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Biomedical subjects

J Lorente

Publications and source records attributed to J Lorente.

At least 19 recordsLinked to original sources
PubMed2006

Radioprotective-antimutagenic effects of rosemary phenolics against chromosomal damage induced in human lymphocytes by gamma-rays.

The radioprotective effects of carnosic acid (CA), carnosol (COL), and rosmarinic acid (RO) against chromosomal damage induced by gamma-rays, compared with those of L-ascorbic acid (AA) and the S-containing compound dimethyl sulfoxide (DMSO), were determined by use of the micronucleus test for antimutagenic activity, evaluating the reduction in the frequency of micronuclei (MN) in cytokinesis-blocked cells of human lymphocytes before and after gamma-ray irradiation. With treatment before gamma-irradiation, the most effective compounds were, in order, CA > RO > or = COL > AA > DMSO. The radioprotective effects (antimutagenic) with treatment after gamma-irradiation were lower, and the most effective compounds were CA and COL. RO and AA presented small radioprotective activity, and the sulfur-containing compound DMSO lacked gamma-ray radioprotection capacity. Therefore, CA and COL are the only compounds that showed a significant antimutagenic activity both before and after gamma-irradiation treatments. These results are closely related to those reported by other authors on the antioxidant activity of the same compounds, and the degree of effectiveness depends on their structure. Furthermore, the results for treatments before and after gamma-ray irradiation suggest the existence of different radioprotective mechanisms in each case.

Abietanes↗
PubMed2006

[Tracheal infection following oncological surgery in larynx and pharynx].

Surgical wound infection is one of the most frequent complications in pharyngo-laryngeal external surgery. They are usually polimicro with gram-positive, negative both aerobial and anaerobial microrganisms. The trachea is usually sterile and contamination is due to the intoduction during intubation of germs from the oropharyngeal area. A retrospective study was performed including 40 patients with pharyngo-laryngeal carcinoma. When the tracheostomy was done a culture from the internal trachea wall was obtained for micro study. Only one patient had an sterile culture from the trachea. There were 3 patients with just one microorganism and all the rest had at least two, being mixed aerobial and anaerobial flora the most frequent.

Adult↗
PubMed2004

[Hodgkin and Non-Hodgkin lymphomas in otorhinolaryngology].

Lymphomas of the head and neck arise in lymph nodes and extranodal areas as Waldeyer ring, nasal cavity, thyroid gland and salivary glands. Though anatomically in close proximity, lymphomas presenting at the ENT area have different clinical characteristics if they are Hodgkin or Non-Hodgkin. We included 31 patients with the diagnosis of lymphoma and diagnosed in our Department between 1999 and 2002. We studied all the different variables that differentiate Hodgkin and Non-Hodgkin's lymphoma. Both types of lymphoma usually present as a cervical mass. Non-Hodgkin lymphoma have extranodal involvement more frequently and also a more advance disease at diagnosis. It is important to include the lymphoma in the differential diagnosis of any cervical mass or ENT lesion.

Adult↗
PubMed2003

Effects of several polyhydroxylated flavonoids on the growth of B16F10 melanoma and Melan-a melanocyte cell lines: influence of the sequential oxidation state of the flavonoid skeleton.

The response of B16F10 melanoma and Melan-a melanocyte cell lines to treatment with five polyhydroxylated flavonoids and gallic acid, after 24 and 72 h of exposure, was determined, and the relationship between any antiproliferative effects observed and the chemical structure is discussed. After 24 h, none of the studied compounds showed significant cytotoxic activity in the B16F10 cell line, whereas compounds with an adjacent trihydroxylated substitution pattern did affect the viability of the Melan-a cell line. After 72 h of exposure, myricetin, baicalein and gallic acid significantly inhibited both B16F10 and Melan-a cell cultures, whereas luteolin and quercetin had only a moderate effect. Eriodictyol only had an effect on Melan-a cell viability, which was reduced slightly. These results suggest that the presence of a C2-C3 double bond and three adjacent hydroxyl groups in the flavonoid A- or B-rings confers greater antiproliferative activity to the flavonoid.

Animals↗
PubMed2002

Radioprotective effects in vivo of phenolics extracted from Olea europaea L. leaves against X-ray-induced chromosomal damage: comparative study versus several flavonoids and sulfur-containing compounds.

The radioprotective effects of a polyphenolic extract of Olea europaea L. leaves (OL); the flavonoids diosmin and rutin, which are widely used as pharmaceuticals; and the sulfur-containing compounds dimethylsulfoxide (DMSO) and 6-n-propyl-2-thiouracil (PTU) were determined by using the micronucleus test for anticlastogenic activity, evaluating the reduction of the frequency of micronucleated polychromatic erythrocytes (MnPCEs) in bone marrow of mouse before and after X-ray irradiation. With treatment before X-irradiation, the most effective compounds were, in order, rutin > DMSO > OL > PTU > diosmin. These results showed, for the polyphenols studied, a linear correlation (r(2) = 0.965) between anticlastogenic activity and antioxidant capacity. The magnitude of protection with treatment after X-irradiation were lower, and the most effective compounds were, in order, OL > diosmin > rutin; DMSO and PTU lacked radioprotective activity. Therefore, OL is the only substance that showed a significant anticlastogenic activity both before and after X-ray irradiation treatments. Structurally, the free oxygen radicals and lipoperoxyradicals scavenging capacity and, consequently, the anticlastogenic activity of these polyphenolic compounds are based principally on the presence of specific functional groups, mainly catechol groups (rutin, oleuropein, hydroxytyrosol, verbascoside, luteolin), that also increase the stability of the aroxyl-polyphenol radical generated in the above processes.

Animals↗
PubMed2002

Effects of several flavonoids on the growth of B16F10 and SK-MEL-1 melanoma cell lines: relationship between structure and activity.

Although flavonoids seem to be capable of acting at all stages of the carcinogenic process, little information is available on their action in melanoma cell lines. The aim of this study was to assess the response of B16F10 and SK-MEL-1 melanoma cell lines to treatment with six different flavonoids after 24 and 72 h of exposure and to relate the response to their structure. We then compared the findings with those for melphalan treatment. When cultures were treated for 24 h, only slight inhibition at the highest concentrations (25 and 50 microM) of tangeretin and luteolin were observed, whereas melphalan caused a dose-related inhibition of growth at all concentrations. Quercetin, hesperetin, 7,3'-dimethylhesperetin and eriodictyol did not produce any effect at 24 h on B16F10 or SK-MEL-1 cells, results which point to the low toxicity of flavonoids. After 72 h of exposure culture growth was inhibited by 7,3'-dimethylhesperetin at 50 microM, but lower concentrations had no effect. Tangeretin was the most effective of the flavonoids in inhibiting B16F10 and SK-MEL-1 cell growth, showing a clear dose-response curve after 72 h. These results suggest that the absence of the C2-C3 double bond on hydroxylated flavonoids results in a loss of effect on both the cell lines, while the higher activity of tangeretin compared with 7,3'-dimethylhesperetin suggests that the presence of at least three adjacent methoxyl groups confers a more potent antiproliferative effect.

Animals↗
PubMed2001

[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↗
PubMed2001

[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↗
PubMed2001

Improved water solubility of neohesperidin dihydrochalcone in sweetener blends.

Significant technological advantages in terms of sweetness synergy and hence cost-saving can be obtained if neohesperidin dihydrochalcone (NHDC) is used in sweetener blends with other intense or bulk sweeteners. The combination of NHDC with sodium saccharin or sodium cyclamate is an excellent method to improve the water solubility at room temperature of NHDC. In the case of NHDC-sodium saccharin, two different methods for blend preparation, a simple mixture and a cosolubilized mixture, can be used, with similar results obtained for solubility and solution stability properties. To improve temporally the water solubility of NHDC in combination with sodium cyclamate, it is absolutely necessary to prepare cosolubilized blends.

Chalcone↗
PubMed2000

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↗
PubMed2000

Antioxidant activity and radioprotective effects against chromosomal damage induced in vivo by X-rays of flavan-3-ols (Procyanidins) from grape seeds (Vitis vinifera): comparative study versus other phenolic and organic compounds.

The quantitative distribution of several flavan-3-ols was determined using HPLC in a grape (Vitis vinifera) seed extract (GSE) of four cultivars grown in the region of Murcia. Polymer >/= C(4) units made up the largest group of procyanidins in the GSE (90.92%, expressed as HPLC % area). The antioxidant activity of GSE and other reference compounds was investigated by measuring their ability to scavenge the ABTS(*)(+) radical cation (TEAC). The most effective compounds were, in order: GSE > rutin > (+)-catechin > diosmin >/= ascorbic acid. The radioprotective effects of GSE and other reference compounds were determined by using the micronucleus test for anticlastogenic activity, any reduction of the frequency of micronucleated polychromatic erythrocytes (MnPCEs) being evaluated in the bone marrow of mouse exposed to X-rays. The most effective compounds were, in order: GSE > rutin > dimethyl sulfoxide (DMSO) > ascorbic acid > 6-n-propyl-2-thiouracil-6c (PTU) > diosmin. The higher ABTS(*)(+) scavenging capacity and anticlastogenic activity of GSE can be explained, structurally, by the high number of conjugated structures between the catechol groups in the B-rings and the 3-OH free groups of the polymeric polyphenolic skeleton and, in addition, by the stability of the aroxyl flavonoid radical generated in the above processes.

Animals↗
PubMed2000

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↗
PubMed2000

[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↗
PubMed1998

Comparison of models used for UV index calculations.

Eighteen radiative transfer models in use for calculation of UV index are compared with respect to their results for more that 100 cloud-free atmospheres, which describe present, possible future and extreme conditions. The comparison includes six multiple-scattering spectral models, eight fast spectral models and four empirical models. Averages of the results of the six participating multiple-scattering spectral models are taken as a basis for assessment. The agreement among the multiple-scattering models is within +/- 0.5 UV index values for more than 80% of chosen atmospheric parameters. The fast spectral models have very different agreement, between +/- 1 and up to 12 UV index values. The results of the empirical models agree reasonably well with the reference models but only for the atmospheres for which they have been developed. The data to describe the atmospheric conditions, which are used for the comparison, together with the individual results of all participating models and model descriptions are available on the Internet: http://www.meteo.physik.uni-muenchen.de/++ +strahlung/cost/.

Computer Simulation↗
PubMed1998

[Omeprazole: a new treatment for paranasal sinus polyps in Widal syndrome. Preliminary study].

A preliminary report is made of the potential therapeutic effect of omeprazol in reducing nasosinusal polyps. This study is based on the empirical observation of nasal airflow improvement in patients suffering from nasosinusal polyposis after administering omeprazol. Different phases of the study suggested that patients with Widal's syndrome benefited the most. Based on the results of this study, we have undertaken a randomized, parallel, double-blind, placebo-controlled clinical trial.

Anti-Inflammatory Agents↗
PubMed1998

[Nitric oxide synthase activity in nasal mucosa].

Nitric oxide (NO) plays an important regulatory role in airway function and seems to be implicated in the pathophysiology of several airway diseases. We studied the presence of NO synthase activity in human nasal mucosa and nasal polyp tissues obtained from patients undergoing septoplasty or polypectomy, respectively. NO synthase activity was quantified in tissue homogenates using citrulline release assay and was located in tissue sections using NADPH-diaphorase histochemistry. The results indicated that nasal polyps contain higher levels of total NO synthase activity than nasal mucosa tissue. In addition, nasal polyps contained mainly inducible NO synthase activity whereas all NO synthase activity detected in the nasal mucosa was in constitutive form. In both cases, NO synthase activity was localized in epithelial cells. In view of these results, we conclude that NO may be an important inflammatory mediator in the respiratory system and that the epithelium may be a source of NO production.

Adult↗
PubMed1998

[Second primary tumors in patients with laryngeal neoplasms].

A cohort epidemiologic study of second primary tumours appeared in patients diagnosed of laryngeal neoplasms, between years 1988 and 1990, and a follow-up term of 5 years, is presented. An statistical analysis of several data to define a possible high risk group for developing primary tumours was performed for all patients.

Adolescent↗