Effect of high dose natural ionizing radiation on the immune system of the exposed residents of Ramsar Town, Iran

Iran is one of several countries that has regions of high dose natural ionizing radiation. Two well-known villages in the suburb of Ramsar Town in the Caspian Sea strip, Taleshmahaleh and Chaparsar, have background radiation that is 13 times higher than normal. This radiation is the result of Radium 226 and Radon gas both of which are highly water soluble. While people living in these regions do not suffer from any major health problems, we decided to study the their immune responses to infection and inflammation in order to determine if their habitat affects their immune defense mechanisms as a way of compensating for their exposure to high dose environmental ionizing radiation. Our results showed that the total serum antioxidant level in the exposed people was significantly lower than the individuals not exposed to high dose natural ionizing radiation. The exposed individuals also had higher lymphocyte-induced IL-4 and IL-10 production, and lower IL-2 and IFN-gamma production. In addition, neutrophil NBT, phagocytosis, and locomotion were higher in the exposed group. In contrast, lymphocyte proliferation in response to PHA was unaffected. We conclude that the immune system of individuals exposed to high dose ionizing radiation has adapted to its environment by shifting from a Type 1 to a Type 2 response to promote anti-inflammation. This may be because inflammatory Type 1 responses generate more free radicals than Type 2 responses, in addition to the free radicals generated as a result of high environmental radiation. Thus, the serum total antioxidant level in the exposed residents was lower than the unexposed group.     

Grafting posterior tibial nerve with ipsilateral sural nerve cables in leg replantation--a common sense approach

In a leg replantation requiring grafting of the posterior tibial nerve, the benefits of utilization of the ipsilateral sural nerve are shown. Sparing the other leg for obtaining nerve graft and using the incision to harvest the sural nerve for achieving fasciotomies minimizes the therapy trauma and helps to accomplish early rehabilitation. The simplicity and effectiveness of the procedure are discussed in context with peripheral nerve reconstructions requiring nerve grafts.     

Activin A promotes multiple myeloma-induced osteolysis and is a promising target for myeloma bone disease

Understanding the pathogenesis of cancer-related bone disease is crucial to the discovery of new therapies. Here we identify activin A, a TGF-β family member, as a therapeutically amenable target exploited by multiple myeloma (MM) to alter its microenvironmental niche favoring osteolysis. Increased bone marrow plasma activin A levels were found in MM patients with osteolytic disease. MM cell engagement of marrow stromal cells enhanced activin A secretion via adhesion-mediated JNK activation. Activin A, in turn, inhibited osteoblast differentiation via SMAD2-dependent distal-less homeobox–5 down-regulation. Targeting activin A by a soluble decoy receptor reversed osteoblast inhibition, ameliorated MM bone disease, and inhibited tumor growth in an in vivo humanized MM model, setting the stage for testing in human clinical trials.     

Examining the consumption of radical content on YouTube

Although it is under-studied relative to other social media platforms, YouTube is arguably the largest and most engaging online media consumption platform in the world. Recently, YouTube’s scale has fueled concerns that YouTube users are being radicalized via a combination of biased recommendations and ostensibly apolitical “anti-woke” channels, both of which have been claimed to direct attention to radical political content. Here we test this hypothesis using a representative panel of more than 300,000 Americans and their individual-level browsing behavior, on and off YouTube, from January 2016 through December 2019. Using a labeled set of political news channels, we find that news consumption on YouTube is dominated by mainstream and largely centrist sources. Consumers of far-right content, while more engaged than average, represent a small and stable percentage of news consumers. However, consumption of “anti-woke” content, defined in terms of its opposition to progressive intellectual and political agendas, grew steadily in popularity and is correlated with consumption of far-right content off-platform. We find no evidence that engagement with far-right content is caused by YouTube recommendations systematically, nor do we find clear evidence that anti-woke channels serve as a gateway to the far right. Rather, consumption of political content on YouTube appears to reflect individual preferences that extend across the web as a whole.

As affective political polarization rises in the United States (1) and trust in traditional sources of authority declines (2, 3), concerns have arisen regarding the presence, prevalence, and impact of false, hyperpartisan, or conspiratorial content on social media platforms. Most research on the potentially polarizing and misleading effects of social media has focused on Facebook and Twitter (4–12), reflecting a common view that these platforms are the most “news-oriented” social media platforms. However, roughly 23 million Americans rely on YouTube as a source of news (13, 14), a number comparable to the corresponding Twitter audience (13, 15), and it is growing in both size and engagement. YouTube news content spans the political spectrum, and includes content producers of all sizes. Recent work (16) has identified a large number of YouTube channels, mostly operated by individuals or small organizations, that promote a collection of “far-right” ideologies (e.g., white identitarian) and conspiracy theories (e.g., QAnon). The popularity of some of these channels, along with salient popular anecdotes, has prompted claims that YouTube’s recommendation engine systematically drives users to this content, and effectively radicalizes its users (17–20). For example, it has been reported that, starting from factual videos about the flu vaccine, the recommender system can lead users to antivaccination conspiracy videos (18).Recent qualitative work (21) has identified a separate collection of channels labeled variously as “reactionary,” “anti-woke” (AW), “anti-social justice warriors” (ASJW), “intellectual dark web” (IDW), or simply “antiestablishment.” Although these channels do not identify themselves as politically conservative, and often position themselves as nonideological or even liberal “free thinkers,” in practice, their positions are largely defined in opposition to progressive social justice movements, especially those concerning identity and race, as well as critiquing institutions such as academia and mainstream media for their “left-wing bias” (21, 22). Concurrently, “anti-woke” rhetoric has increasingly been adopted by mainstream Republican politicians (23), undermining claims that it is intrinsically apolitical. While anti-woke YouTube channels typically do not explicitly endorse far-right ideologies, some channel owners invite guests who are affiliated with the far right onto their shows and allow them to air their views relatively unchallenged, thereby effectively broadcasting and legitimizing far-right ideologies (21). If these channels act as a kind of gateway to the far right, they would constitute a related yet distinct radicalization mechanism from the recommendation system per se (17, 24). Based on these considerations, and recognizing that any label for this loose collection of channels is likely to be inaccurate for at least some members, we refer to them hereafter as anti-woke (AW).Although reports of various mechanisms driving people to politically radical content have received great attention, quantitative evidence to support them has proven elusive. On a platform with almost 2 billion users (25), it is possible to find examples of almost any type of behavior; hence anecdotes of radicalized individuals (17), however vivid, do not, on their own, indicate systematic problems. Thus, the observation that a particular mechanism (e.g., recommendation systems steering users to extreme content; far-right personalities appearing on anti-woke channels acting as gateways to the far right) might plausibly have a large and measurable effect on audiences does not substitute for measuring the effect. Finally, the few empirical studies (24, 26–29) that have examined the question of YouTube radicalization have reached conflicting conclusions, with some finding evidence for it (24, 26) and others finding the opposite (27, 28). These disagreements may arise from methodological differences that make results difficult to fairly compare—for example, ref. 28 examines potential biases in the recommender by simulating logged-out users, whereas ref. 24 reconstructs user histories from scraped comments. The disagreement may also reflect limitations in the available data, which is intrinsically ill suited to measuring either individual or aggregate consumption of different types of content over extended time intervals, such as user sessions or “lifetimes.” Absent such data for a large, representative sample of real YouTube users, it is difficult to evaluate how much far-right content is, in fact, being consumed (vs. produced), how it is changing over time, and to what extent it is being driven by YouTube’s own recommendations, spillovers from anti-woke channels, or other entry points.Here we investigate the consumption of radical political news content on YouTube using a unique dataset comprising a large (N=309,813) representative sample of the US population, and their online browsing histories, both on and off the YouTube platform, spanning 4 years from January 2016 to December 2019. To summarize, we present five main findings. 1) Consistent with previous estimates (30), we find that the total consumption of any news-related content on YouTube accounts for 11% of overall consumption and is dominated by mainstream, and generally centrist or left-leaning, sources. 2) The consumption of far-right content is small in terms of both number of viewers and total watch time, where the former decreased slightly and the latter increased slightly over the observation period. 3) In contrast, the consumption of anti-woke content, while also small relative to mainstream or left-leaning content, grew in both numbers of users and total watch time. 4) The pathways by which users reach far-right videos are diverse, and only a fraction can plausibly be attributed to platform recommendations. Within sessions of consecutive video viewership, we find no trend toward more extreme content, either left or right, indicating that consumption of this content is determined more by user preferences than by recommendation. 5) Consumers of anti-woke, right, and far-right content also consume a meaningful amount of far-right content elsewhere online, indicating that, rather than the platform (either the recommendation engine or consumption of anti-woke content) pushing them toward far-right content, it is a complement to their larger news diet.These results indicate little evidence for the popular claim that YouTube drives users to consume more radical political content, either left or right. Instead, we find strong evidence that, while somewhat unique with its growing and dedicated anti-woke channels, YouTube should otherwise be viewed as part of a larger information ecosystem in which conspiracy theories, misinformation, and hyperpartisan content are widely available, easily discovered, and actively sought out (27, 31).     

Is xenotransplantation of embryonic stem cells a realistic option?

To test the purported immune privilege of embryonic stem cells (ESC) in the challenging setting of xenotransplantation, 14 immunocompetent baboons were subjected to a coronary artery occlusion-reperfusion sequence and, two weeks later, randomized to receive in-scar injections of culture medium or cardiac-committed mouse ESC engineered to express fluorescent reporter genes driven by cardiac-specific promoters. Two months after transplantation, left ventricular function, as assessed by echocardiography, deteriorated to a similar extent in control and treated baboons. This correlated with failure to identify the grafted cells by X-gal histology and immunofluorescence. Rejection did not seem to be mediated by xenoantibodies, but rather by T lymphocytes and natural killer cells as suggested by positive immunostaining for CD3 and CD56 early after transplantation. There was no increase in circulating levels of regulatory T cells. These data raise a cautionary note about the immune privilege of ESC and suggest that from a mere immunologic standpoint, ESC xenotransplantation is likely to be an unrealistic challenge.     

Cystic meningioma. Case report and literature review

BACKGROUND: Cystic meningioma is a rare variety of meningioma. It represents 1,6 to 10% of intracranial meningiomas, the authors report a case of intracranial cystic meningioma with a review of literature. CASE REPORT: A 46-year-old female presented with left parietooccipital headache followed by right side hemiparesis. CT scan brain showed a left parietal tumor with double solid and cystic components thought to be glioma or metastasis preoperatively. At surgery the extraaxial solid and cystic lesion had a well defined capsule that could be easily separated from the perilesional cortical surface. The tumor was totally removed. The histological study showed a cystic meningioma. CONCLUSION: Cystic meningioma is an uncommon tumor that should be considered in the differential diagnosis of brain tumors with a cystic component.