Glucocorticoid-mediated co-regulation of RCAN1-1, E4BP4 and BIM in human leukemia cells susceptible to apoptosis.

Glucocorticoids (GCs) are known to induce apoptosis of leukemia cells via gene regulatory changes affecting key pro-and anti-apoptotic genes. Three genes previously implicated in GC-evoked apoptosis in the CEM human T-cell leukemia model, RCAN1, E4BP4 and BIM, were studied in a panel of human lymphoid and myeloid leukemia cell lines. Of the two RCAN1 transcripts, the synthetic GC Dexamethasone (Dex) selectively upregulates RCAN1-1, but not RCAN1-4, in GC-susceptible Sup-B15, RS4;11, Kasumi-1 cells but not in GC-resistant Sup T1 and Loucy cells. E4BP4 and BIM regulation correlated with that of RCAN1-1. A putative GRE and four EBPREs were identified within 1500bp upstream from the transcription start site of RCAN1-1. GC-refractory CEM C1-15 cells sensitized to GC-evoked apoptosis by ectopic E4BP4 expression, CEM C1-15mE#3, showed restored RCAN1-1 upregulation, suggesting that RCAN1-1 is a downstream target of E4BP4. A model for coordinated regulation of RCAN1-1, E4BP4 and BIM, and their role in GC-evoked apoptosis is proposed.

Impacto de la crisis económica argentina sobre la incidencia de infecciones y la evolución en la Unidad de Cuidados Intensivos / Impact of the economic crisis Argentina on the incidence of infections and the evolution in Intensive care unit

Introducción. La crisis económica argentina disminuyó la provisión adecuada de insumos en los hospitales públicos. Objetivos. 1) Evaluar si la reducción de insumos impactó en la evolución de los pacientes; 2) cuantificar la provisión de insumos durante los períodos precrisis (P1), crisis y poscrisis (P2); 3) evaluar la incidencia de infecciones durante los tres períodos. Materiales y métodos. Se evaluó la densidad de incidencia de las infecciones intrahospitalarias, la estadía en la Unidad de Terapia Intensiva y la mortalidad en los tres períodos. Los datos se presentan como media ± desviación estándar, mediana [IC 0,25-0,75] y porcentajes de acuerdo con su naturaleza. Las comparaciones se efectuaron con la prueba t o ji cuadrado. Se consideró significativo un valor p <0,05. Resultados. Durante la crisis, ingresaron pacientes con menos enfermedades preexistentes, permanecieron más días ventilados y aumentó significativamente el número de infecciones por paciente. En el período P2, se detectó una caída significativa del número de pacientes infectados con respecto a los dos períodos anteriores. En el período P1, no hubo diferencias entre la mortalidad de los infectados y de los no infectados (25% contra 33%, p = 0,31). Durante la crisis, la mortalidad de los no infectados fue menor (19% contra 40%, p = 0,0005). La provisión de insumos disminuyó durante la crisis. Las infecciones intrahospitalarias se incrementaron en forma absoluta y como densidad de incidencia durante la crisis, y descendieron en el período P2. Conclusión. Durante la crisis económica, se recortaron los gastos de insumos y aumentó el número de infecciones por paciente.(AU)

Introduction. The collapse of the Argentinean economy in 2001 caused a shortage of material resources in public hospitals. Objectives. 1) To evaluate whether the decrease of material resources affected the outcome of patients in the Intensive Care Unit; 2) to quantify the provision of resources received in the Intensive Care Unit during three periods: Pre-crisis (P1), crisis, and post-crisis (P2); 3) to evaluate the incidence of infections during the three periods. Materials and methods. We compared the incidence of nosocomial infec- incidence of nosocomial infections; Intensive Care Unit stay, and mortality in the three periods. Data are presented as media ± SD, median [IQ 0.25-0.75], and percentages according to their nature. Comparison were performed using t test and chi-squared test. A p value <.05 was considered significant. Results. During the crisis, patients with less co-morbidities were admitted, they spent more time on mechanical ventilation, and the number of infections per patient was higher. Instead, during P2, there was a significant reduction of patients infected in relation to P1 and the crisis period. In P1, mortality did not differ between infected versus non-infected patients (25% vs. 33%; p = 0.31). However, during the crisis, mortality in non-infected patients was lower (19% vs. 40%; p = 0.0005). In the crisis, provision of materials decreased. Nosocomial infections increased. The incidence of infections decreased during P2. Conclusion. Resource availability decreased significantly during the economic crisis with a marked increase in the incidence of infections in the Intensive Care Unit. (AU)

[Auriculo temporal nerve. Neuroanatomic bases of the Frey's syndrome]. / El nervio auriculotemporal. Bases neuroanatómicas del síndrome de Frey.

The aim of this study was to precise the relationships of the auriculotemporal nerve in the infratemporal and parotid regions. We realized micro-dissections of thirty-two infratemporal and parotid regions of human cadaver's formol-fixed. The pattern of origin was: one root: 15.4%, two roots: 73.1%, three roots: 11.5%. In all cases, the lateral root present the major diameter (2-2.5 mm). In those cases with two roots, these formed a neural loop round the middle meningeal artery in the 89.4% of the cases. The origin of the medial root was the posterior border of the inferior alveolar nerve. The median distance between the lateral root and the temporomandibular joint capsule was 1.5 mm, with asymmetric pattern: right: 2 mm (rank: 0-7 mm; ED: 1.90 mm); left: 1.25 mm (rank: 0-3 mm; ED: 0.88 mm). In 10 cases (31.3%) the lateral root was in direct contact with the articular capsule, with asymmetric pattern: left: 46.1%; right: 21%. The median distance between the superior aspect of the articular disk and the trunk of the auriculotemporal nerve in the posterior aspect of the temporomandibular joint was 10,5 mm (ED: 4.06 mm), with asymmetric pattern: right: 9 mm (rank: 5-18.0 mm; ED: 3.70 mm); left: 11.0 mm (rank: 3.0-20 mm; ED: 4.41 mm). We discussed the rol of this findings in the etiology of the Frey's syndrome.

El nervio auriculotemporal. Bases neuroanatómicas del Síndrome de Frey / Auriculo temporal nerve. Neuroanatomic bases of the Frey´ Syndrome

El propósito de este estudio fue precisar las relaciones del nervio auriculo temporal en las regiones infratemporal y parotídea. Se realizó la microdisección de 32 regiones infratemporales y parotídeas de cadáveres humanos formolados. Los patrones de origen fueron: raíz única: 15.4%, dos raíces: 73.1% y tres raíces: 11.5%. En todos los casos la raíz lateral era la de mayor diámetro (2-2,5 mm). En los casos con dos raíces estas constituían un ojal nervioso a la arteria meníngea media en el 89.4% de los casos. La raíz medial se originaba en todos los casos del borde posterior del segmento inicial del nervio alveolar inferior. La distancia media entre la raíz lateral del nervio auriculotemporal y la cápsula dela articulación temporo mandibular fue de 1.5 mm, con patrón asimétrico, derecha: 2 mm (rango: 0-7 mm; DE1.90 mm); izquierda: 1.25 mm (rango: 0-3 mm; DE 0.88mm). En 10 casos (31.3%) la raíz lateral se encontraba en contacto directo con la cápsula articular, izquierda (46.1%) y a derecha (21.1%). La distancia media en la cara posterior de la articulación temporomandibular, desde la cara superior del disco articular al tronco del nervio auriculo temporal fue de 10,5 mm (DE: 4.06 mm),con patrón asimétrico, derecha: 9 mm (rango: 5,0-18,0mm; DE 3,70 mm), izquierda: 11.0 mm (rango: 3.0-20.0mm; DE 4.41 mm). Se discute el rol de estos hallazgos en la etiología del síndrome de Frey

The aim of this study was to precise the relationships of the auriculo temporal nerve in the infratemporal and parotid regions. We realized micro-dissections of thirty–two infratemporal and parotid regions of human cadaver’s form ol-fixed. The pattern of origin was: one root: 15.4%, two roots: 73.1%, three roots: 11.5%. In all cases, the lateral root present the major diameter(2-2,5 mm). In those cases with two roots, these formed a neural loop round the middle meningeal artery in the 89.4% of the cases. The origin of the medial root was the posterior border of the inferior alveolar nerve. The median distance between the lateral root and the temporo mandibular joint capsule was 1.5 mm, with a symmetric pattern: right: 2 mm (rank: 0-7 mm; ED:1.90mm); left: 1.25 mm (rank: 0-3 mm; ED: 0.88 mm).In 10 cases (31.3%) the lateral root was in direct contact with the articular capsule, with asymmetric pattern: left: 46.1%; right: 21%. The median distance between the superior aspect of the articular disk and the trunk of the auriculo temporal nerve in the posterior aspect of the temporo mandibular joint was 10,5 mm (ED: 4.06 mm), with asymmetric pattern: right: 9 mm (rank: 5-18.0 mm; ED: 3.70 mm); left: 11.0 mm (rank: 3.0-20mm; ED: 4.41 mm). We discussed the rol of this findings in the etiology of the Frey’s syndrome

[Claudio Galeno and the lateral ventricles]. / Claudio Galeno y los ventrículos cerebrales. Parte I, los antecedentes.

Galen of Pergamon is considered one of the fathers of occidental medicine. Because of cultural and religious precepts at his time, many authors hypothesize that the anatomical concepts of Galen were derived from dissection of monkeys. In this paper, the authors analyzed the ventricular system, according to the anatomic and functional concepts described by Galen's early work. Knowing that his work was derived and or influenced from other preceding anatomists and physicians (specially Hipocrates of Cos), we present our investigation in two parts. In the first part, we present the influences of previous religious, philosophic, medical and anatomical theories over the galenic work. The "pregalenic era" can be divided in three periods: 1) the pretecnic era (ending in VI BC) in which the man have only a rudimentary knowledge of human anatomy, 2) the hellenistic science (from VI to III BC) and 3) the period comprised between III BC to Galenic period. In each of the three periods, we analyzed the neuroanatomic knowledge of the most important cultures.

Claudio Galeno y los ventrículos cerebrales. Parte I, los antecedentes / Claudio Galeno and the lateral ventricles

Claudio Galeno es considerado uno de los padres de la medicina occidental. Por el entorno cultural y religioso en el cual estaba inmerso, se duda de que haya disecado cadáveres y se piensa que la mayoría de sus aportes al conocimiento anatómico provengan del estudio de monos. En este trabajo, los autores analizan la teoría anatomo funcional de Galeno sobre los ventrículos cerebrales. Dado que muchos de los conceptos galénicos provienen de sus antecesores (y en particular de la medicina hipocrática), la presentación del mismo se hace en dos partes. En primera instancia, se exponen los antecedentes anatómicos, religiosos y filosóficos que influyeron a Galeno. Este largo periodo de la historia está dividido a nuestros propósitos en tres etapas: 1) la era pretécnica, donde no hay un conocimiento rudimentario y fundamentalmente derivado de prácticas religiosas. Este periodo llega hasta el siglo VI AC. 2) la ciencia helenística, que abarca los siglos VI a III AC. En esta etapa se gesta y desarrolla la medicina hipocrática, y 3) el periodo que comprende el siglo III AC hasta Galeno. En cada una de las eras descritas, se analizan y destacan los mayores aportes al conocimiento neuroanatómico de cada cultura

Galen of Pergamon is considered one of the fathers of occidental medicine. Because of cultural and religious precepts at his time, many authors hypothesize that the anatomical concepts of Galen were derived from dissection of monkeys. In this paper, the authors analyzed the ventricular system, according to the anatomic and functional concepts described by Galen’s early work. Knowing that his work was derived and or influenced from other preceding anatomists and physicians (specially Hipocrates of Cos), we present our investigation in two parts. In the first part, we present the influences of previous religious, philosophic, medical and anatomical theories over the galenic work. The “pregalenic era” can be divided in three periods: 1) the pretecnic era (ending in VI BC) in wich the man have only a rudimentary knowledge of human anatomy, 2) the helenistic science (from VI to III BC) and 3) the period comprised between III BC to Galenic period. In each of the three periods, we analyzed the neuroanatomic knowledge of the most important cultures

First Report of Powdery Mildew Caused by Golovinomyces orontii on Corn-Salad in the United States.

Corn-salad or lamb's lettuce (Valerianella locusta) is a specialty leafy green, annual vegetable that is grown commercially in California for use in salads. During the summer (June through August) of 2004, field plantings in coastal California (Monterey County) showed symptoms and signs of a powdery mildew. White, ectophytic mycelia and conidia were present on leaves and petioles. Extensively colonized leaves were slightly twisted and later developed a tan necrosis. Mycelial growth was spread out, flat, sometimes dense, and colonized both sides of the leaf. Growth was more extensive on the upper leaf surfaces. Hyphae were 5 to 7.5 µm wide with nipple-shaped appressoria. Conidiophores were straight and had foot cells that were simple, mostly curved, measured 50 to 65 × 10 to 12.5 µm, and followed by two to three cells of equal size. Conidia developed in short chains. Conidia were cylindric to doliform, measured 27.5 to 32.5 × 15 to 17.5 µm, and lacked fibrosin bodies. Conidial length-to-width ratios were usually less than or equal to 2.0. Conidia germinated at the ends (cichoracearum-type) and had germ tube lengths that ranged from short to 1.0 to 1.5 times the length of the conidium; germ tubes had swollen tips. Cleistothecia were not observed. On the basis of these characteristics, the fungus is identified as Golovinomyces (Erysiphe) orontii(Cast.) Heluta (1). To demonstrate pathogenicity, heavily colonized corn-salad leaves from commercial plantings were collected and gently pressed onto leaves of potted corn-salad plants. Plants were then maintained in a greenhouse (22 to 24°C). After 8 to 10 days, symptoms and signs of powdery mildew developed on the foliage of inoculated plants, and the pathogen morphology matched that of the originally observed pathogen. Noninoculated control plants did not develop powdery mildew. To our knowledge, this is the first report of powdery mildew of corn-salad caused by G. orontii in the United States. This corn-salad disease has been reported from a number of countries in Europe (2). Because the presence of powdery mildew on the harvested foliage made the leaves unmarketable, part of the crop could not be sold. References: (1) U. Braun. Nova Hedwigia 89:1, 1987. (2) U. Braun. The Powdery Mildews (Erysiphales) of Europe. Gustav Fischer Verlag, Jena, Germany, 1995.

First Report of Powdery Mildew Caused by Erysiphe heraclei on Chervil in California.

Chervil (Anthriscus cerefolium) is a culinary herb in the Apiaceae family that is grown commercially in California. In 2003 and 2004, shade house plantings of chervil in central coastal California exhibited symptoms and signs of a powdery mildew disease. White, epiphytic mycelia and conidia were present on petioles and leaves. Severely affected leaflets became slightly twisted and bent. Mycelium was amphigenous and effused or in patches. Hyphae measured 5.0 to 7.5 µm in diameter and had lobed appressoria. Conidiophores were straight and had cylindric foot cells measuring 25.0 to 37.5 × 7.5 to 10.0 µm, followed by a longer cell and one to two shorter cells. Conidia formed singly, were cylindric, and measured (37.5-) 40.0 to 50.0 (-52.5) × 15.0 to 17.5 µm. Conidia lacked fibrosin bodies and germinated at the ends with either a very short or a long germ tube forming a lobed appressorium (Polygoni type). No cleistothecia were observed. On the basis of these characteristics, the fungus was identified as Erysiphe heraclei (1). To confirm pathogenicity, severely colonized chervil leaves from a commercial nursery were gently pressed onto leaves of potted chervil plants. Plants were then maintained in a greenhouse (22 to 24°C). After 10 to 12 days, signs of powdery mildew developed on the foliage of inoculated plants, and the pathogen morphology matched that of the originally observed pathogen. Noninoculated control plants did not develop powdery mildew. To investigate the host range of this chervil isolate, parsley (Petroselinum crispum) and celery (Apium graveolens) plants were inoculated in the same way as described. However, after more than 3 weeks, no powdery mildew developed on these two Apiaceae plants. Control chervil plants again developed the disease. To our knowledge, this is the first report of powdery mildew of chervil caused by E. heraclei in California. Disease impact was severe, and in some cases, chervil crops were not harvested. The inability of the chervil isolate to infect two other Apiaceae plants that are listed as hosts of E. heraclei indicates that this pathogen may consist of strains having different host ranges. Reference: (1) U. Braun. Nova Hedwigia 89:1, 1987.

Evaluación del Sequential Organ Failure Assessmente (SOFA) score para predecir mortalidad en los pacientes críticos, y comparación con los scores APACHE II Y SAPS II / Sequential Organ Failure Assessment Assessed (SOFA) score to predict mortality in critically ill patients, and comparison with APACHE II scores and SAPS II

Objetivos: 1) Determinar la utilidad del SOFA score y sus variables derivadas como predictores de mortalidad 2) correlacionar la mortalidad estmada por el SOFA score y derivadas, con la predicha por APACHE II y SAPS II. Materiales y métodos: Diseño: cohorte prospectiva. Lugar UTI polivalente de un hospital escuela. Pacientes: los ingresados desde el 1/5/01 al 14/4/03. Al ingreso se calcularon los scores pronósticos APACHE II y SAPS II y SOFA inicial, y diariamente (hasta 30 días de internación), el score SOFA con los peores valores del día anterior. Adicionalmente se calcularon las siguintes variables derivadas: SOFA medio: valor promedio de la internación; SOFA total: suma de todos los valores diarios; delta SOFA 48hs: diferencia entre el SOFA inicial y a las 48 hs del ingreso; y SOFA máximo: el valor más alto registrado. Análisis estadístico: primeramente, se calculó el área bajo la curva ROCd (AUC) correspondiente a las 5 variables citadas, a APACHE IIy a SAPS II, y luego se compararon con refencia a la que presentó mayor AUC en el procedimeinto anterior...

Heteroallelism at the het-c locus contributes to sexual dysfunction in outcrossed strains of Neurospora tetrasperma.

Neurospora tetrasperma is naturally heterokaryotic, with cells possessing haploid nuclei of both a and A mating types. As a result, isolates are self-fertile (pseudohomothallic). Occasional homokaryotic ascospores and conidia arise, however, and they produce strains that are self-sterile and must outcross to complete sexual reproduction. Invariably, laboratory crosses employing sibling a and A strains from the same parental heterokaryon restore the pseudohomothallic, heterokaryotic state. In contrast, outcrosses employing a and A strains from different wild isolates typically result in sexual dysfunction. Diverse sexual dysfunction types have been observed, ranging from complete sterility to reduced viability. We report that one type of dysfunction, characterized by spontaneous loss of the heterokaryotic state upon ascospore germination, can result from the interaction of incompatible alleles at heterokaryon incompatibility loci. Specifically, we demonstrate that homoallelism at the het-c locus in N. tetrasperma is required for heterokaryon stability. Heterokaryon incompatibility therefore provides an obstacle to outcrossing in this species, an observation with important implications for fungal life-cycle evolution.

Frequency of twinning in two Costa Rican ethnic groups: an update.

Variation in the frequency of twinning among human populations has been presumed to reflect genetic differences. It has been commonly reported that populations of African ancestry have the highest, those of Asian ancestry the lowest, and those of European and Middle-Eastern ancestry intermediate frequencies of twinning. Populations from the Americas have been reported to have intermediate twinning frequencies, presumably reflecting their admixture. In this context, Madrigal (1994. Am J Hum Biol 6:215-218) reported virtually identical (and high) twinning frequencies in two Costa Rican ethnic groups, one of African, the other of Euro-Amerindian ancestry. These frequencies were interpreted in light of frequent inter-ethnic unions, and it was predicted that the two groups would not differ substantially in gene frequencies of several blood enzyme systems. This paper reports the gene frequencies of both groups for such systems. The samples differ significantly for systems that have clearly different frequencies in African and European populations. Given that the groups are actually different in gene frequencies and not homogenous as predicted earlier, the conclusion that twinning frequencies are similar as a result of a similar genetic make up can be questioned. The results challenge the assumption that if populations have similar twinning frequencies it is because they are genetically similar and argue for a stronger environmental component for twinning frequencies.

Analysis of the pdx-1 (snz-1/sno-1) region of the Neurospora crassa genome: correlation of pyridoxine-requiring phenotypes with mutations in two structural genes.

We report the analysis of a 36-kbp region of the Neurospora crassa genome, which contains homologs of two closely linked stationary phase genes, SNZ1 and SNO1, from Saccharomyces cerevisiae. Homologs of SNZ1 encode extremely highly conserved proteins that have been implicated in pyridoxine (vitamin B6) metabolism in the filamentous fungi Cercospora nicotianae and in Aspergillus nidulans. In N. crassa, SNZ and SNO homologs map to the region occupied by pdx-1 (pyridoxine requiring), a gene that has been known for several decades, but which was not sequenced previously. In this study, pyridoxine-requiring mutants of N. crassa were found to possess mutations that disrupt conserved regions in either the SNZ or SNO homolog. Previously, nearly all of these mutants were classified as pdx-1. However, one mutant with a disrupted SNO homolog was at one time designated pdx-2. It now appears appropriate to reserve the pdx-1 designation for the N. crassa SNZ homolog and pdx-2 for the SNO homolog. We further report annotation of the entire 36,030-bp region, which contains at least 12 protein coding genes, supporting a previous conclusion of high gene densities (12,000-13,000 total genes) for N. crassa. Among genes in this region other than SNZ and SNO homologs, there was no evidence of shared function. Four of the genes in this region appear to have been lost from the S. cerevisiae lineage.

Ethnicity, gene flow, and population subdivision in Limón, Costa Rica.

In this paper we examine the effects of ethnicity on the gene flow between two groups living in Limón, Costa Rica. Our main interest is to determine if ethnicity has acted as a barrier to the exchange of genes, and if the groups have remained distinct genetically. We report the admixture estimates, F(st) values, and inbreeding coefficients of the two samples. The data consist of blood samples and surnames obtained from 375 individuals. The subjects' two surnames were analyzed to determine the ethnicity of their parents (individuals carry their father's and mother's first surnames). We used the formula of Crow and Mange ([1965] Eugen Q 12:199-203) to compute F(t), F(n), and F(r) with the surnames. Admixture estimates were computed for both groups using the computer program ADMIX.PAS kindly provided by Jeffrey Long. The estimates for the Hispanic-Limonense group are M1 = 0.5866 European, M2 = 0.3383 Amerindian, and M3 = 0.0751 African ancestry. For the Afro-Limonense group, the admixture estimates indicate M1 = 0.1047 European, M2 = 0.1357 Amerindian, and M3 = 0.7595 African ancestry. The F(st) values are F(st) = 0.00558 for the Hispanic group and F(st) = 0.05137 for the Afro-Limonense group. These F(st) values indicate that the Afro-Limonense group has experienced more genetic drift than has the other group, possibly as a result of its long history of isolation in Costa Rica. Indeed, when plotted along a scaled eigenvector R matrix of Caribbean gene frequencies, the two Limonense groups did not cluster with each other. Thus we conclude that the two ethnic groups have remained distinct breeding populations.

First Report of Powdery Mildew Caused by Podosphaera (Sphaerotheca) fusca on Euryops pectinatus in North America.

Gray-leaved Euryops (Euryops pectinatus Cass., Asteraceae) is an evergreen shrub that is widely planted in landscapes in the United States. In the fall of 1999, powdery mildew was observed on E. pectinatus planted in landscapes in Redlands (San Bernardino County), CA. Symptoms consisted only of slight cupping of leaves. Fungal growth was observed on stems, leaves, petioles, and pedicels and was ectophytic and amphigenous. The white mycelium was patchy to effuse. Hyphal appressoria were indistinct (1). Conidiophore foot cells were cylindric and sometimes were tapered toward or constricted at the base. Foot cells measured 30 to 50 by 10 to 12 µm and were followed by one to two shorter cells. Conidia were cylindric to slightly doliform, borne in chains of two to three, and measured 26 to 38 by 14 to 18 µm. Conidial length to width ratios ranged from 1.7 to 2.4. Catenate conidia had crenate edge lines (3). Conidia possessed conspicuous fibrosin bodies and from their sides produced short germ tubes without appressoria. Cleistothecia were not observed. Based on these characters, the fungus was identified as Podosphaera fusca (Fr.) U. Braun & N. Shishkoff (Podosphaera sect. Sphaerotheca) (1,2). Pathogenicity was confirmed by gently pressing diseased leaves onto leaves of healthy E. pectinatus plants. Plants were incubated in a humidity chamber at 22 to 24°C and after 12 to 14 days powdery mildew colonies developed. E. pectinatus cv. Viridis, a cultivar that lacks the extensive pubescence of E. pectinatus, also developed disease when inoculated. This appears to be the first report of powdery mildew on E. pectinatus in North America. A voucher specimen has been deposited into the University of California Herbarium (accession # UC1738635). P. fusca was also observed on cv. Viridis in a nursery in New York in 1999. It is unclear where this pathogen originated. P. fusca parasitizes a large number of asteraceous species including dandelion (Taraxacum officinalis) and sowthistle (Sonchus spp.) weeds, which occur in the area and sometimes are infected with powdery mildew. The Euryops powdery mildew pathogen may be a race that is different than those found on other composites in the United States. The fungus was observed on plants in shaded areas but not on plants in full sun. References: (1) U. Braun. Nova Hedwigia 89:1, 1987. (2) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (3) H. D. Shin and Y. J. La. Mycotaxon 46:445, 1993.

First Report of Powdery Mildew on Nandina domestica (Berberidaceae) in North America.

Nandina domestica Thunb. (heavenly bamboo) is an ornamental plant that is widely planted in landscapes in California and other states. Since 1996, powdery mildew disease has been seen on outdoor landscape N. domestica in various regions of California (Alameda, Monterey, Riverside, and Santa Barbara counties). Symptoms consist of reddening of leaf and stem tissues colonized by the fungus and curling and twisting of infected leaves. The following observations were the same for all collected isolates. White ectophytic mycelium was observed on leaves and petioles. Mycelium on leaves was amphigenous, mostly epiphyllous, and effused or in patches. Hyphal appressoria were nipple-shaped to lobed and sometimes opposite in orientation. Conidiophores were cylindrical, straight, sometimes slightly flexuous, 22 to 32 × 6 to 8 µm in dimension, and followed by one to two shorter cells. Conidia were cylindrical, produced singly, and 27 to 42 × 11.5 to 14 µm in dimension. Fibrosin bodies were not observed. Conidial germ tubes were approximately twice the length of the spore, originated from the ends of the spore, and terminated in simple appressoria. Cleistothecia were not present. Based on these characteristics, the fungus was identified as Microsphaera berberidis (DC) Lév. (1). Pathogenicity was confirmed by gently pressing diseased leaves on leaves of healthy N. domestica plants. Plants were incubated in a humidity chamber at 22 to 24°C, and after 10 to 14 days, powdery mildew colonies developed. A voucher specimen was deposited in the University of California Herbarium (UC 1738622). Additional inoculation experiments showed that four other N. domestica cultivars were susceptible (Compacta Nana, Gulf Stream, Harbour Dwarf, and Royal Princess). Helfer (2) noted several possible candidates for the Nandina powdery mildew pathogen in the United Kingdom. However, due to the conidial characteristics of that fungus and the paucity of character descriptions for the several species mentioned, no species name was given to the Edinburgh isolate. In contrast, the mitosporic characteristics of our isolates fit the description for M. berberidis. This is the first report of powdery mildew on N. domestica in North America. References: (1) U. Braun. Nova Hedwigia 89:1, 1987. (2) S. Helfer. Plant Dis. 79:424, 1995.

Comparison of Erysiphe cichoracearum and E. cruciferarum and a survey of 360 Arabidopsis thaliana accessions for resistance to these two powdery mildew pathogens.

In previous work, UEA1 and UCSC1, two geographically distinct, powdery mildew isolates, were recognized for their ability to infect Arabidopsis thaliana. We have clarified the identity of these isolates by determining their host ranges, reexamining their morphology, and comparing their DNA sequences for the 5.8S ribosomal RNA and two flanking internal transcribed spacer sequences. These experiments confirm that UEA1 is a member of Erysiphe cruciferarum and that UCSC1 belongs to E. cichoracearum. Interactions of the two Erysiphe isolates with 360 A. thaliana accessions were examined to provide a comprehensive profile of naturally occurring powdery mildew resistance in this weedy species. The majority of A. thaliana accessions (213) were susceptible to both isolates. Among the accessions exhibiting some degree of resistance, most (84) responded differentially to UEA1 and UCSC1 and the remainder were resistant to both isolates. Notably, resistance to UCSC1 cosegregated with RPW7, a locus previously demonstrated to confer resistance to UEA1 in Ms-0 x Landsberg (erecta) crosses. With this large collection of resistant accessions, questions about species specificity, genetic diversity and the evolution of resistance to powdery mildews can be addressed.

Powdery Mildew of Spearmint Caused by Erysiphe orontii in California.

In 1997 and 1998, the white fungal growth of a powdery mildew was observed on leaves and stems of both nursery and landscape spearmint (Mentha spicata) growing in coastal California (Monterey County). Mycelia were conspicuous, amphigenous, and epiphytic with indistinct to nipple-shaped appressoria. Conidiophore foot cells were cylindrical, straight, nonconstricted at the base, 61 to 92 µm × 11 to 14 µm in size, and were followed by 1 to 3 cells. Doliiform conidia, which were borne in chains of at least 3 to 5 conidia, measured 28 to 33 µm × 17 to 22 µm. Catenate conidia had sinuate edge lines. Conidia lacked fibrosin bodies. Upon germination, conidia produced germ tubes that were mostly apically inserted and ended in club-shaped appressoria, which fit Braun's Cichoracearum-type of conidial germination (1). Cleistothecia were not observed. Based on these features, the pathogen was identified as Erysiphe orontii Cast. (1). Pathogenicity was demonstrated by gently pressing diseased leaves onto leaves of potted spearmint, incubating plants in a humidity chamber for 48 h, then maintaining plants in a greenhouse. The powdery mildew that later developed was morphologically identical to the original isolates. While powdery mildew on spearmint has been observed previously in the state, this is the first report of the disease and first characterization of the pathogen for California. Reference: (1) U. Braun. Beih. Nova Hedwigia 89:1, 1987.

Structure of bovine pancreatic cholesterol esterase at 1.6 A: novel structural features involved in lipase activation.

The structure of pancreatic cholesterol esterase, an enzyme that hydrolyzes a wide variety of dietary lipids, mediates the absorption of cholesterol esters, and is dependent on bile salts for optimal activity, is determined to 1.6 A resolution. A full-length construct, mutated to eliminate two N-linked glycosylation sites (N187Q/N361Q), was expressed in HEK 293 cells. Enzymatic activity assays show that the purified, recombinant, mutant enzyme has activity identical to that of the native, glycosylated enzyme purified from bovine pancreas. The mutant enzyme is monomeric and exhibits improved homogeneity which aided in the growth of well-diffracting crystals. Crystals of the mutant enzyme grew in space group C2, with the following cell dimensions: a = 100.42 A, b = 54.25 A, c = 106.34 A, and beta = 104.12 degrees, with a monomer in the asymmetric unit. The high-resolution crystal structure of bovine pancreatic cholesterol esterase (Rcryst = 21.1%; Rfree = 25.0% to 1.6 A resolution) shows an alpha-beta hydrolase fold with an unusual active site environment around the catalytic triad. The hydrophobic C terminus of the protein is lodged in the active site, diverting the oxyanion hole away from the productive binding site and the catalytic Ser194. The amphipathic, helical lid found in other triglyceride lipases is truncated in the structure of cholesterol esterase and therefore is not a salient feature of activation of this lipase. These two structural features, along with the bile salt-dependent activity of the enzyme, implicate a new mode of lipase activation.

First Report of Powdery Mildew, Caused by an Oidium sp., on Poinsettia in California.

In December 1996 and January 1997, powdery mildew was observed on potted poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) plants in Monterey County, CA. Mycelia were observed on stems, petioles, mature and immature leaves, and bracts. Severely diseased leaves became twisted and bent and senesced prematurely. The white mycelia were conspicuous, epiphytic, and amphigenous; hyphae measured 4.6 to 6.9 µm in diameter. Growth initially was in patches but eventually became effused. Appressoria were slightly lobed to lobed and sometimes opposite. Conidiophore foot cells were cylindrical, sometimes bent at the base, and slightly flexuous to flexuous. Foot cells measured 30.0 to 46.2 µm × 5.8 to 6.9 µm and were followed by one to two shorter cells. Conidia were cylindrical to slightly doliform and measured 25.4 to 32.3 µm × 11.6 to 18.5 µm. The length-to-width ratios of conidia generally were greater than 2.0. Conidia were produced singly, placing the fungus in the Pseudoidium-type powdery mildew group. Conidia germinated at the ends, and no fibrosin bodies were observed. Cleistothecia were not found. The fungus was identified as an Oidium species. Pathogenicity was demonstrated by gently pressing infected leaves having abundant sporulation onto leaves of potted poinsettia plants (cvs. Freedom Red, Peter Star Marble, and Nutcracker White), incubating the plants in a moist chamber for 48 h, and then maintaining plants in a greenhouse. After 12 to 14 days, powdery mildew colonies developed on the inoculated plants, and the pathogen was morphologically identical to the original isolates. Uninoculated control plants did not develop powdery mildew. This is the first report of powdery mildew on poinsettia in California. This fungus appears similar to Microsphaera euphorbiae but has longer, slightly flexuous foot cells that do not match the description for M. euphorbiae (1,2). An alternative identification would be Erysiphe euphorbiae; however, there are no available mitosporic descriptions for morphological comparisons (1,2). In the United States, powdery mildew of poinsettia previously has been reported in various states in the Pacific Northwest, Midwest, and Northeast. References: (1) U. Braun. Beih. Nova Hedwigia 89:1, 1987. (2) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN.

First Report of Powdery Mildew Caused by Oidium araliacearum on Ivy in California.

Powdery mildew was observed on English ivy (Hedera helix L.) in Berkeley, CA, in the spring of 1997. Fungal growth was ectophytic and amphigenous on leaves and petioles and caused slight reddening and buckling of leaves. The mycelium was white, effuse to dense, and had hyphal diameters of 3.5 to 6.9 µm. Appressoria were nipple-shaped to lobed, and sometimes were opposite. The foot cells of the conidiophores were cylindric, sometimes slightly flexuous, and were 18.5 to 30.0 × 6.9 to 9.2 µm in diameter. The foot cells were followed by 1 or 2 cells. When only one cell followed the foot cell, this cell was longer and slightly wider than the foot cell and measured 20.8 to 46.2 × 6.9 to 9.2 µm. When two cells followed the foot cell, these cells were of similar length to the foot cell, with the second cell usually shorter. Conidia were formed singly, were cylindric to slightly doliiform, and measured 32.0 to 44.0 × 11.5 to 19.0 µm. Fibrosin bodies were not observed. Conidia germinated at the ends and germ tubes terminated in lobed appressoria, placing this fungus in the Polygoni-type germination category (2). Cleistothecia were not observed. Based on these characters, the fungus was identified as Oidium araliacearum U. Braun & E. Oehrens B. A specimen was deposited with the University of California at Berkeley herbarium (accession number UC1713247). Pathogenicity was confirmed by gently pressing infected leaves onto leaves of various stages of maturity on ivy vines (3 to 4 vines per plant; 4 plants). Inoculated plants were kept in a moist chamber for 48 h, and then maintained in a greenhouse. Powdery mildew developed on inoculated plants, primarily on leaves of intermediate maturity, after 14 days, while uninoculated plants did not develop disease. Phyllactinia guttata is the only other powdery mildew recorded on English ivy (2). O. araliacearum differs from P. guttata in conidial shape (cylindric vs clavate), germination habit (end vs side of conidia), and asexual genus (Oidium vs Ovulariopsis) (2). Previous to this report, O. araliacearum was described only on Pseudopanax valdiviensis, another Araliaceae plant, in Chile (1). This is the first report of a powdery mildew disease of ivy in California, and the first report of Hedera helix as a host of O. araliacearum. References: (1) U. Braun. Mycotaxon 25:259, 1986. (2) U. Braun. Nova Hedwigia 89:1, 1987.