Raman microscopy in the diagnosis and prognosis of surgically resected nonsmall cell lung cancer

The main curative therapy for patients with nonsmall cell lung cancer is surgery. Despite this, the survival rate is only 50%, therefore it is important to more efficiently diagnose and predict prognosis for lung cancer patients. Raman spectroscopy is useful in the diagnosis of malignant and premalignant lesions. The aim of this study is to investigate the ability of Raman microscopy to diagnose lung cancer from surgically resected tissue sections, and predict the prognosis of these patients. Tumor tissue sections from curative resections are mapped by Raman microscopy and the spectra analzsed using multivariate techniques. Spectra from the tumor samples are also compared with their outcome data to define their prognostic significance. Using principal component analysis and random forest classification, Raman microscopy differentiates malignant from normal lung tissue. Principal component analysis of 34 tumor spectra predicts early postoperative cancer recurrence with a sensitivity of 73% and specificity of 74%. Spectral analysis reveals elevated porphyrin levels in the normal samples and more DNA in the tumor samples. Raman microscopy can be a useful technique for the diagnosis and prognosis of lung cancer patients receiving surgery, and for elucidating the biochemical properties of lung tumors. (C) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3323088]

Novel biomarkers in early diagnosis of acute myocardial infarction compared with cardiac troponin T

Aims: To evaluate the role of novel biomarkers in early detection of acute myocardial infarction (MI) in patients admitted with acute chest pain.
Methods and results: A prospective study of 664 patients presenting to two coronary care units with chest pain was conducted over 3 years from 2003. Patients were assessed on admission: clinical characteristics, ECG (electrocardiogram), renal function, cardiac troponin T (cTnT), heart fatty acid binding protein (H-FABP), glycogen phosphorylase-BB, NT-pro-brain natriuretic peptide, D-dimer, hsCRP (high sensitivity C-reactive protein), myeloperoxidase, matrix metalloproteinase-9, pregnancy associated plasma protein-A, soluble CD40 ligand. A =12 h cTnT sample was also obtained. MI was defined as cTnT = 0.03 µg/L. In patients presenting <4 h of symptom onset, sensitivity of H-FABP for MI was significantly higher than admission cTnT (73 vs. 55%; P = 0.043). Specificity of H-FABP was 71%. None of the other biomarkers challenged cTnT. Combined use of H-FABP and cTnT (either one elevated initially) significantly improved the sensitivities of H-FABP or cTnT (85%; P = 0.004). This combined approach also improved the negative predictive value, negative likelihood ratio, and the risk ratio.
Conclusion: Assessment of H-FABP within the first 4 h of symptoms is superior to cTnT for detection of MI, and is a useful additional biomarker for patients with acute chest pain.

Clinical Utility of Microarray-Based Gene Expression Profiling in the Diagnosis and Subclassification of Leukemia: Report From the International Microarray Innovations in Leukemia Study Group

The Microarray Innovations in Leukemia study assessed the clinical utility of gene expression profiling as a single test to subtype leukemias into conventional categories of myeloid and lymphoid malignancies. METHODS: The investigation was performed in 11 laboratories across three continents and included 3,334 patients. An exploratory retrospective stage I study was designed for biomarker discovery and generated whole-genome expression profiles from 2,143 patients with leukemias and myelodysplastic syndromes. The gene expression profiling-based diagnostic accuracy was further validated in a prospective second study stage of an independent cohort of 1,191 patients. RESULTS: On the basis of 2,096 samples, the stage I study achieved 92.2% classification accuracy for all 18 distinct classes investigated (median specificity of 99.7%). In a second cohort of 1,152 prospectively collected patients, a classification scheme reached 95.6% median sensitivity and 99.8% median specificity for 14 standard subtypes of acute leukemia (eight acute lymphoblastic leukemia and six acute myeloid leukemia classes, n = 693). In 29 (57%) of 51 discrepant cases, the microarray results had outperformed routine diagnostic methods. CONCLUSION: Gene expression profiling is a robust technology for the diagnosis of hematologic malignancies with high accuracy. It may complement current diagnostic algorithms and could offer a reliable platform for patients who lack access to today's state-of-the-art diagnostic work-up. Our comprehensive gene expression data set will be submitted to the public domain to foster research focusing on the molecular understanding of leukemias

Investigation of molecular markers in the diagnosis of refractory coeliac disease in a large patient cohort

Some patients with coeliac disease, despite strict adherence to a gluten-free diet, continue to have significant symptoms and/or a severe small intestinal histological lesion. The term "refractory coeliac disease" (rCD) is used to describe this condition. The purpose of this study was to investigate the value of tissue molecular markers reported to help in the diagnosis of rCD.

Fundus autofluorescence in the diagnosis of cystoid macular oedema

Aim: To determine the sensitivity and specificity of the non-invasive imaging technique, fundus autofluorescence (AF), in the diagnosis of cystoid macular oedema (CMO), using fluorescein angiography as the reference standard. Design: Retrospective, consecutive, observational case series. Methods: Ninety-six consecutive patients with CMO suspected clinically were selected from the AF database of the Retina Unit, Ophthalmology Department, Grampian University Hospitals-NHS Trust, between August 2004 and June 2006. Only patients in whom CMO was secondary to (1) cataract extraction, (2) inherited retinopathies, (3) inflammatory eye disease or (4) idiopathic cases were included in this study. Only patients in whom AF images had been performed within 2 weeks of FFA and, when obtained following FFA, there was a minimum gap of 4 days ("washing out" period), were considered eligible for this study. A total of 34 eyes from 34 patients were eligible and were included in this study. FFA was used as the reference test to confirm the presence of CMO, and, based on fluorescein angiography (FFA), CMO was graded as either mild or florid. AF images were examined in a masked fashion for the presence or absence of CMO. The sensitivity and specificity of AF in detecting CMO were then calculated. Results: CMO was seen on AF imaging as round or oval areas at the fovea with an AF signal similar to that of background levels. At this site (fovea), the AF signal is usually reduced compared with background, due to the blockage caused by luteal pigment. The diagnosis of CMO based on AF imaging had 81% sensitivity and 69% specificity when compared with the reference standard FFA. Based on the FFA, there were 12 cases of florid CMO and eight of mild CMO. Of the former, CMO was detected with AF imaging in 100% (12/12 eyes), and of the latter, in 50% (4/8 eyes). Conclusions: AF imaging can be used as a rapid, non-invasive technique in the diagnosis of CMO.

EXPERT-SYSTEM SUPPORT USING BAYESIAN BELIEF NETWORKS IN THE DIAGNOSIS OF FINE-NEEDLE ASPIRATION BIOPSY SPECIMENS OF THE BREAST

Aim-To develop an expert system model for the diagnosis of fine needle aspiration cytology (FNAC) of the breast.

Methods-Knowledge and uncertainty were represented in the form of a Bayesian belief network which permitted the combination of diagnostic evidence in a cumulative manner and provided a final probability for the possible diagnostic outcomes. The network comprised 10 cytological features (evidence nodes), each independently linked to the diagnosis (decision node) by a conditional probability matrix. The system was designed to be interactive in that the cytopathologist entered evidence into the network in the form of likelihood ratios for the outcomes at each evidence node.

Results-The efficiency of the network was tested on a series of 40 breast FNAC specimens. The highest diagnostic probability provided by the network agreed with the cytopathologists' diagnosis in 100% of cases for the assessment of discrete, benign, and malignant aspirates. A typical probably benign cases were given probabilities in favour of a benign diagnosis. Suspicious cases tended to have similar probabilities for both diagnostic outcomes and so, correctly, could not be assigned as benign or malignant. A closer examination of cumulative belief graphs for the diagnostic sequence of each case provided insight into the diagnostic process, and quantitative data which improved the identification of suspicious cases.

Conclusion-The further development of such a system will have three important roles in breast cytodiagnosis: (1) to aid the cytologist in making a more consistent and objective diagnosis; (2) to provide a teaching tool on breast cytological diagnosis for the non-expert; and (3) it is the first stage in the development of a system capable of automated diagnosis through the use of expert system machine vision.

The accuracy of accredited glaucoma optometrists in the diagnosis and treatment recommendation for glaucoma

Aim: To compare the diagnostic performance of accredited glaucoma optometrists (AGO) for both the diagnosis of glaucoma and the decision to treat with that of routine hospital eye care, against a reference standard of expert opinion (a consultant ophthalmologist with a special interest in glaucoma). Methods: A directly comparative, masked, performance study was undertaken in Grampian, Scotland. Of 165 people invited to participate, 100 (61%) were examined. People suspected of having glaucoma underwent, within one month, a full ophthalmic assessment in both a newly established community optometry led glaucoma management scheme and a consultant led hospital eye service. Results: Agreement between the AGO and the consultant ophthalmologist in diagnosing glaucoma was substantial (89%; ? = 0.703, SE = 0.083). Agreement over the need for treatment was also substantial (88%; ? = 0.716, SE = 0.076). The agreement between the trainee ophthalmologists and the consultant ophthalmologist in the diagnosis of glaucoma and treatment recommendation was moderate (83%, ? = 0.541, SE = 0.098, SE = 0.98; and 81%, ? = 0.553, SE = 0.90, respectively). The diagnostic accuracy of the optometrists in detecting glaucoma in this population was high for specificity (0.93 (95% confidence interval, 0.85 to 0.97)) but lower for sensitivity (0.76 (0.57 to 0.89)). Performance was similar when accuracy was assessed for treatment recommendation (sensitivity 0.73 (0.57 to 0.85); specificity 0.96 (0.88 to 0.99)). The differences in sensitivity and specificity between AGO and junior ophthalmologist were not statistically significant. Conclusions: Community optometrists trained in glaucoma provided satisfactory decisions regarding diagnosis and initiation of treatment for glaucoma. With such additional training in glaucoma, optometrists are at least as accurate as junior ophthalmologists but some cases of glaucoma are missed.