Citric acid from ferrocyanide-treated blackstrap molasses.
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Aspergillus↗
Biomedical subjects
R Palacios
Publications and source records attributed to R Palacios.
Studies on the advent of ureotelism. The effects of bivalent cations on the capacity of the hepatic arginase of the Mexican axolotl to hydrolyse endogenous arginine.
1. The effects of 19 bivalent cations on the activity, stability and capacity to hydrolyse endogenous arginine of axolotl liver arginase were studied. 2. It was found that Fe(2+), Co(2+), Ni(2+) and Zn(2+), as well as Mn(2+), stabilize the enzyme and render it able to hydrolyse endogenous arginine. 3. By using different concentrations of Co(2+) and Ni(2+) it was possible to dissociate the effect of each of the metal ions on the activity and stability of arginase from that on its capacity to hydrolyse endogenous arginine. 4. The effects of Mn(2+), Co(2+) and Ni(2+) on the activity and stability of arginase in the homogenate were also observed with purer preparations of the enzyme. 5. It is suggested that the capacity to hydrolyse endogenous arginine is a consequence of the integration of arginase with the arginine-formation sites.
Animals↗
Studies on the advent of ureotelism. Factors that render the hepatic arginase of the Mexican axolotl able to hydrolyse endogenous arginine.
1. A study was undertaken of the conditions that might operate in the synthesis and hydrolysis of arginine by axolotl liver homogenate to test a previous postulate that liver arginase of the non-metamorphosed Mexican axolotl is not able to hydrolyse arginine formed from citrulline and aspartic acid, though it can split exogenous arginine, and also that an enhanced capacity to hydrolyse endogenous arginine plays a major role in the advent of ureotelism observed during the metamorphosis of the axolotl. 2. It was found that the arginase from axolotl liver is very unstable under the conditions followed, contrary to what is observed in rat liver. 3. Axolotl arginase is able to hydrolyse endogenous arginine if preserved. 4. Mn(2+) protects the enzyme and renders it able to split endogenous arginine. 5. It is suggested that the metal ion produces a change of conformation of the enzyme that, being stable, is capable of hydrolysing the amino acid, or that the new conformation is appropriate for interaction with the sites of arginine synthesis.
Animals↗
Interleukin-3 supports growth of mouse pre-B-cell clones in vitro.
Study of the differentiation of immunoglobulin-producing B lymphocytes has been hampered by the inability to maintain homogeneous populations of precursor cells in vitro. We describe here that interleukin-3 supports the growth of freshly isolated fetal liver pre-B cells and the long-term culture of interleukin-3 dependent pre-B-cell clones that can be induced to mature into antibody secreting cells in vitro.
Animals↗
Simplicity and efficacy of a once-daily antiretroviral regimen with didanosine, lamivudine, and efavirenz in naïve patients: the VESD study.
PURPOSE: Our aim was to analyze the efficacy and safety of didanosine-lamivudine-efavirenz in a cohort of HIV patients starting antiretroviral therapy between January and September 2003. METHOD: We undertook a prospective, open-label, observational, multicenter study. RESULTS: 163 patients were enrolled. Over a 48-week period, plasma HIV RNA levels declined sharply, with a median decrease at the end of the observation time of >4.62 log copies/mL. The proportion of patients achieving a plasma HIV RNA level below 50 copies/mL was 62.9% (intention-to-treat analysis) at the end of the study period. The mean CD4 cell count increased steadily over time by 199 cells/microL. Antiviral efficacy was similar in patients with a baseline HIV RNA level above or below 100,000 copies/mL. Overall, 57 (34.1%) patients interrupted therapy; 9 due to lack of treatment response, 18 due to adverse side-effects, and 30 patients lost to follow-up or who withdrew their consent. Adherence was very high (90%-95%) and quality of life was good or very good in 69%. CONCLUSION: The once-daily combination of didanosine-lamivudine-efavirenz resulted in sustained viral suppression and was well-accepted by patients under real-life conditions, even immunosuppressed patients and those with a high viral load. Associated adverse events and virological failures were few.
Administration, Oral↗
Further evidence of humans as source of Leishmania viannia for sandflies.
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Adolescent↗
Positive IgG Western blot for Borrelia burgdorferi in Colombia.
In order to evaluate the presence of specific IgG antibodies to Borrelia burgdorferi in patients with clinical manifestations associated with Lyme borreliosis in Cali, Colombia, 20 serum samples from patients with dermatologic signs, one cerebrospinal fluid (CSF) sample from a patient with chronic neurologic and arthritic manifestations, and twelve serum samples from individuals without clinical signs associated with Lyme borreliosis were analyzed by IgG Western blot. The results were interpreted following the recommendations of the Centers for Diseases Control and Prevention (CDC) for IgG Western blots. Four samples fulfilled the CDC criteria: two serum specimens from patients with morphea (localized scleroderma), the CSF from the patient with neurologic and arthritic manifestations, and one of the controls. Interpretation of positive serology for Lyme disease in non-endemic countries must be cautious. However these results suggest that the putative "Lyme-like" disease may correlate with positivity on Western blots, thus raising the possibility that a spirochete genospecies distinct from B. burgdorferi sensu stricto, or a Borrelia species other than B. burgdorferi sensu lato is the causative agent. Future work will focus on a survey of the local tick and rodent population for evidence of spirochete species that could be incriminated as the etiologic agent.
Antibodies, Bacterial↗
Treatment failure in children in a randomized clinical trial with 10 and 20 days of meglumine antimonate for cutaneous leishmaniasis due to Leishmania viannia species.
Clinical response to supervised treatment of Colombian patients with cutaneous leishmaniasis was evaluated in a randomized controlled trial comparing 10 days versus 20 days of treatment with meglumine antimonate (20 mg Sb/kg/day). Masked examiners evaluated clinical response defined as 100% re-epithelialization of all lesions at 13 weeks and no relapses during 52 weeks of follow-up. The efficacy of meglumine antimonate for 10 days' treatment was 61% (28 of 46) compared to 67% (24 of 36) for 20 days. There was a significantly lower clinical response for children < 5 years in both 10-day (11%) and 20-day (25%) groups compared to patients aged 5-14 years (67% and 75%, respectively) and 15 years or more (81% and 83%, respectively). Overall efficacy of treatment schedules was comparable, but lower than expected, mainly because of low efficacy in children. Pathogenicity of infection and pharmacokinetics may affect the treatment response in children. New therapeutic alternatives should be evaluated in trials that include children and women.
Adolescent↗
Serum sickness-like syndrome due to mosquito bite.
Local inflammatory reactions at the site of a mosquito bite are frequent. Immediate systemic reactions have occasionally been reported. The first case of a patient with relapsing episodes of a serum sickness-like syndrome following mosquito bites is reported herein. A 62-year-old patient came to the emergency room complaining of sudden malaise, chills, fever, headache, cervical lymph node enlargement, arthromyalgia, generalized purpura and leukopenia 6 h after a mosquito bite. He had experienced multiple similar episodes in the last 20 years, also following mosquito bites. Infectious and autoimmune diseases were ruled out. Serum IgE was 9,102 kU/l. Prick test of whole-body Culex pipiens extract was positive. Specific IgE to Aedes communis was 2.25 kU/l. SDS-PAGE immunoblotting of the patient's serum with whole-body C. pipiens extract revealed 43 and 17 kDa IgG-binding proteins and 22 and 17 kDa IgE-binding proteins, neither of which were found with control sera. Skin biopsy was consistent with leukocytoclastic vasculitis. The presence of both mosquito-specific IgE and IgG in the patient's serum suggest a possible cooperative immune response leading to clinical manifestations of serum sickness.
Animals↗
[Fungemia by Candida non albicans in patients with HIV infection].
OBJECTIVE: To analyse candidemia by Candida non albicans in adult HIV-infected patients from 1989 to August 1998. PATIENTS AND METHODS: We retrospectively reviewed all HIV patients who presented at least one positive peripheral blood culture for Candida spp. Clinical, epidemiologic, immunologic and evolutive characteristics, and risk factors for candidemia were analysed. RESULTS: During this period of time, 2,025 HIV-infected patients were diagnosed. Five of them developed candidemia by C. albicans and 6 by C. non albicans. These last ones were all men with mean age of 32.1 years old, and intravenous drug use was the risk factor for HIV in 5 of them; aids had previously been diagnosed in 4 patients and 3 had receipt imidazoles. None was neutropenic. Three cases were nosocomially acquired. Median CD4 cell count was 108.6 x 10(6)/l (3-366). Candida krusei was isolated in two intravenous drug users, Candida parapsilosis in two other patients and Candida glabrata and Candida tropicalis in one of the other two cases each. We treated 2 patients with amphotericin B and 2 with fluconazole. One patient died. CONCLUSIONS: Candidemia is not frequent in HIV-infected patients. Candidemia by C. non albicans in HIV-infected patients presents similar characteristics as in other immunodepressed patients and it is fundamentally associated with previous use of imidazoles, nosocomial acquisition and late-stage aids. It is noteworthy that C. krusei was isolated in two intravenous drug users.
AIDS-Related Opportunistic Infections↗
Comparison of in-house reference extracts of Dermatophagoides pteronyssinus and Phleum pratense with the WHO International Standards.
Two of the WHO First International Standards (IS) of allergenic extracts, the corresponding to Dermatophagoides pteronyssinus (House dust mite) and phleum pratense (Thymothy grass), have been used to assess the quality of our in-house reference preparations (IHR) and to calibrate their relative potency. The qualitative comparison was achieved by SDS-PAGE, Agarose-IEF and their respective enzime immunoblottings (Western blot and immunoprinting). The band patterns obtained were fairly similar for both Phleum pratense extracts. With the exception of two basic IgE binding proteins not detected in the IEF-blotting of the International Standard. However, several differences were noted between IS and IHR Dermatophagoides pteronyssinus extracts, indicating so the higher raw material heterogeneity. The difference was specially remarkable at the level of SDS-PAGE Immunoblotting since while our IHR extract showed similar ratio of Der p I to Der p II major allergens, the IS exhibited a large preponderance of Der p I, with Der p II allergen scarcely detected by our chromogenic method. Calibration of potency was done by means of RAST inhibition, therefore allowing the expression of our extract concentrations in International Units. The higher degree of homogeneity between Phleum pratense extracts was corroborated by the comparison of slopes from the RAST-inhibition plots.
Allergens↗
[Congestive myocardiopathy and early dyastolic closure of the tricuspid valve. Report of a case with acute tricuspidization].
A case with congestive cardiomiopathy and early diastolic closure of the tricuspid valve is presented. This abnormal echocardiographic finding was probably the result of severe tricuspid regurgitation occurring in a restricted right ventricle. The absence of paradoxical septum was determinedly the left ventricular pathology. In this case, echocardiography was more sensitive for the detection of the left sided abnormalities, than the heart cath data.
Cardiac Catheterization↗
IgE binding proteins in honey: discussion on their origin.
Pollen proteins, most frequently from Compositae plants, and glandular enzymes from Hymenoptera insects are the only honey allergens involved in every case of honey sensitization reported so far. Surprisingly, we found three patients, all showing the same pattern of honey sensitization with clinical history, cutaneous test and specific IgE clearly positive to honey crude extract but not to the aforementioned components. IgE binding bands, mainly at 54, 46, 17 and 16 kDa, were recognized by the sera of the three patients on blots following electrophoretic separation of a local honey extract under dissociating conditions. Attempts to identify these proteins with the most common honey allergens by means of SDS-PAGE immunoblotting failed, leaving open the question on the origin of protein allergens in cases of honey allergy. Thus, if bee-derived components are not proven to be involved in honey sensitization, other protein sources, such as nectar, should not be disregarded.
Adult↗
Quality parameters for the production of mite extracts.
Mites present in house dust are of great etiological importance in type I hypersensitivity, with those belonging to the Dermatophagoides genus (D. pteronyssinus and D. farinae), of the Pyroglyphidae family, being the most frequent and principal source of allergens. For the production of allergenic extracts destined for specific diagnostic and treatment purposes of allergic diseases, the culture of such mites is absolutely necessary. In accordance with studies carried out in our laboratories to obtain adequate extracts, one must bear in mind the culture mite phase. Three growth phases have been distinguished for both species: latency phase (F1), growth phase (F2) in which the allergenic proteins are expressed with greater intensity, and death phase of the culture (F3). In the same study, the biological standardization of the extracts demonstrated that those produced from the maximum growth phase gave both in vitro and in vivo results, at least three times more sensitive than those from the other phases. We checked the reproducibility of the production method, obtaining different batches in similar conditions with a high homogeneity regarding allergenic activity. The sensitivity and specificity of the allergenic extracts depends just as much upon the production method as the standardization method. During the biological cycle of Dermatophagoides in culture, it is only from the maximum growth phase (F2), that allergenic extracts with an excellent diagnostic value, high sensitivity and specificity, can be obtained.
Allergens↗
Importance of tropomyosin in the allergy to household arthropods. Cross-reactivity with other invertebrate extracts.
The aim of the study was to investigate the involvement of the actin binding protein tropomyosin in the allergic sensitization of patients to household arthropods, as well as to study its panallergenic character in relation to other invertebrate extracts. Three arthropod extracts were prepared, namely fly (Musca domestica), moth (Ephestia spp.) and spider (Tegenaria spp.), and used to evaluate by cutaneous and RAST tests a population of 100 household arthropod allergic patients. Twenty-nine sera were selected for the subsequent SDS-PAGE Immunoblotting assays. IgE binding bands at 36, 34, 31, 27 and 17 kDa were detected in the fly extract by more than 50% of tested sera. In moth and spider extracts, the more relevant allergens were found at 34, 31, 24 and 110, 38, 35, 26, 19 kDa, respectively. A commercial polyclonal antiserum anti-chicken muscle tropomyosin was used for tropomyosin identification. Cross-reactivity studies performed by SDS-PAGE Immunoblotting, using a pool of household arthropod allergic patients and tropomyosin antiserum, preliminarily demonstrated the presence of such protein as a cross-reacting allergen in a large variety of extracts obtained from insects, mites, crustaceans, mollusks and parasites.
Allergens↗
Recombinant DNA technology in allergology: cloning and expression of plant profilins.
Profilin, an ubiquitous protein involved in eukaryotic cytoskeleton regulation, has been previously described as allergen in grasses, weeds and trees and in many fruits and vegetables, and it is in part responsible for cross-reactivities pollen and food allergic patients. Completed cDNA clones coding for Phleum pratense, Olea europaea, Cynodon dactylon, Parietaria judaica and Helianthus annuus pollen profilins were isolated and sequenced. The deduced amino acid sequences share high identity with other plant profilins. Recombinant profilins were produced in Escherichia coli as non-fusion proteins. Induced cells produced high amounts of recombinant profilin, and after a single purification step on poly-(L-proline)-Sepharose, up to 45 mg of pure allergen per liter culture could be obtained. Recombinant profilins have similar allergenic determinants to their natural counterparts. The tertiary structure of Phleum pratense profilin described here showed three regions important for antibody recognition. The availability of a plant profilin tertiary structure opens future ways on the study of structure/antigenity relationships of these important allergens.
Allergens↗
Allergens from Brazil nut: immunochemical characterization.
The increase in the consumption of tropical nuts in the Northern Hemisphere during the last years, has evolved in a simultaneous enhancement of allergic IgE mediated (Hypersensitivity type 1) reported cases produced by this kind of food. The Brazil nut is the seed of the Bertholletia excelsa tree (Family Lecythidaceae) and, as in other seeds, proteins represent one of its major components making up 15-17% of its fresh weight and 50% of defatted flour. Of these, storage proteins are the most important ones, and the 12 S globulin legumin-like protein and the 2 S albumin have been described as the most representative. The 2 S protein, due to its high sulfur-rich amino acid content (3% cysteine and 18% methionine), is being studied, cloned and expressed in some important agronomic seeds (soybean, bean, oilseed rape) in order to enrich the nutritional quality of them. The case of a patient with serious clinical allergic symptoms (vomiting, diarrhoea and loss of consciousness) caused by oral contact with the Brazil nut, is presented. The patient gave a positive Skin Prick Test response to Brazil nut, kiwi and hazelnut extracts, and negative to regionally specific aeroallergens and other food extracts. The patient serum showed a high level of specific IgE by RAST to Brazil nut (> 17.5 PRU/ml, Class 4), and significative levels to hazelnut, and mustard. In vitro immunological studies (SDS-Immunoblotting and IEF-Immunoblotting) revealed IgE-binding proteins present in the extract. It was shown that not only the heavy (Mr 9) and light (Mr 4) subunits of the known allergenic 2 S albumin but also the alpha-subunits (Mr approximately 33.5 and 32) and at least one of the beta-subunits (Mr approximately 21) of the 12 S Brazil nut globulin, hitherto never involved in allergic problems, showed a strong IgE-binding capacity.
Adolescent↗
Production and characterization of profilin monoclonal antibodies.
Profilins have been identified as a pan-allergen of different plant pollens and foods. In this paper, we describe the generation of monoclonal antibodies (MAbs) by immunizing BALB/c mice with Helianthus annuus purified profilin in order to characterize this important and common allergen. A panel of forty MAbs has been obtained, and twenty of them were used to map antigenic determinants in this molecule. At least two different antigenic determinants were recognized in H. annuus profilin by immunoblotting. Using the purified MAbs produced against sunflower profilin, we have analyzed the common epitope determinants in pollens of different plants: Olea europaea, Cynodon dactylon, Mercurialis annua, Phleum pratense, Parietaria judaica and Betula verrucosa. These experiments showed different cross-reactivity patterns.
Allergens↗