Cold abscess of dental origin in a 7-year-old child.

Abscess related to an infected tooth is mostly associated with pyogenic infection, but sometimes, it can be asymptomatic and indicate a chronic condition. This case report shows cold abscess with a draining sinus due to dental origin. A 7-year-old female patient complained of pain with respect to grossly decayed tooth and recurrent swelling with no response to medications. After investigations and management of the lesion, it was concluded as abscess due to chronic granulomatous infection. Cold abscess is a classical manifestation of tuberculosis with no signs of inflammation. More than 60% of cases of this pathology occur in patients below 15 years old. It needs various clinical, histopathological, and laboratory investigations. Although rare, it should be considered as a differential diagnosis when no improvement occurs postroutine therapy to prevent serious complications. Furthermore, various precautions should be taken by the clinicians to prevent cross-infection.

Diagnosis of the hemolytic state using serum levels of erythrocyte adenylate kinase.

Red cell hemolysis is classically diagnosed by a combination of nonspecific laboratory tests, including serum bilirubin, LDH, and the reticulocyte count. None of these tests alone or in combination has the specificity to reliably ascertain the presence of hemolysis. We have previously demonstrated that erythrocyte adenylate kinase (EAK) is a red cell specific enzyme released from damaged red cells. Its activity can be measured in serum by rapid electrophoresis or immunological methods and correlates linearly with the degree of hemolysis in vitro. We now report on a clinical study comparing EAK levels in patients with and without hemolysis. The clinical diagnosis of hemolysis was established in hospitalized patients with anemia by the combined elevation of the bilirubin, LDH, and reticulocyte count in the absence of liver disease and demonstrable blood loss. The normal range of serum EAK was determined in 30 healthy nonanemic voluntary blood donors and was 0-3.5 Units (mean = 0.5). In 25 patients with hemolytic anemia due to sickle cell disease, hemolytic transfusion reactions, or TTP, the mean EAK level was 62.4 with a range 0-298 Units (P < 0.001 compared to normals). Levels of EAK exceeded the normal range in 24 of 25 patients (96%). In a control group of 44 hospitalized patients with liver disease or myocardial infarction and no clinical evidence of hemolysis, the mean EAK level was 0.12 with a range of 0-3.2 (P = 0.1, NS compared to normals and P < 0.001 compared to patients with hemolysis). None of the control patients had EAK levels that exceeded the normal range. The diagnostic sensitivity of the EAK assay for hemolysis, as calculated according to Baye's algorithm, was 96%, with a specificity and accuracy of 97%. Measurement of serum EAK represents a highly sensitive and specific test for the diagnosis of hemolytic anemia.

Unusual interference from primary collection tube in a high-performance liquid chromatography assay of amiodarone.

We describe an unusual interference in our routine high-performance liquid chromatography (HPLC) assay of amiodarone and its active metabolite, desethylamiodarone, used to quantify the parent drug and the active metabolite in serum from the primary sample collection tube. The interfering peak had a retention time very similar to that of the authentic desethylamiodarone. Substitution of Corvac tubes with Vacutainer tubes for the collection and transportation of serum samples eliminated the source of interference. We routinely suggest the use of Vacutainer collection tubes for obtaining blood samples of cardiac patients undergoing amiodarone therapy.

Differentiation and resolution of erythrocyte and muscle adenylate kinase activities in serum by electrophoresis.

Adenylate kinase activity originating from erythrocytes has been shown to be distinct from muscle adenylate kinase or myokinase activity, until now considered to be identical enzyme activities. The two activities can be differentiated by electrophoretic fractionation, thus making it possible to quantify the erythrocyte adenylate kinase activity present in serum.

Erythrocyte adenylate kinase isoenzyme as a marker for hemolysis.

The presence in serum of adenylate kinase isoenzyme originating from erythrocyte can be useful as a marker for detecting hemolysis. We have presented preliminary evidence for identifying hemolytic anemia patients earlier by determining erythrocyte AK isoenzyme activity in serum (or plasma) rather than using measurement of plasma hemoglobin concentration. This test being quite specific for hemolysis should find use as a quick method for estimating the extent of in vivo hemolysis in hemolytic patients earlier than heretofore possible.

Troponin-T as a serum marker for myocardial infarction.

We report here our experience with serum troponin T (TnT), measured with the sandwich immunoassay introduced by Boehringer Mannheim as a marker for myocardial infarction. We assayed TnT in serial serum samples from 30 patients with time courses of serum CK, CK-MB, AST, and LD that we consider typical of acute myocardial infarction (MI). In every patient but one, TnT rose in parallel with both CK-MB and AST, but remained elevated significantly longer. The ratios of the elevations of the different markers varied from patient to patient with marked variation in the ratio of TnT to CK-MB. There appeared to be a significant association between the magnitude of that ratio with the level of ALT.

Promoter of the canine tracheobronchial mucin gene.

The mucin gene is up-regulated in diseases such as cystic fibrosis (CF) and asthma. To understand the mechanisms involved in transcriptional regulation of mucin gene expression we have characterized the region of the mucin gene up-stream of the transcriptional start site and analysed the cis-acting elements required for mucin promoter activity. We isolated clones from a dog genomic library containing the promoter region for the tracheobronchial mucin gene (TBM). The authenticity of the promoter was tested by nucleotide sequencing, primer extension analysis, electrophoretic mobility shift assay (EMSA) and reporter gene expression analysis. The canine TBM promoter is different from housekeeping gene promoters (as it is not rich in GC content and contains TATA- and CAAT-like sequences) and different from that of regulatory genes (because it contains many TATA- and CAAT-like sequences and multiple transcriptional initiation sites). Reporter gene analysis using canine TBM promoter-chloramphenicol acetyltransferase (CAT) fusion plasmids established the regions responsible for promoter activity and verified the positions of the major mucin transcriptional initiation sites. Reporter gene analysis also established that a region of the canine TBM promoter and first exon containing all of the transcriptional initiation sites is more active in mucin expressing cells (e.g. CT1 cells-immortalized canine tracheal epithelial cells, human CFT1 cells-immortalized tracheal epithelial cells from a CF subject, or HBE1 cells-immortalized tracheal epithelial cells from non-CF subject) than in mucin non-expressing cells (COS7, 3T3), suggesting cell specificity. The promoter region contained cAMP response element (CRE) sequences, and the TBM gene transcription was enhanced when cAMP analogs were added to transfected cells. EMSA indicated the presence of at least two DNA binding proteins in CT1 cells. This is the first report describing the characterization of a TBM gene promoter. The information obtained in the present studies will be valuable in understanding mucin gene regulation in normal and pathological conditions.

Performance of Opus immunoassays for thyroxine and beta-human chorionic gonadotrophin in serum.

Two representative immunoassays for measuring thyroxine and beta-subunit of human chorionic gonadotrophin in serum, using the Opus immunoassay analyzer, were evaluated by comparing them to the reference RIA for T4 and beta-HCG enzyme immunoassay. Both assays were superior in accuracy and precision than the reference methods and exhibited good linearity throughout the concentration range needed for discriminating abnormally low and elevated concentrations from the established reference ranges of thyroxine and beta-human chorionic gonadotrophin in serum. Correlation between the results of the Opus immunoassays and the reference assays for T4 and beta-HCG was very good with correlation coefficients of 0.92 and 0.98, respectively.

Lymphocytes produce specific alkaline phosphatase after in vitro stimulation or after in vivo infection with HIV-1.

A unique alkaline phosphatase isoform found in the serum of HIV-1 infected patients is thought to originate from CD4 lymphocytes. Destruction of activated CD4 lymphocytes after HIV-1 infection is probably responsible for the appearance of this isoform in circulation. This band-10 alkaline phosphatase isoform is thus useful as an early marker for detecting AIDS in children born to HIV-1 infected mothers.

Prevalence of tuberculosis in a rural area by an alternative survey method without prior radiographic screening of the population.

SETTING: Mass miniature radiography (MMR) is the usual tool for population screening in tuberculosis case prevalence surveys. However, this facility is not available at most centres in India. OBJECTIVE: The feasibility of conducting a survey without MMR screening was therefore investigated. DESIGN: The study was carried out in Bangalore rural district during 1984-1986. The area was the same as for six earlier prevalence surveys conducted since 1961. The population aged up to 44 years was tuberculin tested. Persons with test induration size of > or = 10 mm were eligible for sputum examination, besides all those aged over 45 years who were eligible without discrimination. RESULTS: Reduction of workload was not adequately achieved through screening, as 78.4% of the registered population (29,400) was still eligible for sputum examination. The changed screening procedure in this survey also made comparison with earlier data difficult. In spite of more liberal and comprehensive screening, the observed prevalence rate of cases (438/100,000 population aged 10+ years) was similar to earlier surveys. The prevalence rate of smear-positive cases, however, was much lower (68/100,000 population aged 10+ years). CONCLUSION: In conclusion, the candidate screening procedure was not suitable. The findings nevertheless conformed to the overall declining trend for the area, as reported earlier.

Use of pyruvate oxidase to overcome pyruvate inhibition during the lactate to pyruvate reaction for assaying lactate dehydrogenase in serum.

Automated assays of lactate dehydrogenase (LD) in serum are based on measuring the rate of NADH produced in a reverse LD reaction using lactate and NAD. The observed nonlinearity of LD reaction used in earlier assays performed in phosphate buffers has generally been attributed to the formation of a ternary complex of NAD, pyruvate, and phosphate. this is not satisfactory to explain the course of assay reaction carried out in organic buffers. Investigation of the possible causes of nonlinearity during the course of the reverse LD reaction during LD assays performed in Tris or other organic buffers indicated that inhibition of LD activity by pyruvate may be chiefly responsible for the observed effects, especially in serum exhibiting abnormally high LD enzyme activity. Most of the LD activity in serum was inhibited by 5 mMoles/L pyruvate. By contrast, the LD isoenzyme activities were inhibited partially at 0.5 mMole/L pyruvate, LD1 being the most and LD4 the least susceptible. In assays of serum samples with abnormally high LD and PYR concentration using LD reagent containing Tris buffer, pH 9.3, the inclusion of a bacterial pyruvate oxidase (PO) enabled the removal of pyruvate accumulating in situ, making it possible to assay LD activity in the absence of inhibitory concentration of pyruvate. The inclusion of 10 U/L of PO in our routine LD reagent was sufficient to overcome pyruvate inhibition, thus permitting the assay of serum exhibiting high LD activity, hence the extension of the upper limits of linearity of LD assay without compromising assay performance.

Alkaline phosphatase band-10 fraction as a possible surrogate marker for human immunodeficiency virus type 1 infection in children.

We report the utility of a possible lymphocyte fraction of alkaline phosphatase (ALP band-10) activity in serum to predict human immunodeficiency virus type 1 (HIV-1) infection in children born to HIV-1-seropositive mothers. The presence of ALP band 10 in serum consistently correlated with HIV-1 infection status as judged by positive HIV-1 culture, two consecutive HIV-1 p24 antigen results greater than 30 pg/mL in serum, and the subsequent confirmation of seroconversion to HIV-1 antibody after clearance of maternal IgG anti-HIV-1 antibody ascertained between 15 to 24 months post partum. Infection with HIV-1 was correctly identified in 31 samples from 18 patients ranging in age between 0.1 to 10 years; the absence of similar infection was noted in 14 samples from nine patients who served as controls and whose serum samples did not exhibit ALP band-10 activity. This ability of serum ALP band-10 activity to predict HIV-1 infection status in children as young as 2 months may be useful as a surrogate marker for early identification of HIV-1 infection in infants born to HIV-1-seropositive women long before the clearance of maternal anti-HIV-1 antibodies can be ascertained.

Adenylate kinase mimics creatine kinase-MM isoenzyme in a CK isoenzyme electrophoresis assay.

Adenylate kinase activity (AK) originating from erythrocytes, present in hemolyzed serum behaves like creatine kinase MM isoenzyme (CK-MM) in some CK electrophoresis assays that employ, in their visualization reagent kits, adenosine monophosphate (AMP) as the sole inhibitor of AK, rather than a combination of AMP and a more potent inhibitor of erythrocyte AK, diadenosine pentaphosphate (Ap5A), to inhibit all contaminating-AK activities in serum and quantify only the CK isoenzyme activities in serum following electrophoretic fractionation on agarose gel. This can spuriously overestimate the CK-MM fraction and thereby result in underestimation of CK-MM or CK-BB isoenzymes if present. A hemolyzed serum sample obtained from an elderly patient was erroneously reported as containing low CK-MB due to such overestimation of CK-MM fraction in the sample. Supplementing the AMP already present in the visualization reagent formulation, used to estimate CK isoenzyme concentration in serum, with Ap5A can eliminate or effectively minimize AK interference, especially that caused by hemolysis, and thereby prevent reporting false-negative CK-MB result obtained with CK isoenzyme electrophoresis assays.

Leukocyte esterase activity in effusion fluid of patients with otitis media.

Fluid obtained during myringotomy and tube placement in 20 patients with middle ear effusions was assayed for leukocyte esterase activity using a quantitative spectrophotometric assay. This quantitative assay used the synthetic substrate, N-tosyl indoxyl alaninate. Seven of the 20 samples showed no measurable enzyme activity (8 U/ml or less). The remaining samples demonstrated activity ranging from 20 to 1600 units. Although enzyme activity did not correlate well with the physical appearance of the fluid, it did correlate with clinical history, suggesting the presence of a purulent exudate rather than serous effusion. Leukocyte esterase activity in the fluid appears to hold promise as an indicator for the presence of chronic middle ear infection. The enzyme can be assayed by a simple and fast diagnostic strip test, with results available almost immediately.

Identification of false-positive CK-MB activity in an elderly patient.

An unusual occurrence of an aberrant CK-MB activity in an elderly female patient is described. The CK-MB-like activity present in serum samples from this patient was definitively identified as an immunoglobulin A complex of CK-MM (macro CK, type 1) using CK isoenzyme agarose gel electrophoresis after pretreating the patient's serum sample with either anti-immunoglobulin A antiserum or anti-CK-M antibody reagent.

A study of the CEDIA digoxin immunoassay.

We evaluated the CEDIA digoxin immunoassay (Microgenics, Inc., Concord, CA), as performed with the Cobas-Bio centrifugal analyzer. In assays of sera with known concentrations of digoxin, the enzyme activity, measured when two beta-galactosidase (EC 3.2.1.23) fragments were combined according to the assay format, was proportional to the digoxin concentration. Results of assays of sera containing 0 to 3 micrograms of digoxin per liter correlated well when compared with an RIA method: CEDIA, microgram/L = 1.00 x RIA - 0.06 microgram/L (n = 90, r = 0.95, Sxy = 0.05). Duplicate assays of three control sera containing 0.8, 2.2, or 3.3 micrograms/L, each analyzed 20 times a day with each group of patients' samples, gave within-run CVs of 1-3% and day-to-day CVs of 3-12%. The reconstituted CEDIA reagents were stable for at least a month at 5 degrees C. As many as 25 samples and controls can be assayed in half the time needed to complete a similar number of RIA measurements with comparable results.

A simple spectrophotometric assay for urinary leukocyte esterase activity.

We have developed a sensitive spectrophotometric method for assaying urinary leukocyte esterase activity by employing a synthetic substrate, N-toluene sulfonyl indoxyl alanine ester. This kinetic assay can be performed with a small aliquot of urine, by following the change in absorbance of the chromophore at 385 nm. It is rapid and specific for leukocyte esterase and therefore can be used in the early diagnosis of urinary tract infection.

Activity concentration and mass concentration (monoclonal antibody immunoenzymometric method) compared for creatine kinase MB isoenzyme in serum.

Results of the "Tandem-E CKMB" immunoenzymometric procedure (y) for creatine kinase (CK; EC 2.9.3.2) were compared with electrophoresis (x) for 160 serum samples from patients suspected of having sustained myocardial infarctions. The results correlated well: y, microgram/L (Tandem assay) = 1.3x-6.3 U/L(electrophoresis) (r = 0.95). CK-MB mass measurement was more stable than enzyme activity after storage and appeared to be more sensitive. Sera from 86 other people, which had no detectable CK-MB upon electrophoresis, gave a mean CK-MB value of 1.1 microgram/L (SD 1.3, range 0-8) with the Tandem assay. To determine whether these low values represented actual isoenzyme, we tested for possible interference by heterophile antibodies in the patients' sera by preincubating the samples with mouse serum before the Tandem assay. The mouse serum did not interfere with the assay of sera that had substantial quantities of CK-MB by electrophoresis. However, in five of six samples that were negative by electrophoresis, the CK-MB values were substantially smaller, indicating that the values measured were false-positives caused by the presence of heterophile antibodies directed against mouse proteins, an interference that could be eliminated by pretreatment with mouse serum.