[Automated detection of microaneurysms by using region growing and Fuzzy Artmap neural network]

OBJECTIVE

To assess whether the methodological changes of this new algorithm improves the results of a previously presented strategy.

METHODS

We enhance the image and filter out the green channel of the digital color retinography. Multitolerance thresholding was applied to obtain candidate points and make a seed growing region by varying intensities. We took 15 characteristics from each region to train a Fuzzy Artmap neural network using 42 retinal photographs. This network was then applied in the study of 11 good quality retinal photographs included in the diabetic retinopathy early detection screening program, with initial stages of retinopathy, obtained with the Topcon NW200 non-mydriatic retinal camera.

RESULTS

Two experienced ophthalmologists detected 52 microaneurysms in 11 images. The algorithm detected 39 microaneurysms and 3,752 more regions, confirming 38 microaneurysm and 135 false positives. The sensitivity is improved compared to the previous algorithm, from 60.53 to 73.08%. False positives have dropped from 41.8 to 12.27 per image.

CONCLUSIONS

The new algorithm is better than the previous one, but there is still room for improvement, especially in the initial determination of seeds.

EMPHYSEMA QUANTIFICATION IN A MULTI-SCANNER HRCT COHORT USING LOCAL INTENSITY DISTRIBUTIONS

This article investigates the suitability of local intensity distributions to analyze six emphysema classes in 342 CT scans obtained from 16 sites hosting scanners by 3 vendors and a total of 9 specific models in subjects with Chronic Obstructive Pulmonary Disease (COPD). We propose using kernel density estimation to deal with the inherent sparsity of local intensity histograms obtained from scarcely populated regions of interest. We validate our approach by leave-one-subject-out classification experiments and full-lung analyses. We compare our results with recently published LBP texture-based methodology. We demonstrate the efficacy of using intensity information alone in multi-scanner cohorts, which is a simpler, more intuitive approach.

[Automatic detection of microaneurysms in colour fundus images]

PURPOSE

We present the development of a tool for the automatic detection of microaneurysms and its clinical evaluation. The intention of this tool is to facilitate the diagnosis of diabetic retinopathy in general screening programs.

METHOD

The designed and developed tool consists of three stages of processing: 1) Obtaining of the basic image of eye with the retinal camera, inverted image on the green channel, and a high-pass filter of the image. This phase enhances the microaneurysms. 2) Detection of the candidates for microaneurysms, by means of an adaptive prediction filter and regions growth. 3) Selection, among the candidates, of whom microaneurysms must be considered to fulfil the criteria of circular shape, high intensity in the inverted green channel and contrasts with respect to the surrounding pixels.

RESULTS

We selected to 20 retinal photographs of good quality and dimensions 600x600 pixels from patients with nonproliferative diabetic retinopathy. The ophthalmologists detected 297 microaneurysms in these images. The tool for automatic detection correctly located 252 microaneurysms, with a mean sensitivity of 89% and a false positives rate of 93%.

CONCLUSIONS

The results obtained seem to indicate that the tool developed will be very useful for its potential use in screening programs in primary care centres. On the other hand, more work is needed on the algorithm to decrease the rate of false positives.

Antioxidant and antibacterial activity of essential oil and extracts of bay laurel Laurus nobilis Linnaeus (Lauraceae) from Portugal

Laurus nobilis L. is an aromatic plant frequently used as a spice in Mediterranean cookery and as a traditional medicine for the treatment of several infectious diseases. The aim of this study was to characterise the antibacterial and antioxidant activities of bay laurel essential oil (EO), ethanolic extract (EE) and hot/cold aqueous extract (AE). The major components detected in bay laurel EO were eucalyptol (27.2%), α-terpinenyl acetate (10.2%), linalool (8.4%), methyleugenol (5.4%), sabinene (4.0%) and carvacrol (3.2%). The EO exhibited strong antibacterial activity against all tested foodborne spoilage and pathogenic bacteria, whereas this activity was less pronounced or even nonexistent in the EE and AE. In contrast, EO exhibited low antioxidant activity compared to extracts (EX), and among the EX, the hot AE revealed the highest antioxidant ability. The results show that bay laurel EO and its EX have potential as natural alternatives to synthetic food preservatives, in order to enhance food safety and increase food shelf life.

The effect of feeding system in the expression of genes related with fat metabolism in semitendinous muscle in sheep

The effect of feeding system on the expression of LPL, ACACA, FASN, FABP4, DGAT1, SCD, CPT1B, PRKAA2, LEP, SREBP1, PPARG, PPARA and CEBPB genes in semitendinous muscle was studied. Forty-four single born male lambs of the Rasa Aragonesa breed, allocated to four different dietary treatments, were used: grazing alfalfa, grazing alfalfa with supplement for lambs, indoor lambs with grazing ewes and drylot. Significant differences were found in the expression of genes LPL, ACACA, FASN, FABP4, CPT1B and SCD. Genes related to adipogenesis (LPL, ACACA, FASN, FABP4, and SCD) are up-regulated in the intensive groups. In grazing groups CPT1B gene expression, related to β-oxidation process, is up-regulated. The relative expression of CPT1B was 1.54 fold higher in ALF+S, and 0.43 and 0.37 fold lower in IND- GRE and IND, respectively. The results support the hypothesis that changes in fatty acid profile due to feeding system implicate changes in the mRNA expression level of genes related with fat metabolism. Feeding strategy is an important tool to manipulate intramuscular fatty acid profile in meat through altering gene expression of enzymes related with fat metabolism.

Significance of the volume of fetomaternal hemorrhage after performing prenatal invasive tests

BACKGROUND

Fetal erythrocytes cross the placenta during gestation, but invasive prenatal procedures might develop into fetomaternal hemorrhage (FMH). We examine whether flow cytometry immunophenotyping might be useful for measuring the volume of FMH after such procedures.

METHODS

Fetal erythrocytes (%) were determined in 153 pregnant women after amniocentesis (129) and chorionic villous sampling (24) using a monoclonal antibody against fetal hemoglobin. Fetal erythrocytes were identified for their high expression of fetal hemoglobin (HbF(++) ). Blood samples from two control groups, 53 healthy males and 21 pregnant women not submitted to invasive tests, were used to establish normal values of circulating HbF(++) erythrocytes in adults.

RESULTS

The highest percentage of HbF(++) erythrocytes in the control groups was 0.015%. The rate of HbF(++) erythrocytes in samples after invasive tests ranged between <0.01% and 0.15%. Seventy-three women (47%) had ≤0.015% HbF(++) erythrocytes, and this rate was higher in 80. Nine women presented >1 ml of FMH (volume of packed cells corresponding to 0.054-0.15% HbF(++) erythrocytes), but only two had sonographic evidence of bleeding.

CONCLUSIONS

Most women in our series had a very low volume of FMH after the invasive tests. Acute bleeding should be thoroughly investigated in women with either more than 1 ml of packed cells or more than 0.05% of HbF(++) erythrocytes. Intermediate values between >0.015% and <0.05%, should be carefully considered depending on the week of gestation. Data obtained before 15 weeks might reflect previous cell trafficking between fetus and mother instead of acute hemorrhage.

Gemcitabine/cisplatin in patients with advanced bladder and impaired renal function: A retrospective analysis

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Background: A four-weekly regimen of gemcitabine and cisplatin (GEMCIS) has similar activity and is less toxic than MVAC in advanced bladder cancer. However, full-dose cisplatin in unfit patients with impaired renal function is contraindicated and other carboplatin-based schedules have been developed. We have previously reported the feasibility of GEMCIS in a biweekly schedule in unfit patients with renal impairment. Here we report a multicenter retrospective study of this biweekly regimen in patients with impaired renal function.

Methods: Between January 2004 and October 2009, 40 patients with locally advanced nonsurgically resectable or metastatic bladder cancer and impaired renal function were included. Treatment consisted of gemcitabine 2500 mg/m2 on day 1 and cisplatin 35 mg/m2 on day 1, every 14 days.

Results: Median age of the patients was 73 years (range: 51-82 years). Median IK was 80% (range: 60-100%). Mean creatinine clearance was 49 ml/min (range:37-59 ml/min). Eight patients had previously received chemotherapy with gemcitabine and/or platinum based therapy. Metastatic localizations were: 17 lymph nodes, 10 pulmonary, 10 bone, 7 liver, 12 pelvic and 1 central nervous system. The median number of cycles/patient was 6 (1-13). Out of 36 patients evaluable for response, there was one complete response, 14 partial responses (ORR: 42%; 95% CI 27-58%), 11 stabilizations and 10 progressive diseases. Hematologic toxicities were grade 1 anaemia in 15 patients, grade 2 in 8; grade 3 in 2; grade 3 neutropenia in 5 patients and grade 4 in 1 patient; grade 3 plaquetopenia in 3 patients. Nonhematologic toxicities were grade 1-2 vomiting in 2 patients. Two patients showed a grade 2 hepatic toxicity. Worsening of the renal function was observed in two patients. Alopecia grade 1-2 was seen in three patients. There was one toxic death related to metabolic acidosis.The median progression-free survival is 15 weeks. The median OS from first cycle of GEMCIS is 35 weeks and 1-year OS is 43% (St error 9%).

Conclusions: A two-weekly schedule of gemcitabine plus cisplatin is feasible, active, and generally well tolerated in an outpatient setting in unfit patients with poor renal reserve.

No significant financial relationships to disclose.

BRAF and KRAS mutations in penile cancer and their correlation with clinical features

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Background: Penile cancer is a rare disease in developed countries. While surgery may be curative for patients with localized disease, for metastatic patients systemic chemotherapy may offer palliation with usually short-lived responses. Thus, new options in this setting are needed. Retrospective series have reported EGFR overexpression in more than 90% of the cases and also interesting results of EGFR directed therapies in these patients have been comunicated. The role of KRAS status or other molecular markers as prognostic or predictive factors remains unclear. The aim of this study was to determine the prevalence of BRAF and KRAS somatic mutations in penile cancer and their correlation with clinicopathologic features.

Methods: We analyzed 28 samples collected from de archives of the Pathology Department at our institution from 1996 to 2009. The DNAs were extracted from FFPE blocks by Biorobot EZ1 following the manufacturer protocol of the EZ1-DNA Tissue kit (Qiagen). KRAS and BRAF mutations were amplified with specific primers, and sequenced by Sanger with Bigdye terminator v3.1 Cycle Sequencing Kit. Medical records were reviewed for clinical data.

Results: No BRAF mutations were found, but we identified somatic missense mutations in the KRAS gene (all activating G12D mutations) in 6/27 samples (22%, one not evaluable). Median age at diagnosis (73 vs. 71), grade and histologic subtype did not differ between wt and mutated (mt) patients. There was a trend toward a more advanced stage at diagnosis in mt versus wt : 33 versus 47% stage I, 16 versus 9% stage II and 50 versus 38% stage III respectively. 2/6 mt patients died (due to other causes) as did 5/21 wt patients (3 of them because of disease progression).

Conclusions: BRAF mutations seem not involved in the EGFR pathway in penile carcinomas. The prevalence of KRAS mutations was unexpectedly high in our series and mt patients tended to be diagnosed at a more advanced stage. Unfortunately, no correlation was found with other clinicopathologic features, including overall survival in our small series. These results suggest a role of KRAS mutation in the development of these carcinomas and support the importance to determine KRAS status in patients to be treated with anti-EGFR based therapies.

No significant financial relationships to disclose.

Evaluation of the Etest method for susceptibility testing of Aspergillus spp. and Fusarium spp. to three echinocandins

We performed Etest and broth microdilution (BMD) susceptibility testing of caspofungin, micafungin and anidulafungin against 67 clinical isolates of Aspergillus spp. and 10 Fusarium spp. Minimal effective concentrations (MECs) by BMD were read after 24 h of incubation at 35 degrees C and Etest MICs were read at 24 and 48 h. MECs < or =0.25 mg/l were obtained with caspofungin for all Aspergillus spp. tested but Etest MICs were < or =1 mg/l at 24 h. The agreement between caspofungin Etest and broth microdilution was good for all Aspergillus species tested (range 82.4-100%) except for A. niger and A. glaucus at 24 h of incubation. Micafungin and anidulafungin MEC and MIC results were lower than those of caspofungin (< or =0.015 mg/l) at 24 and 48 h for all Aspergillus tested. The agreement between the methods was excellent (100%) for micafungin and anidulafungin for all Aspergillus species tested. The three echinocandins were inactive against all isolates of Fusarium spp. showing MECs and MICs >8 mg/l. The Etest method could be a suitable procedure to test the susceptibility of most Aspergillus species to caspofungin, micafungin and anidulafungin; the best agreement was at 24 h.

[Automatic detection of vessels in color fundus images]

PURPOSE

The main purpose of the paper is to evaluate an automated method for blood vessels segmentation in color fundus images, due to its important role in the diagnosis of several pathologies such as diabetes. The final objective is to introduce the algorithm into a Computer Aided Diagnosis (CAD) tool that would be available in those local medical centers without specialists.

METHOD

An automated method for blood vessels segmentation in color fundus images was implemented and tested. The algorithm starts with the extraction of vessel centerlines, which are used as guidelines for the subsequent vessel filling phase. The outputs of four directional differential operators are processed in order to select connected sets of candidate points to be further classified as centerline pixels using vessel derived features. The final segmentation is obtained using an iterative region growing method that integrates the contents of several binary images, resulting from vessel width dependent morphological filters. The method was evaluated using the images of two publicly available databases (STARE and DRIVE) and a database with 24 images.

RESULTS

The algorithm outperforms other published algorithms and approximates the average accuracy of a human observer without a significant degradation of sensitivity and specificity. In addition, results have been subject to the experts' valuation that they think that retinal vessels remain represented with valuable accuracy on having analyzed the test's images.

CONCLUSION

Due to the good segmentation results, the algorithm proposed could be implemented as part of a complete CAD tool in the local medical centers. This would reduce cost and diagnosis time.