Hematological examination

This is a method by which abnormalities of the cells of the blood and their precursors in the bone marrow are investigated to diagnose the different kinds of anemia & leukemia.

METAPLASIA

A reversible replacement of one type of adult tissue by another type of tissue. It is usually an adaptive substitution to a. cell type more suited to an environment, often at the cost of specialised function.

(1) Epithelial metaplasia:

• Squamous metaplasia. This is the commoner type of metaplasia and is seen in:
  • Tracheobronchial lining in chronic smokers and in bronchiectasis.
  • In Vitamin A deficiency.
• Columnar metaplasia:
  • Intestinalisation of gastric mucosa in chronic gastritis.

(2) Connective tissue metaplasia:

• Osseous-Metaplasia in :
  • Scars.
  • Myositis ossificans
• Myeloid metaplasia in liver and spleen.

Lymphopenia:
Causes

-As part of pancytopenia.
-Steroid administration.

Pemphigoid
1. Ulcerative lesions on the skin and oral mucosa.
2. An autoimmune disease in which patients have autoantibodies against basal cells (desmosome attachment to the basement membrane).
3. Histologically, the entire epithelium appears to separate from the connective tissue. There is no acantholysis.
4. A positive Nikolsky sign is observed.
5. Complications include blindness, due to ocular lesions present in some patients.
6. Treatment: corticosteroids.

Coccidioidomycosis (Valley Fever; San Joaquin Fever)

A disease caused by the fungus Coccidioides immitis, usually occurring in a primary form as an acute benign asymptomatic or self-limited respiratory infection, occasionally disseminating to cause focal lesions in skin, subcutaneous tissues, lymph nodes, bones, liver, kidneys, meninges, brain, or other tissues.

Primary coccidioidomycosis is usually asymptomatic, but nonspecific respiratory symptoms resembling influenza or acute bronchitis sometimes occur or, less often, acute pneumonia or pleural effusion. Symptoms, in decreasing order of frequency, include fever, cough, chest pain, chills, sputum production, sore throat, and hemoptysis.

Progressive disseminated coccidioidomycosis may develop a few weeks, months, or occasionally years after primary infections,, is more common in men than women and is more likely to occur in association with HIV infection, immunosuppressive therapy

Symptoms often are nonspecific, including low-grade fever, anorexia, weight loss, and weakness. Extensive pulmonary involvement may cause progressive cyanosis, dyspnea, and discharge of mucopurulent or bloody sputum. Extrapulmonary lesions are usually focal, involving one or more tissue sites in bones, joints, skin, subcutaneous tissues, viscera, brain, or meninges. Draining sinus tracts sometimes connect deeper lesions to the skin. Localized extrapulmonary lesions often become chronic and recur frequently, sometimes long after completion of seemingly successful antifungal therapy.

G-6 PD Deficiency

Occurs in Negroes, Mediterranean races, India and far East. It confers a protection Against falciparum malaria.

It is transmitted as X-linked trait of intermediate dominance (variable effect in homozygous females). 

Haemolysis may be induced by :
•    Primaquin and other anti malarials.
•    Other drugs like chloramphenicol , analgesics, antitubercular drugs etc.
•    Infections.
•    Ingestion of Vicia faba bean (favism).
•    Diabetic acidosis