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Biomedical subjects

P Quesada

Publications and source records attributed to P Quesada.

At least 19 recordsLinked to original sources

Recombinant IFN-alpha2b treatment activates poly (ADPR) polymerase-1 (PARP-1) in KB cancer cells.

In the present paper, we investigated the relationship between the growth inhibitory effects of recombinant interferon-alpha2b (rIFN-alpha2b) and poly (ADPR) polymerase-1 (PARP-1) activity in the human squamous KB cancer cell line. Growth inhibition of the KB cells mediated by 1000 IU/ml of rIFN-alpha2b was accompanied by a transient rise in PARP-1 specific activity 24 h after rIFN-alpha2b treatment, confirmed by both the increase of intracellular poly (ADP-ribose) content and the PARP-1 auto-modification level. At longer times of incubation, the onset of apoptosis accompanied KB cell growth inhibition, as demonstrated by both flow cytometry and western-blotting analysis showing an 89 kDa apoptotic fragment of PARP-1. Moreover, pretreatment of the cells with the PARP-1 inhibitor, 3-aminobenzamide (3-ABA), at non-cytotoxic concentrations (1 mM), reduced the cell-growth inhibition, cell-cycle perturbation and apoptosis caused by rIFN-alpha2b. Taken together, these results strongly suggest that PARP-1 may be directly involved in the effects of rIFN-alpha2b in the KB cancer cell line.

Antineoplastic Agents↗

Mortality in severe sleep apnoea/hypopnoea syndrome patients: impact of treatment.

The aim of this study was to determine mortality in patients with sleep apnoea/hypopnoea syndrome (SAHS) according to the treatments employed and comorbidity. An historical cohort of patients with SAHS diagnosed at a university hospital between 1982 and 1992 and followed until 1996 was studied. From a total of 475 SAHS patients, 444 (94%), with a mean+/-SD apnoea/hypopnoea index at diagnosis of 55+/-27, were located and included in the study. SAHS treatments employed were: surgery (88), weight loss (134), continuous positive airway pressure (124) and 98 patients were not treated. By the end of follow-up, 49 patients had died. According to Cox regression analysis, mortality in treated patients was lower than in those not treated, but higher in those with a history of severe chronic obstructive pulmonary disease. Mortality in nontreated patients compared with that of the general population, adjusted for age and sex, showed excessive mortality, which decreased in treated patients. Stratification by age showed a greater mortality rate ratio in patients <50 yrs. These findings were maintained when mortality from cardiovascular causes was compared. In conclusion, a rise in mortality was found in nontreated sleep apnoea/hypopnoea syndrome patients compared with the general population, whereas mortality in those treated for sleep apnoea/hypopnoea syndrome did not differ significantly from that of the general population.

Comorbidity↗

[Antibiotic prophylaxis in oncologic pharyngolaryngeal surgery: ceftriaxone versus clindamycin and gentamycin].

There are many papers comparing two antibiotic protocols for the profilaxis of head and neck infections after laryngeal surgery. We present one prospective and randomised study in 60 patients comparing the efficacy of two protocols. The comparison was between ceftriaxone versus the association of clindamicyn and gentamicyn. In our database we included the risk factors for infection, the surgical approach, the duration of surgery and the patient characteristics. We observed an incidence of 28% of infection, with a 23.3% in the clindamicyn + gentamicyn group and a 33.3% in the ceftriaxone group. The differences between the two groups were not statistically significant. In this study we observed a small difference between the amount of alcohol comsuption, the effectiveness of the surgical drainage, the surgical approach and the presence of wound infection. The difference was not statistical significant due to the small group of patients. The profilaxis was adequate for the total laryngectomy and cordectomy group, with a higher incidence of wound infection in patients treated with a supraglottic laryngectomy.

Adult↗

[Usefulness of 201T1 gammagraphy in the diagnosis of carcinoma of the larynx].

For the evaluation of a patient with a laryngeal tumor we need the clinical exam and other exams as the CT scan or MRI. Those studies have a sensitivity of less than 80%. For that reason in the last years there has been a development of new techniques trying to increase the accuracy. The 201Tl SPECT is one of them although it was developed for cardiological purposes. We present our experience in 46 patients with laryngeal tumor in whom we did a 201Tl SPECT as part of the extension study. The sensitivity of the study was 81.6% in the diagnosis of the primary tumor and 46.1% for the neck adenopathies. The 201Tl SPECT can be a good method for the evaluation and detection of recurrences in patients with pharyngo-laryngeal tumor.

Aged↗

Rat germinal cells require PARP for repair of DNA damage induced by gamma-irradiation and H2O2 treatment.

The ability of rat germinal cells to recover from genotoxic stress has been investigated using isolated populations of primary spermatocytes and round spermatids. Using a comet assay at pH 10.0 to assess single strand breakage (SSB) in DNA, it was found that a high level of damage was induced by 5 Gy gamma-irradiation and acute exposure to 50 microM H2O2. This damage was effectively repaired during a subsequent recovery period of 1-3 hours culture in vitro but repair was significantly delayed in the presence of the poly(ADP-ribose)polymerase (PARP) inhibitor 3-aminobenzamide (3-ABA). Immunofluorescence detection of PARP with specific antibodies localised the protein to discrete foci within the nucleus of both spermatocytes and spermatids. Poly(ADP-ribose) (pADPR) could also be detected in spermatid nuclei following gamma-irradiation or H2O2 treatment. Moreover, PARP activation occurs both in spermatocytes and spermatids left to recover after both genotoxic stresses. The NO donors, 3-morpholino-sydnonimine (SIN-1) and S-nitrosoglutathione (SNOG), caused significant SSBs in both spermatocytes and spermatids. The effects of SIN-1 could be prevented by exogenous catalase (CAT), but not superoxide dismutase (SOD), in the cell suspensions. SNOG-induced SSBs were insensitive to both CAT and SOD. It is concluded that DNA in spermatocytes and spermatids is sensitive to damage by gamma-irradiation and H2O2 and that efficient repair of SSBs requires PARP activity.

Animals↗

Metabolic changes in the poly(ADP-ribosyl)ation pathway of differentiating rat germinal cells.

Endogenous levels of poly(ADP-ribose) and betaNAD+ have been determined in rat male germinal cells at different stages of differentiation. The levels of both metabolites decreased progressively from primary spermatocytes to secondary spermatocytes and especially in spermatids. We have also determined the size and complexity of the ADP-ribose polymers synthesized in permeabilized germ cells. Polymers of different chain length and complexity were observed in cells incubated with different concentrations of [32P]betaNAD+; short polymers characterized primary spermatocytes incubated with low betaNAD+ concentration. In all cell fractions, polymers of over 20 residues in size were observed at high betaNAD+ levels. Long polymers were associated with the sulfuric acid-insoluble proteins (nonhistone proteins such as PARP itself). By contrast, oligomers of 20 ADP-ribose units or less were found in the sulfuric acid-soluble proteins (histone proteins). We have also identified the main ADP-ribose protein acceptors formed in each cell type. In all cells examined, PARP appears to be extensively automodified. However, by far, the H1t variant of histone H1 appeared to be the preferred ADP-ribose target among the acid-soluble proteins separated by reverse-phase HPLC. Therefore, we conclude that an active protein-poly(ADP-ribosyl)ation system is concentrated in primary spermatocytes, based on a high level of PARP automodification accompanied by the preferential heteromodification of the histone H1 variant specifically expressed in the cells undergoing the pachytene phase of the meiotic division.

Animals↗

Partial epiglottectomy as a possible treatment for globus pharyngeus?

Globus pharyngeus is a relatively common complaint in an ear, nose, and throat consulting room and may account for 3-4% of outpatient referrals. The cause is still unknown, although a number of hypotheses have been suggested. Between 40% and 75% of the patients remain symptomatic despite any treatment regimen. Thirteen patients from a group of 124 with the diagnosis of globus pharyngeus and no response to medical treatment were treated with partial epiglottectomies. One year after the surgery all but one patient were free of symptoms. Our experience indicates that partial epiglottectomy can be a good treatment for those patients with globus pharyngeus in whom no cause is found after all studies are performed or when medical treatment fails.

Adult↗

Comparison of methods for the calculation of energy storage and return in a dynamic elastic response prosthesis.

The standard method used to calculate the ankle joint power contains deficiencies when applied to dynamic elastic response prosthetic feet. The standard model, using rotational power and inverse dynamics, assumes a fixed joint center and cannot account for energy storage, dissipation, and return. This study compared the standard method with new analysis models. First, assumptions of inverse dynamics were avoided by directly measuring ankle forces and moments. Second, the ankle center of rotation was corrected by including translational power terms. Analysis with below-knee amputees revealed that the conventional method overestimates ankle forces and moments as well as prosthesis energy storage and return. Results for efficiency of energy return were varied. Large differences between models indicate the standard method may have serious inadequacies in the analysis of certain prosthetic feet. This research is the first application of the new models to prosthetic feet, and suggests the need for additional research in gait analysis with energy-storing prostheses.

Ankle Joint↗

The analysis of the poly(ADPR) polymerase mode of action in rat testis nuclear fractions defines a specific poly(ADP-ribosyl)ation system associated with the nuclear matrix.

The poly(ADP-ribosyl)ation system, associated with different nuclear fractions of rat testis, has been analyzed for both pADPR and pADPR acceptor proteins. The DNase I sensitive and resistant chromatin contain 35% and 40%, respectively, of the total pADPR synthesized in intact nuclei incubated with [32P]NAD. Moreover, the residual 25% were estimated to be associated with the nuclear matrix. Three different classes of pADPR are present in the nuclei. The longest and branched ADPribose polymers modify proteins present in the DNase I resistant (2 M NaCl extractable) chromatin and in the nuclear matrix, whereas polymers of> 20 residues interact with the components of the DNase I sensitive chromatin and oligomers of 6 ADPribose residues are bound specifically to the acid-soluble chromosomal proteins, present in isolated nuclear matrix. The main pADPR acceptor protein in all the nuclear fractions is represented by the PARP itself (auto-modification reaction). The hetero-modification reaction occurs mostly on histone H1 and core histones, that have been found associated to DNase I sensitive and resistant chromatin, respectively. Moreover, an oligo(ADP-ribosyl)ation occurs on core histones tightly-bound to the matrix associated regions (MARs) of chromatin loops.

Animals↗

Constitutive nuclear factor-kappaB activity in human upper airway tissues and nasal epithelial cells.

Respiratory epithelial cells are actively involved in the host defence and inflammatory reactions of the airways. Nuclear factor-kappaB (NF-kappaB) is a transcription factor that plays a pivotal role in many cellular responses to environmental changes. The inducible nitric oxide synthase (iNOS) isoform has been implicated in airway inflammation as well as in normal airway function. In this study, the hypothesis that NF-kappaB may be associated with iNOS expression in airway epithelium, not only in inflammatory processes but also under physiological conditions was examined. NF-kappaB deoxyribonucleic acid-binding activity was assayed by means of electrophoretic mobility shift assay (EMSA) and iNOS expression examined using immunohistochemical techniques in healthy nasal mucosa and chronically inflamed nasal polyps. Further NF-kappaB activity was assayed; by means of EMSA, in nasal epithelial cells isolated from both tissues. NF-kappaB was activated in nasal polyps, but also to the same extent in healthy nasal mucosa. Uniform iNOS expression was localized within the airway epithelium in both inflamed and noninflamed tissues. Along with iNOS expression, concomitant NF-kappaB activation was found in nasal epithelial cells obtained from both tissues and no differences were observed when nasal mucosa and nasal polyp were compared. These results suggest that constitutive nuclear factor-kappaB and concurrent inducible nitric oxide synthase expression in epithelial cells may play a physiological role in airway function.

Epithelial Cells↗

Stochastic risk estimate for barium radiological examinations in Malaga (Spain).

The aim of this research work has been the estimation of the stochastic risk for five barium examinations. The sample was the population attending the Radiological Service of the 'Nuestra Señora de la Victoria' University Hospital, who had been treated with some barium examinations, set in five different groups: oesophagus tract, oesophagus-gastric-duodenal tract, intestinal tract, enteroclysis and double enema. To estimate the stochastic risk, it is necessary to know the organ dose. This can be calculated from the dose-area product which allows us to determine the effective dose using software. The dose-area product is the most suitable quantity to measure in these types of examination. We have evaluated the contribution that each procedure provides to the genetically significant dose, somatically significant dose, collective effective dose, annual effective dose 'per capita' and detriment, which are useful for assessing the population risk of cancer or hereditary effects after x-ray exposure. The contribution to the genetically significant dose is 6.7 microGy, to the somatically significant dose 8.82 mSv-yr, 16.07 person-Sv for the collective effective dose, 0.03 mSv for the 'per capita' annual effective dose and the annual aggregated detriment is 0.33.

Age Factors↗

Heat stress reduces poly(ADPR)polymerase expression in rat testis.

Poly(ADPR)polymerase (PARP) is a chromatin-associated enzyme with a presumptive role in DNA repair during replication and recovery from strand breaks caused by genotoxic agents. It catalyses the attachment and elongation of ADPribose polymers (pADPR) to a variety of acceptor proteins (including PARP itself, and histones) and is particularly active in the testis where its expression varies according to the stage of germ cell differentiation. PARP degradation is also one of the classic indicators of apoptosis. In this investigation we have examined the effects of heat stress on the adult rat testis with respect to the concentration and activity of PARP, the nature of the pADRP nuclear acceptor proteins, the length of ADPR polymers and the activity of the ADPR depolymerizing enzyme, poly(ADPR)glycohydrolase (PARG). Our results show a significant reduction in the concentration and activity of PARP 4 and 8 days after artificial cryptorchidism, but no significant changes were observed in PARG activity or in pADPR length. Unexpectedly, the apoptotic degradation of PARP was not detected following heat stress. These results confirm that PARP gene expression is developmentally regulated during spermatogenesis and indicate that it is suppressed coincidentally with the loss of meiotic spermatocytes during artificial cryptorchidism.

Animals↗

Characterization of SNP, a novel tissue- and phase-specific nuclear protein expressed during the proliferative phase in the oviduct of the lizard Podarcis sicula Raf.

The amino acid sequence of a novel tissue-and phase-specific nuclear protein (SNP) has been determined, after purification from the nuclei of the oviduct of the lizard Podarcis sicula Raf. during the reproductive period of the seasonal growth. SNP has a pI of 9.0 and contains 81 amino acid residues with a molecular weight of 9211.88 +/- 0.09. It shows a bipartite organization as the first 40 amino acids contain all 8 cysteinyl residues, while the last 41 amino acids contain 16 prolyl residues. Two more components have also been identified and characterized, with the first 79 amino acids matching SNP and missing one or two residues at the C-terminus. They have thus been named [des-(Ala81) SNP1] and [des-(Lys80-Ala81) SNP2], respectively. The molecular weights are 9140.21 +/- 0.83 for [des-(Ala81) SNP1] and 9011 +/- 0.09 for [des-(Lys80-Ala81) SNP2].

Amino Acid Sequence↗

[Nasal leishmaniasis in an HIV-positive patient].

Leishmania is currently one of the most clinically important protozoa in otorhinolaryngology. Mediterranean countries, including Spain, have endemic HIV and L. infantum. Dogs are the most important Leishmania reservoir. Leishmaniasis is transmitted basically by the bite of infected female Phlebotomus sandflies. Its clinical development depends mainly on the host's cellular immunity (TCD4+ lymphocyte count). About 400 cases of HIV-visceral leishmaniasis have been reported in Spain. However, exclusively cutaneous presentation of HIV-leishmaniasis coinfection has been observed in only 2-3% of cases. We report the case of a female HIV+ patient who developed cutaneous leishmaniasis of the nasal vestibule by L. infantum. The patient was treated satisfactorily with a combination of parenteral Pentostam (sodium stilbogluconate) and periodic intralesional injections of Pentostam. The patient was included in a secondary prophylaxis protocol for visceral leishmaniasis with a monthly dose of Glucantime (meglumine antimoniate) for life.

Animals↗

In vitro poly(ADP-ribosyl)ated histones H1a and H1t modulate rat testis chromatin condensation differently.

Rat testis H1 proteins were poly(ADP-ribosyl)ated in vitro. The modifying product, poly(ADP-ribose), was found covalently bound to each histone variant at various extents and exhibited distinct structural features (linear and short, rather than branched and long chains). Interest was focused on the somatic H1a, particularly abundant in the testis, as compared with other tissues, and the testis-specific H1t, which appears only at the pachytene spermatocyte stage of germ cell development. These H1s were modified with poly(ADP-ribose) by means of two in vitro experimental approaches. In the first system, each variant was incubated with purified rat testis poly(ADP-ribose)polymerase in the presence of [(32)P] NAD. In parallel, poly(ADP-ribosyl)ated H1s were also prepared following incubation of intact rat testis nuclei with [(32)P] NAD. In both experiments, the poly(ADP-ribosyl)ated proteins were purified from the native forms by means of phenyl boronic agarose chromatography. The results from both analyses were in agreement and showed qualitative differences with regard to the poly(ADP-ribose) covalently associated with H1a and H1t. Comparison of the bound polymers clearly indicated that the oligomers associated with H1a were within 10-12 units long, whereas longer chains (</=20 ADP-R units) were linked to H1t. Individual poly(ADP-ribosyl)ated H1s were complexed with homologous H1-depleted oligonucleosomes (0.5-2.5 kbp) in order to measure their ability to condensate chromatin, in comparison with the native ones. Circular dichroism showed that the negative charges of the oligomeric polyanion, although present in limited numbers, highly influenced the DNA-binding properties of the analyzed H1s. In particular, the poly(ADP-ribosyl)ated H1a and H1t had opposite effects on the condensation of H1-depleted oligonucleosomes.

Animals↗

[Stapedectomy versus stapedotomy. Our experience].

Otosclerosis surgery has seen three well-differentiated stages of development: a) SHC fenestration; b) stapes mobilization, and c) platinectomy, a procedure introduced in 1960 by Shea. Since then, only one variation has been proposed: platinotomy. After a comparative study of platinectomy versus platinotomy, we, like other authors, concluded that platinotomy was a better technique because of the ease of execution and good functional results.

Adolescent↗