The effect of different substrates on morphological characteristics of acclimatized Bowiea volubilis

Before acclimatization of Bowiea volubilis, in vitro propagated bulbs were cleaned and separated into four sizes (from 6 to 15 mm). We formed a total of 10 groups with 30-30 individuals, distributing the sizes evenly. Four types of substrate (peat, perlite, coconut fiber, sand) and their mixtures of 50-50% were used. Previously we examined three parameters: length, diameter and weight of the bulbs; later the weight of the successfully acclimatized plants, the number and length of roots and leaves were measured. The acclimatization was done in one of the greenhouses of the Buda Arboretum, where the plants were grown with fleece covering till one month, irrigated every three days, without the use of nutrient replenishment and artificial lighting. After 3 month period, survived plants developed effectively on peat + perlite, sand + perlite and sand + peat mixtures. In these cases, we achieved the largest increases in roots, green parts, bulbs and total weight

Consumer acceptance of food nanotechnology

Today, food industry developments are driven by two megatrends: global warming and the need to address nutrition-related adverse health consequences (diseases of civilization, obesity, hunger and an aging society). As a result, consumer preferences have also changed, as „everyday” needs such as the acceptable price, pleasant taste and safe consumption of foods, as well as for the food to satisfy physiological needs, have become essential requirements and do not represent a demonstrable market advantage. The market presence of a product is expected to be successful if, in addition to the above, its ingredients and physiological effects can be demonstrated to improve or increase consumer well-being, their state of health or physical performance. One of the fastest growing disciplines today is nanotechnology, which has many applications in the food industry. Even though this technology brings unprecedented benefits to consumers and may be able to solve many global problems, nanofoods also carry many risks and dangers. Although nanotechnology is still unknown to many, the willingness to buy is very high among those interviewed if the technology improves some of the properties of the food. Based on their attitudes, consumers can be divided into two well-distinguishable groups: those who see potential advantages and disadvantages in radically different ways

Development of a collagen gel sandwich hepatocyte bioreactor for detecting hepatotoxicity of drugs and chemicals

Thesis (Ph. D.)--Massachusetts Institute of Technology, Biological Engineering Division, 2004.Includes bibliographical references (leaves 124-140).Understanding the hepatotoxicity of drugs and chemicals is essential for progress in academic research, medical science and in the development of new pharmaceuticals. Studying hepatotoxicity in vitro is a challenging task because hepatocytes, the metabolically active cells of the liver, are very difficult to maintain in culture. After just 24 hours, the cells detach from the plate and die, and even if they survive they usually do not express the metabolic functions which they have in vivo. It has been observed by others that culturing hepatocytes between two layers of collagen type I maintains in vivo-like morphology and also many drug metabolizing enzymes for weeks. In spite of the research examining drug metabolism in collagen sandwiches, there are very few studies evaluating this system for investigating hepatotoxicity. We cultured primary rat hepatocytes in the collagen sandwich configuration and our goal was to optimize this system for long-term studies and to examine toxicity of a variety of hepatotoxins. By measuring secretions of urea and albumin, and P4501A activity, we determined the optimal cell density to be 50,000 cells/cm2. We also evaluated the need for epidermal growth factor (EGF) in our cultures, by comparing urea and albumin secretions in cultures grown with and without EGF. The cultures without EGF had significantly less secretion of both urea and albumin just two days after plating. Therefore, we decided to include EGF in the medium. The toxins we examined were aflatoxin B1, acetaminophen, carbon tetrachloride, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), methyl methane sulfonate (MMS), cadmium, vinyl acetate and dimethylformamide (DMF). The cells were sensitive to aflatoxin B1, MMS, MNNG and cadmium. However, they were(cont.) immune to acetaminophen, carbon tetrachloride, vinyl acetate and DMF. Our Western Blots showed that CYP1A, 2B and 3A were maintained in the culture for a week, but CYP2E1 was lost gradually over time. CYP2E1 is also the primary metabolic enzyme for acetaminophen, carbon tetrachloride and DMF. Thus, it is possible that the lack of toxicity is due to the loss of the enzyme responsible for the metabolism of these compounds. Immunity to vinyl acetate suggests that carboxylesterase is also lost in culture, since this enzyme is the one which converts vinyl acetate to acetaldehyde. The metabolism of acetaminophen was also examined with liquid chromatography and mass spectrometry. Liquid chromatography showed that acetaminophen is metabolized primarily to the sulfate and glucuronide metabolites. In order to investigate whether the glutathione adduct was formed, we synthesized the adduct and determined its retention time with liquid chromatography and its fragmentation pattern with mass spectrometry. We isolated the fraction with the same retention time from the medium of acetaminophen-treated cells, and showed that it contains a peak with the same mass to charge ratio and fragmentation pattern as the glutathione adduct. We also examined the conditioned medium from the hepatocytes to investigate the secreted protein profile, which could potentially be used to find toxicity biomarkers. We were able to remove most of the albumin from the medium using an immuno-affinity column containing anti-albumin antibodies bound to protein A-agarose beads ...by Dóra Farkas.Ph.D

Pneumonia diagnosis in childhood and incidence of leukaemia, lymphoma and brain cancer:a Danish nationwide cohort study

ObjectivesThere is an ongoing debate on the possible association between infections in early childhood and subsequent cancer risk, but it remains unclear if a hospital admission for infection is associated with risk of childhood cancer diagnosis. We examined if a hospital-based diagnosis of pneumonia was a clinical marker of the three most common childhood cancers.DesignPopulation-based cohort study.SettingDenmark, hospital diagnoses, 1994–2013.MethodsUsing national health registries, we compared the observed incidence of leukaemia, lymphoma and brain cancer among 83 935 children with a hospital-based pneumonia diagnosis with that expected among children in the general population. We calculated absolute cancer risks and standardised incidence ratios (SIRs) as a measure of relative risk.ResultsThe cancer SIRs were substantially increased during the first 6 months of follow-up; lymphoid leukaemia: 6.2 (95% CI 3.5 to 10.3); myeloid leukaemia: 14.8 (95% CI 6.0 to 30.6); Hodgkin’s lymphoma: 60.8 (95% CI 26.2 to 120), non-Hodgkin’s lymphoma: 15.9 (95% CI 5.2 to 37.2) and brain cancer: 4.4 (95% CI 1.9 to 8.7). The 6-month absolute risks of leukaemia, lymphoma and brain cancer were all low, reaching 0.05% when combined. An increased risk persisted beyond 5 years for non-Hodgkin’s lymphoma and brain cancer. However, the 5-year absolute cancer risk was 0.14%.ConclusionsThe short-term incidence of leukaemia, lymphoma and brain cancer was higher than expected and persisted beyond 5 years for non-Hodgkin’s lymphoma and brain cancer. However, the absolute cancer risk was low.</jats:sec

Az egészséges táplálkozás fogyasztói megítélése: egy feltáró kutatás eredményei

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Az élelmiszeripari nanotechnológia fogyasztói elfogadása

Napjainkban az élelmiszeripari fejlesztéseket jellemzően két megatrend irányítja: a globális felmelegedés és a táplálkozással szorosan összefüggő hátrányos egészségügyi következmények (civilizációs betegségek, túlsúly, éhezés, elöregedő társadalom) kiküszöbölésének igénye. Ennek következtében a fogyasztói preferenciák is módosultak, hiszen az olyan „mindennapos” igények, mint az élelmiszerek elfogadható ára, kellemes íze és biztonságos fogyaszthatósága, továbbá az, hogy egy élelmiszer pusztán fiziológiai szükségleteket elégítsen ki, napjainkra alapvető követelménnyé változtak, és nem jelentenek kimutatható piaci előnyt. Egy termék piaci szereplése várhatóan akkor lesz sikeres, ha a fentieken túl összetevői és élettani hatásai a fogyasztó közérzetét, egészségi állapotát, fizikai teljesítőképességét bizonyíthatóan növelik. Az egyik legnagyobb iramban fejlődő tudományterület ma a nanotechnológia, amelynek számos alkalmazása létezik az élelmiszeriparban. Annak ellenére, hogy ez a technológia eddig nem tapasztalt előnyökhöz juttatja a fogyasztókat és számos globális problémára jelenthet megoldást, a nanoélelmiszerek számos kockázatot és veszélyt is hordoznak magukban. Habár a nanotechnológia még sokak számára ismeretlen, a megkérdezettek körében a vásárlási hajlandóság igen magas, ha a technológia révén az élelmiszer valamely tulajdonsága javul. A fogyasztókat attitűdjük alapján két jól elkülöníthető csoportra lehet osztani: azokra, akik a lehetséges előnyöket és hátrányokat egymástól gyökeresen különböző módon látják