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Biomedical subjects

M Navarro

Publications and source records attributed to M Navarro.

At least 19 recordsLinked to original sources

[Current status of follow-up of the upper digestive tract in familial adenomatous polyposis].

Familiar adenomatous polyposis (FAP) is a hereditary disease characterized by the development of multiple adenomatous polyps in the gastrointestinal tract and colorectal cancer in practically all patients who do not receive appropriate treatment. Although the most commonly involved region in this disease is the colorectal area, it is well known that adenomas can also develop in the upper gastrointestinal tract, mainly in the periampullary area of the duodenum. Because of the possibility of malignant transformation of these polyps, adequate monitoring is required, even though the optimal follow-up schedule has not yet been defined. In the present article, we report a case of a gastric adenocarcinoma detected during the follow-up of a patient diagnosed with FAP, as well as a review of the literature on this subject. We stress the need for early detection and appropriate management of this disease. Sufficient information is available to support the use of upper gastrointestinal endoscopy with lateral vision and serial biopsies of the periampullary region in these patients. The first endoscopy in patients with FAP should be performed at the age of 20 years or at diagnosis. Subsequently, a follow-up schedule should be designed, according to the number and histological characteristics of the polyps observed.

Adenocarcinoma↗

Patient with disseminated intravascular coagulation as the first manifestation of adenocarcinoma of the prostate. Risks of prostatic biopsy.

Disseminated intravascular coagulation (DIC) can be a rare initial manifestation of adenocarcinoma of the prostate. We present a case in which DIC was the symptom leading to the suspicion of a prostatic tumour. The performance of a prostate biopsy in this situation exacerbated the initial coagulation disorder. This case highlights the risks of prostate biopsy in patients with a suspicion of advanced adenocarcinoma of the prostate. The difficulty of treating DIC in this clinical situation is also discussed.

Adenocarcinoma↗

Severe acute exacerbations and mortality in patients with chronic obstructive pulmonary disease.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often present with severe acute exacerbations requiring hospital treatment. However, little is known about the prognostic consequences of these exacerbations. A study was undertaken to investigate whether severe acute exacerbations of COPD exert a direct effect on mortality. METHODS: Multivariate techniques were used to analyse the prognostic influence of acute exacerbations of COPD treated in hospital (visits to the emergency service and admissions), patient age, smoking, body mass index, co-morbidity, long term oxygen therapy, forced spirometric parameters, and arterial blood gas tensions in a prospective cohort of 304 men with COPD followed up for 5 years. The mean (SD) age of the patients was 71 (9) years and forced expiratory volume in 1 second was 46 (17)%. RESULTS: Only older age (hazard ratio (HR) 5.28, 95% CI 1.75 to 15.93), arterial carbon dioxide tension (HR 1.07, 95% CI 1.02 to 1.12), and acute exacerbations of COPD were found to be independent indicators of a poor prognosis. The patients with the greatest mortality risk were those with three or more acute COPD exacerbations (HR 4.13, 95% CI 1.80 to 9.41). CONCLUSIONS: This study shows for the first time that severe acute exacerbations of COPD have an independent negative impact on patient prognosis. Mortality increases with the frequency of severe exacerbations, particularly if these require admission to hospital.

Acute Disease↗

Mophometric study of the aortic arch and its major branches in rat fetuses on the 21st day of gestation.

The anatomy and embryology of the aortic arch and its branching tributaries (brachiocephalic trunk, left common carotid artery and left subclavian artery) in man and animals are well substantiated. However, the anatomical variations and morphometry of the aortic arch and its branching tributaries in rat fetus at the 21st gestation day have not been studied. Pregnant rats were hysterectomized and the arterial systems of 114 fetuses were injected with a polymerisable resin through the umbilical artery. After maceration, the vascular casts were dissected out and prepared for observations under a scanning electron microscope (SEM). The resulting SEM pictures were studied with a picture analyser and different vessel parameters (diameters, lengths and angles) were measured. The success rate of the microvascular cast injection was 46.5%. Out of the 53 observed aortic arch casts, 98.1% showed the classical branching pattern and one (1.9%) had no brachiocephalic trunk. Morphological analysis showed many differences, which were not linked to the litter. The statistical processing of the measurements enabled us to determine that the aorta diameter after the branching of the left subclavian artery was the most replicable parameter. Moreover, the results revealed some strong correlations between different parameters. There are probably no discrete categories among the various observed parameters as diameters and angles. Some parameters show very little variability and can thus be used as reference points for further studies such as the comparison of a control population with a population treated with a relevant xenobiotic.

Age Factors↗

Surface characterization of completely degradable composite scaffolds.

The goal of this study was to characterise the surface properties of completely degradable composite, polylactic acid and calcium phosphate glass, scaffolds. The composite scaffolds are made by solvent casting or phase-separation, using chloroform and dioxane as a solvent respectively. The surface properties were measured on composite films which were made using the same procedure as for the three-dimensional (3D) scaffolds without the pore-creating step. The surface morphology, roughness, wettability and protein adsorption capacity of the films was measured before and after sterilisation with ethylene oxide. The results reveal the influence of solvent type, glass weight content and sterilisation on the wettability, surface energy and protein adsorption capacity of the materials. The addition of glass particles increase the hydrophylicity, roughness and protein adsorption capacity of the surface. This effect, however, depends on the extent of the coating of the glass particles by the polymer film, which is much higher for dioxane films than for chloroform films. This information can be used to interpret and understand the biological behaviour of the 3D scaffolds made of this composite materials.

Adsorption↗

In vitro degradation behavior of a novel bioresorbable composite material based on PLA and a soluble CaP glass.

Poly(alpha-hydroxy acids), and in particular polylactic acid (PLA), are nowadays amongst the most used bioabsorbable materials. However, this polymer may not meet some application requirements due to inadequate mechanical properties and or its degradation characteristics. A possible strategy to tackle this problem is the incorporation of an inorganic phase into the polymeric matrix. In this work a new fully biodegradable composite material made with PLA and calcium phosphate soluble glass particles has been developed. The behaviour of the PLA/glass composite has been analysed during its degradation in simulated physiological conditions by means of weight loss, molecular weight and thermal properties analysis and electron microscopy observation. The results showed that the incorporation of phosphate glass particles into the polymer significantly accelerated the degradation of the PLA and induced the formation of calcium phosphate precipitates at the composite surface.

Absorbable Implants↗

Effect of low doses of atorvastatin on adiponectin, glucose homeostasis, and clinical inflammatory markers in kidney transplant recipients.

INTRODUCTION: Various studies describe the pleiotropic antiinflammatory and antioxidant effects of atorvastatin, in addition to its hypolipemic effects. It has been suggested that statins modify glucose homeostasis via their antiinflammatory effects. A further hypothesis suggests that the incidence of posttransplantation diabetes is lower in statin-treated patients. This study sought to ascertain whether atorvastatin modifies glucose homeostasis, adiponectin, and inflammatory markers in kidney transplant recipients. PATIENTS AND METHODS: Sixty-eight kidney transplant recipients (41 men, 27 women; mean age, 53 +/- 12 years) with stable renal function and dyslipidemia were treated with atorvastatin (10 mg/d) for 12 weeks. Glucose, insulin, homeostasis model assessment (HOMA-IR) index, adiponectin, tumor necrosis factor (TNF)-alpha, and serum C-reactive protein (CRP) concentrations were determined at baseline and at 3 months. The lipid profile, renal function parameters (creatinine, creatinine clearance, and proteinuria), as well as GOT, GPT, and CK were determined at baseline and at 3 months. RESULTS: Treatment with atorvastatin achieved a statistically significant decrease in lipid profile. After 3 months of treatment, 74.6% of patients had total cholesterol and 78.7% low-density lipoprotein (LDL) cholesterol concentrations within reference range (<5.2 and 3.3 mmol/L, respectively). Furthermore, 47.5% of patients attained an LDL concentration <2.59 mmol/L. A greater reduction in total cholesterol (P = .05) and LDL cholesterol (P = .04) was achieved in patients with creatinine clearance <60 mL/min. Atorvastatin did not modify glucose homeostasis parameters, adiponectin, TNF-alpha, or CRP. At baseline and after 3 months of treatment, an inverse correlation was found between adiponectin and glucose, insulin, HOMA- IR index, and creatinine clearance, and a positive correlation was found between adiponectin and high-density lipoprotein (HDL) cholesterol. CONCLUSION: Atorvastatin at a dose of 10 mg/d in kidney transplant recipients does not modify glucose homeostasis or alter inflammatory markers, despite its hypolipemic effects. Its efficacy to reduce total cholesterol and LDL cholesterol was greater in patients with worse renal function.

Adiponectin↗

Interaction between omeprazole and tacrolimus in renal allograft recipients: a clinical-analytical study.

Omeprazole is a proton pump inhibitor with a number of pharmacokinetic drug interactions due to interference with cytochrome P450. Some studies show absence of relevant interaction between omeprazole and cyclosporine, but little is known about possible interactions between omeprazole and tacrolimus. In vitro studies suggest such interference, but no clinical data are available so far. We assessed interactions between omeprazole and tacrolimus among patients fulfilling two criteria: (1) renal allograft recipients receiving immunosuppression based on tacrolimus and acid-related disorder prophylaxis with omeprazole 20 mg/d since the day of the transplant procedure and (2) stopped omeprazole when it was considered unnecessary. Fifty-one transplant recipients received concomitant immunosuppression with MMF-prednisone (n = 47) or azathioprine-prednisone (n = 1), or rapamycin-prednisone (n = 2) or only prednisone (n = 1). omeprazole was stopped after 6.2 +/- 3 months of treatment. Tacrolimus doses and levels were recorded during 3 outpatient visits before omeprazole withdrawal (Pre3/Pre2/Pre1), at the withdrawal visit (Susp), and at 3 visits after withdrawal (Pos1/Pos2/Pos3). Weight gain was significant (72.5 +/- 13 kg Pre3; 73.4 +/- 13 kg Susp; 74 +/- 12.9 kg Pos3, P < .0001) and serum creatinine (SCr) decreased (1.70 +/- 0.49 mg/dL Pre3; 1.63 + 0.49 Susp; 1.58 +/- 0.48 Pos3, P < .0001). The progressive decrease in tacrolimus doses and levels was significant (ANOVA including the 7 visits <0.01 in all cases); whereas the level/dose ratio remained constant. Tacrolimus doses and levels continued a slow, progressive and significant decrease without any relevant change between visits during on versus off omeprazole. This clinical-analytical study supported the conclusion that an omeprazole-tacrolimus interaction is not clinically relevant. Despite possible competition or interaction at the molecular level, clinical management was not significantly affected in renal allograft recipients.

Anti-Ulcer Agents↗

Long-term behavioural and neuroendocrine effects of perinatal activation or blockade of CB1 cannabinoid receptors.

The present work studied the long-term effects of chronic perinatal manipulation of cannabinoid CB1 receptors in male and female rats. Perinatal activation of cannabinoid CB1 receptors by chronic administration of delta9-tetrahydrocannabinol at different doses (0.1, 0.5, 2 mg/kg, p.o.) induced sexually dimorphic behavioural changes in adulthood, altering habituation of locomotion, immobility and exploratory activity. These behavioural effects were also accompanied by alterations in corticosterone levels in the adult period. Prenatal blockade of CB1 receptors by chronic administration of 3 mg/kg (s.c.) of SR141716A decreased immobility behaviour in male and female animals, without any significant changes in corticosterone plasma levels. Cannabinoid CB1 receptors appear to play an important role in the ontogeny of psychomotor behaviours, and activation or blockade of these receptors during stages of plasticity, such as the prenatal or perinatal periods, can induce long-term effects, as shown by sexually dimorphic changes in behavioural patterns in adulthood.

Adrenocorticotropic Hormone↗

Behavioural effects of quinpirole following withdrawal of chronic treatment with the CB1 agonist, HU-210, in rats.

The present study investigated spontaneous and quinpirole-induced motor responses of in rats, following withdrawal from chronic treatment with the potent cannabinoid agonist HU-210. Withdrawal from chronic HU-210 (20 microg/kg daily, 14 days) produced a decrease in spontaneous activity at 1 and 2 days and enhanced the hyperactivity induced by acute administration of the dopamine D2 agonist quinpirole (0.5 mg/kg) at 4 days after the end of HU-210 treatment. Administration of quinpirole on day 4 of withdrawal from chronic HU-210 enhanced stereotyped responses and induced jumping behaviour. These results suggest that withdrawal from chronic exposure to cannabinoid agonists could induce a time-dependent alteration in dopamine D2 psychomotor function, leading to a behavioural disorganization, comparable to acute psychotic episodes after continuous cannabinoids.

Animals↗

Response to neoadjuvant therapy for rectal cancer: influence on long-term results.

OBJECTIVE: Pre-operative treatment with chemoradiotherapy (CRT) seems to improve local control and overall survival in patients with rectal cancer. The aims of the study were to analyse the impact on overall, disease free and cancer related survival of tumour response to pre-operative CRT and to analyse the influence of the degree of response on long-terms results. PATIENTS AND METHODS: Patients with a locally advanced rectal cancer, treated by pre-operative CRT were studied. A radical resection of the rectal tumour with mesorectal excision was performed within 6-8 weeks. Judged on the final TNM classification patients were considered responders when the tumour showed histologically a complete response, microscopic residual disease or a partial response. Non-responders were those in whom the extent of disease remained stable or progressed. Results Radical excision was performed in 103 patients, and a palliative resection in five. Forty-three patients underwent abdominoperineal resection and 65 anterior resection of the rectum. Seventy-one (65.7%) patients showed a response to CRT, while 37 (34.3%) did not. The overall local and distant recurrence rates were 6.8% and 21.3%. Tumour recurrence (P < 0.008) and disease free survival (P < 0.007) were significantly different in responders and nonresponders. Of the 71 responders, 16 had a pathological complete response, 27 had persisting microscopic disease and 28 had macroscopic residual disease. No differences in cancer specific outcome were observed in these groups. CONCLUSION: Pathological response to pre-operative CRT is associated with improved tumour recurrence and disease-free survival rates. Any response to pre-operative CRT appears to improve outcomes as much as a complete response.

Adult↗

First record of the rare species Aeromonas culicicola from a drinking water supply.

We describe the recovery of the rare species Aeromonas culicicola, so far known only in mosquitoes in India, from a drinking water supply in Spain. Typing, using enterobacterial repetitive intergenic consensus-PCR, revealed that the 27 new isolates belonged to 3 very closely related strains. These strains were genetically identified by 16S rRNA gene sequencing. Spanish strains differed from the mosquito strains in three nucleotide positions. The AHCYTOEN gene was present in these water strains, which may have a public health significance.

Aeromonas↗

Polymorphisms in prostaglandin synthase 2/cyclooxygenase 2 (PTGS2/COX2) and risk of colorectal cancer.

Inflammation plays a key role in the development of colorectal cancers. We have investigated the relationship between PTGS2 (COX2) polymorphisms and colorectal cancer risk in a hospital based case-control study. We recruited 292 patients with colorectal cancer and 274 controls from new patients admitted to Bellvitge Hospital, Barcelona, Spain, from 1996 to 1998. Subjects responded to a questionnaire on risk factors. Genotypes of the eight more frequent polymorphisms of PTGS2 were determined. Two polymorphisms are located in the promoter sequence, one in the untranslated region of exon 1, one in exon 3, one in intron 5, two in the untranslated region of exon 10, and one downstream of the last polyadenylation (poly-A) signal. Associations were analysed with logistic regression models assuming a dominant effect for rare variants to increase statistical power. An association was detected between colorectal cancer and a polymorphism in the untranslated region of exon 10 of PTGS2, with an odds ratio (OR) of 2.49, 95% confidence interval (CI) of 1.17-5.32, P=0.01. A nearby polymorphism downstream of the last poly-A signal also showed a nonsignificant increase in risk (OR 2.17, 95% CI 0.99-4.78, P=0.05). Analysis of haplotypes confirmed that individuals with these variants were at increased risk of colorectal cancer (OR compared to the most frequent haplotype: 2.17, 95% CI 0.97-4.84, P=0.06) Interactions between PTGS2 genotype and use of nonsteroidal anti-inflammatory drugs and risk of colorectal cancer were also explored.

Adult↗

Intrapartum fetal pulse oximetry and fetal heart rate decelerations.

OBJECTIVES: To determine the behavior of fetal oxygenation (FSpO(2)) in different patterns of fetal heart rate decelerations (FHR). METHODS: A total of 787 decelerations were studied. RESULTS: FSpO(2) decreased significantly during decelerations, especially when the alteration was prolonged. CONCLUSIONS: Modifications in FHR occur simultaneously with alterations in FSpO(2), although the latter do not persist in time. Different degrees of FSpO(2) seen prior to deceleration are an expression of fetal respiratory status.

Adolescent↗

Nicotine in alcohol deprivation increases alcohol operant self-administration during reinstatement.

Tobacco and alcohol are highly co-abused by humans. Most experimental studies have evaluated ethanol consumption in animals exposed concomitantly to nicotine. However, little is known regarding the effects of nicotine administered during periods of alcohol deprivation. In the present study, adult male Wistar rats with an extended background of operant self-administration of ethanol were alcohol-deprived and treated with nicotine (0.1, 0.2, 0.4 and 0.8 mg/kg) or saline during five consecutive days in one chamber of a place conditioning apparatus. Nicotine-induced changes in locomotion were monitored daily, whereas the expression of place conditioning was studied the day after the last nicotine injection. Forty-eight hours after testing for conditioning, the animals resumed operant self-administration of ethanol and their alcohol intake was evaluated during the next 14 days. We observed that alcohol consumption was increased in animals treated with nicotine at doses of 0.2, 0.4 and 0.8 mg/kg but not in animals treated with the dose of 0.1 mg/kg or saline. Additionally, the dose of 0.8 mg/kg of nicotine not only induced persistent changes in alcohol self-administration but also produced conditioned place aversion and depressed locomotor activity. These results indicate that nicotine administration during the ethanol deprivation period can exacerbate the maintenance of alcohol consumption.

Animals↗

Development and cell response of a new biodegradable composite scaffold for guided bone regeneration.

Composites of biodegradable polymers with different calcium phosphate ceramics and glasses, have been developed as scaffolds for applications in bone-tissue engineering. In this work, phosphate glass particles have been incorporated into the polymer, poly(95L/5DL) lactic acid (PLA) and porous structures were elaborated. Their porosity, compressive mechanical properties and biological response were evaluated. Interconnected structures with evenly distributed pores and a porosity as high as 97% were obtained. The incorporation of glass particles into the polymer showed to have a positive effect in the mechanical properties of the foams. Indeed, the compressive modulus increased from 74.5 to 120 KPa and the compressive strength from 17.5 to 20.1 KPa for the PLA and the PLA/glass foams, respectively. The biological response was evaluated by means of the MTT test, the materials resulted to be noncytotoxic.

Absorbable Implants↗

Tinea capitis in infants in their first year of life.

BACKGROUND: Tinea capitis is the most common type of dermatophytosis in children, but is uncommon in the first year of life. OBJECTIVES: To review clinical, mycological and epidemiological data in a series of 10 infants aged under 1 year diagnosed as having tinea capitis in three Spanish hospitals between 1998 and 2002. METHODS: A retrospective case note study. RESULTS: There were six boys and four girls with a mean of age 7 months (range 1.5-12). All the children were born in Spain, but in five cases the parents were immigrants from Africa. In these cases the isolated dermatophytes were two Trichophyton tonsurans, one T. verrucosum and two Microsporum audouinii. Four autochthonous cases were caused by M. canis and one by M. audouinii (but this one was in contact with African immigrants). In two of the five cases produced by anthropophilic dermatophytes other family members were infected by the same fungus. Most cases were treated successfully with griseofulvin. CONCLUSIONS: Although tinea capitis is rare in infants in their first year of life, the condition should be investigated if scaling and/or alopecia are present. A thorough epidemiological study of other family members is mandatory.

Antifungal Agents↗