Mass density images from the diffraction enhanced imaging technique

Conventional x-ray radiography measures the projected x-ray attenuation of an object. It requires attenuation differences to obtain contrast of embedded features. In general, the best absorption contrast is obtained at x-ray energies where the absorption is high, meaning a high absorbed dose. Diffraction-enhanced imaging (DEI) derives contrast from absorption, refraction, and extinction. The refraction angle image of DEI visualizes the spatial gradient of the projected electron density of the object. The projected electron density often correlates well with the projected mass density and projected absorption in soft-tissue imaging, yet the mass density is not an "energy"-dependent property of the object, as is the case of absorption. This simple difference can lead to imaging with less x-ray exposure or dose. In addition, the mass density image can be directly compared (i.e., a signal-to-noise comparison) with conventional radiography. We present the method of obtaining the mass density image, the results of experiments in which comparisons are made with radiography, and an application of the method to breast cancer imaging.

Differential gene expression in infarct scar and viable myocardium from rat heart following coronary ligation

Post-myocardial infarction (MI) remodeling of cardiac myocytes and the myocardial interstitium results in alteration of gross ventricular geometry and ventricular dysfunction. To investigate the mechanisms of the remodeling process of the heart after large MI, the expression of various genes in viable left ventricle and infarct scar tissue were examined at 16 weeks post-MI. Steady-state expression of Na(+)-K+ ATPase alpha-1 and -2, phospholamban (PLB), alpha-myosin heavy chain (alpha-MHC), ryanodine receptor (Rya) and Ca2+ ATPase (Serca2) mRNAs were decreased in the infarct scar vs noninfarcted sham-operated controls (P < 0.05). On the other hand, Gialpha2 and beta-MHC mRNAs were upregulated (P < 0.05, respectively) in the infarct scar whereas Na(+)-K+ ATPase-beta, Na(+)-Ca2+ exchanger and Gs mRNAs were not altered vs control values. In viable left ventricle, the alpha-1 subunit of Na(+)-K+ ATPase, alpha-3, beta-isoforms, Rya, beta-MHC, Gialpha2, Gs and Na(+)-Ca2+ exchanger were significantly elevated while expression of the alpha-2 subunit of Na(+)-K+ ATPase, PLB and Serca2 were significantly decreased compared to controls. Expression of CK2alpha mRNA was elevated in noninfarcted heart (145 +/- 15%) and diminished in the infarct scar (66 +/- 13%) vs controls. Expression of beta-MHC mRNA was elevated in both viable and infarct scar tissues of experimental hearts (140 +/- 31% and 183 +/- 30% vs. controls, respectively). These results suggest that cardiac genes in the infarcted tissue and viable left ventricle following MI are differentially regulated.

Insulin increases CSF Abeta42 levels in normal older adults

BACKGROUND

Abnormal insulin metabolism may contribute to the clinical symptoms and pathophysiology of AD. In vitro studies show that insulin enhances the release of beta-amyloid protein (Abeta) or inhibits its degradation, either of which might increase amyloid burden.

METHODS

On separate mornings, 16 healthy older adults (10 women, 6 men; mean age 68.7 years, SD 8.6 years) each underwent two infusions consisting of either saline (placebo) or insulin (1.0 mU x kg(-1) x min(-1)) plus dextrose to maintain euglycemia. After 120 minutes of infusion, blood, CSF, and cognitive measures were acquired.

RESULTS

As expected, insulin infusion produced an increase in CSF insulin concentration. Insulin infusion also led to an increase in CSF Abeta42 levels, most notably in older subjects. As has been observed previously, insulin infusion facilitated declarative memory, but such facilitation was attenuated in the subjects with the greatest increase in CSF Abeta42 levels.

CONCLUSIONS

These findings are consistent with recent in vitro studies of insulin effects on Abeta and support the notion that insulin may modulate Abeta42 levels acutely in humans.

Diffraction enhanced imaging contrast mechanisms in breast cancer specimens

We have investigated the contrast mechanisms of the refraction angle, and the apparent absorption images obtained from the diffraction enhanced imaging technique (DEI) and have correlated them with the absorption contrast of conventional radiography. The contrast of both the DEI refraction angle image and the radiograph have the same dependence on density differences of the tissues in the visualization of cancer; in radiography these differences directly relate to the contrast while in the DEI refraction angle image it is the density difference and thickness gradient that gives the refraction angle. We show that the density difference of fibrils in breast cancer as measured by absorption images correlate well with the density difference derived from refraction angle images of DEI. In addition we find that the DEI apparent absorption image and the image obtained with the DEI system at the top of the reflectivity curve have much greater contrast than that of the normal radiograph (x8 to 33-fold higher). This is due to the rejection of small angle scattering (extinction) from the fibrils enhancing the contrast.

Can women remember when their milk came in?

The perception of the timing of milk arrival has been identified as an important predictor of breast-feeding success. Because this indicator has the potential to be used as a proxy for the onset of lactogenesis stage II and is relatively simple to measure, it is possible to include it as part of large-scale surveys. It is unknown, however, how likely women are to recall the timing of milk arrival accurately, several months after delivery. To test the validity of maternal recall, we conducted a longitudinal study in Hartford CT with 192 women who delivered healthy, term singletons at Hartford Hospital. All women were interviewed daily from day 1 postpartum until they perceived that milk arrival had occurred. Seven months after delivery, women were able to recall if their milk came in late (i.e. >72h postpartum) with a high level of sensitivity (93.6%) and an acceptable level of specificity (62.5%).

Acceptability of early discharge with drain in situ after breast surgery

The aim of this study was to evaluate a policy of early discharge at 48 hours with suction drains in situ in a cohort of patients undergoing surgery for breast cancer and to compare this with a similar cohort of patients discharged 5 days postoperatively. This was an integrated qualitative/quantitative study using a questionnaire given to both groups providing comparable results by using averages and percentages to describe and synthesize the data. A questionnaire of open and closed questions was given to 19 patients who chose to be discharged at 48 hours with drains in situ, and 16 patients who opted to be discharged at 5 days after drain removal. The study demonstrated that patients regarded early discharge as being safe and were satisfied with their care when they were given a high level of support from hospital and community staff. The results also identified that it was important for patients to make their own decision about either early discharge or standard discharge in order to be satisfied with the outcome of their care.

Acceptability of early discharge with drain in situ after breast surgery

The aim of this study was to evaluate a policy of early discharge at 48 hours with suction drains in situ in a cohort of patients undergoing surgery for breast cancer and to compare this with a similar cohort of patients discharged 5 days postoperatively. This was an integrated qualitative/quantitative study using a questionnaire given to both groups providing comparable results by using averages and percentages to describe and synthesize the data. A questionnaire of open and closed questions was given to 19 patients who chose to be discharged at 48 hours with drains in situ, and 16 patients who opted to be discharged at 5 days after drain removal. The study demonstrated that patients regarded early discharge as being safe and were satisfied with their care when they were given a high level of support from hospital and community staff. The results also identified that it was important for patients to make their own decision about either early discharge or standard discharge in order to be satisfied with the outcome of their care.

Comparative onset of action and symptom relief with cetirizine, loratadine, or placebo in an environmental exposure unit in subjects with seasonal allergic rhinitis: confirmation of a test system

BACKGROUND

The environmental exposure unit (EEU) is an instrument designed to determine onset of action of antiallergic treatment. Confirmation of test results would be useful in defining its role.

OBJECTIVE

This study was intended to confirm a previous study comparing cetirizine, loratadine, and placebo in the EEU using an identical protocol design (randomized, double-blind, parallel-group comparison having the same symptom scoring system, endpoints, and statistical analyses), thus demonstrating reproducibility of studies conducted in the EEU.

METHODS

Onset of action and symptom relief with once-daily cetirizine 10 mg, loratadine 10 mg, and placebo (n = 120 each group) were evaluated replicating a previous study design. Subjects meeting inclusion and exclusion criteria and qualifying symptom scores were randomized to 2 days' exposure (6 to 7 hours daily) with treatment. Changes in total and major symptom complex (TSC, MSC) scores based on 14 symptoms evaluated at 30-minute intervals served as primary efficacy variables.

RESULTS

Onset of action again was earlier with cetirizine (at 1 hour, P < or = 0.001) versus loratadine (at 3 hours, P < or = 0.01). Cetirizine produced a 25.4% least-square mean reduction in TSC scores overall versus an 11.2% decrease with loratadine (P = 0.006) and a 4.8% increase with placebo (P < 0.001); loratadine and placebo were also significantly different (P = 0.002). Similar changes were also noted in MSC scores. Cetirizine consistently reduced TSC and MSC scores after the first dose versus placebo (P < or = 0.001) and at most time points versus loratadine (P < or = 0.05). Adverse events were reported in 1.7% of patients in each active-treatment group and in 2.5% on placebo.

CONCLUSIONS

Cetirizine acted earlier and was more effective than loratadine or placebo in reducing symptoms of seasonal allergic rhinitis in subjects undergoing a controlled pollen challenge, replicating results from an earlier, identically designed study, demonstrating reproducibility of these assessments by the EEU.

Modulation of cardiac sarcoplasmic reticulum gene expression by lack of oxygen and glucose

Although ischemia reperfusion has been shown to depress gene expression of the sarcoplasmic reticulum (SR) proteins, such as the ryanodine receptor, Ca2+-pump ATPase, phospholamban, and calsequestrin in the heart, the mechanisms of these changes are not understood. Given the occurrence of hypoxia and the lack of glucose during the ischemic phase, we investigated the effects of these factors on the cardiac SR gene expression. Isolated rat hearts perfused in the absence of oxygen and/or glucose for 30 min showed an increase in the expression of SR genes. However, perfusion of hearts for 60 min with normal oxygenated medium after 30 min of lack of both oxygen and glucose depressed the transcript levels for the SR proteins; these changes did not occur when hearts were deprived of either oxygen or glucose. The effect of intracellular Ca2+-overload, which occurs during reperfusion, was studied by using hearts perfused for 5 min with Ca2+-free medium and then reperfused for 30 min. Ca2+-depletion/repletion induced a dramatic decrease in the transcript levels of the SR genes. These results suggest that the lack of both oxygen and glucose during ischemia are necessary for reperfusion-induced depression in SR gene expression, possibly due to the occurrence of intracellular Ca2+-overload.

Producing parallel x rays with a bent-crystal monochromator and an x-ray tube

A bent Laue monochromator and a conventional x-ray tube were used to produce a fan beam that was parallel in the plane perpendicular to the plane of the fan. The x-ray fan beam was tunable in energy and had about 12% energy bandwidth at a slice height of 5 mm when tuned to 50 keV. The beam's energy was slightly coupled to the vertical position on the beam's height. The slice height could be varied from 1 to 10 mm. The flux at 50 keV was approximately 2x10(6) photons/mm2/s with a rotating anode tungsten x-ray tube operating at 120 kVp and 100 mA. The narrow energy bandwidth of the beam produced is advantageous over a conventional divergent polychromatic beam for all radiography applications, while the parallelism of the beam enhances its intensity by about threefold and offers some advantages for computed tomography.

The interaction of microgravity and ethylene on the ultrastructure cell and Ca2+ localization in soybean hook hypocotyl

Calcium ions are secondary messenger in numerous cellular processes of plant grown at 1 g. Ca2+ are connected with oxygen atoms, of pectin carboxy groups and/or with H(+)-groups of protein (Roux and Slocum, 1982; Hepler and Wayne, 1985). The influence of altered gravity on the calcium balance in some cells is established. The increased synthesis of ethylene in plant grown in microgravity caused the change of the structural-functional organization of cell (Hensel and Iversen, 1980; Hilaire et al., 1996). Available data put the new question: how do high ethylene level and microgravity influence on the redistribution of Ca2+ in cell of seedling in early stage of growth? Therefore, the goal of our data was the comparable study of the cell ulltrastructure and localization of Ca2+ in hook hypocotyl of soybean seedling under interaction of microgravity and ethylene.

Mesodermal patterning defect in mice lacking the Ste20 NCK interacting kinase (NIK)

We have previously shown that the Drosophila Ste20 kinase encoded by misshapen (msn) is an essential gene in Drosophila development. msn function is required to activate the Drosophila c-Jun N-terminal kinase (JNK), basket (Bsk), to promote dorsal closure of the Drosophila embryo. Later in development, msn expression is required in photoreceptors in order for their axons to project normally. A mammalian homolog of msn, the NCK-interacting kinase (NIK) (recently renamed to mitogen-activated protein kinase kinase kinase kinase 4; Map4k4), has been shown to activate JNK and to bind the SH3 domains of the SH2/SH3 adapter NCK. To determine whether NIK also plays an essential role in mammalian development, we created mice deficient in NIK by homologous recombination at the Nik gene. Nik(−/−) mice die postgastrulation between embryonic day (E) 9.5 and E10.5. The most striking phenotype in Nik(−/−) embryos is the failure of mesodermal and endodermal cells that arise from the anterior end of the primitive streak (PS) to migrate to their correct location. As a result Nik(−/−)embryos fail to develop somites or a hindgut and are truncated posteriorly. Interestingly, chimeric analysis demonstrated that NIK has a cell nonautonomous function in stimulating migration of presomitic mesodermal cells away from the PS and a second cell autonomous function in stimulating the differentiation of presomitic mesoderm into dermomyotome. These findings indicate that despite the large number of Ste20 kinases in mammalian cells, members of this family play essential nonredundant function in regulating specific signaling pathways. In addition, these studies provide evidence that the signaling pathways regulated by these kinases are diverse and not limited to the activation of JNK because mesodermal and somite development are not perturbed in JNK1-, and JNK2-deficient mice.

Decreased nocturnal levels of prolactin and growth hormone in women with fibromyalgia

Fibromyalgia (FM) is a complex syndrome, primarily of women, characterized by chronic pain, fatigue, and sleep disturbance. Altered function of the somatotropic axis has been documented in patients with FM, but little is known about nocturnal levels of PRL. As part of a laboratory study of sleep patterns in FM, we measured the serum concentrations of GH and PRL hourly from 2000--0700 h in a sample of 25 women with FM (mean, 46.9 +/- 7.6 yr) and in 21 control women (mean, 42.6 +/- 8.1 yr). The mean (+/-SEM ) serum concentrations (micrograms per L) of GH and of PRL during the early sleep period were higher in control women than in patients with FM [GH, 1.6 +/- 0.4 vs. 0.6 +/- 0.2 (P < 0.05); PRL, 23.2 +/- 2.2 vs. 16.9 +/- 2.0 (P < 0.025)]. The mean serum concentrations of GH and PRL increased more after sleep onset in control women than in patients with FM [GH, 1.3 +/- 0.4 vs. 0.3 +/- 0.2 (P < 0.05); PRL, 16.2 +/- 2.4 vs. 9.7 +/- 1.5 (P < 0.025)]. Sleep efficiency and amounts of sleep or wake stages on the blood draw night were not different between groups. There was a modest inverse relationship between sleep latency and PRL and a direct relationship between sleep efficiency and PRL in FM. There was an inverse relationship between age and GH most evident in control women. Insulin-like growth factor I levels were not different between the groups. These data demonstrate altered functioning of both the somatotropic and lactotropic axes during sleep in FM and support the hypothesis that dysregulated neuroendocrine systems during sleep may play a role in the pathophysiology of FM.

Characteristics of female psychiatrists

OBJECTIVE

This study assessed within-gender differences between psychiatrists and other physicians by using data taken from a large national sample of U.S. female physicians.

METHOD

The authors used data from the Women Physicians' Health Study, a large, national questionnaire-based survey conducted in 1993-1994, to compare characteristics of female psychiatrists (N=570) with those of other female physicians (N=3,875).

RESULTS

Psychiatrists were older, in poorer health, less likely to be married, more likely to be current or ex-smokers, and more likely to be politically liberal than were the other female physicians. Psychiatrists were somewhat (although not necessarily significantly) more likely than the other female physicians to report having had personal or family histories of various psychiatric disorders. Psychiatrists were more likely to have a solo practice and less likely to be in a group practice. They worked fewer hours than the other female physicians but reported comparable hourly incomes. Psychiatrists did not differ from the other female physicians in perceived work amount, work stress, work control, or career satisfaction. Their satisfaction with their specialty was, however, greater than that of the other female physicians. For nearly all of the 14 preventive health care counseling practices examined, the amount of preventive counseling psychiatrists reported performing, the clinical relevance they ascribed to those practices, their self-confidence in performing the practices, and the amount of training they reported receiving in preventive counseling practices was significantly lower than that of primary care practitioners and lower than or comparable to that of other specialists.

CONCLUSIONS

Female psychiatrists significantly differ from other female physicians with regard to a number of personal and professional dimensions.

Double-blind comparison of sertraline, imipramine, and placebo in the treatment of dysthymia: effects on personality

OBJECTIVE

Although previous studies have shown that dysthymia, or chronic depression, commonly responds to antidepressant medications (with improvements in depressive symptoms and psychosocial functioning), there have been no systematic studies of the impact of antidepressant treatment on personality variables in patients with this disorder.

METHOD

In a multicenter study, 410 patients with early-onset primary dysthymia were treated in a randomized prospective fashion with sertraline, imipramine, or placebo. The data were analyzed in terms of the subjects' scores on the Tridimensional Personality Questionnaire, a 100-item self-report instrument that measures four temperamental dimensions: harm avoidance, reward dependence, novelty seeking, and persistence.

RESULTS

At baseline, the harm avoidance scores of the dysthymic subjects were approximately 1.5 standard deviations higher than those of a previously reported community sample. After treatment, there was a significant decrease in harm avoidance scores, with no significant between-group differences. Remission of dysthymia was associated with significantly greater improvement in harm avoidance, with the greatest numerical change found in the patients treated with sertraline. Subjects' Tridimensional Personality Questionnaire scores were correlated at a 0.50 level with the Social Adjustment Scale both pre- and posttreatment, suggesting that a high degree of harm avoidance may be associated with poor social functioning.

CONCLUSIONS

Before treatment, chronically depressed patients demonstrate an abnormality in temperament, as measured by elevated degrees of harm avoidance. Remission of dysthymia is associated with improvement in this aspect of temperament.