Biomedical subjects
Publications and source records attributed to C Salas.
Inflammatory pseudotumors are rare and usually located in lung, although they can develop in any organ. They are unusual in head and neck and very rare in the larynx. A case of laryngeal pseudotumor in a patient with odinophagia and neck pain is reported. After diagnosis, the patient was treated with steroids, which produced complete resolution. These lesions can simulate malignant neoplasms and must be considered in the differential diagnosis.
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The relation between angiogenesis and tissue expression of vascular endothelial growth factor (VEGF) was studied in a series of 14 capillary cerebellar hemangioblastomas. In the present series, the number of intratumoral microvessels, identified by the endothelial marker CD34, does not correlate with the degree of VEGF expression. This finding suggests that endothelial growth factors other than VEGF may regulate tumor angiogenesis in these neoplasms.
BACKGROUND: Left and right colon carcinomas can display different clinical, pathologic, and genetic characteristics. The purpose of this study was to characterize multiple molecular genetic alterations in sporadic colon carcinoma and to correlate them with the location of the tumors and with lymph node metastasis. METHODS: One hundred and twenty-five cases of sporadic colon carcinoma (50 in the right colon and 75 in the left colon in patients with no family history of colon carcinoma) were studied. Status of the p53 gene was assessed by polymerase chain reaction (PCR), single strand conformation polymorphism, and sequencing at exons 5-8. Microsatellite instability was analyzed with five microsatellite markers at chromosome 18. The mismatch repair genes hMLH1 and hMSH2 were studied in tumors found to have microsatellite instability by PCR and sequencing. RESULTS: In the 125 cases studied, there were 53 tumors with mutations of the p53 gene. p53 mutations correlated with lymph node metastases from right colon carcinoma cases (61%), and all cases with p53 mutations and microsatellite instability were AJCC/UICC Stage III (Dukes Stage C). In the right colon carcinoma cases the rate of microsatellite instability was related to the tumor size (19% in tumors measuring < 4 cm, and 34% in tumors measuring > 4 cm). No correlation between microsatellite instability and p53 mutations was detected. In the left colon carcinoma cases, p53 mutations were detected in 41% of tumors and microsatellite instability in 14%; neither finding was related to the tumor size. Mutations of the hMLH1 and hMSH2 mismatch repair genes were detected in 7 of 24 cases with marked microsatellite instability. CONCLUSIONS: Microsatellite instability is prone to occur in sporadic right colon carcinoma during tumor growth and is not associated significantly with mutations in the hMLH1 and hMSH2 mismatch repair genes or in the p53 gene. Concomitant detection of microsatellite instability and p53 mutations in right colon carcinoma is associated with the presence of lymph node metastases.
This work studies the tail and eye co-ordinated movements evoked by the focal electrical stimulation of the tectum in goldfish. The aim of the study is to understand better those tectal sites and mechanisms that either remain functionally unaltered or are adaptively modified across vertebrates. Stimulation was applied in various tectal zones, and the characteristics of evoked tail and eye movements were examined as a function of the stimulation site over tectal surface and the stimulus parameters. Two types of response were electrically evoked: the former turned the body and the eyes contraversively towards the source of natural stimulus; the second produced initial ipsiversive turning of the body and eyes, followed by several tail beats. Evoking one or other response depended on both the site and parameters of stimulation, and responses were interpreted as orienting- and escape-like, respectively. Depending on the stimulation site, four different zones in the tectum were distinguished: in the medial zone the stimulus elicited eye and tail movements whose size increased with the distance to the rostral pole. The stimulation of the antero-medial zone evoked contraversive or ipsiversive eye saccades but tail movements were similar, irrespective of eye movements. Stimulation within the extreme antero-medial zone evoked convergent eye movements, and tail displacements turning the body either ipsiversively or contraversively. Stimulation of the posterior zone often evoked complex tail movements and pure horizontal eye saccades. Both orienting- and escape-like responses were also dependent on the stimulus parameters. The relationships between stimulus parameters and tail- and eye-orienting movement characteristics suggest that the velocity and duration might be encoded in different aspects of the tectal activity. Current strength also modified the number of tail beats that appeared during escape-like response. In conclusion, the present data suggest the involvement of the optic tectum not only in orienting but also in escape responses and that movements of eye and tail mediating such responses depend on the tectal active locus together with its level of activity.
Three cases are presented of tuberculosis occurring in a series of 410 heart transplant recipients in a Spanish hospital, representing a rate of 0.73%. Twenty-eight cases reported in the literature are also reviewed. In most series reported, tuberculosis occurred in a small percentage of heart transplant recipients, the average rate being 1.25%. Compared to the general population, a higher percentage (28%) of extrapulmonary and disseminated forms of the disease is seen in these patients. Although a cure without recurrence can usually be achieved with a conventional anti-tuberculous antibiotic regimen, the disease is still associated with a significant mortality rate of 11%. Guidelines for the early diagnosis and treatment of these patients are discussed.
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UNLABELLED: We used thoracic SPECT to study the 99mTc-tetrofosmin (TF) uptake in patients with non-small-cell-lung-carcinoma (NSCLC). The results were compared with the percentage of P-glycoprotein (Pgp) found in flow cytometric analysis (FC) of samples of surgically-resected tumor tissue. MATERIAL AND METHODS: A total of 21 patients with NSCLC were studied by means 99mTC-TF and thoracic SPECT. Image analysis included the determination of the TF uptake rate in the lung mass with respect to that of healthy tissue of the contralateral lung. These rates were compared with the percentage of Pgp expression according to FC. FC analysis was also carried out in 16 samples of healthy lung tissue obtained from the patients. RESULTS: In healthy lung tissue, the mean Pgp expression according to FC was 4.58 +/- 1.87%. The cutoff value used to differentiate between Pgp positive and Pgp negative tumors was considered to be the mean plus two standard deviations (8.32). The Pgp-positive tumors (> 8.32%) presented significantly lower uptake levels (1.28 +/- 0.39) than the Pgp-negative lesions (1.66 +/- 0.33) (p = 0.029). CONCLUSIONS: There is a inverse correlation between the Pgp expression as determined by FC analysis and 99mTc-TF in NSCLC. Thus, this radiopharmaceutical provides rapid and non-invasive information on Pgp expression in these lesions.
This work compares the tectal codification of eye movements in goldfish with those reported for other vertebrate groups. Focal electrical stimulation was applied in various tectal zones and the characteristics of evoked eye movements were examined as a function of (i) the position of the stimulation over the tectal surface, (ii) the initial position of the eyes and (iii) the parameters (pulse rate, current strength, duration) of the stimulus. In a large medial zone, stimulation within the intermediate and deep layers of the tectum evoked contraversive saccades of both eyes, whose direction and amplitude were roughly congruent with the retinotopic representation of the visual world within overlying layers. These saccades were minimally influenced by the initial position of the eye in the orbit. The topographical arrangement of evoked saccades and body movements suggests that this tectal zone triggers orienting responses in a similar way to those described in other vertebrates. Stimulations applied within the caudal tectum also evoked contraversive saccades, but in disagreement with the overlying retinotopic map--the vertical component was absent. Taken together with electrically evoked body movements reported in free-swimming fish, these saccades could reveal that this zone is involved in escape responses. When stimulations were applied within the anteromedial zone of the tectum, contraversive movements of both eyes appeared much more dependent on initial eye position. Saccades elicited from this area displayed characteristics of "goal-directed saccades" which were similar to those described in the cat. The generation of goal-directed movements from the anteromedial zone suggests that this portion of the goldfish optic tectum has a different intrinsic organization or is connected with the brainstem saccade generator in a different fashion than the medial zone. Finally, stimulation of the extreme anteromedial zone evoked convergent eye movements. These movements and those reported in free-swimming fish following electrical stimulation of this tectal area suggest that this zone could be involved in feeding responses. The relationships between the parameters of electrical stimulation and the characteristics of elicited saccades suggest that the stimulated location within the tectum determines a constant direction in the evoked saccade, whereas the amount and duration of tectal activity, as mimicked by changes in stimulus parameters, together with the tectal locus, determine the velocity and amplitude of the evoked saccade.
The aims of this study in 50 patients with H. pylori infection and duodenal ulcer were to examine the effect of eradication therapy on the serum levels of gastrin, pepsinogen I, and pepsinogen II and to investigate whether monitoring of the serum changes in these peptides after treatment could predict patient outcome. H. pylori status was assessed at entry and one and six months after therapy by culturing and microscopic analysis of the gastric mucosa and by [14C]urea breath test. Significant decreases were observed in the serum levels of gastrin (-11.4 +/- 3%), pepsinogen I (-28.9 +/- 4%), and pepsinogen II (-40.4 +/- 3%) in the 45 patients whose infection was eradicated, but not in the patients without eradication. Serum values of these peptides were unchanged in an additional group of 10 patients that only received omeprazol, none of whom had H. pylori eradicated. The best cutoff point of the percentage of each peptide to predict patient outcome was 10% for gastrin and pepsinogen I, and 15% for pepsinogen II. A pepsinogen II decrease > 15% resulted in the best marker of H. pylori clearance, accurately identifying patient outcome 86.6% of the time, whereas the diagnostic accuracy of gastrin and pepsinogen I was 61.7% and 76.6%, respectively. Significant correlations were found between the bacterial load assessed by histology with the serum concentrations of pepsinogen I and II and with the urease activity as measured by the amount of 14CO2 excreted. In conclusion, eradication of H. pylori infection is followed by a significant drop in serum levels of gastrin, pepsinogen I, and pepsinogen II. Changes in the latter are the most uniform and may be used as an indirect tool to predict treatment outcome.
We report on a case of the so-called sarcoidosis-lymphoma syndrome in a 65-years-old man diagnosed as having sarcoidosis and, four years later, neurosarcoidosis. The diagnoses of epidermoid carcinoma of the skin and of stage IV monocytoid, small cell lymphocytic lymphoma were made five and seven years, respectively, after the initial diagnosis of sarcoidosis. It has been suggested that the increased mitotic activity of lymphocytes observed in sarcoidosis, favours their malignant transformation. Hypothetically, sarcoidosis might also influence the development of epidermoid carcinomas by depletion of circulating T4 lymphocytes and decreased resistance to oncogenic viruses that could lead to decreased tumour rejection in the epithelia exposed to carcinogenic stimuli.
A 65-year-old cardiac transplant recipient suffered rupture of the mitral valve apparatus during endomyocardial biopsy of the left ventricle. Severe mitral regurgitation resulted, and because of heart failure with progressive clinical deterioration the patient was finally subjected to mitral valve replacement. He had a favorable postoperative course and is now asymptomatic.
This work was aimed to study if goldfish telencephalon is involved differentially in spatial and cue learning. With this purpose, animals were assigned to two learning conditions, 'spatial constancy' and 'directly cued', and their performance was recorded before and after ablation of the telencephalon. During the presurgical acquisition period, animals of both groups learned to solve the task with accuracy, and reached the goal in transfer tests, even though they were released from new starting positions and the response requirements were changed. Ablation impaired selectively the solution of the spatial constancy problem, but had no significant effects on the cued condition. However, with additional training, performance of the ablated animals in the spatial constancy condition improved to control levels. The above data suggest that fishes can implement multiple spatial learning strategies which have different neural substrata. These results are discussed in relation to the possible nature of the representation underlying each task.
The present work investigated whether the fish telencephalon is involved in spatial learning based on place strategies in a manner similar to mammalian hippocampus. Goldfish were trained in a 4-arm maze in a room with relevant spatial cues. Sham and to-be-ablated subjects were trained in each of 4 experimental procedures designed as follows: place, turn, place-turn, and control. After acquisition, complete ablations of both telencephalic hemispheres for the experimental groups were carried out. The results showed that ablation exclusively impaired performance in animals using place strategies; in these, accuracy fell to chance level during both postsurgery retraining and reversal periods. In the other groups, ablation of the telencephalon did not induce any significant deficit. These results suggest that the fish telencephalon plays a crucial role in complex place learning.
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The distribution of neurons projecting to the trochlear nucleus of goldfish (Carassius auratus) was studied by the electrophoretic injection of horseradish peroxidase into the nucleus. The location of the injection site was electrophysiologically determined by the antidromic field potential elicited from the trochlear nucleus after the electrical stimulation of its nerve. Retrogradely labeled neurons were observed in the following structures: (1) anterior, tangential and descending nuclei of the octaval column--afferents to these nuclei were mainly ipsilateral for the former and exclusively contralateral for the other two; (2) cerebellum; (3) rhombencephalic reticular formation, near the abducens nucleus; and (4) nucleus of the medial longitudinal fasciculus. In addition, a few stained neurons were scattered in the nucleus of the posterior commissure and in nucleus pretectalis superficialis pars magnocellularis. These results are compared with the afferent sources to trochlear nucleus in mammals and with the set of structures projecting to the oculomotor and abducens nuclei in goldfish. It is suggested that the neuronal pathways involved in the compensatory vestibular and optokinetic reflexes, as well as in the saccadic system, are similarly organized in vertebrates but that the relative importance of some of the components of these pathways varies.