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Biomedical subjects

M Navarro

Publications and source records attributed to M Navarro.

At least 145 records · Page 8Linked to original sources
PubMed1998

Immune response and cytokines in septic rats undergoing blood transfusion.

BACKGROUND: Intrabdominal sepsis and allogeneic blood transfusion have been associated with a depression of the immune response in patients undergoing surgery. Some authors have considered that an already immunocompromised host is probably primed for a potential detrimental effect of allogeneic blood. The aim of this paper is to ascertain the effects of allogeneic blood transfusion on the lymphocyte subsets and cytokines in septic rats. MATERIALS AND METHODS: Thirty rats were allotted into three groups: Sham-CLP, anesthesia and laparotomy; CLP, cecal ligation and puncture; CLP+BT, CLP and allogeneic blood transfusion. Preoperatively and on the 1st, 3rd, and 7th postoperative days, the cell percentages of lymphocyte subpopulations, the IL-2 receptor expression, and the IL-1, IL-2, TNF-alpha and IFN-gamma were measured in blood by flow cytometry and ELISA: RESULTS: CLP+BT rats showed on Day 3 a decrease of the CD4+%, an increase of the IL-2R expression directly correlated to the increase of the CD8+% phenotype, a steady increase of IL-1 levels, a decrease of the TNF-alpha levels on the 1st and 3rd days, and a decrease of the IL-2 and IFN-gamma on Day 1. CONCLUSIONS: An accumulative effect of the immunodepression induced by sepsis was observed when allogeneic blood transfusion is added. Blood transfusion + sepsis induces an extensive impairment on cellular immune response and an initial cytokine downregulation, except for IL-1.

Animals↗
PubMed1998

Role of the endogenous cannabinoid system in the regulation of motor activity.

One of the prominent pharmacological features of drugs acting at the brain cannabinoid receptor (CB1) is the induction of alterations in motor behavior. Catalepsy, immobility, ataxia, or the impairment of complex behavioral acts are observed after acute administration of either natural and synthetic cannabinoid receptor agonists or the endogenous CB1 ligand anandamide. The dense presence of CB1 receptors in the cerebellum and in the basal ganglia, especially at the outflow nuclei (substantia nigra and the internal segment of the globus pallidus), supports the existence of an endogenous cannabinoid system regulating motor activity. In the basal ganglia, the functionality of the anandamide-CB1 system is poorly understood. Dual effects are often observed after the administration of CB1 ligands in animal models of pharmacological manipulation of basal ganglia transmitter systems, indicating that the activity of the anandamide-CB1 system depends on the ongoing activation of the different elements of the basal ganglia. This finding is in agreement with the proposed activity-dependent release of anandamide from a plasmalemma precursor. Additionally, a potential state-dependent bidirectional coupling of the CB1 receptor to the adenylate cyclase transduction system has also been described. From this perspective, the endogenous cannabinoid system can be proposed as a local regulator of neurotransmission processes within the basal ganglia. This system may serve as a counterregulatory homeostatic mechanism preserving the functional role of basal ganglia circuits in coding the serial order of events that constitute movement.

Animals↗
PubMed1998

Use of microscopic morphology in smears prepared from radiometric cultures for presumptive identification of Mycobacterium tuberculosis complex, Mycobacterium avium complex, Mycobacterium kansasii, and Mycobacterium xenopi.

The aim of this study was to assess the feasibility of a method for presumptive identification of mycobacteria, based on the morphology in smears prepared from radiometric Bactec-positive cultures (Becton Dickinson, USA) and to select the appropriate DNA probe (AccuProbe; Gen Probe, USA). The smear morphology of acid-fast bacilli was evaluated in 468 positive cultures from clinical samples: 313 Mycobacterium tuberculosis complex, 67 Mycobacterium avium complex, 32 Mycobacterium kansasii, 49 Mycobacterium xenopi, and seven Mycobacterium gordonae. The sensitivity and specificity for various morphological patterns were as follows: cord formation for Mycobacterium tuberculosis complex 90% and 100%, respectively; striped bacilli for Mycobacterium kansasii, 66% and 99%; sea urchin for Mycobacterium xenopi, 96% and 99%; short bacilli for Mycobacterium avium complex, 61% and 99%; fine-striped bacilli associated with Mycobacterium avium complex from blood samples, 33% and 98%. This criterion was applied in the selection of a suitable DNA probe for the identification of 178 cultures. The correct probe was selected in 98%, 97%, and 72% of cultures, respectively, for Mycobacterium tuberculosis complex, Mycobacterium avium complex, and Mycobacterium kansasii. The observation of acid-fast bacilli morphology in radiometric cultures is a rapid and cost-efficient method for presumptive identification of common clinical isolates of mycobacteria.

Bacteriological Techniques↗
PubMed1998

Glucagon-like peptide-1 (7-36) amide as a novel neuropeptide.

Although earlier studies indicated that GLP-1 (7-36) amide was an intestinal peptide with a potent effect on glucose-dependent insulin secretion, later on it was found that several biological effects of this peptide occur in the brain, rather than in peripheral tissues. Thus, proglucagon is expressed in pancreas, intestine, and brain, but post translational processing of the precursor yields different products in these organs, glucagon-like peptide-1 (7-36) amide being one of the forms produced in the brain. Also, GLP-1 receptor cDNA from human and rat brains has been cloned and sequenced, and the deduced amino acid sequences are the same as those found in pancreatic islets. Through these receptors, GLP-1 (7-36) amide from gut or brain sources induces its effects on the release of neurotransmitters from selective brain nuclei, the inhibition of gastric secretion and motility, the regulation of food and drink intake, thermoregulation, and arterial blood pressure. Central administration (icv) of GLP-1 (7-36) amide produces a marked reduction in food and water intake, and the colocalization of the GLP-1 receptor, GLUT-2, and glucokinase mRNAs in hypothalamic neurons involved in glucose sensing suggests that these cells may be involved in the transduction of signals needed to produce a state of fullness. In addition, GLP-1 (7-36) amide inhibits gastric acid secretion and gastric emptying, but these effects are not found in vagotomized subjects, suggesting a centrally mediated effect. Similar results have been found with the action of this peptide on arterial blood pressure and heart rate in rats. Synthesis of GLP-1 (7-36) amide and its own receptors in the brain together with its abovementioned central physiological effects imply that this peptide may be considered a neuropeptide. Also, the presence of GLP-1 (7-36) amide in the synaptosome fraction and its calcium-dependent release by potassium stimulation, suggest that the peptide may act as a neurotransmitter although further electrophysiological and ultrastructural studies are needed to confirm this possibility.

Animals↗
PubMed1998

Maternal exposure to low doses of delta9-tetrahydrocannabinol facilitates morphine-induced place conditioning in adult male offspring.

The possible existence of an increased susceptibility to the reinforcing properties of morphine was analyzed in male and female rats born from mothers exposed to delta9-tetrahydrocannabinol (THC, 1, 5, or 20 mg/kg) during gestation and lactation. Maternal exposure to low doses of THC (1 and 5 mg/kg), relevant for human consumption, resulted in an increased response to the reinforcing effects of a moderate dose of morphine (350 microg/kg), as measured in the place-preference conditioning paradigm (CPP) in the adult male offspring. These animals also displayed an enhanced exploratory behavior in the defensive withdrawal test. However, only females born from mothers exposed to THC 1 mg/kg exhibited a small increment in the place conditioning induced by morphine. The possible implication of the hypothalamo-pituitary-adrenal axis (HPA) was analyzed by monitoring plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone in basal and moderate-stress conditions (after the end of the CPP test). Female offspring perinatally exposed to THC (1 or 5 mg/kg) displayed high basal levels of corticosterone and a blunted adrenal response to the HPA-activating effects of the CPP test. However, male offspring born from mothers exposed to THC (1 or 5 mg/kg) displayed the opposite pattern: normal to low basal levels of corticosterone, and a sharp adrenal response to the CPP challenge. The present study reveals that maternal exposure to low doses of THC results in an increased sensitivity to the reinforcing effects of morphine in the adult male offspring, and in sexually dimorphic behavioral and endocrine alterations in the adaptative responses to stressors such as novelty or place-preference testing. These results support the growing evidence of the importance of monitoring the long-term consequences of maternal consumption of cannabis derivatives.

Adrenocorticotropic Hormone↗
PubMed1998

Two-day quadruple therapy for cure of Helicobacter pylori infection: a comparative, randomized trial.

OBJECTIVE: We sought to compare a 2-day quadruple therapy with a 14-day triple therapy in the treatment of Helicobacter pylori infection. METHODS: Eighty-one consecutive patients with an endoscopically diagnosed peptic ulcer and demonstrated infection by H. pylori were included in the study. Patients were randomized to receive omeprazole 40 mg b.i.d., amoxicillin 2.5 g once daily, metronidazole 500 mg t.i.d., and bismuth subcitrate 360 mg t.i.d. for 2 days, followed by omeprazole 20 mg once daily for 6 additional days (Group 1) or a 14-day course of omeprazole 20 mg b.i.d., amoxicillin 1 g t.i.d., and metronidazole 500 mg t.i.d. (Group 2). Eradication was evaluated by antral biopsy and rapid urease test at 2 months after therapy and by C13-urea breath test after a year. RESULTS: Two patients were lost to follow-up at 2 months. Intention-to-treat analysis showed that H. pylori infection was cured in 29 of 42 patients (69%; 95% CI: 53-82%) in Group 1 versus 36 of 39 (92%; 95% CI: 78-98%) of patients in Group 2 (p = 0.009). Per-protocol analysis showed a cure rate of 71% (95% CI: 55-84%) (29/41 patients) and 95% (95% CI: 81-99%) (36/38 patients), respectively (p = 0.007). Fifty-five of 65 cured patients returned 1 year after treatment (26 in Group 1, 29 in Group 2). All but one in Group 2 remained cured. There were no significant differences in compliance (88% in Group 1 versus 92% in Group 2) or in the presence of side effects (27%; 95% CI: 15-43% versus 41%; 95% CI: 26-58%; ns). CONCLUSION: Two-day quadruple therapy is significantly less effective than 2-wk triple treatment.

Adolescent↗
PubMed1998

Epidemiology of peptic ulcer disease in cirrhotic patients: role of Helicobacter pylori infection.

OBJECTIVE: The aim of this study was to investigate the clinical and epidemiological factors associated with the appearance of peptic ulcer in patients with cirrhosis and, in particular, the role of Helicobacter pylori infection. METHODS: A total of 201 of 220 consecutive patients included in a prospective study that aimed to evaluate the effect of dietary intervention on cirrhotic complications and survival underwent upper gastrointestinal endoscopy. At entry, an epidemiological and clinical questionnaire was completed and the presence of peptic ulcer disease or esophageal varices at endoscopy was prospectively collected. Sera were obtained and stored at -70 degrees C until analyzed, being tested afterward for Helicobacter pylori antibodies using a commercial ELISA kit. RESULTS: Eleven of 201 patients had borderline anti-Helicobacter pylori IgG titers and were excluded from further analysis. In the remaining 190 patients, point prevalence of peptic ulcer was 10.5% and lifetime prevalence 24.7%. Multivariate analysis selected male sex (OR 2.3; 95%CI 1.09-4.89) and Helicobacter pylori seropositivity (OR: 1.7, 95%CI 1.02-2.81) as the variables independently related to peptic ulcer disease. CONCLUSIONS: Male sex and seropositivity for Helicobacter pylori are the major risk factors for peptic ulcer in cirrhosis.

Female↗
PubMed1998

Injection technique and scanning electron microscopic study of the arterial pattern of the 20 gestation days (G20) rat fetus.

A technique to obtain microvascular corrosion casts of the G20 rat fetus and the normal pattern of the main arteries of the G20 rat fetus are described. The casts were studied by means of scanning electron microscopy (SEM). The arterial pattern is similar to that described in the adult; however, several variations have been found. It is concluded that the use of vascular corrosion casts studied by SEM may be particularly helpful to observe the extremely small arteries of rat fetuses. Moreover, we suggest that this technique may be useful in practical teratological studies.

Animals↗
PubMed1998

Role of the limbic system in dependence on drugs.

The limbic system is a group of structurally and functionally related areas of the brain that provides the anatomical substrate for emotions and motivated behaviour, including the circuitry for the stress response and reward-related events. This system is strongly implicated in drug abuse from the pleasure and/or positive side associated with acute exposure to the dysphoria and craving associated with withdrawal. The contribution of the main cortical and subcortical elements of the limbic system to drug dependence is briefly reviewed in the present work with a focus on the role of the extended amygdala and its connections as well as on the peripheral feedback signals mediated by adrenal glucocorticoids. The elucidation of the neuroadaptive responses of the limbic system to chronic drug exposure will undoubtedly help to design rational strategies for the treatment of addiction.

Animals↗
PubMed1998

[Seven-day omeprazole, clarithromycin, and amoxicillin for the therapy of Helicobacter pylori infection].

BACKGROUND: There are few series reporting efficacy of seven-day therapy with omeprazole, amoxicillin and clarithromycin for cure of Helicobacter pylori infection in Spain. The aim of the present study was to evaluate the efficacy of this treatment to eradicate H. pylori infection. PATIENTS AND METHODS: One hundred consecutive patients with peptic ulcer disease and H. pylori infection were evaluated for eradication therapy between January and November 1996. Four of them were excluded because of reported penicillin allergy. The remaining 96 patients received a seven days course of omeprazole 20 mg/12h, clarithromycin 500 mg/12h and amoxicillin 1 g/12h. The efficacy of the treatment was evaluated at 2-4 months after therapy either by endoscopic biopsy or by 13C urea breath-test. RESULTS: Seventy-eight patients were found to be cured at the control evaluation. Intention to treat analysis showed a cure rate of 81.3% (95% CI: 74-89%). Per protocol analysis showed a cure rate of 85.7% (95% CI: 79-93%)--78 out of 91 patient who returned for follow-up-. Compliance with the treatment was good in 94.5% of patients. Five patients presented mild side effects (diarrhea, abdominal pain, oral candidiasis and metallic taste). None of them had to interrupt the treatment. CONCLUSION: Seven-day therapy with omeprazole, amoxicillin and clarithromycin achieves a 85% cure rate of H. pylori infection in our area.

Aged↗
PubMed1998

[Resection as elective treatment of hilar cholangiocarcinoma (Klatskin tumor)].

A retrospective analysis of our experience in the treatment of hiliary cholangiocarcinoma or Klatskin tumor was performed with the aim of evaluating the morbi-mortality and prognosis of its treatment to thereby determine the usefulness of the different therapeutic options. From 1989 to 1997, 51 patients diagnosed with hiliary cholangiocarcinoma were treated in our hospital. Surgery was indicated in 16 with curative aims (group I) while palliative treatment with percutaneous biliary drainage was indicated in 35 (group II). Biliary resection was carried out in 8 patients being associated with hepatic resection in 4 (group IA) and in 8 patients undergoing liver transplantation (group IB). Clinico-epidemiologic data and hospital stay were similar in all the groups. The frequency of complications was similar in groups I and II although the frequency of cholangitis (49%) in group II was noticeable. The percentage of readmissions was also greater in group II (12 vs 46%, respectively; p = 0.03) with prosthesis obstruction being the most frequent cause. Accumulated survival at 1, 2, and 3 years in group I was 84, 64 and 48% with a median survival of 33 months, while in group II the median survival was of 6 months with no patient surviving more than 2 years (p = 0.0001). When groups IA and IB were compared, greater frequency of complications in groups IA (100 vs 37%; p = 0.002), similar frequency of readmissions (87 vs 75%; p = NS), median survival greater in group IB (12.5 months vs 48 months) and significantly higher actuarial survival in group IB (48% in 2 years vs 83% to 2 years; p = 0.02) was observed. In conclusion, surgery is the treatment of choice in hiliary cholangiocarcinoma whenever possible, given the greater survival without a significant increase in morbimortality. Likewise, we consider that liver transplantation is a useful option in the treatment of patients with cholangiocarcinoma type IV of Bismuth.

Adult↗
PubMed1998

[Chronic necrotizing pulmonary aspergillosis: infrequent form of aspergillosis].

BACKGROUND: Chronic necrotizing pulmonary aspergillosis (CNPA) is a chronic pulmonary infection caused by the genus Aspergillus, which usually involves moderately immunosuppressed patients. METHOD: We describe 3 patients with a toxic syndrome that had lasted several weeks or months, with lung infiltrates in the chest X-ray and the CT scan. Mycobacterium tuberculosis could not be isolated from different respiratory smears (sputum, bronchoaspiration, Barlett catheter and pulmonary punction in the third case). Moreover, there was no response to anaerobic treatment. RESULTS: All 3 patients were moderately immunosuppressed (2 men were COPD and the woman was an asthmatic patient). One of the men was being treated for a nocardiosis. In all three cases, A. fumigatus was isolated from de different respiratory smears. CONCLUSIONS: To diagnose a CPNA, a high degree of clinical suspicion is needed. The differential diagnose should be done with pulmonary tuberculosis and anaerobic infections. The presence of a member of the genus Aspergillus in the tracheobronchial secretions of a patient should not be systematically considered a saprofit, specially when other microorganisms can not be isolated.

Aged↗
PubMed1998

Clinical, morphological, cytogenetic and molecular aspects of a series of Ph-negative chronic myeloid leukemias.

Clinical, morphological, cytogenetic and molecular (fluorescence in situ hybridization and RT-PCR) data were analyzed in twelve Philadelphia negative chronic myeloid leukemias (Ph-negative CMLs). Four patients were classified as BCR-positive. A standard b2a2 or b3a2 transcript was found, and the BCR-ABL hybrid gene was located on the 22q11 band in three cases and on the 1p35 band in one case with a t(1;9)(p35;q34). All were classified as typical chronic granulocytic leukemia (CGL) according to the French-American-British (FAB) morphological guidelines. Responses to therapy were evaluated by FISH in the four patients, and proved to be poorer than in Ph-positive CMLs. Eight BCR-negative patients were identified. They could be characterized by an older age, a less proliferative form of disease than the BCR-positive patients, and a frequent (six out of eight) abnormal karyotype. The FAB classification identified four CGLs and four atypical CMLs (aCML). A normal karyotype was more frequent in the patients classified as CGL whereas all the aCMLs had a chromosomal abnormality. Three patients had chromatin clumping and this morphologic feature was associated with trisomy 8 in two. No correlation between the cytogenetic, morphologic and the clinical data were found. Five patients had poor tolerance to therapy with a frequent occurrence of bone marrow failure and hemorragic syndrome, whereas three patients responded to a standard treatment of CML. Our study reinforces previous data on Ph-negative BCR-positive CMLs and emphasizes the difficulty in correlating clinical, morphologic, cytogenetic data in Ph-negative BCR-negative CMLs. However, our data also argue in favor of the existence of true Ph-negative BCR-negative CMLs and suggest that some of them can respond to a standard treatment of CML.

Adult↗
PubMed1998

COL1A1-PDGFB fusion in a ring chromosome 4 found in a dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans (DP), an infiltrative skin tumor of intermediate malignancy, presents specific cytogenetic features such as reciprocal translocations t(17;22)(q22;q13.1) or, more often, supernumerary ring chromosomes derived from t(17;22). Different translocations, including t(2;17) and t(X;7), have also been described. We have shown previously that both r(17;22) and t(17;22) present the same molecular rearrangement fusing the COL1A1 gene on chromosome 17 and the PDGFB gene on chromosome 22. Out of our series of 16 DPs, we detected an extra ring chromosome in tumor T96-1175, which juxtaposed sequences from chromosomes 4 and 17. As shown by fluorescence in situ hybridization (FISH) using chromosome painting and alpha-satellite probes, T96-1175 apparently lacked chromosome 22 material in the ring. However, involvement of chromosome 22 through a rearrangement of PDGFB was shown by Southern blotting, reverse transcriptase-polymerase chain reaction (RT-PCR), and FISH. This study demonstrates that a cryptic molecular rearrangement between chromosomes 17 and 22 occurred in addition to the recombination of chromosomes 4 and 17 initially identified by FISH. Assessment for cryptic molecular events should be performed in other variant DP rearrangements.

Adult↗
PubMed1997

Serum concentration and dietary intake of Mg and Ca in institutionalized elderly people.

We determined the serum levels and the dietary intake of Mg and Ca in 93 institutionalized elderly people (24 men and 69 women) in Granada (Spain). The serum samples had mean concentrations of 21.39 +/- 2.08 mg/l magnesium and 93.39 +/- 9.24 mg/l calcium. No significant differences were found in the serum levels of the two minerals as regards the sex of the subjects. Application of linear regression analysis to the serum Mg and Ca levels showed a statistically significant positive correlation (P < 0.05). A low vitamin D intake of these subjects (51.8% of the recommended dietary allowance) was observed. The intakes of Ca and Mg correlated positively together, as well as with the intakes of energy, protein, fibre (in the case of Mg only), iron and phosphorus (P < 0.05). The Ca and energy intake were adequate to their current recommendations, as too was the Ca:P ratio, whereas the diet had a poor supply of fibre, vitamin D and Mg.

Aged↗
PubMed1997

Serum copper in institutionalized elderly subjects: relations with dietary intake of energy, specific nutrients and haematological parameters.

The concentrations of serum copper were determined as an indicator of corporal status of Cu and its relation to aging in 93 institutionalized elderly subjects (24 men and 69 women) in Granada (Spain). We found that aging does not affect serum Cu levels in the two age groups included in the study: Group I < 80 years and Group II > or = 80 years. Application of linear regression analysis to the serum Cu levels and the intake of energy, fibre, iron and magnesium showed a statistically significant negative correlation (P < 0.05) among them in all the subjects. However, no correlation was observed when the serum Cu levels were related to the intake of zinc or vitamin C. Therefore, at the daily intake levels of these two nutrients, they do not interfere in the absorption of copper and hence do not affect the corporal status of this element in the elderly. Blood erythrocyte and haemoglobin concentrations do not show any significant correlation with the serum Cu concentrations (P > 0.05).

Aged↗
PubMed1997

Activation of corticotropin-releasing factor in the limbic system during cannabinoid withdrawal.

Corticotropin-releasing factor (CRF) has been implicated in the mediation of the stress-like and negative affective consequences of withdrawal from drugs of abuse, such as alcohol, cocaine, and opiates. This study sought to determine whether brain CRF systems also have a role in cannabinoid dependence. Rats were treated daily for 2 weeks with the potent synthetic cannabinoid HU-210. Withdrawal, induced by the cannabinoid antagonist SR 141716A, was accompanied by a marked elevation in extracellular CRF concentration and a distinct pattern of Fos activation in the central nucleus of the amygdala. Maximal increases in CRF corresponded to the time when behavioral signs resulting from cannabinoid withdrawal were at a maximum. These data suggest that long-term cannabinoid administration alters CRF function in the limbic system of the brain, in a manner similar to that observed with other drugs of abuse, and also induces neuroadaptive processes that may result in future vulnerability to drug dependence.

Amygdala↗