Venous Pulse Wave Velocity variation in response to a simulated fluid challenge in healthy subjects

Purpose: The evaluation of a mini or simulated fluid challenge is still a complex and open issue in the clinical setting and it is of paramount significance for the fluid therapy optimization. We here investigated the capacity of a new hemodynamic parameter, the venous Pulse Wave Velocity (vPWV), to detect the effect of passive leg raising (PLR). Materials and methods: In 15 healthy volunteers (7 M, 8 F, age 26 ± 3) venous pressure pulses were elicited by pneumatic compressions of the left hand and proximally detected by ultrasound for calculation of the vPWV. We also non-invasively measured the basilic vein (BV) cross-sectional perimeter, and peripheral venous pressure (PVP). The PLR manoeuvre was performed twice to evaluate reliability of the assessment. Results: The PLR had an overall statistically significant effect on the entire set of variables (MANOVA, p < 0.05): vPWV increased from 2.11 ± 0.46 to 2.30 ± 0.47 m/s (p = 0.01; average increase: 10%). This effect was transient and dropped below 5% after about 3 min. A significant increase was also exhibited by BV size and PVP. In consecutive measurements vPWV showed little intra-subject variability (CoV = 8%) and good reliability (ICC = 0.87). Finally, the vPWV responses to the two PLRs exhibited good agreement (paired T-test: p = 0.96), and moderate reliability (ICC = 0.57). Conclusion: These results demonstrated that vPWV can be non-invasively, objectively and reliably measured in healthy subjects and that it is adequate to detect small pressure/volume variations, as induced by PLR-from-supine. These characteristics make it suitable for clinical applications

Aplicação da espectroscopia no infravermelho próximo e médio na avaliação da biomassa microbiana do solo.

A biomassa microbiana tem sido um bom indicador da qualidade do solo devido à sua importante participação nos ciclos biogeoquímicos e à sua interação com a matéria orgânica e minerais presentes no solo. O método comumente utilizado em laboratório para sua determinação é o proposto por Vance et al. (1987), que envolve processos de fumigação e extração, além etapas de preparação de amostras. Por outro lado, a espectroscopia de infravermelho tem sido proposta para a análise de solos e produtos agrícolas, em substituição aos métodos clássicos, pela economia de tempo e custo. Entretanto, a utilização da espectroscopia de infravermelho próximo (NIRS) e médio (DRIFTS) nas análises de solos depende da construção de modelos preditivos que correlacionem os dados espectroscópicos com os valores obtidos com um método de referência. Desse modo, para avaliar a aplicabilidade dessas técnicas na determinação de carbono microbiano (CMIC), nitrogênio microbiano (NMIC) e respiração basal do solo (RB), foram utilizadas amostras provenientes da Fazenda Capivara, pertencente à Embrapa Arroz e Feijão (CNPAF), em Santo Antônio de Goiás-GO, e da Fazenda Canchim, pertencente à Embrapa Pecuária Sudeste (CPPSE), em São Carlos-SP. Os dados de biomassa obtidos com o método utilizado como referência (fumigação-extração) foram correlacionados com os dados de absorbância em infravermelho pelo método PLS (Partial Least Squares), em dois subgrupos amostrais segundo a localidade (CNPAF e CPPSE), assim como em todas as amostras. Os testes de validação dos modelos de regressão construídos confirmaram que há relação quantitativa entre os espectros de infravermelho e os parâmetros de biomassa microbiana, sendo os coeficientes de regressão máximos encontrados iguais a 0,82 para CMIC; 0,76 para NMIC e 0,70 para RB.bitstream/item/64194/1/boletimdepesquisa-38.pd

Acute inhibition of estradiol synthesis impacts vestibulo-ocular reflex adaptation and cerebellar long-term potentiation in male rats

The vestibulo-ocular reflex (VOR) adaptation is an ideal model for investigating how the neurosteroid 17 beta-estradiol (E2) contributes to the modification of behavior by regulating synaptic activities. We hypothesized that E2 impacts VOR adaptation by affecting cerebellar synaptic plasticity at the parallel fiber–Purkinje cell (PF) synapse. To verify this hypothesis, we investigated the acute effect of blocking E2 synthesis on gain increases and decreases in adaptation of the VOR in male rats using an oral dose (2.5 mg/kg) of the aromatase inhibitor letrozole. We also assessed the effect of letrozole on synaptic plasticity at the PF synapse in vitro, using cerebellar slices from male rats. We found that letrozole acutely impaired both gain increases and decreases adaptation of the VOR without altering basal ocular-motor performance. Moreover, letrozole prevented long-term potentiation at the PF synapse (PF-LTP) without affecting long-term depression (PF-LTD). Thus, in male rats neurosteroid E2 has a relevant impact on VOR adaptation and affects exclusively PF-LTP. These findings suggest that E2 might regulate changes in VOR adaptation by acting locally on cerebellar and extra-cerebellar synaptic plasticity sites

Espectroscopia de infravermelho na determinação da textura do solo.

A aplicação de técnicas espectroscópicas que utilizam a radiação infravermelha (NIRS-Near Infrared Spectroscopy e DRIFTS-Diffuse Reflectance Fourier Transformed Spectroscopy ) na análise inorgânica do solo tem sido proposta desde a década de 1970, mas até os dias atuais são raros os métodos implementados rotineiramente no Brasil. Isso deve-se à dificuldade em construir modelos de calibração, por meio de métodos estatísticos multivariados, utilizando-se amostras reais de solo, de constituição complexa, que varia geograficamente e de acordo com o manejo. Por isso, os objetivos deste trabalho foram construir modelos de calibração em NIRS e DRIFTS para a quantificação das frações de argila e areia, em amostras de solos de classes diferentes - Latossolo Vermelho (predominante), Nitossolo, Argissolo Vermelho e Neossolo Quartzarênico - e avaliar qual dessas duas técnicas é mais adequada para essa finalidade, assim como a interferência do agrupamento de amostras e da seleção de variáveis espectrais na qualidade desses modelos. Para isso, valores de referência obtidos pelo método do densímetro, método largamente utilizado nos laboratórios de análise de solo, foram correlacionados com valores de absorbância em NIRS e DRIFTS pela ferramenta estatística PLS (Partial Least Squares ), obtendo-se altos coeficientes de determinação (R 2), de 0,95, 0,90 e 0,91 para argila, silte e areia, respectivamente, na validação externa. Isso confirma a aplicabilidade das técnicas espectroscópicas na análise granulométrica do solo para fins agrícolas. O agrupamento das amostras segundo a localização e a seleção de variáveis espectrais pouco influenciou na qualidade dos modelos. A técnica espectroscópica mais indicada para essa finalidade foi a DRIFT

pharmacokinetic pharmacodynamic evaluation of the efficacy of flumequine in treating colibacillosis in turkeys

Abstract Flumequine (FLU) is used in the treatment of systemic bacterial infections in poultry, including colibacillosis, which is a common disease in turkeys. The pharmacokinetic (PK) behavior of FLU administered to 32 healthy turkeys as an oral bolus via gavage or as 10-h pulsed administration in drinking water were compared, using the authorized dose of 15 mg/kg and the double dose of 30 mg/kg. The minimum inhibitory concentrations (MIC) of 235 Escherichia coli field strains isolated from poultry were determined for pharmacodynamics (PD) to develop a PK/PD model. Blood samples were collected at established times over 24 h, and the obtained plasma was analyzed using a liquid chromatography tandem mass spectrometry method that was validated in-house. A monocompartmental model and a noncompartmental model were applied to the data to obtain the PK results. For both types of administration and both dosages, the ratios of the maximum concentration (Cmax)/MIC50 and the area under the plasma concentration-time curve (AUC)/MIC50 achieved were considerably lower than the fluoroquinolone breakpoints usually adopted for efficacy. The Cmax/MIC50 and AUC0–24/MIC50 ratios were, respectively, 0.67 ± 0.09 and 4.76 ± 0.48 and 1.18 ± 0.35 and 7.05 ± 2.40 for the 15 and 30 mg/kg bolus doses, respectively. After 10-h pulsed administration of 15 mg/kg, values of Cmax/MIC50, 0.19 ± 0.02 on d 1 and 0.30 ± 0.08 on d 5 of therapy were obtained, the AUC/MIC50 ratios were 2.09 ± 0.29 and 3.22 ± 0.93 on d 1 and 5, respectively. Higher values were obtained with the doubled dose of 30 mg/kg: the Cmax/MIC50 ratios were 0.49 ± 0.11 on d 1 and 0.69 ± 0.18 on d 5; the AUC/MIC50 ratios were 5.15 ± 1.15 and 6.57 ± 1.92 on d 1 and 5, respectively. Based on these results, FLU administration should be adopted when specific diagnostic findings indicate its efficacy, and revising the dosage scheme to comply with the prudent and responsible use of antimicrobials in veterinary medicine is advisable

Sensory inflow manipulation induces learning-like phenomena in motor behavior

© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: Perceptual and goal-directed behaviors may be improved by repetitive sensory stimulations without practice-based training. Focal muscle vibration (f-MV) modulating the spatiotemporal properties of proprioceptive inflow is well-suited to investigate the effectiveness of sensory stimulation in influencing motor outcomes. Thus, in this study, we verified whether optimized f-MV stimulation patterns might affect motor control of upper limb movements. Methods: To answer this question, we vibrated the slightly tonically contracted anterior deltoid (AD), posterior deltoid (PD), and pectoralis major muscles in different combinations in forty healthy subjects at a frequency of 100 Hz for 10 min in single or repetitive administrations. We evaluated the vibration effect immediately after f-MV application on upper limb targeted movements tasks, and one week later. We assessed target accuracy, movement mean and peak speed, and normalized Jerk using a 3D optoelectronic motion capture system. Besides, we evaluated AD and PD activity during the tasks using wireless electromyography. Results: We found that f-MV may induce increases (p \u3c 0.05) in movement accuracy, mean speed and smoothness, and changes (p \u3c 0.05) in the electromyographic activity. The main effects of f-MV occurred overtime after repetitive vibration of the AD and PD muscles. Conclusion: Thus, in healthy subjects, optimized f-MV stimulation patterns might over time affect the motor control of the upper limb movement. This finding implies that f-MV may improve the individual’s ability to produce expected motor outcomes and suggests that it may be used to boost motor skills and learning during training and to support functional recovery in rehabilitation

Type 1 diabetes, diabetic nephropathy, and pregnancy: a systematic review and meta-study

BACKGROUND: In the last decade, significant improvements have been achieved in maternal-fetal and diabetic care which make pregnancy possible in an increasing number of type 1 diabetic women with end-organ damage. Optimal counseling is important to make the advancements available to the relevant patients and to ensure the safety of mother and child. A systematic review will help to provide a survey of the available methods and to promote optimal counseling. OBJECTIVES: To review the literature on diabetic nephropathy and pregnancy in type 1 diabetes. METHODS: Medline, Embase, and the Cochrane Library were scanned in November 2012 (MESH, Emtree, and free terms on pregnancy and diabetic nephropathy). Studies were selected that report on pregnancy outcomes in type 1 diabetic patients with diabetic nephropathy in 1980-2012 (i.e. since the detection of microalbuminuria). Case reports with less than 5 cases and reports on kidney grafts were excluded. Paper selection and data extraction were performed in duplicate and matched for consistency. As the relevant reports were highly heterogeneous, we decided to perform a narrative review, with discussions oriented towards the period of publication. RESULTS: Of the 1058 references considered, 34 fulfilled the selection criteria, and one was added from reference lists. The number of cases considered in the reports, which generally involved single-center studies, ranged from 5 to 311. The following issues were significant: (i) the evidence is scattered over many reports of differing format and involving small series (only 2 included over 100 patients), (ii) definitions are non-homogeneous, (iii) risks for pregnancy-related adverse events are increased (preterm delivery, caesarean section, perinatal death, and stillbirth) and do not substantially change over time, except for stillbirth (from over 10% to about 5%), (iv) the increase in risks with nephropathy progression needs confirmation in large homogeneous series, (v) the newly reported increase in malformations in diabetic nephropathy underlines the need for further studies. CONCLUSIONS: The heterogeneous evidence from studies on diabetic nephropathy in pregnancy emphasizes the need for further perspective studies on this issue

Toxicity and activity of docetaxel in anthracycline-pretreated breast cancer patients: a phase II study

: Docetaxel has proven effective in advanced breast cancer. Myelosuppression and cumulative fluid retention syndrome are troublesome, potentially avoidable toxicities. In this consecutive cohort study, docetaxel (100 mg/m2 by 1 hour i.v. infusion, q3 weeks) activity and toxicity was explored in 56 anthracycline-pretreated patients (eligible: 55: median age: 51 years [range: 28-68 years]; median performance status: 0 [range: 0-3]) with metastatic breast cancer, using two different granulocyte colony-stimulating factor and steroid pre- and postmedication schedules. Twenty-nine patients (group A) received a 5-day oral prednisone premedication, and 26 (group B) received 4-day low-dose i.m. dexamethasone; group B patients also received prophylactic granulocyte colony-stimulating factor. All patients were evaluable for toxicity and 53 for response. Prophylactic granulocyte colony-stimulating factor significantly lowered the incidence of grade III-IV neutropenia and neutropenic fever (p = 0.0001 and 0.01, respectively). The incidence of moderate-severe fluid retention syndrome was lower in patients receiving i.m. dexamethasone (p = 0.08). Overall response rate was 53% (4 complete responses/24 partial responses, 95% confidence interval 39.4-66.2%); 32% have stable disease and 15% progressive disease. In 21 anthracycline-refractory/resistant patients, as well as in 10 paclitaxel-pretreated patients, the overall response rate was 50%. Docetaxel is highly active in anthracycline- and paclitaxel-pretreated metastatic breast cancer, with manageable toxicity. Optimal use of both granulocyte colony-stimulating factor support and steroid premedication deserves further investigation