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Biomedical subjects

E Newton

Publications and source records attributed to E Newton.

At least 19 recordsLinked to original sources
PubMed2006

In vivo protective performance of N95 respirator and surgical facemask.

BACKGROUND: The SARS outbreak in 2003 has spawned a major controversy concerning protective performance facemasks for healthcare workers. This study reports a study on in-vivo protective performance of surgical masks and N95 respirators. METHODS: Typical surgical masks and N95 respirators used in Hong Kong hospitals were tested in comparison with those treated with nano-functional materials (called nano-masks) on various physical properties and in-vivo wear filtration efficiency, as well as usability test in hospitals for surgical masks. RESULTS: Tests on physical properties showed that N95 respirators had significantly lower air permeability and water vapor permeability than surgical masks. The in-vivo filtration tests illustrated that N95 respirators filtered out 97% of potassium chloride (KCl) solution, while surgical masks filtered out 95% of KCl solution. Nano-masks show stronger water repellency and antibacterial activities, but no difference in usability, comparing with normal N95 and surgical masks. CONCLUSIONS: Surgical masks can provide in-vivo filtration protection of 95% filtration efficiency. N95 respirators provide higher in-vivo filtration efficiency of 97% with significant reduction of air permeability and water vapor permeability. Compared to normal surgical masks/respirators, the nano-masks can provide additional protective functions in stopping capillary diffusion and antibacterial activities.

Aerosols↗
PubMed2005

Antimicrobial effect of surgical masks coated with nanoparticles.

This study assessed the antimicrobial activity of nanoparticles (consisting of a mixture of silver nitrate and titanium dioxide) and nanoparticle-coated facemasks to protect against infectious agents. The minimum inhibitory concentrations of the nanoparticles against Escherichia coli and Staphylococcus aureus were 1/128 and 1/512, respectively. The antibacterial activity of nanoparticle-coated masks was quantified according to the procedures of AATCC 100-1999. A 100% reduction in viable E. coli and S. aureus was observed in the coated mask materials after 48 h of incubation. Skin irritation was not observed in any of the volunteers who wore the facemasks. Nanoparticles show promise when applied as a coating to the surface of protective clothing in reducing the risk of transmission of infectious agents.

Anti-Bacterial Agents↗
PubMed2005

Effects of wearing N95 and surgical facemasks on heart rate, thermal stress and subjective sensations.

AIM: The study was aimed at investigating the effects of wearing N95 and surgical facemasks with and without nano-functional treatments on thermophysiological responses and the subjective perception of discomfort. METHOD: Five healthy male and five healthy female participants performed intermittent exercise on a treadmill while wearing the protective facemasks in a climate chamber controlled at an air temperature of 25 degrees C and a relative humidity of 70%. Four types of facemasks, including N95 (3M 8210) and surgical facemasks, which were treated with nano-functional materials, were used in the study. RESULTS: (1) The subjects had significantly lower average heart rates when wearing nano-treated and untreated surgical facemasks than when wearing nano-treated and untreated N95 facemasks. (2) The outer surface temperature of both surgical facemasks was significantly higher than that of both N95 facemasks. On the other hand, the microclimate and skin temperatures inside the facemask were significantly lower than those in both N95 facemasks. (3) Both surgical facemasks had significantly higher absolute humidity outside the surface than both N95 facemasks. The absolute humidity inside the surgical facemask was significantly lower than that inside both N95 facemasks. (4) Both surgical facemasks were rated significantly lower for perception of humidity, heat, breath resistance and overall discomfort than both N95 facemasks. The ratings for other sensations, including feeling unfit, tight, itchy, fatigued, odorous and salty, that were obtained while the subjects were wearing the surgical facemasks were significantly lower than when the subjects were wearing the N95 facemasks. (5) Subjective preference for the nano-treated surgical facemasks was the highest. There was significant differences in preference between the nano-treated and untreated surgical facemasks and between the surgical and N95 facemasks. DISCUSSION: We discuss how N95 and surgical facemasks induce significantly different temperature and humidity in the microclimates of the facemasks, which have profound influences on heart rate and thermal stress and subjective perception of discomfort.

Blood Pressure↗
PubMed2002

Effect on outcome of early intensive management of geriatric trauma patients.

BACKGROUND: Despite significant injuries elderly patients (aged 70 years or more) often do not exhibit any of the standard physiological criteria for trauma team activation (TTA), i.e. hypotension, tachycardia or unresponsiveness to pain. As a result of these findings the authors' TTA criteria were modified to include age 70 years or more, and a protocol of early aggressive monitoring and resuscitation was introduced. The aim of the present study was to assess the effect of the new policy on outcome. METHODS: This trauma registry study included patients aged 70 years or more with an Injury Severity Score (ISS) greater than 15 who were admitted over a period of 8 years and 8 months. The patients were divided into two groups: group 1 included patients admitted before age 70 years and above became a TTA criterion and group 2 included patients admitted during the period when age 70 years or more was a TTA criterion and the new management protocol was in place. The two groups were compared with regard to survival, functional status on discharge and hospital charges. RESULTS: There were 336 trauma patients who met the criteria, 260 in group 1 and 76 in group 2. The two groups were similar with respect to mechanism of injury, age, gender, ISS and body area Abbreviated Injury Score. The mortality rate in group 1 was 53.8 per cent and that in group 2 was 34.2 per cent (P = 0.003) (relative risk (RR) 1.57 (95 per cent confidence interval 1.13 to 2.19)). The incidence of permanent disability in the two groups was 16.7 and 12.0 per cent respectively (P = 0.49) (RR 1.39 (0.59 to 3.25)). In subgroups of patients with an ISS of more than 20 the mortality rate was 68.4 and 46.9 per cent in groups 1 and 2 respectively (P = 0.01) (RR 1.46 (1.06 to 2.00)); 12 of 49 survivors in group 1 and two of 26 in group 2 suffered permanent disability (P = 0.12) (RR 3.18 (0.77 to 13.20)). CONCLUSION: Activation of the trauma team and early intensive monitoring, evaluation and resuscitation of geriatric trauma patients improves survival.

Aged↗
PubMed2001

Old age as a criterion for trauma team activation.

BACKGROUND: Elderly trauma patients have been shown to have a worse prognosis than young patients. Age alone is not a criterion for trauma team activation (TTA). In the present study, we evaluated the role of age > or = 70 years as a criterion for TTA. METHODS: The present study was a trauma registry study that included injured patients 70 years of age or older. Patients who died in hospital, were admitted to the intensive care unit (ICU) within 24 hours, or had a non-orthopedic operation were assumed to benefit from TTA. RESULTS: During a 7.5-year period, 883 elderly (> or = 70 years) trauma patients meeting trauma center criteria were admitted to our center. Overall, 223 patients (25%) met at least one of the standard TTA criteria. The mortality in this group was 50%, the ICU admission rate was 39%, and a non-orthopedic operation was required in 35%. The remaining 660 patients (75%) did not meet standard TTA criteria. The mortality was 16%, the need for ICU admission was 24%, and non-orthopedic operations were required in 19%. Sixty-three percent of patients with severe injuries (Injury Severity Score > 15) and 25% of patients with critical injuries (Injury Severity Score > 30) did not have any of the standard hemodynamic criteria for TTA. CONCLUSION: Elderly trauma patients have a high mortality, even with fairly minor or moderately severe injuries. A significant number of elderly patients with severe injuries do not meet the standard criteria for TTA. It is suggested that age > or = 70 years alone should be a criterion for TTA.

Age Factors↗
PubMed1994

Bacterial vaginosis: efficacy and safety of intravaginal metronidazole treatment.

OBJECTIVE: We evaluated the effectiveness and safety of intravaginal metronidazole in the treatment of bacterial vaginosis. Demographic data, Gram stain score, and individual clinical diagnostic criteria for bacterial vaginosis were evaluated for association with therapeutic outcome. METHODS: According to accepted diagnostic criteria and blinded Gram stain scoring for quality control, a multicenter, prospective, double-blinded trial of patients randomized to either 0.75% metronidazole gel 5 gm twice daily for 5 days or placebo was undertaken. Therapeutic response after completion of treatment was evaluated by examination at 4 to 16 days and again at 28 to 32 days for patients initially cured. RESULTS: After metronidazole treatment, 38 (78%) of 49 patients were cured initially, compared with 11 (27%) of 41 placebo recipients (p < 0.001). One month after treatment 31 (91%) of 34 in the group initially cured by metronidazole remained cured. Side effects were uncommon and mild. Significant intercenter differences were noted for vaginal discharge assessment but not for other diagnostic criteria. Among patients cured initially with metronidazole, mean Gram stain score was 0.58 among those in whom cure was maintained versus 2.33 for those in whom recurrent bacterial vaginosis developed 1 month after treatment (p = 0.03). Curative metronidazole treatment was found initially in 4 (100%) of 4 patients with sperm present on gram stain compared with 34 (76%) of 45 with sperm absent (p = 0.56) and in 6 (100%) of 6 and 25 (89%) of 28, respectively, at the final visit (p = 1.0). CONCLUSIONS: Intravaginal metronidazole is effective, safe, well-tolerated, durable therapy for bacterial vaginosis. Characterization of vaginal discharge appears to be the most variable among the diagnostic criteria for bacterial vaginosis. Gram stain score may be able to identify patients cured early after therapy who are at risk for later recurrence. Exposure to semen does not appear to affect efficacy of intravaginal metronidazole.

Administration, Intravaginal↗
PubMed1994

Randomized comparison of ampicillin-sulbactam to cefoxitin and doxycycline or clindamycin and gentamicin in the treatment of pelvic inflammatory disease or endometritis.

OBJECTIVE: To evaluate the efficacy and safety of ampicillin-sulbactam (3 g every 6 hours) in patients with pelvic inflammatory disease or postpartum endometritis using a randomized, comparative, multicenter study of parallel design. METHODS: Eligible patients with pelvic inflammatory disease were randomized to receive either ampicillin-sulbactam or cefoxitin (2 g every 6 hours) plus doxycycline (100 mg every 12 hours). Those with endometritis were randomized to ampicillin-sulbactam or clindamycin (900 mg every 8 hours) plus gentamicin (1.5 mg/kg every 8 hours). In the ampicillin-sulbactam group, chlamydia-positive patients also received oral doxycycline. RESULTS: For pelvic inflammatory disease, the clinical response rates (cure or improvement) were 85.5% (47 of 55) and 89.6% (43 of 48) in the ampicillin-sulbactam and cefoxitin and doxycycline groups, respectively (chi 2 = 0.10, P = .76). For endometritis, the clinical response rates were 88.7% (141 of 159) and 90.8% (139 of 153) in the ampicillin-sulbactam and clindamycin and gentamicin groups, respectively (chi 2 = 0.15, P = .70). The percentages of patients with pelvic inflammatory disease who had adverse experiences were not significantly different in the cefoxitin and doxycycline group (47% [29 of 62]) than in those receiving ampicillin-sulbactam (33% [22 of 66]) (P = .12). These adverse effects were mostly mild or moderate. In the endometritis subjects, the incidence of adverse experiences in the ampicillin-sulbactam group (11% [20 of 179]) was comparable to that during treatment with clindamycin and gentamicin (12% [22 of 180]). These adverse experiences were also mostly mild to moderate. CONCLUSION: Ampicillin-sulbactam is as effective and well tolerated as combination regimens using cefoxitin plus doxycycline and clindamycin plus-gentamicin for the treatment of pelvic inflammatory disease or endometritis, respectively.

Adult↗
PubMed1994

Radiographic diagnosis of ankle fractures: are three views necessary?

One hundred and twenty-three sets of emergency room ankle x-rays (anteroposterior lateral and mortise) were retrospectively reviewed to determine whether all three views were necessary to diagnose the presence of an ankle fracture. Four physicians (two orthopaedic surgeons, one musculoskeletal radiologist, and one emergency room physician) reviewed all randomly ordered sets of films twice--once with all three views and once with only the lateral and mortise views. The overall accuracy of two views was within the 95% expected threshold of accuracy using three views. The lateral and mortise views alone appear sufficient for ankle fracture diagnosis, and imply a substantial decrease in radiation and cost savings to the patient.

Ankle Injuries↗
PubMed1993

Evaluation and management of acute uvular edema.

Acute uvular edema is a potentially life-threatening condition with a variety of causes. Other upper airway structures, most notably the epiglottis, may also become involved, and complete or partial airway obstruction may ensue rapidly. An accurate diagnosis may be essential in establishing effective treatment.

Acute Disease↗
PubMed1993

Successful conversion of unstable supraventricular tachycardia to sinus rhythm with adenosine.

STUDY PURPOSE: To evaluate the efficacy of adenosine in the treatment of emergency department patients with unstable paroxysmal supraventricular tachycardia (PSVT). DESIGN: A retrospective chart review conducted over two years. SETTING: A university-affiliated hospital ED. PARTICIPANTS: Patients with unstable PSVT (systolic blood pressure of less than 90 mm Hg, chest pain, pulmonary edema, and/or altered mental status) who were treated with adenosine. INTERVENTIONS: Patients' preadenosine and postadenosine heart rates, symptoms, and blood pressure were recorded, as were complications and recurrence of PSVT. PSVT was diagnosed by surface ECG. RESULTS: Twelve patients were identified (three men and nine women with a mean age of 47.6 years). Nine patients presented with hypotension (mean systolic blood pressure, 79 mm Hg), ten with chest pain, and six with both chest pain and hypotension. There were no patients with altered mental status or pulmonary edema. Eight patients converted to sinus rhythm with a single 6-mg bolus of adenosine; the remaining four required an additional 12-mg bolus. In all cases, chest pain and hypotension resolved within minutes of conversion to sinus rhythm. There were no clinically significant adverse effects or recurrence of PSVT during ED observation (mean, 1.8 hours). All patients responded to adenosine; none required electrical cardioversion. CONCLUSION: In the unstable patient with PSVT, adenosine appears to be a safe and effective alternative to current advanced cardiac life support-recommended immediate electrical cardioversion.

Adenosine↗
PubMed1993

Reference accuracy in the emergency medicine literature.

STUDY OBJECTIVE: To determine the incidence and nature of errors in the citation and quotation of references contained in the emergency medicine literature. DESIGN: A retrospective analysis of a random sample of articles and references found in the three major emergency medicine journals. SETTING: A university/county hospital. METHODS: We examined single issues of three emergency medicine journals: Annals of Emergency Medicine, Journal of Emergency Medicine, and American Journal of Emergency Medicine. INTERVENTIONS: None. MEASUREMENTS: Four independent reviewers assessed 145 references from 46 referring authors for citational and quotational accuracy. MAIN RESULTS: Major and minor citation errors were found in 10.3% and 17.2% of reference listings, respectively. Qualitative quotational errors were found in 35.2% of references. Eighty-two percent of these errors were considered to be major. Quantitative quotational errors were found in 47% of references reviewed. Secondary rather than primary reference sources were used in 41.4% of references reviewed. CONCLUSION: This study demonstrates a substantial error rate in the citation and quotation of reference sources in the emergency medicine literature. In addition, verification of primary source material was not done by a large percentage of the authors reviewed. Recommendations for improving the accuracy of the emergency medicine literature are offered.

Bias↗
PubMed1991

Vaginal antibody of patients with trichomoniasis is to a prominent surface immunogen of Trichomonas vaginalis.

Twenty vaginal washes (VWs) and ten vaginal mucus (VM) samples from patients with trichomoniasis were examined for the presence of antibody to surface protein immunogens of Trichomonas vaginalis. Fourteen of 20 VWs (70%) and 8 of 10 VM (80%) had immunoglobulin G (IgG) antibody (Ab) that reacted in an immunoprecipitation (IP) assay with one iodinated Trichomonas vaginalis surface protein immunogen with a relative molecular mass of 230,000 daltons (230-kDa) (P230). No similar IP of any iodinated protein was observed when detergent extract was first depleted of P230 with monoclonal antibody (MAb), indicating a highly specific VW IgG response of patients to P230. VWs were also obtained from 10 patients from one to four weeks after treatment. These VWs had the same, or in one case a greater, level of IgG to P230. Under no circumstances was Ab to P230 or any other trichomonad protein detected in VWs or VM from normal, uninfected women. Flow cytofluorometry with VW Ab yielded heterogeneous fluorescent and non-fluorescent populations of trichomonads, reaffirming the restricted Ab response to one or a few epitopes on P230 in the vagina of patients. Under identical conditions, the MAb gave totally fluorescent parasite populations of some isolates, and the MAb again demonstrated variable epitope accessibility to Ab binding (Infect Immun 1987;55:1037). Finally, the MAb or VW Ab was never cytolytic for immunoreactive (fluorescent) parasites, even in the presence of complement. This study identifies the most important trichomonad surface immunogen on the basis of the vaginal Ab response, and data underscore the significance of immune evasion strategies of this sexually transmitted disease agent.

Animals↗
PubMed1991

Antibody in sera of patients infected with Trichomonas vaginalis is to trichomonad proteinases.

BACKGROUND: A recent report demonstrated the immunogenic character of the cysteine proteinases of Trichomonas vaginalis. It was of interest, therefore, to examine for the presence of serum anti-proteinase antibody among patients with trichomoniasis. METHODS: An immunoprecipitation assay was used involving protein A-bearing Staphylococcus aureus first coated with the IgG fraction of goat anti-human Ig and then mixed with individual sera of patients to bind human antibody. These antibody-coated bacteria were then added to detergent extracts of T vaginalis. Bound immune complexes on S aureus were washed and solubilised for electrophoretic analysis on acrylamide copolymerised with gelatin for detection of proteinase activity. RESULTS: Sera from patients (50/50), but none from sera of normal, uninfected women, possessed IgG to numerous trichomonad cysteine proteinases. The presence of this serum anti-proteinase antibody disappeared after drug treatment and cure of patients of the T vaginalis infection. CONCLUSIONS: The commonality of the anti-proteinase antibody in the sera of patients with trichomoniasis provided evidence for the expression of the same repertoire of parasite proteinases during infection. These observations have important implications for the in vivo relevance of the proteinases and indicate that strategies to use a specific serum antibody response for diagnosis of this infection may be possible.

Animals↗
PubMed1991

The vagina of women infected with Trichomonas vaginalis has numerous proteinases and antibody to trichomonad proteinases.

BACKGROUND: Patients with trichomoniasis have serum antibody to numerous T. vaginalis cysteine proteinases, indicating that the proteinases are expressed in vivo. It was important, therefore, to examine for the presence of soluble trichomonad proteinases and/or antibody to the proteinases in the vagina of infected women. METHODS: Vaginal washes (VWs) from 20 women were examined for the presence of proteinases by electrophoresis using acrylamide co-polymerised with gelatin as the indicator system. Antibody to proteinases in VWs was detected by an immunoprecipitation assay involving protein A-bearing Staphylococcus aureus first coated with anti-human immunoglobulin G (IgG) antibody, which was then added to VWs. For VWs having soluble proteinases, the bacteria were used to determine whether immune complexes between antibody and proteinases were present. VWs without soluble proteinases were incubated with the anti-human IgG treated bacteria before adding to detergent extracts of T. vaginalis. Individual isolates from the patients examined in this study were also analysed by one- and two-dimensional electrophoresis for their proteinase content. Finally, VWs were from patients without any history of other sexually transmitted diseases (STDs) as well as from individuals having numerous other STDs, including yeast, group B streptococcus, chlamydia, and syphilis. RESULTS: Approximately one-third of patients had soluble proteinases in the VWs; the remaining two-thirds (70%) of patients and normal women had no detectable proteinases in VWs. Half of the patients without soluble proteinases had IgG which, when bound to S. aureus, immunoprecipitated many proteinases from a detergent extract of T. vaginalis. All soluble proteinases and those precipitated from trichomonal extracts were inhibited by inhibitors of cysteine proteinases. Finally, patients having trichomoniasis in addition to numerous other STD agents, including yeast, group B streptococcus, chlamydia, and syphilis did not have soluble proteinases in VWs. Equally noteworthy, some patients with soluble proteinases in VWs did not have other detectable STD agents. CONCLUSIONS: Proteinases were detected in the vagina of some patients with trichomoniasis, and in most cases the proteinases were complexed with IgG, which was precipitated by S. aureus. Patients without soluble proteinases in VWs also had antibody specifically to trichomonad proteinases, again demonstrating both the expression and immunogenic nature of the proteinases in vivo. The absence of soluble proteinases in normal women and in patients having other STD agents as well as the presence of proteinases in VWs of patients without other detectable STD pathogens reinforced the idea that the proteinases were of T. vaginalis parasite origin. The findings of this study indicate that proteinases may be important to the T. vaginalis-host interrelationship.

Animals↗