Growth pattern of tumours in mice induced by murine Moloney sarcoma-virus and sarcoma-virus-transformed cells.

Transplantation of a Moloney sarcoma-virus (MSV-M)-transformed producer cell line (Sac(+)) induced progressively or regressively growing tumours in mice. Progressive growth always occurred after transplantation of an MSV-M non-producer transformant (Sac(-)), whereas the MSV-M released from the producer cells (Sac virus) always induced tumours which regressed. In contrast to the non-producer, the producer transformant Sac(+) as well as Sac virus induced a strong immune response, detected in vitro by cell- and antibody-mediated cytotoxicity assays, and in vivo by transplantation immunity. Implantation of Sac(-) cells led to solid, under-vascularized tumours, consisting histologically of uniform densely packed tumour cells. Sac-virus-induced tumours, however, were very well vascularized and arose by proliferation of different connective-tissue cells. After transplantation of Sac(+) cells, tumours were found to consist of typical tumour cells morphologically similar to Sac(-) cells intermingled with proliferated connective-tissue cells. Cultivation of tumour fragments from Sac(+) and Sac(-) tumours was followed by outgrowth of transformed tumour cells with the properties of the originally implanted cells. Tumour explant cultures from Sac-virus-induced tumours did not lead to growth of stably transformed cells. Co-culture of mouse embryo fibroblasts (MEF) with Sac(+) cells resulted in overgrowth of the transformed cells. Infection of MEF with Sac virus led to transiently transformed cells. It is concluded that Sac(+) cell tumours will resist the strong immune defence mechanisms they induce and grow progressively, if the inoculated cells are able to build up a solid, poorly vascularized nodule in the tissue. This always happens after implantation of 10(6) cells, but only occasionally when fewer cells are inoculated. Sac-virus-induced tumours will always regress owing to the strong immune response. The regression is furthered by the fact that MSV-M infection rarely if ever leads to a stable transformation

I can feel my heartbeat: Dancers have increased interoceptive accuracy

Interoception is the process of perceiving afferent signals arising from within the body including heart rate (HR), gastric signals, etc. and has been described as a mechanism crucially involved in the creation of self-awareness and selfhood. The heart beat perception task is a tool to measure individuals’ interoceptive accuracy (IAcc). IAcc correlates positively with measures of self-awareness and with attributes including emotional sensitivity, empathy, prosocial behavior, and efficient decision-making. IAcc is only moderate in the general population. Attempts to identify groups of people who might have higher IAcc due to their specific training (e.g., yoga, meditation) have not been successful. However, a recent study with musicians suggests that those trained in the arts might exhibit high IAcc. Therefore, we here tested IAcc in professional dancers. Twenty professional dancers and 20 female control participants performed 4 intervals of a heartbeat perception task while their actual HR was recorded. Dancers had a higher IAcc, and this effect was independent of their lower heart rates (a proxy measure of physical fitness), counting ability and knowledge about HR. An additional between-group analysis after a median split in the dancer group (based on ‘years of dance experience’) showed that junior dancers’ IAcc differed from controls, and senior dancers’ IAcc was higher than both junior dancers and controls. General art experience correlated positively with IAcc. No correlations were found between IAcc and questionnaire measures of empathy, emotional experience, and alexithymia. These findings are discussed in the context of current theories of interoception and emotion –highlighting the features of arts training that might be related to IAcc

Interoception and Autonomic Correlates during Social Interactions. Implications for Anorexia

The aim of this study is to investigate the bodily-self in Restrictive Anorexia, focusing on two basic aspects related to the bodily self: autonomic strategies in social behavior, in which others’ social desirability features, and social cues (e.g., gaze) are modulated, and interoception (i.e., the sensitivity to stimuli originating inside the body). Furthermore, since previous studies carried out on healthy individuals found that interoception seems to contribute to the autonomic regulation of social behavior, as measured by Respiratory Sinus Arrhythmia (RSA), we aimed to explore this link in anorexia patients, whose ability to perceive their bodily signal seems to be impaired. To this purpose, we compared a group of anorexia patients (ANg; restrictive type) with a group of Healthy Controls (HCg) for RSA responses during both a resting state and a social proxemics task, for their explicit judgments of comfort in social distances during a behavioral proxemics task, and for their Interoceptive Accuracy (IA). The results showed that ANg displayed significantly lower social disposition and a flattened autonomic reactivity during the proxemics task, irrespective of the presence of others’ socially desirable features or social cues. Moreover, unlike HCg, the autonomic arousal of ANg did not guide behavioral judgments of social distances. Finally, IA was strictly related to social disposition in both groups, but with opposite trends in ANg. We conclude that autonomic imbalance and its altered relationship with interoception might have a crucial role in anorexia disturbances