Domain analysis of a groundnut calcium-dependent protein kinase: nuclear localization sequence in the junction domain is coupled with nonconsensus calcium binding domains.
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The signature of calcium-dependent protein kinases (CDPKs) is a C-terminal calmodulin-like domain (CaMLD) with four consensus calcium-binding sites. A junction domain (JD) joins the kinase with CaMLD and interacts with them through its autoinhibitory and CaMLD binding subdomains, respectively. We noted several CDPKs additionally have a bipartite nuclear localization signal (NLS) sequence as a subdomain in their JD, and this feature is obligatorily coupled with the absence of consensus calcium-binding sites in their respective CaMLDs. These predicted features are substantiated by undertaking investigations on a CDPK (gi:67479988) isolated from cultured groundnut (Arachis hypogea) cells. This kinase can bind 3.1 mol of Ca(2+) under saturating conditions with a considerably high K(d) of 392 mum as compared with its canonical counterparts. CD spectroscopic analysis, however, indicates the intramolecular structural changes accompanied with calcium binding to be similar to canonical CDPKs. Attesting to the presence of NLS in the JD, the endogenous kinase is localized in the nucleus of osmotically stressed Arachis cells, and in vitro binding assays indicate the NLS in the JD to interact with nuclear transport factors of the importin family. Homology modeling also indicates the feasibility of interaction of importins with the NLS present in the JD of such CDPKs in their activated form. The possible significance of obligatory coupling between the presence of NLS in the junction domain and atypical calcium binding properties of these CDPKs is discussed in the light of the known mechanisms of activation of these kinases. (+info)
The maximal amount of dietary alpha-tocopherol intake in U.S. adults (NHANES 2001-2002).
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The current study was designed to determine the maximal amount of alpha-tocopherol intake obtained from food in the U.S. diet, and to examine the effect of different food group intakes on this amount. Data from 2138 men and 2213 women aged >18 y were obtained from the National Health and Nutrition Examination Survey (NHANES) 2001-2002. Linear programming was used to generate diets with maximal alpha-tocopherol intake, with the conditions of meeting the recommended daily allowances or adequate intakes for a set of nutrients, sodium and fat recommendations, and energy limits, and that were compatible with the observed dietary patterns in the population. With food use and energy constraints in models, diets formulated by linear programming provided 19.3-24.9 mg alpha-tocopherol for men and women aged 19-50 or >50 y. These amounts decreased to 15.4-19.9 mg with the addition of the sodium, dietary reference intake, and fat constraints. The relations between maximal alpha-tocopherol intake and food group intakes were influenced by total fat restrictions. Although meeting current recommendations (15 mg/d) appears feasible for individuals, dramatic dietary changes that include greater intakes of nuts and seeds, and fruit and vegetables, are needed. Careful selection of the highest vitamin E source foods within these groups could further increase the likelihood of meeting the current recommended daily allowance. (+info)
Immunomodulatory and anti-inflammatory effects of Semecarpus anacardium LINN. Nut milk extract in experimental inflammatory conditions.
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Immunomodulatory effects of Semecarpus anacardium LINN. nut milk extract (SA) were investigated in adjuvant induced arthritis by studying the alterations in humoral and cell mediated immune responses and also the anti-inflammatory effects by evaluating the changes in paw edema, tumour necrosis factor (TNF-alpha), nitric oxide and myeloperoxidase activities. Pharmacological studies were also conducted with SA and indomethacin on experimental animals for evaluating the anti-inflammatory, analgesic, antipyretic and ulcerogenic activities. The alterations in the humoral and cell mediated immunity were significantly reverted back to near normal levels on treatment with SA. The drug significantly reduced the elevation in the paw edema, TNF-alpha, nitric oxide and myeloperoxidase levels when compared with adjuvant induced arthritic animals, which shows the anti-inflammatory activity of the drug. SA showed strong anti-inflammatory effects in xylene-induced ear edema and formalin-induced inflammation. In analgesic test, the extract elicited a potential activity on both acetic acid-induced writhing response as well as hot plate test showing its central and peripheral mediated action. The drug also elicited antipyretic action in yeast-induced hyperemia in rats. In addition, the extract did not produce any ulceration on gastric mucosa during ulcerogenic test and did not produce any serious adverse effects. All these effects are nearly similar to the activities of indomethacin except the ulceration where indomethacin produced significant ulceration. From this study, the protective immunological and pharmacological role of SA is demonstrated. (+info)
Detection of abnormally high amygdalin content in food by an enzyme immunoassay.
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Amygdalin is a cyanogenic glycoside compound which is commonly found in the pits of many fruits and raw nuts. Although amygdalin itself is not toxic, it can release cyanide (CN) after hydrolysis when the pits and nuts are crushed, moistened and incubated, possibly within the gastrointestinal tract. CN reversibly inhibits cellular oxidizing enzymes and cyanide poisoning generates a range of clinical symptoms. As some pits and nuts may contain unusually high levels of amygdalin such that there is a sufficient amount to induce critical CN poisoning in humans, the detection of abnormal content of amygdalin in those pits and nuts can be a life-saving measure. Although there are various methods to detect amygdalin in food extracts, an enzyme immunoassay has not been developed for this purpose. In this study we immunized New Zealand White rabbits with an amygdalin-KLH (keyhole limpet hemocyanin) conjugate and succeeded in raising anti-sera reactive to amygdalin, proving that amygdalin can behave as a hapten in rabbits. Using this polyclonal antibody, we developed a competition enzyme immunoassay for determination of amygdalin concentration in aqueous solutions. This technique was able to effectively detect abnormally high amygdalin content in various seeds and nuts. In conclusion, we proved that enzyme immunoassay can be used to determine the amount of amygdalin in food extracts, which will allow automated analysis with high throughput. (+info)
Acute effects of high-fat meals enriched with walnuts or olive oil on postprandial endothelial function.
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OBJECTIVES: We sought to investigate whether the addition of walnuts or olive oil to a fatty meal have differential effects on postprandial vasoactivity, lipoproteins, markers of oxidation and endothelial activation, and plasma asymmetric dimethylarginine (ADMA). BACKGROUND: Compared with a Mediterranean diet, a walnut diet has been shown to improve endothelial function in hypercholesterolemic patients. We hypothesized that walnuts would reverse postprandial endothelial dysfunction associated with consumption of a fatty meal. METHODS: We randomized in a crossover design 12 healthy subjects and 12 patients with hypercholesterolemia to 2 high-fat meal sequences to which 25 g olive oil or 40 g walnuts had been added. Both test meals contained 80 g fat and 35% saturated fatty acids, and consumption of each meal was separated by 1 week. Venipunctures and ultrasound measurements of brachial artery endothelial function were performed after fasting and 4 h after test meals. RESULTS: In both study groups, flow-mediated dilation (FMD) was worse after the olive oil meal than after the walnut meal (p = 0.006, time-period interaction). Fasting, but not postprandial, triglyceride concentrations correlated inversely with FMD (r = -0.324; p = 0.024). Flow-independent dilation and plasma ADMA concentrations were unchanged, and the concentration of oxidized low-density lipoproteins decreased (p = 0.051) after either meal. The plasma concentrations of soluble inflammatory cytokines and adhesion molecules decreased (p < 0.01) independently of meal type, except for E-selectin, which decreased more (p = 0.033) after the walnut meal. CONCLUSIONS: Adding walnuts to a high-fat meal acutely improves FMD independently of changes in oxidation, inflammation, or ADMA. Both walnuts and olive oil preserve the protective phenotype of endothelial cells. (+info)
Effect of glutathione on arecanut treated normal human buccal fibroblast culture.
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BACKGROUND: Experimental studies have shown arecanut to be a cytotoxic substance with mutagenic and carcinogenic potential. OBJECTIVE: The present study was undertaken to evaluate the effect of glutathione on arecanut treated human buccal fibroblast culture and its potential as a chemopreventive agent. MATERIALS AND METHODS: Fibroblast culture was done in Dulbecco's Modified Eagle's Medium MEM) supplemented with 10% Fetal Calf Serum (FCS) and antibiotic at 370C degrees in an atmosphere of 5% carbon di-oxide and 95% air. The fibroblast cells were subjected to different concentrations of aqueous extracts of raw and boiled arecanut. Fibroblasts were plated in two 24-well culture plates and in each plate, cells were dividt,ednto 2 groups; 600gg microml of reduced glutathione was added to the first group of cells; subsequently, aqueous extracts of raw and boiled arecanut at least and highest concentrations i.e., 20j. microml and 100lg microml were added to the first group of cells in the respective plates whereas the second group served as a control. The morphological alterations and cell survival were assayed at 24, 48, 72, and 96 hours. Results Morphologically, the initial (10 hours) attached fibroblast cells were converted from spheroidal shape towards hexagonal and finally to a fully extended spindle shaped configuration. The three morphological types of fibroblasts at 48 hours were F-I, F-II and F-III. Aqueous extract of raw arecanut exhibited significant cytotoxicity (p < .0 001) at all time periods studied, when compared against the control values of untreated fibroblasts. Addition of reduced glutathione to cultures showed a significant (p < 0. 001) reduction in cytotoxicity, as indicated by higher optical density values and morphological reversion to the spindle-shaped configuration. Co CONCLUSION: Addition of glutathione reduced the cytotoxic and morphological alterations of the fibroblasts treated with aqueous extracts of both raw and boiled arecanut. (+info)
The association between soy nut consumption and decreased menopausal symptoms.
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BACKGROUND: Epidemiological studies suggest a low incidence of hot flashes in populations that consume dietary soy. The present study examined the effect of soy nuts on hot flashes and menopausal symptoms. METHODS: Sixty healthy postmenopausal women were randomized in a crossover design to a therapeutic lifestyle changes (TLC) diet alone and a TLC diet of similar energy, fat, and protein content in which one-half cup soy nuts divided into three or four portions spaced throughout the day (containing 25 g soy protein and 101 mg aglycone isoflavones) replaced 25 g of nonsoy protein. During each 8-week diet period, subjects recorded the number of hot flashes and amount of exercise daily. At the end of each 8-week diet period, subjects filled out the menopausal symptom quality of life questionnaire. RESULTS: Compared to the TLC diet alone, the TLC diet plus soy nuts was associated with a 45% decrease in hot flashes (7.5 +/- 3.6 vs. 4.1 +/- 2.6 hot flashes day, respectively, p < 0.001) in women with >4.5 hot flashes/day at baseline and 41% in those with +info)
Long-term fish consumption is associated with protection against arrhythmia in healthy persons in a Mediterranean region--the ATTICA study.
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BACKGROUND: Dietary habits have long been associated with many manifestations of cardiovascular disease. OBJECTIVE: We sought to investigate whether a diet enriched with fish and n-3 fatty acid consumption are associated with changes in the potential duration of the electrical action, as represented by the QT duration on a resting electrocardiogram, in a population-based sample of Greek adults. DESIGN: During 2001 and 2002, we randomly enrolled 1514 men (18-87 y old) and 1528 women (18-89 y old) stratified by age and sex distribution (in the 2001 Greek census) from the Attica area, Greece. We studied several demographic, anthropometric, lifestyle, dietary, and bioclinical factors of the participants. Dietary habits (including fish consumption) were evaluated by using a validated food-frequency questionnaire. All subjects underwent electrocardiography with a 12-lead surface, in which, along with several other indexes, QT duration was measured, and the heart rate-corrected QT (QTc) was calculated (corrected by using Bazett's rate). The tested hypothesis was evaluated through multiple linear regression analysis, after control for physical activity status, sex, age, medication intake, and several other potential confounders. RESULTS: Compared with fish nonconsumers, those who consumed >300 g fish/wk had a mean 13.6% lower QTc (P<0.01). These findings were confirmed after adjustment for age, sex, physical activity status, BMI, smoking habits, intake of nuts, and other confounders. Moreover, compared with fish nonconsumers, those who consumed >or=300 g fish/wk had a 29.2% lower likelihood of having QTc intervals >0.45 s (P=0.03). CONCLUSIONS: Long-term consumption of fish is associated with lower QTc interval in free-eating people without any evidence of cardiovascular disease. Thus, fish intake seems to provide antiarrhythmic protection at a population level. (+info)