Potential isotopic and chemical markers for characterising organic fruits

Several isotopic (¹³C/¹²C, ¹⁵N/¹⁴N, ¹⁸O/¹⁶O, ²H/¹H, ³⁴S/³²S) and chemical–physical parameters (pH, fruit weight, juice yield, titratable acidity, total soluble solids, skin resistance, flesh firmness, colorimetric characteristics, weight loss after harvesting, antioxidant activity, earliness index, total nitrogen, ascorbic acid, synephrine, anthocyanins and polyphenols, citric acid, malic acid, sucrose, glucose and fructose content) were investigated as potential markers of organically cultivated oranges, clementines, strawberries and peaches produced in Italy between 2006 and 2008, in experimental fields and in certified farms. The ratio ¹⁵N/¹⁴N, ascorbic acid and total soluble solids were shown to be the most significant variables for distinguishing between organically and conventionally cultivated fruits. It was not possible to define general threshold limits typical of organic fruits because these parameters are influenced also by fruit specie, cultivar, year and site of production. Combining isotopic and chemical markers a good discrimination between organic and conventional fruits of different species was achieved.     

Multielement stable isotope ratios (H,C, N,S) of honey from different European regions

The aim of this study as a part of the food traceability project “TRACE” funded by the EU was to investigate if honeys produced in regions with different climatic and geological characteristics could be discriminated on the basis of the isotopic data. The hydrogen, carbon, nitrogen and sulphur stable isotope ratios of 516 authentic honeys from 20 European regions are presented and discussed. As honey contains only small quantities of nitrogen and sulphur, the honey protein was precipitated in order to obtain measurable amounts of these elements. The mean hydrogen isotopic ratios of the honey protein were found to be significantly correlated with the mean hydrogen isotopic ratios of precipitation and groundwater in the production regions. Carbon isotopic ratios were influenced by climate. The sulphur stable isotope composition is clearly influenced by geographical location (sea spray effect) and surface geology of the production regions. The results show that the stable isotope ratios of the four bio-elements carbon, nitrogen, hydrogen and sulphur in honey protein can be applied to verify the origin of honey. Carbon and sulphur were identified by canonical discriminant analysis as providing the maximum discrimination between honey samples. For seven regions the percentage of correct classified samples is greater than 70%. It was concluded that the methodology in its current state can be used to provide reliable origin information.     

Referate

Ohne Zusammenfassung     

Abnormal differentiation of thymocytes induced by free cyclosporine is avoided when cyclosporine bound to N-(2-hydroxypropyl)methacrylamide copolymer carrier is used

BACKGROUND: The side effects of cyclosporine (CsA)-including nephrotoxicity and abnormal differentiation of thymocytes developing in the thymus-can be decreased or even avoided using targeted conjugates of CsA, where both targeting moiety and drug are bound to water-soluble polymeric carrier based on N-(2-hydroxypropyl) methacrylamide (HPMA). METHODS: Irradiated, syngeneic bone marrow transplanted-mice (BALB/c and A/Ph) were treated intraperitoneally for 4 weeks with 20 mg/kg of free CsA, HPMA-conjugated CsA, or antibody-targeted HPMA-bound CsA. Immunohistology of the thymus was performed together with two-color flow cytometry to detect the effect of different forms of CsA on individual thymocyte subpopulations. RESULTS:. We have shown that free CsA strongly abrogated T-cell development. The appearance of mature thymocytes expressing CD3(high) is almost completely inhibited (1.8%) after free CsA treatment, whereas these cells are well detectable in controls (22%) and HPMA polymer-bound CsA-treated animals (19%). Immunohistological studies have shown acellular rests of the medulla after free CsA treatment, whereas well-stained medullary thymocytes were detected in controls and after exposure to antibody-targeted HPMA. conjugated CsA. CONCLUSIONS: HPMA-conjugates of CsA are generally more specific in their targeting to T lymphocytes. It was found that nonspecific binding of CsA to erythrocytes and plasma lipoproteins is significantly reduced using anti-CD3 targeted, HPMA polymer-bound CsA In addition, the entry of these macromolecules into the thymus is limited-probably due to the blood-thymus barrier-and HPMA conjugates of CsA, unlike free drug, do not abrogate T-cell development in bone marrow transplanted mice.     

Survival from pulmonary infection with Cunninghamella bertholletiae: case report and review of the literature

Reports on the relationship between diabetes and hearing loss have been controversial. The present study examined this relationship in 1,740 Mexican American adults using data from the Hispanic Health and Nutrition Examination Survey. Hearing threshold levels were obtained for each participant at the following frequencies: 500, 1000, 2000, and 4000 Hertz (Hz). The thresholds from the worse hearing ear were used in the analyses. Diabetes and insulin use were assessed by self-report. The mean crude hearing thresholds in diabetics were significantly higher than in non-diabetics at each of the four frequencies. However, after adjustment for age, gender, and socioeconomic status, diabetics had a significantly higher mean threshold than non-diabetics only at 500 Hz (mean difference +/- SE: 2.8 +/- 1.2, p = 0.04). Diabetics who were not using insulin had significantly higher thresholds than those who were using insulin at 2000 (mean difference +/- SE: 5.6 +/- 2.6, p = 0.03) and 4000 Hz (7.7 +/- 3.3, p = 0.02). Also, at 4000 Hz, insulin users had a significantly lower mean threshold than non-diabetics (mean difference +/- SE: -4.9 +/- 1.6, p = 0.02). Our data suggest that associations between diabetes and decreased hearing acuity in the higher frequencies are present only amongst diabetic Mexican-Americans who do not use insulin.     

Application of longitudinal magnification effect to magnification stereoscopic angiography: a new method of cerebral angiography

A new method of stereoscopic cerebral angiography has been developed which employs 2X radiographic magnification. In order to obtain the same depth perception in the object as with conventional contact stereoscopic angiography, one can made the x-ray exposures at two focal spot positions which are separated by only 1 inch (2.5 cm), whereas the contact technique requires a separation of 4 inches (10 cm). The smaller distance is possible because, with 2X magnification, the transverse detail in the object is magnified by a factor of two, but the longitudinal detail, which is related to the stereo effect, is magnified by a factor of four, due to the longitudinal magnification effect. The small focal spot separation results in advantages such as improved stereoscopic image detail, better image quality, and low radiation exposure to the patient.     

Simulation and Optimization of Regular Motions of a Tube-Crawling Robot

The paper is devoted to issues associated with thetube-crawling robot designed at the Munich Technical University. Wefocus on the simulation of the robot dynamics and the optimization ofstructural parameters of the machine and characteristics of its gait.The mathematical model of the eight-legged tube-crawling robotperforming regular motions at a constant speed along a cylindrical tubeis described. On the basis of this model we investigate the influence ofthe machine design and gait parameters on the robot velocity and findtheir optimal values providing the maximal velocity under givenparametric and drive constraints. Numerical examples are presented anddiscussed.     

In vitro attachment of human gingival fibroblasts to endosseous implant materials

In recent years, the focus of dental implant research has been the nature of the bone-implant interface associated with osseointegration, yet the transgingival portion of endosseous dental implants has received little attention. The purpose of this study was to determine the attachment of human gingival fibroblasts to three different implant materials: commercially pure titanium, non-porous hydroxyapatite, and porous hydroxyapatite. Cell attachment was quantified by radiolabeling gingival fibroblasts with tritiated thymidine and counting attached cells by liquid scintillation following incubation for periods of 20, 40, and 60 minutes. Additional studies coating implant surfaces with fibronectin were also performed. The nature of the implant material itself appeared to affect the number of attached cells. Determined on a surface area basis, fibroblast attachment was greatest to titanium followed by non-porous hydroxyapatite. Porous hydroxyapatite demonstrated the least amount of fibroblast attachment. When incubated with fibronectin at a concentration of 50 micrograms/ml, no increase in the number of cells attached to the various implant materials was observed. A small but statistically significant increase in the number of fibroblasts attached to porous hydroxyapatite at 40 minutes was observed when implant materials were pre-treated with fibronectin.     

Contents of volume 70 (1994/1995)

Contents of volume 70 (1994/1995)