By I. Benito. Notre Dame College of Ohio.
Thus safe levitra extra dosage 40mg erectile dysfunction pump implant video, the antibodies made are still specific to the pathogen that stimulated the initial IgM response discount 60 mg levitra extra dosage with mastercard impotence and prostate cancer. IgG is a major antibody of late primary responses and the main antibody of secondary responses in the blood. IgG is a monomeric antibody that clears pathogens from the blood and can activate complement proteins (although not as well as IgM), taking advantage of its antibacterial activities. Furthermore, this class of antibody is the one that crosses the placenta to protect the developing fetus from disease exits the blood to the interstitial fluid to fight extracellular pathogens. IgA exists in two forms, a four-chain monomer in the blood and an eight-chain structure, or dimer, in exocrine gland secretions of the mucous membranes, including mucus, saliva, and tears. IgA is also of importance to newborns, because this antibody is present in mother’s breast milk (colostrum), which serves to protect the infant from disease. It is present in the lowest concentration in the blood, because its Fc region binds strongly to an IgE-specific Fc receptor on the surfaces of mast cells. IgE makes mast cell degranulation very specific, such that if a person is allergic to peanuts, there will be peanut-specific IgE bound to his or her mast cells. In this person, eating peanuts will cause the mast cells to degranulate, sometimes causing severe allergic reactions, including anaphylaxis, a severe, systemic allergic response that can cause death. Clonal Selection of B Cells Clonal selection and expansion work much the same way in B cells as in T cells. Eventually, the plasma cells secrete antibodies with antigenic specificity identical to those that were on the surfaces of the selected B cells. These memory cells lead to the differentiation of more plasma cells and memory B cells during secondary responses. Primary versus Secondary B Cell Responses Primary and secondary responses as they relate to T cells were discussed earlier. Because antibodies are easily obtained from blood samples, they are easy to follow and graph (Figure 21. As you will see from the figure, the primary response to an antigen (representing a pathogen) is delayed by several days. The second time a person encounters the same antigen, there is no time delay, and the amount of antibody made is much higher. Thus, the secondary antibody response overwhelms the pathogens quickly and, in most situations, no symptoms are felt. When a different antigen is used, another primary response is made with its low antibody levels and time delay. Active versus Passive Immunity Immunity to pathogens, and the ability to control pathogen growth so that damage to the tissues of the body is limited, can be acquired by (1) the active development of an immune response in the infected individual or (2) the passive transfer of immune components from an immune individual to a nonimmune one. Active immunity is the resistance to pathogens acquired during an adaptive immune response within an individual (Table 21. A vaccine is a killed or weakened pathogen or its components that, when administered to a healthy individual, leads to the development of immunological memory (a weakened primary immune response) without causing much in the way of symptoms. Thus, with the use of vaccines, one can avoid the damage from disease that results from the first exposure to the pathogen, yet reap the benefits of protection from immunological memory. The advent of vaccines was one of the major medical advances of the twentieth century and led to the eradication of smallpox and the control of many infectious diseases, including polio, measles, and whooping cough. Active versus Passive Immunity Natural Artificial Active Adaptive immune response Vaccine response Passive Trans-placental antibodies/breastfeeding Immune globulin injections Table 21. IgG is transferred from the maternal circulation to the fetus via the placenta, protecting the fetus from infection and protecting the newborn for the first few months of its life. As already stated, a newborn benefits from the IgA antibodies it obtains from milk during breastfeeding. The fetus and newborn thus benefit from the immunological memory of the mother to the pathogens to which she has been exposed. In medicine, artificially acquired passive immunity usually involves injections of immunoglobulins, taken from animals previously exposed to a specific pathogen. This treatment is a fast-acting method of temporarily protecting an individual who was possibly exposed to a pathogen. The downside to both types of passive immunity is the lack of the development of immunological memory. T cell-dependent versus T cell-independent Antigens As discussed previously, Th2 cells secrete cytokines that drive the production of antibodies in a B cell, responding to complex antigens such as those made by proteins.
Sometime people are surprised to learn that nutrients are ‘burning’ inside their bodies 60 mg levitra extra dosage free shipping erectile dysfunction causes prescription drugs. Nutrients do really burn – but in a different way from a ﬁre so that there is no ﬁre or smoke generic levitra extra dosage 60 mg on-line erectile dysfunction diabetes cure. When they ‘burn’ in the cells, they combine with oxygen from the air that we breathe in. They release energy, and they change into carbon dioxide and water, which we breathe out. Function Reason To keep alive Our bodies are ‘turned’ on and use energy from the moment of conception until we die. To build tissues The body uses nutrients such as starch to provide the energy for building. To secrete ﬂuids The body uses energy to secrete ﬂuids such as saliva and breastmilk. To repair tissues After injury or illness, the body uses energy to repair damaged tissues. To move and work We need energy to move muscles, to move our bodies, to walk, to talk, to play, to run and to work. The population group that needs a lot of energy is children because they are very active (they run and play a lot) and their energy needs, based on their body weight are high. Nutrient Use Carbohydrates (starches and sugars) For energy Fibre To keep gut healthy To help digestion Fats For energy To build cells Stored for use as energy when needed Proteins To build cells To make ﬂuids For chemical processes For energy To protect against infection Minerals To build cells To make ﬂuids For chemical processes Vitamins For chemical processes To build cells To protect against infection Water For chemical processes For building cells To make ﬂuids 1. Pregnancy — women do not receive enough care; the work burden of the mothers is not alleviated. Another belief is that pregnant mothers should not consume milk because the baby will have a whitish covering over its head when it is born. The health of your body depends on what you feed it on, just as a healthy plant or anything else will grow better in rich soil and good conditions. As you have learnt in this study session, everybody needs a variety of foods which contain enough different nutrients to keep them alive and healthy. Better nutrition means stronger immune systems, less illness and better health for people of all ages. Healthy people are stronger, more productive, and better able to break cycles of poverty and realise their full potential. Iron deﬁciency disorder reduces mental capacity and academic achievement of children. Iron deﬁciency anaemia affects energy levels as well as school attendance and performance. Childhood morbidities are compounded by iron, zinc and other nutrient deﬁciencies, leading to increased death rates. Nutrition depends on a good environment as this is important for the processes of food production up to its consumption. The availability of some nutrients (for example iodine) depends on a well-maintained environment. In this study session you have learnt about the magnitude of nutritional problems in Ethiopia. In addition, you have gained some knowledge about the basics of nutrition that you will use in your work. Summary of Study Session 1 In Study Session 1, you have learned that: 1 Ethiopia is affected by a high level of undernutrition (acute and chronic malnutrition). Health Extension Practitioners have an important role to play in providing information about nutrition to families in their communities. Write your answers in your Study Diary and discuss them with your Tutor at the next Study Support Meeting. You can check your answers with the Notes on the Self-Assessment Questions at the end of this Module. Can you name the different kinds of malnutrition and then describe the signs that might tell you that childhood malnutrition is a problem in your community? How can you persuade her that the family needs to eat many different kinds of food?
Counting An area of the film should be chosen for the count where the cells are undistorted and where the staining is good discount levitra extra dosage 60mg with amex erectile dysfunction therapy. To count the cells cheap levitra extra dosage 40mg line drugs for erectile dysfunction in nigeria, the oil immersion objective and if possible eye pieces provided with an adjustable diaphragm are used. If such eyepieces are not available, a paper or cardboard diaphragm in the center of which has been cut a small square with sides about 4mm in length can be inserted into an eyepiece and used as a substitute. The counting procedure should be appropriate to the number of reticulocytes as estimated on the stained blood film. Very large numbers of cells have to be surveyed if a reasonably accurate count is to be obtained when the reticulocyte number is small. When the reticulocyte count is expected to be 10% a total of 500 red cells should be counted noting the number of reticulocytes. This is an eyepiece giving a square field in the corner of which is a second ruled square one-ninth of the area of the total square. Reticulocytes are counted in the large square and red cells in the small square in successive fields until at least 300 red cells are counted. Another correction is made because erythropoietin production in response to anemia leads to premature release of newly formed reticulocytes and these stress reticulocytes take up to two days rather than one to mature into adult erythrocytes. In hemolytic anemia with excessive destruction of red cells in the peripheral blood in a functionally normal marrow, this index may be 3-7 times higher than normal. Identifying reticulocytosis may lead to the recognition of an otherwise occult disease such as hidden chronic hemorrhage or unrecognized hemolysis. Fox example, after doses of iron in iron deficiency anemia where the reticulocyte count may exceed 20%; Proportional increase when pernicious anemia is treated by transfusion or vitamin B12 therapy. A decrease in the reticulocyte number is seen in iron deficiency anemia, aplastic anemia, radiation therapy, untreated pernicious anemia, tumor in marrow. How could the number of reticulocytes in the peripheral blood be a fairly accurate reflection of erythropoietic activity in the bone marrow? How do you manage to count the number of reticulocytes in each field of the microscope after you stain the cells with supravital dyes? What is the clinical interpretation of an increase in the number of reticulocytes in the peripheral blood in general terms? Structure of hemoglobin Hemoglobin (Hb), the main component of the red blood cell, is a conjugated protein that serves as the vehicle for the transportation of oxygen and carbon dioxide. The red cell mass of the adult contains approximately 600g of hemoglobin, capable of carrying 800ml of oxygen. A molecule of hemoglobin consists of two pairs of polypeptide chains (globin) and four prosthetic heme groups, each containing one atom of ferrous iron. Located near the surface of the molecule, the heme reversible combines with one molecule of oxygen or carbon dioxide. At least three distinct hemoglobin types are found postnatally in normal individuals, and the structure of each has been determined. The polypeptide chains of the globin part of the molecules are of two types: two identical α-chains, each with 141 amino acids; and two 141 Hematology identical β-chains, with 146 amino acids each. The two α-chains are identical to those of Hb A; and two γ-chains, with 146 amino acids residues, differ from β-chains. Its two α-chains are the same as in Hb A and Hb F; its two δ-chains differ from β-chains in only 8 of their 146 amino acids. Embryonic hemoglobins: the zeta (ζ) chain is the embryonic analogue of the α-chain and may combine with epsilon (ε) chains to form Hb Gower-1 (ζ ε2 2) or with γ-chains to form Hb Porland-1 (ζ γ2 2). The ε-chain is the embryonic counterpart of the γ-, β-, and δ-chains and combines with α-chains to form Hb Gower-2 (α ε2 2). Hb Gower-1, Hb Portland-1, and Hb Gower-2 are the embryonic hemoglobins and are found in normal human embryos and fetuses with gestational age of less than 143 Hematology three months. Iron is inserted into protoporphyrin by the mitochondrial enzyme ferrochetalase to form the finished heme moiety. Globin synthesis Globin synthesis occurs in the cytoplasm of the 144 Hematology normoblast and reticulocyte. The polypeptide chains released from the ribosomes are folded into their three-dimensional configurations spontaneously. Determination of hemoglobin concentration Hemoglobin is measured to detect anemia and its severity and to monitor an anemic patient’s response to treatment. The hemoglobin content a solution may be estimated by several methods: by measurement of its color, its power of combining with oxygen or carbonmonoxide and by its iron content.
Measures on a 0 (no impairment) to 6 (severe impairment) rating scale were recorded at 2 weeks 92 cheap 60 mg levitra extra dosage erectile dysfunction over 70, 96 generic levitra extra dosage 60 mg overnight delivery impotence zargan, 98 91, 92, 94, 96 89 in three trials and at 4 weeks in four trials. Nocturnal symptoms were scored on a 7-point scale from 0 (not troubled) to 6 (extremely troubled). Individual nasal symptoms (congestion, rhinorrhea, sneezing, and nasal itch) at 2 weeks: Evidence was insufficient to support the use of one treatment over the other based on one trial90 with high risk of bias and imprecise results. Individual nasal symptoms at 4 weeks: Evidence was insufficient to support the use of one treatment over the other based on six trials91-93, 95, 96, 99 (for congestion), five trials92, 93, 95, 96, 99 (for sneezing), and four trials (for rhinorrhea92, 95, 96, 99 and nasal itch92, 93, 95, 99) with high risk of bias and consistent but imprecise results. These results are based on trials of three of five oral selective antihistamines (60 percent) and five of eight intranasal corticosteroids (62. Nasal Symptoms 90 The one trial that reported on nasal congestion at 2 weeks (N=341) reported a treatment effect of 0. This trial was rated poor quality, and the result was not statistically significant. Evidence for the outcome of congestion at 2 weeks is therefore insufficient to support the use of 90 one treatment over the other. One poor quality trial with high risk of bias reported an imprecise treatment effect. All six showed statistically 91, 95 significant improvements in congestion with intranasal corticosteroid. Two were good 95 quality trials of 558 patients total (35 percent of patients reporting this outcome). One reported results using a 0-3 point scale but did not report the magnitude of the treatment effect. Four 92, 93, 96, 99 92, 93, 96 trials were rated poor quality due to noncomparable groups at baseline and 93, 96 inappropriate analysis of results (unadjusted for baseline group differences and not intention 99 92, 99 to treat ). Because trials used different symptom rating scales (0-3 and 0-100), the standardized mean difference was calculated. The magnitude of the pooled effect estimate could not be compared with estimates from individual trials not included in the meta-analysis because the latter were not reported. Sixty-five percent of patients were in poor quality trials, and 35 percent were in good quality trials. All six 91-93, 95, 96, 99 trials were consistent in finding statistically significant treatment effects favoring intranasal corticosteroid, and this finding was confirmed in a meta-analysis of three of these 91, 92, 99 trials. The evidence was therefore insufficient to form a conclusion about the comparative effectiveness of oral selective antihistamine and intranasal corticosteroid for this outcome. This trial 92, 93, 95, 96, 99 was rated poor quality, and the result was not statistically significant. One poor quality trial reported neither the magnitude nor the direction of the treatment effect. This trial was excluded from analysis of this outcome, reducing the total number of patients assessed from 1284 to 979. The remaining four trials all favored 50 95 intranasal corticosteroid over oral selective antihistamine. One trial was a good quality trial of 242 patients (25 percent of patients reporting this outcome) that demonstrated a statistically significant improvement in rhinorrhea with intranasal corticosteroid. The remaining three trials were rated poor quality due to noncomparable groups at baseline and inappropriate analysis of results, as described above. The third poor 92 quality trial reported a statistically nonsignificant treatment effect of 0. Evidence for the outcome of rhinorrhea at 2 weeks was insufficient to support the use of one 90 treatment over the other. One poor quality trial with high risk of bias reported an imprecise treatment effect. Evidence was therefore insufficient to support the use of one treatment over the other for this outcome.
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