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Biomedical subjects

A Guerrero

Publications and source records attributed to A Guerrero.

At least 109 records · Page 6Linked to original sources
PubMed1998

Thyroid abscess due to Rhodococcus equi in a patient infected with the human immunodeficiency virus.

A case of thyroid abscess due to Rhodococcus equi in an HIV-positive patient with previous pulmonary abscess is reported. Rhodococcus equi is a gram-positive rod that can cause infections in both immunocompetent and immunocompromised patients, though it occurs more frequently in patients with dysfunctional cellular immune systems. Several cases of Rhodococcus equi infection in persons infected with HIV have been reported. In these patients Rhodococcus equi usually invades the lungs, producing pneumonia. These infections often relapse, accompanied by intermittent bacteremia, despite conventional treatment. Extrapulmonary abscesses can occur.

AIDS-Related Opportunistic Infections↗
PubMed1998

Optimization of phosphorus localization by EFTEM of nucleic acid containing structures.

Energy Filtered Transmission Electron Microscopy (EFTEM) has been used to study nucleic acids localization in unstained thin sections of virus-infected cells. For this purpose, phosphorus maps (P-maps) have been obtained by applying the N-windows Egerton model for background subtraction from data acquired by a non-dedicated TEM Jeol 1200EXII equipped with a post-column PEELS Gatan 666-9000 and a Gatan Image Filter (GIF-100). To prevent possible errors in the evaluation of elemental maps and thus incorrect nucleic acid localization, we have studied different regions of swine testis (ST) cells with similar local density containing either high concentration of nucleic acids (condensed chromatin and ribosomes) or a very low concentration (mitochondria). Special care was taken to optimize the sample preparation conditions to avoid as much as possible the traditional artifacts derived from this source. Selection of the best set of pre-edge images for background fitting was also considered in order to produce "true P-maps". A new software for interactive processing of images series has been applied to estimate this set. Multivariate Statistical Analysis was used as a filtering tool to separate the "useful information" present in the inelastic image series (characteristic signal) from the "non-useful information" (noise and acquisition artifacts). The reconstitution of the original image series preserving mainly the useful information allowed the computation of P-maps with improved signal-to-noise ratio (SNR). This methodology has been applied to study the RNA content of maturation intermediate coronavirus particles found inside infected cells.

Animals↗
PubMed1998

Multiple sclerosis in Móstoles, central Spain.

OBJECTIVES: Until relatively recently southern Europe was regarded as having a medium to low multiple sclerosis prevalence, of about 20 or less per 100,000. However, recent studies in Sardinia, Sicily, continental Italy, Cyprus and Spain have yielded higher MS prevalence rates, between 32 and 102.6 per 100,000. We present the results of a prevalence study of MS in the municipality of M6stoles, central Spain. MATERIAL AND METHODS: To ascertain the prevalence of multiple sclerosis in M6stoles (195,979 inhabitants), an intensive study was undertaken using several sources of information. We used the Poser criteria in diagnosis. RESULTS: There were 85 patients (53 women and 32 men) classified as definite or probable, prevalence 43.4/100,000 (95% CI, 34.7 to 53.7). The incidence rate was 3.8/100,000/year (95% CI, 2.7 to 5.3) in the last 5 years. Mean age on prevalence day was 38.8+/-10.9 years. Mean age at onset was 31.7+/-9.3 years. Mean interval between initial symptoms and diagnosis was 1.7 years. Mean duration of disease was 7.6+/-6.1 years. Overall, 70.6% had a relapsing-remitting course, 18.8% had a primary progressive and 10.5% had a secondary progressive. Mean EDSS score was 2.7+/-1.9. CONCLUSION: The M6stoles study confirms the conclusions of previous smaller population studies that Spain is a moderately high or medium MS risk zone.

Adolescent↗
PubMed1998

Clinicoepidemiologic characteristics, prognostic factors, and survival analysis of patients coinfected with human immunodeficiency virus and Leishmania in an area of Madrid, Spain.

From 1987 to 1995, a retrospective case study was conducted at the Ramon y Cajal Hospital in Madrid, Spain, a public teaching hospital with 1,100 beds, to determine the clinicoepidemiologic characteristics, survival, and prognostic factors of patients with visceral leishmaniasis (VL) and human immunodeficiency virus (HIV) infection. The prevalence of VL in HIV+ patients compared with HIV- patients was studied. Epidemiologic, clinical, and parasitologic characteristics, as well as the effects of treatment, prognosis, and survival in 54 HIV+ patients (90 episodes) with VL were defined. Comparative survival studies among patients with and without acquired immunodeficiency syndrome (AIDS)-defining criteria and multivariate analysis of survival risk factors were performed. The prevalence of VL in patients with AIDS was much higher than in immunocompetent individuals. In spite of a good initial response to treatment for VL, 60.6% of the patients had relapsed by the end of one year. Mortality from the first episode was 18.5%, and 24% died in the first month after diagnosis of any VL episode. The mean survival of the 29 patients who died was 10.27 months. Survival in patients with and without AIDS at the time of the first episode of VL was compared at 30 months: 53.7% versus 20.5% (P = 0.00149). We found no significant difference (P = 0.24) in the survival of HIV+ patients who had died of VL without AIDS at the time of the first episode of VL compared with those of a control group of 413 dead patients with AIDS without VL. A diagnosis of AIDS at the time of the first episode of VL and thrombocytopenia were the only risk factors found related to survival. We conclude that in AIDS patients, VL is a recurrent disease that is highly prevalent and whose clinical course is modified by HIV.

Acquired Immunodeficiency Syndrome↗
PubMed1998

[Neuroimaging of hypoglycemia].

INTRODUCTION: Sustained hypoglycemia causes serious cerebral damage. The cortex, hippocampus and basal ganglia are particularly vulnerable to this. Exceptionally, there have been communications regarding neuroimaging visualization of cerebral lesions attributable to hypoglycemia only. We present the case of a woman who suffered hypoglycemic coma with permanent neurological damage. Lesions were seen on magnetic resonance (MR) and cranial computerized tomography (CT). CLINICAL CASE: A 22 year old woman with no vascular risk factors was admitted to hospital in hypoglycemic coma, after attempting suicide with oral antidiabetic drugs. The duration of the coma was unknown. On admission the glycaemia was 28 mg/dl. Cranial CT scan was normal during the first 24 hours. Cerebral MR scan one week late showed hyperintense lesions in T2, basal ganglia and left hippocampus. The cranial CT scan one year later showed diffuse atrophy, with bilateral lesions of low attenuation in the basal ganglia and dilatation of the ventricular system. CONCLUSIONS: It is unusual to see lesions secondary to hypoglycemia on neuroimaging investigations. The etiopathogenic mechanism is still unknown and it has generally been described in diabetic patients. In our case these lesions can only be attributed to hypoglycemia. MR is more sensitive than cranial CT scan for the detection of these lesions during the acute phase.

Adult↗
PubMed1998

[Endocarditis caused by Staphylococcus lugdunensis. Hospital incidence].

BACKGROUND: Staphylococcus lugdenensis is a coagulase negative staphylococcus (CNS) associated with a wide spectrum of infections among which infectious endocarditis may be found and in which it is an aggressive pathogen. METHODS: Since 1993 a systematic search for S. lugdenensis in all the staphylococci isolated in blood cultures and the possibility of endocarditis en all of these was determined. A review of all the cases of endocarditis in the literature was performed. RESULTS: Three cases of endocarditis by S. lugdenensis on the native valve were detected from January 1993 to June 1997. None of the patients presented previous heart disease or risk factors. In all the cases, at least three blood cultures were positive for S. lugdenensis and vegetations were observed by echocardiogram. Despite correct antibiotic treatment, disappearance of fever, negativization of control blood cultures and in the third case, valve replacement, two patients presented heart failure and all died. On review of the literature 31 cases of endocarditis were found with valve replacement and mortality being 55%. It should be indicated that 85% of the patients who survived required surgery. CONCLUSIONS: Endocarditis by S. lugdenensis is a severe infection frequently requiring valve replacement and is associated with a high mortality. Therefore, adequate early identification of the microorganism is necessary distinguishing it from the remaining CNS.

Adult↗
PubMed1998

[Clinical aspects of mitochondrial diseases].

Mitochondrial disorders are multisystemic diseases with very heterogeneous clinical manifestations. A same genetic mutation can result in distinctive clinical phenotypes and, on the other hand, distinct mutations can result in the same clinical phenotype. This article review the manifestations of the diverse clinical syndromes, their relationship with the molecular defects, and the diagnostic protocol in the investigation of a suspected mitochondrial disorder.

DNA, Mitochondrial↗
PubMed1997

Nosocomial transmission of Mycobacterium bovis resistant to 11 drugs in people with advanced HIV-1 infection.

BACKGROUND: Since 1990, several nosocomial outbreaks of multidrug-resistant (MDR) tuberculosis have occurred, none of which have involved Mycobacterium bovis. We describe an epidemic of nosocomial and primary MDR M bovis tuberculosis from December, 1993, to February, 1995, among HIV-1-infected patients in a district of Madrid. METHODS: We undertook genetic characterisation of the M bovis strain and investigated its presence in a tuberculosis epidemic in a Madrid hospital in a case-controlled study. We assessed 19 cases diagnosed with MDR tuberculosis due to M bovis during the study period. For the control group, we randomly selected 33 patients with HIV-1 infection and isolation of a strain of M tuberculosis susceptible to isoniazid, rifampicin, or both, who were treated in Ramón y Cajal Hospital. Infection-control policies and practices were implemented. FINDINGS: We detected 19 cases in HIV-1-infected patients of primary MDR tuberculosis produced by M bovis resistant to 11 antituberculosis drugs. We found phenotypic and genotypic similarities in the strains of M bovis. In the case group, the index case and two other cases had had previous contact with another hospital that had had an MDR tuberculosis outbreak. All patients died after a mean of 44 days (range 2-116), despite multidrug treatment with first-line and second-line antituberculosis drugs. The cases with M bovis MDR tuberculosis were significantly more likely than controls to have been admitted to a hospital ward at the same time as patients already infected with MDR tuberculosis during the 10 months before their diagnosis (adjusted odds ratio 94.6 [95% CI 9.4-956.3], p < 0.0001). Advanced HIV-1 immunosuppression was associated with the development of MDR tuberculosis. Implementation of control measures stopped the epidemic. INTERPRETATION: An M bovis primary MDR tuberculosis epidemic that cannot be treated effectively and with high mortality has emerged in Europe and has been transmitted between hospitals.

AIDS-Related Opportunistic Infections↗
PubMed1997

Salmonella lung involvement in patients with HIV infection.

STUDY OBJECTIVE: To determine the frequency, clinical features, and outcome of lung involvement in HIV-infected patients having nontyphoid strains of Salmonella bacteremia. DESIGN: A retrospective clinical study. PATIENTS AND SETTING: We studied the records of all HIV-infected patients with Salmonella bacteremia diagnosed at a university tertiary hospital from January 1987 to December 1995. RESULTS: Lung involvement was found in 18 (35.3%) of 51 HIV-infected individuals with Salmonella bacteremia. Six of 18 (33.3%) were diagnosed as having definite Salmonella pulmonary infection by isolation of Salmonella from respiratory specimens, while probable Salmonella lung disease was considered in two patients who developed lung abscesses without the identification of any pathogen. Predisposing factors for focal disease, such as prior lung disease or Salmonella serotype, were equally prevalent regardless of the presence of Salmonella pulmonary involvement. Cavitary infiltrates or abscess formation were seen in five of the eight patients. With the exception of one patient coinfected with Nocardia asteroides who died 1 month later, all patients were cured with antibiotic treatment. Superinfection with other pulmonary pathogens (10 cases, 56%) was more frequent than Salmonella pneumonia; the most frequent alternative diagnosis was Pneumocystis carinii pneumonia (5 cases, 28%), pyogenic bacterial infection (17%), and tuberculosis (11%). CONCLUSIONS: In HIV-infected patients with Salmonella bacteremia, lung involvement is frequent, although there were no significant factors to explain this association. Cavitary disease was the most common radiologic pattern, and focal lung disease due to Salmonella does not seem to be associated with a worse prognosis. Coinfection and superinfection with other respiratory pathogens are more common than isolated Salmonella lung disease, and therefore, additional diagnostic procedures must be considered in the evaluation of these patients.

AIDS-Related Opportunistic Infections↗
PubMed1997

Oxydation of oleic acid to (E)-10-hydroperoxy-8-octadecenoic and (E)-10-hydroxy-8-octadecenoic acids by Pseudomonas sp. 42A2.

Biotransformation of oleic acid with Pseudomonas sp. 42A2 has been found to produce(E)-10-hydroxy-8-octadecenoic acid (2a), (E)-10-hydroperoxy-8-octadecenoic acid (3a), and (E)-7,10-dihydroxy-8-octadecenoic acid (4a). Structures of the metabolites were fully characterized by infrared and 1H and 13C NMR spectra of the acids, by fast atom bombardment (FAB) and electron impact (EI) and chemical ionization (CI) mass spectrometry of the corresponding methyl esters. This is the first time that the two former compounds of trans stereochemistry have been described to have originated from a Pseudomonas sp. cell culture. Time course of products accumulation showed that biotransformation started with bacterial growth, the amount of products 2a (5.58 g/l) and 4a (2.63 g/l) being optimum after 24 h of incubation while hydroperoxide 3a (1.15 g/l) reached its maximum after 16 h of the biotransformation process. Experiments conducted to ascertain whether the conversion enzyme(s) was cell-bound or extracellular, showed that the enzyme(s) is cell bound, located in the periplasmic space and has lipoxygenase activity.

Biotransformation↗
PubMed1997

Selection of Candida glabrata strains with reduced susceptibility to azoles in four liver transplant patients with invasive candidiasis.

The cases of four liver transplant recipients who developed invasive candidiasis (2 cholangitis, 1 perihepatic abscess, 1 candidemia) due to azole-resistant, Candida glabrata are reported. Three patients were receiving azolic compounds (2 itraconazole, 1 fluconazole) when the infection was diagnosed. All four patients received fluconazole as intestinal decontamination during the first three weeks post transplantation. The infections occurred two months after transplantation in all patients, and in one patient Candida infection was the direct cause of death. Infection of the biliary tree was the origin of candidiasis in three patients; the fourth patient developed neutropenic-related candidemia. Fluconazole MICs exceeded 16 micrograms/ml in all cases; itraconazole MICs were 16, 2, 1, and 2 micrograms/ml, respectively. The potential role of Candida species other than albicans in these patients after administration of azole agents is discussed.

Antifungal Agents↗
PubMed1997

Acute polyradiculopathies in HIV-infected patients.

We studied 17 consecutive cases of acute polyradiculopathy (PR) diagnosed in HIV-infected patients to investigate the possible causes of this syndrome in our milieu. Sixteen patients presented with lumbosacral PR and one patient had predominantly cervical PR. Electrophysiological study showed a predominantly motor axonal neuropathy in all patients examined. Six patients had a laboratory-confirmed aetiology for the PR: cytomegalovirus (CMV) was isolated from cerebrospinal fluid (CSF) in three cases, meningeal lymphomatosis was diagnosed by CSF cytology in two cases, and one patient had cryptococcal meningitis. Another patient was thought to have acute axonal polyradiculoneuritis associated with HIV infection. CMV and Mycobacterium tuberculosis were the probable agents in four and three patients, respectively. Finally, in three patients a cause could not be foscarnet were effective in the treatment of definite or probable CMV PR. The present study confirms that acute lumbosacral PR in HIV-infected patients must be considered a syndrome with different causes. CMV and M. tuberculosis infections were the most frequent causative agents in our series (41% and 18% of the cases, respectively). Early empirical therapy is often necessary as definite diagnosis may be delayed or never achieved. Our experience suggests that, at least in our milieu, anti-tuberculous drugs should be considered in some cases together with ganciclovir or foscarnet in the empirical therapy for PR in HIV-infected patients.

Acute Disease↗
PubMed1997

AM218, a new polyanionic polysaccharide, induces radioprotection in mice when administered shortly before irradiation.

We have shown that the polyanionic polysaccharide AM218 improves the survival rate of the potentially lethally irradiated mice. This radioprotective effect was highly dependent on the administration schedule, the most efficient protocol being that in which the drug was given shortly before irradiation. The haematopoietic implications in the pharmacological action of AM218 were confirmed by the improved recovery in the three peripheral blood lineages observed in the AM218-treated mice. However, because of a marked increase observed in the number of white blood cells during the period of highest mortality of the control irradiated mice, effects on the neutrophil lineage may account for the effects mediated by AM218 in the irradiated mice. Both in vitro and in vivo treatment with AM218 before irradiation improved the survival rate of CFU-GM progenitors, while no effects were observed on the CFU-S pool. This led us to postulate that the improved survival rate of the committed progenitors, at least the granulocyte-macrophage progenitors, accounts for the radioprotective capacity of AM218.

Animals↗
PubMed1997

Effects of trifluoromethyl ketones and related compounds on the EAG and behavioural responses to pheromones in male moths.

Trifluoromethyl ketones (TFMKs) and analogues affect pheromone detection and behaviour in male moths. 3-Octylthio-1,1,1-trifluoropropan-2-one (OTFP), one of the most effective antiesterase agents, decreased the EAG amplitude and increased the repolarization time in Spodoptera littoralis. It also modified EAG responses of Mamestra brassicae and Heliothis zea to their pheromones and analogues, containing an acetate, an alcohol or an aldehyde function. In addition, OTFP also reduced the amplitude of the EAG response to linalool, a monoterpenic alcohol, but not its kinetics. The responses of male S. littoralis to the pheromone in the wind tunnel were significantly reduced after pre-exposure to vapours of OTFP. Comparison of the activity of other TFMKs and analogues with that of OTFP revealed a good agreement on EAG and behaviour. The effects of TFMKs on the EAG kinetics are discussed considering the hypothesis of an inhibition of the pheromone deactivation in the antenna.

Acetone↗