Smoke gets in your eyes... and in your breath!
Explore the source record for details and available documents.
Acetonitriles↗
Biomedical subjects
Michael Phillips
Publications and source records attributed to Michael Phillips.
Evaluation of specific absorption rate as a dosimeter of MRI-related implant heating.
PURPOSE: To compare the magnetic resonance imaging (MRI)-related heating per unit of whole body averaged specific absorption rate (SAR) of a conductive implant exposed to two different 1.5-Tesla/64 MHz MR systems. MATERIALS AND METHODS: Temperature changes at the electrode contacts of a deep brain stimulation lead were measured using fluoroptic thermometry. The leads were placed in a typical surgical implant configuration within a gel-filled phantom of the human head and torso. MRI was performed using two different transmit/receive body coils on two different generation 1.5-Tesla MR systems from the same manufacturer. Temperature changes were normalized to whole body averaged SAR values and compared between the two scanners. RESULTS: Depending on the landmark location, the normalized temperature change for the implant was significantly higher on one MR system compared to the other (P < 0.001). CONCLUSION: The findings revealed marked differences across two MR systems in the level of radiofrequency (RF)-induced temperature changes per unit of whole body SAR for a conductive implant. Thus, these data suggest that using SAR to guide MR safety recommendations for neurostimulation systems or other similar implants across different MR systems is unreliable and, therefore, potentially dangerous. Better, more universal, measures are required in order to ensure patient safety.
Body Temperature↗
Increased breath markers of oxidative stress in normal pregnancy and in preeclampsia.
OBJECTIVES: The purpose of this study was to compare the intensity of oxidative stress in normal pregnancy, preeclampsia, and nonpregnant women using a breath test. STUDY DESIGN: We studied primiparous women in third trimester pregnancy (38 uncomplicated, 26 with preeclampsia) and 60 nonpregnant control subjects. Volatile organic compounds (VOCs) in alveolar breath were analyzed by gas chromatography/mass spectroscopy to construct the breath methylated alkane contour (BMAC), a 3-dimensional display of abundance of C4-C20 alkanes and monomethylated alkanes. RESULTS: The mean volume under curve (VUC) of the BMAC was significantly higher in preeclampsia patients than in normal pregnant women (P < .003) and nonpregnant control subjects (P < .005). A predictive model employing 5 VOCs distinguished preeclampsia from uncomplicated pregnancy (sensitivity = 92.3%, specificity = 89.7%; cross-validated sensitivity = 88.5%, specificity = 79.3%). CONCLUSION: A breath test significantly demonstrated greater oxidative stress in women with preeclampsia than in uncomplicated pregnancy and nonpregnant control subjects. The breath test accurately identified women with established preeclampsia, but further studies are required to determine if this test can predict the onset of disease.
Adult↗
Increased breath biomarkers of oxidative stress in diabetes mellitus.
BACKGROUND: Oxidative stress has been implicated in the major complications of diabetes mellitus, including retinopathy, nephropathy, neuropathy and accelerated coronary artery disease. There is a clinical need for a marker of oxidative stress which could potentially identify diabetic patients at increased risk for these complications. We measured oxidative age, a new breath marker of oxidative stress, in diabetic patients. METHODS: Three groups were studied: type 1 diabetes mellitus (n=9), type 2 diabetes mellitus (n=53) and non-diabetic normals (n=39). Volatile organic compounds (VOCs) in breath were assayed by gas chromatography and mass spectroscopy to construct the breath methylated alkane contour (BMAC), a three-dimensional display of oxidative stress markers, C4-C20 alkanes and monomethylated alkanes. The collective abundance of these VOCs was reduced to a single value, the oxidative age, comprising the volume under the curve of the BMAC corrected for chronological age. RESULTS: Oxidative age was significantly increased in type 1 diabetes (mean=0.103, S.E.M.=0.119, p<0.01) and type 2 diabetes (mean=0.103, S.E.M.=0.047, p<0.05) compared to age-matched normals (mean=-0.248, S.E.M.=0.079). No significant correlation between oxidative age and blood glucose or hemoglobin A1C was observed in either group. CONCLUSIONS: Oxidative age, a marker of oxidative stress, was significantly increased in both type 1 and type 2 diabetes mellitus. Oxidative age merits further study as a candidate marker of risk for the complications of diabetes mellitus.
Adult↗
Heart allograft rejection: detection with breath alkanes in low levels (the HARDBALL study).
BACKGROUND: We evaluated a new marker of heart transplant rejection, the breath methylated alkane contour (BMAC). Rejection is accompanied by oxidative stress that degrades membrane polyunsaturated fatty acids, evolving alkanes and methylalkanes, which are excreted in the breath as volatile organic compounds (VOCs). METHODS: Breath VOC samples (n = 1,061) were collected from 539 heart transplant recipients before scheduled endomyocardial biopsy. Breath VOCs were analyzed by gas chromatography and mass spectroscopy, and BMAC was derived from the abundance of C4-C20 alkanes and monomethylalkanes. The "gold standard" of rejection was the concordant set of International Society for Heart and Lung Transplantation (ISHLT) grades in biopsies read by 2 reviewers. RESULTS: Concordant biopsies were: Grade 0, 645 of 1,061 (60.8%); 1A, 197 (18.6%); 1B, 84 (7.9%); 2, 93 (8.8%); and 3A, 42 (4.0%). A combination of 9 VOCs in the BMAC identified Grade 3 rejection (sensitivity 78.6%, specificity 62.4%, cross-validated sensitivity 59.5%, cross-validated specificity 58.8%, positive predictive value 5.6%, negative predictive value 97.2%). Site pathologists identified the same cases with sensitivity of 42.4%, specificity 97.0%, positive predictive value 45.2% and negative predictive value 96.7%. CONCLUSIONS: A breath test for markers of oxidative stress was more sensitive and less specific for Grade 3 heart transplant rejection than a biopsy reading by a site pathologist, but the negative predictive values of the 2 tests were similar. A screening breath test could potentially identify transplant recipients at low risk of Grade 3 rejection and reduce the number of endomyocardial biopsies.
Adult↗
Selective dose escalation of chemoradiotherapy for esophageal cancer: role of treatment intensification.
This ongoing phase II study is designed to assess the outcomes (survival and failure patterns) of therapy for localized esophageal cancer with conventional dose radiation (50.4 Gy) with concurrent continuous infusion 5-fluorouracil (5-FU) and weekly carboplatin/paclitaxel. Patients with less than complete response or partial response received dose escalation of radiation to 59.4 Gy with the same chemotherapy. This report details the results of the first 18 patients treated. From July 2000 to June 2003, we prospectively enrolled 18 patients with T1-4, N0-1, M0-1a esophageal carcinoma to receive paclitaxel 45 mg/m 2 intravenously over 1 hour and carboplatin AUC 2 intravenously over 30 minutes on days 1, 8, 15, 22, 29, and 36. 5-Fluorouracil 225 mg/m2 was delivered as a continuous infusion on days 1 through 38. Radiation therapy was given 1.8 Gy x 5 days/week x 5.5 weeks (50.4 Gy in 28 fractions). After 6 to 8 weeks, patients underwent repeat staging with computed tomography scan, endoscopic ultrasound, and biopsy. Patients with a positive biopsy, or less than partial response by computed tomography and endoscopic ultrasound, received a boost of 9 Gy with the same concurrent chemotherapy. Patients were followed every 4 months with computed tomography/endoscopic ultrasound the first year and every 6 months thereafter. Median follow-up was 19 months. Eleven of 18 patients (61.1%) attained a complete response/partial response; six of 18 (33.3%) received a boost. Overall survival was 30% at 3 years, with a median of 25 months. Patients with less than 10% pretreatment weight loss had an overall survival of 36% with a median of 26 months. In patients with more than 10% pretreatment weight loss, median survival was 14 months with 0% surviving at 2 years. Local/regional control was 67% (no-boost patients [78%]; boost patients [40%]). Progression-free survival was 31% at 3 years, with a median of 14 months. Distant metastasis-free survival was 40% at 3 years, with a median of 27 months. Seventy-nine percent of patients required at least one dose reduction in chemotherapy because of toxicities. Radiation delays ranged from 0 to 62 days, with a median of 7 days. Grade 2/3 acute esophagitis was experienced by 89% and 39% of patients, respectively; 28% of patients developed esophageal strictures requiring dilatations. The combination of continuous-infusion 5-FU and weekly carboplatin/paclitaxel with selective radiation dose escalation yields promising results without surgery and adjuvant chemotherapy. The toxicities of therapy, while manageable, were significant.
Antineoplastic Combined Chemotherapy Protocols↗
Neurostimulation system used for deep brain stimulation (DBS): MR safety issues and implications of failing to follow safety recommendations.
The use of magnetic resonance imaging (MRI) in patients with neurostimulation systems used for deep brain stimulation requires the utmost care, and no individual should undergo an MR examination in the absence of empirical evidence that the procedure can be performed safely. The risks of performing MRI in patients with neurostimulators include those associated with heating, magnetic field interactions, induced currents, and the functional disruption of these devices. The exact safety recommendations for the particular neurostimulation system with regard to the pulse generator, leads, electrodes, operational conditions for the device, the positioning of these components, and the MR system conditions must be carefully followed for MRI. As highlighted by 2 recent accidents, the failure to strictly follow safety recommendations (eg, use a 1.5-T MR system with a send/receive head radiofrequency coil only; limit the specific absorption rate to 0.4 W/kg; etc.) may result in serious, temporary, or permanent injury to the patient including the possibility of transient dystonia, paralysis, coma, or even death.
Brain Diseases↗
Suicide prevention in developing countries: where should we start?
Explore the source record for details and available documents.
Journal Article↗
Linkage and association mapping of the LRP5 locus on chromosome 11q13 in type 1 diabetes.
Linkage of chromosome 11q13 to type 1 diabetes (T1D) was first reported from genome scans (Davies et al. 1994; Hashimoto et al. 1994) resulting in P <2.2 x 10(-5) (Luo et al. 1996) and designated IDDM4 ( insulin dependent diabetes mellitus 4). Association mapping under the linkage peak using 12 polymorphic microsatellite markers suggested some evidence of association with a two-marker haplotype, D11S1917*03-H0570POLYA*02, which was under-transmitted to affected siblings and over-transmitted to unaffected siblings ( P=1.5 x 10(-6)) (Nakagawa et al. 1998). Others have reported evidence for T1D association of the microsatellite marker D11S987, which is approximately 100 kb proximal to D11S1917 (Eckenrode et al. 2000). We have sequenced a 400-kb interval surrounding these loci and identified four genes, including the low-density lipoprotein receptor related protein (LRP5) gene, which has been considered as a functional candidate gene for T1D (Hey et al. 1998; Twells et al. 2001). Consequently, we have developed a comprehensive SNP map of the LRP5 gene region, and identified 95 SNPs encompassing 269 kb of genomic DNA, characterised the LD in the region and haplotypes (Twells et al. 2003). Here, we present our refined linkage curve of the IDDM4 region, comprising 32 microsatellite markers and 12 SNPs, providing a peak MLS=2.58, P=5 x 10(-4), at LRP5 g.17646G>T. The disease association data, largely focused in the LRP5 region with 1,106 T1D families, provided no further evidence for disease association at LRP5 or at D11S987. A second dataset, comprising 1,569 families from Finland, failed to replicate our previous findings at LRP5. The continued search for the variants of the putative IDDM4 locus will greatly benefit from the future development of a haplotype map of the genome.
Chromosome Mapping↗
Atypical and conventional antipsychotic drugs in treatment-naive first-episode schizophrenia: a 52-week randomized trial of clozapine vs chlorpromazine.
The purported advantages of second-generation or "atypical" antipsychotics relative to first-generation antipsychotics have not been examined in patients with a first episode of schizophrenia. This flexible-dose study examined efficacy and safety in a randomized, double-blind, 52-week trial, comparing chlorpromazine (CPZ) and clozapine (CLZ) in treatment naive patients experiencing their first episode of schizophrenia. In all, 160 inpatients with first-episode schizophrenia or schizophreniform disorder were randomized to CPZ or CLZ and followed them for 52 weeks or until dropout. The primary efficacy measure was time to first remission and proportion of time remaining in remission. The analysis was supplemented by comparisons on a profile of clinical symptoms and side effects. Of these first-episode patients, 80% achieved remission within 1 year (79% CPZ, 81% CLZ). The Kaplan-Meier estimated median time to first remission was 8 weeks for CLZ vs 12 weeks for CPZ (chi(2)(1)=5.56, p=0.02). Both the rate of first achieving remission and the odds for being in remission during the trial were almost doubled for the CLZ group in comparison with the CPZ group. At 12 weeks, CLZ was superior on many rating scale measures of symptom severity while CPZ was not superior on any. These symptom differences remained significant when controlling for EPS differences. By 52 weeks many of the symptom differences between groups were no longer significantly different. Generally, CLZ produced fewer side effects than CPZ, particularly extrapyramidal side effects. There was no significant difference between treatments in weight change or glucose metabolism. For each prior year of untreated psychosis, there was a 15% decrease in the odds of achieving remission (OR=0.85; CI 0.75-0.95). A high proportion of first-episode patients remitted within 1 year. We detected no difference in the proportion of first-episode patients receiving CLZ or CPZ that achieved remission. However, first-episode patients receiving CLZ remitted significantly faster and remained in remission longer than subjects receiving CPZ. While the CLZ group showed significantly less symptomatology on some measures and fewer side effects at 12 weeks, the two treatment groups seemed to converge by 1 year. Longer duration of untreated psychosis was associated with lower odds of achieving remission.
Adolescent↗
Increased oxidative stress in younger as well as in older humans.
BACKGROUND: The free radical theory of aging is based upon the adverse effects of oxidative stress (OS), and indices of OS generally increase with advancing age. However, since OS may also be a normal physiological response in youth, when reactive oxygen species (ROS) act as signal transducers during normal growth and development, we compared markers of OS in normal humans over a wide spectrum of different ages. METHODS: Fasting breath samples were collected from 102 healthy volunteers (age 9 to 89 years) and volatile organic compounds (VOCs) were assayed by gas chromatography and mass spectroscopy. The intensity of OS in each volunteer was estimated by the breath methylated alkane contour (BMAC), a three-dimensional display of the abundance of C4-C20 alkanes and monomethylated alkanes. The collective abundance of these VOCs in a breath sample was reduced to a single value, the volume under curve (VUC), and correlated with chronological age. RESULTS: Compared to subjects aged 20-40 years, the mean BMAC VUC was significantly increased in subjects aged < 20 (p < 0.0001) and >40 years (p < 0.001). A cubic function correlated BMAC VUC (x) with chronological age (y): y = 33.7 - 3.29x + 0.072x(2) - 0.0004x(3) (r = 0.48). CONCLUSIONS: Breath markers of OS were significantly increased both in younger and in older subjects, compared to those aged 20-40 years. Increased OS in older subjects was consistent with previous reports, but increased OS in younger subjects aged < 20 years is a new observation; this may be a normal physiological response in youth.
Adult↗
World Trade Center rescue worker injury and illness surveillance, New York, 2001.
BACKGROUND: The September 11, 2001, terrorist attacks on the World Trade Center in New York City, New York, prompted an unprecedented rescue and recovery response. Operations were conducted around the clock, involved over 5000 workers per day, and extended into months following the attacks. The City of New York Department of Health and Mental Hygiene and the Centers for Disease Control and Prevention implemented prospective surveillance to characterize rescue worker-related injury and illness and to help guide public health interventions. METHODS: From September 11 to October 11, 2001, personnel reviewed medical records at four Manhattan hospital emergency departments (EDs), and healthcare providers completed data collection forms at five temporary Disaster Medical Assistance Team (DMAT) facilities located at the site. Rescue workers included construction workers, police officers, firefighters, emergency medical service technicians, or Urban Search and Rescue workers. Data collected included demographic characteristics, injury type, illness, and disposition. RESULTS: Of 5222 rescue worker visits, 89% were to DMAT facilities and 12% to EDs. Musculoskeletal conditions were the leading cause of visits (19%), followed by respiratory (16%) and eye (13%) disorders. Incidence rates were estimated based on total injuries and/or illnesses reported times 200,000 (100 equivalent full-time workers in 1 year at 40 hours per week x 50 weeks per year), then divided by the total number of hours worked. Eye disorders (59.7) accounted for the highest estimated injury and illness rate, followed by headache (46.8). One death, 52 hospital admissions, and 55 transports were reported. Findings underscored the need to coordinate distribution and enforcement of personal protective equipment use, purchase of diagnostic equipment to diagnose corneal abrasions, and distribution of health advisories. CONCLUSIONS: This system provided objective, timely information that helped guide public health interventions in the immediate aftermath of the attacks and during the prolonged rescue and recovery operations. Lessons learned can be used to guide future surveillance efforts.
Adolescent↗
Social work education for health care: addressing practice competencies.
The study discussed in this article examines how social work graduates are prepared to help clients and families who need health and mental health services. The study identifies recent shifts in social work practice in health care settings, calls for greater integration of practicum and classroom education, and proposes curriculum enhancement to ensure competence in three key areas: self-directed practice, population-based practice and a refocus on basic skills. Findings are based on a New York Academy of Medicine study conducted from 1997-1999 which included a survey of course offerings at 128 CSWE-accredited schools; literature review of current practice models, focus groups, and review by an expert advisory council.
Competency-Based Education↗
Detection of lung cancer with volatile markers in the breath.
STUDY OBJECTIVES: To evaluate volatile organic compounds (VOCs) in the breath as tumor markers in lung cancer. Alkanes and monomethylated alkanes are oxidative stress products that are excreted in the breath, the catabolism of which may be accelerated by polymorphic cytochrome p450-mixed oxidase enzymes that are induced in patients with lung cancer. DESIGN: Combined case-control and cross-sectional study. SETTING: Five academic pulmonary medicine services in the United States and the United Kingdom. PATIENTS AND PARTICIPANTS: One hundred seventy-eight bronchoscopy patients and 41 healthy volunteers. INTERVENTION: Breath samples were analyzed by gas chromatography and mass spectroscopy to determine alveolar gradients (ie, the abundance in breath minus the abundance in room air) of C4-C20 alkanes and monomethylated alkanes. MEASUREMENTS: Patients with primary lung cancer (PLC) were compared to healthy volunteers, and a predictive model was constructed using forward stepwise discriminant analysis of the alveolar gradients. This model was cross-validated with a leave-one-out jackknife technique and was tested in two additional groups of patients who had not been used to develop the model (ie, bronchoscopy patients in whom cancer was not detected, and patients with metastatic lung cancer [MLC]). RESULTS: Eighty-seven of 178 patients had lung cancer (PLC, 67 patients; MLC, 15 patients; undetermined, 5 patients). A predictive model employing nine VOCs identified PLC with a sensitivity of 89.6% (60 of 67 patients) and a specificity of 82.9% (34 of 41 patients). On cross-validation, the sensitivity was 85.1% (57 of 67 patients) and the specificity was 80.5% (33 of 41 patients). The stratification of patients by tobacco smoking status, histologic type of cancer, and TNM stage of cancer revealed no marked effects. In the two additional tests, the model predicted MLC with a sensitivity of 66.7% (10 of 15 patients), and it classified the cancer-negative bronchoscopy patients with a specificity of 37.4% (34 of 91 patients). CONCLUSIONS: Compared to healthy volunteers, patients with PLC had abnormal breath test findings that were consistent with the accelerated catabolism of alkanes and monomethylated alkanes. A predictive model employing nine of these VOCs exhibited sufficient sensitivity and specificity to be considered as a screen for lung cancer in a high-risk population such as adult smokers.
Alkanes↗
[Evaluation on the accuracy of reported suicides in the Chinese population].
OBJECTIVE: To evaluate the accuracy of reports of suicide in the national death registry systems and to estimate a more accurate suicide rate. METHODS: Twenty-three sites from the Disease Surveillance Points Network-one of the national death registry systems-were selected and 1 932 of the deaths that occurred at these sites from August 1995 through August 2000 in which the official cause was classified as "accidental" or "mental illness" were selected for detailed household surveys focusing on reassessing the cause of death. Valid interviews were completed in 1 653 of these cases. The original cause of death recorded on the death certificate was compared with the finding of the detailed household survey and the result was used to adjust the suicide rate. RESULTS: After detailed investigation, 16 of the 857 (1.87%) deaths reported on the death certificate as suicide were considered accidental deaths, 39 of the 721 (5.41%) accidental deaths were considered suicide, 17 of the 35 (48.57%) cases reported as undetermined accidents were considered suicide, and 6 of the 40 (15.00%) cases in which mental illness was the recorded cause of death were considered suicide. After adjustments for errors in the reported cause of death and for missing deaths, the reported crude suicide rate of 13.65/100 000 in China was adjusted to 22.99/100 000 (95% CI: 21.78/100 000 - 24.25/100 000). CONCLUSION: After adjustments the actual suicide rate for China was higher than the reported rate indicating that suicide was an increasingly important public health problem for China.
China↗
[Comparison of the characteristics of suicide attempters treated in general hospitals with and without prior suicide attempts].
OBJECTIVE: We compared the characteristics of persons who had made multiple versus single suicide attempts to determine whether or not these are two independent subgroups and, thus, should be provided with different preventive services. METHODS: We administered a 2 - 3 hour interview that included a structured psychiatric examination to 325 individuals with suicide attempts who were treated at four city and county-level general hospitals. RESULTS: The age, gender, years of education, marital status, work status, and family economic status of the 52 persons who had made more than one suicide attempt were similar to those of the 273 persons who had made a single attempt. But repeaters were less likely than non-repeaters to live in rural villages and to attempt suicide by ingesting agricultural poisons. Moreover, repeaters considered suicide prior to the attempt for a longer time, had a lower quality of life in the prior month, had a stronger suicidal intent, had more chronic life events, had a higher chronic stress score, and were more likely to have mental illness (P's all < 0.05). CONCLUSIONS: Major differences in the characteristics of suicide attempters with and without a prior history of suicide attempts suggest that these are independent subgroups of attempters. These two types of attempted suicide require different preventive approaches.
Adult↗
Should coauthors share liability?
Explore the source record for details and available documents.
Authorship↗
Beautiful vistas, but is this really science?
Explore the source record for details and available documents.
Computer Simulation↗