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R Cicero

Publications and source records attributed to R Cicero.

At least 19 recordsLinked to original sources
PubMed2001

Laryngotracheal reconstruction in subglottic stenosis: an ancient problem still present.

BACKGROUND: Subglottic stenosis is an ancient but persistent problem as a cause of airway obstruction. The etiology and the results of surgical treatment with thyrotracheal anastomosis were reviewed. METHODS: Fifty-six patients with subglottic stenosis were studied. All were subjected to laryngotracheal reconstruction by thyrotracheal anastomosis with partial resection of the cricoid. RESULTS: Of all 56 cases of subglottic stenosis, 48 (86%) had history of previous tracheal intubation, and only 8 (14%) had different non-neoplastic obstructive processes such as scleroma, direct injury, hamartoma, and amyloidosis. Immediate results were good in all cases. After 1 year follow-up, results of thyrotracheal anastomosis were successful in 44 (91%). In 4 other cases a restenosis was observed. Eight patients were lost to follow-up. CONCLUSIONS: Subglottic stenosis is still frequent after tracheal intubation, but other causes must be considered. Laryngotracheal reconstruction with thyrotracheal anastomosis with partial cricoid resection was feasible with good results in 91% of the cases with follow-up, but this procedure must be performed by a skilled surgical team.

Adult↗
PubMed2000

Tyrosinase gene expression in the Kupffer cells of Rana esculenta L.

The liver of Amphibia and Reptilia shows a dark-brown pigmentation due to the presence of particular melanin-containing cells that are different from melanocytes and derive from cells of macrophage lineage (Kupffer Cells), which have been shown to have an autonomous capacity to synthesize melanins. To date, as far as we know, there are no reports in the literature about the genetic system of tyrosinase as regards these melanin-synthesizing cells; we carried out the present study to analyze how the tyrosinase gene may function. We showed that the Kupffer cells of Rana esculenta L. do indeed have a transcriptionally active tyrosinase gene. Evidence of this was obtained by reverse transcription polymerase chain reaction analysis carried out on both the liver tissue and the Kupffer cells in culture. Moreover, analysis of the cells in culture enabled us to observe that, by increasing the culture time from 0 to 72 hr, an appreciable increase occurred in the amplification products of the tyrosinase gene, as well as in the level of dopa oxidase activity and in the quantity of melanin in the cells. The results of the present study demonstrate that frog Kupffer cells possess an active tyrosinase gene and that the increase of the tyrosinase mRNA accumulation closely correlates with phenotypic differentiation, in terms of increased dopa oxidase activity and melanosome content. This provides further strong support of the hypothesis that amphibian Kupffer cells possess an endogenous ability to synthesize melanin and suggests the involvement of the transcriptional level of control in the modulation of their melanogenic activity.

Animals↗
PubMed1998

Ultrastructural and functional study of the liver pigment cells from Rana esculenta L.

A study of the liver pigment cells of Rana esculenta L. has been performed on both liver in toto and cells in culture. Ultrastructural and cytochemical analyses showed a close relationship between this visceral pigment cell system and the cells of hepatic macrophage lineage. Like the latter, the liver pigment cells present phagocytic activity, in the sinusoids and in vitro, and give a positive response to tests for peroxidase and lipase. The liver pigment cells are isolated, together with the Kupffer cells, from the sinusoidal cell fraction of the liver. In culture, they maintain their melanogenetic ability, demonstrated by the presence of dopaoxidase activity in the soluble, membranous, and melanosome fractions. Analysis of the cultures showed that as culture time increased, so did melanosome dopaoxidase activity, the number of pigmented fields, and the level of pigmentation of the cells. The values of dopaoxidase activity of the pigment cells in culture show the same seasonal oscillations as the system in toto, indicating that the cells maintain an internal clock, at least in the first 72 h of culture. There is evidence that the pigment cells are macrophages which can express a melanogenetic function. Our results and other experimental data provide a basis for hypothesizing that the pigment cells in Rana esculenta L. liver may derive from, or have a common origin with, the Kupffer cells.

Animals↗
PubMed1996

Intrapleural fibrinolysis with streptokinase as an adjunctive treatment in hemothorax and empyema: a multicenter trial.

To test the efficacy of intrapleural fibrinolytic therapy in patients with loculated pleural effusions, we conducted an open, prospective, and multicenter trial among five hospitals in Mexico. We enrolled patients with hemothorax or empyema, clotted and/or loculated, that was not resolved through conventional pleural drainage with chest tube and antibiotics in patients with empyema. All patients received repeated doses of 250,000 IU of streptokinase through chest tube. Effectiveness criteria were before and after intrapleural streptokinase (IPSK) drainage, and poststreptokinase radiographic and respiratory function test improvement. Forty-eight patients were studied; there were 30 patients with empyemas, 14 with hemothorax, and 4 patients with malignant pleural effusions without lung trapping. Successful fibrinolysis was obtained in 44 patients, with complete resolution of the pleural collection and adequate radiologic and spirometric improvement. In three of four patients with multiloculated malignant hemothorax with high-yielding pleural drainage, IPSK allowed successful lysis of loci and an adequate pleurodesis was achieved. Only four patients required surgical treatment. The overall success rate in our series was 92%, similar to previous reports. The results in this first prospective and multicentric trial suggest that intrapleural fibrinolysis is an effective and safe adjunctive treatment in patients with heterogeneous pleural coagulated and loculated collections to restore the pulmonary function assessed by respiratory function tests and can obviate surgery in most cases.

Adolescent↗
PubMed1996

Enzyme-linked immunosorbent assay (ELISA) with mycobacterial crude antigens for the sero-epidemiological diagnosis of active tuberculosis.

In search for reliable, nonexpensive procedures for tuberculosis diagnosis suitable for seroepidemiological studies in leprosy-endemic areas, enzyme-linked immunosorbent assays (ELISAs) with whole intact bacilli, whole lipid-free bacilli and protein-enriched soluble extracts from the H37Rv Mycobacterium tuberculosis strain were evaluated. Sera tested came from 47 active, pulmonary tuberculosis adult cases, 60 household contacts of active tuberculosis cases, 20 lepromatous leprosy adult patients, and 67 healthy adult controls obtained from low and high leprosy and tuberculosis endemicity areas. There was no influence of such endemicity levels in the number of positive results in control sera. Antibody levels obtained with each of the antigens in ELISAs were significantly different in tuberculosis patients and the control groups. Ten percent of tuberculosis contacts were positive with some of the antigens and three of them showed suggestive chest radiographs. The best combination for a high number of positive results with tuberculosis sera and low positive results with leprosy sera was the BCG soluble extract (91% and 15%, respectively). This preparation also yielded excellent sensitivity and specificity values for tuberculosis (91.5% and 92.5%, respectively). These data suggest that BCG soluble extract ELISAs could provide helpful information to estimate tuberculosis prevalence only in leprosy-free areas, under a situation of unavailability of purified antigens. In pulmonary cases, sputum microscopic examination and culture have higher sensibility than serodiagnosis; therefore, the utilization of BCG soluble extract ELISAs as a diagnostic aid in individual patients with suspected active tuberculosis only can be useful in extrapulmonary cases.

Antibodies, Bacterial↗
PubMed1991

Behavior of the pulmonary circulation at rest and during exercise in miliary tuberculosis.

We studied the hemodynamic behavior of the pulmonary circulation at rest and during exercise in six patients with MTB. As a group, in contrast to advanced fibrocaseous tuberculosis, these patients exhibited normal pulmonary hemodynamics at rest and during exercise. Only minor abnormalities in pulmonary vascular resistance at exercise (increased PAd-PWP gradient) were noted in two of the patients. The increase in Rp during exercise does not appear to be related to acute hypoxic vasoconstruction but rather to functional changes (compliance or recruitment or both) of the pulmonary microvasculature. In the genesis of these functional changes, chronic alveolar hypoxia and the inflammatory-fibrotic process might be interacting.

Adult↗
PubMed1990

Morpho-functional characterization of cultured pigment cells from Rana esculenta L. liver.

A simple method to isolate and culture liver pigment cells from Rana esculenta L. is described which utilizes a pronase digestion of perfused liver, followed by sedimentation on a Ficoll gradient. A first characterization of isolated and cultured cells is also reported. They show both positivity for nonspecific esterases, and phagocytosis ability, like the cells of phagocytic lineage. Furthermore, after stimulation with a phorbol ester, these cells generate superoxide anions. At phase contrast microscope, liver pigment cells present variability in size, morphology, and in their content of dark-brown granules. Inasmuch as a cell extract obtained from cultured cells exhibits a specific protein band with dopa-oxidase activity, when run on nondenaturing polyacrylamide gel electrophoresis, liver pigment cells from Rana esculenta L. should not be considered as melanophages, but as cells that can actively synthesize melanin. The method presented here seems to be useful to more directly investigate this extra-cutaneous melanin-containing cell system and to clarify its physiologic relevance.

Animals↗
PubMed1990

Effects of copper on the tyrosinase of liver pigment cells from Rana esculenta L.

1. The liver pigment cells of R. esculenta L. constitute a peculiar pigment cell system of histiocytic nature and contain a tyrosinase-like activity localized in the protein component of melanosomes. 2. The effects of addition and/or removal of Cu on the DOPA-oxidase activity of the system were studied. 3. It was concluded that: (a) this tyrosinase behaves as a Cu-enzyme; (b) Cu could be involved in the regulation of the enzyme activity; and (c) mixtures of apoenzyme and active enzyme coexist in the melanosomes.

Animals↗
PubMed1986

Transthoracic needle biopsy in neoplastic and nonneoplastic pathology: experience in a general hospital.

Transthoracic needle biopsy (TNB) was performed in 344 cases of intrathoracic pathology. In 60 of them, the material obtained was inadequate. In the remaining 284, the possibilities of TNB to identify malignant cells were evaluated. Of them, 202 had neoplastic lesions and 82 had nonneoplastic processes. Among the neoplastic cases, malignant cells were found in 188, (true positive), and in 14 the results were false negative. In the group of nonneoplastic processes, there were 80 without malignant cells (true negative), and two were diagnosed as malignant, (false positive). In these 284 cases with cytologic diagnosis, the global sensitivity was 0.93, and the specificity was 0.97; however, including all cases and the inadequate samples as false negatives, the sensitivity is lower--0.71. TNB required some skill, the use of fine needles, and the collaboration of an expert cytopathologist. TNB is an important method with which to explore intrathoracic pathology.

Biopsy, Needle↗
PubMed1986

Open window thoracostomy and plastic surgery with muscle flaps in the treatment of chronic empyema.

Open window thoracostomy (OWT) and plastic surgery using myocutaneous flaps of extrathoracic muscles, was done in nine patients with chronic empyema, after conventional therapy had failed. In all these patients, the pleural cavity and bronchopleural fistulas, when present, closed within eight to 61 days (mean 30), after the second stage of surgery comprising the myoplasty; this in turn was performed between three to seven (mean 3.0) months after the OWT. All patients were considered cured with a minimal deformity of the chest wall. The final scar had an acceptable cosmetic appearance.

Adolescent↗
PubMed1983

Effect of lipophilic vitamins on the erythrocyte membrane. 31P NMR and fluorescence studies.

Structural changes induced by the fat-soluble vitamins A, D3, E and K1 in natural membranes were studied by 31P NMR and fluorescence anisotropy on erythrocyte ghosts; the occurrence of cell fusion following vitamin addition was detected by optical microscopy of intact cells. Vitamins A, E and K1, which produce cell fusion, also induce the formation of configurational phases other than the bilayer and increase, at a different extent for the different vitamins, membrane fluidity. Vitamin D3, on the contrary, induces aggregation without fusion, paralleled by bilayer phase stabilization and microviscosity increase. A correlation between fusion phenomena and structural variations in the bilayer organization is therefore suggested.

Animals↗
PubMed1982

[Biochemical and ultrastructural research on the antagonism between vitamins A and D at the leve of the erythrocyte membrane].

The reason for the antagonistic action between retinol and cholecalciferol on cellular membranes was investigated "in vitro" on human erythrocytes, by testing their lipoperoxide production, the amount of membrane-bound retinol and the morphology of these cells by scanning electron microscope. Lipoperoxides were assayed by TBA-test; the membrane-bound retinol was tested by the Karr-Price method on lipids extracted from red blood cells by the Folch method and vitamin D-deprived by TCL chromatography; the morphological changes of these cells treated with vitamin A, or D, or A+D, were tested by scanning electron microscope. In our experimental system both retinol and cholecalciferol increase the lipoperoxide production from the erythrocytes; nevertheless no synergism of action can be demonstrated between the two vitamins. Cholecalciferol decreases the amount of membrane-bo und retinol as well as the changes produced by vitamin A in red blood cell surface. These results are in good agreement with our previous observations obtained by nuclear magnetic resonance, using the same experimental system.

Binding, Competitive↗