0461 Blunted Baroreflex Sensitivity and Reduced Morning Parasympathetic Activity in Sleep-Onset Insomnia

Introduction

Insomnia is a risk factor for hypertension and cardiovascular events, and this association is strongest for sleep-onset insomnia. However, little is known about insomnia on cardiovascular modulation, especially soon after morning awakening, the peak period of time for cardiovascular incidents. This study explored morning cardiovascular function in individuals with sleep-onset insomnia by analysing heart rate variability, blood pressure variability, and baroreflex sensitivity.

Methods

Sleep structure of the participants (15 good sleepers and 13 individuals with sleep-onset insomnia) was measured by laboratory polysomnography, followed by continuous recordings of the participant’s blood pressure and heart rate for 10 min in the morning.

Results

When compared to the good sleepers, the insomnia group showed significant reductions in total sleep time, a longer sleep-onset latency, and reduced sleep efficiency. The sleep structure, including durations of sleep stages, numbers of awakenings and arousal index did not differ between the groups. After morning awakening (averaged time: 12.33 ± 10.48 min), the shorter R-R intervals, lower total power, and lower high-frequency power of heart rate variability were observed among individuals with sleep-onset insomnia, compared with good sleepers. Elevated slopes of systolic and diastolic blood pressure, as well as lower baroreflex sensitivity, were also shown in the insomnia group. Indices of sympathetic activity, including low-frequency percentage of heart rate variability or low-frequency power of blood pressure variability, did not differ between the groups.

Conclusion

Weak vagal activity and blunted baroreflex sensitivity were evident among sleep-onset insomnia. These findings indicate difficulty in initiating sleep, without significant sleep fragmentation, can independently affect morning cardiovascular function. This study provides a possible link between sleep-onset insomnia and risk of cardiovascular events.

Support

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Advocacy, communication, and partnerships: Mobilizing for effective, widespread cervical cancer prevention

Both human papillomavirus (HPV) vaccination and screening/treatment are relatively simple and inexpensive to implement at all resource levels, and cervical cancer screening has been acknowledged as a "best buy" by the WHO. However, coverage with these interventions is low where they are needed most. Failure to launch or expand cervical cancer prevention programs is by and large due to the absence of dedicated funding, along with a lack of recognition of the urgent need to update policies that can hinder access to services. Clear and sustained communication, robust advocacy, and strategic partnerships are needed to inspire national governments and international bodies to action, including identifying and allocating sustainable program resources. There is significant momentum for expanding coverage of HPV vaccination and screening/preventive treatment in low-resource settings as evidenced by new global partnerships espousing this goal, and the participation of groups that previously had not focused on this critical health issue.

When β-cells fail: lessons from dedifferentiation

Diabetes is caused by a combination of impaired responsiveness to insulin and reduced production of insulin by the pancreas. Until recently, the decline of insulin production had been ascribed to β-cell death. But recent research has shown that β-cells do not die in diabetes, but undergo a silencing process, termed "dedifferentiation." The main implication of this discovery is that β-cells can be revived by appropriate treatments. We have shown that mitochondrial abnormalities are a key step in the progression of β-cell dysfunction towards dedifferentiation. In normal β-cells, mitochondria generate energy required to sustain insulin production and its finely timed release in response to the body's nutritional status. A normal β-cell can adapt its mitochondrial fuel source based on substrate availability, a concept known as "metabolic flexibility." This capability is the first casualty in the progress of β-cell failure. β-Cells lose the ability to select the right fuel for mitochondrial energy production. Mitochondria become overloaded, and accumulate by-products derived from incomplete fuel utilization. Energy production stalls, and insulin production drops, setting the stage for dedifferentiation. The ultimate goal of these investigations is to explore novel treatment paradigms that will benefit people with diabetes.

Correlating precursory declines in groundwater radon with earthquake magnitude

Both studies at the Antung hot spring in eastern Taiwan and at the Paihe spring in southern Taiwan confirm that groundwater radon can be a consistent tracer for strain changes in the crust preceding an earthquake when observed in a low-porosity fractured aquifer surrounded by a ductile formation. Recurrent anomalous declines in groundwater radon were observed at the Antung D1 monitoring well in eastern Taiwan prior to the five earthquakes of magnitude (Mw ): 6.8, 6.1, 5.9, 5.4, and 5.0 that occurred on December 10, 2003; April 1, 2006; April 15, 2006; February 17, 2008; and July 12, 2011, respectively. For earthquakes occurring on the longitudinal valley fault in eastern Taiwan, the observed radon minima decrease as the earthquake magnitude increases. The above correlation has been proven to be useful for early warning local large earthquakes. In southern Taiwan, radon anomalous declines prior to the 2010 Mw 6.3 Jiasian, 2012 Mw 5.9 Wutai, and 2012 ML 5.4 Kaohsiung earthquakes were also recorded at the Paihe spring. For earthquakes occurring on different faults in southern Taiwan, the correlation between the observed radon minima and the earthquake magnitude is not yet possible.

Cardiac myocyte exosomes: stability, HSP60, and proteomics

Exosomes, which are 50- to 100-nm-diameter lipid vesicles, have been implicated in intercellular communication, including transmitting malignancy, and as a way for viral particles to evade detection while spreading to new cells. Previously, we demonstrated that adult cardiac myocytes release heat shock protein (HSP)60 in exosomes. Extracellular HSP60, when not in exosomes, causes cardiac myocyte apoptosis via the activation of Toll-like receptor 4. Thus, release of HSP60 from exosomes would be damaging to the surrounding cardiac myocytes. We hypothesized that 1) pathological changes in the environment, such as fever, change in pH, or ethanol consumption, would increase exosome permeability; 2) different exosome inducers would result in different exosomal protein content; 3) ethanol at "physiological" concentrations would cause exosome release; and 4) ROS production is an underlying mechanism of increased exosome production. We found the following: first, exosomes retained their protein cargo under different physiological/pathological conditions, based on Western blot analyses. Second, mass spectrometry demonstrated that the protein content of cardiac exosomes differed significantly from other types of exosomes in the literature and contained cytosolic, sarcomeric, and mitochondrial proteins. Third, ethanol did not affect exosome stability but greatly increased the production of exosomes by cardiac myocytes. Fourth, ethanol- and hypoxia/reoxygenation-derived exosomes had different protein content. Finally, ROS inhibition reduced exosome production but did not completely inhibit it. In conclusion, exosomal protein content is influenced by the cell source and stimulus for exosome formation. ROS stimulate exosome production. The functions of exosomes remain to be fully elucidated.

Ion source and low energy injection line for a central region model cyclotron

At CIAE, a 100 MeV H(-) cyclotron (CYCIAE-100) is under design and construction. A central region model (CRM) cyclotron was built for various experimental verifications for the CYCIAE-100 project and for research and development of high current injection to accelerate milliampere H(-) beam. The H(-) multicusp source built in 2003 has been improved recently to make the source operation more stable. A new injection line for axial low energy high current injection has been designed and constructed for the CRM cyclotron.

18. INCREASING ACCESS TO SEXUAL HEALTH ADVICE FOR HIGH RISK INDIVIDUALS THROUGH AN AUTOMATED, INTERNET BASED SERVICE

Objective: It may be difficult for young people to know if they need testing for sexually transmitted infections and some primary care physicians may be unsure about what tests to order for patients with different risk profiles. Our aim was to help overcome these barriers by implementing an automated, internet based service that allowed internet users to receive specific recommendations for STI screening based on their online responses to a series of questions relating to their recent sexual practices ('Check Your Risk' (CYR), available at: www.mshc.org.au). This study evaluated this service and compared the risk profile of individuals using CYR with that of patients attending a sexual health centre in the same city over the same time period. Methods: An automated and individualised web based algorithm was developed using current recommendations for STI testing. The characteristics of individuals visiting CYR were compared to those attending the Melbourne Sexual Health Centre (MSHC) for the first time over the same 6 month period, from January to June 2006. Results: There were 2492 (59% men, 41% women) who visited the CYR online service and 2735 (59% men, 41% women) who attended the MSHC over the period. 513 (22%) of the men visiting CYR and 467 (18%) of the men visiting MSHC reported sex with other men, with a median of 6 (SD 26.4) and 6 (SD 29.4) partners in the previous 12 months respectively (p�=�0.9). 43 (1.8%) of the women visiting CYR and 54 (2.1%) of the women visiting MSHC reported sex with other women, with a median of 1 (SD 9.3) and 1 (SD 2.1) partners in the previous 12 months respectively (p�=�0.5). Among men reporting sex with women only, the median number of female sex partners in the preceding 12 months was 2 (SD 10.6) and 3 (SD 5.8) for those visiting CYR and MSHC respectively (p�=�0.8). For women reporting sex with men only, the median number of male partners was 2 (SD 11.1) and 2 (SD 4) for those visiting CYR and MSHC respectively (p�=�0.03). Participants responded favourably to the CYR online service, with 70% rating it as 'useful'; or 'very useful'. Conclusions: This internet based sexual risk assessment tool was accessed frequently by individuals with a high risk profile that was similar to those who attended the sexual health service in the same city. The CYR service cost A$4000 to set up. CYR effectively increased the outreach of the centre's services substantially, via the internet and was given a positive rating by the majority of its users.

A phase I study of the VEGF receptor tyrosine kinase inhibitor vatalanib (PTK787/ZK 222584) and gemcitabine in patients with advanced pancreatic cancer

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Background: The VEGF pathway is the predominant mediator of angiogenesis in pancreatic cancer. Vatalanib (PTK787/ZK 222584) is a small molecule tyrosine kinase inhibitor of all known VEGF receptors. We initiated a phase I study of vatalanib and gemcitabine for advanced pancreatic cancer. Methods: Patients with newly diagnosed unresectable or metastatic pancreatic adenocarcinoma were enrolled. Previous adjuvant chemoradiotherapy with fluorouracil was allowed. Gemcitabine was given by fixed-dose rate infusion weekly x 3 in a 28-day cycle, and vatalanib was given orally daily. Dose-limiting toxicities (DLT) are defined as any grade 3/4 toxicity during the first cycle. The dose levels are as follows: Results: To date, 11 patients are evaluable for toxicity (5M/6F; median age 62 years, range 40–82 years; median KPS 90%). Thus far, 42 cycles have been given, with a median of four cycles per patient. Two patients have experienced DLT. The first patient (cohort 1) experienced grade 3 diarrhea and hypokalemia and grade 4 neutropenia occurring simultaneously and treated without sequelae. The second patient (cohort 3) developed grade 3 deep vein thrombosis. Beyond the first cycle, grade 3 toxicities included neutropenia (1), anemia (3), thrombocytopenia (1), hypertension (2), diarrhea (1), hypokalemia (1), thrombosis (1), and proteinuria (1). Three of eleven patients (27%) did not complete treatment to the first evaluation timepoint (2 cycles); two discontinued due to toxicity and one discontinued due to disease progression. Two of eleven patients (18%) had a partial response by RECIST. Six of eleven patients (55%) had stable disease as the best response ranging from 2–6 months. Conclusions: The combination of gemcitabine and vatalanib is generally well-tolerated with most grade 3/4 toxicities occurring late in the treatment course. Antitumor responses have been observed at initial dose levels and accrual to the final cohort with BID dosing of vatalanib continues.

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No significant financial relationships to disclose.