By M. Tarok. Indiana University Northwest. 2018.
The cloning of transgenic animals will probably open a new era of recombinant protein pro- duction order albendazole 400mg line. Another novel approach for the production of antibodies is the use of transgenic plants as a production system (114) cheap albendazole 400mg without prescription. Transgenic tobacco plants (Nicotiana tabacum) were first used to show stable accumulation of recombinant antibody in the seed (115). Antibody production in a transgenic crop bears a potential of nearly unlimited mass production at low cost (116). The expression and accumulation of up to 280 mg of secretory IgA antibodies per corn cob have been reported. Furthermore, corn is pro- vided with the repertoire of housekeeping genes necessary to properly process com- plicated protein structures such as soluble IgA (sIgA) into their functional form. Up to now antibodies for therapeutic application have been produced in mammalian cell culture. Generally, these are considered to confer proper posttranslational process- ing in order to achieve optimal induction of antibody effector functions (117), phar- macokinetics, and biodistribution in patients. If molecular engineering tech- nologies for antibody production are applied, the choice of the most suitable host cell line is essential. Criteria such as experience in the technologic use of a certain cell host, as well as the potential of posttranslational protein modifications, are also important. The following characteristics are the main criteria for selecting a cell line for industrial production: 1. They obviously have the ability to modify, fold and secrete proteins comparable to that of the human in vivo situation. After processing for optimization, product titers up to 1 g/L for both cell lines have been described. In vitro tests of anti- bodies expressed in both cell lines gave identical results with respect to their func- tionality (122,123). This phenomenon is purposely employed to create and select high-producing cells by cotransfecting selection or amplification marker genes together with the genes of interest. Different selection genes and amplification systems are available to obtain recombinant high producers in various hosts. The goal of the selection procedure is always to amplify expression of the genes of interest in the transfected mammalian host cell line. Different systems can be used to select for high expression, so-called dominant markers and auxotrophic (also termed recessive) markers. Dominant selection markers generally combine the growth in the presence of an efficient drug substance, so that only clones with corresponding drug resistances will survive. The most widely used dominant selection markers are resistances against antibiotics. Auxotrophic or recessive marker systems make use of naturally or intentionally introduced deficien- cies in metabolic pathways of the host cell. The resulting auxotrophy requires that the 86 Kunert and Katinger missing metabolite or a related agent be added to the growth medium or that genes capable of supplementing the metabolic deficit be introduced into the host. Growing the cells in glutamine-free media thus ensures both the survival of the transfected host cell and sta- ble antibody expression. Subsequent to the selection procedure, single high-expression cell clones are iso- lated. The limiting dilution method in microtiter plates is very useful in obtaining cell clones of monoclonal origin. The assumption that monoclonality can be reached after only one round of subcloning is rather theoretical (129,130). Repeated subcloning and intensive screening is necessary to establish stable, high-producing cell lines for industrial manufacture. Other biopharmaceuticals such as tissue plasminogen activator and erythropoietin, which are also manufactured by comparable recombinant technologies, are applied in only nanogram or microgram ranges per kilogram body weight. In other words, a beneficial antibody treatment dose requires an amount of at least a 1000-fold more of the recom- binant protein. This simple comparison clearly shows the challenge and the necessity for the development of cost-effective manufacturing technologies. The manufacture of antibodies in transgenic animals or plants might be expected in the future, but quality considerations exist at the present time. The manufacturing process attempts to obtain the highest possible product qual- ity and safety, consistently produced at low costs in high amounts. A few manufacturing facilities have been established that allow production of several hundred kilograms of purified antibody a year. Very important for the success of the entire manufacturing process is the availabil- ity of cloned cells that express the antibody stably at high levels. Commercial manu- facturers usually do not publish detailed data describing levels of expression. As described previously, the establishment of these cell clones requires several subcloning and/or gene amplification steps. The first logical step is the adaptation of the cloned cells to serum-free growth media.
Can be administered as combined vaccines such as trivalent or quatrivalent vaccines buy generic albendazole 400mg on-line, e generic 400mg albendazole amex. Com- bined vaccines induce similar responses, as do monovalent vaccines, indicating that is no antigen competition. Poor antibody response is seen owing to weak generation of memory B-cells; several boosts are often required. The antibody-mediated response against the protective epitope can be diluted by production of antibodies against the multitude of bacterial macromolecules bearing nonprotective epitopes. There is an inability to stimulate the cell-mediated immune responses that contribute to recovery from disease or alter the course of disease in the case of therapeutic vaccines. These vaccines can eas- ily be developed when the disease is caused by a single or a few serotypes of infectious agents (e. They cannot be generated when multiple serotypes are involved in path- ogenicity, as in the case of the nosocomial infection caused by Klebsiella pneumoniae. Subunit vaccines are produced by purification from bacteria of antigens bearing pro- tective epitopes or by molecular methods of expression and purification of recombi- nant proteins. With the exception of the hepatitis B subunit vaccine (which is of a protein nature), these are bacterial polysaccharides Immunity Polysaccharide vaccines are generally poor immunogens and induce T-independent responses dominated by IgM. Mutation of this gene, as in Wiscott-Aldrich syndrome, makes such patients unrespon- sive to subunit polysaccharide vaccines. Disadvantages Antibody response is generally weak, requires several boosts, and is dominated by low-affinity IgM antibodies. Generally, the vaccines are inefficient in newborns and infants because of the ontogenic delay of expression of a B-cell subset responding to polysaccharide antigens. Induction of high-affinity IgG antibodies can be obtained by coupling the polysaccharide to a protein bearing strong T-cell epitopes. Live Attenuated Vaccines The possibility of preparation of live attenuated vaccines is based on Enders (5) dis- covery of a method of culturing viruses in vitro in permissive cells. Live attenuated vaccines are produced by culturing the microbe in special conditions, leading to loss of pathogenicity without altering immunogenicity. The infected cells can produce peptides subsequent to fragmentation of endogenous viral or microbial proteins. Live attenuated vaccines elicit a long-lasting immunity comparable to that induced during natural infection. Disadvantages The preparation of live attenuated vaccines requires a tedious procedure to select the microbes that are devoid of pathogenicity, and manufacturing is costly. Internal Image Idiotype Vaccines Idiotypes are phenotypic markers of antigen receptors of lymphocytes. Idiotype are immunogenic and able to induce antiidiotypic antibodies (Ab2s), which in turn express their own idiotypes. As a statistical necessity, Jerne (6) introduced the concept that the idiotypes of antiidiotype antibodies could mimic the antigen recognized by antibody-Ab1. This concept is not a simple consequence of the lock and key rule of complementary of antigen-antibody interaction but can be owing to molecular mimicry or sharing of sim- ilar sequences between antigen and Ab2. Of the 18 residues that contact Ab1 with Ab2, and the 17 that interact with lysozyme, 13 were in contact with both lysozyme and Ab2. This important information clearly demonstrated that some antiidiotypic antibodies are internal images of antigens and therefore they may function as antigen surrogates because they represent the positive imprint of antigen. An Ab1 antibody specific for a protective epitope is prepared, and then Ab2 anti- idiotype antibodies are generated. Antigen-inhibitable Ab2, which then can be used as internal image idiotype vaccines, is then selected (8). Advantages The internal image idiotype vaccines are safe, induce humoral immunity, and are able to circumvent the ontogenic delay responsible for unresponsiveness of infants to some vaccines (8). Disadvantages Internal image vaccines are poor immunogens and require coupling with carrier pro- tein, which increases their immunogenicity. Generally they do not induce memory cells, an intrinsic property of a good vaccine. Recombinant Protein Vaccines The preparation of this type of vaccine is limited to microbial proteins bearing pro- tective epitopes. The generation of recombinant proteins is based on cloning a gene encoding a protein, which is then aligned with a promoter and inserted into a suitable plasmid replicon. In this case, the flanking region of the Principles of Vaccine Development 137 Table 5 Idiotype Vaccines Antigen mimicked Property of Microbe by internal image antibodies E. Neutralizing Foot and mouth disease virus Surface antigen Nonneutralizing Hepatitis B virus S antigen?
Multiplication is asynchronous albendazole 400mg sale, and therefore fever for the preceding 2 months buy cheap albendazole 400 mg, associated with inter- hemolysis is never massive. How- patients with babesiosis also had antibodies against the ever, despite appropriate treatment, her fevers did not Lyme spirochete, suggesting that these patients had dual resolve. Treatment with clindamycin and Giemsa stain of thick and thin smears from the periph- quinine caused a rapid resolution of her fever. The classic tetrad is The symptoms of babesiosis are nonspecic, mak- not observed in Plasmodium infection, and the ing the disease difcult to diagnose clinically. Patients often do not give a history of tick bites, having failed to detect the attached nymph because of its small size (the diameter of a small freckle). In the normal host, the disease may cause minimal symptoms and resolve spontaneously. However, in older patients or in those who have undergone splenectomy, infection can be more severe and persistent. Cases of adult respiratory distress syndrome and hypotension have been reported, and on rare occasions, patients have died. In Europe, cases have strictly involved splenectomized patients, and the clinical presentation has been more fulminant, being associated with severe hemolysis and death. Patients with babesiosis may also have symptoms suggestive of Lyme disease, particularly the skin rash of erythema migrans. Often no history of tick bite, because the Ixodes scapularis nymph is mistaken for a small freckle. Treatment should be initiated in splenectomized About Diagnosis and Treatment of Babesiosis patients and in other patients with serious disease. Antiparastic Therapy Dosingh Parasite Preferred therapya Alternative therapya Babesia Intravenous clindamycin 1. Contracted in tropical areas where the phle- Leishmania has caused major epidemics in eastern India, botomine sandy is common;rare in the United Bangladesh, and East Africa. Urban outbreaks have been States Found in South America, India, reported in the cities of northeastern Brazil. Flagellated promastigote introduced by the leishmaniasis during the Persian Gulf War in 1991 and sandy is ingested by macrophages. In the macrophage, Leishmania develops into a been reported occasionally in the United States, but nonflagellated amastigote that lives happily most U. Leishmaniasis can be an opportunistic infection walls of dwellings, in rubbish, and in rodent burrows. Because they are weak iers, sandies remain close to the ground near their breeding sites, resulting in localized pockets of infectious insects. In the digestive Visceral leishmaniasis is a chronic disease that can tract of the insect, the amastigote develops into a agel- cause severe morbidity and death in debilitated lated spindle-shaped promastigote. The pro- mastigote then binds to complement receptors on macrophages and is ingested. Where are lesions of cutaneous leishmaniasis usu- vation of interferon production. Subacute onset presents with increased abdominal swellinig (because of massive and L. After inoculation of pro- splenomegaly and hepatomegaly), intermittent mastigotes into the skin, a small papule may be noticed. Anemia, leukopenia, and hypergammaglobu- In subacute cases, the patient will experience slow linema are common. Increased abdominal girth is showing amastgotes accompanied by intermittent fever, weakness, loss 6. In acute cases, an abrupt onset of high fever and chills mimics malaria or an acute bacterial infection. The skin tends to be dry After a sandy bite, signicant skin lesions gener- and thin, and in light-skinned individuals, it takes on a ally take 2 weeks to several months to develop. This characteristic accounts for the Indian Lesions usually develop on exposed areas. Single or multiple lesions may be The diagnosis is made when a biopsy of lymphatic found, with varying morphology. Lesions may be tissue or bone marrow demonstrates amastigotes on crusted and dry, or moist and exudative. Enzyme-linked immunoab- circular ulcers with sharp, raised borders may develop sorbent assays usually demonstrate high anti-leishmanial and progressively increase in size, becoming pizza- antibody titers. However, this test frequently cross-reacts like in appearance as a result of the beefy red of the with antibodies to other pathogens. Lesions may become secondarily infected with staphy- Splenomegaly may not be present in these patients, and lococci or streptococci. Amastigotes are seen macrophages from bronchoalveolar lavage, pleural on Giemsa stain. Organisms invade mononuclear cells in the tourists in the Middle East and Central and South mucosa.
Acid erosion due to fruit drinks in a xerostomic patient with Sjogren s syndrome (photo courtesy of Dr albendazole 400 mg lowest price. Effects of Xerostomia on Diet and Nutrition In the absence of saliva buy albendazole 400mg without a prescription, it becomes a challenge to chew, swallow, and even taste food (31). Difficulty masticating and lubricating food may make it difficult to eat solid foods. Patients may adapt to a primarily liquid diet that may be low in nutritional value. It is also common that people experiencing dry mouth use items such as hard candies or other slowly dissolving lozenges in an effort to increase salivation. If these items are used frequently and contain sugars, they can be major contributors to increased dental caries incidence. Frequent eating or snacking is a major risk factor for dental caries development that is increased when the oral cleansing effects of saliva are lost. Sufferers may have a dry cough, hoarseness, a decreased sense of smell, and nose bleeds. People may also report having joint or muscle pain (37), low-grade fever, increased fatigue (25), and vasculitis. The new criteria states that a person may be diagnosed as having Sjogren s syndrome if he has at least four of the following six diagnostic tests results (Table 3), including one objective measure (ie, by histopathologic examination or antibody screening) as positive (16,38). Salivary function test: Salivary function tests are used to determine the actual severity of xerostomia (39). Sialometry measures unstimulated salivary flow rate into a calibrated tube for 15 minutes. Salivary gland biopsy: Lip biopsy involves performing biopsy of minor salivary glands in the lower lip. Another test that could be performed for dry eye is the Rose Bengal staining test. Lip biopsy: a small amount of salivary tissue is removed from inside the lip and examined under a microscope for evidence of Sjogrens syndrome Schirmer test for dry eyes: helps determine the dryness of eyes. A small piece of filter paper is placed under the lower eyelid to determine the quantity of tear production Symptom for dry eyes: Patient reports of symptoms of dry eyes are also used to help diagnose Sjogren s syndrome. A positive response to all of the following is considered diagnostic for dry eyes (22): Do you Do your eyes feel dry, gritty or sandy or burn Do you use tear substitutes more than 3x/day? Because the treatment is tailored to the symptoms, each patient s management plan will be different (43). Additionally, a humidifier in the house can be a tremendous help to avoid low humidity conditions. If possible, alternative, non-xerostomic medications should be used as substitutes. Patients should be shown how to avoid any products that can contribute to oral dryness or irritation. Alcohol has a drying effect and should be avoided in both beverages and in oral products such as mouthwashes. Tartar control toothpastes and tooth whitening products should also be avoided as they can be irritating to friable oral tissues. If patients tend to breathe through their mouths, it is often helpful to encourage them to try to increase nasal breathing and check with an otolaryngology specialist if there are impediments to normal nasal breathing. In the presence of xerostomia and decreased immunity, there is often an increase in fungal infections such as oral candidiasis. Eye Palliatives A variety of lubricants are available over the counter and by prescription to lubricate the eyes and minimize eye itching and burning. Oral Palliatives and Therapies (Table 6 (45)) A multitargeted approach is needed for oral care to palliate existing conditions and more importantly, protect oral soft and hard tissues from further damage. Patients should see the dentist at least four times a year for diagnostic evaluations and preventive and palliative treatments. Radiographs should be taken yearly to check for new carious lesions in the dentition. The oral mucosa is often dry and sore as a result of the loss of protective saliva. A saliva substitute can also be used before eating to mimic the effects of actual saliva. Sialogogues are drugs that work by stimulating the M3 receptors stimulating moisture production throughout the body. No serious side effects have been seen but care must be taken if used with concomitant medication or by patients with cardiovascular disease or hypertension (46). Because the loss of protective saliva in xerostomia increases the vulnerability of tooth enamel surfaces, extra effort must be made to protect teeth from demineralization and dental caries. It helps mineralize the outer surfaces of tooth enamel, thereby making enamel destruction more difficult, and impedes the function of the oral bacteria that initiate dental caries. Fluoride is available from a variety of sources from fluoridated drinking water and fluoride dentifrices to over-the-counter and prescription concentrated strength forms. Calcium also has a remineralizing effect on dental enamel and a calcium-containing toothpaste or remineralizing oral rinse may be recommended as well.
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