Accuracy of common drug screen tests

Forty consecutive urine specimens, obtained from patients seen in the emergency center, positive for either cocaine and/or marijuana, were analyzed using five methods of analysis. A new latex agglutination inhibition assay, Abuscreen OnTrak, (Roche Diagnostic Systems, Nutley, NJ), was compared with four other drug abuse assays: mass spectrometry, (Hewlett-Packard Co, Richardson, TX); an automated homogeneous enzyme immunoassay technique, ETS System, (Syva Co, Palo Alto, CA); a manual enzyme multiplied immunoassay technique; EMIT-st, (Syva); and a fluorescence polarization immunoassay, TDx, (Abbott Laboratories, Chicago, IL). For statistical purposes, mass spectrometry was the reference point for the presence or absence of a specific substance. All instrument sensitivities, with the exception of mass spectrometry, were set with the same "cut off" point of 100 micrograms/L for marijuana and 300 micrograms/L for cocaine and its metabolites. Efficiency in the detection of cocaine and its metabolites was 95% by all methods. Efficiency for the detection of marijuana and its metabolites ranged from 70% (Roche's OnTrak) to 90% (Syva's ETS). Simple to use, assays of minimal cost are presently available for rapid, accurate drug of abuse screening.

Fine needle aspiration cytology of malignant melanoma of soft parts. Report of two cases

Two cases of malignant melanoma of soft parts were diagnosed by fine needle aspiration (FNA) biopsy. One case involved the right thumb of a 22-year-old woman; the other involved a submental mass in a 36-year-old man who had been previously diagnosed as having malignant melanoma of soft parts. The FNA smears showed discohesive polygonal or oval and fusiform cells with eccentric nuclei, irregular nuclear chromatin and prominent nucleoli. FNA cell block sections contained polygonal or fusiform cells with clear cytoplasm, eccentrically placed nuclei and prominent nucleoli. Ultrastructural and immunocytochemical studies on aspirated material supported the diagnosis of malignant melanoma.

Revision of the oral glucose tolerance test: a pilot study

Nausea and vomiting have been recurrent problems with the oral glucose tolerance tests (OGTT) used to diagnose diabetes. We believe the nausea is associated with delayed gastric emptying caused by the high osmolarity of the glucose solution. In our pilot study, both the "standard" 100-g glucose OGTT and our new modified (lower osmolar) glucose solution were evaluated. Considerably delayed gastric emptying (along with severe nausea) was consistently noted with the standard OGTT. No nausea and a much more rapid gastric emptying time were recorded when the modified glucose solution was administered. We were able to diagnose diabetes (by using Wilkerson's point system) when our modified OGTT was administered to type 2 diabetics. We plan to develop a more physiological, more reproducible, and better tolerated OGTT to diagnose diabetes more accurately in the general population.

Revision of the oral glucose tolerance test: a pilot study

Nausea and vomiting have been recurrent problems with the oral glucose tolerance tests (OGTT) used to diagnose diabetes. We believe the nausea is associated with delayed gastric emptying caused by the high osmolarity of the glucose solution. In our pilot study, both the "standard" 100-g glucose OGTT and our new modified (lower osmolar) glucose solution were evaluated. Considerably delayed gastric emptying (along with severe nausea) was consistently noted with the standard OGTT. No nausea and a much more rapid gastric emptying time were recorded when the modified glucose solution was administered. We were able to diagnose diabetes (by using Wilkerson's point system) when our modified OGTT was administered to type 2 diabetics. We plan to develop a more physiological, more reproducible, and better tolerated OGTT to diagnose diabetes more accurately in the general population.

Fine needle aspiration cytology of metastatic malignant schwannoma. A case report

A metastatic malignant schwannoma diagnosed by fine needle aspiration (FNA) biopsy in a 56-year-old man is reported. Cytologic examination of smears and cell blocks prepared from aspirates of a vertebral mass suggested the presence of metastases from a previously excised malignant schwannoma on the right leg. Electron microscopic and immunocytochemical studies on the aspirate supported the diagnosis, as did the patient's clinical history and previous pathology and the radiographic demonstration of metastatic lesions in the lung. The cytologic findings (cells with oval-to-spindled nuclei and ill-defined cellular borders suspended within a delicately fibrillar eosinophilic matrix) are discussed in light of the histologic diversity of this lesion and the problems of distinguishing it from other sarcomas. The ability to diagnose metastatic malignant schwannoma by FNA emphasizes the value of this technique.

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.

Serum creatine kinase isoenzyme BB is a poor index to the size of various brain lesions

We divided patients with brain lesions into three groups: (a) patients with primary or metastatic brain cancer, (b) brain infarctions, and (c) brain contusion(s). We analyzed each patient's sera for creatine kinase isoenzyme BB (CK-BB), using a monoclonal antibody kit (Impres-BB; International Immunoassay Laboratories). Computerized axial tomography (CAT) scans were performed on each patient. The size of the various lesions was measured from the CAT scan and recorded in milliliters. Total CK, CK-BB, and their ratios were compared with the volume of damaged brain tissue. We found no correlation between any of the variables and the various brain lesions. We attribute this lack of correlation to an intact blood-brain barrier, the rapid elimination or inactivation of CK-BB, or some combination of these factors.

Clinical and analytical evaluation of different methods for measurement of creatine kinase isoenzyme MB

We evaluated the clinical and analytical performance of the new immunochemiluminometric assay (ICMA; Ciba Corning) for measurement of creatine kinase isoenzyme MB (CK-MB), and compared it with three other methods: immunoradiometric assay (IRMA; International Immunoassay Labs); immunoinhibition assay (Seradyn); and an immunoinhibition/column method (Du Pont). Intra-test precision for all kits was good. We evaluated 32 patients' samples by all four methodologies. Only one of the four methods (aca, Du Pont) showed evidence of linearity. Efficiency in the diagnosis of myocardial injury in our study ranged from 53% (Seradyn) to 96% (Du Pont). We evaluated serial specimens from 20 separate patients by the IRMA and the ICMA to determine whether myocardial injury could be diagnosed earlier by the ICMA. In patients with acute myocardial infarction, the ICMA displayed positive values earlier and longer than the IRMA, suggesting that the ICMA is suited for screening for myocardial damage in hospitalized patients.

Clinical and analytical evaluation of different methods for measurement of creatine kinase isoenzyme MB

We evaluated the clinical and analytical performance of the new immunochemiluminometric assay (ICMA; Ciba Corning) for measurement of creatine kinase isoenzyme MB (CK-MB), and compared it with three other methods: immunoradiometric assay (IRMA; International Immunoassay Labs); immunoinhibition assay (Seradyn); and an immunoinhibition/column method (Du Pont). Intra-test precision for all kits was good. We evaluated 32 patients' samples by all four methodologies. Only one of the four methods (aca, Du Pont) showed evidence of linearity. Efficiency in the diagnosis of myocardial injury in our study ranged from 53% (Seradyn) to 96% (Du Pont). We evaluated serial specimens from 20 separate patients by the IRMA and the ICMA to determine whether myocardial injury could be diagnosed earlier by the ICMA. In patients with acute myocardial infarction, the ICMA displayed positive values earlier and longer than the IRMA, suggesting that the ICMA is suited for screening for myocardial damage in hospitalized patients.

A commercial enzyme immunoassay method (EMIT) compared with liquid chromatography and bioassay methods for measurement of chloramphenicol

A new enzyme immunoassay method (EMIT; Syva Co.) was compared with conventional high-performance liquid chromatography (HPLC) and agar-diffusion bioassay methods for measurement of chloramphenicol in human serum. Forty-nine serum samples were assayed by each of the three methods. Excellent correlation was observed between values by EMIT and by the two conventional methods (r = 0.986 and 0.961). Precision was acceptable (CV less than 5%) with EMIT. Assay of samples containing chloramphenicol glucuronide and chloramphenicol succinate demonstrated that EMIT recognizes only the biologically active (base) form of the drug. The capability to test serum samples as small as 0.2 mL, adaptation to widely available instrumentation, and provision of rapid results are principal advantages of the EMIT method for routine chloramphenicol measurements.

A commercial enzyme immunoassay method (EMIT) compared with liquid chromatography and bioassay methods for measurement of chloramphenicol

A new enzyme immunoassay method (EMIT; Syva Co.) was compared with conventional high-performance liquid chromatography (HPLC) and agar-diffusion bioassay methods for measurement of chloramphenicol in human serum. Forty-nine serum samples were assayed by each of the three methods. Excellent correlation was observed between values by EMIT and by the two conventional methods (r = 0.986 and 0.961). Precision was acceptable (CV less than 5%) with EMIT. Assay of samples containing chloramphenicol glucuronide and chloramphenicol succinate demonstrated that EMIT recognizes only the biologically active (base) form of the drug. The capability to test serum samples as small as 0.2 mL, adaptation to widely available instrumentation, and provision of rapid results are principal advantages of the EMIT method for routine chloramphenicol measurements.

Primary lymphocutaneous Nocardia brasiliensis infection: three case reports and a review of the literature

The occurrence of human nocardiosis is increasing in both immunocompetent as well as immunosuppressed patients. We report three rare cases of primary lymphocutaneous Nocardia brasiliensis infection. The mode of inoculation in each case was that of a puncture wound that occurred 1-3 wk prior to the development of the clinically apparent infections. The original clinical diagnosis was erroneous in each case. A review of 16 previously reported cases is presented as well as a discussion of appropriate medical therapy.

Creatine kinase MB in cases of skeletal muscle trauma

Fifty-eight patients admitted through our emergency room with severe skeletal muscle injury but no obvious cardiac contusions were evaluated for creatine kinase isoenzyme MB (CK-MB). When such patients show an above-normal value for total CK, it is a question of whether or not myocardial injury has been sustained along with skeletal muscle injury when (a) there are no obvious chest contusions or (b) the patient is unconscious and unable to complain of chest pain. Whenever there is doubt concerning the cardiac status of a patient, lactate dehydrogenase (LD) isoenzymes, serial electrocardiograms, and CK isoenzymes are ordered. Our study revealed that serum of 8.6% of the trauma victims had CK-MB values exceeding 5.0 EU/L (reflecting abnormal CK-MB concentrations) as part of their increased total CK. All patients had normal electrocardiographic patterns along with negative results for LD isoenzymes; none had sustained any demonstrable myocardial injury. The CK-MB value must be interpreted together with the total CK value for appropriate diagnosis in patients with skeletal muscle trauma.

Creatine kinase MB in cases of skeletal muscle trauma

Fifty-eight patients admitted through our emergency room with severe skeletal muscle injury but no obvious cardiac contusions were evaluated for creatine kinase isoenzyme MB (CK-MB). When such patients show an above-normal value for total CK, it is a question of whether or not myocardial injury has been sustained along with skeletal muscle injury when (a) there are no obvious chest contusions or (b) the patient is unconscious and unable to complain of chest pain. Whenever there is doubt concerning the cardiac status of a patient, lactate dehydrogenase (LD) isoenzymes, serial electrocardiograms, and CK isoenzymes are ordered. Our study revealed that serum of 8.6% of the trauma victims had CK-MB values exceeding 5.0 EU/L (reflecting abnormal CK-MB concentrations) as part of their increased total CK. All patients had normal electrocardiographic patterns along with negative results for LD isoenzymes; none had sustained any demonstrable myocardial injury. The CK-MB value must be interpreted together with the total CK value for appropriate diagnosis in patients with skeletal muscle trauma.

Fine-needle aspiration biopsy of mycosis fungoides presenting as an ulcerating breast mass

A patient with previously diagnosed Hodgkin's disease presented with ulcerating lesions on her scalp and breast. Fine-needle aspiration of the breast lesion revealed convoluted cells consistent with mycosis fungoides. Review of the patient's previously obtained lymph node biopsy specimens revealed a diagnosis of mycosis fungoides rather than Hodgkin's disease. Better communication between hospitals, pathologists, and clinicians may have prevented the erroneous original diagnosis of Hodgkin's disease in this patient.

Nocardial osteomyelitis: a case report and review of the literature

The occurrence of human nocardiosis is increasing in both immunocompetent as well as immunosuppressed patients. A 63-yr-old male construction worker presented with complaints of left hip pain and rapidly enlarging masses on his left neck and chest. He had been treated for a pneumonia of unknown etiology 3 mo prior to admission. A debridement of the left femur was performed and the curetted material was positive for Nocardia asteroides. Osteomyelitis due to the hematogenous spread of Nocardia asteroides is rare, but will undoubtedly be seen with increasing frequency. The literature, as well as 11 reported cases of the hematogenous spread of this organism, are reviewed.