KIT mutations are common in incidental gastrointestinal stromal tumors one centimeter or less in size

Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms of the gut wall that express the receptor tyrosine kinase KIT. Somatic mutations that result in constitutive activation of KIT kinase have been identified in a number of studies of GISTs, although the reported frequency of these mutations has varied over a wide range (20 to 92%). Several reports have suggested that KIT gene mutations are more common in malignant GISTs than in benign lesions, and it has been proposed that mutations in exon 11 of KIT are a negative prognostic factor. To maximize sensitivity for KIT mutations we have adapted denaturing high-pressure liquid chromatography as a method for screening polymerase chain reaction amplimers of exons 9, 11, 13, and 17 from GIST genomic DNA. This approach was used to assess the frequency of KIT mutations in 13 morphologically benign, incidentally discovered, GISTs identified at autopsy, endoscopy, or laparotomy for unrelated disease. Representing the smallest pathologically recognizable GISTs, these lesions ranged in size from 4 to 10 mm in diameter and were all immunohistochemically positive for KIT. Eleven of the 13 tumors had sequence-confirmed mutations in KIT, including 10 mutations in exon 11 (77%) and one mutation in exon 9 (7.7%). The remaining two tumors were wild type for exons 9, 11, and 17; one of these was also analyzed for exon 13 and was wild type in this exon as well. The mutations found in the incidental GISTs were identical to those that have been documented in larger GISTs. In addition, the overall frequency of mutations in the incidental tumors (85%) did not differ significantly from that we previously reported in a series of 72 advanced/metastatic GISTs (86%), strongly supporting the view that activating mutations in KIT are acquired very early in the development of most GISTs. The findings suggest that KIT mutations per se are of little prognostic importance in GISTs.     

Unterschiede in der Widerstandskraft der weiblichen und männlichen Keimdrüse

Ohne ZusammenfassungMit 15 Textabbildungen.Das Bedürfnis nach Stützung schwächerer Gedanken durch stärkere wird auchKausalitäts bedürfnis genannt und ist die Haupttriebfeder aller naturwissenschaftlichenErklärungen. Ernst Mach.Nach einem auf der 89. Versammlung deutscher Naturforscher und Ärzte in Düsseldorf im September 1926 gehaltenen Vortrage. Vgl. auch Fortschritte d. naturwissenschaftl. Forschung, herausgeg. vonE. Abderhalden, Bd. XII, H. 4.     

Beeinflussung der Atemsteigerung bei Muskelarbeit durch partiellen neuromuskulären Block (Tubocurarin)

Zusammenfassung In 17 Versuchen erhielten 7 Versuchspersonen 0,09–0,16 (Mittel 0,13) mg Tubocurarin/kg i.v. Vor und nach der Injektion wurde die gleiche Muskelarbeit geleistet (Beinarbeit; O₂-Aufnahme etwa das dreifache des Ruheumsatzes). Gemessen wurden Atemzeitvolumen, alveolarer O₂- und CO₂-Druck, Blutdruck und Pulsfrequenz. Die Curaredosen führten zu einer Erschwerung der Arbeit, beeinträchtigten jedoch nicht die Atmung.Bei gleicher Muskelarbeit ventilierte die Mehrzahl der Versuchspersonen, vor allem im Beginn der Arbeit, unter Curare mehr als bei der Kontrollarbeit ohne Curare. Am deutlichsten war dies bei denjenigen Versuchspersonen ausgeprägt, die schon ohne Curare im Beginn der Arbeit eine plötzliche Steigerung der Ventilation zeigten.Es wird angenommen, daß unter Curare die gleiche Muskelarbeit mit einer verstärkten motorischen Innervation geleistet wird. Die dabei beobachtete Ventilationssteigerung wird als weiteres Argument für einen Einfluß der motorischen Innervation auf die Atemzentren angesehen.Mit 3 TextabbildungenHerrn Professor Dr. Hans Winterstein zum 80. Geburtstag gewidmet.     

Significant hybridization differences in comparative genomic hybridization due to nucleotides used for DNA labelling and to DNA chosen for cohybridization.

OBJECTIVE: Comparative genomic hybridization (CGH) has been established as an informative technique in genetic analysis. However, differences in the ratio of hybridization intensities were reported for particular chromosomes, which may affect CGH results. The aim of this study was to define these differences in more detail. For this purpose, CGH results of 70 samples of bone marrow cells (BMC) with normal karyotype in conventional cytogenetics (CC) were evaluated using seven different reference DNAs and two different DNA labeling systems. METHODS AND RESULTS: CGH using fluorochrome-conjugated nucleotides for DNA labeling indicated signal deviations in 21/70 BMC samples. Deviations affected chromosomes 1 (n = 21), 2 (n = 11), 4 (n = 11), 5 (n = 9), 6 (n = 7), 7 (n = 2), 8 (n = 2), 12 (n = 5), 13 (n = 15), 14 (n = 1), 16 (n = 17), 17 (n = 11), 19 (n = 21), 20 (n = 12), and/or 22 (n = 17). None of the imbalances were confirmed by fluorescence in situ hybridization (FISH). Using digoxigenin and biotin-conjugated nucleotides in exemplary cases (n = 5) led to the disappearance of the signal deviations. Repeated CGH experiments using seven different reference DNAs showed remarkable variations in the signal deviations. CONCLUSION: Hybridization differences depend not only on the hapten or fluorochrome-labeled nucleotides used for DNA labeling, but also on the reference DNA chosen. Therefore, close control of CGH experiments is mandatory, and additional techniques such as FISH should be performed to confirm the results obtained by CGH.     

TLR4 gene variants modify endotoxin effects on asthma

BACKGROUND: Environmental exposure to endotoxin might have a crucial role in immune maturation and development of asthma. OBJECTIVE: The aim of this study was to investigate whether the effect of endotoxin concentration in settled house dust on asthma is modified by the presence of variation in the TLR4 gene. METHODS: We performed a cross-sectional study within the German follow-up of the European Community Respiratory Health Survey. Multivariate logistic regression analysis and nonparametric effect estimates (S-Plus) were applied to examine the association between endotoxin exposure and diagnosed asthma, related clinical symptoms, and bronchial hyperreactivity (BHR) stratified for noncarriers and carriers of G299/I399 polymorphism in the TLR4 gene. RESULTS: In the noncarrier group (n = 279), the prevalence of asthma was significantly increased with elevated endotoxin levels in house dust with adjusted odds ratio 6.24 (95% CI, 1.33-29.17) in the second tertile, and 4.54 (95% CI, 0.94-21.96) in the third tertile compared with the lowest endotoxin tertile. The carriers of the polymorphisms (n = 55) showed a nonsignificant trend to have a lower risk of asthma (crude odds ratio, 0.67; 95% CI, 0.06-8.06 for the second tertile and 1.33; 95% CI, 0.17-10.58 for the third tertile). We found a similar association for wheeze and endotoxin exposure that was also attenuated in subjects with G299/I399 polymorphisms. CONCLUSIONS: The G299/I399 polymorphisms were associated with a modified response to endotoxin, but the functional relationship still needs clarification.     

Zur histogenese und cytogenese des tapetum lucidum cellulosum der katze

Zusammenfassung Die postnatale Entwicklung des Tapetum lucidum cellulosum der Katze wird mit licht- und elektronenmikroskopischen Methoden untersucht. Bereits am ersten postnatalen Tag sind im Bereich des prospektiven Tapetum zwei Zellarten voneinander zu unterscheiden: 1. mesenchymale Bindegewebszellen und 2. prospektive Tapetumzellen, die durch elektronendichte Tapetumstäbchen gekennzeichnet sind. Die Mesenchymzellen unterteilen als parallel zur Retinaoberfläche ausgebreitete Zellplatten in der Choriodea am hinteren Augenpol den weiten extracellulären Raum in 20–25 etwa 5 m hohe Schichten. Die Tapetumzellen liegen zwischen den Mesenchymzellplatten und wachsen im Verlaufe der ersten vier postnatalen Wochen innerhalb der Schichten in die Breite, bis sie den extracellulären Raum vollständig ausfüllen und als polygonale Zellen direkt aneinander grenzen. Im weiteren Verlauf der Entwicklung werden die Mesenchymzellplatten rückgebildet, so daß bei der adulten Katze die Tapetumzellschichten direkt übereinander liegen und nur von Netzen elastischer und kollagener Fasern getrennt sind.Die von einer Elementarmembran umgebenen Tapetumstäbchen enthalten einen elektronendichten, in den ersten postnatalen Wochen mit einer Periode von 100 Å quergestreiften Kern. Zunächst nehmen sie an Zahl und Länge zu und füllen am Ende der vierten postnatalen Woche, zu Bündeln von parallel verlaufenden Stäbchen geordnet, das Cytoplasma der Tapetumzellen. Dann nehmen die Tapetumstäbchen an Dicke zu, und ihre Querstreifung wird von einem elektronendichten Material überlagert. Die Entwicklung der Tapetumstäbchen hat eine starke Ähnlichkeit mit der in der Literatur beschriebenen Entwicklung von Melanosomen in Melanocyten. Das Tapetum lucidum cellulosum wird als ein dichter Verband hochdifferenzierter extrakutaner Melanocyten angesehen.

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Summary The postnatal development of the tapetum lucidum cellulosum of the cat was studied by light and electron microscopy. Already by the first postnatal day two cell types can be distinguished in the prospective tapeta area: 1. mesenchymal cells and 2. prospective tapetal cells, characterized by electron dense, membrane bound, rod-like inclusions. The flattened mesenchymal elements form 20–25 separate layers of cells, which are arranged parallel to the surface of the retina, subdividing the extracellular space of the chorioidea at the posterior pole of the eye into 5 m high compartments. These compartments contain the tapetal cells which enlarge (in their longitudinal axis) during the first four weeks post partum until they occupy the extracellular space almost completely. At this stage, the tapetal cells are polygonal in shape and closely attached to each other. During the subsequent period of development there is a gradual involution of the mesenchymal cell plates. Thus, in adult cats the individual layers of tapetal cells are only separated from each other by networks of collagen and elastic fibers.The tapetal rods are bound by unit membranes and contain an electron dense core which, during the early postnatal weeks, exhibits a periodic cross-striation (100 Å). The tapetal rods increase in number and length during the first four weeks post partum; by the end of the fourth week, they occupy the whole cytoplasm of the tapetal cells. Parallelly arranged rods are grouped into individual bundles coursing inside the cytoplasm in different directions. Thereafter, the tapetal rods increase in thickness and their cross-striation becomes obscured by an electron dense material. This development of the tapetal rods closely resembles that of melanosomes.Thus the tapetum lucidum cellulosum can be regarded as a compact tissue made up of modified extracutaneous melanocytes.

Auszugsweise vorgetragen auf der 69. Versammlung der Anatomischen Gesellschaft in Kiel, Juni 1974.     

Untersuchungen zum Problem der Mumpsimmunität

Ohne Zusammenfassung     

Induction of rat acute-phase proteins by interleukin 6 in vivo

Recombinant human interleukin 6 (rhIL 6) was injected i.p. into male Wistar rats to investigate its role as a mediator of the acute-phase response. Hepatic mRNA levels of beta-fibrinogen, alpha 2-macroglobulin, cysteine proteinase inhibitor, alpha 1-acid glycoprotein and albumin were measured at different times after the administration of rhIL 6. Maximal increases of mRNA concentrations were observed already 4 h after the injection of rhIL 6 leading to 4.8-, 19.7-, 10- and 16-fold stimulations in mRNA levels of beta-fibrinogen, alpha 2-macroglobulin, cysteine proteinase inhibitor or alpha 1-acid glycoprotein, respectively. The rhIL 6-induced stimulation of acute-phase protein mRNA was much more rapid than the acute-phase induction after turpentine, where maximal mRNA levels were found between 16 and 24 h. For all acute-phase proteins studied, the stimulation of mRNA synthesis was found to be dependent on the dose of rhIL 6 injected. In the case of alpha 2-macroglobulin mRNA a sex-specific induction by rhIL 6 was found. Only male rats showed an acute-phase response, whereas in female rats an acute-phase reaction of alpha 2-macroglobulin mRNA was not inducible by IL 6. The increases in mRNA levels of the acute-phase proteins studied were followed by corresponding changes of the proteins in the serum determined by rocket immunoelectrophoresis. It is concluded that IL 6 represents a potent mediator of the acute-phase response in the rat.