Binding of strychnocarpine and related beta-carbolines to brain receptors in vitro.

The affinity of strychnocarpine and related beta-carbolines for serotonin, benzodiazepine, tryptamine, opiate and GABA receptors in rat brain was studied. Strychnocarpine showed a low to very low affinity for all the receptors tested. The weak binding to tryptamine receptors might explain part of the tremorigenic effects found earlier in the in vivo studies.     

Prematurity-associated morbidity during the first two years of life. A population-based study

Two-year patterns of postneonatal morbidity, both chronic and non-chronic, reported for all liveborn preterm infants (n = 612; malformations excluded) delivered in the province of Kuopio, Finland, between 1978 and 1982. The overall readmission rate was 30%, the commonest cause being respiratory infections, surgical disorders (inguinal hernias) and neurological problems. The higher readmission rate in preterms born at less than or equal to 33 weeks of gestation was due to a large proportion of children being admitted with chronic prematurity-associated conditions; preterms without chronic disabilities had similar rates of readmission irrespective of gestational age. Neonatal treatment variables were of little help in the identification of children requiring readmission after neonatal care. Instead, intrauterine growth retardation (IUGR) or being of the male sex significantly increased the risk of subsequent readmission.     

Beyond COVID-19 deaths during the COVID-19 pandemic in the United States

Health Care Management Science - COVID-19 has disrupted society and health care systems, creating a fertile environment for deaths beyond the virus. The year 2020 will prove to be the most deadly...     

A 1H- and 13C-NMR study of seven ajmaline-type alkaloids

1H- and 13C-NMR spectral data are presented for ajmaline (1), 17-O-acetylajmaline (2), isoajmaline (3), isosandwichine (4), rauflorine (5), vincamajine (6), and vincamedine (7). Some corrections to the previously reported assignments of compound 6 (1H-NMR) and compounds 3, 4 and 7 (13C-NMR) have been made. The 13C-NMR chemical shifts for rauflorine 5 are presented for the first time.     

Personality traits as risk factors for stroke and coronary heart disease mortality: pooled analysis of three cohort studies

We examined whether personality traits are differently associated with coronary heart disease and stroke mortality. Participants were pooled from three prospective cohort studies (Health and Retirement Study, Wisconsin Longitudinal Study graduate and sibling samples; n = 24,543 men and women, mean age 61.4 years, mortality follow-up between 3 and 15 years). There were 423 coronary heart disease deaths and 88 stroke deaths during 212,542 person-years at risk. Higher extraversion was associated with an increased risk of stroke (hazard ratio per each standard deviation increase in personality trait HR = 1.41, 95 % CI 1.10–1.80) but not with coronary heart disease mortality (HR = 0.93, 0.83–1.05). High neuroticism, in turn, was more strongly related to the risk of coronary heart disease (HR = 1.16, 1.04–1.29) than stroke deaths (HR = 0.95, 0.78–1.17). High conscientiousness was associated with lower mortality risk from both coronary heart disease (HR = 0.74, 0.67–0.81) and stroke (HR = 0.78, 0.63–0.97). Cardiovascular risk associated with personality traits appears to vary between main cardiac and cerebral disease endpoints.     

Measurements of electromagnetic emissions from video display terminals at the frequency range from 30 Hz to 1 MHz

Electric (E) and magnetic field (B) strengths or flux densities were measured at distances of 30 and 50 cm from the screen of video displays at a frequency range from 30 Hz to 1 MHz. The measurement system consisted of an optically coupled active dipole for E-fields, a magnetic field meter, a digital oscilloscope, a portable computer for data storage and a laboratory computer for Fourier analysis of the recorded signals. Comparison of measurement results with available broadband exposure standards or proposed standards indicated that magnetic flux density should be measured at both the (ELF) frequency range from 30 Hz to 300 Hz and at the (RF) frequency range from 10 kHz to 500 kHz. Alternatively, time derivative of magnetic flux density may be measured. Nor should the measurement of the electric field strength at the RF range be neglected. These conclusions, however, are valid only in relative terms. In all cases the exposure is at least one decade below the most stringent exposure limit. The maximum relative exposure 0.077 was obtained by applying the ACGIH standard for magnetic fields at a distance of 30 cm from the screen. The field strengths decrease by a factor varying from 2.5 to 3.5 at a distance of 50 cm, which is a more realistic distance when considering actual working conditions.     

Physiologic and dosimetric considerations for limiting electric fields induced in the body by movement in a static magnetic field

Movement in a strong static magnetic field induces electric fields in a human body, which may result in various sensory perceptions such as vertigo, nausea, magnetic phosphenes, and a metallic taste in the mouth. These sensory perceptions have been observed by patients and medical staff in the vicinity of modern diagnostic magnetic resonance (MR) equipment and may be distracting if they were to affect the balance and eye-hand coordination of, for example, a physician carrying out a medical operation during MR scanning. The stimulation of peripheral nerve tissue by a more intense induced electric field is also theoretically possible but has not been reported to result from such movement. The main objective of this study is to consider generic criteria for limiting the slowly varying broadband (<10 Hz) electric fields induced by the motion of the body in the static magnetic field. In order to find a link between the static magnetic flux density and the time-varying induced electric field, the static magnetic field is converted to the homogeneous equivalent transient and sinusoidal magnetic fields exposing a stationary body. Two cases are considered: a human head moving in a non-uniform magnetic field and a head rotating in a homogeneous magnetic field. Then the electric field is derived from the magnetic flux rate (dB/dt) of the equivalent field by using computational dosimetric data published in the literature for various models of the human body. This conversion allows the plotting of the threshold electric field as a function of frequency for vertigo, phosphenes, and stimulation of peripheral nerves. The main conclusions of the study are: The basic restrictions for limiting exposure to extremely low frequency magnetic fields recommended by the International Commission on Non-Ionizing Radiation Protection ICNIRP in 1998 will prevent most cases of vertigo and other sensory perceptions that result from induced electric fields above 1 Hz, while limiting the static magnetic field below 2 T, as recently recommended by ICNIRP, provides sufficient protection below 1 Hz. People can experience vertigo when moving in static magnetic fields of between 2 and 8 T, but this may be controlled to some extent by slowing down head and/or body movement. In addition, limiting the static magnetic field below 8 T provides good protection against peripheral nerve stimulation.     

Socioeconomic differences in cardiometabolic factors: social causation or health-related selection? Evidence from the Whitehall II Cohort Study, 1991-2004

In this study, the health-related selection hypothesis (that health predicts social mobility) and the social causation hypothesis (that socioeconomic status influences health) were tested in relation to cardiometabolic factors. The authors screened 8,312 United Kingdom men and women 3 times over 10 years between 1991 and 2004 for waist circumference, body mass index, systolic and diastolic blood pressure, fasting glucose, fasting insulin, serum lipids, C-reactive protein, and interleukin-6; identified participants with the metabolic syndrome; and measured childhood health retrospectively. Health-related selection was examined in 2 ways: 1) childhood health problems as predictors of adult occupational position and 2) adult cardiometabolic factors as predictors of subsequent promotion at work. Social causation was assessed using adult occupational position as a predictor of subsequent change in cardiometabolic factors. Hospitalization during childhood and lower birth weight were associated with lower occupational position (both P's ≤ 0.002). Cardiometabolic factors in adulthood did not consistently predict promotion. In contrast, lower adult occupational position predicted adverse changes in several cardiometabolic factors (waist circumference, body mass index, fasting glucose, and fasting insulin) and an increased risk of new-onset metabolic syndrome (all P's ≤ 0.008). These findings suggest that health-related selection operates at younger ages and that social causation contributes to socioeconomic differences in cardiometabolic health in midlife.