Prospective monitoring of a CD4+ CD25high CD45RO+ CD127high T-cell population after first kidney transplantation following thymoglobulin or basiliximab induction

Background: Recent data have suggested that a population of CD4+ CD25high T cells, phenotypically characterized by the expression of CD45RO and CD127, is significantly expanded in stable liver and kidney transplant recipients and represents alloreactive T cells. Induction therapies may have an impact on this alloreactive T cell population. In this study, we prospectively analyzed CD4+ CD25high CD45RO+ CD127high T cells after induction with either thymoglobulin or basiliximab. Patients and methods: A total of twenty-seven kidney transplant recipients were prospectively enrolled; 14 received thymoglobulin induction followed by a 4-day course of steroids with tacrolimus and mycophenolate mofetil (��thymo group��), and 13 received basiliximab induction followed by standard triple immunosuppression (tacrolimus, mycophenolate mofetil and prednisone) (��BSX group��). Phenotypical analysis by flow cytometry of the expression of CD25, CD45RO and CD127 on peripheral CD4+ T cells was performed at 0, 3 and 6 months after transplantation. Twenty-four healthy subjects (HS) were studied as controls. Results: There were no differences in baseline characteristics between the groups; at 6 months, patient survival (100%), graft survival (100%), serum creatinine (thymo group versus BSX group: 129 versus 125 micromol/l) and acute rejection (2/14 versus 2/13) were not significantly different. Thymo induction produced a prolonged CD4 T cell depletion. As compared to pre-transplantation values, an expansion of the alloreactive T cell population was observed at 3 months in both thymo (mean: from 6.38% to 14.72%) and BSX (mean: from 8.01% to 18.42%) groups. At 6 months, the alloreactive T cell population remained significantly expanded in the thymo group (16.92 �� 2.87%) whereas it tended to decrease in the BSX group (10.22 �� 1.38%). Conclusion: Overall, our results indicate that the expansion of alloreactive T cells occurs rapidly after transplantation in patients receiving either thymo or BSX induction. Whether differences at later timepoints or whether different IS regimens may modify this alloreactive population remains to be studied.

Root growth of tomato seedlings intensified by humic substances from peat bogs

Peats are an important reserve of humified carbon in terrestrial ecosystems. The interest in the use of humic substances as plant growth promoters is continuously increasing. The objective of this study was to evaluate the bioactivity of alkaline soluble humic substances (HS), humic (HA) and fulvic acids (FA) isolated from peats with different decomposition stages of organic matter (sapric, fibric and hemic) in the Serra do Espinha��o Meridional, state of Minas Gerais. Dose-response curves were established for the number of lateral roots growing from the main plant axis of tomato seedlings. The bioactivity of HA was greatest (highest response in lateral roots at lowest concentration) while FA did not intensify root growth. Both HS and HA stimulated root hair formation. At low concentrations, HS and HA induced root hair formation near the root cap, a typical hormonal imbalance effect in plants. Transgenic tomato with reporter gene DR5::GUS allowed the observation that the auxin-related signalling pathway was involved in root growth promotion by HA.

Varia����o nos atributos do solo em sistemas de manejo com adi����o de cama de frango

A cama de frango constitui-se em adubo org��nico com boas caracter��sticas agron��micas, podendo ser bom condicionador das propriedades f��sicas do solo. Assim, o objetivo deste trabalho foi verificar altera����es nas propriedades do solo em sistemas de plantio direto com adi����o de cama de frango. O estudo foi feito em tr��s camadas (0-10, 10-20 e 20-30 cm) e tr��s repeti����es, em Latossolo Vermelho-Amarelo distr��fico submetido a plantio direto cont��nuo nos ��ltimos anos, com rota����o principalmente de soja, milho, algod��o e milheto. Os tratamentos foram: sistema com aduba����o mineral (S2), com adi����o de cama de frango crua (S3), com adi����o de cama de frango compostada (S4) e uma ��rea n��o manejada de Cerrado nativo (S1). Os sistemas de manejo induziram em ordem crescente - S4, S2, S3 - �� degrada����o dos atributos do solo em rela����o �� vegeta����o nativa (S1), e isso foi quantificado pelos menores valores de carbono total, di��metro e estabilidade de agregados, macroporosidade e condutividade hidr��ulica saturada e pelos maiores valores de densidade e resist��ncia do solo �� penetra����o e microporosidade. A cama de frango crua revelou-se mais vantajosa na disponibilidade de nitrog��nio total e menos eficiente em garantir a qualidade f��sica do solo. A cama de frango compostada proporcionou atributos mais semelhantes ��s condi����es naturais.

Soil CO2 flux: a method comparison of closed static chambers in a sugarcane field

A large variety of techniques have been used to measure soil CO2 released from the soil surface, and much of the variability observed between locations must be attributed to the different methods used by the investigators. Therefore, a minimum protocol of measurement procedures should be established. The objectives of this study were (a) to compare different absorption areas, concentrations and volumes of the alkali trapping solution used in closed static chambers (CSC), and (b) to compare both, the optimized alkali trapping solution and the soda-lime trapping using CSC to measure soil respiration in sugarcane areas. Three CO2 absorption areas were evaluated (7; 15 and 20 % of the soil emission area or chamber); two volumes of NaOH (40 and 80 mL) at three concentrations (0.1, 0.25 and 0.5 mol L-1). Three different types of alkaline traps were tested: (a), 80 mL of 0.5 mol L-1 NaOH in glass containers, absorption area 15 % (V0.5); (b) 40 mL of 2 mol L-1 NaOH retained in a sponge, absorption area 80 % (S2) and (c) 40 g soda lime, absorption area 15 % (SL). NaOH concentrations of 0.5 mol L-1 or lower underestimated the soil CO2-C flux or CO2 flux. The lower limit of the alkali trap absorption area should be a minimum of 20 % of the area covered by the chamber. The 2 mol L-1 NaOH solution trap (S2) was the most efficient (highest accuracy and highest CO2 fluxes) in measuring soil respiration.

Relevance of dynamic wetting in viscous fingering patterns

We demonstrate that wetting effects at moving contact lines have a strong impact in viscous fingering patterns. Experiments in a rotating Hele-Shaw (HS) cell, dry or prewetted, show consistent morphological differences. When the wetting fluid invades a dry region, contact angle dynamics yield a kinetic contribution to the interface pressure drop that scales with capillary number as Ca2��3 but is significantly larger than the Park-Homsy kinetic correction. Numerical results are in very good agreement with experiments and show that standard HS equations work best for prewetted cells.

Transport of the organic cation N1-methylnicotinamide by the rabbit proximal tubule. I. Accumulation in the isolated nonperfused tubule.

Isolated nonperfused rabbit renal proximal tubules were used to investigate the basolateral step of transport of the organic cation N1-methylnicotinamide (NMN). NMN accumulation was highest and saturable in S2 and S3 segments, but lowest and nonsaturable in S1 segments. In S1 segments, accumulation of [3H]-NMN (0.5-8 microM in the bath) resulted in an average tubular water/medium concentration ratio (T/M) of 8.2, whereas in S2 and S3 segments T/M averaged 19.5 and 18.6, respectively. At these concentrations, about 30% of the label was attached in all segments to a metabolite comigrating with nicotinamide. KCN (10(-2) M) or ouabain (10(-4) M) reduced T/M to about 8 for all segments. NMN accumulation was inhibited (to a T/M of about 3 with mepiperphenidol) by other organic cations (10(-5)-10(-3) M) with the potency sequence mepiperphenidol greater than tetraethylammonium = quinine greater than morphine, these organic cations having no effect on p-aminohippurate accumulation, except for the highest concentration of quinine (10(-3) M). After correction for metabolism, NMN accumulation could be accounted for by simple electrochemical equilibrium across the basolateral membrane. The basolateral step of NMN transport appears therefore to be a carrier-mediated diffusion, in opposition to the active basolateral accumulation described for tetraethylammonium.

Sequential partitioning: an alternative to understanding size distributions of avalanches in first-order phase transitions

We study the problem of the partition of a system of initial size V into a sequence of fragments s1,s2,s3 . . . . By assuming a scaling hypothesis for the probability p(s;V) of obtaining a fragment of a given size, we deduce that the final distribution of fragment sizes exhibits power-law behavior. This minimal model is useful to understanding the distribution of avalanche sizes in first-order phase transitions at low temperatures.

Topologies for poin distributions

The concepts of void and cluster for an arbitrary point distribution in a domain D are defined and characterized by some parameters such as volume, density, number of points belonging to them, shape, etc. After assigning a weight to each void and clusterwhich is a function of its characteristicsthe concept of distance between two point configurations S1 and S2 in D is introduced, both with and without the help of a lattice in the domain D. This defines a topology for the point distributions in D, which is different for the different characterizations of the voids and clusters.

Rationale for consolidation to improve progression-free survival in patients with non-Hodgkin's lymphoma: a review of the evidence.

Non-Hodgkin's lymphoma (NHL) comprises both indolent forms, including follicular lymphoma (FL) and marginal zone lymphoma (MZL), and aggressive forms, including diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL). FL and DLBCL are the most common subtypes of indolent and aggressive NHL, respectively. Although these lymphomas exhibit different clinical behaviors and outcomes, the prognosis is negatively affected in both DLBCL and FL by the lack of a complete response (CR) with standard treatment options. The aim of therapy should therefore be achievement of a CR, which is not only associated with longer progression-free survival (PFS) and overall survival times, but is also a prerequisite for a cure, particularly in DLBCL. Consolidation treatment with radioimmunotherapy (RIT) is an innovative treatment approach to increase CR rates. Phase II studies have indicated promising results with yttrium-90 ((90)Y)-ibritumomab tiuxetan and iodine-131 ((131)I)-tositumomab as consolidation following induction therapy for previously untreated patients with advanced FL. More recently, investigators reported a marked increase in CR rates and significant improvements in PFS using standard chemotherapy regimens followed by (90)Y-ibritumomab tiuxetan in a phase III randomized trial in patients with previously untreated FL. Data also suggest that RIT may play a role in the treatment of high-risk DLBCL, with encouraging PFS results from a phase II trial of (90)Y-ibritumomab tiuxetan consolidation following induction with rituximab plus chemotherapy in elderly patients with previously untreated DLBCL. With the higher CR rates and longer PFS times observed in patients with FL and DLBCL, as well as encouraging early data from MZL and MCL consolidation trials, RIT appears to have an important role in the treatment of patients with NHL.

Visceral leishmaniasis and hemophagocytic syndrome

A 11 months old female infant from Portugal, free of family history, consults for apathy, weight loss, tachycardia, tachypnea, petechiae, pallor without icterus and hepatoslenomegaly. Seven months earlier, while being in Portugal, she presented a persistent bluish pimple on her buttock. Laboratory results showed anemia (35 g/l), leucopenia (3.3 G/l), thrombocytopenia (13 G/l), impaired coagulation (INR 1.4, PTT 41 sec.), hyponatremia (124 mmol/l), elevated CRP (139 mg/l), high ferritin (34.775 μg/l) and high triglycerides (5.22 mmol/l). After correction of vital parameters, a bone marrow aspiration and biopsy (BMB) revealed both the etiological diagnosis, namely a visceral leishmaniasis (VL) as well as one of its potential complications, the hemophagocytic syndrome (HS). Transfusions of whole blood, platelets and fresh frozen plasma were immediately started. Dexamethasone (10 mg/m2) and amphotericin B (3 mg/kg/day) have also been administrated. Visceral leishmaniasis is caused by a protozoan (Leishmania donovani) transmitted by the female sandfly. It is endemic in the Mediterranean basin (including France, Italy, Spain and Portugal), South America, sub-Saharan Africa as well as in India and Bangladesh. The parasite infects macrophages and, after several weeks of incubation, the disease occurs by affection of bloodlines (anemia, leucopenia, thrombocytopenia), hepatosplenomegaly, cachexia, gastrointestinal damage. The complications of the disease may lead to death. Liposomal amphotericin B is the currently recommended treatment. HS is caused by the proliferation and activation of macrophages in the marrow in response to a cytokine storm. It may be of primary cause. When it is secondary, it may be related to infections such as leishmaniasis. Patients present with fever and laboratory diagnostic criteria include cytopenia, hypertriglyceridemia, high ferritin and hemophagocytosis in the BMB. The treatment consists among other in the administration of high doses corticosteroids and, in secondary cases, in the treatment of the underlying cause. In conclusion, the clinical and biological features of VL may mimic haematological disorders as leukemia, but an enlargement of the liver and especially of the spleen should remind in this parasitic infection and its potential fatal complication, the HS.

Dirac and reduced quantization: A Lagrangian approach and Application to Coset Spaces

A Lagrangian treatment of the quantization of first class Hamiltonian systems with constraints and Hamiltonian linear and quadratic in the momenta, respectively, is performed. The first reduce and then quantize and the first quantize and then reduce (Diracs) methods are compared. A source of ambiguities in this latter approach is pointed out and its relevance on issues concerning self-consistency and equivalence with the first reduce method is emphasized. One of the main results is the relation between the propagator obtained la Dirac and the propagator in the full space. As an application of the formalism developed, quantization on coset spaces of compact Lie groups is presented. In this case it is shown that a natural selection of a Dirac quantization allows for full self-consistency and equivalence. Finally, the specific case of the propagator on a two-dimensional sphere S2 viewed as the coset space SU(2)/U(1) is worked out. 1995 American Institute of Physics.

A Supersymmetric black ring

A new supersymmetric black hole solution of five-dimensional supergravity is presented. It has an event horizon of topology S1 X S2. This is the first example of a supersymmetric, asymptotically flat black hole of nonspherical topology. The solution is uniquely specified by its electric charge and two independent angular momenta. These conserved charges can be arbitrarily close, but not exactly equal, to those of a supersymmetric black hole of spherical topology.

ELEMENTOS-TRA��O EM ��REAS DE VEGETA����O NATIVA E AGRICULTURA INTENSIVA DO ESTADO DE MATO GROSSO DETERMINADOS POR FLUORESC��NCIA DE RAIOS-X POR REFLEX��O TOTAL

A espectroscopia de raios-X por reflex��o total (TXRF) �� uma t��cnica promissora para an��lise de elementos-tra��o (ETs), principalmente por n��o ser necess��ria a digest��o das amostras, reduzindo assim a gera����o de res��duos e emiss��o de vapores t��xicos. Este trabalho comparou os teores dos ETs: Cr, Mn, Ni, Zn, Cu, As, Se, Hg e Pb, coletados em solos de ��rea de agricultura intensiva e vegeta����o nativa, determinados por TXRF e por espectrometria de absor����o at��mica de chama ou forno de grafite (FAAS/GFAAS). Adicionalmente, compararam-se os teores dos ET com valores de refer��ncia para solos n��o contaminados. As amostras de solo foram coletadas na profundidade 0,0-0,2 m em munic��pios representativos de cada regi��o agr��cola do Estado de Mato Grosso (Rondon��polis, Alto Gar��a, Primavera do Leste, Campo Novo, Nova Mutum, Lucas do Rio Verde, Sorriso, Sinop, Campo Novo dos Parecis, Campos de Julho e Vila Bela da Sant��ssima Trindade). Em cada munic��pio, foram selecionadas seis ��reas, totalizando 72 amostras, todas georreferenciadas. Para a leitura dos teores de ET no aparelho de TXRF S2 Picofox&#8482;, foram preparadas suspens��es de solo usando Triton X-100 a 5 % v/v utilizando g��lio como padr��o interno, enquanto no FAAS/GFAAS as amostras foram submetidas �� digest��o ��cida pelo m��todo 3051A. Considerando ��rea cultivada e ��rea nativa, respectivamente, os teores m��dios dos ET por TXRF, em mg kg-1, foram: Cr, 69 e 62; Zn, 16 e 8; Pb, 28 e 21; Mn, 56 e 42; As, 2 e 2; Cu, 9 e 8; e Ni, 2 e 2. O Cd, Se e Hg n��o foram detectados por TXRF nas amostras analisadas. Para As, Cr, Mn, Zn, Ni, Cu e Pb, houve correla����o linear (p<0,001) positiva entre as t��cnicas e, no geral, os teores obtidos para esses ET em TXRF foram superiores aos do FAAS/GFAAS. Os teores de todos os elementos detectados pelo TXRF, exceto o Cr, est��o dentro das faixas dos relatados para solos n��o contaminados e muito inferiores aos limites de alerta estipulados na literatura.

Desenvolvimento Inicial de Duas Variedades de Cana-de-a����car Inoculadas com Bact��rias Diazotr��ficas

RESUMO A cana-de-a����car �� uma cultura de grande destaque na economia, em raz��o da produ����o de a����car, etanol e energia. Tecnologias que possam contribuir para o aumento da produtividade e qualidade da cultura com m��nimos danos ao meio ambiente s��o necess��rias. Objetivou-se avaliar a produ����o de ��cido indol ac��tico de cinco estirpes de bact��rias diazotr��ficas e o efeito da inocula����o delas na brota����o de duas variedades de cana-de-a����car, RB867515 e IACSP95-5000. A produ����o de auxina foi determinada pelo teste colorim��trico, usando o reagente de Salkowski. Para avaliar a germina����o, foi conduzido um experimento em casa de vegeta����o, utilizando-se delineamento experimental em blocos ao acaso com quatro repeti����es e sete tratamentos: controle n��o inoculado; inocula����o mista com as cinco estirpes e inocula����o individual com Gluconacetobacter diazotrophicus (Gd) estirpe BR11281T(PAL-5T), Herbaspirillum seropedicae (Hs - BR11335 = HRC54), Herbaspirillum rubrisubalbicans (Hr - BR11504 = HCC103), Burkholderia tropica (Bt - BR11366T = PPe 8 T) e Azospirillum amazonense (Aa - BR11145 = CBAMc). As bact��rias mais eficientes na produ����o de auxina foram Hs e Hr, declinando 48 h ap��s o crescimento. Hr, Aa e Bt aumentaram o ��ndice de velocidade de germina����o e o n��mero de brota����es nas duas variedades. Na var. RB867515, a velocidade de germina����o ainda foi positivamente influenciada pela inocula����o mista, sendo o mesmo observado pela inocula����o de Gd na var. IACSP95-5000.