[Rendu-Osler-Weber disease as an infrequent cause of stroke]. / Enfermedad de Rendu-Osler-Weber como causa infrecuente de ictus.

INTRODUCTION: Hereditary haemorrhagic telangiectasia, or Rendu-Osler disease, is a congenital vascular disease that is associated with the presence of arteriovenous fistulas that cause paradoxical embolisms. CASE REPORT: An 83-year-old female with clinical signs and symptoms of convulsive attacks and multiple cerebral infarctions in the acute phase. She also presented a history of multiple haemorrhages and iron deficiency anaemia with no clear aetiological causation. A thorough examination of her medical history revealed a family history of haemorrhages and a sister who had been diagnosed with Rendu-Osler disease, which suggested the possible existence of a pulmonary arteriovenous fistula as the aetiological causation of her cerebrovascular disease. Neurovascular Doppler ultrasonography with bubble contrast test was positive, and the presence of the fistula was confirmed by a computerised axial tomographic angiography scan of the lungs. CONCLUSIONS: Rendu-Osler disease is a rare cause of stroke due to the fact that it is usually associated with arteriovenous fistulas that can cause paradoxical embolisms. Neurovascular Doppler ultrasound scanning is useful for detecting these pulmonary fistulas by means of the bubble contrast test, which is a non-invasive test that can be carried out easily by neurologists themselves.

Enfermedad de Rendu-Osler-Weber como causa infrecuente de ictus / Rendu-osler-weber disease as an infrequent cause of stroke

La telangiectasia hemorrágica hereditaria o enfermedad de Rendu-Osler es una enfermedad vascularcongénita que se asocia con la presencia de fístulas arteriovenosas que son causa de embolias paradójicas. Caso clínico. Mujer de 83 años que ingresa con clínica de crisis epilépticas y múltiples infartos cerebrales en fase aguda. Asocia historiaprevia de múltiples hemorragias y anemia ferropénica sin clara causa etiológica. Tras una exhaustiva anamnesis, se descubre historia familiar de hemorragias y una hermana diagnosticada de enfermedad de Rendu-Osler-Weber, lo que sugiere la posible existencia de una fístula arteriovenosa pulmonar como causa etiológica de su enfermedad cerebrovascular. Se realiza Doppler neurovascular con infusión de test de burbujas con resultado positivo, lo cual confirma la presencia de la fístula mediante angiotomografía axial computarizada pulmonar. Conclusión. La enfermedad de Rendu-Osler es una causa poco frecuente de ictus debido a que suele asociar fístulas arteriovenosas que pueden ser causa de embolias paradójicas. El Doppler neurovascular es útil para la detección de estas fístulas pulmonares mediante el test de infusión de burbujas; se trata de unaprueba no cruenta y de fácil realización por parte de los propios neurólogos

Hereditary haemorrhagic telangiectasia, or Rendu-Osler disease, is a congenital vascular diseasethat is associated with the presence of arteriovenous fistulas that cause paradoxical embolisms. Case report. An 83-year-old female with clinical signs and symptoms of convulsive attacks and multiple cerebral infarctions in the acute phase. She also presented a history of multiple haemorrhages and iron deficiency anaemia with no clear aetiological causation. A thoroughexamination of her medical history revealed a family history of haemorrhages and a sister who had been diagnosed with Rendu-Osler disease, which suggested the possible existence of a pulmonary arteriovenous fistula as the aetiological causation of her cerebrovascular disease. Neurovascular Doppler ultrasonography with bubble contrast test was positive, and the presence of the fistula was confirmed by a computerised axial tomographic angiography scan of the lungs. Conclusions. Rendu-Osler disease is a rare cause of stroke due to the fact that it is usually associated with arteriovenous fistulas that can cause paradoxical embolisms. Neurovascular Doppler ultrasound scanning is useful for detecting these pulmonary fistulas by means of the bubble contrast test, which is a non-invasive test that can be carried out easily by neurologists themselves

[An analysis of avoidable admissions to a neurology service]. / Análisis de los ingresos evitables en un servicio de neurología.

INTRODUCTION: Inappropriate admissions to a hospital service generate unnecessary costs for our health care service. Most admissions to a hospital service come from the emergency department. The presence of a neurologist to attend hospital emergencies would be an important factor allowing admission criteria to be streamlined. AIMS: To determine the number of avoidable admissions (AA) in a neurology service, and to define their characteristics. PATIENTS AND METHODS: We conducted a prospective, descriptive study of the admissions that took place in the Neurology Service of the Hospital General Universitario de Elche (Alicante) over a period of three months. The neurologist determines whether admission is indicated or not. We collected demographic data concerning the patient, the admission diagnosis, neurological diagnosis, the reason for appropriateness and the reason for AA. RESULTS: A total of 250 admissions were attended; 65 were considered to be AA (26%). The most frequent diagnoses in the cases of AA were non-neurological (32.3%), clinical findings (15.4%), neuropathies (10.8%) and epilepsy (10.8%). The reasons leading to AA were non-neurological and transfer to another service (30.8%), follow-up by neurology outpatient department (NOD) (29.2%), NOD study (21.5%), non-neurological and discharge (16.9%) and not specified (1.5%). The mean length of stay in the case of AA was 4.3 days. CONCLUSIONS: The number of AA in our service is higher than that found in other studies. On-duty neurologists, streamlining outpatient diagnostic testing and the design of flexible schedules for outpatient care would reduce the amount of resources that are used, while at the same time increasing the quality of the health service.

Análisis de los ingresos evitables en un servicio de neurología / An analysis of avoidable admissions to a neurology service

Introducción. Los ingresos inadecuados a un servicio hospitalariogeneran costes innecesarios a nuestro sistema de salud.La mayoría de ingresos en un servicio hospitalario procede delárea de urgencias. La presencia de un neurólogo que atienda lasurgencias hospitalarias constituiría un factor importante pararacionalizar los criterios de hospitalización. Objetivos. Determinarel número de ingresos evitables (IE) en un servicio de neurologíaasí como definir las características de éstos. Pacientes y métodos.Estudio descriptivo prospectivo de los ingresos realizados enel Servicio de Neurología del Hospital General Universitario deElche (Alicante) durante tres meses. El neurólogo determina laindicación de ingreso. Se recogen los datos de filiación del paciente,el diagnóstico del ingreso, el diagnóstico del neurólogo, el motivode adecuación y el motivo de IE. Resultados. Se atendieron untotal de 250 ingresos; 65 se consideraron IE (26%). Los diagnósticosmás frecuentes de los IE fueron: no neurológico (32,3%), síntomasy signos (15,4%), neuropatías (10,8%) y epilepsia (10,8%).Los motivos de IE fueron: no neurológico y traslado de servicio(30,8%), seguimiento en consultas externas de neurología (CEN)(29,2%), estudio en CEN (21,5%), no neurológico y alta (16,9%) yno consta (1,5%). Los IE tuvieron una estancia media de 4,3 días.Conclusiones. El número de IE en nuestro servicio es más elevadoque en otros estudios. La disponibilidad de guardias de neurología,la agilización de la realización ambulatoria de pruebasdiagnósticas y el diseño de agendas flexibles de asistencia ambulatoriasupondrían una reducción en la utilización de recursos, yaumentaría la calidad del servicio asistencial

Introduction. Inappropriate admissions to a hospital service generate unnecessary costs for our health care service.Most admissions to a hospital service come from the emergency department. The presence of a neurologist to attend hospitalemergencies would be an important factor allowing admission criteria to be streamlined. Aims. To determine the number ofavoidable admissions (AA) in a neurology service, and to define their characteristics. Patients and methods. We conducted aprospective, descriptive study of the admissions that took place in the Neurology Service of the Hospital General Universitariode Elche (Alicante) over a period of three months. The neurologist determines whether admission is indicated or not. Wecollected demographic data concerning the patient, the admission diagnosis, neurological diagnosis, the reason for appropriatenessand the reason for AA. Results. A total of 250 admissions were attended; 65 were considered to be AA (26%). The mostfrequent diagnoses in the cases of AA were non-neurological (32.3%), clinical findings (15.4%), neuropathies (10.8%) andepilepsy (10.8%). The reasons leading to AA were non-neurological and transfer to another service (30.8%), follow-up byneurology outpatient department (NOD) (29.2%), NOD study (21.5%), non-neurological and discharge (16.9%) and notspecified (1.5%). The mean length of stay in the case of AA was 4.3 days. Conclusions. The number of AA in our service ishigher than that found in other studies. On-duty neurologists, streamlining outpatient diagnostic testing and the design offlexible schedules for outpatient care would reduce the amount of resources that are used, while at the same time increasingthe quality of the health service

The CaMV 35S promoter is highly active on floral organs and pollen of transgenic strawberry plants.

We have evaluated the expression of the reporter beta-glucuronidase (GUS) gene driven by the cauliflower mosaic virus 35S (CaMV 35S) promoter in flowers and pollen from 14 independent transgenic strawberry lines. Of the 14 lines evaluated, 13 (92.8%) showed GUS activity--as estimated by the histochemical GUS assay--in some floral organs, with expression being most common in the flower stem, sepals, petals, ovary and stigma. Ten of these thirteen transgenic lines (77%) showed GUS activity in pollen, although the percentages of positive pollen per flower varied greatly among the different lines. A study of the GUS expression during pollen maturation showed that the (CaMV 35S) promoter showed low expression in pollen from flower buds before anthesis but was activated in mature pollen following anther dehiscence. The percentages of pollen grains that showed GUS activity ranged from 2.1% to 46.3%. These percentages were similar or even higher when mature pollen was stored dry at room temperature for 2 weeks. After 5 weeks of storage, the percentages of GUS-positive pollen decreased in two of the six lines analysed but remained at similar values in the other four lines. GUS activity was also measured in protein extracts of mature pollen by means of the fluorometric GUS assay, with the values obtained ranging from 3.8 micromol MU mg protein(-1) h(-1) to 0.26 micromol MU mg protein(-1) h(-1). Contrary to the generally held view that the CaMV 35S promoter is virtually silent in pollen, we conclude that it is highly expressed in transgenic strawberry pollen.

Formation of concentration gradient and its application to DNA capillary electrophoresis.

A new method to introduce the concentration gradient into the capillary has been developed and its application to DNA capillary electrophoresis is presented. The concentration gradient produced by mixing 5% w/v polyacrylamide-co-poly(N-dimethylacrylamide) (PAM-co-PDMA) solution and 1 x Tris/N-tris(hydroxymethyl)methyl-3-amino-propanesulfonic acid/EDTA (TT) + 5 M urea buffer was successfully achieved by using two programmable syringe pumps with strict control of dead volume, flow rate, and pressure balance. This method has the advantages of high stability, reproducibility, and versatility. The column with concentration gradient greatly improved the resolution, especially for the large DNA fragments, due to a decrease in band width broadening with time. A column containing 2-4% w/v gradient in four steps had a longer read length, shorter separation time and better resolution (after 380 base) than that of 4% w/v single concentration polymer solution. The number of steps in the gradient had almost no effect on the performance. The change in the average concentration by relocating the position of the same step gradient, i.e., a combination of different low concentration to high concentration polymer solution ratios, resulted in a different migration time, read length and resolution.

Improved germination under osmotic stress of tobacco plants overexpressing a cell wall peroxidase.

The cell wall is a fundamental component in the response of plants to environmental changes. To directly assess the role of the cell wall we have increased the expression and activity of a cell wall associated peroxidase (TPX2), an enzyme involved in modifying cell wall architecture. Overexpression of TPX2 had no effect on wild-type development, but greatly increased the germination rate under high salt or osmotic stress. Differential scanning calorimetry showed that transgenic seeds were able to retain more water available for germination than wild-type seeds. Thermoporometry calculations indicated that this could be due to a lower mean pore size in the walls of transgenic seeds. Therefore, the higher capacity of transgenic seeds in retaining water could result in higher germination rates in conditions where the availability of water is restricted.

Multi-capillary optical waveguides for DNA sequencing.

Cylindrical capillaries can be used as optical elements in a waveguide, where refraction will confine an appropriately focused light beam to pass through the interiors of successive capillaries in a flat parallel array. Such a capillary waveguide allows efficient illumination of samples in multiple capillaries with relatively little laser power. Analytical expressions derived under paraxial and thin-lens approximations provide guidance in selecting the capillary sizes and the refractive indices that will produce the waveguiding effect, but accurate predictions require exact ray tracing. Small reflective losses as the light passes through the capillary surfaces cause cumulative intensity decreases, but the resulting lack of uniformity can be compensated to a considerable extent by illuminating the capillary array from both sides. A 12-capillary waveguide illuminated from both sides in air has a difference of less than 10% from the strongest to the weakest illumination. By increasing the refractive index of both the external medium and the contents of the capillaries, a 96-capillary waveguide for DNA sequencing could be produced that would also provide nearly uniform illumination. A 12-capillary, bi-directionally illuminated waveguide system for DNA sequencing has been constructed. The two focused laser beams are delivered by integrated fiber optic transmitters (IFOTs), and fluorescence is collected by a set of optical fibers whose spacing exactly matches that of the capillaries in the waveguide. The system is easy to align and provides sensitive detection of fluorescence with minimal cross-talk between channels.

Expression of a highly basic peroxidase gene in NaCl-adapted tomato cell suspensions.

A tomato peroxidase gene, TPX2, that is only weakly expressed in the roots of young tomato seedlings is highly expressed in tomato suspension cells adapted to high external NaCl concentration. The protein encoded by this gene, with an isolectric point value of approximately 9.6, is found in the culture medium of the growing cells. Our data suggest that the expression of TPX2 in the salt-adapted cells is not the result of the elicitation imposed by the in vitro culture or the presence of high NaCl concentration in the medium.

Replaceable polymers in DNA sequencing by capillary electrophoresis.

Much progress has been made in the development of replaceable sieving polymers and capillary coatings for high-performance DNA sequencing by capillary electrophoresis. Several studies of parameters that affect resolution, read length and reproducibility have begun to reveal the physical mechanisms acting on single-stranded DNA during electrophoresis through semidilute polymer solutions. Recently developed electro-osmosis-inhibiting matrix polymers have simplified the process of coating capillaries, facilitating the automation of high-throughput parallel systems for large-scale sequencing.

Multiple capillary DNA sequencer that uses fiber-optic illumination and detection.

An 8-capillary prototype electrophoresis system for DNA sequencing has been constructed. The sequence of 400-450 bases can be obtained from each capillary in less than an hour from sequencing reactions generated with four-color fluorescent terminators. Illumination of each capillary and collection of fluorescence is through individual optical fibers. Resolution of the DNA ladder is through a replaceable sieving matrix of linear polyacrylamide in reusable coated capillaries. Light from an argon ion laser is introduced into a fused biconically tapered fiber-optic splitter, and individual fibers deliver approximately 10 mW of 514 nm light to each of the eight electrophoresis capillaries. Illumination and collection are by fibers normal to the surface of the electrophoresis capillary and at right angle to each other. Illumination by a fiber with low numerical aperture and collection by a fiber with high numerical aperture provides good sensitivity and signal-to-noise ratios without the need for microlenses (limit of detection: 1.5 x 10(-11)M fluorescein analog dye with a signal-to-noise ratio of 2). The eight collection fibers are passed in parallel through holographic filters for Rayleigh rejection and into an imaging spectrograph, which simultaneously displays the full fluorescence spectrum (475-648 nm) from the eight capillaries in parallel on the surface of an intensified charge-coupled device (CCD). The CCD is read out at a rate of 3.4 complete images per second.

Polyacrylamide solutions for DNA sequencing by capillary electrophoresis: mesh sizes, separation and dispersion.

Two preparations of linear polyacrylamide with average molecular weights of 0.37 million and 1.14 million Da, and a deuterated preparation with an average molecular weight of 1.71 million Da, were used to study the effects of molecular weight, polydispersity, and concentration on the mesh size of entangled polymers in a DNA sequencing buffer solution and their ability to resolve DNA sequencing reactions by capillary electrophoresis. The polyacrylamide concentrations were above the overlap threshold C*, the concentration above which an entangled polymer network is expected to form. Small angle neutron scattering experiments showed that between 1% and 8% polyacrylamide, the mesh size ( xi ) can be expressed by the relation xi = 2.09C-0.76, where xi is in A and C is the polymer concentration in g/mL. The mesh size depended only on the concentration and was independent of the average molecular weight of the polyacrylamide. Consistent with this result, electrophoretic mobilities of DNA moving through the polymer network depended almost entirely on the polyacrylamide concentration and not on its molecular weight or polydispersity. Although separation was little affected, band sharpness persisted to longer DNAs when the polymer network contained a higher fraction of larger polyacrylamide molecules. We postulate a dispersive effect that depends on the size of the DNA and the resiliency of the polymer network. This interpretation provides a rationale for optimizing the design of polymer solutions to sieve DNA for sequencing by capillary electrophoresis.

Shoot regeneration and Agrobacterium-mediated transformation of Fragaria vesca L.

An efficient and reliable method for shoot regeneration from leaf disks of Fragaria vesca L. has been developed. This protocol has been successfully employed to obtain transformed plants using Agrobacterium tumefaciens as gene vector. Murashige and Skoog basal medium supplemented with benzyladenine (4 mg/l) and indole-3-butyric acid (0.25 mg/l) induced the maximum percentage of shoot regeneration (98%) and the highest number of shoot colonies per explant (4.6) after 8 weeks of culture. Isolated shoots would elongate and proliferate when the benzyladenine concentration was lowered to 0.5 mg/l. The established protocol for shoot regeneration was employed to transform leaf disks using Agrobacterium tumefaciens carrying the plasmid pBI121. A 7.7% of the inoculated explants showed kanamycin resistance after 10 weeks of selection in a medium containing 25 mg/l of this antibiotic. The transgenic shoots obtained were rooted in the presence of 25 mg/ kanamycin and successfully acclimatized. The final percentage of transformation obtained based on beta-glucuronidase expression was 6.9%.

[Chronic demyelinating polyneuropathy associated with multiple sclerosis: a patient with two diseases]. / Polineuropatia crónica desmielinizante asociada a esclerosis múltiple. Un paciente y dos enfermedades.

We studied the clinical, paraclinical and laboratory findings of a patient suffering from multiple sclerosis (MS) with chronic demyelinating polyneuropathy. As well as being a new case of demyelination of the central and peripheral nervous system not normally associated with the presence of antiganglionic antibodies, our patient presented clinical signs distinct from each disease with the characteristic abnormalities of cerebrospinal fluid (CSF) (cytological albumin dissociation at the moment when an outbreak appeared at the peripheral level and an increase in intrathecal secretion when the outbreak was at the central nervous system level). Demyelinating diseases of the central and peripheral nervous systems are a field of great interest in trying to find the antigenic bull's eye for MS.

Induction of a tomato peroxidase gene in vascular tissue.

Expression of a tomato peroxidase gene that is constitutively expressed only in roots was induced in stems and leaves as a result of mechanical wounding. However, wound-induction of TPX1 transcript accumulation in leaves was limited to the mid-rib. No TPX1 transcript was detected in the lamina of the leaf after wounding. Peroxidase isozyme studies indicated the presence of a unique basic isoform in stems after wounding.

Characterization and in situ localization of a salt-induced tomato peroxidase mRNA.

NaCl treatment of tomato plants in hydroponic culture at concentrations as low as 50 mM resulted in enhanced accumulation of transcripts of TPX1, a full-length cDNA clone that we had isolated from a library of NaCl-treated tomato plants using a peroxidase-specific oligonucleotide probe. Although the overall amino acid sequence identity of TPX1 to other peroxidase genes was less than 45%, there was a very high degree of identity in all of the conserved domains. The deduced amino acid sequence included the presence of a N-terminal signal peptide but not the C-terminal extension present in peroxidases targeted to the vacuole. The mature protein has a theoretical pI value of 7.5. Transcripts that hybridized to TPX1 were detected only in the roots with higher levels of mRNA in epidermal and subepidermal cell layers. Isoelectric focusing of root extracts showed two major bands of peroxidase activity at pI 5.9 and 6.2. Both activities increased with salt treatment. Southern analysis indicated the presence of only a single TPX1 gene in tomato.

Picogram detection of stable dye-DNA intercalation complexes with two-color laser-excited confocal fluorescence gel scanner.

The stable complexes between highly fluorescent, polyfunctional intercalators and dsDNA can be used to detect dsDNA in agarose gels at picogram levels and for multicolor detection of multiplexed dsDNA fragments. Development of additional DNA-binding fluorophores with appropriate spectroscopic properties will expand the range of applications. In principle, the DNA-dye intercalation complexes represent a more sensitive alternative to an established approach to fluorescent labeling and detection of restriction fragments by ligation to single-stranded short oligonucleotides labeled with different fluorochromes, followed by separation on denaturing polyacrylamide gels. The latter technique gives near single-base resolution up to 400 bases and the ability to quantitate fragment size up to 2000 bases, and has been successfully applied to cosmid mapping. Detection of DNA fragments as intercalation complexes requires that the separations be performed on agarose gels under nondenaturing conditions. Such conditions have been used for extensive mapping of yeast cosmids with postelectrophoresis staining with ethidium bromide. For the patterns on agarose gels, the magnitude of the "error window," which specifies how similar two fragments must be before the corresponding fragments in different digests are paired, was reported to be strongly size dependent. The error window was expanded by a factor of 1.3 for fragments from 400 to 600 bp, 1.2 for fragments from 600 to 800 bp, and 1.1 for fragments from 800 to 1000 bp. Moreover, it was necessary to introduce corrections for systematic differences between size estimates taken from two different gels. For the multiplexing procedure described here, the size estimates for fragments from 600 bp to over 23 kbp were in close agreement with actual sizes as determined from DNA sequence (Table I), and certainly within the error windows given above. The multiplexing procedure should also minimize errors introduced by gel-to-gel variations in mobility, because the standard and unknowns are always run in the same lanes. Kohara et al. established a physical map of almost the entire Escherichia coli chromosome by analysis of a large genomic library. In this case, partial restriction digests were used to generate patterns of fragments and the mapping was performed by agarose gel electrophoresis. The disadvantage of this approach is that fewer fragments are generated. However, this is compensated for by the fact that partial digests reveal the order of the fragments produced and thus greatly increase the amount of information relevant to the question of overlap between different DNA fragments.(ABSTRACT TRUNCATED AT 400 WORDS)

Fluorometric assay using dimeric dyes for double- and single-stranded DNA and RNA with picogram sensitivity.

Thiazole orange homodimer (TOTO; 1,1'-(4,4,7,7-tetramethyl-4,7-diazaundecamethylene)-bis-4-[3-methy l-2,3- dihydro-(benzo-1,3-thiazole)-2-methylidene]-quinolinium tetraiodide) and oxazole yellow homodimer (YOYO; an analogue of TOTO with a benzo-1,3-oxazole in place of the benzo-1,3-thiazole) bind with very high affinity to nucleic acids with more than a 1000-fold fluorescence enhancement upon binding. A linear dependence of fluorescence intensity on DNA concentration over a range from 0.5 to 100 ng/ml in the presence of 2 x 10(-7) M TOTO or YOYO in 4 mM Tris-acetate/0.1 mM EDTA/50 mM NaCl, pH 8.2 allows sensitive quantitation of double-stranded DNA in a conventional fluorometer. With nucleic acid-dye mixtures in an array of 25-microliters wells in a block of low autofluorescence plastic and detection with a laser-excited confocal fluorescence scanner, as little as 20 pg of double-stranded DNA can be detected per well. The array scanning method is rapid, has high throughput, and requires small amounts of sample. It also allows quantitation of single-stranded DNA and RNA.