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Biomedical subjects

P Lowe

Publications and source records attributed to P Lowe.

At least 19 recordsLinked to original sources
PubMed2005

A critical analysis of the literature on the Internet and consumer health information.

A critical review of the published literature investigating the Internet and consumer health information was undertaken in order to inform further research and policy. A qualitative, narrative method was used, consisting of a three-stage process of identification and collation, thematic coding, and critical analysis. This analysis identified five main themes in the research in this area: (1) the quality of online health information for consumers; (2) consumer use of the Internet for health information; (3) the effect of e-health on the practitioner-patient relationship; (4) virtual communities and online social support and (5) the electronic delivery of information-based interventions. Analysis of these themes revealed more about the concerns of health professionals than about the effect of the Internet on users. Much of the existing work has concentrated on quantifying characteristics of the Internet: for example, measuring the quality of online information, or describing the numbers of users in different health-care settings. There is a lack of qualitative research that explores how citizens are actually using the Internet for health care.

Health Education↗
PubMed2001

Substitution of antibodies and receptors with molecularly imprinted polymers in enzyme-linked and fluorescent assays.

A new technique for coating microtitre plates with molecularly imprinted polymers (MIP), specific for low-molecular weight analytes (epinephrine, atrazine) and proteins is presented. Oxidative polymerization was performed in the presence of template; monomers: 3-aminophenylboronic acid (APBA), 3-thiopheneboronic acid (TBA) and aniline were polymerized in water and the polymers were grafted onto the polystyrene surface of the microplates. It was found that this process results in the creation of synthetic materials with antibody-like binding properties. It was shown that the MIP-coated microplates are particularly useful for assay development. The high stability of the polymers and good reproducibility of the measurements make MIP coating an attractive alternative to conventional antibodies or receptors used in enzyme linked immunosorbent assay (ELISA).

Antibodies↗
PubMed2001

Evaluation of the BacT/Alert automated blood culture system for detecting bacteria and measuring their growth kinetics in leucodepleted and non-leucodepleted platelet concentrates.

BACKGROUND AND OBJECTIVE: To evaluate the BacT/Alert automated blood culture system for the detection of bacteria in platelet concentrates, and to determine bacterial growth kinetics in leucodepleted and non-leucodepleted units. MATERIALS AND METHODS: Apheresis (Cobe Leucocyte Reduction System [LRS]) and pooled buffy coat-derived (Optipress) platelet concentrates (PCs) were tested. Six organisms were used for spiking the PCs: Clostridium perfringens, Bacillus cereus, Group B Streptococcus, Staphylococcus epidermidis, Staphylococcus aureus and Escherichia coli. Units were inoculated to give a final concentration of approximately equal to 1 and 50 colony-forming units (CFU)/ml. On days 0, 2 and 5, BacT/Alert standard aerobic and anaerobic bottles were inoculated with a 5-ml fill volume and bacteria were enumerated. RESULTS: The BacT/Alert Automated blood culture system gave rapid determination times of spiked units, with all positives detected within 48 h and 98.1% detected within 24 h. In general, as the inoculum concentration increased, the detection time decreased. Rapid growth was obtained with all organisms tested except for B. cereus, which failed to grow on four occasions. Bacterial numbers on day 2 ranged from 10(5) to 10(11) CFU/ml and on day 5 ranged from 10(4) to 10(12) CFU/ml. Growth was not significantly greater in leucodepleted units. CONCLUSIONS: The study confirmed that PCs are an excellent growth medium for bacteria. Rapid and substantial growth was obtained with all organisms under test. Leucodepletion does not appear to enhance bacterial proliferation. The BacT/Alert automated blood culture system could rapidly detect contamination of units. Bacterial screening using an automated blood culture system is therefore a potential option.

Bacteria↗
PubMed2001

Evaluation of donor arm disinfection techniques.

BACKGROUND AND OBJECTIVE: To validate a standardized optimal national procedure for donor arm disinfection. MATERIALS AND METHODS: A direct swabbing and plating technique was used to enumerate bacteria present on the arm pre- and postdisinfection. Twelve donor arm disinfection techniques were evaluated. RESULTS: The Medi-Flex Adapted method, consisting of a two-stage process with an initial application of isopropyl alcohol followed by tincture of iodine, produced the best arm disinfection. A percentage reduction in bacterial counts of 99.79% (logarithmic reduction of 2.67) was obtained. Postdisinfection, 70% of donors had bacterial counts of zero, and 98% had counts of 10 or less. CONCLUSION: The Medi-Flex disinfection method offers the English National Blood Service a validated, optimal 'best practice' disinfection technique and should contribute significantly to the reduction in risk of transmission of bacteria by transfusion.

2-Propanol↗
PubMed2001

Hyaluronic acid skin fillers: adverse reactions and skin testing.

BACKGROUND: Hyaluronic acid (HA) fillers have been proposed as alternatives to other temporary skin fillers, such as bovine collagen, for treating facial skin lines and for providing lip augmentation. Several types of commercial HA fillers are now available in many countries. They include Restylane, which is produced by microbiologic engineering techniques, and Hylaform, which is HA extract derived from rooster combs. They have been approved for use in several countries, but not currently in the United States. There are no recommendations to perform pretreatment skin testing by the manufacturers. OBJECTIVE: Our purpose is to describe and comment on our experiences with Hylaform and Restylane fillers. Observation of any side effects and skin testing results were documented. METHODS: Between September 1996 and September 2000, 709 patients were treated with Hylaform and Restylane and were followed up clinically for at least 1 year. Three of these patients (0.42%) developed delayed skin reactions. Three other patients were referred for evaluation of their skin reactions from other practitioners. Five of these 6 patients agreed to skin testing of their forearms. RESULTS: In the 5 patients tested, challenge intradermal skin testing was positive in 4 patients; the reactions started approximately 8 weeks after injection. CONCLUSIONS: There was a slight incidence of delayed inflammatory skin reactions to two HA fillers. Both of these reactions occurred after the first and repeat injections. Challenge skin testing was positive in 4 of 5 tested patients.

Biocompatible Materials↗
PubMed2001

Effects of stimulants on the continuous performance test (CPT): implications for CPT use and interpretation.

An increasing number of treatment plans for individuals with attention-deficit/hyperactivity disorder (ADHD), as well as other disorders, include stimulant medication. The purpose of this study was to investigate the effects of stimulant medications on attention and impulsivity as measured by continuous performance tests (CPTs). The effect of other stimulants (e.g., caffeine, nicotine) on CPT performance was examined as well. Although various versions of the CPT were used in the studies reviewed, the research supports improvements in CPT performance with stimulant treatment. Implications for the use of CPTs in evaluating the effects of medications on attention are discussed. Also presented are implications for control of common substances like nicotine or caffeine when CPT is used and interpreted as a measure of attention.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

Chemical grafting of molecularly imprinted homopolymers to the surface of microplates. Application of artificial adrenergic receptor in enzyme-linked assay for beta-agonists determination.

A technique for coating of microplate wells with a molecularly imprinted polymer (MIP), specific for epinephrine, is presented. 3-Aminophenylboronic acid was polymerized in the presence of epinephrine using oxidation of the monomer by ammonium persulfate. This process resulted in the grafting of a thin polymer layer onto the polystyrene surface of the microplates. The polymer affinity was determined by an enzyme-linked assay using a conjugate of horseradish peroxidase and norepinephrine (HRP-N). It was found that imprinting resulted in increased affinity of the polymer toward HRP-N and epinephrine. Influence of the buffer pH and concentration on the polymer affinity was analyzed. It was shown that the MIP-coated microplates could be used for assay development and drug screening. The high stability of the polymers and good reproducibility of the measurements make MIP coating an attractive alternative to traditional antibodies or receptors, used in ELISA.

Adrenergic beta-Agonists↗
PubMed2000

Longterm central venous access in gynecologic cancer patients.

BACKGROUND: To assess the utility and safety of three different longterm indwelling intravenous catheters in patients with gynecologic malignancies. STUDY DESIGN: A retrospective review was performed of the records of all women with gynecologic malignancies who required longterm venous access catheters and ports between 1990 and 1997. RESULTS: Two hundred sixty-eight women underwent placement of 308 indwelling catheters, of which 305 were available for analysis. Of those, 68 (22%) were Hickman catheters, 162 (53%) were infusaports, and 75 (25%) were Peripheral Access System (PAS) ports. Venous access was obtained percutaneously in 152 (50%) patients and by cutdown in 153 (50%). Prophylactic anticoagulation was used with 96 catheters (31%). Catheter placement was associated with 12 (4%) immediate complications and 87 (29%) delayed complications. The average duration of a catheter in place was 5.6 months for the Hickman, 12.5 months for the infusaport, and 16.0 months for the PAS port (p < 0.001). Bacteremia was more likely to develop in patients with Hickman catheters when compared with those with infusaports and PAS ports (19% versus 6% and 5%, respectively, p = 0.002). Thrombosis was significantly less likely to develop in patients receiving prophylactic anticoagulation (11% versus 4%, p = 0.004). Overall, the complication rate was lower with cutdown versus percutaneous access (p = 0.004). There was no statistically significant difference between the frequency of complications when correlated with the stage of disease, patient age, body mass index, or type of malignancy. CONCLUSIONS: Infusaports and PAS ports were associated with a lower risk of infection and have a longer life than Hickman catheters. The cutdown approach was associated with a lower complication rate. Low-dose prophylactic anticoagulation should be given to all patients with longterm central venous catheters.

Adult↗
PubMed1999

The posterior tibial tendon and the tarsal sinus in rheumatoid flat foot: magnetic resonance imaging of 40 feet.

OBJECTIVE: To investigate the role of the posterior tibial tendon in the flat foot deformity of rheumatoid arthritis (RA). METHODS: Eleven patients with hyperpronated feet and 9 without hyperpronation underwent magnetic resonance imaging (MRI) of the feet and ankles. Radial oblique double echo images provided cross sectional views of the posterior tibial tendon as it coursed behind and under the medial malleolus and inserted beneath the midfoot. RESULTS: Complete tears (Type III) of the posterior tibial tendon were seen in one patient with hyperpronation and in one without hyperpronation. However, partial tears (Types I and II) of the posterior tibial tendon were common, and when Type I-III posterior tibial tendon tears were grouped together, they were seen in 68% of flat feet and in 43% of feet that were not flat. Abnormalities of the tarsal sinus, including cortical erosions and replacement of the normal fat signal with intermediate signal soft tissue, were seen in 74% of flat feet and in 5% of feet that were not flat. CONCLUSION: Posterior tibial tendon tears are common in RA flat feet, but are usually incomplete and are not solely responsible for the flat foot deformity.

Ankle Joint↗
PubMed1998

Real-time analysis of cell surface HLA class I interactions.

Characterisation of the kinetics of assembly and dissociation of the HLA class I heterotrimeric complex provides valuable insights into the relative contributions of each element to complex stability. However, to date there has been no real-time binding analysis on whole cells. Here we have developed an optical biosensor model to investigate the binding of class I HLA complexes on whole cells to human beta 2-microglobulin (beta 2m) and the effects of different HLA-specific peptides on this binding. We immobilised beta 2m on an IAsys biosensor surface and established conditions to analyse the binding of this to HLA-A2 expressing cells (T2 cells). Using 721.221 cells as an HLA negative control we showed that HLA-A2 binding was optimal using a) a carboxymethylated dextran surface and b) no growth factors or supplements in the culture medium at the binding event. Using these conditions we verified specificity of binding by inhibition of the reaction with free beta 2m and determined the dissociation rate constant for T2 cell binding to beta 2m (0.03 s-1). In addition, we demonstrated the ability of different HLA specific peptides to modulate cellular HLA-A2 binding to beta 2m. This is the first time that interactions of cell surface HLA class I molecules has been investigated using real-time analysis. Furthermore, our peptide analysis has shown that this model can be used to characterise peptide specific HLA-binding responses on the whole cell surface in real-time.

Cell Line↗
PubMed1996

Bladder wall pedicle wraparound sling for neurogenic urinary incontinence in children.

PURPOSE: To improve the results of current bladder neck reconstruction a modification was developed to provide tapering, circumferential compression and suspension of the bladder neck. MATERIALS AND METHODS: Nine female and 15 male patients with spinal dysraphism and incontinence, despite intermittent catheterization and pharmacotherapy, and low outlet resistance underwent surgery. The procedure involves wrapping a pedicle strip of anterior bladder wall around the bladder neck and suspending it to the pubic symphysis. RESULTS: All 9 girls are completely continent, whereas 10 boys are dry and 5 have stress incontinence after 9 to 14 months of followup. Subjective symptoms correlate with changes in leak point pressure. CONCLUSIONS: This technique is an efficacious addition to bladder augmentation in female patients with poor compliance and low outlet resistance.

Adolescent↗
PubMed1995

Skin resurfacing with the Ultrapulse carbon dioxide laser. Observations on 100 patients.

BACKGROUND: The Ultrapulse carbon dioxide (CO2) laser has been shown to be a highly effective treatment for photodamaged skin including improvement of rhytides, precancerous and benign skin lesions, as well as superficial benign pigmented lesions. OBJECTIVE: We describe our experiences using the Ultapulse CO2 laser in treating 100 patients with different severities of photodamaged skin. METHODS: All patients had moderately or severely photodamaged skin and were selected for treatment with the Ultrapulse CO2 laser to evaluate the efficacy and toxicity of this treatment. The patients were placed on a pretreatment regimen for 2-6 weeks prior to receiving treatment with the Ultrapulse CO2 laser. Patients were evaluated for pre- and posttreatment severity of photodamage. In addition, skin surface replicas were obtained in selected patients and evaluated by computer image analysis technology. RESULTS: At 1 month post-laser treatment, 68 patients received a moderate improvement, five patients achieved a marked improvement, and the remaining 27 patients showed minimal improvement. By 2 months post-laser treatment, 20 of the 27 patients who at 1 month showed only minimal improvement revealed a moderate to marked improvement from baseline. All the patients studied developed a transient erythema that lasted up to 6 weeks, and many of these patients showed a transient hyperpigmentation that persisted for up to 4 months. CONCLUSION: The Ultrapulse CO2 laser is confirmed as an effective treatment for skin resurfacing of photodamaged skin.

Adult↗
PubMed1994

Infant pyeloplasty is a low-risk procedure.

Early pyeloplasty for the treatment of congenital ureteropelvic junction obstruction to maximize nephron salvage is only justified if the potential hazards of operating on small infants are avoided. The records of all infants who underwent pyeloplasty by the authors over a 7-year period were analyzed. The outcome of surgery in the younger infant group (YIG; patients less than 2 months of age) was compared with that of the older infant group (OIG; patients more than 2 months of age). Preoperative evaluation in cases of mild or moderate hydronephrosis was directed toward ruling out a nonobstructed collecting system and included voiding cysto-urethrography and serial ultrasonography and/or dual isotope diuretic renography. Open pyeloplasty was performed if collecting systems had deteriorated or were demonstrated to be obstructed; it was also performed for severe cases of hydronephrosis. Postoperative assessment consisted of serial ultrasonography and/or nuclear imaging to confirm decompression and relief of obstruction. Thirty three pyeloplasties were performed in 31 patients in the YIG (two bilateral), and 33 were performed in 32 infants in the OIG (one bilateral). The only significant differences between the groups were as follows. Patients in the YIG were more likely to present in utero (87% v 53%; P < .01), whereas those in the OIG were more likely to present with a urinary tract infection (44% v 0%; P < .01). The YIG was more likely to have nephrostomy drainage postoperatively (67% v 45%; P < .01). In the overall series, there were five complications, all of which were postoperative infections requiring intravenous antibiotic therapy. Two occurred in the YIG and three in the OIG.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1993

T cell recognition of a point mutation in the P21 Ras protein.

Point mutations of p21 Ras proteins correlate with many human malignancies. To determine whether the mutations of Ras proteins generate immunogenic determinants which can be recognized by T cells and possibly serve as targets for immunotherapy, we studied the murine T helper responses to synthetic Ras peptides corresponding to amino acids 1-23 of normal or mutant Ras protein. Immunization of C3H/He and B10.BR mice with Ras peptides containing a valine mutation at position 12 stimulated MHC class II-restricted T helper cells which recognised specifically the Ras mutation. Surprisingly C57BL/10 mice generated T helper responses not only against mutant but also against normal Ras peptides. Importantly, natural processing of Ras protein was found to generate the epitopes recognized by the peptide-induced T cells.

Amino Acid Sequence↗
PubMed1992

Seroepidemiology of Helicobacter pylori infection in vegans and meat-eaters.

An enzyme-linked immunosorbent assay has been used to diagnose serologically the prevalence of Helicobacter pylori infection in Asian life-long vegans. There was no difference in the seropositivity between these individuals and a group of age- and sex-matched Asian meat-eaters, indicating the meat consumption is not a risk factor for H. pylori infection. However, both Asian groups had a higher prevalence of infection than age- and sex-matched Caucasian meat-eaters. Additionally, the Asian individuals had a wider range of specific IgG antibody concentrations than the Caucasians. This did not appear to be due to antigenic cross-reactivity between H. pylori and Campylobacter jejuni. The significance of these observations to the establishment of cut-off levels for the serodiagnosis of certain ethnic groups is discussed.

Adolescent↗
PubMed1992

Colonic absorption of human calcitonin in man.

1. Human calcitonin was administered into the distal colon and by intravenous infusion in eight healthy subjects in an open, fixed sequence, cross-over bioavailability study. 2. Intravenously infused human calcitonin elicited a standard pharmacokinetic profile in eight healthy subjects with a biphasic elimination with half-lives of 10.2 +/- 0.7 min and 37.8 +/- 2.5 min. 3. Colonoscopically administered human calcitonin was absorbed across the distal colonic mucosa in low amounts with a bioavailability of 0.00-0.22%. 4. Absorption from the distal colon was impeded by the presence of faecal material in three of the eight subjects. 5. We conclude that human calcitonin crosses the gastrointestinal epithelium of man. This may demonstrate the feasibility of an oral form for clinical use.

Adult↗