IgE responses to Ascaris and mite tropomyosins are risk factors for asthma.

BACKGROUND: The relationship between helminthiases and allergy is a matter of considerable interest and research. In the tropics, house dust mite exposure, a known risk factor for asthma, is frequently concurrent with helminth infections. It remains to be defined whether infection with the common roundworm Ascaris or its bystander immunological effects influence the prevalence and pathogenesis of asthma independently of mite sensitization. OBJECTIVE: To investigate the relationship between the IgE responses to Ascaris and its purified allergens and the risk of asthma in a tropical country. METHODS: A nested case-control study was performed in 356 subjects who reported current and past asthma symptoms (asthmatics) and 435 controls that had never experienced such symptoms. They were tested for serum levels of total IgE and specific IgE to Ascaris extract, Asc s 1 (ABA-1), Asc l 3 (tropomyosin) and GST (glutathione transferase). In addition, specific IgE to Dermatophagoides pteronyssinus, Blomia tropicalis and their tropomyosins Der p 10 and Blo t 10 was measured. Sensitization was defined as a positive specific IgE result to any extract or recombinant allergen. RESULTS: Sensitization to Ascaris and D. pteronyssinus was independently associated with asthma after adjustment for age, gender, socio-economic stratum, city and other IgE levels (adjusted ORs: 2.17; 95% CI 1.37-3.42 and 2.46; 95% CI 1.54-3.92), respectively. There was also a significant association with sensitization to the highly allergenic and cross-reactive tropomyosins Asc l 3, Blo t 10 and Der p10 (aORs: 1.76; 95% CI 1.21-2.57, 1.64; 95% CI 1.14-2.35 and 1.51; 95% CI 1.02-2.24), respectively. CONCLUSION AND CLINICAL RELEVANCE: IgE responses to Ascaris are associated with asthma symptoms in a population living in the tropics. Sensitization to the cross-reactive Ascaris and mite tropomyosins partially underlies this finding. These results have potential relevance in asthma diagnosis and management.

Impaired post exercise heart rate recovery in anabolic steroid users.

Previous study showed that muscle sympathetic nerve activity (MSNA) was augmented in anabolic steroids users (AASU). In the present study, we tested the hypothesis that the heart rate (HR) responses after maximal exercise testing would be reduced in AASU. 10 male AASU and 10 AAS nonusers (AASNU) were studied. Cardiopulmonary exercise was performed to assess the functional capacity and heart rate recovery. MSNA was recorded directly from the peroneal nerve by microneurography technique. Peak oxygen consumption (VO2) was lower in AASU compared to AASNU (43.66±2.24 vs. 52.70±1.68 ml/kg/min, P=0.005). HR recovery (HRR) at first and second minute was lower in AASU than AASNU (21±2 vs. 27±2 bpm, P=0.02 and 37±4 vs. 45±2 bpm, P=0.05, respectively). MSNA was higher in AASU than AASNU (29±3 vs. 20±1 bursts/min, P=0.01). Further analysis showed a correlation between HRR and MSNA (r=- 0.64, P=0.02), HRR at first minute and peak VO2 (r=0.70, P=0.01) and HRR at second minute and peak VO2 (r=0.62, P=0.02). The exacerbated sympathetic outflow associated with a lower parasympathetic activation after maximal exercise, which impairs heart rate recovery, strengthens the idea of autonomic imbalance in AASU.

Evidence for biological nitrification inhibition in Brachiaria pastures.

Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named "brachialactone," this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a gamma-lactone ring. It contributed 60-90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in Nitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH(4)(+)) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH(4)(+). Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment.

Sandfly saliva of Lutzomyia ovallesi (Diptera: Psychodidae) as a possible marker for the transmission of Leishmania in Venezuela Andes region.

BACKGROUND & OBJECTIVES: The saliva of the Phlebotominae is highly immunogenic to the vertebrate host and is a determining factor in the Leishmania infection. The aim of this work was to study the saliva of Lutzomyia ovallesi as a possible risk marker for the transmission of Leishmania. METHODS: Two populations of L. ovallesi from different geographical areas and subjected to different environmental conditions were compared by geometric morphometry of the wings, by protein profile analysis of salivary glands and by assessing the presence of anti-saliva protein in human sera confronted with laboratory L. ovallesi saliva. RESULTS: The results showed differences in the isometric size and structure of the wings but no allometric effects. Protein profiles of salivary glands of both the L. ovallesi populations studied were found to be similar, based on 11 protein bands with molecular weights ranging from 16 to 99 kDa. Anti-saliva antibodies were present in human sera, but human sera infected and uninfected with leishmaniasis could not be differentiated. INTERPRETATION & CONCLUSION: We conclude that the saliva of laboratory-reared L. ovallesi is representative of that of the wild population. It is suggested to study the presence of anti-saliva antibodies in other species of sandflies and mosquitoes.

Clinical Factors Associated with High Glycemic Variability Defined by Coefficient of Variation in Patients with Type 2 Diabetes.

BACKGROUND: High glycemic Variability (HGV) has become a stronger predictor of hypoglycemia. However, clinical factors associate with HGV still are unknown. OBJECTIVE: To determine clinical variables that were associated with a coefficient of variation (CV) above 36% evaluated by continuous glucose monitoring (CGM) in a group of patients with diabetes mellitus. METHODS: A cohort of patients with type 2 diabetes (T2D) was evaluated. Demographic variables, HbA1c, glomerular filtration rate (GFR) and treatment regimen were assessed. A bivariate analysis was performed, to evaluate the association between the outcome variable (CV> 36%) and each of the independent variables. A multivariate model was constructed to evaluate associations after controlling for confounding variables. RESULTS: CGM data from 274 patients were analyzed. CV> 36% was present in 56 patients (20.4%). In the bivariate analysis, demographic and clinical variables were included, such as time since diagnosis, hypoglycemia history, A1c, GFR and treatment established. In the multivariate analysis, GFR <45 mL/min (OR 2.81; CI 1.27,6.23; p:0.01), A1c > 9% (OR 2.81; CI 1.05,7.51; p:0.04) and hypoglycemia history (OR 2.09; CI 1.02,4.32; p:0.04) were associated with HGV. Treatment with iDPP4 (OR 0.39; CI 0.19,0.82; p:0.01) and AGLP1 (OR 0.08; CI 0.01,0.68; p:0.02) was inversely associated with GV. CONCLUSION: Clinical variables such as GFR <45 mL/min, HbA1C>9% and a history of hypoglycemia are associated with a high GV. Our data suggest that the use of technology and treatments able to reduce glycemic variability could be useful in this population to reduce the risk of hypoglycemia and to improve glycemic control.

Chronic HPA activity in mothers with preterm delivery: A pilot nested case-control study.

BACKGROUND: Chronic hypothalamic-pituitary-adrenal (HPA) axis activity role in the pathogenesis of preterm birth (PTB) remains unclear due to inconsistent measures with limited ability to monitor long-term cortisol concentrations. We explored this relationship using the novel method of assessing cortisol in hair, which is a valid and reliable measure of chronic HPA axis activity. METHODS: 137 participants (40 PTB cases and 97 controls from a birth cohort of pregnant women in Peru) were interviewed and invited to provide a 9-cm hair sample from the posterior vertex position of the scalp (mean = 13 weeks gestation). Hair cortisol concentration (HCC) was determined using luminescence immunoassay and values were natural-log transformed. PTB cases were defined as women who delivered before 37 gestational weeks. Case-control differences were assessed using multivariable linear and logistic regressions. RESULTS: Overall, combined pre-conception and first-trimester HCC was 13% lower among cases as compared with controls (p-value = 0.01). Compared with controls, maternal HCC among PTB cases were 14% (p = 0.11), 10% (p = 0.22) and 14% (p = 0.08) lower for 3-6 months pre-conception, 0-3 months pre-conception, and first trimester, respectively. After adjusting for putative confounders, a 1-unit increase in HCC was associated with 55% reduced odds of PTB (aOR = 0.45; 95% CI: 0.17-1.17). For a 1-unit increase in HCC in the scalp-intermediate and scalp-distal segments (representing HCC concentrations in 0-3 months pre-conception and first trimester), the corresponding odds for PTB were 0.53 (95% CI: 0.19-1.48) and 0.39 (95% CI: 0.13-1.13), respectively. CONCLUSIONS: Women who deliver preterm, as compared with those who deliver at term, have lower preconception and first trimester HCC. Our findings suggest that HPA axis activation, integral to the adaptive stress-response system, may be chronically dysregulated in women at increased risk of PTB.

Cardiovascular, metabolic and hormonal responses to the progressive exercise performed to exhaustion in patients with type 2 diabetes treated with metformin or glyburide.

OBJECTIVES: To evaluate the effects of Metformin and Glyburide on cardiovascular, metabolic and hormonal parameters during progressive exercise performed to exhaustion in the post-prandial state in women with type 2 diabetes (T2DM). DESIGN AND METHODS: Ten T2DM patients treated with Metformin (M group), 10 with Glyburide (G group) and 10 age-paired healthy subjects exercised on a bicycle ergometer up to exercise peak. Cardiovascular and blood metabolic and hormonal parameters were measured at times -60 min, 0 min, exercise end, and at 10 and 20 minutes of recovery phase. Thirty minutes before the exercise, a standard breakfast was provided to all participants. The diabetic patients took Metformin or Glyburide before or with meal. RESULTS: Peak oxygen uptake (VO(2)) was lower in patients with diabetes. Plasma glucose levels remained unchanged, but were higher in both diabetic groups. Patients with diabetes also presented lower insulin levels after meals and higher glucagon levels at exercise peak than C group. Serum cortisol levels were higher in G than M group at exercise end and recovery phase. Lactate levels were higher in M than G group at fasting and in C group at exercise peak. Nor epinephrine, GH and FFA responses were similar in all 3 groups. CONCLUSION: Progressive exercise performed to exhaustion, in the post-prandial state did not worsen glucose control during and after exercise. The administration of the usual dose of Glyburide or Metformin to T2DM patients did not influence the cardiovascular, metabolic and hormonal response to exercise.

Myths and realities about knowledge, attitudes and practices of household contacts of tuberculosis patients.

SETTING: Five Colombian cities: Villavicencio, Pereira, Cucuta, Bucaramanga and Bosa. OBJECTIVE: To describe the knowledge, attitudes and practices related to tuberculosis (TB) in household contacts (HHCs) of TB patients. METHODS: A cross-sectional study was conducted. The estimated sample size required was 855. The World Health Organization guide 'Advocacy, communication and social mobilization for TB control: a guide to developing knowledge, attitude and practice surveys' was translated into Spanish and adapted to the dialect of each city. HHCs were invited to participate in the study and included if they agreed. RESULTS: We interviewed 878 HHCs. Most of them knew that TB was transmitted by airborne droplets; however, 52.2% also said that TB could be transferred from one person to another by sharing plates or clothes or shaking hands. Fifty-five per cent of HHCs acquired TB-related information from health care workers, and 44% from family members and friends. Fear was the main reaction reported by HHCs when they were informed of a TB diagnosis (60%). Eighty-five per cent of HHCs answered that the community rejects or avoids TB cases. CONCLUSION: There are significant gaps in the knowledge about TB and the stigmatisation associated with it. Educational strategies should be designed together with the community to demystify many misconceptions about TB.

Preparing to launch the 'Thinking Healthy Programme' perinatal depression intervention in Urban Lima, Peru: experiences from the field.

BACKGROUND: An estimated 19-25% of perinatal women in low- and middle-income countries are affected by depression which, untreated, is associated with multiple health problems for mothers and children. Nonetheless, few perinatal women have access to depression care. The Thinking Healthy Programme (THP), promoted by the World Health Organization (WHO), is an evidence-based, non-specialist delivered depression intervention that addresses this care gap. However, the WHO THP manual explains intervention delivery but not the antecedents to implementation. Here, we describe a principled, planned approach leading to the implementation of THP in Lima, Peru by the non-profit organization Socios En Salud with community health workers (CHW) to inform its implementation in other settings. METHODS: The Replicating Effective Programs (REP) framework guided THP implementation, following four phases: (I) pre-conditions; (II) pre-implementation; (III) implementation; and (IV) maintenance and evolution. This paper centers on REP phases I and II, including (1) documented high perinatal depression rates in Peru; (2) designation of perinatal depression as a government priority; (3) THP Implementation Team orientation and training; (4) data collection plan development; (5) public health system coordination; (6) CHW selection and training; and (7) THP launch. RESULTS: Between December 2016 and March 2017, a THP training program was developed and seven CHW were trained to deliver the intervention to 10 perinatal women, the first of whom was enrolled on 17 April 2017. CONCLUSIONS: THP was rapidly implemented by a community-based organization with no prior experience in delivering non-specialist perinatal depression care. The steps followed may inform the implementation of THP in other settings.

Acute water ingestion increases arterial blood pressure in hypertensive and normotensive subjects.

In patients with severe autonomic dysfunction, water ingestion elicits an acute pressor response. Hypertension may be associated with changes in cardiovascular autonomic modulation, but there is no information on the acute effects of water ingestion in patients with hypertension. In this study, we compared the effect of acute water ingestion on haemodynamic and autonomic responses of hypertensive and normotensive individuals. Eight patients with mild hypertension were compared to 10 normotensive individuals. After 30 min resting in the supine position all subjects ingested 500 ml of water. At baseline and after water ingestion, venous blood samples for plasma volume determination were collected, and electrocardiographic tracings, finger blood pressure, forearm blood flow and muscle sympathetic nerve activity (MSNA) were obtained. Water ingestion resulted in similar and minor reduction in plasma volume. Systolic and diastolic blood pressure increased in both hypertensive (mean+/-s.d.: 19/14+/-6/3 mm Hg) and normotensive subjects (17/14+/-6/3 mm Hg). There was an increase in forearm vascular resistance and in MSNA. Heart rate was reduced (hypertensive: 5+/-1 beats/min, normotensive: 5+/-6 beats/min) and the high-frequency component of heart rate and systolic blood pressure variability was increased. In hypertensive and normotensive individuals, acute water ingestion elicits a pressor response, an effect that is most likely determined by an increased vasoconstrictor sympathetic activity, and is counterbalanced by an increase in blood pressure and heart rate vagal modulation.

Effects of diet and exercise training on neurovascular control during mental stress in obese women.

Since neurovascular control is altered in obese subjects, we hypothesized that weight loss by diet (D) or diet plus exercise training (D + ET) would improve neurovascular control during mental stress in obese women. In a study with a dietary reduction of 600 kcal/day with or without exercise training for 4 months, 53 obese women were subdivided in D (N = 22, 33 +/- 1 years, BMI 34 +/- 1 kg/m2), D + ET (N = 22, 33 +/- 1 years, BMI 33 +/- 1 kg/m2), and nonadherent (NA, N = 9, 35 +/- 2 years, BMI 33 +/- 1 kg/m2) groups. Muscle sympathetic nerve activity (MSNA) was measured by microneurography and forearm blood flow by venous occlusion plethysmography. Mental stress was elicited by a 3-min Stroop color word test. Weight loss was similar between D and D + ET groups (87 +/- 2 vs 79 +/- 2 and 85 +/- 2 vs 76 +/- 2 kg, respectively, P < 0.05) with a significant reduction in MSNA during mental stress (58 +/- 2 vs 50 +/- 2, P = 0.0001, and 59 +/- 3 vs 50 +/- 2 bursts/100 beats, P = 0.0001, respectively), although the magnitude of the response was unchanged. Forearm vascular conductance during mental stress was significantly increased only in D + ET (2.74 +/- 0.22 vs 3.52 +/- 0.19 units, P = 0.02). Weight loss reduces MSNA during mental stress in obese women. The increase in forearm vascular conductance after weight loss provides convincing evidence for D + ET interventions as a nonpharmacologic therapy of human obesity.

Molecular biological access to the chemistry of unknown soil microbes: a new frontier for natural products.

Cultured soil microorganisms have provided a rich source of natural-product chemistry. Because only a tiny fraction of soil microbes from soil are readily cultured, soil might be the greatest untapped resource for novel chemistry. The concept of cloning the metagenome to access the collective genomes and the biosynthetic machinery of soil microflora is explored here.

The Earth's bounty: assessing and accessing soil microbial diversity.

The study of microbial diversity represents a major opportunity for advances in biology and biotechnology. Recent progress in molecular microbial ecology shows that the extent of microbial diversity in nature is far greater than previously thought. Here, we discuss methods to analyse microorganisms from natural environments without culturing them and new approaches for gaining access to the genetic and chemical resources of these microorganisms.

High levels of transcription factor RpoS (sigma S) in mviA mutants negatively affect 1,2-propanediol-dependent transcription of the cob/pdu regulon of Salmonella typhimurium LT2.

Expression of the cobalamin biosynthetic (cob) and 1,2-propanediol utilization (cob/pdu) regulon of Salmonella typhimurium LT2 is controlled at the transcriptional level by global and specific regulatory proteins. In this paper we show that mutations in the mviA gene negatively affect cob/pdu transcription in response to 1,2-propanediol in the environment. The effects of mviA mutations were consistent with its role in the regulation of RpoS levels in the cell. Null mutations in rpoS eliminated the negative effect of mviA mutations on cob/pdu transcription, and restored growth on succinate, propionate and 1,2-propanediol. In addition, mviA mutants were deficient in the utilization of succinate, propionate and 1,2-propanediol as carbon and energy sources.

Effects of losartan combined with exercise training in spontaneously hypertensive rats.

We investigate whether combined treatment with losartan, an angiotensin II receptor blocker, and exercise training (ET) in spontaneously hypertensive rats (SHR) would have an additive effect in reducing hypertension and improving baroreflex sensitivity when compared with losartan alone. Male SHR (8 weeks old) were assigned to 3 groups: sedentary placebo (SP, N = 16), sedentary under losartan treatment (SL, N = 11; 10 mg kg-1 day-1, by gavage), and ET under losartan treatment (TL, N = 10). ET was performed on a treadmill 5 days/week for 60 min at 50% of peak VO2, for 18 weeks. Blood pressure (BP) was measured with a catheter inserted into the carotid artery, and cardiac output with a microprobe placed around the ascending aorta. The baroreflex control of heart rate was assessed by administering increasing doses of phenylephrine and sodium nitroprusside (iv). Losartan significantly reduced mean BP (178 16 vs 132 12 mmHg) and left ventricular hypertrophy (2.9 0.4 vs 2.5 0.2 mg/g), and significantly increased baroreflex bradycardia and tachycardia sensitivity (1.0 0.3 vs 1.7 0.5 and 2.0 0.7 vs 3.2 1.7 bpm/mmHg, respectively) in SL compared with SP. However, losartan combined with ET had no additional effect on BP, baroreflex sensitivity or left ventricular hypertrophy when compared with losartan alone. In conclusion, losartan attenuates hypertension and improves baroreflex sensitivity in SHR. However, ET has no synergistic effect on BP in established hypertension when combined with losartan, at least at the dosage used in this investigation.

Muscle sympathetic nerve activity and hemodynamic alterations in middle-aged obese women.

To study the relationship between the sympathetic nerve activity and hemodynamic alterations in obesity, we simultaneously measured muscle sympathetic nerve activity (MSNA), blood pressure, and forearm blood flow (FBF) in obese and lean individuals. Fifteen normotensive obese women (BMI = 32.5 +/- 0.5 kg/m2) and 11 age-matched normotensive lean women (BMI = 22.7 +/- 1.0 kg/m2) were studied. MSNA was evaluated directly from the peroneal nerve by microneurography, FBF was measured by venous occlusion plethysmography, and blood pressure was measured noninvasively by an autonomic blood pressure cuff. MSNA was significantly increased in obese women when compared with lean control women. Forearm vascular resistance and blood pressure were significantly higher in obese women than in lean women. FBF was significantly lower in obese women. BMI was directly and significantly correlated with MSNA, blood pressure, and forearm vascular resistance levels, but inversely and significantly correlated with FBF levels. Obesity increases sympathetic nerve activity and muscle vascular resistance, and reduces muscle blood flow. These alterations, taken together, may explain the higher blood pressure levels in obese women when compared with lean age-matched women.

[Heart rate response and its variability during different phases of maximal graded exercise]. / Comportamento da freqüência cardíaca e da sua variabilidade durante as diferentes fases do exercício físico progressivo máximo.

PURPOSE: Heart rate variability (HRV) has been studied at rest as a non-invasive tool for the assessment of cardiac autonomic control and, its attenuation is related to cardiovascular risk. However, during exercise, when important neural changes take place, HRV behaviour is not well established. The aim of this investigation was to study the heart rate (HR) and HRV responses during the different metabolic phases of maximal graded exercise in young men. METHODS: Seventeen men (age 28 +/- 6 years) were submitted to a graded cardiopulmonary exercise test in a cycloergometer (30W/3 min). To study HR and HRV (standard-deviation), the electrocardiographic signal was amplified and acquired beat-to-beat in a computer at a frequency of 125 Hz (AT/Codas). RESULTS: The HR increases concomitantly to the increase in exercise intensity. The HRV was significantly lower than rest values after exercise intensities of 60% of peak exercise oxygen uptake, 45-60% of maximal power and, after anaerobic threshold intensity. CONCLUSION: This results suggest that HRV measured by standard deviation of HR decreases during exercise phases when HR increment is determined mainly due to vagal withdrawal.

[Comparison between the prescription of physical training intensity based on the standard ergometric test and on the ergospirometric test]. / Comparação entre a prescrição de intensidade de treinamento físico baseada na avaliação ergométrica convencional e na ergoespirométrica.

PURPOSE: To compare the lower (LL) and upper limits (UL) of exercise intensity prescription based on standard exercise test (60-70% of estimated VO2max or 70-85% of HRmax measured) with exercise intensity prescription based on cardiopulmonary exercise test [anaerobic threshold (AT) and respiratory compensation point (RCP)]. METHODS: Fourty seven men (30 +/- 5 years) who were submitted to a progressive cardiopulmonary exercise test until exhaustion were divided in subgroups according to treadmill speed during exercise test (4 or 5 mph) and the physical capacity [lower (LPC) and moderate physical capacity (MPC)]. RESULTS: The LL of the indirect exercise intensity prescription showed VO2 and HR values significantly higher than VO2 and HR values measured at AT (4 mph = 34.4 +/- 4.5 vs 19.6 +/- 4.6 and 5 mph = 28.9 +/- 2 vs 18.9 +/- 5.4, and LPC = 32.0 +/- 4.1 vs 17.2 +/- 2.8 and MPC = 31.6 +/- 4.9 vs 21.1 +/- 5.7 mlO2.kg-1.min-1) and (4 mph = 128.9 +/- 7.8 vs 113.1 +/- 15.6 and 5 mph = 130.3 +/- 5.2 vs 114.1 +/- 18.9, and LPC = 127.6 +/- 7.2 vs 109.3 +/- 13.2 and MPC = 131.2 +/- 5.7 vs 117.4 +/- 19.2 bpm) The UL of the indirect exercise intensity prescription in 4 mph and LPC group showed VO2 values significantly higher than those measured at RCP (40.1 +/- 5.3 vs 32.2 +/- 4.3 and 37.4 +/- 4.8 vs 30.6 +/- 2.5 mlO2.kg-1.min-1, respectively), but similar HR values to those obtained at RCP. CONCLUSION: The LL of prescription based on standard exercise test overestimate the AT, whereas the UL seem adequate only for subjects with moderate physical capacity.