Alien parasitic infections in the endangered Ryukyu long-furred rat (Diplothrix legata) on Amami-Oshima Island,Japan

There is limited knowledge about parasites of the endangered Ryukyu long-furred rat, Diplothrix legata (Murinae, Rodentia) endemic to Okinawa, Tokunoshima, and Amami-Oshima Islands in Japan. In the present study, postmortem histopathological examination of an individual found on Amami-Oshima Island revealed a mixed helminth infection of Calodium hepaticum, Hydatigera taeniaeformis, and Angiostrongylus cantonensis. These helminths are considered non-native to Amami-Oshima Island and are maintained by invasive mammals, such as non-native rats and outdoor cats. This observation presents a new host record for C. hepaticum and H. taeniaeformis and the first record of A. cantonensis in Ryukyu long-furred rat on Amami-Oshima Island.     

Effect of Proton Pump Inhibitors on Serum Thyroid-Stimulating Hormone Level in Euthyroid Patients Treated with Levothyroxine for Hypothyroidism

ObjectiveTo examine retrospectively the effect of proton pump inhibitors (PPIs) on thyrotropin (thyroid-stimulating hormone or TSH) values in patients with hypothyroidism and normal TSH levels receiving levothyroxine (LT₄) replacement therapy.MethodsThe data collection was done by retrospective review of electronic medical records from the period of December 2002 to August 2005 from patients with hypothyroidism who were receiving at least 25 μg of LT₄ replacement daily at Queens Hospital Center. The first 92 patients meeting all inclusion and exclusion criteria were included in the study. The study group (N = 37) patient data were collected by selecting euthyroid patients who had received stable LT₄ replacement for at least 6 months and in whom PPI therapy (lansoprazole) was later initiated. TSH levels were collected before and at least 2 months after the PPI treatment was started. The control group (N = 55) patient data were collected by reviewing TSH levels among euthyroid patients with a history of hypothyroidism receiving stable LT₄ therapy and not receiving a PPI during the period of data collection. The statistical analysis was done by comparing the mean change in TSH level in each group with use of the Student t test.ResultsIn the study group, the mean change in the TSH level from before to at least 2 months after initiation of PPI therapy, 0.69 ± 1.9 μIU/mL, was statistically significant (P = 0.035). In the control group, the mean change in the TSH level during the study period, 0.11 ± 1.06 μIU/mL, was not statistically significant (P = 0.45).ConclusionTo our best knowledge, this is the first study in humans with hypothyroidism demonstrating the effect of PPIs on serum TSH levels. PPIs should be added to the list of medications affecting the level of thyroid hormone in patients with hypothyroidism treated with LT₄ replacement. Patients with hypothyroidism and normal TSH values during LT₄ replacement therapy may need additional thyroid function testing after treatment with PPIs and may need adjustment of their LT₄ dose. (Endocr Pract. 2007;13:345-349)     

The Biosynthesis of Flavin Cofactors in Listeria monocytogenes

Listeria monocytogenes is riboflavin auxotrophic, but it has two genes envisaged to transform riboflavin into FMN and FAD after its uptaked by specialized transporters. One encodes a bifunctional type I FAD synthase (FADS, herein LmFADS-1), while the other produces a protein similar to type I at the FMN:ATP adenylyltransferase (FMNAT) site but with a shorter C-terminal that lacks any riboflavin kinase (RFK) motif. This second protein is rare among bacteria and has been named FADS type II (LmFADS-2). Here we present a biochemical and biophysical study of LmFADS-1 and LmFADS-2 by integrating kinetic and thermodynamic data together with sequence and structural prediction methods to evaluate their occurrence in Listeria, as well as their function and molecular properties. Despite LmFADS-1 similarities to other type I FADSs, (i) its RFK activity has not riboflavin substrate inhibition and occurs under reducing and oxidizing conditions, (ii) its FMNAT activity requires strong reducing environment, and (iii) binding of reaction products, but not substrates, favors binding of the second ligand. LmFADS-2 produces FAD under oxidizing and reducing environments, but its C-terminus module function remains unknown. Listeria species conserve both FADSs, being sequence identity high within L. monocytogenes strains. Our data exemplify alternative strategies for FMN and FAD biosynthesis and homeostasis, envisaging that in Listeria two FADSs might be required to fulfill the supply of flavin cofactors under niches that can go from saprophytism to virulence. As FADSs are attractive antimicrobial targets, understanding of FADSs traits in different species is essential to help in the discovery of specific antimicrobials.     

Immunology on chip: Promises and opportunities

Microfluidics has facilitated immunological studies by enhancing speed, efficiency and sensitivity of current analysis methods. It offers miniaturization of current laboratory equipment, and enables analysis of clinical samples without the need for sophisticated infrastructure. More importantly, microfluidics offers unique capabilities; including conducting multiple serial or parallel tasks as well as providing complex and precisely controlled environmental conditions that are not achievable using conventional laboratory equipment. Microfluidics is a promising technology for fundamental and applied immunological studies, allowing generation of high throughput, robust and portable platforms, opening a new area of automation in immunology.     

Gapped permutation pattern discovery for gene order comparisons.

The list of species whose complete DNA sequence have been read is growing steadily, and it is believed that comparative genomics is in its early days. Permutations patterns (groups of genes in some "close" proximity) on gene sequences of genomes across species is being studied under different models, to cope with this explosion of data. The challenge is to (intelligently and efficiently) analyze the genomes in the context of other genomes. In this paper, we present a generalized model that uses three notions, gapped permutation patterns (with gap g), genome clusters, via quorum, K>1, parameter, and, possible multiplicity in the patterns. The task is to automatically discover all permutation patterns (with possible multiplicity), that occur with gap g in at least K of the given m genomes. We present (log mN (I) + /Sigma/log/Sigma/N (O)) time algorithm where m is the number of sequences, each defined on Sigma, N (I) is the size of the input and N (O) is the size of the maximal gene clusters that appear in at least K of the m genomes.     

Form equals function? Bacterial shape and its consequences for pathogenesis

Bacteria exhibit a wide variety of morphologies. This could simply be a consequence of an elaboration of bacterial cellular architecture akin to the famous decorative but not structurally essential Spandrels in the Basilica di San Marco in Venice that are a side-effect of an adaptation, rather than a direct product of natural selection. However, it is more likely that particular morphologies facilitate a specific function in cellular physiology. Two recent publications including one in this issue of Molecular Microbiology and another in Cell provide new insights into the molecular basis for the helical shape of the bacterium Helicobacter pylori and the role of this shape in pathogenesis. They identify a novel endopeptidase that is necessary to generate the helical shape by processing the peptidoglycan and report that catalytically inactive mutants lead to defects in colonization that appear to be independent of an effect on cellular motility. Here, we put these findings in the context of some of what is known about peptidoglycan and cell shape and suggest that the role of this endopeptidase in forming coccoid morphology may be critical for pathogenesis.     

Interpreting evidence: why values can matter as much as science

Despite increasing awareness of the ways in which non-epistemic values play roles in science, many scientists remain reluctant to acknowledge values at stake in their own work. Even when research clearly relates to risk assessment and establishing public policy, contexts in which the presence of values is less likely to be contentious, scientists tend to present such research as merely involving empirical questions about what the evidence is. As a result, debates over policy-related science tend to be framed as purely epistemic debates over the state of the evidence. We argue that this neglects the important ways that ethical and social values play legitimate roles in judgments about what we take to be evidence for a particular policy. Using the case of recent disputes about the relative safety of home birth, we argue that although the debate has been framed as a purely scientific one about the empirical evidence for home birth, it actually involves disagreements about underlying value assumptions. If our claims are correct, then in order to move the debate forward, scientists will need to engage in a critical discussion about the values at stake.     

Chinese medical ward: an American's observations

Physicians base their practices on scientific knowledge that varies little from one country to another, but their experience and their careers are shaped by the culture in which they live and work. This essay casts light on medical practice in mainland China, based on three months of field work with an elite group of physicians at a tertiary academic medical center in summer 2009. It is a story of a diverse group of Chinese professionals navigating a demanding profession, and of the foreign college student on whom they left an indelible impact. Many of the normative features of the Chinese medical profession-its chain of command, commitment to medical ethics, and scientific orientation-are highly comparable to the working lives of American physicians.