Orbicules do not significantly contribute to the allergenic micro-aerosol emitted from birch trees.
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Biomedical subjects
Publications and source records attributed to M Grote.
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Although Candida albicans is the most common human yeast pathogen, other Candida species such as C. krusei are now recognized as emerging agents, especially in patients with human immunodeficiency virus (HIV) disease. C. krusei is inherently resistant to the widely used triazole antifungal fluconazole and poses therapeutic problems, especially in systemic candidiasis. In a surveillance study of leprosy patients (with arrested or burnt-out disease) in a leprosarium in northern Thailand, we found a rate of oral carriage of C. krusei (36%) significantly (P < 0.05) higher than that for a healthy control group (10%). Among the Candida-positive patients, 16 of 35 (46%) carried C. krusei, while C. albicans was the second most common isolate (12 of 35 patients; 34%). The corresponding figures for the control group were 2 of 13 (15%) and 6 of 13 (46%), respectively. Studies of the antifungal resistance of the C. krusei isolates from patients indicated that all except one of the isolates were resistant to fluconazole, two isolates were resistant to ketoconazole, and all isolates were sensitive to amphotericin B. Evaluation of their genetic profiles by randomly amplified polymorphic DNA analysis with three different primers and subsequent analysis of the gel profiles by computerized cluster-derived dendrograms revealed that the C. krusei isolates from patients belonged to 10 disparate clusters, despite the origin from a single locale. These nascent findings indicate an alarmingly high prevalence of a Candida species resistant to a widely used antifungal in a part of the world where HIV disease is endemic.
BACKGROUND: Platelet activating factor (PAF) is associated with ischemia/reperfusion injury (I/R) after lung transplantation. Following promising experimental results, this prospective trial investigated the potential effect of PAF antagonist BN 52021 (ginkolide B) on clinical Euro-Collins (EC)-based lung preservation. METHODS: We analyzed 8 double-lung transplant patients in each of 3 groups. In the low-dose group (LDG), donor lungs were perfused with EC containing 2 mg/kg BN 52021, whereas we used 10 mg/kg in the high-dose group (HDG) and placebo in the control group (CG). Before reperfusing the first lung, we administered intravenously 120 mg BN 52021 (LDG), 600 mg BN 52021 (HDG), or placebo (CG). Hemodynamics in terms of pulmonary arterial pressure, pulmonary vascular resistance and serial determinations of the alveolo-arterial oxygen difference (AaDO(2)) were recorded. We measured blood levels of PAF pre-operatively and post-operatively, after 10 minutes and after 3, 8, 24, 48, and 144 hours. RESULTS: Within 32 hours, we noted a tendency toward better AaDO(2) in the LDG and the HDG compared with the CG (p > 0.05). We observed a significant improvement of AaDO(2) after 3 hours (HDG, p = 0.033) and 8 hours (LDG, p = 0.024), with poorest values in the CG. The PAF concentrations were lowest in the HDG, with significant deterioration 10 minutes after reperfusion. In contrast, placebo led to higher PAF levels. We measured significantly lower PAF concentrations (HDG vs CG) at 10 minutes and at 6 days post-operatively. CONCLUSIONS: Use of high-dose PAF antagonist BN 52021 can easily be combined with clinical preservation methods and may help optimize pulmonary function with reduced PAF levels, in the early post-ischemic period.
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Eighty-seven HIV-infected patients in a provincial hospital in Northern Thailand were examined for oral manifestations of HIV disease and AIDS. The median age was 31.3 years. Seventy-four of the patients were women, 13 were men. 96.6% had a history of heterosexual transmission. Sixty-one patients were CDC-category A, 20 were category B and 6 were category C (AIDS). Thirty-eight percent of the patients revealed oral lesions; 23% had one oral lesion and 13.8% had two oral lesions. Common lesions were oral candidiasis (10.3% pseudomembranous candidiasis, 6.9% erythematous candidiasis and 3.4% both forms), oral hairy leukoplakia (11.5%) and exfoliative cheilitis (6.9%). Gingival linear erythema was seen in 8% of the patients; periodontal lesions and necrotising ulcerative gingivitis were not observed. Men were more commonly affected by oral manifestations than women (P < 0.004). The spectrum of oral lesions is comparable to other studies from the region, although most of these reported more men than women. Also, the degree of immunosuppression was more marked (AIDS).
Forty-five Northern Thai children with HIV infection or AIDS were examined for oral manifestations. Of these children, 51.1% (n=23) were asymptomatic (category N), 48.9% were mildly, moderately or severely symptomatic (category A, B, C) and 48.9% (n=22) revealed oral lesions. Eleven patients (24.4%) showed one oral lesion, eight (17.8%) had two and three (6.6%) had three oral lesions. Erythematous candidiasis was the most common lesion (17.8%). Oral hairy leukoplakia was seen in 6.7% (n=3). Geographic tongue, not usually considered to be associated with HIV infection, was seen in 6.7% (n=3). Only 15 patients (33.3%) received antiretroviral therapy (ART). Comparison of patients with or without ART did not show differences in the prevalence of oral lesions. More studies in Thai HIV-infected children are needed to reveal the prevalence of oral manifestations, as well as for the predictive value of the most common or specific oral manifestations.
BACKGROUND: The release of submicronic particles from grass pollen after rainfall was suggested to be responsible for outbreaks of grass pollen asthma. Recently, we provided evidence for the release of respirable allergen-bearing particles from hydrated ryegrass (Lolium perenne ) pollen as a possible explanation for this phenomenon. OBJECTIVE: We investigated whether water-induced release of respirable allergen-bearing particles could be a mechanism common to several members of the sweet grass family Poaceae (Gramineae). METHODS: Pollens from 6 different Poaceae species were hydrated in water and examined by means of scanning electron microscopy for release of cytoplasmic materials. Rabbit antisera raised against purified recombinant group 1 and 5 allergens were used for immunogold labeling of expelled materials by means of field emission scanning electron microscopy. In addition, group 1 and 5 allergens were immunogold-localized on ultrathin sections. RESULTS: Fresh Poaceae pollens expelled cytoplasmic materials containing group 1 and 5 allergens on hydration in water. Expulsion of submicronic particles strongly decreased after 1 month of storage. CONCLUSIONS: Our results suggest expulsion of cytoplasm after hydration as a mechanism common to pollens of important allergenic grasses. The water-induced release of respirable allergen-bearing particles from grass pollens might explain asthma attacks observed after rainfall during the grass pollen season.
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In the chemolysis products of extracted humic acids (HAs) and tetramethylammonium hydroxide, different compounds can be identified which allow a description of the sources of soil organic matter (SOM). It is possible to draw conclusions concerning stability, degree of intramolecular cross-linking and degradation of aliphatic and lignin components from the distinctive product ratios. The ratio of lignin derived acidic phenolic derivatives and their analogous aldehydes and the ratio of phenylpropenoic acids and analogous benzoic acids provide comparably good parameters for the characterization of the state of degradation of lignin compounds to relatively stable HA building blocks. Regarding the aliphatic chemolysis products, alpha,omega-dicarboxylic acid and methoxy fatty acid contents indicate an intramolecular cross-linking state within the HA molecules and the degree of stable aliphatic constituent parts. High contents of unsaturated fatty acids can be considered as an indicator of an easy degradable humic skeleton because with their double bonds they represent active sites for further transformations. The suitability of the carbon preference index as an indicator of a biogenic carbon source can be confirmed. It is remarkable how the results obtained from extracted humic acids are in accordance with the expectations for the different SOMs derived from land use.
BACKGROUND: Latex proteins represent relevant allergens, particularly for those persons who are frequently exposed to latex products (eg, health care workers and patients with chronic disorders). Although several latex allergens have been characterized by biochemical and molecular biologic techniques, little information is available concerning the in situ localization of allergenic proteins in latex products. OBJECTIVE: The objective of the present study was the in situ localization of latex allergens. METHODS: Serum IgE from patients with latex allergy reacting with a broad range (5-200 kd) of latex allergens was used for the in situ localization of latex allergens. One surgical and 2 examination latex glove brands were investigated by using immunogold field emission scanning and transmission electron microscopy. RESULTS: Allergens were detected on the inner and outer surface of the gloves, particularly near the edges, crests, or folds of the bleb-like structures visible on the surface of the latex material at high magnifications. In ultrathin cross-sections, latex allergens were found throughout the sections. CONCLUSIONS: Latex allergens were localized on the outer and inner surface but also in the interior of latex gloves. The occurrence of latex allergens on the surface of latex products may be related to their potential to induce local reactions and, perhaps, to sensitize individuals by means of contact.
BACKGROUND: Several studies demonstrated episodes of grass pollen-induced allergic asthma after heavy rainfalls. It has been hypothesized that these asthma attacks might be due to the release of respirable allergen-bearing particles from pollen cytoplasm. OBJECTIVE: In this study we investigated the release mechanism of the most potent and frequently recognized grass pollen allergens, group 1 and group 5, from freshly harvested and subsequently hydrated rye grass pollen at the ultrastructural level. METHODS: Rabbit antisera against purified recombinant group 1 and group 5 allergens were used to investigate, by using field emission scanning and transmission immunogold electron microscopy, the allergen release from rye grass pollen grains into isotonic aqueous solutions or water. RESULTS: Pollen grains exposed to isotonic aqueous solutions remained intact and released allergens by means of diffusion. However, pollen grains hydrated in distilled water or rainwater expelled starch grains and cytoplasmic debris of respirable size. Group 1 and group 5 allergens were observed on and within these materials. CONCLUSIONS: Exposure of rye grass pollen to water leads to an expulsion of subcellular allergen-containing pollen components of respirable size. Our ultrastructural data thus support the idea that this release of allergen-containing respirable pollen materials may be a cause of asthma attacks after heavy rainfalls.
BACKGROUND: Almost 4% of the population suffer from food allergy which is an adverse reaction to food with an underlying immunological mechanism. AIMS: To characterise one of the most frequent IgE defined food allergens, fish parvalbumin. METHODS: Tissue and subcellular distribution of carp parvalbumin was analysed by immunogold electron microscopy and cell fractionation. Parvalbumin was purified to homogeneity, analysed by mass spectrometry and circular dichroism (CD) spectroscopy, and its allergenic activity was analysed by IgE binding and basophil histamine release tests. RESULTS: The isoelectric point (pI) 4.7 form of carp parvalbumin, a three EF-hand calcium-binding protein, was purified to homogeneity. CD analysis revealed a remarkable stability and refolding capacity of calcium-bound parvalbumin. This may explain why parvalbumin, despite cooking and exposure to the gastrointestinal tract, can sensitise patients. Purified parvalbumin reacted with IgE of more than 95% of individuals allergic to fish, induced dose-dependent basophil histamine release and contained, on average, 83% of the IgE epitopes present in other fish species. Calcium depletion reduced the IgE binding capacity of parvalbumin which, according to CD analysis, may be due to conformation-dependent IgE recognition. CONCLUSIONS: Purified carp parvalbumin represents an important cross reactive food allergen. It can be used for in vitro and in vivo diagnosis of fish-induced food allergy. Our finding that the apo-form of parvalbumin had a greatly reduced IgE binding capacity indicates that this form may be a candidate for safe immunotherapy of fish-related food allergy.
Due to the wide distribution and heavy pollen production of grasses, approximately 50% of allergic patients are sensitized against grass pollen allergens. cDNAs coding for two isoforms and four fragments of a major timothy grass (Phleum pratense) pollen allergen, Phl p 6, were isolated by IgE immunoscreening from a pollen expression cDNA library. Recombinant Phl p 6 (rPhl p 6), an acidic protein of 11.8 kDa, was purified to homogeneity as assessed by mass spectrometry and exhibited almost exclusive alpha-helical secondary structure as determined by circular dichroism spectroscopy. Phl p 6 reacted with serum IgE from 75% of grass pollen-allergic patients (n = 171). IgE binding experiments with rPhl p 6 fragments indicated that the N terminus of the allergen is required for IgE recognition. Purified rPhl p 6 elicited dose-dependent basophil histamine release and immediate type skin reactions in patients allergic to grass pollen. A rabbit antiserum raised against purified rPhl p 6 identified it as a pollen-specific protein that, by immunogold electron microscopy, was localized on the polysaccharide-containing wall-precursor bodies (P-particles). The association of Phl p 6 with P-particles may facilitate its intrusion into the deeper airways and thus be responsible for the high prevalence of IgE recognition of Phl p 6. Recombinant native-like Phl p 6 can be used for in vitro as well as in vivo diagnoses of grass pollen allergy, whereas N-terminal deletion mutants with reduced IgE binding capacity may represent candidates for immunotherapy of grass pollen allergy with a low risk of anaphylactic side effects.
We have previously identified a birch pollen profilin hexadecapeptide (Bp36/51), which was recognized by a monoclonal antibody (moAb 4A6) with high affinity. Here, we report the construction of a T7 RNA polymerase-driven high-level plasmid expression system, pET-prof, capable of producing proteins and peptides containing the Bp36/51 birch profilin-derived peptide fused to their N-terminus. As examples, the cDNAs coding for two major timothy grass (Phleum pratense) pollen allergens, Phl p 2 and Phl p 6, as well as for an alder (Alnus glutinosa) pollen allergen, Aln g 4, were overexpressed in Escherichia coli as BP36/51-tagged proteins. All three recombinant allergens were readily detected in nitrocellulose-blotted E. coli extracts by the Bp36/51-specific moAb 4A6. We demonstrate comparable IgE recognition of Bp36/51-tagged and untagged recombinant allergens by immunoblotting. A sandwich ELISA was developed using plate-bound moAb 4A6 to immobilize and present Bp36/51-tagged recombinant allergens to IgE antibodies of allergic patients. Using immunoelectronmicroscopy, we demonstrate that even under harsh fixation conditions, tagged allergens can be localized simultaneously in situ by moAb 4A6 and allergen-specific antisera. We suggest the use of the pET-prof system for the high-level expression of Bp36/51-tagged polypeptides that can be rapidly detected in total protein extracts, immunolocalized in situ, immobilized and presented to other antigen-specific antibodies (e.g. IgE), even when they occur in minute concentrations.
The present study evaluated the risk of hepatitis C virus-infected (HCV) patients in Germany to develop oral lichen planus (OLP). We screened 127 patients with chronic HCV-infection for OLP. In three of 127 patients (2.4%) OLP was found. Twenty-four patients with OLP were examined for hepatitis C. Only one patient (4.2%) was positive for HCV-RNA. Our data show no increased prevalence for OLP in German patients infected with HCV. Also no increased rate of HCV infection in OLP patients was found in this study. Further studies of HCV-infected patients from different geographical areas and ethnic groups are necessary to determine the rate of OLP in HCV-infection and to clarify whether HCV acts locally to develop OLP, or whether host immune response to HCV is of importance.
Samples from dry kidney bean cotyledons were fixed in acrolein vapor and embedded in Lowicryl K4M using a modified dehydration and embedding technique. The preservation of morphology as investigated by transmission electron microscopy was excellent showing desiccated cells and organelles in life-like preservation. Postembedding immunogold labeling for kidney bean purple acid phosphatase (KbPAP) showed association of kbPAP with ribosome-rich areas of the cytoplasm.
The windborne pollen grains of many trees and grasses contain a number of highly water-soluble (glyco)proteins which upon moistening, e.g. on the human respiratory mucosa, rapidly diffuse out of the pollen grain. In susceptible individuals, they may cause allergic reactions. Because of their rapid release from the pollen, pollen allergens were expected to be located in the outermost layers of the pollen grain, i.e. on the surface and in the wall (exine, intine). First attempts to localize allergens by microscopic methods in the pollen grain supported this view. However, since conventional preparation methods were used, artificial mobilization of allergens could not be excluded. Based on new, completely anhydrous preparation protocols and on the immunogold-labeling technique, pollen allergens were electron-microscopically shown to be located in the interior of the pollen grain, i.e. in the cytoplasm, often within ribosome-rich areas. This unexpected result was obtained in all strictly anhydrously prepared pollen species. The biological function of these allergens is largely unknown, however, clues as to possible cellular functions have been obtained for the birch pollen major allergen Bet v 1.
BACKGROUND: Recently, a novel family of low-molecular-weight (8-9 kD), two-EF-hand calcium-binding proteins has been described as allergens in plant pollens. Approximately 10% of pollen-allergic patients have IgE antibodies which cross-react with the two-EF-hand allergens in tree, grass and weed pollens. The aim of the present study was to localize Bet v 4, the two-EF-hand allergen from birch, in mature, dry pollen and to study the release of this allergen after hydration of the pollen by immunogold electron microscopy. METHODS: Using completely anhydrous fixation techniques in combination with immunogold electron microscopy, we localized Bet v 4 and, for control purposes, the major birch pollen allergen Bet v 1, in dry birch pollen as well as in pollen grains after different periods of hydration. Parallel with these morphological studies, we monitored the release of Bet v 4 and Bet v 1 into aqueous supernatants of hydrated birch pollen grains by immunoblotting. RESULTS: Bet v 4 was found in the electron-dense cytosol, in particular between the vesicles and cisternae of the endoplasmic reticulum, inside mitochondria and in the vegetative as well as in the generative nucleus. Bet v 1 was localized in similar cellular compartments except for the mitochondria. After 30 s to 1 min of hydration, Bet v 4 migrated into the pollen exine and into the aqueous supernatants. Bet v 1 also moved out of the pollen grain, though not as quickly as Bet v 4. CONCLUSION: Bet v 4 represents an intracellular pollen protein which, following hydration of pollen grains, rapidly migrates to the pollen surface (exine) and is washed out. This behavior explains how Bet v 4, being primarily an intracellular pollen protein, becomes available to sensitize patients.