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Biomedical subjects

N Reider

Publications and source records attributed to N Reider.

17 recordsLinked to original sources
PubMed2006

Early exposure to latex products mediates latex sensitization in spina bifida but not in other diseases with comparable latex exposure rates.

BACKGROUND: The high prevalence of latex sensitization in patients with spina bifida (SB) has been attributed to repeated and early exposure to latex products. Other diseases such as gastroschisis/omphalocoele and post-haemorrhagic/congenital hydrocephalus are also associated with repeated and early latex exposure. OBJECTIVE: The aim of the study was to evaluate whether the high prevalence of latex sensitization in patients with SB is rather related to the underlying disease itself than to disease-associated known risk factors. METHODS: We compared children with SB (n=35), children with gastroschisis/omphalocoele (G/O, n=20) and children with post-haemorrhagic/congenital hydrocephalus (PH, n=45). All children with SB and PH had a ventriculo-peritoneal shunt since a very young age. Patients who underwent three or less surgical procedures matched in terms of age, number of operations, atopy and gender distribution, and were analysed for IgE sensitization rates to latex. RESULTS: In the SB group, 16 of 35 patients (46%) showed elevated latex-specific IgE antibodies in contrast to one of 20 patients (5%) in the G/O group and four of 45 patients (8.9%) in the PH group (P<0.0005 and P<0.005, Fisher's exact test). Comparing matched control groups (<or=3 operations), the effects remained significant (P<0.05 and P<0.01). CONCLUSION: This study suggests that the SB population bears a disease-associated propensity for latex sensitization. This effect cannot be explained exclusively by a higher number of operations and differences related to atopy, age or gender.

Adolescent↗
PubMed2005

Absence of contact sensitization to Aloe vera (L.) Burm. f.

Aloe vera has been used as a cosmetic and medical remedy since ancient times and has gained increasing popularity in recent years. Despite its widespread use, reports of allergic reactions are rare. We patch tested 702 consecutive patients with an oily extract from the leaves, Aloe pulvis from the entire plant and concentrated Aloe vera gel. A specially designed questionnaire was used for the use of Aloe vera, reasons and location of application, adverse reactions, occupation, hobbies and atopy. None of the subjects showed any reaction to one of the preparations. 2 components of the plant have to be distinguished: the bark of the leaves contains anthrachinones with pro-peristaltic and potential antibiotic and anticancer properties. Constraints have been imposed due to their considerable toxic potential. Today, mostly the Aloe gel from the center of the leaves is processed. It almost exclusively consists of carbohydrates to which also many medical effects have been attributed. Carbohydrates are not likely to induce contact sensitization, which might explain the outcome of our study. However, this does not justify unrestrained promotion of Aloe products, as scientific studies investigating the claims on its constitutional effects are few in number, and the majority of them have been unable to diminish the intuitive scepticism against miracle cures, like Aloe seems to be.

Allergens↗
PubMed2002

Outcome of a latex avoidance program in a high-risk population for latex allergy - a five-year follow-up study.

BACKGROUND: Children with a shunted hydrocephalus are at highest risk for developing an immediate type allergy to latex. Limited data are available for preventive or therapeutical approaches. OBJECTIVE: To evaluate the effectiveness of latex avoidance, with special regard to status of sensitization and compliance. METHODS: In 1995, 131 children with a shunted hydrocephalus were screened for sensitization to latex by skin prick test and determination of specific IgE. Patients and parents were instructed on latex-avoiding strategies. Hospital physicians, family doctors and dentists were advised to perform further surgical and other medical interventions under latex-free conditions. In 2000, 100 of these 131 patients were re-evaluated according to the same testing procedures. Special attention was directed at the extent prophylaxis had been performed. RESULTS: In 1995, 30/100 patients re-evaluable in 2000 proved sensitized to latex, 70 had negative testing results. In 2000, 64/70 patients were still negative, six had meanwhile developed latex-specific IgE. Seven out of thirty subjects with former positive testing had changes within the same RAST-class, 20 showed a decline of at least one RAST-class, whereas in three cases an increase of latex-specific IgE was found. However, only 34 patients, mainly those being already sensitized, had thoroughly followed both medical and private prophylaxis. Within this group, 16 subjects (47.1%) had improved and another nine (26.5%) were still negative. Only three (8.8%) already previously sensitized patients presented with a further increase of latex-specific IgE. Medical prevention contributed more to the outcome than home prevention. No statistically significant correlation with latex-avoidance was observed, however, in previously unsensitized subjects. Underlying disease, atopy, number of operations, and age did not prove as significant variables. CONCLUSION: Secondary prevention results in a decrease of specific IgE in latex-sensitized patients with hydrocephalus. This is due to medical more than home prophylaxis. Sensitization obviously occurs mainly in early childhood, thus primary prevention remains to be the main target.

Adolescent↗
PubMed2001

The seamy side of natural medicines: contact sensitization to arnica (Arnica montana L.) and marigold (Calendula officinalis L.).

Medical remedies of plant origin have gained increasing popularity in recent years. Both anaphylactic and eczematous allergic reactions are on the rise, accordingly. Arnica and marigold, both of the Compositae family, are in widespread use, but only limited data are available on their allergenic potential. We tested 443 consecutive patients, in addition to the European standard and other series, with Compositae mix, sesquiterpene lactone mix, arnica, marigold, and propolis. 5 subjects ( approximately 1.13%) reacted to arnica, 9 ( approximately 2.03%) to marigold. The Compositae mix was positive in 18 cases ( approximately 4.06%). Among them were 3 out of 5 individuals with a sensitization to arnica, and 4 out of 9 who reacted to marigold. Sensitization to arnica and marigold was often accompanied by reactions to nickel, Myroxylon Pereirae resin, fragrance mix, propolis, and colophonium. We conclude that Compositae allergy contributes significantly to the epidemiology of contact dermatitis and that sensitization to arnica and marigold cannot be assessed by testing with the Compositae or sesquiterpene mix alone. As extracts of these plants are frequently used in occupational and cosmetic products, patch testing with additional plant extracts or adjustment of the commercial Compositae mix to regional conditions is recommended.

Adult↗
PubMed2001

Delayed-type hypersensitivity and cross-reactivity to heparins and danaparoid: a prospective study.

BACKGROUND: Delayed-type hypersensitivity (DTH) reactions in patients receiving heparin may occur with both unfractionated (UFHs) and low molecular weight heparins (LMWHs). Skin testing is a clue to detect tolerated heparin or heparinoid preparations for further treatment. OBJECTIVE: To study in vivo cross-reactivity between LMWHs, UFHs, and danaparoid by skin testing in patients with suspected DTH to heparin. METHODS: Patients who fulfilled the criteria for the diagnosis of suspected heparin allergy were involved in a prospective study after informed consent. Patients presented with or had a history of typical erythematous plaques at the heparin injection sites. Skin testing was performed by subcutaneous injections of heparin (300-500 IU anti-Xa activity) and danaparoid (375 IU, eight patients). Desirudin (27,000 IU) was tested in three patients. We read skin reactions after 24, 48, and 96 hours and after 7 days. RESULTS: Fourteen female and 4 male patients were included in our series. Erythematous plaques had been reported or developed after 14-35 days in patients during first-time heparin treatment and after 2-10 days in reexposed patients. Positive skin test results were seen in 15 of 18 (83.3%) patients. Of these, 11 (73.3%) showed cross-reactivity between heparins and/or danaparoid. Six patients reacted to LMWHs only, nine patients to both LMWHs and UFHs. Danaparoid was tolerated in six of eight patients; desirudin was tolerated in all three patients tested. CONCLUSIONS: DTH to heparins is characterized by considerable cross-reactivity between LMWHs, UFHs, and danaparoid. UFHs may be tolerated even if LMWHs are not. Subcutaneous testing of a panel of heparins, danaparoid, and desirudin (hirudin) is recommended to determine acceptable treatment options for patients allergic to specific heparins.

Adult↗
PubMed2001

Spina bifida as an independent risk factor for sensitization to latex.

PURPOSE: Patients with spina bifida are at a high risk for having an immediate type allergy to latex products. The number of surgical interventions, atopy and catheterization are well known responsible factors, whereas the condition of spina bifida per se has not been established as an independent risk factor. MATERIALS AND METHODS: A total of 131 patients with a shunted hydrocephalus (48 with spina bifida and 83 of other origin) were investigated for sensitization to latex by skin prick tests and determination of specific IgE. We hypothesized that the diagnosis of spina bifida will increase the risk for latex sensitization while considering potential confounding factors. Thus, we performed a multiple logistic regression analysis to determine independent risk factors. RESULTS: Whereas 56.3% (27/48) of children with spina bifida proved sensitized against latex, this result was the case in only 16.9% (14/83) with another cause of hydrocephalus (p <0.001). The mean number of surgical interventions was 6.2 for patients with no latex sensitization and 9.3 for those with sensitization (p = 0.02). Of patient sensitized to latex 43.9% had a history of atopy compared to 15.5% of those not sensitized (p = 0.02). Sensitized and nonsensitized patients were comparable regarding gender and catheterization. In a multiple logistic regression analysis the cause of the hydrocephalus (odds ratio 6.76 for spina bifida), atopy (odds ratio 3.37) and the number of surgical interventions (odds ratio 1.14 per operation) were identified as independent risk factors. CONCLUSIONS: The increased risk of latex sensitization in patients with spina bifida seems to be disease associated. Possible explanations for this finding may be genetic, antigen mediated, early latex exposure and immunological reasons.

Adolescent↗
PubMed2000

Anaphylaxis to camomile: clinical features and allergen cross-reactivity.

BACKGROUND: Medicinal remedies of plant origin became very popular in recent years, and allergic reactions to these are on the rise, accordingly. Camomile has been reported as a potential trigger of severe anaphylaxis. The allergens responsible for camomile allergy have not been characterized as yet. OBJECTIVE: The present study aims at reviewing the clinical symptomatology of immediate-type reactions in a series of patients sensitized to camomile and at characterizing the responsible allergens. METHODS: Fourteen patients with a history of allergy either to camomile or to spices or weeds, and a positive skin prick test/RAST to camomile were investigated for related allergic reactions to food, pollen and others. IgE-binding patterns were determined by immunoblotting, inhibition tests and deglycosylation experiments. RESULTS: Ten of 14 patients had a clinical history of immediate-type reactions to camomile, in some cases life threatening. Eleven subjects were also sensitized to mugwort in prick or RAST, eight to birch tree pollen. Using a polyclonal rabbit anti-Bet v 1 antibody, a homologue of the major birch pollen allergen Bet v 1 was detected in two camomile blots. In four cases a group of higher molecular weight allergens (23-50 kDa) showed IgE-binding to camomile. All allergens proved heat stable. Binding was inhibited in variable degrees by extracts from celery roots, anize seeds and pollen from mugwort, birch and timothy grass. Deglycosylation experiments proved the presence of carbohydrate determinants in camomile which were not responsible for IgE-binding, though. Profilins (Bet v 2) were not detected in our camomile extracts. CONCLUSION: Incidence and risk of type I allergy to camomile may be underestimated. Concurrent sensitization to mugwort and birch pollen is not infrequent. Bet v 1 and noncarbohydrate higher molecular weight proteins were found to be eliciting allergens and are responsible for cross-reactivity with other foods and pollen.

Adolescent↗
PubMed1992

Ion dependence of the partially purified mitochondrial dihydropyridine Ca2+ antagonist receptor.

The mitochondrial inner membrane contains specific binding sites for dihydropyridine (DHP) Ca2+ antagonists that are associated with an inner mitochondrial membrane anion channel (IMAC) [Mol. Pharmacol. 38:362-369 (1990)]. As in particulate preparations, binding of the DHP (+/-)-[3H]nitrendipine [( 3H]NTR) to partially purified mitochondrial DHP receptors strongly depended on a variety of cations and inorganic as well as organic anions. Monovalent anions saturably stimulated [3H]NTR binding with a potency rank order of I- greater than Br- greater than Cl- greater than F-. The potency rank order for monovalent cations was Cs+ greater than Rb+ greater than Li+ greater than K+ greater than Na+. [3H]NTR binding stimulation potency of the cations strikingly depended on their charge density, with EC50 values being 125 mM for K+, 5 mM for Ca2+, and 41 microM for La3+. This selectivity order clearly differed from one predicted on the basis of a simple surface charge-screening effect of the cations. In general, allosteric ion effects were due to changes in [3H]NTR affinity for the partially purified mitochondrial DHP receptor. SCN- and NO3-, known permeators of the IMAC [J. Biol. Chem. 262:15085-15093 (1987)], stimulated [3H]NTR binding with EC50 values of 26 mM and 96 mM, respectively. The IMAC permeators butylmalonate2- and 1,2,3-benzenetricarboxylate3- were ineffective when given alone but dose-dependently inhibited 500 mM NaCl-stimulated [3H]NTR binding, as did PO4(1.5-) and SO4(2-). Gluconate-, which was reported not to permeate the IMAC, qualitatively behaved as a partial agonist with respect to Cl-. Glucuronate- was without effect on [3H]NTR binding to the partially purified mitochondrial DHP receptor. These results point to the existence of rather large ion-binding domains. The cation-binding site was estimated to have a minimum diameter of 0.67 nm. The anion-binding domain could accommodate either spherical ligands with diameters of up to 0.6 nm or molecules with a flat backbone with dimensions of approximately 0.9 nm x 0.7 nm x 0.3 nm.

Animals↗
PubMed1990

Mitochondrial Ca2+ antagonist binding sites are associated with an inner mitochondrial membrane anion channel.

The inner mitochondrial membrane contains specific Ca2+ antagonist binding sites unrelated to the L-type Ca2+ channel. The mitochondrial 1,4-dihydropyridine (DHP) and phenylalkylamine sites are reciprocally allosterically coupled, require anions (e.g., Cl-, No3-) for optimal binding, and are inhibited by purine and pyrimidine nucleotides in a noncompetitive manner. In mitochondrial swelling experiments, a concentration-dependent inhibition of an inner mitochondrial membrane anion channel (IMAC) by Ca2+ antagonists from different chemical classes can be demonstrated. Under the conditions of the swelling experiments, affinity of different Ca2+ antagonists and amiodarone, a known IMAC inhibitor, for the mitochondrial (+/-)-[3H]nitrendipine binding site (Kd, 7.2 +/- 2.0 microM; Bmax, 1.03 +/- 0.37 nmol/mg of protein) strongly correlated with their inhibitory potency for the IMAC. Linear regression of pIC50 values for IMAC-induced swelling versus pIC50 values for (+/-)-[3H]nitrendipine binding inhibition yielded a correlation coefficient of 0.91 for all tested DHPs (n = 12, p less than 0.001). Amiodarone inhibited (+/-)-[3H]nitrendipine binding and IMAC-induced swelling with pIC50 values of 6.11 and 5.93, respectively. The correlation coefficient between binding and inhibition of IMAC-induced swelling for amiodarone and all tested Ca2+ antagonists (including non-DHP compounds) was 0.76 (n = 20, p less than 0.001), with the slopes approaching unity. These results suggest the association of the mitochondrial Ca2+ antagonist binding sites with an IMAC.

Amiodarone↗