Multiplex PCB-based electrochemical detection of cancer biomarkers using MLPA-barcode approach.

Asymmetric multiplex ligation-dependent probe amplification (MLPA) was developed for the amplification of seven breast cancer related mRNA markers and the MLPA products were electrochemically detected via hybridization. Seven breast cancer genetic markers were amplified by means of the MLPA reaction, which allows for multiplex amplification of multiple targets with a single primer pair. Novel synthetic MLPA probes were designed to include a unique barcode sequence in each amplified gene. Capture probes complementary to each of the barcode sequences were immobilized on each electrode of a low-cost electrode microarray manufactured on standard printed circuit board (PCB) substrates. The functionalised electrodes were exposed to the single-stranded MLPA products and following hybridization, a horseradish peroxidase (HRP)-labelled DNA secondary probe complementary to the amplified strand completed the genocomplex, which was electrochemically detected following substrate addition. The electrode arrays fabricated using PCB technology exhibited an excellent electrochemical performance, equivalent to planar photolithographically-fabricated gold electrodes, but at a vastly reduced cost (>50 times lower per array). The optimised system was demonstrated to be highly specific with negligible cross-reactivity allowing the simultaneous detection of the seven mRNA markers, with limits of detections as low as 25pM. This approach provides a novel strategy for the genetic profiling of tumour cells via integrated "amplification-to-detection".

Diverse glial cell line-derived neurotrophic factor (GDNF) support between mania and schizophrenia: a comparative study in four major psychiatric disorders.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) have essential roles in synaptic plasticity which is involved in pathogenesis and treatment of psychiatric disorders. However, it is not clear whether they act simultaneously during illness states in major psychiatric disorders. METHODS: BDNF and GDNF serum levels were measured concomitantly by enzyme-linked immunosorbent assay (ELISA) method in 171 patients diagnosed with schizophrenia (n=33), bipolar disorder-manic episode (n=39), bipolar/unipolar depression (n=64, 24/40) and obsessive-compulsive disorder (n=35) according to DSM-IV, and 78 healthy volunteers. SCID-I and SCID non-patient version were used for clinical evaluation of the patients and healthy volunteers, respectively. Correlations between the two trophic factor levels, and illness severity scores, duration of illness and medication dosages were studied across different illnesses. RESULTS: While patients had equally lower BDNF levels in all diagnoses, GDNF levels were significantly higher in mania and lower in schizophrenia compared to healthy controls. BDNF levels were negatively correlated to illness severity scores in affective episodes (mania and depression). Longer duration of illness (>5 years) had an impact on lower GDNF levels in schizophrenia. BDNF levels and antipsychotic drug dosages in schizophrenia, and GDNF levels and antidepressant drug dosages in obsessive-compulsive disorder were positively correlated. CONCLUSION: Our data confirmed the evidence of equally deficient neuronal support by BDNF in all major psychiatric illnesses, but suggested a diverse glial functioning between schizophrenia and mania.

Is awareness of its risk enough to stop people from smoking?

A questionnaire to elicit information about smoking habits and knowledge of the risks of smoking was administered to 100 students (53 men and 47 women) in the graduating class of 1993 at the Cerrahpasa Medical School of Istanbul. Forty-three percent of the men and 27% of the women students were smokers. All but one of the 100 students were aware that smoking is a risk factor for both lung and laryngeal cancers, and 44% of the smokers believed that cessation of smoking by the smoking population could decrease the incidence of lung cancers to less than half of its present level. These data suggest that awareness of the risks of smoking is not enough to motivate smokers to quit, even when they are young physicians. Of the nonsmokers, 87.5% indicated that they would attempt to restrain their younger siblings from smoking, whereas the corresponding figure for smokers was 58.3%. The smokers and the nonsmokers answered two of the questions on the questionnaire significantly differently. Thirty-six percent of the mothers of the nonsmokers and 31% of their siblings were also smokers, whereas the corresponding figures for the nonsmokers were 18% and 13% (half of the fathers in both groups smoked). Thus, family and the environment appear to influence smoking behavior. Successful modification of smoking habits will necessitate more education of the general public.

Adapting undergraduate preclinical courses to changes in clinical applications.

The availability of new technologic tools has greatly changed differential diagnosis. To assess the importance of these tools in current clinical practice, the authors determined the frequencies of use of new imaging methods in diagnosis, staging, and follow-up in 71 oncology cases. The new methods were found to have replaced traditional diagnostic procedures to a substantial extent. To familiarize medical students with the new techniques, lectures on sectional anatomy given by radiologists were integrated into traditional anatomy courses for a group of 50 students. Two years later, after their initial exposure to clinical practice, the 42 students remaining in the group answered a questionnaire regarding the usefulness of the sectional anatomy segment of their anatomy training. Of these 42 students, 14 rated the sectional anatomy exposure "very helpful" to comprehension in the clinical internship and 21 rated it "helpful." The students suggested that the program be reinforced by an integrated textbook. This preliminary study suggests that basic preclinical courses should be modulated to reflect new methods that come into routine use in clinical practice.