Temporal lobe volume in panic disorder--a quantitative magnetic resonance imaging study

Although previous studies have used magnetic resonance imaging (MRI) to demonstrate qualitative abnormalities of the temporal lobes in patients with panic disorder, no study to date has applied quantitative volumetric methods to evaluate brain changes in panic disorder. The purpose of this study was to measure the volume of the temporal lobe and the hippocampus in patients with panic disorder and healthy control subjects using quantitative MRI measures. The volume of the temporal lobe, hippocampus and whole brain was measured in 13 patients with panic disorder and 14 healthy subjects. The mean volume of the left and right temporal lobes was significantly smaller in panic disorder compared to healthy subjects (16770+/-909 mm(3) vs. 18343+/-1740 mm(3)). This result was significant after controlling for differences in whole brain volume. There was no significant difference in volume of the hippocampus between patients and control subjects. These findings are consistent with smaller temporal lobe volume in panic disorder despite normal hippocampal volume.

Hippocampal volume reduction in major depression

OBJECTIVE

Elevated levels of glucocorticoids in depression have been hypothesized to be associated with damage to the hippocampus, a brain area involved in learning and memory. The purpose of this study was to measure hippocampal volume in patients with depression.

METHOD

Magnetic resonance imaging was used to measure the volume of the hippocampus in 16 patients with major depression in remission and 16 case-matched nondepressed comparison subjects.

RESULTS

Patients with depression had a statistically significant 19% smaller left hippocampal volume than comparison subjects, without smaller volumes of comparison regions (amygdala, caudate, frontal lobe, and temporal lobe) or whole brain volume. The findings were significant after brain size, alcohol exposure, age, and education were controlled for.

CONCLUSIONS

These findings are consistent with smaller left hippocampal volume in depression.

Clinimetric evaluation of the Sinonasal Outcome Test-16. Student Research Award 1998

This study describes the reliability, validity, and responsiveness of the Sinonasal Outcome Test-16 (SNOT-16), a rhinosinusitis-specific health-related quality-of-life instrument, in the University of Washington Department of Otolaryngology-Head and Neck Surgery patient population. The SNOT-16 was completed by 47, 24, and 22 patients at weeks 0, 6, and 12, respectively. In addition, all 47 patients completed the Short-form 36-item Health Survey (SF-36) at week 0. Furthermore, an additional cohort of patients from the otology clinic who denied symptoms of rhinosinusitis or previous physician diagnoses of rhinosinusitis were asked to complete the SNOT-16. These scores were subsequently used to determine discriminant validity of the instrument. Cronbach's alpha was 0.89, indicating a high degree of homogeneity of the test items. The SNOT-16 demonstrated excellent discriminant validity, and mean total SNOT-16 scores were significantly correlated with patient-reported overall health, overall bother, and 7 of the 8 SF-36 subscales. The standardized response mean calculated between weeks 0 and 6 was 0.69, indicating moderate sensitivity to change. We conclude that the SNOT-16 is a reliable, valid, and responsive instrument for measuring rhinosinusitis-specific health-related quality of life.

Don't know, don't care. III

The knowledge of and interest in Department of Defense programs to help medical students with their educational expenses in exchange for military service as a physician was studied at three medical schools representing the eastern (University of Medicine and Dentistry of New Jersey/New Jersey Medical School [UMDNJ/NJMS]), midwestern (University of Missouri at Kansas City), and western (University of Utah) United States. Despite staggering indebtedness (40% of the class of 1998 at the University of Medicine and Dentistry of New Jersey were in debt in excess of $100,000 at graduation), surprisingly few students were aware of programs such as the Health Professions Scholarship Program, the Health Professionals Loan Repayment Program, and the Specialized Training Assistance Program. Even fewer were interested when made aware of such financial assistance. Hostility to military service as a physician was common. "Patriotism" was seemingly anathema. Dwindling recruitment and retention of medical corps officers in the reserve components of our nation's armed forces is of grave concern to national security and flies in the face of medical students', hence young physicians', indebtedness for their education. Clearly Department of Defense programs must become more imaginative, certainly more financially appealing.

Non-invasive measurements of breast tissue optical properties using frequency-domain photon migration

A multiwavelength, high bandwidth (1 GHz) frequency-domain photon migration (FDPM) instrument has been developed for quantitative, non-invasive measurements of tissue optical and physiological properties. The instrument produces 300 kHz to 1 GHz photon density waves (PDWs) in optically turbid media using a network analyser, an avalanche photodiode detector and four amplitude-modulated diode lasers (674 nm, 811 nm, 849 nm, and 956 nm). The frequency of PDW phase and amplitude is measured and compared to analytically derived model functions in order to calculate absorption, mu a, and reduced scattering, mu s, parameters. The wavelength-dependence of absorption is used to determine tissue haemoglobin concentration (total, oxy- and deoxy- forms), oxygen saturation and water concentration. We present preliminary results of non-invasive FDPM measurements obtained from normal and tumour-containing human breast tissue. Our data clearly demonstrate that physiological changes caused by the presence of small (about 1 cm diameter) palpable lesions can be detected using a handheld FDPM probe.

Frequency-domain photon migration measurements of normal and malignant tissue optical properties in a human subject

A 1-GHz multifrequency, multiwavelength frequency-domain photon migration instrument is used to measure quantitatively the optical absorption (mu(a)) and effective optical scattering (mu(s) ?) of normal and malignant tissues in a human subject. Large ellipsoidal (~10-cm major axis, ~6-cm minor axes) subcutaneous malignant lesions were compared with adjacent normal sites in the abdomen and back. Absorption coefficients recorded at 674, 811, 849, and 956 nm were used to calculate tissue hemoglobin concentration (oxyhemoglobin, deoxyhemoglobin, and total), water concentration, hemoglobin oxygen saturation, and blood volume fraction in vivo. Our results show that the normal and the malignant tissues measured in the patient have clearly resolvable optical and physiological property differences that may be broadly useful in identifying and characterizing tumors.

Differential Rotation and Dynamics of the Solar Interior

Splitting of the sun's global oscillation frequencies by large-scale flows can be used to investigate how rotation varies with radius and latitude within the solar interior. The nearly uninterrupted observations by the Global Oscillation Network Group (GONG) yield oscillation power spectra with high duty cycles and high signal-to-noise ratios. Frequency splittings derived from GONG observations confirm that the variation of rotation rate with latitude seen at the surface carries through much of the convection zone, at the base of which is an adjustment layer leading to latitudinally independent rotation at greater depths. A distinctive shear layer just below the surface is discernible at low to mid-latitudes.

The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.

The Current State of Solar Modeling

Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.

Genetic questions for environmental studies. Differential parenting and psychopathology in adolescence

BACKGROUND

Recent genetic evidence suggests that the most important environmental influences on normal and pathologic development are those that are not shared by siblings in the same family. We sought to determine the relationship between differences in parenting styles and depressive symptoms and antisocial behavior in adolescence, and to compare the influence of these nonshared experiences with genetic influences.

METHODS

We studied 708 families with at least two same-sexed adolescent siblings who were monozygotic twins (93 families), dizygotic twins (99 families), ordinary siblings (95 families), full siblings in step families (181 families), half siblings in step families (110 families), and genetically unrelated siblings in step families (130 families). Data on parenting style were collected by questionnaire and by video recording of interaction between parents and children.

RESULTS

Almost 60% of variance in adolescent antisocial behavior and 37% of variance in depressive symptoms could be accounted for by conflictual and negative parental behavior directed specifically at the adolescent. In contrast, when a parent directed harsh, aggressive, explosive, and inconsistent parenting toward the sibling, we found less psychopathologic outcome in the adolescent.

CONCLUSIONS

Parenting behavior directed specifically at each child in the family is a major correlate of symptoms in adolescents. Furthermore, harsh parental behavior directed at a sibling may have protective effects for adolescents, a phenomenon we call the "siblin barricade."

Portable, high-bandwidth frequency-domain photon migration instrument for tissue spectroscopy

We describe a novel frequency-domain photon migration instrument employing direct diode laser modulation and avalanche photodiode detection, which is capable of noninvasively determinating the optical properties of biological tissues in near real time. An infinite medium diffusion model was used to extract absorption and transport scattering coefficients from 300-kHz to 800-MHz photon-density wave phase data. Optical properties measured in tissue-simulating solutions at 670 nm agreed to within 10% of those expected.

Analyzing change in short-term longitudinal research using cohort-sequential designs

This article illustrates a method for approximating longitudinal data analysis by combining information from different overlapping age groups to form a single developmental growth curve. Using this method, hypotheses about the form of growth, the extent of individual differences in growth, and factors that affect the rate and pattern of growth are investigated. The example used to illustrate this method examines the growth of externalizing behavior and of negativity in parent-child relationships during early adolescence using assessments from multiple methods and multiple informants. These 3 dimensions changed significantly during this period, with parental negativity increasing more rapidly after age 12. However, there were substantial individual differences in the pattern of change in these dimensions. Gender of child and type of family situation (nondivorced, divorced, and remarried) were investigated as possible factors affecting change.

Analyzing change in short-term longitudinal research using cohort-sequential designs

This article illustrates a method for approximating longitudinal data analysis by combining information from different overlapping age groups to form a single developmental growth curve. Using this method, hypotheses about the form of growth, the extent of individual differences in growth, and factors that affect the rate and pattern of growth are investigated. The example used to illustrate this method examines the growth of externalizing behavior and of negativity in parent-child relationships during early adolescence using assessments from multiple methods and multiple informants. These 3 dimensions changed significantly during this period, with parental negativity increasing more rapidly after age 12. However, there were substantial individual differences in the pattern of change in these dimensions. Gender of child and type of family situation (nondivorced, divorced, and remarried) were investigated as possible factors affecting change.

Blood pressure, hemodynamic, and thermal responses after cycling exercise

Seated recovery [at 5, 15, 20, 40, and 60 min (R5,15,20,40,60)] body temperature (T) and blood pressure were examined after 45 min of cycling exercise (54 +/- 5% maximal O2 uptake) in 12 normotensive males to study the relationship between postexercise thermal and hemodynamic responses. Data were analyzed with a repeated-measures analysis of variance. Systolic (SBP, R15,20,40; P < 0.01) and mean arterial (MAP, R15,20; P < 0.05) blood pressures were significantly lower, but diastolic blood pressure (DBP) was unchanged. Heart rate (R5,15,20, P < 0.001) was above that measured at rest. Decreases in mean skin T (Tsk, R15,20,60; P < 0.01) and increases in core T (Tc, R5,15,20; P < 0.01) were found. Significant negative correlations averaging -0.68 (R15,20,40) and -0.69 (R15,20,40) were demonstrated for Tsk and SBP and MAP, respectively. Increases in thigh Tsk (R5,15,20; P < 0.00001) and decreases in calf (R15,20,40,60; P < 0.00001) and chest (Tchest, R5,15,20,40; P < 0.00001) Tsk were found. Significant negative correlations averaging -0.67 (R5,15,20,40) and -0.71 (R20,40,60) were demonstrated for Tchest and SBP and MAP, respectively. Inverse relationships between various regional Ts and blood pressure and the increased R Tc suggest a vasodilatory response in the visceral organs and/or lower limbs leading to a pooling of blood and transient decreases in blood pressure by a reduced venous return, although not affecting stroke volume and cardiac output.

Role stress and strain among nondoctorally prepared undergraduate faculty in a school of nursing with a doctoral program

Initiation of a doctoral program within existing schools of nursing causes significant change in organizational structure and function. The role expectations of the current faculty change as well. The purpose of the qualitative study was to identify if role stress and strain are present in nondoctorally prepared undergraduate nursing faculty in a southern university school of nursing with a doctoral program. The design was a qualitative, open-ended interview. The primary research question was: Does the initiation of a doctoral program in a school of nursing impose role stress and strain on nondoctorally prepared faculty members? Academic educators will find our results interesting because faculty report that role stress and strain affect both their teaching and decisions to remain in academia. Use of these findings may contribute toward improved role relationships, better role performance, greater job satisfaction, and decreased job turnover.

Physiologic comparison and validation of Stairobic stepping with bench stepping

To compare the oxygen cost of submaximal exercise on the Stairobic stepping (SS) machine with bench stepping (BS), 12 healthy men and women (mean age 23 years) underwent six different five minute exercise bouts that were randomly assigned. Tests were conducted using standard open circuit calorimetry. SS at 40 and 60 st/min was equal to BS at 20 st/min and SS at 80 st/min was equal to BS at 30 st/min for VE and RER. VO2 was equal at 20 st/min (BS) and 60 st/min (SS), and 30 st/min (BS) and 80 st/min (SS). Stairobic MET (SM) displayed values over-estimated actual MET (AM) values at the two lowest SS rates and under-estimated the AM value at the highest SS rate. Forty-eight observations of the MET response of SS were conducted and analyzed (BMDP2R) in a forward stepping solution. The multiple regression equation calculated for AM was: AM = -0.567 + -0.012 (WT) + 0.063 (rate) + 0.612 (SM) with an adjusted R2 of 0.82 and a SEE of 0.90. The physiologic cost of BS was approximately equal to SS at two to three times the BS rate of stepping.

Cellular levels of messenger ribonucleic acids encoding vasoactive intestinal Peptide and gastrin-releasing Peptide in neurons of the suprachiasmatic nucleus exhibit distinct 24-hour rhythms

There is strong evidence supporting the view that the Suprachiasmatic nucleus (SCN) functions as a circadian clock; however, the neural and molecular events underlying SCN function remain unclear. A specific subpopulation of neurons within the ventrolateral aspect of the SCN that contains three peptides, vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI) and gastrin-releasing peptide (GRP), play an important role in SCN function. VIP-containing neurons of the SCN receive synapses from photic projections, and co-injection of all three peptides mimics the phase-delaying effects of light on circadian activity rhythms. In principle, the signaling potential of a neuron containing several transmitters may be affected by the concentration ratio of co-released factors; hence, one mechanism by which VIP/PHI/GRP-containing neurons could influence SCN function is by changing the concentration ratio of these peptides throughout the light-dark cycle. The present study was performed to examine this possibility. Relative cellular levels of mRNA encoding both VIP/PHI and GRP were determined within the SCN every 4 h in rats housed in a 14 h light: 10 h dark cycle. Quantitative in situ hybridization revealed a statistically significant (P<0.005) 24-h profile of changes in VIP/PHI mRNA that peaked during the dark phase, and a significant (P<0.005) 24-h profile of changes in GRP mRNA that peaked during the light phase. These data support the interpretation that cellular levels of mRNAs encoding VIP/PHI and GRP within the SCN exhibit distinct profiles of changes throughout the light-dark cycle. Further, these findings are consistent with the hypothesis that the concentration ratio of VIP and PHI to GRP changes over the light-dark cycle, and that this may be an important mechanism by which circadian rhythms are generated or entrained.

Neuropeptide Y in the hypothalamus: effect on corticosterone and single-unit activity

The purpose of the present study was to determine whether neuropeptide Y (NPY) acts within the hypothalamic paraventricular nucleus (PVN) or the suprachiasmatic nucleus (SCN) to alter circulating levels of corticosterone and to evaluate the effects of NPY on the single-unit response of PVN and SCN neurons using the hypothalamic slice preparation. Blood levels of corticosterone were determined in groups of rats that received microinjections of NPY or saline (Sal) into the PVN or SCN. NPY injected into the PVN 4 h after light onset resulted in corticosterone levels of 13.15 +/- 2.18 (SE) micrograms/dl within 1 h, which were significantly higher than the corticosterone levels of 4.08 +/- 1.78 micrograms/dl seen in rats receiving Sal injections. In contrast, no significant differences were observed in circulating levels of corticosterone between groups of rats 1 or 4 h after NPY or Sal microinjection into the SCN. In the hypothalamic slice, NPY was found to produce primarily inhibitory responses in both SCN and PVN neurons. Forty-nine percent of the SCN units examined were inhibited. In addition, another 20% of the neurons tested in the SCN displayed excitation followed by more sustained inhibition. In the PVN, 45% of the units examined were inhibited by NPY, however, nearly 30% of the remaining neurons were significantly excited by NPY. In summary, NPY alters the electrical activity of both SCN and PVN neurons but appears to act only within the PVN to influence circulating levels of corticosterone. These and other data indicate that NPY acts as an important neurochemical messenger within several hypothalamic sites.