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Biomedical subjects

L Kaufman

Publications and source records attributed to L Kaufman.

At least 451 records · Page 25Linked to original sources

Measurement of glomerular filtration rate by fluorescent excitation of non-radioactive meglumine iothalamate.

The clearance of non-radioactive meglumine Iothalamate (Conray 60), assayed by fluorescent excitation analysis, has been shown to be a good indicator of the glomerular filtration rate (GFR). Investigations in rats by the constant infusion technique showed a good correlation with insulin clearance. In a group of ten children and one adult, we obtained excellent agreement between GFR determinations by clearance of Conray 60 and I-125 sodium Iothalamate, using the single injection technique, and taking samples from 10 min to 4 hr after injection. The decay curve was resolved into two exponential components. We have also shown that the 3 and 4 hr samples, fitted to a single exponential function, yield good agreement with GFR determinations using a double exponential model. The GFR determination method presented here is accurate, simple, cost effective, and involves no radiation exposure to the patient.

Adult↗

Determination of the bromide space in man by fluorescent excitation analysis of oral bromine.

The bromide dilutional volume determined by intravenous administration of 82Br has been compared with the corresponding volume determined by oral administration of stable bromide in 11 patients with various medical disorders. Stable bromide was assayed by fluorescent excitation analysis using a 109Cd source and a lithium-drifted silicon detector. The average deviation between the fluorescent and the radiobromide dilutional volumes was 4.2% with a standard deviation of +/- 8.5%. This substantiates both the accuracy of the fluorescent excitation method as applied to this tracer and the validity of utilizing oral tracer administration in comparison with intravenous administration. The derived estimates of extracellular fluid volume averaged 28.7% of body weight in the entire group of 11 patients and 25.8% in the 4 normal subjects included in the group. Evaluation of the extracellular fluid space utilizing fluorescent excitation of stable bromide permits high statistical accuracy of sample measurement with great simplicity compared with current chemical methods and with avoidance of the patient radiation exposure associated with 82Br.

Administration, Oral↗

Value of the concomitant use of complement fixation and immunodiffusion tests in the diagnosis of coccidioidomycosis.

Complement fixation titers of 1:2 and 1:4 with coccidioidin are not always of diagnostic significance. The concurrent use of the complement fixation and immunodiffusion tests is an effective means for specific serologic diagnosis of coccidioidomycosis in patients with low levels of complement-fixing antibodies. In routine testing, it is recommended that only sera that are negative for complement-fixing antibodies at 1:8 but positive in the immunodiffusion test with coccidioidin be selected for titration at the 1:2 and 1:4 levels.

Antibodies, Fungal↗

Comparative evaluation of five serological methods for the diagnosis of sporotrichosis.

The diagnosis of sporotrichosis can be time consuming. Serological procedures could facilitate the rapid and accurate diagnosis of this disease. A slide latex agglutination (SLA) test for sporotrichosis was developed and compared with the tube agglutination (TA), complement fixation (CF), and immunodiffusion (ID) tests in the serological study of 80 proven human cases of sporotrichosis representing the cutaneous, subcutaneous, and extracutaneous forms of the disease. In addition, the indirect fluorescent antibody (IFA) technique was applied to 61 case sera. In the SLA test, latex particles sensitized with culture filtrate antigens from the yeast form of Sporothrix schenckii (B 959) detected 94% of the cases, as compared to 96% of the cases detected by the TA test, 68% by the CF test, and 56% by the ID test. The IFA test detected 90% of the 61 cases. The SLA and ID tests were specific, showing no reactions with sera from 86 persons with no disease or with diseases other than sporotrichosis. Because of its sensitivity, specificity, ease of performance, and ability to provide results in 5 min, the SLA test is highly recommended for routine use in the clinical laboratory.

Agglutination Tests↗

Detection and identification of diagnostic Histoplasma capsulatum precipitates by counterelectrophoresis.

Studies were carried out to develop and evaluate a counterelectrophoresis (CEP) technique for the rapid and specific identification of the diagnostically important histoplasmosis H and M precipitin bands. Well-defined and centrally located precipitin bands were produced by using a discontinuous buffer system and a gel matrix composed of agarose and ionagar no. 2. A template was devised which allowed the selective identification of the H and M precipitins. Comparative evaluations were performed with the microimmunodiffusion (ID) and complement fixation tests. In 52 sera from persons with histoplasmosis, either the H or M precipitin, or both, were identified in 42 (81%) of the cases with the CEP technique and in 43 (83%) with the ID test. With sera from 28 persons with heterologous diseases, the CEP technique, like the ID test, failed to react. The specificity of the CEP technique was dependent upon the use of the identity template. The CEP technique is recommended for routine use in laboratories testing moderate numbers of sera. It provides accurate and reproducible results within 90 min, in contrast to the ID test, which requires 18 to 24 h.

Antibodies, Fungal↗

Specific immunodiffusion test for blastomycosis.

A specific immunodiffusion test for blastomycosis has been developed. The test permitted the detection of approximately 80% of 113 proven cases of blastomycosis. Two diagnostically important precipitins designated A and B were frequently recognized in patients with blastomycosis. Routine use of reference sera containing the A and B precipitins in immunodiffusion tests would permit the specific diagnosis of blastomycosis without the need for parallel tests with coccidioidin and histoplasmin.

Antigens, Fungal↗

Use of the immunodiffusion test in the serodiagnosis of aspergillosis.

The diagnostic value of an immunodiffusion (ID) test with standardized precipitinogens derived from five Aspergillus species was determined with sera from 60 proven and 12 suspected cases of aspergillosis. The data demonstrated that the greatest number of aspergillosis cases were detected by the concurrent use of A. fumigatus and A. niger precipitinogens. With these precipitinogens, the ID test permitted the serodiagnosis of aspergillosis in 82% of the 60 proven cases and in 83% of the 12 suspected cases. The presence of one or more precipitins was indicative of aspergilloma, of allergic bronchopulmonary aspergillosis, or of invasive aspergillosis. Precipitins were detected in 93% of the sera from patients with aspergilloma, in 50% of the sera from patients with allergic bronchopulmonary aspergillosis, and in 88% of the sera from patients with invasive aspergillosis. Although the presence of one or two precipitin bands could indicate any form of aspergillosis, the presence of three or four was strong evidence of either aspergilloma or invasive aspergillosis. The ID test was found to be 100% specific in an evaluation of its effectiveness with 65 sera from individuals with other systemic mycotic infections, bacterial or neoplastic diseases, and from apparently normal humans. In diagnosed cases of aspergillosis, the examination of serial serum specimens provided information about the clinical course of the disease. A reduction in the number of precipitin bands and significant titer changes were noted as the patients responded to therapy.

Animals↗