On the func­tion of the Megakaryocyte (Motility, Separation of the Platelet and Phagocytosis), Observations Both in Idiopathic Thrombo-cytopenic Purpura and in Normal Adult

The idiopathic thrombocytopenic purpura was described by Werlhof as an independent disease first in 1738. Kaznelson reported the excellent effect of splenectomy for its chronic type in 1915. For the genesis of its thrombocytopenia, there have been many theories to be concluded into the followings, 1) the development of an auto-immune mechanism resulting in platelet destruction, 2) increased platelet destruction in the spleen, 3) the inhibition of platelet production from the marrow megakaryocytes by a humoral factor produced in the spleen, 4) both increased destruction and decreased production of the platelet. Among the above four theories, the third one is the most popular in the chronic type.</p

Modelling state-dependent interference in common cranes

1. Interference is a key component of food competition, but is difficult to measure in natural animal populations. Using data from a long-term study, we show that interference between common cranes Grus grus L., feeding on patches of cereal seeds, reduces intake rates at high competitor densities, and that the strength of interference is unrelated to food abundance. 2. An alternative to measuring interference directly is to predict its strength using behaviour-based models. We test an interference model, originally developed for shorebirds feeding on invertebrate prey, for cranes. We compare the predictions of a rate-maximizing model, in which animals steal food if this increases intake rate, and a state-dependent model, in which they only rate-maximize if their intake rate is below a target value, otherwise they minimize injury risk by not stealing food. State-dependent aggression occurs in cranes. 3. The state-dependent model predicts more accurately the relative aggression rates of cranes of different dominance. However, both models predict accurately the observed strength of interference, that the strength of interference is unrelated to food abundance, at least within the observed range of crane and seed densities, and that cranes of a higher dominance have a higher intake rate than those of lower dominance. 4. This paper shows how state-dependent behaviour can be incorporated into an interference model, and that the model can produce accurate predictions for a system quite different to that for which it was developed.RAS was funded by the Natural Environment Research Council. LMB was partially funded by Ministerio de Ciencia y Tecnología (MCyT) and research grant PB97-1252 of MCyT. Field work was funded by DGICYT project PB87-0389 of the MCyT.Peer reviewe

Realising a species-selective double well with multiple-radiofrequency-dressed potentials

Techniques to manipulate the individual constituents of an ultracold mixture are key to investigating impurity physics. In this work, we confine a mixture of the hyperfine ground states of Rb-87 in a double-well potential. The potential is produced by dressing the atoms with multiple radiofrequencies. The amplitude and phase of each frequency component of the dressing field are individually controlled to independently manipulate each species. Furthermore, we verify that our mixture of hyperfine states is collisionally stable, with no observable inelastic loss.Comment: 11 pages, 4 figure

Cyclooxygenase-2 overexpression correlates with tumour recurrence, especially haematogenous metastasis, of colorectal cancer

Epidemiological studies have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs), known to inhibit cyclooxygenase (COX), reduce the risk of colorectal cancer. COX is a key enzyme in prostaglandin biosynthesis, and two isoforms of COX, COX-1 and COX-2, have been identified. Recently COX-2 has been reported to frequently overexpress in colorectal neoplasms and to play a role in colorectal tumorigenesis and tumour progression. In this study, using immunohistochemistry, we examined COX-2 expression in advanced human colorectal cancer and its correlation with clinicopathological features. COX-2 expression was observed mainly in the cytoplasm of cancer cells in all the specimens examined, but some stromal cells and endothelial cells were also stained. According to the grade of COX-2 expression of the cancer cells, patients were divided into high- and low-COX-2 expression groups. High-COX-2 expression significantly correlated with tumour recurrence, especially haematogenous metastasis. These results suggest that a selective COX-2 inhibitor can be a novel class of therapeutic agents not only for tumorigenesis but also for haematogenous metastasis of cololectal cancer. To our knowledge, this is the first report on the correlation between COX-2 overexpression and recurrence of colorectal cancer. © 2000 Cancer Research Campaig

Loss of the mammal-specific tectorial membrane component CEA cell adhesion molecule 16 (CEACAM16) leads to hearing impairment at low and high frequencies

The vertebrate-restricted carcinoembryonic antigen gene family evolves extremely rapidly. Among their widely expressed members, the mammal-specific, secreted CEACAM16 is exceptionally well conserved and specifically expressed in the inner ear. To elucidate a potential auditory function we inactivated murine Ceacam16 by homologous recombination. In young Ceacam16-/- mice the hearing threshold for frequencies below 10 kHz and above 22 kHz was raised. This hearing impairment progressed with age. A similar phenotype is observed in hearing-impaired members of Family 1070 with non-syndromic autosomal dominant hearing loss (DFNA4) who carry a missense mutation in CEACAM16. CEACAM16 was found in interdental and Deiters cells and was deposited in the tectorial membrane of the cochlea between postnatal day 12 and 15, when hearing starts in mice. In cochlear sections of Ceacam16-/- mice tectorial membranes were significantly more often stretched out as compared to wild-type mice where they were mostly contracted and detached from the outer hair cells. Homotypic cell sorting observed after ectopic cell surface expression of the carboxy-terminal immunoglobulin variable-like N2 domain of CEACAM16 indicated that CEACAM16 can interact in trans. Furthermore, Western blot analyses of membrane-bound CEACAM16 under reducing and non-reducing conditions demonstrated oligomerization via unpaired cysteines. Taken together, CEACAM16 probably can form higher order structures with other tectorial membrane proteins such as α-tectorin and β-tectorin and influences the physical properties of the tectorial membrane. Evolution of CEACAM16 might have been an important step for the specialization of the mammalian cochlea allowing hearing over an extended frequency range

Visualization and assessment of saccular duct and endolymphatic sinus

Conclusion: The saccular duct and endolymphatic sinus run in the bony groove, before reaching the orifice of the vestibular aqueduct. We first clinically visualized this sulciform groove using three-dimensional (3D) cone beam CT images. This strategy can be useful to assess the condition of the saccular duct and endolymphatic sinus concerning the longitudinal flow system of endolymph. Objective: To assess the saccular duct and endolymphatic sinus in the endolymphatic system in order to advance clinical studies on inner ear dysfunction. Methods: The sulciform groove of the saccular duct and endolymphatic sinus of human subjects was analyzed by cone beam CT and compared with that of a cadaver. Results: We could obtain reconstructed 3D CT images of the sulciform groove of the saccular duct and endolymphatic sinus using several CT window levels