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Biomedical subjects

S Navarro

Publications and source records attributed to S Navarro.

At least 163 records · Page 9Linked to original sources
PubMed1979

Triglyceride metabolism in Ephestia cautella pupae exposed to carbon dioxide.

The triglyceride content of Ephestia cautella pupae exposed to increased carbon dioxide atmospheres at low relative humidity was not markedly affected. There was a significant increase in weight loss of pupae exposed to low relative humidity. Results indicate that for E. cautella, metabolic water formation by fat utilization can hardly regulate water exigencies for the pupae and cannot fully compensate for water losses in high carbon dioxide atmospheres.

Animals↗
PubMedDate not supplied

Collagenolytic activity in human pancreatic tissue with different degrees of fibrosis.

The present study was designed to establish a valid method for expressing collagenolytic activity in pancreatic tissue with different degrees of fibrosis. Collagenolytic activity was measured in pancreatic tissue of control and alcoholic chronic pancreatitis (CP) patients and data were expressed as percent digestion/mg tissue or as percent digestion/mg protein obtaining different results. The values were 18.4 +/- 4.7% digestion/mg tissue in the control group, and 8.4 +/- 3.2% digestion/mg tissue in the chronic pancreatitis group (p < 0.001). When collagenolytic activity was expressed as percent digestion/mg protein, measured by the Bradford assay, the values of the control group were 190.2 +/- 69.0% digestion/mg protein, and those of chronic pancreatitis patients were 187.2 +/- 61.7% digestion/mg protein (p = ns). Protein determination in pancreatic tissue of control and CP patients was seen to be influenced by the method assayed. Protein content per mg of fresh tissue, measured by the methods of Lowry, Bradford, and Bradford-SDS, were similar and twofold higher in controls than in CP samples. However, the Kjeldahl assay showed that protein content per mg of dry tissue was the same in both groups. The high degree of fibrosis in the pancreas of CP patients (60.2 +/- 28.0%) with regard to controls (4.7 +/- 1.8%) (p < 0.001) and the low response of collagen proteins to the Lowry and Bradford assays could explain the differences observed in protein content of human samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Effects of ethanol feeding and malnutrition on collagen synthesizing and degrading enzymes in rat pancreas.

This study was performed to delineate the combined effects of a low-fat diet and chronic ethanol ingestion on collagen metabolism in rat pancreas. Rats fed a very low-fat diet (5% of total calories as lipid) for 12 weeks developed malnutrition as judged by weight loss (-33% of the initial body weight) and low serum albumin and amylase levels. The pancreas of malnourished rats showed increased collagenase activity with respect to animals fed a 35% lipid diet (p < 0.05). Hydroxyproline content was higher in the pancreas of malnourished rats and collagenase activity correlated well with hydroxyproline content (r = 0.57, p = 0.0013). Ethanol feeding for 12 weeks, regardless of the nutritional state of the rats, did not change the synthesis and degradation rates of collagen in the pancreas. The present study suggests that malnutrition may have profound effects on collagen metabolism.

Amylases↗
PubMedDate not supplied

Transcriptional repression of type I IFN genes.

Transcriptional regulation is a consequence of the combination of both activation and repression for establishing specific patterns of eukaryotic gene expression. The regulation of the expression of type I interferon (IFN-A and IFN-B) multigene family is controlled primarily at the transcriptional level and has been widely studied as a model for understanding the mechanisms of stable repression, transient virus induction and postinduction repression of the genes. The positive and negative regulatory elements required for this on/off switch have been defined within a complex 5' upstream region of their transcription start site. The differential expression pattern of type I IFN genes is thought to involve both substitutions in the virus responsive element (VRE) and presence or absence of negatively acting sequences surrounding the VRE. In this review we discuss several mechanisms of negative regulation due to the existence of common or specific elements in the IFN-B and IFN-A genes and we summarize recent studies on transcriptional repressors that bind to these promoters.

Animals↗
PubMedDate not supplied

[Immunological and inflammatory pathogenesis of asthma: the predominance of ontogenic Th2 and its relation to developing immunological mechanisms during fetal and neonatal stages. Therapeutic implications].

From an immunopathogenic vantage point, asthma appears to be a complex allergic/inflammatory disorder involving mechanism in which the specific immunological response shifts toward Th2 responses instead of Th1 responses. As a consequence of this shift, the cytokines IL-4, IL-5, IL-10, IL-13, TNF-alpha and CSF-GM are produced. The actions of these cytokines explain the phenomena of eosinophilic infiltration and mastocytic degranulation that characterize allergic asthma. The authors propose that the process of deviation toward Th2 responses occurs in the fetal stage and is a result of maternal immunological remodeling processes characteristics of pregnancy. In this period, the mother's mechanisms of immune rejection (mediated by Th1 lymphocytes and their cytokines IFN-gamma and IL-2) are detained or slowed, leading to the predominance of the Th-2 circuit. This predisposes the child to the development of an allergic response to a chance encounter with allergens, viruses and/or bacteria and/or parasites that activate the Th2 circuit. Moreover, deficits in the function of the Th1 circuit explain the sensitivity of the newborn to infections by viruses and other intracellular pathogens. Knowledge of these immunopathogenic mechanisms suggests that the future treatment of asthma and other allergic diseases will be based on the use of immunomodulators capable of stimulating Th1 response, thus achieving a) a god state of resistance to infection, and b) reductions of the production of pro-inflammatory cytokines. The experimental results of IL-12 in human beings with AM3 (an inductor of IFN-gamma and IL-12) support the pathogenic hypothesis proposed and open new ways for the treatment of asthma and other allergic diseases.

Asthma↗
PubMedDate not supplied

Determination of simazine, terbuthylazine, and their dealkylated chlorotriazine metabolites in soil using sonication microextraction and gas chromatography.

A rapid analytical method is proposed for the determination of simazine, terbuthylazine, and their chloro dealkylated metabolites (simazine-desethyl, simazine-bisdesethyl, and terbuthylazine-desethyl) in soil. A sonication micromethod is presented for the extraction of -triazine herbicides and their metabolites. Final determination is by gas chromatography (GC) with nitrogen-phosphorus detection. The identity of all compounds was confirmed by GC with mass selective detection in the selected-ion monitoring mode. All chromatograms were very clean, without interfering peaks, and no cleanup was needed. The limits of detection were 1 pg for simazine-bisdesethyl; 5 pg for simazine, terbuthylazine, and terbuthylazine-desethyl; and 10 pg for simazine-desethyl. The limits of quantitation were 1, 5, and 10 ppb, respectively. Mean recoveries from fortified soils ranged from 76% for simazine-bisdesethyl to 102% for simazine-desethyl, with relative standard deviations of 3-6%.

Chromatography, Gas↗
PubMedDate not supplied

[Mumps meningitis: a case mix in a Neurology Department].

INTRODUCTION: Parotiditis is a viral infection that produces a non-suppurative inflammation of the parotid glands, although it may affect other salivary glands, the testicles, meninges and the pancreas. Clinical meningitis appears in 1-10% of cases, normally between the 4th and the 10th day after infection of the parotid glands. In this study, we analyse the clinical and analytic characteristics of the patients admitted to our Neurology Department over the last 12 years. CASE REPORTS: A retrospective study was conducted by analysing the hospital discharge reports. The eligibility criterion was the existence of an acute meningeal syndrome linked to the presence of positive IgM titres for the parotiditis virus. In all, 13 cases were found, with a mean age of 16.5 years, and most of them were males (92.3%). Parotiditis preceded meningitis in all our patients with an average of 8.3 days, while orchiepididymitis, when it occurred, appeared at the same time or after meningitis. Analysis of the cerebrospinal fluid showed a lymphocyte profile with glycorrhachia above 40%, except in two cases that showed a non-persistent neutrophilic profile. There was a transient 30.7% reduction in prothrombin time in the patients. No sequelae were observed. CONCLUSIONS: Vaccination campaigns have drastically reduced the number of cases of meningitis due to this germ since the second half of the 90s. This virus must be borne in mind in cases of meningitis in young males who come from underdeveloped countries.

Adolescent↗
PubMedDate not supplied

[Aphasia and parietal syndrome as the presenting symptoms of a demyelinating disease with pseudotumoral lesions].

INTRODUCTION: Multiple sclerosis (MS) often presents with sensory symptoms, which are usually due to spinothalamic or spinal cord disorders; parietal syndrome is, however, very rare as the initial symptom. Likewise, aphasia is also an infrequent symptom of MS; in the few cases that have been reported, it is usually linked to the existence of important pseudotumoral lesions. CASE REPORT: We describe the case of a 31-year-old female with a 48-hour history of a progressive clinical picture consisting in nominal aphasia and a sensory parietal syndrome. Magnetic resonance imaging showed a lesion 3.6 cm in diameter that was hyperintense in T2 with perilesional edema and minimal gadolinium uptake, along with other images that revealed increased signal intensity in the periventricular subcortical white matter on the right-hand side and in the left-hand frontal subcortical region. A spectroscopic analysis of the largest lesion revealed that this lesion showed evidence of inflammation, with cell destruction and replacement, although it was not possible to distinguish between a demyelinating disease and a high grade glioma. Hence, a brain biopsy was required in order to reach the final diagnosis of demyelinating pseudotumoral lesion. CONCLUSIONS: Giant pseudotumoral plaques are a rare form of presenting symptom in MS; use of the clinical features, simple images and spectroscopy is not a very reliable means of reaching a differential diagnosis with a tumour and this often makes it necessary to conduct a biopsy study of the lesion.

Adult↗
PubMedDate not supplied

Laparoscopic treatment of acute biliary pancreatitis.

UNLABELLED: Laparoscopic cholecystectomy (LC) has become the standard treatment of gallstones. Application of LC in certain complications of biliary stones such as acute biliary pancreatitis (ABP) is not well defined. 10-30% of patients with ABP present associated bile duct stones, and the realization of a preoperative ERCP has been routinely proposed. Nevertheless, this examination may be unnecessary in most patients. AIM: To investigate the applicability of laparoscopic surgery for treatment of ABP. MATERIALS AND METHODS: Between Jan-1992 and June-1995, 368 patients were prospectively evaluated for LC, 274 for indications other than ABP. (Group I, LC) and 91 as a consequence of ABP. (Group II, ABPxL). ERCP was indicated when ultrasonography showed a dilated bile duct (> 8 mm) or when the liver function test (LFT) presented high scores. Age, sex, operative time, incidence of bile duct stones, postoperative stay and morbimortality were evaluated. RESULTS: The two groups were well matched for age, sex and associated medical risk factors. There were no differences in the operative time, conversion rate or postoperative morbidity (10% vs 10%). ERCP was performed in 25 patients in Group II and bile duct stones were found in 12 cases. In all cases an intraoperative cholangiography was performed, and in 6 patients, bile duct stones were removed by laparoscopic means. Three patients were converted to open surgery on finding duct stones which could not be treated by laparoscopic means. Mean postoperative stay was significantly longer in Group II than in Group I. In two cases, pancreatic pseudocyst was attempted with a laparoscopic approach. CONCLUSIONS: Definitive treatment of ABP could be accomplished effectively by laparoscopy, with selective indication of ERCP.

Acute Disease↗
PubMedDate not supplied

Conservative pancreatic resection in patients with obstructive chronic pancreatitis.

The purpose of this paper is to present the results of our experience in using a conservative pancreatic resection approach in a certain group of patients suffering from chronic pancreatitis. From January 1988 to December 1995, 110 patients underwent surgical therapy for chronic pancreatitis at the Hospital Clinic of the University of Barcelona. In 35 patients with an inflammatory mass at the pancreatic head, pylorus-preserving duodeno-pancreatectomy was performed. Forty male patients with localized focal pancreatitis at the body or tail underwent distal pancreatectomy and drainage of the pancreatic remnant. In 30 patients with pancreatic ducts greater than 7 mm in diameter, side-to-side pancreaticojejunostomy was carried out. Five patients could not be included in any of these three categories because of their particular characteristics. In all cases, resolution of the symptoms was achieved at the mean follow-up of 18 months (range 12 to 21 months). No patient showed a deterioration of glucose homeostasis, and exocrine dysfunction was not observed. Patients with obstructive chronic pancreatitis by inflammatory cystic mass, short strictures or intraductal stones located in the central pancreas or uncinate process may be surgically managed with conservative pancreatic resection or extraction of the stones from the Wirsung duct. The jejunal interposition and pancreaticojejunal anastomosis achieved pain control without any deterioration of the endocrine or exocrine function.

Cholangiography↗
PubMedDate not supplied

[The usefulness of the timeliness of endoscopic sphincterotomy in severe acute pancreatitis of biliary origin].

There are evidence indicating that endoscopic retrograde cholangiopancreatography with sphincterotomy (ERCP+S) reduces the rate of complications in patients with severe acute biliary pancreatitis (ABP). The aim of this study was to analyze our experience in the treatment of severe ABP with ERCP+S and compare the evolution of the patients treated early (3 days or less following admission) with those treated late (after the 3rd day). A retrospective review of the clinical histories of the 16 patients with severe ABP treated with ERCP+S over the last two years is presented, analyzing their clinical features on admission and evolution. Biliary stones or biliary sludge was observed in 11 cases (69%). Nine patients had undergone early, and 7 late, ERCP+S. The patients of the latter group presented a greater number of complications during evolution than the former group (43% vs 0%; p = 0.025). The mortality of the patients of the late ERCP+S was also greater although without statistical significance (28.6% vs 0%; p = 0.15). No complication secondary to ERCP+S was detected. These findings confirm the fact that ERCP+S performed early in severe ABP significantly reduces the number of complications and is associated with a lower mortality.

Acute Disease↗