[Increasing incidence of thin melanomas in the Netherlands]. / Stijgende incidentie van dunne melanomen in Nederland.

OBJECTIVE: In the Netherlands the incidence of melanomas in situ and thin invasive melanomas is rising more quickly than that of thicker melanomas. Our aim was to gain insight into this increase and to test the hypothesis that it is attributable to over-diagnosis. METHOD: We analysed data taken from the Netherlands Cancer Registry on all primary melanomas diagnosed between 1994 and 2010. We assessed trends in European standardised rates (ESR) using joinpoint analysis, and expressed these trends as estimated annual percentage change (EAPC). Thin melanomas were subdivided into four subgroups. RESULTS: Between 1994 and 2010, 34 156 persons were diagnosed with melanoma in situ or thin invasive melanoma. The incidence of melanoma in situ doubled during this period, with an acceleration in incidence in men from 2004, and in women from 2007. In men the ESR of thin melanoma doubled, whereby the thinnest category (< 0.25 mm) rose more quickly, but not significant compared to the other Breslow thicknesses ≤ 1 mm. In women, the ESR of thin melanomas nearly doubled, with the exception of the thinnest melanoma. CONCLUSION: Between 1994 and 2010, the incidence of melanomas increased steadily. In part, this was a real rise as a result of increased exposure to ultraviolet rays. However, from 2006 the incidence of melanomas in situ and thin invasive melanomas in men has risen comparatively more quickly. This could point to over-diagnosis, but also to increased awareness, early detection, a diagnostic shift from benign to malignant lesions and changes in the Dutch health care system.

Effect of bath temperature on the properties of nanocrystalline ZnO thin films.

The nanocrystalline zinc oxide (ZnO) thin films have been prepared by chemical bath deposition (CBD) method from aqueous zinc nitrate solution at room temperature (25 degrees C) and at higher temperature (75 degrees C). The changes in structural, morphological and optical properties were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical absorption. The structural studies revealed that the film deposited at room temperature showed mixed phases of ZnO and Zn(OH)2 with wurtzite and orthorhombic crystal structure whereas at higher temperature, the deposited film is ZnO with wurtzite crystal structure. After air annealing at 400 degrees C, all the films converted into pure ZnO with wurtzite crystal structure. The films deposited at room temperature showed fibrous surface morphology with interconnected flakes while films deposited at higher temperature shows well-developed nano-rod morphology. Optical study shows that band gap energy (E(g)) of as-deposited thin films deposited at room temperature and at higher temperature are 3.81 and 3.4 eV, decreases up to 3.20 eV, after annealing treatment.

The impact of dermoscopy on the management of pigmented lesions in everyday clinical practice of general dermatologists: a prospective study.

BACKGROUND: Dermoscopy greatly improves the clinical diagnosis of pigmented lesions. Few studies have investigated, however, how dermoscopy is guiding management decisions in everyday clinical practice. In addition, most studies have been performed in the setting of dermoscopy experts working in pigmented lesion clinics. OBJECTIVES: To assess the impact of dermoscopy on clinical diagnosis and management decisions for pigmented lesions in everyday practice of general dermatologists. METHODS: We performed a prospective study in general dermatology clinics in community hospitals run by dermatologists with intermediate dermoscopy experience and expertise. Each clinician independently included suspicious lesions from consecutive patients. Pre- and postdermoscopy diagnoses and management decisions were recorded. Pathology was used as reference diagnosis. RESULTS: In total, 209 suspicious lesions were included in the study by 17 dermatologists. Fourteen lesions were histologically proven in situ or invasive malignant melanomas. Based on clinical diagnoses, dermoscopy improved sensitivity from 0.79 to 0.86 (P = 1.0). All 14 melanomas were intended to be excised based on naked eye examination alone, independent of dermoscopic evaluation. Specificity increased from 0.96 to 0.98 (P = 0.22). Dermoscopy resulted in a 9% reduction of the number of excisions. CONCLUSIONS: Dermoscopy reduced the number of excisions, but did not improve the detection of melanomas. Our results suggest that in everyday clinical practice of general dermatologists the main contribution of dermoscopy is a reduction of unnecessary excisions.

Modeling of the controlled expression of a harmful protein by a three-plasmid harboring system.

A genetically structured mathematical model was developed and used to evaluate the influence of molecular parameters involved in the expression of a harmful recombinant protein (SPA::EcoRI). The system consists of the controlled expression of the endonuclease EcoRI cloned in the plasmid pMTC48. The control is exerted by the lambda CI repressor expressed from the plasmid pRK248cIts. The deleterious effect of the activity of the enzyme EcoRI on the host DNA is prevented by the action of the EcoRI methylase that is expressed constitutively from a third plasmid, pEcoR4. The model includes molecular mechanisms involved in the regulation of the expression of these genes and is used to determine cultural conditions that maximize the production of the recombinant protein.

Flow-injection sandwich ELISA for bioprocess monitoring.

A fully automated flow-injection immunoassay based on sandwich enzyme-linked immunosorbent assay (ELISA) is described for the model system: protein G-sepharose, rabbit IgG and horseradish peroxidase (HRP)-labelled protein A. After injecting rabbit IgG and HRP-labelled protein A into a cartridge containing protein G-sepharose sequentially, a mixture of hydrogen peroxide and the redox indicator, 2.2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) is passed through the cartridge. The HRP-labelled protein A bound in the cartridge is directly proportional to the concentration of rabbit IgG. The colour variation of ABTS caused during the reaction between HRP and H202 in the cartridge is detected photometrically. The whole assay procedure is controlled and evaluated by a computer. Rabbit IgG and HRP-labelled protein A are also detected by a fluorometer, which is introduced into the flow system. In the flow-injection sandwich ELISA, the slope of the calibration curve is 0.4491 in the range of 0 and 300 microg ml(-1) rabbit IgG, while it is 0.1274 in the heterogeneous immunoassay. So the flow-injection sandwich ELISA system is found to be more sensitive than a heterogeneous immunoassay for the monitoring of the model protein.

Influence of the medium composition and plasmid combination on the growth of recombinant Escherichia coli JM109 and on the production of the fusion protein EcoRI::SPA.

Plasmid-free and plasmid-harbouring E. coli JM109 strains were investigated in shaken flasks, stirred tanks in batch and continuous operation. The shaken flask cultivations were performed in M9 minimal medium and in media with various protein supplements. The host hardly grows on M9 minimal medium as opposed to the plasmid-harbouring cells, which grow well on this medium. All of the investigated cells propagate well on protein-containing media. The influence of the combinations of repressor plasmid pRK248cI, the protection plasmid EcoR4 and the production plasmid pMTC48 were determined on the initial specific growth rate of the E. coli JM109 without gene expression, on the yield coefficient of cell growth, acetate concentration and acetate yield coefficient in the yeast extract-containing (HM) medium. The influence of various media on the induction of the gene expression were evaluated. In cultivation media with protein supplement, the growth rate and yield coefficient increased. The variation of the volumetric and specific beta-lactamase activities with the cultivation time were determined in a stirred tank reactor in HM medium. With increasing dilution rate the process performance decreased. Simple relationships exist between the substrate uptake rate and the specific growth rate of the continuous cultivated cells in M9 and HM media. The influence of the dilution rate on the cell mass concentration, colony forming units, acetate formation, yield coefficients of growth and acetate formation, substrate uptake rate, CO2 production rate, ammonium formation rate and beta-lactamase activity in M9 and HM media were determined as well. Carbon balances of the batch and continuous cultivations indicated high carbon recoveries. On account of the higher growth rate of plasmid-harbouring cells than than of the plasmid-free cells, the behaviour of the investigated plasmid-free and plasmid-harbouring E. coli JM109 cells deviates from the published properties of other plasmid-free and plasmid-harbouring E. coli cells.

Gene expression enhancement due to plasmid maintenance.

Analysis of the chromosomic beta-galactosidase activity in strains of Escherichia coli with and without plasmids indicated that plasmid maintenance enhances gene expression. Cyclic AMP (cAMP) determinations confirmed that the gene enhancement observed in strains carrying plasmids was due to a small increase in the intracellular concentration of cAMP. Also, cells carrying plasmids displayed higher specific glucose uptake rates than did cells without plasmids. The increases in the expression of beta-galactosidase and the glucose uptake rate suggest a cAMP-mediated release of the glucose effect due to plasmid maintenance. Our results suggested that this effect is independent of the host and type and number of plasmids.

Fed-batch cultivation of recombinant escherichia coli JM103 and production of the fusion protein SPA::EcoRI in a 60-L working volume airlift tower loop reactor.

SPA::EcoRI fusion protein was produced by Escherichia coli JM103 carrying the multicopy expression plasmid pMTC48, the multicopy repressor plasmid pRK248, and the multicopy protection plasmid pEcoR4 in a 60-L working volume airlift tower loop reactor on M9 minimal medium with glucose. Cell mass concentration, total cell count, number of colony-forming units, specific growth rate, yield coefficient, and metabolite (acetate, pyruvate, succinate, lactate, ethanol) concentrations were monitored during the growth phase and gene expression. Gene expression was induced by temperature shift or chemically by isopropyl-thiogalactosidase in the airlift tower loop reactor (ALTR) at constant cultivation time and in a small stirred tank reactor at different cultivation times. During induction, the cultivation medium was supplemented with concentrated Luria-Bertani (LB) medium. The intracellular enzyme activity was evaluated as a function of the time after the start of the induction. It was found that the reduction of the glucose concentration and increase of the dissolved oxygen concentration reduced the acetate produced and increased the intracellular enzyme activity.