Articles on Medical Diseases and Conditions

Entries for January, 2010

Diagnostic Procedures that Complement and Supplement Laboratory Tests

The clinical pathologist frequently encounters situations in which laboratory tests alone are not sufficient to provide a diagnosis. If this happens, certain diagnostic procedures may be suggested to provide additional information. These procedures are noted together with the laboratory tests that they complement or supplement. Nevertheless, it seems useful to summarize some basic information about […]

Laboratory Tests in Psychiatry

Until recently, the laboratory had relatively little to offer in psychiatry. Laboratory tests were used mainly to diagnose or exclude organic illness. For example, in one study about 5% of patients with dementia had organic diseases such as hyponatremia, hypothyroidism, hypoglycemia, and hypercalcemia; about 4% were caused by alcohol; and about 10% were due to […]

Tests for Allergy

The atopic diseases were originally defined as sensitization based on hereditary predisposition (thus differentiating affected persons from nonaffected persons exposed to the same commonly found antigens) and characterized by immediate urticarial skin reaction to offending antigen and by the Prausnitz-Kьstner reaction. Prausnitz and Kьstner demonstrated in 1921 that serum from a sensitized person, when injected […]

Selected Tests of Interest in Pediatrics

Neonatal immunoglobulin levels. Maternal IgG can cross the placenta, but IgA or IgM cannot. Chronic infections involving the fetus, such as congenital syphilis, toxoplasmosis, rubella, and cytomegalic inclusion disease, induce IgM production by the fetus. Increased IgM levels in cord blood at birth or in neonatal blood during the first few days of life suggest […]

Fat Embolization

Fat embolization is most often associated with severe bone trauma, but may also occur in fatty liver, diabetes, and other conditions. Symptoms may be immediate or delayed. If they are immediate, shock is frequent. Delayed symptoms occur 2 – 3 days after injury, and pulmonary or cerebral manifestations are most prominent. Frequent signs are fever, […]

C-Reactive Protein

C-reactive protein (CRP) is a glycoprotein produced during acute inflammation or tissue destruction. The protein gets its name from its ability to react (or cross-react) with Pneumococcus somatic C-polysaccharide and precipitate it. The CRP level is not influenced by anemia or plasma protein changes. It begins to rise about 4-6 hours after onset of inflammation […]

Erythrocyte Sedimentation Rate

The erythrocyte sedimentation rate (ESR) is determined by filling a calibrated tube of standard diameter with anticoagulated whole blood and measuring the rate of red blood cell (RBC) sedimentation during a specified period, usually 1 hour. When the RBCs settle toward the bottom of the tube, they leave an increasingly large zone of clear plasma, […]


This disease, of as yet unknown etiology, is manifested by noncaseating granulomatous lesions in many organ systems, most commonly in the lungs and thoracic lymph nodes. The disease is much more common in African Americans. Laboratory results are variable and nonspecific. Anemia is not frequent but appears in about 5% of cases. Splenomegaly is present […]

Pulmonary Embolism

Pulmonary emboli are often difficult both to diagnose and to confirm. Sudden dyspnea is the most common symptom; but clinically there may be any combination of chest pain, dyspnea, and possibly hemoptysis. Diseases that must be also considered are acute myocardial infarction (MI) and pneumonia. Pulmonary embolism is often associated with chronic congestive heart failure, […]


This section includes a selected list of conditions that seem especially important in drug detection, overdose, or poisoning. Treatment of drug overdose by dialysis or other means can often be assisted with the objective information derived from drug levels. In some cases, drug screening of urine and serum may reveal additional drugs or substances, such […]