The pluripotency transcription factor OCT4 represses heme oxygenase-1 gene expression.

In embryonic stem (ES) cells, oxidative stress control is crucial for genomic stability, self-renewal, and cell differentiation. Heme oxygenase-1 (HO-1) is a key player of the antioxidant system and is also involved in stem cell differentiation and pluripotency acquisition. We found that the HO-1 gene is expressed in ES cells and induced after promoting differentiation. Moreover, downregulation of the pluripotency transcription factor (TF) OCT4 increased HO-1 mRNA levels in ES cells, and analysis of ChIP-seq public data revealed that this TF binds to the HO-1 gene locus in pluripotent cells. Finally, ectopic expression of OCT4 in heterologous systems repressed a reporter carrying the HO-1 gene promoter and the endogenous gene. Hence, this work highlights the connection between pluripotency and redox homeostasis.

Multicomponent synthesis and preliminary anti-inflammatory activity of lipophilic diphenylamines.

Non-Steroidal Anti-inflammatory Drugs (NSAIDs) are some of the most prescribed medications for pain but the incidence of adverse effects -especially during chronic treatment- points out the requirement of new analgesics. In this study, we showed an efficient two-steps synthesis of diphenylamine-containing dipeptides consisting of a multicomponent process followed by a Buchwald-Hartwig cross-coupling reaction. We prepared 16 diphenylamine derivatives and evaluated their in vivo anti-inflammatory activity through an ear edema model using 12-O-tetradecanoylpholbol-13-acetate. Furthermore, the toxicity of the more potent compounds in the Artemia salina model and their cell viability using murine RAW 264.7 cells is reported. The fluorinated compound 10k becomes a reliable candidate since it reduced the TPA-induced edema to 92%, lacked cytotoxicity against murine macrophages, and had minimal toxicity in Artemia salina.

Effect of single and combined treatments with MPF or MAPK inhibitors on parthenogenetic haploid activation of bovine oocytes.

In bovine, correct oocyte artificial activation is a key step in ICSI and other reproductive biotechnologies, and still needs to be improved. The current study was designed to compare the activating efficiency of ionomycin (Io) followed by: a 4 h time window and ethanol (4h-Et), roscovitine (Rosc), dehydroleucodine (DhL), cycloheximide (CHX) or PD0325901 (PD), each as a single treatment, and then combine them in novel protocols. Parthenogenetic haploid activation was evaluated in terms of pronuclear (PN) formation, second polar body (2PB) extrusion, ploidy of day 2 embryos and in vitro development. Combined treatments with Io-4h-Et-Rosc and Io-Rosc/CHX increased PN formation (92.2% and 96%, respectively) compared with Io-Rosc, Io-CHX or Io-4h-Et, which were equally efficient at inducing PN formation (82-84%) and 2PB extrusion (62.1-70.5%). Oocyte activation with Io-DhL and Io-Rosc/DhL resulted in higher 2PB extrusion rates (90% and 95.9%, respectively) but lower PN formation (49.4-58.8%) and cleavage rates (36-57.9%), as occurred with Io-CHX/DhL (76.4% and 70.4%, respectively). For the first time, results show that Io followed by the MAPK inhibitor PD induces PN formation and 2PB extrusion, but PD combined with Rosc or CHX resulted in low rates of haploid day 2 embryos. In conclusion, DhL strongly induces 2PB extrusion but leads to poor PN formation and embryo development. PD induces bovine oocyte activation but results in low rates of haploid embryos. In contrast, the improved PN formation rates after treatment with combined Io-4h-Et-Rosc and Io-Rosc/CHX suggest they should be further evaluated in ART, aiming to increase success rates in bovine.

A dose-dependent response to MEK inhibition determines hypoblast fate in bovine embryos.

BACKGROUND: The segregation of the hypoblast and the emergence of the pluripotent epiblast mark the final stages of blastocyst formation in mammalian embryos. In bovine embryos the formation of the hypoblast has been partially studied, and evidence shows that MEK signalling plays a limited role in the segregation of this lineage. Here we explored the role of different signalling pathways during lineage segregation in the bovine embryo using immunofluorescence analysis of NANOG and SOX17 as readouts of epiblast and hypoblast, respectively. RESULTS: We show that SOX17 starts to be expressed in 16-32-cell stage embryos, whereas NANOG is first detected from 8-cell stage. SOX17 is first co-expressed with NANOG, but these markers become mutually exclusive by the late blastocyst stage. By assessing the expression kinetics of NANOG/SOX17 we show that inhibition of MEK signalling can eliminate SOX17 expression in bovine blastocysts, without altering NANOG expression. Modulation of WNT, PKC and LIF did not affect NANOG expression in the epiblast when used in combination with the ERK inhibitor. CONCLUSIONS: This study shows that SOX17 can be used as a reliable early marker of hypoblast in the bovine, and based on its expression profile we show that the hypoblast segregates in day 7 blastocysts. Furthermore, SOX17 expression is abolished using 1 µM of PD0325901, without affecting the NANOG population in the epiblast. Modulation of WNT, PKC and LIF are not sufficient to support enhanced NANOG expression in the epiblast when combined with ERK inhibitor, indicating that additional signalling pathways should be examined to determine their potential roles in epiblast expansion.

Synthesis of diphenylamine macrocycles and their anti-inflammatory effects.

A collection of fourteen diphenylamine macrocyclic derivatives containing a peptide chain with different substituents was synthesized using a protocol of two Ugi four component reactions (Ugi-4CR) and a Buchwald-Hartwig macrocyclization. Their anti-inflammatory effects were assayed with an ear edema model using 12-O-tetradecanoylphorbol-13-acetate, while the activity of myeloperoxidase was determined to evaluate the index of leukocyte infiltration. Compound 5e had an ID50 of 0.18 µM per ear with a potency higher than that of the reference drugs indomethacin and celecoxib (0.24 and 0.91 µM per ear, respectively). Moreover, the cytotoxicity of the macrocycles was determined in two healthy cell lines, showing a low percentage of toxicity.

Mitogen-activated protein kinase inhibition reduces mucin 2 production and mucinous tumor growth.

Excessive accumulation of mucin 2 (MUC2) protein (a gel-forming secreted mucin) within the peritoneal cavity is the major cause of morbidity and mortality in pseudomyxoma peritonei (PMP), a unique mucinous malignancy of the appendix. Mitogen-activated protein kinase (MAPK) signaling pathway is upregulated in PMP and has been shown to modulate MUC2 promoter activity. We hypothesized that targeted inhibition of the MAPK pathway would be a novel, effective, and safe therapeutic strategy to reduce MUC2 production and mucinous tumor growth. We tested RDEA119, a specific MEK1/2 (MAPK extracellular signal-regulated kinase [ERK] kinase) inhibitor, in MUC2-secreting LS174T cells, human PMP explant tissue, and in a unique intraperitoneal murine xenograft model of PMP. RDEA119 reduced ERK1/2 phosphorylation and inhibited MUC2 messenger RNA and protein expression in vitro. In the xenograft model, chronic oral therapy with RDEA119 inhibited mucinous tumor growth in an MAPK pathway-dependent manner and this translated into a significant improvement in survival. RDEA119 downregulated phosphorylated ERK1/2 and nuclear factor κB p65 protein signaling and reduced activating protein 1 (AP1) transcription factor binding to the MUC2 promoter in LS174T cells. This study provides a preclinical rationale for the use of MEK inhibitors to treat patients with PMP.

Molecular structure-optical property relationships for a series of non-centrosymmetric two-photon absorbing push-pull triarylamine molecules.

This article reports on a comprehensive study of the two-photon absorption (2PA) properties of six novel push-pull octupolar triarylamine compounds as a function of the nature of the electron-withdrawing groups. These compounds present an octupolar structure consisting of a triarylamine core bearing two 3,3'-bis(trifluoromethyl)phenyl arms and a third group with varying electron-withdrawing strength (H < CN < CHO < NO2 < Cyet < Vin). The 2PA cross-sections, measured by using the femtosecond open-aperture Z-scan technique, showed significant enhancement from 45 up to 125 GM for the lowest energy band and from 95 up to 270 GM for the highest energy band. The results were elucidated based on the large changes in the transition and permanent dipole moments and in terms of (i) EWG strength, (ii) degree of donor-acceptor charge transfer and (iii) electronic coupling between the arms. The 2PA results were eventually supported and confronted with theoretical DFT calculations of the two-photon transition oscillator strengths.

Triacylglycerol accumulation and oxidative stress in Rhodococcus species: differential effects of pro-oxidants on lipid metabolism.

In general, members of Rhodococcus genus are highly resistant to desiccation. Desiccation is a complex process which includes the formation of reactive oxygen species that results in significant damage to cells. In this study, we demonstrate that extremophile actinobacterial strains isolated from diverse environments, mainly belonging to Rhodococcus genus, exhibited high tolerance to the pro-oxidants hydrogen peroxide (H2O2) and methyl viologen (MV). In addition, we investigated the possible interconnections between the responses of the oleaginous Rhodococcus opacus PD630 to oxidative stress and lipid metabolism, since both processes demand a metabolic reorganization of cells. Experiments with metabolic inhibitors showed differential effects of both pro-oxidants on lipid metabolism in PD630 cells. The inhibition of carotenoid biosynthesis by the addition of diphenylamine to the media negatively affected the tolerance of cells to H2O2, but not to MV. The inhibition of triacylglycerol (TAG) biosynthesis and accumulation in PD630 did not affect the tolerance of cells to H2O2 and MV; whereas, the blockage of lipolysis decreased the tolerance of cells to H2O2 (but not MV) under carbon-starvation conditions. Interestingly, the addition of MV to the media (but not H2O2) induced a reduction of TAG accumulation by cells. Resuming, results of this study revealed metabolic connections between lipid metabolism and oxidative stress responses in R. opacus PD630, and probably in other extremophile TAG-accumulating rhodococci.

Intoxicação espontânea e experimental por nitrato/nitrito em bovinos alimentados com Avena sativa (aveia) e/ou Lolium spp. (azevém) / Spontaneous and experimental poisoning by nitrate/nitrite in cattle fed Avena sativa (oat) and/or Lolium spp. (ryegrass)

Descrevem-se os dados epidemiológicos, sinais clínicos e lesões da intoxicação espontânea e experimental por nitrato e nitrito em bovinos alimentados com pastagens de Avena sativa (aveia) e/ou Lolium spp (azevém). A enfermidade ocorre em diferentes regiões do Estado de Santa Catarina, quando as pastagens tem crescimento exuberante, após receberem quantidades excessivas de adubo químico e/ou orgânico, principalmente quando ocorrem condições climáticas de seca e posteriormente chuva. Os animais em contato com essas pastagens desenvolvem rapidamente mucosas de coloração marrom, taquipnéia, andar cambaleante, micção frequente, timpanismo, decúbito lateral e morte em poucos minutos, ou recuperação algumas horas após. Na necropsia de quatro animais que adoeceram espontaneamente, as principais alterações encontradas foram a coloração marrom das mucosas, a cor escura do sangue (cor de chocolate) e a coloração vermelho intensa da musculatura esquelética e do miocárdio esquerdo. A reprodução experimental da doença foi realizada em sete bovinos, com pastagens de quatro propriedades onde ocorreu adoença. Aveia e/ou azevém verdes e sob a forma de feno foram administradas aos bovinos. Destes bovinos quatro morreram, dois adoeceram e se recuperam, um naturalmente e outro com a aplicação de azul de metileno a 1%, na dose de 2mg/kg/peso vivo, e um bovino não apresentou alterações. Os sinais clínicos observados e as lesões nos animais que adoeceram e morreram foram idênticos aos casos naturais. Alterações microscópicas não foram observadas nos casos naturais e experimentais. O teste da difenilamina nas amostras de pastagens onde ocorreram os surtos resultou positivo em todas as propriedades. A análise bromatológica realizada em amostras coletadas de várias propriedades em que ocorreram surtos revelou de 0,30 a 3,36% de nitrato na matéria seca. A enfermidade caracterizou-se principalmente por respiração ofegante, sangue de coloração escura, mucosas de coloração marrom e morte rápida dos bovinos e está relacionada á ingestão de pastagens de aveia e/ou azevém super adubados, que acumularam alto teor de nitrato, após um período de chuvas precedido de seca.

Epidemiological data, clinical and pathological findings of the spontaneous andexperimental poisoning by nitrate and nitrite in cattle fed oats (Avena sativa) and/or ryegrass (Lolium spp.), diphenylamine test, and the nitrate content in the samples of the pasture where the outbreaks occurred, are described. The disease occurs in different regions of the State of Santa Catarina, in which pastures have exuberant growth, after receiving excessive amounts of chemical and/or organic fertilizer, mainly when raining occurs after a period of dry wheather. The animals grazing these pastures quickly develop brown mucosa, tachypnea, staggering gait, frequent urination, bloating, lateral recumbency and death in few minutes or hours. At necropsy of four animals that died spontaneously, the main lesions found were brown mucosa, dark color of the blood (chocolate), intense red color of the skeletal muscles and of the left part of the myocardium. The experimental reproduction of the disease was performed in seven cattle, with pastures from four farms where the disease occurred. The animals were fed with fresh oats and ryegrass and/or hay of it. Four animals died, two became ill and recovered, and one was treated with 2mg/kg per body weight of methylene blue 1%, and one cattle did not show changes. Clinical signs and lesions of the diseased animals that died were similar to natural cases. Microscopic changes were not observed in spontaneous and experimental poisoning. The diphenylamine test was positive in all the farms where the outbreaks occurred. The chemical analysis performed on samples of the pastures from several farms, in which outbreaks of the disease occurred, ranged from 0.30to 3.36% of nitrate in the dry matter. The disease is associated with the ingestion of oats and/or ryegrass pastures heavily fertilized, which accumulates high levels of nitrate after a period of rain and is characterized by rapid breathing, dark-colored blood, brown mucous and rapid death.

Intoxicação espontânea e experimental por nitrato/nitrito em bovinos alimentados com Avena sativa (aveia) e/ou Lolium spp. (azevém) / Spontaneous and experimental poisoning by nitrate/nitrite in cattle fed Avena sativa (oat) and/or Lolium spp. (ryegrass)

Descrevem-se os dados epidemiológicos, sinais clínicos e lesões da intoxicação espontânea e experimental por nitrato e nitrito em bovinos alimentados com pastagens de Avena sativa (aveia) e/ou Lolium spp (azevém). A enfermidade ocorre em diferentes regiões do Estado de Santa Catarina, quando as pastagens tem crescimento exuberante, após receberem quantidades excessivas de adubo químico e/ou orgânico, principalmente quando ocorrem condições climáticas de seca e posteriormente chuva. Os animais em contato com essas pastagens desenvolvem rapidamente mucosas de coloração marrom, taquipnéia, andar cambaleante, micção frequente, timpanismo, decúbito lateral e morte em poucos minutos, ou recuperação algumas horas após. Na necropsia de quatro animais que adoeceram espontaneamente, as principais alterações encontradas foram a coloração marrom das mucosas, a cor escura do sangue (cor de chocolate) e a coloração vermelho intensa da musculatura esquelética e do miocárdio esquerdo. A reprodução experimental da doença foi realizada em sete bovinos, com pastagens de quatro propriedades onde ocorreu adoença. Aveia e/ou azevém verdes e sob a forma de feno foram administradas aos bovinos. Destes bovinos quatro morreram, dois adoeceram e se recuperam, um naturalmente e outro com a aplicação de azul de metileno a 1%, na dose de 2mg/kg/peso vivo, e um bovino não apresentou alterações. Os sinais clínicos observados e as lesões nos animais que adoeceram e morreram foram idênticos aos casos naturais. Alterações microscópicas não foram observadas nos casos naturais e experimentais. O teste da difenilamina nas amostras de pastagens onde ocorreram os surtos resultou positivo em todas as propriedades. A análise bromatológica realizada em amostras coletadas de várias propriedades em que ocorreram surtos revelou de 0,30 a 3,36% de nitrato na matéria seca. A enfermidade caracterizou-se principalmente por respiração ofegante, sangue de coloração escura, mucosas de coloração marrom e morte rápida dos bovinos e está relacionada á ingestão de pastagens de aveia e/ou azevém super adubados, que acumularam alto teor de nitrato, após um período de chuvas precedido de seca.(AU)

Epidemiological data, clinical and pathological findings of the spontaneous andexperimental poisoning by nitrate and nitrite in cattle fed oats (Avena sativa) and/or ryegrass (Lolium spp.), diphenylamine test, and the nitrate content in the samples of the pasture where the outbreaks occurred, are described. The disease occurs in different regions of the State of Santa Catarina, in which pastures have exuberant growth, after receiving excessive amounts of chemical and/or organic fertilizer, mainly when raining occurs after a period of dry wheather. The animals grazing these pastures quickly develop brown mucosa, tachypnea, staggering gait, frequent urination, bloating, lateral recumbency and death in few minutes or hours. At necropsy of four animals that died spontaneously, the main lesions found were brown mucosa, dark color of the blood (chocolate), intense red color of the skeletal muscles and of the left part of the myocardium. The experimental reproduction of the disease was performed in seven cattle, with pastures from four farms where the disease occurred. The animals were fed with fresh oats and ryegrass and/or hay of it. Four animals died, two became ill and recovered, and one was treated with 2mg/kg per body weight of methylene blue 1%, and one cattle did not show changes. Clinical signs and lesions of the diseased animals that died were similar to natural cases. Microscopic changes were not observed in spontaneous and experimental poisoning. The diphenylamine test was positive in all the farms where the outbreaks occurred. The chemical analysis performed on samples of the pastures from several farms, in which outbreaks of the disease occurred, ranged from 0.30to 3.36% of nitrate in the dry matter. The disease is associated with the ingestion of oats and/or ryegrass pastures heavily fertilized, which accumulates high levels of nitrate after a period of rain and is characterized by rapid breathing, dark-colored blood, brown mucous and rapid death.(AU)

Photoprotection by carotenoid pigments in the yeast Rhodotorula mucilaginosa: the role of torularhodin.

In this paper we report the relationship between carotenoids and ergosterol and cell UV-B resistance in different strains of the yeast Rhodotorula mucilaginosa. Cell survival was studied using a set of 13 strains; additionally, two mutants (a hyper-producing one and a colourless one) in combination with diphenylamine (DPA), a carotenogenesis inhibitor, were used. A positive correlation between total carotenoids and survival to UV-B radiation was found. However, when individual carotenoid concentrations were tested, only torularhodin was found to be significantly related to UV-B survival. On the contrary, ergosterol did not affect survival. The hyper-pigmented strain showed an enhanced survival (up to 250%) compared to the parental strain, while the survival of the albino mutant was similar to that experienced by the parental strain; however, observed changes in survival were dose dependent. The cyclobutane pyrimidine dimers (CPDs), one of the major forms of DNA damage caused by UV exposure, appears as unrelated to the accumulation of carotenoids and cell survival. These results indicate that bearing higher torularhodin concentrations enhances UV-B survival in yeasts and, thus, the accumulation of this pigment constitutes an important mechanism that improves the resistance of yeasts to UV-B.

Pharmacological Suppression of rat distal colon chloride secretion requires two blockers

Rat distal colon epithelium is frequently employed to assess the effect of natural and synthetic chemicals on chloride secretion. Inhibition of chloride secretion is often reported as the loop diuretic-sensitive portion of short-circuit current (Isc). The present work challenges the hypothesis that a loop diuretic alone is able to fully abolish chloride secretion. Isolated mucosa preparations were mounted in an Ussing chamber. The effects on short-circuit current of replacement of normal Ringer by a low (2.5 mmol/L) Cl solution and of blockers of basolateral Na, K, 2 Cl symport (bumetanide), apical Cl channels (diphenylamine-2-carboxylate, DPC), and anion exchange (4-acetamido-4-isothiocyanatostilbene-2,2-disulfonic acid, SITS) alone and combined were assessed. Low Cl reversibly decreased Isc by 76%. In normal Ringer, bumetanide decreased Isc by 65%. SITS also had a significant effect at the serosal side, but not at the apical side, where DPC caused a 40% decrease. Chloride replacement, bumetanide and DPC, but not SITS, increased epithelial resistivity. Combined blockade of Na, K, 2 Cl symport and apical Cl channels, of Na, K, 2 Cl symport and anion antiport, or of anion antiport and apical Cl channels was needed to achieve reduction of short circuit current to the same extent seen with chloride replacement. Present results indicate that Isc of the unstimulated epithelium is mostly due to chloride secretion, and at least two blockers are required to abolish it. This fact should be taken into account in studies of chloride secretion-stimulating agents. (AU)

Pharmacological Suppression of rat distal colon chloride secretion requires two blockers

Rat distal colon epithelium is frequently employed to assess the effect of natural and synthetic chemicals on chloride secretion. Inhibition of chloride secretion is often reported as the loop diuretic-sensitive portion of short-circuit current (Isc). The present work challenges the hypothesis that a loop diuretic alone is able to fully abolish chloride secretion. Isolated mucosa preparations were mounted in an Ussing chamber. The effects on short-circuit current of replacement of normal Ringer by a low (2.5 mmol/L) Cl solution and of blockers of basolateral Na, K, 2 Cl symport (bumetanide), apical Cl channels (diphenylamine-2-carboxylate, DPC), and anion exchange (4-acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic acid, SITS) alone and combined were assessed. Low Cl reversibly decreased Isc by 76%. In normal Ringer, bumetanide decreased Isc by 65%. SITS also had a significant effect at the serosal side, but not at the apical side, where DPC caused a 40% decrease. Chloride replacement, bumetanide and DPC, but not SITS, increased epithelial resistivity. Combined blockade of Na, K, 2 Cl symport and apical Cl channels, of Na, K, 2 Cl symport and anion antiport, or of anion antiport and apical Cl channels was needed to achieve reduction of short circuit current to the same extent seen with chloride replacement. Present results indicate that Isc of the unstimulated epithelium is mostly due to chloride secretion, and at least two blockers are required to abolish it. This fact should be taken into account in studies of chloride secretion-stimulating agents.

Selective inhibitory effects of niflumic acid on 5-HT-induced contraction of the rat isolated stomach fundus.

The effects of niflumic acid (NFA), an inhibitor of calcium-activated chloride currents I(Cl(Ca)), were compared with the actions of the voltage-dependent calcium channel (VDCC) blocker nifedipine on 5-hydroxtryptamine (5-HT)- and acetylcholine (ACh)-induced contractions of the rat isolated fundus. NFA (1 - 30 microM) elicited a concentration-dependent inhibition of contractions induced by 5-HT (10 microM) with a reduction to 15. 5+/-6.0% of the control value at 30 microM. 1 microM nifedipine reduced 5-HT-induced contraction to 15.2+/-4.9% of the control, an effect not greater in the additional presence of 30 microM NFA. In contrast, the contractile response to ACh (10 microM) was not inhibited by NFA in concentrations /=10 microM. Our results show that NFA can exert selective inhibitory effects on the chloride-dependent 5-HT-induced contractions of the rat fundus. The data support the hypothesis that activation of Cl((Ca)) channels leading to calcium entry via VDCCs is a mechanism utilized by 5-HT, but not by ACh, to elicit contraction of the rat fundus.

Evaluación de la clorprofepiridamina como anestésico local alternativo en odontología / An evaluation of the chlorprofenpiridamine as an alternative local anesthetic in dentistry

Las reacciones de hipersensibilidad a los anestésicos locales en odontología son infrecuentes, no obstante, los pacientes que las presentan requieren un manejo diferente, ya que pueden presentar desde una simple reacción cutánea a una anafilaxia mortal. Desde hace 40 años se han estudiado el efecto anestésico local de los antihistamínicos y sus posibles usos en medicina y odontología. Nuestra investigación consistió en la evaluación de la cloroprofendiridamina (clorfenamina 10 mg/ml + adrenalina 1 x 100.000), como anestésico local infiltrativo, en 20 pacientes con indicación de extracción dental simple, comparándolo con un grupo control (n=20) al que se le administró anestesia convencional (lidocaína al 2 por ciento + adrenalina 1 x 100.000). Se obtuvo una anestesia adecuada en el 75 por ciento de las extracciones realizadas (n=15) pudiendo concluir que la clorfenamina puede constituir una alternativa efectiva para realizar extraccionse dentales simples, en pacientes con hipersensibilidad demostrada a los anestésicos locales convencionales; pero no es adecuada para ser utilizada de rutina en odontología, pues la anestesia que otorga es de corta duración y poca profundidad, lo que hace indudablemente los procedimientos más dolorosos y molestos, que al utilizar lidocaína 2 por ciento + adrenalina 1 x 100.000

Loss of the basement membrane matrix molecule, bamin, in diphenylamine-treated mice.

Polycystic kidney disease (PKD) is a life-threatening disease characterized by focal dilatations or cysts in certain kidney tubules. Changes (i.e. thickening) in the support structure for these tubules, the basement membrane, have been related to the development of the cysts. Analysis of changes in basement membranes of humans with PKD is difficult, however, due to the restricted amount of material available for study. Several genetic and induced animal models, including diphenylamine-treated rats, have been employed to study the effects of PKD on basement membrane synthesis. While all these studies agree that PKD has a significant influence on basement membranes, no clear understanding as to how PKD effects basement membrane composition has emerged. Here, we report our findings of the effect of diphenylamine treatment on the composition of the basement membrane. Our immunohistological studies indicate that bamin, a recently described glycoprotein associated with glomerular basement membranes (Robinson et al., 1989), is not present in the glomerular basement membranes of diphenylamine-treated mice. This finding was confirmed by analysis of the composition of the basement membrane matrix synthesized by EHS tumors grown in control and diphenylamine-treated mice. The possible role of bamin in the pathogenesis of renal cysts is discussed.

Activation of Ca2+ uptake and inhibition of reversal of the sarcoplasmic reticulum Ca2+ pump by aromatic compounds.

The effects of aromatic compounds in sarcoplasmic reticulum Ca2+-ATPase were investigated. The solubility of the drugs in various organic solvents and water was measured. The ratio between the solubility in organic solvents and that in water (distribution coefficient) was used as an index of their hydrophobicity. The order found was triphenylphosphine greater than diphenylamine greater than 3-nitrophenol greater than 4-nitrophenol greater than 1,3-dihydroxybenzene. The effects observed on the Ca2+-ATPase were correlated with hydrophobicity of the drugs, activation and inhibition being obtained at a lower concentration the greater the distribution coefficient of the drug into organic solvent. In leaky vesicles, the effects of each compound on the ATPase activity varied depending on the Ca2+ concentration in the medium: it inhibited in the presence of 5 microM Ca2+ and activated when the Ca2+ concentration was raised to 2 mM. In intact vesicles, 3- and 4-nitrophenol, diphenylamine, and triphenylphosphine enhanced both the rate of ATP hydrolysis and the amount of Ca2+ accumulated by the vesicles. These four drugs inhibited Ca2+ uptake when ITP was used as substrate. 1,3-Dihydroxybenzene enhanced the amount of Ca2+ accumulated by the vesicles regardless of whether ATP or ITP was the substrate. All five compounds inhibited the phosphorylation of the enzyme by Pi, the efflux of Ca2+, and the synthesis of ATP measured during the reversal of the Ca2+ pump. The results indicate that the hydrophobic character of various organic compounds determines their access to sensitive domains of the membrane-bound calcium pump. Additional specific effects are then produced, depending on the structure of each compound.

Acao da difenilamina (DPA) sobre Candida utilis em condicoes proliferativas. / The effects of diphenylamine on Candida utilis under proliferating conditions

Os efeitos da DPA, sobre o desenvolvimento de Candida utilis, foram examinados em varias concentracoes, sendo detectaveis com 0,15 micros/ml de meio. O crescimento da levedura sofreu inibicao, da ordem de 99% a concentracao de DPA de 75 micros/ml, enquanto 15 micros/ml produziram cerca de 50% de inibicao. Nesta ultima concentracao foi possivel constatar que a droga atua sobre o crescimento e eficiencia na utilizacao da glicose pela levedura, afetando, ainda, o teor em trealose, glicidios totais e proteinas, em varias etapas do desenvolvimento, frente a suprimentos de glicose de 0,5; 2 e 4%. Os resultados obtidos indicam uma atuacao da substancia, nas vias do metabolismo oxidativo

Determinación de residuos de polvora por cromatagrafía en capa fina en armas de fuego, castillas y zonas de impacto / Powder residue determination by chromatography in fine cloak in firearms, and impact zone

Los análisis de residuos de pólvora efectuados en el presente trabajo, despúes de haberse producido la detonación en el disparo, se han llevado a cabo en el arma de fuego, el los casquillos y en las manchas dejadas por el fogonazo. La técnica empleada es la de Cromatografia en capa fina. El arma usada es el revólver Smith & Wesson calibre 38, de fabricación americana; los cartuchos, también de calibre 38 han sido de las 2 marcas y calibres más usados en la actualidad por las fuerzas policiales: Fame y Remington. Las manchas dejadas por el fogonazo se tomaron en papel wattman 40, en virtud a que éste retiene mayor cantidad los residuos de pólvora que se sometéran al análisis. Los resultados obtenidos nos revelan que en los residuos de pólvora Fame podemos encontrar: diferelamina, en el arma de fuego, mercurio, plomo, difemilamina y difeniluretana, en el casquillo; mercurio; plomo, difenilomina; difeniluretana y centralito en la zona de impacto. Por su parte en los residuos de pólvora Remington podemos hallar: ftalata de dibutilo en el casquillo: casquillo, mercurio, plomo, difenilamina, difeniluretana, centialita y ftalato de dibutilo en la zona de impacto.