Cardiac responses to 24 hrs hyperoxia in Bmp2 and Bmp4 heterozygous mice.

BACKGROUND: Hyperoxia or clinical oxygen (O2) therapy is known to result in increased oxidative burden. Therefore, understanding susceptibility to hyperoxia exposure is clinically important. Bone morphogenetic proteins (BMPs) 2 and 4 are involved in cardiac development and may influence responses to hyperoxia. METHODS: Bmp2(+/)(-). Bmp4(+/)(-) and wild-type mice were exposed to hyperoxia (100% O2) for 24 hrs. Electrocardiograms (ECG) were recorded before and during exposure by radio-telemetry. RESULTS: At baseline, a significantly higher low frequency (LF) and total power (TP) heart rate variability (HRV) were found in Bmp2(+/)(-) mice only (p < 0.05). Twenty-four hours hyperoxia-induced strain-independent reductions in heart rate, QTcB and ST-interval and increases in QRS, LF HRV and standard deviation of RR-intervals were observed. In Bmp4(+/)(-) mice only, increased PR-interval (PR-I) (24 hrs), P-wave duration (P-d; 18 and 21-24 hrs), PR-I minus P-d (PR - Pd; 24 hrs) and root of the mean squared differences of successive RR-intervals (24 hrs) were found during hyperoxia (p < 0.05). DISCUSSION: Elevated baseline LF and TP HRV in Bmp2(+/)(-) mice suggests an altered autonomic nervous system regulation of cardiac function in these mice. However, this was not related to strain specific differences in responses to 24 hrs hyperoxia. During hyperoxia, Bmp4(+/-) mice were the most susceptible in terms of atrioventricular conduction changes and risk of atrial fibrillation, which may have important implications for patients treated with O2 who also harbor Bmp4 mutations. This study demonstrates significant ECG and HRV responses to 24 hrs hyperoxia in mice, which highlights the need to further work on the genetic mechanisms associated with cardiac susceptibility to hyperoxia.

Physical mapping of the serotonin 5-HT(7) receptor gene (HTR7) to chromosome 10 and pseudogene (HTR7P) to chromosome 12, and testing of linkage disequilibrium between HTR7 and autistic disorder.

The gene encoding the serotonin 5-HT(7) receptor (HTR7) has been considered as a candidate locus in several neuropsychiatric disorders, based on pharmacological evidence and ligand-binding studies. After determining over 3 kb of previously unpublished sequence from introns 1 and 2 of HTR7, a single base (C/T) polymorphism in the second intron of HTR7 was found. Allele-specific PCR was used to genotype the HTR7 marker in 53 trios consisting of subjects with autistic disorder and both parents. Using the transmission disequilibrium test (TDT), no evidence of preferential transmission of either allele was found (TDT chi(2) = 0.252, p = 0.602). Sequence data obtained from both intron 1 and intron 2 of HTR7, and from the 5-HT(7) pseudogene (HTR7P), was used to confirm localization of HTR7 to 10q23 and HTR7P to 12p13 using radiation hybrid analyses.

Orbital fractures in women due to sexual assault and domestic violence.

PURPOSE: Because domestic violence and sexual assault have a widespread societal and medical impact, this retrospective study was designed to determine the frequency of sexual assault and domestic violence as causes of orbital fractures in women. METHODS: The records of 54 consecutive patients with orbital fractures presenting to the Ophthalmic Plastic and Orbital Surgery service of Penn State University's Department of Ophthalmology were reviewed. The type of trauma resulting in each patient's orbital injury was identified. The frequency of orbital fractures resulting from sexual assault or domestic violence was determined. RESULTS: The study included 35 male and 19 female patients, ranging in age from 27 months to 63 years. Orbital fracture was the result of sexual assault or domestic violence in one third of the female patients, but no male patients. Motor vehicle accidents accounted for another 31.6 percent of orbital fractures in female patients. CONCLUSIONS: Based on this retrospective study, sexual assault and domestic violence are frequent causes of orbital fractures in women. Healthcare workers evaluating female patients with orbital fractures should have a high index of suspicion regarding sexual assault or domestic violence as a possible origin of the injury. A pointed but sensitive approach may be necessary to elicit this history from the patient.

A psychophysical comparison of two methods for adaptive histogram equalization.

Adaptive histogram equalization (AHE) is a method for adaptive contrast enhancement of digital images. It is an automatic, reproducible method for the simultaneous viewing of contrast within a digital image with a large dynamic range. Recent experiments have shown that in specific cases, there is no significant difference in the ability of AHE and linear intensity windowing to display gray-scale contrast. More recently, a variant of AHE which limits the allowed contrast enhancement of the image has been proposed. This contrast-limited adaptive histogram equalization (CLAHE) produces images in which the noise content of an image is not excessively enhanced, but in which sufficient contrast is provided for the visualization of structures within the image. Images processed with CLAHE have a more natural appearance and facilitate the comparison of different areas of an image. However, the reduced contrast enhancement of CLAHE may hinder the ability of an observer to detect the presence of some significant gray-scale contrast. In this report, a psychophysical observer experiment was performed to determine if there is a significant difference in the ability of AHE and CLAHE to depict gray-scale contrast. Observers were presented with computed tomography (CT) images of the chest processed with AHE and CLAHE. Subtle artificial lesions were introduced into some images. The observers were asked to rate their confidence regarding the presence of the lesions; this rating-scale data was analyzed using receiver operating characteristic (ROC) curve techniques. These ROC curves were compared for significant differences in the observers' performances. In this report, no difference was found in the abilities of AHE and CLAHE to depict contrast information.