Implications of cell wall immunocytochemical profiles on the structural and functional traits of root and stem galls induced by Eriosoma lanigerum on Malus domestica.

Alterations in cell wall composition imply in new structural and functional traits in gall developmental sites, even when the inducer is a sucking exophytophagous insect with strict feeding sites as the aphid associated to Malus domestica Borkh. This host plant is an economically important, fruit-bearing species, susceptible to gall induction by the sucking aphid Eriosoma lanigerum Hausmann, 1802. Herein, the immunocytochemical detection of arabinogalactan-proteins (AGPs), pectins, and hemicelluloses using monoclonal antibodies was performed in samples of non-galled roots and stems, and of root and stem galls on M. domestica. The dynamics of these cell wall components was discussed under the structural and functional traits of the galls proximal, median, and distal regions, according to the proximity of E. lanigerum colony feeding site. In the proximal region, the epitopes of AGPs and homogalacturonans (HGs) are related to cell growth and divisions, which result in the overproduction of parenchyma cells both in root and stem galls. In the proximal and median regions, the co-occurrence of HGs and arabinans in the cell walls of parenchyma and secondary tissues favors the nutrient flow and water-holding capacity, while the xylogalacturonans and hemicelluloses may function as additional carbohydrate resources to E. lanigerum. The immunocytochemical profile of the cell walls support the feeding activity of E. lanigerum mainly in the gall proximal region. The similarity of the cell wall components of the gall distal region and the non-galled portions, both in roots and stems, relates to the decrease of the cecidogenetic field the more distant the E. lanigerum colony is.

A cell surface arabinogalactan-peptide influences root hair cell fate.

Root hairs (RHs) develop from specialized epidermal trichoblast cells, whereas epidermal cells that lack RHs are known as atrichoblasts. The mechanism controlling RH cell fate is only partially understood. RH cell fate is regulated by a transcription factor complex that promotes the expression of the homeodomain protein GLABRA 2 (GL2), which blocks RH development by inhibiting ROOT HAIR DEFECTIVE 6 (RHD6). Suppression of GL2 expression activates RHD6, a series of downstream TFs including ROOT HAIR DEFECTIVE 6 LIKE-4 (RSL4) and their target genes, and causes epidermal cells to develop into RHs. Brassinosteroids (BRs) influence RH cell fate. In the absence of BRs, phosphorylated BIN2 (a Type-II GSK3-like kinase) inhibits a protein complex that regulates GL2 expression. Perturbation of the arabinogalactan peptide (AGP21) in Arabidopsis thaliana triggers aberrant RH development, similar to that observed in plants with defective BR signaling. We reveal that an O-glycosylated AGP21 peptide, which is positively regulated by BZR1, a transcription factor activated by BR signaling, affects RH cell fate by altering GL2 expression in a BIN2-dependent manner. Changes in cell surface AGP disrupts BR responses and inhibits the downstream effect of BIN2 on the RH repressor GL2 in root epidermis.

Chemical characterization and complement modulating activities of an arabinogalactan-protein-rich fraction from an aqueous extract of avocado leaves.

The aim of this study was to chemically characterize an arabinogalactan-protein-rich fraction (FRAGP) obtained from an aqueous extract of avocado leaves and investigate its effects on the classical pathway of the complement system. The FRAGP contained 4.6% ±â€¯1.8%, 22.5% ±â€¯4.9%, and 76.7% ±â€¯8.8% of total protein, arabinogalactan-protein, and carbohydrates, respectively. Arabinose and galactose were the main monosaccharide constituents. FT-IR and NMR data, together with linkage analyses, indicated the presence of a structure that included a (1 → 3)-linked ß-D-Galp main chain, mainly substituted at O-6 by Gal and Ara residues, which was characteristic of a type II arabinogalactan. The effect of FRAGP on the classical pathway of complement system was examined by a hemolytic fixation test and comparing with heparin, which was used as a control for inhibition. With pre-incubation, the IC50 of FRAGP was 1.90 ±â€¯1.1 µg/mL, which was similar to that of heparin (IC50 = 2.90 ±â€¯0.3 µg/mL). Without pre-incubation, the IC50 values were 18.6 ±â€¯3.7 and 8.0 ±â€¯4.1 µg/mL for FRAGP and heparin, respectively. Collectively, these results suggested that FRAGP has an inhibitory effect on the classical pathway of the complement system.

Reduced expression of selected FASCICLIN-LIKE ARABINOGALACTAN PROTEIN genes associates with the abortion of kernels in field crops of Zea mays (maize) and of Arabidopsis seeds.

Abortion of fertilized ovaries at the tip of the ear can generate significant yield losses in maize crops. To investigate the mechanisms involved in this process, 2 maize hybrids were grown in field crops at 2 sowing densities and under 3 irrigation regimes (well-watered control, drought before pollination, and drought during pollination), in all possible combinations. Samples of ear tips were taken 2-6 days after synchronous hand pollination and used for the analysis of gene expression and sugars. Glucose and fructose levels increased in kernels with high abortion risk. Several FASCICLIN-LIKE ARABINOGALACTAN PROTEIN (FLA) genes showed negative correlation with abortion. The expression of ZmFLA7 responded to drought only at the tip of the ear. The abundance of arabinogalactan protein (AGP) glycan epitopes decreased with drought and pharmacological treatments that reduce AGP activity enhanced the abortion of fertilized ovaries. Drought also reduced the expression of AthFLA9 in the siliques of Arabidopsis thaliana. Gain- and loss-of-function mutants of Arabidopsis showed a negative correlation between AthFLA9 and seed abortion. On the basis of gene expression patterns, pharmacological, and genetic evidence, we propose that stress-induced reductions in the expression of selected FLA genes enhance abortion of fertilized ovaries in maize and Arabidopsis.

Gastroprotective effects and structural characterization of a pectic fraction isolated from Artemisia campestris subsp maritima.

The aim of this study was to investigate the chemical structure and biological activity of a pectic fraction isolated from the aerial parts of A. campestris L. subsp. maritima Arcangeli. The chemical and spectroscopic analyses of the pectic fraction (ACP-E10) demonstrated that ACP-E10 was composed of homogalacturonan (HG) (60%) and rhamnogalacturonan-I (RG-I) (29%) regions. Side chains of the RG-I included mainly branched arabinans and type II arabinogalactans (AG-II). The molar mass of ACP-E10 determined by HPSEC-MALLS was 16,600g/mol. ACP-E10 was evaluated for its gastroprotective effect against ethanol-induced gastric lesions in rats. Oral pretreatment of animals with ACP-E10 (0.3, 3 and 30mg/kg) significantly reduced gastric lesions by 77±7.9%, 55±11.1% and 65±11.8%. ACP-E10 also maintained mucus and glutathione (GSH) contents in the gastric mucosa. In addition, ACP-E10 demonstrated antioxidant activity in vitro by the DPPH assay. These results demonstrated that the pectin from A. campestris had significant gastroprotective effects in vivo, which were likely attributable to their capacity to increase the protective defenses of gastric mucosa.

Effect of the native polysaccharide of cashew-nut tree gum exudate on murine peritoneal macrophage modulatory activities.

The native polysaccharide of cashew-nut tree gum exudate (CNTG) and its arabinogalactan-protein component (CNTG-AGP) were tested by using immuno-stimulant and anti-inflammatory in vitro assays of murine peritoneal macrophage activities. In the assay for immuno-stimulant activity (without previous treatment with lipopolysaccharide; LPS), CNTG increased the production of interleukin (IL)-10 and both CNTG and CNTG-AGP decreased the concentrations of IL6. When the macrophages were incubated in the presence of LPS and CNTG a decrease in the levels of nitric oxide (NO(·)) and IFN-γ was observed. The results could explain the popular use of CNTG as an anti-inflammatory. In addition, CNTG is the main component of the cashew-nut tree gum exudate, which has been considered a versatile polymer with potential pharmaceutical and food industry applications. These data may contribute to the study of the immunomodulation activity of plant polysaccharides, as well as encourage future experiments in the field of cashew-nut tree gum exudate applications.

The classical arabinogalactan protein AGP18 mediates megaspore selection in Arabidopsis.

Female gametogenesis in most flowering plants depends on the predetermined selection of a single meiotically derived cell, as the three other megaspores die without further division or differentiation. Although in Arabidopsis thaliana the formation of the functional megaspore (FM) is crucial for the establishment of the gametophytic generation, the mechanisms that determine the specification and fate of haploid cells remain unknown. Here, we show that the classical arabinogalactan protein 18 (AGP18) exerts an active regulation over the selection and survival of megaspores in Arabidopsis. During meiosis, AGP18 is expressed in integumentary cells located in the abaxial region of the ovule. Overexpression of AGP18 results in the abnormal maintenance of surviving megaspores that can acquire a FM identity but is not sufficient to induce FM differentiation before meiosis, indicating that AGP18 positively promotes the selection of viable megaspores. We also show that all four meiotically derived cells in the ovule of Arabidopsis are competent to differentiate into a gametic precursor and that the function of AGP18 is important for their selection and viability. Our results suggest an evolutionary role for arabinogalactan proteins in the acquisition of monospory and the developmental plasticity that is intrinsic to sexual reproduction in flowering plants.

CCL25 induces α4ß7 integrin-dependent migration of IL-17⁺ γδ T lymphocytes during an allergic reaction.

Herein, we provide evidence that during allergic inflammation, CCL25 induces the selective migration of IL-17(+) γδ T cells mediated by α(4) ß(7) integrin. Intrapleural injection of CCL25 into ovalbumin (OVA)-immunized C57BL/6 mice triggered the accumulation of γδ T lymphocytes expressing CCR9 (CCL25 receptor) and α(4) ß(7) integrin in the pleura, but failed to attract αß T lymphocytes. CCL25 attracted CCR6(+) γδ T cells producing IL-17 (but not IFN-γ or IL-4). OVA challenge triggered increased production of CCL25 followed by the accumulation of CCR9(+) , α(4) ß(7) (+) , and CCR6(+) /IL-17(+) γδ T cells into the pleural cavities of OVA-immunized mice, which was inhibited by the in vivo neutralization of CCL25. The in vivo blockade of α(4) ß(7) integrin also inhibited the migration of IL-17(+) γδ T lymphocytes (but not of αß T lymphocytes) into mouse pleura after OVA challenge, suggesting that the CCL25/α(4) ß(7) integrin pathway is selective for γδ T cells. In addition, α(4) ß(7) integrin blockade impaired the in vitro transmigration of γδ T cells across endothelium (which expresses α(4) ß(7) ligands VCAM-1 and MadCAM-1), which was induced by CCL25 and by cell-free pleural washes recovered from OVA-challenged mice. Our results reveal that during an allergic reaction, CCL25 drives IL-17(+) γδ T-cell mobilization to inflamed tissue via α(4) ß(7) integrin and modulates IL-17 levels.

Cellular and molecular changes associated with somatic embryogenesis induction in Agave tequilana.

In spite of the importance of somatic embryogenesis for basic research in plant embryology as well as for crop improvement and plant propagation, it is still unclear which mechanisms and cell signals are involved in acquiring embryogenic competence by a somatic cell. The aim of this work was to study cellular and molecular changes involved in the induction stage in calli of Agave tequilana Weber cultivar azul in order to gain more information on the initial stages of somatic embryogenesis in this species. Cytochemical and immunocytochemical techniques were used to identify differences between embryogenic and non-embryogenic cells from several genotypes. Presence of granular structures was detected after somatic embryogenesis induction in embryogenic cells; composition of these structures as well as changes in protein and polysaccharide distribution was studied using Coomassie brilliant blue and Periodic Acid-Schiff stains. Distribution of arabinogalactan proteins (AGPs) and pectins was investigated in embryogenic and non-embryogenic cells by immunolabelling using anti-AGP monoclonal antibodies (JIM4, JIM8 and JIM13) as well as an anti-methyl-esterified pectin-antibody (JIM7), in order to evaluate major modifications in cell wall composition in the initial stages of somatic embryogenesis. Our observations pointed out that induction of somatic embryogenesis produced accumulation of proteins and polysaccharides in embryogenic cells. Presence of JIM8, JIM13 and JIM7 epitopes were detected exclusively in embryogenic cells, which supports the idea that specific changes in cell wall are involved in the acquisition of embryogenic competence of A. tequilana.

Speciation genes in free-spawning marine invertebrates.

Research on speciation of marine organisms has lagged behind that of terrestrial ones, but the study of the evolution of molecules involved in the adhesion of gametes in free-spawning invertebrates is an exception. Here I review the function, species-specificity, and molecular variation of loci coding for bindin in sea urchins, lysin in abalone and their egg receptors, in an effort to assess the degree to which they contribute to the emergence of reproductive isolation during the speciation process. Bindin is a protein that mediates binding of the sperm to the vitelline envelope (VE) of the egg and the fusion of the gametes' membranes, whereas lysin is a protein involved only in binding to the VE. Both of these molecules are important in species recognition by the gametes, but they rarely constitute absolute blocks to interspecific hybridization. Intraspecific polymorphism is high in bindin, but low in lysin. Polymorphism in bindin is maintained by frequency-dependent selection due to sexual conflict arising from the danger of polyspermy under high densities of sperm. Monomorphism in lysin is the result of purifying selection arising from the need for species recognition. Interspecific divergence in lysin is due to strong positive selection, and the same is true for bindin of four out of seven genera of sea urchins studied to date. The differences between the sea urchin genera in the strength of selection can only partially be explained by the hypothesis of reinforcement. The egg receptor for lysin (VERL) is a glycoprotein with 22 repeats, 20 of which have evolved neutrally and homogenized by concerted evolution, whereas the first two repeats are under positive selection. Selection on lysin has been generated by the need to track changes in VERL, permitted by the redundant structure of this molecule. Both lysin and bindin are important in reproductive isolation, probably had a role in speciation, but it is hard to determine whether they meet the strictest criteria of "speciation loci," defined as genes whose differentiation has caused speciation.

Arabinogalactan-proteins from cell suspension cultures of Araucaria angustifolia.

Arabinogalactan-proteins (AGPs), found in the culture medium of suspension cells of Araucaria angustifolia grown in plant growth regulator-free and plant growth regulator-containing BM media, BM0 and BM2, respectively, were evaluated quantitatively and qualitatively. The concentrated extracellular fractions (CEFs), obtained from suspension cell cultures grown for 20 days in BM0 and BM2 media yielded two fractions, CEF-0 and CEF-2, respectively. CEF-0 and CEF-2 was submitted to selective precipitation using the beta-glucosyl Yariv reagent (beta-GlcY) to isolate AGPs for structural characterization; this yielded fractions designated CEF-0YPF and CEF-2YPF, respectively. The monosaccharide composition analysis established that samples were composed of Rha, Ara, Gal and uronic acid in a molar ratio 3:37:55:5 (CEF-0YPF) and 1:37:58:4 (CEF-2YPF), although trace amounts (<0.5 mol%) of Xyl were also found. Methylation analysis of CEF-YPF fractions showed similar results for both CEF-0YPF and CEF-2YPF, with non-reducing terminal units of Araf, Arap, Galp, Rhap and Xylp, as well as 3-O-substituted and 5-O-substituted Araf units and 3-O-substituted, 6-O-substituted and 3,6-di-O-substituted Galp units. The amino acid composition analysis established Ser, Ala, and Hyp as major amino acids in both samples. In conclusion, this investigation has shown that CEF-0YPF and CEF-2YPF contain macromolecules having typical AGP characteristics, including a Hyp/Ala/Ser-rich protein moiety, a (1-->3) and/or (1-->6) linked beta-d-galactopyranosyl main chain substituted by Gal, Ara, Rha and Xyl residues, and binding affinity for beta-GlcY and monoclonal anti-AGP antibodies.

Obstrução uretral em gatos machos - revisão literária / Urethral obstruction in male cats - literature review

A obstrução uretral em gatos machos enquadra-se na doença do trato urinário inferior dos felinos, constituindo em um quadro dramático de não emissão da urina, que dependendo de horas obstruído, pode levar o animal ao óbito. A obstrução é usualmente causada por mucoproteínas, mas também pode ser devida a urólitos, transtornos funcionais da musculatura e neoplasias. Assim, a presente revisão de literatura, teve como objetivo, descrever a patofisiologia, epidemiologia, recursos em diagnóstico, condutas e opções terapêuticas a serem adotadas com o paciente obstruído e provável prognóstico dos gatos acometidos por esta afecção.

The urethral obstruction in male cats is framed in the feline lower urinary tract disease, constituting a dramatic condition of non-issuance of urine which, depending on the hours of obstruction, it can take the animal to death. This obstruction is usually caused by mucoprotein, but it can also be due to uroliths, functional disorders of the muscles and neoplasms. Thus, the present literature review had the objective of describing the pathophysiology, epidemiology, resources in diagnosis, lines and treatment options to be adopted with the obstructed patient and probable prognostic of the cats suffering from this affection.

Effect of an isotonic rehydration sports drink and exercise on urolithiasis in rats.

The objective of the present study was to evaluate the role of physical exercise as well as the influence of hydration with an isotonic sports drink on renal function in male Wistar rats. Four groups were studied over a period of 42 days: 1) control (N = 9); 2) physical exercise (Exe, N = 7); 3) isotonic drink (Drink, N = 8); 4) physical exercise + isotonic drink (Exe + Drink, N = 8). Physical exercise consisted of running on a motor-driven treadmill for 1 h/day, at 20 m/min, 5 days a week. The isotonic sports drink was a commercial solution used by athletes for rehydration after physical activity, 2 ml administered by gavage twice a day. Urine cultures were performed in all animals. Twenty-four-hour urine samples were collected in metabolic cages at the beginning and at the end of the protocol period. Urinary and plasma parameters (sodium, potassium, urea, creatinine, calcium) did not differ among groups. However, an amorphous material was observed in the bladders of animals in the Exe + Drink and Drink groups. Characterization of the material by Western blot revealed the presence of Tamm-Horsfall protein and angiotensin converting enzyme. Physical exercise and the isotonic drink did not change the plasma or urinary parameters measured. However, the isotonic drink induced the formation of intravesical matrix, suggesting a potential lithogenic risk.

Effect of an isotonic rehydration sports drink and exercise on urolithiasis in rats

The objective of the present study was to evaluate the role of physical exercise as well as the influence of hydration with an isotonic sports drink on renal function in male Wistar rats. Four groups were studied over a period of 42 days: 1) control (N = 9); 2) physical exercise (Exe, N = 7); 3) isotonic drink (Drink, N = 8); 4) physical exercise + isotonic drink (Exe + Drink, N = 8). Physical exercise consisted of running on a motor-driven treadmill for 1 h/day, at 20 m/min, 5 days a week. The isotonic sports drink was a commercial solution used by athletes for rehydration after physical activity, 2 ml administered by gavage twice a day. Urine cultures were performed in all animals. Twenty-four-hour urine samples were collected in metabolic cages at the beginning and at the end of the protocol period. Urinary and plasma parameters (sodium, potassium, urea, creatinine, calcium) did not differ among groups. However, an amorphous material was observed in the bladders of animals in the Exe + Drink and Drink groups. Characterization of the material by Western blot revealed the presence of Tamm-Horsfall protein and angiotensin converting enzyme. Physical exercise and the isotonic drink did not change the plasma or urinary parameters measured. However, the isotonic drink induced the formation of intravesical matrix, suggesting a potential lithogenic risk.

Valor dos exames laboratoriais no diagnóstico e no seguimento de pacientes com febre reumática / Laboratory in rheumatic fever

Embora não haja provas laboratoriais patognomônicas para o diagnóstico de certeza da febre reumática, existem alguns achados de laboratório e algumas considerações que nos auxiliam tanto na conclusão de uma hipótese clínica como no acompanhamento e nos critérios de cura da doença. Por isso é sempre bom lembrar que o diagnóstico dessa doença se faz com um conjunto de dados clínicos como história e exame clínico, bem como de resultados de provas laboratoriais. Existem dois tipos de exames laboratoriais que são úteis no diagnóstico e na avaliação da evolução, assim como na cura: os que pesquisam processos imunogenéticos (celulares, mole culares e humorais) importantes para determinar a gênese da afecção, e os que reconhecem a existência de um processo inflamatório agudo, que seriam as chamadas reações da "fase aguda do soro". Dentre estas últimas encontram-se as muco proteínas e a fração alfa-2-globulina, que se comportam como provas seguras e sensíveis, devendo-se somente à normalização das mesmas o desaparecimento do processo inflamatório agudo.

A classical arabinogalactan protein is essential for the initiation of female gametogenesis in Arabidopsis.

Classical arabinogalactan proteins (AGPs) are an abundant class of cell surface proteoglycans widely distributed in flowering plants. We have used a combination of enhancer detection tagging and RNA interference (RNAi)-induced posttrancriptional silencing to demonstrate that AGP18, a gene encoding a classical arabinogalactan protein, is essential for female gametogenesis in Arabidopsis thaliana. AGP18 is expressed in cells that spatially and temporally define the sporophytic to gametophytic transition and during early stages of seed development. More than 75% of the T1 transformants resulted in T2 lines showing reduced seed set during at least three consecutive generations but no additional developmental defects. AGP18-silenced T2 lines showed reduced AGP18 transcript levels in female reproductive organs, the presence of 21-bp RNA fragments specific to the AGP18 gene, and the absence of in situ AGP18 mRNA localization in developing ovules. Reciprocal crosses to wild-type plants indicate that the defect is female specific. The genetic and molecular analysis of AGP18-silenced plants containing a single T-DNA RNAi insertion suggests that posttranscriptional silencing of AGP18 is acting both at the sporophytic and gametophytic levels. A cytological analysis of all defective AGP18-RNAi lines, combined with the analysis of molecular markers acting at key stages of female gametogenesis, showed that the functional megaspore fails to enlarge and mitotically divide, indicating that AGP18 is essential to initiate female gametogenesis in Arabidopsis. Our results assign a specific function in plant development to a gene encoding a classical AGP.

Role of Tamm-Horsfall protein and uromodulin in calcium oxalate crystallization.

One of the defenses against nephrolithiasis is provided by macromolecules that modulate the nucleation, growth, aggregation and retention of crystals in the kidneys. The aim of the present study was to determine the behavior of two of these proteins, Tamm-Horsfall and uromodulin, in calcium oxalate crystallization in vitro. We studied a group of 10 male stone formers who had formed at least one kidney stone composed of calcium oxalate. They were classified as having idiopathic nephrolithiasis and had no well-known metabolic risk factors involved in kidney stone pathogenesis. Ten normal men were used as controls, as was a group consisting of five normal women and another consisting of five pregnant women. Crystallization was induced by a fixed supersaturation of calcium oxalate and measured with a Coulter Counter. All findings were confirmed by light and scanning electron microscopy. The number of particulate material deposited from patients with Tamm-Horsfall protein was higher than that of the controls (P<0.001). However, Tamm-Horsfall protein decreased the particle diameter of the stone formers when analyzed by the mode of the volume distribution curve (P<0.002) (5.64 +/- 0.55 microm compared to 11.41 +/- 0.48 microm of uromodulin; 15.94 +/- 3.93 microm and 12.45 +/- 0.97 microm of normal men Tamm-Horsfall protein and uromodulin, respectively; 8.17 +/- 1.57 microm and 9.82 +/- 0.95 microm of normal women Tamm-Horsfall protein and uromodulin, respectively; 12.17 +/- 1.41 m and 12.99 +/- 0.51 microm of pregnant Tamm-Horsfall protein and uromodulin, respectively). Uromodulin produced fewer particles than Tamm-Horsfall protein in all groups. Nonetheless, the total volume of the crystals produced by uromodulin was higher than that produced by Tamm-Horsfall protein. Our results indicate a different effect of Tamm-Horsfall protein and uromodulin. This dual behavior suggests different functions. Tamm-Horsfall protein may act on nucleation and inhibit crystal aggregation, while uromodulin may promote aggregation of calcium oxalate crystals.

Mucoproteína versus alfa-1-glicoproteína ácida: o que quantificar? / Mucoprotein versus alpha-1-acid glycoprotein: what should be measured?

A quantificaçäo sérica da alfað1ðglicoproteína (GPA) ácida é útil no diagnóstico e no acompanhamento dos processos agudos resultantes de múltiplas causas. Esta proteína também pode ser estimada pela quantificaçäo da mucoproteína (Muco), ensaio que reflete as glicoproteínas com elevado teor de açúcar, entre as quais a GPA é majoritária. O objetivo deste trabalho é verificar a correlaçäo e a performance analítica das determinações de mucoproteína (Muco) e alfað1ðglicoproteína ácida (GPA), propondo uma equaçäo de regressäo linear. Amostras de soros e 540 pacientes, com idades entre 10 e 79 anos (média de 34,6), predominando mulheres (71,3 por cento), foram analisadas simultaneamente para Muco (Winzler, manual com reagentes próprios) e GPA (imunoturbidimetria automatizada, Roche; Cobas mira). A análise de regressäo, fixando a Muco como variável dependente, apresentou Muco (mg/dl em tirosina) = 0,031 x GPA (mg/dl) + 0,8 (r = 0,91); e, fixando o intercepto em zero, Muco = 0,039 x GPA (r = 0,98). A imprecisäo interensaio foi de 23,4 por cento e 5,2 por cento (coeficiente de variaçäo), respectivamente, para Muco e GPA. Conclusäo: a elevada variabilidade analítica da quantificaçäo da mucoproteína pelo método de Winzler recomenda que este ensaio seja substituído pela dosagem da alfað1ðglicoproteína ácida. Quanto necessário, recomendamos estimar a mucoproteína, quantificando a alfað1ðglicoproteína ácida com ensaios de mesmo desempenho que o do utilizado neste trabalho, e usar a equaçäo de regressäo AGP (mg/dl) x 0,039 = Muco (mg/dl em tirosina)

Tamm-Horsfall protein excretion to predict the onset of renal insufficiency.

OBJECTIVE: Immunosuppressive therapy after liver transplantation may be a risk for kidney dysfunction. This work was designed to determine whether Tamm-Horsfall Protein (THP) could be considered as a marker for nephrotoxicity. DESIGN AND METHODS: THP was determined by an ELISA method in serial 24-h urine from liver transplant patients. Fourteen patients suffered renal insufficiency (LTr(1)) and 20 showed no acute renal damage (LTr(2)) after liver transplantation. RESULTS: No clear association could be seen between daily THP excretion and plasma creatinine levels by comparing serial samples collected at the same time. Nevertheless, significant differences were observed in pretransplant THP excretion between both groups of patients. The results (Median/Interquartile Range) were: CONTROLS: 113.2/84.9 to 146.8 mg/24 h (n = 30); LTr(1): 36.9/18.3 to 54.5 mg/24 h (p<<0.001 with respect to C and LTr(2)); LTr(2): 90.8/61.5 to 139.7 mg/24 h. CONCLUSIONS: The higher pretransplant synthesis and/or secretion of THP seem to have a protective role on the kidney during and after liver transplantation.

Endogenous vasopressin regulates Na-K-ATPase and Na(+)-K(+)-Cl(-) cotransporter rbsc-1 in rat outer medulla.

Previous reports have shown a stimulatory effect of vasopressin (VP) on Na-K-ATPase and rBSC-1 expression and activity. Whether these VP-dependent mechanisms are operating in vivo in physiological conditions as well as in chronic renal failure (CRF) has been less well studied. We measured ATPase expression and activity and rBSC-1 expression in the outer medulla of controls and moderate CRF rats both before and under in vivo inhibition of VP by OPC-31260, a selective V(2)-receptor antagonist. OPC-31260 decreased Na-K-ATPase activity from 11.2 +/- 1.5 to 3.7 +/- 0.8 in controls (P < 0.05) and from 19.0 +/- 0.8 to 2.9 +/- 0.5 micromol P(i). mg protein(-1) x h(-1) in moderate CRF rats (P < 0.05). CRF was associated with a significant increase in Na-K-ATPase activity (P < 0.05). Similarly, CRF was also associated with a significant increase in Na-K-ATPase expression to 164.4 +/- 21.5% compared with controls (P < 0.05), and OPC-31260 decreased Na-K-ATPase expression in both controls and CRF rats to 57.6 +/- 9.5 and 105.3 +/- 10.9%, respectively (P < 0.05). On the other hand, OPC-31260 decreased rBSC-I expression in both controls and CRF rats to 60.8 +/- 6.5 and 30.0 +/- 6.9%, respectively (P < 0.05), and was not influenced by CRF (95.7 +/- 5.2%). We conclude that 1) endogenous VP modulated Na-K-ATPase and rBSC-1 in both controls and CRF; and 2) CRF was associated with increased activity and expression of the Na-K-ATPase in the outer medulla, in contrast to the unaltered expression of the rBSC-1. The data suggest that endogenous VP could participate in the regulation of electrolyte transport at the level of the outer medulla.