A common epitope on major allergens from non-biting midges (Chironomidae)

A synthetic peptide corresponding to sequence 91-101 of the Chironomus thummi thummi haemoglobins (Chi t I) components III and IV was used to investigate binding and cross-reactivity with polyclonal human IgE and rabbit IgG antibodies and murine IgG1 subclass monoclonal antibodies (MABs). The synthetic peptide reacted with antibodies from all three mammals. The specificity of the reaction, especially that with IgE antibodies was shown by dose dependent inhibition with native Chi t I component III. Epitope(s) reacting with these antibodies were also found in haemoglobins from 14 of the 15 chironomid species analyzed. The synthetic peptide III/IV 91-101 enabled the identification of an important antigenic/allergenic determinant of the broadly distributed insect family Chironomidae. The antigenic potency of this synthetic peptide as shown by testing with human IgE, rabbit IgG and mouse MABs, and the widespread occurrence of the epitope in an identical or homologous sequence and/or superficial location, qualifies the peptide for therapeutic applications in medicine.     

Plasma and red blood cell magnesium concentrations in Zucker rats: influence of a high fibre diet

Because of the possible influence of obesity and insulin levels on magnesium metabolism, we have examined plasma and red blood cell (RBC) Mg in Zucker rats. There were reduced plasma and RBC Mg levels in Zucker rats compared with Wistar rats, and phenotype differences in Zucker rats. In obese rats, a high fibre diet reduced body weight, hyperinsulinaemia and hyperlipaemia and returned the plasma Mg concentration toward normal. However RBC levels were significantly lower than in lean rats of the same strain. The significance of the altered Mg concentration in obese Zucker rats may have metabolic implications and needs further study.     

Endodermal sinus tumor and mucinous cystadenofibroma of the ovary. Occurrence in an 82-year-old woman

We encountered an unusual ovarian tumor consisting of a mixture of typical endodermal sinus tumor (EST) and mucinous cystadenofibroma that occurred in the ovary of an 82-year-old female patient. The EST component showed the classic histologic features of this tumor. Serum alpha-fetoprotein (AFP) level was not determined. Tumor stains were negative for AFP but positive for alpha-1-antitrypsin. The malignant germ cell component was intimately associated with the benign mucinous component. Focal production of epithelial mucin and carcinoembryonic antigen (CEA) in the EST component suggested a probable association between the two tumor types. The tumor was confined to one ovary, and the patient is disease-free 2 years after surgical therapy. This neoplasm is unique not only for the malignant germ cell component occurring in an 82-year-old woman, but for the unusual combination of tumor types. The pathogenesis is unknown.