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Biomedical subjects

J Mayo

Publications and source records attributed to J Mayo.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1998

Fever of unknown origin in the setting of HIV infection: guidelines for a rational approach.

Fever of unknown origin constitutes a common problem in HIV-infected patients that, paradoxically, has received little attention in the literature. A review on this topic collecting data from different series showed that mycobacterial infections, particularly tuberculosis, were responsible for the fever in more than half of the patients. However, the relative frequencies of the different etiologies may vary substantially depending on the local prevalences of certain infections. With the notable exception of tuberculosis, which may develop at any stage of HIV infection, fever of unknown origin usually presents in patients with advanced disease when the CD4 cell count is below 100/microliter. In this overview we stress, from a practical point of view, some points to be considered in the evaluation of the HIV-infected patient who presents with fever of unknown origin, as well as the usefulness and yield of several diagnostic procedures.

AIDS-Related Opportunistic Infections↗
PubMed1998

Hospitalization parameters in patients infected with HIV: an analysis of the period 1992-1997.

The course of several hospitalization parameters of HIV-infected patients in a general hospital during the past 6 years was analyzed. There was a decrease observed in the number of non-AIDS diagnosed patients admitted during the observation period, but this decrement was noted only in the past 2 years in AIDS patients. This decline was not accounted for by a decrease in the incidence of AIDS patients seen each year, and was very probably due to the efficacy of antiretroviral combination therapy. The average length of stay of both AIDS and non-AIDS diagnosed patients decreased markedly during the first 3 years to stabilize during the remaining observation period. An analysis of the mode in which the patients were seen for the first time in the hospital (admitted from the emergency department because of complications of advanced HIV infection or attended in the outpatient clinic) revealed that, after a steady decrease from 1985 to 1995 in the relative proportion of patients hospitalized (p < 0.0001), there was an inversion of the downward trend in the past two years (p = 0.04). Most of the patients admitted during these 2 years were persons who did not know that they were infected with HIV. This observation reinforces the need for education campaigns and voluntary HIV testing which are particularly directed toward persons with high risk factors for the infection, in order to provide medical care before complications of advanced HIV infection appear.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Sequential evaluation of serum adenosine deaminase in patients treated for tuberculosis.

STUDY OBJECTIVE: To delineate the course of serum adenosine deaminase (s-ADA) in patients with tuberculosis who are receiving effective therapy. SETTING: A medical ward and an outpatient clinic in a general hospital. PATIENTS: Twenty-five immunocompetent patients with pleural or pulmonary tuberculosis. INTERVENTIONS: All patients received standard chemotherapeutic regimens with isoniazid, rifampin, and pyrazinamide. MEASUREMENTS AND RESULTS: Six measurements of several variables, including s-ADA, were carried out at different periods of time during the 6 months of follow-up. There were no significant differences in s-ADA values between sexes and there was no significant correlation with age or with the other variables analyzed. There was a significant decline in the s-ADA values during the first 2 months in the patients as a whole (p=0.04), followed by a stabilization of the s-ADA activity. This decline was due to a marked decrease in the s-ADA in the 13 patients (52%) who had initial high levels of the enzyme (p=0.03), whereas there were no changes in those patients with normal initial levels (p=0.27). Patients with increased s-ADA activity at the time of the first measurement reported symptoms for a longer period than patients with normal s-ADA (median, 15 vs 10 days; p=0.02). CONCLUSIONS: s-ADA levels in patients with tuberculosis decrease during the initial months of effective treatment. Perhaps this decrease might reflect the normalization of the altered lymphocyte turnover induced by tuberculosis. The measurement of s-ADA could be of some help to evaluate the response to therapy, particularly in those patients with increased values of the enzyme.

Adenosine Deaminase↗
PubMed1998

Sonographic features of ovarian remnants.

Ovarian remnants occur after a portion of ovarian tissue is left behind unintentionally after oophorectomy. The ovarian remnant may be functional and cystic, producing pelvic pain and, in some patients, extrinsic compression of the distal ureter. Ovarian remnants frequently are associated with adhesions from previous pelvic surgery for endometriosis or pelvic inflammatory disease. Ovarian remnants also may be included within pelvic peritoneal inclusion cysts. In this retrospective study, the sonographic features of ovarian remnants in 10 patients with surgical proof or clinical follow-up data are described. Most ovarian remnants were simple cysts (seven of 10), three had multiple septations, and six had a rim of presumably ovarian tissue with arterial and venous flow. Three patients with ovarian remnant masses that were aspirated had symptomatic relief without recurrence. In one patient, guided aspiration was unsuccessful, probably owing to the presence of organized hemorrhage within the mass. Extrinsic compression of the distal ureter was observed in one patient, who was treated with gonadotropin releasing hormone agonist (Lupron). The sonographic findings of a completely cystic or multiseptated pelvic mass with a rim of vascularized solid tissue in a postoophorectomy patient, although such cases are rare, suggest the diagnosis of an ovarian remnant. If the diagnosis can be established with a high degree of certainty, sonographically guided aspiration may be attempted in an effort to provide symptomatic relief. Otherwise, sonography is useful in serial assessment of these masses in patients receiving medical treatment.

Adult↗
PubMed1997

1H NMR measurements of wet/dry ratio and T1, T2 distributions in lung.

Proton-magnetic-resonance measurements have been carried out on juvenile porcine peripheral lung parenchyma. The free-induction-decay signal contained a motionally restricted component which decayed in a few tens of microseconds and a mobile component with a T2 time greater than 1 ms. The average second moment, M2, for the motionally restricted signal was found to be 3.42 +/- (0.25) x 10(9) s-2. The T2 distribution for the mobile signal consistently showed four resolvable components of T2 range: 2-6, 10-40, 80-110, and 190-400 ms. The 2-6 ms component was present in a fully dehydrated preparation and was therefore assigned to a nonaqueous lung constituent. The motionally restricted FID component had a T1 = 0.772 +/- 0.11 s and the mobile component had a T1 = 0.967 +/- 0.02 s. The hydrogen content per unit mass for lung parenchyma and water were estimated in two ways: (1) on the basis of chemical content and (2) on the basis of comparison of restricted and mobile signals to the gravimetric (G) water content for a lung sample studied at a wide range of water contents. Lung wet/dry weight ratios were estimated from the free-induction decays and compared with gravimetric measurement. The ratio of (wet/dry)NMR/(wet/dry)G was 1.00 +/- 0.08 and 1.00 +/- 0.05 for the two methods of estimation.

Animals↗
PubMed1997

Bronchiolitis obliterans in a patient with HIV infection.

Bronchiolitis obliterans, with or without organizing pneumonia, represents an uncommon response of the lung to several injuries, that results in characteristic histopathologic changes in the small airways. The present case report describes a patient with HIV infection who developed bronchiolitis obliterans, and reviews the previously reported cases of this condition in HIV-infected patients.

Adult↗
PubMed1997

Fever of unknown origin in the HIV-infected patient: new scenario for an old problem.

Many conditions may present as fever of unknown origin in the HIV-infected patient, and their relative frequency is influenced by multiple factors. The history and physical examination may provide some useful clues for the diagnosis. Haematological, biochemical, and conventional radiological tests are rarely diagnostic; even serological and/or microbiological tests have some limitations in these patients. The geographical setting and the local prevalence of diseases are of the utmost importance. Infections that have a world-wide distribution, such as tuberculosis, should be intensively searched for, particularly in areas of high prevalence. The measurement of the CD4+ cell count is essential, as there is a strong association between this count and certain opportunistic diseases that may manifest as fever of unknown origin. Imaging procedures, such as CT and radionuclide scans, are useful for the location of inflammatory and neoplastic lesions. Liver and bone marrow biopsies are helpful in certain subsets of patients and the efficacy of empirical treatments has been clearly documented in certain infections. Some HIV-infected patients with fever of unknown origin remain undiagnosed after a thorough investigation; these individuals should be managed conservatively. Finally, symptomatic treatment is the best option for terminally ill patients in whom benefit from a detailed investigation of the cause of fever is not expected.

AIDS-Related Opportunistic Infections↗
PubMed1997

Flavopiridol (L86-8275): selective antitumor activity in vitro and activity in vivo for prostate carcinoma cells.

We have selected a panel of human tumor xenografts for in vitro and in vivo studies that allows an indication of selectivity of action of novel chemotherapeutic agents. We report here the antitumor activity of the flavone flavopiridol (previously designated L86-8275), which has been selected for further studies based in part on its behavior in the anticancer drug screening system of the United States National Cancer Institute. Eighteen human tumor and five cell line-derived xenografts established by serial passage in nude mice in our laboratory were used as tumor models for in vitro investigations using a modified double-layer soft agar assay. In vivo investigations were completed in nude mice bearing advanced-stage s.c. growing prostate cancer xenografts. Antitumor activity in vitro (test/control </= 30%) of flavopiridol was observed at the very low concentration of 0.1 ng/ml in three of four prostatic xenografts and in one melanoma xenograft. Overall, in 14 of 23 (61%) tumor xenografts, drug treatment resulted in a IC70 of <10 ng/ml, demonstrating the high antiproliferative potential of flavopiridol. Toxicity to in vitro bone marrow cultures was evident only at 100 ng/ml, indicating potential high selectivity for susceptible tumor cells. Comparison of tumor cells with bone marrow samples tested showed clear prostate carcinoma and moderate melanoma selectivity. In vivo studies of flavopiridol confirmed antitumor activity in both prostate cancer xenografts investigated. At the maximal tolerated dose of 10 mg/kg/day administered p.o. on days 1-4 and 7-11, flavopiridol effected tumor regression in PRXF1337 and tumor stasis lasting for 4 weeks in PRXF1369. We conclude that flavopiridol shows strong prostate-and moderate melanoma-specific antitumor activity in vitro. The prostate antitumor activity is also reflected by the two in vivo models studied. Initial clinical efforts with flavopiridol might consider early evaluation in patients with prostate carcinoma.

Animals↗