Feasibility of an endoscopic secretin test: preliminary results.
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Bicarbonates↗
Biomedical subjects
A Ruiz
Publications and source records attributed to A Ruiz.
How malleable is the eukaryotic genome? Extreme rate of chromosomal rearrangement in the genus Drosophila.
During the evolution of the genus Drosophila, the molecular organization of the major chromosomal elements has been repeatedly rearranged via the fixation of paracentric inversions. Little detailed information is available, however, on the extent and effect of these changes at the molecular level. In principle, a full description of the rate and pattern of change could reveal the limits, if any, to which the eukaryotic genome can accommodate reorganizations. We have constructed a high-density physical map of the largest chromosomal element in Drosophila repleta (chromosome 2) and compared the order and distances between the markers with those on the homologous chromosomal element (3R) in Drosophila melanogaster. The two species belong to different subgenera (Drosophila and Sophophora, respectively), which diverged 40-62 million years (Myr) ago and represent, thus, the farthest lineages within the Drosophila genus. The comparison reveals extensive reshuffling of gene order from centromere to telomere. Using a maximum likelihood method, we estimate that 114 +/- 14 paracentric inversions have been fixed in this chromosomal element since the divergence of the two species, that is, 0.9-1.4 inversions fixed per Myr. Comparison with available rates of chromosomal evolution, taking into account genome size, indicates that the Drosophila genome shows the highest rate found so far in any eukaryote. Twenty-one small segments (23-599 kb) comprising at least two independent (nonoverlapping) markers appear to be conserved between D. melanogaster and D. repleta. These results are consistent with the random breakage model and do not provide significant evidence of functional constraint of any kind. They support the notion that the Drosophila genome is extraordinarily malleable and has a modular organization. The high rate of chromosomal change also suggests a very limited transferability of the positional information from the Drosophila genome to other insects.
Animals↗
Molecular characterization of two natural hotspots in the Drosophila buzzatii genome induced by transposon insertions.
Transposable elements (TEs) have been implicated in the generation of genetic rearrangements, but their potential to mediate changes in the organization and architecture of host genomes could be even greater than previously thought. Here, we describe the naturally occurring structural and nucleotide variation around two TE insertions in the genome of Drosophila buzzatii. The studied regions correspond to the breakpoints of a widespread chromosomal inversion generated by ectopic recombination between oppositely oriented copies of a TE named Galileo. A detailed molecular analysis by Southern hybridization, PCR amplification, and DNA sequencing of 7.1 kb surrounding the inversion breakpoints in 39 D. buzzatii lines revealed an unprecedented degree of restructuring, consisting of 22 insertions of ten previously undescribed TEs, 13 deletions, 1 duplication, and 1 small inversion. All of these alterations occurred exclusively in inverted chromosomes and appear to have accumulated after the insertion of the Galileo elements, within or close to them. The nucleotide variation at the studied regions is six times lower in inverted than in noninverted chromosomes, suggesting that most of the observed changes originated in only 84,000 years. Galileo elements thus seemed to promote the transformation of these, otherwise normal, chromosomal regions in genetically unstable hotspots and highly efficient traps for transposon insertions. The particular features of two new Galileo copies found indicate that this TE belongs to the Foldback family. Together, our results strengthen the importance of TEs, and especially DNA transposons, as inducers of genome plasticity in evolution.
Animals↗
Outer membrane proteins and DNA profiles in strains of Haemophilus parasuis recovered from systemic and respiratory sites.
Polyserositis caused by Haemophilus parasuis is an important disease that affects mostly weaned pigs. Recent studies have shown that virulence can differ among strains recovered from distinct body sites and also that it may be related to the presence of certain outer membrane proteins (OMPs). The objective of this study was to compare the OMP and DNA profiles of H. parasuis strains isolated from systemic and respiratory sites from diseased and healthy pigs. Strains evaluated in this study were processed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and repetitive-PCR techniques. Two experiments were conducted in order to better define the relationship among genotype, phenotype, and site of isolation. Experiment 1 included 53 H. parasuis isolates recovered from healthy and diseased pigs from unrelated herds. Experiment 2 included 31 isolates of H. parasuis obtained from diseased pigs involved in an outbreak in a large, multifarm system. Results showed that strains recovered from systemic sites had more homogeneous OMP and DNA profiles than those isolated from respiratory sites. Evaluation of isolates involved in the multifarm outbreak showed that only two H. parasuis strains were causing disease. These strains had homogeneous OMP and DNA profiles. However, it was noted that these two parameters were unrelated, since strains classified in the same genotype group expressed different OMP profiles. The homogeneity of OMP and DNA profiles of strains isolated from systemic sites strongly suggests the existence of clonal relationships between virulent strains and also suggests that expression of certain OMP profiles may be related to virulence.
Animals↗
Genomic organization and mutation analysis of the gene encoding lecithin retinol acyltransferase in human retinal pigment epithelium.
PURPOSE: To determine the structure of the human lecithin retinol acyltransferase (LRAT) gene, map its chromosomal localization, and screen for mutations in humans with various hereditary retinal degenerations. METHODS: Using DNA probes specific for LRAT, a bacterial artificial chromosome (BAC) clone containing the LRAT gene was isolated, subcloned into DNA fragments and relevant subclones characterized by sequencing. Exon-intron junctions were determined by comparison with the cDNA sequence previously published. Southern blot analysis was performed on human genomic DNA samples digested with several restriction enzymes. Fluorescence in situ hybridization (FISH) analysis of normal metaphase chromosomes derived from phytohemagglutinin (PHA) stimulated peripheral blood lymphocytes and radiation hybrid mapping were used for localization of the LRAT gene. Single-strand conformation polymorphism analysis (SSCP) was used to screen for potential mutations in patients with age-related macular degeneration, Leber congenital amaurosis, retinitis pigmentosa, and cone-rod dystrophy. RESULTS: The human LRAT gene is organized into three exons of 219, 541, and 2058 bp and two introns of 103 and 4117 bp. Southern blot analysis of digested genomic DNA revealed a single band, suggesting a single copy of the LRAT gene. The human LRAT gene was localized to chromosome 4q31.2, a locus having no previous association with human eye disease. Additionally, the bovine LRAT homologue sequence was deduced and a general LRAT protein topology is suggested. No polymorphisms that segregated with retinal disease phenotypes were identified in 374 unrelated probands. CONCLUSIONS: The organization of the LRAT gene, based on cDNA clones derived from the retinal pigment epithelium (RPE) has been determined. Its structure is less complex than other acyltransferases such as lecithin cholesterol acyltransferase (LCAT) and acyl CoA acyltransferase (ACAT). The absence of polymorphisms in the probands examined suggests a very low mutation level in the LRAT gene from the diseases analyzed.
Acyltransferases↗
Detection of nucleotide c985 A-->G mutation of medium-chain acyl-CoA dehydrogenase gene by real-time PCR.
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Acyl-CoA Dehydrogenase↗
[Clinical and psychometric diagnosis of depression in patients in general medicine].
BACKGROUND: The Hamilton scale, applied by an external evaluator and the self rating Beck inventory for depression, can give discrepant results in psychiatric patients with depression. AIM: To compare depression scores obtained with the Hamilton scale and the Beck inventory in general medical patients. PATIENTS AND METHODS: Patients attending an outpatient clinic of a University Hospital were studied. Clinical psychiatric diagnoses were based on DSM-III. Hamilton scale was applied to 100 patients and 80 answered the Beck depression inventory. RESULTS: Patients with major depression obtained the higher scores with both scales. However, Beck inventory had false positive and false negative results. Moreover, some patients overstated their depressive symptoms. CONCLUSIONS: Self assessment of depression can be distorted by anxiety and somatic symptoms.
Adult↗
Effect of Lepidium meyenii (maca) roots on spermatogenesis of male rats.
AIM: To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii (maca) on spermatogenesis in adult male rats. METHODS: Male rats received an aqueous extract of the root (66.7 mg in one mL) twice a day for 14 consecutive days. RESULTS: Treatment with Lepidium meyenii resulted in an increase in the weights of testis and epididymis but not the seminal vesicle weight. The length and frequency of stages IX-XIV seminiferous tubules, where mitosis occurred, were increased and stages I-VI were reduced in rats treated with Lepidium meyenii. CONCLUSION: The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initial stages (IX-XIV).
Administration, Oral↗
[The TPM Project (Transplant Procurement Management): international advanced training of transplant coordination].
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Curriculum↗
Novel technique for scanning of codon 634 of the RET protooncogene with fluorescence resonance energy transfer and real-time PCR in patients with medullary thyroid carcinoma.
BACKGROUND: The multiple endocrine neoplasia 2 (MEN 2) syndromes [MEN 2A, MEN 2B, and familial medullary thyroid carcinoma (FMTC)] are caused by germline mutations of the RET protooncogene. Because 85% of MEN 2A patients and 30% of FMTC patients have mutations at codon 634, the recommended molecular analyses begin at exon 11, where codon 634 is located. METHODS: We scanned codon 634 of the RET protooncogene with real-time PCR and fluorescence resonance energy transfer (FRET), using a unique pair of internal probes to detect mutations localized at codon 634. We compared results with sequencing results in 66 patients. RESULTS: The method detected all codon 634 mutations available in our laboratory (Cys634Tyr, Cys634Arg, Cys634Phe, Cys634Trp). Comparing this method with the direct sequencing of exon 11 in a cohort of 66 patients with MTC, the system identified all 14 MTC patients carrying germline mutations at codon 634. One apparent false-positive result occurred among 52 patients. CONCLUSIONS: The simultaneous scanning of multiple mutations is possible with the FRET system. The method allows rapid characterization of germline mutations at codon 634 in MTC patients.
Carcinoma, Medullary↗
[Prevalence of prostatic intraepithelial neoplasia in Spain].
OBJECTIVE: To study the prevalence of high grade prostatic intraepithelial neoplasia in a Spanish population and to compare it with the prevalence in Caucasians of other countries and Afro-Americans. METHODS: 162 prostates obtained at autopsy from Spanish men aged 20-80 years, were fixed in 10% formalin and slices perpendicular to the posterior margin were made every 3-4 mm along its entire length. All blocks were embedded in paraffin and examined microscopically. Mapping of focality and site of the high grade prostatic intraepithelial neoplasia was done for each case. The Wayne University autopsy study was used for comparison of the prevalence in other countries and races. RESULTS: 146 prostates from men with a mean age of 48.5 years were considered valid for histological analysis. There were 42 high grade prostatic intraepithelial neoplasia; 20 were focal and 22 multifocal. By age group, the prevalence of high grade prostatic intraepithelial neoplasia were 7.1%, 14.7%, 28.5%, 33.3%, 45.4% and 51.8% for the 3rd, 4th, 5th, 6th, 7th, and 8th decades. CONCLUSIONS: High grade prostatic intraepithelial neoplasia begins to manifest in the Spanish population after the 3rd decade. It is usually focal and peripheral, and significantly increases with age and becomes multifocal. Its prevalence in the Spanish population is moderately lower than in American Caucasians and significantly lower than in Afro-Americans.
Adult↗
[Clinical experience with icodextrin. Multicenter study].
UNLABELLED: The aim of this study was to analyse our experience with icodextrin in Andalusia, Spain. The study includes 51 patients (30 women and 21 men) on peritoneal dialysis (21 on CAPD and 30 on Automated Peritoneal Dialysis) treated with icodextrin for 10.3 +/- 7 months (0-41 months). Their mean age was 57 +/- 18 years (18-86 years). We have recorded the appearance of side effects, and the evolution of several biochemical parameters at baseline and after 6, 12 ans 18 months from initiation of icodextrin. We also studied drainage fluid from 12 patients after an icodextrin exchange. RESULTS: There were side effects (all cutaneous) in 4 out of 51 patients (7.8%). Two of the affected suffered from cutaneous hypersensitivity reactions, and icodextrin had to be suspended; the other two had exfoliative dermatitis affecting hands and feet that disappeared without have to withdraws icodextrin. Biochemical parameters: Serum sodium levels decreased from baseline to six months (138 +/- 6 mEq/l vs 136 +/- 3 mEq/l; p = 0.006), and then persisted at the same levels throughout the rest of the study period. There was a slight but significant decreased of serum HDL-cholesterol at six months vs baseline (55 +/- 26 mg/dl vs 51 +/- 20 mg/dl, p = 0.04), and a further decrease at twelve months vs six months (42 +/- 15 mg/dl vs 51 +/- 13 mg/dl, p = 0.054). There were no significant variations of glucose, osmolality, cholesterol, LDL-cholesterol (tendency to increase), triglycerides, beta 2 m and weight (tendency to increase; p = 0.08). In relation with the icodextrin exchange: average ultrafiltration 296 +/- 119 ml (ranging from 104 to 480 ml), creatinine clearance 1.9 +/- 0.5 litres (20.5% of daily creatinine clearance), urea clearance 2.08 +/- 0.5 litres (18.7% of daily urea clearance), total protein losses 3.2 +/- 0.9 g, albumin losses 1.4 +/- 0.5 g; urea and creatinine clearances were negatively correlated with ratios D/P4 of urea and creatinine of PET and positively correlated with ratio G4/G0. In conclusion, side effects are scarce with the use of icodextrin. As described in other studies, there is a trend to a slight decrease in serum sodium. The long-term use of icodextrin does not-prevent weight gain or deterioration of patients on peritoneal dialysis, despite the diminution of glucose load.
Adolescent↗
Isolation and characterisation of a novel human gene (C9orf11) on chromosome 9p21, a region frequently deleted in human cancer.
The chromosome 9p21 region has been described to be frequently deleted in several neoplasias. The cyclin dependent kinase inhibitor 2A (CDKN2A or P16) gene was cloned in this region and identified as a tumour suppressor gene. However, much evidence indicates the existence of another tumour suppressor gene located proximal to the CDKN2A gene, which could be involved in cutaneous malignant melanoma (CMM) initiation. In the present report we have further investigated this 9p21 chromosomal region and cloned and characterised a novel gene within it (C9orf11). This gene shares no similarities to any known gene or predicted protein representing a novel human gene. Nevertheless, a putative leucine zipper pattern is located at the C-terminal end of the predicted protein, suggesting that it could dimerise. C9orf11 encodes for a protein of 294 amino acids with a predicted molecular mass of 32.8 kDa. C9orf11 is organised in eight exons that encompass a region of approx. 13 kb. Expression analysis demonstrates that C9orf11 is highly expressed in testis, although minor expression was seen in other tissues. Mutations in the C9orf11 gene were not detected in CMM families that were negative for CDKN2A mutations. Two SNPs for the C9orf11 gene have been identified, which could be used in segregation or association studies for other disorders.
Amino Acid Sequence↗
Administration of a liposomal FGF-2 peptide vaccine leads to abrogation of FGF-2-mediated angiogenesis and tumor development.
Basic fibroblast growth factor (FGF-2) is an important stimulator of angiogenesis that has been implicated in neoplastic progression. Attempts to neutralize or modulate FGF-2 have met with some success in controlling neovascularity and tumor growth. In the present study, two peptides: one corresponding to the heparin binding domain and the other to the receptor binding domain of FGF-2, exerted dose-dependent inhibition of FGF-2-stimulated human umbilical vein endothelial cell proliferation (IC(50)=70 and 20 microg/ml, respectively). The identification of these functional regions suggested that targeting these domains might be an approach for the modulation of FGF-2 function. To investigate this possibility, we vaccinated mice with either the heparin binding domain peptide or the receptor binding domain peptide of FGF-2 in a liposome/adjuvant format, and analyzed the effect of vaccination on FGF-2-driven angiogenesis, tumor development and immune status. Mice vaccinated with the heparin binding domain peptide generated a specific antibody response to FGF-2, blocked neovascularization in a gelfoam sponge model of angiogenesis, and inhibited experimental metastasis by >90% in two tumor models: the B16BL6 melanoma and the Lewis lung carcinoma. These effects were not observed in mice treated with the receptor binding domain peptide conjugated to liposomes or liposomes lacking conjugated peptide. These data suggest that a heparin binding domain peptide of FGF-2, when presented to a host in a liposomal adjuvant formulation, can ultimately lead to inhibition of angiogenesis and tumor growth.
Amino Acid Sequence↗
Intracytoplasmic sperm injection with cryopreserved testicular spermatozoa.
To assess if testicular sperm cryopreservation is a valid alternative to repetition of testicular sperm retrieval techniques, results of a cryopreservation technique in pills have been retrospectively analyzed. Enough motile spermatozoa for ICSI were obtained in 172 from 190 (90.5%) frozen-thawed testicular sperm samples. Overall, 249 couples underwent 390 ICSI cycles, 156 using fresh and 234 using cryopreserved testicular sperm. Mean two-pronuclear fertilization rates per cycle were not significantly different after ICSI with fresh (62.0%) or with cryopreserved (63.2%) spermatozoa. Mean embryo cleavage rate per cycle was higher in the fresh (90.6%) than in the cryopreserved (84.6%) group (P = 0.016). However, clinical pregnancy rates per cycle (28.2% with fresh vs 27.8% with cryopreserved), implantation rates (12.2% vs 13.1%) and ongoing pregnancy rates per cycle (22.4% vs 21.8%) were not significantly different. Cryopreservation of testicular spermatozoa is an effective technique that can be used both in obstructive and in non-obstructive azoospermia.
Adolescent↗
Validation of an analysis method for 4-amino-3-hydroxybutyric acid by reversed-phase liquid chromatography.
A rapid and simple reversed-phase liquid chromatographic method that did not require the derivatization of 4-amino-3-hydroxybutyric acid (GABOB) was developed and validated. The method proved to be suitable for the determination of GABOB concentrations in finished pharmaceutical product (tablets). The method was developed using a RP-18 column, UV detection at 210 nm and 0.01 M sodium heptasulphonate solution, at pH 2.4, as the mobile phase. Different validation parameters were included and satisfactorily evaluated. The specificity of the method was demonstrated. Linearity was established in the range 0.40-0.60 mg/ml (r=0.997). The method showed excellent accuracy (100.1%). Precision (repeatability) gave a relative standard deviation value of 0.68%, while the intermediate precision was 1.70%. A robustness test showing the influence of different pH values and counter-ion concentrations was also performed.
Chromatography, Liquid↗