Physico-chemical analysis of metronidazole encapsulation processes in Eudragit copolymers and their blending with amphiphilic block copolymers.

A physico-chemical analysis of metronidazole-Eudragit copolymers L100 and RLPO (a cationic polymeric matrix with an electrophilic character) was carried out in order to explore the drug-polymer interaction and its possible effects on the encapsulation and release profiles. An oil-in-oil encapsulation procedure was designed to obtain more intimate drug-matrix mixtures and to obtain a better insight into the details of the interaction. The encapsulation efficiency obtained in these cases was high (in the range of 85-95%), but the release rates were quite rapid. Solubility and interaction between metronidazole and copolymers are discussed in detail with a view to explaining the results. Amphiphilic block copolymers of poly(ethylene)-b-(polyethylene oxide) (20, 50 and 80% PEO) were tested as a matrix for metronidazole release in order to improve drug profiles. The performance of RLPO as the matrix for drug release was improved by blending it with amphiphilic block copolymer poly(ethylene)-b-(polyethylene oxide) (20% PEO). The release mechanism of metronidazole is governed mainly by the swelling of RLPO, yielding a better fit with the second-order Schott equation.

Physical chemistry behavior of enteric polymer in drug release systems.

We report an analysis based on the electrical impedance (EI) spectrum of the samples of enteric random copolymer poly-methacrylic acid-co-methyl methacrylate as a function of pH of media. Important aspects of the charge transport and conformational processes in enteric polymer can be identified by mapping the complex impedance as a function of the frequency, which allows that some parallelism between titration and EI measurements can be obtained. However, the latter technique reveals details of this complex equilibrium that not appear using common titration methods. The relaxation frequency observed in the impedance spectrum act as a probe for the detection of phase transitions and conformational changes of the polymeric chains, once the distribution of size of particles can be related with this parameter. The progressive introduction of the alkali and the variation of pH between 4 and 10 are associated with a three steps process, related to the equilibrium shift from a precipitated solid or suspension, to a colloidal-like dispersion and to a complete solubilization of the copolymer. All those experimental features were reflected simultaneously as a turning point in plots of impedance, relaxation frequency and visible absorption with alkali addition giving a better and detailed insight to these processes.

Acquired angioedema associated with hereditary angioedema due to C1 inhibitor deficiency.

Angioedema caused by C1 inhibitor deficiency is a rare disorder that may be either hereditary or acquired, the latter being mainly associated with lymphoproliferative disorders. A 51-year-old woman who had suffered from episodes of acute peripheral edema since she was 12 was diagnosed with hereditary angioedema at the age of 40 and remained stable with stanozolol. Due to a worsening of her symptoms she was reassessed and low levels of C1q and an abnormal lymphocyte count were detected. Immunophenotyping of peripheral blood revealed 9% monoclonal lambda B cells with a follicular center phenotype. The histopathology was consistent with a grade II follicular lymphoma stage IV-A.With chemotherapy, the hematologic disease was controlled and C1q levels returned to normal values. This represents a rare case of a patient with hereditary angioedema who developed acquired angioedema due to a lymphoma that was associated with a reduction in the levels of C1q as her symptoms worsened.

Asma por animal de compañía / Pet-related asthma

No disponible

Reacción poco usual provocada por la inmunoterapia con Apis mellifera / Usual reaction to Apis mellifera immunotherapy

No disponible

Characterisation of immune mediator release during the immediate response to segmental mucosal challenge in the jejunum of patients with food allergy.

BACKGROUND: Food allergy is a common complaint among patients with a broad spectrum of abdominal and extra-abdominal symptoms that must be distinguished from other more common non-immunological food intolerances. AIMS: To investigate whether human intestinal hypersensitivity reactions are associated with detectable release of inflammatory mediators from activated cells, which may serve as a biological marker of true allergic reactions. PATIENTS/METHODS: In eight patients with food allergy and seven healthy volunteers, a closed-segment perfusion technique was used to investigate the effects of jejunal food challenge on luminal release of tryptase, histamine, prostaglandin D(2), eosinophil cationic protein, peroxidase activity, and water flux. RESULTS: Intraluminal administration of food antigens induced a rapid increase in intestinal release of tryptase, histamine, prostaglandin D(2), and peroxidase activity (p<0.05 v basal period) but not eosinophil cationic protein. The increased release of these mediators was associated with a notable water secretory response. CONCLUSIONS: These results suggest that human intestinal hypersensitivity reactions are characterised by prompt activation of mast cells and other immune cells, with notable and immediate secretion of water and inflammatory mediators into the intestinal lumen. Analysis of the profile of markers released into the jejunum after food provocation may be useful for the objective diagnosis of food allergy.

Release of mast cell mediators into the jejunum by cold pain stress in humans.

BACKGROUND & AIMS: The central nervous system regulates gut functions via complex interactions between the enteric nervous and immune systems. The aim of this study was to investigate whether mast cell mediators are released into the human jejunal lumen during stress. METHODS: A closed-segment perfusion technique was used to investigate jejunal release of tryptase, histamine, prostaglandin D2, and water flux in response to the cold pressor test in 8 healthy subjects and 9 patients with food allergy. In 6 food-allergic patients, jejunal biochemical responses to cold pain stress were compared with those induced by food intraluminal challenge. RESULTS: Cold pain stress elevated heart rate and blood pressure and increased luminal release of mast cell mediators and jejunal water secretion in both groups. Stress-induced release of tryptase and histamine, but not of prostaglandin D2 and water flux, was greater in food-allergic patients than in healthy volunteers. In food-allergic patients, jejunal biochemical responses induced by cold pain stress were similar to those induced by antigen challenge. CONCLUSIONS: These results show the ability of the central nervous system to modulate intestinal mast cell activity and suggest that mast cells have a role in stress-related gut dysfunction.

Blood sample processing effect on eosinophil cationic protein concentration.

BACKGROUND: Asthma is considered to be an inflammatory disease. The most important cell involved in the inflammation is the eosinophil. These cells and their mediators, such as eosinophil cationic protein (ECP), are potential markers of the inflammation's severity. Eosinophil cationic protein may be used for monitoring antiasthma treatment. It is well known that sample processing conditions can affect the ECP blood levels. OBJECTIVE: The aim of this work is to study the effect of temperature, time, and anticoagulants on ECP levels. METHODS: We studied five asthmatic patients and five healthy controls. We obtained three different blood samples from each subject, one with heparin, one with EDTA, and one without anticoagulant. To evaluate the effect of temperature, serum samples were clotted for an hour, one at 0 degree C, one at room temperature, and the other at 37 degrees C. Plasma (heparin and EDTA) samples were treated as follows: one was immediately centrifuged, and two were stored for an hour, one at 0 degree C, and the other at room temperature. Eosinophil cationic protein levels were measured by fluoroimmunoassay (CAP-System ECP FEIA Pharmacia). RESULTS: A higher temperature during blood clotting resulted in a higher ECP concentration. There were no differences between ECP determination in serum samples and plasma samples with heparin, under the same conditions of time and temperature; so clotting may not be necessary for ECP release in vitro. Eosinophil cationic protein was not released in plasma samples with EDTA, neither at 0 degree C nor room temperature. CONCLUSIONS: More studies must be done to clarify the mechanism of the ECP release in vitro.

[Anaphylaxis caused by royal jelly]. / Anafilaxia por jalea real.

Royal jelly is the food on which are fed and which causes them to develop into queen bees. It is claimed to have rejuvenating virtues for human beings. This report describes a 15-year-old atopic woman who presented, 15 minutes after the intake of royal jelly, local angioedema, generalised urticaria, dysphonia and bronchospasm. She was given antihistaminics and corticoesteroids and responded well. The ingested product contains royal jelly, lactose and potassium sorbate. No anaphylactic reactions to lactose and sorbates have been described previously. Prick test to common food allergens hymenoptera venoms and pollens were negative. RAST to meletin was also negative. Blood eosinophils were 600 and total IgE 465. Non-commercial prepared specific IgE to royal jelly was positive (0.8 KU/l). Prick by prick was positive to 1/10 dilution, being negative in controls (undiluted). No oral provocation test was performed due to the risk of anaphylaxis. No reported cases of royal jelly allergy were founded in a review of the medical literature. Concluding, it is the first described case of IgE anaphylactic reaction due to royal jelly.

[Anaphylaxis caused by human seminal fluid]. / Anafilaxia por fluido seminal humano.

Anaphylaxis to human seminal fluid (HSF) is rare. We present an atopic woman with postcoital cutaneous and respiratory symptoms. Prick by prick to HSF was positive. CAP to FSH was also positive (4 KU/l). The clinical findings, differential diagnosis and different treatments are discussed.

[Hereditary angioedema. Control and treatment in 7 cases]. / Angioedema hereditario. Control y tratamiento en 7 casos.

Hereditary angioedema (HAE) is due to a deficit of the C1 inhibitor (C1 INH) of a dominant autosomic inheritance. Seven patients are presented from a family with HAE, four of whom with poor prognosis due to the frequency and site of the angioedema. Prophylaxis was obtained with long-term danazol since antifibrinolytic drugs are not efficient in the prevention of outbreaks of angioedema. In three cases a concentrate of C1 INH was administered and in another as short term prophylaxis prior to surgery. C1 INH was more efficient under these indications than fresh plasma or antifibrinolytic drugs.