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61.
Navigation, the ability to reach desired goal locations, is critical for animals and humans. Animal navigation has been studied extensively in birds, insects, and some marine vertebrates and invertebrates, yet we are still far from elucidating the underlying mechanisms in other taxonomic groups, especially mammals. Here we report a systematic study of the mechanisms of long-range mammalian navigation. High-resolution global positioning system tracking of bats was conducted here, which revealed high, fast, and very straight commuting flights of Egyptian fruit bats (Rousettus aegyptiacus) from their cave to remote fruit trees. Bats returned to the same individual trees night after night. When displaced 44 km south, bats homed directly to one of two goal locations--familiar fruit tree or cave--ruling out beaconing, route-following, or path-integration mechanisms. Bats released 84 km south, within a deep natural crater, were initially disoriented (but eventually left the crater toward the home direction and homed successfully), whereas bats released at the crater-edge top homed directly, suggesting navigation guided primarily by distal visual landmarks. Taken together, these results provide evidence for a large-scale "cognitive map" that enables navigation of a mammal within its visually familiar area, and they also demonstrate the ability to home back when translocated outside the visually familiar area.  相似文献   
62.
Mutations in the IL-2-inducible T-cell kinase gene have recently been shown to cause an autosomal recessive fatal Epstein Barr virus (EBV) associated lymphoproliferation. We report 3 cases from a single family who presented with EBV-positive B-cell proliferation diagnosed as Hodgkin's lymphoma. Single nucleotide polymorphism array-based genome-wide linkage analysis revealed IL-2-inducible T-cell kinase as a candidate gene for this disorder. All 3 patients harbored the same novel homozygous nonsense mutation C1764G which causes a premature stop-codon in the kinase domain. All cases were initially treated with chemotherapy. One patient remains in durable remission, the second patient subsequently developed severe hemophagocytic lymphohistiocytosis with multi-organ failure and died, and the third patient underwent a successful allogeneic bone marrow transplantation. IL-2-inducible T-cell kinase deficiency underlies a new primary immune deficiency which may account for part of the spectrum of Epstein Barr virus related lymphoproliferative disorders which can be successfully corrected by bone marrow transplantation.  相似文献   
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64.

Objective

The aim of the present study was to compare the outcomes of conservative versus surgical treatment for acute appendicitis.

Background

Although acute appendicitis is a common disease, great debate exists regarding the appropriate management of patients. Conservative treatment has shown positive results in several RCTs, eliciting questions about indications to surgery, therapeutic appropriateness and ethical conduct.

Methods

Data were prospectively collected; a Propensity Score-based matching method was implemented in order to reduce bias arising from characteristics of the patients; a proportion of patients (69 in total) were excluded to obtain two comparable groups of study (1a). Main outcomes of the study were: failure rate, in-hospital length of stay (at first admission and cumulative), post-discharge absence from work. Within the medical group, failure was defined as the necessity for appendectomy after conservative treatment, while it was identified with complications and negative appendectomy within the surgical group (Failure 1). In parallel, an additional definition of failure was proposed (Failure 2) and excluded negative appendectomy from the reasons for failure within the surgical group (5b).

Results

The failure rate for the conservative treatment resulted to be inferior, as compared to the surgical treatment (16.5 vs. 28.4%, OR 0.523 p = 0.019), considering negative appendectomy as a reason for failure. When excluding negative appendectomy from the definition of failure, medical and surgical treatment appeared to perform equally (failure rate: 16.5 vs. 18.3%, OR 1.014 p = 0.965). Patients managed conservatively showed to have a shorter length of stay at first admission than the patients who underwent appendectomy (3.11 vs. 4.11 days, β = ?0.628 days, p < 0.0001). A lower number of lost work days after discharge resulted from a conservative approach (6 vs. 14.64 days, β = ?8.7 days, p < 0.0001).

Conclusions

Considering each outcome as part of a wide-angle analysis, the conservative management of acute appendicitis resulted to be safe and effective in the selected group of patients. In terms of failure rate, the medical treatment resulted to perform as effectively as surgical treatment, if negative appendectomy was excluded from failure, or better, when negative appendectomy was included in the definition of failure. A diminished length of stay during the first admission and a reduced number of lost work days were evident with a conservative approach. The comparison between medical and surgical treatment for acute appendicitis requires a change in perspective, from a spare ‘effectiveness analysis’ to a more thorough ‘appropriateness analysis’: in the present study, the conservative treatment showed to address the clinical requirements in terms of therapeutic appropriateness. Although acute appendicitis is considered a ‘surgical disease’, increasing evidence supports the effectiveness and safety of a conservative approach for selected groups of patients.
  相似文献   
65.
Widespread osteoblastic metastases, as well as marked elevations of CA19-9 and carcino-embryonic antigen (CEA), are the initial manifestations of gastric signet ring cell carcinoma. CT Imaging revealed diffuse sclerotic metastases in the axial skeleton. It was only following gastric biopsy that the primary site of metastatic bone tumor was identified. Recent studies suggest that early diagnosis of cancer origin, including tumor molecular profiling, may dictate specific therapy, improve prognosis and increase patient survival rates.  相似文献   
66.
The Nuclear Age began in 1945 with testing in New Mexico, USA, and the subsequent bombings of Hiroshima and Nagasaki. Regardless of attempts to limit the development of nuclear weapons, the current world arsenal has reached the staggering dimensions and presents a significant concern for the biosphere and mankind. In an explosion of a nuclear weapon, over 400 radioactive isotopes are released into the biosphere, 40 of which pose potential dangers including iodine, cesium, alkaline earths, and actinides. The immediate health effects of nuclear explosions include thermal, mechanical, and acute radiation syndrome. Long-term effects include radioactive fallout, internal contamination, and long-term genotoxicity. The current controversial concern over depleted uranium’s somatic and genetic toxicity is still a subject of worldwide sustained research. The host of data generated in the past decades has demonstrated conflicting findings, with the most recent evidence showing that its genotoxicity is greater than previously considered. Of particular concern are the osteotropic properties of uranium isotopes due to their final retention in the crystals of exchangeable and nonexchangeable bone as well as their proximity to pluripotent stem cells. Depleted uranium remains an unresolved issue in both warfare and the search for alternative energy sources.  相似文献   
67.
Infectious agents including viruses are important abortifacients and can cause fetal abnormalities in livestock animals. Here, samples that had been collected in Israel from aborted or malformed ruminant fetuses between 2015 and 2019 were investigated for the presence of the following viruses: the reoviruses bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), the flaviviruses bovine viral diarrhea virus (BVDV) and border disease virus (BDV), the peribunyaviruses Shuni virus (SHUV) and Akabane virus (AKAV), bovine herpesvirus type 1 (BoHV-1) and bovine ephemeral fever virus (BEFV). Domestic (cattle, sheep, goat) and wild/zoo ruminants were included in the study. The presence of viral nucleic acid or antigen could be confirmed in 21.8 % of abnormal pregnancies (213 out of 976 investigated cases), with peribunyaviruses, reoviruses and pestiviruses being the most prevalent. At least four different BTV serotypes were involved in abnormal courses of pregnancy in Israel. The subtyping of pestiviruses revealed the presence of two BDV and several distinct BVDV type 1 strains. The peribunyaviruses AKAV and SHUV were identified annually throughout the study period, however, variation in the extent of virus circulation could be observed between the years. In 2018, AKAV even represented the most detected pathogen in cases of small domestic ruminant gestation abnormalities. In conclusion, it was shown that various viruses are involved in abnormal courses of pregnancy in ruminants in Israel.  相似文献   
68.
69.
Tobacco control must remain a critical global health priority given the growing burden of tobacco-induced disease in the developing world. Insights from the emerging field of global health delivery suggest that tobacco control could be improved through a systematic, granular analysis of the processes through which it is promoted, implemented, and combated. Using this framework, a critical bottleneck to the delivery of proven health promotion emerges in the role that the tobacco industry plays in promoting tobacco use and blocking effective tobacco-control policies. This "corporate bottleneck" can also be understood as a root cause of massive disease and suffering upon vulnerable populations worldwide, for the goal of maximizing corporate profit. Naming, understanding, and responding to this corporate bottleneck is crucial to the success of tobacco-control policies. Three case studies of tobacco-control policy--South Africa, the Framework Convention on Tobacco Control, and Uruguay--are presented to explore and understand the implications of this analysis.  相似文献   
70.
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