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Biomedical subjects

A Guerrero

Publications and source records attributed to A Guerrero.

At least 127 records · Page 7Linked to original sources
PubMed1997

Genetic characterization of multidrug-resistant Mycobacterium bovis strains from a hospital outbreak involving human immunodeficiency virus-positive patients.

Nineteen multidrug-resistant (MDR) Mycobacterium complex strains isolated in a nosocomial outbreak were characterized at the molecular level. The strains were microbiologically characterized as Mycobacterium bovis. The mpt40 sequence was not present in chromosomal DNA from these strains, supporting the fact that they were M. bovis. All of the isolates were resistant to isoniazid, rifampin, pyrazinamide, ethambutol, streptomycin, para-aminosalicylic acid, clarithromycin, cycloserine, ethionamide, ofloxacin, capreomycin, and amikacin. By performing the standardized IS6110 fingerprinting by restriction fragment length polymorphism (RFLP) analysis, we were able to differentiate two groups (groups A and B) containing two (16 isolates) and three (3 isolates) IS6110 copies, respectively. These strains were typed by spoligotyping, developed to distinguish M. bovis strains and also to distinguish them from M. tuberculosis strains (J. Kamerbeek et al., J. Clin. Microbiol. 35:907-914, 1997). All the strains were confirmed to be M. bovis. In addition, spoligotyping showed a difference in only 1 of 43 spacers between RFLP groups A and B. The rpo beta region of several strains representative of each identified group was cloned and sequenced, and identical mutations (Ser-531 to Leu) responsible for the rifampin resistance phenotype were found. To our knowledge, this is the first characterization at the molecular level of an MDR M. bovis strain responsible for a nosocomial outbreak.

AIDS-Related Opportunistic Infections↗
PubMed1997

[Neurological manifestations in patients with sera positive for Borrelia burgdorferi].

Eight years of case histories of patients with positive serum tests for Borrelia burgdorferi (Bb) are reviewed with the aims of analyzing the neurological manifestations involved and of assessing the value of serology in the diagnosis of neuroborreliosis (NB) in our clinical setting. Of the 105 cases with neurological manifestations that could be examined, 25 patients (24%) with other infections, neoplasms or other diseases had false positive serologies. Forty-one patients (39%) met the criteria for NB diagnosis: 26 had lymphocytic meningitis, 13 had polyradiculitis and 20 had cranial neuropathy. Spinal fluid cultures were positive in 43% of the patients on whom the test was performed, and all patients in this group who were treated with antibiotics improved. The other 39 patients (37%) had only neurological manifestations, which were not typical of NB (peripheral neuropathy, stroke, demyelinating disease, dementia or myelopathy), but for which no other etiology could be demonstrated. Spinal fluid serology was positive in 16% of those cases studied and none of those treated only with antibiotics improved. Among patients with both neurological manifestations and Bb positive serology, there were many false positives and cases with signs that were of dubious relation to infection by Bb; therefore, the prevalence of cases consistent with NB is low [corrected].

Borrelia burgdorferi Group↗
PubMed1996

Intramedullary cysticercosis cured with drug treatment. A case report.

STUDY DESIGN: A report of a patient with cervical intramedullary cysticercosis is presented. OBJECTIVES: To report the first case of intramedullary. cysticercosis cured with drug management only, which supports the hypothesis that management with anthelmintics might be successfully used in this form of cysticercosis. SUMMARY OF BACKGROUND DATA: Intramedullary cysticercosis is a rare manifestation of neurocysticercosis. Every treated patient reported to date has undergone surgery, frequently necessary for diagnosis. Since the anthelmintics praziquantel and albendazole were shown to be effective in parenchymal brain cysticercosis, these drugs have been considered potentially useful in patients with intramedullary cysticercosis. Nevertheless, no case yet had been reported to be cared with only medical therapy. METHODS: The treatment of a patient who suffered multiple cysticercal reinfestations of the nervous system is presented. RESULTS: The patient received prolonged treatment with albendazole because of superimposed cerebral reinfestations. During this treatment, she suffered acute paraparesis, and cervical magnetic resonance imaging showed cyst-like lesions with linear gadolinium enhancement and perilesional edema, indicative of dying cysticerci and inflammatory host reaction. Dexamethasone was added, and progressive neurologic improvement followed with complete resolution of intramedullary lesions. CONCLUSIONS: A preoperative diagnostic suspicion of cysticercosis is important in patients with intramedullary cystic lesions because specific drug treatment is available. Treatment with anthelmintics, particularly albendazole, should be considered in patients with intramedullary cysticercosis before surgery. Corticosteroids may be added to the therapeutic regimen because this may reduce the perilesional edema and prevent neurologic deterioration during the course of anthelmintic treatment.

Adult↗
PubMed1996

New trifluoromethyl ketones as potent inhibitors of esterases: 19F NMR spectroscopy of transition state analog complexes and structure-activity relationships.

A variety of trifluoromethyl ketones (TFMKs) have been studied as inhibitors of the antennal esterases of the Egyptian armyworm Spodoptera littoralis. The chemicals behaved as tight slow-binding inhibitors, the beta-thio derivatives being the most potent ones, particularly 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP) with an IC50 of 0.08 microM. Other TFMKs, containing a propenyl group at the non-polar end of the molecule as in the natural pheromone structure (compounds 4, 8 and 9), were also notably active. Correlation studies of inhibition with lipophilicity (log P) indicated that the optimum log P values for activity of the beta-thio compounds are in the range of 3.03-5.11, while a higher lipophilicity (range 5.37-5.89) was required among the devoid of sulfur ketones. 19F NMR studies, carried out with OTFP, showed that the inhibitor binds the enzyme in a reversible manner, forming an adduct (probably a hemiacetal) of tetrahedral geometry with the active site of the enzyme. To our knowledge, this is the first time that such a study on a natural esterase extract has been undertaken.

Acetone↗
PubMed1996

Correlation between in vitro resistance to fluconazole and clinical outcome of oropharyngeal candidiasis in HIV-infected patients.

Fifty episodes of oropharyngeal candidiasis in HIV-infected patients were analyzed prospectively in order to evaluate the clinical response to fluconazole. The minimum inhibitory concentrations (MICs) of fluconazole for the Candida strains isolated from the pharynx were correlated with the clinical response. Treatment with fluconazole (100 mg/day) was successful in 86% of the cases. A good clinical outcome followed in 97% of the cases when a strain sensitive to fluconazole was isolated. This figure fell to 22% when the strain was resistant to fluconazole (p < 0.001). The rate of post-treatment colonization was high (87%), and selection of non-albicans Candida species occurred in 23% of the cases. In conclusion, fluconazole treatment for oropharyngeal candidiasis of HIV-infected patients was useful in most cases, but less sensitive non-albicans species can be selected. Most treatment failures were associated with increased MICs of fluconazole for the strains isolated before treatment; therefore, susceptibility testing is recommended as an aid in clinical decision-making for the use of the azole group of drugs.

Antifungal Agents↗
PubMed1996

Difluoropalmitic acids as potential inhibitors of the biosynthesis of the sex pheromone of the Egyptian armyworm Spodoptera littoralis--IV.

2,2-, 3,3- and 4,4-Difluoropalmitic acids (1-3) have been synthesized and fully characterized. Acids 2 and 3 were prepared through fluorination of the corresponding dithioacetal-protected ketoesters followed by enzymatic saponification. The acids 1-3 were evaluated in vivo as inhibitors of the beta-oxidation step of the biosynthesis of (Z,E)-9,11-tetradecadienyl acetate, the major component of the sex pheromone of the Egyptian armyworm Spodoptera littoralis. Only, the 2,2- and 3,3-derivatives, i.e. those containing the two fluorine atoms at the positions involved in the chain-shortened step, have been found to be active, the activity being similar to or lower than that displayed by the corresponding monofluorinated acids.

Animals↗
PubMed1996

Colonization and infection with methicillin-resistant Staphylococcus aureus: associated factors and eradication.

OBJECTIVES: To identify characteristics associated with methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection, and to evaluate the efficacy of systemic and topical antimicrobials in the eradication of MRSA carriage among hospitalized patients. DESIGN: A case-control study was done to identify associations. Odds ratios were estimated by unconditional multiple logistic regression. Cohort study was done to evaluate MRSA decolonization efficacy by an oral regimen. Patients infected or colonized with MRSA received a 5-day course of oral (160 mg/800 mg) trimethoprim-sulfametroxazole twice daily and 600 mg of rifampin once daily as decolonization treatment. The proportion of MRSA-free patients after decolonization treatment was determined. Persistence of clearing was estimated by the Kaplan-Meier method. SETTING: Ramón y Cajal Hospital, a 1,249-bed, tertiary-care teaching hospital in Madrid, Spain. PATIENTS: One hundred ninety-two patients with hospital-acquired MRSA infection/colonization and 195 MRSA-free random controls. RESULTS: Six factors were associated independently with MRSA infection/colonization: age (every 10 years of age, odds ratio [OR] = 1.3); ward (surgical, OR = 1; medical, OR = 3.1; intensive care unit, OR = 60); previous hospitalization (OR = 6.9); coma (OR = 25.3); invasive procedures (each, OR = 1.7); 3 or more weeks of hospitalization (OR = 3.8). We failed to show antibiotic therapy to be an independent risk factor for MRSA hospital infection/colonization. Overall, MRSA eradication was 64.2% by day 2 to 9 after completion of treatment. Kaplan-Meier product limit survival analysis showed that the probability of remaining MRSA-free was 65.3% (SE = 0.09) at 32 days after completion of treatment. CONCLUSIONS: The results offer a rationale for reduction of MRSA infection/colonization in the hospital by interventions aimed at early identification of patients at higher risk, at prompt discharge of patients, and at preventing dissemination while performing invasive procedures. They also provide estimates of antibiotic treatment efficacy to reduce the reservoir of MRSA in the hospital.

Adolescent↗
PubMed1996

Central venous catheter infections in AIDS patients receiving daily home therapy for cytomegalovirus disease.

We studied the infection rate of long-term intravenous access used for daily home treatment of cytomegalovirus (CMV) disease in 61 AIDS patients who had 75 central venous catheters implanted for antiviral maintenance therapy between February 1989 and December 1994. In 39 patients (64%) the risk factor for AIDS was intravenous drug abuse. Sixty-three catheters were Hickman type and 12 were totally implanted ports. The cumulative follow-up time was 19000 catheter-days (52 patient-years), with median duration of placement of 249 days. The infection rate was 0.22 infections per 100 catheter days. The probability of remaining free of catheter-related sepsis was 58% at 6 months. In 25 cases (61%) antimicrobial therapy without catheter removal was successful. Three patients died because of a catheter-related infection (mortality rate 7.3%). Infection-free survival time was not related to the risk factor for AIDS (p = 0.44) or type of device (p = 0.41). The total infection rate in these patients receiving daily home maintenance therapy for CMV disease through a long-term catheter was similar to that in other AIDS patients receiving weekly treatment in hospital facilities.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Plasma lipids, erythrocyte membrane lipids and blood pressure of hypertensive women after ingestion of dietary oleic acid from two different sources.

OBJECTIVE: To study the effect of a diet rich in mono-unsaturated fatty acids (MUFA), from high-oleic sunflower oil (HOSO) and olive oil, on plasma lipids, erythrocyte membrane lipids (including fatty acid composition) and blood pressure of hypertensive (normocholesterolaemic or hypercholesterolaemic) women. METHODS: There were 16 participants who were hypertensive women aged 56.2 +/- 5.4 years. The participants ate a diet enriched with HOSO or olive oil for two 4-week periods with a 4-week washout period before starting the second type of MUFA diet. At entry and during study of each diet, plasma lipids and apolipoproteins were measured by conventional enzymatic methods. Erythrocyte membrane lipid and fatty acid compositions were analysed by means of the latroscan thin-layer chromatography/flame ionization detection technique and by gas chromatography, respectively. Blood pressure was also measured. The statistical analysis was conducted by using Student's two-tailed paired t-test. RESULTS: In both groups of hypertensive patients, there was a significant increase in plasma high-density lipoprotein (HDL) cholesterol concentration after the HOSO or olive oil diets, with regard to baseline. Additionally, a significant decrease in plasma HDL2 cholesterol concentration and an increase in plasma HDL3 cholesterol concentration were evident. The membrane free-cholesterol concentration increased significantly and the phospholipid concentration decreased significantly in erythrocytes after the olive oil diet, though both MUFA diets produced a significant decrease in the concentration of membrane esterified cholesterol. Therefore, the molar ratio of cholesterol to phospholipids was raised significantly in the erythrocyte membrane of hypertensive women after the dietary olive oil, but not after the HOSO diet. In the hypertensive and normo-cholesterolaemic group the HOSO diet significantly increased the content in the erythrocyte membrane of oleic, eicosenoic, arachidonic and docosapentaenoic acids, whereas the olive oil diet increased the content of palmitoleic acid and long-chain polyunsaturated fatty acids of the n-3 family besides, compared with baseline. A significant decrease in linoleic acid was also evident. In the hypertensive and hypercholesterolaemic group, the HOSO diet resulted in significant increases in palmitoleic, oleic, eicosenoic and behenic acids, whereas the olive oil diet enhanced the content of arachidonic, docosapentaenoic and docosahexaenoic acids besides, with respect to baseline. In addition, there was a significant decrease in stearic acid, but only after dietary olive oil was there a decrease in linoleic acid. The most important differences between the two MUFA diets were the increase in n-3 fatty acids and the decrease in the n-6; n-3 fatty acids ratio after dietary olive oil in the erythrocyte membranes of hypertensive patients. Interestingly, a significant reduction in systolic and diastolic blood pressures was only evident after the ingestion of olive oil. CONCLUSION: These data suggest that the beneficial effects of dietary olive oil on the plasma lipids and lipoprotein profile, lipid and fatty acid composition of erythrocyte membrane, and blood pressure in women with untreated essential hypertension are not found equally for the HOSO-rich diet, despite both vegetable oils providing a similar concentration of MUFA.

Aged↗
PubMed1996

Supportive care after active periodontal treatment: a review.

This review concerns the most significant questions regarding supportive (maintenance) care after active periodontal treatment: the effectiveness and ideal frequency of maintenance appointments, the adequacy of the supportive therapy according to patient needs, the possible alternatives to currently accepted protocols, and the relative value of personal oral hygiene in the overall context of supportive care. Periodontal diseases are infections with a high potential for recurrence, progressive loss of attachment and eventually, tooth loss. Current therapies for periodontal diseases are highly predictable in arresting disease activity. Supportive periodontal care has been shown to be very effective in maintaining support when adapted to each particular case. Nevertheless, current maintenance therapies may be unsuccessful in preventing further loss of attachment in a small number of sites for some patients. Tests aiming at bacterial identification and the subgingival application of antimicrobials may be helpful in the management of such cases, however the practical value in a specific setting is not known. There is growing evidence of the fundamental role of personal oral hygiene in supportive periodontal care. In cases with rapid and severe periodontal destruction and where local and/or systemic risk factors are present, personal oral hygiene becomes a key factor in the long-term preservation of periodontal support.

Anti-Bacterial Agents↗
PubMed1996

[Frequency of the clinical manifestations of Lyme borreliosis in Spain].

INTRODUCTION: There are differences in the clinical manifestations of Lyme borreliosis (LB) in different parts of the world. The aim of this work was to analyze its clinical manifestations in Spain. METHODS: We evaluated by ELISA and IFI the sera of 1,500 patients with clinical suspicion of LB between January 1987 to February 1993. Spanish criteria of LB (amplified CDC criteria of LB for epidemiological purpuse) were used. Clinical and serological data were evaluated with the patients' physicians and other etiologies were reasonably excluded in accepted cases of LB. RESULTS: Sixty-four patients of 138 with a positive serology (46%) met the LB criteria. Neurological manifestations were presented by 40 patients (62.5%) (in control group 23%, p < 0.05) cutaneous lesions by 20 patients (31%), articular manifestations by 18 patients (28%) (in control groups 56%; p < 0.05) and cardiac manifestations in two. Cutaneous manifestations included 17 erythema migrans, 2 acrodermatitis chronica atrophicans and 1 lymphocytoma). Artritis was present in 18 cases. Neurological manifestations included 16 cases of meningitis (2 with encephalitis), 11 of craneal neuropathy and 25 of peripheral neuropathy (13 of polyneuropathy). Cardiac manifestations acepted was 2 atrioventricular blockade. We detected 21% of false positive serology and in 33% of the positive cases, the LB criteria was not met. CONCLUSIONS: The low percentage of cutaneous manifestations is probably due to the fact that this series consist predominantly of hospital patients. In Spain, as in the rest Europe the predominant manifestations are neurological, however artritis are not infrequent manifestations.

Adolescent↗