Sexual relationship power, intimate partner violence, and condom use among minority urban girls

This study examined the association between sexual relationship power, intimate partner violence, and condom use among African American and Hispanic urban girls. In this sample of 56 sexually active girls, 50% did not use condoms consistently and therefore were at higher risk for acquiring HIV or sexually transmitted diseases (STDs). Teens who experienced more intimate partner violence had a significantly higher likelihood of inconsistent condom use and therefore a greater risk for HIV/STDs. Girls' sense of sexual control in their relationships was not directly associated with inconsistent condom use but was inversely related to verbal and emotional abuse. Interventions aimed at reducing HIV/STD risk for adolescent girls need to address patterns of dominance and control in adolescent relationships as well as multiple forms of partner violence. This suggests the need for multilevel intervention approaches that promote girls' agency and multiple ways to keep girls safe from perpetrators of partner abuse.

Transit delay and flow quantification in muscle with continuous arterial spin labeling perfusion-MRI

PURPOSE

To test the hypothesis that flow measurements using continuous arterial spin labeling (CASL) magnetic resonance imaging (MRI) in muscle depend upon transit delay, and examine the repeatability of CASL measurements.

MATERIALS AND METHODS

A total of 23 healthy subjects underwent CASL imaging of the calf, foot, and forearm with varying postlabeling delay (PLD = 1000, 1500, and 1900 msec). Experiments were conducted on a 3.0T system. An orthopedic tourniquet system was employed to create a five-minute period of ischemia followed by a transient hyperemic flow. Imaging commenced two minutes prior to cuff inflation and ended three minutes after cuff release.

RESULTS

CASL was found able to well resolve the time course of the hyperemic flow pattern with an effective TR of 16 seconds, although we were unable to establish that a plateau had been reached in the flow measurements even at a PLD as long as 1900 msec. Peak hyperemic flow measurements compared favorably with those obtained with contrast-enhanced (CE) MRI following a similar period of ischemia. Region-of-interest (ROI)-based repeated measurements varied by approximately 20% over a period of one hour.

CONCLUSION

In all anatomic regions studied, flow measurements were found to increase with PLD, suggesting the prolonged transit delay in muscle.

Restless legs syndrome in type 2 diabetes: implications to diabetes educators

PURPOSE

The purpose of this study was to provide a background of restless legs syndrome (RLS), present the prevalence and demographic findings of a descriptive study of type 2 diabetes with RLS, and provide implications to diabetes educators on the management and education of RLS.

METHODS

Participants with type 2 diabetes who met the diagnostic criteria for RLS based on the International RLS Study Group Criteria were recruited from the PENN Rodebaugh Diabetes Center from July 2005 through September 2006. Participants who met inclusion and exclusion criteria were mailed a survey to collect data.

RESULTS

Of 121 patients with type 2 diabetes, 54 (45%) of the screened sample met the 4 diagnostic criteria for RLS. Of those who met the inclusion and exclusion criteria of the primary study, 18 patients with type 2 diabetes with RLS participated in this study. Along with diabetes, the participants had a variety of comorbid health conditions including hypertension, neuropathies, rheumatoid arthritis, renal failure, and irritable bowel syndrome. Only one third of the participants were being treated for RLS. Thirty-nine percent of the participants with type 2 diabetes were using insulin to manage their diabetes with other oral agents.

CONCLUSIONS

RLS is a sleep disorder that may affect the management of type 2 diabetes. Diabetes educators must know that sleep disorders can affect long-term health outcomes, and RLS is frequently seen in this cohort of patients.

Availability of activated CD4+ T cells dictates the level of viremia in naturally SIV-infected sooty mangabeys

Naturally SIV-infected sooty mangabeys (SMs) remain asymptomatic despite high virus replication. Elucidating the mechanisms underlying AIDS resistance of SIV-infected SMs may provide crucial information to better understand AIDS pathogenesis. In this study, we assessed the determinants of set-point viremia in naturally SIV-infected SMs, i.e., immune control of SIV replication versus target cell limitation. We depleted CD4+ T cells in 6 naturally SIV-infected SMs by treating with humanized anti-CD4 mAb (Cdr-OKT4A-huIgG1). CD4+ T cells were depleted almost completely in blood and BM and at variable levels in mucosal tissues and LNs. No marked depletion of CD14+ monocytes was observed. Importantly, CD4+ T cell depletion was associated with a rapid, significant decline in viral load, which returned to baseline level at day 30-45, coincident with an increased fraction of proliferating and activated CD4+ T cells. Throughout the study, virus replication correlated with the level of proliferating CD4+ T cells. CD4+ T cell depletion did not induce any changes in the fraction of Tregs or the level of SIV-specific CD8+ T cells. Our results suggest that the availability of activated CD4+ T cells, rather than immune control of SIV replication, is the main determinant of set-point viral load during natural SIV infection of SMs.

Recent and past intimate partner abuse and HIV risk among young women

OBJECTIVE

To examine the associations between past intimate partner abuse experienced during adolescence (verbal and physical), recent intimate partner abuse (verbal, physical, and sexual), and HIV risk (as indicated by lack of condom use) for sexually active young adult women in relationships with male partners.

DESIGN

Secondary data analysis of waves II and III of the National Longitudinal Study of Adolescent Health (Add Health).

SETTING

The Add Health Study is a longitudinal, in-home survey of a nationally representative sample of adolescents.

SAMPLE

Analyses involved 2,058 sexually active young adult women.

MAIN OUTCOME MEASURES

HIV risk was measured by consistent condom use over the past 12 months.

RESULTS

Physical and verbal abuse experienced in adolescence were associated with physical/verbal abuse experienced in young adulthood. Young, sexually active women experiencing no abuse in their relationships were more likely to consistently use condoms in the past 12 months than were their abused counterparts.

CONCLUSION

A causal pathway may exist between prior abuse, current abuse, and HIV risk.

Parent--Adolescent Communication About Sexual Pressure, Maternal Norms About Relationship Power, and STI/HIV Protective Behaviors of Minority Urban Girls

Racial/ethnic minority adolescent girls bear a disproportionate risk for HIV and face barriers to autonomous sexual decision making, but parental messages may help protect against sexual risk taking. The authors examined African American and Hispanic girls' sexually transmitted infection (STI) and HIV prevention practices, parent-adolescent communication about sexual pressure, and maternal gender norms (N = 118). Teens were more likely to practice consistent STI/HIV prevention when mothers talked about partner sexual pressure (p = .017) and fathers talked about resisting partner sexual pressure (p = .034). Sexually active girls who perceived that their mothers held egalitarian beliefs about partner decision making had more consistent condom use (p = .029). Given the context of increased STI/HIV risk, it is critical that parents discuss partner dynamics with daughters. Nurses play a unique role in facilitating these conversations; they provide parents with age-appropriate resources and assist in normalizing fears, which can help increase parent-child sexual-risk communication. J Am Psychiatr Nurses Assoc, 2008; 14(1), 50-60. DOI : 10.1177/1078390307311770.

Hyperemic flow heterogeneity within the calf, foot, and forearm measured with continuous arterial spin labeling MRI

Arterial spin labeling (ASL) is a noninvasive magnetic resonance imaging (MRI) technique for microvascular blood flow measurement. We used a continuous ASL scheme (CASL) to investigate the hyperemic flow difference between major muscle groups in human extremities. Twenty-four healthy subjects with no evidence of vascular disease were recruited. MRI was conducted on a 3.0 Tesla Siemens Trio whole body system with a transmit/receive knee coil. A nonmagnetic orthopedic tourniquet system was used to create a 5-min period of ischemia followed by a period of hyperemic flow (occlusion pressure = 250 mmHg). CASL imaging, lasting from 2 min before cuff inflation to 3 min after cuff deflation, was performed on the midcalf, midfoot, and midforearm in separate sessions from which blood flow was quantified with an effective temporal resolution of 16 s. When muscles in the same anatomic location were compared, hyperemic flow was found to be significantly higher in the compartments containing muscles known to have relatively higher slow-twitch type I fiber compositions, such as the soleus muscle in the calf and the extensors in the forearm. In the foot, the plantar flexors exhibited a slightly delayed hyperemic response relative to that of the dorsal compartment, but no between-group flow difference was observed. These results demonstrate that CASL is sensitive to flow heterogeneity between diverse muscle groups and that nonuniform hyperemic flow patterns following an ischemic paradigm correlate with relative fiber-type predominance.

A comparison of glycemic control, sleep, fatigue, and depression in type 2 diabetes with and without restless legs syndrome

OBJECTIVE

The purpose of this pilot study was to determine how sleep quality, glycemic control, sleepiness, fatigue, and depression differ in persons with type 2 diabetes with and without restless legs syndrome (RLS). RESEARCH DESIGNS/METHODS: The design was a descriptive, case-control study of participants with type 2 diabetes with and without RLS at the University of Pennsylvania, Rodebaugh Diabetes Center. Thirty-nine participants (adults over 21 years of age who had been diagnosed with type 2 diabetes and had a HbA1c in the last 3 months) were stratified based on RLS diagnostic criteria. Exclusion criteria included severe hypoglycemia identified by seizures or coma related to hypoglycemia or known sleep disorder other than RLS. The primary outcome of sleep was measured by self-report sleep quality (Pittsburgh Sleep Quality Index) with secondary outcomes including HbA1c, sleepiness (Epworth Sleepiness Scale), fatigue (Fatigue Severity Scale), and depression (Center for Epidemiologic Studies-Depression Scale).

RESULTS

Participants with type 2 diabetes with RLS reported a significant difference in quality of sleep (p = .001), sleep latency (p = .04), sleep efficiency (p = .035), use of sleep medications (p < .001), and daytime dysfunction (p = .005). In the total group, higher HbA1c levels were positively correlated with sleepiness (p = 038). Global Pittsburgh Sleep Quality Index scores were positively correlated with fatigue (r = .58, p = .002) and depression (r =.74, p < .001). As well, fatigue and sleepiness were positively correlated (r = .36, p = .04).

CONCLUSIONS

RLS is a significant sleep disorder that may have an impact on diabetes management and health outcomes. More research should be conducted on the impact of RLS in sleep to improve diabetic management.

Clinically silent cerebral ischemic events after cardiac surgery: their incidence, regional vascular occurrence, and procedural dependence

BACKGROUND

The reported frequency of stroke after coronary artery bypass grafting varies between 1.5% and 6%, approaches 10% after aortic valve replacement, and may occur in between 40 to 70% in high-risk groups. Clinically silent infarction may be far more frequent and could contribute to long-term cognitive dysfunction in patients after cardiac procedures. Using diffusion-weighted magnetic resonance imaging we document the occurrence, vascular distribution, and procedural dependence of silent infarction after cardiac surgery with cardiopulmonary bypass. We also document the association of preexisting white matter lesions with new postoperative ischemic lesions.

METHODS

Thirty-four patients underwent T2-weighted fluid attenuated inversion recovery and diffusion-weighted magnetic resonance imaging before and after cardiac surgery with cardiopulmonary bypass for coronary artery bypass grafting, aortic valve replacement, and mitral valve repair or replacement surgery. Images were evaluated by experienced neuroradiologists for number, size, and vascular distribution of lesions.

RESULTS

Mean age of participants was 67 +/- 15 years. Imaging occurred before and 6 +/- 2 days after surgery. New cerebral infarctions were evident in 6 of 34 patients (18%), were often multiple, and in 67% of patients were clinically silent. The occurrence of new infarctions by surgical procedure was as follows: aortic valve replacement (2 of 6), coronary artery bypass grafting and aortic valve replacement (3 of 8), aortic valve replacement with root replacement (1 of 1), coronary artery bypass grafting and mitral valve repair or replacement (0 of 4), mitral valve repair or replacement (0 of 2), and isolated coronary artery bypass grafting (0 of 13). New infarction occurred in 6 of 15 (40%) of all procedures involving aortic valve replacement. The severity of preexisting white matter lesions trended toward predicting the occurrence of new lesions (p = 0.055).

CONCLUSIONS

Diffusion-weighted imaging reveals new cerebral infarctions in nearly 40% of patients after aortic valve replacement.

Symptoms of Restless Legs Syndrome in Older Adults: Outcomes on Sleep Quality, Sleepiness, Fatigue, Depression, and Quality of Life

OBJECTIVES

To compare differences in sleep quality, sleepiness, fatigue, depression, and quality of life according to severity of symptoms of restless legs syndrome (RLS) in older adults.

DESIGN

Descriptive, comparative study; cross-sectional design.

SETTING

Penn Sleep Center at the University of Pennsylvania and RLS support groups in Philadelphia.

PARTICIPANTS

Thirty-nine adults, aged 65 and older, diagnosed with RLS with symptoms at least 3 nights per week. Participants were stratified according to symptom severity based on scores from the RLS Symptom Severity Scale. Exclusion criteria were dementia, cognitive impairments, and sleep disorders other than RLS.

MEASUREMENTS

Sleep quality, measured using the Pittsburgh Sleep Quality Index (PSQI), was the primary outcome. Secondary outcomes were sleepiness, fatigue, depression, and quality of life measured using the Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), Center for Epidemiological Studies--Depression Scale (CES-D), and RLS Quality of Life Instrument (RLS-QLI), respectively.

RESULTS

Significant differences were found in subjective sleep quality (P=.007) and sleep duration (P=.04), as well as in PSQI global score (P=.007). RLS-QLI sleep quality (beta=-0.12, 95% confidence interval (CI)=-0.18 to -0.06, P<.001) and sleepiness (beta=0.35, 95% CI=0.09-0.61, P=.01) were significantly related to PSQI global score. Subjects with severe symptoms were five times as likely to use medication to treat RLS (OR=5.3, 95% CI=1.2-22.2).

CONCLUSION

The severity of RLS symptoms in older adults affects not only sleep quality but also many aspects of quality of life, including social functioning, daily functioning, and emotional well-being.

Integrity of the Cerebral Blood-Flow Response to Hyperoxia After Cardiopulmonary Bypass

OBJECTIVE

In this study, the hypothesis that cardiopulmonary bypass (CPB) alters the cerebral blood flow (CBF) vasoconstrictive response to hyperoxia was tested.

DESIGN

A prospective, observational study was conducted.

SETTING

The study was conducted at a single university hospital.

PARTICIPANTS

Subjects were patients who presented for cardiac surgery with CPB.

INTERVENTIONS

CBF was measured before and after CPB in 12 subjects while breathing 21% O(2) and 100% O(2). CBF was measured by using continuous arterial spin labeling (CASL) perfusion magnetic resonance imaging. Arterial pO(2) (mmHg), pCO(2) (mmHg), hemoglobin (Hgb), and oxygen content (CaO(2)) were also measured.

MEASUREMENTS AND MAIN RESULTS

Mean age of the 12 subjects was 63 +/- 16 years. Hgb decreased from 12.0 (+/-2.4) g/dL to 9.2 (+/-2.9) g/dL postoperatively (p = 0.008). CBF increased by 39%, from 37.2 (+/-10.8) mL/100 g/min to 49.2 (+/-14.3)mL/100 g/min postoperatively (p = 0.01). In response to the hyperoxic challenge CBF decreased by 8.0 (+/-7.1) mL/100 g/min (21%) preoperatively and by 9.4 (+/-6.4) mL/100 g/min (19%) postoperatively (p = 0.58). By using multiple regression, the contribution of CPB to the hyperoxic CBF response (DeltaCBF) was evaluated, while controlling for other potentially important covariates known to influence CBF, including age, baseline CBF on 21% O(2), and changes in arterial pO(2), pCO(2), and CaO(2). CPB state was not found to be a significant covariate in controlling the CBF response to hyperoxia.

CONCLUSIONS

CPB does not impair the CBF response to hyperoxia.

Determinants of serum total and free testosterone levels in women over the age of 65 years

CONTEXT

Little is known about testosterone (T) levels and their determinants in women of late postmenopausal age.

OBJECTIVE

We describe levels of total and free T and selected factors that influence these levels in a random sample of older women.

DESIGN

Levels of serum total T and free T by microdialysis were measured using ultrasensitive assays in 347 community-dwelling women aged 65-98 yr enrolled in the Cardiovascular Health Study. Cross-sectional analyses were performed to define factors associated with total and free T levels.

RESULTS

In adjusted models: 1) total T levels declined with age until 80, whereas free T levels did not vary by age; 2) women with bilateral oophorectomy had 23% lower total T and 16% lower free T levels than those with at least one intact ovary; 3) oral estrogen users had total and free T levels that were 47% lower than never users; 4) obese women had 47% higher total T and 20% higher free T levels, and overweight women had 24% higher total T and 14% higher free T levels, than normal weight women; and 5) free T levels were 51% higher in black women. Corticosteroid users had 75% lower total T and 43% lower free T levels than nonusers.

CONCLUSIONS

Bilateral oophorectomy, estrogen use, corticosteroid use, and low body mass index are independent risk factors for lower T levels in women aged 65 yr and over. Although highly prevalent in women of this age, the physiological significance of low T levels in late postmenopausal women requires further investigation.

Sex-based differences in myocardial contractile reserve

Recent studies have identified sex differences in heart function that may affect the risk of developing heart failure. We hypothesized that there are fundamental differences in calcium (Ca) regulation in cardiac myocytes of males and premenopausal females. Isometric force transients ( n = 45) were measured at various stimulation frequencies to define the force frequency responses (FFR) (0.5, 1.0, 1.5, and 2.0 Hz) during either changes in bath Ca ([Ca]o) (1.0, 1.75, 3.5, and 7.0 mM) or length-tension (20, 40, 60, 80, and 100% Lmax) in right ventricle trabeculae from normal male (MT) and premenopausal female (FT) cats. Force-Ca measurements were also obtained in chemically skinned trabeculae. Under basal conditions (0.5 Hz, 1.75 mM Ca, 80% Lmax) both MT and FT achieved similar developed forces (DF) (MT 11 ± 1, FT = 10 ± 1 mN/mm2). At low rates and lengths, there is no sex difference. At higher preloads and rates, there is a separation in DF in MT and FT. At basal [Ca]o both MT and FT exhibited positive FFR (2.0 Hz, 1.75 mM Ca: MT 38 ± 3, FT 21 ± 4 mN/mm2); however, at higher [Ca]o, MT achieved greater DF (2.0 Hz, 7.0 mM Ca: MT 40 ± 3 and FT = 24 ± 4 mN/mm2). We detected no sex difference in myofilament Ca sensitivity at a sarcomere length of 2.1 μm. However, rapid cooling contractures indicated greater sarcoplasmic reticulum (SR) Ca load in MT at higher frequencies. Despite virtually identical contractile performance under basal conditions, significant sex differences emerge under conditions of increased physiological stress. Given the lack of sex differences in myofilament Ca sensitivity, these studies suggest fundamental sex differences in cellular Ca regulation to achieve contractile reserve, with myocardium from males exhibiting higher SR Ca load.

Incidence of type 1 diabetes in Philadelphia is higher in black than white children from 1995 to 1999: epidemic or misclassification?

OBJECTIVE

To determine the epidemiology of type 1 diabetes in children in Philadelphia, Pennsylvania, from 1995 through 1999 and compare these data with previous cohorts.

RESEARCH DESIGN AND METHODS

This is a report of a retrospective population-based registry maintained since 1985. Hospital records meeting the following criteria were reviewed: newly diagnosed type 1 diabetes, age 0-14 years, residing in Philadelphia at the time of diagnosis, and diagnosed from 1 January 1995 to 31 December 1999. The secondary source of validation was the School District of Philadelphia. Incidence rates by race and age were compared with 1985-1989 and 1990-1994 cohorts.

RESULTS

A total of 234 case subjects were identified, and the registry was determined to be 96% complete. The overall age-adjusted incidence rate in Philadelphia was 14.8 per 100,000/year. Incidence rates in Hispanic children (15.5 per 100,000/year) and white children (12.8 per 100,000/year) have been relatively stable over 15 years. The incidence in black children (15.2 per 100,000/year), however, has increased dramatically, rising 64% in children 5-9 years of age (14.9 per 100,000/year) and 37% in the 10- to 14-year age-group (26.9 per 100,000/year).

CONCLUSIONS

The overall incidence of type 1 diabetes in Philadelphia is increasing and is similar to other U.S. registries. These are the first data reporting a higher incidence in black children in a registry of children 0-14 years of age. The etiology of the marked increase in incidence in the black population is unknown and underscores the need to establish type 1 diabetes as a reportable disease, so that environmental risk factors may be thoroughly investigated.

Ethical Conflict in Nurse Practitioners and Physician Assistants in Managed Care

BACKGROUND

More patients are receiving healthcare services from nurse practitioners (NPs) and physician assistants (PAs). These providers are likely to be confronted with a variety of ethical issues as they balance quality care with their patients' rising cost concerns. However, very little is known about the ethical conflicts and causes of these conflicts experienced by these clinicians in their daily practice.

OBJECTIVE

To identify ethical concerns and conflicts NPs and PAs encounter related to managed care in the delivery of primary care to patients and the factors that influence ethical conflict.

METHODS

A cross-sectional self-administered mailed questionnaire was sent to 3,900 NPs and PAs randomly selected from primary care and primary care subspecialties in the United States (adjusted response rate, 50.6%). Respondents were surveyed on ethical issues and concerns, ethics preparedness, and ethical conflict. Bivariate and multiple linear regression analyses were used to evaluate predictors of ethical conflict.

RESULTS

Insurance constraints were reported to have interfered with the ability to provide quality patient care by 72% of respondents, with 55.3% reporting daily to weekly interferences. Nearly half of respondents (47%) have been asked by a patient to mislead insurers to assist them in receiving care. A perceived obligation to advocate for patients, even if it means exaggerating the severity of a patient's condition, was the single most significant predictor of ethical conflict, explaining 25% of the variance.

DISCUSSION

NPs and PAs are experiencing ethical conflict often associated with their perceived professional obligations to advocate for patients. Being well-prepared in ethics and having sufficient professional independence help clinicians balance the ethical complexities and demands of meeting patients' needs within a constrained healthcare system.

Is vaginal birth after cesarean (VBAC) or elective repeat cesarean safer in women with a prior vaginal delivery?

OBJECTIVE

This study was undertaken to determine whether vaginal birth after cesarean (VBAC) or elective repeat cesarean delivery is safer overall for a woman with a prior vaginal delivery.

STUDY DESIGN

This retrospective cohort study of pregnant women from 1996 to 2000 who had a prior cesarean delivery, was conducted in 17 centers. Trained nurses extracted historical and maternal outcome data on subjects by using standardized tools. This planned secondary analysis examined the subcohort that had also previously undergone a vaginal delivery, comparing those who underwent a VBAC trial with those who elected to have a repeat cesarean delivery. Outcomes included uterine rupture, bladder injury, fever, transfusion and a composite (uterine rupture, bladder injury, and artery laceration). We performed bivariate and multivariable analyses.

RESULTS

Of 6619 patients with a prior cesarean delivery who had also had a prior vaginal delivery, 5041 patients attempted a VBAC delivery and 1578 had an elective cesarean delivery. Although there was no significant difference in uterine rupture or bladder injury between the two groups, women who underwent a VBAC attempt were less likely to experience the composite adverse maternal outcome, have a fever, or require a transfusion.

CONCLUSION

Among VBAC candidates who have had a prior vaginal delivery, those who attempt a VBAC trial have decreased risk for overall major maternal morbidities, as well as maternal fever and transfusion requirement compared with women who elect repeat cesarean delivery. Physicians should make this more favorable benefit-risk ratio explicit when counseling this patient subpopulation on a trial of labor.

Comparison of Cool Tip Versus 8-mm Tip Catheter in Achieving Electrical Isolation of Pulmonary Veins for Long-Term Control of Atrial Fibrillation: A Prospective Randomized Pilot Study

OBJECTIVE

To compare safety and efficacy of 8-mm versus cooled tip catheter in achieving electrical isolation (EI) of pulmonary veins (PV) for long-term control of atrial fibrillation (AF).

BACKGROUND

There is paucity of studies comparing safety/efficacy of 8-mm and cooled tip catheters in patients undergoing AF ablation.

METHODS AND RESULTS

This was a randomized and patient-blinded study. Subjects were followed by clinic visits (at 6 weeks and 6 months) and transtelephonic monitoring (3-week duration) done around each visit. Primary endpoints were: (1) long-term AF control (complete freedom and/or >90% reduction in AF burden on or off antiarrhythmic drugs at 6 months after a single ablation), and (2) occurrence of serious adverse events (cardiac tamponade, stroke, LA-esophageal fistula, and/or death). Eighty-two patients (age 56 +/- 9 years, 60 males, paroxysmal AF = 59) were randomized (42 patients to 8-mm tip and 40 patients to cooled tip). EI of PVs was achieved in shorter time by the 8-mm tip as compared with cooled tip catheter (40 +/- 23 minutes vs 50 +/- 30 minutes; P < 0.05) but long-term AF control was not different between the two (32 patients [78%] vs 28 patients [70%], respectively; P = NS). One serious adverse event occurred in each group (LA-esophageal fistula and stroke, respectively) and no significant PV stenosis was observed in either.

CONCLUSION

EI of PVs using either 8-mm or cooled tip catheter results in long-term AF control in the majority after a single ablation procedure, with comparable efficacy and safety.

Aging: Impact Upon Local Cerebral Oxygenation and Blood Flow With Acute Isovolemic Hemodilution

Data from the neurosurgical critical care arena demonstrate a correlation between cerebral oxygenation, survival, and cognitive function. Transfusion may increase and hemodilution decrease cerebral oxygenation. Both acute and chronic anemia have been associated with cognitive dysfunction. Aggressive blood conservation protocols have been instituted across all age groups without conclusive evidence for their impact upon outcome. Aged subjects are at the greatest risk of cognitive sequelae after major surgery associated with significant blood loss. We hypothesize that cerebral physiologic changes associated with "normal" aging may compromise cerebral oxygenation in the presence of severe anemia.Fischer 344 rats, the NIH National Institute of Aging normal aging rat model, underwent a stepwise isovolemic hemodilution protocol. Age groups (Age Grp) studied were as follows: Age Grp-A (3 months), n=14; Age Grp-B (9 to 12 months), n=14; and Age Grp-C (24 months), n=14. Brain oxygen tension (PBrO2), laser Doppler flow, and mean arterial pressure were measured. Final hemoglobin averaged 6.1+/-0.9 g/dL. PBrO2 levels decreased from a baseline of 18.1+/-4.1 to 17.5+/-6.8 mm Hg (P=0.49), and laser Doppler flow increased by 18+/-20% (P<0.0001) after hemodilution. Employing repeated measures multiple regression, Age Grp (P=0.30) was not a significant controlling covariate of PBrO2 in response to isovolemic hemodilution. PBrO2 levels were actually higher in Age Grp-C animals at all time points of the hemodilution protocol, although this was not statistically significant. Aged animals were also fully capable of mounting a robust local cerebral hyperemic response to the anemic challenge that was not separable from the response of younger animals.

Acceptance of hepatitis B vaccination by pregnant adolescents

PURPOSE

To determine (1) the rate of prenatal hepatitis B virus (HBV) vaccine acceptance in HBV nonimmune pregnant adolescents, (2) if postulated behavioral and attitudinal factors are associated with HBV vaccine, and (3) the rate of actual receipt of HBV vaccine postpartum in eligible subjects.

DESIGN AND METHODS

During 1999-2000, at an inner-city tertiary-care center prenatal clinic, 160 HBV nonimmune adolescents <18 years who were receiving prenatal and delivery care at the center were identified. The research nurse provided an HBV information pamphlet and offered immediate in-hospital postpartum HBV vaccination. Risk factors for nonacceptance of the vaccine were measured with structured questionnaires and medical record review documenting care attendance. Subsequently, all subjects, irrespective of prenatal acceptance of vaccine, were offered vaccine before postpartum discharge, and the rate of actual acceptance was determined.

RESULTS

In these predominantly African American (95%) adolescents, the rate of vaccine acceptance was 91%. Actual vaccination rate was 86%, but it was not associated with prior acceptance of vaccination or behavioral or attitudinal factors.

CLINICAL IMPLICATIONS

Acceptance of vaccination and actual vaccination were high in this population of high-risk adolescents. The authors found that reoffering vaccine was a successful intervention, even with adolescents who had less-than-optimal attendance at prenatal visits. Given the high rate of acceptance and vaccination in this setting, the authors would encourage public health programs to implement vaccination programs in adolescent prenatal clinics and to offer vaccination postpartum to those who do not receive it prenatally.

The cost of prenatal care attendance and pregnancy outcomes in low-income working women

OBJECTIVE

To examine personal costs (dollar costs and time spent) associated with prenatal care (PNC) attendance and outcomes (gestation length, PNC adequacy, and birth weight) for low-income, working women (N = 165).

DESIGN

Prospective, descriptive study.

SETTING

Participants were recruited from a pre-natal clinic located at an inner city tertiary care center.

PARTICIPANTS

A convenience sample of 165 low-income, working women.

MAIN OUTCOME MEASURES

Personal costs were measured as dollar costs and time spent associated with PNC attendance. Perinatal outcomes were measured as gestation length, PNC adequacy, and birth weight.

RESULTS

Per visit, the mean cost associated with PNC was 33.31 dollars (range 1-125.60 dollars, SD = 32.33 dollars) and the time needed to attend care was 228 min (20-720, SD = 205). Women delivered at 37.8 (18-42) weeks; 17.6% of the women received inadequate PNC, and 17.0% of the women delivered low-birth-weight newborns.

CONCLUSIONS

The findings indicated that personal costs associated with PNC attendance were not associated with inadequate care attendance.

Maternal complications with vaginal birth after cesarean delivery: a multicenter study

OBJECTIVE

This study was undertaken to determine incidence and risk factors for uterine rupture in women attempting vaginal birth after cesarean delivery (VBAC) in a wide range of hospital settings.

STUDY DESIGN

We performed a case-control study nested within a cohort of women who have had a prior cesarean to determine the incidence and risk factors for uterine rupture in women attempting VBAC.

RESULTS

The incidence rate of uterine rupture in those who attempt VBAC was 9.8 per 1000. A prior vaginal delivery was associated with a lower risk of uterine rupture (adjusted odds ratio [OR] = 0.40, 95% CI 0.20-0.81). Although prostaglandins alone were not associated with uterine rupture, sequential use of prostaglandin and pitocin was associated with uterine rupture (adjusted OR = 3.07, 95% CI 0.98-9.88).

CONCLUSION

Women with a prior cesarean should be offered VBAC, and women with a prior cesarean and prior vaginal delivery should be encouraged to VBAC. Although other studies have suggested that prostaglandins should be avoided, we suggest that inductions requiring sequential agents be avoided.

Development of preterm infants: feeding behaviors and brazelton neonatal behavioral assessment scale at 40 and 44 weeks' postconceptional age

The purpose of this study was twofold: (1) to explore potential changes in the Brazelton Neonatal Behavioral Assessment Scale (BNBAS) from 40 to 44 weeks postconceptional age (PCA) and (2) to determine the relationship between the BNBAS scores and feeding behaviors in preterm infants at 40 and 44 weeks PCA. The BNBAS and sucking behavior measurements were completed on 104 preterm infants at 40 and 44 weeks PCA. The Orientation (p = .001), Motor (p = .001), Range of State (p = .001), Autonomic Regulation (p = .01), and Reflexes (p = .00) clusters were significantly more mature at 44 weeks PCA than at 40 weeks. Infants that were extremely early born (n = 24) had a significantly larger change in BNBAS scores over time as compared to the more mature preterm infants (n = 77), largely catching up with their more mature preterm counterparts. At 40 and 44 weeks PCA, the BNBAS cluster scores for orientation (p = .02), motor (p = .048), range of state (p = .048), and regulation of state (p < .001) were significantly related to the average maximum pressure, adjusted for gestational age and weeks PCA. Significant neurobehavioral maturation takes place between 40 and 44 weeks PCA in preterm infants, with the greatest changes occurring in the most preterm infants. These findings highlight the relationship between neurobehavioral maturation and feeding behaviors.

An exploratory study of depression among older African American users of an academic outpatient rehabilitation program

Variation in the presentation of depressive illness among older African Americans may complicate assessment of depression, especially among those with multiple medical comorbidities and functional disabilities. The purpose of this study was to explore the prevalence of depression among older poor African Americans attending an academic outpatient rehabilitation program, using a depression measure with low somatic item content. Correlates of depression in this population also were explored. Health-care records of 150 older African Americans seen over a 2-year period were examined. Depression was assessed on admission using the 30-item Geriatric Depression Scale (GDS). Using a GDS cutoff score for depression of 11 or higher, 30% of the sample (age 75.5 +/- 7.16 years, range 65-95, 75% women) scored positive for depression. Nine percent also reported having suicidal thoughts within the previous week. Consistent with existing literature, depressed patients, as compared to nondepressed patients, were significantly younger, more suicidal, more likely to rate their general health as poor, had higher mean ratings of pain, and more often limited their social activities. Six GDS items were found to have little ability to discriminate between depressed and nondepressed patients: satisfaction with life, getting bored easily, prefer staying at home, find life exciting, getting started on new projects, and full of energy. The authors recommend further testing of the GDS with similar populations of older, poor, medically ill, and functionally disabled older adults.

Joint Modeling of Longitudinal and Survival Data via a Common Frailty

We develop a joint model for the analysis of longitudinal and survival data in the presence of data clustering. We use a mixed effects model for the repeated measures that incorporates both subject- and cluster-level random effects, with subjects nested within clusters. A Cox frailty model is used for the survival model in order to accommodate the clustering. We then link the two responses via the common cluster-level random effects, or frailties. This model allows us to simultaneously evaluate the effect of covariates on the two types of responses, while accounting for both the relationship between the responses and data clustering. The model was motivated by a study of end-stage renal disease patients undergoing hemodialysis, where we wished to evaluate the effect of iron treatment on both the patients' hemoglobin levels and survival times, with the patients clustered by enrollment site.

Deviations from the population-averaged versus cluster-specific relationship for clustered binary data

There has been much debate about the relative merits of mixed effects and population-averaged logistic models. We present a different perspective on this issue by noting that the investigation of the relationship between these models for a given dataset offers a type of sensitivity analysis that may reveal problems with assumptions of the mixed effects and/or population-averaged models for clustered binary response data in general and longitudinal binary outcomes in particular. We present several datasets in which the following violations of assumptions are associated with departures from the expected theoretical relationship between these two models: 1) negative intra-cluster correlations; 2) confounding of the response-covariate relationship by cluster effects; and 3) confounding of autoregressive relationships by the link between baseline outcomes and subject effects. Under each of these conditions, the expected theoretical attenuation of the population-averaged odds ratio relative to the cluster-specific odds ratio does not necessarily occur. In all cases, the naive fitting of a random intercept logistic model appears to lead to bias. In response, the random intercept model is modified to accommodate negative intra-cluster correlations, confounding due to clusters, or baseline correlations with random effects. Comparisons are made with GEE estimation of population-averaged models and conditional likelihood estimation of cluster-specific models. Several examples, including a cross-over trial, a multicentre nonrandomized treatment study, and a longitudinal observational study are used to illustrate these modifications.

Precision of the CASL-perfusion MRI technique for the measurement of cerebral blood flow in whole brain and vascular territories

PURPOSE

To analyze the precision of cerebral blood flow (CBF) measurements made with continuous arterial spin labeling(CASL) perfusion magnetic resonance imaging (MRI) over experimentally relevant intervals.

MATERIALS AND METHODS

CASL perfusion MRI measurements of CBF on a 1.5-T GE Signa magnet were repeated in young healthy male and female subjects at one hour and one week. Precision of the measurement was evaluated at both time intervals.

RESULTS

CASL perfusion MRI measurements of CBF yielded within-subject coefficients of variation (wsCV) of 5.8% for global and 13% for individual vascular regions when measurements were repeated within one hour. Differences in these values represent the error in post-processing. Global and regional CBF measurements over one week yielded wsCVs of 13% and 14%, respectively. At one week, error secondary to physiologic variability affected global and regional measurements to the same degree and masked the software post-processing error seen at one hour. The magnitude of the difference in repeated measures correlated with the magnitude of the measurement.

CONCLUSION

CASL perfusion MRI CBF measurements are accurate and precise. Variability over longer periods of time appears attributable to physiologic factors. Repeatability of the CASL measurement is sensitive to the magnitude of the measurement. This should be taken into account when studies requiring repeated measures involve subjects with significant variability in CBF.

Functional data analysis with application to periodically stimulated foetal heart rate data. I: functional regression

Functional regression is used to model longitudinal data where the number of measurements on the functional covariate is much greater than the number of subjects in the study. Thus, functional regression can be thought of as singular longitudinal analysis. We have modified existing functional regression techniques to the case of a functional covariate with a repeated stimulus. We applied this modified functional regression to periodically stimulated foetal heart rates. The heart rate tracings were used as a predictor of the child's psychomotor development at approximately 18 months of age. In the past, this type of data has been analysed using the partially subjective concept of habituation. By using the entire heart rate tracings through functional regression, we have the advantage that habituation does not need to be defined and all available information is used to predict later child development.

Functional data analysis with application to periodically stimulated foetal heart rate data. II: functional logistic regression

We present a basis solution for the modelling of a binary response with a functional covariate plus any number of scalar covariates. This can be thought of as singular longitudinal data analysis as there are more measurements on the functional covariate than subjects in the study. The maximum likelihood parameter estimates are found using a basis expansion and a modified Fisher scoring algorithm. This technique has been extended to model a functional covariate with a repeated stimulus. We used periodically stimulated foetal heart rate tracings to predict the probability of a high risk birth outcome. It was found that these tracings could predict 94.1 per cent of the high risk pregnancies and without the stimulus, the heart rates were no more predictive than chance.

ASP1 (BACE2) cleaves the amyloid precursor protein at the beta-secretase site

Sequential proteolytic processing of the Amyloid Precursor Protein (APP) by beta- and gamma-secretases generates the 4-kDa amyloid (A beta) peptide, a key component of the amyloid plaques seen in Alzheimer's disease (AD). We and others have recently reported the identification and characterisation of an aspartic proteinase, Asp2 (BACE), as beta-secretase. Here we describe the characterization of a second highly related aspartic proteinase, Asp1 as a second beta-secretase candidate. Asp1 is expressed in brain as detected at the mRNA level and at the protein level. Transient expression of Asp1 in APP-expressing cells results in an increase in the level of beta-secretase-derived soluble APP and the corresponding carboxy-terminal fragment. Paradoxically there is a decrease in the level of soluble A beta secreted from the cells. Asp1 colocalizes with APP in the Golgi/endoplasmic reticulum compartments of cultured cells. Asp1, when expressed as an Fc fusion protein (Asp1-Fc), has the N-terminal sequence ALEP..., indicating that it has lost the prodomain. Asp1-Fc exhibits beta-secretase activity by cleaving both wild-type and Swedish variant (KM/NL) APP peptides at the beta-secretase site.

Characterization of the binding of [(125)I]-human prolactin releasing peptide (PrRP) to GPR10, a novel G protein coupled receptor

GPR10 is a novel G-protein coupled receptor that is the human orthologue of rat Unknown Hypothalamic Receptor-1 (UHR-1). Human prolactin-releasing peptide (PrRP) has been identified as an endogenous ligand for GPR10, and occurs as 31 and 20 amino acid forms. The present study characterizes the binding of [(125)I]-PrRP-20 to HEK293 cells stably expressing GPR10 receptors. Specific binding of [(125)I]-PrRP-20 was saturable, and analysis suggested evidence of both high and low affinity sites, with K:(D:) values of 0.026+/-0.006 and 0.57+/-0.14 nM respectively, and B(max) values of 3010+/-400 and 8570+/-2240 fmol mg protein(-1) respectively. Kinetic studies were unable to distinguish two sites, but single site analysis of association and dissociation data produced a K:(D:) of 0.012 nM. Competition studies revealed that human and rat PrRP-20 and PrRP-31 all display high affinity for GPR10. A range of other drugs which are known ligands at receptors which share limited homology with GPR10 were also tested. None of the drugs tested, including the RF-amide neuropeptide FF, demonstrated any affinity for GPR10. Human PrRP-20 failed to alter basal or forskolin-stimulated levels of intracellular cyclic AMP in HEK293-GPR10 cells, suggesting that GPR10 does not couple via either G(s) or G(i). Functional studies using measurements of intracellular calcium confirmed that human and rat PrRP-20 and PrRP-31 are all potent, full agonists at the GPR10 receptor. The response was blocked both by thapsigargin, indicating mobilization of intracellular Ca(2+) stores. These studies indicate that [(125)I]-PrRP-20 is a specific, high affinity radioligand for GPR10. The availability of this radioligand binding assay will be a valuable tool for the investigation of the key features involved in PrRP binding and studies on the localization and function of GPR10.

Hydroxy- and amino-protection based on the 4-dimethylcarbamoylbenzyl group

0-4-Dimethylcarbamoylbenzyl-L-tyrosine, N (epsilon)-4-dimethylcarbamoylbenzyloxycarbonyl-L-lysine, and simple derivatives, have been prepared. The protecting groups are markedly more stable to trifluoroacetic acid than are the unsubstituted benzylanalogues. N-t-Butoxycarbonyl-O-4-dimethylcarbamoylbenzyl-L-serine (cyclohexylammonium salt) is also described.