Cloning of the Streptococcus mutans gene encoding glucan binding protein B and analysis of genetic diversity and protein production in clinical isolates

Streptococcus mutans, the primary etiological agent of dental caries, produces several activities that promote its accumulation within the dental biofilm. These include glucosyltransferases, their glucan products, and proteins that bind glucan. At least three glucan binding proteins have been identified, and GbpB, the protein characterized in this study, appears to be novel. The gbpB gene was cloned and the predicted protein sequence contained several unusual features and shared extensive homology with a putative peptidoglycan hydrolase from group B streptococcus. Examination of gbpB genes from clinical isolates of S. mutans revealed that DNA polymorphisms, and hence amino acid changes, were limited to the central region of the gene, suggesting functional conservation within the amino and carboxy termini of the protein. The GbpB produced by clinical isolates and laboratory strains showed various distributions between cells and culture medium, and amounts of protein produced by individual strains correlated positively with their ability to grow as biofilms in an in vitro assay.

Liquid dose pulmonary instillation of gentamicin PulmoSpheres formulations: tissue distribution and pharmacokinetics in rabbits

PURPOSE

To assess the pharmacokinetics and biodistribution of gentamicin, delivered as PulmoSpheres formulations in rabbit serum and lung tissue following intratracheal instillation in a perflubron vehicle.

METHODS

Rabbits were anesthetized, intubated, and mechanically ventilated with O2 (FiO2 = 0.50). Animals were then given 5 mg/kg gentamicin either intravenously, intramuscularly (TM), or intratracheally (IT) gentamicin PulmoSpheres formulation, instilled in 1.8 ml/kg of liquid perflubron vehicle. Serum and lung lobe sections were collected at multiple time points and assayed for gentamicin content.

RESULTS

Serum gentamicin levels peaked at 64.7 microg/ml, 11.2 microg/ml, and 5.0 microg/ml following intravenous, TM, and IT administration, respectively. Absolute bioavailabilitv at 8 h for IM administration was 76.8% and 57.0% when delivered IT. Although peak lung levels of drug were reached within 1 h, total lung gentamicin concentration after IT administration was more than two orders of magnitude greater than that achieved following TM administration (680,540 vs. 4,985 microg min, respectively) with significant levels of the antibiotic remaining in the lung even after 1 week.

CONCLUSIONS

High levels of gentamicin in lung tissue can be achieved by instillation of a gentamicin PulmoSpheres formulation in a perflubron vehicle, termed liquid dose installation, without reaching toxic systemic levels allowing for increased local delivery of agents such as gentamicin at the site of the infection.

A longitudinal study of hippocampal volume in first episode psychosis and chronic schizophrenia

Brain abnormalities have been identified in patients with schizophrenia, but what is unclear is whether these changes are progressive over the course of the disorder. In this longitudinal study, hippocampal and temporal lobe volumes were measured at two time points in 30 patients with first episode psychosis (mean follow-up interval=1.9 years, range 0.54-4.18 years) and 12 with chronic schizophrenia (mean follow-up interval=2.3 years, range 1.03-4.12 years) and compared to 26 comparison subjects (mean follow-up interval 2.2 years, range 0.86-4.18 years). Hippocampal, temporal lobe, whole-brain and intracranial volumes (ICV) were estimated from high-resolution magnetic resonance images. Only whole-brain volume showed significant loss over the follow-up interval in both patient groups. The rate of this volume loss was not different in the first episode group compared to the chronic group. There were no changes in either hippocampal or temporal lobe volumes. The negative findings for the hippocampus and temporal lobes may mean that the abnormalities in these regions are stable features of schizophrenia. Alternatively, the period before the onset of frank psychotic symptoms may be the point of greatest risk for progressive change.

Selective bilateral hippocampal volume loss in chronic schizophrenia

BACKGROUND

The hippocampus is implicated in the pathophysiology of schizophrenia; however, volumetric changes are subtle and have limited diagnostic specificity. It is possible that the shape of the hippocampus may be more characteristic of schizophrenia.

METHODS

Forty-five patients with chronic schizophrenia and 139 healthy control subjects were scanned using magnetic resonance imaging. Hippocampi were traced manually, and two-dimensional shape information was analyzed.

RESULTS

Two shape factors were found to be adequate to represent variance in the shape of the hippocampus. One of these factors, representing volume loss behind the head of the hippocampus, provided a degree of discrimination between patients with chronic schizophrenia and healthy control subjects; however, overall hippocampal volume following appropriate adjustment for brain volume showed a similar level of discrimination. Patients with chronic schizophrenia were best characterized using these two measures together, but diagnostic specificity was only moderate.

CONCLUSIONS

This study identified that less of the hippocampus was distributed in its posterior two-thirds in patients with chronic schizophrenia, and specifically in the region just posterior to the hippocampal head. Group discrimination on the basis of hippocampal volume and shape measures was moderately good. A full three-dimensional analysis of hippocampal shape, based on large samples, would be a useful extension of the study.

Survey results of women who have been strangled while in an abusive relationship

Few studies attempt to examine individual methods of domestic abuse. The objectives of this study are to evaluate strangulation as a method of domestic violence abuse: to determine the incidence of strangulation occurrence within the cycle of domestic violence, the subjective medical symptoms experienced by victims of intimate partner strangulation, and the elective utilization of health care following a strangulation incident. Sixty-two women were surveyed at two women's shelters in Dallas, Texas and Los Angeles, California and the Parkland Health & Hospital (PHHS) Violence Intervention Prevention (VIP) Center in Dallas, Texas. Each patient was individually interviewed and verbal responses were recorded. Statistics were performed using the SPSS program. Of the 62 surveyed, 42 (68%) had been strangled by their intimate partner who was a husband (23, 55%), boyfriend (13, 31%), or fiancé (2, 5%), by a mother, stranger, or friend (1 each). Strangulation, as a method of domestic violence, is quite common in women seeking medical help or shelter in a large urban city. This study suggests that strangulation occurs late in the abusive relationship; thus, women presenting with complaints consistent with strangulation probably represent women at higher risk for major morbidity or mortality.

Frequency and relationship of reported symptomology in victims of intimate partner violence: the effect of multiple strangulation attacks

The objective of this study is to examine the correlation between the number of times a victim of intimate partner violence (IPV) has been strangled and symptom development subsequent to the attacks. One hundred and one female subjects responded to a series of questions regarding the history and characteristics of the strangulation and the development of specific medical symptoms. Multiple strangulation victims, individuals who had experienced more than one strangulation attack, on separate occasions, by the same abuser, reported neck and throat injuries, neurologic disorders, and psychological disorders with increased frequency. Despite the increased frequency of symptoms, only 39% of the multiple strangulation victims sought medical care. These observations strongly support the need for health care professionals to inquire about the incidence of strangulation, examine the victim closely for evidence of injuries caused by the attacks, and recommend immediate care in anticipation of the potentially long term medical needs.

Frequency and relationship of reported symptomology in victims of intimate partner violence: the effect of multiple strangulation attacks

The objective of this study is to examine the correlation between the number of times a victim of intimate partner violence (IPV) has been strangled and symptom development subsequent to the attacks. One hundred and one female subjects responded to a series of questions regarding the history and characteristics of the strangulation and the development of specific medical symptoms. Multiple strangulation victims, individuals who had experienced more than one strangulation attack, on separate occasions, by the same abuser, reported neck and throat injuries, neurologic disorders, and psychological disorders with increased frequency. Despite the increased frequency of symptoms, only 39% of the multiple strangulation victims sought medical care. These observations strongly support the need for health care professionals to inquire about the incidence of strangulation, examine the victim closely for evidence of injuries caused by the attacks, and recommend immediate care in anticipation of the potentially long term medical needs.

Distinct ligand binding properties of Mac-2-binding protein and mouse cyclophilin [correction of mousephilin] C-associated protein

Human Mac-2-binding protein (Mac-2-BP) is a secreted glycoprotein that is widely expressed. It binds to the human macrophage-associated lectin Mac-2 and has been suggested to have a role in host defence. Mouse cyclophilin C-associated protein (mCyCAP) is also a secreted glycoprotein that binds with high affinity to cyclophilin C in the absence of the immunosuppressive drug cyclosporin A. The two proteins share a similar domain structure and considerable sequence identity, including a highly conserved scavenger receptor cysteine-rich domain, and both of them exert their function within the immune system. To elucidate whether these molecules are also functional homologues, we compared their ligand binding properties using cell lines which express Mac-2-BP or mCyCAP as well as transfected cell lines stably expressing mCyCAP or a mutant version lacking the scavenger domain. These experiments show that Mac-2-BP is unable to bind to either human or mouse cyclophilin C and thatmCyCAP cannot bind to Mac-2. The scavenger domain is not required for the interaction between mCyCAP and cyclophilin C. We conclude that these proteins may be part of a larger family of proteins of immunological importance in which closer functional homologues might exists.

Genotypic diversity of mutans streptococci in Brazilian nursery children suggests horizontal transmission

Streptococcus mutans strains were isolated from cohorts of Brazilian nursery school children and genotyped by arbitrarily primed PCR and restriction fragment length polymorphism analysis. Of 24 children with two to five S. mutans isolates, 29% carried two or more genotypes. The presence of matching genotypes of S. mutans among children attending one nursery suggests horizontal transmission.

Renal tubular injury is present in acute inflammatory bowel disease prior to the introduction of drug therapy

BACKGROUND

5-aminosalicylic acid (5-ASA) has been associated with renal complications in inflammatory bowel disease. Renal function is typically monitored using serum creatinine; however, significant disease may predate increases in creatinine.

AIMS

To identify whether markers of early renal disease (urinary albumin, alpha-1-microglobulin [alpha-1-M] and N-acetyl-beta-D-glucosaminidase [NAG], and serum cystatin C) are useful in the assessment of renal function in inflammatory bowel disease patients receiving 5-ASA.

METHODS

Twenty-one patients with a new diagnosis of inflammatory bowel disease were investigated. Samples were taken at diagnosis, and at 3-monthly intervals after the commencement of 5-ASA, for 1 year.

RESULTS

Mean creatinine clearance was 100 mL/min and did not change following treatment. Inflammatory bowel disease was not associated with albuminuria. Urinary N-acetyl-beta-D-glucosaminidase and alpha-1-microglobulin at diagnosis were increased in 10 (48%) and 11 (52%) patients, respectively: treatment was not associated with consistent changes in urinary protein excretion. There was a significant correlation between cystatin C and creatinine clearance both at diagnosis (r=-0.533, P=0.0275) and combining the initial and follow-up data (r=-0.601, P < 0.01), but not between creatinine and creatinine clearance (P > 0.05).

CONCLUSIONS

Tubular proteinuria is an extra-intestinal manifestation of inflammatory bowel disease irrespective of 5-ASA treatment. Tubular proteins are not useful predictors of an adverse renal response to 5-ASA. Serum cystatin C may be an improved marker of glomerular filtration rate in this setting.

Test of a potential link between analytic and nonanalytic category learning and automatic, effortful processing

The link between automatic and effortful processing and nonanalytic and analytic category learning was evaluated in a sample of 29 college undergraduates using declarative memory, semantic category search, and pseudoword categorization tasks. Automatic and effortful processing measures were hypothesized to be associated with nonanalytic and analytic categorization, respectively. Results suggested that contrary to prediction strong criterion-attribute (analytic) responding on the pseudoword categorization task was associated with strong automatic, implicit memory encoding of frequency-of-occurrence information. Data are discussed in terms of the possibility that criterion-attribute category knowledge, once established, may be expressed with few attentional resources. The data indicate that attention resource requirements, even for the same stimuli and task, vary depending on the category rule system utilized. Also, the automaticity emerging from familiarity with analytic category exemplars is very different from the automaticity arising from extensive practice on a semantic category search task. The data do not support any simple mapping of analytic and nonanalytic forms of category learning onto the automatic and effortful processing dichotomy and challenge simple models of brain asymmetries for such procedures.

Facilitated intranasal induction of mucosal and systemic immunity to mutans streptococcal glucosyltransferase peptide vaccines

Synthetic peptide vaccines which are derived from functional domains of Streptococcus mutans glucosyltransferases (GTF) have been shown to induce protective immunity in Sprague-Dawley rats after subcutaneous injection in the salivary gland region. Since mucosal induction of salivary immunity would be preferable in humans, we explored methods to induce mucosal antibody in the rat to the GTF peptide vaccines HDS and HDS-GLU after intranasal administration. Several methods of facilitation of the immune response were studied: the incorporation of peptides in bioadhesive poly(D,L-lactide-coglycolide) (PLGA) microparticles, the use of monoepitopic (HDS) or diepitopic (HDS-GLU) peptide constructs, or the use of mucosal adjuvants. Salivary immunoglobulin A (IgA) responses were not detected after intranasal administration of diepitopic HDS-GLU peptide constructs in alum or after incorporation into PLGA microparticles. However, significant primary and secondary salivary IgA and serum IgG antibody responses to HDS were induced in all rats when cholera holotoxin (CT) or a detoxified mutant Escherichia coli heat-labile enterotoxin (R192G LT) were intranasally administered with HDS peptide constructs in PLGA. Coadministration of LT with HDS resulted in predominantly IgG2a responses in the serum, while coadministration with CT resulted in significant IgG1 and IgG2a responses to HDS. Serum IgG antibody, which was induced to the HDS peptide construct by coadministration with these adjuvants, also bound intact mutans streptococcal GTF in an enzyme-linked immunosorbent assay and inhibited its enzymatic activity. Thus, immune responses which are potentially protective for dental caries can be induced to peptide-based GTF vaccines after mucosal administration if combined with the CT or LT R192G mucosal adjuvant.

Cloning and characterization of a canine UDP-glucuronosyltransferase

UDP-glucuronosyltransferases (UGTs) are a major family of enzymes catalyzing the transfer of glucuronic acid to a range of endogenous compounds and xenobiotics facilitating their elimination in either urine or bile. Although the dog is commonly used in drug metabolism studies, relatively little is known about the expression and activity of UGTs in this species. This report describes the molecular cloning and functional characterization of the first dog UGT, UGT1A6. The cloned protein is composed of 528 amino acids with the variable region demonstrating a 67-72% identity with the variable regions of mouse, rat, and human UGT1A6. The enzyme expressed stably in V79 cells predominantly catalyzed the glucuronidation of simple, planar phenols (e.g., for 1-naphthol, K(m) = 41 microM, V(max) = 0.07 nmol/min/mg protein), a class of compounds extensively glucuronidated by human UGT1A6. Based on sequence homology and common catalytic activity, this dog UGT1A protein appears to be the canine orthologue of human UGT1A6.

Diepitopic construct of functionally and epitopically complementary peptides enhances immunogenicity, reactivity with glucosyltransferase, and protection from dental caries

Coimmunization with peptide constructs from catalytic (CAT) and glucan-binding (GLU) domains of glucosyltransferase (GTF) of mutans streptococci has resulted in enhanced levels of antibody to the CAT construct and to GTF. We designed and synthesized a diepitopic construct (CAT-GLU) containing two copies of both CAT (B epitope only) and GLU (B and T epitope) peptides. The immunogenicity of this diepitopic construct was compared with that of individual CAT and GLU constructs by immunizing groups of Sprague-Dawley rats subcutaneously in the salivary gland vicinity with the CAT-GLU, CAT, or GLU construct or by treating rats by sham immunization. Levels of serum immunoglobulin G (IgG) antibody to GTF or CAT in the CAT-GLU group were significantly greater than in GLU- or CAT-immunized groups. Immunization with CAT-GLU was compared to coimmunization with a mixture of CAT and GLU in a second rodent experiment under a similar protocol. CAT-GLU immunization resulted in serum IgG and salivary IgA responses to GTF and CAT which were greater than after coimmunization. Immunization with the diepitopic construct and communization with CAT and GLU constructs showed proliferation of T lymphocytes to GTF. Immunization with either the CAT or GLU construct has been shown to elicit significant protection in a rodent dental caries model. Similarly in this study, the enhanced response to GTF after immunization with the CAT-GLU construct resulted in protective effects on dental caries. Therefore, the CAT-GLU diepitopic construct can be a potentially important antigen for a caries vaccine, giving rise to greater immune response than after immunization with CAT, GLU, or a mixture of the two.

Receptor-mediated targeting of spray-dried lipid particles coformulated with immunoglobulin and loaded with a prototype vaccine

PURPOSE

Spray-dried lipid-based microparticles (SDLM) serve as a platform for delivery of a wide variety of compounds including peptides, proteins, and vaccines to the respiratory mucosa. In the present study, we assessed the impact of IgG-mediated targeting to phagocytic cells of inactivated influenza virus formulated in SDLM, on subsequent immune responses.

METHODS

SDLM were produced containing inactivated influenza virus strain A/WSN/32/H1N1 (WSN), with or without IgG. Using phagocytic antigen presenting cells (APC) and a T cell hybridoma (TcH) line specific for a dominant influenza virus epitope, we compared the in vitro responses elicited by ligand-formulated (SDLM-IgG-WSN) and non-ligand particles (SDLM-WSN). The effect of including the IgG ligand in the formulation was further characterized by measuring the immune responses of rodents vaccinated with SDLM.

RESULTS

SDLM-IgG-WSN were internalized in an Fc receptor (FcR)-dependent manner by phagocytic APC that were then able to effectively present a dominant, class II-restricted epitope to specific T cells. While SDLM-WSN elicited a lower response than administration of plain inactivated virus in saline, the level of the T cell response was restored both in vitro and in vivo by incorporating the APC FcR ligand, IgG, in the SDLM.

CONCLUSIONS

Incorporation of FcR ligand (IgG) in SDLM restored the limited ability of formulated virus to elicit T-cell immunity, by receptor-mediated targeting to phagocytes.

Effect of nasal dilators on nasal structures, sniffing strategies, and olfactory ability

This paper describes the effects that nasal dilators have on olfactory ability. Experimental results demonstrate that nasal dilators increase odorant identification, lower odorant threshold, and increase perceptual odorant intensity. In other experiments, magnetic resonance imaging (MRI) data demonstrates that the size of the nasal cavity especially around the region of the nasal valve is increased when nasal dilators are worn. Additionally, pneumotachograph data demonstrates that during a sniff, the peak flow, maximum flow rate, volume, and duration are all increased when nasal dilators are worn. Taken together, the increase in olfactory ability can most easily be explained by an increase in both the amount and the proportion of inspired odorant molecules that are directed to the olfactory mucosa and are, therefore, available for odorant perception.

Passive transfer of immunoglobulin Y antibody to Streptococcus mutans glucan binding protein B can confer protection against experimental dental caries

Active immunization with Streptococcus mutans glucan binding protein B (GBP-B) has been shown to induce protection against experimental dental caries. This protection presumably results from continuous secretion of salivary antibody to GBP-B, which inhibits accumulation of S. mutans within the oral biofilm. The purpose of this study was to explore the influence of short-term (9- or 24-day) passive oral administration of antibody to S. mutans GBP-B on the longer-term accumulation and cariogenicity of S. mutans in a rat model of dental caries. Preimmune chicken egg yolk immunoglobulin Y (IgY) or IgY antibody to S. mutans GBP-B was supplied in lower (experiment 1) and higher (experiment 2) concentrations in the diet and drinking water of rats for 9 (experiment 1) or 24 (experiment 2) days. During the first 3 days of IgY feeding, all animals were challenged with 5 x 10(6) streptomycin-resistant S. mutans strain SJ-r organisms. Rats remained infected with S. mutans for 78 days, during which rat molars were sampled for the accumulation of S. mutans SJ-r bacteria and total streptococci. Geometric mean levels of S. mutans SJ-r accumulation on molar surfaces were significantly lower in antibody-treated rats on days 16 and 78 of experiment 2 and were lower on all but the initial (day 5) swabbing occasions in both experiments. Relative to controls, the extent of molar dental caries measured on day 78 was also significantly decreased. The decrease in molar caries correlated with the amount and duration of antibody administration. This is the first demonstration that passive antibody to S. mutans GBP-B can have a protective effect against cariogenic S. mutans infection and disease. Furthermore, this decrease in infection and disease did not require continuous antibody administration for the duration of the infection period. This study also indicates that antibody to components putatively involved only in cellular aggregation can have a significant effect on the incorporation of mutans streptococci in dental biofilm.

Infection of endothelial cells with equine herpesvirus-1 (EHV-1) occurs where there is activation of putative adhesion molecules: a mechanism for transfer of virus

Evidence is presented to show that activation of endothelial and leucoyte adhesion molecules is a key step in transferring virus from infected leucocytes; and determines the restricted tissue tropism. A range of tissues from 2 experimentally infected mares in late pregnancy at 4 and 8 days after infection with EHV-1 were compared with those from normal pregnant and nonpregnant mares. Rabbit antisera to equine activated endothelial cell molecules were used to identify which tissues expressed these molecules in normal nongravid and gravid mares, and to investigate whether the range of tissues was altered in pregnant mares as a consequence of infection. The results indicated that the endothelium of the pregnant reproductive tract did express these molecules. In the 2 pregnant mares infected with EHV-1, the endothelial cells in the nasal mucosa also expressed these activated endothelial cell molecules. Therefore, the sites expressing these molecules closely correlated with those where virus infection of endothelial cells has been described and is consistent with experimental in vitro data, indicating that expression of these molecules is an essential stage in the transference of virus from leucocytes to endothelial cells.

An assessment of the data quality for NHEXAS--Part I: Exposure to metals and volatile organic chemicals in Region 5

A National Human Exposure Assessment Survey (NHEXAS) was performed in U.S. Environmental Protection Agency (U.S. EPA) Region V, providing population-based exposure distribution data for metals and volatile organic chemicals (VOCs) in personal, indoor, and outdoor air, drinking water, beverages, food, dust, soil, blood, and urine. One of the principal objectives of NHEXAS was the testing of protocols for acquiring multimedia exposure measurements and developing databases for use in exposure models and assessments. Analysis of the data quality is one element in assessing the performance of the collection and analysis protocols used in NHEXAS. In addition, investigators must have data quality information available to guide their analyses of the study data. At the beginning of the program quality assurance (QA) goals were established for precision, accuracy, and method quantification limits. The assessment of data quality was complicated. First, quality control (QC) data were not available for all analytes and media sampled, because some of the QC data, e.g., precision of duplicate sample analysis, could be derived only if the analyte was present in the media sampled in at least four pairs of sample duplicates. Furthermore, several laboratories were responsible for the analysis of the collected samples. Each laboratory provided QC data according to their protocols and standard operating procedures (SOPs). Detection limits were established for each analyte in each sample type. The calculation of the method detection limits (MDLs) was different for each analytical method. The analytical methods for metals had adequate sensitivity for arsenic, lead, and cadmium in most media but not for chromium. The QA goals for arsenic and lead were met for all media except arsenic in dust and lead in air. The analytical methods for VOCs in air, water, and blood were sufficiently sensitive and met the QA goals, with very few exceptions. Accuracy was assessed as recovery from field controls. The results were excellent (> or = 98%) for metals in drinking water and acceptable (> or = 75%) for all VOCs except o-xylene in air. The recovery of VOCs from drinking water was lower, with all analytes except toluene (98%) in the 60-85% recovery range. The recovery of VOCs from drinking water also decreased when comparing holding times of < 8 and > 8 days. Assessment of the precision of sample collection and analysis was based on the percent relative standard deviation (% RSD) between the results for duplicate samples. In general, the number of duplicate samples (i.e., sample pairs) with measurable data were too few to assess the precision for cadmium and chromium in the various media. For arsenic and lead, the precision was excellent for indoor, and outdoor air (< 10% RSD) and, although not meeting QA goals, it was acceptable for arsenic in urine and lead in blood, but showed much higher variability in dust. There were no data available for metals in water and food to assess the precision of collection and analysis.

Oligonucleotide containing CpG motifs enhances immune response to mucosally or systemically administered tetanus toxoid

Oligodeoxynucleotides (ODN) containing unmethylated CpG dinucleotides induce proliferation of B cells and activation of macrophages and thus stimulation of the immune system. We tested an oligonucleotide containing an unmethylated CpG dinucleotide flanked by two 5' purines and two 3' pyrimidines (GAGAACGCTCGACCTTCGAT) for the ability to affect antibody levels to tetanus toxoid (Tt). Groups of male Rowett rats (n=5-6/group) received colloidal aluminium hydroxide (Al(OH)3) either alone, or with Tt bound to the Al(OH)3, or with Tt bound to Al(OH)3 with the addition of the CpG oligonucleotide. Antigens were administered subcutaneously in the salivary gland vicinity once, or by gastric intubation on 3 consecutive days. On day 124 all animals were given a boost with the same material by the same route. Serum IgG and saliva IgA antibody to Tt was determined by ELISA. Serum antibody levels were significantly higher in ODN+Tt treated rats than in Tt-alone rats immunized by either route after primary or booster immunizations. Thus, administration of an ODN containing unmethylated CpG motifs along with an immunogen bound to Al(OH)3 can result in enhanced specific antibody when administered by intragastric as well as subcutaneous routes.

Understanding the mechanism of ice binding by type III antifreeze proteins

Type III antifreeze proteins (AFPs) are present in the body fluids of some polar fishes where they inhibit ice growth at subzero temperatures. Previous studies of the structure of type III AFP by NMR and X-ray identified a remarkably flat surface on the protein containing amino acids that were demonstrated to be important for interaction with ice by mutational studies. It was proposed that this protein surface binds onto the (1 0 [\bar 1] 0) plane of ice with the key amino acids interacting directly with the water molecules in the ice crystal. Here, we show that the mechanism of type III AFP interaction with ice crystals is more complex than that proposed previously. We report a high-resolution X-ray structure of type III AFP refined at 1.15 A resolution with individual anisotropic temperature factors. We report the results of ice-etching experiments that show a broad surface coverage, suggesting that type III AFP binds to a set of planes that are parallel with or inclined at a small angle to the crystallographic c-axis of the ice crystal. Our modelling studies, performed with the refined structure, confirm that type III AFP can make energetically favourable interactions with several ice surfaces.

Melanocyte-conditioned medium stimulates while melanocyte/keratinocyte contact inhibits keratinocyte proliferation

The interaction between melanocytes and keratinocytes in epidermal tissue suggest a bidirectional interchange between these two cell types. Although keratinocytes appear to affect melanocyte function, there are no reported effects of melanocytes on keratinocytes. Using cell strains, we examined the effect of melanocytes on keratinocyte proliferation. Two conditioned medium techniques were used: one was a co-culture system, where both cell types, grown on separate surfaces shared a common volume of medium. The second was simply feeding keratinocytes melanocyte-conditioned medium. Mixed cultures (both cell types together in a monolayer) where also studied. Our results showed that melanocyte-conditioned medium and melanocytes in co-culture significantly stimulated keratinocyte proliferation as measured by bromodeoxyuridine incorporation assay. However, growth of both cell types together in culture did not affect the growth rate of either cell type. Our results showed that cultured human melanocytes produce one or more soluble factors that stimulate the growth of cultured keratinocytes.

Stereochemical composition of clenbuterol residues in edible tissues of swine

A gas chromatography-mass spectrometry method was developed to measure the stereochemical residues of clenbuterol derivatives in edible tissues of swine. Clenbuterol present in tissue extracts was derivatized with phosgene to form clenbuterol oxazolidin-3-one, which was then separated into component enantiomers using a dimethyl beta-cyclodextrin capillary gas chromatographic column. Purified clenbuterol stereoisomers, isolated using published liquid chromatographic techniques, were used to determine stereoisomer elution order, stereoisomer racemization potential, and accuracy of the method. The stereochemical composition of clenbuterol could be measured at tissue concentrations of <2 ppb using the method. The dextrorotatory stereoisomer was the predominant clenbuterol stereoisomer present in edible tissues of hogs slaughtered after withdrawal periods of 0, 3, and 7 days, with a (+)/(-) isomer ratio of about 3:1. The prevalence of the dextrorotatory stereoisomer in edible tissues of hogs at all withdrawal periods suggests that stereoselective processes are occurring during the absorption, distribution, metabolism, and (or) excretion of clenbuterol. The effect of clenbuterol dose on its stereochemical composition in edible tissues is unknown but will be an area of further investigation.

Off-axis electron holography of patterned magnetic nanostructures

Magnetization reversal processes in lithographically patterned magnetic elements that have lateral dimensions of 70-500 nm, thicknesses of 3-30 nm and a wide range of shapes and layer sequences have been followed in situ using off-axis electron holography in the transmission electron microscope. This technique allows domain structures within individual elements and the magnetic interactions between them to be quantified at close to the nanometre scale. The behaviour of 30 nm-thick Co elements was compared with that of 10 nm-thick Ni and Co elements, as well as with Co/Au/Ni trilayers. The hysteresis loops of individual elements were determined directly from the measured holographic phase images. The reproducibility of an element's domain structure in successive cycles was found to be affected by the out-of-plane component of the applied magnetic field and by the exact details of its initial magnetic state. Close proximity to adjacent elements led to strong intercell coupling, and remanent states with the in-plane magnetic field removed included domain structures such as solenoidal (vortex) states that were never observed during hysteresis cycling. Narrow rectangular bars reversed without the formation of end domains, whereas closely separated magnetic layers within individual elements were observed to couple to each other during field reversal.

Outcomes in breast reduction surgery

Previous studies have established that patients with macromastia rate their physical and emotional health as substantially poorer than a control population. The aim of the current study was to confirm this discrepancy, and to evaluate the hypothesis that patients with macromastia who undergo bilateral reduction mammaplasty experience a marked improvement of their general health, both physical and emotional, when compared with their preoperative state and age-matched control population. Sixty-nine consecutive patients were enrolled and evaluated preoperatively and 9 months postoperatively. The methods used for patient evaluation were the Short Form SF-36, a health-related quality-of-life questionnaire, and the Brief Symptom Inventory (BSI), a self-reporting instrument used to assess psychological symptoms. Preoperatively, all patients reported physical health poorer than the age-matched control group. At 9 months postoperatively, patients reported substantial improvement in all areas measured by SF-36 and in the variables this study measured with BSI. Postoperative groups reported their health to be similar to the nonpatient control groups. These findings confirm the therapeutic role of bilateral reduction mammaplasty in alleviation of symptoms associated with macromastia and in restoration of normal physical and emotional functioning.

Genetic dissection of region associated with behavioral abnormalities in mouse models for Down syndrome

Two animal models of Down syndrome (human trisomy 21) with segmental trisomy for all (Ts65Dn) or part (Ts1Cje) of human chromosome 21-homologous region of mouse chromosome 16 have cognitive and behavioral abnormalities. To compare these trisomies directly and to assess the phenotypic contribution of the region of difference between them, Ts65Dn, Ts1Cje, and a new segmental trisomic (Ms1Ts65) for the region of difference (APP: to Sod1) have been generated as littermates and tested in parallel. Although the performance of Ts1Cje mice in the Morris water maze is similar to that of Ts65Dn mice, the reverse probe tests indicate that Ts65Dn is more severely affected. By contrast, the deficits of Ms1Ts65 mice are significantly less severe than those of Ts65Dn. Therefore, whereas triplication of Sod1 to Mx1 plays the major role in causing the abnormalities of Ts65Dn in the Morris water maze, imbalance of APP: to Sod1 also contributes to the poor performance. Ts65Dn mice are hyperactive and Ts1Cje mice are hypoactive; the activity of Ms1Ts65 mice is not significantly above normal. These findings indicate that genes in the Ms1Ts65 trisomic region must interact with others in the Ts1Cje region to produce hyperactivity in Ts65Dn mice.

Total radioactive residues and clenbuterol residues in swine after dietary administration of [14C]clenbuterol for seven days and preslaughter withdrawal periods of zero, three, or seven days

Nine barrows (23.8 +/- 0.9 kg) and 9 gilts (23.1 +/- 0.9 kg) were used to determine the disposition of radiocarbon after oral [14C]clenbuterol (4-amino-alpha-[t-butylaminomethyl]-3,5-dichlorobenzyl [7-(14)C]alcohol hydrochloride) administration and to determine total and parent residues in edible tissues. Three barrows and three gilts, housed in metabolism crates, were fed 1 ppm [14C]clenbuterol HCl for seven consecutive days in three separate trials; a single barrow and gilt from each trial was slaughtered after 0-, 3-, or 7-d preslaughter withdrawal periods. Urine and feces were collected during the dosing and the withdrawal period; edible and inedible tissues were collected at slaughter. Total recovery of radiocarbon was 94.2 +/- 6.5%. Total clenbuterol absorption was greater than 75% for barrows and 60% for gilts. Total radioactive residues in tissues were not different (P > 0.05) between barrows and gilts. Concentrations of parent clenbuterol in liver, kidney, skeletal muscle, adipose tissue, and lung did not differ between barrows and gilts (P > 0.05). Total radioactive and parent residues declined in tissues as withdrawal period increased. After the 0-d withdrawal period, total liver residues (286 ppb) were approximately equal to lung residues, twice those of the kidney, and about 15 times those of adipose tissue and skeletal muscle. After a 7-d withdrawal period, total radioactive residues in liver (15 ppb) were roughly three times greater than lung, kidney, and adipose tissue total residues and about 13 times those of skeletal muscle total residues. Parent clenbuterol represented 79, 63, 42, 67, and 100% of the total radioactive residue in adipose tissue, kidney, liver, lung, and skeletal muscle, respectively, in hogs slaughtered with a 0-d withdrawal period. With increasing withdrawal period, the percentage of total radioactive residue present as parent clenbuterol within edible tissues (including lung) decreased, so that after a 7-d withdrawal period, 7, 16, and 29% of the total residue was composed of parent clenbuterol in kidney, liver, and lung, respectively. After a 7-d withdrawal period, parent clenbuterol exceeded the European maximum residue limit (0.5 ppb) 4.6-fold in liver and 2.4-fold in lung. In muscle, clenbuterol was approximately 40 times the limit after a 0-d withdrawal period but had dropped below 0.5 ppb after a 3-d withdrawal period. Results from this study indicate that clenbuterol HCl is well absorbed in swine and that the use of clenbuterol in this species in an off-label manner is inconsistent with human food safety standards used in developed countries.

Evaluation of commercial immunoassays for cross-reactivity to clenbuterol stereoisomers and bovine metabolites

Several commercially available immunoassay kits have been developed to detect the beta-adrenergic agonist clenbuterol HCl. Technical materials supplied with the kits do not generally report cross-reactivity with clenbuterol metabolites. Use of such kits to quantitate clenbuterol might lead to an overestimation of parent drug if metabolites were present. The objective of this study was to measure the cross-reactivity of clenbuterol metabolites with several commercially available clenbuterol immunoassays. Three clenbuterol-glucuronide conjugates, clenbuterol-sulphamate, 4-amino-3,5-dichloro-hippuric acid (clenbuterol-hippurate), and purified clenbuterol-stereoisomers were tested for cross-reactivity. The clenbuterol-sulphamate metabolite showed significant cross-reactivity (42-77%), but clenbuterol-hippurate showed very little competition (< 0.2%) towards clenbuterol. Clenbuterol-glucuronides had little (0.1-1.6%) cross-reactivity. In addition, (R)-, (S)-, and racemic clenbuterol were used to determine the stereospecificity of the kits. Both (R)- and (S)-clenbuterol competed for binding in two of the kits, however, in one kit the (S)-clenbuterol stereoisomer had an affinity 100 times greater than the (R)-stereoisomer. The presence of significant quantities of the sulphamate metabolite of clenbuterol in a biological matrix would cause an overestimation of the amount of parent clenbuterol. This study illustrates the inherent problems of using unvalidated immunoassays for quantitation purposes.

Flight to Los Angeles: CRISIS AT 30,000 FEET

1. Using therapeutic communication, the nurse can begin to assess the individual in crisis, establish rapport, and evaluate the crisis situation. 2. Offering self while remaining calm assists in de-escalating the anxiety felt by an individual in crisis. 3. Communications with others at the crisis situation, as well as the individual in crisis, should be direct, calm, clear, and incorporate safety assessments as the situation unfolds. Assuring everyone that the nurse is there to help enlists cooperation in crisis resolution.

Production and characterization of a monoclonal antibody against the beta-adrenergic agonist ractopamine

A monoclonal antibody was generated toward the beta-adrenergic agonist ractopamine hydrochloride ¿(1R,3R),(1R, 3S)-4-hydroxy-alpha-[[[3-(4-hydroxyphenyl)-1-methylpropyl]amino]methy l]benzenemethanol hydrochloride¿. Ractopamine-glutarate-keyhole limpet hemocyanin (KLH) was used as the antigen for antibody generation in mice. Clone 5G10, secreted antibody with isotype IgG1kappa, was used for the development of an immunoassay. The selected antibody was specific for racemic ractopamine with an IC(50) of 2.69 +/- 0.36 ng/mL (n = 15). Antibody binding toward ractopamine was stereoselective with (1R,3R)-ractopamine having an IC(50) of 0.55 +/- 0.09 ng/mL (n = 3). IC(50) values for the (1S, 3R)-, (1S,3S)-, and (1R,3S)-ractopamine stereoisomers were 2.00 +/- 0.37, 140 +/- 23, and 291+/- 32 ng/mL (n = 3), respectively. Phenethanolamine beta-agonists showed low cross-reactivity. Studies using a series of ractopamine metabolites and ractopamine analogues demonstrated structural requirements for the antibody binding. A free phenolic group on the N-butylphenol moiety was required for high-affinity binding because methoxylated analogues and metabolites glucuronidated at this phenol generally had IC(50) values greater than 200 ng/mL. Ractopamine analogues methoxylated or glucuronidated at the ethanolamine phenol had IC(50) values of 0.7-2.6 ng/mL. Lack of a benzylic hydroxyl group was of less importance to antibody binding than was the correct stereochemical orientation (3R) of ractopamine's N-phenylalkyl group. In conclusion, a highly specific monoclonal antibody to ractopamine hydrochloride was developed that could be of potential utility in screening assays.

High dietary manganese lowers heart magnesium in pigs fed a low-magnesium diet

Young pigs were fed a diet moderately high or low in manganese (Mn) (0.95 +/- 0.10 mmol Mn/kg, n = 8 or 0.040 +/- 0.003 mmol Mn/kg, n = 6) and deficient in magnesium (Mg) (4.1 mmol Mg/kg) for 5 wk. All eight pigs consuming the high Mn diet died following convulsive seizures, whereas only two of six died in the group fed low Mn. In an attempt to determine the cause of death, a subsequent study examined the interactive effect of deficient dietary Mg and Mn on the tissue distribution of Mg and Mn. Pigs were individually fed, for 5 wk, diets that contained: 4.1 mmol Mg/kg and 36.0 micromol Mn/kg, 4.1 mmol Mg/kg and 0.91 mmol Mn/kg, 4.1 mmol Mg/kg and 0.91 mmol Mn/kg with added ultratrace minerals, or 41.1 mmol Mg/kg and 0. 91 mmol Mn/kg, and ultratrace minerals. Liver and skeletal muscle Mn concentrations were significantly elevated by increased dietary Mn. Increased dietary Mn did not affect heart Mn, but heart Mg concentrations were significantly depressed by high, as compared to low, dietary Mn (38.7 +/- 3.3 vs. 32.7 +/- 2.6 mmol Mg/kg). These data suggest high dietary Mn may exacerbate Mg deficiency in heart muscle and thus may be a complicating factor in the deaths observed in Mg-deficient pigs.

Soluble nitric oxide donor and surfactant improve oxygenation and pulmonary hypertension in porcine lung injury

Acute lung injury (ALI) is associated with diminished surfactant activity and pulmonary hypertension. NONOates are soluble NO donors which release NO in solution. Intratracheal NONOates reduce pulmonary hypertension and improve oxygenation in ALI. We hypothesized that the pharmacologic properties of NO donors would be unaltered after surfactant admixture in vitro and that aerosolized NONOate activity would be enhanced by surfactant pretreatment in vivo. NO donors were added to saline or surfactant and analyzed for nitrite/nitrate production and aortic ring vasodilation. Surfactant did not alter nitrate/nitrite production or aortic ring vasodilation. A porcine model of ALI with pulmonary hypertension was produced using intravenous oleic acid. Animals were assigned to Surfactant-Saline, Surfactant-NONOate, Saline-Saline, or Saline-NONOate groups. Saline or surfactant was instilled into the trachea, followed by gas exchange, pulmonary function, and hemodynamic measurements. NONOate or saline was then aerosolized, and additional data were collected. Oxygenation was improved in the Surfactant-NONOate group, while pulmonary hypertension was selectively reduced in both NONOate groups. Aerosolized NONOate following surfactant pretreatment improves oxygenation and reduces pulmonary hypertension in ALI.

Model for cw laser collisionally induced fluorescence in low-temperature discharges

A perturbed steady-state rate-equation model has been developed for the cw laser collisionally induced fluorescence (LCIF) produced by excitation on one of the 1s-2p noble gas transitions. This work is one part of a wider complementary modeling program which includes cw optogalvanic spectroscopy, optical emission spectroscopy, and optical absorption spectroscopy, with the overall aim of testing all of these models with the same stringently assembled atomic and discharge data set. Our aim here is to demonstrate the principal features of our cw LCIF model by using it to describe our experimental observations produced by pumping transitions originating on the 1s(5) metastable and 1s(4) resonance states of neon atoms in the positive column of a normal glow discharge at 2.0 Torr and a discharge current of 5 mA. The model shows that these cw LCIF spectra are dominated by 1s-2p excitation and electron collisional coupling among the 2p states. We show that the model allows us to quantify explicitly the various individual contributions to each line in the cw LCIF spectra. The theory and analyses presented here apply equally well to other noble gases and we believe can be modified appropriately for trace noble gases in atomic-molecular mixtures.

Cytokine profiles of T-lymphocytes from gingival tissues with pathological pocketing

Periodontal disease is an infection in which destruction occurs at sites remote from the infection, resulting in pathological pocketing. Intervening between the infection and the destruction is a dense mononuclear inflammatory infiltrate. It has been suggested that this infiltrate might have characteristics and the destructive potential of Th1-type T lymphocytes. To ascertain the nature of the infiltrates we investigated the expression of mRNA for IL-2, IL-5, and IFN-gamma by gingival mononuclear cells (GMC) from healthy (n = 8) or adult periodontitis (AP) patients (n = 25) by using cytokine-specific reverse-transcription/polymerase-chain-reaction (RT-PCR). GMC, as obtained from patients' tissues, expressed IL-2, IFN-gamma, or IL-5 mRNA. Significantly higher proportions of GMC from AP patients expressed IL-2 and IFN-gamma mRNA than did those from healthy subjects. IFN-gamma was the most consistent cytokine message detected. In other experiments, gingival T-lymphocytes (n = 12) and CD4+ and CD8+ gingival T-lymphocytes (n = 16) were isolated from gingival tissues removed surgically from AP patients. AP gingival T-lymphocytes expressed mRNA for IL-2, IFN-gamma, or IL-6 prior to stimulation. After stimulation with Con A, the cells significantly up-regulated IL-5 and IL-6 message expression. Both CD4+ and CD8+ gingival T-lymphocytes expressed IFN-gamma, IL-5, and some IL-2. This cumulative cytokine profile observed in these experiments is consistent with the predominance of Th1-type cells in pathological tissues and with Th2-type cells, which can also be present, being up-regulated under appropriate stimulation. Importantly, CD4+ and CD8+ lymphocytes were shown to express T1- and T2-type cytokine message, emphasizing the potential for CD8+ T-lymphocytes to participate in periodontal disease pathology.

A student-directed community project to support sexually abused women veterans suffering from post-traumatic stress disorder

While awareness of post-traumatic stress disorder (PTSD) and sexual abuse continues to grow, it has only been during the past few years that the military has realized the prevalence and impact of sexual abuse inflicted upon women while on active military duty. Though Veteran Administration (VA) agencies throughout the United States have given concerted attention to this problem, published resources specific to PTSD and military sexual abuse have been limited. In this article the authors present the results of a 2(1/2)-year endeavor to address the problem of PTSD and military sexual abuse at the Tulsa VA Outpatient Clinic. The project started with a research study and the subsequent initiation of a PTSD women veterans support group, and culminated in the development of resource manuals for both professional staff and women veterans.

A genetic screen for novel behavioral mutations in mice

A genetic screen using mice was performed to identify dominant loci affecting behavior. Mice were mutagenized with ENU, then bred to examine their G1 offspring for behavioral abnormalities. Potentially mutant G1 pups were screened through a variety of behavioral assays, including tests of learning and memory, sensorimotor gating, fear and anxiety, nociception (pain perception) and locomotor activity. Mice falling outside the normal performance distribution in these tests were considered potential behavioral mutants and were bred for further analysis. Outliers included both animals with very discrete defects and animals with abnormal performance across a range of tests. To date, we have identified two confirmed mutants affecting sensorimotor gating. These results provide further impetus for the use of random mutagenesis screens as a tool for dissecting the genetic basis of brain and behavior.

Electron Crystallography of Room Temperature Charge Ordering in Fe(3)O(4)

A previously unknown form of charge ordering has been observed in dislocation free thin films of magnetite, Fe(3)O(4). This charge ordering exists on tetrahedral sites and is unrelated to the well known low temperature ordering on octahedral sites that occurs below 120K. From modeling of electron diffraction patterns we deduce that the best fit to the observed diffraction patterns was obtained by reducing the scattering power on one tetrahedral site per unit cell by about 80%.

Pharmacodynamics of anticholinergic agents measured by ambulatory urodynamic monitoring: a study of methodology

The aim of the study was to establish a methodology whereby ambulatory urodynamic monitoring (AUM) may be used in the assessment of the effects of darifenacin on urodynamic measures of detrusor function and symptoms associated with detrusor instability. Six patients (one man and five women) with detrusor instability (DI) on conventional urodynamic monitoring were recruited into this placebo-controlled crossover study. The study was divided into two periods of 7 days of treatment with either darifenacin 5 mg t.d.s. or placebo with the patient crossing over to the alternative treatment after a washout period of 7 days. On the 7th day of each treatment, AUM was carried out. Parameters used to quantify detrusor activity on AUM were the number, amplitude, and duration of detrusor contractions and the total area under the detrusor pressure/time curve. "Events" recorded were urge, leakage episodes, voids, and pain. Six comparable hours of AUM for each treatment period could be analyzed in four patients and 4 hr in one. In three of the five patients, reduction in activity on AUM while on darifenacin was apparent. Symptom data closely matched the changes in detrusor activity measured on AUM. This is the first study reporting the use of AUM in the development of a drug with an effect on detrusor activity. AUM has clear advantages over conventional cystometry, which can only measure surrogate urodynamic parameters at a single time point. The optimal duration of monitoring in this context appears to be 6 hr with prolongation of monitoring time beyond this being unlikely to yield additional useful information. Correlation between symptoms and findings on AUM is good with changes in parameters recorded on AUM relating closely to the improvement in symptoms.

Water-insoluble glucan synthesis by mutans streptococcal strains correlates with caries incidence in 12- to 30-month-old children

Early mutans streptococci (MS) infection has been associated with higher caries activity in childhood. Since colonization with MS does not always lead to caries activity, additional factors may be involved in MS cariogenicity. For example, MS may differ in virulence traits such as the potential to synthesize glucan polymers from sucrose. In the present study, we tested the hypothesis that caries activity can be associated with variations in virulence factor expression of MS-infecting strains. At baseline, levels of MS obtained by the tongue-blade sampling method, and the presence of visible plaque on upper incisors, were measured in 101 12- to 30-month-old children. Dental caries lesions were diagnosed at baseline and after one year. Caries incidence data were then used to select ten caries-free and nine caries-active children from whom a total of 20 MS fresh isolates was studied. Water-insoluble glucan (WIG) synthesis, final pH, and sucrose-dependent adherence on glass surfaces were measured in these MS isolates. Concentrated culture supernatants were separated in duplicate SDS-PAGE gels, which were then either stained for protein or incubated with 5% sucrose. The intensities of the WIG bands developed in the 5% sucrose PAGE gels and the corresponding protein-stained GTF bands were measured by scanning densitometry. High MS levels (> or = 100 CFU) were associated with high caries incidence (p < 0.01). The presence of visible plaque did not correlate with caries incidence. The intensities of WIG bands were positively correlated with caries incidence (p < 0.05) and with the ability of MS to adhere to glass surfaces (p < 0.05). Analysis of our data suggests that the ability to synthesize WIG is an important virulence factor in initial caries development by increasing MS adherence and accumulation in the plaque of young children.

T(h)1 transmigration anergy: a new concept of endothelial cell-T cell regulatory interaction

Stimulation of endothelial cells (EC) with IFN-gamma generates selective enhancement of T(h)1 cell transmigration and induction of MHC class II expression on EC. In the present study, we tested whether antigen presentation by EC could influence transmigrating T cells in an in vitro system. Bacterial antigen presentation by EC from primary culture and after cloning induced antigen-specific anergy of transmigrating T(h)1 clone cells in a MHC class II-dependent manner as characterized by non-responsiveness to subsequent antigen presentation and inability to produce IL-2. This T cell transmigration anergy induced by EC was abrogated by anti-rat CD28 mAb, suggesting that lack of B7 co-stimulatory signals by EC might be related to the induction of anergy. While MHC class II expression on primary and cloned EC was observed after IFN-gamma stimulation, these cells never expressed B7. B7-1 gene-transfected endothelial clone cells (ECC/B7-1) were developed to elucidate the influence of B7 co-stimulation by EC. ECC/B7-1 induced proliferation of T(h)1 clone cells, whereas ECC did not induce proliferation in co-culture of T(h)1 clone cells and EC stimulated with IFN-gamma and antigen. In the transmigration assay, ECC/B7-1 did not induce transmigration anergy of T(h)1 clones or T(h)1 lines unless anti-rat B7-1 blocking mAb was added. Therefore, in rats, the T cell anergy induced during transmigration across a layer of EC seemed to be due to antigen presentation in the absence of B7 on the EC. We introduce the concept of transmigration anergy in this manuscript. Thus, EC can play a critical immune regulatory role in the context of antigen presentation by MHC class II to transmigrating T cells.

Coimmunization with complementary glucosyltransferase peptides results in enhanced immunogenicity and protection against dental caries

Peptide constructs from the catalytic (CAT) and glucan-binding (GLU) regions of the mutans streptococcal glucosyltransferase enzymes (GTF) can provide immunity to dental caries infection. A strategy of coimmunization was tested to determine whether protection could be enhanced. Rats were immunized with one of the previously described peptide constructs from the CAT or GLU region of the GTF of mutans streptococci or coimmunized with a combination of these constructs (CAT-GLU). Coimmunized animals demonstrated significantly higher serum immunoglobulin G (IgG) and salivary IgA antibody levels to CAT or GTF than rats immunized with either construct alone. To assess the functional significance of coimmunization with these constructs, animals were immunized as above or with Streptococcus sobrinus GTF and then infected with S. sobrinus to explore the effects of immunization on immunological, microbiological, and disease (dental caries) parameters. Serum antibody from the communized group inhibited S. sobrinus GTF-mediated insoluble glucan synthesis in vitro above that of the individual-construct-immunized groups. Immunization with CAT or GLU constructs resulted in significantly reduced dental caries after infection with S. sobrinus compared with sham-immunized animals. Coimmunization produced greater reductions in caries than after immunization with either CAT or GLU. Also, significant elevations in lymphocyte proliferative responses to CAT, GLU, and GTF were observed after coimmunization with CAT-GLU compared with the responses after immunization with the individual constructs. The results suggested that increased numbers of memory T cells, which could proliferate to CAT, were generated by coimmunization. The experiments support the functional significance of these GTF domains in dental caries pathogenesis and present coimmunization as a simple alternative to intact GTF to enhance protective immunity against cariogenic microorganisms.

Ovine male genital duct epithelial cells differentiate in vitro and express functional CFTR and ENaC

To investigate the biology of the male genital duct epithelium, we have established cell cultures from the ovine vas deferens and epididymis epithelium. These cells develop tight junctions, high transepithelial electrical resistance, and a lumen-negative transepithelial potential difference as a sign of active transepithelial ion transport. In epididymis cultures the equivalent short-circuit current (I(sc)) averaged 20.8+/-0.7 microA/cm(2) (n = 150) and was partially inhibited by apical application of amiloride with an inhibitor concentration of 0.64 microM. In vas deferens cultures, I(sc) averaged 14.4+/-1.1 microA/cm(2) (n = 18) and was also inhibited by apical application of amiloride with a half-maximal inhibitor concentration (K(i)) of 0.68 microM. The remaining amiloride-insensitive I(sc) component in epididymis and vas deferens cells was partially inhibited by apical application of the Cl(-) channel blocker diphenylamine-2-carboxylic acid (1 mM). It was largely dependent on extracellular Cl(-) and, to a lesser extent, on extracellular HCO(-)(3). It was further stimulated by basolateral application of forskolin (10(-5) M), which increased I(sc) by 3.1+/-0.3 microA/cm(2) (n = 65) in epididymis and 0.9+/-0.1 microA/cm(2) (n = 11) in vas deferens. These findings suggest that cultured ovine vas deferens and epididymis cells absorb Na(+) via amiloride-sensitive epithelial Na(+) channels (ENaC) and secrete Cl(-) and HCO(-)(3) via apical cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels. This interpretation is supported by RT-PCR data showing that vas deferens and epididymis cells express CFTR and ENaC mRNA.

Identification of turkey biliary metabolites of ractopamine hydrochloride and the metabolism and distribution of synthetic [14C]ractopamine glucuronides in the turkey

1. The bile duct cannulated turkey poult (n = 3) dosed orally with [14C]ractopamine HCl [(1R*,3R*),(1R*,3S*)-4-hydroxy-alpha-[[[3-(4-hydroxy[14C]phenyl)-1-methy lpropyl]amino]methyl]-benzenemethanol hydrochloride; 19.9 mg; 9.28 microCi] excreted 37.4 +/- 12.1% (mean +/- SD) of the administered radioactivity in bile by 24 h post-dosing. 2. A mono-glucuronide, conjugated at C-10 (the methylpropylamino phenol) of ractopamine, accounted for 76.6% of biliary radioactivity. 3. Urine collected from the colostomized turkey poult (n = 3) orally dosed with synthetic [14C]ractopamine-glucuronides (10.1 mg; 3.6 microCi) contained 11.9 +/- 1.0% (mean +/- SD) of the administered radioactivity 24 h after dosing, indicating that some absorption of radioactivity occurred. Faeces contained 60.6% of the administered radioactivity and carcasses (with gastrointestinal tracts) contained 23.3% of the starting radioactivity. 4. Five colostomized poults were fitted with bile duct cannulas and were dosed intraduodenally with 10.2 mg (3.6 microCi) synthetic [14C]ractopamine-glucuronides. Urine and bile contained 15.5 +/- 2.2 and 16.8 +/- 2.1% respectively of the administered radiocarbon by 24 h post-dosing. Faeces contained 54.3% of the administered radioactivity. Total absorption of the dosed radioactivity averaged 33.4%. 5. Bile and urine collected from the colostomized, bile-duct cannulated bird contained mainly ractopamine glucuronides. Indirect evidence suggests that the dosed ractopamine glucuronides were not absorbed intact.

Induction of secretory immunity with bioadhesive poly (D,L-lactide-co-glycolide) microparticles containing Streptococcus sobrinus glucosyltransferase

The effect of mucosal delivery of Streptococcus sobrinus glucosyltransferase (GTF) in bioadhesive poly (D,L-lactide-co-glycolide) (PLGA) microparticles on induction of salivary IgA and serum IgG antibody responses was measured in Sprague-Dawley rats. Preparations of GTF/PLGA/gelatin microparticles, or PLGA/gelatin microparticles or GTF in alum, were administered four times at weekly intervals by intranasal or intragastric routes. Two subcutaneous injections of GTF in PLGA/gelatin microparticles or in alum were given to separate groups of rats. Significant elevations in salivary IgA antibody levels to S. sobrinus GTF were observed only in the groups immunized intranasally 28 days after immunizations were begun. Five of six rats given the GTF microparticles intranasally had positive salivary IgA antibody responses to GTF, and the mean salivary IgA antibody level of this group was 30-fold higher than any other mucosally or systemically immunized group. Salivary IgA responses in the GTF-microparticle group remained significantly higher than all other mucosally immunized groups for at least 10 weeks after the primary immunization. All rats in this group demonstrated aspects of anamnesis following a more limited secondary course of intranasal administration. Intranasal administration of GTF in microparticles also induced a serum IgG response to GTF in some rats. After secondary intranasal GTF microparticle administration, several rats had sustained serum IgG antibody levels that were within the range of sera from rats subcutaneously injected with GTF in microparticles or in alum. Thus intranasal delivery of GTF-containing bioadhesive microparticles induced the highest and longest lasting salivary immune response of any mucosal or systemic route or vehicle tested and could be expected to be a useful method for induction of mucosal immunity.

Novel lipid-based hollow-porous microparticles as a platform for immunoglobulin delivery to the respiratory tract

PURPOSE

Delivery of specific antibodies or immunoglobulin constructs to the respiratory tract may be useful for prophylaxis or active treatment of local or systemic disorders. Therefore, we evaluated the utility of lipid-based hollow-porous microparticles (PulmoSpheres) as a potential delivery vehicle for immunoglobulins.

METHODS

Lipid-based microparticles loaded with human immunoglobulin (hIgG) or control peptide were synthesized by spray drying and tested for: i) the kinetics of peptide/protein release, using ELISA and bioassays; ii) bioavailability subsequent to nonaqueous liquid instillation into the respiratory tract of BALB/c mice, using ELISA and Western blotting; iii) bioactivity in terms of murine immune response to xenotypic epitopes on human IgG, using ELISA and T cell assays; and iv) mechanisms responsible for the observed enhancement of immune responses, using measurement of antibodies as well as tagged probes.

RESULTS

Human IgG and the control peptide were both readily released from the hollow-porous microspheres once added to an aqueous environment, although the kinetics depended on the compound. Nonaqueous liquid instillation of hIgG formulated in PulmoSpheres into the upper and lower respiratory tract of BALB/c mice resulted in systemic biodistribution. The formulated human IgG triggered enhanced local and systemic immune responses against xenotypic epitopes and was associated with receptor-mediated loading of alveolar macrophages.

CONCLUSIONS

Formulation of immunoglobulins in hollow-porous microparticles is compatible with local and systemic delivery via the respiratory mucosa and may be used as means to trigger or modulate immune responses.

Changes in glutamine and glutamate concentrations for tracking training tolerance

PURPOSE

The purpose was to monitor high-performance athletes throughout training macrocycles and competitions and examine the changes in plasma glutamine (Gm) and glutamate (Ga) concentrations in order to develop a model of tolerance to training.

METHODS

Plasma glutamine and glutamate concentrations of 52 National team athletes (31 male and 21 female) divided into male and female groups of speed skating, swimming, and cross-country skiing were measured in an early season rested condition to determine highest Gm and lowest Ga concentrations and over 2-4 macrocycles, which included heavy training to establish lowest Gm and highest Ga concentrations.

RESULTS

In the rested condition, there were no differences within and between the male and female groups, excluding five athletes (OTA) who became overtrained in heavy training. The mean (+/-SD) Gm concentration was 585 +/- 54 micromol x L(-1), Ga concentration 101 +/- 16 micromol x L(-1), and Gm/Ga ratio 5.88 +/- 0.84 micromol x L(-1). The OTA had a significantly higher Ga concentration of 128 +/- 16 micromol x L(-1) and lower Gm/Ga ratio of 4.43 +/- 0.49 micromol x L(-1) than all the other groups. In heavy training, there was a significant decrease (P < 0.05) in Gm concentration to 522 +/- 53 micromol x L(-1), significant increase in Ga concentration to 128 +/- 19 micromol x L(-1) and significant decrease in Gm/Ga ratio to 4.15 +/- 0.57 micromol x L(-1). The OTA Gm concentration of 488 +/- 31 micromol x L(-1) was significant lower than only the male speed skating and swimming groups. However, the Ga concentration of 171 +/- 17 micromol x L(-1) and Gm/Ga ratio of 2.88 +/- 0.27 micromol x L(-1) were significantly higher and lower respectively than all other groups.

CONCLUSIONS

Based on the changes in Gm and Ga concentration under different training conditions, we propose an athlete tolerance to training model where glutamine concentration reflects tolerance to volume of work and glutamate concentration reflects tolerance to high intensity training. We suggest that the Gm/Ga ratio may globally represent overall tolerance to training.