Malaria

Malaria

Aetiology: Malaria is due to infection with specific protozoa of the Plasmodium genus. It is transmitted by the bite of an infective female Anopheles mosquito. The plasmodia undergo a single sexual cycle in the mosquito and recurrent asexual cycles, with the production of sexual forms (gametocytes) in man. Clinical features: The initial incubation period of malaria is 9-11 days. The disease is […]

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Human Immunodeficiency Virus

Aetiology: Infection by the Human Immunodeficiency Virus (HIV) first appears as a transient flu-like illness. There then follows a variable period of good health which may last many years. The HIV virus has tropism for lymphocytes expressing CD4 antigen (T helper cells). As the disease progresses there is a steady decline in the number of CD4+ lymphocytes in the peripheral blood. […]

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Infectious Mononucleosis

Aetiology: Infectious Mononucleosis (Glandular Fever), also known as mono, is due to infection by the Ebstein-Barr herpes Virus (EBV). The disease was first described in the 1920s. The virus spreads through saliva, which is why it’s sometimes called “kissing disease“. the incubation period for mono is four to eight weeks. Using contaminated items, such as drinking glasses or toothbrushes, can spread the infection. […]

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Miscellaneous Red Cell Abnormalities

Introduction In the chapter of Miscellaneous Red Cell Abnormalities, we will discuss some of the commonly seen red blood cell abnormalities. Adult human bone marrow synthesizes 4 X 1014 molecules of hemoglobin every second. Heme and globin chains (alpha and beta) in adults are manufactured in separate cell compartments—mitochondria and cytoplasm, respectively—and then combined in cytoplasm in an amazingly accurate manner. Four major problems […]

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Sickle Cell Disease

Sickle cell disease (HbS) is a severe hereditary form of anemia in which a mutated form of hemoglobin distorts the red blood cells (RBC’s) into a crescent shape at low oxygen levels. Sickle cell disease (HbS) is commonest among those of African descent. In this disease, a single base mutation in the β-globin gene leads to the substitution of valine for […]

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Thalassemias

Thalassemias are inherited disorders in which there is an abnormality of one or more of the globin genes leading to reduced globin protein production. There is, therefore, an imbalance of ß:α globin chain synthesis leading to globin chain precipitation, ineffective erythropoiesis and hemolysis. The hemoglobin molecule is a tetramer consisting of 4 polypeptide chains, known as globins, which are usually: 2 […]

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Pyruvate Kinase Deficiency

Pyruvate kinase (PK) deficiency is one of the most common enzymatic defects of the RBCs, it manifests clinically as a hemolytic anemia that can range from mild to severe. Pyruvate kinase (PK) deficiency is inherited in an autosomal recessive pattern. The birth history of patients with pyruvate kinase deficiency includes severe anemia, severe jaundice, kernicterus, and a history of exchange transfusion. […]

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G6PD Deficiency

Introduction: Glucose 6 phosphate dehydrogenase (G6PD) deficiency affects approximately 400 million individuals worldwide. It is the most common human enzyme defect. The global distribution of this disorder is remarkably similar to that of malaria, lending support to the so-called malaria protection hypothesis. It is common in Africa, around the Mediterranean, and in the Orient. G6PD deficiency is an X-linked recessive disorder. The hereditary genetic […]

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Paroxysmal Nocturnal Hemoglobinuria

PNH

Thromboses may occur in PNH at unusual sites Introduction: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired, life-threatening disease of the blood. The disease is characterized by destruction of red blood cells by the complement system, a part of the body’s innate immune system (hemolytic anemia), blood clots (thrombosis), and impaired bone marrow function (not making enough of the three blood components). PNH is […]

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