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Biomedical subjects

A Marcos

Publications and source records attributed to A Marcos.

At least 19 recordsLinked to original sources
PubMed1999

Central venous catheter exchange by guidewire for treatment of catheter-related bacteraemia in patients undergoing BMT or intensive chemotherapy.

Current guidelines for the treatment of catheter-related bacteraemia (CRB) advise against central venous catheter (CVC) exchange because of the potential risk of prolonging infection. However, there are no consistent data proving this recommendation. We evaluated prospectively the usefulness of CVC exchange by guidewire for the treatment of CRB in patients undergoing BMT or intensive chemotherapy. CVC exchange was considered when fever and positive blood cultures persisted after 2 days of adequate antimicrobial therapy and no potential source of bacteraemia other than CVC could be identified. The guidewire exchange was preceded and followed by a slow infusion of adequate antimicrobial therapy. Bacteraemia was confirmed as catheter-related by demonstrating concordance between isolates from the tip and blood cultures by pulsed-field electrophoresis of genomic DNA. This procedure was performed in 19 episodes of bacteraemia during a 1-year period. Fourteen episodes (74%) were catheter-related and 71% of these were due to coagulase-negative staphylococci. Guidewire replacement was accomplished uneventfully 4 days after development of sepsis (range 3-6). In all cases, clinical signs of sepsis disappeared in less than 24 h after replacement. Definitive catheter withdrawal was carried out a median of 16 days (range 3-42) after guidewire exchange; in all cases, the tip culture was negative. We conclude that CVC replacement by guidewire under adequate antimicrobial therapy may be a reasonable option for the treatment of CRB when antimicrobial therapy alone has been unsuccessful.

Adult↗
PubMed1998

A prospective randomized trial of mycophenolate mofetil with neoral or tacrolimus after orthotopic liver transplantation.

BACKGROUND: The success of liver transplantation in this decade has become the stimulus to extend the donor and recipient pool. Reducing early posttransplant morbidity to maintain our success, as we expand our frontiers, has led us to focus on balanced testing of multidrug immunosuppression regimens. METHODS: A prospective trial in orthotopic liver transplantation using Mycophenolate Mofetil and an identical steroid taper with randomization of patients to Neoral (N) or Tacrolimus (FK) is the basis of this report. This was an intent-to-treat study designed to compare the 6-month primary endpoints of rejection and infection and to compare the 6-month secondary endpoints of liver function, renal function, bone marrow function, hypertension, and serum cholesterol levels. RESULTS: Ninety-seven patients completed the 6-month follow-up period (N=49, FK=48). The actual 6-month patient and graft survival rates were 98% and 94%, respectively. There was no difference in the number of patients with rejection episodes (N=11, FK=8) (P=0.61). There were 24 infections (3 cytomegalovirus) in the FK group and 30 infections (9 cytomegalovirus) in the N group. The cholesterol levels at 6 months were not significantly different (P=0.07) between the groups. The other secondary 6-month endpoints were not significantly different, except total bilirubin, which was lower in the FK arm (P=0.02). CONCLUSIONS: The use of Mycophenolate Mofetil with N or FK and an identical steroid taper after orthotopic liver transplantation is associated with excellent graft and patient survival, and at 6 months, only 191% of the patients experienced rejection, with a 48% overall infection rate.

Adolescent↗
PubMed1998

Intraocular pressure as a risk factor for visual field loss in pseudoexfoliative and in primary open-angle glaucoma.

OBJECTIVE: To analyze the relationship between intraocular pressure (IOP) and visual field loss in patients with primary open-angle glaucoma (POAG) and in those with pseudoexfoliative glaucoma (PEXG). DESIGN: A cross-sectional, observational study. PARTICIPANTS: Thirty-one patients with PEXG and 31 patients with POAG that was newly diagnosed were included in this study. MAIN OUTCOME MEASURES: The authors recorded the untreated IOP and the amount of the visual field loss, at presentation, in both study groups. RESULTS: The authors found a significant relationship between IOP and visual field mean deviation (MD) index (P = 0.0001, r = 0.68) in PEXG but not in POAG eyes (P = 0.7). CONCLUSION: The authors found that untreated IOP levels can explain the amount of visual field loss, as measured by the MD index, much better in patients with PEXG than in comparable patients with POAG. Thus, vulnerability of the optic nerve head to increased IOP appears to be different in these two diagnostic categories.

Aged↗
PubMed1998

Viscoelastic-injecting cystotome.

This continuous curvilinear capsulorhexis (CCC) technique is for use in complicated surgical cases such as when the anterior chamber is shallow, the red reflex is not good, or eye movements are present. This technique is easier and safer in such cases because it uses a cystotome connected to a viscoelastic syringe. First, the anterior chamber is filled with viscoelastic material using a conventional cannula. The cannula is replaced with a bent needle (or cystotome), and the CCC is performed in the usual way. This instrument allows the surgeon to inject small amounts of viscoelastic material exactly where and when it is needed. The anterior chamber remains deep while the CCC is performed, and the anterior capsule tear is done in a more controlled fashion.

Anterior Chamber↗
PubMed1998

Immunodeficiency associated with anorexia nervosa is secondary and improves after refeeding.

Several studies have addressed the question of starvation effects on immune function by means of changes in lymphocyte subsets, cytokine induction or lymphocyte activation. Anorexia nervosa (AN) patients are severely malnourished and contradictory results have been obtained regarding the accompanying immunodeficiency, including its assignation as a part of the primary nervous disorder. In the present work, an extensive immunological function examination was carried out on 40 AN patients who were compared with a control group of 14 healthy girls. The AN patients were also classified according to their nutritional status (by the Body Mass Index: BMI), this being critical for a better understanding of these secondary immunodeficiency bases. Moreover, another immune system study was performed on five patients after refeeding. Lymphocyte subsets and function, cytokine induction and peripheral blood concentrations, and innate as well as humoral immunity were evaluated. Deregulation in the cytokine network, owing to the interaction of the central nervous (CNS) and immune systems, seems to be the initial immune alteration in AN immunodeficiency but it has not been disproved that the immunodeficiency is a direct consequence of the original psychiatric perturbation. Spontaneous high levels of circulating interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) have been observed; this is probably one of the causes of the anomalies found in the T-cell subpopulations (mainly the naive CD4+CD45RA+ reduction and the cytotoxic CD8+ increase) and T-cell activation status (mainly the down-regulation of the CD2 and CD69 activation pathways). This finally leads to an impairment, not only in T-cell function but also in T-cell to B-cell co-operation. The AN specificity of these results is confirmed by the fact that these immune alterations improve after refeeding and when nutritional status becomes less critical, which also suggests that AN immunodeficiency is indeed secondary to malnutrition.

Adolescent↗
PubMed1997

The immune system in eating disorders: an overview.

Eating disorders, such as anorexia nervosa and bulimia nervosa, are becoming more and more common in our society. Although they are psychiatric illnesses, there are many factors involved, including abnormal food behavior. Nutrients play an important role in the development and functionality of immunocompetent cells. An impaired immunocompetence has been shown to be an important causal factor in the increased susceptibility of malnourished individuals to infectious disease. Therefore, studies on the immune system are of great interest when assessing the extent to which the nutritional status of these patients could be affected. However, the literature in this field is controversial, and the mechanisms are not yet completely defined, although some hypotheses try to clarify the disturbances caused in the organism under these bizarre circumstances. In spite of the fact that the immune system is altered by distorted food behaviors, such as in eating disorders, the awareness of characteristics of other systems involved, and therefore altered, by these pathologies would be very helpful for understanding the mechanisms triggered in these syndromes. In fact, the interactions among the immune and other systems in eating disorders are beginning to be studied. Finally, the main goals are to limit the evolution of these illnesses through early diagnosis, and to devise a long-lasting, definitive cure for these patients through appropriate therapy.

Adolescent↗
PubMed1997

Immunocompetence in relation to a heat-processed diet (Maillard reaction) in weanling rats.

Diets containing unheated casein (CD; control) or a casein-glucose mixture (CGD) previously heated at 140 degrees for 2 h were fed to two groups of young rats for 21 d. Differences in body weight, feed consumption, thymus, and spleen growth, protein metabolism and in vivo immune response were then determined. For this last experiment, animals were inoculated with sheep erythrocytes (SRBC) on day 15 to provide an immunological challenge. No changes were seen in body weight, feed consumption or feed conversion ratios. Neither were significant differences found in spleen weight, protein content, DNA content, DNase (EC 3.1.4.6) activity or lymphocyte count, suggesting that spleen cell growth remained similar in all the animals studied. The CGD induced marked increases in thymus DNA content whilst the protein:DNA ratio became lower. Spleen RNA content was similar in all rats, but thymus RNA content was 29% lower in the CGD group, although this difference did not reach statistical significance. This fact might be a consequence of the low RNase (EC 2.7.7.16) activity and RNase:RNA ratios in the thymus glands of CGD-fed animals. Further, the number of splenic plasma cells secreting anti-SRBC antibodies (direct plaque-forming cells) was significantly decreased in the same group. It might be concluded that both diets are adequate for rat growth and that the differences observed in the thymus of CGD-fed rats may be directed towards preserving tissue function. Nevertheless, the CGD did cause immunological disturbances affecting the humoral immune response.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Interactions between nutrition and immunity in anorexia nervosa: a 1-y follow-up study.

Nutritional status and immunocompetence were evaluated in 15 patients suffering from anorexia nervosa in comparison with a control group (n = 15). After 1 y, data from six phases of the study were evaluated: immediately after admittance to the hospital (AN1), after 1 mo (AN2), after 2 mo (AN3), after 3 mo (AN4), after 6 mo (AN5), and after 1 y, (AN6). Patients recovered weight from AN4 until AN6 although, according to body mass index values, all patients had low weights during the 1-y follow-up. Likewise, leukocyte and lymphocyte values were borderline and lower in patients in all phases tested than in control subjects. All lymphocyte subpopulations were lower in AN1 and AN2 patients (inpatients) than in control subjects, except for CD19 cells, which remained unmodified. There seemed to be a recovery of lymphocyte subsets after hospitalization in AN3 and AN4 patients (outpatients), except for CD57, which remained below control values. However, there was a global decrease of the lymphocyte subsets in AN5 and AN6. Ratios of CD4 to CD8 cells were not altered but the ratio of CD2 to CD19 cells was lower in all phases except AN6. Moreover, cell-mediated immune function was impaired and none of the patients showed normal responses. Thus, despite the slight weight increase found in AN4, AN5, and AN6 and the apparent cell subset recovery after hospitalization, these results suggest a greatly depleted nutritional status that remained during the whole year in all patients.

Adolescent↗
PubMed1997

Evaluation of nutritional status by immunologic assessment in bulimia nervosa: influence of body mass index and vomiting episodes.

The nutritional status of 21 patients suffering from bulimia nervosa was evaluated by anthropometric and immunologic indexes in comparison with a control group (n = 15). In addition, the influence of body mass index (BMI; in kg/m2) values and vomiting episodes on the nutritional status of bulimic patients was assessed. Anthropometry showed no signs of malnutrition in either group, except for those patients with low weights (BMI < 19). Bulimic patients had lower lymphocyte counts than did control subjects, except for those without vomiting (NVBN). All T lymphocyte subsets tested as well as CD57 cells were lower (22% and 55%, respectively) in bulimic patients than in control subjects, but the CD19 cell subset remained unmodified. The low-weight bulimic group (LWBN) had lower CD4 cell counts than did the normal-weight (BMI > 19) bulimic group. The NVBN group had lymphocyte subpopulations similar to those in the control group, except for CD57, which was lower. The bulimic patients with vomiting had the lowest cell subset values. These results suggest a depleted nutritional status in all bulimic patients studied, even those with normal weights. The LWBN group had the most depleted nutritional status and the NVBN group was least affected at a subclinical level. CD57 can be considered a good marker of nutritional status in this syndrome because it was the only subpopulation altered in all groups.

Anthropometry↗
PubMed1997

Human immunodeficiency virus infection and nutritional status in female drug addicts undergoing detoxification: anthropometric and immunologic assessments.

To clarify the interrelations among drug abuse, malnutrition, and immunosuppression, the effects of human immunodeficiency virus (HIV) infection on the nutritional status of 17 noninfected and 19 HIV-infected asymptomatic female drug addicts undergoing detoxification were evaluated by measuring anthropometric and immunologic indexes. Anthropometric measurements were normal in both groups as a result of weight gain (approximately 10 kg) in every patient after the detoxification period. Leukocyte and lymphocyte values and CD2 lymphocyte subset counts were also similar in both groups. CD4 counts (P = 0.04) and the ratio of CD4 to CD8 cells (P = 0.6 x 10(-4)) were lower whereas CD8 counts (P = 0.003) were higher in the HIV-infected than in the noninfected group. Responses to a delayed-hypersensitivity skin test were below normal in both groups but significantly more so in the HIV-positive group (P = 0.05). CD19 counts were lower (P = 0.02) and values for serum immunoglobulins G and M were higher (51% and 37%, respectively) in the HIV-infected females than in the noninfected women. These results may suggest that despite anthropometric recovery, the HIV-infected women had depleted immune function, resulting not only from HIV infection but also from the subclinical malnutrition triggered by previous drug addiction.

Adult↗
PubMed1997

Effects of human immunodeficiency virus infection and detoxification time on anthropometric measurements and dietary intake of male drug addicts.

Anthropometric measurements and dietary intakes of male drug addicts (n = 62), infected (n = 23) or not infected (n = 39) with human immunodeficiency virus (HIV), who underwent two phases of detoxification (P1:15 d to 1 mo and P2: 5-6 mo) were assessed. Body weight, weight gain during detoxification, height, body mass index, and ideal body weight were measured. A prospective food-record questionnaire was compiled and energy and nutrient contents of ingested food were determined. Food intakes were compared with dietary recommendations for the Spanish population. At the time of the study, all patients had substantial weight gains, mostly in P1. Nutrient consumption was lower in P2 (energy, protein, and lipids) and in groups not infected with HIV. In P2, lipid intake was higher in the HIV-positive than in the HIV-negative group (P < 0.05, Student's t test). Moreover, an interactive effect of HIV by phase was shown for lipid intake (P = 0.04, two-way analysis of variance). Magnesium, folate, and vitamin E intakes were lower than recommended in nearly all patients. Energy, zinc, riboflavin, and vitamin B-6 intakes were lower than recommended or were borderline. HIV infection did not have a negative effect on anthropometric measurements or on nutrient intakes. The anthropometric assessment may suggest an adequate recovery of the indexes measured in all patients, which principally took place during P1. Measurement of nutrient intakes showed certain imbalances and deficits that should be corrected.

Adult↗
PubMed1995

Mutation in the gyrA gene of quinolone-resistant clinical isolates of Acinetobacter baumannii.

The gyrA gene mutations associated with quinolone resistance were determined in 21 epidemiologically unrelated clinical isolates of Acinetobacter baumannii. Our studies highlight the conserved sequences in the quinolone resistance-determining region of the gyrA gene from A. baumannii and other bacteria. All 15 isolates for which the MIC of ciprofloxacin is > or = 4 micrograms/ml showed a change at Ser-83 to Leu. Six strains for which the MIC of ciprofloxacin is 1 microgram/ml did not show any change at Ser-83, although a strain for which the MIC of ciprofloxacin is 1 microgram/ml exhibited a change at Gly-81 to Val. Although it is possible that mutations in other locations of the gyrA gene, the gyrB gene, or in other genes may also contribute to the modulation of the MIC level, our results suggest that a gyrA mutation at Ser-83 is associated with quinolone resistance in A. baumannii.

4-Quinolones↗
PubMed1994

A comparative study of ribotyping and arbitrarily primed polymerase chain reaction for investigation of hospital outbreaks of Acinetobacter baumannii infection.

Arbitrarily primed polymerase chain reaction (AP-PCR) and ribotyping were compared in an investigation of an outbreak of Acinetobacter baumannii infections. Twenty-five clinical isolates shown previously by other criteria to belong to two different groups, and nine randomly selected A. baumannii clinical isolates from other hospitals were investigated. Among the strains analysed, nine different EcoRI rRNA gene restriction pattern fingerprints were observed. While similarity was detected between strains of the same group, these fingerprints differed clearly between the two A. baumannii groups defined in the outbreak. Two of the nine strains selected randomly had the same ribotype as those strains involved in the outbreak, whereas the remaining seven strains each had a different ribotype. When the strains were tested by AP-PCR with 0.25, 0.5 or 1 microM of M13 forward primer, 10 different profiles were obtained. However, 11 profiles were observed if two different primer concentrations (0.25 and 1 microM) were used. It was concluded that ribotyping and AP-PCR exhibited a similar discriminatory power, although AP-PCR had the additional advantages of speed and simplicity.

Acinetobacter↗