Recombination in heterozygote inversion carriers.
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Chromosome Inversion↗
Biomedical subjects
F Vidal
Publications and source records attributed to F Vidal.
Giardia lamblia: the effects of extracts and fractions from Mentha x piperita Lin. (Lamiaceae) on trophozoites.
Giardia lamblia is a parasite that causes giardiasis in humans and other mammals. The common treatment includes different classes of drugs, which were described to produce unpleasant side effects. Mentha x piperita, popularly known as peppermint, is a plant that is frequently used in the popular medicine to treat gastrointestinal symptoms. We examined the effects of crude extracts and fractions from peppermint against G. lamblia (ATCC 30888) on the basis of trophozoite growth, morphology and adherence studies. The methanolic, dichloromethane and hexanic extracts presented IC(50) values of 0.8, 2.5 and 9.0microg/ml after 48h of incubation, respectively. The aqueous extract showed no effect against the trophozoites with an IC(50)>100microg/ml. The aqueous fraction presented a moderate activity with an IC(50) of 45.5microg/ml. The dichloromethane fraction showed the best antigiardial activity, with an IC(50) of 0.75microg/ml after 48h of incubation. The morphological and adhesion assays showed that this fraction caused several alterations on plasma membrane surface of the parasite and inhibited the adhesion of G. lamblia trophozoites. Cytotoxic assays showed that Mentha x piperita presented no toxic effects on the intestinal cell line IEC-6. Our results demonstrated antigiardial activity of Mentha x piperita, indicating its potential value as therapeutic agent against G. lamblia infections.
Animals↗
New p53 related genes in human tumors: significant downregulation in colon and lung carcinomas.
Human epithelial tumors need to accumulate multiple genetic alterations to form invasive carcinomas. These genetic alterations are related with growth factor receptors, cell signalling, the cell cycle and cell invasiveness. Importantly, cells need to avoid senescence and become immortalized for this process. Recently, five genes: RPS6KA6, HDAC4, KIAA0828, TCP1 and Tip60, which modulate p53-dependent function and avoid senescence were identified in a large-scale RNA interference screen. Twenty colon, 20 prostate and 20 lung carcinomas were studied to investigate whether these genes might be related with human tumors. RNA was extracted from both normal and tumor tissue from each patient. Real-time RT-PCR was performed using TaqMan probes corresponding to the RPS6KA6, HDAC4, KIAA0828, TCP1, Tip60 and p53 genes. In colon carcinomas, the RPS6KA6, HDAC4, KIAA0828 and Tip60 genes were downregulated in tumor tissue as compared with normal tissue (P < 0.001 for all genes). In lung carcinomas, HDAC4, KIAA0820 and Tip60 were downregulated (P < 0.01, P < 0.001 and P < 0.001 respectively). Whereas no significant differences were observed in prostate carcinomas, striking downregulation of the RPS6KA6 and KIAA0828 genes was observed in colon carcinomas and KIAA0828 in a subset of lung carcinomas. mRNA expression of these genes may control p53 function as well as the ras-MAPK pathway, methylation and transcriptional cellular programs. These results could unravel a novel set of regulatory suppressor genes involved in human colon and lung tumors.
Chaperonin Containing TCP-1↗
Susceptibility of Giardia lamblia to Hovenia dulcis extracts.
Giardia lamblia is the causative agent of giardiasis, a common parasitic infection of the human and animal digestive tract. Although several drugs have been available to treat this infection, they present unpleasant side effects or cytotoxicity. In order to find a more natural treatment for the disease, we analyzed the effects of the methanolic extract and three fractions obtained from Hovenia dulcis Thunb. (Rhamnaceae) leaves on G. lamblia. Comparing all fractions, dichloromethane was more efficient in reducing Giardia growth. The exposition of G. lamblia to this fraction lead to degenerations in the surface, modifications in the cell shape and alterations in the localization of nuclei. Besides that, the adhesion of G. lamblia was also altered. Experiments revealed that the obtained fraction did not present cytotoxic effects in mammalian cells. In summary, dichloromethane fraction has strong antigiardial effects and could become an important new substance for the treatment of giardiasis.
Animals↗
[Exploration of traumatic brain-injury attention difficulty by event-related potentials].
OBJECTIVE: To specify, in cognitive processing leading to an action, the localization of difficulties in attention following severe, traumatic brain injury. METHOD: Stimulus-locked and response-locked event-related potentials were recorded during a Stroop task in 25 patients with traumatic brain injury and 25 control subjects approximately 4 months after the accident. The latency and amplitude of the waves were compared between the two groups and correlated with clinical data. RESULTS: The reaction times of brain-injured patients were significantly longer than those of the control group, but neither the number of errors nor the interference differed between the groups. Electrophysiological recordings showed early abnormalities between 100 and 200 ms after stimulus onset. The key area could be the medial occipitotemporal side connected with frontal regions. Recordings also showed disruptions in motor program monitoring, which implied frontomedial areas. CONCLUSION: This protocol allows for precisely dating cognitive abnormalities. Future studies should relate cognitive with neuropsychological abnormalities and examine the possibilities of later regression.
Adult↗
Spatial enhancement of EEG traces by surface Laplacian estimation: comparison between local and global methods.
OBJECTIVE: Surface Laplacian estimation enhances EEG spatial resolution. In this paper, we compare, on empirical grounds, two computationally different estimations of the surface Laplacian. METHODS: Surface Laplacian was estimated from the same monopolar data set with both Hjorth's method [local; Electroenceph Clin Neurophysiol 39 (1975) 526] as modified by MacKay [Electroenceph Clin Neurophysiol 56 (1983) 696] and with spherical spline interpolation [global; Electroenceph Clin Neurophysiol 72 (1989) 184]. RESULTS: The grand averages computed with the two methods proved to be very similar but differed markedly from the monopolar ones. The two different computations were highly correlated, presented low relative errors and allowed to evidence comparable experimental effects. CONCLUSIONS: These results suggest that Hjorth's method and spherical spline interpolation convey similar topographic and chronometric informations. SIGNIFICANCE: We provide empirical evidence that local and global methods of surface Laplacian estimation are equivalent to improve the spatial resolution of EEG traces. Global methods allow to explore the scalp topography and local methods allow to spare time in electrode setting that can be useful for studies on special populations (i.e. children, aged subjects) and for clinical purposes.
Artifacts↗
Tumour necrosis factor alpha in fat redistribution syndromes associated with combination antiretroviral therapy in HIV-1-infected patients: potential role in subcutaneous adipocyte apoptosis.
BACKGROUND: The pathogenesis of fat redistribution syndromes (FRS) observed in the setting of highly active antiretroviral therapy (HAART) for the treatment of HIV-1-infection remains elusive. A dysregulation of the tumour necrosis factor alpha (TNF-alpha) system occurs in HIV-infected patients with FRS. MATERIALS AND METHODS: The study looked at both the in vivo and in vitro relationship between TNF-alpha and the degree of subcutaneous adipocyte apoptosis in 60 HIV-1-infected patients on HAART with FRS, another 60 HIV-1-infected patients on HAART without FRS and 60 uninfected control patients. Apoptosis was assessed by the terminal deoxynucleotidyl transferase dUTP (deoxyuridine 5'-triphosphate)-digoxigenin Nick End Labelling (TUNEL) method. Soluble receptors of TNF-alpha were determined by the sandwich enzyme immunoassay technique. The in vitro viability was assessed by staining with 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and apoptosis by TUNEL. RESULTS: HIV-1-infected patients with FRS had significantly higher degrees of subcutaneous adipocyte apoptosis than those without FRS (P = 0.0001) and uninfected controls (P < 0.0001). There was a statistically significant association between serum levels of soluble TNF-alpha receptors #1 and #2 and the degree of subcutaneous adipocyte apoptosis in patients with and without FRS (P < 0.0001 for both receptors). In vitro, the addition of TNF-alpha (10 ng mL(-1)) to an adipocyte culture embedded with indinavir, either alone or in clinically relevant combinations with stavudine (d4T) and lamivudine (3TC), significantly decreased adipocyte viability (P = 0.0001) and increased adipocyte apoptosis (P < 0.0001) with respect to that observed with the addition of antiretrovirals alone. CONCLUSIONS: TNF-alpha plays a significant role in subcutaneous adipocyte apoptosis, which occurs in the setting of FRS in HIV-1-infected patients on highly active antiretroviral therapy.
3T3 Cells↗
Clinical characterization of breakthrough bacteraemia: a survey of 392 episodes.
BACKGROUND: Few data are available on the clinical features of patients who develop breakthrough bacteraemia, understood as positive blood cultures despite appropriate antibiotic therapy. OBJECTIVES: To determine the clinical significance and outcome of a large series of breakthrough bacteraemia. DESIGN: Retrospective analysis of a prospectively collected database. SETTING: Two university-affiliated hospitals in Catalonia, Spain. SUBJECTS: A total of 392 individuals who suffered an episode of breakthrough bacteraemia recorded between 1997 and 2002. INTERVENTIONS: Demographic characteristics, underlying diseases, origin of infection, sources of infection, microorganisms isolated, McCabe and Jackson prognostic criteria, and mortality were analysed. RESULTS: Breakthrough bacteraemia was detected in 392 of 6324 (6.1%) episodes of bacteraemia. Eighty per cent of episodes were nosocomial. The most frequent source of infection in breakthrough bacteraemia was endovascular (70%). Coagulase-negative staphylococci, Staphylococcus aureus, and Pseudomonas aeruginosa were the most significant microorganisms involved. Nosocomial acquisition together with selected sources (central venous catheter, endocarditis and other endovascular foci), underlying conditions (neutropenia, polytraumatism, allogenic bone marrow and kidney transplantation), and particular microbial aetiologies (S. aureus, P. aeruginosa and polymicrobial) were independently associated with increased risk for developing breakthrough bacteraemia. Crude mortality rate was greater in patients with breakthrough bacteraemia (16% vs. 12.3%; P<0.05), and this condition was an independent predictor of death (OR 1.4, 95% CI, 1-1.9; P=0.04). CONCLUSIONS: In view of a case of breakthrough bacteraemia it is mandatory to search for an endovascular focus. Empiric treatment should be directed to cover S. aureus, coagulase-negative staphylococci and nonfermentative Gram-negative bacilli. Breakthrough bacteraemia is an independent predictor of death.
Anti-Bacterial Agents↗
Rapid single-step detection of the inversion hotspot of mutation in hemophilia A by real-time PCR.
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Chromosome Inversion↗
Sperm studies in heterozygote inversion carriers: a review.
The risk of producing unbalanced gametes in heterozygous inversion carriers mostly depends on the occurrence of recombination events within the inverted segment. Recombination determines the possibility of producing chromosomes with duplications/deficiencies (pericentric inversions) or with duplications/deficiencies which furthermore appear as dicentric and acentric fragments (paracentric inversions). In this work, a general description of the close relationship between the occurrence of crossovers in pericentric and paracentric inversions and the final segregation outcome is presented. After this introduction, a compilation of inversion segregation data and interchromosomal effect results from previously published sperm studies have been reviewed. Segregation results indicate a great heterogeneity in the percentage of unbalanced gametes, from 0 to 37.38%. The size of the inverted segments and their proportion in the chromosome are two parameters closely related with the incidence of recombination (P < 0.0001; using a quadratic model and Pearson's correlation test). These results suggest that the production of a significant level of unbalanced gametes would require a minimum inversion size of 100 Mbp and the inversion of at least 50% of the chromosome. Interchromosomal effects are seldom observed in chromosomal inversions. Finally, implications of the meiotic behavior of the inversions in the progeny of the carriers and the incorporation of sperm FISH segregation analysis for reproductive genetic counseling are discussed.
Chromosome Inversion↗
Meiotic abnormalities in infertile males.
Meiotic anomalies, as reviewed here, are synaptic chromosome abnormalities, limited to germ cells that cannot be detected through the study of the karyotype. Although the importance of synaptic errors has been underestimated for many years, their presence is related to many cases of human male infertility. Synaptic anomalies can be studied by immunostaining of synaptonemal complexes (SCs), but in this case their frequency is probably underestimated due to the phenomenon of synaptic adjustment. They can also be studied in classic meiotic preparations, which, from a clinical point of view, is still the best approach, especially if multiplex fluorescence in situ hybridization is at hand to solve difficult cases. Sperm chromosome FISH studies also provide indirect evidence of their presence. Synaptic anomalies can affect the rate of recombination of all bivalents, produce achiasmate small univalents, partially achiasmate medium-sized or large bivalents, or affect all bivalents in the cell. The frequency is variable, interindividually and intraindividually. The baseline incidence of synaptic anomalies is 6-8%, which may be increased to 17.6% in males with a severe oligozoospermia, and to 27% in normozoospermic males with one or more previous IVF failures. The clinical consequences are the production of abnormal spermatozoa that will produce a higher number of chromosomally abnormal embryos. The indications for a meiotic study in testicular biopsy are provided.
Chromosome Aberrations↗
[Tuberculous chylothorax: case report and review of the literature].
Chylothorax is an unusual manifestation of tuberculous disease. Anecdotal cases of chylothorax due to Mycobacterium tuberculosis have been reported in the literature. We describe a case of tuberculous chylothorax and review the previously published cases. None of these cases was diagnosed by the application of polymerase chain reaction in pleural effusion. This test applied to different specimens has shown high specificity and sensitivity; for this reason, the routine use of this test, on pleural effusion, could be very useful, quick, and few aggressive in the diagnosis of tuberculous chylothorax, especially when chest X-ray is normal.
Adult↗
Sperm FISH studies in seven male carriers of Robertsonian translocation t(13;14)(q10;q10).
BACKGROUND: Robertsonian translocation t(13;14) is one of the most common structural reorganization in humans, but meiotic segregation studies in these carriers are still limited. The segregation pattern of the chromosomes involved, the possible influence of the translocated chromosomes on the synapsis and disjunction of other chromosome pairs [interchromosomal effects (ICE)] and the rates of unbalanced spermatozoa produced still deserve attention, not only to obtain a better characterization of the meiotic behaviour of this reorganization, but also to offer carrier couples accurate genetic counselling. METHODS: Multicolour fluorescence in-situ hybridization was used to analyse the segregation of chromosomes 13 and 14 and the possible occurrence of ICE (on chromosomes 18, 21, 22, X and Y) in seven male carriers of a t(13;14)(q10;q10). RESULTS AND CONCLUSIONS: The individuals analysed showed a homogeneous segregation pattern, with a clear predominance of alternate segregations resulting in the production of normal/balanced spermatozoa (83-88.23%). A significant increase in the disomy rates for the sex chromosomes, which could be considered as a positive ICE, was observed in two of the carriers analysed.
Adult↗
Distribution of prepubertal and adult goat oocyte cortical granules during meiotic maturation and fertilisation: ultrastructural and cytochemical study.
The aim of this study was evaluate cortical granule (CG) distribution during in vitro maturation (IVM) and fertilisation of prepubertal goat oocytes compared to CG distribution of ovulated and in vitro fertilised oocytes from adult goats. Oocytes from prepubertal goats were recovered from a slaughterhouse and were matured in M199 with hormones and serum for 27 hr. Ovulated oocytes were collected from gonadotrophin treated Murciana goats. Frozen-thawed spermatozoa were selected by centrifugation in percoll gradient and were capacitated in DMH with 20% steer serum for 1 hr. Ovulated and IVM-oocytes were inseminated in DMH medium with steer serum and calcium lactate for 20 hr. Oocytes and presumptive zygotes were stained with FITC-LCA (Lens culinaris agglutinin labelled with fluorescein isothiocyanate) and observed under a confocal laser scanning microscope. Ultrastructure morphology of oocytes and presumptive zygotes were analysed by transmission electron microscopy (TEM). Prepubertal goat oocytes at germinal vesicle stage show a homogeneous CG distribution in the cytoplasm. IVM-oocytes at Metaphase II (MII) and ovulated oocytes presented CGs located in the cortex with the formation of a monolayer beneath to the plasma membrane. At 20 hr postinsemination (hpi), zygotes from IVM-oocytes showed a complete CG exocytosis whereas zygotes from ovulated oocytes presented aggregates of CGs located at the cortical region. Images by TEM detected that CGs were more electrodense and compacts in oocytes from prepubertal than from adult goats.
Animals↗
[Auditive and somato-sensory event-related potentials in comas: prognostic value for awakening, social and professional reinstatement].
OBJECTIVE: To appreciate prognostical value of event-related potentials in comatose states and the influence of the stimulation's modality. PATIENTS AND METHODS: Thirty-five patients were recorded with the auditory modality whose thirteen were also recorded with the somesthetic modality. They were free of sedation except for five. For 21 patients out of coma, it was possible to get information about their social readaptation 14 months later. RESULTS: When present, cognitive components predict awakening in 100 % of the cases, but only 50 % of the patients who awake had these components. The somesthetic modality seemed to enlarge their detection, but did not improve short-term forecasts. We could not confirm their absence could hamper social reinstatement. CONCLUSION: Event-related potentials are strengthened as having excellent positive prognostic value. Further studies should clarify the interest of the somesthetic modality, and the possibility to get remote prognostic.
Adolescent↗
Response selection and motor areas: a behavioural and electrophysiological study.
OBJECTIVE: The involvement of the supplementary motor areas (SMAs) and primary motor areas (M1s) in motor processes was studied. METHODS: A between-hand choice and a simple reaction time (RT) task were mixed in a precueing paradigm. Laplacians were estimated by the source derivation method from the electroencephalogram recorded over the SMAs and M1s. RESULTS: RT was shorter in the simple than in the choice RT task. Response-locked averages showed a negative potential over M1 contralateral to the response and a positive wave over M1 ipsilateral. This ipsilateral positivity was much smaller in the simple than in the choice RT task, whereas the contralateral negativity was not different. A negativity preceding the activations of the M1s developed over the SMAs. This negativity was larger in the choice than in the simple RT task. CONCLUSIONS: In light of previous results, the present data confirm that, in between-hand choice tasks, response execution is implemented by an activation of the contralateral M1 and by an inhibition of the ipsilateral M1. SMAs and contralateral M1 appear hierarchically organized, the SMAs being more involved in response preparation and M1s in response execution. The task-dependent inhibition of ipsilateral M1 could reflect an active suppression of the erroneous response in the choice task. SIGNIFICANCE: The task context in which one movement is executed can affect the pattern of activities recorded over cortical motor structures. Cognitive context is of importance for understanding the nature of the motor command.
Adult↗
Response monitoring without sensory feedback.
OBJECTIVE: The elicitation of an evoked potential, the 'error negativity' (Ne) when subjects commit errors in speeded tasks, is often taken as an index of response monitoring processes. The presence of a Ne-like wave on purely correct trials challenges the current conceptions about the nature of such a monitoring system. Here, we evaluate the possibility that the Ne-like wave on correct trials is merely due to reafferences, and at the same time, we test directly the general opinion according to which the Ne is generated by an internal signal. METHODS: We studied the presence of a Ne-like wave in a completely deafferented patient. The patient performed two reaction time (RT) tasks: a two-responses RT task and a go/no-go task. RESULTS: In this patient, a Ne occurs on errors, on incorrect EMG activations, and on purely correct responses. On errors, the Ne was clearly followed by an error positivity (Pe). CONCLUSIONS: The Ne and the Ne-like wave are not generated by reafferences. This similarity is a further argument to consider that these two waves are of same nature. SIGNIFICANCE: The present data demonstrate that sensory information is not mandatory for the brain to monitor and correct ongoing responses.
Afferent Pathways↗
[Hepatitis G virus and labile blood products: role of transfusional transmission].
The GBV-C/HGV (HGV) virus was discovered a few years ago. This virus is known to be parenterally as well as sexually transmitted. However, no study has found some pathogenic roles for HGV so far. In the present study, we aimed to investigate the transmission of HGV by blood components transfused to 284 patients hospitalized in surgery unit in 1995. We tested two parameters of infection in blood components transfused to infected recipients: viral RNA by PCR and anti-E2 antibodies by ELISA. We tried to suspect some potent hepatocyte impacts by assessing the levels of two enzymes in serums: alanine aminotransferase (ALT) and alpha-glutathion S-transferase (alpha-GST). We found that HGV-RNA was detectable in 3.6% of recipients prior to transfusion and 7.5% post-transfusion. For each infected recipient, we retrospectively did a search for HGV-RNA in each transfused blood component, and we found at least one blood component as HGV-RNA-positive for each transfusional infected recipient. Anti-E2 antibody prevalence standing for a former and cured infection was 39.6% in all the recipients. In viremic recipients, ALT levels were mostly normal, while alpha-GST levels were found more commonly elevated than in non-viremic recipients although non-significantly (20% vs. 6.3%; P = 0.07). The present study underlines that HGV transmission is mostly transfusional in surgery units, and that infectiosity of blood components can be anticipated by detection of the viral RNA by PCR. Furthermore, the possible relationship between the serum activity of alpha-GST and the hepatotropism of HGV, although non-admitted as pathogenic, should be investigated.
Aged↗