Learning: Neural analysis in the isolated brain of a previously trained mollusc,Pleurobranchaea californica

The neural manifestations of food avoidance learning in the mollusc, Pleurobranchaea, survive the surgical reduction of the preparation to the nearly isolated brain. These manifestations include increased synaptic inhibition and reduced synaptic excitation of the phasic paracerebral feeding command interneurons (PCps) in the brain in response to food stimulation of chemosensory structures left attached to the brain. The same changes are not evident, however, in brains removed from naive, control or satiated specimens. Therefore the nearly isolated brain preparation permits analysis of the cellular substrates of learning in relative isolation from non-associative motivational variables. The isolated brain preparation is here used to show that the increased synaptic inhibition consequent to associative training is distributed not only to the PCps but also to their identified central presynaptic inputs, including other identified feeding command interneurons (PSEs and ETIIs; ref. 21). The decrease in PCp excitation is explained in part by a training-induced inhibition of excitatory inputs to the PCps, and in part by a training-induced reduction in the efficacy of an identified polysynaptic excitatory pathway presynaptic to the PCps.     

Double antibody radioimmunoassay for monitoring metastatic breast cancer

We previously reported the production of a panel of murine monoclonal antibodies which recognize glycoproteins abnormally expressed in human breast tumours. Using two of these antibodies, a double antibody radioimmunoassay was designed to quantify levels of these breast tumour marker glycoproteins in serum. Marker levels greater than 28 units were considered abnormal. Using this criterion, 63% and 75% of patients with breast cancer stages I and II, respectively, and 88% of those with metastatic disease were found to have elevated marker levels. Thirteen percent of patients with non-malignant breast disease also had elevated marker levels. Elevated marker levels were also detected in patients with non breast neoplasms. One hundred and eleven women with metastatic disease were followed. Eighty-two percent of those with progressive disease and 73% of those where disease regressed had 20% changes in marker levels. These changes in marker levels preceded by up to 6 months changes in disease state. From these results we conclude that this assay may be useful for monitoring the course of disease in breast cancer patients.     

Wirkung von hochdosiertem Vitamin A auf das Keimepithel der Ratte

Andrologische Untersuchungen vor, während und nach Behandlung mit hochdosiertem Vitamin A, zeigten bei 15 Patienten keinen signifikanten Einfluß auf die Zusammensetzung des Ejakulates. Diese Untersuchungen waren Anlaß zu einem tierexperimentellen Modellversuch.
80 Wistar-Ratten wurden mit verschieden hohen Dosen Vitamin A durch 4 Wochen behandelt. Ein Großteil der Tiere verstarb unter toxischen Symptomen noch vor Ende der 4. Woche und zeigte eine progressive Schädigung des Keimepithels. Bei den überlebenden Tieren fanden sich histologisch die entfernten Hoden nur gering geschädigt, unabhängig von der verwendeten Dosis. Eine spezifische Schädigung des Keimepithels durch hochdosiertes Vitamin A konnte somit nicht festgestellt werden.     

The nature of the immune response (Ir) gene defect for pigeon cytochrome c in [B10.A(4R) x B10.PL]F1 mice: A Comparison Between Thymic Selection and Antigen Presentation

[B10.A(4R) x B10.PL]F₁ mice are low responders to pigeon cytochromec, while [B10.A(2R) x B10.PL]F₁ and B10.A mice are high responders.The in vivo site at which the different aliomorphs of the E_aIa molecule exert their Ir gene effect on the immune responseto pigeon cytochrome c was examined by creating two differentsets of radiation-induced bone marrow chimeras. [B10.A(4R) xB10.PL]F₁(b.m.) B10.A(lrr.) chimeras, which possess antigen-presentingcells (APC) of the low responder, but whose T cells are educatedin a high responder environment, were found to be low respondersto pigeon cytochromec. In contrast, B10.A(b.m.) [B10.A(4R)x B10.PL]F₁(lrr.) chimeras, which possess APC of the high respondertype, but whose T cells are educated in a low responder environment,responded to pigeon cytochrome c Addition of B10.A APC to thefirst type of chimera, both prior to antigen priming and atthe time of the secondary challenge in vitro, converted 50%of the animals to responders Furthermore, [B10.A(4R) x B10.PL]F₁mice responded to pigeon cytochrome c If they were primed witha 10-fold greater antigen dose and restimulated in vitro Inthe presence of B10.A APC. These results suggest that the primarysite of the Ir gene defect in this system is at the level ofantigen presentation and not in the T cell repertoire.     

Coronal renal ultrasound: II

Coronal renal imaging with ultrasound has a number of advantages over other routine scanning orientations in nephrosonography. In a series of 214 patients Coonal transverse, but especially longitudinal orientation was found to be superior to other scanning methods. The main advantages were: differentiation between renal cysts and hydronephrosis as well as demonstration of renal lithiasis. This approach also should be used to augment the diagnostic sequence of investigating renal masses.