Association of comorbid obstructive sleep apnea and insomnia with risk of major adverse cardiovascular events in sleep medicine center patients

OBJECTIVES

To investigate the association between comorbid obstructive sleep apnea and insomnia and major adverse cardiovascular events, including myocardial infarction, unstable angina, congestive heart failure, and stroke, in adults with suspected sleep disorders who underwent sleep apnea testing.

METHODS

We conducted a retrospective analysis of electronic medical records data from patients with clinical encounters at sleep medicine centers to identify patients with comorbid obstructive sleep apnea and insomnia, obstructive sleep apnea only, insomnia only, and patients without a diagnosis of obstructive sleep apnea or insomnia (i.e., controls). Obstructive sleep apnea, insomnia, comorbidities, and new-onset major adverse cardiovascular events were ascertained by ICD-9-CM and ICD-10-CM codes. Multivariable adjusted Cox proportional regression models evaluated the risk of major adverse cardiovascular events over a 10-year follow-up period.

RESULTS

A total of 3951 patients, 226 controls, 2107 with obstructive sleep apnea only, 276 with insomnia only, and 1342 with comorbid obstructive sleep apnea and insomnia, were included in the analysis. Compared to controls, comorbid obstructive sleep apnea and insomnia were associated with a significantly higher risk of developing major adverse cardiovascular events (hazard ratio 3.60, 95 CI%: 2.33-5.91) in unadjusted analyses. The relationship between comorbid obstructive sleep apnea and insomnia and major adverse cardiovascular events remained after adjustment for demographic and behavioral factors, but not after further adjustment for comorbidities. The greatest risk of major adverse cardiovascular events was found among younger adults with comorbid obstructive sleep apnea and insomnia. Obstructive sleep apnea only was associated with greater risk of major adverse cardiovascular events in unadjusted analyses only (hazard ratio 2.77, 95% CI: 1.80-4.54). Insomnia only was not significantly associated with increased risk of major adverse cardiovascular events.

CONCLUSIONS

Comorbid obstructive sleep apnea and insomnia may be a high-risk group for major adverse cardiovascular events, particularly younger adults. Further research is needed to better understand the association between comorbid obstructive sleep apnea and insomnia and major adverse cardiovascular events risk.

Patient-level factors associated with the self-report of trouble sleeping to healthcare providers in adults at high risk for obstructive sleep apnea

INTRODUCTION

In adults at risk for obstructive sleep apnea, it is unclear what patient-level factors and symptoms may influence communication with healthcare providers regarding sleep difficulties. This analysis examined associations between sociodemographic characteristics, comorbidities, and obstructive sleep apnea-related symptoms and whether adults at high risk for obstructive sleep apnea reported trouble sleeping to an healthcare provider.

METHODS

The sample included participants from the 2015-2018 National Health and Nutrition Examination Survey determined by a modified STOP-Bang to be at high risk for obstructive sleep apnea (n = 2009). Participants were asked if they had ever reported trouble sleeping to an healthcare provider. Self-reported comorbidities and obstructive sleep apnea-related symptoms (ie, snoring, snorting, gasping, or breathing cessation during sleep, daytime sleepiness, fatigue, insomnia, and nocturia) were assessed.

RESULTS

Half of the sample (50.8%) never reported trouble sleeping to an healthcare provider. Factors associated with an increased likelihood of reporting trouble sleeping included female sex, former smoker, and prediabetes or diabetes, obstructive lung disease, daytime sleepiness, insomnia, nocturia, and symptoms of snorting, gasping, and/or breathing cessation during sleep. Factors associated with a decreased likelihood of reporting trouble sleeping included Mexican American background or Asian race and having less than a high school education.

CONCLUSION

Differences in sex, race, education, comorbidities, and obstructive sleep apnea-related symptoms exist between adults at high risk for obstructive sleep apnea who have and have not reported trouble sleeping to an healthcare provider. It is important for healthcare providers to ask all adults about sleep problems, recognizing that men, minorities, and persons with lower educational attainment may be less likely to report trouble sleeping.

Risk stratification by sex and menopausal status in the multivariable apnea prediction index

STUDY OBJECTIVES

To determine the sensitivity of the Multivariable Apnea Prediction (MAP) index for obstructive sleep apnea (OSA) in pre- and post-menopausal women with the goal of developing a tailored scoring classification approach.

METHODS

Data from two studies (N = 386); the diabetes sleep treatment trial (N = 236) and EMPOWER (N = 150) were used to assess the sensitivity and specificity of the MAP index by comparing men (n = 129) to women (n = 257), and premenopausal (n = 100) to post-menopausal women (n = 136). We evaluated participants at two cut points, apnea-hypopnea index (AHI) values of ≥ 5 and ≥ 10, using 0.5 as a predicted probability cut point to establish baseline sensitivity and specificity. Contingency tables and receiver operating characteristic (ROC) analysis were conducted to evaluate the accuracy of the MAP index in predicting OSA in men versus women, and in pre-versus post-menopausal women. To select optimal predicted probabilities for classification by sex and menopausal status, Youden's J statistic was generated from ROC coordinates.

RESULTS

The MAP index was more sensitive to women in the AHI ≥ 5 group (76%) compared to AHI ≥ 10 group (30%). Among post-menopausal women with AHI ≥ 5, sensitivity was similar to men (98%), but less than men when AHI ≥ 10 (32%). Suggested probability cut points for women with an AHI ≥ 10 are 0.24 overall; 0.15 for premenopausal, and 0.38 for postmenopausal women.

CONCLUSIONS

Because women's risk for OSA (AHI ≥ 10) was underestimated by the MAP index, we suggest the use of tailored cut points based on sex and menopausal status or assessing for OSA risk with an AHI of ≥ 5.

Nurse-led pre-test counseling for Alzheimer's disease biomarker testing: Knowledge and skills required to meet the needs of patients and families

INTRODUCTION

Biomarker testing for Alzheimer's disease and related disorders (ADRD) brings new opportunities for nurses to foster shared decision-making by leading pre-test counseling (PTC) for patients and families.

METHODS

Audio-recordings of 18 nurse-led PTC sessions were analyzed to characterize questions posed by patient and family members dyads considering whether to pursue amyloid positron emission tomography.

RESULTS

Sessions lasted 20 to 75 minutes and generated rich discussion of the purpose and potential implications of amyloid imaging. Dyads posed questions regarding: basic neuroanatomy; the spectrum of normal cognitive aging to dementia; clinical phenotypes and pathological hallmarks of ADRD; secondary prevention of ADRD; and advance planning. In response, PTC facilitators provided disease-specific education, clarification of overt misconceptions, caregiver support, and emotion de-escalation.

CONCLUSION

Nurses conducting PTC for AD biomarker testing should be equipped to answer questions about topics both directly and indirectly related to testing, and also provide emotional support.

Five-year Transitions of Symptom Subtypes in Untreated Obstructive Sleep Apnea

Objectives

It is unknown if symptom subtypes of obstructive sleep apnea (OSA) transition over time and what clinical factors may predict transitions.

Methods

Data from 2,643 participants of the Sleep Heart Health Study with complete baseline and 5-year follow-up visits were analyzed. Latent Class Analysis on 14 symptoms at baseline and follow up determined symptom subtypes. Individuals without OSA (AHI<5) were incorporated as a known class at each time point. Multinomial logistic regression assessed the effect of age, sex, body mass index (BMI) and AHI on specific class transitions.

Results

The sample consisted of 1,408 women (53.8%) and mean (SD) age 62.4 (10.5) years. We identified four OSA symptom subtypes at both baseline and follow-up visits: minimally symptomatic, disturbed sleep, moderately sleepy and excessively sleepy . Nearly half (44.2%) of the sample transitioned to a different subtype from baseline to follow-up visits; transitions to moderately sleepy were the most common (77% of all transitions). A five-year older age was associated with a 6% increase in odds to transit from excessively sleepy to moderately sleepy [OR (95% CI) = 1.06 (1.02, 1.12)]. Women had 2.35 times higher odds (95% CI: 1.27, 3.27) to transition from moderately sleepy to minimal symptoms . A 5-unit increase in BMI was associated with 2.29 greater odds (95% CI: 1.19, 4.38) to transition from minimal symptoms to excessively sleepy .

Interpretation

While over half of the sample did not transition their subtype over 5 years, among those who did, the likelihood of transitioning between subtypes was significantly associated with a higher baseline age, higher baseline BMI and with women, but was not predicted by AHI.

Clinical Trials

Sleep Heart Health Study (SHHS) Data Coordinating Center, (SHHS) https://clinicaltrials.gov/ct2/show/NCT00005275 , NCT00005275.

Statement of significance

There is very little research assessing symptom progression and its contributions to clinical heterogeneity in OSA. In a large sample with untreated OSA, we grouped common OSA symptoms into subtypes and assessed if age, sex, or BMI predicted transitions between the subtypes over 5 years. Approximately half the sample transitioned to a different symptom subtype and improvements in symptom subtype presentation were common. Women and older individuals were more likely to transition to less severe subtypes, while increased BMI predicted transition to more severe subtype. Determining whether common symptoms like disturbed sleep or excessive daytime sleepiness occur early in the course of the disease or as a result of untreated OSA over an extended period can improve clinical decisions concerning diagnosis and treatment.

Financial Hardship and its Associations with Perceived Sleep Quality in Participants with Type 2 Diabetes and Obstructive Sleep Apnea

OBJECTIVES

The purpose of this study was to explore social determinants of health (SDoH), and disease severity as predictors of sleep quality in persons with both Obstructive Sleep Apnea (OSA) and type 2 diabetes (T2D).

METHODS

Disease severity was measured by Apnea-Hypopnea Index [(AHI) ≥ 5] and HbA1c for glycemic control. SDoH included subjective and objective financial hardship, race, sex, marital status, education, and age. Sleep quality was measured by Pittsburgh Sleep Quality Index (PSQI).

RESULTS

The sample (N = 209) was middle-aged (57.6 ± 10.0); 66% White and 34% African American; and 54% men and 46% women. Participants carried a high burden of disease (mean AHI = 20.7 ± 18.1, mean HbA1c = 7.9% ± 1.7%). Disease severity was not significantly associated with sleep quality (all p >.05). Worse sleep quality was associated with both worse subjective (b = -1.54, p = .015) and objective (b = 2.58, p <.001) financial hardship. Characteristics significantly associated with both subjective and objective financial hardship included being African American, female, ≤ 2 years post high school, and of younger ages (all p < .01).Discussion: Financial hardship is a more important predictor of sleep quality than disease severity, age, sex, race, marital status, and educational attainment, in patients with OSA and T2D.

Effects of continuous positive airway pressure treatment on sleep architecture in adults with obstructive sleep apnea and type 2 diabetes

Obstructive sleep apnea (OSA) severely impacts sleep and has long-term health consequences. Treating sleep apnea with continuous positive airway pressure (CPAP) not only relieves obstructed breathing, but also improves sleep. CPAP improves sleep by reducing apnea-induced awakenings. CPAP may also improve sleep by enhancing features of sleep architecture assessed with electroencephalography (EEG) that maximize sleep depth and neuronal homeostasis, such as the slow oscillation and spindle EEG activity, and by reducing neurophysiological arousal during sleep (i.e., beta EEG activity). We examined cross-sectional differences in quantitative EEG characteristics of sleep, assessed with power spectral analysis, in 29 adults with type 2 diabetes treated with CPAP and 24 adults undergoing SHAM CPAP treatment (total n = 53). We then examined changes in spectral characteristics of sleep as the SHAM group crossed over to active CPAP treatment (n = 19). Polysomnography (PSG) from the CPAP titration night was used for the current analyses. Analyses focused on EEG frequencies associated with sleep maintenance and arousal. These included the slow oscillation (0.5–1 Hz), sigma activity (12–16 Hz, spindle activity), and beta activity (16–20 Hz) in F3, F4, C3, and C4 EEG channels. Whole night non-rapid eye movement (NREM) sleep and the first period of NREM spectral activity were examined. Age and sex were included as covariates. There were no group differences between CPAP and SHAM in spectral characteristics of sleep architecture. However, SHAM cross-over to active CPAP was associated with an increase in relative 12–16 Hz sigma activity across the whole night and a decrease in average beta activity across the whole night. Relative slow oscillation power within the first NREM period decreased with CPAP, particularly for frontal channels. Sigma and beta activity effects did not differ by channel. These findings suggest that CPAP may preferentially enhance spindle activity and mitigate neurophysiological arousal. These findings inform the neurophysiological mechanisms of improved sleep with CPAP and the utility of quantitative EEG measures of sleep as a treatment probe of improvements in neurological and physical health with CPAP.

Metabolic outcomes in adults with type 2 diabetes and sleep disorders

PURPOSE

Insomnia is frequently co-morbid with obstructive sleep apnea (OSA); the effect of insomnia or co-morbid insomnia and OSA (OSA + I) on associated metabolic outcomes in adults with type 2 diabetes (T2D) remains unclear. This study in adults with T2D compared metabolic outcomes among persons with OSA, insomnia, or OSA + I.

METHODS

This study analyzed baseline data from the Diabetes Sleep Treatment Trial of persons recruited for symptoms of OSA or poor sleep quality. Home sleep studies determined OSA presence and severity. Insomnia was evaluated using the Insomnia Severity Index. Height and weight to calculate body mass index (BMI) and blood for laboratory values were obtained. Multivariate general linear models were used to examine the impact of the type of sleep disorder and sociodemographic, lifestyle, and sleep risk factors on metabolic outcomes.

RESULTS

Participants (N = 253) were middle-aged (56.3 ± 10.5 years), white (60.5%), obese (mean BMI of 35.3 ± 7.1 kg/m²), and male (51.4%) with poor glucose control (mean HbA1c of 8.0 ± 1.8%). Most participants had OSA + I (42.7%) or insomnia only (41.0%). HbA1c and BMI differed among the sleep disorder groups. In addition, in the adjusted models, having insomnia only, compared to OSA only, was associated on average with higher HbA1c levels (b = 1.08 ± 0.40, p < 0.007) and lower BMI (b =  - 7.03 ± 1.43, p < 0.001).

CONCLUSIONS

Findings suggest that insomnia frequently co-exists with OSA, is independently associated with metabolic outcomes in adults with T2D, and should be considered in investigations of the effects of OSA in persons with T2D.

TRIAL REGISTRATION

Diabetes-Obstructive Sleep Apnea Treatment Trial (NCT01901055), https: Clinicaltrials.gov/ct2/show/NCT01901055; Registration date: July 17, 2013.

Covid-19 vaccine confidence and hesitancy in nursing students and faculty at a large academic medical center

Background

Little is known about nursing faculty and nursing student's confidence or potential hesitancy to receive the Covid-19 vaccine once it was available.

Methods

An anonymous electronic survey of nursing students and faculty was conducted at a large academic center in the eastern U.S.

Findings

Both students and faculty reported they were fairly or completely confident that the vaccine was safe (n = 235, 89.4%) and that it would effectively mitigate their risk (n = 230, 87.5%). There was a 52.6% decrease in vaccine hesitancy from 6 months prior (p <.01); 22% (n = 58) of those currently willing to receive the vaccine reported moderate to high concern about its side-effects and/or long-term efficacy. Access to vaccine research, vaccine education, and watching others be inoculated, had mitigated their concerns from the previous six months.

Discussion

While both nursing students and faculty reported having high confidence in the efficacy and safety of the Covid-19 vaccine, concerns remained.

Insomnia and Daily Function in Older Adults With Asthma

The current study examined the prevalence of insomnia and its relationship with daily function in older adults with asthma. Data on 278 older adults with asthma (aged ≥60 years) from the 2005-2008 National Health and Nutrition Examination Survey were analyzed. Insomnia was present in 40% of the study sample and was associated with a greater number of activities of daily living (ADL) and instrumental ADL (IADL) limitations. In multivariate analyses accounting for covariates including depressive symptoms, insomnia was not associated with having at least two ADL/IADL limitations. However, those with co-occurring insomnia and depressive symptoms were more likely to have at least two ADL/IADL limitations compared to those with either condition singly. Insomnia in the presence of depressive symptoms may impede one's ability to perform ADL/IADL. Current findings suggest that assessment and treatment of insomnia and depression in older adults with asthma may be important for maintaining active, independent living. [Journal of Gerontological Nursing, 46(11), 28-36.].

Sleep and Metabolic Syndrome

Metabolic syndrome (MetS) refers to the clustering of risk factors for cardiovascular disease and diabetes, including central adiposity, hypertension, dyslipidemia, and hyperglycemia. During the past 20 years, there have been parallel and epidemic increases in MetS and impaired sleep. This article describes evidence on the association between MetS and short sleep duration, circadian misalignment, insomnia, and sleep apnea. Potential mechanisms where impaired sleep desynchronizes and worsens metabolic control and interventions to improve sleep and potentially improve MetS are presented.

Gender as a principle of the organization of clinical sleep research

In 2014 the National Institutes of Health required researchers to examine sex as a biological variable. While this approach is necessary to ensure adequate and appropriate female inclusion in research studies, it puts researchers at high risk for attributing their findings to biological sex differences when instead they may be more appropriately attributed to the influence and expectations of gender. In this paper, we specify how gender works as a principle of the social organization of symptoms, experiences, research, and clinical practice using obstructive sleep apnea symptomology to illustrate these patterns. We draw from psychologist Sandra Bem's account differentiating three specific mechanisms of gender: gender polarization, androcentrism, and biological essentialism.

1056 Perceived Financial Difficulty Predicts Sleep Quality In Participants With Type 2 Diabetes And Obstructive Sleep Apnea

Introduction

People with multiple chronic conditions such as type 2 diabetes (T2D) and obstructive sleep apnea (OSA) are at increased risk for poor sleep quality. It is unclear if social determinants of health (SDoH) such as race, perceived financial difficulty, education, gender, and marital status are associated with sleep quality in this population. The purpose of this cross-sectional secondary analysis of data from the Diabetes Sleep Treatment Trial was to explore SDoH and disease severity as predictors of sleep quality in persons with both OSA and T2D.

Methods

Disease severity was measured by Apnea-Hypopnea Index [(AHI) ≥ 5] and A1C for glycemic control. SDoH included perceived financial difficulty (none/moderate-severe), race (White/African American), sex (f/m), marital status (no/yes), education (≤ or &gt; 2 years post high school), and age. Sleep quality was measured by Pittsburgh Sleep Quality Index (PSQI). Correlations and linear regression modeling investigated associations between SDoH and disease severity on sleep quality. Post-hoc correlations were explored for significant relations among SDoH.

Results

The sample (N = 229) was middle-aged (57.6 ± 10.0; 66 % White and 34% African American; and 54 % men vs. 46% women. Participants carried a high burden of disease (mean AHI = 20.7±18.1, mean A1C = 7.9 %±1.7%). Disease severity was not significantly associated with sleep quality (all p &gt;.05). The perception of worse financial difficulty was the only SDoH that predicted worse sleep quality (b=-1.54, p=.015). Characteristics significantly associated with worse financial difficulty were being African American, female, ≤ 2 years post high school, and younger (all p&lt;.01).

Conclusion

Financial difficulty may be a more important predictor of subjective measures of sleep quality than disease severity in patients with OSA and T2D. Researchers and clinicians should be aware of these characteristics as potential markers of vulnerability to poor sleep quality in this population.

Support

The National Institute of Diabetes and Digestive and Kidney Diseases (R01DK096028) and through the Clinical +Translational Research Institute grants UL1TR001857 and UL1TR000005.

Associations of sleep duration with patient-reported outcomes and health care use in US adults with asthma

BACKGROUND

Asthma contributes to considerable morbidity and health care utilization in adults. Insufficient and excessive sleep duration have known adverse effects on health. Little is known regarding the effect of sleep duration on health outcomes in adults with asthma.

OBJECTIVE

To examine associations between sleep duration, patient-reported outcomes, and health care use in adults with asthma from the National Health and Nutrition Examination Survey.

METHODS

Cross-sectional data from the 2007 to 2012 National Health and Nutrition Examination Survey were analyzed. Asthma was identified by self-report. Habitual hours of sleep duration were categorized as short (≤5), normal (6-8), and long (≥9). Multivariate regression analyses were used to examine the associations between sleep duration and patient-reported outcomes and health care use.

RESULTS

Of the 1389 adults with asthma, 26% reported short sleep duration, 66% reported normal sleep duration, and 8% reported long sleep duration. Those with short sleep duration had increased asthma attacks (adjusted odds ratio [aOR] 1.58; 95% confidence interval [CI] 1.13-2.21), coughing (aOR 1.95; 95% CI 1.32-2.87), and overnight hospitalizations (aOR 2.14; 95% CI 1.37-3.36) compared with those having normal sleep duration. They also reported worse health-related quality of life, including days of poor physical health, mental health, and inactivity because of poor health (P values < .05). Those with long sleep had more activity limitations because of wheezing compared with those with normal sleep (aOR 1.82; 95% CI 1.13-2.91).

CONCLUSION

Compared with adults having asthma and normal sleep duration, those having short sleep duration experience more frequent asthma attacks, increased health care use, and worse health-related quality of life, whereas those with long sleep duration experience more frequent activity limitation.

Correlates of Endothelial Function in Older Adults With Untreated Obstructive Sleep Apnea and Cardiovascular Disease

BACKGROUND

Obstructive sleep apnea (OSA) is a highly prevalent and consequential sleep disorder in older adults. Untreated moderate to severe OSA substantially increases the risk for hypertension and cardiovascular disease (CVD), which can be attributed to the accelerated progression of atherosclerosis and endothelial dysfunction.

OBJECTIVE

The aim of this study was to identify factors that can function as correlates of endothelial function in older adults with untreated, moderate to severe OSA and CVD or CVD risk factors.

METHODS

A subsample (N = 126) of adults aged 65 years and older from the HeartBEAT study were included in the analyses. Univariate analyses and multiple linear regression models were conducted to establish which demographic and CVD risk factors were the best correlates of endothelial function.

RESULTS

In the univariate analyses, sex, employment status, body mass index, waist circumference, hip-to-waist ratio, neck circumference, diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, total cholesterol to high-density lipoprotein cholesterol ratio, plasminogen activator inhibitor-1, calcium channel blocker use, and β-blocker use were associated with endothelial function at a level of P < .10. In the most parsimonious model, male sex (b = -0.305, P < .001), calcium channel blocker use (b = -0.148, P < .019), and body mass index (b = -.014, P < .037) were negatively associated with endothelial function after adjusting for the other covariates.

CONCLUSIONS

The authors identified correlates of endothelial function in older adults with untreated OSA and CVD or CVD risk factors, which are different than the correlates in middle-aged adults with the same conditions.

Patients' and Family Members' Subjective Experiences of a Diagnostic Evaluation of Mild Cognitive Impairment

Background:

People with a diagnosis of mild cognitive impairment (MCI) often struggle with uncertainty and fear when learning of and coping with their diagnosis. However, little is known about their experiences and perspectives, and those of their care partners, when seeking out and undergoing a diagnostic evaluation for their cognitive symptoms.

Method:

This study is a secondary analysis of a focus group discussion that was initially conducted to learn the perspectives and experiences of participants and their care partners during a mock disclosure session of brain scan results. Participant’s broader views on their experience of completing a cognitive evaluation resulting in an MCI diagnosis were evaluated in this study. Analysis used qualitative content methodology and line-by-line coding which generated categories and themes.

Results:

The (1) “presence of a threat” and (2) attempts to “minimize the threat” emerged as overarching themes driving the process of seeking out a diagnostic evaluation for cognitive symptoms. Subthemes that highlight the complexity of the presence of a threat included the “fear of stigma,” and the “emotional reactions” related to an MCI diagnosis. Three additional subthemes represented approaches that participants and their care partners used to minimize threat of MCI: “use of language” to minimize the threat; “information sharing and withholding”; and the “use of social support to legitimize personal experiences.”

Conclusion:

These findings add to the literature by elucidating the uncertainty, fears, and coping strategies that accompany a diagnostic evaluation of MCI.

Amyloid positron emission tomography candidates may focus more on benefits than risks of results disclosure

Introduction

Given mounting calls to disclose biomarker test results to research participants, we explored factors underlying decisions by patients with mild cognitive impairment to receive amyloid imaging results.

Methods

Prospective, qualitative interviews were conducted with 59 participants (30 = mild cognitive impairment patients, 29 = care partners) from the scan arm of a randomized controlled trial on the effects of amyloid PET results disclosure in an Alzheimer Disease Research Center setting.

Results

Sixty-three percent of the participants were female, with an average age of 72.9 years, and most had greater than a high school level of education (80%). Primary motivations included: (1) better understanding one's mild cognitive impairment etiology and prognosis to plan ahead, and (2) learning one's brain amyloid status for knowledge's sake, regardless of whether the information is actionable. Most participants demonstrated an adequate understanding of the scan's limitations, yet instances of characterizing amyloid PET as a definitive test for Alzheimer's disease occurred. Mention of potential drawbacks, such as negative psychological outcomes, was minimal, even among care partners.

Discussion

Findings demonstrate a risk of disproportionate focus on possible benefits of testing among amyloid scan candidates and suggest a need to clearly emphasize the limitations of amyloid PET when counseling cognitively impaired patients and their families before testing. Future research should examine whether minimizing drawbacks at the pre-imaging stage has adverse consequences on results disclosure.

Defining the osteoarthritis patient: back to the future

The history of osteoarthritis (OA) is important because it can help broaden our perspective on past and present controversies. The naming of OA, beginning with Heberden's nodes, is itself a fascinating story. According to Albert Hoffa, R. Llewellyn Jones and Archibald Edward Garrod, the name OA was introduced in the mid-nineteenth century by surgeon Richard von Volkmann who distinguished it from rheumatoid arthritis and gout. Others preferred the terms 'chronical rheumatism', 'senile arthritis', 'hypertrophic arthritis' or 'arthritis deformans'. A similar narrative applies to the concept of OA affecting the whole joint vs the 'wear-and-tear' hypothesis, inflammation and the role of the central nervous system (CNS). In the late nineteenth and early twentieth centuries, the Garrods (father and son) and Hermann Senator argued that OA was a whole joint disease, and that inflammation played a major role in its progression. Garrod Jnr and John Spender also linked OA to a neurogenic lesion 'outside the joint'. The remaining twentieth century was no less dynamic, with major advances in basic science, diagnostics, treatments, surgical interventions and technologies. Today, OA is characterized as a multi-disease with inflammation, immune and CNS dysfunction playing central roles in whole joint damage, injury progression, pain and disability. In the current 'omics' era (genomics, proteomics and metabolomics), we owe a great debt to past physicians and surgeons who dared to think 'outside-the-box' to explain and treat OA. Over 130 years later, despite these developments, we still don't fully understand the underlying complexities of OA, and we still don't have a cure.

Sex Differences in the Psychometric Properties of the Pittsburgh Sleep Quality Index

BACKGROUND

The Pittsburgh Sleep Quality Index (PSQI) is a well-known, validated, and reliable instrument used to measure the clinical construct of sleep quality. Little research has been done to measure its psychometric properties by sex. Previous researchers have established the validity of a three-factor structure, but it is unknown whether it applies to both men and women equally.

MATERIALS AND METHODS

This study examined 198 participants; women (n = 104), men (n = 94) who were participants in the Diabetes Sleep Treatment Trial, an ongoing study examining the effect of continuous positive airway pressure on glycemic control in people with type 2 diabetes. A principal components analysis with varimax rotation, scree plots, parallel analysis, and Eigenvalues confidence intervals were all computed to determine factor structure using the seven components measured in the PSQI.

RESULTS

Component one, a question about perceived sleep quality, loaded with "sleep efficiency" and "sleep duration" in men and with "daytime dysfunction" and "sleep disturbances" in women.

CONCLUSION

This study confirms a three-factor structure as previously suggested; however, "perceived sleep quality" may load differently depending on the sex being examined. This result suggests that men and women may interpret what is meant by "overall sleep quality" differently.

Effect of nocturia on next-day sedentary activity in adults with type 2 diabetes

PURPOSE

Nocturia, a common cause of disturbed sleep quality and next-day fatigue, may contribute to difficulty with diabetes self-management. The purpose of this study was to examine the effect nocturia has on next-day subjectively measured mental and physical energy and objectively measured physical activity.

METHODS

This secondary analysis utilized sleep diaries over one week which measured nocturia frequency and other sleep quality indicators (wake after sleep onset, sleep quality and sleep duration) along with next-day reports of mental and physical energy. Next-day physical activity was measured with the BodyMedia Sensewear armband.

RESULTS

Sleep quality and sleep duration were associated with next-day physical and mental energy. Nocturia frequency (≥2 times per night) was associated with increased next-day sedentary activity.

CONCLUSION

These results suggest that nocturia could negatively affect next-day physical activity in people with diabetes.

Gender Differences in the Response to Impaired Sleep in Adults with Diabetes

This study analyzed cross-sectional data to examine gender differences in the association of sleep quality and daytime sleepiness with mood and functional outcomes in adults with type 2 diabetes (T2DM). Measures included demographic and clinical data as well as scales that measured subjective daytime sleepiness, sleep quality, mood disturbances, and functional outcomes. The majority of the sample (N = 116) had poor sleep quality and was subjectively sleepy. We observed in males and females significantly different associative patterns between the predictor variables of daytime sleepiness and sleep quality and the outcome variables of mood and functional outcome. There was no significant difference in daytime sleepiness or impaired sleep quality between men and women with T2DM; however, there was a difference in the expression of impaired sleep on mood and functional outcomes between genders.

Differential expression of calcium channels in sympathetic and parasympathetic preganglionic inputs to neurons in paracervical ganglia of guinea-pigs

Neurons in pelvic ganglia receive nicotinic excitatory post-synaptic potentials (EPSPs) from sacral preganglionic neurons via the pelvic nerve, lumbar preganglionic neurons via the hypogastric nerve or both. We tested the effect of a range of calcium channel antagonists on EPSPs evoked in paracervical ganglia of female guinea-pigs after pelvic or hypogastric nerve stimulation. omega-Conotoxin GVIA (CTX GVIA, 100 nM) or the novel N-type calcium channel antagonist, CTX CVID (100 nM) reduced the amplitude of EPSPs evoked after pelvic nerve stimulation by 50-75% but had no effect on EPSPs evoked by hypogastric nerve stimulation. Combined addition of CTX GVIA and CTX CVID was no more effective than either antagonist alone. EPSPs evoked by stimulating either nerve trunk were not inhibited by the P/Q calcium channel antagonist, omega-agatoxin IVA (100 nM), nor the L-type calcium channel antagonist, nifedipine (30 microM). SNX 482 (300 nM), an antagonist at some R-type calcium channels, inhibited EPSPs after hypogastric nerve stimulation by 20% but had little effect on EPSPs after pelvic nerve stimulation. Amiloride (100 microM) inhibited EPSPs after stimulation of either trunk by 40%, while nickel (100 microM) was ineffective. CTX GVIA or CTX CVID (100 nM) also slowed the rate of action potential repolarization and reduced afterhyperpolarization amplitude in paracervical neurons. Thus, release of transmitter from the terminals of sacral preganglionic neurons is largely dependent on calcium influx through N-type calcium channels, although an unknown calcium channel which is resistant to selective antagonists also contributes to release. Release of transmitter from lumbar preganglionic neurons does not require calcium entry through either conventional N-type calcium channels or the variant CTX CVID-sensitive N-type calcium channel and seems to be mediated largely by a novel calcium channel.

CD4(+) and CD8(+) cells are key participants in the development of recurrent herpetic stromal keratitis in mice

Ocular herpes simplex virus (HSV) infection results in an immune-mediated inflammation of the corneal stroma known as herpetic stromal keratitis (HSK). Recurrent HSK is a common cause of virus-induced corneal blindness in humans. The role of CD4(+) and CD8(+) T cell subsets in the disease pathogenesis is ill defined and varies with the virus strain and host genetic background. To examine the contribution of T cell subsets to corneal disease, we studied the development of recurrent HSK in CD4 or CD8 gene knockout (KO) mice ocularly infected with HSV-1 McKrae strain. Following UV-B induced viral reactivation, corneal opacity in latently infected BALB/c (HSV sensitive) CD4 and CD8 KO mice was reduced compared to infected BALB/c mice with normal genotype. In contrast, opacity in C57BL/6 (HSV resistant) CD4 and CD8 KO latent mice did not differ from genetically normal latent mice. Virus-induced corneal opacity was not demonstrable in C57BL/6 CD4/CD8 double KO mice. Increased viral shedding, measured by reactivation rate, days shedding or viral titers, occurred in CD4 KO mice of both strains. Our findings indicate that both CD4(+) and CD8(+) cells play a role in the immunopathogenesis of recurrent HSK, and their role is dependent upon the host genetic profile.

Expression of immunoreactivity to neurokinin-1 receptor by subsets of cranial parasympathetic neurons: correlation with neuropeptides, nitric oxide synthase, and pathways

We examined the patterns of coexistence of immunoreactivity to the neurokinin-1 (NK(1)) tachykinin receptor, nitric oxide synthase, and neuropeptides in the sphenopalatine and otic ganglia of guinea pigs using a combination of multiple-labeling immunohistochemistry and pathway tracing in vitro. Most neurons had immunoreactivity to vasoactive intestinal peptide (85-96%) and neuropeptide Y (60%). Subpopulations of vasoactive intestinal peptide-immunoreactive neurons also had immunoreactivity to nitric oxide synthase (37-48%) or enkephalin (25-35%), but these formed mutually exclusive populations. Almost all neurons expressing NK(1) receptor immunoreactivity contained immunoreactivity to enkephalin, vasoactive intestinal peptide, and neuropeptide Y, but not nitric oxide synthase. Using a combination of retrograde axonal tracing and axonal crushing, we found that most neurons with immunoreactivity to nitric oxide synthase projected along the nasopalatine and ethmoidal nerves to the nasal mucosa. In contrast, most neurons with immunoreactivity to enkephalin followed the zygomatic nerve to the facial skin and lacrimal gland. Based on their peptide content, we conclude that the neurons with immunoreactivity to enkephalin and NK(1) receptor projected selectively to the skin. In both the sphenopalatine and the otic ganglia, about half of the neurons with NK(1) receptor immunoreactivity were surrounded by varicose nerve fibers with substance P immunoreactivity. Many of these fibers are likely to have originated in the trigeminal ganglion. Taken together, these observations establish a strong anatomical basis for a range of interactions between trigeminal and cranial parasympathetic pathways that may underlie pathophysiological conditions such as trigeminal neuralgia.

Differential inhibition by botulinum neurotoxin A of cotransmitters released from autonomic vasodilator neurons

The role of the soluble NSF attachment protein receptor (SNARE) protein complex in release of multiple cotransmitters from autonomic vasodilator neurons was examined in isolated segments of guinea pig uterine arteries treated with botulinum neurotoxin A (BoNTA; 50 nM). Western blotting of protein extracts from uterine arteries demonstrated partial cleavage of synaptosomal-associated protein of 25 kDa (SNAP-25) to a NH2-terminal fragment of approximately 24 kDa by BoNTA. BoNTA reduced the amplitude (by 70-80%) of isometric contractions of arteries in response to repeated electrical stimulation of sympathetic axons at 1 or 10 Hz. The amplitude of neurogenic relaxations mediated by neuronal nitric oxide (NO) was not affected by BoNTA, whereas the duration of peptide-mediated neurogenic relaxations to stimulation at 10 Hz was reduced (67% reduction in integrated responses). In contrast, presynaptic cholinergic inhibition of neurogenic relaxations was abolished by BoNTA. These results demonstrate that the SNARE complex has differential involvement in release of cotransmitters from the same autonomic neurons: NO release is not dependent on synaptic vesicle exocytosis, acetylcholine release from small vesicles is highly dependent on the SNARE complex, and neuropeptide release from large vesicles involves SNARE proteins that may interact differently with regulatory factors such as calcium.

Neuropeptide Y immunoreactivity in cutaneous sympathetic and sensory neurons during development of the guinea pig

Different levels of the cutaneous vasculature are innervated selectively by subpopulations of sympathetic neurons distinguished by the presence or absence of immunoreactivity (-IR) for neuropeptide Y (NPY). This study used multiple-labelling immunohistochemistry to examine the appearance of NPY-IR in neurons innervating cutaneous vessels in the ear pinna of embryonic, fetal, and neonatal guinea pigs. NPY-immunoreactive axons were detected in the ear bud at embryonic day 25. However, these axons lacked IR for tyrosine hydroxylase (TH) and often ran in bundles with substance P (SP)-immunoreactive axons close to the epidermis. Many neuronal somata in the cervical dorsal root ganglia (DRG) at late embryonic stages contained NPY-IR with or without SP-IR, but no NPY-IR was detected in DRG or subepidermal axons by late fetal stages. IR for calcitonin gene-related peptide increased in DRG neurons from midfetal to late fetal stages, after the decrease in NPY-IR. Populations of TH-IR neurons with or without NPY-IR were present in the superior cervical ganglion (SCG) from midembryonic stages. TH-immunoreactive axons were not detected in the ear pinna until midfetal stages, when axons with TH-IR and NPY-IR innervated proximal arteries and TH-immunoreactive axons without NPY-IR innervated distal vessels. Vasoactive intestinal peptide-IR was detected transiently in most fetal SCG neurons with TH-IR and NPY-IR but was not detected in cutaneous axons. These results demonstrate that selective expression of NPY by subpopulations of sympathetic neurons occurs prior to innervation of their targets. This suggests that target contact is not required to establish appropriate patterns of expression of peptide neurotransmitters by cutaneous sympathetic neurons.

Transdermal dopaminergic D(2) receptor agonist therapy in Parkinson's disease with N-0923 TDS: a double-blind, placebo-controlled study

N-0923 is a non-ergot, dopaminergic D(2) agonist designed to be transdermally available. It has anti-parkinsonian effects when infused intravenously. An adhesive matrix patch was developed to deliver N-0923 transdermally (N-0923 TDS). In this phase II trial, we evaluated the effectiveness of various doses of N-0923 TDS at replacing levodopa. Eighty-five Parkinson's disease (PD) patients were randomized to placebo or one of four doses of N-0923 TDS for 21 days. Change in daily levodopa dose was the primary efficacy measure. Significantly greater reductions in levodopa dose were achieved as compared to placebo for the two highest doses of N-0923 TDS. Patients treated with 33.5 mg and 67 mg N-0923 TDS decreased levodopa use by 26% and 28%, vs. 7% for placebo. N-0923 TDS was safe and well tolerated.

Neurochemical differentiation of functionally distinct populations of autonomic neurons

The coeliac ganglion of guinea pigs displays a unique topographical arrangement of neurochemically and functionally distinct populations of sympathetic neurons. The authors used multiple-labeling immunohistochemistry to investigate the neurochemical differentiation of these neurons during embryonic and fetal development. Sympathoadrenal precursors, located on either side of the abdominal aorta, were intensely immunoreactive for tyrosine hydroxylase (TH-IR), neurofilament, and the human natural killer 1 antibody at midembryonic stages (Carnegie stages 16-19). During late embryonic stages (stages 20-23), a single bilobed ganglion had formed. At this time, neuropeptide Y immunoreactivity (NPY-IR) was widely expressed in sympathetic neurons (with moderate TH-IR) and chromaffin cells (with intense TH-IR). The onset of somatostatin (Som-IR) expression followed that of NPY-IR and was restricted to sympathetic neurons. However, at late embryonic stages, most TH-IR neurons with Som-IR also expressed NPY-IR (a combination of peptides not found in the mature coeliac ganglion). Between late embryonic stages and the end of the early fetal period, there was a significant increase in the proportion of neurons in lateral regions that had both NPY-IR and TH-IR. At the same time, there was an increase in the proportion of neurons in medial regions that had both Som-IR and TH-IR. Neurons expressing both Som-IR and TH-IR were rarely observed in lateral regions of the coeliac ganglion. Thus, a clear topography within the coeliac ganglion is established during late embryonic and early fetal stages of development and reflects that found in the mature animal by the end of the early fetal period.

Different levels of immunoreactivity for synaptosomal-associated protein of 25 kDa in vasoconstrictor and vasodilator axons of guinea-pigs

Immunoreactivity (IR) for synaptosomal-associated protein of 25 kDa (SNAP-25) was examined in axons of autonomic vasoconstrictor and vasodilator neurons innervating the lingual and uterine arteries of guinea-pigs. Polyacrylamide gel electrophoresis and immunoblotting of protein extracts demonstrated a SNAP-25-IR band at 25 kDa in both arteries. Quantitative confocal microscopy demonstrated significantly higher levels of SNAP-25-IR in varicosities with IR for vasoactive intestinal peptide (VIP) than in adjacent axons with IR for tyrosine hydroxylase (TH). Levels of SNAP-25-IR in TH-IR axons, relative to adjacent VIP-IR axons, were significantly higher in the lingual artery than the uterine artery. These differences in IR for SNAP-25, a protein considered essential for calcium-dependent exocytosis of neurotransmitters, raise the possibility that mechanisms of transmitter release may vary between different classes of autonomic neurons.

Ventricular dilation after anterior ST-elevation myocardial infarction in the thrombolytic era

BACKGROUND

The aim of this work was to study changes in end-diastolic volume 6 months after Q-wave and non-Q-wave anterior ST-elevation myocardial infarction by echocardiography. Ventricular dilation after anterior Q-wave myocardial infarction is well-recognized. However, there is a dearth of information about the natural history of ventricular volumes after non-Q-wave myocardial infarction.

METHODS

One hundred ninety patients receiving thrombolytic therapy after anterior ST-elevation myocardial infarction were studied. All patients had 2D echocardiograms and 12-lead electrocardiograms recorded within 24 hours of symptoms and at 3, 42, and 180 days later. In addition, a further electrocardiogram was recorded on day 7 to assess patients for the presence of Q waves. Peak creatine kinase over the first 3 days of admission was recorded. End-diastolic volume index was the study end point.

RESULTS

Peak creatine kinase was strongly associated with ventricular dilation in both groups (P <.001). Mean end-diastolic volume in the Q-wave group increased significantly from day 1 to 6 months (P <.05) but did not alter after non-Q-wave infarction. However, when patients were selected on predefined criteria for significant change in ventricular dilation (>10 mL/m(2)), then 35% of those with and 15% of those without Q waves fell into this category. Within this group, the increase in end-diastolic volume followed a similar pattern, with the maximum percentage increase occurring between day 1 and 6 weeks.

CONCLUSIONS

In the postthrombolytic group of anterior ST-elevation myocardial infarction, a minority of patients without Q-wave development also undergo significant ventricular dilation.

Pathway specific expression of neuropeptides and autonomic control of the vasculature

In this article, we review the immunohistochemical evidence for the pathway-specific expression of co-existing neuropeptides in autonomic vasomotor neurons, and examine the functional significance of these expression patterns for the autonomic regulation of the vasculature. Most final motor neurons in autonomic vasomotor pathways contain neuropeptides in addition to non-peptide co-transmitters such as catecholamines, acetylcholine and nitric oxide. Neuropeptides also occur in preganglionic vasomotor neurons. The precise combinations of neuropeptides expressed by neurons in vasomotor pathways vary with species, vascular bed, and the level within the vascular bed. This applies to both vasoconstrictor and vasodilator pathways. There is a similar degree of variation in the expression of neuropeptide receptors in the vasculature. Consequently, the contributions of different peptides to autonomic vasomotor control are closely matched to the functional requirements of specific vascular beds. This arrangement allows for a high degree of precision in vascular control in normal conditions and has the potential for considerable plasticity under pathophysiological conditions.

Neuronal morphology and the synaptic organisation of sympathetic ganglia

In this article, we provide a short review of the structure and synaptic organisation of the final motor neurons in the sympathetic ganglia of mammals. Combinations of pathway tracing, multiple-labelling immunofluorescence and intracellular dye injection have shown that neurons in different functional pathways differ not only in their patterns of neuropeptide expression, but also in the size of their cell bodies and dendritic fields. Thus, vasoconstrictor neurons consistently are smaller than any other major functional class of neurons. Serial section ultrastructural analysis of dye filled neurons, together with electron microscopic and confocal microscopic analysis of immunolabelled synaptic inputs to sympathetic final motor neurons indicate that synapses are rare and randomly distributed over the surface of the neurons. The total number of synapses is simply proportional to the total surface area of the neurons. Many terminal boutons of peptide-containing preganglionic neurons do not make conventional synapses with target neurons. Furthermore, there is a spatial mismatch in the distribution of peptide-containing terminals and neurons expressing receptors for the corresponding peptides. Together, these results suggest that there are likely to be significant differences in the ways that the final sympathetic motor neurons in distinct functional pathways integrate their synaptic inputs. In at least some pathways, heterosynaptic actions of neuropeptides probably contribute to subtle modulation of ganglionic transmission.

Nalmefene to prevent epidural narcotic side effects in pediatric patients: a pharmacokinetic and safety study

STUDY OBJECTIVE

To determine the pharmacokinetics and preliminary efficacy of nalmefene in children in preventing epidural-induced narcotic side effects.

DESIGN

Double-blind, placebo-controlled study.

SETTING

University-affiliated children's hospital.

PATIENTS

Thirty-four children (aged 2-12 yrs) undergoing cardiothoracic surgery with epidural anesthesia.

INTERVENTIONS

Patients were randomized to receive intravenous bolus nalmefene 1 microg/kg or placebo.

MEASUREMENTS AND MAIN RESULTS

Six blood samples (one before nalmefene administration and five from 13 randomly designated time points) from each patient were assayed to determine plasma nalmefene concentrations. Patients were assessed for pain, nausea, vomiting, and urinary retention for 24 hours after administration. Concentration-time data were analyzed by a limited sampling strategy with adult pharmacokinetic parameters used as Bayesian priors. A two-compartment, first-order model was fitted to the data using ADAPT II. Pharmacokinetic parameter estimates in these patients were similar to values reported in adults. The initial disposition half-life (t(1/2alpha)) was 0.36+/-0.11 hour, the terminal elimination half-life (t(1/2beta)) 8.7+/-2.3 hours, clearance 0.729+/-0.172 L/kg/hr, and steady-state volume of distribution 7.21+/-2.49 L/kg. Ability to prevent epidural narcotic-induced side effects could not be documented at the 1-microg/kg dose. No statistically significant differences were noted between study and placebo groups with regard to pain, nausea, vomiting, or urinary retention.

CONCLUSION

Nalmefene has similar pharmacokinetics in children as in adults. It was administered safely to these patients and did not produce unmanageable pain.

Analgesia for pediatric thoracostomy tube removal

Eutectic mixture of local anesthetics (EMLA; Astra Pharmaceuticals, Wayne, PA) has been shown to reduce the pain of blood draws in children. We investigated the use of EMLA versus IV morphine for providing analgesia during chest tube removal (CTR) in children. One hundred twenty pediatric cardiothoracic surgery patients were enrolled. Patients were randomly assigned to receive either morphine (0.1 mg/kg up to 10 mg IV 30 min before CTR) or EMLA cream (5 g per chest tube cutaneously 3 h before CTR). A single, trained observer rated the patient's pain before, during, and after CTR using a 10-cm visual analog scale. The sites were evaluated for adverse effect. Methylhemoglobin levels were monitored in infants. Before CTR, the pain scores of the children who received morphine were rated lower than those who received EMLA (P < 0.01). During CTR, there was no difference in the pain score between the morphine or EMLA group. The change from baseline pain score in the morphine group was significantly larger than in the EMLA group (P < 0.01). We conclude that EMLA is safe and useful for blunting the pain of CTR.

Heterogeneity of vascular innervation in hamster cheek pouch and retractor muscle

The hamster cheek pouch and its retractor muscle have provided valuable insights into microvascular physiology of an epithelial tissue and striated muscle, respectively. Nevertheless, the innervation of these vascular beds has not been resolved. This study has investigated the nature of autonomic and sensory innervation of these vascular beds and has tested whether it varies within or between tissues. Multiple-labelling immunohistochemistry identified autonomic and peptide-containing sensory nerve fibres. Presumptive sympathetic vasoconstrictor axons with immunoreactivity (IR) for tyrosine hydroxylase (TH) and neuropeptide Y (NPY) innervated feed arteries and arterioles (but not veins or venules) of the retractor and anterior (muscular) cheek pouch; these axons were absent from the posterior (epithelial) region of the cheek pouch, as confirmed by catecholamine fluorescence. Presumptive autonomic vasodilator axons with IR for vasoactive intestinal peptide (VIP) consistently innervated feed arteries and proximal arterioles of the cheek pouch, but generally not those of the retractor muscle nor distal arterioles of either tissue. Sparse presumptive sensory axons with IR for calcitonin gene-related peptide (CGRP) and substance P were found near arterial and venous vessels in all regions of the cheek pouch and retractor muscle; CGRP-IR was also located in motor end plates associated with striated muscle fibres. Such regional differences in vascular innervation by autonomic and sensory neurons may selectively effect local and regional control of blood flow between and within vascular beds.

Subpopulations of sympathetic neurons project to specific vascular targets in the pinna of the rabbit ear

We have characterised sympathetic neurons projecting to a range of cutaneous and striated muscle vascular targets in the pinna of the rabbit ear by examining neurotransmitter-related enzymes and peptides in perivascular axons and in somata identified by retrograde axonal tracing. Fast Blue was injected into one of seven sites in each pinna (n = 21 pinnae). The soma cross-sectional area and immunoreactivity (IR) for tyrosine hydroxylase (TH) and neuropeptide Y (NPY) were determined for each of 2,041 retrogradely labelled neurons in the ipsilateral superior cervical ganglion (SCG) or stellate ganglion (StG). Larger neurons in the SCG with TH-IR but not NPY-IR projected predominantly to veins along the medial edge of the pinna. Larger neurons in the StG with TH-IR but not NPY-IR projected predominantly to arteries and veins in the tip and lateral edge of the pinna. Smaller neurons in the SCG with IR to both TH and NPY projected predominantly to arteries in the striated muscles at the base of the ear. The smallest retrogradely labelled neurons in the SCG or StG lacked TH-IR but contained NPY-IR and projected almost exclusively to arterial vessels in the lateral muscle at the base of the ear. Thus, somata of sympathetic neurons projecting to cutaneous versus striated muscle vessels or to different regions of the cutaneous bed could be distinguished by a combination of location, size, and immunohistochemical profile. Consequently, regulation of blood flow within the rabbit ear is likely to involve coordination between neuronal pathways containing neurochemically and morphologically distinct populations of sympathetic neurons.

Cotransmission from sympathetic vasoconstrictor neurons to small cutaneous arteries in vivo

This study has characterized constrictions of small cutaneous arteries in the guinea pig ear in response to electrical stimulation of the cervical sympathetic nerve (SNS) in vivo. Video microscopy and on-line image analysis were used to examine diameter changes of ear arteries (80-140 micrometers resting diameter) in anesthetized guinea pigs. Trains of 50-300 impulses, but not single pulses or short trains, produced frequency-dependent (2-20 Hz) constrictions. The purinoceptor antagonist suramin (30 microM) greatly reduced constrictions produced by exogenous ATP but did not affect constrictions produced by SNS at 10 Hz or exogenous norepinephrine. The alpha(2)-adrenoceptor antagonist yohimbine (1 microM) enhanced the peak amplitude of sympathetic constrictions at lower stimulation frequencies (1-5 Hz). The amplitude of constrictions to SNS at 10 Hz was reduced, and the latency of constrictions was increased by the alpha(1)-adrenoceptor antagonist prazosin (1 microM). Constrictions to SNS at 10 Hz remaining after prazosin treatment were reduced in amplitude by dihydroergotamine (2 microM) and were attenuated further by the neuropeptide Y Y(1)-receptor antagonist 1229U91 (0.3 microM). Thus norepinephrine and neuropeptide Y act as cotransmitters to mediate sympathetic constriction of small ear arteries at higher stimulation frequencies (10 Hz), but ATP does not seem to contribute directly to these constrictions.

Octreotide is not useful for clomiphene citrate resistance in patients with polycystic ovary syndrome but may reduce the likelihood of ovarian hyperstimulation syndrome

OBJECTIVE

To determine whether octreotide is effective for ovulation induction in patients with polycystic ovary syndrome (PCOS) and clomiphene citrate resistance or for reduction of the risk of ovarian hyperstimulation syndrome (OHSS) with gonadotropin therapy.

DESIGN

Prospective, double-blind, placebo-controlled, crossover trial.

SETTING

Private infertility practice.

PATIENT(S)

Twelve patients with PCOS undergoing therapy for infertility.

INTERVENTION(S)

The patients were assigned randomly to receive either octreotide or placebo. Those with clomiphene citrate-resistant PCOS received clomiphene citrate, 150 mg. Patients at risk for the development of OHSS received urinary FSH for ovulation induction.

MAIN OUTCOME MEASURE(S)

Ovulation, pregnancy, the development of OHSS, and levels of fasting insulin, insulin-like growth factor 1, insulin-like growth factor binding proteins 1 and 3, testosterone, androstenedione, DHEAS, E2, LH, and FSH.

RESULT(S)

Octreotide significantly reduced levels of fasting insulin, insulin-like growth factor 1, and LH in both clomiphene citrate- and urinary FSH-stimulated cycles. Levels of insulin-like growth factor binding protein 3 were increased. Two of six clomiphene citrate-stimulated cycles reached ovulation with the use of either octreotide or placebo. In urinary FSH-stimulated cycles, patients who received octreotide had significantly lower E2 levels at the time of hCG administration and fewer mature follicles. No cases of OHSS occurred in either group. One pregnancy occurred in each group.

CONCLUSION(S)

Octreotide was no more effective than placebo for clomiphene citrate resistance in patients with PCOS, but it did reduce E2 levels and follicle numbers when combined with urinary FSH. Thus, octreotide may reduce the incidence of OHSS in patients with PCOS.

Regional differences in sympathetic neurotransmission to cutaneous arteries in the guinea-pig isolated ear

The effects of sympathetic nerve stimulation on different cutaneous arteries were examined in arteries isolated from guinea-pig ears, by measuring membrane potential changes in smooth muscle cells in response to electrical field stimulation. Resting membrane potential (RMP) was similar in proximal (main ear artery) and distal (3rd or 4th branch order) cutaneous arteries (mean -71 mV). Single stimuli evoked excitatory junction potentials (EJPs) in all arteries. The EJPs in proximal arteries were twice the amplitude, and the time constant of EJP decay was almost half the value, compared with distal cutaneous arteries. EJP amplitude was reduced by > 90% by suramin (30 microM) or alpha,beta,methylene-ATP (alpha,beta,m-ATP)(1 microM) in all proximal, and most distal arteries. Residual responses in distal arteries were resistant to tetrodotoxin. The N-type calcium channel blocker, omega-conotoxin GVIA (30 nM), reduced EJP amplitude by 70-100% in both proximal and distal arteries. Successive EJPs evoked by trains of stimuli at 1 to 5 Hz were depressed in amplitude in proximal arteries, but showed facilitation in distal arteries. EJP depression in proximal arteries was reversed to facilitation by the alpha2-adrenoceptor antagonist, yohimbine (30 nM). Trains of stimuli delivered at 10-20 Hz produced summation of EJPs and active membrane responses in 30% of proximal arteries. Active responses were never detected in distal arteries. Slow depolarizations following the EJPs were detected in most arteries after trains of stimuli, and were abolished by prazosin (0.3 microM) or omega-conotoxin GVIA (30 nM). The density of the perivascular plexus of axons innervating proximal arteries, demonstrated with catecholamine fluorescence histochemistry, was twice that in distal cutaneous arteries. These regional differences in sympathetic neurotransmission suggest that cutaneous vasoconstriction in response to thermoregulatory stimuli, which occurs predominantly in distal cutaneous segments, is likely to be qualitatively different from cutaneous vasoconstriction of proximal arteries in response to other physiological stimuli.

Repair of coronary artery perforation after rotastenting by implantation of the JoStent covered stent

Coronary artery perforation is an unusual but well recognised complication of Percutaneous Transluminal Coronary Angioplasty (PTCA) and coronary atherectomy and may lead to hemopericardium and cardiac tamponade. If the perforation cannot be sealed by prolonged inflation with a perfusion balloon catheter, emergency cardiac surgery is usually necessary. This case report describes the potential use of a "covered" coronary artery stent for sealing perforations in the coronary circulation.