Earliest Palaeocene purgatoriids and the initial radiation of stem primates

Plesiadapiform mammals, as stem primates, are key to understanding the evolutionary and ecological origins of Pan-Primates and Euarchonta. The Purgatoriidae, as the geologically oldest and most primitive known plesiadapiforms and one of the oldest known placental groups, are also central to the evolutionary radiation of placentals and the Cretaceous-Palaeogene biotic recovery on land. Here, we report new dental fossils of Purgatorius from early Palaeocene (early Puercan) age deposits in northeastern Montana that represent the earliest dated occurrences of plesiadapiforms. We constrain the age of these earliest purgatoriids to magnetochron C29R and most likely to within 105–139 thousand years post-K/Pg boundary. Given the occurrence of at least two species, Purgatorius janisae and a new species, at the locality, we provide the strongest support to date that purgatoriids and, by extension, Pan-Primates, Euarchonta and Placentalia probably originated by the Late Cretaceous. Within 1 million years of their arrival in northeastern Montana, plesiadapiforms outstripped archaic ungulates in numerical abundance and dominated the arboreal omnivore–frugivore niche in mammalian local faunas.

Outcomes after reirradiation of spinal metastasis with stereotactic body radiation therapy (SBRT): a retrospective single institutional study

ABSTRACT This study was aimed at assessing the feasibility and toxicity of using stereotactic body radiation therapy (SBRT) for reirradiation of spinal metastatic tumors. We conducted a retrospective review, from our institutional database, of the data of patients who received reirradiation, with overlap of some prescribed isodose lines to the vertebra from the initial radiation therapy, between 2007 and 2019. We identified 40 patients with spinal metastatic tumors, of whom 2 had 2 metastatic vertebral lesions each, totaling up to 42 target lesions. The median dose to spinal cord at the initial radiation therapy was 30 Gy. SBRT based on the intensity-modulated radiation therapy (IMRT) technique was used for reirradiation to spare the spinal cord. All patients received a prescription dose of 25 Gy in 5 fractions to the planning target volume (PTV). Among the 40 cases who had pain, pain relief was obtained in 24 (60%) after reirradiation. Neurologic improvement was obtained in 8 of 15 cases (53%). The adverse events were evaluated using the Common Terminology Criteria for Adverse Events Version 5.0. Reirradiation was well-tolerated, with only 2 patients experiencing adverse events ≥grade 2 in severity, including 1 patient with grade 3 pain, and another patient with grade 3 spinal fracture. None of the patients developed radiation myelopathy. Our data demonstrated that reirradiation of spinal metastasis using SBRT provided effective pain relief and neurologic improvement, with minimal toxicity.

Risk Factors for Disease Progression and Prognosis Analysis in Pediatric Head and Neck Rhabdomyosarcoma Patients: a Historical Cohort Study From a Single Center

Background: The purposes of this study are to explore risk factors for disease progression during primary treatment, and to analyze disease prognosis of different event groups in a historical cohort of 56 pediatric patients with head and neck rhabdomyosarcoma.Methods: From June 1st, 2016 to June 30th, 2019, a historical cohort of 56 pediatric patients diagnosed as head and neck rhabdomyosarcoma was chosen. Clinical data were collected including general information about diagnosis, treatment, prognostic factors, and follow up results. Patients were divided into non-event group, disease-progression group and disease-relapse group according different types of events. Comparison among the three groups was made to reveal different clinical features and prognosis. Patients were further divided into disease-progression group and non-progression group to explore risk factors for disease progression, with univariate and multivariate analysis.Results: The median follow-up time of all 56 patients was 31.8 months (range 3.5-74.6 months). There were 30 non-event patients, 12 disease relapse patients, and 14 disease-progression patients. The estimated 5-year overall survival rates were 100.0%, 82.5%, and 11.9% for non-event, disease-relapse and disease-progression patients respectively (p<0.001). Compared with non-event patients, disease-progression patients had higher rates of tumor size>5cm (p=0.008) and non-initial radiation therapy (p=0.001). Compared with disease-relapse patients, disease-progression patients had a higher rate of tumor size>5cm (p=0.002), and higher ranks of surgical-pathologic group (p=0.009) and risk group (p<0.001). Compare with non-progression patients, univariate analysis demonstrated that tumor size>5cm, alveolar histology, non-initial radiation therapy, and higher ranks of surgical-pathologic group as well as risk group were statistically significant risk factors for disease progression. The multivariate analysis result showed tumor size>5cm (OR=6.75, 95%CIs 1.02-44.78), alveolar histology (OR=7.10, 95%CIs 1.08-46.57), and non-initial radiation therapy (OR=15.26, 95%CIs 2.38-97.70) to be independent risk factors for disease progression.Conclusions: Pediatric head and neck rhabdomyosarcoma patients with disease progression have significantly worse overall survival, and the prognosis is obviously different from patients with disease relapse and patients without events. Tumor size>5cm, alveolar histology and non-initial radiation therapy are independent risk factors for disease progression. Patients with disease progression tend to have higher ranks of surgical-pathologic group and risk group.

A paraphyletic ‘Silesauridae' as an alternative hypothesis for the initial radiation of ornithischian dinosaurs

Whereas ornithischian dinosaurs are well known from Jurassic and Cretaceous deposits, deciphering the origin and early evolution of the group remains one of the hardest challenges for palaeontologists. So far, there are no unequivocal records of ornithischians from Triassic beds. Here, we present an alternative evolutionary hypothesis that suggests consideration of traditional ‘silesaurids' as a group of low-diversity clades representing a stem group leading to core ornithischians (i.e. unambiguous ornithischians, such as Heterodontosaurus tucki ). This is particularly interesting because it fills most of the ghost lineages that emerge from the Triassic. Following the present hypothesis, the lineage that encompasses the Jurassic ornithischians evolved from ‘silesaurids' during the Middle to early Late Triassic, while typical ‘silesaurids' shared the land ecosystems with their relatives until the Late Triassic, when the group completely vanished. Therefore, Ornithischia changes from an obscure to a well-documented clade in the Triassic and is represented by records from Gondwana and Laurasia. Furthermore, according to the present hypothesis, Ornithischia was the first group of dinosaurs to adopt an omnivorous/herbivorous diet. However, this behaviour was achieved as a secondary step instead of an ancestral condition for ornithischians, as the earliest member of the clade is a faunivorous taxon. This pattern was subsequently followed by sauropodomorph dinosaurs. Indeed, the present scenario favours the independent acquisition of an herbivorous diet for ornithischians and sauropodomorphs during the Triassic, whereas the previous hypotheses suggested the independent acquisition for sauropodomorphs, ornithischians, and ‘silesaurids'.

Clinical and morphological substantiation of need for application narrow-wave ultraviolet therapy for improving the quality of treatment and duration of remission in patients with psoriasis

The goal is substantiating clinically and morphologi­cally the need for narrow-wave (311 nm) ultraviolet (UV) therapy to improve the quality of treatment and the du­ration of remission in patients with psoriasis. Materials and methods. Under observation were 134 patients with common psoriasis (82 men and 52 women aged 23 to 65 years). For UV therapy, the PSOROLIGHT 100-6 photo- therapeutic apparatus (medical equipment Viola Ukraine, Poltava) with a wavelength of 311 nm was used. Initial radiation doses were determined depending on the skin photo type. The standard course of treatment consisted of 15-20 procedures with a regimen 3-4 times a week. Results. In patients of group I, 2 times faster regression of the rash was observed, and in 54 (81.8%) patients of group I, the rash disappeared after 15-20 procedures, in 52 (78.8%) after 6-8 months, the skin process was stable , after a year in 41 (62.12%). In biopsy samples in 8 (88.9%) patients of group I, moderate acanthosis and hyperkeratosis were observed, there were no signs of parakeratosis in 7 (77.8%), the thickness of the horny layer was restored in 8 (88.9%) and granular layers of patients of the first group. Conclusions. All of the above gives reason to justify the need for narrow-wave ultravio­let therapy in patients with psoriasis to improve the qual­ity of treatment and the duration of remission in patients with psoriasis. Conclusions. All of the above gives reason to justify the need for narrow-wave ultraviolet therapy in patients with psoriasis to improve the quality of treatment and the duration of remission in patients with psoriasis.

Gnathovorax cabreirai: a new early dinosaur and the origin and initial radiation of predatory dinosaurs

Predatory dinosaurs were an important ecological component of terrestrial Mesozoic ecosystems. Though theropod dinosaurs carried this role during the Jurassic and Cretaceous Periods (and probably the post-Carnian portion of the Triassic), it is difficult to depict the Carnian scenario, due to the scarcity of fossils. Until now, knowledge on the earliest predatory dinosaurs mostly relies on herrerasaurids recorded in Carnian strata of South America. Phylogenetic investigations recovered the clade in different positions within Dinosauria, whereas fewer studies challenged its monophyly. Although herrerasaurid fossils are much better recorded in present-day Argentina than in Brazil, Argentinean strata so far yielded no fairly complete skeleton representing a single individual. Here, we describe Gnathovorax cabreirai, a new herrerasaurid based on an exquisite specimen found as part of a multitaxic association form southern Brazil. The type specimen comprises a complete and well-preserved articulated skeleton, preserved in close association (side by side) with rhynchosaur and cynodont remains. Given its superb state of preservation and completeness, the new specimen sheds light into poorly understood aspects of the herrerasaurid anatomy, including endocranial soft tissues. The specimen also reinforces the monophyletic status of the group, and provides clues on the ecomorphology of the early carnivorous dinosaurs. Indeed, an ecomorphological analysis employing dental traits indicates that herrerasaurids occupy a particular area in the morphospace of faunivorous dinosaurs, which partially overlaps the area occupied by post-Carnian theropods. This indicates that herrerasaurid dinosaurs preceded the ecological role that later would be occupied by large to medium-sized theropods.