Possible association between maternal recurrent orofacial herpes in pregnancy and a lower rate of preterm birth

Objective.?To study the possible association between orofacial herpes during pregnancy and pregnancy complications including preterm birth and low birth weight, since the results of previous studies are inconsistent.

Method.?The population-based large data set of the Hungarian Case-Control Surveillance System of Congenital Abnormalities was used; pregnancies in mothers with and without recurrent orofacial herpes were compared.

Results.?Of 38 151 newborn infants, 572 (1.5%) had mothers with recurrent orofacial herpes during pregnancy, while 37 577 had mothers with no orofacial herpes. Pregnant women with recurrent orofacial herpes had a higher prevalence of severe nausea and vomiting, threatened preterm delivery, and placental disorders but a lower prevalence of preeclampsia. Mothers with recurrent orofacial herpes during pregnancy also had a somewhat longer (0.4 weeks) gestation (adjusted t = 2.7; p = 0.006) and an obviously lower proportion of preterm births (3.5% vs. 9.3%; adjusted POR with 95% CI = 0.42, 0.27–0.65). However, there was no significant difference in the mean birth weight and rate of low birth weight infants between the two study groups.

Conclusion.?Recurrent orofacial herpes during pregnancy is associated with a smaller proportion of preterm births.     

Statistical validation based on parametric receiver operating characteristic analysis of continuous classification data

Rationale and Objectives. The accuracy of diagnostic test and imaging segmentation is important in clinical practice because it has a direct impact on therapeutic planning. Statistical validations of classification accuracy was conducted based on parametric receiver operating characteristic analysis, illustrated on three radiologic examples.

Materials and Methods. Two parametric models were developed for diagnostic or imaging data. Example 1: A semi-automated fractional segmentation algorithm was applied to magnetic resonance imaging of nine cases of brain tumors. The tumor and background pixel data were assumed to have bi-beta distributions. Fractional segmentation was validated against an estimated composite pixel-wise gold standard based on multi-reader manual segmentations. Example 2: The predictive value of 100 cases of spiral computed tomography of ureteral stone sizes, distributed as bi-normal after a nonlinear transformation, under two treatment options received. Example 3: One hundred eighty cases had prostate-specific antigen levels measured in a prospective clinical trial. Radical prostatectomy was performed in all to provide a binary gold standard of local and advanced cancer stages. Prostate-specific antigen level was transformed and modeled by bi-normal distributions. In all examples, areas under the receiver operating characteristic curves were computed.

Results. The areas under the receiver operating characteristic curves were: Example 1: Fractional segmentation of magnetic resonance imaging of brain tumors: meningiomas (0.924–0.984); astrocytomas (0.786–0.986); and other low-grade gliomas (0.896–0.983). Example 3: Ureteral stone size for treatment planning (0.813). Example 2: Prostate-specific antigen for staging prostate cancer (0.768).

Conclusion. All clinical examples yielded fair to excellent accuracy. The validation metric area under the receiver operating characteristic curves may be generalized to evaluating the performances of several continuous classifiers related to imaging.     

Only Hyperuricemia with Crystalluria,but not Asymptomatic Hyperuricemia,Drives Progression of Chronic Kidney Disease

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Comparison of single-shot echo-planar and line scan protocols for diffusion tensor imaging

RATIONALE AND OBJECTIVES: Both single-shot diffusion-weighted echo-planar imaging (EPI) and line scan diffusion imaging (LSDI) can be used to obtain magnetic resonance diffusion tensor data and to calculate directionally invariant diffusion anisotropy indices, ie, indirect measures of the organization and coherence of white matter fibers in the brain. To date, there has been no comparison of EPI and LSDI. Because EPI is the most commonly used technique for acquiring diffusion tensor data, it is important to understand the limitations and advantages of LSDI relative to EPI. MATERIALS AND METHODS: Five healthy volunteers underwent EPI and LSDI diffusion on a 1.5 Tesla magnet (General Electric Medical Systems, Milwaukee, WI). Four-mm thick coronal sections, covering the entire brain, were obtained. In addition, one subject was tested with both sequences over four sessions. For each image voxel, eigenvectors and eigenvalues of the diffusion tensor were calculated, and fractional anisotropy (FA) was derived. Several regions of interest were delineated, and for each, mean FA and estimated mean standard deviation were calculated and compared. RESULTS: Results showed no significant differences between EPI and LSDI for mean FA for the five subjects. When intersession reproducibility for one subject was evaluated, there was a significant difference between EPI and LSDI in FA for the corpus callosum and the right uncinate fasciculus. Moreover, errors associated with each FA measure were larger for EPI than for LSDI. CONCLUSION: Results indicate that both EPI- and LSDI-derived FA measures are sufficiently robust. However, when higher accuracy is needed, LSDI provides smaller error and smaller inter-subject and inter-session variability than EPI.     

Subcellular Biochemical Investigation of Purkinje Neurons Using Synchrotron Radiation Fourier Transform Infrared Spectroscopic Imaging with a Focal Plane Array Detector

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Biexponential diffusion tensor analysis of human brain diffusion data.

Several studies have shown that in tissues over an extended range of b-factors, the signal decay deviates significantly from the basic monoexponential model. The true nature of this departure has to date not been identified. For the current study, line scan diffusion images of brain suitable for biexponential diffusion tensor analysis were acquired in normal subjects on a clinical MR system. For each of six noncollinear directions, 32 images with b-factors ranging from 5 to 5000 s/mm2 were collected. Biexponential fits yielded parameter maps for a fast and a slow diffusion component. A subset of the diffusion data, consisting of the images obtained at the conventional range of b-factors between 5 and 972 s/mm2, was used for monoexponential diffusion tensor analysis. Fractional anisotropy (FA) of the fast-diffusion component and the monoexponential fit exhibited no significant difference. FA of the slow-diffusion biexponential component was significantly higher, particularly in areas of lower fiber density. The principal diffusion directions for the two biexponential components and the monoexponential solution were largely the same and in agreement with known fiber tracts. The second and third diffusion eigenvector directions also appeared to be aligned, but they exhibited significant deviations in localized areas.     

500-element ultrasound phased array system for noninvasive focal surgery of the brain: a preliminary rabbit study with ex vivo human skulls.

The aim of this study was to test a prototype MRI-compatible focused ultrasound phased array system for trans-skull brain tissue ablation. Rabbit thigh muscle and brain were sonicated with a prototype, hemispherical 500-element ultrasound phased array operating at frequencies of 700-800 kHz. An ex vivo human skull sample was placed between the array and the animal tissue. The temperature elevation during 20-30-sec sonications was monitored using MRI thermometry. The induced focal lesions were observed in T2 and contrast-enhanced T1-weighted fast spin echo images. Whole brain histology evaluation was performed after the sonications. The results showed that sharp temperature elevations can be produced both in the thigh muscle and in the brain. High-power sonications (600-1080 W) produced peak temperatures up to 55 degrees C and focal lesions that were consistent with thermal tissue damage. The lesion size was found to increase with increasing peak temperature. The device was then modified to operate in the orientation that will be used in the clinic and successfully tested in phantom experiments. As a conclusion, this study demonstrates that it is possible to create ultrasound-induced lesions in vivo through a human skull under MRI guidance with this large-scale phased array.     

Comparative Evaluation of Local and International Reference Databases for Forearm Densitometry: Different Impacts on Diagnostic Decisions

Reference databases play a key role in the management of osteoporosis. The aim of this preliminary study was to compare the diagnostic consequences of using either an international or a local reference database in peripheral densitometry. For this purpose, standard curves for bone mineral density (measured by dual-energy X-ray absorptiometry at the distal and proximal forearm) were generated for healthy Hungarian men and women. In total, 303 healthy volunteers of both sexes (age range: 20–94 yr) were recruited from four osteoporosis centers. Subjects with medical conditions or taking medication affecting the bone metabolism were excluded. Bone densitometry was performed with pDEXA (Norland-Stratec, Fort Atkinson, WI) devices in each center after cross-calibration of the machines. The precision error of the forearm measurement was also determined (< 1% in vitro, and 1.2–2.5% in vivo). In females, the peak forearm density was detected in the 30–39-yr group. The density decreased by 8% per 5 yr in early postmenopausal females, and by 10% per 10 yr in late postmenopausal females. In males, the highest bone mineral density was found in the 30–39-yr group for the distal forearm, but 1 decade later for the proximal site. Subsequently, a 5% decrease in density occurred per 10 yr, except in the 8th decade, in which a 20% decrease was demonstrated. One thousand four hundred thirty-four patients with suspected osteoporosis were classified according to the forearm density T-scores using both the new Hungarian reference database and the international database provided by the manufacturer. Comparison of the results measured at the distal forearm with the two different databases led to similar outcomes. However, at the proximal site, one fifth of the female patients were reclassified from the low-density group to the normal group using the domestic normative database. An opposite difference was observed for the males: use of the Hungarian reference data resulted in 40% more men being categorized in the low-density group than when the international normal database was applied. Our results suggest that not only geographic differences, but also the reference database used, can influence the prevalence of the diagnosis of osteoporosis. Further data are currently being collected to increase the statistical power of the study.     

Sleep in spontaneous dwarf rats

Spontaneous dwarf rats (SDRs) display growth hormone (GH) deficiency due to a mutation in the GH gene. This study investigated sleep in SDRs and their somatotropic axis and compared to Sprague-Dawley rats. SDRs had almost undetectable levels of plasma GH. Hypothalamic GH-releasing hormone (GHRH) mRNA was increased, whereas GHRH-receptor (GHRH-R) and somatostatin mRNAs were decreased in SDRs. Hypothalamic GHRH and somatostatin peptide content decreased in SDRs. Quantitative immunohistochemistry for GHRH and GHRH-R corroborated and extended these findings. In the arcuate nucleus, the number of GHRH-positive cells was significantly higher, whereas GHRH-R-positive perikarya were diminished in SDRs. Cortical GHRH and GHRH-R measurements showed similar expression characteristics as those found in the hypothalamus. SDRs had less rapid eye movement sleep (REMS) and more non-REMS (NREMS) than the control rats during the light period. The electroencephalogram (EEG) delta and theta power decreased during NREMS in the SDRs. After 4-h of sleep deprivation, SDRs had a significantly reduced REMS rebound compared to the controls, whereas NREMS rebound was normal in SDRs. The enhancement in delta power was significantly less than in the control group during recovery sleep. Intracerebroventricular (icv) administration of GHRH promoted NREMS in both strains of rats; however, increased REMS and EEG delta activity was observed only in control rats. Icv injection of insulin-like growth factor 1 increased NREMS in control rats, but not in the SDRs. These results support the ideas that GHRH is involved in NREMS regulation and that GH is involved in the regulation of REMS and in EEG slow wave activity regulation during NREMS.     

Apolipoprotein A5 gene promoter region T-1131C polymorphism associates with elevated circulating triglyceride levels and confers susceptibility for development of ischemic stroke

The possible pathogenic role of triglycerides (TG) in the development of ischemic stroke is still under extensive investigation. Recently, apolipoprotein (apo)A5 gene promoter region T-1131C polymorphism has been shown to associate with elevated serum TG levels. In the current work, a total of 302 subjects were classified as being large vessel-associated, small vessel-associated, or belonging to a mixed group of ischemic stroke-affected patients. The level of TG was increased in all groups (p<0.01). The apoA5-1131C allele frequency was approximately twofold in all groups of stroke patients compared with the controls (5 vs 10–12%; p<0.05); and the apoA5-1131C allele itself was also found to associate with increased TG levels in all groups. In a multivariate logistic regression analysis model adjusted for differences in age, gender, serum cholesterol, hypertension, pressence of diabetes mellitus, smoking and drinking habits, and ischemic heart disease, a significantly increased risk of developing stroke disease was found in patients carrying the apoA5-1131C allele (p<0.05; odds ratio OR=2.1 [1.3–4.7]); this association was also proven for all subtypes of the stroke. The results presented here suggest that the apoA5-1131C allele is an independent risk factor for the development of stroke. Being that apoA5 gene is under the control of the peroxisome proliferator-activated receptor α, theoretically, the current observations also can have long-term therapeutic consequences.