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Saeed A Jortani

Publications and source records attributed to Saeed A Jortani.

12 recordsLinked to original sources
PubMed2007

Immunological evaluation of urinary trypsin inhibitors in blood and urine: role of N- & O-linked glycoproteins.

Urinary trypsin inhibitors (uTi) suppress serine proteases during inflammation. After liberation from proinhibitors (P-alpha-I and I-alpha-I) by the white blood cell (WBC) response, uTi readily pass through the kidneys into urine. A key uTi, bikunin, is attached to O-linked and N-linked glycoconjugates. Recently, uTi inhibitors, called uristatins, were found to lack the O-linked glycoconjugates. Monoclonal antibodies were produced using purified uristatin and screened for binding differences to uristatin, bikunin, P-alpha-I, and I-alpha-I. Antibody-binding patterns were characterized using immunoaffinity binding onto protein-chip surfaces and analysis by Surface Enhanced Laser Desorption/Ionization mass spectrometry (SELDI), using specimens from patients and from purified uTi standards. Antibodies were developed and used in an enzyme-linked immunosorbent assay (ELISA) method for uTi measurement in urine and plasma specimens. ELISA was performed on specimens from normal, presumed healthy, controls and from patients who had been screened for inflammation using a high sensitivity C-reactive protein (CRP) test and a complete blood count (CBC). Polyclonal antibody against uTi showed cross-reactivity with the Tamm-Horsfall protein (THP) and with proinhibitors. Screening of anti-uTi monoclonal antibodies (Mab) revealed antibodies that did not cross-react with either of the above, thus providing a tool to measure both uristatin and bikunin in urine with Mab 3G5 and in plasma with Mab 5D11. The monoclonal antibody 5D11 cross-reacts with specific N-linked glycoconjugates of uristatin present in plasma. In ca 96% of healthy adults, uTi were present at <12 mg/l in urine and <4 mg/l in plasma. We also found that patients with an inflammation and a CRP of >2.0 mg/l had higher urinary concentrations of uTi than the control population in every subject. Free uristatin and bikunin pass readily into urine and are primarily bound to heavy chains that constitute the proinhibitor form in plasma.

Animals↗
PubMed2006

Proteomics: a new diagnostic frontier.

BACKGROUND: Analysis of proteins has been an integral part of the field of clinical chemistry for decades. Recent advances in technology and complete identification of the human genome sequence have opened up new opportunities for analysis of proteins for clinical diagnostic purposes. METHODS: Content of a recent conference of proteomics is summarized. RESULTS: New analytical methods allow the simultaneous analysis of a large number of proteins in biological fluids such as serum and plasma, offering partial views of the complete set of proteins or proteome. Plasma presents many analytical challenges, such as the complexity of components, predominance of a few major components, and the large concentration range of components, but the number of proteins that can be detected in plasma has expanded dramatically from hundreds to thousands. At the same time, there is increased capability to detect structural variations of proteins. Recent studies also identified the presence of complex sets of small protein fragments in plasma. This set of protein fragments, the fragmentome or peptidome, is potentially a rich source of information about physiologic and disease processes. CONCLUSIONS: Advances in proteomics offer great promise for the discovery of markers that might serve as the basis for new clinical laboratory tests. There are many challenges, however, in the translation of newly discovered markers into clinical laboratory tests.

Biomarkers↗
PubMed2006

Analysis of ligand binding by bioaffinity mass spectrometry.

BACKGROUND: Ligand binding is commonly analyzed using various immunoassays that are generally time-consuming and some may require secondary antibodies or gel electrophoresis which are also time-consuming and sometimes subjective. We introduced various examples for a more rapid approach using pre-activated surface chips which are analyzed by surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS). Specific applications presented in this study include immobilization of antigen, antibody or oligo DNA on pre-activated chips with subsequent identification of the binding antibodies, antigens or DNA binding proteins to demonstrate the universal utility of this novel approach. METHODS: BSA-digoxin conjugate (BSA-Dig), anti-digoxin antibody, anti-urinary trypsin inhibitor (uTi) antibody, or a double stranded oligo nucleotide based on the nucleotide sequence between -91 and -10 of the human CYP 450 2E1 promoter were immobilized on the Ciphergen pre-activated surface chips. Anti-digoxin antibody, BSA-digoxin conjugate, uTi, and CYP450 2E1 promoter binding protein were captured on the chip and identified by SELDI-TOF MS. RESULTS: A protein with 141kDa was identified from anti-digoxin serum using BSA-Dig chips. This binding was competitively inhibited by addition of digoxin. Using anti-digoxin antibody, a peak at approximately 66kDa was detected in the preparation of BSA-Dig. This peak was also inhibited by free digoxin, suggesting BSA-Dig is detected. uTi fragments with approximately 3kDa to approximately 30kDa in the standard and urine samples were captured on the chip by anti-uTi antibody. Finally, we identified a 95-kDa CYP 450 2E1 promoter binding protein in HeLa cells nuclear extracts. CONCLUSIONS: Bioaffinity SELDI-TOF MS is a powerful and versatile approach for analysis of ligands. It eliminates tracer-labeled secondary antibodies and allows for determination of molecular weights of binding proteins and their ligands directly. This approach may also be considered for the detection of enzymes, receptors, or any other specific ligands.

Antibodies↗
PubMed2006

Serum proteomic patterns associated with sleep-disordered breathing in children.

Obstructive sleep apnea (OSA) is a major public health problem affecting approximately 2% to 3% of children. However, snoring, the cardinal symptom of OSA, affects at least 5-fold more children, such that evaluation by overnight polysomnography (ONP) is required for the diagnosis. ONP is laborious, expensive, and relatively unavailable to children. Proteomic mass spectrometry coupled with bioinformatic tools provide valuable means for discovery of new biomarkers in serum for a variety of human disorders. The possibility exists that snoring children with and without OSA may exhibit different protein expression profiles in serum that could be useful in the development of novel diagnostic tools for this condition. The proteomic patterns of 20 children with OSA and of 20 children with habitual primary snoring but no evidence of OSA (HS) were evaluated using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Linear discriminative analysis identified three differentially regulated proteins with molecular masses of 5896, 3306, 6068 Da that were capable of diagnosing OSA with 93% sensitivity and 90% specificity. Thus, the proteomic signatures of sera from children with OSA differ from those of HS who do not fulfill the current criteria for treatment. Identification and sequencing of those differentially expressed proteins discovered through proteomic strategies may lead to future development of serum-based diagnostic tests for OSA in snoring children.

Adolescent↗
PubMed2005

Application of bioaffinity mass spectrometry for analysis of ligands.

Bioaffinity mass spectrometry is a novel technology for analysis of binding proteins and their ligands. In this review, we introduce the concepts and principles of bioaffinity surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF MS). Various preactivated chip types and several approaches for binding of ligands or their binders to the chips are discussed. We also provide specific examples for the use of this technology for screening antibodies, analyzing ligands, glycoconjugates, protein-protein inter-actions, and DNA (RNA) binding proteins. In pursuit of developing new tests or studies of mechanism of drug action in therapeutic drug monitoring practice, this technology may provide a more rapid approach for ligand-binder studies.

Ligands↗
PubMed2004

Sensitive noninvasive marker for the diagnosis of probable bacterial or viral infection.

Urinary trypsin inhibitor (uTi) is a product of elastase-mediated degradation of interleukin-alpha-inhibitor (I-alpha-I). Its activity increases in the urine of patients with a malignancy, inflammation, or infection, or in late pregnancy. The objective of this study was to compare the sensitivity of uTi in urine with that of serum quantitative C-reactive protein (CRP) for diagnosing infection, as indicated by white cell response and clinical assessment. Ninety controls and 171 patients with various systemic infections were enrolled. We measured uTi enzymatically on a Cobas Fara (Roche Diagnostics). Patients were separated into bacterial, probable bacterial, viral, or probable viral groups based on the results of a complete blood count with differential (CBC), urinalysis (UA), and clinical assessment. In the bacterial (n=70) and control (n=90) groups, the uTi values (mean+/-SE) were 25.3+/-3.1 mg/L and 2.8+/-0.8 mg/L, respectively. uTi (at 2.7 mg/L) had a diagnostic sensitivity of 91% and specificity of 82% (AUC=0.889), whereas CRP (at a cutoff of 10 mg/L) had a sensitivity and specificity of 82% and 96%, respectively (AUC=0.921). As a marker of infection (positive in both bacterial and viral groups), uTi had a sensitivity of 91% (AUC=0.884) vs. 89% (AUC=0.828) for CRP. Our data indicate that uTi has sufficient clinical sensitivity for screening systemic infections, and may have diagnostic value as a noninvasive test.

Adult↗
PubMed2004

The uristatin dipstick is useful in distinguishing upper respiratory from urinary tract infections.

BACKGROUND: We determined the diagnostic value of the trypsin inhibitor, uristatin, that is commonly found in urine and plasma in patients with infections or inflammations of any kind. METHODS: We collected urine specimens from patients with infections of the urinary or upper respiratory tract and from healthy controls. We also collected blood from patients with a likely upper respiratory tract infection and healthy controls. A bacterial count of >10(5) organisms/ml in urine was considered to represent infection rather than contamination. RESULTS: The uristatin dipstick test in urine showed acceptable negative predictive values (NPV of up to 93%) for patients without infection or inflammation. Here, the dipsticks could eliminate some urine cultures. For those with infection or inflammation, the positive predictive values (PPV) of the dipsticks were lower (up to 57%). Including the leukocyte esterase and nitrite values increased the PPV of the dipsticks for those with disease. CONCLUSIONS: The uristatin strip was more accurate than the leukocyte and nitrite dipsticks for predicting upper respiratory infections (URI) and C-reactive protein for those with infection or inflammation. The uristatin dipstick was able to detect both the bikunin and uristatin inhibitors.

Adolescent↗
PubMed2004

Multicenter evaluation of the performance characteristics of the bayer VERSANT HCV RNA 3.0 assay (bDNA).

In this multicenter evaluation, the VERSANT HCV RNA 3.0 Assay (bDNA) (Bayer Diagnostics, Tarrytown, N.Y.) was shown to have excellent reproducibility, linearity, and analytical sensitivity across specimen collection matrices (serum, EDTA, ACD-A), and hepatitis C virus (HCV) genotypes 1 to 6. The VERSANT HCV bDNA Assay has a reportable range of 615 to 7690000 (7.69 x 10(6)) IU/ml. The total coefficient of variation (CV) ranged from 32.4% at 615 IU/ml to 17% at 6.8 x 10(6) IU/ml. The assay was linear across the reportable range. Analytical specificity of 98.8% was determined by testing 999 specimens from volunteer blood donors. Evaluation of HCV genotypes using RNA transcripts of representative clones of 1a, 1b, 2a, 2b, 2c, 3a, 4a, 5a, and 6a and patient specimens showed that the largest difference between genotype 1, upon which the assay is standardized, and non-1 genotypes was within 1.5-fold. Testing of potentially interfering endogenous substances and exogenous substances and conditions found no interference in HCV-positive or HCV-negative specimens except for unconjugated bilirubin at concentrations of >or=20 mg/dl and protein at concentrations of >or=9 g/dl. Biological variability was estimated from 29 clinically stable individuals not on HCV therapy who were tested weekly over an 8-week period. The combined estimate of total (biologic plus assay) variability was 0.15 log(10) standard deviation (CV, 36.1%), a fold change of 2.6. Thus, the observed fold change between any two consecutive HCV RNA measures is expected to be less than 2.6-fold (equivalent to 0.41 log(10) IU/ml) 95% of the time in clinically stable individuals.

Branched DNA Signal Amplification Assay↗
PubMed2003

Strategies for developing biomarkers of heart failure.

BACKGROUND: Heart failure (HF) is a devastating disease with increasing prevalence in elderly populations. One-half of all patients die within 5 years of diagnosis. The annual cost of treating patients with HF in the US is more than $20 billion, which is estimated to be greater than that of myocardial infarction and all cancers combined. Given the complex pathophysiology and varied manifestations of HF, interest has intensified in developing biological markers to predict susceptibility and aid in the early diagnosis and management of this disease. METHODS: We searched Medline via Ovid for studies published during the period 1966-2003 regarding various biomarkers suggested for HF. Our review focused on developing strategies for discovering and using new biomarkers, particularly those potentially linked to pathophysiologic mechanisms. We also point out strategic advantages, limitations, and methods available for measuring each of the currently proposed markers. RESULTS: Biomarkers reviewed include those released from the heart during normal homeostasis (natriuretic peptides), those produced elsewhere that act on the heart (endogenous cardiotonic steroids and other hormones), and those released in response to tissue damage (inflammatory cytokines). The concept of using a combination of multiple markers based on diagnosis, prognosis, and acute vs chronic disease is also discussed. In view of recent advances in our understanding of molecular biochemical derangements observed during cardiac failure, we consider the concept of myocardial remodeling and the heart as part of an endocrine system as strategies. CONCLUSION: Strategically, biomarkers linked to mechanisms involved in the etiology of HF, such as dysregulation of ion transport, seem best suited for serving as early biological markers to predict and diagnose disease, select therapy, or assess progression.

Animals↗
PubMed2003

Cardioactive steroid poisoning from an herbal cleansing preparation.

We describe a case of unintentional poisoning from a cardioactive steroid and the subsequent analytic investigation. A 36-year-old woman with no past medical history and taking no conventional medications ingested an herbal preparation marketed for "internal cleansing." Its ingredients were neither known to the patient nor listed on the accompanying literature. The next morning, nausea, vomiting, and weakness developed. In the emergency department, her blood pressure was 110/60 mm Hg, and her pulse rate was 30 beats/min. Her ECG revealed a junctional rhythm at a rate of 30 beats/min and a digitalis effect on the ST segments. After empiric therapy with 10 vials of digoxin-specific Fab (Digibind), her symptoms resolved, and she reverted to a sinus rhythm at a rate of 68 beats/min. Her serum digoxin concentration measured by means of the fluorescence polarization immunoassay (Abbott TDx) was 1.7 ng/mL. Further serum analysis with the Tina Quant digoxin assay, a more digoxin-specific immunoassay, found a concentration of 0.34 ng/mL, and an enzyme immunoassay for digitoxin revealed a concentration of 20 ng/mL (therapeutic range 10 to 30 ng/mL). Serum analysis by means of high-performance liquid chromatography revealed the presence of active digitoxin metabolites; the parent compound was not present. When the diagnosis of cardioactive steroid poisoning is suspected clinically, laboratory analysis can confirm the presence of cardioactive steroids by using immunoassays of varying specificity. An empiric dose of 10 vials of digoxin-specific Fab might be beneficial in patients poisoned with an unknown cardioactive steroid.

Adult↗
PubMed2003

What is next in pharmacogenomics? Translating it to clinical practice.

Pharmacogenomics (PG) holds promise for transforming medical therapeutics but the details of how the promise will become reality are still vague. In this article, we focus on the role that laboratory medicine, as a discipline, might play in transitioning the application of pharmacogenomics into the healthcare system and begin to frame a perspective on how PG may be viewed in this context. Development of clinical diagnostic tests usually evolves as a continuum of information starting with the discovery of a potential biological marker through to its routine use in clinical practice. This process has traditionally been rooted in the practice of laboratory medicine and, importantly, includes the development of testing strategies to optimize the predictive value of single or a combination of biological markers. In this context, we also discuss a perspective on some future strategies that may prove useful in advancing the application of PG, including the need for an evidenced-based approach and the potential role of proteomics as a means to drive more comprehensive strategies.

Humans↗