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MICROSCOPY AND STAINING

MICROSCOPY AND STAINING. CHAPTER 3. New Novartis Drug Effective in Treating Heart Failure By ANDREW POLLACK

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MICROSCOPY AND STAINING

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  1. MICROSCOPY AND STAINING CHAPTER 3

  2. New Novartis Drug Effective in Treating Heart Failure By ANDREW POLLACK The experimental drug developed by the Swiss company Novartis reduced the risk of dying from cardiovascular causes and could replace what has been the bedrock treatment for more than 20 years, researchers said. The drug, which is being developed by the Swiss company Novartis, reduced both the risk of dying from cardiovascular causes and the risk of being hospitalized for worsening heart failure by about 20 percent in a large clinical trial. “I think that when physicians see these data, they will find it compelling, and what we will see is a paradigm shift,” said Dr. Milton Packer, a professor of clinical sciences at the University of Texas Southwestern Medical Center in Dallas and one of the two principal investigators in the study. Five million to six million Americans, and an estimated 26 million people globally, have heart failure, and it is the leading cause of hospitalization in the United States and Europe, according to a recent paper in the Journal of the American College of Cardiology. LCZ696 is a combination of two drugs. One is valsartan, the blockbuster heart drug that Novartis sells as Diovan. The other component inhibits the enzyme neprilysin, a new mechanism of action for a heart failure drug.

  3. Mechanism of action Valsartan blocks the angiotensin II receptor type 1 (AT1) and thereby causes vasodilatation and increases excretion of sodium and water via the kidneys (by reducing aldosterone production). The latter mechanism leads to a reduction in blood volume.[7] AHU-377 is a prodrug that is activated to LBQ657 by de-ethylation via esterases.[8] LBQ657 inhibits the enzyme neprilysin,[1] which is responsible for the degradation of atrial and brain natriuretic peptide, two blood pressure lowering peptides that work mainly by reducing blood volume.[9]

  4. In a First, Test of DNA Finds Root of Illness Joshua Osborn, 14, lay in a coma at American Family Children’s Hospital in Madison, Wis. For weeks his brain had been swelling with fluid, and a battery of tests had failed to reveal the cause. The doctors told his parents, Clark and Julie, that they wanted to run one more test with an experimental new technology. Scientists would search Joshua’s cerebrospinal fluid for pieces of DNA. Some of them might belong to the pathogen causing his encephalitis. The case, signals an important advance in the science of diagnosis. For years, scientists have been sequencing DNA to identify pathogens. But until now, the process has been too cumbersome to yield useful information about an individual patient in a life-threatening emergency. “About 60 percent of the time, we never make a diagnosis” in encephalitis, said Dr. Michael R. Wilson, a neurologist at the University of California, San Francisco, and an author of the new paper. “It’s frustrating whenever someone is doing poorly, but it’s especially frustrating when we can’t even tell the parents what the hell is going on.” The researchers’ latest method is called unbiased next-generation sequencing. To identify a pathogen, the researchers extract every scrap of DNA in a sample from a patient, which might be blood, cerebrospinal fluid or stool. Then they sift the genetic fragments for those belonging to pathogens. “It could be one test to rule them all,” Dr. DeRisi said in an interview. But such a test would be useful only if it were fast, and sorting through millions of DNA fragments has been an intensive technological challenge. Playing this match game can take weeks. “The problem is that your critically ill patient will be dead by the time you make a diagnosis,” said Dr. Charles Chiu, a pathologist at the university who collaborates with Dr. DeRisi on diagnostic technologies. Dr. Chiu and his colleagues have developed software that rapidly compares DNA fragments with genetic sequences stored in online databases.

  5. Single Dose of Antibiotic Found Effective in Quelling MRSA single infusion of an antibiotic can clear serious bacterial skin infections — including methicillin-resistant Staphylococcus aureus, or MRSA — just as effectively as the 10-day regimen now used to treat patients, researchers reported Wednesday. The study was led by researchers at Duke University and designed and funded by the Medicines Company, the maker of the antibiotic, oritavancin. The drug, to be sold as Orbactiv, may be approved by the Food and Drug Administration as early as August under a special fast-track process, the company said. In the new study, 475 patients with acute bacterial skin infections received a large single infusion of oritavancin, while 479 similar patients received vancomycin, the current treatment, twice a day for seven to 10 days. Response rates to the two regimens were similar: 82 percent of the patients receiving oritavancin and 78.9 percent of those on vancomycin saw skin lesions shrink or stop spreading, and their fevers disappeared; additional antibiotics were not required. Oritavancin is effective because it persists in the body. Though none of the trial participants developed an allergic reaction to the drug, a serious reaction could result in extended illness, Dr. Chambers said. There is no way to stop the treatment if a patient turns out not to have an drug-resistant infection, some experts noted. And if patients are sent home after the treatment is administered, there is a chance that doctors could miss even more serious infections, like necrotizing fasciitis, the so-called flesh-eating bacteria, said Dr. G. Ralph Corey of Duke University Medical Center, the lead author of the study. oritavancin is an analogue of vancomycin (chemically modified) and therefore is a peptidoglycan inhibitor. We will talk at great length about peptidoglycan inhibitors.

  6. CHAPTER 3 MICROSCOPY AND STAINING- Most of the material in this chapter is much better presented in Bio 209 laboratory and the laboratory for Bio 309 where you can actually do hands on work with the microscope and sample preparation. Hence, I will cover only those topics needed to understand material in subsequent chapters. http://www.youtube.com/watch?v=77J4i3uyna0 Compound light microscope for those not taking the laboratory Electron microscope for those not taking The laboratory http://www.youtube.com/watch?v=fToTFjwUc5M Fluorescent microscope for those not taking the laboratory http://www.youtube.com/watch?v=O6JVAUgz0MU

  7. Gram + CV-I complex Gram - CV-I complex is not extracted from Gram positive orgs. Fig. 3.3 Gram stain

  8. This stain produces vivid red color in acid fast organisms such as Mycobacterium leprae, the cause of leprosy or Mycobacterium tuberculosis, the cause of tuberculosis. Fig. 3. 31 The Ziehl-Neelsen acid-fast stain

  9. The clear area around the crystal violet stained organism is the capsule- which does not accept the India ink . Negative staining for capsules reveals a clear area (the capsule, which does not accept stain) in a dark pink background of India ink and crystal violet counter stain Fig. 3.32 Negative staining

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