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Biomedical subjects

I Durán

Publications and source records attributed to I Durán.

18 recordsLinked to original sources
PubMed2003

Palpable breast lesions: utility of Doppler sonography for diagnosis of malignancy.

This study was designed to find whether there are any differences between benign and malignant palpable breast lesions as they are seen on grey-scale and colour-Doppler and on power-Doppler sonography; to determine which variables for each technique are most helpful in distinguishing any such differences; and to see whether the use of an echo-enhancing agent gives better results in the differential diagnosis. Forty-five palpable breast lesions (16 benign and 29 malignant) were evaluated in a preoperative study using grey-scale sonography, colour-Doppler sonography and power-Doppler sonography before and after administration of an echo-enhancing agent (Levovist). We reached the following conclusions: (1) In the grey-scale ultrasound study of palpable breast lesions the presence of microcalcifications, acoustic shadowing and non-well-defined margins are related to malignancy. (2) Colour- and power-Doppler sonography may help in the differential diagnosis. (3) The use of an echo enhancer (Levovist) accentuates these differences and enables them to be noted in other variables, such as pulsatility index, nodule-to-vascularity ratio and number of poles.

Adult↗
PubMed2002

Ray-interray interactions during fin regeneration of Danio rerio.

Teleost fin ray bifurcations are characteristic of each ray in each fin of the fishes. Control of the positioning of such morphological markers is not well understood. We present evidence suggesting that the interray blastema is necessary for a proper bifurcation of each ray during regeneration in Danio rerio (Hamilton-Buchanan) (Cyprinidae, Teleostei). We performed single ray ablations, heterotopical graftings of ray fragments and small holes in lateral rays which do not normally bifurcate, to generate recombinants in which the lateral rays are surrounded with ectopic interrays originating from different positions within the tail fin. These ray-interray recombinants do now bifurcate. Furthermore, we show that the interray tissue and surrounding epidermis can modulate the length of the ray. These results stress the role of the interray in inducing bifurcations of the ray blastema as well as modulating ray morphogenesis in general. In addition, gene expression analysis under these experimental conditions suggests that msxA and msxD expression in the ray and interray epidermis is controlled by the ray blastema and that bmp4 could be a candidate signal involved in these inductions.

Animals↗
PubMed2001

Similar pro- and anti-inflammatory cytokine production in the different clinical forms of multiple sclerosis.

Cytokines play an important role in the initiation and maintenance of the inflammatory reaction in multiple sclerosis, a chronic inflammatory demyelinating disease of the central nervous system. Magnetic resonance imaging evidence supports clinical divergence between forms of multiple sclerosis with relapses and the primary progressive form without relapses, which shows fewer and smaller inflammatory lesions. With the aim of understanding better the relative role of pro-inflammatory and/or anti-inflammatory cytokines in primary progressive multiple sclerosis in comparison to relapsing forms, we analysed in 65 patients (24 primary progressive, 20 relapsing-remitting and 21 secondary progressive) and 29 healthy controls, the production of cytokines (IFN-gamma, TNF-alpha, IL-6, IL-10 and IL-12) by peripheral blood mononuclear cells after in vitro stimulation. We found a similar percentage of cytokines producing cells between healthy controls and the different clinical forms of multiple sclerosis patients.

Adult↗
PubMed2000

Masculine copulatory behavior is facilitated by intrathecally administered muscarine.

Behavioral experiments were conducted to examine the role of the cholinergic receptor-agonist muscarine or its antagonist homatropine on the mating behavior of sexually experienced male rats. Male copulatory behavior was recorded after intrathecally administered saline, muscarine (7.5 microg), or homatropine (25 microg). Changes in copulatory behavior were assessed by the following parameters: intromission latency, intromission frequency, intercopulatory interval, ejaculation latency, and postejaculatory interval. Intromission frequency, intercopulatory interval, and ejaculation latency were decreased significantly by muscarine. Intrathecal homatropine decreased the number of copulating animals (five out of 13). In the five animals that were able to ejaculate after homatropine, intromission latency, intercopulatory interval, and ejaculation latency increased significantly. The effects of both drugs on locomotion were also tested. Muscarine induced no significant changes in locomotion compared with saline. A significant increase in locomotion was found after homatropine treatment. These results suggest that acetylcholine, acting at spinal-cord muscarinic receptors, may be involved in ejaculation.

Animals↗
PubMed2000

Muscarinic mediation of the urethro genital reflex in spinal cord-transected rats.

The effects of muscarinic receptor stimulation were tested on the urethro genital reflex (UGR) in anesthetized and spinal cord-transected rats. Drugs were applied directly to the spinal cord. The electromyographic activity (EMG) of the bulbospongiosus (BS) muscle was used for recording UGR. In six animals BS as well as soleus, posterior biceps or peroneus tertius muscle EMG was recorded simultaneously. Muscarine (5, 10, 20, 50 and 100 microg) was applied in 22 animals after cutting L6-S1 dorsal roots. Some observations were made on another six animals, to which an extensive bilateral dorsal rhizotomy (L3-S2) was performed. Rhythmic bursts of similar frequency and size to those seen during UGR were found in BS muscle a few minutes after muscarine application. No rhythmic bursting was found on the hindlimb muscles, but exclusively on BS muscles. The effects of homatropine (25, 50, 100 and 200 microg), an acetylcholine muscarinic receptor antagonist, were tested in 21 rats after UGR was elicited three times at low stimulation intensity (7 mm Hg). Homatropine produced two effects: (i) A significant increase in the latency of UGR. (ii) A facilitation of UGR inhibition. In view of these results it can be speculated that muscarinic receptor stimulation is involved in the elicitation of UGR.

Animals↗
PubMed1999

Immunological profile of patients with primary progressive multiple sclerosis. Expression of adhesion molecules.

Adhesion molecules are important in the trafficking of peripheral leucocytes into the central nervous system, a major event in the pathogenesis of multiple sclerosis, which is an inflammatory and demyelinating disease. The latest MRI evidence supports clinical divergence between forms of multiple sclerosis with relapses and the primary progressive form without relapses, which shows fewer and smaller inflammatory lesions. With the aim of elucidating whether different pathogenic mechanisms are involved in primary progressive multiple sclerosis, we compared membrane expression of the adhesion molecules ICAM-1 (CD54), LFA-1alpha (CD11a), VLA-4 [alpha(4)/beta(1) integrin (CD49d/CD29)], L-selectin (CD62L) and ICAM-3 (CD50) in peripheral blood and the serum-soluble forms ICAM-1, L-selectin, VCAM-1 and ICAM-3 in 89 patients (39 with the primary progressive form, 25 with the secondary progressive form and 25 with the relapsing-remitting form) and 38 healthy controls. We found a significant decrease in leucocyte surface expression of most of the adhesion molecules tested and an increase in soluble ICAM-1 and L-selectin levels in secondary progressive and relapsing-remitting multiple sclerosis compared with primary progressive multiple sclerosis, which gave results similar to those in controls. These results, which are supported by MRI evidence, show that trafficking of autoreactive leucocytes through the blood-brain barrier is crucial to the pathogenesis of secondary progressive and relapsing-remitting forms of multiple sclerosis, whereas other mechanisms leading to progressive axonal damage would account for primary progressive forms of the disease.

Adult↗
PubMed1998

Amelioration of flulike symptoms at the onset of interferon beta-1b therapy in multiple sclerosis by low-dose oral steroids is related to a decrease in interleukin-6 induction.

Low-dose oral steroid use at the onset of interferon beta-1b (IFNbeta-1b) therapy in relapsing-remitting multiple sclerosis (RR-MS) patients reduces flulike symptoms. To determine the mechanism by which steroid treatment minimizes these side effects, we analyzed the percentage of interleukin-6 (IL-6)-, interferon-gamma (IFN-gamma)-, tumor necrosis factor alpha (TNF-alpha)-, and IL-10-producing cells before and after 3 months of IFNbeta-1b therapy onset. Our results support a relationship between IL-6 induction and fever. Such side effects can be ameliorated by steroids.

Acetaminophen↗
PubMed1998

The activity of ON and OFF cells at the rostroventromedial medulla is modulated by vagino-cervical stimulation.

In anesthetized rats it was tested whether or not the activity of the ON and OFF cells within the rostral ventromedial medulla (RVM) is modulated by the mechanical stimulation of the uterine cervix (VS). ON cells were identified by an abrupt increase in their firing rate before the tail flick in response to a noxious heat. OFF cells were identified by a sudden decrease in their firing rate before the tail flick. All (27 out of 27) identified ON cells decreased their firing rate immediately after VS was applied. The effect of VS on the activity of the cells persisted for the entire stimulation period. On the other hand, all (19 out of 19) identified OFF cells increased their firing rate immediately after VS. The effect of VS on the activity of these cells also persisted for the entire stimulation period. The activity of the neutral cells showed no change, neither during the application of noxious heat, nor during VS. These results suggest that the analgesic-like effect produced by VS can be mediated by the activity of the antinociceptive circuit at the RVM. Alternatively, it can be suggested that the afferent inflow from the genital tract can induce the activity of the antinociceptive circuit at RVM, either by projections to the periaqueductal gray matter or by direct projections to RVM.

Animals↗
PubMed1996

Neural mechanisms accounting for the increase in blood pressure and heart rate during vagino-cervical stimulation.

The rise in blood pressure and heart rate produced by the mechanical stimulation of the uterine cervix (VS) was examined after adrenalectomy, after pelvic or hypogastric neurectomies or after spinal cord transection in anesthetized rats. Neither adrenalectomy, nor hypogastric neurectomy prevented the rise in heart rate and blood pressure produced by VS. After the spinal cord transection at T6 level, VS was still able to produce the rise in blood pressure. However, the rise in blood pressure was significantly lower than that produced in the same animals before the transection. No changes in heart rate were produced by VS after spinal cord transection. This result can be explained because this level of transection prevents the reach of the afferent inflow to the superior cervical ganglia. Pelvic neurectomy abolished completely the effects of VS on blood pressure and heart rate. Low intensity (1-2 times the threshold) electrical stimulation of the pelvic nerve produced a rise in blood pressure. Even though heart rate increased during electrical stimulation, the change in heart rate was not statistically different from the pre-stimulation value. These results suggest that the changes in blood pressure and heart rate produced by VS represent a neuronal reflex response mediated by the pelvic nerve. The fact that the effects of VS on blood pressure persist in spinal cord-transected animals suggests that the reflex is integrated at the spinal level. However, the cardiovascular responses to VS were significantly lower than before transection, suggesting that supraspinal centers are also involved in the reflex.

Adrenalectomy↗
PubMed1996

FTIR monomer conversion analysis of UDMA-based dental resins.

The utility of the amide II absorption band at 1537 cm-1 as internal reference for calculation of monomer conversion in urethane dimethacrylates (UDMA)-based dental restorative materials and sealants by means of Fourier transform infrared spectroscopy (FTIR) is demonstrated in this paper.

Amides↗
PubMed1992

[Cholelithiasis in the region of Cartagena: an approximation to its real incidence based on the study of its symptomatic group].

We have studied the frequency of cholelithiasis in a group of patients who complained of clinical symptoms of cholelithiasis and lived in the region of Cartagena. This group of patients accounts for 40% of all the patients suffering from cholelithiasis this would account for 0.5% of the whole population and 1% of the exposed population over 30 year-of-age. Our results suggest that the population living in the region of Cartagena has a low-risk for cholelithiasis.

Adult↗
PubMed1992

[Cholelithiasis and cancer: a study using precursor changes in a population with low incidence of cholelithiasis].

In order to assess the role of cholelithiasis in the pathogenesis of gallbladder carcinoma in a low-risk population for cholelithiasis and gallbladder cancer, we have studied the relationship between cholelithiasis and cancer. Our findings suggest that, both the relationship between cancer and cholelithiasis, and the frequency of precursors lesions, are very similar to those obtained in surveys carried out in high-risk populations for both conditions. Our findings bear out our hypothesis that cholelithiasis plays a main role in the pathogenesis of gallbladder carcinoma.

Adult↗
PubMedDate not supplied

Different antiganglioside antibody pattern between relapsing-remitting and progressive multiple sclerosis.

INTRODUCTION: Multiple sclerosis (MS) is an autoimmune disorder, but an unique antigen has not been found. Antiganglioside antibodies (AGA) have been reported in MS, nevertheless, a clinical significance of AGA in MS has not been established. The aims of this study were to study AGA in sera of MS patients and to investigate relationships between AGA and clinical course of MS. MATERIAL AND METHODS: 42 patients with MS who fulfilled the criteria of clinically definite disease (59% RRMS, 21% SPMS, 20% PPMS), 89 patients with systemic lupus erythematosus and 36 healthy controls were studied. A modification of previously described ELISA techniques was used to estimate serum IgG and IgM anti-GM1, asialoGM1 and anti-GD1a antibodies. RESULTS: 47.6% of the patients showed AGA reactivity. Anti-GM1 was found in 38% of MS patients, anti-asialoGM1 in 23.8% and anti-GD1a in 33.3%. IgG was the isotype more commonly found. A correlation between presence of AGA and progressive disease and between anti-GD1a and PPMS was found. CONCLUSIONS: The presence of AGA in MS patients is elevated. In contrast with the results of others authors, a strong correlation between AGA and progressive disease is showed in our study.

Adult↗