Papel de la proteína asociada a pancreatitis en el cribado neonatal de la fibrosis quística / [Role of pancreatitis-associated protein in neonatal screening for cystic fibrosis]

Objetivo: El objetivo es comparar la eficacia de dos métodos de cribado de fibrosis quística (FQ) mediante la utilización de la medición del tripsinógeno inmunorreactivo (TIR) y la proteína asociada pancreatitis (PAP) en gota de sangre seca.Métodos: Estudio observacional prospectivo que evaluó a neonatos con niveles de TIR inicial (TIR1) mayor de 50ng/mL a los que se le ha realizado cuantificación de la PAP y una segunda determinación de TIR (TIR2) entre diciembre 2017 y junio 2020. Se comparó la detección de FQ entre dos protocolos de cribado TIR1/ TIR2 vs TIR1/PAP/TIR2.Resultados: Durante el período analizado se sometieron a cribado neonatal 60.399 neonatos, de los que 316 tuvieron TIR1 elevada. Se confirmaron 10 casos de FQ, con una incidencia de 1 caso por cada 6.039 neonatos cribados. El protocolo TIR1/TIR2 identificó 34 casos con una sensibilidad del 88,89%, especificidad 91,53%, valor predictivo positivo 23,53% y valor predictivo negativo de 99,65%. El protocolo TIR1/PAP/TIR2 obtuvo una sensibilidad 88,89 %, especificidad 96,42%, valor predictivo positivo 42,11% y valor predictivo negativo 99,66%. El alelo c.1521_1523delCTT se identificó en el 80% de los casos.Conclusiones: El protocolo TIR1/PAP/TIR2 aumenta la especificidad del cribado neonatal, obteniendo una disminución del 4,89% de la proporción de falsos positivos respecto al protocolo TIR1/TIR2. Este nuevo protocolo de cribado puede permitir hacer un cribado de la FQ más eficiente. (AU)

Objective: The aim is to compare the efficacy of two screening methods for cystic fibrosis (CF) by measuring immunoreactive trypsinogen (IRT) and pancreatitis-associated protein (PAP) in dried blood spots.Methods: Prospective observational study that evaluated neonates with initial IRR levels (IRR1) greater than 50ng/mL who underwent PAP quantification and a second IRR determination (IRR2) between December 2017 and June 2020. The CF detection between two screening protocols TIR1/TIR2 vs TIR1/PAP/TIR2.Results: During the analyzed period, 60,399 neonates underwent neonatal screening, of which 316 had elevated IRR1. 10 cases of CF were confirmed, with an incidence of 1 case per 6,039 newborns screened. The TIR1/TIR2 protocol identified 34 cases with a sensitivity of 88.89%, specificity 91.53%, positive predictive value 23.53%, and negative predictive value 99.65%. The TIR1/PAP/TIR2 protocol obtained a sensitivity of 88.89%, a specificity of 96.42%, a positive predictive value of 42.11%, and a negative predictive value of 99.66%. The c.1521_1523delCTT allele was identified in 80% of cases.Conclusions: The TIR1/PAP/TIR2 protocol increases the specificity of neonatal screening, obtaining a 4.89% decrease in the proportion of false positives compared to the TIR1/TIR2 protocol. This new screening protocol may allow CF screening to be more efficient. (AU)

Contribution of the spanish agency for medicines and healthcare products to the European committee for the evaluation of medicinal products for human use. / Contribución de la Agencia Española de Medicamentos y Productos Sanitarios al Comité Europeo de Evaluación de Medicamentos de Uso Humano.

The centralized procedure for registering medicinal products involves a joint assessment by all regulatory agencies of European Union member states, which are coordinated by the European Medicines Agency. Since its implementation in 1995, the Spanish Agency for Medicines and Healthcare Products (AEMPS) has actively contributed to the committee on medicinal products for human use. The therapeutic areas in which AEMPS has the greatest presence are cardiovascular, sensory organs (mainly ophthalmology) and genitourinary/sexual hormones. The technical staff of AEMPS contributes their expertise and extensive experience to this task, as do the practitioners of the Spanish healthcare system who act as external experts, providing their clinical vision and bringing the daily clinical practice to the evaluation of medicinal products. As with other European decision spaces, the joint participation of the member states is not homogeneous, with a minority of countries still heading the majority of assessments for the committee on medicinal products for human use, although all member countries take part in the final decision.

Telomere-length regulation in inter-ecotype crosses of Arabidopsis.

Telomeres, the nucleoprotein complexes at the ends of eukaryotic chromosomes, are maintained at a species-specific equilibrium length. Arabidopsis thaliana is a self-fertilizing plant and different geographical isolates or ecotypes show differing telomere-lengths. We have exploited this telomere-length polymorphism between Arabidopsis ecotypes to investigate the genetic regulation of telomere length by analysing telomere lengths in 16 different inter-ecotype crosses between plants with differing telomere sizes. With two exceptions, the inter-ecotype hybrid plants present a new telomere-length set point, intermediate between that of the two parents. A regulation mechanism thus shortens the longer and lengthens the shorter telomeres.

Carcinoma suprarrenal virilizante en la infancia. Revisión de la bibliografía / Virilizing adrenal carcinoma in infancy. Review of the literature

Presentamos a una niña de 10 meses remitida al hospital por presentar signos evidentes de virilización (vello pubiano y aumento marcado del tamaño del clítoris). No presentaba otros signos puberales. En la exploración física se palpaba una masa abdominal bien delimitada. Los resultados de laboratorio mostraron unos 17-cetosteroides urinarios muy elevados y una testosterona en plasma elevada. La ecografía abdominal puso de manifiesto una masa hiperecogénica de tamaño 8 6 4 cm, independiente del riñón y el bazo que correspondía a la zona suprarrenal. A los 10 días de su ingreso fue intervenida, y se le extirpó una masa grande bien delimitada en la zona suprarrenal, con el diagnóstico de presunción de carcinoma suprarrenal virilizante, que fue posteriormente confirmado por el estudio anatomo-patológico. Sin otro tratamiento que el quirúrgico, su evolución fue favorable, con un crecimiento longitudinal y un desarrollo puberal normales. En la actualidad tiene una edad cronológica de 20 años y una talla de170,5 cm. Se discuten y revisan otras opciones terapéuticas del carcinoma suprarrenal, cuya entidad es muy poco frecuente en la infancia (AU)

A 10-month-old girl was referred to hospital because of obvious signs of virilization (pubic hair and marked increasein the size of the clitoris). There were no others signs of puberty. On examination, a well-defined abdominal mass was palpable. The results of laboratory investigations showed markedly elevate durinary 17-ketosteroid levels and elevated plasma testosterone. Abdominal ultrasonography revealed a hyper echogenic mass measuring 8 x 6 x 4cm, independent of the kidney and spleen which corresponded to the adrenal area. The patient underwent surgery 10 days after admission. A large, well-defined mass was removed from the adrenal area. The presumptive diagnosis was virilizing adrenal carcinoma, which was subsequently confirmed by pathological analysis. No further treatments were administered and outcome was favorable with normal growth and puberal development. Currently, the patient has a chronological age of 20 years and a height of 170.5 cm. Other therapeutic options for adrenal carcinoma, a very rare entity in infancy, are reviewed (AU)

Ku80 plays a role in non-homologous recombination but is not required for T-DNA integration in Arabidopsis.

Chromosomal breaks are repaired by homologous recombination (HR) or non-homologous end joining (NHEJ) mechanisms. The Ku70/Ku80 heterodimer binds DNA ends and plays roles in NHEJ and telomere maintenance in organisms ranging from yeast to humans. We have previously identified a ku80 mutant of the model plant Arabidopsis thaliana and shown the role of Ku80 in telomere homeostasis in plant cells. We show here that this mutant is hypersensitive to the DNA-damaging agent methyl methane sulphonate and has a reduced capacity to carry out NHEJ recombination. To understand the interplay between HR and NHEJ in plants, we measured HR in the absence of Ku80. We find that the frequency of intrachromosomal HR is not affected by the absence of Ku80. Previous work has clearly implicated the Ku heterodimer in Agrobacterium-mediated T-DNA transformation of yeast. Surprisingly, ku80 mutant plants show no defect in the efficiency of T-DNA transformation of plants with Agrobacterium, showing that an alternative pathway must exist in plants.

The plant Rad50-Mre11 protein complex.

The Rad50-Mre11-Xrs2/Nbs1 protein complex plays critical roles in cellular processes involving DNA ends. This complex is implicated in DNA recombination and replication, meiosis, telomere maintenance and cellular DNA damage responses. The Rad50 and Mre11 proteins are essential for viability in animals, although not in yeast. We have prepared antibodies to the Rad50 protein of the model plant Arabidopsis thaliana which recognize a 175 kDa protein in wild-type Arabidopsis protein extracts. Furthermore, we report here demonstration of the existence of the Rad50-Mre11 complex by co-immunoprecipitation of the Rad50 and Mre11 proteins from the plant cell extracts.

Homologous recombination in planta is stimulated in the absence of Rad50.

Chromosomal double-strand DNA breaks must be repaired; in the absence of repair the resulting acentromeric (and telomereless) fragments may be lost and/or the broken DNA ends may recombine causing general chromosomal instability. The Rad50/Mre11/Xrs2 protein complex acts at DNA ends and is implicated in both homologous and non-homologous recombination. We have isolated a rad50 mutant of the plant Arabidopsis thaliana and show here that it has a somatic hyper-recombination phenotype in planta. This finding supports the hypothesis of a competition between homologous and illegitimate recombination in higher eukaryotes. To our knowledge, this is the first direct in vivo support for the role of this complex in chromosomal recombination in a multicellular organism and the first description of a mutation of a known gene leading to hyper-recombination in plants.

RAD50 function is essential for telomere maintenance in Arabidopsis.

We have identified and characterized an Arabidopsis thaliana rad50 mutant plant containing a T-DNA insertion in the AtRAD50 gene and showing both meiotic and DNA repair defects. We report here that rad50/rad50 mutant cells show a progressive shortening of telomeric DNA relative to heterozygous rad50/RAD50 controls and that the mutant cell population rapidly enters a crisis, with the majority of the cells dying. Surviving rad50 mutant cells have longer telomeres than wild-type cells, indicating the existence in plants of an alternative RAD50-independent mechanism for telomere maintenance. These results report the role of a protein essential for double-strand break repair in telomere maintenance in higher eukaryotes.

Disruption of the Arabidopsis RAD50 gene leads to plant sterility and MMS sensitivity.

The Rad50 protein is involved in the cellular response to DNA-double strand breaks (DSBs), including the detection of damage, activation of cell-cycle checkpoints, and DSB repair via recombination. It is essential for meiosis in yeast, is involved in telomere maintenance, and is essential for cellular viability in mice. Here we present the isolation, sequence and characterization of the Arabidopsis thaliana RAD50 homologue (AtRAD50) and an Arabidopsis mutant of this gene. A single copy of this gene is present in the Arabidopsis genome, located on chromosome II. Northern analysis shows a single 4.3 Kb mRNA species in all plant tissues tested, which is strongly enriched in flowers and other tissues with many dividing cells. The predicted protein presents strong conservation with the other known Rad50 homologues of the amino- and carboxy-terminal regions. Mutant plants present a sterility phenotype which co-segregates with the T-DNA insertion. Molecular analysis of the mutant plants shows that the sterility phenotype is present only in the plants homozygous for the T-DNA insertion. An in vitro mutant cell line, derived from the mutant plant, shows a clear hypersensitivity to the DNA-damaging agent methylmethane sulphonate, suggesting a role of RAD50 in double-strand break repair in plant cells. This is the first report of a plant mutated in a protein of the Rad50-Mre11-Xrs2 complex, as well as the first data suggesting the involvement of the Rad50 homologue protein in meiosis and DNA repair in plants.

[Assessment with the Epworth scale of daytime somnolence in patients with suspected obstructive apnea syndrome during sleep. Differences between patients and their partners]. / Valoración mediante escala de Epworth de la somnolencia diurna en pacientes con sospecha de síndrome de apneas obstructivas durante el sueño. Diferencias entre los pacientes y sus parejas.

UNLABELLED: Daytime sleepiness is an important symptom in obstructive sleep apnea syndrome. The Epworth sleepiness scale gives a subjective estimate of the level of sleepiness by asking the patient to estimate the probability of falling asleep during each of eight activities of daily living. OBJECTIVE: We aimed to see whether patients suspected of sleep apnea and their partners or other living companions assessed daytime sleepiness differently. MATERIAL AND METHOD: One hundred fifty-nine consecutive patients referred for suspicion of sleep respiratory disorder were studied. Patients and their partners assessed sleepiness separately using the Epworth scale. RESULTS: One hundred forty subjects were men and 19 were women. The mean global Epworth score provided by the patients was significantly lower than that of their companions (10 +/- 0.37 versus 11 +/- 0.42; p < 0.001). However, the two were closely correlated (rho = 0.79). CONCLUSION: Our results indicate that living companions' subjective Epworth scale assessment of sleepiness is greater than is that of patients themselves.

[Hyponatremia in the postoperative period after a neurosurgical tumor condition]. / Hiponatremia en el postoperatorio de la patología tumoral neuroquirúrgica.

A four-year-old girl suffered difficult-to-diagnose hyponatremia resistant to treatment following surgery for a suprasellar tumor. The final diagnosis was diabetes insipidus evolving in three stages. Hyponatremia is a common problem following surgery to remove brain tumors. Early diagnosis and treatment of this electrolytic imbalance are essential for preventing serious neurological symptoms or death. The conditions most closely related to hyponatremia are inappropriate antidiuretic hormone secretion syndrome (IADHSS) and cerebral salt wasting syndrome (CSWS). The latter has become more common in recent years among patients undergoing brain surgery. Whereas IADHSS is treated by restricting fluids, CSWS requires administration of salt and volume fluid volume. We believe that for differential diagnosis of postoperative hyponatremia, a fluid restriction test takes priority over of fluid loading following neurosurgery. The course of hyponatremia must be carefully monitored and a complete endocrinological workup must be performed to detect the possible presence of hypophyseal deficiencies, particularly hypothyroidism and suprarenal insufficiency.

Positive-negative selection and T-DNA stability in Arabidopsis transformation.

We have analysed the application of positive-negative selection for the selection of homologous recombination interactions between the chromosome and a T-DNA molecule after transformation of plant cells. Two different genomic loci in a cell suspension of Arabidopsis thaliana were chosen to study gene targeting events. One was the chalcone synthase (CHS) gene present as a single copy and the second an hemizygous chromosomally inserted T-DNA containing the hpt gene, conferring resistance to hygromycin, flanked by CHS sequences. The target lines were transformed with replacement-type T-DNA vectors which contained a positive selectable marker flanked by the regions of the CHS gene and a negative selectable marker to counter-select random insertions. As negative marker we used the Escherichia coli codA gene encoding cytosine deaminase, conferring upon the cells sensitivity to 5-flourocytosine (5-FC). Doubly selected transformants represent 1-4% of the primary transformed cells. Targeting events were not found at the chalcone synthase locus nor at the artificial hpt locus in a total of 4379 doubly selected calli, corresponding to at least 109,475 individual primary transformants. We show by PCR and Southern analysis that the 5-FC resistance in the majority of these cells is associated with substantial deletions of the T-DNA molecule from the right-border end.

The SR splicing factors ASF/SF2 and SC35 have antagonistic effects on intronic enhancer-dependent splicing of the beta-tropomyosin alternative exon 6A.

Exons 6A and 6B of the chicken beta-tropomyosin gene are mutually exclusive and selected in a tissue-specific manner. Exon 6A is present in non-muscle and smooth muscle cells, while exon 6B is present in skeletal muscle cells. In this study we have investigated the mechanism underlying exon 6A recognition in non-muscle cells. Previous reports have identified a pyrimidine-rich intronic enhancer sequence (S4) downstream of exon 6A as essential for exon 6A 5'-splice site recognition. We show here that preincubation of HeLa cell extracts with an excess of RNA containing this sequence specifically inhibits exon 6A recognition by the splicing machinery. Splicing inhibition by an excess of this RNA can be rescued by addition of the SR protein ASF/SF2, but not by the SR proteins SC35 or 9G8. ASF/SF2 stimulates exon 6A splicing through specific interaction with the enhancer sequence. Surprisingly, SC35 behaves as an inhibitor of exon 6A splicing, since addition to HeLa nuclear extracts of increasing amounts of the SC35 protein completely abolish the stimulatory effect of ASF/SF2 on exon 6A splicing. We conclude that exon 6A recognition in vitro depends on the ratio of the ASF/SF2 to SC35 SR proteins. Taken together our results suggest that variations in the level or activity of these proteins could contribute to the tissue-specific choice of beta-tropomyosin exon 6A. In support of this we show that SR proteins isolated from skeletal muscle tissues are less efficient for exon 6A stimulation than SR proteins isolated from HeLa cells.

Tissue-specific splicing of two mutually exclusive exons of the chicken beta-tropomyosin pre-mRNA: positive and negative regulations.

Alternative splicing of premessenger RNA (pre-mRNA) is a widespread process used in higher eucaryotes to regulate gene expression. A single primary transcript can generate multiple proteins with distinct functions in a tissue- and/or developmental-specific manner. A central question in alternative splicing concerns the selection of splice sites in different cell environments. In this review, we present our results on the alternative splicing of the chicken beta-tropomyosin gene which provides an interesting model for understanding mechanisms involved in splice site selection. The beta-tropomyosin gene contains in its central portion a pair of exons (6A and 6B) that are used mutually exclusively in a tissue and developmental stage-specific manner. Exon 6A is present in mRNA of non-muscle and smooth muscle tissues while exon 6B is only present in mRNA of skeletal muscle. Regulation of both exons is necessary to ensure specific expression of beta-tropomyosin gene in non-muscle cells. Several cis-acting elements involved in the repression of exon 6B and activation of exon 6A have been identified. In addition, we show that the tissue-specific choice of exon 6A is mediated through interaction with a specific class of splicing factors, the SR proteins. In the last part of this review we will focus on possible mechanisms needed to switch to exon 6B selection in skeletal muscle tissue. We propose that tissue-specific choice of exon 6B involves down regulation of exon 6A and activation of exon 6B. A G-rich enhancer sequence downstream of exon 6B has been defined that is needed for efficient recognition of the exon 6B 5' splice site. Moreover, we suggest that alteration of the ratio between proteins of the SR family contributes to tissue-specific splice site selection.

cis-acting sequences involved in exon selection in the chicken beta-tropomyosin gene.

The chicken beta-tropomyosin gene contains an internal pair of mutually exclusive exons (6A and 6B) that are selected in a tissue-specific manner. Exon 6A is incorporated in fibroblasts and smooth muscle cells, whereas exon 6B is skeletal muscle specific. In this study we show that two different regions in the intron between the two mutually exclusive exons are important for this specific selection in nonmuscle cells. Sequences in the 3' end of the intron have a negative effect in the recognition of the 3' splice site, while sequences in the 5' end of the intron have a positive effect in the recognition of the 5' splice site. First, sequences in exon 6B as well as in the intron upstream of exon 6B are both able to inhibit splicing when placed in a heterologous gene. The sequences in the polypyrimidine stretch region contribute to splicing inhibition of exons 5 or 6A to 6B through a mechanism independent of their implication in the previously described secondary structure around exon 6B. Second, we have identified a sequence of 30 nucleotides in the intron just downstream of exon 6A that is essential for the recognition of the 5' splice site of exon 6A. This is so even after introduction of a consensus sequence into the 5' splice site of this exon. Deletion of this sequence blocks splicing of exon 6A to 6B after formation of the presplicing complex. Taken together, these results suggest that both the mutually exclusive behavior and the choice between exons 6A and 6B of the chicken beta-tropomyosin gene are trans regulated.

Myosin light-chain 1/3 gene alternative splicing: cis regulation is based upon a hierarchical compatibility between splice sites.

The mechanisms involved in the selective joining of appropriate 5' and 3' splice sites are still poorly understood in both constitutive and alternatively spliced genes. With two promoters associated with different exons, the myosin light-chain 1/3 gene generates two pre-mRNAs that also differ by the use of a pair of internal exons, 3 and 4, that are spliced in a mutually exclusive fashion. When the promoter upstream from exon 1 is used, only exon 4 is included. If the promoter upstream from exon 2 is used, only exon 3 is included. In an attempt to understand the molecular basis for the mutually exclusive behavior of these two exons and the basis of their specific selection, a number of minigene constructs containing exons 3 and 4 were tested in a variety of homologous or heterologous cis and trans environments. The results demonstrate that the mutually exclusive behavior of myosin light-chain exons 3 and 4 and selection between the two exons are cis regulated and are affected by the nature of the flanking sequences. Both exons competed for the common flanking 5' and 3' splice sites. Flanking exons were found that favored inclusion into mature mRNA of exon 3, exon 4, both, or neither, suggesting a specific cooperative interaction between certain 5' and 3' splice sites. Thus, alternative splicing of myosin light-chain 1/3 pre-mRNAs is regulated in cis by a hierarchy of compatibilities between pairs of 5' and 3' splice sites.

Identification of the transcriptional initiation site of ribosomal RNA genes in the crustacean Artemia.

The proximal part of the Intergenic Spacer, as well as most of the External Transcribed Spacer of the ribosomal RNA type I genes from the crustacean Artemia have been sequenced. We have identified in the Intergenic Spacer five repeats of around 600 bp in length and, possibly, two imperfect or truncated repeats, derived from the principal ones. These sequences are separated by 485 bp from the 17S rRNA coding sequence. We have also identified the start point of transcription by S1 nuclease analysis. This start point is found 248 bp inside the first repeat. The sequence around the start point shows homology with that described for other members of the same phylum, mostly insects. The most conserved regions are from -1 to +25, and the G residue at position -16. At least the three 600-bp repeats upstream from that containing the promoter also contain the start point sequence, and could therefore act as initiation sites for snPIRNA and/or as enhancer sequences for ribosomal RNA gene transcription.

Characterization of two types of rRNA gene repeat units from the crustacean Artemia.

We have previously described that Artemia rRNA genes are organized with a basic repeat unit of 16.5 kb [Cruces et al., Biochem. Biophys. Res. Commun. 98 (1981) 404-409]. Here we describe the organization of the DNA coding for rRNA of a different population of this crustacean that has a repeat unit of 12.2 kb. Both types of repeat units have been cloned and the organization of the external spacers studied by restriction analysis. Both external spacers contain repeated sequences, but they are not homologous to each other. Sequences from the external spacer of the 16.5 kb repeat are also found elsewhere in the genome, within sequences not related to rRNA genes.

[Leydig cell tumor with pseudoprecocious puberty (author's transl)]. / Tumor de células de Leydig con pseudopubertad precoz.

Authors present a case of a Leydig cell testicular tumor in a boy aged three years with a six-month follow-up. This type of tumor which is usually hormone-producing has in children a virilizing effect giving signs of pseudoprecocious puberty. Hormonal tests before and after surgery are described as well as the histological study. The various possibilities of differential diagnosis, treatment and prognosis in the presence of a unilateral testis enlargement in a boy are commented.