Mechanical properties and decay resistance of wood-polymer composites prepared from fast growing species in Turkey

Some mechanical properties of wood-polymer composites from maritime pine (Pinus pinaster Ait.) and poplar (Populus x. euramericana cv. I-214) wood were investigated. Three different monomers; styrene (ST), methyl methacrylate (MMA) and styrene/methyl methacrylate (ST/MMA) mixture were used in preparation of wood-polymer composites (WPCs). Full-loading (FL), half-loading (HL) and quarter-loading (QL) were used as polymer content levels. Untreated pine and pine-polymer composite samples were tested in compression strength parallel to grain and static bending strength. WPCs mechanical properties increased compared to untreated wood. The polymer had greater effect on the strengths of the ST/MMA treated pine than on the ST and MMA treated pine samples. Increasing of the mechanical properties should improve the structural competitiveness of WPCs made from fast growing-low density woods. Weight losses due to fungal attack for pine and poplar-polymer composites were also determined. Although polymers at full and half loading levels helped decreasing weight losses due to both fungi for each wood species, weight losses were still found to be higher.     

Carvacrol and <Emphasis Type="Italic">p</Emphasis>-cymene inactivate <Emphasis Type="Italic">Escherichia coli</Emphasis> O157:H7 in apple juice

Background  

Outbreaks of food poisoning associated with drinking un-pasteurised apple juice contaminated with enterohaemorrhagic Escherichia coli O157:H7 are a cause of serious illness and occasionally death. Whilst a well-established heat process (pasteurisation) will readily eliminate the pathogen, some consumers are demanding more fresh-like foods that have not been subjected to processing methods that are perceived as severe and may lead to loss of flavour and vitamins. Therefore, alternative methods are being investigated to replace pasteurisation and improve the safety of minimally-processed juices. The addition of natural antimicrobial substances such as the phenolic substances carvacrol and p-cymene (derived from the essential oils of herbs and spices) provides a potential new route to assure safety and extend the shelf-life of raw fruit juices.     

Cleavage of disulfide-linked fetuin-bisphosphonate conjugates with three physiological thiols

An effective therapeutic agent for treatment of bone diseases is expected to exhibit a high affinity to bone. Conjugating proteins to bisphosphonates (BPs), a class of molecules with an exceptional affinity to bone mineral hydroxyapatite (HA), is a feasible means to impart such a bone affinity. Protein-BP conjugates with cleavable linkages, which allow protein release from the mineral, are preferable over conjugates with stable linkages. To this end, 2-(3-mercaptopropylsulfanyl)-ethyl-1,1-bisphosphonic acid (thiolBP) was conjugated onto fetuin, a model protein, using N-succinimidyl-3-(2-pyridyldithio)propionate to create disulfide-linked conjugates. Although the fetuin-thiolBP conjugates were stable under aqueous conditions, the disulfide linkage was readily cleaved in the presence of the physiological thiols l-cysteine, dl-homocysteine, and l-glutathione. dl-Homocysteine exhibited the highest cleavage of the disulfide linkage among these thiols. The imparted bone affinity as a result of thiolBP conjugation, as assessed by HA binding in vitro, was eliminated upon cleavage of the disulfide linkage. The cleavage of the conjugates bound to HA was as effective as the conjugate cleavage in solution, and even more so at high concentrations of l-glutathione. In conclusion, disulfide-linked fetuin-thiolBP conjugates exhibited a high affinity to HA, which was readily lost upon cleavage with thiols found in physiological milieu.     

Mutations in SLC34A2 cause pulmonary alveolar microlithiasis and are possibly associated with testicular microlithiasis

Pulmonary alveolar microlithiasis (PAM) is a rare disease characterized by the deposition of calcium phosphate microliths throughout the lungs. We first identified a PAM locus by homozygosity mapping to 4p15, then identified, by a candidate-gene approach, the gene responsible for the disease as SLC34A2 (the type IIb sodium-phosphate cotransporter gene), which is involved in phosphate homeostasis in several organs. We identified six homozygous exonic mutations in the seven unrelated patients with PAM we studied. Three of the mutations were frameshifts, one was a chain termination, one was an amino acid substitution, and one was a deletion spanning the minimal promoter and the first exon. Absence of functional protein product of the gene is compatible with calcium phosphate deposition in alveolar airspaces. We show that impaired activity of the phosphate transporter is presumably responsible for the microliths and that PAM is a recessive monogenic disease with full penetrance. Testicular microlithiasis (TM) is a disease that is more common than PAM. It is often associated with cancer and infertility. Since the gene we identified is also expressed in testis, we searched for mutations in subjects with TM. In 2 of the 15 subjects with TM we studied, we identified two rare variants, one synonymous and the other noncoding, that are possibly associated with the condition.     

Chemical composition effects onto antimicrobial and antioxidant activities of propolis collected from different regions of Turkey

Chrysin, apigenin, flavonoids, flavanones, naringenin, ethyl oleate, 3-4-dimethoxy-cinnamic acid and 9-octadecenoic acid were the predominant components of propolis samples collected from different regions of Turkey. The extracts of P3 from Denizli-Ba?karci, P5 from Denizli and P7 from Tekirda? had effective antibacterial activities on Gram-negatives. Chrysin, which has antibacterial activity, was found to be high concentration. The extracts of P3, P2B from Aydin and P6 from Konya had much more effective antibacterial activities on Gram-positives. The total antioxidant activity increased with the increasing amount of extracts added to linoleic acid emulsion. All doses of propolis ethanol extract displayed antioxidant activity.     

Brain-stem listeriosis: a comparison of SPECT and MRI findings

Listeria monocytogenes, although uncommon as a cause of illness in the general population, can result in serious illness when it affects pregnant women, neonates, the elderly, and immunocompromised individuals. Typically, it is a food-borne organism. This report describes a case of brain-stem listeriosis in a previously healthy 51-year-old woman. The diagnosis was based on clinical findings, the results of cerebrospinal fluid (CSF) analysis, CSF culture, and magnetic resonance imaging (MRI) findings. MRI demonstrated upper brain stem and cerebellar peduncle involvement. In addition, Tc-99m exametazime (HMPAO)-labeled single photon emission computed tomography (SPECT) of the brain revealed bilateral cerebellar hypoperfusion. Antibiotic therapy resulted in partial clinical recovery after 3 weeks. At the end of 6 months, brain-stem findings had nearly resolved. However, although minimal residual findings were observed on MRI at 6 months, bilateral diffuse cerebellar hypoperfusion remained on Tc-99m HMPAO brain SPECT.     

The effect of Trifolium, Raphanus, and Cistus pollen grains on some blood parameters and mesentery mast cells

Three kinds of pollen taxa belonging to 3 families (Fabaceae--Trifolium spp., Brassicaceae--Raphanus spp. and Cistaceae--Cistus spp.) and commonly collected by honeybees were fed to mature male rats separately, in the form of 60 mg/animal/day for a 30-day period. The objective of this study was to investigate any positive effects or possible side effects of the use of pollen on the immune system. This was achieved through blood analysis and cell count on blood, hemoglobin, erythrocyte and immune system cells. The cell concentration of mast cells, degranulization and cell localization were investigated in prepared mesentery tissue samples. Histological investigations of the stomach and duedenum sections of pollen-fed rats were carried out to learn the reason for eosinophil gastroenteritis in the alimentary canal. The eosinophil and lymphocyte levels of rats fed with pollen of Trifolium spp., Raphanus spp., and Cistus spp. were observed to have increased blood cell counts, while neutrophil and monocyte levels decreased; different values were found in basophil leucocytes between the pollen groups. Differing reductions in mesentery mast cell concentration, degranulization and cell localization were found. Within the three separate pollens, the rats having been fed with Cistus spp. pollen were observed to have higher blood lymphocyte, eosinophil, hemoglobin and hematocrit values than those fed with the others, as well as low mesentery mast cell concentration. Hemoglobin values were determined to increase at a proportion of between 10.0-11.3%. No difference was found in other blood parameters. The fat proportion of the male rats fed with the three taxa was between 4.03-8.75%, while that for protein proportion was between 16.11-24.25%. Male rats receiving these taxa did not experience allergic reactions and it is possible to argue that the low protein and fat content of these pollens have a strengthening effect on the immune systems by the increase in lymphocyte content and the amount of hemoglobin leads to an increase of oxygen transport capacity in the tissues.     

Investigation of the in vitro antioxidant behaviour of some 2-phenylindole derivatives: discussion on possible antioxidant mechanisms and comparison with melatonin

Oxidative stress has been implicated in the development of many neurodegenerative diseases and also responsible from aging and some cancer types. Indolic compounds are a broad family of substances present in microorganisms, plants and animals. They are mainly related to tryptophan metabolism, and present particular properties that depend on their respective chemical structures. Due to free radical scavenger and antioxidant properties of indolic derivatives such as indolinic nitroxides and melatonin, a series of 2-phenyl indole derivatives were prepared and their in vitro effects on rat liver lipid peroxidation levels, superoxide formation and DPPH stable radical scavenging activities were determined against melatonin, BHT and alpha-tocopherol. The compounds significantly inhibited (72-98%) lipid peroxidation at 10(-3) M. These values were similar to that observed with BHT (88%). Possible structure-activity relationships of the compounds were discussed.     

Synthesis and antioxidant activity evaluations of melatonin-based analogue indole-hydrazide/hydrazone derivatives

Melatonin (MLT) is a hormone synthesized from the pineal gland. It is a direct scavenger of free radicals, which is related to its capability to defend cells from oxidative stress. Recently MLT-related compounds are under investigation to establish which exhibit the maximum activity with the lowest side effects. In this study 5-chloroindole hydrazide/hydrazone derivatives were synthesized from 5-chloroindole-3-carboxaldehyde and phenyl hydrazine derivatives. All the compounds characterized and in vitro antioxidant activity was investigated against MLT and BHT. Most of the compounds showed strong inhibitory effect on the superoxide radical scavenging assay at 1?mM concentration (79 to 95%). Almost all the tested compounds possessed strong scavenging activity against the DPPH radical scavenging activity with IC(50) values (2 to 60 μM). Lastly, compound 1j revealed stronger inhibitory activity against MLT in the LP inhibitory assay at 0.1mM concentration (51%) while the rest of the compounds showed moderate inhibition.