Presence of complete or incomplete septa in human jugular foramens / Presencia de septos completos o incompletos en forámenes yugulares humanos

SUMMARY: The objective of this study was to determine the occurrence of anatomical variants in the exocranial surface of the jugular foramen, specifically, the presence of single or double and complete or incomplete septation. A cross-sectional anatomical study was performed using 96 Brazilian dry human skulls (53 male and 43 female). One examiner determined the number (single or double) and type (i.e. complete or incomplete) of osseous septation at the outer surface of jugular foramens. Data went through statistical analysis on GraphPad Prism 6.01. Our results shown that Male individuals where more likely to present normal jugular foramens (male = 71.69%, female = 34.88%; p = 0.003). However, one incomplete septation occurred more often on the right side of female individuals (1 incomplete septation, male = 16.98%; 1 incomplete septation, female = 34.88%; p = 0.044). Similarly, one complete septation (i.e. the presence of two fully divided jugular compartments) also occurred more often on the right side of female individuals (1 complete septation, male = 9.43%; 1 complete septation, female = 25.58%; p = 0.038). Anatomical variants of the jugular foramen regarding single or double complete or incomplete septations were more likely to be found on the right side of female individuals, whose also presented a higher rate of jugular foramens with any type of septation than regular non-altered jugular foramens.

RESUMEN: El objetivo de la presente investigación fue determinar la presencia de variaciones anatómicas en la superficie exocraneal del foramen yugular, especificamente, la presencia de septos únicos o dobles, completos o incompletos. El estudio fue realizado en 96 cráneos secos (53 masculinos y 43 femeninos) de indivíduos Brasileños. Se determinaron septos óseos completos o incompletos y número de ellos. Los resultados obtenidos fueron tratados estadísticamente con el programa GraphPad Prism 6.01. Los sujetos de sexo masculino fueron más propensos a presentar forámenes yugulares normales (sexo masculino: 71,69%; sexo femenino: 34,88%, p= 0,003). Sin embargo, se observaron septos incompletos con mayor frecuencia en el lado derecho y en el sexo femenino (sexo masculino: 16,98%; sexo femenino: 34,88%, p=0,044). Adicionalmente, una septación completa (presencia de dos compartimientos yugulares, divididos completamente), se presentaron más frecuentemente en el lado derecho de indivíduos femeninos (sexo masculino: 9,43%; sexo femenino: 25,58%, p= 0,038). Las variantes anatómicas del foramen yugular, en relación a septos simples o dobles, completos o incompletos, se encontraron con mayor frecuencia en el lado derecho de las mujeres, las que presentaron un alto rango de forámenes yugulares con algún tipo de septos respecto a los forámenes yugulares regulares no alterados.

Biological behavior of magnesium-substituted hydroxyapatite during bone repair / Comportamento biológico de hidroxiapatita substituída com magnésio durante o reparo ósseo

Abstract The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.

Resumo O objetivo deste estudo foi analisar o comportamento biológico de microesferas de hidroxiapatita (HA) substituída com magnésio (Mg) durante o reparo de defeito ósseo crítico, tendo em vista que este íon é de grande interesse clínico, pois está intimamente associado à homeostasia e à mineralização óssea. Para tanto, utilizou-se 30 ratos para compor três grupos experimentais: GI - defeito ósseo preenchido com microesferas de HA; GII - defeito ósseo preenchido com microesferas de HA substituída com Mg; GIII (controle) - defeito ósseo vazio; avaliados nos pontos biológicos de 15 e 45 dias. Os resultados histológicos evidenciaram, aos 15 dias, discreto infiltrado inflamatório crônico e neoformação óssea restrita às bordas, em todos os grupos. Nos grupos GI e GII, os biomateriais mantiveram-se íntegros e circundados por tecido conjuntivo frouxo. Aos 45 dias, notou-se resposta inflamatória do tipo crônica granulomatosa discreta nos grupos GI e GII, e no GIII presença escassa de células inflamatórias mononucleares. As microesferas implantadas no GI e GII mantiveram-se, em sua maioria, íntegras e envolvidas por tecido conjuntivo fibroso. Notou-se discreta neoformação óssea próxima às bordas e circunjacente a algumas microesferas. No GIII, a mineralização limitou-se às bordas e a área remanescente foi preenchida por tecido conjuntivo fibroso. Conclui-se que os biomateriais foram biocompatíveis, bioativos, osteocondutores e apresentaram biodegradação lenta, indicando seu grande potencial para em aplicações clínica como biomaterial de preenchimento.

Latent class analysis of attention and white matter correlation in children with attention-deficit/hyperactivity disorder

This study aimed to explore attentional patterns among children with inattentive attention-deficit/hyperactivity disorder (ADHD-I) and children with typical development (TD), using a latent class analysis (LCA). Patterns of brain connectivity were also explored. The sample comprised 29 ADHD-I and 29 TD matched children. An LCA was conducted to reclassify subjects according to their attentional performance, considering cognitive measures of attention and behavioral symptoms, regardless of group of origin. The new clusters were then compared in respect to brain white matter measurements (extracted from diffusion tensor imaging). Participants were rearranged in 2 new latent classes, according to their performance in an attention task and the results of behavioral scales, resulting in groups with more homogeneous attentional profiles. A comparison of the 2 new classes using the white matter measurements revealed increased fractional anisotropy in the left inferior fronto-occipital fasciculus and left inferior longitudinal fasciculus for the class composed by participants with a higher risk of attentional problems. The findings indicated that it was possible to observe variability regarding neuropsychological profile, accompanied by underpinning neurobiological differences, even among individuals with the same disorder subtype - inattentive ADHD. This specific data-driven clustering analysis may help to enhance understanding of the pathophysiology of the disorder's phenotypes.

Tropical forages: morphoanatomy of plants grown in areas with the death of pasture syndrome / Forrageiras tropicais: anatomia e morfometria de plantas cultivadas em áreas com síndrome da morte de pastagens

Abstract Roots and leaves of Panicum maximum Tanzânia, Mombaça and Massai; Urochloa brizantha Piatã, Marandu and Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II and Cynodon nlemfuensis Estrela-roxa were analyzed, seeking to identify characters for better adaptation to the environment that may interfere with digestibility of tissue from the point of view of the rumen in cattle. Were planted ten cultivars in a completely randomized blocks with three repetitions. Was collected vegetative material, which histological slides were prepared from middle third of the sections of roots and leaves. Were observed differences (p>0.05) in the roots: higher volume of epidermal cells (28.62 µm) and overall diameter (1926.41 µm) of Llanero; thicker vascular cylinder (975.09 µm) and more protoxylem (42.25) in Estrela-roxa and occurrence of aerenchyma in cultivars Piatã, Mulato II, Xaraés, Massai, Llanero and Estrela-roxa; Were found higher proportions of bulliform cells in the leaves (121.07 µm) and thicker leaf mesophyll in U. humidicola Llanero (263.63 µm); higher proportion of sclerenchyma fibers in Xaraés and Marandu; lower results for amount of fibers in P. maximum Massai. We conclude that the cultivars Estrela-roxa, Llanero and Massai have greater adaptability to the environment and better nutritional quality.

Resumo Foram analisadas raízes e folhas de Panicum maximum Tanzânia, Mombaça e Massai; Urochloa brizantha Piatã, Marandu e Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II e Cynodon nlemfuensis Estrela-roxa, procurando identificar caracteres relacionados à melhor adaptação ao ambiente e à qualidade nutritiva das forrageiras. As dez cultivares foram semeadas em blocos inteiramente casualizados com três repetições. Após estabelecidas foi coletado material vegetativo, do qual lâminas histológicas foram confeccionadas a partir de secções do terço médio de raízes e folhas. Foram observadas diferenças significativas (p>0,05) nas raízes: maior volume de células epidérmicas (28,62 µm) e diâmetro total (1926,41 µm) de Llanero; em Estrela-roxa maior espessura do cilindro vascular (975,09 µm) e número maior de protoxilemas (42,25) e formação de aerênquimas nas cultivares Piatã, Mulato II, Xaraés, Massai, Llanero, e Estrela-roxa; Nas folhas, foram constatadas maiores proporções de células buliformes (121,07 µm) e mesofilo foliar mais espesso (263,63 µm) em Llanero; em Xaraés e Marandu maiores proporções de fibras esclerenquimáticas; em Massai menores resultados para quantidade de fibras. Conclui-se que as cultivares Estrela-roxa, Llanero e Massai apresentam maior adaptabilidade ao ambiente e melhor qualidade nutritiva.

Anatomy and micromorphometric analysis of leaf Catasetum x apolloi Benelli & Grade with addition of potassium silicate under different light sources / Anatomia e análise micromorfométrica foliar de Catasetum x apolloi Benelli & Grade com adição de silicato de potássio em diferentes fontes de luz

Abstract The aim of this study was to compare vitroplants Catasetum x apolloi grown under natural light and artificial light and different concentrations of potassium silicate, providing data on the anatomical differentiation that aids the acclimatization process of this species. Plants from in vitro seeding were used; 5 protocorms of approximately 0.5 cm were inoculated into vials with a capacity of 500 mL containing 100 mL of alternative culture medium plus potassium silicate (0.0, 0.5; 1.0 mL L–1), pH adjusted to 5.5 ± 0.5 and gelated with 4GL–1 agar before the autoclaving process. Cultures were maintained under natural light (TNE) and artificial light (TAE) for 90 days, and micromorphometric analysis was performed for polar and equatorial diameter, density and stomatal index, blade thickness in the central rib, and secondary veins. Applications in K2SiO4 alternative medium provided the following: elongation of the hypodermis, thicker mesophyll, and more prominent midrib; elipptical guard cells; formation of epistomatal chamber; and lower stomatal density and stomatal with lower equatorial and polar diameters. The conditions that favored the acclimatization were lower light intensities and lower potassium silicate doses.

Resumo O objetivo desse trabalho foi comparar vitroplantas de Catasetum x apolloi cultivadas sob luz natural e luz artificial e diferentes concentrações de silicato de potássio, fornecendo dados sobre diferenciação anatômica que auxiliem no processo de aclimatação dessa espécie. Utilizou-se plantas provenientes da semeadura in vitro, 5 protocormos de aproximadamente 0,5 cm foram inoculados em frascos com capacidade para 500 mL contendo 100 mL de meio de cultura alternativo, acrescido de silicato de potássio (0,0; 0,5; 1,0 mL L–1), pH ajustado para 5,5 ±0,5 e gelificado com 4gL–1 de ágar antes do processo de autoclavagem. As culturas foram mantidas sob luz natural (TAA) e luz artificial (TAN) por 90 dias, e feitas análises micromorfométricas (diâmetro polar e equatorial, densidade e índice estomático, espessura do limbo na nervura central e nervuras secundárias). As aplicações de K2SiO4 em meio alternativo, propiciaram: alongamento da hipoderme; mesofilo mais espesso e nervura central mais proeminente; células guardas elípticas; formação de câmaras supraestomáticas; menor densidade estomática e estômatos com menores diâmetros equatorial e polar. As condições que podem favorecer a aclimatação são menores intensidades de luz e menores doses de silicato de potássio.

Biological behavior of magnesium-substituted hydroxyapatite during bone repair

Abstract The aim of this study was to analyze the biological behavior and osteogenic potential of magnesium (Mg) substituted hydroxyapatite (HA) microspheres, implanted in a critical bone defect, considering that this ion is of great clinical interest, since it is closely associated with homeostasis and bone mineralization. For the purpose of this study, 30 rats were used to compose three experimental groups: GI - bone defect filled with HA microspheres; GII - bone defect filled with HA microspheres replaced with Mg; GIII - empty bone defect; evaluated at biological points of 15 and 45 days. The histological results, at 15 days, showed, in all the groups, a discrete chronic inflammatory infiltrate; biomaterials intact and surrounded by connective tissue; and bone neoformation restricted to the borders. At 45 days, in the GI and GII groups, an inflammatory response of discrete granulomatous chronic type was observed, and in the GIII there was a scarce presence of mononuclear inflammatory cells; in GI and GII, the microspheres were seen to be either intact or fragmented, surrounded by fibrous connective tissue rich in blood vessels; and discrete bone neoformation near the edges and surrounding some microspheres. In GIII, the mineralization was limited to the borders and the remaining area was filled by fibrous connective tissue. It was concluded that the biomaterials were biocompatible and osteoconductive, and the percentage of Mg used as replacement ion in the HA did not favor a greater bone neoformation in relation to the HA without the metal.

Resumo O objetivo deste estudo foi analisar o comportamento biológico de microesferas de hidroxiapatita (HA) substituída com magnésio (Mg) durante o reparo de defeito ósseo crítico, tendo em vista que este íon é de grande interesse clínico, pois está intimamente associado à homeostasia e à mineralização óssea. Para tanto, utilizou-se 30 ratos para compor três grupos experimentais: GI - defeito ósseo preenchido com microesferas de HA; GII - defeito ósseo preenchido com microesferas de HA substituída com Mg; GIII (controle) - defeito ósseo vazio; avaliados nos pontos biológicos de 15 e 45 dias. Os resultados histológicos evidenciaram, aos 15 dias, discreto infiltrado inflamatório crônico e neoformação óssea restrita às bordas, em todos os grupos. Nos grupos GI e GII, os biomateriais mantiveram-se íntegros e circundados por tecido conjuntivo frouxo. Aos 45 dias, notou-se resposta inflamatória do tipo crônica granulomatosa discreta nos grupos GI e GII, e no GIII presença escassa de células inflamatórias mononucleares. As microesferas implantadas no GI e GII mantiveram-se, em sua maioria, íntegras e envolvidas por tecido conjuntivo fibroso. Notou-se discreta neoformação óssea próxima às bordas e circunjacente a algumas microesferas. No GIII, a mineralização limitou-se às bordas e a área remanescente foi preenchida por tecido conjuntivo fibroso. Conclui-se que os biomateriais foram biocompatíveis, bioativos, osteocondutores e apresentaram biodegradação lenta, indicando seu grande potencial para em aplicações clínica como biomaterial de preenchimento.

Trigeminal neuralgia: literature review

The trigeminal nerve, fifth equal of cranial nerves, a mixed nerve is considered by possessing motor and sensitive components. The sensitive portion takes to the Nervous System Central somesthesics information from the skin and mucous membrane of great area of the face, being responsible also for a neural disease, known as the Trigeminal Neuralgia. The aim of this study was to review the literature on the main characteristics of Trigeminal Neuralgia, the relevant aspects for the diagnosis and treatment options for this pathology. This neuralgia is characterized by hard pains and sudden, similar to electric discharges, with duration between a few seconds to two minutes, in the trigeminal nerve sensorial distribution. The pain is unchained by light touches in specific points in the skin of the face or for movements of the facial muscles, it can be caused by traumatic sequels or physiologic processes degenerative associate the vascular compression. Prevails in the senior population, frequently in the woman. In a unilateral way it attacks more the maxillary and mandibular divisions, rarely happens in a simultaneous way in the three branches of trigeminal nerve three branches.

Morphological characteristics of foramen of Vesaliusand its relationship with clinical implications

The aim of this study was to evaluate the incidence as well morphometry of the foramen of Vesalius in humanskulls and analyzing their clinical importance. Dry human skulls (n = 80) and with gender distinction wereused (40 male and 40 female). The results demonstrates an total incidence of 40%, 13.75% skulls with thebilateral presence of the foramen, 26.25% skulls with the unilateral presence of the foramen, 31.25% skullswith foramen only of the right side, 22.50% skulls with foramen only of the left side, 25% masculine skulls withat least 1 foramen and 52.25% skulls with at least 1 foramen. The morphometry showed an average diameterof 1.457 ± 1.043 mm on the right and 1592 ± 0938 mm to the left. The average distance to the foramenovale was 1.853 ± 0.303 mm on the right side and 2.464 ± 0.311 mm on the left. It can be concluded that adeepened anatomical study of the foramen of Vesalius collaborates not only for anatomical knowledge of thisstructure, but also in clinical situations involving this foramen.

Incidence of the ossified pterygoalar ligamentin Brazilian human skulls and its clinical implications

The ossified pterygoalar ligament is formed between the lateral lamina of the pterygoid process and theinfratemporal surface of the sphenoid bone or its greater wing and was not connected to the sphenoid spine.The aim of this study was to evaluate the incidence of the ossified pterygoalar ligament in Brazilian humanskulls and analyzing its clinical importance. 183 Brazilian adult (between 30 to 60 years old) dry human skullswere evaluated. Was evaluated the incidence of skulls with complete or partial ossification of the pterygoalarligament, bilaterally and unilaterally and in the presence on the right and left sides. Were found 5 skulls had theossified pterygoalar ligament, resulting in an overall incidence of 2.73%. There was 1 skull in the presence ofthe incomplete ossification of the pterygoalar ligament, unilaterally and on the left side resulting in incidence of0.54%. There were 4 skulls in the presence of the complete ossification of the pterygoalar ligament, unilaterallyand on the right side resulting in incidence of 2.18%. The ossified pterygoalar ligament is a major cause of theentrapment of the lingual nerve or a branch of the mandibular nerve and may cause mandibular neuralgia. Theincidence of the ossified pterygoalar ligament and the pterygoalar foramen is low in the Brazilian population.However, these structures have clinical significance as this ligament establish relationships with the ovaleforamen and difficulty in accessing in this foramen in a therapeutic approach.

Identification of nutrient-dependent changes in extracellular pH and acid phosphatase secretion in Aspergillus nidulans

The present study was designed to identify nutrient-dependent changes in extracellular pH and acid phosphatase secretion in the biA1 palC4 mutant strain of Aspergillus nidulans. The palC4 mutant was selected as lacking alkaline phosphatase, but having substantially increased acid phosphatase activity when grown on solid minimal medium under phosphate starvation, pH 6.5. Gene palC was identified as a putative member of a conserved signaling cascade involved in ambient alkaline sensing whose sole function is to promote the proteolytic activation of PacC at alkaline pH. We showed that both poor growth and conidiation of the palC4 mutant strain on solid medium, alkaline pH, were relative to its hypersensitivity to Tris (hydroxymethyl) aminomethane buffer. Also, the secretion of acid phosphatase was repressed when both the wild-type and palC4 mutant strains were grown in low-phosphate yeast extract liquid medium, pH 5.0, indicating that the secretion of this enzyme is not necessary to regenerate inorganic phosphate from the organic phosphate pool present in yeast extract.

Identification of non-specific alkaline phosphatases in hyphal cells of the fungus Neurospora crassa by in situ histochemistry

The present study was designed to identify alkaline phosphatases in non-permeabilized hyphal cells of the fungus Neurospora crassa by staining these enzymatic activities with a modified azo dye coupling method. Our strategy allowed the identification of three non-specific alkaline phosphatase activities, one of them possibly being a novel putative enzyme, which is not responsive to either Mg2+ or EDTA. Another alkaline phosphatase activity, whose location in the hyphal cell is regulated by phosphate, is stimulated by Mg2+, inhibited by EDTA, and somehow dependent on the expression of the pho-2+-encoded Pi-repressible alkaline phosphatase.

Efeitos da administração sistemica de corticosteroide sobre propriedades mecanicas musculares / Effects of systemic corticosteroid administration on mechanical muscle properties

Costicosteroides sistemicos em altas doses podem causar miopatia metabolica. O Objetivo deste estudo foi valiar, por meio de ensaios de tracao, os efeitos da miopatia induzida por corticosteroides nas propriedades mecanicas do musculo gastrocnemio medial de coelhos. Foram estudados dois grupos de 15 coelhas da raca Nova Zelandia: grupo experimental (GE), que recebeu injecoes subcutaneas de metil-prednisolona (2mg/kg/dia), e grupo-controle (GC), que recebeu solucao fisiologica por via subcutanea. Os grupos foram tratados por 21 dias. Foram feitos ensaios de tracao nos musculos gastrocnemios mediais esquerdos. Resultados: o peso final dos animais do GE foi 3,6+-0,1kg e do GC, 40+-0,1kg. O peso final do gastrocnemio do GE foi 5,6+-1,0g e do GC, 7,0+-1,3g. Os valores de area, largura e espessura do gastrocnemio...

Fístulas postlaringectomía: variables que favorecen su desarrollo / Posttlaringectomy fistula: factors that favour its development

Antecedentes: A pesar del gran número de autores que se refieren a esta complicación, no hay aún hoy acuerdo sobre causas. Objetivo: Reconocer los factores que favorecen su desarrollo. Lugar de aplicación: Hospital público de atención terciaria de pacientes oncológicos. Diseño: Prospectivo no randomizado. Población: 100 enfermos, 93 por ciento masculinos, edad media 59,13 años, 98 por ciento portadores de carcinoma epidermoide sometidos a laringectomía total. Método: Análisis uni y multivariado de 21 variables potencialmente favorecedoras de fístulas postoperatorias. Resultados: Ninguna de las vriables resultó estadísticamente significativa. La radioterapia previa se comportó como el factor de mayor probabilidad del evento. La incidencia de fístulas alcanzó el 55 por ciento de los operados. Su momento de aparición tuvo una media de 9 días. El 76,3 por ciento cerró espontáneamente. Las peores consecuencias del evento resultaron la prolongación en el uso 3,6 veces mayor a la media de la sonda de alimentación, la necesidad de nuevos tiempos quirúrgicos en 13 pacientes y la rehabilitación 2 meses después que el resto. Conclusiones: La dimensión de la muestra resultó insuficiente para desarrollar el modelo predictivo del fenómeno

Memória seqüencial verbal de três e quatro sílabas em escolares / Sequential verbal memory for three and four syllables in school children

BACKGROUND: Auditory memory ability. AIM: To characterize the auditory memory ability for verbal sequences in children with ages ranging from 3 to 12 years. METHOD: A memory test for verbal sequences was used, as well as a variation with the addition of one syllable to each sequence. Participants were 223 students of public and private schools. RESULTS: All subjects repeated at least two out of the three sequences of three syllables. At the age of nine, they were capable of repeating all of the three sequences. At the age of six, they repeated at least two out of the three sequences of four syllables. CONCLUSION: The behavioral responses to verbal sounds presented in sequences, improves as children grow older. Children of private schools demonstrated an earlier development of this ability.

Tema: habilidade auditiva de memória. Objetivo: caracterizar a habilidade auditiva de memória seqüencial verbal em crianças de três a 12 anos. Método: aplicou-se o teste de memória seqüencial verbal e uma modificação deste pelo acréscimo de uma sílaba a cada seqüência, em 223 escolares, do ensino público e privado. Resultados: todos repetiram corretamente pelo menos duas das três seqüências de três sílabas. Aos nove anos, foram capazes derepetir as três seqüências. Aos seis anos, repetiram pelo menos duas das três seqüências de quatro sílabas. Conclusão: as respostas comportamentais para sons verbais emseqüência melhoram com o avanço da idade. As crianças de escola privada apresentaram evolução mais precoce dessa habilidade.

Properties of a constitutive alkaline phosphatase from strain 74A of the mold Neurospora crassa

A constitutive alkaline phosphatase was purified to apparent homogeneity as determined by polyacrylamide gel electrophoresis from mycelia of the wild strain 74A of the mold Neurospora crassa, after growth on acetate and in the presence of saturating amounts of inorganic phosphate (Pi) for 72 h at 30ºC. The molecular mass was 58 kDa and 56 kDa as determined by exclusion chromatography and SDS-PAGE, respectively. This monomeric enzyme shows an apparent optimum pH ranging from 9.5 to 10.5 and Michaelis kinetics for the hydrolysis of p-nitrophenyl phosphate (the Km and Hill coefficient values were 0.35 mM and 1.01, respectively), alpha-naphthyl phosphate (the Km and Hill coefficient values were 0.44 mM and 0.97, respectively), ß-glycerol phosphate (the Km and Hill coefficient values were 2.46 mM and 1.01, respectively) and L-histidinol phosphate (the Km and Hill coefficient values were 0.47 mM and 0.94, respectively) at pH 8.9. The purified enzyme is activated by Mg2+, Zn2+ and Tris-HCl buffer, and is inhibited by Be2+, histidine and EDTA. Also, 0.3 M Tris-HCl buffer protected the purified enzyme against heat inactivation at 70ºC(half-life of 19.0 min, k = 0.036 min-1) as compared to 0.3 M CHES (half-life of 2.3 min, k = 0.392 min-1) in the same experiment

Actividad in vitro de trovafloxacina, otras fluoroquinolonas y de diferentes antimicrobianos frente a aislamientos clínicos. Grupo colaborativo WHONET-Argentina / [In vitro activity of trovafloxacin, of other fluoroquinolones and of related antimicrobials against clinical isolates. Grupo colaborativo WHONET-Argentina]

The in vitro activity of trovafloxacin (TRV) has been evaluated in comparison with that of other antimicrobial agents against 5671 clinical isolates recovered by representative institutions of different provinces in our country. The resistance percentage to gentamicin and third generation cephalosporins among enterobacteriaceae was high: 17

respectively, with a considerable variation according to the analyzed species. The resistance to ciprofloxacin (CIP) and TRV affected approximately 9

of the isolates, without significant differences between both drugs. Fluoroquinolones (FQ) presented excellent activity on 166 isolates of Salmonella spp., 208 of Shigella flexneri and 76 of Shigella sonnei, where only one S.sonnei isolate was resistant to CIP, but susceptible to TRV. About half the isolates of Salmonella spp. and S.sonnei and almost all S.flexneri isolates were resistant to ampicillin, and more than 60

of Shigella spp. isolates were resistant to trimethoprim-sulfamethoxazole. A 41

of Staphylococcus aureus and 55

of coagulase-negative staphylococci isolates were resistant to oxacillin, presenting a highly associated multi-resistance. The resistance to FQ was also strongly related to oxacillin resistance, but the resistance to TRV was significantly lower than the CIP resistance: 9

for S.aureus and 4

for coagulase-negative staphylococci. A similar behavior was observed with Enterococcus spp., where 54

of the isolates were resistant to norfloxacin and only 13

were resistant to TRV. Neither Streptococcus pneumoniae (n = 193) nor Haemophilus influenzae (n = 139) isolates presented resistant to TRV.

Contenido de vitamina C en jugo de limón fresco y procesado / C vitamin content in fresh and processing lemon juice

La vitamina C incluye dos formas activas, ácido ascórbico (AA) y ácido dehidroascórbico (ADHA), que funcionan como un sistema redox interconvertible. El nivel de vitamina C en vegetales está condicionado por factores de orden climático y agronómico, por el manejo poscosecha y las condiciones de almacenamiento. Por tratarse de un nutriente extremadamente lábil, se producen pérdidas o deterioro durante su procesamiento. En los vegetales recién cosechados la vitamina se encuentra mayormente como AA, pero gradualmente pasa a ADHA, su forma oxidada. El ADHA es muy inestable y al escindirse su anillo lactónico se pierde la actividad vitamínica. A los efectos de determinar el nivel de vitamina C en jugos de limón fresco y procesado, tal cual lo adquiere el consumidor, se analizó el contenido de vitamina C y de sus formas biológicamente activas, en muestras tomadas al azar en supermercados y negocios minoristas. Los resultados obtenidos demuestran que en los jugos analizados, los tiempos de poscosecha, las condiciones de almacenamiento y el procesado influyen notablemente sobre el contenido de la vitamina

Does gene palB regulate the transcription or the post-translational modification of Pi-repressible phosphatases of Aspergillus nidulans?

When grown on low-Pi medium, the chaA1 pabaA1 palB7 mutant of Aspergillus nidulans excretes an acid phosphatase with steady-state kinetic properties, temperature sensitivity and electrophoretic mobility different from those of the enzyme excreted by the pabaA1 strain. The enzyme excreted by the pabaA1 strain at pH 6.5 showed PNP-P activity with negative cooperativity (K0.5 = 0.87 + or - 0.06 mM, n = 0.68 + or - 0.03) whereas the enzyme excreted by the chaA1 pabaA1 palB7 mutant showed Michaelian kinetics (Km = 0.46 + or - 0.03 mM, n = 1.00 + or - 0.02). The apparent half-lives at 60§C, pH 5.5, of acid phosphatase excreted by the pabaA1 and chaA1 pabaA1 palB7 strains were 58.6 + or - 4.9 min and 21.5 + or - 1.8 min, respectively. Furthermore, the electrophoretic mobility of acid phosphatases excreted by the palA1, palB7, palC4, palE11 and palF15 mutants of A. nidulans was altered and differed from the electrophoretic mobility of the enzyme excreted by the wild-type strain. Also, the palB7 mutation altered the electrophoretic pattern of acid phosphatases synthesized on high-Pi medium. These results are compatible with the post-translational modifications in the Pi-repressible phosphatases rather than with the action of gene palB in controlling the transcription of structural genes of these enzymes

Effect of carbon source and extracellular pH on the acidification of the culture medium and phosphatase excretion in Neurospora crassa

Exogenous Ca2+ at concentrations up to 3.5 mM increases the sucrose-induced acidification of the culture medium when the mold Neurospora crassa is grown on low-phosphate (Pi) medium at pH 7.8. Induction depends on the pH of the culture medium adjusted for conidial inoculation and on the absence of carbon sources generating cytoplasmic acetyl CoA. Furthermore, the excretion of Pi-repressible acid and alkaline phosphatases was not stimulated by increasing exogenous Ca2+ levels. We also provide evidence that the extracellular pH monitoring by Neurospora crassa may be a determinant in the selective excretion of Pi-repressible acid and alkaline phosphatases.