

Effect of growth temperature on gallium nitride nanostructures using HVPE technique

Munawar Basha, S.,Ryu, S.R.,Kang, T.W.,Srivastava, O.N.,Ramakrishnan, V.,Kumar, J. North-Holland 2012 Physica E, Low-dimensional systems & nanostructure Vol.44 No.9

The growth of hexagonal wurzite one dimensional (1D) gallium nitride (GaN) nanostructures on sapphire substrates using hydride vapor phase epitaxy (HVPE) process was carried out at two different temperatures (973K and 1023K). The GaN nanoneedles were formed at 973K and hexagonal nanorods get formed at 1023K. The morphologies of these nanostructures were studied using high resolution scanning electron microscope. X-ray diffraction and micro-Raman spectroscopy measurements confirmed that the as grown GaN nanostructures are of hexagonal wurtzite structure without any oxide phase. The emission properties of these nanostructures have been investigated using photoluminescence.