Identification and quantification of catecholamines in potato plants (Solanum tuberosum) by GC-MS

Dopamine, norepinephrine, and normetanephrine were identified by GC-MS in potato (Solanum tuberosum L.) plants, the latter was new for plants. The highest amount of catecholamines was found in leaves. A developmental stage dependent variation in potato leaf catecholamines accumulation was also observed with highest level in third leaves. Catecholamine contents decrease during cold storage of tubers to undetectable levels. Mechanical wounding of leaves led to a small increase in the level of catecholamines investigated.     

Changes in plasma membrane fluidity of immortal rodent cells induced by anticancer drugs doxorubicin, aclarubicin and mitoxantrone

The aim of this study was to examine the effect of three structurally different anticancer drugs-the pro-oxidative anthracyclines doxorubicin (DOX) and aclarubicin (ACL), and antioxidative anthraquinone mitoxantrone (MTX) on the fluidity of plasma membrane of immortalized rodent fibroblasts using fluorescence spectroscopy and electron spin resonance (ESR) techniques. Two kinds of fluorescent probes (TMA-DPH and 12-AS) and spin labels (5-DS and methyl-12-DS) were used to monitor fluidity in the hydrophobic core and in the polar headgroup region of the lipid bilayer. Immortalized hamster B14 and NIH 3T3 mouse fibroblasts were exposed to DOX, ACL and MTX. We demonstrate that these drugs influence predominantly the hydrophobic core of the lipid bilayer, inducing significant decrease in its fluidity at low concentrations (2-5 microM). A decreased membrane fluidity at the surface of the lipid bilayer was observed only at a higher concentration (20 microM) of the drugs, which indicates that DOX, ACL and MTX intercalate mainly into the hydrophobic core of the membrane, thereby perturbing its structure.     

Lung carcinoids. Tumor angiogenesis in relation to clinicopathologic characteristics

OBJECTIVE: To evaluate the prognostic value of carcinoid angiogenesis for the presence of lymph node metastases, histologic subtype and tumor size. STUDY DESIGN: The study group consisted of 72 resected primary lung carcinoids, 57 typical and 15 atypical. TNM staging was performed. The histologic criteria for carcinoids was based on the Flieder classification. Angiogenesis, expressed as tumor microvessel density, was estimated in sections stained with CD34 antibody, according to Weidner's method. RESULTS: The size of carcinoids was related to the histologic type: the average tumor diameter of typical carcinoids was significantly smaller than the average diameter of atypical carcinoids (P = .003, U = 207, Z = -3.023). Atypical carcinoids represented a more aggressive form of tumors than typical carcinoids; patients with typical carcinoids developed lymph node metastases less frequently (10% vs. 33%) as compared to patients with atypical carcinoids; the difference was statistically significant (P = .032). Tumor angiogenesis failed to distinguish the histologic type of carcinoids and did not indicate the presence or absence of regional lymph node metastases; neither did pTN stage or tumor size. CONCLUSION: Angiogenesis is not a determining factor of the metastatic potential of pulmonary carcinoids.