Biochemical Testing (biochemical + testing)

Distribution by Scientific Domains


Selected Abstracts


Assessing diabetic control , reliability of methods available in resource poor settings

DIABETIC MEDICINE, Issue 3 2002
A. P. Rotchford
Abstract Aims and methods To examine the reliability of random venous or capillary blood glucose testing, random urine glucose testing, and a current symptom history in predicting a high HbA1c in Type 2 diabetic patients taking oral hypoglycaemic agents in a poorly controlled rural African population. Results For a cut-off point for HbA1c of , 8%, for random venous plasma glucose of , 14 mmol/L (present in 47.2% of subjects), specificity was 97.1% (95% CI 85.1,99.9), sensitivity 56.8% (48.8,64.5) and positive predictive value (PPV) 98.9% (94.2,99.9). HbA1c, 8% is predicted by a random capillary blood glucose of 17 mmol/L (present in 28.4% of subjects) with specificity 100% (90.0,100.0), PPV 100% (93.7,100.0) and sensitivity of 34.3% (27.2,42.1). HbA1c, 8% is predicted by the presence of heavy glycosuria (, 55 mmol/L) (present in 35.6%) with specificity 94.1% (80.3,99.3), sensitivity of 41.9% (34.1,49.9) and PPV 97.1% (89.9,99.6). Polyuria/nocturia (present in 31.3%) was the only symptom found to be associated with poor control, with a specificity for predicting HbA1c of , 8% of 81.5% (61.9,93.7), PPV 89.1% (76.4,96.4) and sensitivity 30.6% (22.9,39.1). Conclusions Where resources are short, random glucose testing can be used to detect a significant proportion of those with the worst control with a high degree of specificity enabling primary care staff to modify treatment safely. Where facilities are limited capillary blood or urine testing with reagent strips, may be substituted for venous plasma testing in the laboratory. A symptom history was insufficient to replace biochemical testing, but where this is unavailable, urinary symptoms may be helpful. Diabet. Med. 19, 195,200 (2002) [source]


Comparison of 16S rRNA sequencing with conventional and commercial phenotypic techniques for identification of enterococci from the marine environment

JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006
D.F. Moore
Abstract Aims:, To compare accuracy of genus and species level identification of presumptive enterococci isolates from the marine environment using conventional biochemical testing, four commercial identification systems and 16S rRNA sequence analysis. Methods and Results:, Ninety-seven environmental bacterial isolates identified as presumptive enterococci on mEI media were tested using conventional and Enterococcus genus screen biochemical tests, four commercial testing systems and 16S rRNA sequencing. Conventional and Enterococcus genus screen biochemical testing, 16S rRNA sequencing and two commercial test systems achieved an accuracy of ,94% for Enterococcus genus confirmation. Conventional biochemical testing and 16S rRNA sequencing achieved an accuracy of ,90% for species level identification. Conclusions:, For confirmation of Enterococcus genus from mEI media, conventional or genus screen biochemical testing, 16S rRNA sequencing and the four commercial systems were correct 79,100% of the time. For speciation to an accuracy of 90% or better, either conventional biochemical testing or 16S rRNA sequencing is required. Significance and Impact of the Study:, Accurate identification of presumptive environmental Enterococcus isolates to genus and species level is an integral part of laboratory quality assurance and further characterization of Enterococcus species from pollution incidents. This investigation determines the ability of six different methods to correctly identify environmental isolates. [source]


Folinic acid,responsive seizures are identical to pyridoxine-dependent epilepsy,

ANNALS OF NEUROLOGY, Issue 5 2009
Renata C. Gallagher MD
Objective Folinic acid,responsive seizures and pyridoxine-dependent epilepsy are two treatable causes of neonatal epileptic encephalopathy. The former is diagnosed by characteristic peaks on cerebrospinal fluid (CSF) monoamine metabolite analysis; its genetic basis has remained elusive. The latter is due to ,-aminoadipic semialdehyde (,-AASA) dehydrogenase deficiency, associated with pathogenic mutations in the ALDH7A1 (antiquitin) gene. We report two patients whose CSF showed the marker of folinic acid,responsive seizures, but who responded clinically to pyridoxine. We performed genetic and biochemical testing of samples from these patients, and seven others, to determine the relation between these two disorders. Methods CSF samples were analyzed for the presence of ,-AASA and pipecolic acid. DNA sequencing of the ALDH7A1 gene was performed. Results Both patients reported here had increased CSF ,-AASA, CSF pipecolic acid, and known or likely pathogenic mutations in the ALDH7A1 gene, consistent with ,-AASA dehydrogenase deficiency. Analysis of CSF samples from seven other anonymous individuals diagnosed with folinic acid,responsive seizures showed similar results. Interpretation These results demonstrate that folinic acid,responsive seizures are due to ,-AASA dehydrogenase deficiency and mutations in the ALDH7A1 gene. Thus, folinic acid,responsive seizures are identical to the major form of pyridoxine-dependent epilepsy. We recommend consideration of treatment with both pyridoxine and folinic acid for patients with ,-AASA dehydrogenase deficiency, and consideration of a lysine restricted diet. The evaluation of patients with neonatal epileptic encephalopathy, as well as those with later-onset seizures, should include a measurement of ,-AASA in urine to identify this likely underdiagnosed and treatable disorder. Ann Neurol 2008 [source]


The use of nuchal translucency measurement and second trimester biochemical markers in screening for Down's Syndrome

BJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2001
G.D. Michailidis
Objective To assess the effectiveness of antenatal screening for trisomy 21 by first trimester sonography followed by second trimester biochemical screening. Design Retrospective five-year review. Setting Maternity unit of a university hospital. Population An unselected group of 7447 pregnant women who had a first trimester scan and nuchal translucency measurement in our unit after January 1995 and had an estimated date of delivery before 1 January 2000. 11.9% were , 37 years old. A subgroup (n=4864) also had second trimester biochemical testing by alpha-fetoprotein and free ,-human chorionic gonadotrophin. Main outcome measures Prenatal and postnatal diagnosis of trisomy 21. Results There were 23 fetuses affected with trisomy 21. The overall prenatal detection rate was 87% (20/23; 95% CI 66% to 97%) and we performed invasive procedures in 8.5% of our population. First trimester sonography identified 74% (95% CI 51.6% to 89.8%) of affected fetuses. Second trimester biochemical screening detected half of the fetuses with trisomy 21 which were missed by first trimester screening, increasing the sensitivity to 90.5% (19/21; 95% CI 69.6% to 98.8%) for an invasive procedure rate of 4.2% performed in screened positive women. However, the positive predictive value of the biochemical test was very low (0.5%). In screen negative women, karyotyping for advanced maternal age did not detect any affected fetuses. Conclusion First trimester nuchal translucency measurement is an effective screening test for the prenatal detection of fetuses with Down's Syndrome. Although the measurement of biochemical markers in the second trimester can detect additional affected fetuses this may be outweighed by the delay in diagnosis, the extra visits and cost so that the right time for biochemical screening is most likely to be in the first trimester. [source]


Locally advanced prostate cancer,biochemical results from a prospective phase II study of intermittent androgen suppression for men with evidence of prostate-specific antigen recurrence after radiotherapy

CANCER, Issue 5 2007
Nicholas Bruchovsky MD
Abstract BACKGROUND. Biochemical results from a prospective Phase II trial of intermittent androgen suppression for recurrent prostate cancer after radiotherapy were analyzed for correlations to the onset of hormone-refractory disease. METHODS. Patients with histologically confirmed adenocarcinoma of the prostate and a rising serum prostate-specific antigen (PSA) level after external beam irradiation of the prostate were treated intermittently with a 36-week course of cyproterone acetate and leuprolide acetate. Then, patients were stratified according to their serum PSA range at the start of each cycle and were followed with further biochemical testing until disease progression was evident. RESULTS. The mean PSA reduction was 95.2% irrespective of stratification group. A baseline serum PSA level <10 ,g/L and a serum PSA nadir ,0.2 ,g/L were associated with the longest time off treatment. The overall mean nadir PSA value in the progression group at 1.40 ± 0.19 ,g/L was 2.6-fold greater than the value of 0.55 ± 0.88 ,g/L in the no-progression group (P = .0002). Recovery of serum testosterone to a level of ,7.5 nmol/L was observed in 75%, 50%, 40%, and 30% of men in Cycles 1 to 4, respectively, and was sufficient to normalize the level of hemoglobin in each cycle, which dropped by an average of 10.8 g/L during treatment (P < .0001). CONCLUSIONS. The length of the off-treatment interval during cyclic androgen withdrawal therapy was related inversely to baseline and nadir levels of serum PSA. Nadir PSA was a powerful predictor of early progression to androgen independence. Cancer 2007 © 2007 American Cancer Society. [source]