Humoral anti-idiotypic and anti-anti-idiotypic immune response in cancer patients treated with monoclonal antibody 17-1A

 A group of 96 patients with advanced colorectal carcinoma were treated with the mouse (m) or chimeric (c) (mouse variable regions × human IgG1 constant regions) monoclonal antibody (mAb) 17-1A recognizing the tumour-associated antigen GA733-2. Eighty-two of the 83 patients treated with mmAb17-1A and 69% of the patients given cmAb17-1A (n = 13) developed anti-idiotypic antibodies (ab₂). Auto-antibodies binding to tumour cells expressing GA733-2 were found in 7% of the patients. In a further 38 patients (40%) antitumour-cell antibodies, i.e. anti-anti-idiotypic antibodies (ab₃), were induced by the mAb17-1A therapy. Patients with detectable ab₃ after treatment had significantly higher ab₂ levels than those not developing ab₃. Addition of granulocyte/macrophage-colony-stimulating factor (GM-CSF) to mmAb17-1A significantly enhanced the induction of ab₂ as well as induction of anti-anti-idiotypic antibodies (ab₃), compared to mmAb17-1A alone. Patients with a high increase in antitumour-cell antibodies (ab₃) induced by the therapy lived significantly longer than patients with no or a low level of induction of ab₃ (P = 0.016). The results indicate that induction of an idiotypic network response might be an important effector mechanism in mAb therapy. Received: 20 October 1995 / Accepted: 18 December 1995     

Bau und Innervation der Lorenzinischen Ampullen und deren Bedeutung als niederes Sinnesorgan

Zusammenfassung An Serienschnitten, die nach Bodian-Ziesmer silberimprägniert sind, wurden die Lorenzinischen Ampullen von Scyllium canicula und Mustelus laevis nach Darstellung in plastischer Rekonstruktion und Berichtigung des bisher ungenau geschilderten Baues auf die Form ihrer Nervenausbreitungen untersucht.Die Ampullen, welche nach elektrophysiologischen Untersuchungen durch Hensel als Kälterezeptoren ähnlich denen der Warmblüter gelten, sind an ihren Endaussackungen reich innerviert. Nahe dem Epithel überzieht ein feinmaschiges Flächennetz mit intraepithelialen Ausläufern jede der sackförmigen Ausbuchtungen. Die Anordnung der Nervenelemente wird mit jenen verglichen, die man an kälteempfindlichen Stellen beim höheren Tier und beim Menschen beobachtet. Eine Faserspezifität (im Sinne der Physiologie) räumen die Untersucher ein; eine Spezifität peripherischer Nervenausbreitungsformen, also der intraepithelialen Fasern, der Netzformationen und der Nervenkörperchen bestreiten sie erneut.Herrn Prof. Dr. W. Kindler zum 65. Geburtstag gewidmet.     

Gelation of xanthan with trivalent metal ions

In-situ gelation of semidilute xanthan solutions with trivalent chromium, aluminum or iron ions was studied by rheology and UV-spectroscopy. Measurements of the elastic modulus of xanthan gel cylinders prepared by dialysis against the complexing ion at pH values from 2 to 6 indicate that monomeric species of the ion are ineffective, whereas dimeric or higher oligomeric species are effective in crosslinking the polysaccharide. When chromium was used as the crosslinking species, the dependence of the gelation rate on the ionic concentration followed a power law with a coefficient of 1·7. The gelation time and the gelation rate were found to extrapolate to zero at 1 m Cr for 2·5 mg/ml xanthan. The limiting concentration of xanthan needed for gelation with 5 m Cr(III) at 20°C was estimated as 0·35 mg/ml. This critical xanthan concentration is close to the overlap concentration c^* estimated from the experimentally determined intrinsic viscosity [η] using c^* = 1·4/[η]. An apparent activation energy for crosslinking of xanthan was calculated as E_a = 42 kJ/mol and E_a = 108 kJ/mol for Cr and Al ions, respectively. The fractal dimensionality of xanthan-Cr at the sol-gel transition was estimated as 1·3 applying the Chambon-Winter criterion for gelation, thus indicating that this gelation criterion is applicable also to stiff-chain polysaccharides such as xanthan.     

Le Crocodilien Diplocynodon (Eusuchia,Alligatoridae) dans la«série du gypse d'Aix à Venelles (Bouches-du-Rhône,France)

A crocodilian skeleton from the «série du gypse d'Aix (basal Aquitanian) at Venelles (Bouches-du-Rhône) is described and referred to Diplocynodon cf. rateli. The specimen seems to have been mutilated by scavengers before burial. The occurrence of the freshwater crocodilian Diplocynodon in the «série du gypse d'Aix is in agreement with recent reconstructions of the depositional environment, which suggest a basin with a fluctuating, but usually low, salinity.     

Spore ultrastructure in Sporothrix schenckii

Pathogenic strains of Sporothrix schenkii may show triangular spores, whose angular shape is maintained by a tiebeam effect in the inner cell wall structure. This difference in wall structure lies adjacent to a folded and possibly more active part of the spore cytoplasm. The supposed generation of asci in old cultures was simulated by the death of hyphae which are reinvaded by intrahyphal growth with intrahyphal spore production, while true asci were not seen.     

The role of displacement of the mitral annulus in left atrial filling and emptying in the intact dog

The variations in ventricular-atrial mitral annular position during the cardiac cycle and the simultaneous changes in left atrial silhouette area (obtained by angiography after injections of contrast material into the main pulmonary artery) were investigated in six experiments on intact dogs with chronically implanted intracardiac markers. Frame-by-frame measurements of the angiograms (120 frames/s) were used to determine, under various hemodynamic conditions, the duration, magnitude, and average rate of the mitral annular motion and of the simultaneous changes in left atrial area during atrial filling (ventricular systole) and atrial emptying (early in ventricular diastole). The mitral annulus was seen to move towards the ventricular apex during systole and towards the atrium early in diastole with the duration, average rate, and magnitude of displacement (although varying widely) showing good statistical correlations (P less than 0.0005-0.005) with the changes in projected left atrial area. These findings suggest that the duration, rate, and magnitude of atrial filling and emptying may be, in the intact heart, determined by the movements of the atrioventricular junction.     

Ants impact the composition of the aquatic macroinvertebrate communities of a myrmecophytic tank bromeliad

In an inundated Mexican forest, 89 out of 92 myrmecophytic tank bromeliads (Aechmea bracteata) housed an associated ant colony: 13 sheltered Azteca serica, 43 Dolichoderus bispinosus, and 33 Neoponera villosa. Ant presence has a positive impact on the diversity of the aquatic macroinvertebrate communities (n = 30 bromeliads studied). A Principal Component Analysis (PCA) showed that the presence and the species of ant are not correlated to bromeliad size, quantity of water, number of wells, filtered organic matter or incident radiation. The PCA and a generalized linear model showed that the presence of Azteca serica differed from the presence of the other two ant species or no ants in its effects on the aquatic invertebrate community (more predators). Therefore, both ant presence and species of ant affect the composition of the aquatic macroinvertebrate communities in the tanks of A. bracteata, likely due to ant deposition of feces and other waste in these tanks.