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Nicotine as a mitogenic stimulus for pancreatic acinar cell proliferation

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World Journal of Gastroenterology 2006年第46期12卷 7428-7432页

作者： parimal Chowdhury Kodetthoor B Udupa Departments of Physiology and Biophysics University of Arkansas for Medical Sciences 4301 W Markham Street Little Rock Arkansas 72205 United States Departments of Physiology and Biophysics and Geriatrics University of Arkansas for Medical Sciences 4301 W Markham Street Little Rock Arkansas 72205 United StatesMedical Service Central Arkansas Veterans Healthcare System Little Rick Arkansas 72205 United States

Cell proliferation is an important process in life for growth of normal and cancer cells. The signal transduction pathways activated during this process are strictly regulated. This editorial focuses on the role of nicotine, a mitogen, in the induction of signaling pathways resulting in proliferation of pancreatic tumor cells and compares these events with those in normal acinar cells isolated from the rat pancreas. The data shows striking similarities between these two cellular systems. In addition, the editorial reviews very recent literature of the contribution of MAPK signaling in cell lines associated with human diseases. A prospective cellular model of nicotine induced activation of MAPK cascade is presented.

关键词：胰腺腺细胞病理胰腺癌细胞增殖烟碱 ERK 有丝分裂 MAPK

Endogenous modulators in the regulation of ion transporting enzymes: structure, function, interactions, recent advancements and future perspectives

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Advances in Biological Chemistry 2011年第3期1卷 74-92页

作者： parimal C. Sen 不详

A prerequisite for life is the ability to uphold electro-chemical imbalance across biomembranes. Ion trans- porting enzymes, known as specific pumps, are re-sponsible for the transport of various ions across cell membranes to sustain the same. In all eukaryotes, the plasma membrane potential and secondary transport systems are maintained by the activity of P-type ion transporting enzymes, commonly known as ATPase membrane pumps. Malfunction of pumps leads to various cell disorders and subsequently diseases like cardiac problems, renal malfunctionings, diabetes, cataract, even cancer. Activities/functions of these pumps are regulated either by exogenous agents or by endogenous substances like proteins, peptides, hormones, etc., which are collectively known as mo- dulators. Some of these endogenous modulators may be useful for developing drugs depending on the na-ture of regulation. For more than last two decades, researchers across the globe are exploring the me- chanism of action of different endogenous modulators on these ion transporting enzymes with the aim of developing target-specific drugs. In this review, we have discussed recent advances in our understanding of ATPase pumps, e.g., Ca2+-, Na+, K+-, Ca2+, Mg2+-, H+, K+-ATPases, with the emphasis on their functional regulation by a number of endogenous modulators, and the implications of development of some of these modulators as potential drugs.

关键词： ATPases Endogenous Protein/Peptides FX- YD Phospholamban Sarcolipin Interleukin Regulations.

Distribution of ^3H—nicotine in Rat Tissues Under the Influence of Simulated Microgravity

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Biomedical and Environmental Sciences 1999年第2期12卷 103-109页

作者： parimal CHOWDHURY MICHAEL E. SOULSBY AND JAMES N. PASLEY (Department of Physiology and Biophysics, University of Arkansas for Medical Scienses, Little Rock, Arkansas 72205, USA) Univeristy of Arkansas for Medical Sciences 美国

Rat tail suspension offers a useful model to reproduce physiologic responses to *** present study was conducted in the head-down-tilt(HDT) rat model to assess changes in metabolism of body tissues employing 3H-nicotine. Twelve male rats were used in the study. Half of the rats were tail suspended at 30°for two weeks on a 12/12 light/dark cycle. During this period,body weight, food and fluid intakes were measured. At term, animals were anesthetized and injected IV withe a solution contaming 4 microuries of micotine. After 90 min the animals were sacrificed, exsanguinated and tissues (brain,blood,trachea,salivary gland,lung,heart,esophagus,spleen, kidneys and testes) were harvested. The distribution of 3H-nicotine per gram of each tissue was determinded and ealeulated as percent of total injected radioactivity. Final body weights of suspended ammals were significantly (P < 0.0 5) lower than those of eontrols(309±21 vs 350±11g). 3HNicotine waw retained in greatest amounts by the kindneys, followed inorder by salivary glands, spleen, and gastrointestinal tissues. compared to non-suspended control, the tissue retention of nicotine in suspended animals was decreased in the following tissues:esphyagus (25 %), aorta (25%). fundus (25%), trachea (22%), adrenals (18%), spleen (17 %), and pancreas (12 %). The decreased retention of mcotine in tissues from suspended animals may be indicative of the fluid shifts and changes in blood flow to those tissue beds. The lack of differnces in nicotine retention in liver and kidney between control and suspended groups may implicate a normal metabolic function of these organs even under simulated weightlessness.

关键词： Gravitation Animals Male Nicotine Rats Rats, Sprague-Dawley Research Support, Non-U.S. Gov't Tissue Distribution Tritium Weightlessness Simulation

The genetics of nicotine dependence:Relationship to Pancreatic cancer

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World Journal of Gastroenterology 2006年第46期12卷 7433-7439页

作者： Stewart L MacLeod parimal Chowdhury Department of Pediatrics University of Arkansas for Medical Sciences and Arkansas Children's Hospital Research Institute Arkansas Center for Birth Defects Research and Prevention Little Rock AR United States Department of Physiology University of Arkansas for Medical Sciences Little Rock AR United States

SmoKing or tobacco products continues to De a major cause of worldwide health problems. Epidemiological studies have shown that tobacco smoking is the greatest risk factor for the development of pancreatic cancer. Smokers who are able to quit smoking can reduce their risk of pancreatic cancer by nearly 50% within two years, however, their risk of developing pancreatic cancer remains higher than that of non-smokers for 10 years. Nicotine is the major psychoactive substance in tobacco, and is responsible for tobacco dependence and addiction. Recent evidence suggests that individuals have genetically based differences in their ability to metabolize nicotine, as well as genetic differences in the psychological reward pathways that may influence individual response to smoking initiation, dependence, addiction and cessation. Numerous associations have been reported between smoking behavior and genetic polymorphisms in genes that are responsible for nicotine metabolism. In addition, polymorphisms in genes that encode neurotransmitters and transporters that function in psychological reward pathways have been implicated in differences in smoking behavior. However, there is a large degree of between-study variability that demonstrates the need for larger, well-controlled case-control studies to identify target genes and deduce mechanisms that account for the genetic basis of inter-individual differences in smoking behavior. Understanding the genetic factors that increase susceptibility to tobacco addiction may result in more effective tobacco cessation programs which will, in turn, reduce the incidence of tobacco related disease, including pancreatic cancer.

关键词：烟碱依赖胰腺癌遗传因素抽烟遗传多态性尼古丁代谢

Titanasilsesquioxane-Alkylaluminum Catalyst System for Ethylene Polymerization

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Modern Research in Catalysis 2012年第3期1卷 29-42页

作者： Akshay Mehta Gopal Tembe parimal Parikh Girish Mehta Applied Chemistry Department S. V. National Institute of Technology Surat India Chemical Engineering Department S. V. National Institute of Technology Surat India Reliance Technology Group Reliance Industries Limited Vadodara Manufacturing Division Vadodara India

Homogeneous Ti(IV) complexes covalently anchored to Polyhedral Oligomeric Silsesquioxane (POSS) have been synthesized by the stoichiometric reaction between titanium(IV)alkoxide and (iso-Octyl)7Si7O9(OH)3. These catalyst precursors formulated as [Ti(OR)(iso-Octyl)7Si7O12] were characterized by physicochemical and spectroscopic methods. These supported catalysts are found to be active in polymerization of ethylene at high temperatures in presence of ethylaluminum sesquichloride (Et3Al2Cl3, EASC) as co-catalyst. The polyethylene obtained are generally linear, crystalline and display low molecular weight distribution. The microstructure of the polymer was analyzed by NMR and FT-IR spectroscopic methods which indicated a chain transfer reaction to aluminum. The unique molecular properties of PE formed has been compared with commercial micronized PE wax which find industrial applications in surface coating and ink formulations. The effect of reaction conditions on catalytic behaviour is described.

关键词： POSS Titanasilsesquioxane Polyethylene Ethylaluminum Sesquichloride Polymer Microstructure

Experimental Investigation on Fuel Coolant Interaction Using Simulant Ceramic Melts in Water: Insights and Conclusions

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World Journal of Nuclear Science and Technology 2020年第4期10卷 139-157页

作者： Nitendra Singh Arun K. Nayak parimal P. Kulkarni Homi Bhabha National Institute Mumbai India Bhabha Atomic Research Centre Reactor Engineering Division Mumbai India

Steam explosion is one of the crucial and poorly understood phenomena which may occur during severe accident scenario and may lead to containment failure. In spite of several experimental and analytical studies, the root cause of steam explosion has not been understood. Recent claims in the literature suggest that the presence of fine fragmentation during steam explosion causes its occurrence. In order to investigate this and understand the root cause of steam explosion, series of experiments were performed with 50 g to 2500 g of CaO-B2O3, a corium simulant in 4.5 litre of water. It was observed that steam explosion may occur even in the absence of fine fragments, which is contrary to the claims in the literature. To investigate further, conversion efficiency analysis was performed. This suggested that the amount of thermal energy converted to mechanical energy is more important deciding factor in explaining the occurrence of steam explosion. The present study discusses the importance of conversion efficiency in deciding steam explosion and also gives a new perspective to look at steam explosion phenomenology.

关键词： Severe Accident Core Catcher Steam Explosion Fuel Coolant Interaction Fragmentation

Modeling bovine lameness with limb movement variables

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Journal of Biomedical Science and Engineering 2011年第6期4卷 419-425页

作者： Yukun Wu Nagaraj Neerchal Robert Dyer Uri Tasch parimal Rajkondawar 不详

Lameness detection is a world-wide challenge to far-mers and veterinarians. Traditionally, one uses visual observation to make judgment on a cow's lameness or soundness. Visual observation heavily depends on the observer's experience, hence is subjective or ob-server-dependent. And even worse, it is inconsistent. It's reported that the agreement between veterinarians can be as low as 45% [1]. It is necessary and urgent to develop an objective detection method that can automatically detect lameness when it occurs. In this paper, we describe how statistical models can be used to develop such methods and how well the statistical models perform.

关键词： Statistical Modeling Bovine Lameness Detection

Excess adsorption of biomolecules on soft surfaces: Adsorption of DNA, proteins and lactose on fatty surfaces

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Advances in Biological Chemistry 2013年第1期3卷 40-47页

作者： Dipta Shani Dutta Dipti Kumar Chattoraj parimal Chattopadhyay Kali P. Das Department of Chemistry Bose Institute Kolkata India Department of Food Technology & Biochemical Engineering Jadavpur University Kolkata India

Insoluble fatty surfaces are involved in many important interactions such as in biomembranes with soluble biological macro and micromolecules. In this paper we have studied the adsorption interaction of aqueous solution of DNA, some proteins and lactose on several sparingly soluble fatty substances namely milk fat, stearic acid, palmitic acid, phosphatidyl choline and cholesterol surfaces by measuring the depletion of the adsorbates by analytical methods. Adsorption () of DNA on the soft surfaces of stearic acid, milk fat, phosphatidyl choline, palmitic acid and cholesterol was measured as a function of DNA concentration C2. In each case was found to increase with C2 until it reached the maximum value at a critical concentration . For different surfaces stands in the order: stearic acid > milk fat > phosphatidyl choline > cholesterol > palmitic acid. DNA forms multilayers on stearic acid surface. Adsorption of hemoglobin on cholesterol surface is found to be negative or zero but that of BSA on cholesterol is positive. Adsorption of gelatin on cholesterol surface is significantly higher than that of BSA. Lysozyme on cholesterol surface forms multilayers and on casein forms bilayer. The lowering of free energies ?DGo for all systems have been calculated using integrated form of the Gibbs adsorption and their values have been compared with each other. It is concluded that despite differences in the adsorption behavior of the biomolecules on various soft surfaces, free energy change expressed as Bull’s free energy change (Δ) remain nearly constant except for BSA-fatty acid interaction which may be likely due a specific interaction.

关键词： Excess Adsorption Surface Adsorption of Biomolecules Soft Surfaces Adsorption on Soft Surfaces DNA Globular Proteins

Tissue Distribution of [^3H]—Nicotine in Rats

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Biomedical and Environmental Sciences 1993年第1期6卷 59-64页

作者： parimalCHOWDHURY RYUICHIRODOIPHILLIPL.RAYFORD LOUISW.CHANG Departments DepartmentsDepartments of Physiology BiopgysicsToxicologyUniversity of Arkansas for Medical Sciences4301W.Markham StLittle RockA R 72205USAof Physiology and BiophysicsUniversity of Arkansan for Medical Sciences4301W.Markham StLittle RockA R 72205USAof Physiology and ToxicologyUniversity of Arkansas for Medical Sciences4301W.Markham StLittle RockA R 72205USA

This study was conducted in adult male Sprague -- Dawley rats to determine the distribution of [3H]-nicotine in blood and tissues following a bolus injection and a constant infusion of pure nicotine. The animals were anesthetized and injected with either 0.5 ml of nicotine solution or given a constant infusion of the same nicotine solution with identical amounts of radioactive nicotine. After sacrifice, blood, brain, trachea, salivery gland, esophagus, lung, heart, liver, fundus, antrum, spleen, pancreas, duodenum, jejunum, ileum, cecum, colon, kidneys, adrenal gland, and testes were collected and measured for radioactivity by scintillation counting. The distribution of nicotine was found highest in kidneys by both routes of administration. Higher accumulations were also found in salivary and adrenal glands, fundus, antrum, duodenum, jejunum, ileum and colon. Retention of nicotine via constant infusion was significantly higher in esophagus, fundus antrum, spleen, cecum, pancreas, testes, heart and muscle when compared with bolus injection. Six-fold increase in retention of blood levels of nicotine were found with constant infusion. (P<0.05). The results indicate that longer retention of nicotine occurs in blood and other specific tissues such as esophagus, fundus, antrum, spleen, cecum, pancreas, testes, heart and muscle via constant exposure. These data may implicate the predisposition of these tissues to pathologic manifestations.

关键词： Tissue Distribution of Nicotine in Rats