Citral induces auxin and ethylene-mediated malformations and arrests cell division in Arabidopsis thaliana roots

Citral is a linear monoterpene which is present, as a volatile component, in the essential oil of several different aromatic plants. Previous studies have demonstrated the ability of citral to alter the mitotic microtubules of plant cells, especially at low concentrations. The changes to the microtubules may be due to the compound acting directly on the treated root and coleoptile cells or to indirect action through certain phytohormones. This study, performed in Arabidopsis thaliana, analysed the short-term effects of citral on the auxin content and mitotic cells, and the long-term effects of these alterations on root development and ethylene levels. The results of this study show that citral alters auxin content and cell division and has a strong long-term disorganising effect on cell ultra-structure in A. thaliana seedlings. Its effects on cell division, the thickening of the cell wall, the reduction in intercellular communication, and the absence of root hairs confirm that citral is a strong phytotoxic compound, which has persistent effects on root development.

New insights into antioxidant activity of Brassica crops

Antioxidant activity of six Brassica crops-broccoli, cabbage, cauliflower, kale, nabicol and tronchuda cabbage-was measured at four plant stages with DPPH and FRAP assays. Samples taken three months after sowing showed the highest antioxidant activity. Kale crop possessed the highest antioxidant activity at this plant stage and also at the adult plant stage, while cauliflower showed the highest antioxidant activity in sprouts and in leaves taken two months after sowing. Brassica by-products could be used as sources of products with high content of antioxidants. Phenolic content and composition varied, depending on the crop under study and on the plant stage; sprout samples were much higher in hydroxycinnamic acids than the rest of samples. Differences in antioxidant activity of Brassica crops were related to differences in total phenolic content but also to differences in phenolic composition for most samples.

Artificial neural network model to predict biochemical failure after radical prostatectomy

BACKGROUND

Biochemical failure, defined here as a rise in the serum prostate specific antigen (PSA) concentration to >0.3 ng/mL or the initiation of adjuvant therapy, is thought to be an adverse prognostic factor for men who undergo radical prostatectomy (RP) as definitive treatment for clinically localized cancer of the prostate (CAP). We have developed an artificial neural network (ANN) to predict biochemical failure that may benefit clinicians and patients choosing among the definitive treatment options for CAP.

MATERIALS AND METHODS

Clinical and pathologic data from 196 patients who had undergone RP at one institution between 1988 and 1999 were utilized. Twenty-one records were deleted because of missing outcome, Gleason sum, PSA, or clinical stage data. The variables from the 175 remaining records were analyzed for input variable selection using principal component analysis, decision tree analysis, and stepped logistic regression. The selected variables were age, PSA, primary and secondary Gleason grade, and Gleason sum. The records were randomized and split into three bootstrap training and validation sets of 140 records (80%) and 35 records (20%), respectively.

RESULTS

Forty-four percent of the patients suffered biochemical failure. The average duration of follow up was 2.5 years (range 0-11.5 years). Forty-two percent of the patients had pathologic evidence of non-organ-confined disease. The average area under the receiver operator characteristic (ROC) curve for the validation sets was 0.75 +/- 0.07. The ANN with the highest area under the ROC curve (0.80) was used for prediction and had a sensitivity of 0.74, a specificity of 0.78, a positive predictive value of 0.71, and a negative predictive value of 0.81.

CONCLUSION

These results suggest that ANN models can predict PSA failure using readily available preoperative variables. Such predictive models may offer assistance to patients and physicians deciding on definitive therapy for CaP.

A comparative evaluation of immunohistochemical markers for the differential diagnosis of malignant pleural tumours

AIMS

To determine the value of immunocytochemistry in differentiation of malignant pleural mesothelioma from carcinoma in a pleural biopsy using commercially available monoclonal antibodies.

METHODS AND RESULTS

A panel of monoclonal antibodies against keratins, epithelial membrane antigen (EMA), epithelial antigen Ber-EP4, carcinoembryonic antigen (CEA), tumour-associated glycoprotein (B72.3), Leu-M1, CD30 (Ber-H2), vimentin and desmin, was applied to 40 cases of malignant pleural mesothelioma and 23 cases of carcinoma metastatic to the pleura (16 pulmonary and seven extrapulmonary). Positivities for Ber-EP4, CEA, B72.3 and Leu-M1 were found to have the highest nosologic sensitivities (87.0%, 65.2%, 52.5% and 43.5%, respectively) and specificities (97.5%, 97.5%, 100% and 95%, respectively) for carcinoma. Positive staining for vimentin had the highest sensitivity (87.5%) with 95.7% specificity for mesothelioma. Positive staining for desmin was found in 45% of mesotheliomas and 0% of carcinomas. Diagnostic sensitivity and diagnostic specificity (P-values) were calculated for these markers. In respect to the diagnostic power defined by the clinically relevant predictive values of positive and negative tests, we found that a two-marker panel of antibodies including vimentin and Ber-EP4 is most useful for the histopathological distinction between carcinoma (pulmonary or extrapulmonary) and malignant pleural mesothelioma.

CONCLUSIONS

A combination of Ber-EP4 and vimentin provides the most sensitive and specific pair of markers for distinguishing between malignant pleural mesothelioma and carcinoma metastatic to the pleura. The prevalence of the tested tumours should be taken into account when evaluating the clinical value of ancillary techniques in pathology.

[Analysis of proliferating cell nuclear antigen (PCNA) expression in 24 cases of primary non-small cell pulmonary carcinomas and correlation with survival]

Proliferating cell nuclear antigen (PCNA) is a 36 kD nuclear protein involved in DNA replication that is believed to provide an indication of proliferation in some neoplasms. This study analyzes PCNA expression in 24 cases of primary non-small cell lung cancer using monoclonal PC-10 antibodies in paraffin embedded material. We found significant inter- and intra-tumoral variations in PCNA expression, and no statistically significant relation between the amount of PCNA expression and the size and location of tumors, index of mitosis, histological tumor type or patient age. We found a statistically significant relation (r = 0.47; p < 0.05) between survival and amount of PCNA expression in a sample of 19 cases, but no statistically significant differences in survival related to whether PCNA expression was slight (0-25), moderate (25%-50%) or high (> 50%), and no prognostic value for degree of PCNA expression.

Biochemical basis of a novel T lymphocyte receptor immunodeficiency by immunohistochemistry. A possible CD3 gamma abnormality

Necropsic lymphoid tissues obtained from an infant with a novel type of immunodeficiency consisting of a peripheral blood T lymphocyte antigen receptor (TCR) surface expression defect, were analyzed by immunohistochemistry for the expression of various TCR-associated epitopes. The work was aimed to characterize the biochemical basis of this kind of disorder and confirm the defect in different lymphoid tissues. Within an assessed lymphoid depletion, the patient's tissues showed a normal expression of several TCR epitopes (those associated to CD3 epsilon, CD3 delta and the clonotypic -Ti- alpha and beta chains). In contrast, the expression of the epitopes recognized by the monoclonals OKT3, WT31, and BMA031 was severely diminished. Our results therefore support that CD3 epsilon, CD3 delta, Ti alpha and Ti beta are probably not involved in this type of immunodeficiency, and strongly suggest that CD3 gamma (forming part of the epitope recognized by OKT3) may rather be the affected chain giving rise to the defective surface T cell phenotype; however, alternative interpretations are not ruled out. The disrupted TCR thus formed, containing Ti alpha beta heterodimers and CD3 epsilon and CD3 delta subunits, but lacking normal CD3 gamma, would in this scheme lack the conformational framework determinants recognized by WT31 and BMA031.

Neurocutaneous melanosis. Report of a case and review of the literature

A case of neurocutaneous melanosis in a 15 year old male is described. A primary malignant meningeal melanoma caused the death of the patient in six months. The skin lesions were benign. The literature is reviewed, and the nature of the disease and its relationship with other phakomatoses is discussed.