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Biomedical subjects

S Porter

Publications and source records attributed to S Porter.

At least 37 records · Page 2Linked to original sources
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↗
PubMed2000

The recurrence of deformity after surgical centralization for radial clubhand.

Fourteen children representing 19 cases of radial clubhand had centralization of the carpus on the distal ulna during an 18-year period. Age at the time of the initial surgery averaged 3.2 years (range, 0.7-8.1 years) and the follow-up periods averaged 6.5 years (range, 1.5-22.2 years). There were 16 type IV radial and 3 type III clubhands. Preoperative, postoperative, and follow-up x-rays were used to determine the initial deformity, amount of surgical correction, and degree of recurrence. The total angulation (the combination of the radial deviation of the hand and the ulna bow) was measured. The average preoperative angulation measured 83 degrees (range, 55 degrees to 110 degrees ). Centralization corrected the angulation an average of 58 degrees (range, 15 degrees to 95 degrees ) to an average immediate postoperative total angulation of 25 degrees (range, 5 degrees to 60 degrees ). At the final follow-up examination there was a loss of 38 degrees (range, 5 degrees to 105 degrees ) and the total angulation increased to an average of 63 degrees (range, 20 degrees to 120 degrees ). The difference between the preoperative, postoperative, and follow-up angles was statistically significant. There was a significant correlation between the preoperative angle and the final angle, the preoperative angle and the amount of correction, the amount of correction obtained at surgery and the recurrence of the deformity, and the age at time of initial surgery and the amount of recurrence.

Biomechanical Phenomena↗
PubMed2000

Human herpesvirus 8 and oral health care: an update.

OBJECTIVE: The purpose of this report was to review the current literature on human herpesvirus 8 (HHV-8) with particular attention to the aspects of interest for dental health care workers. MATERIAL AND METHODS: The authors searched original research and review articles on specific aspects of HHV-8 infection, including virology, epidemiology, transmission, diagnosis, natural history, therapy, and oral aspects. The relevant material was evaluated and reviewed. RESULTS: HHV-8 is a recently discovered DNA virus that is present throughout the world but with major geographic variation. In the Western world, the virus, transmitted mainly by means of sexual contact, is strongly associated with Kaposi's sarcoma and body cavity-based lymphoma and more controversially with multiple myeloma and non-neoplastic disorders. There is no specific effective treatment, but human immunodeficiency virus protease inhibitors may play an indirect role in the clearance of HHV-8 DNA from peripheral blood mononuclear cells of patients infected with human immunodeficiency virus. HHV-8 DNA is present in saliva, but as yet, there are no documented instances of nosocomial transmission to health care workers. The prevalence of HHV-8 among dental health care workers is probably similar to that in the general population. CONCLUSION: HHV-8 does not appear to be ubiquitous in most populations, particularly in western Europe and the United States, where it may be restricted to a population at risk of having Kaposi's sarcoma develop (men infected with human immunodeficiency virus and patients who are iatrogenically immunosuppressed). Most serologic studies suggest a global HHV-8 seroprevalence of 2% to 10% and show that the virus may be under immunologic control in people who are healthy but infected with HHV-8. Also, HHV-8 certainly has the means to overcome cellular control and immune responses and thus predispose to malignancy. To date, there are no data to suggest that health care staff members are at particular risk of HHV-8 acquisition through occupational routes.

Antibodies, Viral↗
PubMed2000

Negotiating false memories: interviewer and rememberer characteristics relate to memory distortion.

In a recent study, more than half of the participants were led to create a partial or complete false memory for an emotional childhood event (e.g., serious animal attack). Using a subsample from that study, we examined the hypothesis that memory distortion is related to characteristics of interviewers and rememberers. The relations between susceptibility to memory distortion and (a) dissociation (Dissociative Experiences Scale) and (b) personality traits (NEO-Five Factor Inventory) were investigated. Results indicated that participants who exhibited memory distortion scored significantly higher on the dissociative scale than their counterparts who did not exhibit memory distortion. Further, susceptibility to memory distortion was associated with higher extraversion scores in interviewers and lower extraversion scores in participants. This pattern of findings suggests that false memories may derive from a social negotiation between particular interviewers and rememberers.

Adult↗
PubMed2000

HIV topic update: oro-genital transmission of HIV.

Several viruses, including the human immunodeficiency virus (HIV), can be found in blood and many body fluids including saliva, and are transmissible sexually across genital and particularly anal mucosae. A persisting concern has been the question of transmission of HIV by oral sexual practices. This review discusses the evidence for oro-genital transmission of HIV, detailing the presence and infectivity of HIV in genital fluids and saliva, the case reports and epidemiology of oro-genital HIV transmission, and the evidence from animal studies. Oral intercourse is not risk-free. The evidence suggests that the risk of HIV transmission from oro-genital sexual practices is substantially lower than that from penile-vaginal or penile-anal intercourse, that exposure to saliva presents a considerably lower risk than exposure to semen, and that oral trauma and ulcerative conditions might increase the risk of HIV transmission.

Animals↗
PubMed2000

Cost-effective prescribing of proton pump inhibitor therapy: an audit in general practice.

General practitioners must prescribe cost effectively to control drug expenditure and provide optimal treatment for patients requiring long-term management. An audit was implemented in general practices to review the management of dyspepsia, improve care, rationalise therapy and reduce costs. Policy included identifying patients receiving proton pump inhibitor (PPI) therapy and changing to low-dose cost-effective therapy. If PPI therapy was not required, patients were changed to antacids, H2 receptor antagonists or no treatment. This was an audit in general practice, not a clinical trial, therefore findings reflect outcomes in normal clinical practice. This paper describes the implementation and findings of the audit between January 1997 and July 1999 in 91 general practices involving 7121 patients. Extrapolation of the results concluded that savings of up to 50,000 Pounds could be made in a practice of 10,000 patients, allowing reinvestment in health improvement plans and optimal care.

Adolescent↗