Optimized immunocytochemistry using leukocyte and tissue markers on Romanowsky-stained slides from dogs and cats.

BACKGROUND: Romanowsky staining is often the initial method used to stain hematologic and cytologic materials. While immunocytochemistry (ICC) is a well-established method on air-dried smears, there are rare veterinary reports of ICC involving Romanowsky-stained slides. OBJECTIVES: This study aimed to compare immunoreactivity of unstained vs Romanowsky-stained specimens, evaluate reactions over time, and assess ICC associations with confirmatory tests of 50 lymphoma cases. Another goal aimed to optimize manual ICC protocols with cellular and tissue immunomarkers to detect CD3ε, CD20, Pax5, MHCII, lysozyme, MUM1, vimentin, cytokeratin, and Melan-A antigens on Romanowsky-stained specimens. MATERIALS AND METHODS: Cytologic specimens from cases of lymphoid and nonlymphoid neoplasms were stained with a methanolic Romanowsky method. Additional unstained slides from these cases were used for comparison with the stained materials. Antigen retrieval involved a citrate buffer pH6 or Tris/EDTA pH9 at 95°C for 25 minutes in a decloaking chamber. Immunocytochemistry used known positive and secondary antibody-only negative cytologic controls. Immunoreactivity of unstained and prestained lymphoma slides was graded by the intensity and percent of stained cells. Signal grading was monitored over time for diagnostic differences. RESULTS: Unstained and Romanowsky-stained slides had similar membrane/cytoplasm graded reactions, but unstained slides produced stronger signals. Romanowsky-stained blood films from B-cell and T-cell leukemias showed minimal loss of signal when monitored over 20 weeks. Signal differences did not change the diagnosis. There was a significant association between ICC and confirmatory tests. Optimization involved antibody dilution and antigen retrieval methodology for each antibody tested. CONCLUSIONS: Immunocytochemistry of Romanowsky-stained material can be successfully performed using antibodies against CD3ε, CD20, cytokeratin, lysozyme, Melan-A, MHCII, MUM1, Pax5, and vimentin.

Exfoliative cytology for diagnosing basal cell carcinoma and other skin cancers in adults.

BACKGROUND: Early accurate detection of all skin cancer types is essential to guide appropriate management, reduce morbidity and improve survival. Basal cell carcinoma (BCC) is usually localised to the skin but has potential to infiltrate and damage surrounding tissue, while cutaneous squamous cell carcinoma (cSCC) and melanoma have a much higher potential to metastasise and ultimately lead to death. Exfoliative cytology is a non-invasive test that uses the Tzanck smear technique to identify disease by examining the structure of cells obtained from scraped samples. This simple procedure is a less invasive diagnostic test than a skin biopsy, and for BCC it has the potential to provide an immediate diagnosis that avoids an additional clinic visit to receive skin biopsy results. This may benefit patients scheduled for either Mohs micrographic surgery or non-surgical treatments such as radiotherapy. A cytology scrape can never give the same information as a skin biopsy, however, so it is important to better understand in which skin cancer situations it may be helpful. OBJECTIVES: To determine the diagnostic accuracy of exfoliative cytology for detecting basal cell carcinoma (BCC) in adults, and to compare its accuracy with that of standard diagnostic practice (visual inspection with or without dermoscopy). Secondary objectives were: to determine the diagnostic accuracy of exfoliative cytology for detecting cSCC, invasive melanoma and atypical intraepidermal melanocytic variants, and any other skin cancer; and for each of these secondary conditions to compare the accuracy of exfoliative cytology with visual inspection with or without dermoscopy in direct test comparisons; and to determine the effect of observer experience. SEARCH METHODS: We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We also studied the reference lists of published systematic review articles. SELECTION CRITERIA: Studies evaluating exfoliative cytology in adults with lesions suspicious for BCC, cSCC or melanoma, compared with a reference standard of histological confirmation. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on QUADAS-2). Where possible we estimated summary sensitivities and specificities using the bivariate hierarchical model. MAIN RESULTS: We synthesised the results of nine studies contributing a total of 1655 lesions to our analysis, including 1120 BCCs (14 datasets), 41 cSCCs (amongst 401 lesions in 2 datasets), and 10 melanomas (amongst 200 lesions in 1 dataset). Three of these datasets (one each for BCC, melanoma and any malignant condition) were derived from one study that also performed a direct comparison with dermoscopy. Studies were of moderate to poor quality, providing inadequate descriptions of participant selection, thresholds used to make cytological and histological diagnoses, and blinding. Reporting of participants' prior referral pathways was particularly poor, as were descriptions of the cytodiagnostic criteria used to make diagnoses. No studies evaluated the use of exfoliative cytology as a primary diagnostic test for detecting BCC or other skin cancers in lesions suspicious for skin cancer. Pooled data from seven studies using standard cytomorphological criteria (but various stain methods) to detect BCC in participants with a high clinical suspicion of BCC estimated the sensitivity and specificity of exfoliative cytology as 97.5% (95% CI 94.5% to 98.9%) and 90.1% (95% CI 81.1% to 95.1%). respectively. When applied to a hypothetical population of 1000 clinically suspected BCC lesions with a median observed BCC prevalence of 86%, exfoliative cytology would miss 21 BCCs and would lead to 14 false positive diagnoses of BCC. No false positive cases were histologically confirmed to be melanoma. Insufficient data are available to make summary statements regarding the accuracy of exfoliative cytology to detect melanoma or cSCC, or its accuracy compared to dermoscopy. AUTHORS' CONCLUSIONS: The utility of exfoliative cytology for the primary diagnosis of skin cancer is unknown, as all included studies focused on the use of this technique for confirming strongly suspected clinical diagnoses. For the confirmation of BCC in lesions with a high clinical suspicion, there is evidence of high sensitivity and specificity. Since decisions to treat low-risk BCCs are unlikely in practice to require diagnostic confirmation given that clinical suspicion is already high, exfoliative cytology might be most useful for cases of BCC where the treatments being contemplated require a tissue diagnosis (e.g. radiotherapy). The small number of included studies, poor reporting and varying methodological quality prevent us from drawing strong conclusions to guide clinical practice. Despite insufficient data on the use of cytology for cSCC or melanoma, it is unlikely that cytology would be useful in these scenarios since preservation of the architecture of the whole lesion that would be available from a biopsy provides crucial diagnostic information. Given the paucity of good quality data, appropriately designed prospective comparative studies may be required to evaluate both the diagnostic value of exfoliative cytology by comparison to dermoscopy, and its confirmatory value in adequately reported populations with a high probability of BCC scheduled for further treatment requiring a tissue diagnosis.

Exploring the interaction of Azure dyes with t-RNA by hybrid spectroscopic and computational approaches and its applications toward human lung cancer cell line.

In the present study, in depth characterization of binding aspects of Azure A (AZA) and Azure B (AZB) with transfer Ribonucleic acid (t-RNA) from Escherichia coli (E.coli) is investigated using spectroscopic techniques. The absorbance and fluorescence properties of these dyes have been remarkably changed upon binding with t-RNA. Significant changes in the absorption maxima of the dyes evidence the t-RNA induced metachromasy and the binding clearly revealed the high affinity of AZA and AZB to t-RNA. Strong emission polarization of the bound dyes and strong energy transfer from the guanine base pairs of t-RNA suggested intercalative binding interaction. The stoichiometry of AZA and AZB with t-RNA complexes are determined by the Benesi-Hildebrand plot from emission data. The negative values of free energy change indicated the involvement of hydrophobic forces and noncovalent interactions in the complexation of both the dyes with t-RNA. The 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay in A-549 human lung cancer cell lines reveals that binding of t-RNA reduces the toxicity of AZA and AZB. The utility of the present work explores the potential binding applicability of these dyes to t-RNA for their development as effective therapeutic agents and its target at molecular level for the treatment of diseases like cancer.

Diagnostic accuracy of Wright-Giemsa and rhodanine stain protocols for detection and semi-quantitative grading of copper in canine liver aspirates.

BACKGROUND: Canine hepatic copper content has been increasing. Recognition of canine copper-associated hepatopathies is becoming more common. OBJECTIVES: The purpose of the study was to assess the diagnostic performance of Wright-Giemsa (WG) and rhodanine staining for detection of increased canine hepatic copper following a proposed cytologic protocol for semi-quantitative evaluation of liver aspirates and the effect of previous WG staining. METHODS: Retrospectively, 40 canine hepatic WG-stained cytology cases were rhodanine stained. Diagnostic performance of WG staining for increased hepatic copper was evaluated. A rhodanine-stained cytologic copper grading system was developed. Prospectively, 67 canine liver samples with quantitative copper measurement, a WG-then rhodanine-stained slide, and a non-WG rhodanine-stained slide were used to assess the performance of the grading system and the effect of previous WG staining. RESULTS: Copper was not described in 40 retrospective cases on initial cytologic evaluation; 8/40 cases had increased copper content after rhodanine staining or quantitative copper assessment. Prior WG staining and destaining significantly affected the cytologic copper grade but not the diagnostic performance as measured by receiver-operating characteristic curve analysis. Quantitative copper concentration and previously WG-stained copper grade were moderately correlated (n = 67, ρ = .79 [.68-.87]). For detection of ≥ 600 ppm, dry weight (dw) copper, sensitivity was .75 and specificity was .97. For detection of ≥ 1500 ppm, dw copper, sensitivity was 1.0 and specificity was .97. CONCLUSIONS: Wright-Giemsa staining alone does not reliably detect hepatic copper. Grading of rhodanine-stained canine hepatic cytologic samples demonstrates acceptable diagnostic performance for detection of copper content.

Dyes as bifunctional markers of DNA hybridization on surfaces and mutation detection.

The interaction of small molecules with DNA has found diagnostic and therapeutic applications. In this work, we propose the use of two different dyes, in particular Azure A and Safranine, as bifunctional markers of on-surface DNA hybridization and potent tools for screening of specific gene mutations directly in real DNA PCR amplicons extracted from blood cells. By combining spectroscopic and electrochemical methods we demonstrate that both dyes can interact with single and double stranded DNA to a different extent, allowing reliable hybridization detection. From these data, we have also elucidated the nature of the interaction. We conclude that the binding mode is fundamentally intercalative with an electrostatic component. The dye fluorescence allows their use as nucleic acid stains for the detection of on-surfaces DNA hybridization. Its redox activity is exploited in the development of selective electrochemical DNA biosensors.

First Molecular Identification and Genetic Characterization of Theileria lestoquardi in Sheep of the Maghreb Region.

Theileria lestoquardi is the most prominent Theileria species in small ruminants that causes malignant theileriosis of sheep in Africa and Asia. In the present survey, blood samples and ticks were collected in Kebili (southern Tunisia) from 166 Queue Fine de l'Ouest sheep. Giemsa-stained blood smears, immunofluorescent antibody test (IFAT) and PCR were performed. The DNA was extracted from blood and analysed by PCR targeting 18S rRNA gene of Theileria spp. and then sequenced. A total number of 140 ticks were collected from a total number of 166 sheep during the four seasons. The ticks belonged to two genera and 4 species; the most frequent tick was Hyalomma excavatum 84.3% (118/140) and then Rhipicephalus spp. 15.7% (22/140). Only two animals had positive Giemsa-stained blood smears, and they were also positive by IFAT. The amplicons had 99.3 and 99.6% homology with the BLAST published T. lestoquardi amplicons. To our knowledge, this is the first report of T. lestoquardi in small ruminants within the Maghreb region.

[Investigation of Pneumocystis jirovecii in clinical specimens by different methods]. / Klinik Örneklerde Çesitli Yöntemlerle Pneumocystis jirovecii Arastirilmasi

Pneumocystis jirovecii causes pneumonia in premature, newborn or malnourished children, as well as in immunocompromised subjects such as chemotherapy receiving, transplant and AIDS patients. Since the mortality and morbidity rates of Pneumocystis pneumonia (PCP) in these patients were high, rapid and accurate diagnosis is important. The aim of this study was to evaluate the diagnostic value of Giemsa staining (GS), direct fluorescent antibody (DFA) assay, (1→3)-ß-D-Glucan (BDG) test and real-time polymerase chain reaction (PCR) for the detection of P.jirovecii in clinical specimens. A total of 100 PCP-suspected patients with underlying diseases who were followed-up in outpatient and inpatient clinics of our hospital between December 2008-July 2010 were included in the study. All the patients (66 male, 34 female; mean age: 42.04 years) were under long-term immunosuppressive drug therapy due to their hematological malignancies, kidney transplantation, neutropenia or chronic diseases. Respiratory samples [86 bronchoalveolar lavage (BAL), 8 endotracheal aspirate, 1 nasotracheal aspirate, 3 pleural, 2 lung biopsy samples] obtained from the patients have been studied with GS (Merck, Germany), DFA (Pneumo Cel, Cellabs, Australia) and PCR (primers targeting MSG gene, LightCycler, Roche, USA), while serum samples (n= 100) with BDG (Fungitell, ACC Inc, USA) and PCR methods. In BAL samples two were found positive by GS, DFA and PCR, and six were positive only by PCR, yielding a total positivity in 8 (8%) samples. All of the sera were negative with PCR, however 29 of them were positive (> 80 pg/ml), five were equivocal (61-79 pg/ml) and 66 were negative (< 60 pg/ml) with BDG test. Eight patients with positive results in BAL-PCR were also positive with BDG test. Although the agreement between GS and DFA was high (κ= 1), it was observed as low between PCR and DFA (κ= 0.38), DFA and BDG (κ= 0.07), BAL-PCR and BDG (κ= 0.28). DFA taken as the gold standard, the sensitivity and specificity values of GS, PCR and BDG methods were calculated as 100% and 100%; 100% and 93%; 100% and 67%, respectively. In the ROC analysis performed for BDG test, with DFA and BAL-PCR taken as the gold standards, the sensitivity, specificity and cut-off values of BDG were estimated as 100%, 93.9% and 494 pg/ml, and 100%, 72.8% and 62 pg/ml, respectively. Our data indicated that, overall specificity was high (100%) when using GS and DFA tests together, while the sensitivity has been elevated to 93% with the additional use of PCR and BDG tests, in the diagnosis of PCP-suspected patients. In conclusion, combination of all these tests should be performed for the laboratory diagnosis of P.jirovecii.

In vitro micronucleus assay for the analysis of total particulate matter in cigarette smoke: comparison of flow cytometry and laser scanning cytometry with microscopy.

The possible genotoxicity of the total particulate matter (TPM) in cigarette smoke has typically been evaluated using the in vitro micronucleus assay. In recent years, automated scoring techniques have been developed to replace the manual counting process in this assay. However, these automated scoring techniques have not been applied in routine genotoxicity assays for the analysis of TPM to improve the assay efficiency. Chinese hamster ovary (CHO) cells were treated with TPM produced from 14 types of cigarettes at five concentrations (25-200µg/ml) without exogenous metabolic activation. The three following methods were used to score the micronucleus (MN) frequency: (a) flow cytometry with SYTOX and EMA dyes, which differentially stain micronuclei and apoptotic/necrotic chromatin to enhance assay reliability; (b) laser scanning cytometry with FITC and PI dyes, which is a system that combines the analytical capabilities of flow and image cytometry; and (c) visual microcopy with Giemsa dye. The test results obtained using the three methods were compared using correlation analysis. The key findings for this set of compounds include the following: (a) both flow cytometry- and laser scanning cytometry-based methods were effective for MN identification, (b) the three scoring methods could detect dose-dependent micronucleus formation for the 14 types of TPM, and (c) the MN frequencies that were measured in the same samples by flow cytometry, laser scanning cytometry, and visual microscopy were highly correlated, and there were no significant differences (p>0.05). In conclusion, both flow cytometry and laser scanning cytometry can be used to evaluate the MN frequency induced by TPM without exogenous metabolic activation. The simpler and faster processing and the high correlation of the results make these two automatic methods appropriate tools for use in in vitro micronucleus assays for the analysis of TPM using CHO cells.

A robust procedure for distinctively visualizing zebrafish retinal cell nuclei under bright field light microscopy.

To simultaneously visualize individual cell nuclei and tissue morphologies of the zebrafish retina under bright field light microscopy, it is necessary to establish a procedure that specifically and sensitively stains the cell nuclei in thin tissue sections. This necessity arises from the high nuclear density of the retina and the highly decondensed chromatin of the cone photoreceptors, which significantly reduces their nuclear signals and makes nuclei difficult to distinguish from possible high cytoplasmic background staining. Here we optimized a procedure that integrates JB4 plastic embedding and Feulgen reaction for visualizing zebrafish retinal cell nuclei under bright field light microscopy. This method produced highly specific nuclear staining with minimal cytoplasmic background, allowing us to distinguish individual retinal nuclei despite their tight packaging. The nuclear staining is also sensitive enough to distinguish the euchromatin from heterochromatin in the zebrafish cone nuclei. In addition, this method could be combined with in situ hybridization to simultaneously visualize the cell nuclei and mRNA expression patterns. With its superb specificity and sensitivity, this method may be extended to quantify cell density and analyze global chromatin organization throughout the retina or other tissues.

Decolourisation of dyes under electro-Fenton process using Fe alginate gel beads.

This study focuses on the application of electro-Fenton technique by use of catalytic activity of Fe alginate gel beads for the remediation of wastewater contaminated with synthetic dyes. The Fe alginate gel beads were evaluated for decolourisation of two typical dyes, Lissamine Green B and Azure B under electro-Fenton process. After characterization of Fe alginate gel beads, the pH effect on the process with Fe alginate beads and a comparative study of the electro-Fenton process with free Fe and Fe alginate bead was done. The results showed that the use of Fe alginate beads increases the efficiency of the process; moreover the developed particles show a physical integrity in a wide range of pH (2-8). Around 98-100% of dye decolourisation was obtained for both dyes by electro-Fenton process in successive batches. Therefore, the process was performed with Fe alginate beads in a bubble continuous reactor. High color removal (87-98%) was attained for both dyes operating at a residence time of 30 min, without operational problems and maintaining particle shapes throughout the oxidation process. Consequently, the stable performance of Fe alginate beads opens promising perspectives for fast and economical treatment of wastewater polluted by dyes or similar organic contaminants.

Application of central composite face-centered design and response surface methodology for the optimization of electro-Fenton decolorization of Azure B dye.

PURPOSE: The aim of this work was to improve the ability of electro-Fenton technique for the remediation of wastewater contaminated with synthetic dyes using a model azo dye such as Azure B. METHODS: Batch experiments were conducted to study the effects of main parameters, such as dye concentration, electrode surface area, treatment time, and voltage. In this study, central composite face-centered experimental design matrix and response surface methodology were applied to design the experiments and evaluate the interactive effects of the four studied parameters. A total of 30 experimental runs were set, and the kinetic data were analyzed using first- and second-order models. RESULTS: The experimental data fitted to the empirical second-order model of a suitable degree for the maximum decolorization of Azure B by electro-Fenton treatment. ANOVA analysis showed high coefficient of determination value (R(2) = 0.9835) and reasonable second-order regression prediction. Pareto analysis suggests that the variables, time, and voltage produce the largest effect on the decolorization rate. CONCLUSION: Optimum conditions suggested by the second-order polynomial regression model for attaining maximum decolorization were dye concentration 4.83 mg/L, electrode surface area 15 cm(2), voltage 14.19 V, and treatment time of 34.58 min.

Image analysis approach for development of a decision support system for detection of malaria parasites in thin blood smear images.

This paper describes development of a decision support system for diagnosis of malaria using color image analysis. A hematologist has to study around 100 to 300 microscopic views of Giemsa-stained thin blood smear images to detect malaria parasites, evaluate the extent of infection and to identify the species of the parasite. The proposed algorithm picks up the suspicious regions and detects the parasites in images of all the views. The subimages representing all these parasites are put together to form a composite image which can be sent over a communication channel to obtain the opinion of a remote expert for accurate diagnosis and treatment. We demonstrate the use of the proposed technique for use as a decision support system by developing an android application which facilitates the communication with a remote expert for the final confirmation on the decision for treatment of malaria. Our algorithm detects around 96% of the parasites with a false positive rate of 20%. The Spearman correlation r was 0.88 with a confidence interval of 0.838 to 0.923, p<0.0001.

How Romanowsky stains work and why they remain valuable - including a proposed universal Romanowsky staining mechanism and a rational troubleshooting scheme.

An introduction to the nomenclature and concept of "Romanowsky stains" is followed by a brief account of the dyes involved and especially the crucial role of azure B and of the impurity of most commercial dye lots. Technical features of standardized and traditional Romanowsky stains are outlined, e.g., number and ratio of the acidic and basic dyes used, solvent effects, staining times, and fixation effects. The peculiar advantages of Romanowsky staining are noted, namely, the polychromasia achieved in a technically simple manner with the potential for stain intensification of "the color purple." Accounts are provided of a variety of physicochemically relevant topics, namely, acidic and basic dyeing, peculiarities of acidic and basic dye mixtures, consequences of differential staining rates of different cell and tissue components and of different dyes, the chemical significance of "the color purple," the substrate selectivity for purple color formation and its intensification in situ due to a template effect, effects of resin embedding and prior fixation. Based on these physicochemical phenomena, mechanisms for the various Romanowsky staining applications are outlined including for blood, marrow and cytological smears; G-bands of chromosomes; microorganisms and other single-cell entities; and paraffin and resin tissue sections. The common factors involved in these specific mechanisms are pulled together to generate a "universal" generic mechanism for these stains. Certain generic problems of Romanowsky stains are discussed including the instability of solutions of acidic dye-basic dye mixtures, the inherent heterogeneity of polychrome methylene blue, and the resulting problems of standardization. Finally, a rational trouble-shooting scheme is appended.

Diagnostic performance of gastric imprint smear for determination of Helicobacter pylori infection.

BACKGROUND: Despite the availability of several methods (invasive and noninvasive) for the diagnosis of Helicobacter pylori infection, no test is considered to be the 'gold standard'. Endoscopy-based tests are regarded as the reference method in most studies. OBJECTIVE: To evaluate the diagnostic performance of imprint cytology smears of antral biopsies compared with Gram-stained smears, the rapid urease test and culture methods, separately and in combination. METHODS: Antral biopsies were obtained from consecutive patients undergoing upper gastrointestinal endoscopy at a single centre. The biopsies were examined for the presence of H pylori by Gram-stained smear, the rapid urease test, culture methods and imprint cytology smear.  RESULTS: A total of 273 biopsies were studied. All tests were positive in 36% of the patients. Of 252 biopsies tested, 73% were positive using the imprint cytology technique. Using Gram-stained smear, the rapid urease test and culture methods individually, the sensitivity and specificity of imprint cytology smears for the detection of H pylori were found to be 92.7% and 50%; 92.7% and 49%; and 92.4% and 38.5%, respectively. Combining the three microbiological methods resulted in a sensitivity of 92.1%, a specificity of 51.0% and an efficiency of 71.7% for imprint cytology smears. CONCLUSIONS: Endoscopic examination provides useful clinical information. Imprint gastric cytology can be used as a rapid test to establish the diagnosis of H pylori infection at the time endoscopy is performed, enabling the endoscopist to start treatment with immediate effect.

Confocal laser endomicroscopy for diagnosis of Helicobacter pylori infection: a prospective study.

BACKGROUND AND AIM: Confocal laser endomicroscopy (CLE) is a new endoscopy technique for subsurface analysis of the gastric mucosa and in vivo histology examination during endoscopy. We aimed to compare the clinical applicability and predictive power of CLE with the diagnosis of Helicobacter pylori infection in patients with gastrointestinal symptoms. METHODS: A total of 103 consecutive patients scheduled to undergo endoscopy were enrolled. CLE image criteria for H. pylori infection were established in a pilot study of 20 patients, then images for 83 consecutive patients were prospectively evaluated, and data were correlated with the final diagnosis of H. pylori infection in a blinded manner. RESULTS: We found good association between histopathology and CLE findings. H. pylori infection was identified by CLE with any of the following three features: white spots, neutrophils and microabscesses. The accuracy, sensitivity and specificity of CLE diagnosis of H. pylori infection were 92.8%, 89.2% and 95.7%, respectively. The mean kappa-value for interobserver agreement in the prediction of H. pylori infection was 0.78. Neutrophils were the best diagnostic feature and had good sensitivity (83.8%) and specificity (97.8%). H. pylori-associated changes were more common in the antrum than in the corpus among infected patients (P < 0.001). CONCLUSIONS: H. pylori infection can be identified by specific cellular and subcellular changes of the surface gastric mucosa with CLE. CLE is a novel, useful method for predicting H. pylori infection in vivo during endoscopy.

Correlations among Helicobacter pylori infection and the expression of cyclooxygenase-2 and vascular endothelial growth factor in gastric mucosa with intestinal metaplasia or dysplasia.

BACKGROUND AND AIMS: To examine the rate of Helicobacter pylori infection and the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in gastric mucosa with intestinal metaplasia or dysplasia, and explore their correlations in precancerous gastric lesions. METHODS: A total of 172 patients were included in the study. H. pylori infection was evaluated by hematoxylin-eosin and modified Giemsa staining. The expression of COX-2 and VEGF proteins was detected by immunohistochemistry. RESULTS: The rates of H. pylori infection in gastric mucosal dysplasia (DYS), intestinal metaplasia in gastric mucosa (IM), chronic atrophic gastritis (CAG) and chronic superficial gastritis (CSG) patients were significant differences (P = 0.001). The average optical density (AOD) values of COX-2 staining in CSG, CAG, IM and DYS patients were 13.81 +/- 5.53, 45.28 +/- 21.44, 73.67 +/- 26.02 and 91.23 +/- 45.11, respectively, with significant differences among CSG, CAG and IM patients (P = 0.037, 0.001 and 0.047 for CSG vs CAG, CSG vs IM and CAG vs IM, respectively). The expression level of VEGF in DYS patients was significantly higher than those in other patients (P = 0.001, 0.001 and 0.001 for DYS vs CSG, DYS vs CAG and DYS vs IM, respectively). The expression levels of COX-2 in H. pylori-positive IM, CAG and DYS patients were significantly higher than those in H. pylori-negative counterparts (P = 0.043, 0.009, 0.001, respectively). Additionally, the expression level of COX-2 was positively correlated with that of VEGF with the aggravation of gastric mucosal lesions (r = 0.640, P = 0.006). CONCLUSION: H. pylori infection might be able to induce the expression of COX-2 in precancerous gastric lesions, which in turn upregulates the expression of VEGF.

Diagnosis of visceral leishmaniasis by polymerase chain reaction of DNA extracted from Giemsa's solution-stained slides.

Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani and is a potentially fatal disease in endemic areas of the world. Nepal is an endemic area in which VL causes major public health problems in the lowland areas of the southeast regions. The aim of the present study was to evaluate the sensitivity of polymerase chain reaction (PCR) amplification for the detection of Leishmania DNA from Giemsa's solution-stained bone marrow slides. Bone marrow samples were aspirated from a total of 115 VL suspected patients and used to prepare smears on glass slides and for the initiation of in vitro culture. Bone marrow slides were used for microscopic observation, DNA extraction, and subsequent PCR amplification. PCR analysis showed that all the positive samples were of Leishmania parasites. The PCR assay also showed a higher sensitivity (69%) than microscopic examination (57%) and culture (21%). In addition, PCR was able to detect VL in 12% of samples which were negative by microscopy. PCR of DNA extracted from Giemsa's solution-stained bone marrow slides is a suitable tool for confirming diagnosis in patients with VL and may also be useful in the diagnosis of difficult cases. Bone marrow smears are easily stored and can be easily sent to research centers where PCR is available. This makes PCR a good option for diagnosis in the field.