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PubMedDate not supplied

Development of ambulatory arterio-venous carbon dioxide removal (AVCO2R): the downsized gas exchanger prototype for ambulation removes enough CO2 with low blood resistance.

We are developing an ultra compact gas exchanger to allow ambulation during arterial-venous CO2 removal (AVCO2R). The ambulatory AVCO2R gas exchanger (135 ml prime volume and 1.3 M2 gas exchange surface area) is made of polymethylpentene hollow fibers. The gas exchanger was attached to sheep carotid artery (12F) and jugular vein (14F) by percutaneous cannulae for 6 hours (n = 5). Device CO2 removal was measured and calculated at a constant blood flow rate of 1 L/min coupled with varying sweep gas from 1 to 15 L/min, and at constant sweep gas flow of 2 L/min coupled with varying blood flow from 0.5 to 1.25 L/min to determine capacity of CO2 removal at Pa CO2 = 40-50 mm Hg. Blood gases, CO2 removal and hemodynamics were recorded at 0, 3, and 6 hours. CO2 removal increased with sweep gas flow rate and with increase of device blood flow. Hemodynamics remained unchanged throughout study. Gas exchanger resistance remained stable at 2.3 +/- 0.53 mm Hg/L/min. CO2 removal with 1 L/min blood flow and 2 L/min sweep gas was 110 +/- 12 then stabilized at 85 +/- 14 mL/min to 6 hours. The compact ambulatory AVCO2R gas exchanger achieves stable, near total CO2 removal for at least 6 hours with a simple arteriovenous shunt.

Animals↗
PubMed2004

Flat panel detector-based volumetric CT: prototype evaluation with volumetry of small artificial nodules in a pulmonary phantom.

PURPOSE: To evaluate amorphous silicone-based flat panel detector volumetric CT (VCT) in volumetric assessment of small nodules in a pulmonary phantom, and to perform comparative experiments with 4-row multislice CT (MSCT). MATERIALS AND METHODS: Seventy synthetic nodules (volume range (VR): 0.99-185.77 mm; estimated diameter range (ED): 1.4-7.8 mm) were scanned in spherical shape and after iso-volumetric deformation with VCT and MSCT using 0.63 mm (MSCT I) and 1.25 mm (MSCT II) collimations. Measured volumes and percent measurement errors (PME) were compared between the 3 CT modes before and after nodule deformation. For each measurement pair before and after deformation, the post-deformation relative volumetric inaccuracy (RIA) was determined. Volume, PME, and RIA differences were tested using Wilcoxon and Friedman methods. RESULTS: The volumes of the smallest nodules (VR = 0.99-2.83 mm, ED = 1.4-1.9 mm) were computable only from VCT scans. In VCT, measured volumes and PMEs before and after deformation differed significantly less compared with MSCT (VCT: P = 0.06 and 0.56, respectively; MSCT I: P = 0.0012 and 0.006, respectively; and MSCT II: P < 0.0001 for measured volumes and PMEs). In VCT PMEs of 5.51-32.21 mm nodules (ED = 2.4-4.1 mm) before and after deformation were significantly below MSCT (VCT averages = 1.43-1.91% and 1.98-3.48%, for spherical and deformed nodules, respectively; MSCT I averages = 9.97-26.1% and 12.16-38.10%, respectively; MSCT II averages = 17.79-46.18 and 18.14-54.66%, respectively, P < 0.0001) and RIAs in VCT were significantly below MSCT (VCT: 0.50-2.62%, MSCT I: 3.35-15.97%, and MSCT II: 4.29-18.46%; P = 0.0001-0.0039). CONCLUSION: VCT volumetry is highly accurate in volumetry of smallest nodules with estimated diameters of 1.4-4.1 mm.

Humans↗
PubMed1989

Nucleotide sequence analysis of the small (S) RNA segment of Bunyamwera virus, the prototype of the family Bunyaviridae.

The nucleotide sequence of the small (S) RNA segment of the Bunyamwera virus genome has been determined. The S RNA is 961 bases in length and, in common with other bunyaviruses, encodes two proteins, N and NSs, in overlapping reading frames. A six-way alignment of the amino acid sequences of the N and NSs proteins of viruses representing three serogroups within the Bunyavirus genus indicates regions which are strongly conserved, and provides targets for future analysis of protein function.

Amino Acid Sequence↗
PubMed1994

Nucleotide sequence of RNA 1, the largest genomic segment of rice stripe virus, the prototype of the tenuiviruses.

The complete nucleotide sequence of RNA 1, the largest genomic segment of rice stripe virus (RSV), was determined using two sets of overlapping cDNA clones. RNA segment 1 comprises 8970 nucleotides and on the viral complementary sequence has a single long open reading frame coding for a protein of 2919 amino acids with an estimated M(r) of 336860. Amino acid sequence comparisons of the putative protein indicated strong homology (30% amino acid identity over about 1500 residues) with the L protein of the genus Phlebovirus of the Bunyaviridae, but no detectable similarity with other members of the Bunyaviridae. However, weak similarity was detected with the L protein of Tacaribe arenavirus. The highly homologous sequence domain includes the conserved motifs of the putative RNA-dependent RNA polymerase. The data presented here, along with previous work clearly show significant similarities in genome organization, structure and expression between RSV and members of the genus Phlebovirus of the Bunyaviridae. Taken together, we propose that tenuiviruses should be included in the Bunyaviridae under the genus Tenuivirus.

Amino Acid Sequence↗
PubMed2001

Evaluation of a prototype sub-unit vaccine against equine arteritis virus comprising the entire ectodomain of the virus large envelope glycoprotein (G(L)): induction of virus-neutralizing antibody and assessment of protection in ponies.

An Escherichia coli-expressed recombinant protein (6hisG(L)ecto) comprising the entire ectodomain (aa 18-122) of equine arteritis virus (EAV) glycoprotein G(L), the immunodominant viral antigen, induced higher neutralizing antibody titres than other G(L)-derived polypeptides when compared in an immunization study in ponies. The potential of the recombinant G(L) ectodomain to act as a sub-unit vaccine against EAV was evaluated further in three groups of four ponies vaccinated with doses of 35, 70 or 140 microg of protein. All vaccinated animals developed a virus-neutralizing antibody (VNAb) response with peak titres 1-2 weeks after the administration of a booster on week 5 (VNAb titres of 1.8-3.1), 13 (VNAb titres of 1.4-2.9) or 53 (VNAb titres of 1.2-2.3). Vaccinated and unvaccinated control ponies were infected with EAV at different times post-vaccination to obtain information about the degree of protection relative to the levels of pre-challenge VNAb. Vaccination conferred varying levels of protection, as indicated by reduced or absent pyrexia, viraemia and virus excretion from the nasopharynx. The degree of protection correlated well with the levels of pre-challenge VNAb and, in particular, with levels of virus excretion. These results provide the first evidence that a sub-unit vaccine protects horses against EAV. The use of the sub-unit vaccine in combination with a differential diagnostic test based on other EAV antigens would enable serological discrimination between naturally infected and vaccinated equines.

Amino Acid Sequence↗
PubMed2001

The Chryseobacterium meningosepticum PafA enzyme: prototype of a new enzyme family of prokaryotic phosphate-irrepressible alkaline phosphatases?

Chryseobacterium meningosepticum is an aerobic Gram-negative rod widely distributed in natural environments. Unlike many bacteria, it produces a phosphate-irrepressible periplasmic alkaline phosphatase (AP). This work describes cloning of the gene encoding that enzyme from C. meningosepticum CCUG 4310 (NCTC 10585), and preliminary characterization of its product. The gene, named pafA, encodes a protein (PafA) of 546 amino acids with a calculated molecular mass of the mature peptide of 58682 Da. PafA exhibits high sequence identity with the PhoV AP of Synechococcus PCC 7942 (49.9% identity) and with the Cda Ca(2+)-dependent ATPase of Myroides odoratus (51.9% identity), while being more distantly related to the PhoD AP of Zymomonas mobilis (22.1% identity) and to the PhoA AP of Escherichia coli (14.0% identity). PafA was partially purified; it exhibits optimal activity at pH 8.5 and is active towards a broad spectrum of substrates including both phosphomonoesters and ATP, with preferential activity for the latter compound. The present findings allow definition of a new family of APs including 60 kDa, periplasmic enzymes whose expression is not influenced by freely available P(i) in the medium. Moreover, PafA can be considered an evolutionary intermediate between Ca(2+)-ATPase of M. odoratus and the APs PhoV of Synechococcus PCC 7942 and PhoD of Z. mobilis.

Alkaline Phosphatase↗
PubMed2006

Pharmacologic targets and prototype therapeutics in the kallikrein-kinin system: bradykinin receptor agonists or antagonists.

The kallikrein-kinin system (KKS) is a complex system produced in various organs. This system includes kininogen (precursor for kinin), kallikreins, and pharmacologically active bradykinin (BK), which is considered to be proinflammatory and/or cardioprotective. It is a proinflammatory polypeptide that is involved in many pathological conditions and can cause pain, inflammation, increased vascular permeability, vasodilation, contraction of various smooth muscles, as well as cell proliferation. On the other hand, it has been shown that BK has cardioprotective effects, as all components of KKS are located in the cardiac muscles. Numerous observations have indicated that decreased activity of this system may lead to cardiovascular diseases, such as hypertension, cardiac failure, and myocardial infarction. BK acts on two receptors, B1 and B2, which are linked physiologically through their natural stimuli and their common participation in a variety of inflammatory responses. Recently, numerous BK antagonists have been developed in order to treat several diseases that are due to excessive BK formation. Although BK has many beneficial effects, it has been recognized to have some undesirable effects that can be reversed with BK antagonists. In addition, products of this system have multiple interactions with other important metabolic pathways, such as the renin-angiotensin system.

Bradykinin↗
PubMed2003

XOL-1, primary determinant of sexual fate in C. elegans, is a GHMP kinase family member and a structural prototype for a class of developmental regulators.

In Caenorhabditis elegans, an X chromosome-counting mechanism specifies sexual fate. Specific genes termed X-signal elements, which are present on the X chromosome, act in a concerted dose-dependent fashion to regulate levels of the developmental switch gene xol-1. In turn, xol-1 levels determine sexual fate and the activation state of the dosage compensation mechanism. The crystal structure of the XOL-1 protein at 1.55 A resolution unexpectedly reveals that xol-1 encodes a GHMP kinase family member, despite sequence identity of 10% or less. Because GHMP kinases, thus far, have only been characterized as small molecule kinases involved in metabolic pathways, for example, amino acid and cholesterol synthesis, XOL-1 is the first member that controls nonmetabolic processes. Biochemical investigations demonstrated that XOL-1 does not bind ATP under standard conditions, suggesting that XOL-1 acts by a mechanism distinct from that of other GHMP kinases. In addition, we have cloned a XOL-1 ortholog from Caenorhabditis briggsae, a related nematode that diverged from C. elegans approximately 50-100 million years ago. These findings demonstrate an unanticipated role for GHMP kinase family members as mediators of sexual differentiation and dosage compensation and, possibly, other aspects of differentiation and development.

Adenosine Triphosphatases↗