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Biomedical subjects

R Castillo

Publications and source records attributed to R Castillo.

At least 55 records · Page 3Linked to original sources
PubMed1994

Von Willebrand factor availability in platelet concentrates stored for 5 days.

Von Willebrand factor (vWF) availability was assessed in platelet concentrates (PCs). After 5 days of storage, 82 +/- 9% of basal levels of ristocetin cofactor activity (vWF:RCo) remained in PCs. vWF antigen (vWF:Ag) increased up to 166 +/- 38% (P < 0.05) in the same period. Autoradiograph pattern of vW:Ag showed an increase in low molecular weight multimers, and fast migrating multimeric forms were visualized by crossed immunoelectrophoresis on day 5. Studies carried out in platelet free plasma stored as PCs showed similar changes in vWF:RCo but increments in vWF:Ag were not detected. These data indicate that PCs maintain vWF:RCo levels of clinical value even after 5 days of storage and suggest that vWF comes out from platelets to plasma during storage.

Blood Platelets↗
PubMed1994

Specific skin tests in subjects with chronic bronchitis exposed to pigeons.

We have studied the diagnostic reliability of the specific skin tests done in 30 subjects who presented with chronic bronchitis (CB) as the only clinical manifestation related to exposure to pigeons and in 21 subjects with CB and known risk factors. Additionally, two control groups were included (24 asymptomatic subjects exposed and sensitized to pigeons and 10 subjects not exposed and not sensitized to pigeons). The skin prick tests with pigeon serum were negative in all the subjects tested. The intradermal skin tests showed an immediate positive reaction in 16 of the 30 CB-affected patients and in six of the control group of exposed asymptomatic subjects (chi square: 3.376) (P < 0.1; nearly significant); after 6 h, a positive reaction was recorded in 14 of the CB-affected patients and in three subjects of the control group (chi square: 5.187) (P < 0.005). A delayed reaction was seen in 10/30 CB patients and in only three of the 24 subjects of the control group (chi square: 2.218) (nonsignificant). In the group of the 21 CB patients with known risk factors and not sensitized to pigeons, only two patients showed immediate skin reactivity; the remaining readings were negative. Lastly, in the control group of 10 unexposed, nonsensitized subjects, the intradermal skin tests in the different readings were negative. Our results show that although the skin tests with pigeon serum have low sensitivity, they can be a useful supplement in distinguishing cases of CB attributable to chronic pigeon exposure from those cases attributable to another cause, especially in the consideration of immediate and late readings.

Adolescent↗
PubMed1994

Avocado hypersensitivity.

The avocado (Av) is a fruit that belongs to the Lauraceae family. We report 17 patients with immediate hypersensitivity to avocado. Clinical manifestations in relation to avocado ingestion were as follows: systemic anaphylaxis in seven patients, angioedema/urticaria in six, vomiting in two, bronchial asthma in one, and rhinoconjunctivitis in one. Skin prick test (SPT) with fresh avocado was positive in all patients with the Strong avocado variety (SAv) and in 14 patients with the Hass avocado variety (HAv). Our patient-associated sensitizations were as follows: 10 to latex, eight to chestnut, eight to banana, four to kiwi, and four to walnut. Avocado-sensitized patients with latex allergy were typically middle-aged women, professionally exposed to latex, who also exhibited frequent associated sensitizations to chestnut, banana, and other fruits. Specific IgE against avocado was demonstrated in 11 of our patients, by both commercial CAP and RAST with avocado extract coupled to nitrocellulose disks. Despite its lower protein content, SAv seems to be more allergenic than HAv, both in vivo and in vitro. On incubating a pool of sera from our patients with avocado, latex, chestnut, and banana extracts, a progressive RAST inhibition was obtained, with SAv- and chestnut-marked disks. This suggests the existence of common antigenic determinants among these allergens.

Adolescent↗
PubMed1994

[Cyto-histologic evaluation of parametrial involvement in cervico-uterine cancer using aspiration puncture guided by transvaginal echography].

Vaginal tact is not sufficient for staging the extension of cervical Ca in its adnexal compromise. The use of transvaginal echography with a cytological hystological parametrial biopsy allow the diagnosis to be certified. In 23 cases studied, 21 epidermoid carcinoma and one adenocarcinoma related with of original cervical tumor were revealed. The clinical staging had a 8.3% error margin.

Adenocarcinoma↗
PubMed1994

Characterization of partial gene deletions in type III von Willebrand disease with alloantibody inhibitors.

von Willebrand factor gene deletions were characterized in four patients with severe type III von Wilebrand disease and alloantibodies to von Willebrand factor. A PCR-based strategy was used to characterize the boundaries of the deletions. Identical 30 kb von Willebrand factor gene deletions which include exons 33 through 38 were identified in two siblings of one family by this method. A small 5 base pair insertion (CCTGG) was sequenced at the deletion breakpoint. PCR analysis was used to detect the deletion in three generations of the family, including two family members who are heterozygous for the deletion. In a second family, two type III vWD patients, who are distant cousins, share an approximately 56 kb deletion of exons 22 through 43. The identification and characterization of large vWF gene deletions in these type III vWD patients provides further support for the association between large deletions in both von Willebrand factor alleles and the development of inhibitory alloantibodies.

Base Sequence↗
PubMed1994

Latex allergy: clinical features and cross-reactivity with fruits.

BACKGROUND: Latex IgE-mediated allergy is an important medical problem, but its clinical characteristics and association with food allergies are not well defined. OBJECTIVE: Our objectives were to determine the clinical features of latex-allergic patients, and latex-associated food hypersensitivities. METHODS: A prospective study was performed in our outpatient clinic. It consisted of a clinical questionnaire, skin prick tests with aeroallergens and foods, skin test with a latex extract, determination of total and specific IgE by CAP/RAST methods, and RAST inhibition. Latex and food allergies were diagnosed on the basis of a suggestive clinical history and a positive skin test with the corresponding allergen. RESULTS: Twenty-five patients were diagnosed as having latex allergy. Their mean age was 33 +/- 9.0 years, with female predominance (23:2). There were nine greenhouse and six hospital workers. Latex-induced reactions included systemic anaphylaxis in nine patients (36%). Average total IgE was 161 kU/L, and it was within normal limits in 16 cases. Latex skin prick tests had excellent diagnostic precision with no adverse reactions, and CAP for latex diagnostic sensitivity was 80%. Forty-two food allergies were diagnosed in 13 of our patients (52%), and 23 of these consisted of systemic anaphylaxis. The most frequent food hypersensitivities were to avocado (9), chestnut (9), banana (7), kiwi (5) and papaya (3). Through RAST-inhibition, cross-reactivity among latex, avocado, chestnut, and banana was demonstrated. CONCLUSIONS: In our experience, latex allergy affects middle-aged women in certain professions at increased risk. Our data suggest the existence of a "latex-fruit syndrome," because 52% of our latex allergic patients had allergies to certain fruits.

Adolescent↗
PubMed1994

Anaphylaxis due to limpet ingestion.

BACKGROUND: The limpet, phylum Mollusca, is one of the most frequent sea mollusks in the Canary Islands. Limpet IgE hypersensitivity reactions have been described. OBJECTIVE: To describe six patients with anaphylactic reactions due to limpet ingestion and to demonstrate by in vivo methods and by in vitro techniques specific IgE responses. METHODS: Six subjects who developed severe bronchospasm 30 to 120 minutes after eating limpets were included in the present study. The antigenic material for the in vivo and in vitro studies was an extract of cooked limpet prepared in our laboratory. Skin prick tests were performed in all patients using commercially available aeroallergens, mollusk, and crustacean extracts; the same skin tests were performed using the extracts prepared in our laboratory. Specific IgE by CAP and RAST and CAP inhibition studies were also performed. Limpet contamination by mites was excluded through a commercial ELISA using monoclonal antibodies. RESULTS: All patients had positive skin prick tests to D. pteronyssinus and cooked limpet extract and weak reactivity to cockroach and raw limpet extract. Specific IgE to mites and cooked limpet extract was also found using CAP and RAST techniques, respectively. The possible existence of common epitopes between limpet and D. pteronyssinus was excluded by CAP inhibition studies. Finally, no significant mite concentration was detected in the cooked limpet extract analyzed by a commercially available ELISA. CONCLUSIONS: Limpet is a potentially dangerous allergen specially in patients sensitized to D. pteronyssinus.

Adolescent↗
PubMed1993

Relationships between characteristics of exposure to pigeon antigens. Clinical manifestations and humoral immune response.

An extensive clinical study has been performed on pigeon breeders in the Canary Islands. Three hundred forty-three subjects have participated in this study through the filling of a clinical and epidemiologic questionnaire. A venous blood sample was also taken from each fancier for a further serologic analysis. Detection of specific IgG antibodies was made by an indirect enzyme-linked immunosorbent assay (ELISA) using pigeon serum as antigenic material. Twenty-nine (8 percent) breeders fulfilled the "classic" pigeon breeders' disease (PBD) criteria. One hundred six (31 percent) had rhinitis, 62 (19 percent) had immediate bronchial symptoms, and 51 (15 percent) suffered from chronic bronchitis. A significant level of specific IgG was detected in 139 (40 percent) cases. Rates were correlated with pneumonitis symptomatology (p < 0.001) and with chronic bronchitis (p < 0.05). There was a significant association between the number of pigeons and the level of sensitization (p < 0.001). Finally, a statistical relationship between the intensity of exposure and specific IgG response was also found (p < 0.001). Titers of specific IgE could not be related either to the reported symptomatology in the questionnaire or to any of the exposure parameters analyzed.

Adolescent↗
PubMed1993

Abnormal cytoskeletal assembly in platelets from uremic patients.

The mechanisms involved in the hemostatic abnormality of uremic patients remain obscure. We have explored the response of normal and uremic platelets to surface activation at the ultrastructural level and analyzed changes in the composition of proteins associated with normal and uremic platelet cytoskeletons after stimulation with thrombin (0.01 and 0.1 U/ml). Cytoskeletons were obtained by extraction with Triton X-100, processed by sodium dodecylsulfate-polyacrylamide gel electrophoresis, and the presence of cytoskeletal proteins analyzed by densitometry. Under static conditions, uremic platelets spread with difficulty on formvar-coated grids. The percentage of platelets that spread fully on this polymer surface was statistically reduced compared with that of control platelets (11 +/- 1.4 vs. 21 +/- 1.6; P < 0.05). An impairment of cytoskeletal organization was observed in resting uremic platelets but abnormalities were more evident after thrombin activation. The incorporation of actin into the cytoskeletons of thrombin-stimulated uremic platelets was significantly reduced with respect to controls (6 +/- 3% vs. 29 +/- 5%; P < 0.01 after 0.01 U/ml and 28 +/- 9% vs. 59 +/- 10%; P < 0.05 after 0.1 U/ml). Decreased associations of actin-binding protein (P < 0.01), alpha-actinin (P < 0.05), and tropomyosin (P < 0.05) with the cytoskeletons of uremic platelets were also noted. No difference was observed for the incorporation of myosin into the cytoskeletons of activated uremic platelets. These results suggest functional and biochemical alterations of the platelet cytoskeleton in uremia, which may contribute to the impairment of platelet function observed in uremic patients.

Adult↗
PubMed1992

Differential responsiveness of human neutrophils to the autocrine actions of 1-O-alkyl-homologs and 1-acyl analogs of platelet-activating factor.

The phlogistic actions of six molecular species of platelet-activating factor (PAF) (1-O-alkyl-PAF homologs, 16:0-, 18:0- and 18:1-alkyl-PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (AGEPC) and their respective 1-acyl-PAF analog counterparts, 16:0-, 18:0- and 18:1-acyl-PAF, 1-acyl-2-acetyl-sn-glycero-3-phosphocholine (AGPC)) were assessed relative to five human neutrophilic polymorphonuclear leukocyte (PMN) functional responses: 1) lysosomal enzyme secretion; 2) specific desensitization to 16:0-AGEPC-induced lysosomal enzyme secretion; 3) O2- production; 4) chemotaxis; and 5) priming for enhanced O2- production. With respect to inducing lysozyme secretion, 18:0-AGEPC was 30- and 75-fold less potent than 16:0-AGEPC and 18:1-AGEPC, respectively, and was 25- and 40-fold less potent for inducing beta-glucuronidase secretion. 18:0-AGEPC was also 10-fold less active than 18:1- and 16:0-AGEPC for inducing O2- production. Thus, the rank order of potency of the alkyl-PAF homologs for inducing both lysosomal enzyme secretion and O2- production was 18:1- greater than or equal to 16:0- much greater than 18:0-AGEPC. In contrast, these three alkyl-PAF homologs had the same potency for desensitizing PMN to subsequent 16:0-AGEPC-induced lysosomal enzyme secretion and for priming PMN for augmented O2- production in response to FMLP or human recombinant C5a. Paradoxically, however, the rank order of potency of the alkyl-PAF homologs for effecting PMN chemotaxis was 18:0- greater than 18:1- much greater than 16:0-AGEPC. At concentrations as high as 1.0 microM, the acyl-PAF analogs did not initiate PMN lysosomal enzyme secretion, O2- production, or chemotaxis. However, the acyl-PAF analogs induced partial PMN desensitization to 16:0-AGEPC. A novel finding of potential (patho)-physiologic significance was the ability of acyl-PAF at nM concentrations to prime PMN for significantly enhanced O2- production after stimulation with FMLP or human recombinant C5a. The priming action of acyl-PAF was due to an increase in the rate as opposed to a prolongation of O2- production. The differing rank orders of potency of the alkyl-PAF homologs and acyl-PAF analogs for stimulating several physiologic responses of the same target cell, the human PMN, support the premise that there may be more than one PAF receptor subtype on the PMN and/or that differences in the biophysical properties of the various molecular species of PAF modulate their interaction with PAF receptor(s) linked to stimulus-response coupling.

Acylation↗
PubMed1992

Recombinant human erythropoietin treatment improves platelet function in uremic patients.

The effect of recombinant human erythropoietin (rHuEPO) on primary hemostasis was tested in 19 hemodialyzed patients. Bleeding time, platelet aggregation and platelet interaction with vessel subendothelium (SE) under flow conditions were determined before treatment and after patients reached hematocrits greater than or equal to 30%. Two thrombotic events (an acute myocardial infarction and an AV fistula clotting) were recorded during the early stages of treatment. A shortening of average bleeding times (P less than 0.01), an increase in platelet count (P less than 0.01) and an improvement of platelet aggregation (P less than 0.01) and of platelet-SE interaction (P less than 0.01) were observed. A low correlation index was found between hematocrit and bleeding time (r = -0.351, P less than 0.05). To assess a possible effect of rHuEPO on platelet function, the same parameters were evaluated before and after receiving three doses of rHuEPO (40 U/kg i.v. post-hemodialysis) in 14 of the patients. No changes in platelet or erythrocyte counts were observed, the mean bleeding time remained unchanged, but platelet aggregation induced by arachidonic acid (P less than 0.05), ADP (P less than 0.01) and ristocetin (P less than 0.05) improved. Perfusion studies confirmed moderate but significant increases in the parameters that quantify platelet-SE interaction (P less than 0.05). Improvement of ADP-induced aggregation correlated with the increase of platelet adhesion to SE (r = 0.675, P less than 0.05). We conclude that rHuEPO treatment improves primary hemostasis in uremia through an increase of red cell mass but also through a beneficial effect on platelet function, which is independent of the hematocrit rise.

Adult↗
PubMed1992

Visceral leishmaniasis in HIV-1-infected individuals: a common opportunistic infection in Spain?

OBJECTIVE: To investigate the epidemiological, clinical and biological features of visceral leishmaniasis (VL) in patients with HIV-1 infection. DESIGN: Retrospective study. SETTING: Three university hospitals in southern Spain. PATIENTS: Forty-seven adult patients with VL and HIV-1 infection diagnosed between January 1986 and November 1991. RESULTS: Forty-five out of the 47 (96%) cases were diagnosed in the last 2 years. Fever (87%), hepatomegaly (74%), splenomegaly (72%) and pancytopenia (77%) were the most common presenting features. Most patients (79%) were strongly immunocompromised when VL was diagnosed, and were in stage IV of the Centers for Disease Control classification; 87% had a CD4 lymphocyte count < 200 x 10(6)/l. However, VL was the first severe infection diagnosed in 10 cases. Significant titres (> 1:40) of antileishmanial antibodies were detected by indirect immunofluorescence in five out of 16 (31%) cases only. Clinical response to the therapy was difficult to assess. Microbiological response was achieved in only 38% of the patients evaluated. CONCLUSIONS: Leishmaniasis is a relatively common infection in HIV-1-infected individuals in southern Spain. Its clinical picture is quite uniform and it can be the first opportunistic infection in individuals with HIV-1. In endemic areas, a high index of clinical suspicion should be maintained in order to avoid underdiagnosis of leishmaniasis.

AIDS-Related Opportunistic Infections↗
PubMed1992

A variant of Glanzmann's thrombasthenia which fails to express a GPIIb-IIIa related epitope that is recognized by a specific monoclonal antibody (C17).

Binding of different antibodies to the GPIIb-IIIa complex in resting (AP2, EDU3, C17) or activated platelets (PAC1) was studied by flow cytometry in a patient with a platelet defect involving GPIIb-IIIa related functions. The patient has a mild history of bleeding. Aggregation induced by ADP and collagen were absent but normal response was obtained with ristocetin. Platelets from the patient do not bind fibrinogen. Perfusion studies with flowing blood showed that patient's platelets have a marked impairment in the process of spreading and aggregate formation on vascular subendothelium. Electrophoretic studies in SDS-polyacrylamide gels demonstrated the presence of normal amounts and normal mobility of GPIIb-IIIa. Fibrinogen was present in the patient's platelets (68-74% of controls). The binding of AP2 and EDU3 to patient's resting platelets was normal as assessed by flow cytometry. In contrast, a decreased presence of the C17 antigen (10 fold lower than control platelets) was detected in resting platelets and a markedly reduced binding of PAC1 was found in thrombin activated platelets. These studies suggest that C17 recognizes an epitope of the GPIIb-IIIa in resting platelets that is implicated in the regulation of adhesive and cohesive properties of GPIIb-IIIa. Studies on this patient might be helpful for the understanding of GPIIb-IIIa functions.

Adenosine Diphosphate↗
PubMed1992

Hemostatic effect of platelet von Willebrand factor.

In type III von Willebrand disease (vWD) patients, the bleeding time was only partially corrected or not modified after cryoprecipitate infusion, although the levels and the multimeric structure of plasma von Willebrand factor (vWF) were normal. However, the adhesion of normal platelets on the vessel wall subendothelium in the presence of postinfusion patient plasma improved more significantly than the bleeding time. These results suggest a role of the vWF released from normal platelets which is absent in type III vWD platelets. In 5 patients transfusion of normal platelet concentrates performed 1 h after cryoprecipitate infusion without modification of the bleeding time (> 30 min) normalized this parameter, and platelet adhesion to the subendothelium elicited a marked improvement. These last results confirm the suggestion that platelet vWF plays an important 'in vivo' role in the hemostatic process, particularly in patients suffering from severe vWD.

Animals↗
PubMed1992

Plasma from systemic lupus erythematosus patients with antiphospholipid antibodies promotes platelet aggregation. Studies in a perfusion system.

The possible platelet-aggregating effect of plasma from systemic lupus erythematosus (SLE) patients (n = 19) was investigated under flow conditions. Aliquots of the SLE plasmas with (n = 10) or without (n = 9) anticardiolipin antibodies (ACAs) were added to anticoagulated blood (1:20, vol/vol). Plasma from normal donors was used as a control. Blood was incubated for 15 minutes at 37 degrees C and then perfused through annular chambers containing denuded arterial segments. Perfusions were performed for 10 minutes at a shear rate of 800 sec-1. The interaction of platelets with vessel subendothelium (SE) was morphometrically evaluated in thin sections. In control experiments, the percentage of the SE covered with platelets was 23.6 +/- 4.3% (mean +/- SD). Large aggregates (more than 5 microns in height) covering 11.8 +/- 5.7% of the exposed SE were noted. The deposition of platelets was statistically increased (38.5 +/- 7.6%, p less than 0.01 versus control) in the presence of SLE plasmas with demonstrated antiphospholipid antibodies (APAs). The formation of large aggregates was also augmented (30.3 +/- 5.9%, p less than 0.01 versus control). A similar response was obtained after addition of affinity-purified immunoglobulin G and immunoglobulin M fractions from two patients with ACAs. SLE plasmas with no detectable APAs did not influence the morphometric parameters studied. Results of the present study indicate that the presence of APAs in SLE plasma promotes platelet aggregation under flow conditions. These observations may help to explain the pathophysiology of the thrombotic events occurring in patients with APAs.

Adolescent↗
PubMed1992

Contribution of perfusion techniques to the evaluation of the hemostatic effectiveness of platelet concentrates.

Perfusion systems allowing the morphometric analysis of platelet interactions with vessel subendothelium under flow conditions have been applied to evaluate the quality and function of stored platelets. Studies performed in vitro indicate that despite the existence of storage lesions, platelets in concentrates stored for up to 5 days retain their ability to interact with the subendothelium. Perfusion studies ex vivo with nonanticoagulated blood from anemic-thrombocytopenic patients have shown the critical hemorrheological role of red blood cells facilitating platelet interactions with subendothelium. Similar studies performed on severely thrombocytopenic patients who received transfusions of platelets stored at 4 degrees C indicate that incompletely viable platelets can contribute to primary hemostasis through procoagulant mechanisms. The latter results suggest that storage lesions which contribute to impairment of platelet function may result in enhancement of platelet procoagulant activities. Perfusion techniques have contributed to the evaluation of the hemostatic effectiveness of platelet concentrates. These techniques will provide a useful model to test the impact of new storage technologies on platelet hemostatic function.

Animals↗