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Insomnia is the most prevalent sleep disorder, particularly among middle and older aged adults, and is associated with a variety of negative health consequences, including higher risk for cardiovascular disease. Unfortunately, the mechanisms linking insomnia with cardiovascular risk remain largely unknown, thus limiting targeted therapeutic interventions. The hyperarousal hypothesis has attracted the most support, positing that insomnia is a result of multisystem over-activation, including sympathetic hyperactivity, which promotes wakefulness and blocks the occurrence of sleep at the desired time. The results from literature in support of this hypothesis are inconclusive and mainly relay on studies that used methods to assess sympathetic activity lacking in specificity and reproducibility. The present review aims at summarizing the primary findings on autonomic nervous system regulation in insomnia while highlighting the advantages and limitations of the methods mainly used to support the increase in sympathetic function in insomnia. Collectively, this review aims to provide novel perspectives on conceptualizing insomnia and suggest innovative approaches to help elucidate the relationship between insomnia and autonomic nervous system activity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Physiological adaptations to exercise training are well recognized and contribute importantly to health and fitness. Cardiovascular diseases, such as hypertension and heart failure, are often associated with elevated activity of the sympathetic nervous system. This review aims to provide comprehensive overview on the role of exercise training on muscle sympathetic nerve activity (MSNA) regulation in humans, with a focus on recent advances in at-risk populations. Collectively, these studies converge to demonstrate that aerobic exercise training reduces resting MSNA in populations at heightened cardiovascular risk, but do not appear to alter resting MSNA in healthy adults. We provide directions for future research which might address gaps in our knowledge regarding sympathoneural adaptations to exercise training., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The menstrual cycle has been reported to alter mean arterial pressure (MAP), but not muscle sympathetic nerve activity (MSNA), during vestibular activation. Specifically, MAP responses to head-down rotation (HDR) are augmented during the mid-luteal (ML) phase compared to the early follicular (EF) phase in young, eumenorrheic women. The purpose of the present study was to determine if the menstrual cycle influences vestibular-mediated changes in limb blood flow. MSNA, MAP, heart rate, and limb blood flow responses to HDR were measured in 12 healthy women. Resting MSNA, MAP, heart rate, forearm blood flow and calf blood flow were not altered by the menstrual cycle. HDR elicited similar increases in MSNA during the EF (Delta3+/-1 bursts/min; P<0.05) and ML (Delta2+/-1 bursts/min; P<0.05) phase, but only increased MAP during the ML phase (Delta4+/-2 mmHg; P<0.05). HDR did not change heart rate during either the EF or ML phase. HDR elicited similar increases in calf vascular resistance during the EF (Delta6+/-2 mmHg/mL/100 mL/min; P<0.05) and ML (Delta7+/-2 mmHg/mL/100mL/min; P<0.05) phases of the menstrual cycle. In contrast, HDR increased forearm vascular resistance during the ML phase (Delta4+/-2 mmHg/mL/100mL/min; P<0.05), but not the EF phase (Delta0+/-2 mmHg/mL/100mL/min). These findings suggest an increased transduction of sympathetic nerve activity into forearm vascular resistance during the ML phase, and reveal the first recorded divergent vascular response to vestibular excitation in human limbs., (2009 Elsevier B.V. All rights reserved.)

With the multitude of new chemicals being synthesized and the paucity of long-term test data on chemicals that could be introduced into the environment, innovative approaches must be developed to determine the health and environmental effects of chemicals. Research was conducted to employ quantitative structure-activity relationship (QSAR) techniques to study the feasibility of developing models to estimate the noncarcinogenic toxicity of chemicals that are not addressed in the literature by relevant studies. A database of lowest-observed-adverse effect level (LOAEL) was assembled by extracting toxicity information from 104 U.S. EPA documents, 124 National Cancer Institute/National Toxicology Program (NCI/NTP) reports, and 6 current reports from the literature. A regression model, based on 234 chemicals of diverse structures and chemical classes including both alicyclic and aromatic compounds, was developed to assess the chronic oral LOAELs in rats. The model was incorporated into an automated computer package. Initial testing of this model indicates it has application to a wide range of chemicals. For about 55% of the compounds in the data set, the estimated LOAELs are within a factor of 2 of the observed LOAELs. For over 93%, they are within a factor of 5. Because of the paucity or absence of long-term toxicity data, the public health and risk assessment community could utilize such QSAR models to determine initial estimates of toxicity for the ever-increasing numbers of chemicals that lack complete pertinent data. However, this and other such models should be used only by expert toxicologists who must objectively look at the estimates thus generated in light of the overall weight of evidence of the available toxicologic information of the subject chemical(s).

Objectives: Our purpose was to investigate the blood flow characteristics of benign and malignant ovarian tumors. Questions posed by our research were as follows: (1) Can malignant ovarian tumors be predicted by color flow Doppler imaging? (2) What are the sensitivity, specificity, and positive and negative predictive values of such prediction? (3) Which color flow Doppler parameter is superior in its accuracy of prediction?, Study Design: One hundred twenty-three consecutive patients seen for suspected pelvic masses were evaluated by transvaginal ultrasonography and color flow Doppler imaging. A morphologic assessment was initially performed, followed by color flow Doppler analysis. A comparison of findings between the benign and malignant tumors was made by analyzing different thresholds of the intratumoral pulsatility and resistance index values by means of receiver-operator characteristic curves. By calculation of the area index under each receiver-operator characteristic curve the efficiency of the pulsatility and resistance index values in predicting malignancy was determined., Results: Fifty-six benign and 23 malignant tumors were pathologically confirmed. Patients with malignant tumors were more likely to be postmenopausal and were older than patients with benign tumors. Malignant tumors were more likely to be larger and to have either a complex or solid pattern. Absent color flow was more common in benign tumors, and increased color flow was found equally among benign and malignant tumors. There was no difference in systolic, diastolic, or mean velocities between benign and malignant tumors. The calculated pulsatility and resistance index values were lower in patients with malignant tumors compared with those with benign tumors. No significant difference exists in performance of either the pulsatility or resistance index in predicting malignancy. The best thresholds for predicting malignancy were obtained with a pulsatility index of 1.0 and resistance index of 0.6., Conclusions: Transvaginal ultrasonography is accurate in distinguishing benign from malignant ovarian tumors. Color flow Doppler findings are not specific enough to be used independent of gray-scale ultrasonography.

We report the clinicopathologic findings in two cases of chondrosarcoma of the small bones of the hand arising from a preexisting solitary enchondroma. A critical review of the previously reported 18 cases shows that only one is actually well-documented.

Multiple neurilemomas in two patients show that these tumors may indeed be multiple, may involve the same nerve trunk, may occur over a period of years, and may involve different regions of the body. Twelve neurilemomas were removed from the right upper extremity of a patient over a 3-year period. They varied in size from 0.5 cm to 4 cm in diameter and had the typical histopathologic appearance of neurilemomas. The second patient had median nerve compression and at operation a neurilemoma was found compressing the nerve. Two years later, the patient had evidence of median nerve compression in the opposite extremity, and again a neurilemoma was found. Both of these patients had evidence of peripheral nerve compression, but the existence of multiple neurilemomas was not apparent on initial examination. These cases show that patients with neurilemomas may have additional sequential tumors discovered at a later date that were not apparent initially.

An enzyme has been found in particulate fractions of Escherichia coli that catalyzes the incorporation of cytidine triphosphate (CTP) into lipid in the presence of exogenous phosphatidic acid and Mg(++). The product has been identified enzymatically and by chromatography as cytidine diphosphate diglyceride. The reaction is optimal at a pH of 6.5 and Mg(++) concentration of 5-10 mm. The apparent K(m) for CTP is 7 x 10(-4)M and for phosphatidic acid, 2 x 10(-3)M. The reaction rate falls off rapidly with time and ceases entirely after 1 hr as the result of inactivation of the system by Mg(++).

Evidence is presented for the enzymatic formation of cytidine diphosphate diglyceride in microsomal preparations from guinea pig liver according to the reaction: CTP + phosphatidic acid right harpoon over left harpoon CDP-diglyceride + p-O-P. Conditions have been found in which the incorporation of labeled CTP into CDP-diglyceride is almost entirely dependent upon added phosphatidic acid. The incorporation of CMP into lipid is very slight. A substantial net synthesis of CDP-diglyceride takes place under these conditions. Some properties of the enzyme system are described.