Towards single cell ICP-MS normalized quantitative experiments using certified selenized yeast.

In the search for a normalized procedure to replicate and compare single cell-inductively coupled plasma-mass spectrometry (SC-ICP-MS) experiments, SELM-1, a certified reference material containing selenium enriched yeast cells has been used. Selenium concentrations (both, intra- and extracellular) have been measured using either sequential or simultaneous procedures. Regarding quantitative results, the sequential procedure involving cell washing followed by freeze drying of the washed material and intracellular Se quantification using SC-ICP-MS provided best results. In this case, intracellular Se accounted for 1304 ± 48 mg kg-1 (corresponding to 64% of the certified Se content). The average mass of Se per yeast cell was 41.6 fg Se with a dispersion of 1.6-279 fg Se/cell. In the isolated extracellular Se fraction, the Se concentration accounted for 412 ± 48 mg kg-1 (about 21% of the total Se). Thus, the sequential procedure provided a total Se recovery of about 85% with respect to the certified value. The direct dilution and simultaneous measurement of intra- and extracellular Se by SC-ICP-MS provided results of 1024 ± 42 mg kg-1 for intracellular and 316 ± 30 mg kg-1 for extracellular Se representing a total recovery of about 66%. In both cases, an initial thorough characterization of the cell density per solid weighed material was conducted by flow cytometry and the cell integrity ensured using confocal microscopy. These results clearly demonstrated that with appropriate sample preparation, SC-ICP-MS is a unique tool, which is capable of providing quantitative information about intracellular and extracellular Se. In addition, SELM-1 seems the ideal tool to enable data normalization at the single cell level to replicate, benchmark, and improve new SC-ICP-MS studies by using the same material for data validation.

Microwave-induced combustion for petroleum coke digestion: a promising sample preparation strategy for subsequent elemental determination.

The increasing demand for the elemental determination of petrochemical samples by inductively coupled plasma techniques requires the development of suitable sample preparation methods that permit high sample throughput and are in accordance with green chemistry recommendations. For this aim, the development of microwave-induced combustion (MIC) method has been attempted to completely digest petroleum coke samples and address quantitative determination of elements, such as Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Mg, Mn, Mo, Na, Ni, Pb, Sr, V and Zn, by inductively coupled plasma optical emission spectrometry (ICP OES). A sequential procedure to evaluate the sample mass and the solution to retain the analytes quantitatively was first conducted. Satisfactory results were obtained (residual carbon content in final solutions was lower than 0.5%) by digesting 400 mg of samples using 20 bar of oxygen and analytes were quantitatively retained in a dilute acid solution such as 4.2 mol L-1 HNO3. An agreement better than 87% was achieved using certified reference materials and the performance of the proposed method was also compared to that of the standard procedure recommended by the American Society of Testing and Materials ASTM D 5600. Despite both methods producing similar results, the proposed method by MIC was much simpler, offered a higher sample throughput and the digests were compatible with ICP OES measurements avoiding interferences in the determination step compared the ASTM D 5600 method. These results clearly demonstrated that the proposed MIC method in combination with ICP OES could be a promising alternative to obtain quantitative information about the elemental composition of petroleum coke.

Sluggish anion transport provides good kinetic stability to the anhydrous anti-perovskite solid electrolyte Li3OCl.

Some lithium oxyhalides have been proposed as low-cost solid electrolytes for having room-temperature Li+ conductivity close to commercial liquid electrolytes, but with the advantages of enabling higher energy densities through the use of the Li metal anode and not being flammable. However, the stability of anhydrous anti-perovskite lithium oxyhalides, such as Li3OCl, is not well understood yet: whereas theoretical calculations show they should decompose into lithium halides and Li2O (except at high temperatures), there is no experimental evidence of such decomposition. Thus, here we use a combination of analytical calculations and force-field-based atomistic modelling to investigate the role of kinetics in the stability of anhydrous Li3OCl. The results show that due to sluggish Cl- and O2- transport this material has good kinetic stability below ∼400 K under high concentration gradients, below ∼450 K under typical cell voltages, and at all temperatures against local composition fluctuations. Furthermore, the good kinetic stability explains the apparent discrepancy between theoretical thermodynamics calculations and experimental observations and contributes to enlighten the nature and extent of this material's stability. The methods presented here can also be extended to other battery materials that are predicted to decompose, to access the safe temperature range they can undergo without degrading.

Dose to the interventional radiologist in CTF-guided procedures.

The aim of this work was to assess the occupational dose received by an interventional radiologist (IR) during computed tomography fluoroscopy (CTF)-guided procedures; to identify the most exposed areas of the body including the hands and fingers; to suggest recommendations for individual monitoring; and to improve radiation safety of the practice. A total of 53 CTF-guided procedures were studied. Twelve whole-body dosimeters were worn by the IR in each procedure for the assessment of the personal dose equivalent, Hp(10), on the chest, waist, and back, both over and under the lead apron, as well as the personal dose equivalent, Hp(0.07), on both arms, knees, and feet. Special gloves with casings to fit extremity dosimeters were prepared to assess Hp(0.07) to the fingers. The measured chest dose values were higher than those on the waist and back; the dominant hand or the left side was the most exposed. In general, the ring, middle, and index fingers of the dominant hand were the most exposed (maximum in the 36-39 mSv range), while wrist dose was negligible compared to finger doses. Based on the results obtained the following recommendations are suggested: protective devices (lead aprons, thyroid shield, and goggles) should be worn; Hp(10) should be assessed at the chest level both above and below the lead apron; finger doses can be measured on the basis of each middle finger; the arm closer to the beam should be monitored; and finally, a wrist dosimeter will not provide useful information.

TYPE TESTING OF LiF:Mg,Cu,P (TLD-100H) WHOLE-BODY DOSEMETERS FOR THE ASSESSMENT OF Hp(10) AND Hp(0.07).

In this work, the initial results of the type testing of the LiF:Mg,Cu,P (TLD-100H) whole-body personal dosemeters are presented. An assessment of reproducibility, linearity of the response, the residual signal as a function of the dose, energy and angular dependence of the response was performed. In general, the dosemeters show good reproducibility for different dose values and a linear behaviour for a range between 0.1 and 300 mSv. The detection limits obtained are lower than 50 µSv. The system presents a good energy and angular response for different radiation qualities.

A simple and automated sample preparation system for subsequent halogens determination: Combustion followed by pyrohydrolysis.

A simple and automated system based on combustion followed by a pyrohydrolysis reaction was proposed for further halogens determination. This system was applied for digestion of soils containing high (90%) and also low (10%) organic matter content for further halogens determination. The following parameters were evaluated: sample mass, use of microcrystalline cellulose and heating time. For analytes absorption, a diluted alkaline solution (6 mL of 25 mmol L-1 NH4OH) was used in all experiments. Up to 400 mg of soil with high organic matter content and 100 mg of soil with low organic matter content (mixed with 400 mg of cellulose) could be completely digested using the proposed system. Quantitative results for all halogens were obtained using less than 12 min of sample preparation step (about 1.8 min for sample combustion and 10 min for pyrohydrolysis). The accuracy was evaluated using a certified reference material of coal and spiked samples. No statistical difference was observed between the certified values and results obtained by the proposed method. Additionally, the recoveries obtained using spiked samples were in the range of 98-103% with relative standard deviation values lower than 5%. The limits of quantification obtained for F, Cl, Br and I for soil with high (400 mg of soil) and low (100 mg of soil) organic matter were in the range of 0.01-2 µg g-1 and 0.07-59 µg g-1, respectively. The proposed system was considered as a simple and suitable alternative for soils digestion for further halogens determination by ion chromatography and inductively coupled plasma mass spectrometry techniques.

Cleaning cassava genotypes infected with cassava frogskin disease via in vitro shoot tip culture.

This study aimed to develop a methodology for eliminating cassava frogskin disease (CFSD) from in vitro shoot tip culture by associating thermotherapy and tetracycline. Cuttings from different accessions (BGM0232, BGM0315, BGM0464, BGM584, BGM0841, and BGM1342), infected with CFSD according to visual inspection of the disease symptoms, were used for cleaning. To verify the absence of other diseases, the plants were indexed for Cassava common mosaic virus - CsCMV (by ELISA) and Cassava vein mosaic virus - CsVMV (by polymerase chain reaction, PCR), proving that the accessions were free of these viruses, except for BGM0315 and BGM0464, which were infected with CsVMV. Subsequently, the cuttings were submitted to different tetracycline concentrations for 3 min, and then subjected to thermotherapy under different temperatures (35°, 38°, 40°, 45°, and 55°C). Shoots of 2 cm were harvested, and their surfaces were sterilized in a laminar flow chamber. Subsequently, the shoot tips of different sizes were removed (0.2, 0.4, 0.5, and 1.0 mm) for inoculation in a culture medium with tetracycline at the same concentrations in which the cuttings were dipped. After 60 days of cultivation, the explants were transferred to a multiplication medium without antibiotics. Thirty days after the transfer, the viability of the regenerated plants was evaluated, which were then acclimatized for 70 days in a greenhouse and transferred to the field. After 7 months, a visual analysis of the symptomatic roots and a PCR analysis were held to prove the elimination of CFSD and CsVMV from the accessions infected with these viruses (BGM0315 and BGM0464), respectively. Most of the treatments resulted in 100% cleaning of CFSD-infected plants. From accessions that were also infected with CsVMV, only 2% of the plants remained infected, also demonstrating the cleaning efficiency of this protocol for this disease.

Multitechnique Determination of Halogens in Soil after Selective Volatilization Using Microwave-Induced Combustion.

A method for digestion of soils with high inorganic matter content (ranging from 50 to 92%) by microwave-induced combustion (MIC) is proposed for the first time for further halogens (F, Cl, Br, and I) determination by ion chromatography (IC) and also by inductively coupled plasma mass spectrometry (ICP-MS). Microcrystalline cellulose (100-500 mg), used as a combustion aid, was mixed with sample and water or NH4OH solutions (10-100 mmol L-1) were investigated for analytes absorption. The use of cellulose (400 mg) was mandatory to volatilize the halogens from soils with high inorganic matter. It was possible to use diluted absorbing solutions (up to 100 mmol L-1 NH4OH) for halogens retention, providing limits of quantification in the range of 0.06 (I) to 60 (Cl) µg g-1. Accuracy was evaluated using certified reference materials (CRMs), spiked samples, and pyrohydrolysis method. Recoveries for halogens after spiked samples were in the range of 94 to 103% and the results after digestion of CRMs by MIC were in agreement better than 95% to certified values. Blanks were low, relative standard deviation was below 8% for all soils and no statistical difference was observed for results by pyrohydrolysis and MIC methods showing the feasibility of the proposed method for further halogens determination in soil samples.

Controlling stomatal aperture in semi-arid regions-The dilemma of saving water or being cool?

Stomatal regulation of leaf gas exchange with the atmosphere is a key process in plant adaptation to the environment, particularly in semi-arid regions with high atmospheric evaporative demand. Development of stomata, integrating internal signaling and environmental cues sets the limit for maximum diffusive capacity of stomata, through size and density and is under a complex genetic control, thus providing multiple levels of regulation. Operational stomatal conductance to water vapor and CO2 results from feed-back and/or feed-forward mechanisms and is the end-result of a plethora of signals originated in leaves and/or in roots at each moment. CO2 assimilation versus water vapor loss, proposed to be the subject of optimal regulation, is species dependent and defines the water use efficiency (WUE). WUE has been a topic of intense research involving areas from genetics to physiology. In crop plants, especially in semi-arid regions, the question that arises is how the compromise of reducing transpiration to save water will impact on plant performance through leaf temperature. Indeed, plant transpiration by providing evaporative cooling, is a major component of the leaf energy balance. In this paper we discuss the dilemma of 'saving water or being cool' bringing about recent findings from molecular genetics, to development and physiology of stomata. The question of 'how relevant is screening for high/low WUE in crops for semi-arid regions, where drought and heat co-occur' is discussed.

Clinical and genetic investigation of a Brazilian family with Huntington's disease.

The aim of this study was to investigate a Brazilian family carrying full penetrance alleles for Huntington's disease (HD) in order to correlate each member's genetic and clinical features. To this end, the following scales were administered in each patient: the Beck Depression Inventory, the Mini-Mental State Examination (MMSE) and the Unified Huntington's Disease Rating Scale (UHDRS). The patterns of CAG and CCG polymorphic regions in the HTT gene were determined, the disease burden score was calculated, and genotypes were correlated with phenotypes within this family. We suggest that HD duration, the number of years of formal education, and UHDRS status variables can explain 96.6% of the MMSE variability in HD patients. A strong significant correlation was found between the disease burden score and the UHDRS (r = 0.76; p-value = 0.049) and the MMSE (r = -0.90; p-value = 0.006). The correlations between CAG allele size and the three clinical evaluations performed in the HD patients were not statistically significant.

Microwave-induced combustion of crude oil for further rare earth elements determination by USN-ICP-MS.

A procedure for light and heavy crude oils digestion by microwave-induced combustion (MIC) is proposed for the first time for further rare earth elements (REE) determination by inductively coupled plasma mass spectrometry (ICP-MS) equipped with an ultrasonic nebulizer (USN). Samples of crude oil (API density of 10.8-23.5, up to 250 mg) were inserted in polycarbonate capsules and combusted using 20 bar of oxygen and 50 µL of 6 mol L(-1) ammonium nitrate as igniter. Nitric acid solutions (1-14.4 mol L(-1)) were evaluated for analyte absorption and a reflux step was applied after combustion (5 min of microwave irradiation at 1400 W) in order to achieve better analyte recoveries. Accuracy was evaluated using a spiked sample and also by comparison of results obtained by microwave-assisted digestion combined to ultraviolet radiation (MW-UV) and by neutron activation analysis (NAA). Using 3 mol L(-1) HNO3, quantitative recoveries (better than 97%) were obtained for all analytes. Blank values were always negligible. Agreement was higher than 96% for La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y by comparison of results with those obtained by MW-UV and by NAA (only for La, Ce, Nd, Sm, and Yb). Residual carbon content in digests using MIC was always below 1%. As an advantage over conventional procedures for crude oil digestion, using MIC, it was possible to use diluted acid as absorbing solution, obtaining better limits of detection and avoiding interferences in REE determination by USN-ICP-MS.

High-efficiency microwave-assisted digestion combined to in situ ultraviolet radiation for the determination of rare earth elements by ultrasonic nebulization ICPMS in crude oils.

A method for heavy and extraheavy crude oil digestion based on microwave-assisted wet digestion (MW-AD) and ultraviolet (UV) radiation using diluted HNO3 was applied for the determination of rare earth elements (REE) by inductively coupled plasma mass spectrometry (ICPMS) with an ultrasonic nebulizer (USN). Even using pressurized systems conventional acid digestion is not feasible for efficient crude oil digestion, especially for heavy and extraheavy crude oils that generally present high amounts of asphaltenes and resins. In the proposed system, UV radiation is generated in situ by immersed electrodeless Cd discharge lamps positioned inside quartz vessels. The use of diluted solutions (1-14.4 mol L(-1) HNO3 and 1-4 mol L(-1) H2O2) were evaluated for heavy and extraheavy crude oil digestion (API density of 11.1-19.0). With the proposed method the residual carbon content was lower than 13 mg C/100 mg of sample, and it was possible to digest sample masses up to 500 mg using 4 mol L(-1) HNO3 and 4 mol L(-1) H2O2. Interferences caused by excessive acid concentration and carbon content in digests were minimized allowing limits of quantification for REEs as low as 0.3 ng g(-1). Samples were also digested using MW-AD in pressurized systems with concentrated HNO3, but even using 280 °C, 80 bar, and concentrated HNO3, MW-AD method was not suitable for REE determination due to interferences in ICPMS determination. The combination of microwave heating with UV was considered a suitable and effective way to digest crude oil allowing further determination of low concentrations of REE by ICPMS.

Analysis of the frequency and nature of hyaline ring granulomas in inflammatory odontogenic cysts.

AIM: To determine the prevalence of hyaline ring granulomas (HRGs) in a large case series of inflammatory odontogenic cysts, and to investigate the nature of these structures. METHODOLOGY: All records from the patients diagnosed with inflammatory odontogenic cysts between January 1970 and April 2009 were reviewed. Histologic sections were evaluated by light microscopy and cases with HRGs for which sufficient biological material was available were submitted to histochemical analysis (Masson's trichrome) and immunohistochemistry (CD34, CD68 and collagen IV). RESULTS: Twenty-two (3.3%) of the 661 cases of inflammatory odontogenic cysts diagnosed during the study period presented HRGs. The relative frequency of HRGs was higher amongst residual radicular cysts (6.1%), followed by paradental cysts (5.6%) and radicular cysts (3.0%). HRGs appeared as roughly circular homogeneous/fibrillar masses in 14 (63.6%) cases and as round structures enclosing amorphous material in 3 (13.6%) cases. Most (77.8%) roughly circular homogeneous/fibrillar masses were positive for collagen, whereas all (100.0%) round structures enclosing amorphous material were negative for this protein. Immunohistochemistry showed that most mononucleated cells and all multinucleated giant cells were positive for CD68, but negative for CD34, in all cases. In addition, collagen IV immunostaining was negative in amorphous structures and weakly positive in homogeneous/fibrillar masses. CONCLUSIONS: The present results suggest a very low frequency of HRGs in inflammatory odontogenic cysts and support the hypothesis that these structures arise from the implantation of foreign material, most likely food particles of plant or vegetable origin. The diverse microscopic features of HRG possibly represent different developmental stages of this structure.

Progressive increase of glucose transporter-3 (GLUT-3) expression in estrogen-induced breast carcinogenesis.

INTRODUCTION: Increased glucose uptake and glycolysis are main metabolic characteristics of malignant cells. A family of glucose transporters (GLUTs) facilitates glucose movement across the plasma membranes in a tumor-specific manner. Glucose transporter-1 (GLUT-1), GLUT-3 and recently GLUT-12, have been previously shown in breast cancer cells and are found to be associated with poor prognosis. In addition, it has been shown that estrogen plays critical roles in GLUT regulation, however, the stage-specific GLUT regulation of mammary carcinogenesis is unclear. METHODS: GLUT expression patterns were investigated in an in vitro-in vivo progressive, estrogen-induced, mammary carcinogenesis model which consisted of four cell lines, with same genetic background. In this model, different stages of tumor initiation and progression are represented, MCF-10F being the normal stage, E2 cells the transformed stage by estrogen, C5 cells, the invasive stage, and T4 cells the tumorigenic stage. In addition, loss of ductulogenesis and solid mass formation in collagen matrix and invasiveness of the cells were counted. RESULTS: Real time PCR showed that GLUT1 expression was downregulated in MCF10F after treatment with 17ß-estradiol (E2), and in the invasive cell type (C5), but not in the tumor cells (T4), which had no changes compared to MCF10F. C5 and T4 cells showed the highest rate of GLUT-3 expression. These cells were also found to be associated with loss of ductulogenesis, solid mass formation and higher invasive capacity, whereas, GLUT-12 was downregulated in C5 and T4 cells. CONCLUSION: Estrogen-induced malignant transformation is associated with remarkable and progressive GLUT-3 expression, GLUT-1 re-expression at further stages, as well as GLUT-12 downregulation.

Focused microwave-induced combustion for digestion of botanical samples and metals determination by ICP OES and ICP-MS.

The advantages and shortcomings of focused microwave-induced combustion (FMIC) for digestion of plant samples were studied. The effects of sample mass, absorbing solution, oxygen gas flow-rate, and time of reflux step on recoveries of major, minor and trace metals were systematically evaluated. Afterwards, Al, Ba, Ca, Co, Cr, Cu, Mg, Mn, Ni, Sr, V, and Zn were determined by inductively coupled plasma optical emission spectrometry (ICP OES) and by inductively coupled plasma mass spectrometry (ICP-MS). The main advantages of FMIC when compared to microwave-assisted wet digestion (MAWD) and focused-microwave-assisted wet digestion (FMAWD) are the possibility to digest larger masses of samples (up to 3g) using shorter heating times and diluted nitric acid solution for absorbing all analytes. Using the selected experimental conditions for FMIC, residual carbon content was lower than 0.7% for all samples and relative standard deviation (RSD) varied from 1.5 to 14.1%. Certified reference materials (NIST 1515 apple leaves and NIST 1547 peach leaves) were used for checking accuracy and determined values for all metals were in agreement with certified values at a 95% confidence level. No statistical difference (ANOVA, 95% of confidence level) was observed for results obtained by FMIC, FMAWD, and MAWD. Limits of detection were lower when using FMIC in the range of 0.02-0.15 µg g(-1) for ICP OES and 0.001-0.01 µg g(-1) for ICP-MS, which were about 3 and 6 times lower than the values obtained by FMAWD and MAWD, respectively. It is important to point out that FMIC was a suitable sample preparation method for major, minor and trace metals by both determination techniques (ICP OES and ICP-MS). Additionally, since it allows lower LODs (because up to 3g of sample can be digested) and diluted acid solutions are used (without any further dilution), the use of ICP-MS is not mandatory.

Correlation between total nitrite/nitrate concentrations and monoamine oxidase (types A and B) and semicarbazide-sensitive amine oxidase enzymatic activities in human mesenteric arteries from non-diabetic and type 2 diabetic patients

The aim of this study was to determine the correlation between total nitrite/nitrate concentrations (NOx) and the kinetic parameters of monoamine oxidase enzymes (MAO-A and MAO-B) and semicarbazide-sensitive amine oxidase (SSAO) in human mesenteric arteries. Arteries were from non-diabetic and type 2 diabetic patients with sigmoid or rectum carcinoma for whom surgery was the first option and who were not exposed to neo-adjuvant therapy. Segments of human inferior mesenteric arteries from non-diabetic (61.1 ± 8.9 years old, 7 males and 5 females, N = 12) and type 2 diabetic patients (65.8 ± 6.2 years old, 8 males and 4 females, N = 12) were used to determine NOx concentrations and the kinetic parameters of MAO-A, MAO-B and SSAO by the Griess reaction and by radiochemical assay, respectively. The NOx concentrations in arteries from diabetic patients did not differ significantly from those of the non-diabetic group (10.28 ± 4.61 vs 10.71 ± 4.32 nmol/mg protein, respectively). In the non-diabetic group, there was a positive correlation between NOx concentrations and MAO-B parameters: Km (r = 0.612, P = 0.034) and Vmax (r = 0.593, P = 0.042), and a negative correlation with the SSAO parameters: Km (r = -0.625, P = 0.029) and Vmax (r = -0.754, P = 0.005). However, in the diabetic group no correlation was found between NOx concentrations and the three kinetic parameters of the enzymes. These results suggest an important function of sympathetic nerves and vascular NOx concentrations in arteries of non-diabetic patients. Thus, these results confirm the importance of a balance between oxidants and antioxidants in the maintenance of vascular homeostasis to prevent oxidative stress.

Correlation between total nitrite/nitrate concentrations and monoamine oxidase (types A and B) and semicarbazide-sensitive amine oxidase enzymatic activities in human mesenteric arteries from non-diabetic and type 2 diabetic patients.

The aim of this study was to determine the correlation between total nitrite/nitrate concentrations (NOx) and the kinetic parameters of monoamine oxidase enzymes (MAO-A and MAO-B) and semicarbazide-sensitive amine oxidase (SSAO) in human mesenteric arteries. Arteries were from non-diabetic and type 2 diabetic patients with sigmoid or rectum carcinoma for whom surgery was the first option and who were not exposed to neo-adjuvant therapy. Segments of human inferior mesenteric arteries from non-diabetic (61.1 ± 8.9 years old, 7 males and 5 females, N = 12) and type 2 diabetic patients (65.8 ± 6.2 years old, 8 males and 4 females, N = 12) were used to determine NOx concentrations and the kinetic parameters of MAO-A, MAO-B and SSAO by the Griess reaction and by radiochemical assay, respectively. The NOx concentrations in arteries from diabetic patients did not differ significantly from those of the non-diabetic group (10.28 ± 4.61 vs 10.71 ± 4.32 nmol/mg protein, respectively). In the non-diabetic group, there was a positive correlation between NOx concentrations and MAO-B parameters: Km (r = 0.612, P = 0.034) and Vmax (r = 0.593, P = 0.042), and a negative correlation with the SSAO parameters: Km (r = -0.625, P = 0.029) and Vmax (r = -0.754, P = 0.005). However, in the diabetic group no correlation was found between NOx concentrations and the three kinetic parameters of the enzymes. These results suggest an important function of sympathetic nerves and vascular NOx concentrations in arteries of non-diabetic patients. Thus, these results confirm the importance of a balance between oxidants and antioxidants in the maintenance of vascular homeostasis to prevent oxidative stress.

[Functional evaluation in patients with pulmonary tuberculosis sequelae]. / Avaliação funcional em pacientes com sequela pulmonar de tuberculose.

INTRODUCTION: In pulmonary tuberculosis, the presence of extensive residual lung lesions can be a predictor of permanent disability due to respiratory failure. OBJECTIVE: To compare functional and respiratory changes in patients with pulmonary tuberculosis sequel who have completed treatment. METHOD: The study included patients who completed treatment within a period of 6 months (group I) and multidrug-resistant pulmonary tuberculosis patients who completed treatments of longer duration after the failure of the initial treatment (group II). We evaluated lung function by spirometry (Microlab ML 3500), the strength of respiratory muscles through the manovacuometry (MEP-maximal expiratory pressure and MIP- maximal inspiratory pressure) and the distance walked during the 6-minute walk (6MWT). RESULTS: 27 patients were included, 12 of whom belonged to group II, multidrug-resistant tuberculosis (MDRTB). Severe combined respiratory disorder was the most prevalent problem in group II of MDRTB; it was present in 9 patients. The MDRTB group (group II) showed significantly lower values when compared to Group I in FVC (72.06±14.95 vs 43.58±16.03% predicted), FEV1 (66.13±19.87 vs 33.08±15.64% predicted), MIP (68.40±22.78 vs 49.58±12.55 cmH(2)O), MEP (87.20±27.30 vs 59.08±12.23 cmH(2)O) and distance covered in 6MWT (484.21±74.01 vs 334.75±104.07 meters). CONCLUSION: Patients with multidrug resistant pulmonary tuberculosis who have undergone multiple treatments have more severe respiratory and functional impairment than patients who have had just a single treatment.

Monoamine oxidase and semicarbazide-sensitive amine oxidase kinetic analysis in mesenteric arteries of patients with type 2 diabetes.

Monoamine oxidase (MAO, type A and B) and semicarbazide-sensitive amine oxidase (SSAO) metabolize biogenic amines, however, the impact of these enzymes in arteries from patients with type 2 diabetes remains poorly understood. We investigated the kinetic parameters of the enzymes to establish putative correlations with noradrenaline (NA) content and patient age in human mesenteric arteries from type 2 diabetic patients. The kinetic parameters were evaluated by radiochemical assay and NA content by high-performance liquid chromatography (HPLC). The activity of MAO-A and SSAO in type 2 diabetic vascular tissues was significantly lower compared to the activity obtained in non-diabetic tissues. In the correlation between MAO-A (K(m)) and NA content, we found a positive correlation for both the diabetic and non-diabetic group, but no correlation was established for patient age. In both groups, MAO-B (V(max)) showed a negative correlation with age. The results show that MAO-A and SSAO activities and NA content of type 2 diabetic tissues are lower compared to the non-diabetic tissues, while MAO-B activity remained unchanged. These remarks suggest that MAO-A and SSAO may play an important role in vascular tissue as well as in the vascular pathophysiology of type 2 diabetes.

General stabilizing effects of plant diversity on grassland productivity through population asynchrony and overyielding.

Insurance effects of biodiversity can stabilize the functioning of multispecies ecosystems against environmental variability when differential species' responses lead to asynchronous population dynamics. When responses are not perfectly positively correlated, declines in some populations are compensated by increases in others, smoothing variability in ecosystem productivity. This variance reduction effect of biodiversity is analogous to the risk-spreading benefits of diverse investment portfolios in financial markets. We use data from the BIODEPTH network of grassland biodiversity experiments to perform a general test for stabilizing effects of plant diversity on the temporal variability of individual species, functional groups, and aggregate communities. We tested three potential mechanisms: reduction of temporal variability through population asynchrony; enhancement of long-term average performance through positive selection effects; and increases in the temporal mean due to overyielding. Our results support a stabilizing effect of diversity on the temporal variability of grassland aboveground annual net primary production through two mechanisms. Two-species communities with greater population asynchrony were more stable in their average production over time due to compensatory fluctuations. Overyielding also stabilized productivity by increasing levels of average biomass production relative to temporal variability. However, there was no evidence for a performance-enhancing effect on the temporal mean through positive selection effects. In combination with previous work, our results suggest that stabilizing effects of diversity on community productivity through population asynchrony and overyielding appear to be general in grassland ecosystems.