Design and Implementation of a Specialised Millimetre-Wave Exposure System for Investigating the Radiation Effects of 5G and Future Technologies

As the fifth-generation (5G) network is introduced in the millimetre-wave (mmWave) spectrum, and the widespread deployment of 5G standalone (SA) is approaching, it becomes essential to establish scientifically grounded exposure limits in the mmWave frequency band. To achieve this, conducting experiments at specific frequencies is crucial for obtaining reliable evidence of potential biological impacts. However, there is a literature gap where experimental research either does not utilise the mmWave high band (e.g., the 26 Gigahertz (GHz) band) or most studies mainly rely on computational approaches. Moreover, some experimental studies do not establish reproducible test environment and exposure systems. Addressing these gaps is vital for a comprehensive exploration of the biological implications associated with mmWave exposure. This study was designed to develop and implement a mmWave exposure system operating at 26 GHz. The step-by-step design and development of the system are explained. This specialised system was designed and implemented within an anechoic chamber to minimise external electromagnetic (EM) interference, creating a controlled and reproducible environment for experiments involving high-frequency EM fields. The exposure system features a 1 cm radiation spot size, enabling highly localised exposure for various biological studies. This configuration facilitates numerous dosimetry studies related to mmWave frequencies.

A trial of nebulised heparin to limit lung injury following cardiac surgery

Cardiac surgery with cardiopulmonary bypass triggers an acute inflammatory response in the lungs. This response gives rise to fibrin deposition in the microvasculature and alveoli of the lungs. Fibrin deposition in the microvasculature increases alveolar dead space, while fibrin deposition in alveoli causes shunting. We investigated whether prophylactic nebulised heparin could limit this form of lung injury. We undertook a single-centre double-blind randomised trial. Forty patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomised to prophylactic nebulised heparin (50,000 U) or placebo. The primary endpoint was the change in arterial oxygen levels over the operative period. Secondary endpoints included end-tidal CO₂, the alveolar dead space fraction and bleeding complications. We found nebulised heparin did not improve arterial oxygen levels. Nebulised heparin was, however, associated with a lower alveolar dead space fraction (P <0.05) and lower tidal volumes at the end of surgery (P <0.01). Nebulised heparin was not associated with bleeding complications. In conclusion, prophylactic nebulised heparin did not improve oxygenation, but was associated with evidence of better alveolar perfusion and CO₂elimination at the end of surgery.

Monte Carlo simulations of the electric field close to the body in realistic environments for application in personal radiofrequency dosimetry

Personal dosemeters can play an important role in epidemiological studies and in radiofrequency safety programmes. In this study, a Monte Carlo approach is used in conjunction with the finite difference time domain method to obtain distributions of the electric field strength close to a human body model in simulated realistic environments. The field is a proxy for the response of an ideal body-worn electric field dosemeter. A set of eight environments were modelled based on the statistics of Rayleigh, Rice and log-normal fading to simulate outdoor and indoor multipath exposures at 450, 900 and 2100 MHz. Results indicate that a dosemeter mounted randomly within 10-50 mm of the adult or child body model (torso region) will on average underestimate the spatially averaged value of the incident electric field strength by a factor of 0.52 to 0.74 over the frequencies of 450, 900 and 2100 MHz. The uncertainty in results, assessed at the 95 % confidence level (between the 2.5th and 97.5th percentiles) was largest at 2100 MHz and smallest at 450 MHz.

Changes in the management and outcome of rectal cancer over a 10-year period in Oxford

AIM

The changes in the management and outcome of rectal cancer in Oxford were studied over a 10-year period.

METHOD

Rectal cancer data using a prospectively collected data base were divided into curative (global) and palliative groups. The global curative group was further divided into those with and without (selected group) the following features: emergency cases, local excision, salvage surgery for recurrence or incomplete local excision, metastatic disease, perioperative death, hereditary cancer, inflammatory bowel disease-related cancer, and synchronous cancer.

RESULTS

Between 1994 and 2003, 709 cases of rectal cancer were treated, 532 for cure and a selected group of 393 after removing patients with the aforementioned exclusions. For the selected group, the average follow-up was 51.2 months, overall survival 65.4% and cancer-specific survival 75.3%. There was no 2-year survival difference between each of the 10-year periods of study. Two-year local recurrence was 5.6% for the first 5-year period and 2.3% for the second (P = 0.11). MRI staging increased during the 10 years (0% in 1994; 66.7% in 2003) as did use of definitive chemoradiotherapy (dCRT) (0% in 1994; 64.7% in 2003). The anastomotic leakage rate was significantly higher in the second 5-year period (2.6%vs 9.6%; P = 0.01).

CONCLUSION

Despite increasing use of MRI and dCRT, 2-year survival and local recurrence were not significantly different within the 10 years studied.

Factors influencing uncertainty in measurement of electric fields close to the body in personal RF dosimetry

This paper provides an insight into factors that can influence uncertainty in measurements at 900 MHz of electric fields close to the body for use in personal dosimetry. Computational simulations using the finite difference time domain method were used to determine the total electric field near the surface of the torso of heterogeneous (adult and child) human body models for a set of exposure scenarios that simulated both spatially constant and randomly varying incident fields. Modelling has shown that a properly responding isotropic electric field dosemeter mounted between 10 and 50 mm of the torso will on average underestimate the incident field strength by up to 6.45 dB. In the worst case (i.e. spatially constant field), the standard deviation or uncertainty reached 6.42 dB. Uncertainty was reduced to <2.17 dB by combining the simultaneous outputs of a pair of body-worn dosemeters (mounted front and rear of torso).

Predictors of mobile telephone use and exposure analysis in Australian adolescents

AIM

Australian adolescents are increasingly using mobile telephones (MP) while the debate on MP safety persists. This group is not generally engaged in full-time employment, suggesting that their MP use is not work related. We investigated possible predictors of MP use in young people.

METHODS

We assessed exposure to radiofrequency energy from MP by means of a self-administered questionnaire adapted from INTERPHONE--an international case-control study of adult brain, head and neck tumours. We investigated possible determinants of MP use in adolescent Australians using self-reported number of incoming and outgoing voice calls as exposure metric.

RESULTS

There is a high prevalence of MP use amongst Australian adolescents (94%). Males were significantly younger than females at age of first uptake of MP (P= 0.02). Participants without siblings were significantly younger at age of first uptake. Personality traits were associated with regular MP usage: higher psychoticism scores were associated with regular use (IRR = 1.06, P= 0.03); there was a tendency for students with higher extraversion scores to report more MP use. Parental socio-economic status was associated with MP use, but parents who expressed moderate/high level concerns about possible health risks of use were more likely to have children who used MP (OR = 4.06, P= 0.05).

CONCLUSIONS

Almost all adolescent Australians use MP, but regular exposure was associated with personality traits. Parental socio-economic status and perceived health risks of MP use were also associated with use of phones. Longitudinal studies are needed to assess the predictors of mobile phone use in the long term.

Evaluation of Cardiac Comorbidities in Patients with Metastatic Breast Cancer Receiving Doxorubicin-Based and Non-Doxorubicin-Based Chemotherapy

Background: Some metastatic breast cancer (MBC) treatments are associated with cardiac toxicity. Real-world data regarding baseline cardiac comorbidities in patients with MBC prior to chemotherapy initiation are scarce. Such information would be useful in guiding treatment decisions. This study aims to describe the cardiac comorbidity profile of patients with MBC initiating doxorubicin-based (DOX) versus non-doxorubicin-based (Non-DOX) chemotherapy regimens from a managed-care perspective.Methods: Medical claims from the Ingenix Impact National Managed Care Database between 07/2002 and 06/2008 were analyzed. Patients included were aged ≥ 18 years, and had ≥ 2 diagnoses for breast cancer as well as ≥ 1 diagnosis for metastatic site within 12 months of chemotherapy initiation. Cardiac comorbidities [hypertension (HTN), cardiac arrhythmia (CAr), coronary artery disease (CAD), congestive heart failure (CHF), and myocardial infarction (MI)] were evaluated within 6 months prior to chemotherapy initiation. Patients were categorized based on receipt of DOX vs. Non-DOX-based chemotherapy.Results: A total of 12,345 patients (Non-DOX: 7,023, DOX: 5,322) formed the study population. Compared with the DOX group, the Non-DOX group was slightly older. Both groups reported a significant proportion of patients with cardiac comorbidities prior to chemotherapy, with significantly greater proportions reported in the Non-DOX group. Mean age (SD)HTNCArCADCHFMINon-DOX (n=7,023)56.9 (10.6)35.7%11.8%5.5%3.5%1.3%DOX (n=5,322)52.1 (9.1)30.8%8.1%3.3%2.0%0.5%P-value&lt;.001&lt;.001&lt;.001&lt;.001&lt;.001&lt;.001 Conclusions: Cardiac comorbidities were commonly reported in women with MBC prior to chemotherapy, with significantly greater proportions reported in the Non-DOX group. Such information is useful to healthcare professionals when considering potential interventions for patients with MBC.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2078.

A new method to determine laterality of mobile telephone use in adolescents

OBJECTIVES

As more children use mobile (cellular) telephones, public anxiety grows about the possible adverse health effects of radiofrequency (RF) exposure upon developing nervous systems. Most epidemiological studies investigating the health effects of mobile telephones have relied on self-reports from questionnaires. While there are some validation studies investigating the accuracy of self-reported mobile phone use in adults and adolescents, self-reported laterality of use has not been validated at any age. Although this study mainly sought to validate the accuracy of self-reported laterality of mobile telephone use in adolescents, investigation also covered number and duration of calls.

METHODS

We monitored 455 calls in 30 students, mean age (SD) 14 (0.4) years. For 1 week, participants used hardware modified phones (HMPs) which logged dosimetric parameters such as laterality (side of head), date, number and duration of calls. These 'gold standard' measurements were compared with questionnaire self-reported laterality and estimated typical weekly phone use.

RESULTS

Agreement between HMPs and self-reported laterality was modest (kappa=0.3, 95% CI 0.0 to 0.6). Concordance between HMP measured and self-reported number of calls was fair (intraclass correlation coefficient (ICC)=0.38, 95% CI 0.07 to 0.69), but poor for duration (ICC=0.01, 95% CI 0.00 to 0.37) with wide limits of agreement for both.

CONCLUSIONS

These results suggest that adolescent self-reported laterality was of limited validity. Adolescent self-reported phone use by number and duration of calls was generally inaccurate but comparable to recent adult studies. Epidemiological studies of mobile phone use based on self-reported information may underestimate true associations with health effects.

How well do adolescents recall use of mobile telephones? Results of a validation study

BACKGROUND

In the last decade mobile telephone use has become more widespread among children. Concerns expressed about possible health risks have led to epidemiological studies investigating adverse health outcomes associated with mobile telephone use. Most epidemiological studies have relied on self reported questionnaire responses to determine individual exposure. We sought to validate the accuracy of self reported adolescent mobile telephone use.

METHODS

Participants were recruited from year 7 secondary school students in Melbourne, Australia. Adolescent recall of mobile telephone use was assessed using a self administered questionnaire which asked about number and average duration of calls per week. Validation of self reports was undertaken using Software Modified Phones (SMPs) which logged exposure details such as number and duration of calls.

RESULTS

A total of 59 adolescents participated (39% boys, 61% girls). Overall a modest but significant rank correlation was found between self and validated number of voice calls (rho = 0.3, P = 0.04) with a sensitivity of 57% and specificity of 66%. Agreement between SMP measured and self reported duration of calls was poorer (rho = 0.1, P = 0.37). Participants whose parents belonged to the 4th socioeconomic stratum recalled mobile phone use better than others (rho = 0.6, P = 0.01).

CONCLUSION

Adolescent recall of mobile telephone use was only modestly accurate. Caution is warranted in interpreting results of epidemiological studies investigating health effects of mobile phone use in this age group.

Comparison of measuring instruments for radiofrequency radiation from mobile telephones in epidemiological studies: implications for exposure assessment

The debate on mobile telephone safety continues. Most epidemiological studies investigating health effects of radiofrequency (RF) radiation emitted by mobile phone handsets have been criticised for poor exposure assessment. Most of these studies relied on the historical reconstruction of participants' phone use by questionnaires. Such exposure assessment methods are prone to recall bias resulting in misclassification that may lead to conflicting conclusions. Although there have been some studies using software-modified phones (SMP) for exposure assessment in the literature, until now there is no published work on the use of hardware modified phones (HMPs) or RF dosimeters for studies of mobile phones and health outcomes. We reviewed existing literature on mobile phone epidemiology with particular attention to exposure assessment methods used. Owing to the inherent limitations of these assessment methods, we suggest that the use of HMPs may show promise for more accurate exposure assessment of RF radiation from mobile phones.

[Comparative study of surgical efficacy in open versus laparoscopic prostatectomy: virtual prostate reconstruction and periprostatic tissue quantification]

INTRODUCTION

The introduction of laparoscopic surgery as a procedure to perform radical prostatectomy needs an objective method to evaluate the suitability of this new surgical procedure. The traditional parameters, including the incidence of positive surgical margins, are useful, but not sufficiently objective. Different authors publish different criteria to define positive surgical margins. In addition, there are some technical problems that may ocur during the processing of the surgical specimen by the pathologist, which can give false positive margins. We have used a computer modeling software in connection to scanned images from serial sections of the whole gland, to determine the percentage of extracapsular tissue that surrounds the prostate glands, removed by both, open retropubic and laparoscopic procedures. This percentage can be considered as an objective parameter which can potentially predict the benefit of surgery in predicting cancer control, as well as the clinical success of the surgical procedure. The correlation with the clinical results in the long term--survival and bioche--mical recurrence--will be useful to validate as a last resort the clinical utility of this parameter in the coming years.

MATERIALS AND METHODS

We had a total of 32 prostate surgical specimens, 15 from patients who underwent open retropubic prostatectomy and 17 from patients who underwent laparoscopic prostatectomy for this study. After surgery and 24 hours formol fixation, serial cuts were taken at 5 mm thickness intervals to make complete sections ("whole mount") of the prostate. An expert uropathologist reviewed all the surgical sections and drew in each tissue cut the prostatic capsule and tumor contours. The serial images of the whole gland and surrounding prostate tissue were scanned to produce digital images, using a computer software to create a file with capsule information and a file with information on the surrounding fibroadipose tissue (extraprostatic). These procedures allowed the reconstruction of a three dimensional tissue model of the prostatic capsule and the surrounding extraprostatic tissue. Two separate point clouds files were generated, with the purpose of representing capsule and extraprostatic tissue models and software algorithms were used to generate differences in point clouds and thereby quantifying the extracapsular tissue coverage dimension, a parameter that we considered indicative of the adequeacy and feasibility of the surgical procedure.

RESULTS

The global percentage of prostate gland surface covered by extracapsular fibroadipose tissue was statistically higher in specimens removed by a laparoscopic procedure when compared to the open retropubic procedure. When a segmental analysis of the gland percentage of coverage was evaluated, it was found this percentage was significantly higher in the apical and inferolateral segments of those glands removed without nerves preservation and in the apical segments of those glands removed with nerves preservation for the laparoscopic prostatectomy.

CONCLUSIONS

In our series. laparoscopic prostatectomy contributed superior extracapsular tissue coverage than retropubic prostatectomy. Similarly laparoscopic prostatectomy produced a superior tissue coverage in inferolateral and apical regions on those glands removed without nerve preservation and in the apical regions of those glands removed with nerve preservation. Therefore, the surgical suitability of this technique, when compared to the retropubic, seems to be higher

Epoetin-alfa initiation at Hb 10–11 or Hb <10 g/dL: Analysis of safety and efficacy

19628

Background: Current guidelines recommend consideration of epoetin alfa (EPO) therapy for chemotherapy-induced anemia (CIA) either when Hb <11 g/dL (National Comprehensive Cancer Network) or when Hb < 10g/dL (ASCO/ASH 2002). The objective was to evaluate the safety and efficacy of EPO in patients (pts) with CIA when EPO was initiated at Hb 10–11 or at <10 g/dL. Methods: A post hoc analysis was performed on data from randomized, well-controlled trials conducted from 2002–2006. Trials in which EPO therapy was initiated at the approved dose of 40,000 Units weekly in male and female pts with Hb <11g/dL and =1 post-baseline Hb value were included. Two trials were identified, T1 and T2. Safety was assessed by the proportion of pts experiencing clinically relevant thrombovascular events (CR- TVEs) who received =1 dose of EPO. Efficacy was assessed by RBC transfusion requirements (Day 1 - end of treatment [EOT] and Day 29 - EOT) and achievement of durable Hb response (Hb =11 g/dL for =2 consecutive weeks). Results: Baseline (BL) characteristics (age, gender, platinum-based therapy, ECOG PS, and tumor type) were similar between the Hb 10–11 and <10 g/dL groups. BL Hb was 10.53 and 9.29 g/dL in T1 and 10.28 and 9.53 g/dL in T2 for the Hb 10–11 and Hb<10 g/dL subsets, respectively. Results are summarized below ( table ). Conclusions: These results show that patients treated with EPO at an Hb of 10–11 g/dL appear to have a lower incidence of CR-TVEs compared to patients treated at Hb <10 g/dL. In addition, patients who started EPO treatment at an Hb of 10–11 g/dL had fewer RBC transfusions and higher durable Hb response. Trial 1 - Waltzman et al. The Oncologist. 2005;10:642–650. Trial 2 - Henry et al. Curr Med Res Opin. 2006;22:1403–1413.

No significant financial relationships to disclose.

[Table: see text]

Anemia management with erythropoietic stimulating therapies (ESTs) in patients (pts) with gastrointestinal (GI) malignancies: Results from a prospective observational study

19614

Background: Chemotherapy-induced anemia is a common problem for pts with GI malignancies. To assess dosing patterns and outcomes in GI malignancy pts treated with ESTs (epoetin alfa (EPO) and darbepoetin alfa (DARB), a subset analysis of an ongoing registry was conducted. Methods: Data drawn between1/04 and 10/06 from 41 U.S. oncology clinics from the Dosing and Outcomes Study of Erythropoietic Stimulating Therapies (D.O.S.E.) registry were assessed. Pts were included in this analysis if they were diagnosed with a GI malignancy (colon, rectal, gastric, esophageal, or pancreatic), = 18 years, and received = 2 doses of either EPO or DARB. Outcomes assessed included mean baseline (BL) characteristics, transfusion utilization, hemoglobin (Hb) at Weeks 4, 8, and 12 after initiation of EPO or DARB, and cumulative EST doses with associated cost (based on 9/2006 wholesale acquisition cost). Results: 186 pts (82 EPO, 104 DARB) were identified. BL characteristics were similar between treatment groups: age 64 years, 45% women, and Hb 10.5g/dL. Both groups had a similar treatment duration (7 weeks) and number of Hb determinations (7.6); however, the DARB group had significantly more office visits (EPO 7, DARB 9.8, p=.0006). The proportion of pts transfused from Week 5 to end of study and number of units transfused/pt were similar between both groups. Hb values were similar at Weeks 4 (11.1 g/dL), 8 (11.1 g/dL), and 12 (11.0 g/dL). The mean administered dose per injection was 42,143 Units for EPO and 225 mcg for DARB. Mean cumulative administered dose during the treatment episode was 296,476 Units for EPO and 1,131 mcg for DARB, resulting in a dose ratio of 262:1 (Units EPO:mcg DARB). Overall EST cost was significantly lower in the EPO group compared to the DARB group (EPO $3,608, DARB $5,028, p=.0024). Conclusions: Similar hematological outcomes for EPO- and DARB-treated pts with GI malignancies were observed. Based on observed dosing patterns and cumulative EST utilization from this prospective observational study, EST costs were 28% lower in the EPO group than the DARB group. The observed dose ratio is consistent with previously reported clinical studies.

No significant financial relationships to disclose.

Hematologic outcomes of epoetin-alpha-treated cancer patients based on initial intervention of Hb <10 compared to Hb 10–11 g/dL: Results from a prospective observational study

19542

Background: Current guidelines recommend consideration of epoetin alfa (EPO) therapy for chemotherapy-induced anemia (CIA) when Hb <11 g/dL (National Comprehensive Cancer Network) or Hb < 10g/dL (ASCO/ASH). To evaluate clinical outcomes in EPO-treated patients initiated at Hb < 10 v. 10–11 g/dL, an analysis was conducted of clinical outcomes from practice settings. Data were analyzed from the Dosing and Outcomes Study of Erythropoiesis-Stimulating Therapies (D.O.S.E.) Registry, an ongoing, prospective registry collecting data on real-world practice patterns. Methods: Data from 29 U.S. hospital and community-based outpatient practices were assessed from 1/04–10/06. Chemotherapy-treated adult patients with a non-myeloid malignancy, baseline anemia (Hb < 11 g/dL), receipt of at least two EPO doses, and study completion were included. This analysis stratified patients based on Hb level at EPO initiation. Outcomes assessed included proportion of patients requiring RBC transfusion, mean treatment duration, and proportion of patients achieving an Hb = 11 g/dL. Results: 245 patients were eligible for analysis. 97 patients were initiated at a Hb < 10 g/dL and 148 patients were initiated at Hb 10–11 g/dL Baseline characteristics (age, gender distribution, weight, platinum-based therapy, Karnofsky score, primary tumor type) were similar except baseline Hb (9.4 g/dL v. 10.5 g/dL). Treatment duration was similar in both groups at approximately nine weeks. Transfusion outcomes and time to NCCN target Hb level (Hb =11 g/dL) are described in the table . Conclusions: This ongoing observational study demonstrated over two-thirds of patients achieved NCCN target Hb = 11 g/dL. Additional benefits for the patients initiated at Hb 10–11 g/dL were a shorter time to NCCN target Hb and a lower proportion of patients requiring transfusions. These results support the use of EPO for patients with chemotherapy-induced anemia and Hb < 11 g/dL.

[Table: see text]

No significant financial relationships to disclose.

Hematologic outcomes and drug cost considerations of erythropoiesis stimulating agents (ESTs) in cancer patients (pts) with fixed dosing regimens: Results from practice patterns in a prospective observational study

17063

Background: The erythropoietic agents available today have FDA-approval for weight-based as well as fixed dosing in cancer pts with chemotherapy-induced anemia [epoetin alfa (EPO) 40,000 Units QW, darbepoetin alfa (DARB) 500 mcg Q3W]. To understand hematologic outcomes and EST cost considerations based on actual patterns of use, not protocol-driven use, data were analyzed from the Dosing and Outcomes Study of Erythropoiesis-Stimulating Therapies (D.O.S.E.) Registry, an ongoing registry of real-world practice. Methods: Data from 18 U.S. practice settings from 1/06–12/06 were assessed. Chemotherapy-treated adult cancer pts initiated at either EPO 40,000 Units or DARB 500 mcg were evaluated. Outcomes assessed included mean treatment duration, hematologic outcomes, mean administered dose, mean cumulative administered dose, and total EST cost (based on 9/2006 wholesale acquisition cost). Results: 168 pts (145 EPO, 23 DARB) were eligible. Patient groups were similar with regard to baseline age, gender distribution, tumor type, Karnofsky score and Hb. Treatment duration was similar for both agents, approximately 7 weeks. The proportion of pts transfused from Week 5 to end of study and number of units/ pt was not significantly different between groups (% transfused: EPO 10%, DARB 13%; Units/pt: EPO 0.2, DARB 0.3). Mean administered dose was 42,879 Units in the EPO group and 497 mcg in the DARB group. Mean cumulative administered dose for the treatment episode was 305,241 Units for EPO and 1,665 mcg for DARB, corresponding to an EST cost of $3,715 for EPO and $7,404 for DARB (p <.0001). Conclusions: Real-world practice pattern data from this observational study found similar treatment duration and transfusion patterns in the EPO-treated group versus the DARB-treated group in pts initiated with FDA-approved fixed dosing regimens. Cumulative EST cost was $3689 lower in the EPO group, a 50% reduction versus the DARB group.

No significant financial relationships to disclose.

Determining the influence of population variation on compliance with radiofrequency exposure limits: proposed study

Currently, compliance with safety limits for human exposure to radiofrequency (RF) fields is demonstrated by methods that rely on certain assumptions and approximations, which include among other things, human anatomical features, tissue types and the dielectric properties of these tissues. This paper reviews some of the available data and outlines a proposal for an encompassing study to investigate which of these assumptions are appropriate; what approximation can be used in physical and computational modeling of humans for specific energy absorption rate (SAR) calculations (a key compliance metric); and what trade-offs can be made between accuracy and modeling requirements for practical considerations. Key issues to be investigated are how SAR varies between children and adults, between males and females, and how to model SAR in the fetus of pregnant females. It is hoped that the proposed study will produce models and methods which allow for faster, more accurate and more efficient compliance with radiofrequency exposure limits.

Walkie talkies cause more electromagnetic interference to medical equipment than mobile phones

It is generally realised that mobile phones can interfere with medical electrical equipment and many hospitals have policies which aim to minimise the risk to their patients from this cause. Walkie talkies are also used in hospitals, but very little information is available concerning their ability to interfere with hospital equipment. Two walkie talkies and three mobile phones have been used to study and compare interference in 29 items of patient-connected equipment in a large hospital. Test results show that with some equipment there will be signal distortion and/or false alarms, and a Power off/on Reset may be necessary. In rare cases, when equipment is subjected to extreme signal strengths, it is possible to observe equipment failure requiring the replacement of failed components. For these tests the walkie talkies were set at 4W of output power and they caused significantly more interference than the mobile phones. The observed effects have been classified according to the maximum distance at which they were observed and according to the criticality of the possible outcome for the patient. It is concluded that, except for emergency services, the use of walkie talkies should be restricted in hospital buildings.

Personal, non-invasive dosimetry for radio-frequency human exposure assessment

The integrity of data gathered by a body worn personal radiofrequency exposure meter has been investigated using computational methods. Simulations show that the distortion of the field by the body will cause measurement errors with a traditional 3-axis dipole field sensor. A modified measurement method for body worn personal exposure meters based on an array of 2-axis dipole field sensors is proposed. The approach minimizes the impact of body shielding (shadowing of the field) and could provide information on the average internal specific absorption rate (SAR) in various parts of the body.

Comparison of the antibody in lymphocyte supernatant (ALS) and ELISPOT assays for detection of mucosal immune responses to antigens of enterotoxigenic Escherichia coli in challenged and vaccinated volunteers

In the present study we compared the ELISPOT and antibody in lymphocyte supernatants (ALS) assays as surrogate measures of mucosal immunity. In separate studies, 20 inpatient volunteers received oral doses of 6 x 10(8) or 4 x 10(9)cfu of ETEC strain E24377A (LT+, ST+, CS1+, CS3+) and 20 subjects received 1 (n = 9) or 2 (n = 11) oral doses of the attenuated ETEC vaccine, PTL-003 expressing CFA/II (CS1+ and CS3+) (2 x 10(9)cfu/dose). Peripheral blood mononuclear cells (PBMCs) from all subjects were assayed for anti-colonization factor or toxin-specific IgA antibody responses using the ALS and ELISPOT procedures. ALS responses were measured using a standard ELISA, as well as by time-resolved fluorescence (TRF). Following challenge with E24377A, significant anti-CS3, CS1 and LT ALS responses were detected in the lymphocyte supernatants of 75-95% of the subjects. A similar proportion (75%) of subjects mounted an ALS response to CFA/II antigen after vaccination with the PTL-003 vaccine. Inter-assay comparisons between ALS and ELISPOT methods also revealed a high degree of correlation in both immunization groups. ALS sensitivity versus the ELISPOT assay for LT, CS3 and CS1-specific responses following challenge were 95%, 94% and 78%, respectively and 83% for the ALS response to CFA/II antigen after vaccination with PTL-003. Correlation coefficients for the LT and CS3 antigens were 0.94 (p<0.001) and 0.82 (p<0.001), respectively after challenge and 0.78 (p<0.001) after vaccination. The association between ALS and ELISPOT for the CS1 antigen was however, significant only when ALS supernatants were tested by TRF (r = 0.91, p<0.001). These results demonstrate the value and flexibility of the ALS assay as an alternative to ELISPOT for the measurement of mucosal immune responses to ETEC antigens, particularly when the complexities of ELISPOT may make it impractical to perform.

Safety and immunogenicity of an oral, inactivated, whole-cell vaccine for Shigella sonnei: preclinical studies and a Phase I trial

Orally delivered, inactivated whole-cell vaccines are safe methods of inducing local and systemic immunity. To increase surface proteins associated with adherence and invasion, Shigella sonnei were grown in BHI broth containing deoxycholate. A whole-cell vaccine (SsWC) was then produced by formalin inactivation. In pre-clinical studies, the SsWC vaccine was immunogenic and protected against S. sonnei-induced keratoconjunctivitis in the guinea pig model. In a randomized, double-blind, placebo-controlled, Phase I study, 10 evaluable subjects received either three doses of SsWC on Days 0, 14, and 28 (N = 3); five doses of SsWC on Days 0, 2, 4, 6, and 28 (N = 4); or placebo (N = 3). Each dose contained 2.0 x 10(10) inactivated cells. Serum and fecal antibodies against SsWC, LPS, and IpaC were measured by ELISA. A > or = 4-fold increase in titer was considered significant. Both SsWC dosing regimens were well tolerated. No fever or severe gastrointestinal symptoms were noted by any of the vaccinated subjects. Antibody responses were similar in the two dosing groups. Serum IgG or IgA responses to SsWC were seen in six of seven vaccinees (86%), to LPS in four of seven (57%), and to IpaC in five of seven (61%). Fecal IgA responses to these three antigens developed in five of five, three of five, and three of five subjects, respectively. Among the seven vaccinees, geometric mean rises in serum IgA levels to all three immunogens were significant; IgG increases trended toward significance (paired one-tailed t-test). We conclude that SsWC was immunogenic and protective in animal studies and well tolerated and immunogenic in a Phase I trial.

8-oxo-7,8-dihydroguanine is removed by a nucleotide excision repair-like mechanism in Porphyromonas gingivalis W83

A consequence of oxidative stress is DNA damage. The survival of Porphyromonas gingivalis in the inflammatory microenvironment of the periodontal pocket requires an ability to overcome oxidative stress caused by reactive oxygen species (ROS). 8-oxo-7,8-dihydroguanine (8-oxoG) is typical of oxidative damage induced by ROS. There is no information on the presence of 8-oxoG in P. gingivalis under oxidative stress conditions or on a putative mechanism for its repair. High-pressure liquid chromatography with electrochemical detection analysis of chromosomal DNA revealed higher levels of 8-oxoG in P. gingivalis FLL92, a nonpigmented isogenic mutant, than in the wild-type strain. 8-oxoG repair activity was also increased in cell extracts from P. gingivalis FLL92 compared to those from the parent strain. Enzymatic removal of 8-oxoG was catalyzed by a nucleotide excision repair (NER)-like mechanism rather than the base excision repair (BER) observed in Escherichia coli. In addition, in comparison with other anaerobic periodontal pathogens, the removal of 8-oxoG was unique to P. gingivalis. Taken together, the increased 8-oxoG levels in P. gingivalis FLL92 could further support a role for the hemin layer as a unique mechanism in oxidative stress resistance in this organism. In addition, this is the first observation of an NER-like mechanism as the major mechanism for removal of 8-oxoG in P. gingivalis.

AUStralian study of titration to effect profile of safety (AUS-STEPS): high-dose gabapentin (neurontin) in partial seizures

PURPOSE

To evaluate the safety, tolerability, efficacy, and impact on quality of life of gabapentin (Neurontin; GBP) as adjunctive therapy in patients with refractory partial seizures.

METHODS

AUS-STEPS was an open-label, multicenter, prospective study in patients experiencing partial seizures who were inadequately controlled with one to three concurrent antiepileptic drugs (AEDs). GBP treatment was titrated to a maximum of 4,800 mg/day, over a treatment period of 24 weeks, to achieve an efficacious and tolerable dosage. Efficacy was assessed by seizure-frequency data. Quality of life was evaluated by using the QOLIE-10 questionnaire, and safety was assessed by adverse-event reports and clinical laboratory findings.

RESULTS

A total of 176 patients received treatment with GBP, with 174 evaluable for intention-to-treat (ITT) efficacy analysis. A reduction of >50% in overall seizure frequency was observed in 93 patients (53%). There was a small (4.6%) overall improvement in QOLIE-10 score. The most frequent adverse events were dizziness (31%), fatigue (29%), somnolence (27%), headache (21%), and ataxia (20%), with no major increase seen in adverse events necessitating discontinuation as the dose of GBP was titrated upward.

CONCLUSIONS

This study indicates that patients with partial epilepsy may be effectively treated with GBP at dosages of < or =4,800 mg/day, without altering the safety profile of the drug.

Fludrocortisone acetate to treat neurally mediated hypotension in chronic fatigue syndrome: a randomized controlled trial

CONTEXT

Patients with chronic fatigue syndrome (CFS) are more likely than healthy persons to develop neurally mediated hypotension (NMH) in response to prolonged orthostatic stress.

OBJECTIVE

To examine the efficacy of fludrocortisone acetate as monotherapy for adults with both CFS and NMH.

DESIGN

Randomized, double-blind, placebo-controlled trial conducted between March 1996 and February 1999.

SETTING

Two tertiary referral centers in the United States.

PATIENTS

One hundred individuals aged 18 to 50 years who satisfied Centers for Disease Control and Prevention criteria for CFS and had NMH provoked during a 2-stage tilt-table test. Eighty-three subjects had adequate outcome data to assess efficacy.

INTERVENTION

Subjects were randomly assigned to receive fludrocortisone acetate, titrated to 0.1 mg/d (n = 50) or matching placebo (n = 50) for 9 weeks, followed by 2 weeks of observation after discontinuation of therapy.

MAIN OUTCOME MEASURE

Proportion of subjects in each group with at least a 15-point improvement on a 100-point global wellness scale.

RESULTS

Baseline demographic and illness characteristics between the groups were similar; CFS had been present for at least 3 years in 71%. Using an intention-to-treat analysis, 7 subjects (14%) treated with fludrocortisone experienced at least a 15-point improvement in their wellness scores compared with 5 (10%) among placebo recipients (P =.76). No differences were observed in several other symptom scores or in the proportion with normal follow-up tilt test results at the end of the treatment period.

CONCLUSIONS

In our study of adults with CFS, fludrocortisone as monotherapy for NMH was no more efficacious than placebo for amelioration of symptoms. Failure to identify symptomatic improvement with fludrocortisone does not disprove the hypothesis that NMH could be contributing to some of the symptoms of CFS. Further studies are needed to determine whether other medications or combination therapy are more effective in treating orthostatic intolerance in patients with CFS.

Decreased bone mineral density during low dose glucocorticoid administration in a randomized, placebo controlled trial

OBJECTIVE

While osteoporosis and bone fractures are clearly recognized side effects of high dose glucocorticoids, the effect of low dose glucocorticoids remains controversial. We investigated the effect of 3 months of low dose hydrocortisone on bone mineral density (BMD).

METHODS

Subjects, 18 to 55 years old with chronic fatigue syndrome and no medical or psychiatric illness requiring medication, were randomized in a double blind, placebo controlled trial to receive oral hydrocortisone, 13 mg/m2 body surface area every morning and 3 mg/m2 every afternoon (25 to 35 mg/day, equivalent to about 7.5 mg prednisone/day) or placebo for 12 weeks. Before and after treatment BMD of the lumbar spine was measured by dual energy x-ray absorptiometry.

RESULTS

We studied 23 subjects (19 women, 4 men). For the 11 hydrocortisone recipients there was a mean decrease in BMD: mean change from baseline of the lateral spine was -2.0% (95% CI -3.5 to -0.6. p = 0.03) and mean change of the anteroposterior spine was -0.8% (95% CI -1.5 to -0.1, p = 0.06). Corresponding changes for the 12 placebo recipients were +1.0% (95% CI -1.0 to 3.0, p = 0.34) and +0.2% (95% CI -1.4 to 1.5, p = 0.76).

CONCLUSION

A 12 week course of low dose glucocorticoids given to ambulatory subjects with chronic fatigue syndrome was associated with a decrease in BMD of the lumbar spine. This decrease was statistically significant in lateral spine measurements and nearly so in anteroposterior spine measurements.

Induced sputum examination: diagnosis of pulmonary involvement in Fabry's disease

Fabry's disease is a rare inherited metabolic disorder caused by a deficiency in the enzyme alpha-galactosidase A. It can affect almost every organ, including the lungs. Confirmation of lung involvement has depended on invasive bronchial biopsy specimens or brushings to confirm the presence of typical lamellar inclusion bodies within bronchial epithelial cells. We report a patient with known Fabry's disease in whom these inclusion bodies were identified by examination of induced sputum.

Development of a PCR marker for rapid identification of the Bt-10 gene for common bunt resistance in wheat

In western Canada, the Bt-10 resistance gene in wheat (Triticum aestivum) is effective against all the known races of common bunt caused by Tilletia tritici and T laevis. The genotypes of 199 F2 plants, originated from a cross between BW553 containing Bt-10 and the susceptible spring wheat cultivar 'Neepawa,' were established in greenhouse and field inoculation studies. A ratio of 1:2:1 resistant : heterozygous : susceptible was observed for bunt reaction, indicating that Bt-10 was expressed in a partially dominant fashion. A polymorphic DNA fragment, amplified using RAPD, and previously shown to be linked to Bt-10 was sequenced and SCAR (sequence characterized amplified region) primers devised. However, SCAR primers failed to amplify the polymorphic fragment. Restriction of PCR products with DraI revealed a polymorphic fragment of 490 bp resulting from a single base pair difference between lines possessing Bt-10 and those lacking the gene. As per the base pair difference, FSD and RSA primers were designed to generate a 275-bp polymorphic DNA fragment. Both 275- and 490-bp polymorphic fragments were present in all of the 22 cultivars known to carry Bt-10, and absent in all 16 cultivars lacking Bt-10. A 3:1 ratio was observed for presence: absence of the 275-bp marker in the F2 population. Using Southern analysis, the 490-bp fragment was effective in differentiating homozygous resistant plants from those heterozygous for Bt-10, based on its presence and the hybridization signal strength. A 1:2:1 resistant : heterozygous : susceptible ratio was also observed for the molecular marker and corresponded to 88% of the phenotypes deduced from the original F2 population. The molecular marker was estimated to be between 1.1 cM and 6.5 cM away from the Bt-10 resistance gene, based on the segregation analysis. Segregation analyses of Bt-10 and the 275-bp marker, evaluated in three different Canada Prairie Spring (CPS) wheat populations, demonstrated a segregation ratio of 3:1 for the molecular marker in two of the populations. These results demonstrated that the PCR marker system using the FSD and RSA primer pair permitted a rapid and reliable identification of individual lines carrying the Bt-10 gene for resistance to common bunt.

Development of a PCR marker for rapid identification of the Bt-10 gene for common bunt resistance in wheat

In western Canada, the Bt-10 resistance gene in wheat (Triticum aestivum) is effective against all the known races of common bunt caused by Tilletia tritici and T. laevis. The genotypes of 199 F2 plants, originated from a cross between BW553 containing Bt-10 and the susceptible spring wheat cultivar 'Neepawa,' were established in greenhouse and field inoculation studies. A ratio of 1:2:1 resistant : heterozygous : susceptible was observed for bunt reaction, indicating that Bt-10 was expressed in a partially dominant fashion. A polymorphic DNA fragment, amplified using RAPD, and previously shown to be linked to Bt-10 was sequenced and SCAR (sequence characterized amplified region) primers devised. However, SCAR primers failed to amplify the polymorphic fragment. Restriction of PCR products with DraI revealed a polymorphic fragment of 490 bp resulting from a single base pair difference between lines possessing Bt-10 and those lacking the gene. As per the base pair difference, FSD and RSA primers were designed to generate a 275-bp polymorphic DNA fragment. Both 275- and 490-bp polymorphic fragments were present in all of the 22 cultivars known to carry Bt-10, and absent in all 16 cultivars lacking Bt-10. A 3:1 ratio was observed for presence: absence of the 275-bp marker in the F2 population. Using Southern analysis, the 490-bp fragment was effective in differentiating homozygous resistant plants from those heterozygous for Bt-10, based on its presence and the hybridization signal strength. A 1:2:1 resistant : heterozygous : susceptible ratio was also observed for the molecular marker and corresponded to 88% of the phenotypes deduced from the original F2 population. The molecular marker was estimated to be between 1.1 cM and 6.5 cM away from the Bt-10 resistance gene, based on the segregation analysis. Segregation analyses of Bt-10 and the 275-bp marker, evaluated in three different Canada Prairie Spring (CPS) wheat populations, demonstrated a segregation ratio of 3:1 for the molecular marker in two of the populations. These results demonstrated that the PCR marker system using the FSD and RSA primer pair permitted a rapid and reliable identification of individual lines carrying the Bt-10 gene for resistance to common bunt.

Key words: resistance gene, genetic segregation, molecular marker, RAPD analysis.

Pooled analysis of three large clinical trials to determine the optimal dose of dolasetron mesylate needed to prevent postoperative nausea and vomiting. The Dolasetron Prophylaxis Study Group

STUDY OBJECTIVE

To identify the maximally effective dolasetron dose (i.e., maximum efficacy with minimum adverse events) for prevention of postoperative nausea and vomiting (PONV) using the statistical power generated in a pooled patient sample from three large, nearly identical clinical trials.

DESIGN

Three randomized, multicenter, placebo-controlled, double-blinded trials.

SETTING

Trials 1, 2, and 3 enrolled patients at 10, 25, and 17 hospitals and/or surgical centers, respectively.

PATIENTS

A total of 1,946 ASA physical status, I, II, and III patients. Trials 1 and 2 enrolled only female patients (n = 916) undergoing gynecologic surgery. Trial three enrolled 722 females (approximately 70% gynecologic surgeries) and 308 males (approximately 46% orthopedic surgeries) undergoing a variety of surgical procedures.

INTERVENTIONS

All surgical procedures used balanced general anesthesia. Patients received 12.5, 25, 50, or 100 mg of the antiemetic, dolasetron, near the end of anesthesia.

MEASUREMENTS AND MAIN RESULTS

Efficacy endpoints were identical and measured for 24 hours: complete response (no vomiting or rescue medication) and maximum nausea, reported using a 100-mm visual analog scale (VAS). Safety was assessed using adverse event reports, laboratory and electrocardiographic data, and vital signs. All four dolasetron doses produced significant increases in complete response and decreases in maximum VAS nausea compared with placebo (p < 0.01). No increased efficacy was observed with dolasetron doses higher than 12.5 mg. Safety was similar between each dolasetron dose and placebo.

CONCLUSION

Dolasetron 12.5 mg, given near the end of anesthesia, is the maximally effective dose studied for preventing postoperative nausea and vomiting.

Dolasetron for the prevention of postoperative nausea and vomiting following outpatient surgery with general anaesthesia: a randomized, placebo-controlled study. The Dolasetron PONV Prevention Study Group

In a multicentre, randomized, double-blind, placebo-controlled dose-ranging study, 1030 patients undergoing outpatient surgery with general anaesthesia received i.v. dolasetron mesylate (12.5, 25, 50, or 100 mg) or placebo. The principal outcome measure was the proportion of patients who were free of emesis or rescue medication for the 24-h period after the study drug was given; the subsidiary outcome measure was survival time without rescue medication. Effects on nausea were quantified using a visual analogue scale. Compared with placebo, a complete response was significantly higher when all four dolasetron doses were combined (49% vs. 58%, P =0.025). In females, dolasetron, 12.5-mg, dolasetron provided maximum clinical benefit (effectiveness compared with adverse events), with no additional benefit in complete response rates or nausea visual analogue scale scores at higher doses. No significant differences were observed in complete response for any dolasetron dose in males compared with placebo. The majority of adverse events reported were mild or moderate. Dolasetron provided well-tolerated, safe, and effective prophylaxis for post-operative nausea and vomiting with maximum effectiveness observed at a dose of 12.5 mg.