Running demands and tactical individual actions of wingers appear to depend on the playing formations within an amateur football team

We examine the differences in running performance demands and tactical individual actions for male amateur football wingers in four tactical formations: 4-2-3-1, 4-4-2, 3-5-2 and 3-4-2-1 during an entire season. Running demands were assessed in terms of: total distance run; distance traveled at 3 different speed ranges (Jogging, Running, and Sprinting); and number of accelerations registered in two different magnitude bands (Medium and High) while tactical individual actions were assessed through 3269 team match observations. 3-5-2 formation entails the highest running demands, exhibiting significant disparities in Jogging when compared to 4-2-3-1 and 3-5-2, in Sprinting when comparing 4-2-3-1 with both the 3-5-2 and the 3-4-2-1 formations. Moreover, the wingers in the 3-5-2 formation demonstrate the lowest scores in various tactical individual actions, including Shots: 3-5-2 vs. 3-4-2-1; Goal Area Shots: 3-5-2 vs. 3-4-2-1; and Dribbles: 3-5-2 vs. 3-4-2-1. Finally, wingers registered the highest levels of defensive tactical individual actions in 4-4-2 and 3-5-2. Findings suggest it would be of benefit for coaches to focus on formulating specific training plans to address the specific demands placed on wingers playing in these amateur matches and running performance demands and tactical individual actions should be considered together with tactical formation.

Effect of concurrent training on trainability performance factors in youth elite golf players

Background

Due to the early specialization of golf players, examining the within session sequence of training should be considered to enhance performance and prevent injury risk. The present study analyzed the effects of an 18-week concurrent training developed before or after a specific golf session in adolescence elite golfers on several performance factors.

Methods

Sixteen right-handed male golfers, were randomly divided into two groups: after golf specific training (AG) (n = 8, age: 16.77 ± 0.58 years) and before golf specific training (BG) (n = 8, age: 16.93 ± 0.59 years). AG and BG players followed a concurrent physical conditioning program (CT) after or before the golf specific training, respectively. Body mass, body fat, muscle mass, jumping ability (CMJ), ball speed (Sball), golf movements screens (GMS), power in a golf swing-specific cable woodchop (Wmax) and the perceived training load (TL) in golf specific training (TL-G) and TL in CT (TL-CT) were measured on three separate occasions.

Results

BG demonstrates a lower TL-CT than AG (p < .001, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}${\eta }_{p}^{2}=0.90$\end{document}ηp2=0.90) along the training program without effects on TL-G, achieving significant percentage of change on CMJ (9.38%; p = .165; d = 0.73), GMS (50.52%; p = .41, d = 0.91), Wmax (16.93%; p = .001; d = 2.02) and Sball (1.82%; p = .018; d = 0.92) without interaction effects on anthropometric measures.

Conclusions

Performing CT sessions before the regular golf training can improve specific performance factors with a lower perceived TL than the same training carried out after the regular golf training.

Influence of competition on performance factors in under-19 soccer players at national league level

The aim of this study was to analyse and quantify the acute effects of competition on several performance factors in under-19 male soccer players. To this end, 198 national league players (17.56 ± 0.78 years) performed various tests to measure jump capacity, kicking velocity and sprint times immediately pre-match (T1), at half-time (T2) and post-match (T3). Tests included kicking the ball to measure ball velocity (KICK), sprinting for 40 meters, timing the first 30 meters (30mACCEL), the last 10 meters (10mACCEL) and the total distance (40mACCEL), and performing countermovement jumps (CMJ). For subsequent analysis, the sample was divided into 5 playing positions: goalkeepers (n = 24), defenders (n = 51), midfielders (n = 36), wingers (n = 54) and forwards (n = 33). For all positions, we found a significant decline in performance (p<0.05) for kicking velocity (2.91% - 6.51%) and sprinting (0.44%-5.85%). For the CMJ, all positions except defenders presented a significant decline in performance that ranged from 1.5% to 4.56%. These findings highlight the need to individualise fitness training, taking into account the match needs and demands of the different playing positions in order to minimise the effects of match fatigue and accelerate post-match recovery.

T-cell intracellular antigens function as tumor suppressor genes

Knockdown of T-cell intracellular antigens TIA1 and TIAR in transformed cells triggers cell proliferation and tumor growth. Using a tetracycline-inducible system, we report here that an increased expression of TIA1 or TIAR in 293 cells results in reduced rates of cell proliferation. Ectopic expression of these proteins abolish endogenous TIA1 and TIAR levels via the regulation of splicing of their pre-mRNAs, and partially represses global translation in a phospho-eukaryotic initiation factor 2 alpha-dependent manner. This is accompanied by cell cycle arrest at G1/S and cell death through caspase-dependent apoptosis and autophagy. Genome-wide profiling illustrates a selective upregulation of p53 signaling pathway-related genes. Nude mice injected with doxycycline-inducible cells expressing TIA1 or TIAR retard, or even inhibit, growth of xenotumors. Remarkably, low expressions of TIA1 and TIAR correlate with poor prognosis in patients with lung squamous cell carcinoma. These findings strongly support the concept that TIA proteins act as tumor suppressor genes.

Strict 3' splice site sequence requirements for U2 snRNP recruitment after U2AF binding underlie a genetic defect leading to autoimmune disease

We report that the 3' splice site associated with the alternatively spliced exon 6 of the Fas receptor CD95 displays strict sequence requirements and that a mutation that disrupts this particular sequence arrangement leads to constitutive exon 6 skipping in a patient suffering from autoimmune lymphoproliferative syndrome (ALPS). Specifically, we find an absolute requirement for RCAG/G at the 3' splice site (where R represents purine, and / indicates the intron/exon boundary) and the balance between exon inclusion and skipping is exquisitely sensitive to single nucleotide variations in the uridine content of the upstream polypyrimidine (Py)-tract. Biochemical experiments revealed that the ALPS patient mutation reduces U2 snRNP recruitment to the 3' splice site region and that this effect cannot be explained by decreased interaction with the U2 snRNP Auxiliary Factor U2AF, whose 65- and 35-kDa subunits recognize the Py-tract and 3' splice site AG, respectively. The effect of the mutation, which generates a tandem of two consecutive AG dinucleotides at the 3' splice site, can be suppressed by increasing the distance between the AGs, mutating the natural 3' splice site AG or increasing the uridine content of the Py-tract at a position distal from the 3' splice site. The suppressive effects of these additional mutations correlate with increased recruitment of U2 snRNP but not with U2AF binding, again suggesting that the strict architecture of Fas intron 5 3' splice site region is tuned to regulate alternative exon inclusion through modulation of U2 snRNP assembly after U2AF binding.

Publishing science in the digital age. The case of Neurocirugía

Neurocirugía publishes a printed edition for subscribers, and also an electronic edition which is available online free of charge. The coexistence of these two formats raises some issues regarding their justification and their future evolution, e.g. why does a subscription- based journal offer free online access? Would it be wise to charge for -or somewhat limit- the electronic access to the Journal? How is the Internet changing the benefits to society that the Journal provides? Will the printed and the electronic edition of the Journal continue to coexist? This paper provides some answers and reflections on these questions. Many of our considerations are based on ideas that have been presented and discussed in a series of editorials in Neurocirugía (see Neurocirugía 17 (2), 2006); in this paper we reconsider, complement, and rearrange previous arguments to address the issues mentioned above. Based on an analysis of economic costs and of all the stakeholders involved (authors, readers, the Journal, the Spanish Society of Neurosurgery, and society as a whole), we justify the present coexistence of the two publishing formats, defend free online access, and provide our view on the expected evolution of the Journal. While we focus primarily on Neurocirugía, most of our reflections can be carried over to other scientific journals.

Regulation of Fas alternative splicing by antagonistic effects of TIA-1 and PTB on exon definition

Fas exon 6 can be included or skipped to generate mRNAs encoding, respectively, a membrane bound form of the receptor that promotes apoptosis or a soluble isoform that prevents programmed cell death. We report that the apoptosis-inducing protein TIA-1 promotes U1 snRNP binding to the 5' splice site of intron 6, which in turn facilitates exon definition by enhancing U2AF binding to the 3' splice site of intron 5. The polypyrimidine tract binding protein (PTB) promotes exon skipping by binding to an exonic splicing silencer and inhibiting the association of U2AF and U2 snRNP with the upstream 3' splice site, without affecting recognition of the downstream 5' splice site by U1. Remarkably, U1 snRNP-mediated recognition of the 5' splice site is required both for efficient U2AF binding and for U2AF inhibition by PTB. We propose that TIA-1 and PTB regulate Fas splicing and possibly Fas-mediated apoptosis by targeting molecular events that lead to exon definition.

[Cervical myelopathy: retrospective analysis of surgical results in 53 cases treated by anterior cervical discectomy and interbody fusion]

PATIENTS AND METHODS

We perform a retrospective analysis of clinical results in 53 consecutive patients surgically treated for cervical myelopathy or myelo-radiculopathy with anterior cervical discectomy and interbody fusion by means of the Cloward procedure.

RESULTS

64.2% of the patients had good outcome as measured by the improvement in one or more grades in the Nurick's scale. No mortality related to the surgical procedure was noted, although 9.4% of the cases suffered neurological deterioration. Correct fusion was achieved in 92.5% of the patients, with a rate of post-surgical kyphosis of 9.4%. Multivariate analysis identified as factors related to the clinical outcome: age (p = 0.008), vascular risk factors (p = 0.031), duration of symptoms (p = 0.002), pre-surgical neurological status (p < 0.001), neuroradiological diagnosis (p = 0.014), intra-medullary high signal intensity changes in T2-weighted images (p = 0.008), prolongation of the central somato-sensory or motor conduction times (p = 0.004) and neurologic complications (p = 0.012)

CONCLUSIONS

Treatment optimisation of the patient suffering cervical spondylotic myelopathy requires individualised evaluation. Prospective randomised studies are needed to answer the questions when and how to operate.

[Anterior cervical diskectomy and interbody arthrodesis using Cloward technique: retrospective study of complications and radiological results of 167 cases]

PATIENTS AND METHODS

We performed a retrospective analysis of complications and radiological results in 167 patients surgically treated, for discal or spondylotic disease of the cervical spine, with Cloward procedure. Using uni and multivariate analysis, we tried to identify risk factors that might be correlated with surgical complications or radiological results.

RESULTS

Surgical treatment was indicated for cervical radiculopathy in 68% of the patients and for myelopathy or radiculomyelopathy in the remaining 32%. The pathologic disease responsible of the symptomatology was soft disk herniation in 59% of the cases and spondylotic changes in 41%. The patients that underwent surgery because of myelopathy were one decade older, had a longer symptomatic period and presented multi-segmentary spondylotic disease with higher frequency than patients affected of radiculopathy. The most common segments operated were CS-C6 (44.3%) and C6-C7 (30.5%). Surgical mortality was 0.6% and morbidity 29.3%. Most of the complications were transient, although 4.8% of the patients developed permanent neurological deterioration.

CONCLUSIONS

Complications were most commonly seen in the group of the patients undergoing surgery because of long-lasting myelopathy with multi-segmentary spondylotic disease, in those with vascular risk factors and in those operated of more than one segment. Surgeon anatomic knowledge and experience are critical for diminishing such complications. Non-union rate was 9.6%, and another 9.6% of the patients developed post-surgical kyphosis. Both factors correlated with the need of re-operation.

BPS states in M theory and twistorial constituents

We provide a complete algebraic description of Bogomol'nyi-Prasad-Sommerfield (BPS) states in M theory in terms of primary constituents that we call BPS preons. We argue that any BPS state preserving k of the 32 supersymmetries is a composite of (32-k) BPS preons. In particular, the BPS states corresponding to the basic M2 and M5 branes are composed of 16 BPS preons. By extending the M algebra to a generalized D = 11 conformal superalgebra osp(1/64) we relate the BPS preons with its fundamental representation, the D = 11 supertwistors.

3'-untranslated regions of oxidative phosphorylation mRNAs function in vivo as enhancers of translation

Recent findings have indicated that the 3'-untranslated region (3'-UTR) of the mRNA encoding the beta-catalytic subunit of the mitochondrial H(+)-ATP synthase has an in vitro translation-enhancing activity (TEA) [Izquierdo and Cuezva, Mol. Cell. Biol. (1997) 17, 5255-5268; Izquierdo and Cuezva, Biochem. J. (2000) 346, 849-855]. In the present work, we have expressed chimaeric plasmids that encode mRNA variants of green fluorescent protein in normal rat kidney and liver clone 9 cells to determine whether the 3'-UTRs of nuclear-encoded mRNAs involved in the biogenesis of mitochondria have an intrinsic TEA. TEA is found in the 3'-UTR of the mRNAs encoding the alpha- and beta-subunits of the rat H(+)-ATP synthase complex, as well as in subunit IV of cytochrome c oxidase. No TEA is present in the 3'-UTR of the somatic mRNA encoding rat mitochondrial transcription factor A. Interestingly, the TEA of the 3'-UTR of mRNAs of oxidative phosphorylation is different, depending upon the cell type analysed. These data provide the first in vivo evidence of a novel cell-specific mechanism for the control of the translation of mRNAs required in mitochondrial function.

Internal-ribosome-entry-site functional activity of the 3'-untranslated region of the mRNA for the beta subunit of mitochondrial H+-ATP synthase

Translation in vitro of the mammalian nucleus-encoded mRNA for the beta subunit of mitochondrial H(+)-ATP synthase (beta-mRNA) of oxidative phosphorylation is promoted by a 150 nt translational enhancer sequence in the 3'-untranslated region (3' UTR). Titration of the eukaryotic initiation factor eIF4E with cap analogue revealed that translation of capped beta-mRNA was pseudo-cap independent. The 3' UTR of beta-mRNA stimulates the translation of heterologous uncapped mRNA species, both when the 3' UTR is placed at the 3' end and at the 5' end of the transcripts. The 3' UTRs of the alpha subunit of mitochondrial H(+)-ATP synthase (alpha-F1-ATPase) and subunit IV of cytochrome c oxidase (COX IV) mRNA species, other nucleus-encoded transcripts of oxidative phosphorylation, do not have the same activity in translation as the 3' UTR of beta-mRNA. On dicistronic RNA species, the 3' UTR of beta-mRNA, and to a smaller extent that of COX IV mRNA, is able to promote the translation of the second cistron to a level comparable to the activity of internal ribosome entry sites (IRESs) described in picornavirus mRNA species. These results indicate that the 3' UTRs of certain mRNA species of oxidative phosphorylation have IRES-like functional activity. Riboprobes of the active 3' UTRs on dicistronic assays formed specific RNA-protein complexes when cross-linked by UV to proteins of the lysate, suggesting that cytoplasmic translation of the mRNA species bearing an active 3' UTR is assisted by specific RNA-protein interactions.

A conserved mechanism for controlling the translation of beta-F1-ATPase mRNA between the fetal liver and cancer cells

To characterize the mechanisms governing the biogenesis of mitochondria in cancer, we studied the mitochondrial phenotype and the mechanisms controlling the expression of the beta subunit of the mitochondrial H(+)-ATP synthase (beta-F1-ATPase) gene in the rat FAO and AS30D hepatomas. When compared with normal adult rat liver, the relative cellular content of the mitochondrial beta-F1-ATPase and glutamate dehydrogenase, as well as of mitochondrial DNA, was severely reduced in both cell lines. A paradoxical increase in the cellular abundance of beta-F1-ATPase mRNA was observed in cancer cells. Run-on transcription assays and the estimation of mRNA half-lives revealed that the increased abundance of beta-F1-ATPase mRNA results from the stabilization of the transcript in cancer. In vitro translation assays revealed a specific inhibition of the synthesis of the beta-precursor when translation reactions were carried out in the presence of extracts derived from cancer cells. The inhibitory effect was recapitulated using an RNA chimera that contained the 3'-untranslated region of beta-F1-ATPase mRNA. Hepatoma extracts also contained an increased activity of the developmentally regulated translation-inhibitory proteins that bind the 3'-untranslated region of beta-F1-ATPase mRNA. The results indicate that the expression of this gene in hepatoma cells is controlled by the same mechanisms that regulate its expression in the liver during fetal development.

Control of the translational efficiency of beta-F1-ATPase mRNA depends on the regulation of a protein that binds the 3' untranslated region of the mRNA

The expression of the nucleus-encoded beta-F1-ATPase gene of oxidative phosphorylation is developmentally regulated in the liver at both the transcriptional and posttranscriptional levels. In this study we have analyzed the potential mechanisms that control the cytoplasmic expression of beta-F1-ATPase mRNA during liver development. Remarkably, a full-length 3' untranslated region (UTR) of the transcript is required for its efficient in vitro translation. When the 3' UTR of beta-F1-ATPase mRNA is placed downstream of a reporter construct, it functions as a translational enhancer. In vitro translation experiments with full-length beta-F1-ATPase mRNA and with a chimeric reporter construct containing the 3' UTR of beta-F1-ATPase mRNA suggested the existence of an inhibitor of beta-F1-ATPase mRNA translation in the fetal liver. Electrophoretic mobility shift assays and UV cross-linking experiments allowed the identification of an acutely regulated protein (3'betaFBP) of the liver that binds at the 3' UTR of beta-F1-ATPase mRNA. The developmental profile of 3'betaFBP parallels the reported changes in the translational efficiency of beta-F1-ATPase mRNA during development. Fractionation of fetal liver extracts revealed that the inhibitory activity of beta-F1-ATPase mRNA translation cofractionates with 3'-UTR band-shifting activity. Compared to other tissues of the adult rat, kidney and spleen extracts showed very high expression levels of 3'betaFBP. Translation of beta-F1-ATPase mRNA in the presence of kidney and spleen extracts further supported a translational inhibitory role for 3'betaFBP. Mapping experiments and a deletion mutant of the 3' UTR revealed that the cis-acting element for binding 3'betaFBP is located within a highly conserved region of the 3' UTR of mammalian beta-F1-ATPase mRNAs. Overall, we have identified a mechanism of translational control that regulates the rapid postnatal differentiation of liver mitochondria.

Mitochondrial biogenesis in the liver during development and oncogenesis

The analysis of the expression of oxidative phosphorylation genes in the liver during development reveals the existence of two biological programs involved in the biogenesis of mitochondria. Differentiation is a short-term program of biogenesis that is controlled at post-transcriptional levels of gene expression and is responsible for the rapid changes in the bioenergetic phenotype of mitochondria. In contrast, proliferation is a long-term program controlled both at the transcriptional and post-transcriptional levels of gene expression and is responsible for the increase in mitochondrial mass in the hepatocyte. Recently, a specific subcellular structure involved in the localization and control of the translation of the mRNA encoding the beta-catalytic subunit of the H(+)-ATP synthase (beta-mRNA) has been identified. It is suggested that this structure plays a prominent role in the control of mitochondrial biogenesis at post-transcriptional levels. The fetal liver has many phenotypic manifestations in common with highly glycolytic tumor cells. In addition, both have a low mitochondrial content despite a paradoxical increase in the cellular representation of oxidative phosphorylation transcripts. Based on the paradigm provided by the fetal liver we hypothesize that the aberrant mitochondrial phenotype of fast-growing hepatomas represents a reversion to a fetal program of expression of oxidative phosphorylation genes by the activation, or increased expression, of an inhibitor of beta-mRNA translation.

Subcellular structure containing mRNA for beta subunit of mitochondrial H+-ATP synthase in rat hepatocytes is translationally active

We have recently reported that the nuclear-encoded mRNA for the beta subunit of mitochondrial H+-ATP synthase (beta-mRNA) is localized in rounded, electron-dense clusters in the cytoplasm of rat hepatocytes. Clusters of beta-mRNA are often found in close proximity to mitochondria. These findings suggested a role for these structures in controlling the cytoplasmic expression and sorting of the encoded mitochondrial precursor. Here we have addressed the question of whether the structures containing beta-mRNA are translationally active. For this purpose a combination of high-resolution in situ hybridization and immunocytochemical procedures was used. Three different co-localization criteria showed that beta-mRNA-containing structures always revealed positive immunoreactive signals for mitochondrial H+-ATP synthase (F1-ATPase), ribosomal and hsc70 proteins. Furthermore, clusters show evidence in situ of developmental changes in the translational efficiency of the beta-mRNA. These findings suggest that structures containing beta-mRNA are translationally active irrespective of their cytoplasmic location. The immunocytochemical quantification of the cytoplasmic presentation of hsc70 in the hepatocyte reveals that approx. 86% of the protein has a dispersed distribution pattern. However, the remaining hsc70 is presented in clusters of which only half reveal positive hybridization for beta-mRNA. The interaction of hsc70 with the beta-F1-ATPase precursor protein is documented by the co-localization of F1-ATPase immunoreactive material within cytoplasmic clusters of hsc70 and by the co-immunoprecipitation of hsc70 with the beta-subunit precursor from liver post-mitochondrial supernatants. Taken together, these results suggest a role for hsc70 in the translation/sorting pathway of the mammalian precursor of the beta-F1-ATPase protein.

mRNA encoding the beta-subunit of the mitochondrial F1-ATPase complex is a localized mRNA in rat hepatocytes

Subcellular mRNA localization has emerged as a mechanism for regulation of gene expression and protein-sorting pathways. Here we describe the different cytoplasmic presentation in rat hepatocytes of two nuclear mRNA species encoding subunits alpha and beta of the mitochondrial F1-ATPase complex. alpha-F1-ATPase mRNA is dispersed and scattered in the cytoplasm. In contrast, beta-F1-ATPase mRNA appears in rounded electron-dense clusters, often in close proximity to mitochondria. Hybridization experiments with beta2-microglobulin and beta-actin cDNA species reveal an expected subcellular distribution pattern of the mRNA species and a non-clustered appearance. Development does not alter the presentation of beta-F1-ATPase mRNA hybrids, although it affects the relative abundance of beta-F1-ATPase mRNA clusters in the cytoplasm of the hepatocyte. These findings illustrate in vivo the existence of two different sorting pathways for the nuclear-encoded mRNA species of mitochondrial proteins. High-resolution immunocytochemistry and immunoprecipitation experiments allowed the identification of the beta-subunit precursor in the cytoplasm of the hepatocyte, also suggesting a post-translational import pathway for this precursor protein. It is suggested that the localization of beta-F1-ATPase mRNA in a subcellular structure of the hepatocyte might have implications for the control of gene expression at post-transcriptional levels during mitochondrial biogenesis in mammals.

Gene therapy in brain tumours: implications of the size of glioblastoma on its curability

The authors have used the thymidine kinase/ganciclovir system to block glioblastoma multiforme neoplastic cells in vivo, both in experimental animals and in two patients in which the more conventional therapies had been unsuccessful. In the Wistar rat it was found that the curability potential of the system is correlated with tumoral volume. Tumours smaller than 20 mm3 can be cured with defective retrovirus that do not carry the Herpes simplex thymidine kinase (Hsvtk) gene. While tumours smaller than 150 mm3 can regress totally by the kinase/ganciclovir system, those above that size cannot be cured by this treatment. In humans the situation seems very similar in that the authors have been unable either to reduce the tumour size of recurrent patients with tumour volumes larger than 100 cm2 applying the standard thymidine kinase/ganciclovir gene therapy or to prolong their survival time more than 8 months [7]. When a combination of size reduction by neurosurgery and gene therapy was used the survival time increased considerably. Two patients have been treated by partial surgery and repeated treatment with thymidine kinase/ganciclovir through an Ommaya reservoir connected to a catheter leading into the tumour cavity. The magnetic resonance imaging (MRI) of these patients show only a residual tumoral growth along side the tumoral bed. The procedure may be partially controlling the proliferation of cancerous cells, because, these two patients having recurrent glioblastoma, are alive 11 and 17 months after the beginning of the treatment.

[Tracheobronchial amyloidosis: apropos of 3 cases]

We report 3 cases of tracheobronchial amyloidosis starting with post-obstructive pneumonitis, suggesting underlying neoplasm. The diagnosis was by fiberoptic bronchoscopy. We also describe radiological findings and their usefulness, therapeutic options, and course of disease.

Human malignant brain tumor response to herpes simplex thymidine kinase (HSVtk)/ganciclovir gene therapy

Growing cells from human brain tumors have been treated in vitro and in vivo with murine therapeutic retroviral producer cells. The therapeutic retrovirus carried the potential suicide gene thymidine kinase (tk) from the herpes simplex virus (HSV). After a few days, in which a large proportion of the tumoral cells had the opportunity to acquire a copy of the retrovirus, treatment with ganciclovir was initiated and considered responsible for considerable cell death both in vitro and in vivo. The in vivo experiments were performed in five adult patients who had failed standard therapy and were expected to survive only a few weeks.

Transient activation of mitochondrial translation regulates the expression of the mitochondrial genome during mammalian mitochondrial differentiation

Regulation of the expression of the nuclear-encoded beta-subunit of H(+)-ATP synthase (beta-F1-ATPase) gene of oxidative phosphorylation during differentiation of liver mitochondria is mainly exerted at two post-transcriptional levels affecting both the half-life [Izquierdo, Ricart, Ostronoff, Egea and Cuezva (1995) J. Biol. Chem. 270, 10342-10350] and translational efficiency [Luis, Izquierdo, Ostronoff, Salinas, Santarén and Cuezva (1993) J. Biol. Chem. 268, 1868-1875] of the transcript. Herein, we have studied the expression of the mitochondrial (mt) genome during differentiation of rat liver mitochondria in an effort to elucidate the mechanisms of nucleo-mitochondrial cross-talk during biogenesis of the organelle. Estimation of the relative cellular representation of met-DNA in liver reveals a negligible increase in mt-DNA copy number during organelle differentiation. Concurrently, the lack of changes in transcription rates of the mt-DNA "in organello', as well as in steady-state levels of the mt-transcripts, suggests that organelle differentiation is not controlled by an increase in transcription of the mt-genome. However, translation rates in isolated mitochondria revealed a transient 2-fold increase immediately after birth. Interestingly, the transient activation of mitochondrial translation at this stage of liver development is dependent on the synthesis of proteins in cytoplasmic polyribosomes. These findings support the hypothesis that the expression of nuclear and mitochondrial genes during biogenesis of mammalian mitochondria is developmentally regulated by a post-transcriptional mechanism that involves concerted translational control of both genomes.

[Videothoracoscopy in the surgical treatment of pneumothorax: report of 46 cases]

We report our 3-years experience with video-thoracoscopy for pneumothorax. Forty-six endoscopies (34 men, 12 women; mean age 27 +/- 9 years) were performed. Patients were under general anesthesia and intubation was selective. The conventional approach was used, with 3 incisions through which the camera and endoscopic instruments were inserted. Results were good in 39 (84.7%) patients. Pneumothorax recurred in 4 (8.7%) patients during the 3 years of follow-up. Thoracotomy was performed in 3 patients, because of lack of lung expansion in 1, persistent leak in another and encapsulated empyema in the third. Mean hospital stay after surgery was 7.3 days. Video-thoracoscopy can be considered a good therapeutic alternative to thoracotomy in the surgical treatment of patients with pneumothorax.

mt-mRNA stability regulates the expression of the mitochondrial genome during liver development

We have recently reported that regulation of the expression of the nuclear-encoded beta-F1-ATPase gene during development of rat liver is exerted also by the control of beta-F1-ATPase mRNA decay (Izquierdo, J.M., Ricart, J., Ostronoff, L.K., Egea, G. and Cuezva, J.M. (1995) J. Biol. Chem. 270, 10342-10350). In this paper, we report that high steady-state levels of the mitochondrial encoded mRNAs for subunits of the ATP synthase (ATP 6-8) in developing liver result from profound changes in the stability of the mitochondrial transcripts. The results strongly suggest that developmental regulation of nuclear and mitochondrial genes during biogenesis of mammalian mitochondria is concertedly controlled by a posttranscriptional mechanism that involves the regulation of mRNA degradation of both genomes.

Hypothyroidism affects the expression of the beta-F1-ATPase gene and limits mitochondrial proliferation in rat liver at all stages of development

In order to analyze the role of thyroid hormones in mitochondrial biogenesis, we have studied the expression pattern of the beta subunit of the mitochondrial ATP-synthase complex in liver and in isolated mitochondria during postnatal development of hypothyroid rats. Chemically induced hypothyroidism promoted a significant reduction in body and liver masses at all stages of development. Furthermore, plasma 3,5,3'-triiodo-L-thyronine (T3) and 3,5,3',5'-tetraiodo-L-thyronine (T4) concentrations were significantly reduced in hypothyroid animals when compared to euthyroid animals. Remarkably, steady-state beta-F1-ATPase mRNA levels in livers of hypothyroid animals showed an approximately 50% reduction when compared to age-matched euthyroid rats at all stages of development. The relative amounts of beta-F1-ATPase protein determined in isolated mitochondria of 1-day-old and adult hypothyroid animals were similar to those determined in mitochondria of age-matched euthyroids, indicating that hypothyroidism does not affect organelle differentiation in the liver of suckling and adult rats. In contrast, the relative amount of beta-F1-ATPase protein in liver homogenates varied (0-30% reduction) due to the hypothyroid condition during development. These findings suggest the existence of compensatory mechanisms operating at the translational and/or post-translational levels which promote proliferation of mitochondria in the hypothyroid liver. However, when the liver mass was considered, hypothyroidism significantly reduced overall mitochondrial proliferation in rat liver. Interestingly, the effects of thyroid hormones on the biogenesis of the ATP synthase complex at latter stages of development provide an example in which the hypothyroid condition limits the expression of the nuclear-encoded gene with no apparent effect on the expression of the mitochondrial-encoded genes (ATP synthase subunits 6-8).

[Lung resection surgery in patients with functional limits]

To determine whether there exists in our area concordance between forced expiratory volume in one second (FEV1) estimated before surgery by ventilation/perfusion scintigraphy and real values after surgery in patients undergoing pneumonectomy and lobectomy. Prospective descriptive study. We studied 15 patients undergoing pneumonectomy (M/F 14:1, age 62 +/- 7.5 years) and 11 undergoing lobectomy (M/F 11:0 age 66 +/- 3.5 years) in the thoracic surgery unit of Hospital de Cruces between 1 March 1990 and 1 March 1993. The FEV1 of all patients before surgery was under 2.1 liters. Tumors were malignant in 23 patients and benign in 3. Ventilation/perfusion gammagrams were obtained for all patients before surgery in order to predict the loss of function after resection of the parenchyma. Two months after surgery spirometric testing was done. The FEV1 calculated based on the results of scintigraphy was compared to the real FEV1 after resection by way of graphic concordance and by calculation of a within-group correlation coefficient. A correlation coefficient of 0.82 (p < 0.001) was obtained for FEV1 estimated by ventilation and real FEV1 in patients who underwent pneumonectomy, indicating good concordance. The correlation coefficient was 0.59 (p < 0.001) indicating moderate agreement between FEV1 estimated by perfusion and real FEV1 after resection. Correlation was statistically insignificant in lobectomy patients (0.28 by the method of Ali and 0.35 by Wernly's; p = 0.19 and 0.13, respectively). Ventilation scintigraphy offers an acceptably reliable prediction of FEV1 after lung resection. The reliability of measurements estimated by scintigraphy in lobectomized patients is not acceptable.

Changing patterns of transcriptional and post-transcriptional control of beta-F1-ATPase gene expression during mitochondrial biogenesis in liver

To elucidate the mechanisms that regulate the expression of nuclear genes during biogenesis of mammalian mitochondria, the expression pattern of the beta-subunit of the ATP synthase gene has been characterized in rat liver between day 20 in utero and 12 weeks postnatal. The parallelism existing between transcriptional activity of the gene and the amount of beta-F1-ATPase protein in liver indicates that proliferation of mitochondria is controlled at the transcriptional level. On the other hand, an increased stability (4-5-fold) of beta-F1-ATPase mRNA during early neonatal life as well as a rapid postnatal activation of translation rates affecting mitochondrial proteins appear to control mitochondrial differentiation. Immunoelectron microscopy of the F1-ATPase complex during liver development revealed that the rapid postnatal increase in the in vivo rate of F1-ATPase synthesis was mostly used for functional differentiation of pre-existing organelles (Valcarce, C., Navarrete, R. M., Encabo, P., Loeches, E., Satrústegui, J., and Cuezva, J. M. (1988) J. Biol Chem. 263, 7767-7775). The findings support that beta-F1-ATPase mRNA decay is developmentally regulated in liver, indicating that gene expression is also controlled at this level during physiological transitions that affect biogenesis of mitochondria.

Mammalian adaptation to extrauterine environment: mitochondrial functional impairment caused by prematurity

In this paper we report that, compared with term rat neonates, both mitochondrial content and function are diminished in liver of preterm neonates (delivered 24 h before full term) compromising cellular energy provision in the postnatal period. In addition, there is a parallel reduction in the content of mRNAs encoding mitochondrial proteins in preterm rats. Also, efficient oxidative phosphorylation is not attained in these pups until 3 h after birth. Although isolated liver mitochondria from preterm neonates show a two-fold increase in F1-ATPase beta-subunit and cytochrome c oxidase activity 1 h after birth, the abnormal coupling efficiency between respiration and oxidative phosphorylation (ADP/O ratio) is due to maintenance of high H(+)-leakage values in the inner mitochondrial membrane. Postnatal reduction of the H+ leak occurs concomitantly with an increase in intra-mitochondrial adenine nucleotide concentration. Accumulation of adenine nucleotides in preterm and term liver mitochondria parallels the postnatal increase in total liver adenine nucleotides. Delayed postnatal induction of adenine biosynthesis most likely accounts for the lower adenine nucleotide pool in the liver of preterm neonates. The delayed postnatal accumulation of adenine nucleotides in mitochondria is thus responsible for the impairment in oxidative phosphorylation displayed by organelles of the preterm liver.

Emergency embolectomy of middle cerebral artery occlusion due to microcoil migration: case report

We report a successful emergency embolectomy in a patient presenting a left middle cerebral artery occlusion by an embolizing microcoil that was being used to thrombose an aneurysm of the ophthalmic artery. In selected cases, emergency embolectomy can be considered as the treatment of distal embolization by the materials used in neuroendovascular procedures.

Isolated headache as the presenting clinical manifestation of intracranial tumors: a prospective study

We prospectively studied over two years the incidence of headache as the initial and isolated clinical manifestation of adult patients suffering from intracranial tumors (n = 183). Fifteen patients (8%) exhibited headache as their first and isolated clinical manifestation. Age, sex, neoplasm localization, or pathological diagnosis did not correlate with the presence of headache. Posterior fossa location and hydrocephalus, though not reaching statistical significance, were more frequent in patients who presented with headache as the first symptom. At the moment of diagnosis, 59 (31%) of the patients admitted to headache, though only 1 out of the 15 patients starting as headache still had this symptom as the only manifestation. From our experience in adults, isolated headache for longer than 10 weeks will only exceptionally be secondary to an intracranial neoplasm.

Cervical schwannoma presenting as a spinal subdural haematoma

We report a case of cervical spinal subdural haematoma as the presenting manifestation of a small intradural schwannoma. In patients without a bleeding diathesis and an apparently spontaneous spinal subdural haematoma, the possibility of an underlying tumour should always be considered.

Evidence of post-transcriptional regulation in mammalian mitochondrial biogenesis

We have previously shown that the nuclear-encoded gene's expression of mitochondrial beta-subunit of the F1-ATPase complex in rat liver is regulated at the translational level (Luis, A.M., Izquierdo, J.M., Ostronoff, L.K., Santarén, J., Salinas, M., and Cuezva, J.M. (1993) J. Biol. Chem. 268, 1868-1875). In this paper we report that the different steady-state levels of ATP synthase beta subunit mRNA detected in rat tissues are not paralleled by a proportional content of immunodetectable beta-F1-ATPase protein. The results suggest that tissue-specific transcriptional and post-transcriptional mechanisms contribute to differential mitochondrial biogenesis in mammalian cells. On the other hand, steady-state mRNA levels of the mitochondrial encoded ATP synthase subunits (ATP 6+8) indicate that nuclear and mitochondrial-encoded transcripts for this complex are in close relation, that is, the expression of both nuclear and mitochondrial genes is coordinated in all tissues examined.

Timing of p53 mutations during astrocytoma tumorigenesis

Using a combination of polymerase chain reaction and single-strand conformation polymorphism techniques (PCR-SSCP) we have analyzed 78 brain tumor samples (70 primary and 8 metastatic) for the presence of mutations in the conserved regions of the Tp53 (tumor p53) gene. We have found that only two groups, gliomas (exclusively in astrocytomas) and metastases, displayed Tp53 mutations. Three of eight (37.5%) metastases showed a mutant Tp53 allele accompanied by loss of the normal one. In contrast, the frequency of Tp53 mutations in the primary brain tumors examined was lower (5.7%). Although we have examined different types of primary brain tumors, Tp53 mutations were exclusively observed in both, low and high-grade astrocytomas (four of 24). The Tp53 mutations detected in astrocytic tumors appear to be correlated with the malignancy grade. The low-grade astrocytomas were heterozygous for the mutation, whereas the high-grade astrocytomas had affected the two Tp53 alleles, suggesting a two-steps model for inactivation of the p53 gene in astrocytomas. Thus, single p53 mutation seems to occur in initial stages of astrocytoma tumorigenesis; the later lost of the remaining wild-type allele appears associated with the progression towards a more malignant stage.

Thyroid hormones promote transcriptional activation of the nuclear gene coding for mitochondrial beta-F1-ATPase in rat liver

Thyroid hormones acutely regulate gene expression of the beta-catalytic subunit of the mitochondrial F1-ATPase complex in the liver of hypothyroid rat neonates at either a transcriptional and/or post-transcriptional level [(1990) J. Biol. Chem. 265, 9090-9097]. Administration at birth of various thyroid hormone doses to hypothyroid newborn rats promote a rapid (1 h) increase in liver steady-state amounts of both beta-F1-ATPase protein and mRNA. Induction of the beta-F1-ATPase mRNA is coincident with an elevation in gene transcription detected using nascent RNA chains synthesized by isolated nuclei. These results suggest that thyroid hormones induction of postnatal mitochondrial differentiation in the liver of hypothyroid rat neonates is mostly triggered by transcriptional regulation of beta-F1-ATPase gene.

Translational regulation of mitochondrial differentiation in neonatal rat liver. Specific increase in the translational efficiency of the nuclear-encoded mitochondrial beta-F1-ATPase mRNA

Postnatal (1-h) mitochondrial differentiation in normal neonatal rat liver is regulated at the translational level (Izquierdo, J. M., Luis, A. M., and Cuezva, J. M. (1990) J. Biol. Chem. 265, 9090-9097). The rapid postnatal increase in liver global rate of protein synthesis preferentially affects mitochondrial proteins (Valcarce, C., Navarrete, R. M., Encabo, P., Loeches, E., Satrústegui, J., and Cuezva, J. M. (1988) J. Biol. Chem. 263, 7767-7775). Analysis of polysome profiles and determination of both eukaryotic initiation factor 2 (eIF-2) activity and amount of eIF-2 beta protein in the liver of fetal and 1-h-old neonatal rats, indicate a rapid activation of translation initiation without changes in the amount of the translational machinery available between both stages of liver development. Appearance of a more acidic eIF-2 beta-subunit form in two-dimensional Western blots from 1-h-old rat livers suggests that covalently regulated modifications of the initiation factor phosphoproteins might be responsible for increased translation in the neonatal liver. On the other hand, preferential cytosolic translation of the mitochondrial nuclear-encoded beta-F1-ATPase mRNA at this stage of liver development is accomplished by (i) the antenatal accumulation of this mRNA in the fetal liver in 5-6-fold excess than that found in adults, although fetal liver beta-F1-ATPase mRNA shows negligible translational efficiency when compared to the adult counterpart; (ii) a 2-fold increase of the stored beta-F1-ATPase mRNA being rapidly mobilized into cytosolic polyribosomes, and (iii) a 3-fold increase in the in vitro determined translational efficiency of beta-F1-ATPase mRNA. Increased translational efficiency of beta-F1-ATPase mRNA at 1-h postnatal is specific for the nuclear-encoded template since beta-tubulin mRNA did not show any postnatal alteration in its translational efficiency. The results presented suggest that developmental changes in the poly(A)+ RNA fraction or in the reporter template itself are responsible for the increased and preferential translation of the nuclear-encoded mitochondrial mRNAs needed for mitochondrial differentiation and, thus, for mammalian adaptation to the extrauterine environment.

[Evaluation of the degree of compliance in arterial hypertension protocol]

We report an evaluation of the hypertension protocol. Its aims were to assess the degree of compliance with its variables, the number, age and sex of hypertensives, and the rate in whom blood pressure levels were controlled in the patients included and not included in the protocol. The study was carried out in the Basauri Teaching Unit from January 1987 to June 1989. We reviewed all the parameters of the medical and nursing protocol of 1,429 patients diagnosed as hypertensive and the mean value of the three last blood pressure readings. A total of 67.2% of patients were included in the protocol. The compliance was higher than 80% in most of its items; 61.8% of the prescribed nursing controls were carried out. Blood pressure was less than or equal to 159/94 in 68.1% of patients. This rate was higher in the patients included in the protocol. The protocol was useful for the control of hypertension, although it should be modified directing it to primary care.

Immunological detection of the mitochondrial F1-ATPase alpha subunit in the matrix of rat liver peroxisomes. A protein involved in organelle biogenesis?

Rat liver peroxisomes contain in their matrix the alpha-subunit of the mitochondrial F1-ATPase complex. The identification of this protein in liver peroxisomes has been achieved by immunoelectron microscopy and subcellular fractionation. No beta-subunit of the mitochondrial F1-ATPase complex was detected in the peroxisomal fractions obtained in sucrose gradients or in Nycodenz pelletted peroxisomes. The consensus peroxisomal targeting sequence (Ala-Lys-Leu) is found at the carboxy terminus of the mature alpha-subunit from bovine heart and rat liver mitochondria. Due to the dual subcellular localization of the alpha-subunit and to the structural homologies that exist between this protein and molecular chaperones [(1990) Biol. Chem. 265, 7713-7716] it is suggested that the protein should perform another functional role(s) in both organelles, plus to its characteristic involvement in the regulation of mitochondrial ATPase activity.

A programme of neurosurgical education

We present a programme of Neurosurgery concerning pre- and post-graduate education. Objectives are divided into general objectives, intermediate and specific. We suggest also a syllabus for students and another for residents, containing a list of theoretical lectures, seminars and guidelines for practical tuition. Schedule of training period, services requirements and facilities for didactic purposes are mentioned. In this respect we follow the recent recommendations of the E.A.N.S. We emphasize the need for personal teaching as the only element of general guidance for the programme. We also emphasize the necessity of criticism, change and evolution, in order to perfect the programme we are offering.

Postnatal mitochondrial differentiation in rat liver. Regulation by thyroid hormones of the beta-subunit of the mitochondrial F1-ATPase complex

Postnatal development of rat liver mitochondrial functions, i.e. differentiation of pre-existing mitochondria, is a key regulatory process that is accomplished during the first postnatal hour (Valcarce, C., Navarrete, R. M., Encabo, P., Loeches, E., Satrústegui, J., and Cuezva, J. M. (1988) J. Biol. Chem. 263, 7767-7775). The general mechanism that appears to control this process is the rapid (2-fold) increase in inner mitochondrial membrane proteins, as a result of a rapid increase in the rates of protein synthesis for mitochondrial proteins. Fetal hypothyroidism induced by administration of methimazole to pregnant rats resulted in half the ATPase activity and amount of beta-F1-ATPase protein in liver homogenates compared with normal fetuses. Furthermore, hypothyroid neonates showed no postnatal increase in the amount of mitochondrial beta subunit of the F1-ATPase complex. Administration of thyroid hormones to hypothyroid neonates at birth promoted a 2-fold increase in liver ATPase activity and in the amount of beta-F1-ATPase protein both in liver homogenates and in isolated mitochondria. The rapid increase in beta-F1-ATPase protein observed in thyroid hormone-treated hypothyroid neonates was paralleled by a 2-fold increase in the relative rates of beta-F1-ATPase synthesis and by a 2-fold increase in the relative amount of hepatic beta-F1-ATPase mRNA. The results show that the basal expression of the beta-F1-ATPase gene is regulated by thyroid hormones at either a transcriptional and/or post-transcriptional level. Thus, these results show the requirement of thyroid hormones for proliferation and differentiation of mitochondria in the fetal and neonatal liver, respectively. On the other hand, the fact that liver mRNA level of beta-F1-ATPase protein does not change between 0 and 1 postnatal h in the normal neonatal liver indicates that postnatal mitochondrial differentiation is regulated at a translational level.

Recurrent meningitis and transethmoidal intranasal meningoencephalocele

A three-year-old girl with hypertelorism suffered seven episodes of meningitis. X-ray, CT scan and gamma-cisternography revealed a meningoencephalocele at the base of the skull. At operation, a 'hole' of about 25mm was clearly visible in the midline, just behind the lamina cribrosa; through this a piece of brain tissue protruded towards the nasal cavities. The herniated brain-tissue was removed and the gap was closed. Meningitis did not recur.