Morphologic and clinical observations in human infection with Babesia microti

On admission to the hospital, a splenectomized man was found to have 85% of his erythrocytes parasitized by Babesia microti. His extensive parasitemia allowed for direct study of the morphology and ultrastructure of this organism as it appears in human infection; the need for animal inoculation and rescue techniques was thus eliminated. Positive characteristics (other than the tetrad form) that are diagnostic for babesiosis were identified. By transmission and scanning electron microscopy, parasite-induced changes in the erythrocyte membrane were observed; these alterations may explain the hemolysis seen in babesiosis. Factors that may have allowed the patient to sustain such high-level parasitemia are considered. The experience with this patient confirms that exchange transfusion is a reliable, rapid method for reduction of the parasite load in serious infection with B microti.

Printcultures for postmortem microbiology

A modified printculture method for postmortem bacteriology was compared to the traditional tissue homogenate inoculum method. The two methods were comparable in their recovery rate of bacterial isolates. However, printcultures is an easy and rapid method; thus, it is superior to the traditional technique for postmortem culture. Histologic examination of most postmortem lung specimens with no bacterial growth showed no evidence of pneumonia or bronchitis, suggesting that the lack of growth is a reliable indicator of no bacterial infection.

The accurate determination of serum glucose by isotope dilution mass spectrometry--two methods

Two isotope dilution mass spectrometric methods have been developed for the determination of D-glucose in human serum. Each uses a uniformly labeled (13C)glucose as the internal standard. The first method involves conversion of glucose into 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose and an extensive clean-up, followed by quantitation using packed column gas chromatography mass spectrometry. In the second method, glucose is converted into alpha-D-glucofuranose cyclic 1,2:3,5-bis(butylboronate)-6-acetate. The wet chemistry work-up is simpler, but analysis by capillary gas chromatography mass spectrometry is required. Both methods exhibit excellent precision (coefficients of variation less than 0.3%) and provided mean values that agree within 1% for all serum pools tested.

Multiple myeloma protein with three light chains

A case of immunoglobulin G (kappa) myeloma showed, in addition to the monoclonal IgG(kappa) arc, two kappa chains in the serum. The urine specimen contained 7.75 g of kappa chains per liter. The electrophoretically fast-moving kappa chain in serum was shown by immunoelectrophoresis and Ouchterlony immunodiffusion to be a complex of kappa chains and alpha 1-antitrypsin. This complex, which was detected only transiently in the patient's blood, was composed of a monomeric kappa chain bound to the antitrypsin by a disulfide bond. The predisposing factor for the formation of this complex is unclear, but patients showing this complex usually have kappa type myeloma protein and excrete kappa chain in urine at more than 1 g/L. The relationship between chemotherapy and formation of the kappa chain-antitrypsin complex needs further investigation.

Multiple myeloma protein with three light chains

A case of immunoglobulin G (kappa) myeloma showed, in addition to the monoclonal IgG(kappa) arc, two kappa chains in the serum. The urine specimen contained 7.75 g of kappa chains per liter. The electrophoretically fast-moving kappa chain in serum was shown by immunoelectrophoresis and Ouchterlony immunodiffusion to be a complex of kappa chains and alpha 1-antitrypsin. This complex, which was detected only transiently in the patient's blood, was composed of a monomeric kappa chain bound to the antitrypsin by a disulfide bond. The predisposing factor for the formation of this complex is unclear, but patients showing this complex usually have kappa type myeloma protein and excrete kappa chain in urine at more than 1 g/L. The relationship between chemotherapy and formation of the kappa chain-antitrypsin complex needs further investigation.

Enzyme immunoassay for tartrate-resistant acid phosphatase

An immunochemical method for quantitative analysis of the tartrate-resistant acid phosphatase (EC 3.1.3.2), band 5, is presented. This method involves precipitation of the enzyme from the serum by the antibody specific to band 5 and by sheep anti-rabbit immunoglobulin, followed by analysis of the enzyme activity in the precipitate. The precipitation procedure eliminates the interferences of the tartrate-sensitive phosphatase of all tissues, of the tartrate-resistant phosphatase of erythrocytes, and of unknown substances that interfere with the colorimetric method. We compare the present method with previously described colorimetric and electrophoretic methods.

Enzyme immunoassay for tartrate-resistant acid phosphatase

An immunochemical method for quantitative analysis of the tartrate-resistant acid phosphatase (EC 3.1.3.2), band 5, is presented. This method involves precipitation of the enzyme from the serum by the antibody specific to band 5 and by sheep anti-rabbit immunoglobulin, followed by analysis of the enzyme activity in the precipitate. The precipitation procedure eliminates the interferences of the tartrate-sensitive phosphatase of all tissues, of the tartrate-resistant phosphatase of erythrocytes, and of unknown substances that interfere with the colorimetric method. We compare the present method with previously described colorimetric and electrophoretic methods.

Clinical applicability of acid phosphatase isoenzyme assay

We compared electrophoretic evaluation of acid phosphatase isoenzymes with spectrophotometric determination of prostatic acid phosphatase in terms of clinical utility. In all of 33 cases of prostatic carcinoma, an increased prostatic fraction was detected; in nine prostatectomized patients, this fraction returned to normal as measured by either technique. Abnormal spectrophotometric results were also seen in 10 cases of benign prostatic hypertrophy and seven cases of non-prostatic disorders, but only two benign prostatic hypertrophy and one non-prostatic case showed a prostatic band (band 2) in an electrophoretogram. Band 2 was not demonstrated in 463 patients affected by a great variety of diseases but without prostatic disorders. A weak band 5 was seen in patterns for most patients, except for cases with metastatic bone tumor and Gaucher's disease, whose serum showed a strong band 5. The specificity of bands 2 and 5 seems to be confirmed by this large series of patients. Measurement of acid phosphatase isoenzymes is recommended as a routine screening test for patients whose serum acid phosphatase is abnormally high, because the isoenzyme study not only indicates the presence or absence of prostatic cancer but also whether or not there is bony metastasis. Other disorders such as Gaucher's disease, different kinds of leukemias, and thrombocythemia may also be detected and distinguished by this screening technique.

Synthesis of immunoglobulin within the central nervous system in multiple sclerosis and other neurological diseases. Detection by analysis of CSF/serum IgG ratio

This study included 49 patients with clinical multiple sclerosis (MS), 105 patients with other neurological diseases (OND), and 30 controls. It compared seven assays for CNS IgG synthesis with the oligoclonal banding (agarose electrophoresis) method. A newly developed assay which determined the differences between the measured and calculated CSF/serum IgG ratio (M-C value), using albumin as a reference protein, was particularly sensitive to the diagnosis of MS. In 40/46 (87%) of patients with MS, the M-C value was 0.001 or more, while oligoclonal banding was found in CSF of 38/49 (78%). In the 30 controls, the M-C value was invariably less than 0.001 and oligoclonal banding was not found. In patients with OND, 26/104 (25%) had an M-C value of 0.001 of greater while 11/105 (11%) had oligoclonal banding in CSF. The M-C value also offers a convenient means of quantifying CNS IgG synthesis during disease activity of treatment. It is concluded that the combined use of the oligoclonal banding method and the M-C value determination gives the greatest predictive value for the diagnosis of MS.

Clinical applicability of acid phosphatase isoenzyme assay

We compared electrophoretic evaluation of acid phosphatase isoenzymes with spectrophotometric determination of prostatic acid phosphatase in terms of clinical utility. In all of 33 cases of prostatic carcinoma, an increased prostatic fraction was detected; in nine prostatectomized patients, this fraction returned to normal as measured by either technique. Abnormal spectrophotometric results were also seen in 10 cases of benign prostatic hypertrophy and seven cases of non-prostatic disorders, but only two benign prostatic hypertrophy and one non-prostatic case showed a prostatic band (band 2) in an electrophoretogram. Band 2 was not demonstrated in 463 patients affected by a great variety of diseases but without prostatic disorders. A weak band 5 was seen in patterns for most patients, except for cases with metastatic bone tumor and Gaucher's disease, whose serum showed a strong band 5. The specificity of bands 2 and 5 seems to be confirmed by this large series of patients. Measurement of acid phosphatase isoenzymes is recommended as a routine screening test for patients whose serum acid phosphatase is abnormally high, because the isoenzyme study not only indicates the presence or absence of prostatic cancer but also whether or not there is bony metastasis. Other disorders such as Gaucher's disease, different kinds of leukemias, and thrombocythemia may also be detected and distinguished by this screening technique.

Clonorchiasis: a report of four cases and discussion of unusual manifestations

Clonorchiasis is still a problem for Asian immigrants to North America, and is occasionally seen among American residents who contract the disease during long-term or short-term visits to endemic areas. The incidence of clonorchiasis is especially high among Chinese immigrants from Hong Kong. The acute symptoms most frequently encountered in this group of patients are those of recurrent pyogenic cholangitis and acute pancreatitis. Two American cases are reported together with a brief discussion of the pathology and immunology of this disease. Two unusual lesions in Hong Kong patients, an egg-granuloma of the liver and an adenoma of the bile duct, are also discussed.

Meningeal involvement in IgD myeloma with cerebrospinal fluid paraprotein analysis

Myelomatous meningitis is a rare occurrence in multiple myeloma. We report 2 cases of documented IgD myeloma with cytologic evidence of meningeal involvement in 1 and detailed paraprotein analysis in both. The occurrence of meningeal involvement in this rare form of plasma cell neoplasm may be more common than previously thought.

Total serum cholesterol by isotope dilution/mass spectrometry: a candidate definitive method

We describe a highly accurate and precise method for determination of total cholesterol in serum by isotope dilution/mass spectrometry. The method was developed for a Study Group of the Committee on Standards of the American Association for Clinical Chemistry, for use in establishing the accuracy of a candidate reference method for total cholesterol, and fulfills their criteria for a definitive method. Cholesterol-d7 is added to serum, with the weight ratio of cholesterol-d7 to total serum cholesterol kept near to 1:1. The esters are hydrolyzed and the cholesterol is separated and converted into the trimethylsilyl ether derivative for measurement by combined gas chromatography/mass spectrometry. The intensity ratio of the molecular ions at m/z 465 and 458 is measured for each sample and for two calibration mixtures, according to a prescribed bracketing protocol. A weight ratio for the sample is obtained by linear interpolation of the ion-intensity ratios, and the total cholesterol is then calculated. The method was applied four times over several weeks to each of five serum pools. Statistical analysis involving consideration of both replication error and variability between weeks gave a coefficient of variation for a single measurement of 0.36%. The absence of interferences in the method was demonstrated by measurements at several other masses.

The diagnosis of giardiasis

Giardiasis is the most prevalent intestinal parasitic disease in the United States. Most cases can be diagnosed by a single stool examination. However, in periodic cyst excretors, cysts may not be detected unless repeated stool examinations are performed. In clinically highly suspected cases, duodenal fluid should be studies after three negative stool examinations. Scanning electron microscopy is probably superior to light microscopy in screening duodenal fluid if the parasite is scanty or degenerated. A small intestinal biopsy is a last resort for the diagnosis; a mucosal impression smear should be routinely performed on such specimens. The latter is the most sensitive and reliable technique in making the diagnosis.

Total serum cholesterol by isotope dilution/mass spectrometry: a candidate definitive method

We describe a highly accurate and precise method for determination of total cholesterol in serum by isotope dilution/mass spectrometry. The method was developed for a Study Group of the Committee on Standards of the American Association for Clinical Chemistry, for use in establishing the accuracy of a candidate reference method for total cholesterol, and fulfills their criteria for a definitive method. Cholesterol-d7 is added to serum, with the weight ratio of cholesterol-d7 to total serum cholesterol kept near to 1:1. The esters are hydrolyzed and the cholesterol is separated and converted into the trimethylsilyl ether derivative for measurement by combined gas chromatography/mass spectrometry. The intensity ratio of the molecular ions at m/z 465 and 458 is measured for each sample and for two calibration mixtures, according to a prescribed bracketing protocol. A weight ratio for the sample is obtained by linear interpolation of the ion-intensity ratios, and the total cholesterol is then calculated. The method was applied four times over several weeks to each of five serum pools. Statistical analysis involving consideration of both replication error and variability between weeks gave a coefficient of variation for a single measurement of 0.36%. The absence of interferences in the method was demonstrated by measurements at several other masses.

Acquired alpha-1-antitrypsin deficiency and dysgammaglobulinemia

Alpha-1-antitrypsin (AAT) levels were measured in patients with three types of dysgammaglobulinemia: monoclonal gammopathy, polyclonal hypergammaglobulinemia and hypogammaglobulinemia. A fourth group comprised of subjects with normogammaglobulinemia served as a control. The frequency of hypoalpha-1-antitrypsinemia was significantly higher in those with monoclonal gammopathy compared with controls. The basis for this evaluation is unknown. It was not associated with phenotypic variation nor was it related to sex, age, total protein, albumin and immunoglobulin levels, liver function, bone marrow and bone x-ray findings.

Study of gammopathies with immunofixation electrophoresis

Immunofixation electrophoresis and immunoelectrophoresis were compared in 60 samples (51 sera and 9 urines) containing apparently homogenous bands, detected by electrophoresis. To determine the correlation with clinical findings, the patients were divided into three groups: (1) symptomatic with monoclonal immunoelectrophoretic patterns; (2) asymptomatic with monoclonal immunoelectrophoretic patterns; (3) asymptomatic with polyclonal immunoelectrophoretic patterns. The results from immunoelectrophoresis and immunofixation electrophoresis were consistent with each other in all cases of Groups I and III in terms of clonality (i.e., whether monoclonal or polyclonal) and immunoglobulin class; whereas in Group II, which was composed of asymptomatic patients, two sera and three urines were identified to have monoclonal changes by immunoelectrophoresis but polyclonal changes by immunofixation electrophoresis. It is recommended that immunoelectrophoresis still be used for routine clinical service, but supplemented by immunofixation electrophoresis in equivocal cases, namely: (1) light-chain changes masked by an umbrella effect of immunoglobulin G (IgG); (2) abnormal bands located in atypical areas or overlapped with a normal serum protein; (3) a normal-looking "free" light chain present in the urine, mimicking Bence Jones protein; (4) controversial cases of biclonal gammopathy; (5) mini-monoclonal or oligoclonal protein bands; (6) immune complexes.