Comparison of an Adherence Domain and a Structural Region of Streptococcus mutans Antigen I/II in Protective Immunity against Dental Caries in Rats after Intranasal Immunization

Previous studies have identified an N-terminal saliva-binding region (SBR) on Streptococcus mutans surface antigen I/II (AgI/II) and suggested its importance in the initial adherence of S. mutans to saliva-coated tooth surfaces and subsequent development of dental caries. In this study, we compared the SBR with a C-terminal structural region of AgI/II (AgII) in their abilities to induce protective immunity against caries in rats. When SBR, AgII, or the whole AgI/II molecule was administered intranasally as a conjugate with the B subunit of cholera toxin (CT), in the presence of CT adjuvant, substantial levels of salivary immunoglobulin A anti-AgI/II antibodies were induced. Evaluation of caries activity showed that the SBR, though not as protective as the parent molecule, was superior to AgII and thus can be further considered as a component in a multivalent caries vaccine.     

Inflammatory Markers in Acute Myocardial Infarction Patients: Preliminary Evidence of a Prospective Association With Depressive Symptoms

Inflammatory activity has been associated with both coronary disease and depressive symptoms. We sought to determine whether inflammatory markers in myocardial infarction (MI) patients are prospectively associated with depressive symptomatology. Participants were a convenience sample of MI patients. Depressive symptoms were assessed soon after the MI and again 7 months postdischarge. Inflammatory markers examined were interleukin-6 (IL-6) and interleukin-1β. Results suggest no significant cross-sectional association between inflammatory markers and depressive symptoms at baseline. However, bivariate and multiple regression analyses revealed a significant positive prospective association between baseline IL-6 and depressive symptoms 7 months later ( β  = .57, p  < .01). The results suggest that temporal considerations are important in understanding relationships between inflammation and depressive symptoms following MI.     

Reduced hippocampal insulin-degrading enzyme in late-onset Alzheimer's disease is associated with the apolipoprotein E-epsilon4 allele

Abeta is the major component of amyloid plaques characterizing Alzheimer's disease (AD). Abeta accumulation can be affected by numerous factors including increased rates of production and/or impaired clearance. Insulin-degrading enzyme (IDE) has been implicated as a candidate enzyme responsible for the degradation and clearance of Abeta in the brain. We have previously shown that AD patients exhibit abnormalities in insulin metabolism that are associated with apoliprotein E (APOE) status. The possible association of IDE with AD, as well as the link between APOE status and insulin metabolism, led us to examine the expression of IDE in AD. We report that hippocampal IDE protein is reduced by approximately 50% in epsilon4+ AD patients compared to epsilon4- patients and controls. The allele-specific decrease of IDE in epsilon4+ AD patients is not associated with neuronal loss since neuron-specific enolase levels were comparable between the AD groups, regardless of APOE status. Hippocampal IDE mRNA levels were also reduced in AD patients with the epsilon4 allele compared to AD and normal subjects without the epsilon4 allele. These findings show that reduced IDE expression is associated with a significant risk factor for AD and suggest that IDE may interact with APOE status to affect Abeta metabolism.     

The influence of calcium on sodium efflux in squid axons

1. Previous work has shown that the sodium efflux from the axons of Loligo forbesi increases when external sodium is replaced by lithium.

2. The increase in efflux in lithium was unaffected by ouabain but was abolished by removal of external calcium; in these respects it differed from the potassium-dependent sodium efflux which was abolished by ouabain but not reduced by removal of external calcium.

3. Strontium but not magnesium could replace calcium in activating the ouabain-insensitive sodium efflux; lanthanum had an inhibitory effect.

4. Replacing all the external NaCl by choline chloride or dextrose gave a rise in Na efflux which was abolished by ouabain but not by removal of external calcium.

5. The rise in Na efflux resulting from partial replacement of NaCl by dextrose or choline chloride consisted of two components one of which was ouabain-insensitive and calcium-dependent and the other was inhibited by ouabain but calcium-insensitive.

6. The ouabain-insensitive component of the Na efflux was activated by low concentrations of Na, Li or K but inhibited by high concentrations of Na and to a lesser extent Li. The inhibiting effect of high Na was of the kind expected if these ions displace calcium from an external site.

7. The ouabain-insensitive component of the Na efflux was abolished by cyanide, had a Q₁₀ of 2·7; and was roughly proportional to [Na]_i². It was much more variable in magnitude than the ouabain-sensitive, potassium-dependent component of the sodium efflux.

8. The calcium influx increased five to fortyfold when external NaCl was replaced by LiCl or dextrose, the increase for Li being larger than the increase for dextrose.

9. The calcium influx from Na, Li or dextrose sea water was increased three to tenfold by increasing the internal Na about fourfold.

10. The experiments provide evidence for a coupling between an inward movement of calcium and an outward movement of sodium.

     

Novel sequence variants in the TMC1 gene in Pakistani families with autosomal recessive hearing impairment

Though many hearing impairment genes have been identified, only a few of these genes have been screened in population studies. For this study, 168 Pakistani families with autosomal recessive hearing impairment not due to mutations in the GJB2 (Cx26) gene underwent a genome scan. Two-point and multipoint parametric linkage analyses were carried out. Twelve families had two-point or multipoint LOD scores of 1.4 or greater within the transmembrane cochlear expressed gene 1 (TMC1) region and were subjected to further screening with direct DNA sequencing. Five novel putatively functional non-synonymous sequence variants, c.830A>G (p.Y277C), c.1114G>A (p.V372M), c.1334G>A (p.R445H), c.2004T>G (p.S668R), and c.2035G>A (p.E679K), were found to segregate within seven families, but were not observed in 234 Pakistani control chromosomes. The variants c.830A>G (p.Y277C), c.1114G>A (p.V372M), and c.1334G>A (p.R445H) occurred at highly conserved regions and were predicted to lie within hydrophobic transmembrane domains, while non-synonymous variants c.2004T>G (p.S668R) and c.2035G>A (p.E679K) occurred in extracellular regions that were not highly conserved. There is evidence that the c.2004T>G (p.S668R) variant may have occurred at a phosphorylation site. One family has the known splice site mutation c.536 -8T>A. The prevalence of non-syndromic hearing impairment due to TMC1 in this Pakistani population is 4.4% (95%CI: 1.9, 8.6%). The TMC1 protein might have an important function in K(+) channels of inner hair cells, which would be consistent with the hypothetical structure of protein domains in which sequence variants were identified.     

Representing nursing assessments in clinical information systems using the logical observation identifiers, names, and codes database

In recent years, the Logical Observation Identifiers, Names, and Codes (LOINC) Database has been expanded to include assessment items of relevance to nursing and in 2002 met the criteria for "recognition" by the American Nurses Association. Assessment measures in LOINC include those related to vital signs, obstetric measurements, clinical assessment scales, assessments from standardized nursing terminologies, and research instruments. In order for LOINC to be of greater use in implementing information systems that support nursing practice, additional content is needed. Moreover, those implementing systems for nursing practice must be aware of the manner in which LOINC codes for assessments can be appropriately linked with other aspects of the nursing process such as diagnoses and interventions. Such linkages are necessary to document nursing contributions to healthcare outcomes within the context of a multidisciplinary care environment and to facilitate building of nursing knowledge from clinical practice. The purposes of this paper are to provide an overview of the LOINC database, to describe examples of assessments of relevance to nursing contained in LOINC, and to illustrate linkages of LOINC assessments with other nursing concepts.     

Cellular mechanisms of the adjuvant activity of the flagellin component FljB of Salmonella enterica Serovar Typhimurium to potentiate mucosal and systemic responses

An expanding area of interest is the utilization of microbe-based components to augment mucosal and systemic immune responses to target antigens. Thus, the aim of the present study was to assess if the flagellin component FljB from Salmonella enterica serovar Typhimurium could act as a mucosal adjuvant and then to determine the cellular mechanism(s) by which FljB mediates its adjuvant properties. To determine if FljB could act as a mucosal adjuvant, mice were immunized by the intranasal (i.n.) route with antigen alone or in conjunction with FljB. Additionally, we assessed how FljB affected the levels of the costimulatory molecules B7-1 and B7-2 on dendritic cells by flow cytometry and determined the functional role these costimulatory molecules played in the adjuvant properties of FljB in vivo. Mice immunized by the i.n. route with antigen and FljB exhibited significantly elevated levels of mucosal and systemic antibody and CD4(+)-T-cell responses compared to mice given antigen only. Stimulation of dendritic cells in vitro with FljB resulted in a pronounced increase in the surface expression of B7-1 and B7-2. The percentage of dendritic cells expressing B7-2 but not B7-1 increased significantly when stimulated with FljB over a concentration range of 10 to 10,000 ng/ml. Immunization of wild-type and B7-1, B7-2, and B7-1/2 knockout mice by the i.n. route revealed that the ability of FljB to increase B7-2 expression is largely responsible for its adjuvant effect in vivo. These findings demonstrate that FljB can act as an effective mucosal adjuvant and that its ability to enhance the level of B7-2 expression is predominantly responsible for its adjuvant properties.     

Comparison of the sensitivities of the version 1.5 and version 1.0 ultrasensitive Roche AMPLICOR HIV-1 MONITOR kits at low concentrations of human immunodeficiency virus RNA

The sensitivities of the version 1.5 and 1.0 Roche UltraSensitive AMPLICOR HIV-1 MONITOR tests were compared using panels of coded samples of subtype B human immunodeficiency virus type 1 spiked into plasma at predetermined concentrations. Results indicate that the version 1.5 kit is more sensitive than the version 1.0 kit.     

Egfl7 knockdown causes defects in the extension and junctional arrangements of endothelial cells during zebrafish vasculogenesis.

The endothelial cell (EC) -specific secreted protein EGFL7 is important for tubulogenesis in newly forming blood vessels. We studied its role in vascular tube formation by a quantitative ultrastructural analysis of Egfl7-knockdown zebrafish embryos. At 24 hours postfertilization, the endothelia of dorsal aorta (DA) and posterior cardinal vein (PCV) were correctly anchored to the hypochord and endoderm, respectively, but failed to expand into the vascular area. This resulted in vessels with reduced or split lumen and open sheets of ECs. Concomitantly, the organization of hematopoietic cells-identified by the presence of previously undescribed membrane tubules-between DA and PCV, and within the vessels, was severely disturbed. Strikingly, ectopic cell junctions occurred across the obstructed vessel lumen, on the luminal EC surfaces, which in control conditions never display junctions of any kind. These data suggest that Egfl7 provides ECs with a cue for their extension into the vascular area and in establishing EC cell polarity.     

Receptors for neurohypophyseal hormones along the rat nephron: 125I-labelled d(CH2)5[Tyr(Me)2, Thr4, Orn8, Tyr-NH 2 9 ] vasotocin binding in microdissected tubules

A microassay was developed to measure the binding of the labelled monoiodinated analogue [1-(mercapto-,-cyclopentamethylenepropionic acid), 2-O-mithyltyrosine, 4-threonine, 8-ornithine, 9-¹²⁵I-tyrosylamide]vasotocin ¹²⁵I-d(CH₂)₅[Tyr (Me)², Thr⁴, Tyr-NH ₂ ⁹ ]OVT to isolated nephron segments microdissected from collagenase-treated rat kidneys. When determined using 1.7 nM labelled ligand at 4° C, specific binding sites (expressed at 10^–18 mol ¹²⁵I-d(CH₂)₅[Tyr (Me)², Thr⁴, Tyr-NH ₂ ⁹ ]OVT bound/mm tubule length) were found in medullary thick ascending limbs (MTAL), 1.67±0.49; cortical thick ascending limbs, 2.20±0.80; cortical collecting ducts, 2.39±0.86; outer medullary collecting ducts (OMCD), 2.54±0.53 and inner medullary collecting ducts, 5.33±0.40, whereas no specific binding could be detected in glomeruli and proximal tubules. Specific ¹²⁵I-d(CH₂)₅[Tyr (Me)², Thr⁴, Tyr-NH ₂ ⁹ ]OVT binding to OMCD was saturable with incubation time and reversible after elimination of free labelled ligand (the association and dissociation rate constants at 4° C were 1.06×10⁷ M^–1 min^–1 and 1.95×10^–2 min^–1 respectively). The stereospecificity of MTAL and OMCD binding sites was assessed in competitive experiments revealing the following recognition pattern for a series of eight vasopressin analogues:ddAVP>AVP>d(CH₂)₅-[Tyr (Me)², Thr⁴, Tyr-NH ₂ ⁹ ]OVT=AVT=OT>d(CH₂)₅[Tyr(Me)²]AVP=[Thr⁴, Gly⁷]OT>[Phe², Orn⁸]VT, whereas pharmacological concentrations of insulin and glucagon did not impair radioligand binding. These results indicate that the detected labelled binding sites might correspond mainly to physiological V₂ vasopressin receptors.