High tryptophan diet reduces CA1 intraneuronal β-amyloid in the triple transgenic mouse model of Alzheimer's disease

Alzheimer’s disease (AD) is a progressive neurodegenerative disease that impairs mnesic functions. The histopathology of the disease is manifested by the accumulation of intracellular β‐amyloid (Aβ) and subsequent formation of neuritic plaques as well as the presence neurofibrillary tangles in specific brain regions associated with learning and memory including the hippocampus. Here, we analysed the effect of chronic (1 month) food diets containing low (LTrP), normal (NTrP) and high tryptophan (HTrP), 0.04, 0.20 and 0.40 g/100 g, respectively, on CA1 serotonin transporter (SERT) fibre density, intraneuronal Aβ deposition and total number of serotonergic (5‐HT) neurons in an AD triple transgenic (3xTg‐AD) mouse model. Nontransgenic (non‐Tg) animals fed with HTrP displayed increased SERT fibre density in CA1 (35%) and in stratum lacunosum moleculare (S.Mol) (48%) compared to LTrP diet. Transgenic animals showed increased SERT fibre density in CA1 S.Mol compared to diet‐matched non‐Tg irrespective of dietary tryptophan content (104% for LTrP, 74% for NTrP and 35% for HTrP); no differences were observed in the total number of 5‐HT neurons neither in the dorsal nor in the median raphe nuclei. However, and more relevant to AD, HTrP diet reduced intraneuronal Aβ density (by a 17%) in transgenic animals compared to transgenic animals fed with NTrP diet. Our results show that increased dietary TrP intake reduces intraneuronal Aβ load in the 3xTg‐AD mouse model of AD, suggesting that enhanced TrP intake and in consequence a potential increase in 5‐HT neurotransmission may be effective in reducing plaque pathology in AD.     

Hazards of living on the edge of water: The case of Minnesota Point,Duluth, Minnesota

Based on a systematic sample survey among the residents of Minnesota Point, a fresh-water spit/baymouth bar on the southwest shore of Lake Superior, this study tests a number of hypotheses related to the perceived causes of lake level fluctuation and shore property hazards. The study found that, despite significant differences in property setting and the nature of flood and erosion hazards between the lakeside and the bayside of the spit, the majority of the respondents perceived that their property hazards were induced primarily by the manipulation of lake levels by the International Joint Commission (IJC). Consequently, one in every two respondents would like to lower the lake level by amounts ranging from 30 cm to more than 1 m. The study points out the physical limitations of controlling water levels and recommends that greater attention should be given to shoreline management, which could proivde guidelines for protecting existing coastal structures and for developing minimum standards for future encroachment of the remaining unused sections of the shoreline.Formly of the Department of Geography, University of Minnesota, Duluth, Minnesota 55812.     

Continuous biosynthesis of biodiesel from waste cooking palm oil in a packed bed reactor: optimization using response surface methodology (RSM) and mass transfer studies

This study aimed to develop an optimal continuous procedure of lipase-catalyzes transesterification of waste cooking palm oil in a packed bed reactor to investigate the possibility of large scale production further. Response surface methodology (RSM) based on central composite rotatable design (CCRD) was used to optimize the two important reaction variables packed bed height (cm) and substrate flow rate(ml/min) for the transesterification of waste cooking palm oil in a continuous packed bed reactor. The optimum condition for the transesterification of waste cooking palm oil was as follows: 10.53 cm packed bed height and 0.57 ml/min substrate flow rate. The optimum predicted fatty acid methyl ester (FAME) yield was 80.3% and the actual value was 79%. The above results shows that the RSM study based on CCRD is adaptable for FAME yield studied for the current transesterification system. The effect of mass transfer in the packed bed reactor has also been studied. Models for FAME yield have been developed for cases of reaction control and mass transfer control. The results showed very good agreement compatibility between mass transfer model and the experimental results obtained from immobilized lipase packed bed reactor operation, showing that in this case the FAME yield was mass transfer controlled.     

A proteome analysis of the cadmium and mercury response in Corynebacterium glutamicum

Cadmium and mercury are well-known toxic heavy metals, but the basis of their toxicity is not well understood. In this study, we analyzed the cellular response of Corynebacterium glutamicum to sublethal concentrations of cadmium and mercury ions using 2-DE and MS. Mercury induced the over-expression of 13 C. glutamicum proteins, whereas 35 proteins were induced, and 8 proteins were repressed, respectively, under cadmium stress. The principal response to these metals was protection against oxidative stress, as demonstrated by upregulation of, e.g., Mn/Zn superoxide dismutase. Thioredoxin and oxidoreductase responded most strongly to cadmium and mercury. The increased level of heat-shock proteins, enzymes involved in energy metabolism, as well as in lipoic acid and terpenoid biosynthesis after the treatment of cells with cadmium was also registered. Identification of these proteins and their mapping into specific cellular processes enable a global understanding of the way in which C. glutamicum adapts to heavy-metal stress and may help to gain deeper insight into the toxic mechanism of these metals.     

Care-seeking patterns for fatal malaria in Tanzania

Background

Once malaria occurs, deaths can be prevented by prompt treatment with relatively affordable and efficacious drugs. Yet this goal is elusive in Africa. The paradox of a continuing but easily preventable cause of high mortality raises important questions for policy makers concerning care-seeking and access to health systems. Although patterns of care-seeking during uncomplicated malaria episodes are well known, studies in cases of fatal malaria are rare. Care-seeking behaviours may differ between these groups.

Methods

This study documents care-seeking events in 320 children less than five years of age with fatal malaria seen between 1999 and 2001 during over 240,000 person-years of follow-up in a stable perennial malaria transmission setting in southern Tanzania. Accounts of care-seeking recorded in verbal autopsy histories were analysed to determine providers attended and the sequence of choices made as the patients' condition deteriorated.

Results

As first resort to care, 78.7% of malaria-attributable deaths used modern biomedical care in the form of antimalarial pharmaceuticals from shops or government or non-governmental heath facilities, 9.4% used initial traditional care at home or from traditional practitioners and 11.9% sought no care of any kind. There were no differences in patterns of choice by sex of the child, sex of the head of the household, socioeconomic status of the household or presence or absence of convulsions. In malaria deaths of all ages who sought care more than once, modern care was included in the first or second resort to care in 90.0% and 99.4% with and without convulsions respectively.

Conclusions

In this study of fatal malaria in southern Tanzania, biomedical care is the preferred choice of an overwhelming majority of suspected malaria cases, even those complicated by convulsions. Traditional care is no longer a significant delaying factor. To reduce mortality further will require greater emphasis on recognizing danger signs at home, prompter care-seeking, improved quality of care at health facilities and better adherence to treatment.     

High pressure effects step-wise altered protein expression in Lactobacillus sanfranciscensis

In this study we investigated the cellular response to the application of high hydrostatic pressure. High pressure is increasingly used for food preservation. With high resolution 2-D electrophoresis we compared the protein patterns of atmospherically grown Lactobacillus sanfranciscensis with those pressure treated up to 200 MPa. We performed the comparative study by using overlapping immobilized pH gradients covering the pH range from 2.5 up to 12 in order to maximize the resolution for the detection of stress relevant proteins. For improved quantitative analysis, staining with SyproRuby was used in addition to silver staining. By computer aided image analysis we detected more than a dozen spots within the pH range from 3.5 to 9 that were more than two-fold increased or 50% decreased in their intensity upon high pressure treatment. Two of them (approx. values: pI 4.0 and 4.2, respectively; M(r) approximately 15 000) have almost identical matrix-assisted laser desorption/ionization-time of flight mass spectrometry spectra and were identified by liquid chromatography-tandem mass spectrometry as putative homologs/paralogs to cold shock proteins of Lactococcus lactis. Their expression is opposed (i.e. the more acidic one is repressed, while the other one is induced); this effect is maximal at 1 h, 150 MPa. It was further remarkable that by monitoring the barosensitivity of the cells within 25 MPa steps, we observed a differential pressure induction or repression of the detected proteins as well. For example one protein (approx. values: pI 4.2, M(r) approximately 15 000) shows a maximum induction after 1 h, 150 MPa while another one (pI 7.5, M(r) approximately 25 000) is maximally induced after 1 h, 50/75 MPa. This indicates a successive cell response and different signalling pathways for these responses.     

Characterization and Sensitivity to Fungicides of Rhizoctonia spp. Recovered from Potato Plants in Bolu,Turkey

Isolates of Rhizoctonia spp. associated with stem canker and black scurf disease of potato were examined for their anastomosis group, sequence variations in the ITS‐5.8S rDNA region, pathogenicity and sensitivity to fungicides. A total of 92 isolates were obtained from diseased tuber, stolon and sprouts of the potato plants, collected from five districts of Bolu province, Turkey. Based on the anastomosis group and the similarity of the nucleotide sequence of the ITS‐5.8S rDNA, most of the isolates (81.5%) were identified as AG 3 PT. Other isolates belonged to AG 2‐1 (1.08%), AG 2‐2 IV (1.08%), AG 4 HG II (8.07%), AG 5 (2.17%), binucleate Rhizoctonia AG A (1.08%) and AG K (4.35%). Pathogenicity tests showed that isolates of AG 3 PT, AG 4 HG II and AG 5 caused similar degrees of disease severity on 45‐day‐old potato seedlings, whereas AG 2‐1 was moderately virulent. AG 2‐2 IV and binucleate Rhizoctonia spp. were weakly pathogenic or non‐pathogenic on potato seedlings. In this study, anastomosis groups of Rhizoctonia spp. isolates associated with potato in Turkey were characterized for the first time using molecular techniques and classified at the level of subgroups. Furthermore, the effect of selected fungicides was evaluated on disease development caused by soil‐borne inoculums of different anastomosis groups (AGs). Flutolanil and Bacillus subtilis QST 713 were found to be most effective against the Rhizoctonia isolates tested. These results revealed significant differences among the fungicides on disease development resulted from the different AGs.     

Growth responses and essential oil profile of Salvia officinalis L. Influenced by water deficit and various nutrient sources in the greenhouse

Salvia officinalis L. is a medicinal plant extensively used in foods, traditional medicine, and the pharmacological industry. In the current study, the effects of different irrigation regimes [irrigation after 70 ± 5 (regular), 105 ± 5 (moderate drought stress), and 140 ± 5 (severe drought stress) mm evaporation] and nutrient sources (control, NPK, farmyard manure, foliar fertilizer, and hydrogel) were investigated on the growth parameters and essential oil (EO) components of S. officinalis in the greenhouse. The plants were harvested two times. The regular irrigation treatment had the most significant effect on plant height (51 cm), fresh and dry herb weight (51.5 and 18.1 g plant⁻¹), and fresh and dry leaf weight (40.1 and 13.1 g plant⁻¹). The highest amount of EO was observed after moderate drought stress (1.48%). The NPK treatment had the greatest effect on plant height (40 cm), branch number (19 per plant), fresh and dry herb weight (53.4 and 18.9 g plant⁻¹), fresh and dry leaf weight (41.2 and 13.6 g plant⁻¹), and EO content (1.67%). The 1^st cutting was superior in EO amount, while the 2^nd cutting had a high agronomic yield. α-Thujone (from 21.6 to 34.2%) was identified as the predominant compound. Additionally, the content of α-thujone in the 2^nd cutting was higher after moderate drought stress, NPK, and hydrogel treatments. Moreover, 1,8-cineole, β-thujone, camphene, α-pinene, α-humulene, viridiflorol, borneol, and bornyl acetate were the other main compounds. As a general result, regular irrigation and NPK treatments improved the agronomic yield of S. officinalis. The plants under drought stress produced high amounts of EO. The farmyard manure also improved plant yield by providing a part of the plant's nutritional needs. Therefore, it could be concluded that it is crucial to determine the effects of limited water availability and various nutrient sources on yield and chemical compositions for medicinal and aromatic plant growth.