Testverfahren für inhalative Testung auf allergenes Potenzial

There is an increasing need for suitable methods for prospective identification of the allergenic potential of industrial chemicals in the respiratory tract. Animal models have been established for this purpose which show allergic airway reactions after appropriate sensitization similar to humans. Sensitization of the experimental animals is induced by multiple systemic (non-inhalational) application of the test substance and then acute airway obstruction (early allergic response), which is monitored by lung function measurement, is provoked by inhalational allergen exposure. In the late allergic phase, a non-specific provocation is performed to test for an induced bronchial hyperresponsiveness and the concentration of serum IgE antibodies as well as the induced local inflammation in the lungs (eosinophilia) is determined by means of bronchoalveolar lavage. Among the available models, the guinea pig model will loose its importance in the future because of its limitations and difference to humans. The only available and established test for the mouse, the “mouse IgE test”, only registers the induction of IgE antibodies and not the actual allergic airway response. The mouse models developed for asthma research for some years are not yet validated for inhalational testing for allergenic potential (especially for low-molecular-weight substances). The allergic asthma model of the Brown Norway rat is similar to humans in its IgE-dependent allergic reaction and already well established. All properties and reactions characteristic for the allergic asthma like e.g. early and late response, hyperresponsiveness and eosinophilia can be demonstrated in the BN rat. In the field of low-molecular-weight substances, this model still requires a more comprehensive validation.     

Auditory brainstem evoked responses in autistic children

Previous studies have implicated a brainstem dysfunction in the syndrome of autism. This study matched six autistic children with six normal children by age and sex to evaluate brainstem evoked response (BSER) to auditory stimuli. An evaluation of pure tone audiometric threshold showed no evidence of impairment; however, the electrophysiologic responses differed for the autistic and control groups. The BSER of the autistic children was remarkable for showing increased latency and markedly increased variability. The findings from this study add additional evidence of a brainstem dysfunction in autistic children, while the electrophysiologic variability supports the hypothesis of perceptual inconstancy. The authors wish to thank Dr. James H. O'Brien for considerable assistance in computer programming and data analysis, and Patricia J. Almond for help in preparing the children for testing. This study was supported in part by Portland State University's Research and Publication Committee.     

Biplane arteriography in ischemia of the lower extremity

A technique for simultaneous bilateral biplane arteriography of the abdomen, pelvis, and lower extremities is described. The biplane views provided clinically significant information in approximately 40% of cases.     

Spectrophotometric investigations on aflatoxin B1 and aflatoxin G1 (author's transl)]

UV-spectrophotometric and fluorescence-spectrophotometric investigations have been performed on the aflatoxins B1 and G1 with the aim of their unequivocal identification and quantitative estimation in the routine examination. The lower limits of the quantitative and semiquantitative estimations have been found to be 0,4 ng (thin layer chromatography, semiquantitative), Imug/ml (UV-spectroscopy) and 10 ng/ml (fluorescence spectroscopy) for the aflatoxin B1 and 0,3 ng (TLC, semiquantitative), 1 mug/ml (UV-spectroscopy) and 1 ng/ml (fluorescence spectroscopy). Quinine sulfate in 0.1 n sulfuric acid was successfully utilized as a convenient standard substance for quantitative fluorescence spectroscopic estimations of the aflatoxins B1 and G1. In an extensive series of estimations the fluorescence intensity of aflatoxin B1 in chloroform in the range of 0,01-10 mug/ml has been compared with that of equally concentrated solutions of quinine sulfate in sulfuric acid. The ratio of the intensities was 0.5 : 1(0.509 : 1). Similar comparative estimations of aflatoxin G1 in chloroform in the range of 0.001 bis 1 mug/ml and quinine sulfate in sulfuric acid resulted in a ratio of 5 : 1 (4.99 : 1). These ratios have been found using a fluorescence spectrophotometer Beckman SF 1078.     

Pulmonary neuroendocrine tumors: What (little) do we know?

Pulmonary neuroendocrine tumors are a distinct subset of tumors composing approximately 20% of all lung cancers. The major categories of pulmonary neuroendocrine tumors include typical and atypical carcinoids, large cell neuroendocrine carcinoma, and the more common small cell lung cancer. They are classified into different categories in the 2004 World Health Organization system, but share structural and morphologic features. Despite these shared features, their clinical characteristics range from indolent to aggressive, and therefore the approach to treatment depends on the histologic subtype. This article discusses the current understanding of the epidemiology, pathologic characteristics, treatment, and prognosis of this spectrum of diseases.     

The effect of enterectomy on gastric secretion in dogs with biliary fistulas

Bile was excluded from the gastrointestinal tract of 5 dogs with Heidenhain pouches by total external biliary fistulas. After a major portion of the jejunum and the ileum was resected Heidenhain pouch secretions increased in all instances. The results indicate that the increase in gastric secretion which regularly follows small-bowel resection is independent of the presence or absence of bile in the gastrointestinal tract.Supported by Grant AM-7750 from the US Public Health Service.The opinions expressed in this publication are those of the authors and not necessarily those of the US Air Force Medical Service.