Search PubMed⌕ Search

Biomedical subjects

S Porter

Publications and source records attributed to S Porter.

At least 19 recordsLinked to original sources
PubMed2002

The modulation of matrix metalloproteinase and ADAM gene expression in human chondrocytes by interleukin-1 and oncostatin M: a time-course study using real-time quantitative reverse transcription-polymerase chain reaction.

OBJECTIVE: Previous studies have reported elevated levels of interleukin-1 (IL-1) and oncostatin M (OSM) in rheumatoid joints, as well as the synergistic degradation of human articular cartilage by this cytokine combination. The present study was undertaken to investigate the ability of IL-1 and OSM to modulate gene expression of matrix metalloproteinase (MMP), ADAM, and ADAM-TS (ADAM with thrombospondin motifs) family members in human chondrocytes. METHODS: T/C28a4 human chondrocytes were stimulated for 2-48 hours with IL-1 and/or OSM. Total RNA was harvested, reverse transcribed, and assessed by real-time polymerase chain reaction for the expression of various MMP, ADAM, and ADAM-TS messenger RNAs (mRNA). Results were normalized to 18S ribosomal RNA. RESULTS: IL-1 and OSM synergized to markedly induce the expression of the collagenases MMP-1, MMP-8, and MMP-13 as well as MMP-3, an activator of proMMPs. Expression of mRNA for MMPs 1, 3, and 13 was induced early, whereas that of MMP-8 mRNA occurred late. Gene expression of MMP-14, an MMP that degrades collagen and activates proMMP-13, was elevated by this combination. IL-1 and OSM also synergized to induce gene expression of the aggrecanase ADAM-TS4, but not ADAM-TS5. CONCLUSION: These data indicate that the potent cartilage-degrading properties of the combination of IL-1 and OSM are potentially mediated by a synergistic induction of the aggrecan-degrading enzyme ADAM-TS4 and the collagen-degrading enzymes MMP-1, MMP-8, MMP-13, and MMP-14, although differences in the magnitude of response and in the time course of induction were observed. A role for MMPs 3 and 14 in the activation of proMMPs may also be implicated.

Cell Line, Transformed↗
PubMed2002

Down syndrome: lip lesions (angular stomatitis and fissures) and Candida albicans.

BACKGROUND: The incidence of angular cheilitis (angular stomatitis, perleche, commissural fissures) appears to be increased in people with Down syndrome (DS). Lip fissures are also (in our clinical impression) a fairly regular feature, yet this is scarcely mentioned in the literature. OBJECTIVES: To establish the incidence of angular cheilitis and lip fissures in a substantial group of patients with DS and to examine the relationship with Candida albicans. PATIENTS AND METHODS: The prevalence of orofacial soft tissue lesions was investigated in a group of 77 DS patients. Swabs were taken from lip lesions, palate and tongue and inoculated on Sabouraud's agar discs for the isolation of C. albicans, identified with commercially available kits. RESULTS: Lip fissures were seen in at least one-quarter of DS patients. Angular cheilitis was also found in a similar percentage. CONCLUSIONS: C. albicans was isolated from a substantial proportion of lesions tested, and was present more frequently than in those without lip lesions, but it is uncertain whether this represents cause or effect.

Adolescent↗
PubMed2002

Molecular characterization of vancomycin-resistant Enterococci repopulating the gastrointestinal tract following treatment with a novel glycolipodepsipeptide, ramoplanin.

We characterized baseline and repopulating stool isolates recovered during a phase II trial of ramoplanin for the treatment of patients with stool carriage of vancomycin-resistant enterococci (VRE). Repopulation with a strain with a related genotype was found in 74, 60, and 53% of individuals in groups treated with placebo, 100 mg of ramoplanin, and 400 mg of ramoplanin, respectively. All ramoplanin-treated patients with a culture positive for VRE at day 7 had a relapse caused by a genotypically related isolate. In ramoplanin-treated patients, antibiotics with activities against anaerobic organisms were associated with positive cultures on day 7 (relative risk [RR] = 8.8; P = 0.004), and the avoidance of such antibiotics was significantly associated with culture negativity through day 21 (RR = 0.16; P = 0.02).

Anti-Bacterial Agents↗
PubMed2001

Human immune response to recombinant human proteins.

Delivery of pharmacological doses of proteins to people has raised concerns of inducing immune responses, especially when the protein is provided in multiple doses over an extended period of time. Immune responses could impact the therapeutic exposure and efficacy of the protein itself. In addition, there have been fears of anaphylaxis or autoimmunity. This review summarizes the available literature regarding the measurement and evaluation of immune responses observed during clinical assessment of recombinant human proteins. Immune responses have ranged from none at all to inactivation and/or accelerated clearance. Presence of antibodies does not necessarily impact therapeutic viability. While responses are related to frequency and route of delivery, there is no clear relationship that enables one to predict the clinical experience.

Antibodies↗
PubMed2001

Investigation of the criminal and conditional release profiles of Canadian federal offenders as a function of psychopathy and age.

Using the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991) diagnostic cut-off score of 30, the complete criminal career and community release profiles of 317 Canadian federal offenders (224 low scorers and 93 scoring within the psychopathic range) were investigated. Adult crimes were coded according to age at commission as well as either violent, nonviolent, or nonsexually violent. Changes in performance following release into the community also were examined. Results indicated that offenders scoring within the psychopathic range consistently committed more violent and nonviolent crimes than their counterparts for about three decades, spanning their late adolescence to their late 40s. Numbers of nonviolent criminal offenses committed by high PCL-R scorers declined considerably after age 30 relative to violent offenses, which declined and then rebounded in the late 30s before a major reduction was evidenced. Throughout adulthood, high PCL-R scorers failed during community release significantly faster than did low scorers. Importantly, from a risk management perspective, the release performance of low PCL-R scorers improved with age, whereas the opposite was seen for high scorers. Further, offenders scoring high on the PCL-R did not show a lower charge to conviction ratio with age, suggesting that they may not have been getting better at manipulating the legal system.

Adult↗
PubMed2001

Oral cancer.

Explore the source record for details and available documents.

Biopsy, Needle↗
PubMed2001

Increased effective lung volume following lung volume reduction surgery in emphysema.

STUDY OBJECTIVES: Lung volume reduction surgery (LVRS) for emphysema has a variable effect on spirometry with improvement linked to increases in lung elastic recoil. The mechanism by which recoil increases following LVRS has not been described completely. This study examines preoperative and postoperative pulmonary function to describe a mechanism for changes in airflow obstruction. DESIGN: Change in pulmonary function following LVRS. Setting : Public teaching hospital in Australia. PATIENTS: Patients with severe emphysema and pulmonary function measurements made before and after LVRS. MEASUREMENTS: Routine pulmonary function testing performed with ventilated lung alveolar volume (VA) derived from the gas transfer measurement used as a proxy for the effective lung volume. RESULTS: Pulmonary function tests from 36 consecutive patients with measurements made at the same laboratory were analyzed. The mean FEV(1) was 29.1% predicted presurgery and increased following LVRS from 0.900 L (SD, 0.427 L) to 1.283 L (SD, 0.511 L; p < 0.0001) and TLC (143% predicted) decreased from 8.19 L (SD, 1.492 L) to 7.07 L (SD, 1.52 L; p < 0.0001; n = 35). The mean VA increased by 0.674 L (SD, 0.733 L) from 4.04 to 4.72 L (p < 0.0001; n = 34). The change in FEV(1) correlated well with the change in VA (r = 0.63). The change in FEV(1) in those patients whose VAs did not increase (n = 7) was not significant. CONCLUSIONS: The increase in VA reflects an increase of functional or ventilating lung volume and is associated with an improvement in spirometry following LVRS.

Aged↗
PubMed2001

Respiratory instability of term and near-term healthy newborn infants in car safety seats.

OBJECTIVE: Premature infants who are discharged from intensive care nurseries are known to be at increased risk for apnea, bradycardia, and oxygen desaturation while in the upright position. These small infants also do not fit securely in standard infant car seats. Because of these problems, the American Academy of Pediatrics recommends a period of observation in a car seat for all infants who are born at <37 weeks' gestation. It is not clear whether this recommendation should apply to the minimally preterm infants (born at 35-36 weeks' gestation) who are healthy at birth and are hospitalized in the normal newborn nursery. The objective of this study was to evaluate the respiratory stability and safety requirements of healthy, minimally preterm infants in car seats compared with term infants. METHODS: Fifty healthy, nonmonitored, preterm infants (mean gestational age: 35.8 +/- 0.6 weeks) and 50 term infants (mean gestational age: 39.5 +/- 1.4 weeks) were recruited from a level I newborn nursery in a community hospital. Appropriateness of car seat fit was documented for each infant. Heart rate, respiratory rate, and pulse oximetry were evaluated while infants were supine and in their car seats. Apneic and bradycardic events were recorded in addition to a continuous recording of oxygen saturation values. RESULTS: Twenty-four percent of preterm and 4% of term newborn infants did not fit securely into suitable car seats despite the use of blanket rolls. Mean oxygen saturation values declined significantly in both preterm and term infants from 97% in the supine position (range: 92%-100%) to 94% after 60 minutes in their car seats (range: 87%-100%). Seven infants (3 preterm and 4 term) had oxygen saturation values of <90% for longer than 20 minutes in their car seats. Twelve percent of the preterm infants (95% confidence interval: 4.5%-24.3%) but no term infants had apneic or bradycardic events in their car seats. CONCLUSIONS: Our data support the current American Academy of Pediatrics recommendations that all infants who are born at <37 weeks' gestation, including those who are admitted to level I community hospitals, be observed for respiratory instability and secure fit in their car seats before hospital discharge. Because lowering of oxygen saturation values was seen uniformly in all newborn infants, car seats should be used only for travel, and travel should be minimized during the first months of life.

Apnea↗
PubMed2000

The human transmissible spongiform encephalopathies (TSEs): implications for dental practitioners.

Transmissible spongiform encephalopathies (TSEs) are rare, fatal degenerative brain diseases which affect humans and certain animals, and are caused by inheritance or acquisition of prions (PrPs). Inherited TSEs include Fatal Familial Insomnia (FFI), Gerstmann-Straussler-Scheinker syndrome (GSS) and other less well clinically characterised disorders, while the human infective TSEs include sporadic, iatrogenic and variant Creutzfeldt-Jakob disease (vCJD). The causative prions are found especially in neural tissues and spinal fluid, and in the case of vCJD, in lymphoreticular tissue. Available epidemiological evidence suggests that normal social or routine clinical contact with affected patients does not present a risk to health care workers, relatives or the community. Isolation of patients is not considered necessary. Nevertheless as the prions are resistant to conventional chemical, irradiation and heat sterilisation methods, highly specific cross-infection control measures are required for the dental management of patients with, or at notable risk, of TSE. The present article reviews current knowledge of the clinical consequences of prion disease and provides information regarding necessary changes to the cross-infection routine when managing patients infected, or at risk of, prion disease.

Animals↗
PubMed2000

Biomaterial developments for bone tissue engineering.

The development of bone tissue engineering is directly related to changes in materials technology. While the inclusion of materials requirements is standard in the design process of engineered bone substitutes, it is also critical to incorporate clinical requirements in order to engineer a clinically relevant device. This review presents the clinical need for bone tissue-engineered alternatives to the present materials used in bone grafting techniques, a status report on clinically available bone tissue-engineering devices, and recent advances in biomaterials research. The discussion of ongoing research includes the current state of osseoactive factors and the delivery of these factors using bioceramics and absorbable biopolymers. Suggestions are also presented as to the desirable design features that would make an engineered device clinically effective.

Biocompatible Materials↗
PubMed2000

Truth, lies, and videotape: an investigation of the ability of federal parole officers to detect deception.

The ability of a group of Canadian federal parole officers to detect deception was investigated over the course of 2 days of lie detection training. On the first day of training, 32 officers judged the honesty of 12 (6 true, 6 fabricated) videotaped speakers describing personal experiences, half of which were judged before and half judged after training. On the second day, 5 weeks later, 20 of the original participants judged the honesty of another 12 videotapes (again, 6 pre- and 6 posttraining). To isolate factors relating to detection accuracy, three groups of undergraduate participants made judgments on the same 24 videotapes: (1) a feedback group, which received feedback on accuracy following each judgment, (2) a feedback + cue information group, which was given feedback and information on empirically based cues to deception, and (3) a control group, which did not receive feedback or cue information. Results indicated that at baseline all groups performed at or below chance levels. However, overall, all experimental groups (including the parole officers) became significantly better at detecting deception than the control group. By the final set of judgments, the parole officers were significantly more accurate (M = 76.7%) than their baseline performance (M = 40.4%) as well as significantly more accurate than the control group (M = 62.5%). The results indicate that detecting deceit is difficult, but training and feedback can enhance detection skills.

Adult↗