Skeletal muscle fatigue and physical endurance of young and old mice

In order to evaluate the role played by muscular and extramuscular factors in the development of fatigue in old age, the time course of fatigue in isolated skeletal muscles and spontaneous motor activity and endurance of whole animals were monitored using young (3-6 months) and old (34-36 months) CF57BL/6J mice. The isolated extensor digitorum longus (EDL) and soleus muscles from old mice had smaller (P < 0.05) mass and developed lower (P < 0.02) maximal tetanic tension at 100-Hz stimulation than the muscles of young mice. During stimulation at 30 Hz every 2.5 s, a 50% decline in original tetanic tension occurred by 109 s in young EDL and 129 s in old EDL, but by 482 s in young soleus and 1134 s (projected) in old soleus, indicating more (P < 0.05) resistance to fatigue in old than young soleus. However, the old mice showed significantly fewer (P < 0.002) spontaneous ambulatory movements than the young mice. On a treadmill with a belt speed of 10 m/min at an inclination of 0 degrees, the old mice could only run for 22 min compared to 39 min ran by young mice (P < 0.02). They took more rest periods (P< 0.02) than the young mice. In a quantitative swimming monitor, the old mice swam for a shorter (P < 0.05) time than young mice (20.4 min compared to 28.6 min). Integrated swimming activity at 20 min was smaller (P < 0.05) in old mice than in young mice (413 g/s compared to 628 g/s). Hence increased fatigue in old age is not caused by impairment of processes within the muscles, but by impairment of central or extramuscular processes.     

Assurance of compliance within the production chain of food contact materials by good manufacturing practice and documentation – Part 1: Legal background in Europe and compliance challenges

EU legislation requires that compliance of food contact materials with the legal requirements must be assured at each stage of the supply chain. The process has to respect good manufacturing practice (GMP), and for this purpose GMP is defined as the tool to ensure compliance. Communication through the production chain is an essential part, clarifying which work has been done and what is delegated to subsequent business stages.At early production stages it is often not possible to conclude on compliance of the final material or article. For instance, migration can only be measured from the final material and compliance of a non-regulated substance may be uncertain at an early stage. In fact, assuming responsibility either means concluding compliance with justification in the supporting documentation or specifying the work to be done at later stages in the documentation accompanying the product.This paper interprets existing legislation and indicates difficulties regarding the needs of food business operators and the role of the enforcement authorities.     

Transfer factor therapy in a patient with anergic pulmonary tuberculosis

Report on a patient suffering from severe, relapsing pulmonary tuberculosis showing progressive clinical deterioration accompanied by the appearance of cutaneous anergy to tuberculin. In addition, the sputum cultures showed growth of Mycobacterium intracellulare. During therapy with transferfactorZurich there was a slow but impressive clinical improvement, the skin reactivity to tuberculin was reconstitued and the sputum cultures became negative. The radiological findings remained unchanged.     

Food contamination by hydrocarbons from lubricating oils and release agents: determination by coupled LC-GC.

We have found that many foods are contaminated with mineral oil products used as lubricating oils/greases or as release agents. The mineral oil base of such products usually consists of branched alkanes ranging between C17 and C35. It forms a broad 'hump' of unresolved compounds in the gas chromatogram. Examples of such products are described; contamination is shown for a sample of bread, bonbon, and chocolate, respectively. The results suggest that contamination of foodstuffs with mineral oils does not always receive the required attention. However, there is also a lack of guidelines.     

Inability of unpacked gooseneck liners to stop the sample liquid after injection with band formation (fast autosampler) into hot GC injectors

With the introduction of the fast autosampler, the rules on how to perform splitless injection should have been revisited: the fast autosampler releases the sample liquid as a band that is no longer nebulized by solvent vapors as in previous injection techniques. In empty gooseneck liners, the sample liquid is shot to the bottom of the injector and jumps around in a largely uncontrolled manner. Visual experiments showed that the liquid is partially rejected. Another portion passes by the column inlet into the column attachment region, while the last part may directly enter the column. The impact on chromatography was investigated by using a mixture of n-alkanes: the higher boiling components passing by the column entrance into the zone of the column attachment were largely lost, i.e., were discriminated against the volatile components. It was concluded that empty gooseneck liners are not suitable for injection by fast autosamplers.     

Contamination of vegetable oils marketed in Italy by phthalic acid esters

More than 90% of the phthalic acid esters (PAEs) produced in Europe is used to plasticize polyvinyl chloride (PVC). Animal studies have shown that some PAEs can damage the liver and interfere with the endocrine system, whereas data on the toxic effects on humans are inconsistent. For the general population, the diet is believed to be the main source of PAEs. Food can be contaminated from environmental pollution, industrial food processing (PVC tubing) and certain storage containers. The present study evaluates the contamination levels of the four main PAEs named Di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), diisobutyl phthalate (DIBP), diisononyl phthalate (DINP), in 172 samples of vegetable oils marketed in Italy. Diluted oils were directly analysed by GC–MS. PAEs concentrations in vegetable oils were lower than those reported in other studies. Olive-derived oils showed the highest levels. Considering their high consumption in Italy, this finding is significant and some hypotheses on environmental or technological causes have been made. In the case of extravirgin olive oil, the higher levels of PAEs can be ascribed to the absence of the refining process since it has been verified that this technological treatment partially decontaminates the final product while for olive and olive pomace oils, both refined oils, the reasons for a higher contamination are less clear. Probably, a different plant uptake of PAEs from the air, water and soil could give account of this finding. Finally, the percentage Italian intake of PAEs due to the various types of vegetable oils analysed has been calculated.     

Legal limit for reducing sugars in prefabricates targeting 50 μg/kg acrylamide in French fries

A legal limit for the reducing sugars in the prefabricates for French fries is a simple and efficient measure to reduce the exposure to acrylamide from the predominant source for many consumers. The acrylamide content of French fries of comparable crispiness is approximately proportional to the concentration of the reducing sugars glucose and fructose in the potato sticks. On average, optimally prepared French fries from prefabricates with a (moderately low) sugar content of 0.3 g/kg contained 32 g/kg acrylamide. With 0.15 g/kg reducing sugar even severe overfrying at 170 °C only resulted in 90 g/kg acrylamide, i.e. a low sugar content keeps acrylamide low even under inappropriate frying conditions. In the prefabricates, the sugar content is about 10% lower than in the raw potato (resulting from the effects of blanching and prefrying). It is similar to that in the finished French fries, which enables one to distinguish whether a high acrylamide content in French fries results from high sugars in the raw material or unsuitable frying conditions. An average concentration of 50 g/kg acrylamide in French fries could be targeted by limiting the reducing sugars in the prefabricates to 0.7 g/kg and the frying temperature to 170 °C. Even considerable overfrying in terms of duration can be tolerated then.     

Food contamination by hydrocarbons from packaging materials determined by coupled LC-GC

Summary Paraffins from raw extracts of foods and packing materials were isolated by LC and directly transferred to GC, applying concurrent eluent evaporation and a loop-type interface. Paraffins from various packing materials have been characterized: sisal bags, cardboard boxes, plastic films, wax-coated paper and cardboard as well as paraffin coatings. Important food contamination was found for sisal bags, cardboard boxes, and waxcoated paper/cardboard. Contamination by paraffin coatings on cheese was surprisingly small.

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Verunreinigung von Lebensmitteln mit Kohlenwasserstoffen aus Verpackungsmaterialien und Nachweis mittels gekoppelter LC-GC

Zusammenfassung Die Paraffinfraktion aus rohen Extrakten von Lebensmitteln und Verpackungsmaterialen wurde mittels LC isoliert und durch simultane Abdampfung direkt in den GC transferiert. Typische Paraffinmuster verschiedener Verpackungsmaterialien (Sisalsäcke, Karton, Plastikfolien, Wachspapier und Paraffin) werden charakterisiert. Starke Verunreinigungen der Lebensmittel wurden bei Sisalsäcken, Kartonschachteln, Wachspapieren und Wachskarton gefunden. Die Verunreinigung von Käse durch eine Schicht Paraffin war vergleichbar gering.

     

Barriers Against the Migration from Recycled Paperboard into Food: Measuring Efficiency by Surrogate Components

Functional barriers might soon be required by certain countries to protect foods against contaminants from recycled paperboard used as primary packaging or transport boxes. Such a requirement presupposes a method for specifying and checking the efficiency of a barrier. The proposed method uses four surrogate compounds of similar boiling point covering a broad range of polarities: n‐heptadecane, 4‐methyl benzophenone, dipropyl phthalate and triethyl citrate. They are applied to a donor paper that is attached to one side of the barrier (plastic film or lined paperboard). On the other side, a silicone paper absorbs the material broken through the barrier. Periodically, pieces of this silicone paper are extracted and analysed by gas chromatography and flame ionization detection. The performance of the method was tested on various barrier materials of modest efficiency using a mixture of 12 test substances, varying the molecular mass for a given substance type of which a member was finally selected. Large differences in selectivity were observed, i.e. properties of a given barrier for different types of components, but also for varied molecular mass/volatility vary widely. Copyright © 2014 John Wiley & Sons, Ltd.     

Immune responses, and autoimmune outcome, during virus infection of the central nervous system

A combined role of a virus infection of the central nervous system (CNS) and an autoimmune response to myelin basic protein (MBP), an autoantigen of the CNS, is suggested in the pathogenesis of multiple sclerosis (MS). SJL mice are highly susceptible while B6 mice are less susceptible to the induction of experimental autoimmune encephalomyelitis (EAE), the autoimmune model of MS. Peripheral inoculation of Semliki forest virus (SFV) into SJL and B6 mice resulted in: (1) Higher viral titers, more severe clinical disease, and hence a stronger nonspecific and SFV-specific lymphoproliferation, and production of IFN-gamma and TNF/LT was observed by splenocytes (SPL) of B6 than by those of SJL mice, on Day 7 postinfection. (2) Following viral clearance, however, proliferation to SFV, and to MBP, and the production of IFN-gamma and TNF/LT by SPL of SFV-infected SJL mice were significantly higher, while the production of TGF-beta was significantly lower than by those of B6 mice. In conclusion, the immune responses to SFV, and to MBP, which were triggered by SFV infection were significantly higher and more prolonged in the SPL of SJL mice, the EAE-susceptible mice, than by those of B6 mice after the infection was cleared.