Quantitative enzyme-linked immunosorbent assay determination of an abundant hemoglobin-derived anti-infective peptide in human placenta

A fragment of the human β-chain of hemoglobin (HEM), hHEMβ111-146, was shown to have broad antimicrobial properties. The 3.9-kDa peptide was postulated to occur in high concentrations in placenta tissue. We established a reliable method to quantify hHEMβ111-146 in placenta tissue. Our methodology consists of a tissue extraction step (step 1), a chromatographic enrichment step (step 2), and a final quantification step (step 3) by enzyme-linked immunosorbent assay (ELISA). The specificity of the ELISA reaction was confirmed by parallel analysis of the samples via Western blot (step 4). The ELISA measured the absorbance of a tetramethylbenzidine substrate at 450 nm. It showed no cross-reactivity with the corresponding γ- and α-HEM regions and low cross-reactivity with the β-HEM region and full-length HEM. The sample preparation procedure enabled a prepurification of hHEMβ111-146, completely eliminating cross-reactive proteins and HEM peptides. The linear range of detection in step 3 was 20-200 ng/well (200-2000 μg/L) with a limit of quantification of 23 ng/well (230 μg/L) and a limit of detection of 7 ng/well (70 μg/L). The assay was characterized by good linearity (r² > 0.99), intraday precision (coefficient of variation [CV] = 2.2-8.3%), interday precision (CV = 1.8-9.1%), and accuracy (76-109%). The mean recovery of the ELISA was determined to be 97%, and the overall recovery during steps 1-3 was found to be 40.3 ± 2.5%. We measured concentrations from 0.28 to 0.74 mg/g placenta tissue of the hHEMβ111-146 in different placenta samples with an average concentration of 0.57 mg/g. This abundant concentration supports an important physiological role of hHEMβ111-146 in the placenta infective barrier.     

Somatostatin-immunoreactive nerve cell bodies and fibers in the medulla oblongata et spinalis.

Complete serial sectioning of the medulla oblongata in monkey, cat, guinea pig, and japanese dancing mouse and incubation for somatostatin-immunoreaction was carried out. Numerous regions of the medulla oblongata such as the nucleus reticularis gigantocellularis, nucleus cuneatus et gracillis, nucleus raphe magnus, nucleus tractus solitarius, nucleus vestibularis, and parts of the oliva contain dense networks of somatostatin-immunoreactive nerve fibers. Cell bodies were seen in the nucleus reticularis medullae oblongatae. In the spinal cord the sections from each segment were analyzed, showing the highest concentrations of somatostatinergic fibers in the substantia gelantinosa of the columna dorsalis. Cell bodies were seen in the zona intermedia centralis, especially in the upper cervical segments. Many positive fibers were also seen in the entire zona intermedia and the columna ventralis. Especially prominent was the immunoreactivity in the zona intermediolateralis of the thoracic segments and the columna ventralis of the lower lumbar and sacral segments.     

Glucagon and glicentin immunoreactive cells in human colon

Summary An immunohistochemical study of glucagon and glicentin immunoreactive endocrine cells in the human colon epithelium was performed. Serial sections and qualitative analysis show a cell population containing both immunoreactivities. However, there is another cell population exhibiting only an immunoreactivity with glicentin. The exact distribution of these immunoreactive endocrine cells within the colon crypt segments is also analysed. The significance of these findings concerning the synthesis of glucagon and glicentin and their function is discussed.Supported by a grant of the German Research Foundation and by a research grant AM 17537 from the National Institutes of Health, Bethesda, Maryland (USA) Dr. Colony was the recipient of a stipend for a research project in the Federal Republic of Germany from the Deutscher Akademischer Austauschdienst (DAAD)     

L'Utrastructure du ganglion cervical supérieur du rat

Résumé Le ganglion cervical supérieur du rat, maintenu in vitro dans une solution de Krebs, peut conserver pendant plus de 48 heures sa capacité de transmettre des excitations nerveuses.L'irradiation aux rayons X. à la dose d'environ 153000 rad en 30 minutes abrège le fonctionement électrophysiologique de la préparation. Elle rend cette dernière plus sensible à des changements de composition de la solution.Du point de vue morphologique, l'irradiation provoque des lésions graves et précoces des cellules satellites. Les changements au niveau des neurones sont plus tardifs; ils intéressent le noyau, les lysosomes, la substance de Nissl et, à un degré moindre, les mitochondries. Les prolongements cellulaires, dendrites et axones, sont les structures nerveuses qui résistent le plus longtemps.Les régions synaptiques ne montrent aucune modification morphologique, même lorsque le fonctionnement des préparations est profondément altéré à la suite de l'irradiation.

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Summary The superior cervical sympathetic ganglion of the rat, maintained in vitro in Krebs' solution, may preserve its ability to transmit nervous impulses for more than 48 hours.Irradiation with X-rays at a dose of approximately 153,000 rad in 30 minutes shortens electrophysiological function of the ganglion. It renders the preparation more susceptible to changes in the chemical make up of Krebs' solution.From the morphologic point of view, irradiation produces early and severe lesions of satellite cells. The changes within the neuron occur later and affect the nucleus, the lysosomes, Nissl's substance, and, to a lesser degree, the mitochondria. Cell processes, dendrites and axones show the greatest resistance to irradiation.The synapses do not show any morphologic changes even at a time when the function of the ganglion shows marked deterioration.

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Travail réalisé avec l'aide du Fonds National Suisse pour la Recherche Scientifique.