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Biomedical subjects

P González

Publications and source records attributed to P González.

At least 19 recordsLinked to original sources

Behaviour of MG-63 osteoblast-like cells on wood-based biomorphic SiC ceramics coated with bioactive glass.

The aim of this study was to test the in vitro cytotoxicity of wood-based biomorphic Silicon Carbide (SiC) ceramics coated with bioactive glass, using MG-63 human osteoblast-like cells, with a view to their application in bone implantology. To better understand the scope of this study, it should be taken into account that biomorphic SiC ceramics have only recently been developed and this innovative product has important properties such as interconnected porosity, high strength and toughness, and easy shaping. In the solvent extraction test, all the extracts had almost no effect on cellular activity even at 100% concentration, and cells incubated in the bioactive glass-coated SiC ceramics extracts showed a proliferation rate similar to that of the Thermanox control. There were no significant differences when the cellular attachment response of the cells on the wood-based biomorphic SiC ceramics, uncoated or coated with bioactive glass, was compared to the one exhibited by reference materials like Ti6Al4V and bulk bioactive glass. This fact looks very promising for biomedical applications.

Biomimetic Materials↗

Pharmacoeconomic analysis of adjuvant therapy with exemestane, anastrozole, letrozole or tamoxifen in postmenopausal women with operable and estrogen receptor-positive breast cancer.

OBJECTIVE: To compare the efficiency of adjuvant therapy with aromatase inhibitors or with tamoxifen in postmenopausal women with operable breast cancer and positive estrogen receptors. MATERIAL AND METHODS: A cost-utility analysis was performed based on a Markov model, from the Spanish National Health Care System perspective, comparing the treatment with exemestane (EXE: 25 mg/day) or tamoxifen (TAM: 20 mg/day) after 2-3 years of monotherapy with TAM; anastrozole (ANA, 1 mg/day) or TAM (20 mg/day) without previous TAM therapy; and letrozole (LET: 2.5 mg/day) or placebo after 5 years of monotherapy with TAM. The follow-up of a hypothetical cohort of women starting treatment at 63 years of age was simulated during 10 and 20 years. The probabilities of transition between health states and quality adjusted life years (QALYs) were obtained from the literature, and the unit costs (euro corresponding to 2004) from a Spanish database. RESULTS: After 10 and 20 years of follow-up, more QALYs per patient would be gained with the EXE scheme (0.230-0.286 and 0.566-0.708, respectively) than with ANA (0.114 and 0.285) and LET (0.176 and 0.474). The cost of gaining one QALY was lower with the EXE scheme (50,801-62,522 euro and 28,849- 35,371 euro, respectively) than with ANA (104,272 euro and 62,477 euro) and LET (91,210 euro and 49,460 euro). The result was stable for the cost per life-year gained (LYG) and in the sensitivity analysis. CONCLUSIONS: The EXE scheme after TAM is more cost-effective than the ANA and LET schemes.

Anastrozole↗

Sensitivity to antiviral therapy may change after liver transplantation in patients with chronic hepatitis C virus infection.

In hepatitis C virus (HCV)-infected patients, it is generally assumed that the pattern of response to antiviral therapy remains unaltered after liver transplantation (LT). However, changes in the circulating HCV quasispecies and in the gene expression profiles of the graft might influence response to treatment after LT. We evaluated 22 HCV-infected patients who received antiviral treatment while awaiting LT and in whom HCV infection recurred. Eleven of these patients underwent a new antiviral treatment course. Our study analyses the early virological response to both treatment courses to assess the influence of the changes in HCV on the response to therapy. Patients were considered early virological responders (EVR) if viral load declined > or = 2 log10 during the first 12 weeks of therapy. The remaining individuals were considered nonresponders (NR). HCV sequences from hypervariable region 1 and nonstructural 5A (NS5A) region before both treatment regimens were compared. Of 11 patients, 8 (73%) showed identical early response to both courses of therapy (group A: five EVR-EVR, three NR-NR). Interestingly, the response changed in three patients (27%) (group B): two NR became EVR after transplantation, whereas one EVR became NR. Fixation of mutations within the NS5A occurred preferentially in group B (100%) compared with group A (37%)(P = 0.12). However, the number of fixed mutations was not significantly different between groups, suggesting that the changes in sensitivity to therapy after LT are not exclusively dependent on variations in HCV strains. In conclusion, in HCV-infected patients undergoing LT, the pattern of response to antiviral treatment may change after transplantation, and this possibility needs to be incorporated in clinical practice.

Adult↗

The Pro279Leu variant in the transcription factor MEF2A is associated with myocardial infarction.

BACKGROUND: A myocyte enhancer factor 2A (MEF2A) mutation that segregated with coronary artery disease/myocardial infarction (CAD/MI) in a large family has recently been described. Missense mutations in sporadic coronary artery disease patients were also reported. These data suggest that mutations in exons 7 and 11 of MEF2A cause CAD/MI, though the association was refuted by another study. OBJECTIVE: To analyse the genetic variation of exons 7 and 11 in a large cohort of Spanish CAD/MI patients and controls. METHODS AND RESULTS: A rare polymorphism, P279L, was detected both in patients and controls. Carriers of the 279Leu allele had a threefold risk of suffering CAD/MI compared with controls (p = 0.009; odds ratio = 3.06 (95% confidence interval, 1.17 to 8.06)). In the controls the allele was found only in those under 50 years of age. Exon 11 showed a high degree of heterogeneity caused by a polyglutamine (CAG)n polymorphism, but no significant differences in genotype or allelic frequencies were found. CONCLUSIONS: The 279Leu allele appears to be a genetic risk factor for CAD/MI in the population studied. This effect could be the result of a reduced transcriptional activity on MEF2A with 279Leu.

Alleles↗

Lymphocytic hypophysitis with cystic MRI appearance.

Lymphocytic hypophysitis (LH) is an infrequent primary inflammatory disorder, which is usually diagnosed after surgery for lesions suspected to be pituitary adenomas. Some radiological features have been described that may allow a preoperative diagnosis, such as a symmetric enlargement of the gland with diffuse contrast enhancement extending to the basal hypothalamus in a tongue-like fashion. We describe the case of a patient with LH presenting with the MR imaging of a cystic lesion with ring contrast enhancement. It seems that this appearance in imaging studies is not unusual, and should be considered among the features suggesting this disease in an appropriate clinical context.

Adolescent↗

Effect of parathyroidectomy on renal graft function.

Some authors have reported acute impairment of renal transplant function after parathyroidectomy (PTx). Since 1996 PTx has been performed in 22 renal transplant recipients (follow-up, 24.2 +/- 15 months; serum creatinine concentration (SCr) pre-PTx, 1.26 +/- 0.4 mg/dL). We analyzed the serum levels of immunoreactive parathyroid hormone, calcitriol, calcium, phosphate, alkaline phosphatase, SCr, and hemoglobin, as well as proteinuria, blood pressure, and immunosuppressive treatment at several times: before PTx and at 7 days, 1 month, and then every 3 months post-PTx. After PTx we observed acute renal function deterioration until the third post-PTx month, when SCr levels returned to baseline values. We found no changes in blood pressure, although there was a trend toward a reduced dosage of antihypertensive drugs. We compared the patients who showed more significant increases (>30% from baseline) in SCr (group A, n = 7) with those who did not (group B, n = 15). Group A had higher SCr levels pre-PTx. We observed no other significant differences, either pre-PTx or post-PTx. In 2 patients in group A, SCr returned to baseline at the third month after PTx, but in the other 5 the renal function impairment persisted. Taking into account this risk and that severe hyperparathyroidism does not revert after transplantation, it would seem more appropriate in such cases to perform PTx while the patient is on the waiting list. The causes of this renal functional impairment are not clear, but the patients who showed worse deterioration also had a worse renal function pre-PTx.

Antihypertensive Agents↗

Treatment with adefovir dipivoxil in a renal transplant patient with renal insufficiency and lamivudine-resistant hepatitis B infection.

Lamivudine is a safe, effective treatment for hepatitis B virus (HBV) reactivation after renal transplantation. However, prolonged lamivudine therapy can produce resistance to the drug. Adefovir dipivoxil (ADV) has demonstrated efficacy in patients with lamivudine resistance, but there is limited clinical experience in patients with either renal transplants or severe renal insufficiency. A 47-year-old man with asymptomatic HBV infection underwent renal transplantation in November 1995. In September 2000 lamivudine therapy was initiated to treat HBV reactivation. The outcome was good, with negative HBV DNA levels. Two years later, significant viral replication developed again. At that time the patient already had advanced renal insufficiency due to chronic graft nephropathy. The transaminase levels were increased, and the HBV DNA reached greater than 200,000 copies/mL by polymerase chain reaction, with development of ascites and cirrhosis. The patient was started on ADV 10 mg every 72 hours (dose adjusted to renal function). There was rapid normalization of hepatic enzymes and progressive decline of the viral load. HBV DNA became negative after 6 months of ADV treatment. The renal function has since remained stable. This case suggests that ADV can be safe and effective in the treatment of renal transplant patients with lamivudine-resistant hepatitis B, even in the presence of advanced renal insufficiency.

Adenine↗

[Oncolytic viral therapy of gliomas: review of the literature].

Gliomas are the most frequent primary tumors of the brain. The standard treatment includes surgery, radiotherapy and chemotherapy, but the outcomes of patients with these tumors have remained nearly unchanged for past years. Hopefully, recent advances in molecular biology are rising new clinical expectation for patients with brain tumors. Among the novel techniques in this new field of research a new field of research, the use of oncolytic viruses has been explored in different trials during last years. In the present review we analyze the advances in the understanding of the oncolytic viral therapy of gliomas.

Brain Neoplasms↗

Potential use of a Yersinia ruckeri O1 auxotrophic aroA mutant as a live attenuated vaccine.

The aroA gene of Yersinia ruckeri, which encodes 5-enolpyruvylshikimate 3-phosphate synthase, was insertionally inactivated with a DNA fragment containing a kanamycin resistance determinant and reintroduced by allelic exchange into the chromosome of Y. ruckeri 21102 O1 by means of the suicide vector pIVET8. The Y. ruckeri aroA::Kan(r) mutant was highly attenuated when inoculated intraperitoneally into rainbow trout, with a 50% lethal dose of >5 x 10(7) CFU. The mutants were not recoverable from the internal organs 48 h post-inoculation or later. The vaccination of rainbow trout with the AroA mutant as a live vaccine conferred significant protection (relative percentage survival = 90%) against the pathogenic wild-type strain of Y. ruckeri.

Animals↗

[Idiopathic hypertrophic pachymeningitis of the cavernous sinus mimicking meningioma with complete occlusion of the carotid artery].

Idiopathic hypertrophic pachymeningitis (IHPM) is a rare inflammatory entity characterized by the idiopathic thickening of the dura mater. An increasing number of cases have been reported involving the cavernoss sinus. We present the case of a patient with IHPM who was diagnosed of meningioma and showed a complete occlusion of the intracavernous carotid artery. This 42 years old woman was sent to our hospital to be treated radiosurgicaly with the diagnosis of meningioma. The diagnosis was based on MRI findings and on the temporal resistance to corticoid treatment. A complete study of the patient demonstrated the inflammatory nature of the lesion, which improved after long corticosteroid treatment. The differential diagnosis between meningioma and IHPM may be complex because of the similarities in image findings and the temporal resistance to corticosteroids shown by IHPM, thus we emphasize the usefulness of the SPECT to differentiate between inflammation and tumor in this clinical setting. In addition, our patient showed a total occlusion of the intracavernous carotid artery and, as far as we know, this is the first case with such a finding reported in the literature.

Adult↗

Comparative effects of thiopental and propofol on atrial vulnerability: electrophysiological study in a porcine model including acute alcoholic intoxication.

BACKGROUND: Atrial tachyarrhythmias (AT) frequently complicate the perioperative period. Alcohol intoxication is a recognized causative factor for dysrrhythmias. We studied the effects of propofol and thiopental on atrial electrophysiology and vulnerability to AT in a closed-chest porcine model in which AT are facilitated by ethanol. METHODS: Thirty-eight pigs were randomly assigned to thiopental (T-group, n=19) or propofol (P-group n=19). All animals were assigned to undergo a right atrial electrical stimulation protocol (RASP) at baseline. Thirty pigs were assigned to undergo additional RASP during ethanol infusion, while the remaining eight were assigned to undergo additional RASP during saline infusion (control group). We analysed effective refractory period (ERP), and intra-atrial conduction interval (ICI) (between atrial sites 4 cm apart), at several cycle lengths (CL). RESULTS: There were no significant differences at baseline. During ethanol infusion, propofol produced a greater rate-dependent decrease in excitability, manifested by a longer minimum paced CL with 1:1 atrial capture: 145 (11) vs 164 (27) ms in the T- and P-group, respectively (P=0.01). Propofol was associated with a greater rate-related slowing in conduction: difference between ICI at CL of 300 ms and ICI at minimum CL: 30 ms in P-group and 22 ms in T-group (P<0.03). In the P-group we observed a longer duration of induced arrhythmias (145 (131) vs 74 (91) s, P<0.03) and a higher proportion with atrial flutter (AFl) (76 vs 19%, P<0.001). CONCLUSIONS: Propofol in this model was more arrhythmogenic than thiopental, as manifested by a longer duration of induced arrhythmias, particularly AFI.

Alcoholic Intoxication↗

Lhermitte-Duclos disease and Cowden disease: clinical and genetic study in five patients with Lhermitte-Duclos disease and literature review.

BACKGROUND: Lhermitte-Duclos Disease (LDD) is an infrequent cerebellar disorder characterized by focal or diffuse enlargement of cerebellar folia presenting as a slowly growing mass in the posterior fossa. Over the past decade its association with Cowden disease (CD) has been recognized with increasing frequency. This latter disease is a genetic condition leading to the presence of multiple hamartomas and neoplasias which affect mainly the skin, thyroid, breast and genito-urinary and gastro-intestinal tracts. It has even been hypothesized that LDD and CD constitute a single entity. This work is aimed to analyse to what extent this association was present in patients treated for LDD at our institution. METHOD: We reviewed the medical records of five patients and performed clinical studies for CD manifestations, among them, genetic investigation for PTEN mutations. The International Cowden Consortium Criteria were applied for the diagnosis of CD. FINDINGS: Four of the five patients treated for LDD were also diagnosed of CD. The genetic study found PTEN mutations in two of them. Interpretation. LDD has been found to be closely related to CD in this series, in accordance with previous literature. However, the absence of CD diagnosis in one of the patients led us to suggest that, despite the strong association between these two diseases, LDD can also appear as an isolated condition.

Adult↗

Longitudinal assessment of nutritional status in children treated for acute lymphoblastic leukaemia in Cuba.

Malnutrition has a deleterious effect on the results of therapy for malignant diseases in childhood. The impact of radiotherapy on growth is well known but the impact of cytotoxic drugs on nutritional status is more controversial. The purpose of this study was to determine the nutritional status of a cohort of children treated for acute lymphoblastic leukaemia (ALL) in Cuba. The study involved 49 children admitted to a single center and treated with a Berlin-Frankfurt-Munster-based protocol. Nutritional assessment included measurements of height, weight, body mass index and skin-fold thickness, made at diagnosis, after the intensive phase of treatment and at the end of therapy. Z-scores were used for height and comparison of percentiles for the rest of the variables. All the patients were above the third percentile in all the measurements. There were no statistically significant differences between the results at diagnosis, after intensive therapy and at the end of treatment. Although the sample was small, there was no demonstrable effect of chemotherapy on nutritional status in this Cuban paediatric population, in contrast to that reported in children with ALL in other developing countries.

Antineoplastic Combined Chemotherapy Protocols↗

[Silent corticotroph adenomas: presentation of two cases that presented with pituitary apoplexy].

Among the group of pituitary adenomas surgically treated, about 25-30% are not associated with clinical or analytical findings of hormonal hypersecretion. The development of immunohistochemical techniques has allowed the demonstration of a subgroup of adenomas that show immunoreactivity against several hormones among the group of, apparently, non-functioning adenomas. This subgroup has been called silent adenomas. Silent adenomas positive for ACTH show a singular clinical picture and different from those adenomas producing Cushing's disease, as they present more frequently as macroadenomas, with more frequent pituitary apoplexy, invasion of cavernous or sphenoidal sinus and recurrences. We present two new cases of silent corticotroph adenomas in two female patients that presented with pituitary apoplexy, one of them after giving birth after a normal full-term pregnancy. Both of them presented with macroadenomas that invaded the sphenoidal and cavernous sinus. Although both tumors were immunoreactive for ACTH, none of the patients presented clinical or analytical findings compatible with Cushing's disease.

Adenoma↗

Action of different monoterpenic compounds against Anisakis simplex s.l. L3 larvae.

Different natural monoterpenes (geraniol, citronellol, citral, carvacrol, cuminaldehyde and eugenol) are studied in vitro against Anisakis simplex s.l. L3 larvae, employing perillaldehyde as a reference substance. Final concentrations used were: 12.50, 6.25 and 3.12 microg/ml for each of the tested products. The parameters average survival, survival 50 and maximum survival were determined at 4, 8, 24 and 48 hours after the start of the experiment. All tested products, except eugenol, were active at the highest concentration (12.50 microg/ml). The damage caused to A. simplex s.l. L3 was by examining histological sections. The antioxidant activity of the tested products by DPPH free radical scavenging does not appear to be associated with their larvicide activity against A. simplex s.l. L3.

Animals↗

Coronary heart disease in a patient with cerebrotendinous xanthomatosis.

Coronary heart disease is a prevalent condition and a leading cause of death in developed countries. Most cases are due to the cluster of classical risk factors, such as smoking, diabetes, high blood pressure and dyslipidaemia. However, a few patients develop severe and premature arteriosclerosis in spite of absence of common risk factors. Here, we present the clinical, analytical and molecular features of a 36-years-old man who died from advanced ischaemic heart disease as a result of cerebrotendinous xanthomatosis (CTX), a rare condition characterized by elevation in plasma and most tissues of cholestanol and where neurological impairment is the hallmark of this disease. We discuss the relevance of heart disease and the mechanism leading to accelerate arteriosclerosis is CTX.

Adult↗

Characterization of human transferrin glycoforms by capillary electrophoresis and electrospray ionization mass spectrometry.

Carbohydrate Deficient Glycoprotein Syndrome (CDGS) is an inherited metabolic disease affecting all parts of the body. The biochemical diagnosis of this syndrome is based on the presence of a special marker in blood, Carbohydrate Deficient Transferrin (CDT), which is also a marker of chronic alcohol abuse. CDT is characterized by abnormal glycoforms of serum transferrin (Tf). In the present study, electrophoretic separation of human serum transferrin glycoforms was carried out using a bare fused-silica capillary and the glycoforms present in commercial Tf were baseline separated. The limit of detection (LOD) of human Tf was around the nmol concentration range. The LOD of the trisialo- and disialo-Tf, expressed as percentages of the tetrasialo-Tf peak area, were 0.5% for trisialo-Tf and 0.4% for disialo-Tf, and these values were appropriate for CDGS diagnosis. Moreover, Tf glycoforms were characterized using mass spectrometry (MS). The method was applied to the analysis of normal and pathological serum samples, after dilution. The results obtained suggest a way of making a rapid and simple CDGS diagnosis.

Electrophoresis, Capillary↗