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Biomedical subjects

D J Smith

Publications and source records attributed to D J Smith.

At least 55 records · Page 3Linked to original sources

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.

Adult↗

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.

Asphyxia↗

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.

Adult↗

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.

Administration, Inhalation↗

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.

Administration, Inhalation↗

RAGE and PRAY.

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Cloning, Molecular↗

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.

Acetylglucosaminidase↗

A randomized double-blind, placebo-controlled trial of the EMLA patch for the reduction of pain associated with intramuscular injection in four to six-year-old children.

UNLABELLED: The effectiveness of a eutectic mixture lidocaine-prilocaine topical anaesthetic cream (EMLA) patch compared with a placebo patch in the reduction of pain associated with intramuscular immunization was evaluated. As part of the study, 161 children (aged 4-6-y) undergoing routine diphtheria, pertussis, tetanus and polio (DPTP) immunization in five urban and five rural private office settings were randomly assigned to an EMLA patch (n = 83) or a placebo patch control group (n = 78). Pain measurements included: child's self-report on a Faces Pain Scale; facial action on the Child Facial Coding System; the Children's Hospital of Eastern Ontario Pain Scale and parent and technician ratings on a Visual Analogue Scale. Parents also rated their own and their child's immunization-related anxiety on a Visual Analogue Scale. The EMLA patch group had significantly less pain on all four pain measures compared with the placebo group. Of the children in the placebo group, 43% had clinically significant pain, compared with 17% of children in the EMLA patch group. No severe adverse symptoms occurred as a result of either EMLA or placebo patch application. CONCLUSION: The EMLA patch reduced immunization pain in 4 to 6-y-old children during needle injection.

Anesthetics, Combined↗

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.

Animals↗

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.

Amino Acid Sequence↗

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.

Animals↗

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.

Amino Acid Sequence↗

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.

Adjuvants, Immunologic↗

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.

Brazil↗

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.

Adult↗

Multiple potential intragenic regulatory elements in the CFTR gene.

The CFTR gene exhibits a complex pattern of expression that shows temporal and spatial regulation though the control mechanisms have not been fully elucidated. We have mapped DNase I hypersensitive sites (DHS) flanking the CFTR gene to identify potential regulatory elements. We previously characterized DHS at -79.5 and -20.9 kb with respect to the CFTR translational start site, DHS 3' to the gene at 4574 + 5.4-7.4 and 4574 + 15.6 kb, and a regulatory element in the first intron of the gene at 185 + 10 kb. We generated a cosmid contig to provide probes to evaluate the whole of the CFTR gene for DHS and have now mapped novel sites in introns 2, 3, 10, 16, 17a, 18, 20, and 21. These DHS show different patterns of cell-specific expression.

Caco-2 Cells↗