Antibiotic drugs are commonly used in veterinary medicine to treat infectious diseases that are caused by bacteria and certain other microorganisms. There are many different classes of antibiotics available for use in animals, including penicillins, cephalosporins, cephamycins, aminoglycosides, quinolones, sulfonamides, tetracyclines, and macrolides. Some are effective against a wide range of organisms, while others are more closely targeted (for example, they may be effective against some bacteria but less effective against other bacteria). Thus, antibiotics are often referred to as broad-spectrum or narrow-spectrum drugs, respectively.
Successful antibiotic treatment is based on 4 principles: 1) identifying the disease-causing agent and selecting the appropriate drug for treatment; 2) attaining effective concentrations of the drug at the site of infection for a sufficient period of time; 3) choosing a dose rate, frequency, and method of administering the dose that maximizes the likelihood of a cure, prevents relapse, and minimizes the risk of developing resistance while causing no harm to the animal; and 4) using specific and appropriate supportive treatment to improve the animal’s ability to overcome the infection and associated disease conditions.
The emergence of bacteria that are resistant to currently available antibiotics within the animal or human population is of great concern. When resistance occurs, previously successful drugs can no longer be considered effective treatment, and new drugs must be developed. Resistance may develop in several different ways. However, when used properly (that is, the right antibiotic is used and it is given as prescribed for the appropriate amount of time), antibiotics are less likely to contribute to the selection of antibiotic-resistant organisms.
When given a prescription from your veterinarian for your pet, make sure that it is given exactly as instructed and that the entire prescription is given. Not following dosage schedules or not giving all of the prescription can cause a relapse, a reinfection, or development of antibiotic-resistant organisms.
Anthelmintic drugs
Anthelmintics are drugs that are used to treat infections with parasitic worms. This includes both flat worms, e.g., flukes and tapeworms and round worms, i.e., nematodes. They are of huge importance for human tropical medicine and for veterinary medicine. The World Health Organization estimates that a staggering 2 billion people harbour parasitic worm infections. Parasitic worms also infect livestock and crops, affecting food production with a resultant economic impact. Also of importance is the infection of domestic pets. Indeed, the companion animal market is a major economic consideration for animal health companies undertaking drug discovery programmes. Despite the prevalence of parasitic worms, anthelmintic drug discovery is the poor relation of the pharmaceutical industry. The simple reason is that the nations which suffer most from these tropical diseases have little money to invest in drug discovery or therapy. It comes as no surprise therefore that the drugs available for human treatment were first developed as veterinary medicines. There is thus a pitifully small repertoire of chemotherapeutic agents available for treatment (see Table 1). In some respects, this situation has been exacerbated by the remarkable success of ivermectin over the last twenty years (Geary, 2005), which has decreased motivation for anthelmintic drug discovery programmes (Geary, Sangster and Thompson, 1999). This prompts concern, as anthelmintic resistance has been widely reported in livestock and it may also only be a matter of time before this phenomenon occurs in parasites of humans.
Broad spectrum anthelmintics are effective against parasitic flat worms and nematodes. However, the majority of drugs are more limited in their action, e.g., praziquantel, a drug used in the treatment of schistosomiasis and thought to act by disrupting calcium homeostasis (Greenberg, 2005), has no activity against nematodes (see Table 1). For the purpose of this review we will focus on drugs used in human and veterinary medicine to treat parasitic nematode infection.
How to Prepare for a Career in Veterinary Medicine
Get Started in High School
For a career in veterinary medicine, a high school student should develop a strong background in biology, chemistry, and physics. Courses in English, social science, and speech are also necessary since interpersonal and professional communications skills are important assets in veterinary medicine. Like most professions, veterinary medicine is very much a "people business." The most successful veterinarians are competent doctors as well as good communicators.
Practical experience with animals is very important. Students should spend time volunteering for or working with veterinarians to develop an understanding of the profession. Non-veterinary animal experience may also be beneficial to students interested in veterinary medicine.
No specific undergraduate program is preferred at Oregon State University, but students must complete a set of pre-veterinary requirements in chemistry, physics, mathematics, statistics, biology, genetics, physiology, and additional biological sciences. Courses in English, public speaking and humanities/social sciences are also required.
Many students choose an animal science or biological science major because these bachelor's degree programs generally include most of the pre-veterinary requirements. Also, some of these programs allow students accepted into the DVM program after their junior year to apply credits earned in their first year of veterinary study toward completing a bachelor's degree.
Students interested in veterinary medicine, should consult with a pre-veterinary medicine adviser when planning their undergraduate program. Oregon State University students may choose to contact one of the OSU pre-veterinary medicine advisers.
Difference Between Mixture and Solution
In chemistry, student tend to mix up or be confused about concepts like mixture and solution. These are basic concepts and there should be no excuse in mixing up the concepts. Besides students should master such concepts and it will help them avoid negative marking during exams. Thus, it is important to know the difference between mixture and solution.
To help you understand the concepts, a mixture is a combination of usually two substances. Here, the substances are not combined chemically and their properties also remain the same. However, when we talk about a solution it is totally different. different. Solution is a type of mixture where substances are dissolved. Here you have to know about solute which is a substance that dissolves and solvent which dissolves the solutes to form a solution.
Before diving into the differences, it is important to understand and remember that a solution is a type of mixture but a mixture may or may not be a solution. Now that we know a little about these two concepts, let’s look at some of the key differences between mixture and solution.
Mixture
Solution
In a mixture, substances are generally just mixed and are not completely dissolved.
In a solution, substances are dissolved completely and they cannot be filtered out.
Mixture comprises two or three compounds that aren’t fused chemically. They have no physical interactions.
A solution contains two substances that are chemically mixed to form a new compound.
The chemical properties of each substances are retained without change.
Chemical properties usually changes.
The amount of substances in a mixture can vary and amounts don’t have a fixed ratio.
A solution usually has a fixed ratio or amount of substances.
Mixtures can be classified primarily into two groups, namely homogeneous mixtures and heterogeneous mixtures.
A solution is a type of a homogeneous mixture.
These are some of the differences between mixture and solution. To know more about the mixtures and solutions and other chemistry topics you can keep visiting BYJU’s or download our app for interesting content and learning experience.
Liquid refrigerant injection
Liquid refrigerant injection technique can be a very effective method for controlling subcooling and the compressor discharge temperature of a refrigeration system at high ambient temperatures. In this study, the effects of liquid refrigerant injection on the performance of a refrigeration system with an accumulator heat exchanger were investigated by varying the liquid injection rate at the conditions of constant expansion valve opening in the evaporator and constant total flow rate. During the tests, the ambient temperature was maintained at 43 °C. With the increase of the liquid injection rate, the subcooling at the inner heat exchanger outlet increased and the superheat at the accumulator outlet decreased. However, unacceptable results such as the increase of the compressor discharge pressure and decrease of the system performance were also observed depending on the control method applied. To obtain high system performance and reliability, optimum control methods for liquid injection in the accumulator heat exchanger are suggested. The liquid injection technique for the refrigeration system with an accumulator heat exchanger was found to be an effective method for controlling adequate subcooling and the compressor discharge temperature of the refrigeration system at high ambient temperatures.
Sie sind vermutlich noch nicht im Forum angemeldet - Klicken Sie hier um sich kostenlos anzumelden