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Biomedical subjects

J Mayo

Publications and source records attributed to J Mayo.

At least 19 recordsLinked to original sources
PubMed2001

The evolving mode of presentation of HIV-infected patients to health services of northern Spain: 1985 through December 1999.

To evaluate the mode in which human immunodeficiency virus (HIV)-infected patients have had their first contact with the health services throughout time as well as their demographic and immunologic features, all 1,076 adult HIV-infected patients seen at our institution were grouped by the year of presentation. The patients' age and gender, the mode of presentation (admitted through the emergency department or seen at the outpatient clinic), and the presence of acquired immune deficiency syndrome (AIDS)-defining conditions and CD4 counts at the time of presentation were analyzed. The patients' age at presentation and the rate of female patients increased throughout time (p < 0.001, and p = 0.01, respectively). There was a progressive decline in the proportion of patients who were hospitalized until the mid-1990s (p < 0.0001), followed by a rise during the subsequent years (p = 0.04). This U-shaped curve was opposite to that of CD4 counts, which was ascending until 1994 (p = 0.04), to decline progressively later (p = 0.1). Patients whose first contact with the hospital was through admission had lower CD4 counts (p = 0.007), and higher rates of AIDS diagnosis throughout time (p < 0.0001). We conclude that some features of HIV-infected patients at the time of their first contact with the health services are changing over time, such as older age, increasing numbers of women, and higher degrees of immunosuppression. These findings seem to reflect the increasing number of patients unaware of their past risk factors, and should be considered for the development of strategies targeted to this population in order to allow earlier detection of their infection.

Adolescent↗
PubMed2000

Response of lymphocyte subsets in patients under treatment for tuberculosis.

Thirty-six immunocompetent patients with tuberculosis underwent six sequential measurements of blood lymphocyte subsets after the onset of therapy. Two different responses were observed, depending on each patient's initial lymphocyte count. Patients with initial lymphocytopaenia showed a marked increase in all lymphocyte subpopulations shortly after the initiation of treatment, whereas those without lymphocytopaenia showed a decrease in the cell counts during the initial 2 months, followed by a slow increase during the following 4 months. The lymphocytes as a whole and all lymphocyte subsets showed remarkably parallel curves in each group. These results strongly suggest that the lymphocytic responses to tuberculosis involve all lymphocyte subsets, not only the T or CD4+ lymphocytes as previously thought.

Adolescent↗
PubMed2000

Tuberculosis as a cause of recurrent fever of unknown origin.

Recurrent fever constitutes a diagnostic challenge for clinicians, due mainly to the intermittent nature of the fever that results in incomplete investigations. We describe three patients with recurrent fever thought to be due to tuberculosis, and review the 14 previously reported cases who fulfil the criteria of recurrent fever for at least 1 month's duration. The median duration of symptoms before diagnosis was 5 months, and the duration of the febrile bouts ranged from a few hours to 1 week. The most common complaints were constitutional symptoms and abdominal pain, and most patients had significant underlying conditions. The mortality rate was 31%, and was limited to the earlier cases. Routine laboratory studies are not very helpful for the diagnosis of this condition, and chest radiographs showed some alteration in half the cases at the time of diagnosis, although in some cases represented old, healed lesions. PPD testing was positive in most cases, particularly in those without underlying conditions. Empirical antituberculous therapy should be considered in cases of recurrent fever, especially in areas of high prevalence or in patients with predisposing conditions.

Aged↗
PubMed2000

Sequential evaluation of serum urate concentrations in AIDS patients with infections of the central nervous system.

To evaluate the serum urate levels in AIDS patients with infections of the central nervous system (CNS), 46 patients who had at least two measurements of urate were included. A maximum of four measurements per patient were considered: prior to the CNS involvement (U-PRIOR), at the time of CNS involvement (U-CNS), after treatment for the CNS infection (U-AFTER), and the last measurement before death (U-LAST). Serum U-CNS levels were significantly lower than U-PRIOR values (p=0.038). U-AFTER levels were higher than U-CNS in the patients who improved (p=0.25), and lower in the patients who did not improve (p=0.026). There were no significant differences among the four diagnostic groups in U-CNS measurement (p=0.29) but they were found in U-AFTER determinations (p=0.018), probably as a result of the different response to treatment. Hypouricemia seemed to be associated with lower survival periods. We conclude that hypouricemia is common in AIDS patients with CNS infections, probably as a result of increased renal losses of urate, and that it may have prognostic significance. CNS infections are associated with significant decreases in serum urate levels in comparison with previous values. The urate concentrations seem to increase after successful treatment of the CNS infections, whereas they decrease further in patients who do not improve.

Acquired Immunodeficiency Syndrome↗
PubMed1999

In vitro measurements of water content and T2 relaxation times in lung using a clinical MRI scanner.

The purpose of this study was to validate water content measurements and to determine the T2 distribution in lung on a 1.5 T clinical magnetic resonance imaging (MRI) scanner. A single-slice 16 echo pulse sequence with an echo spacing of 10 msec was employed to scan 19 healthy juvenile pig lungs. The in vitro water content of each lung was measured using MRI techniques and compared with gravimetric measurements. The mean difference between the gravimetric and MRI water contents was -4.1 +/- 7.6%, and an excellent linear correlation (R2 = 0.98) was observed between the two independent measurements. The dependence of the geometric mean T2 time upon lung water density exhibited two distinct regions (inflated and deflated) separated by a threshold density of about 0.4 g/mL.

Animals↗
PubMed1999

Evolution of serum beta2-microglobulin concentrations during treatment of tuberculosis patients.

A total of 36 human immunodeficiency virus-seronegative patients were studied in order to evaluate serum beta2-M levels in immunocompetent patients with tuberculosis who were receiving treatment. Six measurements of several clinical and laboratory parameters were carried out at different intervals during the 6 months of treatment. The mean serum beta2-M at presentation was 149 nmol/l and 4 patients had values above the upper normal limit. Significant decreases in the mean serum beta2-M concentration were observed in the follow-up determinations in the patients as a whole (p = 0.002), in the patients with normal (p = 0.039) and in the patients with increased beta2-M at presentation (p = 0.037). beta2-M significantly correlated with erythrocyte sedimentation rate (p = 0.002). The statistically significant decrease observed in patients with both normal and increased beta2-M values at presentation, suggests that the immunological dysfunction responsible for the increase in beta2-M involves most, if not all, patients with tuberculosis. The measurement of beta2-M in conjunction with other clinical and laboratory parameters could be helpful in evaluating the response to therapy, particularly in those patients with increased beta2-M at presentation.

Adolescent↗
PubMed1999

Muscle infections caused by Salmonella species: case report and review.

We describe a patient with salmonella pyomyositis and review 30 other cases reported during the past 4 decades. Men outnumbered women by 2.9 to 1, and the median age of the patients was 51 years. Approximately one-half the cases were caused by Salmonella enteritidis. Infected vascular aneurysms were observed in seven patients. Prior salmonella infections and local trauma or lesions were common. Diverse underlying conditions, mainly diabetes and human immunodeficiency virus infection, were present in 81% of the patients, and the psoas muscle was involved in 55% of the cases. One-third of the patients died, and relapses were common after a median time of 5 weeks (range, 4.5-27 weeks) in those who survived. Most patients had anemia, and pathogens were recovered from blood samples from two-thirds of the patients. Salmonella should be considered as a causative agent of muscle infections in the appropriate clinical setting, particularly in patients with underlying diseases or preexisting vascular aneurysms.

Aged↗
PubMed1999

Changing spectrum of HIV infection and its associated conditions in Spain: the end of the beginning?

To evaluate the natural history and the impact that different strategies have had on HIV infection and its associated conditions, a cohort of 970 patients (432 had AIDS) who had been seen over a period of 13 years were studied. The incidence of new HIV-infected patients had increased steadily since 1985, peaking in 1993 (52.9 cases/100,000 population), to significantly decrease in the subsequent years. The most common AIDS-defining illnesses (ADIs) were tuberculosis (52.3% of the patients), Pneumocystis carinii pneumonia (30%), and candidal esophagitis (28.6%). The frequency of new cases of tuberculosis per patient with ADI clearly decreased over this period (p < 0.0001), whereas that of P. carinii pneumonia decreased slowly until 1994, to fall thereafter to about half the previous levels (p = 0.005). Candidal esophagitis showed a biphasic pattern, the second peak probably due to the emergence of fluconazole resistance. The number of ADIs per patient increased from the beginning of the observation period, peaking in 1995 (1.67 ADI/patient), followed by a statistically significant decrease that, in 1997, reached the 1987 levels (1.22 ADI/patient). We conclude that the clinical spectrum of HIV infection is improving in the last years. Except for tuberculosis, prophylaxis for other ADIs, although effective, does not seem to have had a dramatic impact on occurrence. The most impressive reductions have been observed only after the introduction of antiretroviral combination therapy.

AIDS-Related Opportunistic Infections↗
PubMed1999

Hypersensitivity reactions to rifampin. Pathogenetic mechanisms, clinical manifestations, management strategies, and review of the anaphylactic-like reactions.

Many of the adverse events induced by rifampin have been considered allergic in origin. The flu-like syndrome and other hypersensitivity reactions seem to be caused by immune complexes, although their pathogenetic mechanisms are not fully elucidated. Many cases have been reported of the flu-like syndrome, thrombocytopenia, hemolytic anemia, and renal failure caused by rifampin. In almost all of the patients in whom they were sought, nonreaginic antirifampin antibodies were detected. On the other hand, anaphylactic reactions seem to be IgE-mediated. We have analyzed the 18 reported cases of anaphylactic reactions severe enough to cause marked hypotension. The interval between the onset of treatment and the anaphylactic reaction was highly variable. Most patients presented with prodromes, mainly rash, before the development of anaphylactic symptoms, and, in most cases, the reaction occurred after reexposure to rifampin. Clinical findings include a variety of symptoms, such as fever, exanthem, dyspnea, abdominal pain, and vomiting. Seven of the 9 patients in whom HIV status was known were seropositive, including the only 2 patients who died. We believe that, in case of a non-life-threatening adverse reaction caused by immune complexes, rifampin could be readministered, if necessary, at a more frequent and reduced dose, perhaps with the addition of corticosteroids. In case of anaphylactic reactions the drug should be avoided, although desensitization procedures may be useful. Certain laboratory findings may serve as a clue to predict anaphylactic reactions in patients who have experienced minor adverse events to rifampin. However, the diagnostic value of such findings is not well established and, therefore, patients with previous adverse reactions should be carefully monitored if reexposure to rifampin is essential.

Anaphylaxis↗