A new method to bind allergens for the measurement of specific IgE antibodies

BACKGROUND: Detection of allergen-specific IgE antibodies in patients' sera plays a key role for the diagnosis of IgE-mediated allergy. If no validated test system is available, diagnostic tools must be developed, usually by coupling or binding the allergens to a solid phase. Streptavidin ImmunoCAP is a new solid phase for binding of allergens which can be used in the Pharmacia CAP system. OBJECTIVE: It was the aim of this study to assess the diagnostic validity of Streptavidin ImmunoCAP. METHODS: Biotinylation and allergen concentration for binding to Streptavidin ImmunoCAP were optimized and IgE obtained with natural rubber latex, obeche wood, wheat and rye flour Streptavidin ImmunoCAP were compared with the results of ImmunoCAP and Enzyme Allergo-Sorbent Test (EAST) using sera from patients complaining of workplace-related respiratory symptoms. RESULTS: While the relation of biotin-label and protein was critical (best results were obtained with a 5- fold molar excess), labelled protein for coupling to streptavidin ImmunoCAP was applicable in a wide concentration range. On average, IgE values with streptavidin ImmunoCAP were as high as with ImmunoCAP but considerably higher than values obtained by EAST. CONCLUSION: Streptavidin ImmunoCAP is a valuable tool for sensitive and specific measurement of IgE binding to new allergens superior to cellulose disk-based methods.     

Molecular characterization of a heme-binding protein of Bacteroides fragilis BE1.

An iron-repressible 44-kDa outer membrane protein plays a crucial role in the acquisition of heme by the anaerobic bacterium Bacteroides fragilis. The DNA sequence of the gene encoding the 44-kDa protein (hupA) was determined. The hupA gene encodes a protein of 431 amino acid residues with a calculated molecular mass of 48,189 Da. The hupA gene is preceded by an open reading frame of 480 bp that probably encodes a protein with a calculated molecular mass of 18,073 Da. hupA and this open reading frame are likely organized in an operon, and a sequence homologous to the Escherichia coli consensus Fur box was present in the putative promoter region of the operon. Heme-binding studies showed that HupA binds heme. Analysis of the deduced amino acid sequence revealed signature heme-binding consensus motifs, characteristic of heme lyases. Subcellular localization studies in E. coli revealed that HupA was mainly found in the cytoplasmic membrane but not in the outer membrane of E. coli. This suggested that B. fragilis uses another strategy for the translocation of this outer membrane protein across its cell envelope than E. coli does. HupA did not have significant homology with other putative bacterial heme receptors.     

Über den Tätigkeitsstoffwechsel des Nerven

Ohne ZusammenfassungVortrag, gehalten am 23. November 1928 auf dem Dahlemer Abend im Kaiser Wilhelm-Institut für Biologie.     

Serum CK-MB activity in progressive muscular dystrophy: Is it of nosologic value?

Serum creatine-kinase (CK) isoenzyme MB was measured in 53 patients affected by different types of myopathies (20 with Duchenne muscular dystrophy (DMD), eight with the Becker form (BMD), ten with the limb-girdle form (LGMD), six with the facioscapulohumeral form (FSH), and nine affected by polymyositis and in 21 normal control subjects). The aim of this study was to compare each group with the control individuals and to assess the nosologic value of CK-MB activity among some clinically similar dystrophies, which may have an important application for genetic counseling. A statistically significant increased CK-MB activity was found only in the Duchenne and Becker patients when compared with control persons (p < 0.05). When the different groups of patients were compared among themselves, no significant difference was found between DMD and BMD or LGMD and polymyositis. However, a significant difference was found between BMD and LGMD. Based on these data, it is possible, through discriminant analysis, to estimate the relative biochemical probability of an isolated male patient belonging to either group.     

Major depression in panic disorder patients with comorbid social phobia

Rates of depression among panic disorder patients are particularly elevated in patients with comorbid social phobia. However, it is unclear whether this association is specific to social phobia, or whether any comorbid anxiety disorder increases the risk of depression. We assessed 100 panic disorder patients and found a significantly higher incidence of lifetime major depression for panic patients with comorbid social phobia or generalized anxiety disorder (GAD). Panic patients with comorbid social phobia had significantly higher scores on measures of dysfunctional attitudes and lower scores on measures of assertiveness; these variables may mediate the link between social phobia and depression in this population.     

Nonfermentative bacilli: evaluation of three systems for identification.

Three systems for the identification of nonfermentative bacilli were evaluated for their rapidity and accuracy of identification of 217 strains. Two of the systems, API 20E (API) and Oxi/Ferm tube (OxiF), are available as kits; the oxidative attack (OA) system is not commerically available. The overall accuracies of the OA, API, and OxiF systems were 91, 69, and 50%, respectively. Identification within 48 h was achieved for 98% of the strains by OA, for 50% by API, and for 18% by OxiF. Most of the organisms that were either misidentified or not identified by API and OxiF were those nonfermentative bacilli which are relatively more fastidious or rarely encountered or both. All three systems accurately identified nonfermentative bacilli commonly isolated at Olive View Medical Center, namely, Pseudomonas aeruginosa, Acinetobacter anitratus, Pseudomonas maltophilia, Acinetobacter lwoffi, saccharolytic flavobacteria (CDC IIb), moraxellae, Pseudomonas fluorescens, and Pseudomonas putida. The OA system identified 100% of the above organisms correctly, API identified 99.4%, and OxiF identified 99.3%. Since these organisms comprise 92% of the total number of nonfermentative bacilli isolated at Olive View Medical Center, we conclude that both API and OxiF may be useful alternatives to conventional methods, based on accuracy of identification alone. These two systems were considered substantially inferior to the OA system when both accuracy and rapidity of identification were taken into account.     

In vitro Metabolism of Bumetanide

A new metabolite of the diuretic drug bumetanide, the 4-[(4-hydroxy)-phenoxy] analog (7), was identified in incubation mixtures of rat liver microsomes. Phenobarbital and clofibrate pretreatment to induce microsomal enzymes changed the relative amounts of the six metabolites formed. Compound 7was the most prevalent metabolite after clofibrate pretreatment.