By Z. Ningal. Huntingdon College.
Lowenstein-Jensen medium It is the ordinary selective media for tubercle bacilli Raised combivent 100 mcg fast delivery, dry order combivent 100mcg without prescription, cream colored colonies of tubercle bacilli after 3-6 wks of incubation 264 3 discount 100mcg combivent with visa. Pasteurization of milk and milk products Mycobacterium leprae Characteristics: • Typical acid-fast bacilli, arranged in singly, parallel bundles or in globular masses. Foot pads of mice Armadillos Clinical features: Incubation period is months to years. Clinical triads: Anaesthetic skin patches 266 Peripheral neuritis Presence of acid-fast bacilli from skin lesion Two major types of leprosy 1. Comparison of the two types of leprosy Characteristics Lepromatous leprosy Tuberculoid leprosy 1. Usually positive Laboratory diagnosis: Specimen: Skin scrapings from the ear lobe. Non-viable bacilli stain poorly and unevenly as fragmented, beaded and granular red bacilli. When dry, hold fold of skin tightly between the thumb and forefinger until it becomes pale. Using the sterile blade, make a small cut through the skin surface, 5mm long and 2-3mm deep, where the bacteria is be found. Make a small circular smear of the tissue juice (Cover the cut with a small dressing). Wipe the back of the slide clean, and place in a draining rack for the smears to air-dry (protect from direct sun light). Most are soil saprophytes, but some are human pathogens responsible to cause actinomycosis nocardiosis and actinomycetoma. Large group of gram positive bacilli with a tendency to form chains and filaments. Endogenous members of the bacterial flora in the mouth and lower gastrointestinal tract Actinomycosis Chronic suppurative and granulomatous infection with interconnecting sinus tracts that contain sulfur granules Etiology: Actinomyces israeli Actinomyces naeslundii Characteristics:. Gram positive, facultative anaerobe substrate filaments that grow in co2 enriched condition Pathogenesis and clinical features:. Infection is initiated by trauma that introduces these endogenous bacteria into the mucosa 1. Cervico facial actinomycosis 270 Fluctuant mass with draining fistula in jaw area, and may extend to involve bone and lymphnodes in the head and neck 2. Thoracic actinomycosis Resemle subacute pulmonary infection with extension to chest wall and ribs 3. Abdominal actinomycosis May be secondary to ruptured appendix or ulcer with extensive involvement of abdominal organs Lab. Diagnosis: Specimen: Tissue, pus, sputum Smear: Gram-positive filaments with lobulated sulfur granules Culture: Thioglycolate broth or blood agar incubated anaerobically or co2 enriched condition Biochemical reacrion: Catalase positive/negative Treatment: Penicillin Clindamycin + Surgery Erythromycin Nocardiosis Etiology: Nocardia asteroides complex N. Aerobic gram positive, partially aci fast bacilli Pathogenesis and cloinical features: Route of transmission: Inhalation Usual presentation is subacute or chronic pulmonary infection with dissemination to the brain and skin Lab. Spirochete consist of protoplasmic cylinder bounded by a cell wall and outer membrane. There is an axial filament or endoflagella between the cell wall and outer membrane. Not cultured in artificial media, in fertilized eggs and tissue culture, but the saprophytic Reiter strain grows in anaerobic culture. Remain viable in the blood or plasma store at 4 c at least for 24 hrs (transmitted via blood transfusion) Antigenic structure:. Primary stage: Hard chancre: Clean-based, non-tender, indurated genital ulcer with inguinal lymphadenopathy. Secondary stage: Manifests with generalized maculopapular rash condylomata lata and white patches 274 in the mouth. There may be syphilitic meningitis, nephritis, periostitis, hepatitis and retinitis. Primary and secondary syphilis are rich in spirochete from the site of the lesion and patients are highly infectious. Early latent stage: Relapse of symptoms and signs occur, and patients are infectious. Tertiary stage: Manifesting with gumma(granulomatous lesion) in bone, skin and liver; meningovascular syphilis, syphilitic paresis, tabes dorsalis, syphilitic aortitis and aortic aneurysm. One third of cases seems spontaneously cured during primary and secondary syphilis but no clear evidence 2. Out come: Abortion Fetal death Still birth Early neonatal death Organ damage: Congenital syphilis triad. Positive result revert to negative with in 6- 18 months of effective therapy of syphilitic infection Principle: Antigen and antibody (Reagin) reaction results in clumping after aggitation. It can give quantitative results, and valuable in establishing a diagnosis and in evaluating effect of treatment 2. Complement fixation test: Wasserman test; Kolmer test Principle: Reagin-containing sera (mixture of IgM and IgA) fix complement in the presence of “cardiolipin-cholestrol-lecithin complex” antigen. Add diluted serum containing antibody to the sensitized gelatin particle in a microdilution tray. Positive result when agglutination occurs Treatment: Penicillin Tetracycline Erythromycin Control measures: Treatment of cases and screen contacts Practice safe sex with condoms Health education 278 2. Tightly coiled, thin, flexible spiraled spirochetes forming one polared hooked ends. Grow best in semisolid (Fletcher’s or Stuart’s) media under O aerobic condition at 28-30 c. Fatty acid oxidation is major source of energy Antigenic structure: Lipopolysaccharide: Determine the specificity of human immune response to the organism and serologic classification of leptospirae Pathogenesis and clinical features: Essentially zoonotic infection and humans are accidental host Source of infection is contaminated foood and water with leprospia spp. Obligate intracellular pleomorphic gram-negative coccobacilli occurring in single, pairs, short rods and filaments. Antigenic structure: Group-specific antigens Species-specific antigens Clinical Features: Clinical illness is due to the invasion and multiplication of rickettsiae in the endothelial cells of small blood vessels. It manifests with fever, headache, malaise, skin rash and enlargement of liver and spleen. Hosts and vectors of the medically important rickettsiae Organism Disease Hosts Vectors 1. It causes epidemic or louse-borne typhus and the milder recrudescence form, Brill-Zinser disease. Clinical Features: It is transmitted by self-inoculation of the organism by scratching after bite by infected louse(Pediculous humanus corporis and pediculous humanus capitis). The illness manifests with sudden onset of fever, headache, malaise, prostration and skin rash. Epidemics of the disease are associated with overcrowding, cold weather, lack of washing facilities and fuel, famine and war. The disease is milder than louse-borne typhus and occurs in those individuals living or working in highly rat-infested area.
In the United States order 100 mcg combivent with amex, metastatic liver tumors are 20 times as common as primary tumors quality combivent 100mcg. Almost every cancer site can metastasize to the liver combivent 100 mcg mastercard, and liver metastases represent systemic disease. Only in the speciﬁc setting of colon and rectal cancer can liver metastases poten- tially represent regional disease without systemic spread. Patients with one or several metastases technically amenable to resection and no sign of systemic disease can expect a 25% to 35% 5-year survival 414 T. Patients with symptomatic liver metastases from neuroendocrine tumors also beneﬁt from liver resection even if this is not curative. Primary malignant liver tumors are rare in the United States, but worldwide these represent a signiﬁcant cancer burden. Hepatocellular carcinoma (also known as hepatoma) usually arises in patients with cirrhosis. The underlying parenchymal liver disease severely limits the ability to safely perform liver resection in most patients. Patients undergoing liver transplantation for end-stage liver disease sometimes have incidentally discovered small hepatomas. Other forms of primary liver tumors include intrahepatic cholangiocarcinoma and angiosarcoma. The diagnosis usually can be obtained with core needle biopsy or ﬁne- needle aspiration. Occasionally, biopsy requires laparoscopic or open surgical techniques, but this situation is rare. In South American or Mediterranean countries and Australia, echinococcal (hydatid) cysts are prevalent. Examination of patient selection and outcome for hepatic resection for metastatic disease. Resection of the liver of colorectal carcinoma metastases: a multi- institutional study of indications for resection. One hundred patients with hepatic metastases from colorectal cancer treated by resection: analysis of prognostic determinants. Perioperative blood transfusion and determinants of survival after liver resection for metastatic colorectal carcinoma. Experience in hepatic resection for metastatic colorectal cancer: analysis of clinical and pathologic risk factors. A new macroscopic classiﬁcation predicts prognosis for patient with liver metas- tases from colorectal cancer. Resection of hepatic and pulmonary metastases in patients with colorectal car- cinoma. Treatment requires excision of the cyst, with special care taken to avoid spillage of the parasitic contents. Pyogenic bac- terial abscess usually follows an episode of biliary or gastrointestinal tract sepsis. Treatment with metronidazole is effective, and drain- age is required only in complicated cases. Pancreatic Masses In Case 2, the patient’s history and examination immediately do not suggest the cause of her problem. The head and body of the pancreas were well visualized, but the tail seemed to blend into the mass. The mass did not appear to invade surround- ing structures and radiographically appeared resectable. The pancreatic duct in the tail of the pan- creas did not communicate with the mass, but it was displaced cau- dally. The presentation of a pancreatic mass is dependent on the location and nature of the mass. Masses in the head of the pancreas (usually neoplasms) obstruct the common bile duct due to proximity. These patients present with obstructive jaundice, and the masses tend to be only a few centimeters in diameter. Neoplasms in the body or tail of the pancreas grow larger and cause symptoms by impinging on sur- rounding structures. In this case, the mass had caused splenic vein thrombosis, leading to bleeding gastric varices from left-sided portal hypertension. Pancreatic enlargement associated with pan- creatitis usually involves signs of systemic inﬂammation. An algorithm for the evaluation and treatment of pancreatic masses is pre- sented in Algorithm 22. Classically, tumors of the body and tail of the pancreas grow silently and eventually produce symp- toms by invasion of surrounding organs. Tumors of the head of the pancreas occasionally come to attention earlier due to the development of obstructive jaundice. Kearney of the common bile duct to the head of the pancreas allows small pan- creatic tumors the opportunity to obstruct the bile duct. A patient with painless obstructive jaundice should be assumed to have pancreatic cancer until proven otherwise. A small proportion of such patients (15%) have no evidence of systemic disease on imaging. These patients are candidates for curative pancreaticoduodenectomy (Whipple proce- dure). Patients with potentially resectable cancers of the head of the pancreas should not undergo percutaneous needle biopsy. This pro- cedure may risk seeding the abdominal cavity and eliminating a chance of cure. The techniques of pancreatic surgery are advanced enough that mortality rates should be under 3% at specialized centers. If the tumor is technically resectable, the surgeon must be pre- pared to perform deﬁnitive resection without a tissue diagnosis. Five- year survival may be as high as 20% with truly localized disease resected with a negative margin and combined with adjuvant therapy. The differential diagnosis is between a true cystic neoplasm and a pancreatic pseudocyst. Persistent pain and the development of an abdominal mass follow- ing a bout of acute pancreatitis should raise suspicion about a pseudo- cyst. About one third to one half of acute pseudocysts resolve spontaneously within about 6 weeks. Chronic pseudocysts with symptoms of pain, obstruction, and infection usually require treatment. Various treatment options exist, including external percutaneous drainage, internal endoscopic drainage (cystogastros- tomy), and internal surgical drainage (cystogastrostomy or cystoje- junostomy). Percutaneous drainage works well for some patients, but, when the technique fails, the patient often has a complicated course.
In case the presence of a banned substance is reported whereas it is not truly present in the sample order 100 mcg combivent mastercard, farmers may be falsely accused of using banned carcinogenic antibiotics and go bankrupt after prosecution; certain branches may get a bad reputation and people may choose to avoid buying certain products; shipments of perfect quality food products might be destroyed cheap combivent 100 mcg on line, affecting the economy combivent 100 mcg without a prescription, international relations and food security. From this it is clear that, especially for confirmatory methods, selectivity is a very important parameter. This depends on the point of view taken: strict criteria result in an increased probability of false negative results whereas less strict criteria result in an increased possibility of obtaining a false positive result. Although all of the ion ratio criteria were established based on experts’ judgment, it is not unlikely that incorrect identification takes place. The influence of matrix constituents on the ion ratio was described and appointed as a possible cause of deviating ion abundances. In summary, maximum tolerance limits for ion ratio and retention time as established in several legal documents are very useful tools for the confirmation but not necessarily for the identification of compounds. However, some aspects that are not explicitly stated in the guidelines should be taken into account: - The selectivity of the whole procedure, including the sample preparation procedure. An alternative to the use of a priori established tolerance limits as indicated by the legal framework was presented by Van de Voet et al. The applicability of constructing a confidence interval for the ion ratio based on empirical data was demonstrated using a multi-variate approach. This approach was found very useful to replace a priori established tolerance limits, especially at very low concentration levels. Using these approaches, the confidence needed for determination of the identity can be easily set by adjusting the confidence interval parameters. But the chance on false positives and false negatives is set based on empirical data (e. First, potentially interfering substances that are likely to be encountered shall be evaluated. Representative blank samples shall be fortified at a relevant concentration with these substances to test for interferences. Second, at least 20 representative blank samples shall be analysed under within-laboratory reproducibility conditions to detect the presence of possible interferences and to estimate the effect of these interferences. According to the regulations, from the combination of the ‘identification points concept’ and the recommendations to test for interferences, optimal selectivity should be obtained, even though the guidelines do not seem to originate from statistically supported data. At the same time the document states: “An estimate to which extent this (the occurrence of a false positive result) is possible has to be provided. A selectivity number was assigned based on the number of compounds that would respond to the reaction in the most favorable circumstances possible. It would not be necessary to have more than about six or seven groups because if several compounds respond in a reaction the term selectivity would become meaningless . This approach was further improved in 1976 differentiating natural selectivity (under general conditions) and selectivity under the most favorable conditions . An approach for evaluation of the certainty of analytical methods, among which chromatography and mass spectrometry, was reported in 1989 . An uncertainty factor was introduced representing the reciprocal value of the number of possibilities for an open set and the ratio of the number of indistinguishable items to the total number of items for a closed set. However, this is based upon the number of peaks fitting in a chromatogram and is not correlated to any parameters (e. Binary coded mass spectra were used and thus the abundance of the ions was discarded. On this basis the information given by a specific ion was determined indicating that the presence of an ion at m/z 77 gave the most information and is therefore the most selective. Furthermore, a nearly linear correlation was found between the mass and the occurrence of ions above m/z 115. Based on this probability matching was carried out based upon the probability theory which states that if a number of events occur with a certain probability, the 32 Chapter 1 probability of all these events to occur is the multiplication of all the individual probabilities. This overall probability is a measure for the uniqueness of a spectrum and thus for selectivity. Methods of analysis Methods are generally divided in screening and confirmatory methods. Screening methods are usually inexpensive, rapid and suitable for high-throughput analysis, but do not provide unequivocal identification and usually do not result in exact quantitative results. Confirmatory methods must be instrumental spectrometric techniques and therefore are more expensive and time-consuming, but are supposed to be highly selective in order to provide unequivocal identification. The combination of a bio-based screening method and an instrumental confirmatory method is very strong in residue analysis. With a bio-based screening a fast qualification (compliant or suspect) of samples can be made based on biological activity. Compliant samples can be reported right away and the usually few suspect samples can be subsequently analysed by a more elaborate confirmatory method based on chemical properties of the compound. Bio-based screening methods Several bio-based tests have been reported for the screening of antibiotic substances in different matrices. Bio-based screening methods used for the detection of antibiotics in products of animal origin have been reviewed recently [117-120]. The most commonly applied bio-based screening techniques for antibiotics are immunoassays, microbiological inhibition assays and reporter gene assays . The sample that is screened for antibiotic content is incubated with antibodies, under the production of an analyte-antibody binding complex. Next, the degree of binding, which is related to the level of antibiotics present in the sample, is determined (e. An important advantage of immunoassays is that they are able to detect the presence of antibiotics at very low levels, which makes them even useful for screening of banned substances but the main challenge of immunoassays is the production and supply of antibodies, which should be selective towards the aimed antibiotic compound or group. Microbiological inhibition assays Microbiological inhibition assays are based on a reaction between a bacteria and the antibiotic present in the sample. The tube and plate test are the most common formats for this type of screening assays. The tube test consists of a growth medium inoculated with a bacterium, supplemented with a pH or redox indicator. If no specific antibiotics are present, the bacteria start to grow and produce acid, which will cause a detectable color change. If antibiotics are present that inhibit bacterial growth, no color change will occur [119,138]. The plate test consists of a layer of inoculated nutrient agar and samples are brought onto the surface. If no specific antibiotics are present, the bacteria start to grow throughout the plate. If a specific antibiotic is present, no bacterial growth will occur around the sample, which can be observed from the bacteria- 34 Chapter 1 free inhibition zone. In Europe this has been the main test format since screening of slaughter animals for the presence of antibiotics started .
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