A novel breast tissue density classification methodology

It has been shown that the accuracy of mammographic abnormality detection methods is strongly dependent on the breast tissue characteristics, where a dense breast drastically reduces detection sensitivity. In addition, breast tissue density is widely accepted to be an important risk indicator for the development of breast cancer. Here, we describe the development of an automatic breast tissue classification methodology, which can be summarized in a number of distinct steps: 1) the segmentation of the breast area into fatty versus dense mammographic tissue; 2) the extraction of morphological and texture features from the segmented breast areas; and 3) the use of a Bayesian combination of a number of classifiers. The evaluation, based on a large kappa = 0.81 and 0.67 for the two data sets) between automatic and expert-based Breast Imaging Reporting and Data System mammographic density assessment.

Abundance, biting behaviour and parous rate of anopheline mosquito species in relation to malaria incidence in gold-mining areas of southern Venezuela

A longitudinal entomological and epidemiological study was conducted in five localities of southern Venezuela between January 1999 and April 2000 to determine the abundance, biting behaviour and parity of anopheline mosquitoes (Diptera: Culicidae) in relation to climate variables and malaria incidence. A total of 3685 female anopheline mosquitoes, representing six species, were collected. The most abundant species were Anopheles marajoara Galvão & Damasceno (60.7%) and Anopheles darlingi Root (35.1%), which together represented 95.8% of the total anophelines collected. Abundance and species distribution varied by locality. Malaria prevalence varied from 12.5 to 21.4 cases per 1000 population. Transmission occurred throughout the year; the annual parasite index (API) for the study period was 813.0 cases per 1000 population, with a range of 71.6-2492 per 1000 population, depending on locality. Plasmodium vivax (Grassi & Feletti) (Coccidia: Plasmodiidae) accounted for 78.6% of cases, Plasmodium falciparum (Welch) for 21.4% and mixed infections (Pv+Pf) for < 0.1%. Anopheles marajoara and An. darlingi were more abundant during the rainy season (April-September). There was no significant correlation (P > 0.05) between mosquito abundance and rainfall. Correlations between malaria incidence by parasite species and mosquito abundance were not significant (P > 0.05). Monthly parous rates were similar for An. marajoara and An. darlingi throughout the year, with two peaks that coincided with the dry-rainy transition period and the period of less rain. Peaks in the incidence of malaria cases were observed 1 month after major peaks in biting rates of parous anophelines. Anopheles darlingi engages in biting activity throughout the night, with two minor peaks at 23.00-00.00 hours and 03.00-04.00 hours. Anopheles marajoara has a different pattern, with a biting peak at 19.00-21.00 hours and 76.6% of biting occurring before midnight. Although both vectors bite indoors and outdoors, they showed a highly significant (P < 0.01) degree of exophagic behaviour. The present study constitutes the first effort to characterize the bionomics of anophelines in malaria endemic foci in different ecological situations in relation to malaria transmission in southern Venezuela and to provide relevant information to be considered when planning and implementing vector control programmes.

Probabilistic model-based methodology for the conformational study of cyclic systems: application to copper complexes double-bridged by phosphate and related ligands

A methodology for the conformational study of cyclic systems through the statistical analysis of torsion angles is presented. It relies on a combination of different methods based on a probabilistic model which takes into account the topological symmetry of the structures. This methodology is applied to copper complexes double-bridged by phosphate and related ligands. Structures from the Cambridge Structural Database (CSD) are analyzed and the chair, boat-chair and boat conformations are identified as the most frequent conformations. The output of the methodology also provides information about distortions from the ideal conformations, the most frequent being: chair ↔ twist-chair, chair ↔ twist-boat-chair and boat ↔ twist-boat. Molecular mechanics calculations identify these distortions as energetically accessible pathways.

Biweekly paclitaxel as second-line treatment in advanced non-small cell lung-cancer (NSCLC). A phase II study of the Lung Cancer Galician Group

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Background: Paclitaxel is an active drug for NSCLC. Our purpose was to evaluate the efficacy and toxicity of biweekly administration of this drug in previously treated patients with advanced NSCLC. Methods: Patients with stage IIIB and IV NSCLC, which progressed after or during first-line chemotherapy, measurable disease, ECOG PS=0–1 and adequate organ function were included. Paclitaxel was administered at 150 mg/m2 iv, days 1 and 14, every 28 days, for a maximum of six cycles. Both, toxicity and efficacy analyses, were performed on the intent-to-treat (ITT) population. Results: Between September 2004 and November 2006, 42 patients (M/F, 39/3) were included, with median age 64 years (39–79). Tumor histology mainly included epidermoid (40.5%) and adenocarcinoma (35.7%). Tumor stage was IIIB (23.8%) and IV (76.2%). Median number of metastatic lesions was 1 (55%), located mainly in lymph nodes (30%), lung (25%), adrenal glands (16%) and bone (11%). Previous chemotherapy included platinum (76.1%), docetaxel (66.6%) and gemcitabine (52.4%). A total of 167 cycles (median 4, range 1–6) were administered. Median relative dose intensity was 94%. Toxicity: Grade III/IV hematologic toxicities per patient were neutropenia (2.5%) and anemia (2.5%). Grade III/IV non-hematologic toxicities were asthenia (2.5%), arthralgias/myalgias (2.5%) and peripheral neuropathy (2.5%). Efficacy: Of 39 ITT patients (3 patients have just begun chemotherapy), 7 achieved PR, 11 SD and 16 progressed, resulting in an ORR of 17.95% (95% CI: 5.9–30%). Five patients could not be evaluated for response due to early withdrawal (4 tumor-related exitus and 1 PS deterioration). Median TTP and OS were 174 days (95% CI: 115.52–232.48) and 332 days (95% CI: 261.18–402.82), respectively. Conclusions: Biweekly paclitaxel is an active and very well tolerated regimen in previously treated patients with advanced NSCLC.

No significant financial relationships to disclose.

Risk of acute liver injury associated with the use of drugs: a multicentre population survey

BACKGROUND

Acute liver injury of uncertain aetiology is often drug related and quantitative information about the associated risk is scarce.

AIM

To estimate the risk of acute liver injury associated with the use of drugs.

METHODS

In a population survey study, 126 cases of acute liver injury were prospectively assembled from January 1993 to December 1999, in patients over 15 years of age, in 12 hospitals in Barcelona (Spain). We estimated the relative risk for each drug as the ratio between the incidence of acute liver injury among the exposed population to the drug and the incidence of acute liver injury among those not exposed to it. Drug consumption data were used to estimate the exposed population.

RESULTS

Isoniazid, pyrazinamide, rifampicin, amoxicillin with clavulanic acid, erythromicin, chlorpromazine, nimesulide, and ticlopidine presented the highest risk (point relative risk > 25). Amoxicillin, metoclopramide, captopril and enalapril, furosemide, hydrochlorothiazide, fluoxetine, paroxetine, diazepam, alprazolam, lorazepam, metamizole, low-dose acetylsalicylic acid and salbutamol showed the lowest risk (point relative risk < 5).

CONCLUSIONS

This study provides a risk estimation of serious liver disease for various drugs that will be useful in its diagnosis and management, and when comparing with the drug therapeutic benefit in each indication. Some observed associations would be worth specific studies.

[Pharmacoeconomic analysis of a maintenance strategy with lopinavir/ritonavir monotherapy in HIV-infected patients]

AIMS

To conduct a cost-efficacy analysis of lopinavir/ritonavir (LPV/r) monotherapy as a maintenance regimen following induction of virological response with triple therapy including LPV/r. The pharmacoeconomic analysis was performed from the perspective of the Spanish public health system.

METHODS

A cost-efficacy analysis was performed in a phase IV-II, comparative, randomized, multicenter, open-label clinical trial evaluating the efficacy and safety of maintenance therapy with LPV/r monotherapy versus continuation of triple therapy in HIV-infected patients with a persistently undetectable viral load for 6 months. For the pharmacoeconomic analysis, efficacy was defined as the proportion of patients with plasma HIV RNA concentrations < 50 copies/mL at 48 weeks from the start of the study. An intent-to-treat analysis was performed. Only direct costs were considered. Cost, efficacy and the cost-efficacy ratio were calculated for each treatment option.

RESULTS

The cost-efficacy ratio of LPV/r maintenance monotherapy was 5186 euros per unit of achieved effect (patient with plasma HIV RNA concentrations < 50 copies/mL at 48 weeks), whereas maintenance with triple therapy had a cost-efficacy ratio of 8688 euros per unit of achieved effect.

CONCLUSION

The option of LPV/r monotherapy as maintenance therapy in HIV-infected patients following induction of virological response with triple therapy including LPV/r might be a more efficient alternative than maintaining triple therapy, as evidenced by a more favorable cost-efficacy ratio.

Evaluation of acute copper toxicity during early life stages of gilthead seabream, Sparus aurata

In this study, the effects of exposure to copper (mortality and morphological alterations) on the early life stages of the gilthead seabream, Sparus aurata, were examined. Eggs/embryos and larvae were exposed to nominal concentrations of copper ranging from 0.0001 to 10 mg/L Cu (II) in the tests with eggs/embryos and 0.025 to 0.5 mg/L Cu (II) in the test with larvae. Duration of the assays was 48 hours for embryos and 96 hours for larvae. A high percentage of mortality was observed in embryos exposed to 0.1 mg/L (97.2%) and in larvae exposed to 0.5 mg/L (100%). The embryos proved the most sensitive to copper for the same duration of exposure. The acute toxicity expressed as LC(50) 48 hours was 0.054 (0.048-0.058) mg/L for embryos and 0.261 (0.182- 0.375) mg/L for larvae. Morphological alterations or abnormalities in embryos included irregular shapes of chorion, opacity and vitellus retraction/degeneration. In larvae we observed poor capacity to swim, trembling, myoskeletal defects, opacity and exophthalmia. Histopathological alterations are observed in S. aurata larvae. Mucous cells of the digestive tissue present a severe alteration with an increment of exudates. A great cellular disorganization in the renal tissue is observed. Results from this work indicate the high sensitivity of early life stages of Sparus aurata to copper (II) and the persistence of sublethal effects.

Expression of cytokines IL-4, IL-12, IL-15, IL-18, and IFNgamma and modulation by different growth factors in cultured human osteoblast-like cells

The antigenic phenotype of cultured human osteoblast-like cells, their ability to phagocytose particles of different nature and size, and their capacity to stimulate allogeneic T cells suggest that they are related to other cell populations with which they may also have immunological functions in common. The objective of this study was to investigate the intracytoplasmatic presence of cytokines and their modulation by different biomolecules. Immunocytochemistry and flow cytometry were used to study the expression of IL-4, IL-12, IL-15, IL-18, and IFNgamma cytokines. To investigate whether FGF, TGF, PDGF, IL-1, and IFNgamma modulate expression of these cytokines in cultured human osteoblast-like cells we used flow cytometry. IL-4, IL-12, IL-15, IL-18, and IFNgamma cytokines were expressed by all the cultured human osteoblast-like cells studied. Treatment with FGF and TGFbeta1 reduced the percentage expression and fluorescence intensity of the cytokines. PDGF treatment enhanced their fluorescence intensity but did not modify their expression. IL-1 treatment produced a small reduction in expression and fluorescence intensity of IL-12 and IL-15, but did not produce major changes in the expression of IL-4, IL-18, or IFNgamma. IFNgamma markedly increased the fluorescence intensity of the cytokines. The results indicate that human osteoblast-like cells may perform immunological functions (e.g., synthesizing cytokines with immune regulator function) that can be modulated by different biomolecules related to bone tissue and/or immune response.

Assessment of a new brand of determinants for skin testing in a large group of patients with suspected beta-lactam allergy

BACKGROUND

Skin testing with major and minor determinants of benzylpenicillin is recommended standard practice for the evaluation of patients with immediate hypersensitivity reactions to beta-lactams. However, commercial reagents for this purpose were recently dropped from the European market.

OBJECTIVE

In the present study, we assessed a new brand of reagents for use in skin testing in patients with suspected penicillin allergy.

METHODS

Prick tests and intradermal tests were performed with benzylpenicilloyl polylysine (PPL) and minor determinant mixture (MDM). Penicillin G, amoxicillin, and the culprit beta-lactam were also tested. If skin tests were negative, a single-blind oral challenge test was performed with the culprit active principle or penicillin. If both skin tests and challenge tests were negative, the same procedure was repeated between 2 and 4 weeks later.

RESULTS

A total of 636 patients were assessed. The allergy study was positive in 69 patients. Skin tests with PPL were positive in 30 patients (46.8%) and with MDM in 28 (43.7%). Sixteen patients displayed a positive reaction to both PPL and MDM (25%), while 42 patients (65.6%) had a positive reaction to either PPL or MDM alone. Thirty-two patients had positive skin test reactions to penicillin G or another p-lactam antibiotic. Five patients in whom a negative result was obtained in skin tests had a positive reaction to oral challenge.

CONCLUSIONS

Our results indicate that a new brand of determinants that is commercially available in Europe is a reliable and useful tool for the diagnosis of beta-lactam allergy. The new reagents are a safe alternative to the previously available brand.

Aquaporin expression in the cerebral cortex is increased at early stages of Alzheimer disease

Abnormalities in the cerebral microvasculature are common in Alzheimer disease (AD). Expression levels of the water channels aquaporin 1 and aquaporin 4 (AQP1, AQP4) were examined in AD cases by gel electrophoresis and Western blotting, and densitometric values normalized with beta-actin were compared with corresponding values in age-matched controls processed in parallel. In addition, samples of cases with Pick disease (PiD) were examined for comparative purposes. A significant increase in the expression levels of AQP1 was observed in AD stage II (following Braak and Braak classification). Individual variations were seen in advanced stages which resulted in non-significant differences between AD stages V-VI and age-matched controls. No differences in AQP1 levels were observed between familial AD cases (FAD, all of them at advanced stages) and corresponding age-matched controls. Immunohistochemistry showed increased AQP1 in astrocytes at early stages of AD. Double-labelling immunofluorescence and confocal microscopy disclosed AQP1 immunoreactivity at the cell surface of astrocytes which were recognized with anti-glial fibrillary acidic protein antibodies. No differences in the levels of AQP4 were observed in AD, FAD and PiD when compared with corresponding controls. These results indicate abnormal expression of AQP1 in astrocytes in AD, and they add support to the idea that abnormal regulation of mechanisms involved in the control of water fluxes occurs at early stages in AD.