Experimental study on photodynamic diagnosis of cancer mediated by chemiluminescence probe

A novel method of photodynamic diagnosis of cancer mediated by chemiluminescence probe is presented. The mechanism for photodynamic therapy involves singlet oxygen ((1)O(2)) generated by energy transfer from photosensitizers. (1)O(2) can react with 3,7-dihydro-6-[4-[2-(N'-(5-fluoresceinyl)thioureido)ethoxy]phenyl]-2-methylimidazo[1,2-a]pyrazin-3-one sodium salt (FCLA), which is a Cypridina luciferin analog and a specific chemiluminescence probe for detecting (1)O(2) and superoxide (O(2)(-)). The reaction of FCLA and (1)O(2) can give emission with peak wavelength at about 532 nm. In the present study, FCLA was chosen as an optical reporter of (1)O(2) produced from the photosensitization reaction of hematoporphyrin derivative in model solution and in nude mice with transplanted mammary cancer. Photosensitized chemiluminescence from the reaction of FCLA with (1)O(2) was detected by a highly sensitive Intensified Charge-Coupled Device detector. The chemiluminescence was markedly inhibited by the addition of 10 mmol/l sodium azide (NaN(3)) to the model solution and minor effects were observed at the addition of 10 micromol/l superoxide dismutase, 20 mmol/l mannitol and 100 microg/ml catalase, respectively, thus indicating that (1)O(2) generation from photosensitization reaction mainly results in light emission. Experiments in vivo with tumor-bearing mice showed a clear chemiluminescence image of tumor. The study suggests that this novel method may be applicable to the diagnosis of superficial tumors.     

Preliminary experience with resistin assessment in common population

Resistin is a signal peptide produced by adipose tissue. Mice models have confirmed that resistin may play an important role in insulin resistance. Its function in the human organism has not been elucidated yet. Since in common population the resistin concentrations are not known (no validated commercial set is available), we performed resistin assessment using the ELISA method (with satisfying analytical characteristics) in a population of 123 non-obese probands without signs of insulin resistance and/or inflammation. Mean resistin values amounted to 14.3 ng/ml (reference limit of 7.3-21.3 ng/ml).     

Vocalizations of Amazon River Dolphins,Inia geoffrensis: Insights into the Evolutionary Origins of Delphinid Whistles

Oceanic dolphins (Odontoceti: Delphinidae) produce tonal whistles, the structure and function of which have been fairly well characterized. Less is known about the evolutionary origins of delphinid whistles, including basic information about vocal structure in sister taxa such as the Platanistidae river dolphins. Here we characterize vocalizations of the Amazon River dolphin (Inia geoffrensis), for which whistles have been reported but not well documented. We studied Inia at the Mamirauá Sustainable Development Reserve in central Brazilian Amazônia. During 480 5‐min blocks (over 5 weeks) we monitored and recorded vocalizations, noted group size and activity, and tallied frequencies of breathing and pre‐diving surfaces. Overall, Inia vocal output correlated positively with pre‐diving surfaces, suggesting that vocalizations are associated with feeding. Acoustic analyses revealed Inia vocalizations to be structurally distinct from typical delphinid whistles, including those of the delphinid Sotalia fluviatilis recorded at our field site. These data support the hypothesis that whistles are a recently derived vocalization unique to the Delphinidae.     

P‐15COMPARISON OF RESULTS FOR A NON‐GYNAECOLOGICAL CYTOLOGY EQA SCHEME

The problems encountered with a glass slide circulation are legion but timely circulation is a major problem and is an inherent deficiency of our Non‐gynaecological EQA scheme. This applies not only to consultants but also to specialist registrars (SpRs) and technical staff that are not formally included in the circulation list. In 2005 only 7 technical staff and 4 out of 47 SpRs took part on a formal basis, their participation being dependant on access to slides during their cytology attachment. The results for the 2005 circulation have been analysed and despite the small numbers of participating technical staff and SpRs their answers concur with the consultant body. To address the issues of timeliness and circulation problems a pilot teaching set has been developed by SlidePath into a virtual microscope web based circulation and sent to all SpRs in our region. They have recorded their answers and been given immediate access to the consensus consultant opinion with illustrations of follow up histology. A questionnaire was completed to evaluate the scheme. The facility of immediate feedback of consultant consensus is particularly pertinent to the educational element of the scheme and use of virtual microscopy addresses the issue of timely circulation. If further funding was made available technical staff could also be given the opportunity to try this web‐based circulation.     

Nitric Oxide Alleviates Submergence-Induced Maize Seedling Root Tip Cell Death

Journal of Plant Growth Regulation - Submergence results in submergence-induced hypoxia in plants. Hypoxia sensing and signaling in the root, as a main organ sensing hypoxic stress, play critical...     

The regulation of lactate dehydrogenase activity in soy-bean seedlings

An electrophoretically homogeneous lactate dehydrogenase was isolated from soybean seedlings, the specific activity of which was approximately 1800 times higher than the crude extract. From the dependence of the rate of reaction catalyzed by lactate dehydrogenase on substrate concentration, Michaelis constants and Hill coefficients were determined for four natural substrates,i.e. lactate, pyruvate, NAD and NADH. The enzyme from soy-bean plants is non-competitively inhibited by oxalate and mesoxalate,i.e. by the compounds analogous to the substrate. At pyruvate concentrations above 0.8 mM, the rate of reaction catalyzed by lactate dehydrogenase from soy-bean plants decreases, fructose diphosphate and ATP function as inhibitors as well. The inhibition by ATP is pH dependent, which seems to be of importance for the regulation of enzyme activityin vivo.     

Heterogeneity of mutations in the uroporphyrinogen III synthase gene in congenital erythropoietic porphyria

Summary Congenital erythropoietic porphyria (CEP) or Günther's disease is an inborn error of heme biosynthesis transmitted as an autosomal recessive trait and characterized by a profound deficiency of uroporphyrinogen III synthase (UROIIIS) activity. We have previously described two missense mutations in the UROIIIS gene, confirming that the primary defect responsible for CEP is a structural alteration of this gene. We have extended our work to 5 additional unrelated families. Two new point mutations, a deletion and an insertion have been found in the messenger RNA. Our study shows that a molecular heterogeneity of the mutations exists in Günther's disease. One mutation (C73R), however, appears to be more frequent than the others. Finally, the different normal and mutated proteins have been expressed in Escherichia coli to determine the consequence of the mutations on the enzyme activity.     

Analysis of a ribosomal RNA operon in the actinomycete Frankia.

The organisation of ribosomal RNA-encoding (rrn) genes has been studied in Frankia sp. strain ORS020606. The two rrn clusters present in Frankia strain ORS020606 were isolated from genomic banks in phage lambda EMBL3 by hybridization with oligodeoxyribonucleotide probes. The 5'-3' gene order is the usual one for bacteria: 16S-23S-5S. The two clusters are not distinguishable by restriction enzyme mapping inside the coding section, but vary considerably outside it. Sequencing showed that the 16S-rRNA-encoding gene of ORS020606 is very closely related to that of another Alnus-infective Frankia strain (Ag45/Mut15) and highly homologous to corresponding genes of Streptomyces spp. Two possible promoter sequences were detected upstream from the 16S gene, while no tRNA-encoding gene was detected in the whole operon. Regions with a high proportion of divergence for the study of phylogenetic relationships within the genus were looked for and found in the first intergenic spacer, in the 23S and in the 16S gene.     

The defense-related STH-2 gene product of potato shows race-specific accumulation after inoculation with low concentrations of Phytophthora infestans zoospores

The defense-related STH-2 gene is rapidly activated following infection or elicitor treatment of potato (Solanum tuberosum L.) tubers. However, its physiological or biochemical function is unknown. To study the STH-2 gene product and its accumulation during the defense response, we raised antibodies to a β-galactosidase-STH-2 fusion protein in Escherichia coli. The antiserum specifically recognized a protein of the predicted 17-kDa size in extracts of elicited tuber disks when analyzed by Western blot. In control extracts this band was not detected. The accumulation of STH-2 protein in response to incompatible and compatible zoospores of Phytophthora infestans (Mont.) de Bary depended on the inoculum density applied. Whereas a low concentration of spores induced accumulation of STH-2 protein faster in the incompatible than the compatible interaction, this difference in timing was less pronounced at higher inoculum densities. Inoculation with a high concentration of compatible spores also resulted in the disappearance of STH-2 protein late during the infection. In both control and induced tuber tissue the antibody strongly reacted with an unknown protein of 18 kDa. This protein was present constitutively in tubers, but in leaves its accumulation was stimulated by inoculation with P. infestans.