Risk of Infection with Leishmania spp. in the Canine Population in the Netherlands

The dog is the main reservoir of Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in humans in Southern Europe. In order to identify the risk of dogs from a Leishmania non-endemic area traveling to a Leishmania -endemic area becoming infected and the risk of transmitting infection to humans in non-endemic areas an investigation was performed, in which the results of a questionnaire were combined with the results of a serologic survey.     

Structures of the Gasdermin D C-Terminal Domains Reveal Mechanisms of Autoinhibition

1. Download high-res image (212KB)
2. Download full-size image

     

A UNIQUELY CALCIFIED BROWN ALGA FROM HAWAII: NEWHOUSIA IMBRICATA GEN. ET SP. NOV. (DICTYOTALES,PHAEOPHYCEAE)1

An encrusting brown alga from subtidal habitats around the island of Oahu (Hawaiian Islands) represents only the second genus of the class Phaeophyceae to form calcium carbonate, which it deposits primarily as both extracellular and intracellular aragonite, admixed with small (3.3%) amounts of calcite. Plants form expanses 15–100+ cm in extent consisting of horizontally aligned imbricating tiers of distromatic blades 1–4 mm in diameter that are separated from one another by cementing layers of extracellular aragonite, the tiers forming stacks of dozens of laminae and anchored to coral substrata by a basement layer that adheres tightly without haptera or rhizoids. The hypodermal layer of each blade consists of lightly pigmented rectilinear cells bearing either one or two smaller deeply pigmented epidermal cells in cross‐sectional profiles and three or four in long‐sectional profiles, the cells of both layers becoming encased in rigid carbonate skeletons laid down in their outer wall matrices. The successive tiers become stacked by either overgrowing marginal proliferations or new blade primordia that arise from the hypodermal layer of surface laminae and initially spread centrifugally by means of continuous marginal meristems. Neither plurilocular nor unilocular reproductive structures are known. The alga is described as the new genus and species Newhousia imbricata Kraft, G.W. Saunders, Abbott et Haroun and is assigned on the basis of small subunit rDNA gene sequence analyses to the order Dictyotales, family Dictyotaceae, within a strongly supported monophyletic clade that includes Distromium, Lobophora, and Zonaria.     

Requirement for cell proliferation for the effects of 5-bromo-2′-deoxyuridine on cultures of chick chondrocytes

Replication was inhibited in cultures of chick chondrocytes either by growing the cells at high density in ‘pellets’, or by use of inhibitors of DNA synthesis. Exposure to BUdR in either condition did not result in the fibroblast-like morphology and marked inhibition of chondroitin sulfate synthesis which is obtained if replicating cells are exposed to the analog. Growth of chondrocytes for 3 days in media containing embryo extract resulted in a switch from predominantly chondroitin sulfate synthesis to the exclusive synthesis of a hyaluronic acid-like molecule.     

Agglutinin Response to Pertussis Vaccination in the Child

Children were immunized with plain pertussis vaccine made by three manufacturers in 1967. After a primary course of three injections at monthly intervals, starting at 3-4 months of age, the agglutinin response was poor. Even after a “booster” dose, given five months later, not all of the vaccines had stimulated a response to all three pertussis agglutinogens. A further investigation with current vaccines of different kinds administered according to more than one schedule is recommended.