Analysis of Galanin Using Mass Spectrometry Essay

Analysis of Galanin Using Mass Spectrometry - Essay Example It is reported that obese human beings have been observed to have high levels of serum galanin; this suggests that peripheral galanin has a role to play in the regulation of balance of energy and that high circulating galanin levels are a contributing factor to the development of obesity and obesity-related metabolic impairments. In their findings, they report that high levels of galanin in the serum can help regulate body weight, metabolic rate and carbohydrate-lipid metabolism through a mechanism that does not depend on the feeding regulation Galanin may also be responsible for high altitude induced anorexia. Singh et al. (2001) carried out studies on the roles played by galanin and neuropeptide Y in high altitudes in food uptake. Male Sprague-Drawley rats were exposed to conditions mimicking those at a high altitude of 7620 meters for 1, 7, 14 and 21 days for a six-hour period each day and to an altitude of 6096 meters for a continuous 72 hours to study the effects of intermittent and continuous exposure. Galanin and neuropeptide Y levels were estimated in various parts of the brain and plasma of exposed and unexposed rats. They found that plasma galanin levels decreased in both groups of rats. They asserted that the changes in the levels of galanin may be responsible for anorexia at high altitudes. Galanin signaling occurs through three G protein-coupled receptors. After mucosal stomach biopsies, the galanin can be analyzed using mass spectrometry. The technique Mass spectrometry involves measuring the mass of a compound, this with very high sensitivity. Mass spectrometers require molecules to be charged and in gaseous form for analysis. Peptide molecules in galanin being large and polar, are not easily transferred into the gas phase and ionised. Electrospray (ES) Fenn et al (1989) and matrix-assisted laser desorption ionization (MALDI) Karas and Hillenkamp (1988) are the ionization techniques that are used to transform the galanin into the gas-phase. Mass spectrometers measure the mass/charge ratio (m/z) of analytes. Mass spectrometry and MS/MS is applied in protein study as it makes use of the large array of genome and protein data stored in databases. The lists of peak intensities and mass-to-charge (m/z) values produced by a mass spectrometer can be processed and compared with lists generated from the theoretical digestion of a protein or the theoretical fragmentation of a peptide. Mass spectroscopy makes use of the fact that many protein molecules can be adequately displayed on a single gel. This technology was developed in the 1970s, as noted by Klose (1975) and O’Farrell (1975). Identification of the spots separated on these gels remained laborious and was limited to the most abundant proteins until the 1990s, when biological mass spectrometry had developed into a sufficiently sensitive and robust technique. In the analysis of galanin using mass spectroscopy: 1. The galanin sample will undergo vaporisation to transform i t into a gaseous form. 2. The gaseous form will then be bombarded by an electron beam to generate ions. 3. The generated ions are them separated depending on their mass-to-charge ratio by an electromagnetic field in an analyser. The analyser can be Time of Flight (TOF) or a quadruple ion trap. 4. The ions are detected. 5. The ion signal is processed into mass spectra. Ionization techniques 1. Matrix-assisted laser desorption ionisation MALDI Matrix-assisted laser desorption ionisation (MALDI) employs the use of an excess of matrix material. This matrix is precipitated with the analyte molecules (the analyte contains the galanin molecules to be analysed) by placing a very small volume of the mixture onto a metal substrate and allowing it to dry. This solid is then

Issues in Human Sexuality Unit 4 Essay Example | Topics and Well Written Essays - 1000 words

Issues in Human Sexuality Unit 4 - Essay Example Users very often quickly reveal sexual fantasies, intimate secrets and talk about personal and marital problems (Mileham, 2004). Clearly, this is dangerous and can be very harmful. But is it cheating? There are contradictory opinions regarding this. Those who are in favor of cybersex claim that it cant be defined as cheating because there is no physical contact between the two people having the cybersex, they are only typing and masturbating. Others also say that cybersex is like porn- you do it in order to please yourself, but you dont actually have any contact with others for sex purposes. They claim it is just visual harmless fun. But those who oppose it and claim cybersex is a form of cheating have overwhelming claims, based primarily on logic. When a person is in a monogamous relationship, the one he is with is supposed to be the only with whom he is having an intimate, emotional and sexual relationship. A monogamous relationship means committing to only one person, sharing things with him and experience things with him- and with him alone. If a person is encountering another person for the sake of satisfying his sexual or emotional needs, it doesnt matter that there is no actual physical connection- it is cheating, because it is betraying in the other person that is in the relationship. While this isnt physical cheating, it is an emotional one. This is enhanced due to the fact that the person having cybersex reveals to a complete stranger her innermost hidden sexual fantasies and private feelings and emotions, sometimes revealing information about him and his spouse. This is definitely a situation that port rays betrayal of the person in his spouse, and consequently can most certainly be defined as cheating.