Diagnostic performance of the PTSD checklist and the Vietnam Era Twin Registry PTSD scale.

AIMS: Self-report questionnaires are frequently used in clinical and epidemiologic studies to assess post-traumatic stress disorder (PTSD). A number of studies have evaluated these scales relative to clinician administered structured interviews; however, there has been no formal evaluation of their performance relative to non-clinician administered epidemiologic assessments such as the Composite International Diagnostic Interview (CIDI). We examined the diagnostic performance of two self-report PTSD scales, the PTSD checklist (PCL) and the Vietnam Era Twin Registry (VET-R) PTSD scale, compared to the CIDI. METHODS: Data were derived from a large epidemiologic follow-up study of PTSD in 5141 Vietnam Era Veterans. Measures included the PCL, VET-R PTSD scale and CIDI. For both the PCL and VET-R PTSD scale, ROC curves, areas under the curve (AUC), sensitivity, specificity, % correctly classified, likelihood ratios, predictive values and quality estimates were generated based on the CIDI PTSD diagnosis. RESULTS: For the PCL and VET-R PTSD scale the AUCs were 89.0 and 87.7%, respectively. Optimal PCL cutpoints varied from the 31-33 range (when considering sensitivity and specificity) to the 36-56 range (when considering quality estimates). Similar variations were found for the VET-R PTSD, ranging from 31 (when considering sensitivity and specificity) to the 37-42 range (when considering quality estimates). CONCLUSIONS: The PCL and VET-R PTSD scale performed similarly using a CIDI PTSD diagnosis as the criterion. There was a range of acceptable cutpoints, depending on the metric used, but most metrics suggested a lower PCL cutpoint than in previous studies in Veteran populations.

Circuit techniques for wireless brain interfaces.

Efficient, miniaturized wireless recording is critical for both existing and emerging health-monitoring applications. One important example of this is in the brain interface community, where new technologies allow improved observation and understanding of brain functions. This, in turn, drives the need for ever smaller, lower power, and higher performance circuitry for chronic recording. This paper describes circuit and system techniques for low power wireless brain interfaces. Active and passive architectures are described and compared, and measured in-vivo data from both are presented.

NeuralWISP: A Wirelessly Powered Neural Interface With 1-m Range.

We present the NeuralWISP, a wireless neural interface operating from far-field radio-frequency RF energy. The NeuralWISP is compatible with commercial RF identification readers and operates at a range up to 1 m. It includes a custom low-noise, low-power amplifier integrated circuit for processing the neural signal and an analog spike detection circuit for reducing digital computational requirements and communications bandwidth. Our system monitors the neural signal and periodically transmits the spike density in a user-programmable time window. The entire system draws an average 20 muA from the harvested 1.8-V supply.

Religious involvement and health outcomes among older persons in Taiwan.

We use data from a nationally representative, longitudinal survey of older Taiwanese to examine the relationship between religious involvement-including religious affiliation, religious attendance, beliefs, and religious practices-and self-reported measures of overall health status, mobility limitations, depressive symptoms, and cognitive function; clinical measures of systolic and diastolic blood pressure, serum interleukin-6, and 12-h urinary cortisol; and 4-year mortality. Frequency of religious attendance shows the strongest, most consistent association with health outcomes. But, with only one exception, this relationship disappears in the presence of controls for health behaviors, social networks, and prior health status. Religious attendance remains significantly associated with lower mortality even after controlling for prior self-assessed health status, but the coefficient is substantially reduced. Other aspects of religiosity are only sporadically associated with health and, in all cases, private religious practices and stronger beliefs are associated with worse health; again, this relationship disappears after controlling for prior health status. These results suggest that reverse causality may partly account for both the positive and negative correlations between religiosity and health. We find no significant associations between religious involvement and biological markers. Notably, even after controlling for prior health, participation in social activities has a more robust effect on health than religious attendance. Consequently, we question whether the purported health benefits are attributable to religion or to social activity in general.

The effects of contamination on biological monitoring.

We investigated the frequency and patterns of biological-monitoring-test contamination and the effect of contamination on the growth of test organisms. Overall, the contamination rate was 0.81%, but the rate of contamination varied significantly by sterilization method. Contamination did not appear to inhibit growth of test organisms.

Influenza vaccination in pregnancy.

The objective of this paper is to determine the acceptance rate of and incidence of adverse reactions to the influenza vaccine in pregnant women, and to determine the immunized patients' attitudes toward future vaccination. A total of 448 eligible pregnant women were offered the influenza vaccine at routine prenatal visits. Vaccinated women were interviewed at their subsequent visit regarding adverse effects and attitudes toward future vaccination. Of the 448 women studied, 319 (71.2%) accepted the vaccine. There was no difference in acceptance rates between English- and Spanish-speaking women. Mild adverse reactions were experienced by 5.3%. Women who reported adverse reactions were less likely to agree to future vaccination as compared with unaffected women (64.7 vs. 94.0% p < 0.001). The influenza vaccine is readily accepted by pregnant women, and is infrequently associated with mild side effects. Women who experience side effects are less likely to accept the vaccine in the future.

Female voice communications in high level aircraft cockpit noises--part II: vocoder and automatic speech recognition systems.

BACKGROUND: The intelligibility of female and male speech is equivalent under most ordinary living conditions. However, due to small differences between their acoustic speech signals, called speech spectra, one can be more or less intelligible than the other in certain situations such as high levels of noise. Anecdotal information, supported by some empirical observations, suggests that some of the high intensity noise spectra of military aircraft cockpits may degrade the intelligibility of female speech more than that of male speech. METHODS: In an applied research study, the intelligibility of female and male speech was measured in several high level aircraft cockpit noise conditions experienced in military aviation. RESULTS: In Part I, (Nixon CW, et al. Aviat Space Environ Med 1998; 69:675-83) female speech intelligibility measured in the spectra and levels of aircraft cockpit noises and with noise-canceling microphones was lower than that of the male speech in all conditions. However, the differences were small and only those at some of the highest noise levels were significant. Although speech intelligibility of both genders was acceptable during normal cruise noises, improvements are required in most of the highest levels of noise created during maximum aircraft operating conditions. These results are discussed in a Part I technical report. This Part II report examines the intelligibility in the same aircraft cockpit noises of vocoded female and male speech and the accuracy with which female and male speech in some of the cockpit noises were understood by automatic speech recognition systems. The intelligibility of vocoded female speech was generally the same as that of vocoded male speech. No significant differences were measured between the recognition accuracy of male and female speech by the automatic speech recognition systems. The intelligibility of female and male speech was equivalent for these conditions.

Female voice communications in high levels of aircraft cockpit noises--Part I: spectra, levels, and microphones.

HYPOTHESIS: Female produced speech, although more intelligible than male speech in some noise spectra, may be more vulnerable to degradation by high levels of some military aircraft cockpit noises. The acoustic features of female speech are higher in frequency, lower in power, and appear more susceptible than male speech to masking by some of these military noises. Current military aircraft voice communication systems were optimized for the male voice and may not adequately accommodate the female voice in these high level noises. METHODS: This applied study investigated the intelligibility of female and male speech produced in the noise spectra of four military aircraft cockpits at levels ranging from 95 dB to 115 dB. The experimental subjects used standard flight helmets and headsets, noise-canceling microphones, and military aircraft voice communications systems during the measurements. RESULTS: The intelligibility of female speech was lower than that of male speech for all experimental conditions; however, differences were small and insignificant except at the highest levels of the cockpit noises. Intelligibility for both genders varied with aircraft noise spectrum and level. Speech intelligibility of both genders was acceptable during normal cruise noises of all four aircraft, but improvements are required in the higher levels of noise created during aircraft maximum operating conditions. CONCLUSIONS: The intelligibility of female speech was unacceptable at the highest measured noise level of 115 dB and may constitute a problem for other military aviators. The intelligibility degradation due to the noise can be neutralized by use of an available, improved noise-canceling microphone, by the application of current active noise reduction technology to the personal communication equipment, and by the development of a voice communications system to accommodate the speech produced by both female and male aviators.

A system for measurement of prosthetic eye movements using a magnetic search coil technique.

We describe the use of a magnetic search coil technique for measuring the movement of prosthetic eyes. The technique allows for accurate comparison of implant designs and surgical techniques.

A continuous flow immunoassay for rapid and sensitive detection of small molecules.

An immunosensor operating in continuous flow and capable of detecting low molecular weight antigens is described. The approach differs from previously described continuous flow assays by not requiring incubation steps or the introduction of additional reagents following the loading of the sample into the system. Detection of the antigen is rapid, occurring within 3 min in the system described. The assay is based on the binding of labeled antigen to an immobilized antibody, with subsequent displacement of the labeled antigen when antigen is present in the buffer flow. Signal detection occurs downstream of the antigen recognition event. In this study, the hapten 2,4-dinitrophenol (DNP) as DNP-lysine was used as model antigen. To generate a labeled antigen, DNP was coupled to the terminal amino group of insulin A chain (tetra S-sulfonate form) which provides two tyrosine residues for the introduction of an 125I-label (DNP-Ins-125I) or three carboxyl groups for the attachment of three fluorescein residues (DNP-Ins-Fl). The radiolabeled antigen was used to establish assay conditions. Subsequently, fluorescein was substituted for the radioisotope label in order to develop an assay independent of the restrictions associated with isotopes. Using this flow immunoassay, we were able to detect DNP-lysine down to a detection limit of 143 nM (29 pmol/200 microliters) using DNP-Ins-125I or DNP-Ins-Fl as labeled antigen. The density of immobilized antibody and the flow rate were identified to be critical parameters for the sensitivity of the assay.

Total body burdens and tissue concentrations of lead, cadmium, copper, zinc, and ash in 55 human cadavers.

Trace metal contents of human tissues and total body burdens are useful for studies of nutrition and certain diseases. Data are summarized and analyzed for individuals exposed to the normal Cincinnati environment, for 29 tissues from 55 cadavers for lead and ash concentrations, and from 26 cadavers for cadmium, copper, and zinc concentrations. Total body burdens also were calculated and correlated against each other and age. The distributions for ash, copper, and zinc were close to normal, but those for lead and cadmium were closer to lognormal. Bone lead increased with age, whereas soft tissue lead did not. The calculated mean percentage of total body lead in the bones ranged from 78% at age 20 to 96% at age 80. Correlations of blood concentrations with total body burdens were negligible for cadmium and zinc. For copper the correlation coefficient was a poor 0.54. For lead in blood vs soft tissue burden it was a very poor 0.37, and vs total body lead it was negligible. Thus the use of blood samples as a convenient clinical measure of body burdens for these metals may be of limited value. These and other findings provide a useful bank of information for health studies.

Speech and language disorders in children.

Speech and language development is a sensitive and important diagnostic tool for the family physician. Speech defects and delayed speech and language development can be the presenting evidence for neurologic abnormalities, cognitive difficulties and abnormal hearing. They can also be signs of emotional, social, family and behavioral problems. Finally, they can signify the need for evaluation of abnormalities of tracheal and laryngeal function and oral-motor development.

Blood pressure of chickens selected for leanness or obesity.

Four lines of chickens selected for divergence in body weight followed by selection for obesity or leanness within each body weight line were used as a genetic model to determine the relationship of blood pressure and obesity. Forty females, 10 of each line, and 20 males, 10 from the heavy-weight obese and 10 from the light-weight obese, were used. Direct measurements of blood pressure were obtained from the left brachial artery of seven-month old birds. Systolic, diastolic, and mean blood pressures were recorded in this study. The systolic, diastolic, and mean blood pressure for the light-obese and light-lean females did not differ significantly; likewise, no difference was found for these three parameters in the heavy-obese and heavy-lean females. However, the blood pressures in the light-obese and light-lean lines were significantly higher than the heavy-obese and heavy-lean lines. Also, the blood pressures of the light-obese males were higher than those of the heavy-obese males; both male lines exceeded the females of the two respective lines.

Reproducibility and quality control in the analysis of biological samples for lead and mercury.

A simple statistical calculation was applied to 8 years of data on routine control sample and duplicate analyses from a laboratory quality control program. This provided standard deviations truly representative of this laboratory at no additional analytical expense, and accurate information on how they varied with concentrations. From these, the detection limit of the method, upper warning limits, and upper control limits for differences between duplicate analyses were calculated. These values were conveniently used for quality control in determinations of lead in blood and of mercury in urine.

Irritants in cigarette smoke plumes.

Concentrations of the irritants formaldehyde and acrolein in side stream cigarette smoke plumes are up to three orders of magnitude above occupational limits, readily accounting for eye and nasal irritation. "Low-tar" cigarettes appear at least as irritating as other cigarettes. More than half the irritant is associated with the particulate phase of the smoke, permitting deposition throughout the entire respiratory tract and raising the issue of whether formaldehyde in smoke is associated with bronchial cancer.

Cadmium in liver, kidney, and hair of humans, fetal through old age.

Cadmium concentrations were measured in the liver, kidney, and hair of 107 individuals from the Cincinnati area. The tissue samples were obtained from hospital and coroner autopsy cases and represent a cross-section of individuals from fetal to old age. The sections used were standardized and analyzed for cadmium by atomic absorption. Information obtained at the time of autopsy included the cause of death, the conditions of the tissues, the body height and weight, the amount of anthracosis in the lungs, as well as age, sex, and race. The liver concentrations increased steadily until the late decades. The kidney concentrations increased to the fourth decade, peaked, and decreased steadily from the sixth decade thereafter. The leveling effect in the liver may have been due to the increased presence of fatty livers, and the kidney decreases to nephrosclerosis. The kidney and liver were statistically well correlated. Hair, which achieved a surprisingly high Cd concentration in early infancy, tended to decrease throughout the rest of the age span and correlated poorly with the liver and kidney. There seemed to be no relationship between the amount of pulmonary anthracosis and the cadmium found in any of the tissues. The results obtained here for liver and kidney were in line with other reports in the literature; however, the hair results were somewhat different.

Idiopathic thrombocytopenic purpura: report of case.

A patient with classic symptoms of blood dyscrasia, specifically idiopathic thrombocytopenic purpura, failed to receive laboratory tests because the condition had gone undetected by a dentist and a physician. However, after the patient was given a provisional diagnosis supported by laboratory test results, one of the general treatment procedures for idiopathic thrombocytopenic purpura that consisted of a regimen of corticosteroids was instituted and was proved successful. More radical procedures, such as transfusions of fresh whole blood or of fresh platelets, or a splenectomy, were unnecessary. The responsibility of a dentist to detect oral changes that are not of dental origin is emphasized.