Primitive Appearance Research Articles

Molecular Docking of Fisetin as a Multi-target drug in the treatment of Alzheimer’s disease

Alzheimer’s disease is a slow deadly form of dementia occurring in almost 70% of the older generation. Throughout the world, there are approximately 47 million people affected. Countries that are mostly affected by Alzheimer’s disease with the highest are Turkey and Lebanon by 57% and 56% respectively. The lowest rates include India, Cambodia, Georgia, and Singapore. This includes symptoms such as disorientation, mood swings, behavioral issues, etc. ultimately leading to death. The primitive appearance of the alpha-beta plaques and neurofibrillary tangles in the different regions of the brain leads to the cause of AD progression. In this present study, Fisetin which is a plant flavonoid having neurotropic and neuroprotective properties is docked with the drug targets of Alzheimer’s disease. The study was focused on analysing the molecular interaction of Fisetin with potential drug targets of Alzheimer’s disease. The docking was performed using AutoDock 4.2. The minimum binding energy studies explain the efficiency of the ligand binding with the therapeutic target proteins. Proteins play a significant role in Alzheimer’s disease as it is responsible for various functions which also are the major attributes of Alzheimer's disease namely amyloid-β production, tau phosphorylation, synaptic function, neurogenesis, and memory which all are influenced by dysregulation of this enzyme. Four proteins were selected based on the action and function they play in the progression of Alzheimer’s disease namely FYN tyrosine kinase, Beta Secretase (BACE 1), Gamma secretase, and Glycogen synthase kinase 3-beta (GSK3-β). The minimum binding energy scores for the following 3D molecular structures were FYN tyrosine kinase = -8.2 kcal/mol, BACE1= -10.67kcal/mol, Gamma secretase = - 10.03kcal/mol, GSK3 Beta = -10.47kcal/mol; No. of hydrogen bonds: 12, 10, 10 and 21 respectively. From the 4 potential Alzheimer’s drug targets, Glycogen synthase kinase 3-beta (GSK3-β) and Beta Secretase, had the best interaction with Fisetin with the lowest binding energy. Along with this Fisetin was analyzed for its molecular properties, drug-likeness, biological activity, and toxicity using the Way2drug bio tool.

3D reconstruction of the bronchial tree of the Gray short-tailed opossum (Monodelphis domestica) in the postnatal period.

Recent didelphid marsupials resemble the assumed mammalian ancestor and are suitable to inform on the evolution of the mammalian lung. This study uses X-ray computed tomography (μCT) to three-dimensionally reconstruct the bronchial tree of the marsupial Gray short-tailed opossum (Monodelphis domestica) in order to reveal the timeline of morphogenesis during the postnatal period. The development of the bronchial tree was examined in 37 animals from embryonic day 13, during the postnatal period (neonate to 57 days) and in adults. The first appearance and the branching of lobar, segmental and sub-segmental bronchioles in the lungs were documented. Based on the reconstructions, the generation of end-branching airways, the median and maximum generation and the number of branches were calculated for each pulmonary lobe. At birth, the lung of M. domestica has a primitive appearance since it consists of a simple system of branching airways that end in a number of terminal air spaces, lobar bronchioles, and first segmental bronchioles are present. During the postnatal period, the volumes of the lung and bronchial tree steadily increase and development, differentiation, and expansion of the bronchial tree takes place. By 14 days, the fundamental bronchial tree consisting of lobar, segmental, and sub-segmental bronchioles has been established. A mature bronchial tree, including respiratory bronchioles and alveolar ducts is present by day 35. The asymmetry of the right (predominately four lobes) and the left lung (predominately two lobes), as present in M. domestica, can be considered as plesiomorphic for Mammalia. In marsupials, the process of branching morphogenesis, which takes place intrauterine in the placental fetus, is shifted to the postnatal period, but follows similar patterns as described in placentals. Lung maturation in general and the branching morphogenesis in particular seems to be highly conservative within mammalian evolution.

Infective endocarditis with systemic bacterial embolism caused by Staphylococcus aureus in a free-ranging Amami rabbit (Pentalagus furnessi)

The Amami rabbit (Pentalagus furnessi) is found only on the two islands of Amami-Ōshima and Tokunoshima in southwest Japan. It has a primitive appearance and ecology, is an evolutionarily valuable animal and has been assigned to the International Union for Conservation of Nature Red List of Threatened Species. We describe a case with mild purulent wounds on the distal digital skin of both forelimbs and multiple nodular lesions in various organs, including the heart and kidney. Microscopically, the heart lesions were characterized by disruption of the mitral valve and multifocal myocardial necrosis and abscesses due to infection with gram-positive cocci. Similar bacterial infarctions were also found in other organs, including the kidneys. The bacteria were identified as Staphylococcus aureus by immunohistochemical and molecular biological examinations. This first report of infective endocarditis and systemic infarctions caused by S.aureus in an Amami rabbit indicates the importance of monitoring purulent injuries, even if mild, to prevent secondary infections in this species.

Small round cell tumor of cervical region: a case report with unusual site & course

Ewing’s sarcoma belongs to a spectrum of neoplastic diseases known as Ewing’s family of tumors. Ewing sarcoma can arise in either bone or soft tissue. Small round cell tumors comprise a heterogeneous group of neoplasms that predominate in childhood and adolescence, share similar morphological features, consisting of dense cellular proliferation of small round cells with primitive appearance. Ewing sarcoma is the second most common malignant bone tumour in children and young adults, although, rarely, it may be of extraskeletal origin. Extra-osseous tumor with metastatic or recurrent disease has a worse outcome; 5-year overall survival remains about 25 %. A female patient presented in surgical OPD for the first time at the age of 12 years with swelling in right supraclavicular region. The swelling was excised & a provisional diagnosis of small round cell tumor was given & patient was lost to follow up. Swelling recurred at the age of 23 years & was gradually increasing in size, measuring 20 x 20 x 20 cm. Radiologically, lesion was suggestive of sarcoma / lymphoma. Patient was operated & histopathological diagnosis of malignant round cell tumor was given with differential diagnosis of Ewing’s sarcoma, PNET, lymphoma. Patient had third recurrence of swelling at the age of 28 years at same site. On IHC, diagnosis of Soft Tissue Ewing sarcoma was given. Inspite of recurrence & huge size of tumor, patient was otherwise asymptomatic. Ours is a rare case of more than 16 years of survival inspite of recurrence. Immunochemistry is mandatory for diagnosis of Extraskeletal Ewing sarcoma in younger age group patients. Regular follow up of such patients is essential for timely detection & complete treatment of recurrent tumors.

A novel group of spindle cell tumors defined by S100 and CD34 co-expression shows recurrent fusions involving RAF1, BRAF, and NTRK1/2 genes.

Tumors characterized by co-expression of S100 and CD34, in the absence of SOX10, remain difficult to classify. Triggered by a few index cases with monomorphic cytomorphology and distinctive stromal and perivascular hyalinization, immunopositivity for S100 and CD34, and RAF1 and NTRK1 fusions, the authors undertook a systematic review of tumors with similar features. Most of the cases selected were previously diagnosed as low-grade malignant peripheral nerve sheath tumors, while others were deemed unclassified. The tumors were studied with targeted RNA sequencing and/or FISH. A total of 25 cases (15 adults and 10 children) with kinase fusions were identified, including 8 cases involving RAF1, 2 BRAF, 14 NTRK1, and 1 NTRK2 gene rearrangements. Most tumors showed a monomorphic spindle cell proliferation with stromal and perivascular keloidal collagen, in a patternless architecture, with only occasional scattered pleomorphic or multinucleated cells. Most cases showed low cellularity, a low mitotic count, and absence of necrosis. Although a subset showed overlap with lipofibromatosis-like neural tumors, the study group showed distinctive hyalinization and overt malignant features, such as highly cellular fascicular growth and primitive appearance. All tumors showed co-expression of S100 and CD34, ranging from focal to diffuse. SOX10 was negative in all cases. NTRK1 immunohistochemistry showed high levels of expression in all tumors with NTRK1 gene rearrangements. H3K27me3 expression performed in a subset of cases was retained. These findings together with the recurrent gene fusions in RAF1, BRAF, and NTRK1/2 kinases suggest a distinct molecular tumor subtype with consistent S100 and CD34 immunoreactivity.

Comparative Myology of the Forelimb in Capuchin and Night Monkeys

Background: The capuchin monkey (Sapajus apella) and the night monkey (Aotus azarae infulatus) are primates with broad distribution in South America. Sapajus apella is best-studied species in the genus Cebus, and is commonly found in captivity in parks, zoos, and sorting centers in Brazil. Species in the genus Aotus have a primitive appearance with large eye sockets, and their nocturnal habits are unique among the apes today. Because these two species belong to the same order, they have similar morphological characteristics. In this work, we conduct a comparative study of the forelimb musculature between these two species to produce data for use in veterinary procedures.Materials, Methods & Results: Three capuchin monkey and three night monkey specimens were used, two females and one male for each species. Specimens were acquired from the National Center for Primates under approval from the Animal Research (CEPAN/IEC/SVS/MS) No. 008/2010. Specimens were frozen and donated after death by natural causes to the LaPMA (Animal Morphology Research Laboratory) at the Federal Rural University of Amazonia (UFRA). After being thawed in running water, the animals were fixed by intramuscular injection with 10% formaldehyde in aqueous solution and dissected to display thoracic limb muscle groups. Dissections were performed using basic instrumentation by creating a medial incision from the carpal region to the axillary region. After incision, the skin was folded and muscles were separated in order to identify muscle groups. The nomenclature adopted was based on the veterinary anatomy, and books about human anatomy for comparison of forearm muscles. The muscles that compound the shoulder was the supraspinal and infra-spinal. The arm was composed by the teres major and minor, the triceps brachii (long head, lateral head, and medial head), brachialis, biceps brachii, tensor muscle of the antebrachial fascia, coracobrachialis, and anconeous. The forearm included the extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorus, extensor digiti minimum, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis brevis, flexor carpi ulnaris, flexor digitorum profundus, flexor digitorum superficialis, flexor carpi radialis, flexor pollicis longus, extensor carpi radialis brevis, and brachioradialis muscles. In general, the two species have the same muscle groups, except for the absence of the teres minor and brachioradialis in Capuchin monkey, and the absence of the long head of the triceps brachii and extensor carpi radialis brevis at night monkey.Discussion: The forelimb musculature in the capuchin and night monkey is similar that described in the literature for both domestic and wild species such as coati, paca, and bush dogs, with little variation among the studied species. Regarding the muscles of the forearm, the capuchin monkey and the night monkey have muscular anatomy similar to that of humans, with some variations. The anatomical variations in common traits do not impede function. Interspecific variation is a common occurrence in nature, and can be explained by species divergence which occurs over many years, for various reasons. Knowledge of the comparative miology of the capuchin monkey and the night monkey is still nascent, thus future research is needed to better understand the structure of these animals, which can then serve as a basis for studies of other ethological aspects of the species biology.

Urethral dysontogenic metaplasia in cat with bilateral renal dysplasia

This paper to describe a case of dysontogenic urethral metaplasia in a one month old mongrel feline who also had bilateral renal dysplasia. Dysontogenic metaplasia in cats are scarce and this change may be associated with renal dysplasia and/or lower urinary tract. The animal had history of abdominal enlargement since birth and dysuria, eliminating urine only dropwise. Due to the poor prognosis we opted for euthanasia. At necropsy was observed enlarged and distended bladder, reduced kidneys and dilated and tortuous ureters. The urethra was thickened, hard to cut, and histologically, was replacing the connective tissue, cartilage and endochondral ossification areas, which features dysontogenic metaplasia. Both kidneys presented primitive appearance featuring dysplasia. Dysontogenic metaplasia in urinary tract feline with renal dysplasia, has not been described.

Paraná Pine, Araucaria angustifolia: An Ancient-Looking Conifer for Modern Landscapes

Paraná pine is a primitive-looking conifer valued for its unusual horizontal branching, interesting triangular-shaped needles, and neat, symmetrical form. The primitive appearance of this evergreen tree results from its resemblance to and relationship with an ancient group of Araucaria-related conifers that dominated forests more than 145 million years ago. This tree once covered vast areas in southern Brazil, Argentina and Paraguay. Native Americans harvest the seeds for food. It was an important timber tree for European settlers, and it was logged extensively through the 20th century. Now one of the rarest trees in Brazil, Paraná pine is considered critically endangered due to habitat loss and exploitation. This evergreen conifer grows too large for most residential situations, but is best used as an accent or conversation piece in large-scale landscapes. This 3-page fact sheet was written by Gary W. Knox and published by the UF Department of Environmental Horticulture, November 2014.
 ENH1248/EP509: Paraná Pine, Araucaria angustifolia: An Ancient-Looking Conifer for Modern Landscapes (ufl.edu)

Using 3D digital models for the virtual restoration of polychrome in interesting cultural sites

In most cases, the polychrome paintings that decorated heritage buildings no longer exist or are reduced to mere remnants. These facts decontextualize the sites in their historical and artistic evolution, distort the intention under which they were conceived, and hamper their accomplishment. Current recovery methods are restricted to the stabilization of the remains in their present status, requiring a lot of completely manual work that is expensive and almost unrelated to the use of new technologies. Three-dimensional digitalization and modelling is proved to be the basis for the virtual recovery of paintings in a significant edifice. To do so, an innovative methodology is presented that allows the 3D geometric information of a site (captured using a laser scanner) to be combined with specially designed 2D artistic images. The resulting 3D digital models can then be focused, with high efficiency projectors, on the equivalent area of the original site, and also used as raw material to compose a video-projection without perspective effects to emulate, with due rigour, the primitive appearance, its evolution along time, the effects of the deterioration, or other interesting aspects. The results obtained at Sta. María de Mave (Palencia, Spain) are presented, supporting the potential of this new methodology not only as a scientific way to discuss possible restoration hypotheses with experts or as a didactic tool for narrating the historical evolution of a monument, but also as a spectacular show for tourists.

Spatial difference and regularity of seed dispersal of Ulmus macrocarpa in Horqin Sandy Land, China

Aims Ulmus macrocarpa is a typical anemochorous plant. It can form mono-dominant woodland in Keerqin Sandy Land, China. Our objectives were to investigate seed-fall characteristics of U. macrocarpa in the understory and away from both the woodland edges and isolated trees at different distances in different compass directions, and to illustrate the underlying mechanisms of seed dispersal in U. macrocarpa. Methods In mid June 2011, we investigated seed dispersal after seeds fall in a nature reserve of U. macrocarpa woodland in Tongyu County in western Jilin Province. The woodland is about 50 km2 in area which has nearly primitive landscape appearance. The seed density of U. macrocarpa was randomly sampled in the understory and orderly sampled at 1 m intervals from the tree bases away from the woodland edges and isolated trees along vertical sections of different directions. The quadrat was 50 cm × 50 cm in area. Differences in the seed density among the understory and parallel sections of different distance away from the woodland edges were tested by one-way ANOVA. Two types of density functions of theoretical distribution were used to reflect the patterns of seed dispersal away from seed sources along vertical sections of different directions. Important findings The understory of U. macrocarpa had the highest mean seed density. The mean seed density was significantly reduced at 3 m away from the woodland edges, and it decreased exponentially with increasing in distance away from the woodland edges. We observed the highest cumulative seeds per unit area in the northeast direction; whereas the lowest numbers in the southwest and west directions, which may attribute to a high frequency of southerly winds. The pattern of seed dispersal matched the Weibull and Log-normal distributions (χ2(α) 0.900). In conclusion, U. macrocarpa has the same long-distance seed dispersal mechanism in different directions under natural conditions in Horqin Sandy Land.

BioEssays 6/2009

Cover Photograph: Composite of an adult specimen of Branchiostoma lanceolatum in a sand clock. The picture represents an allegory of the slow evolving nature of amphioxus. As recently revealed by the publication of its genome sequence, amphioxus is at present the best proxy to the ancestral chordate genome, not only in gene content but also in genome structure. This might well be refl ected in its primitive appearance. While having a basic vertebrate‐like gene toolkit, amphioxus shares with vertebrates basic chordate features, lacking further vertebrate‐like evolutionary innovations as if they had remained in stasis for hundreds of millions of years. See the article by Garcia‐Fernàndez and Benito‐Gutiérrez on pages 665–675 of this issue.

Amoebae as Exemplary Cells: The Protean Nature of an Elementary Organism

In the nineteenth century protozoology and early cell biology intersected through the nexus of Darwin's theory of evolution. As single-celled organisms, amoebae offered an attractive focus of study for researchers seeking evolutionary relationships between the cells of humans and other animals, and their primitive appearance made them a favourite model for the ancient ancestor of all living things. Their resemblance to human and other metazoan cells made them popular objects of study among morphologists, physiologists, and even those investigating animal behaviour. The amoeba became the exemplar of the new protoplasmic cell concept of mid-century and because its apparent simplicity made it widely generalizable it became a popular subject in a breadth of experimental investigations and theoretical speculations. It was able to do this because "the amoeba" denotes not a particular organism, but a general type of behaviour common to the cells of a range of protozoa, simple plants and higher animals. Its status as an exemplary cell also rested upon auxiliary philosophical assumptions about what constitutes a primitive characteristic and the thesis that evolution is a progressive development of order from chaos.

Early core formation in asteroids and late accretion of chondrite parent bodies: Evidence from 182Hf- 182W in CAIs, metal-rich chondrites, and iron meteorites

The 182Hf- 182W isotopic systematics of Ca-Al-rich inclusions (CAIs), metal-rich chondrites, and iron meteorites were investigated to constrain the relative timing of accretion of their parent asteroids. A regression of the Hf-W data for two bulk CAIs, various fragments of a single CAI, and carbonaceous chondrites constrains the 182Hf/ 180Hf and ε W at the time of CAI formation to (1.07 ± 0.10) × 10 −4 and −3.47 ± 0.20, respectively. All magmatic iron meteorites examined here have initial ε W values that are similar to or slightly lower than the initial value of CAIs. These low ε W values may in part reflect 182W-burnout caused by the prolonged cosmic ray exposure of iron meteorites, but this effect is estimated to be less than ∼0.3 ε units for an exposure age of 600 Ma. The W isotope data, after correction for cosmic ray induced effects, indicate that core formation in the parent asteroids of the magmatic iron meteorites occurred less than ∼1.5 Myr after formation of CAIs. The nonmagmatic IAB-IIICD irons and the metal-rich CB chondrites have more radiogenic W isotope compositions, indicating formation several Myr after the oldest metal cores had segregated in some asteroids. Chondrule formation ∼2–5 Myr after CAIs, as constrained by published Pb-Pb and Al-Mg ages, postdates core formation in planetesimals, and indicates that chondrites do not represent the precursor material from which asteroids accreted and then differentiated. Chondrites instead derive from asteroids that accreted late, either farther from the Sun than the parent bodies of magmatic iron meteorites or by reaccretion of debris produced during collisional disruption of older asteroids. Alternatively, chondrites may represent material from the outermost layers of differentiated asteroids. The early thermal and chemical evolution of asteroids appears to be controlled by the decay of 26Al, which was sufficiently abundant (initial 26Al/ 27Al >1.4 × 10 −5) to rapidly melt early-formed planetesimals but could not raise the temperatures in the late-formed chondrite parent asteroids high enough to cause differentiation. The preservation of the primitive appearance of chondrites thus at least partially reflects their late formation rather than their early and primitive origin.

Primary desmoplastic small round cell tumor of bone: report of a case with cytogenetic confirmation

We report a case of desmoplastic small round cell tumor occurring in the right ilium of a 13-year-old boy. Morphologically, the neoplasm consisted of small round cells of primitive appearance with a diffuse growth pattern replacing marrow space and eroding bone. Immunohistochemical staining was positive for vimentin, synapsin, CD99 (MIC2 protein), and FLI-1, prompting an initial diagnosis of Ewing sarcoma/primitive neuroectodermal tumor. However, a diagnosis of desmoplastic small round cell tumor was rendered after the detection by cytogenetic analysis of the reciprocal chromosomal translocation, t(11;22)(p13;q12), which is uniquely associated with this tumor. This is the first documented instance of desmoplastic small round cell tumor arising in bone.

The Mauer mandible and the evolutionary significance of Homo heidelbergensis

The significance of the species H. heidelbergensis is discussed by means of the comparison of the holotypeof this species-the mauer mandible- with a large set of Homo fossils. It is argued that the primitive appearance of the Mauer mandible occurs along with unequivocal indications of Neandertal apomorphies. The BL dimensions of the incisors and morphology of premolars as well as the variables related to the position of the mental foramen and retromolar space definitely indicate that Mauer should be classified as a member of the evolutionary lineage which evolved into classic Neandertals. We conclude that the Mauer mandible represents a population forming part of the Neandertals evolutionary lineage. Therefore, the name H. heidelbergensis cannot be used to denote the last common ancestor to Neandertals and Modern humans. It is proposed that the taxon H. heidelbergensis should be used only to name a European Middle Pleistocene chronospecies of the Neandertal evolutionary lineage.

Characterization of a Hierarchy in Human Acute Myeloid Leukemia Progenitor Cells

Despite the usual uniform and primitive appearance of cells derived from the leukemic clone in most patients with acute myeloid leukemia (AML), there is considerable heterogeneity among leukemic blasts, particularly with respect to their capacity to proliferate and/or self renew. We have assessed whether these differences in proliferative potential are correlated with the phenotypic changes that characterize normal hematopoiesis, which might suggest an analogous hierarchy of AML progenitors. We have used the ability of primitive AML cells to persist or produce blast colony forming cells (CFU-blast) detected after 2 to 8 weeks in the presence of growth factors in suspension cultures (SC) termed SC-initiating cells (IC), or with stroma in long-term cultures (LTC-IC) as a quantitative assay for a cell that may have primitive characteristics. This SC assay is linear, cell concentration independent, and the frequency of SC-IC by limiting dilution analysis is lower than primary CFU-blast. The average output of CFU-blast after 2 to 8 weeks by individual SC-IC varied between 2 and more than 100 in individual patients. Leukemic blasts were sorted based on their expression of antigens previously found useful to characterize normal progenitor differentiation, and analyzed for the percentage of CFU-blast SC-IC, and leukemic LTC-IC within each fraction. All of these progenitor types were heterogeneous in their expression of CD45RA and CD33, but expressed uniformly low levels of CD15 and differed from normal primitive progenitors in their high expression of HLA-DR. CFU-blast had a significantly higher expression of CD71 and CD38 as compared with SC-IC or leukemic LTC-IC. In patients with CD34+ blasts, the majority of their SC-IC at 4 weeks were CD34+/CD38-; however, patients with CD34- blasts had at least some CD34- progenitors. These results show that while heterogeneity exists between patients, it is possible to physically separate subpopulations of AML cells with different proliferative potentials. It also provides some support for the concept that quantitation of leukemic cells capable of producing CFU-blast for 4 weeks or more in vitro measures a less frequent leukemic progenitor with higher proliferative potential that may be the only relevant cell for maintaining the leukemic clone in vivo.

Intracranial Desmoplastic Small-Cell Tumor

We report a case of desmoplastic small-cell tumor occurring in the CNS in relation to the tentorium in a 24-year-old man. Morphologically, the neoplasm had the typical appearance of small, round tumor cells of primitive appearance growing as well-defined nests separated by abundant desmoplastic stroma. The diagnosis was confirmed through the demonstration of immunoreactivity for keratin, desmin, and neuron-specific enolase and the detection by Southern blot analysis of a unique gene resulting from the fusion of the WT1 gene in chromosome 11 and the EWS gene in chromosome 22. This is the first documented instance of the occurrence of this tumor type at a distance from a mesothelial-lined surface.

Elevated serum alpha-fetoprotein in a patient with undifferentiated carcinoma of the gall bladder.

An uncommon case of undifferentiated carcinoma of the gall bladder in a 65 year old Chinese man, who presented with an increased serum alpha-fetoprotein concentration, is reported. Histologically, the tumour had a primitive appearance and was composed of a pavement-like array of poorly differentiated columnar/polygonal cells. Alpha-fetoprotein was demonstrated in some of the tumour cells using an immunoperoxidase technique. Alpha-fetoprotein secretion in this instance may have occurred because the gall bladder and the liver are of similar embryological origin. Alpha-fetoprotein may also be related to the resurgent expression of oncofetal antigens. This tumour may represent another rare cause of increased serum alpha-fetoprotein concentrations.

Evolutionary trends in Latest Norian through Hettangian radiolarians from the Queen Charlotte Islands, British Columbia

Uppermost Triassic and lowermost Jurassic (Hettangian) radiolarians from continuous sequences of the Sandilands Formation (Kunga Group), Queen Charlotte Islands, British Columbia, Canada, provide a rare glimpse into faunal patterns of evolution, radiation, extinction, and regeneration near a major stratigraphic boundary. The radiolarians are dated by Triassic ammonoids and conodonts, and Jurassic ammonites. Uppermost Triassic radiolarians are from strata equivalent to the Amoenum and Crickmayi ammonoid zones. Lowest Jurassic faunas are Planorbis Zone equivalent. The direction and pace of evolution in the highly diverse uppermost Triassic fauna is variable. Conservative taxonomic groups such as the pantanelliids and canoptids evolve gradually with only minor morphological change. Species extinctions occur regularly throughout the interval and across the boundary, with most genera ranging into the Jurassic. Current data confirm that Betraccium persists to the topmost Triassic but not into the Jurassic. Architecturally complex forms such as Squinabollela and Praecitriduma apparently have short ranges; they are common in uppermost Triassic beds but not found in the Lower Jurassic. Other radiolarian groups experience periodic bursts of radiation evidenced by multiple new species, and even new genera, most of which survive to the topmost Triassic but not beyond e.g. Ferresium and Laxtorum.. Finally, ancestral forms of some typical Lower Jurassic taxa are first recognized in uppermost Triassic beds e.g. Bipedis, Canutus, Crucella,, and Droltus.. Lowermost Jurassic radiolarians are easily distinguished from uppermost Triassic ones by their primitive appearance and low diversity, and by the absence of all distinctive uppermost Triassic taxa. Lower Hettangian faunas are characterized by latticed, spherical, irregularly spinose forms with poorly organized meshwork; non-distinctive spongy forms with spines; very simple nassellarians; and Archaeocenosphaera laseekensis. Pantanellium tanuense is the only pantanelliid species in Lower Hettangian collections.

Evidence for neural origin and PAS-positive variants of the malignant small cell tumor of thoracopulmonary region ("Askin tumor").

The differential diagnoses of childhood and adolescent tumors composed of small round cells include a distinctive clinicopathological entity called malignant small cell tumor (MSCT) of the thoracopulmonary region in childhood. In the present study, 15 such tumors that fulfilled the criteria by Askin et al. were examined for features of possible neural differentiation by light and electron microscopy (EM). With hematoxylin-eosin stain (H&E) the tumors were made up of small undifferentiated cells; rosette formation was noticed in four cases. By immunohistochemistry all 15 tumors were positive for neuron/specific enolase (NSE), which is a specific marker for neural elements and their tumors including neuroblastomas. Ten of 15 MSCT had positive PAS staining. Ultrastructurally dense core (neurosecretory) granules and cell processes indicative of neuronal differentiation could be recognized in 10 of 14 tumors. The dense core granules were often atypical. Filamentous cytoskeleton, never observed in Ewing's sarcoma, was often present. Based on the current results, MSCT of the thoracopulmonary region can be considered a peripheral neuroectodermal tumor with the possible origin in intercostal nerves. MSCTs are generally misdiagnosed as Ewing's sarcoma due to their primitive appearance in H&E sections and their periodic acid-Schiff positivity. NSE immunostaining, preferably augmented by electron microscopy, is necessary for their correct diagnosis.