Glossary - B

B Cells

B Cells-small lymphocytes that respond to antigenic stimulation by producing humoral antibodies.

Bacterial pneumonia

Bacterial pneumonia is an acute, bacterial infection of the lung parenchyma. It is more common in adults and much less so in children than in viral pneumonia. Infection may be community acquired or nosocomial. Most commonly, community acquired disease is caused by Streptococcus pneumonia or Hemophilus influenza. Hospital acquired pneumonia is usually the result of gram negative rods (60%) such as pseudomonas, or if gram positive from staphylococcus (14.5%). It affects the pulmonary/respiratory systems. There is no known genetic pattern of the disease. The incidence of community acquired bacterial pneumonia is 1200 /100,000 people in the United States. The incidence of the nosocomial form is 800/100,000 admitted per year, while the prevalence of the nosocomial form is 80/100,000. It affects all ages, males more than females. Cardinal signs include cough, fever, chest pain, chill with sudden onset, and dark, thick, bloody sputum. Causes include hematogenous spread of the microorganism, inhalation of the microorganism, aspiration of the infectious agent from the oropharynx. The bacterial pathogens are streptococcus pneumonia, Hemophilus influenza, staphylococcus aureus, legionella pneumonia, moraxella catarrhalis, mycoplasma pneumonia, klebsiella pneumonia, pseudomonas aerogenous, and escherichia coli. Risk factors include viral infections, hospitalization, age extremes, alcoholism, AIDS or other immunosuppression, tobacco smoking, renal failure, cardiovascular disease, functional asplenia, chronic obstructive pulmonary disease, diabetes mellitus, malnutrition, malignancy, general anesthesia, mechanical ventilation, altered level of consciousness or gag.

Benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a benign adenomatous growth of the prostate which may result in bladder outlet obstruction. It affects the reproductive and renal/urologic systems. Genetic factors may be involved. It is a universal pathologic phenomenon seen in older men. There is no hard evidence suggesting racial predisposition. The disease is rarely seen in men under the age of forty. It is seen in 50% of men older than 50 and in 80% of men older than 70 years of age. Males are exclusively effected. Prostate size correlates poorly with its symptoms. Obstructive symptoms are due to mechanical obstruction and/or detrusor muscle decomposition. There is a decrease in force or caliber of stream, hesitancy, post-void dribbling, sensation of incomplete bladder emptying, overflowing incontinence, inability to voluntarily stop stream and urinary retention. Irritative symptoms are due to the incomplete bladder emptying and/or detrusor muscle instability. This includes frequency, nocturia, urgency and urge incontinence. Other symptoms include, gross hematuria, observation of weak stream, distended bladder, increased post-void residual, enlarged prostate, alterations in perianal sensation, anal sphincter tone or bulbocavernosus reflex suggest a neurogenic component to voiding symptoms, and clinical clues suggesting renal failure due to obstructive uropathy. Its exact etiology is unknown, but evidence suggests that benign prostatic hyperplasia arises from a systemic hormonal alteration which may or may not act in combination with growth factors stimulating stromal or glandular hyperplasia. Risk factors include intact testes, aging, and there are no dietary, environmental, or sexual practices implicated yet.

Bone Tumors, Primary malignant

Primary malignant bone tumors are rare. Four types make up the majority. 1. Malignant fibrous histiocytoma (MFH)- a pleomorphic sarcoma of storiform pattern without differentiation. 2. Osteosarcoma- a similar to malignant fibrous histiocytoma with differentiation to osteoid production. 3. Chondrosarcoma- cellular cartilaginous lesion with abundant binucleate cells, myoid areas, and pushing borders. Ewing's sarcoma- small, blue-round cell neoplasm. It affects the musculoskeletal system. Genetic factors are unknown. Osteosarcoma is associated with the retinoblastoma gene and possibly with P53. The prevalence of the disease is rare. The predominant age it affects: for MFH- teens and elderly; Osteogenic sarcoma- teens and early twenties; Chondrosarcoma- the very young and very old. Males and females are equally susceptible to the disease. The signs and symptoms of the disease include pain with weight bearing, swelling, tenderness, fracture with minor trauma, while a minor injury may bring attention to the lesion. The causes of the disease are generally unknown. MFH often follows irradiation. Osteosarcoma is associated with the retinoblastoma gene. Chondrosarcoma may arise in pre-existing enchondroma or exostosis. Risk factors include those with Oilier's disease (chondrosarcoma), previous irradiation (MFH), multiple hereditary exostosis (chondrosarcoma), and those with a previous history of bilateral retinoblastoma (osteosarcoma).

Brain cancer

Brain cancer is a primary cancerous tumor in the brain. Eighty- five percent of cases occur in adults over the age of 40; the remaining 15% occur primarily in children and young adults up to the age of twenty. More men than women are affected. Brain cancer is relatively rare. There are many different types of brain tumors, only some of which are cancerous. A malignant tumor can spread to other parts of the brain. While a benign brain tumor does not spread, it can be equally devastating because the skull cannot expand to accommodate the mass growing inside. Some benign tumors become malignant. The symptoms of a brain tumor can vary depending on what part of the brain is affected. The most frequent signs of a brain tumor are subtle changes in personality, memory, and intellectual performance that may go unnoticed. A common symptom is a headache (not necessarily persistent or severe). Nausea and vomiting unrelated to food consumption occur in about a quarter of the people with a brain tumor.

Breast cancer

Breast cancer is a malignant neoplasm in the disease, classified as non-invasive or invasive, with approximately 70% of the cases containing a component of invasion. It affects the skin/exocrine system. Only 20% of patients have a significant family history of disease. The predisposition tend to be autosomal dominant with maternal lineage. 150,00 new cases are diagnosed annually and 50,000 women expire annually. The predominant age range is between 30 and 80 years of age with a peak between ages 45 and 65. 1% percent of males get the disease. Signs and symptoms include palpable mass (55%), abnormal mammogram without a palpable mass (35%), color change, dimpling, nipple retraction, breast enlargement, axillary mass, and bone pain (rare). The causes are unknown. Increased breast cancer risk occurs in first degree relatives, with bilateral disease in premenopausal relatives or bilateral disease in postmenopausal relatives. Increased hormone risks include early menarche, late menopause, or first full term pregnancy after age 30. Women with a prior history of breast cancer or previous breast biopsies revealing atypical changes are at increased risk for subsequent cancer. Inconclusive risk factors include exogenous estrogen use, high dietary fat, or high alcohol use.

 

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