Executive Systems Constrain the Flexibility of Online Control in Children During Goal-Directed Reaching

We examined the influence of inhibitory load on online motor control in children. A sample of 129 school children was tested: younger, mid-age, and older children. Online control was assessed using a double-step perturbation paradigm across three trail types: non-jump, jump, and anti-jump. Results show that mid-aged children were able to implement online adjustments to jump trials as quickly as older children, but their performance on anti-jump trials regressed toward younger children. This suggests that rapid unfolding of executive systems during middle childhood may constrain the flexibility with which online control can be implemented, particularly when inhibitory demands are imposed.

Minimum inhibitory and bacterial concentrations of theaflavin and synergistic combinations with epicatechin and quercetin against clinical isolates of Stenotrophomonas Maltophilia

Stenotrophomonas maltophilia is an important nosocomial pathogen with intrinsic resistance to multiple antibiotics. Previous investigations have shown flavanols from black tea to possess antibacterial activity. This study describes the determination of minimum inhibitory concentrations and minimum bactericidal concentration for theaflavin independently and in formulations with the polyphenols epicatechin and quercetin against nine clinical isolates of Stenotrophomonas maltophilia and the control isolate NCTC 130141 via the microtitre assay. The results demonstrate that theaflavin has strong antibacterial activity and also shows significant synergism with epicatechin and quercetin. The minimum inhibitory concentrations of the isolates range between 200-400 g/mL for theaflavin and 100-200 g/mL for both theaflavin:epicatechin and theaflavin:quercetin combinations. The minimum bactericidal concentrations were discovered to be a 2 fold increase on those of the minimum inhibitory concentrations. The research highlights the potential use of polyphenols for the clinical treatment of highly antibiotic resistant bacteria.

The inhibitory effect of stevioside on bacillus cereus growth in milk: validation and its response surface optimization

Stevioside, a glycoside present in the leaves of Stevia rebaudiana Bertoni, offers therapeutic benefits such as anti-hyperglycemic, anti-hypertensive, antiinflammatory, anti-tumor, diuretic and immune influencing properties. In this work antimicrobial activity of stevioside against Bacillus cereus, a major source of milk contamination was investigated. The isolate was confirmed by various biochemical and 16S rRNA gene sequencing. The effect of temperature, incubation time and concentration of stevioside was optimized from a central composite response surface design. The standard plate count (SPC) of pasteurized milk was drastically reduced in comparison to toned and fresh milk. The optimal temperature, incubation time and stevioside concentration were observed to be 60.23°C, 21 h, and 275 μg/ mL respectively. The synergism of stevioside with the external factors (temperature and time) against B. cereus was observed. Our studies showed that addition of stevioside in fresh as well as pasteurised milk would control growth of B. cereus in milk.

The autonomic control and functional significance of the changes in heart rate associated with air breathing in the jeju, Hoplerythrinus unitaeniatus

The jeju is a teleost fish with bimodal respiration that utilizes a modified swim bladder as an air-breathing organ (ABO). Like all air-breathing fish studied to date, jeju exhibit pronounced changes in heart rate (f(H)) during air-breathing events, and it is believed that these may facilitate oxygen uptake (M-O2) from the ABO. The current study employed power spectral analysis (PSA) of f(H) patterns, coupled with instantaneous respirometry, to investigate the autonomic control of these phenomena and their functional significance for the efficacy of air breathing. The jeju obtained less than 5% of total M-O2 (M-tO2) from air breathing in normoxia at 26 degrees C, and PSA of beat-to-beat variability in fH revealed a pattern similar to that of unimodal water-breathing fish. In deep aquatic hypoxia (water P-O2=1 kPa) the jeju increased the frequency of air breathing (f(AB)) tenfold and maintained M-tO2 unchanged from normoxia. This was associated with a significant increase in heart rate variability (HRV), each air breath (AB) being preceded by a brief bradycardia and then followed by a brief tachycardia. These f(H) changes are qualitatively similar to those associated with breathing in unimodal air-breathing vertebrates. Within 20 heartbeats after the AB, however, a beat-to-beat variability in f(H) typical of water-breathing fish was re-established. Pharmacological blockade revealed that both adrenergic and cholinergic tone increased simultaneously prior to each AB, and then decreased after it. However, modulation of inhibitory cholinergic tone was responsible for the major proportion of HRV, including the precise beat-to-beat modulation of f(H) around each AB. Pharmacological blockade of all variations in f(H) associated with air breathing in deep hypoxia did not, however, have a significant effect upon f(AB) or the regulation of M-tO2. Thus, the functional significance of the profound HRV during air breathing remains a mystery.

The dorsal raphe nucleus exerts opposed control on generalized anxiety and panic-related defensive responses in rats

It has been proposed that the ascending dorsal raphe (DR)-serotonergic (5-HT) pathway facilitates conditioned avoidance responses to potential or distal threat, while the DR-periventricular 5-HT pathway inhibits unconditioned flight reactions to proximal danger. Dysfunction on these pathways would be, respectively, related to generalized anxiety (GAD) and panic disorder (PD). To investigate this hypothesis, we microinjected into the rat DR the benzodiazepine inverse receptor agonist FG 7142, the 5-HT1A receptor agonist 8-OH-DPAT or the GABA(A) receptor agonist muscimol. Animals were evaluated in the elevated T-maze (ETM) and light/dark transition test. These models generate defensive responses that have been related to GAD and PD. Experiments were also conducted in the ETM 14 days after the selective lesion of DR serotonergic neurons by 5,7-dihydroxytriptamine (DHT). In all cases, rats were pre-exposed to one of the open arms of the ETM 1 day before testing. The results showed that FG 7142 facilitated inhibitory avoidance, an anxiogenic effect, while impairing one-way escape, an anxiolytic effect. 8-OH-DPAT, muscimol, and 5,7-DHT-induced lesions acted in the opposite direction, impairing inhibitory avoidance while facilitating one-way escape from the open arm. In the light/dark transition, 8-OH-DPAT and muscimol increased the time spent in the lighted compartment, an anxiolytic effect. The data supports the view that distinct DR-5-HT pathways regulate neural mechanisms underlying GAD and PD. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Lateral parabrachial nucleus and central amygdala in the control of sodium intake

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Macrophage Migration Inhibitory Factor in the Paraventricular Nucleus Plays a Major Role in the Sympathoexcitatory Response to Salt

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Important GABAergic mechanism within the NTS and the control of sympathetic baroreflex in SHR

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Inhibitory Action of Neem Aqueous Extract (Azadirachta indica A. Juss) on the Vitellogenesis of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) Ticks

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of the medicinal plants Curcuma zedoaria and Camellia sinensis on halitosis control

Volatile sulphur compounds (VSC) are the gases mainly responsible for halitosis (bad breath). The aim of this research was to evaluate the effects of medicinal plants on halitosis control. Two commonly used plants were tested: Curcuma zedoaria and Camellia sinensis (green tea). These plants were prepared as an aqueous solution and used as mouthwashes, compared with a standard mouthwash of 0.12% chlorhexidine gluconate and a placebo (water). The experiment was conducted with 30 volunteers from the School of Dentistry of Sao Jose dos Campos, Univ. Estadual Paulista - UNESP, SP, Brazil. Each volunteer tested the four mouthwashes. The Cysteine Challenge Method, modified for this study, was used for initial breath standardization. Four breath assessments were conducted after volunteers rinsed orally with acetylcysteine: one before the test mouthwash was used; the second, one minute after its use; a third 90 minutes later; and the last 180 minutes later. The results showed that chlorhexidine gluconate lowered VSC production immediately, and that this effect lasted up to 3 hours, while the tested plants had immediate inhibitory effects but no residual inhibitory effects on VSC. We concluded that Curcuma zedoaria and Camellia sinensis, prepared as infusions and used as mouthwashes, did not have a residual neutralizing effect on VSC.

In vitro antifungal susceptibility of Candida spp. oral isolates from HIV-positive patients and control individuals

Oropharyngeal candidiasis is the most common fungal infection among HIV-positive patients. This condition can be treated with either systemic or topical antifungal agents; treatments are usually indicated empirically on the basis of clinical data. The knowledge of in vitro antifungal susceptibility is important to determine correct therapeutic guides for the treatment of fungal infections. Therefore, the objective of this study was to determine the antifungal susceptibility profile of oral Candida isolates from HIV-positive patients and control individuals. Amphotericin B, fluconazole, flucytosine, nystatin and ketoconazole were tested according to the methodology of microdilution proposed by the Clinical and Laboratory Standards Institute (CLSI); results were recorded in values of minimal inhibitory concentration (MIC). A total of 71 Candida isolates from HIV-positive patients were examined with the following species represented: C. albicans (59), C. tropicalis (9), C. glabrata (1), C. guilliermondii (1) and C. krusei (1). A total of 15 Candida isolates were evaluated from control individuals comprised of 11 C. albicans and 4 C. tropicalis samples. Our results demonstrated that the tested antifungal agents showed good activity for most isolates from both groups; however, variability in MIC values among isolates was observed.

Inhibitory activity of compounds isolated from Polymnia sonchifolia on aflatoxin production by Aspergillus flavus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Applications of the hexanic fraction of Agave sisalana Perrine ex Engelm (Asparagaceae): control of inflammation and pain screening

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immunologic aspects of West syndrome and evidence of plasma inhibitory effects on T cell function

OBJETIVO: O objetivo deste estudo foi determinar o perfil da deficiência imune em um grupo bem definido de epilepsia: crianças com síndrome de West (SW) e seus padrões EEG de evolução, idade-dependentes, como os complexos onda-aguda- onda lenta generalizadas da síndrome de Lenox-Gastaut (SLG) e as pontas multifocais independentes (PMI). MÉTODO: Um grupo de 50 crianças, 33 com SW, 10 com SLG, 7 com PMI e 20 crianças sadias (controle) foram avaliadas em relação aos seguintes parâmetros:determinação de subpopulações de linfócitos T (CD1, CD3, CD4 e CD8), relação CD4/CD8 e resposta proliferativa de linfócitos frente a fitohemaglutinina (PHA), na presença de plasma autólogo ou de plasma AB (homólogo). A prova cutânea de sensibilização ao Dinitroclorobenzeno (DNCB) foi realizada apenas nos pacientes. Os níveis séricos de IgG, IgA e IgM foram comparados aos valores normais em crianças Brasileiras, em diferentes faixas etárias. RESULTADOS: A resposta ao DNCB foi ausente ou fracamente reativa em 76% dos pacientes. Níveis séricos elevados de IgG (45,7%) e de IgM (61,4%) e baixos de IgA (23,9%) foram detectados nos pacientes. A determinação das subpopulações de linfócitos T em sangue periférico mostrou: deficiência nas proporções de células CD3+ (p<0,05) e de CD4+ (p<0,05), aumento de CD8+ (p<0,01) e diminuição da relação CD4 / CD8 (p<0,001). A proporção de células CD1+ no grupo controle manteve-se menor que 3%, enquanto que em 18% dos pacientes esses níveis variaram entre 3 e 11%. A resposta proliferativa de linfócitos frente a PHA revelou índices blastogênicos significativamente mais baixos apenas quando células dos pacientes foram cultivadas na presença do próprio plasma (plasma autólogo). Quando estas células foram cultivadas na presença de plasma AB, não se evidenciou diferença significativa em relação ao grupo controle. CONCLUSÃO: A imunodeficiência na SW caracterizou-se por: anergia, alteração de imunidade mediada por células e dos níveis de imunoglobulinas, presença de timócitos imaturos na circulação periférica e deficiência funcional de linfócitos T induzida por fatores plasmáticos inibidores. Discutem-se as principais evidências de disfunção imune como imunodeficiência e autoimunidade.

Central serotonergic and adrenergic/imidazoline inhibitory mechanisms on sodium and water intake

Recent studies have shown the existence of two important inhibitory mechanisms for the control of NaCl and water intake: one mechanism involves serotonin in the lateral parabrachial nucleus (LPBN) and the other depends on alpha(2)-adrenergic/imidazoline receptors probably in the forebrain areas. In the present study we investigated if alpha(2)-adrenergic/imidazoline and serotonergic inhibitory mechanisms interact to control NaCl and water intake. Male Holtzman rats with cannulas implanted simultaneously into the lateral ventricle (LV) and bilaterally into the LPBN were used. The ingestion of 0.3 M NaCl and water was induced by treatment with the diuretic furosemide (10 mg/kg of body weight)+the angiotensin converting enzyme inhibitor captopril (5 mg/kg) injected subcutaneously 1 h before the access of rats to water and 0.3 M NaCl. Intracerebroventricular (i.c.v.) injection of the alpha(1)-adrenergic/imidazoline agonist clonidine (20 nmol/l RI) almost abolished water (1.6 +/- 1.2, vs. vehicle: 7.5 +/- 2.2 ml/2 h) and 0.3 M NaCl intake (0.5 +/- 0.3, vs. vehicle: 2.2 0.8 ml/2 h). Similar effects were produced by bilateral injections of the 5HT(2a/2b) serotonergic agonist 2,5-dimetoxy-4-iodoamphetamine (DOI, 5 mug/0.2 mul each site) into the LPBN on water (3.6 +/- 0.9 ml/2 h) and 0.3 M NaCl intake (0.4 +/- 0.2 m1/2 h). Injection of the (alpha(2)-adrenergic/imidazoline antagonist idazoxan (320 nmol) i.c.v. completely blocked the effects of clonidine on water (8.4 +/- 1.5 ml/2 h) and NaCl intake (4.0 +/- 1.2 ml/2 h), but did not change the effects of LPBN injections of DOI on water (4.2 +/- 1.0 ml/2 h) and NaCl intake (0.7 +/- 0.2 ml/2 h). Bilateral injections of methysergide (4 mug/0.2 mul each site) into the LPBN increased 0.3 M NaCl intake (6.4 +/- 1.9 ml/2 h), not water intake. The inhibitory effect of i.c.v. clonidine on water and 0.3 M NaCl was still present after injections of methysergide into the LPBN (1.5 +/- 0.8 and 1.7 +/- 1.4 ml/2 h, respectively). The results show that the inhibitory effects of the activation of a,-adrenergic/imidazoline receptors in the forebrain are still present after blockade of the LPBN serotonergic mechanisms and vice versa for the activation of serotonergic mechanisms of the LPBN. Therefore, each system may act independently to inhibit NaCl and water intake. (C) 2002 Elsevier B.V. B.V. All rights reserved.