Regulatory effects of an inhibitor from Plathymenia foliolosa seeds on the larval development of Anagasta kuehniella (Lepidoptera)

The Mediterranean flour moth, Anagasta kuehniella, is one of the most important insect pests of grains, reported worldwide, feeding on stored grains and products of rice, rye, corn and wheat. Plants synthesize a variety of molecules, including trypsin inhibitors, to defend themselves against attack by insects. In this study, a trypsin inhibitor (PFTI) was purified from Plathymenia foliolosa (Benth.) seeds and was tested for insect growth regulatory effect. The survival and mass of A. kuehniella larvae feeding on control seeds were about 82.7% and 5 ring, respectively, whereas survival on seeds containing 0.7% PFTI was about 56%, while a 66.1% reduction in the average mass of the larvae was observed. The results from dietary utilization experiments with A. kuehniella larvae showed a reduction in efficiency of conversion of ingested food and digested food, and an increase in approximate digestibility and metabolic cost. The level of trypsin was significantly decreased in larval midgut and increased in the feces of larvae reared on a diet containing 0.7% PFTI. Results indicate that PFTI possesses a toxic effect against A. kuehniella larvae. (C) 2008 Elsevier Inc. All rights reserved.

Effects of soybean proteinase inhibitors on development of the soil mite Scheloribates praeincisus (Acari : Oribatida)

Proteinase inhibitors (PI) are present in plant tissues, especially in seeds, and act as a defense mechanism against herbivores and pathogens. Serine PI from soybean such as Bowman-Birk (BBPI) and Kunitz have been used to enhance resistance of sugarcane varieties to the sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae), the major pest of this crop. The use of these genetically-modified plants (GM) expressing PI requires knowledge of its sustainability and environmental safety, determining the stability of the introduced characteristic and its effects on non-target organisms. The objective of this study was to evaluate direct effects of ingestion of semi-purified and purified soybean PI and GM sugarcane plants on the soil-dwelling mite Scheloribates praeincisus (Berlese) (Acari: Oribatida). This mite is abundant in agricultural soils and participates in the process of organic matter decomposition; for this reason it will be exposed to PI by feeding on GM plant debris. Eggs of S. praeincisus were isolated and after larvae emerged, immatures were fed milled sugarcane leaves added to semi-purified or purified PI (Kunitz and BBPI) or immatures were fed GM sugarcane varieties expressing Kunitz and BBPI type PI or the untransformed near isogenic parental line variety as a control. Developmental time (larva-adult) and survival of S. praeincisus was evaluated. Neither Kunitz nor BBPI affected S. praeincisus survival. On the other hand, ingestion of semi-purified and purified Kunitz inhibitor diminished duration of S. praeincisus immature stages. Ingestion of GM senescent leaves did not have an effect on S. praeincisus immature developmental time and survival, compared to ingestion of leaves from the isogenic parental plants. These results indicate that cultivation of these transgenic sugarcane plants is safe for the non-target species S. praeincisus.

LEAF AREA REDUCTION IN CORN GROWN IN A TROPICAL REGION OF BRAZIL AND ITS EFFECTS ON AGRONOMIC TRAITS

Global climate change may reduce leaf area in crop plants due to factors such as increasing occurrence of pests and diseases. The aim of this work was to estimate the impact of leaf area reduction on agronomic traits in corn. An experiment simulating leaf area reduction was carried out in a tropical region of Brazil. The agronomic performance of corn plants was evaluated at different percentages of leaf loss. It was observed that leaf area reductions over 41.01% significantly harm yield, mass of 1000 grains, cob density, and stem and root quality Crop improvement programs should take into account the development of genotypes resistant to factors that cause leaf area reduction in tropical crops.

Acute, subacute toxicity and mutagenic effects of anacardic acids from cashew (Anacardium occidentale Linn.) in mice

Aim of the study: Anacardium occidentale Linn. (cashew) is a Brazilian plant that is usually consumed in natura and is used in folk medicine. Anacardic acids (AAs) in the cashew nut shell liquid are biologically active as gastroprotectors, inhibitors of the activity of various deleterious enzymes, antitumor agents and antioxidants. Yet, there are no reports of toxicity testing to guarantee their use in vivo models. Materials and methods: We evaluated AAs biosafety by measuring the acute, subacute and mutagenic effects of AAs administration in BALB/c mice. In acute tests, BALB/c mice received a single oral dose of 2000 mg/kg, whereas animals in subacute tests received 300, 600 and 1000 mg/kg for 30 days. Hematological, biochemical and histological analyses were performed in all animals. Mutagenicity was measured with the acute micronucleus test 24 h after oral administration of 250 mg/kg AAs. Results: Our results showed that the AAs acute minimum lethal dose in BALB/c mice is higher than 2000 mg/kg since this concentration did not produce any symptoms. In subacute tests, females which received the highest doses (600 or 1000 mg/kg) were more susceptible, which was seen by slightly decreased hematocrit and hemoglobin levels coupled with a moderate increase in urea. Anacardic acids did not produce any mutagenic effects. Conclusions: The data indicate that doses less than 300 mg/kg did not produce biochemical and hematological alterations in BALB/c mice. Additional studies must be conducted to investigate the pharmacological potential of this natural substance in order to ensure their safe use in vivo. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Box-Behnken design for the optimization of an enantioselective method for the simultaneous analysis of propranolol and 4-hydroxypropranolol by CE

An experimental design optimization (Box-Behnken design, BBD) was used to develop a CE method for the simultaneous resolution of propranolol (Prop) and 4-hydroxypropranolol enantiomers and acetaminophen (internal standard). The method was optimized using an uncoated fused silica capillary, carboxymethyl-beta-cyclodextrin (CM-beta-CD) as chiral selector and triethylamine/phosphoric acid buffer in alkaline conditions. A BBD for four factors was selected to observe the effects of buffer electrolyte concentration, pH, CM-beta-CD concentration and voltage on separation responses. Each factor was studied at three levels: high, central and low, and three center points were added. The buffer electrolyte concentration ranged from 25 to 75 mM, the pH ranged from 8 to 9, the CM-beta-CD concentration ranged from 3.5 to 4.5%w/v, and the applied run voltage ranged from 14 to 20 W. The responses evaluated were resolution and migration time for the last peak. The obtained responses were processed by Minitab (R) to evaluate the significance of the effects and to find the optimum analysis conditions. The best results were obtained using 4%w/v CM-beta-CD in 25 mM triethylamine/H(3)PO(4) buffer at pH 9 as running electrolyte and 17 kV of voltage. Resolution values of 1.98 and 1.95 were obtained for Prop and 4-hydroxypropranolol enantiomers, respectively. The total analysis time was around of 15 min. The BBD showed to be an adequate design for the development of a CE method, resulting in a rapid and efficient optimization of the pH and concentration of the buffer, cyclodextrin concentration and applied voltage.

Antidepressant-Like Effects of Medial Prefrontal Cortex Deep Brain Stimulation in Rats

Background: Subcallosal cingulate gyrus (SCG) deep brain stimulation (DBS) is being investigated as a treatment for major depression. We report on the effects of ventromedial prefrontal cortex (vmPFC) DBS in rats, focusing on possible mechanisms involved in an antidepressant-like response in the forced swim test (FST). Methods: The outcome of vmPFC stimulation alone or combined with different types of lesions, including serotonin (5-HT) or nore-pineprhine (NE) depletion, was characterized in the FST. We also explored the effects of DBS on novelty-suppressed feeding, learned helplessness, and sucrose consumption in animals predisposed to helplessness. Results: Stimulation at parameters approximating those used in clinical practice induced a significant antidepressant-like response in the FST. Ventromedial PFC lesions or local muscimol injections did not lead to a similar outcome. However, animals treated with vmPFC ibotenic acid lesions still responded to DBS, suggesting that the modulation of fiber near the electrodes could play a role in the antidepressant-like effects of stimulation. Also important was the integrity of the serotonergic system, as the effects of DBS in the FST were completely abolished in animals bearing 5-HT, but not NE, depleting lesions. In addition, vmPFC stimulation induced a sustained increase in hippocampal 5-HT levels. Preliminary work with other models showed that DBS was also able to influence specific aspects of depressive-like states in rodents, including anxiety and anhedonia, but not helplessness. Conclusions: Our study suggests that vmPFC DES in rats maybe useful to investigate mechanisms involved in the antidepressant effects of SCG DBS.

Adult rats are more sensitive to the vascular effects induced by hyperhomocysteinemia than young rats

We aimed to investigate the vascular effects of hyperhomocysteinemia (HHcy) on carotid arteries from young and adult rats. With this purpose young and adult rats received a solution of DL-homocysteine-thiolactone (1 g/kg body weight/day) in the drinking water for 7, 14 and 28 days. Increase on plasma homocysteine occurred in young and adult rats treated with DL-homocysteine-thiolactone in all periods. Vascular reactivity experiments using standard muscle bath procedures showed that HHcy enhanced the contractile response of endothelium-intact, carotid rings to phenylephrine in both young and adult rats. However, in young rats, the increased phenylephrine-induced contraction was observed after hyperhomocysteinemia for 14 and 28 days, whereas in adult rats this response was already apparent after 7 day treatment. HHcy impaired acetylcholine-induced relaxation in arteries from adult but not young rats. The contraction induced by phenylephrine in carotid arteries in the presence of Y-27632 was reversed to control values in arteries from young but not adult rats with hyperhomocysteinemia. HHcy did not alter the contraction induced by CaCl(2) in carotid arteries from young rats, but enhanced CaCl(2)-induced contraction in the arteries from adult rats. HHcy increased the basal levels of superoxide anion in arteries from both groups. Finally, HHcy decreased the basal levels of nitrite in arteries from adult but not young rats. The major new finding of the present work is that arteries from young rats are more resistant to vascular changes evoked by HHcy than arteries from adult rats. Also, we verified that the enhanced vascular response to phenylephrine observed in carotid arteries of DL-homocysteine thiolactone-treated rats is mediated by different mechanisms in young and adult rats. (C) 2010 Published by Elsevier Inc.

Treatment of Resistant Obsessive-Compulsive Disorder With Ventral Capsular/Ventral Striatal Gamma Capsulotomy: A Pilot Prospective Study

A subgroup of obsessive-compulsive disorder (OCD) patients remains refractory to conventional treatments. For them, a new stereotactic radiosurgery has been recently developed: the ventral capsular/ventral striatal (VC/VS) gamma capsulotomy. The authors aim to report efficacy and adverse events of VC/VS gamma capsulotomy. Five refractory OCD patients were selected. The authors assessed OCD, anxiety and depressive symptoms, and side effects pre- and postoperatively. Three patients (60%) met response criteria 48 months after surgery. Adverse effects were episodic and transient. Ventral capsular/ventral striatal gamma capsulotomy holds therapeutic promise, with few adverse effects. (The Journal of Neuropsychiatry and Clinical Neurosciences 2009; 21:381-392)

Optimizing Medical Therapy of Acromegaly: Beneficial Effects of Cabergoline in Patients Uncontrolled with Long-Acting Release Octreotide

Background: Previous data indicate a beneficial effect of cabergoline (CAB) association to somatostatin analogs (SA) in acromegalics resistant to SA monotherapy. Objective: To assess the efficacy of CAB association on acromegalics with high IGF-I on stable long-acting release octreotide (OCT-LAR) (30 mg/28 days). Design, Subjects and Methods: 34 patients (17 male, 25-85 years, 33 macroadenomas) were enrolled in this prospective study. OCT-LAR was administered as primary (n = 4) and as secondary (n = 30) treatment: after surgery (n = 16), after surgery + radiotherapy (RT) (n = 11), and after RT only (n = 3). Duration of OCT-LAR therapy prior to CAB was 24 8 12 months. The immunohistochemical features of the tumors disclosed GH/PRL co-secretion in 11/21 patients. 13 patients had high PRL levels prior to CAB. The initial CAB dose was 1.5 mg/week. No IGF-I normalization led to a dose increase to 3.5 mg/week. The OCT-LAR dose was kept stable during treatment. IGF-I, GH and PRL levels were compared before and after CAB association. OCT-LAR was withdrawn in patients who achieved IGF-I normalization, in order to assess the influence of CAB. Results: Comparing OCT-LAR to OCT-LAR/CAB treatment, there was a significant decrease in mean GH, IGF-I, %ULNR- IGF-I and PRL levels. During OCT-LAR/CAB treatment, IGF-I normalized in 19 patients (56%). IGF-I normalization was correlated to lowest IGF-I levels on OCT-LAR monotherapy, but not to baseline PRL levels or GH/PRL co-expression. OCT-LAR withdrawn in all who had achieved IGF-I normalization on combined therapy resulted in IGF-I elevation to abnormal levels in all patients. Gastro intestinal symptoms were reported by 12 patients. Conclusion: OCT-LAR and CAB association has been shown to be an effective alternative therapy for those acromegalics who still have active acromegaly despite monotherapy with SA, mainly for those with lower pretreatment IGF-I concentrations. According to previous studies, the beneficial effects of CAB occur even when pretreatment PRL is normal and/or there is no tumor GH/PRL co-expression. Copyright (C) 2009 S. Karger AG, Basel

Folic acid supplementation during early hepatocarcinogenesis: cellular and molecular effects

Folic acid (FA) supplementation during carcinogenesis is controversial. Considering the impact of liver cancer as a public health problem and mandatory FA fortification in several countries, the role of FA supplementation in hepatocarcinogenesis should be elucidated. We evaluated FA supplementation during early hepatocarcinogenesis. Rats received daily 0.08 mg (FA8 group) or 0.16 mg (FA16 group) of FA/100 g body weight or water (CO group, controls). After a 2-week treatment, animals were subjected to the ""resistant hepatocyte"" model of hepatocarcinogenesis (initiation with diethylnitrosamine, selection/promotion with 2-acetylaminofluorene and partial hepatectomy) and euthanized after 8 weeks of treatment. Compared to the CO group, the FA16 group presented: reduced (p < 0.05) number of persistent and increased (p < 0.05) number of remodeling glutathione S-transferase (GST-P) positive preneoplastic lesions (PNL); reduced (p < 0.05) cell proliferation in persistent GST-P positive PNL; decreased (p < 0.05) hepatic DNA damage; and a tendency (p < 0.10) for decreased c-myc expression in microdissected PNL. Regarding all these parameters, no differences (p > 0.05) were observed between CO and FA8 groups. FA-treated groups presented increased hepatic levels of S-adenosylmethionine but only FA16 group presented increased S-adenosylmethionine/S-adenosylhomocysteine ratio. No differences (p > 0.05) were observed between experimental groups regarding apoptosis in persistent and remodeling GST-P positive PNL, and global DNA methylation pattern in microdissected PNL. Altogether, the FA16 group, but not the FA8 group, presented chemopreventive activity. Reversion of PNL phenotype and inhibition of DNA damage and of c-myc expression represent relevant FA cellular and molecular effects.

Relationship between changes in insulin sensitivity and associated cardiovascular disease risk factors in thiazolidinedione-treated, insulin-resistant, nondiabetic individuals: pioglitazone versus rosiglitazone

This study compared the effects of administering rosiglitazone (RSG) vs pioglitazone (PIO) oil cardiovascular disease risk factors in insulin-resistant. nondiabetic individuals with no apparent disease. Twenty-two nondiabetic, apparently healthy individuals, classified as being insulin resistant oil the basis of a steady-state plasma glucose concentration of at least 10 mmol/L during the insulin suppression test, were treated with either RSG or 1110 for 3 months. Measurements were made before and after drug treatment of weight; blood pressure; fasting and daylong glucose, insulin, and free fatty acid (FFA) levels; and lipid and lipoprotein concentrations. Insulin sensitivity (steady-state plasma glucose concentration) significantly improved in both treatment groups, associated with significant decreases in daylong plasma concentrations of glucose, insulin, and FFA. Diastolic blood pressure fell somewhat in both groups, and this change reached significance in those receiving PIO. Improvement in lipid metabolism was confined to the PIO-treated group, signified by a significant decrease in plasma triglyceride concentration, whereas triglyceride concentration did not decline in the RSG-treated group, and these individuals also had increases in total (P = .047) and low-density lipoprotein cholesterol (P = .07). In conclusion, RSG and PIO appear to have comparable abilities to improve insulin sensitivity and lower daylong glucose, insulin, and FFA concentrations in nondiabetic, insulin-resistant individuals. However, despite these similarities, their effects on lipoprotein metabolism seem to be quite different, with beneficial effects confined to PIO-treated individuals. (C) 2009 Elsevier Inc. All rights reserved.

The effects of systemic stress on orthodontic tooth movement

Objectives: To determine if systemic stress affects the biological reactions occurring during orthodontic tooth movement. Methods: Four groups of male 10 week-old Wistar rats were used. Group A animals (N=10) were restrained for one hour per day for 40 days; Group B animals (N=10) were restrained for one hour per day for three days; Group C (N=10) and Group D (N=8) animals were unrestrained. The upper left first molars in the rats in Groups A (long-term stress), B (short-term stress) and C (control) were moved mesially during the last 14 days of the experiment. The animals in Group D (N=8) were used for body weight and hormonal dosage comparisons only. They were not subjected to any stress and did not have appliances fitted. All animals were killed at 18 weeks of age and blood collected for measurement of plasma corticosterone. Tooth movement was measured with an electronic caliper. The right and left hemi-maxillae of five rats from each group were removed and the number of tartrate-resistant acid phosphatase (TRAP) positive cells, defined as osteoclasts, adjacent to the mesial roots of the upper first molars counted. The contralateral side in each animal served as the control (split-mouth design). Results: Corticosterone levels were significantly higher in the stressed groups (Groups A and B) than in the control group (Group C). Tooth movement was significantly greater in Group A (long-term stress) compared with Group B (short-term stress) and Group C (control), which did not differ from each other. There were significantly more osteoclasts in the long-term stress group than in the short-term stress and control groups. Conclusion: Persistent systemic stress increases bone resorption during orthodontic tooth movement. Systemic stress may affect the rate of tooth movement during orthodontic treatment.

Comparison of the effects of aerobic and resistance training on cardiac autonomic adaptations in ovariectomized rats

We have compared the effects of two types of physical training on the cardiac autonomic control in ovariectomized and sham-operated rats according to different approaches: double autonomic blockade (DAB) with methylatropine and propranolol; baroreflex sensibility (BRS) and spectral analysis of heart rate variability (HRV). Wistar female rats (+/- 250 g) were divided into two groups: sham-operated and ovariectomized. Each group was subdivided into three subgroups: sedentary rats, rats submitted to aerobic trained and rats submitted to resistance training. Ovariectomy did not change arterial pressure, basal heart rate (HR), DAB and BRS responses, but interfered with HRV by reducing the low-frequency oscillations (LF = 0.20-0.75 Hz) in relation to sedentary sham-operated rats. The DAB showed that both types of training promoted an increase in the predominance of vagal tonus in sham-operated rats, but HR variations due to methylatropine were decreased in the resistance trained rats compared to sedentary rats. Evaluation of BRS showed that resistance training for sham-operated and ovariectomized rats reduced the tachycardic responses in relation to aerobic training. Evaluation of HRV in trained rats showed that aerobic training reduced LF oscillations in sham-operated rats, whereas resistance training had a contrary effect. In the ovariectomized rats, aerobic training increased high frequency oscillations (HF = 0.75-2.5 Hz), whereas resistance training produced no effect. In sham-operated rats, both types of training increased the vagal autonomic tonus, but resistance training reduced HF oscillations and BRS as well. In turn, both types of training had similar results in ovariectomized rats, except for HRV, as aerobic training promoted an increase in HF oscillations. (C) 2011 Elsevier B.V. All rights reserved.

Effects of processing methods on amaranth starch digestibility and predicted glycemic index

Amaranth has attracted a great deal of interest in recent decades due to its valuable nutritional, functional, and agricultural characteristics. Amaranth seeds can be cooked, popped, roasted, flaked, or extruded for consumption. This study compared the in vitro starch digestibility of processed amaranth seeds to that of white bread. Raw seeds yielded rapidly digestible starch content (RDS) of 30.7% db and predicted glycemic index (pGI) of 87.2, the lowest among the studied products. Cooked, extruded, and popped amaranth seeds had starch digestibility similar to that of white bread (92.4, 91.2, and 101.3, respectively), while flaked and roasted seeds generated a slightly increased glycemic response (106.0 and 105.8, respectively). Cooking and extrusion did not alter the RDS contents of the seeds. No significant differences were observed among popped, flaked, and roasted RDS contents (38.0%,46.3%, and 42.9%, respectively), which were all lower than RDS content of bread (51.1%). Amaranth seed is a high glycemic food most likely because of its small starch granule size, low resistant starch content (< 1%), and tendency to completely lose its crystalline and granular starch structure during those heat treatments.

Biological effects of insulin on murine melanoma cells and fish erythrophoroma cells: A comparative study

Insulin is the hormone that plays an essential role in metabolism and mitosis of normal and tumor cells, exerting its pleiotropic effects through binding to specific membrane receptors and promoting the phosphorylation of tyrosine residues of the receptor itself and of other components of the signaling pathway. The aim of this study was to investigate the effects of insulin on melanogenesis and cell growth in three different cell lines: the goldfish GEM-81 erythrophoroma cells (undifferentiated and differentiated with 1.5% dimethylsulfoxide-DMSO), and the murine B16F10 and Cloudman S91 melanoma cells. Undifferentiated GEM-81 and B16F10 cells responded to insulin with a small increase of cell proliferation, whereas S91 cells responded with a decrease of growth. In the two mammalian cell lines, and in DMSO-differentiated GEM-81 cells, the hormone strongly inhibited melanogenesis, by decreasing tyrosinase activity. In undifferentiated GEM-81 cells, insulin had no effect on tyrosinase activity. An increase in the tyrosine phosphorylation status of pp 185 (insulin receptor substrate 1 and 2-IRS-1/2) phosphorylation degree was observed in S91 mouse melanoma and in differentiated GEM-81 erythrophoroma cells, suggesting that this specific protein was maintained during transformation process and participates in insulin signaling. Our results imply an ancient and diverse history of the insulin signaling system in vertebrate pigment cells. (C) 2008 Elsevier Inc. All rights reserved.