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Biomedical subjects

F Muñoz

Publications and source records attributed to F Muñoz.

At least 37 records · Page 2Linked to original sources
PubMed2001

Electrostatic and structural similarity of classical and non-classical lactam compounds.

Various electrostatic and structural parameters for a series of classical and non-classical beta-lactams were determined and compared in order to ascertain whether some specific beta-lactams possess antibacterial or beta-lactamase inhibitory properties. The electrostatic parameters obtained, based on the Distributed Multipole Analysis (DMA) of high-quality wavefunctions for the studied structures, suggest that some non-classical beta-lactams effectively inhibit the action of beta-lactamases. As shown in this work, such electrostatic parameters provide much more reliable information about the antibacterial and inhibitory properties of beta-lactams than do structural parameters.

Anti-Bacterial Agents↗
PubMed2001

An endophyte of the tropical forage grass Brachiaria brizantha: isolating, identifying, and characterizing the fungus, and determining its antimycotic properties.

Brachiaria, predominantly an African genus, contains species, such as B. brizantha, an apomictic C4 grass, that are commercially important forage grasses in tropical America, where they now cover about 55 million hectares. From B. brizantha accession CIAT 6780, we isolated an endophytic fungus that may be economically significant. The fungus was identified as Acremonium implicatum (J. Gilman & E.V. Abott). 18S rDNA and ITS rDNA sequences were used to characterize isolates of the endophyte, and showed that they belonged to the Acremonium genus, being close to A. strictum and A. kiliense. Using the random amplified polymorphic DNA (RAPD) technique, involving arbitrary primers of 10 bases, we showed that the isolates were highly similar to each other. Antiserum produced from a monoconidial culture of A. implicatum isolated from B. brizantha 6780, differentiated the isolates consistently in line with the DNA data. When we compared endophyte-free with endophyte-infected B. brizantha CIAT 6780 plants, both artificially inoculated with the pathogenic Drechslera fungus, we found that the endophyte-infected plants had fewer and smaller lesions than did the endophyte-free plants. Sporulation of Drechslera sp. on artificially inoculated leaf sheath tissues was also much less on tissue infected with the endophyte.

Acremonium↗
PubMed2001

[Management of epistaxis in Rendu-Osler-Weber disease].

The Rendu-Osler-Weber disease is an hereditary hemorrhagic dysfunction with muco-cutaneous telangiectasia of diverse localization, being able to internal organs and committing the life in some cases, not alone for the derived systemic complications, but for the quantity of the recurrent nosebleed that are the most frequent feature and sometimes restrictive that these patients present. We report two family groups with multidisciplinary diagnosis, and analyze them most important ENT aspects for this syndrome.

Aged↗
PubMed2001

[Idiopathic thrombosis of the internal jugular vein].

The internal jugular vein thrombosis is an infrequent vascular complication associated in the past to severe infections of the head and neck. We report a case with unknown etiology and make a review on the subject discussing on etiology, clinical features, diagnosis and treatment.

Anticoagulants↗
PubMed2001

C282Y and H63D mutations of the haemochromatosis gene in patients with iron overload.

OBJECTIVE: To determine the relevance of C282Y and H63D mutations of HEF gene in patients with iron overload. PATIENTS AND METHODS: Patients with iron overload referred to our Liver Unit were included in the study. The association of mutations to different diagnosis and their impact on the severity of the hepatopathy were explored. Sensitivity, specificity and positive and negative predictive values of mutations for the diagnosis of haemochromatosis were determined. RESULTS: The study included 78 patients with iron overload. The control group included 21 patients of similar age and sex ratio without iron overload nor hepatopathy. Twenty three patients had haemochromatosis, 22 alcoholic liver disease and 33 other diseases unrelated to iron metabolism. Seventy three per cent of patients with haemochromatosis were homozygous for the C282Y mutation. All the C282Y homozygous subjects had also haemochromatosis. Fifty three per cent of patients with alcoholic hepatopathy had some kind of mutation. This has been also observed in 70% of patients with iron-unrelated diseases. Such percentage was significantly greater than in the control group (24% with H63D mutation). C282Y homozygosity in patients with iron overload had a sensitivity of 73.9%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 89.6%. CONCLUSIONS: In our population, as in all the Western countries, haemochromatosis is mainly associated to homozygous C282Y mutation. The high frequency of mutations in patients with iron overload and without haemochromatosis suggests the involvement of such mutations in iron overload.

Female↗
PubMed2000

Ischemia-induced phosphorylation of initiation factor 2 in differentiated PC12 cells: role for initiation factor 2 phosphatase.

An in vitro model of ischemia was obtained by subjecting PC12 cells differentiated with nerve growth factor to a combination of glucose deprivation plus anoxia. Immediately after the ischemic period, the protein synthesis rate was significantly inhibited (80%) and western blots of cell extracts revealed a significant accumulation of phosphorylated eukaryotic initiation factor 2, alpha subunit, eIF2(alphaP) (42%). Upon recovery, eIF2(alphaP) levels returned to control values after 30 min, whereas protein synthesis was still partially inhibited (33%) and reached almost control values within 2 h. The activities of the mammalian eIF2alpha kinases, double-stranded RNA-activated protein kinase, mammalian GCN2 homologue, and endoplasmic reticulum-resident kinase, were determined. None of the eIF2alpha kinases studied showed increased activity in ischemic cells as compared with controls. Exposure of cells to cell-permeable inhibitors of protein phosphatases 1 and 2A, calyculin A or tautomycin, induced dose- and time-dependent accumulation of eIF2(alphaP), mimicking an ischemic effect. Protein phosphatase activity, as measured with [(32)P]phosphorylase a as a substrate, diminished during ischemia and returned to control levels upon 30-min recovery. In addition, the rate of eIF2(alphaP) dephosphorylation was significantly lower in ischemic cells, paralleling both the greatest translational inhibition and the highest eIF2(alphaP) levels. The endogenous phosphatase activity from control and ischemic extracts showed different sensitivity to inhibitor 2 and fostriecin in in vitro assays, inhibitor-2 effect in ischemic cells being lower than in control cells. Together these results indicate that an eIF2alpha phosphatase, probably protein phosphatase 1, is implicated in the ischemia-induced eIF2(alphaP) accumulation in PC12 cells.

Adenosine Triphosphate↗
PubMed2000

A prospective multicenter study on the safety of a pacemaker with automatic energy control: influence of the electrical factor on chronic stimulation threshold. PEACE Investigators.

The effectiveness and safety of a pacemaker with automatic control of capture was evaluated in 162 patients followed at 27 Spanish centers. The aim of our prospective, multicenter, and randomized trial was to determine the relationship between the voltage output of the pulse generator and the stimulation threshold. We randomized 162 patients (107 men, mean age 75 +/- 12 years). We implanted a ventricular pacemaker model Regency SR+ or SC+ with Pacesetter's low polarization bipolar leads Membrane E 1450. The patients were randomized to receive Autocapture or not; group I (81 patients) Autocapture On, pulse output automatically adjusted and group II (81 patients) Autocapture Off, fixed output parameters (3.9 V, 0.37 ms). We performed a 6-month follow-up measuring stimulation threshold by means of the VARIO test and Autocapture test, evoked response signal, and R wave signal. The mean R wave was 15.77 +/- 3.5 mV at the end of the follow-up for group I, and 14.91 +/- 6.8 mV for group II (P = NS). The measured evoked response at the end of the follow-up was 9.25 mV in Group I and 8.48 mV in Group II (P = NS). The stimulation threshold was not different between groups. The current density created with the voltage and pulse width used in this study (< or = 3.9 V and 0.37 ms) at the tip of this electrode during the maturation process had no influence on the development of the chronic detection and stimulation thresholds.

Adult↗
PubMed2000

[Helical CT compared to ERCP in obstructive biliary pathology].

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is the examination of choice in the diagnosis of biliary tract pathology although newer, less invasive techniques with high diagnostic sensitivity should be evaluated. The aim of this study was to evaluate the diagnostic efficacy of helical computed tomography (CT) in bile duct obstruction, particularly in choledocholithiasis. PATIENTS AND METHODS: Forty-four patients with suspected bile duct obstruction were prospectively evaluated. Helical TC was carried out 12 hours before ERCP and patients were grouped according to risk of choledocholithiasis. RESULTS: Choledocholithiasis was found in 20 patients (45.4%). Helical TC identified this pathology in 17 and correctly ruled it out in 18 of 24 patients (S: 85%, E: 75%, positive predictive value 74%, negative predictive value 85.7%. Of the patients with choledocholithiasis, bile duct dilatation was found in 18. Helical TC correctly diagnosed this pathology in 16 of the 18 patients (88.8%). Helical TC correctly diagnosed one of two patients (50%) with choledocholithiasis and normal bile ducts. CONCLUSIONS: Helical TC is effective in the diagnosis of choledocholithiasis but is not sufficiently accurate to be used in the screening of this entity.

Adult↗
PubMed2000

[Toxic hepatitis caused by nimesulide, presentation of a new case and review of the literature].

Nimesulide is a potent non-steroidal anti-inflammatory drug. It is a new, selective cyclooxygenase-2 inhibitor with few adverse effects on the gastrointestinal system. We present a case of hepatotoxicity in which other possible causes of liver damage were excluded. A biochemical pattern of cholestasis was predominant. Evolution was favorable after the drug was stopped and enzymatic alterations progressively returned to normal. The cases reported to date are reviewed. The precise mechanism by which nimesulide produces liver damage is not known but it is probably caused by an idiosyncratic reaction. Because of the severity of the hepatitis described in some cases, treatment should be stopped when liver dysfunction is detected and the patients should be closely monitored.

Aged↗
PubMed2000

[Dysphagia caused by Zenker's diverticulum after total laryngectomy].

Zenker's diverticulum is a mucosal lined outpouching of pharynx through Lainert's space that causes dysphagia of the upper digestive tract. Multiples theories try to explain the acquired etiology of this entity, attributing its origin to a disfunction of pharynx-esophageal sphincter. A case of total larynguectomy with hypopharyngeal diverticulum and progressive dysphagia to solid food is presented. We analyze the etiopathogenic mechanisms and the definitive characteristics of this entity. We review mundial literature, being exceptional the fact of finding clinical manifestations in diverticulum of larynguectomized patients.

Deglutition Disorders↗
PubMed1999

Obstetrical outcome of pregnancy in patients with systemic Lupus erythematosus. A study of 60 cases.

OBJECTIVE: To analyze the course of maternal diseases and the outcome of pregnancy in patients with systemic Lupus Erythematosus (SLE). STUDY DESIGN: During a period of 11 years we prospectively followed 60 pregnancies in 46 SLE patients in a tertiary care center in Barcelona (Spain). The management protocol included: (1) planning of conception when disease was inactive; (2) frequent follow-up visits by an internist-obstetrician team; (3) use of sequential ultrasonographic, Doppler and fetal echocardiographic examinations; (4) serial evaluations of maternal immunological condition; and (5) low dose aspirin from 1 month before attempting conception and throughout pregnancy was added in women with antiphospholipid antibodies. From 1985 until 1994 prednisone prophylaxis was used in all lupus patients during the last month of pregnancy and during the first month of the puerperium; from 1995 onwards this regime was abandoned. RESULTS: The mean (S.D.) age of patients was 28.6 (4.8) years (range 20 to 42) and the mean (S.D.) previous duration of SLE was 6.25 (4.8) years (range 0 to 17). SLE was diagnosed during the pregnancy in two cases (3.3%) and the disease was active at conception in four cases (6.7%); at that time nine patients (15%) were taking prednisone. Antiphospholipid antibodies were positive in 16 patients (30.4%) and there were 10 (16.7%) pregnancies in patients having lupus nephropathy. There were three first-trimester miscarriages (5%) and four (6.7%) voluntary abortions. Obstetric complications in the remaining 53 pregnancies included: preterm delivery, 11 cases (20.8%); intrauterine growth retardation, five cases (9.4%); hypertension, 10 patients (18.9%), five of them fulfilling the criteria of preeclampsia; premature rupture of membranes, four patients (7.5%); finally, 13 neonates had a birthweight lower than 2500 g. There were 15 lupus flares (28.3%), giving a flare rate of 0.044 per patient/month. There were five neonatal deaths (perinatal mortality rate, 94 per thousand): one because of complete heart block, three due to severe hyaline membrane disease resulting from extreme prematurity and one intrauterine death in a patient having the Leiden mutation. CONCLUSION: Pregnancy in patients with SLE should not be regarded as an unacceptable high-risk condition for the mother or her baby provided that conception is accurately planned and patients are managed according to a careful multidisciplinary treatment schedule.

Female↗
PubMed1999

Impact of chronic liver disease due to hepatitis viruses as cause of hospital admission and death in HIV-infected drug users.

The life expectancy of HIV-positive individuals has been prolonged in recent years, as a consequence of the wide use of antiretroviral drugs and primary prophylaxis for the most common opportunistic infections. In HIV-positive persons infected parenterally, chronic viral liver disease (CVLD), mainly that caused by hepatitis C virus (HCV), is frequently seen. Moreover, chronic hepatitis C seems to present a more accelerated course in HIV-infected patients, leading to cirrhosis and liver failure in a shorter period of time. The aim of the present study was to investigate the impact of CVLD on the morbidity and mortality of HIV-positive patients. A retrospective analysis of the causes of hospital admission during a 4.5-year period in a reference centre for AIDS situated in Madrid was performed. Decompensated liver disease (encephalopathy, ascites, jaundice), or complications directly related to it (gastrointestinal bleeding, hepatorenal syndrome, peritonitis) were diagnosed in 143 (8.6%) of 1670 hospital admissions. These episodes of CVLD corresponded to 105 different individuals, a quarter of whom had two or more re-admissions. HCV alone or in combination with other hepatotropic viruses was involved in 93 (88.6%) patients admitted for CVLD. Death directly associated with CVLD occurred in 15 individuals, which represented 4.8% of the total causes of inhospital mortality during the study period, and represented the fifth cause of death in hospital for HIV-infected patients. In conclusion, CVLD represents an important cause of hospital admission and death in HIV-infected drug users.

HIV Infections↗