Assessing fitness costs of the resistance of Spodoptera frugiperda (Lepidoptera: Noctuidae) to pyramided Cry1 and Cry2 insecticidal proteins on different host plants.

Fall armyworm (FAW), Spodoptera frugiperda (Smith), is one of the major pests targeted by transgenic crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) Berliner. However, FAW presents a high capacity to develop resistance to Bt protein-expressing crop lines, as reported in Brazil, Argentina, Puerto Rico and the southeastern U.S. Here, FAW genotypes resistant to pyramided maize events expressing Cry1F/Cry1A.105/Cry2Ab2 (P-R genotype) and Cry1A.105/Cry2Ab2 (Y-R genotype) from Brazil were used to investigate the interactions between non-Bt hosts (non-Bt maize, non-Bt cotton, millet and sorghum) and fitness costs. We also tested a FAW genotype susceptible to Bt maize and F1 hybrids of the resistant and susceptible genotypes (heterozygotes). Recessive fitness costs (i.e., costs affecting the resistant insects) were observed for pupal and neonate to adult survival of the P-R genotype on non-Bt cotton; larval developmental time of the P-R genotype on millet and sorghum; larval and neonate-to-adult developmental time of the Y-R genotype on non-Bt cotton and sorghum; the fecundity of the Y-R genotype on non-Bt cotton; and mean generation time of both resistant genotypes. However, on non-Bt cotton and non-Bt maize, the P-R genotype had a higher fitness (i.e., fitness benefits), displaying greater fecundity and rates of population increases than the Sus genotype. Non-recessive fitness costs (i.e., costs affecting heterozygotes) were found for fecundity and population increases on millet and sorghum. These findings suggest that, regardless of the disadvantages of the resistant genotypes in some hosts, the resistance of FAW to Cry1 and Cry2 Bt proteins is not linked with substantial fitness costs, and may persist in field conditions once present.

Transcriptome Analysis of Pyrethroid-Resistant Chrysodeixis includens (Lepidoptera: Noctuidae) Reveals Overexpression of Metabolic Detoxification Genes.

Chrysodeixis includens (Walker, [1858]) is one of the most important defoliator of soybean in Brazil because of its extensive geographical distribution and high tolerance to insecticides compared with other species of caterpillars. Because of this, we conducted bioassays to evaluate the efficacy of pyrethroid λ-cyhalothrin on a C. includens resistant strain (MS) and a susceptible (LAB) laboratory strain. High throughput RNA sequencing (RNA-seq) of larval head and body tissues were performed to identify potential molecular mechanisms underlying pyrethroid resistance. Insecticide bioassays showed that MS larvae exhibit 28.9-fold resistance to pyrethroid λ-cyhalothrin relative to LAB larvae. RNA-seq identified evidence of metabolic resistance in the head and body tissues: 15 cytochrome P450 transcripts of Cyp6, Cyp9, Cyp4, Cyp304, Cyp307, Cyp337, Cyp321 families, 7 glutathione-S-transferase (Gst) genes, 7 α-esterase genes from intracellular and secreted catalytic classes, and 8 UDP-glucuronosyltransferase (Ugt) were overexpressed in MS as compared with LAB larvae. We also identified overexpression of GPCR genes (CiGPCR64-like and CiGPCRMth2) in the head tissue. To validate RNA-seq results, we performed RT-qPCR to assay selected metabolic genes and confirmed their expression profiles. Specifically, CiCYP9a101v1, CiCYP6ae149, CiCYP6ae106v2, CiGSTe13, CiCOE47, and CiUGT33F21 exhibited significant overexpression in resistant MS larvae. In summary, our findings detailed potential mechanisms of metabolic detoxification underlying pyrethroid resistance in C. includens.

Performance of Seed Treatments Applied on Bt and Non-Bt Maize Against Fall Armyworm (Lepidoptera: Noctuidae).

Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is the main pest of maize in Brazil, attacking plants from emergence to reproductive stages. Here, we conducted studies to evaluate the efficacy of two seed treatments (chlorantraniliprole alone and imidacloprid combined with thiodicarb) on Bt and non-Bt maize in laboratory bioassays with distinct FAW strains that are susceptible, selected for resistance to Bt-maize single (Cry1F) or pyramided (Cry1A.105 + Cry2Ab2) events and F1 hybrids of the selected and susceptible strains (heterozygotes), and in the field against a natural infestation. In the laboratory, leaf-discs from seed treated Bt-maize plants at 7 d after emergence (DAE) increased the mortality of FAW resistant, heterozygote, and susceptible strains up to 24.8%, when compared with the respective maize grown without a seed treatment. In the field against natural infestations of FAW, Bt maize with a seed treatment had ~30% less FAW damage than non-Bt maize with the same seed treatment at 7 and 14 DAE. No differences in FAW damage was observed between Bt and non-Bt maize grown with and without a seed treatment at 21 DAE. Maize seeds treated with chlorantraniliprole alone or imidacloprid and thiodicarb combined presented limited protection against early infestations of FAW strains under laboratory and field studies.

Field-evolved resistance to chitin synthesis inhibitor insecticides by soybean looper, Chrysodeixis includens (Lepidoptera: Noctuidae), in Brazil.

Soybean looper (SBL), Chrysodeixis includens (Walker), is an economically important soybean and cotton pest in Brazil. Here, we selected an SBL strain resistant to teflubenzuron using F2 screening, estimated the resistance allele frequency, characterized the inheritance of resistance, investigated fitness costs, evaluated patterns of cross-resistance, and determined the magnitude of resistance. The teflubenzuron-resistant strain (Teflu-R) was selected from field-collected populations with an estimated allele frequency of 0.1700. Estimated LC50 values were 0.010 and 363.61 µg a.i. cm-2 for the susceptible (Sus) and Teflu-R strains, respectively, representing a 36,361-fold resistance ratio (RR). The LC50 values of reciprocal crosses were 1.02 and 0.59 µg a.i. cm-2, suggesting that resistance is autosomally inherited. The low survival of reciprocal crosses (16 and 20%) on teflubenzuron-sprayed leaves indicates incomplete recessive resistance. The number of segregations influencing resistance was 2.72, suggesting a polygenic effect. The Teflu-R strain showed longer development periods as well as lower survival and population growth than the Sus strain, revealing fitness costs. The Teflu-R strain also showed high cross-resistancesto other chitin inhibitor insecticides, such as novaluron (RR = 6147-fold) and lufenuron (RR = 953-fold), but low cross-resistance to methoxyfenozide, flubendiamide, and indoxacarb (RR < 3.45-fold). On discriminatory concentrations of teflubenzuron and novaluron, populations of SBL showed survival rates from 15 to 52%, indicating field resistance to these insecticides. Our findings indicated that resistance to teflubenzuron in SBL is autosomal, recessive, polygenic, and associated with fitness cost. We also found a high cross-resistance to other benzoylphenylureas and a high frequency of resistance to this mode-of-action in SBL in Brazil.

Crioablación total o hemiglandular para el cáncer de próstata primario localizado: resultados oncológicos y funcionales a corto y medio plazo / Whole and hemi-gland cryoablation for primary localized prostate cancer: Short and medium-term oncological and functional outcomes

INTRODUCCIÓN: Comparar los resultados oncológicos, funcionales y postoperatorios de la crioablación hemiglandular (CH) vs. crioablación de toda la glándula (CT) como terapia primaria del cáncer de próstata localizado. MATERIAL Y MÉTODO: Se incluyeron 66 pacientes consecutivos tratados entre 2010 y 2018 con crioablación total (CT = 40) o crioablación hemiglandular (CH = 26) en un centro de referencia terciario. Todos los pacientes tenían cáncer de próstata de riesgo bajo-intermedio según criterios D'Amico. Se propuso crioablación hemiglandular en caso de cáncer de próstata unilateral comprobado por biopsia y RM. La variable principal de evaluación fue el fracaso de la crioterapia, para el que se consideraron y compararon tres definiciones: 1) fallo bioquímico (> PSA nadir + ≥ 2 ng/mL), 2) rebiopsia positiva de próstata Gleason ≥ 7, y 3) inicio de un tratamiento adicional para el cáncer de próstata. RESULTADOS: La edad media de los pacientes durante el tratamiento fue 74 [42-81] vs.76 [71-80] años en el grupo de CT vs. CH, respectivamente (p = 0,08). Los grupos de riesgo bajo e intermedio (D'Amico) fueron 15% y 85% frente a 23% y 77% (p = 0,75), respectivamente. El tiempo medio de seguimiento fue de 41 [1,5-99,0] vs.27 [0,9-93] meses (p = 0,03). La supervivencia libre de fracaso de la crioterapia a cuatro años en CT vs. CH fue de 69% vs.53% con la definición 1 (p = 0,24), 82% vs.80% con la definición 2 (p = 0,95), y 83% vs.77% con la definición 3 (p = 0,73). La continencia urinaria postoperatoria y al año fue de 60% y 83% en CT frente a 72% y 83% en CH (p = 0,26). La impotencia de novo tras la crioterapia fue del 75% frente al 46% (p = 0,33) en CT y CH, respectivamente. CONCLUSIONES: En nuestra cohorte de pacientes altamente seleccionados con CP unilateral de riesgo bajo-intermedio, la crioterapia hemiglandular puede proporcionar resultados oncológicos similares y menos complicaciones tempranas en comparación con la crioablación de toda la glándula

INTRODUCTION: To compare oncological, functional and post-operative outcomes of hemi (HC) vs. whole gland (WGC) cryoablation as first line treatment of localized prostate cancer. MATERIAL AND METHOD: Sixty-six consecutive patients undertaking whole-gland cryoablation (WGC = 40) or hemi-cryoablation (HC = 26) in a tertiary referral centre between 2010 and 2018 were included. All patients had a low-intermediate risk prostate cancer according to D'Amico risk classification. Hemi-ablation was proposed in case of biopsy and prostate MRI proven unilateral prostate cancer. Primary endpoint was Cryotherapy Failure for which 3 definitions were considered and compared: 1) biochemical failure (> PSA nadir+ ≥ 2 ng/mL), 2) positive prostate re-biopsy with Gleason score ≥ 7, 3) initiation of further prostate cancer treatment. RESULTS: Median patients age at treatment was 74 [42-81] vs.76 [71-80] years in WGC vs. HC group, respectively (p=.08). Low and intermediate D'Amico risk group were 15% and 85% vs.23% and 77% (p=.75), respectively. Median follow- up time was 41 [1.5-99.0] vs.27 [0.9-93] months (p=.03). Four-years cryotherapy failure free survival in WGC vs. HC were 69% vs.53% with definition 1 (p=.24), 82% vs.80% with definition 2 (p=.95), 83% vs.77% with definition 3 (p=.73). Early and 1-year urinary continence were 60% and 83% in WGC vs.72% and 83% in HC (p=.26). De novo impotency after cryotherapy was 75% vs.46% (p=.33) in WGC vs. HC. CONCLUSIONS: In our cohort of highly selected patients with unilateral low/intermediate risk PCa, hemi-cryoablation may provide similar oncological outcomes and less early complications compared to whole-gland cryoablation

Whole and hemi-gland cryoablation for primary localized prostate cancer: Short and medium-term oncological and functional outcomes. / Crioablación total o hemiglandular para el cáncer de próstata primario localizado: resultados oncológicos y funcionales a corto y medio plazo.

INTRODUCTION: To compare oncological, functional and post-operative outcomes of hemi (HC) vs. whole gland (WGC) cryoablation as first line treatment of localized prostate cancer. MATERIAL AND METHOD: Sixty-six consecutive patients undertaking whole-gland cryoablation (WGC=40) or hemi-cryoablation (HC=26) in a tertiary referral centre between 2010 and 2018 were included. All patients had a low-intermediate risk prostate cancer according to D'Amico risk classification. Hemi-ablation was proposed in case of biopsy and prostate MRI proven unilateral prostate cancer. Primary endpoint was Cryotherapy Failure for which 3 definitions were considered and compared: 1) biochemical failure (> PSA nadir+≥ 2 ng/mL), 2) positive prostate re-biopsy with Gleason score ≥ 7, 3) initiation of further prostate cancer treatment. RESULTS: Median patients age at treatment was 74 [42-81] vs. 76 [71-80] years in WGC vs. HC group, respectively (p=.08). Low and intermediate D'Amico risk group were 15% and 85% vs. 23% and 77% (p=.75), respectively. Median follow- up time was 41 [1.5-99.0] vs. 27 [0.9-93] months (p=.03). Four-years cryotherapy failure free survival in WGC vs. HC were 69% vs. 53% with definition 1 (p=.24), 82% vs. 80% with definition 2 (p=.95), 83% vs. 77% with definition 3 (p=.73). Early and 1-year urinary continence were 60% and 83% in WGC vs. 72% and 83% in HC (p=.26). De novo impotency after cryotherapy was 75% vs. 46% (p=.33) in WGC vs. HC. CONCLUSIONS: In our cohort of highly selected patients with unilateral low/intermediate risk PCa, hemi-cryoablation may provide similar oncological outcomes and less early complications compared to whole-gland cryoablation.

No cross-resistance between ChinNPV and chemical insecticides in Chrysodeixis includens (Lepidoptera: Noctuidae).

Chrysodeixis includens nucleopolyhedrovirus (ChinNPV: Baculoviridae: Alphabaculovirus) is an active ingredient of a biological-based insecticide (Chrysogen®) recommended against soybean looper (SBL), Chrysodeixis includens (Walker, [1858]), in soybean in Brazil. We investigated if SBL strains resistant to chemical insecticides are cross-resistant to the baculovirus ChinNPV. In droplet feeding bioassays, SBL strains resistant to lambda-cyhalothrin and teflubenzuron showed equivalent susceptibility to ChinNPV as heterozygous and susceptible strains, indicating no cross-resistance between ChinNPV and chemical insecticides in SBL. Therefore, the ChinNPV is a valuable new "mode-of-action" tool for SBL resistance management in Brazil.

Susceptibility of Brazilian Populations of Chrysodeixis includens (Lepidoptera: Noctuidae) to Selected Insecticides.

Soybean looper (SBL), Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae), is an important pest of soybean and cotton in Brazil. The use of insecticides is one of the main control tactics against this pest. To support Integrated Pest Management (IPM) and Insect Resistance Management (IRM) programs, we characterized the susceptibility of Brazilian populations of SBL to insecticides. Field populations were collected from soybean fields during the 2016-2017 and 2017-2018 crop seasons. In the laboratory, late L2/early L3 larvae were exposed to insecticides in diet-overlay or topical bioassays. Field populations of SBL showed high susceptibility to spinetoram (LC50 = 0.074-0.25 µg a.i. per cm2), indoxacarb (LC50 = 0.46-0.94 µg a.i. per cm2), thiodicarb (LC50 = 9.14-36.61 µg a.i. per cm2), chlorantraniliprole (LC50 = 0.15-0.57 µg a.i. per cm2), flubendiamide (LC50 = 0.45-2.01 µg a.i. per cm2), and chlorfenapyr (LC50 = 0.15-0.25 µg a.i. per cm2); the resistance ratios were less than 16-fold. In contrast, SBL populations have reduced susceptibility to lambda-cyhalothrin (LC50 = 3.71-9.54 µg a.i./cm2), methoxyfenozide (LC50 = 0.67-4.23 µg a.i. per cm2), novaluron (LC50 = 27.52-77.63 µg a.i. per cm2), and teflubenzuron (LC50 = 13.41-73.02 µg a.i. per cm2). The resistance ratios relative to a Lab population (susceptible of reference) was up to 38-, 63-, 1,553-, and 5,215-fold, respectively. These high resistance ratios can be associated with resistance evolution. Implications of these findings to IPM and IRM programs are discussed.

Laboratory and field survival of Spodoptera frugiperda (Lepidoptera: Noctuidae) on Bt and non-Bt maize and its susceptibility to insecticides.

BACKGROUND: Field-evolved resistance of fall armyworm (FAW), Spodoptera frugiperda (Smith), has been reported to Bt maize technologies in Brazil. The control failures of FAW by Bt maize increased the use of insecticides for their control. However, no information is available on the interaction between resistant FAW and their response to insecticides. Here, we evaluated the survival of FAW strains on Bt and non-Bt maize in laboratory and field conditions, and their susceptibility to insecticides. RESULTS: In the laboratory, resistant FAW larvae reared on Bt and non-Bt maize showed a similar susceptibility to spinetoram (LC50 = 0.16-0.18 µg a.i. cm-2 ) and chlorfenapyr (LC50 = 0.17-0.20 µg a.i. cm-2 ). However, their susceptibility was lower than that of the susceptible strain reared on non-Bt maize: LC50 = 0.05 (spinetoram) and 0.08 (chlorfenapyr) µg a.i. cm-2 . In contrast, heterozygous strains had similar susceptibility to the susceptible strain. In field trials, no differences in FAW survival were detected between strains when the commercial dose of two insecticides was applied in Bt and non-Bt maize. CONCLUSION: FAW strains surviving on Bt and non-Bt maize, at the same development stage, have similar susceptibility to insecticides. The integrated pest management practices and insect resistance management importance of these results are discussed. © 2019 Society of Chemical Industry.

Baseline Susceptibility of Brazilian Populations of Chrysodeixis includens (Lepidoptera: Noctuidae) to C. includens Nucleopolyhedrovirus and Diagnostic Concentration for Resistance Monitoring.

The Chrysodeixis includens nucleopolyhedrovirus (ChinNPV: Baculoviridae: Alphabaculovirus) is a registered insecticide for the management of soybean looper, Chrysodeixis includens (Walker, [1858]) in Brazil. We conducted studies of baseline susceptibility of Brazilian populations of C. includens to the ChinNPV (Chrysogen, AgBiTech, Fort Worth, TX) as valuable knowledge in support of Integrated Pest Management and Insect Resistance Management programs. In bioassays, neonates were infected with different concentrations of ChinNPV using the droplet feeding bioassay method. Larvae were then transferred to artificial diet and mortality was assessed at 7 d. Results confirm that neonates from Brazilian populations of C. includens are susceptible to ChinNPV. Concentrations from 1.0 × 103 to 1.0 × 108 occlusion bodies (OBs) per ml caused mortality from 1.5 to 99%, respectively. The LC50 ranged from 1.4 × 105 to 7.7 × 105 OBs per ml for populations of C. includens (5.5-fold variation). Similar variation was detected for the LC90 which ranged from 1.6 × 107 to 7.7 × 107 OBs per ml (4.8-fold variation). Importantly, the field-collected populations showed equivalent susceptibility to the reference susceptible population. This indicates a low interpopulation variation in susceptibility of Brazilian populations of C. includens to ChinNPV, representing natural geographic variation and not variation caused by previous selection pressure. The candidate diagnostic concentration of 2.9 × 108 OBs per ml was estimated based on the pooled data and caused mortality ranging from 98.6 to 100%. This concentration will be used in proactive resistance monitoring programs. The Chrysogen will be a valuable tool as a new mode of action in C. includens resistance management in Brazil.

R-α-lipoic acid does not reverse hepatic inflammation of aging, but lowers lipid anabolism, while accentuating circadian rhythm transcript profiles.

To determine the effects of age and lipoic acid supplementation on hepatic gene expression, we fed young (3 mo) and old (24 mo) male Fischer 344 rats a diet with or without 0.2% (wt/wt) R-α-lipoic acid (LA) for 2 wk. Total RNA isolated from liver tissue was analyzed by Affymetrix microarray to examine changes in transcriptional profiles. Results showed elevated proinflammatory gene expression in the aging liver and evidence for increased immune cell activation and tissue remodeling, together representing 45% of the age-related transcriptome changes. In addition, age-related increases in transcripts of genes related to fatty acid, triglyceride, and cholesterol synthesis, including acetyl-CoA carboxylase-ß (Acacb) and fatty acid synthase (Fasn), were observed. Supplementation of old animals with LA did not reverse the necroinflammatory phenotype but, intriguingly, altered the expression of genes governing circadian rhythm. Most notably, Arntl, Npas2, and Per changed in a coordinated manner with respect to rhythmic transcription. LA further caused a decrease in transcripts of several bile acid and lipid synthesis genes, including Acacb and Fasn, which are regulated by first-order clock transcription factors. Similar effects of LA supplementation on bile acid and lipid synthesis genes were observed in young animals. Transcript changes of lipid metabolism genes were corroborated by a decrease in FASN and ACC protein levels. We conclude that advanced age is associated with a necroinflammatory phenotype and increased lipid synthesis, while chronic LA supplementation influences hepatic genes associated with lipid and energy metabolism and circadian rhythm, regardless of age.

(R)-α-Lipoic acid treatment restores ceramide balance in aging rat cardiac mitochondria.

Inflammation results in heightened mitochondrial ceramide levels, which cause electron transport chain dysfunction, elevates reactive oxygen species, and increases apoptosis. As mitochondria in aged hearts also display many of these characteristics, we hypothesized that mitochondrial decay stems partly from an age-related ceramidosis that heretofore has not been recognized for the heart. Intact mitochondria or their purified inner membranes (IMM) were isolated from young (4-6 mo) and old (26-28 mo) rats and analyzed for ceramides by LC-MS/MS. Results showed that ceramide levels increased by 32% with age and three ceramide isoforms, found primarily in the IMM (e.g. C(16)-, C(18)-, and C(24:1)-ceramide), caused this increase. The ceramidosis may stem from enhanced hydrolysis of sphingomyelin, as neutral sphingomyelinase (nSMase) activity doubled with age but with no attendant change in ceramidase activity. Because (R)-α-lipoic acid (LA) improves many parameters of cardiac mitochondrial decay in aging and lowers ceramide levels in vascular endothelial cells, we hypothesized that LA may limit cardiac ceramidosis and thereby improve mitochondrial function. Feeding LA [0.2%, w/w] to old rats for two weeks prior to mitochondrial isolation reversed the age-associated decline in glutathione levels and concomitantly improved Complex IV activity. This improvement was associated with lower nSMase activity and a remediation in mitochondrial ceramide levels. In summary, LA treatment lowers ceramide levels to that seen in young rat heart mitochondria and restores Complex IV activity which otherwise declines with age.

Characteristics of the rat cardiac sphingolipid pool in two mitochondrial subpopulations.

Mitochondrial sphingolipids play a diverse role in normal cardiac function and diseases, yet a precise quantification of cardiac mitochondrial sphingolipids has never been performed. Therefore, rat heart interfibrillary mitochondria (IFM) and subsarcolemmal mitochondria (SSM) were isolated, lipids extracted, and sphingolipids quantified by LC-tandem mass spectrometry. Results showed that sphingomyelin (approximately 10,000 pmol/mg protein) was the predominant sphingolipid regardless of mitochondrial subpopulation, and measurable amounts of ceramide (approximately 70 pmol/mg protein) sphingosine, and sphinganine were also found in IFM and SSM. Both mitochondrial populations contained similar quantities of sphingolipids except for ceramide which was much higher in SSM. Analysis of sphingolipid isoforms revealed ten different sphingomyelins and six ceramides that differed from 16- to 24-carbon units in their acyl side chains. Sub-fractionation experiments further showed that sphingolipids are a constituent part of the inner mitochondrial membrane. Furthermore, inner membrane ceramide levels were 32% lower versus whole mitochondria (45 pmol/mg protein). Three ceramide isotypes (C20-, C22-, and C24-ceramide) accounted for the lower amounts. The concentrations of the ceramides present in the inner membranes of SSM and IFM differed greatly. Overall, mitochondrial sphingolipid content reflected levels seen in cardiac tissue, but the specific ceramide distribution distinguished IFM and SSM from each other.

Alpha-lipoic acid as a dietary supplement: molecular mechanisms and therapeutic potential.

Alpha-lipoic acid (LA) has become a common ingredient in multivitamin formulas, anti-aging supplements, and even pet food. It is well-defined as a therapy for preventing diabetic polyneuropathies, and scavenges free radicals, chelates metals, and restores intracellular glutathione levels which otherwise decline with age. How do the biochemical properties of LA relate to its biological effects? Herein, we review the molecular mechanisms of LA discovered using cell and animal models, and the effects of LA on human subjects. Though LA has long been touted as an antioxidant, it has also been shown to improve glucose and ascorbate handling, increase eNOS activity, activate Phase II detoxification via the transcription factor Nrf2, and lower expression of MMP-9 and VCAM-1 through repression of NF-kappa B. LA and its reduced form, dihydrolipoic acid, may use their chemical properties as a redox couple to alter protein conformations by forming mixed disulfides. Beneficial effects are achieved with low micromolar levels of LA, suggesting that some of its therapeutic potential extends beyond the strict definition of an antioxidant. Current trials are investigating whether these beneficial properties of LA make it an appropriate treatment not just for diabetes, but also for the prevention of vascular disease, hypertension, and inflammation.

Is alpha-lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity.

The chemical reduction and oxidation (redox) properties of alpha-lipoic acid (LA) suggest that it may have potent antioxidant potential. A significant number of studies now show that LA and its reduced form, dihydrolipoic acid (DHLA), directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of insults where oxidative stress is part of the underlying etiology. However, owing to its limited and transient accumulation in tissues following oral intake, the efficacy of nonprotein-bound LA to function as a physiological antioxidant has been questioned. Herein, we review the evidence that the micronutrient functions of LA may be more as an effector of important cellular stress response pathways that ultimately influence endogenous cellular antioxidant levels and reduce proinflammatory mechanisms. This would promote a sustained improvement in cellular resistance to pathologies where oxidative stress is involved, which would not be forthcoming if LA solely acted as a transient ROS scavenger.

Infection by CagA-positive Helicobacter pylori strains in patients with ischemic heart disease: prevalence and association with exercise-induced electrocardiographic abnormalities.

The role of H. pylori infection in increasing the risk of ischemic heart diseases (IHD) is still debated. We determined serologically the prevalence of overall H. pylori and CagA-positive H. pylori infection in 63 consecutive patients with IHD and 189 gender- and age-matched controls. We also determined in patients the influence of the infection and the CagA serological status on the results of an exercise ECG test and other parameters considered possible variables that may enhance the risk of IHD. The prevalence of H. pylori infection in patients and controls was 79.3% and 73.0%, respectively (P = 0.403) and that of CagA-positive H. pylori infection was 69.8% and 42.3%, respectively (P = 0.0002). The scores of the ECG S-T segment and T-wave abnormalities in the course of an exercise ECG in uninfected patients and in patients infected by CagA-negative and CagA-positive H. pylori strains were (mean +/- SD): 1.59 +/- 0.67, 1.92 +/- 0.64, and 2.19 +/- 0.70, respectively; (P = 0.011, 95% confidence limits of difference 0.15-1.07, CagA-positive infected vs uninfected patients). There was no intergroup difference in the levels of peripheral white blood cells, glucose, cholesterol, triglycerides, creatinine, and systolic and diastolic pressure. In conclusion, genetic heterogeneity of H. pylori could possibly explain some conflicting results concerning the association of H. pylori infection with IHD. Coronary vessels of IHD patients infected by CagA-positive H. pylori strains may be damaged more severely than those of uninfected patients.

[Traumatic brain injury: differences among pedestrians and motor vehicle occupants]. / Traumatismo crânio-encefálico: diferenças das vítimas pedestres e ocupantes de veículos a motor.

OBJECTIVE: The purpose of this study was to discover the differences among victims who had traumatic brain injury due to traffic accidents. METHODS: Medical record of the head injury patients were analyzed according to their classification as traffic accident victims (pedestrian, motorcyclist or passenger and other motor vehicle deriver or passenger), age, gender, admission type (admitted from scene of the injury or from another hospital), duration of hospitalization, type of head injury, types of lesions present in other body segments and mortality. Patient's injury severity was measured by Injury Severity Score and head injury severity was analyzed using the ranking on the Glasgow Coma Scale, recorded by neurosurgeons during their first neuro assessment. All head injured patients admitted to a trauma center in S. Paulo city over a four-month period from March through June 1993, were included in the study. The sample was of 156 victims, with subsets of 80 pedestrians, 26 occupants of motorcycles and 50 occupants of other motor vehicles. RESULTS AND CONCLUSION: The results of this study showed that the mortality rate was higher in the pedestrian subset (25.0%) than among other victims and higher for motorcycle occupants (19.2%) than for motor vehicle victims (8.0%). Statistical differences between the subsets were established when the head injury severity variable was analyzed using the Glasgow Coma Scale. On the other hand, the differences between the three subsets was not statistically significant when the measurement used was the Injury Severity Score. Analyses of other variables showed important differences among subset distributions.