Effect of dexamethasone on Fc gamma receptor expression in foetal and neonatal rat gut

When injected into 12-day-old suckling rats, dexamethasone caused a precocious disappearance of Fc gamma receptors from enterocytes of the proximal small intestine. However, dexamethasone appeared to be necessary for the maintenance or production of such receptors in foetal rat gut cultured in vitro.     

Quinine dimorphism among ‘non-tasters’ of 6-n-propylthiouracil

Zusammenfassung Geschmacksblinde gegenüber 6-n-Propylthiouracil zerfallen in zwei Gruppen (Dimorphismus): eine mit niedrigen und eine mit hohen Geschmacksschwellenwerten gegenüber Chinin. Jene der ersten Gruppe haben niedrige Schwellenwerte auch gegenüber den andere Geschmacksqualitäten — sauer, salzig und süss — und gehören zur -Geschmacksgruppe. Vertreter der zweiten Gruppe, das heisst 6-n-Propylthiouracil-Geschmacksblinde mit hohen Geschmacksschwellenwerten gegenüberChinin gehören zu der -Geschmacksgruppe. Patienten mit paroxysmal vaskulärem Kopfschmerz (Migräne mit familiärer Komponente), jedoch ohne elektronencephalographische Anomalie, gehören ausschliesslich zu der -Geschmacksgruppe. Die Eltern von mongoloiden Kindern weisen hohe Geschmacksschwellenwerte gegenüber Chinin auf, wobei die Väter zur -Geschmacksgruppe gehören.

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MeinerAlma Mater, der Universität Basel, zu ihrem 500jährigen Jubiläum in Dankbarkeit gewidmet.

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Acknowledgements. This work has been supported by the State of Ohio, Department of Mental Hygiene and the U.S. Public Health Service, National Institutes of Health, Division of Mental Health, Grant No. M-2731. The active interest and helpful suggestions of Dr.B. Pasamanick is thankfully acknowledged. Our very special and sincere thanks go to Mr.S. England for his most valuable assistance, advice, and skillful help during many phases of this study.     

Effect of dexamethasone on Fc γ receptor expression in foetal and neonatal rat gut

Summary When injected into 12-day-old suckling rats, dexamethasone caused a precocious disappearance of Fc receptors from enterocytes of the proximal small intestine. However, dexamethasone appeared to be necessary for the maintenance or production of such receptors in foetal rat gut cultured in vitro.Supported by an award from the Science and Engineering Research Council.     

Occurrence and habitat use of passage neotropical migrants in the Sonoran Desert

Little is known about stopover habitat use by neotropical migratory birds in the deserts of North America. We determined distribution, abundance, and habitat associations of neotropical migrants during spring migration in the Sonoran Desert of southwestern Arizona along large washes that supported xeroriparian scrub vegetation. We detected 91 bird species during surveys, 50 (52%) of which were passage neotropical migrants. Although xeroriparian scrub covered less than 55% of the area surveyed, 97% of all detections of passage migrants were from this vegetation type. By calculating habitat breadth for each species, we classified 87% of passage migrants as xeroriparian specialists. Richness of passage migrants was strongly associated with the presence of overstory (> 2.5 m) mesquite and paloverde. The highest species richness of breeding neotropical migrants was associated with width of the xeroriparian corridor. Habitat characteristics we have shown to be important to neotropical migrants can be preserved and managed by protecting xeroriparian areas, particularly those supporting mature (> 2.5 m) paloverde, mesquite, desert willow, and catclaw acacia trees. Additionally, xeroriparian scrub within the creosote-bursage vegetation type may be particularly important to passage neotropical migrants.     

Identification of foreign gene sequences by transcript filtering against the human genome.

We have developed a computational subtraction approach to detect microbial causes for putative infectious diseases by filtering a set of human tissue-derived sequences against the human genome. We demonstrate the potential of this method by identifying sequences from known pathogens in established expressed-sequence tag libraries.     

Submillimetre galaxies reside in dark matter haloes with masses greater than 3 × 10(11) solar masses

The extragalactic background light at far-infrared wavelengths comes from optically faint, dusty, star-forming galaxies in the Universe with star formation rates of a few hundred solar masses per year. These faint, submillimetre galaxies are challenging to study individually because of the relatively poor spatial resolution of far-infrared telescopes. Instead, their average properties can be studied using statistics such as the angular power spectrum of the background intensity variations. A previous attempt at measuring this power spectrum resulted in the suggestion that the clustering amplitude is below the level computed with a simple ansatz based on a halo model. Here we report excess clustering over the linear prediction at arcminute angular scales in the power spectrum of brightness fluctuations at 250, 350 and 500?μm. From this excess, we find that submillimetre galaxies are located in dark matter haloes with a minimum mass, M(min), such that log(10)[M(min)/M(⊙)] = 11.5(+0.7)(-0.2) at 350?μm, where M(⊙) is the solar mass. This minimum dark matter halo mass corresponds to the most efficient mass scale for star formation in the Universe, and is lower than that predicted by semi-analytical models for galaxy formation.     

The patterns and dynamics of genomic instability in metastatic pancreatic cancer

Pancreatic cancer is an aggressive malignancy with a five-year mortality of 97-98%, usually due to widespread metastatic disease. Previous studies indicate that this disease has a complex genomic landscape, with frequent copy number changes and point mutations, but genomic rearrangements have not been characterized in detail. Despite the clinical importance of metastasis, there remain fundamental questions about the clonal structures of metastatic tumours, including phylogenetic relationships among metastases, the scale of ongoing parallel evolution in metastatic and primary sites, and how the tumour disseminates. Here we harness advances in DNA sequencing to annotate genomic rearrangements in 13 patients with pancreatic cancer and explore clonal relationships among metastases. We find that pancreatic cancer acquires rearrangements indicative of telomere dysfunction and abnormal cell-cycle control, namely dysregulated G1-to-S-phase transition with intact G2-M checkpoint. These initiate amplification of cancer genes and occur predominantly in early cancer development rather than the later stages of the disease. Genomic instability frequently persists after cancer dissemination, resulting in ongoing, parallel and even convergent evolution among different metastases. We find evidence that there is genetic heterogeneity among metastasis-initiating cells, that seeding metastasis may require driver mutations beyond those required for primary tumours, and that phylogenetic trees across metastases show organ-specific branches. These data attest to the richness of genetic variation in cancer, brought about by the tandem forces of genomic instability and evolutionary selection.