Sex Differences in Vascular Aging and Impact of GPER Deletion

Aging is a nonmodifiable risk factor for cardiovascular disease associated with arterial stiffening and endothelial dysfunction. We hypothesized that sex differences exist in vascular aging processes and would be attenuated by global deletion of the G protein-coupled estrogen receptor. Blood pressure was measured by tail cuff plethysmography, pulse wave velocity (PWV) and echocardiography were assessed with high resolution ultrasound, and small vessel reactivity was measured using wire myography in adult (25 weeks) and middle-aged (57 weeks) male and female mice. Adult female mice displayed lower blood pressure and PWV, but this sex difference was absent in middle-aged mice. Aging significantly increased PWV but not blood pressure in both sexes. Adult female carotids were more distensible than males, but this sex difference was lost during aging. Acetylcholine-induced relaxation was greater in female than male mice at both ages, and only males showed aging-induced changes in cardiac hypertrophy and function. GPER deletion removed the sex difference in PWV as well as ex vivo stiffness in adult mice. The sex difference in blood pressure was absent in KO mice and was associated with endothelial dysfunction in females. These findings indicate that the impact of aging on arterial stiffening and endothelial function is not the same in male and female mice. Moreover, nongenomic estrogen signaling through GPER impacted vascular phenotype differently in male and female mice. Delineating sex differences in vascular changes during healthy aging is an important first step in improving early detection and sex-specific treatments in our aging population.

Sex and the G Protein-Coupled Estrogen Receptor Impact Vascular Stiffness

[Figure: see text].

Alterations in the estrogen receptor profile of cardiovascular tissues during aging

Estrogen exerts protective effects on the cardiovascular system via three known estrogen receptors: alpha (ERα), beta (ERß), and the G protein-coupled estrogen receptor (GPER). Our laboratory has previously showed the importance of GPER in the beneficial cardiovascular effects of estrogen. Since clinical studies indicate that the protective effects of exogenous estrogen on cardiovascular function are attenuated or reversed 10 years post-menopause, the hypothesis was that GPER expression may be reduced during aging. Vascular reactivity and GPER protein expression were assessed in female mice of varying ages. Physiological parameters, blood pressure, and estrogen receptor transcripts via droplet digital PCR (ddPCR) were assessed in the heart, kidney, and aorta of adult, middle-aged, and aged male and female C57BL/6 mice. Vasodilation to estrogen (E2) and the GPER agonist G-1 were reduced in aging female mice and were accompanied by downregulation of GPER protein. However, ERα and GPER were the predominant receptors in all tissues, whereas ERß was detectable only in the kidney. Female sex was associated with higher mRNA for both ERα and GPER in both the aorta and the heart. Aging impacted receptor transcript in a tissue-dependent manner. ERα transcript decreased in the heart with aging, while GPER expression increased in the heart. These data indicate that aging impacts estrogen receptor expression in the cardiovascular system in a tissue- and sex-specific manner. Understanding the impact of aging on estrogen receptor expression is critical for developing selective hormone therapies that protect from cardiovascular damage.

Abstract P112: Sex Differences and the Role of G Protein-Coupled Estrogen Receptor in Arterial Stiffening

Pulse wave velocity (PWV) independently predicts cardiovascular events and is exacerbated in women following menopause. Since our previous work shows that G protein-coupled estrogen receptor (GPER) plays a protective role in the vasculature, the current study evaluated sex differences and the impact of GPER on arterial stiffening. We hypothesized that genetic deletion of GPER attenuates sex differences in arterial stiffness. Male and female wildtype (wt) and global GPER knockout (ko) mice (n=46) were used between 16-21 weeks of age. Ang II infusion (700 ng/kg/day for two weeks) was used to induce hypertension, and SBP was measured using tail cuff plethysmography. Local PWV within the carotid artery was obtained via high frequency ultrasound in both color Doppler and M-mode. The excised carotid was subjected to passive biaxial mechanical testing followed by four fiber family constitutive modeling. Statistical analysis was performed using two-way ANOVA with Sidak’s multiple comparisons test. Baseline SBP was significantly lower in females (P=0.035) but was not impacted by genotype. Baseline PWV was significantly higher in male versus female wt mice (P<0.01) but was not different in ko mice. Baseline axial (P<0.01) and circumferential (P=0.027) stiffness was higher in female wt mice but was not impacted by genotype. Ang II infusion significantly increased SBP (P<0.001) and PWV (P<0.001) in all groups, removing any impact of sex or genotype. Ang II increased axial stiffness and decreased diagonal collagen in male and female GPER ko mice. In conclusion, we found that GPER deletion did not impact blood pressure but removed sex differences in PWV. While female wt mice had the lowest PWV at baseline, genetic deletion of GPER or Ang II infusion removed this protection independent of BP. Therefore, local carotid PWV may provide information on vascular status independent of BP, and GPER plays an important role in vascular compliance and arterial stiffening.

Estrogen receptor profiles across tissues from male and female Rattus norvegicus

Background

Estrogen is formed by the enzyme aromatase (CYP19A1) and signals via three identified receptors ERα (ESR1), ERß (ESR2), and the G protein-coupled estrogen receptor (GPER). Understanding the relative contribution of each receptor to estrogenic signaling may elucidate the disparate effects of this sex hormone across tissues, and recent developments in PCR technology allow absolute quantification and direct comparison of multiple targets. We hypothesized that this approach would reveal tissue- and sex-specific differences in estrogen receptor mRNA.

Methods

ESR1, ESR2, GPER, and CYP19A1 were measured in four cardiovascular tissues (heart, aorta, kidney, and adrenal gland), three brain areas (somatosensory cortex, hippocampus, and prefrontal cortex), and reproductive tissues (ovaries, mammary gland, uterus, testes) from six male and six female adult Sprague-Dawley rats.

Results

GPER mRNA expression was relatively stable across all tissues in both sexes, ranging from 5.49 to 113 copies/ng RNA, a 21-fold difference. In contrast, ESR1/ESR2 were variable across tissues although similar within an organ system. ESR1 ranged from 4.46 to 614 copies/ng RNA (138-fold difference) while ESR2 ranged from 0.154 to 83.1 copies/ng RNA (540-fold). Significant sex differences were broadly absent except for renal ESR1 (female 206 vs. male 614 copies/ng RNA, P < 0.0001) and GPER (62.0 vs. 30.2 copies/ng RNA, P < 0.05) as well as gonadal GPER (5.49 vs. 47.5 copies/ng RNA, P < 0.01), ESR2 (83.1 vs. 0.299 copies/ng RNA, P < 0.01), and CYP19A1 (322 vs. 7.18 copies/ng RNA, P < 0.01). Cardiovascular tissues showed a predominance of ESR1, followed by GPER. In contrast, GPER was the predominant transcript in the brain with similarly low levels of ESR1 and ESR2. CYP19A1 was detected at very low levels except for reproductive tissues and the hippocampus.

Conclusion

While the data indicates a lack of sex differences in most tissues, significant differences were found in the range of receptor gene expression across tissues as well as in the receptor profile between organ systems. The data provide a guide for future studies by establishing estrogen receptor expression across multiple tissues using absolute PCR quantification. This knowledge on tissue-specific estrogen receptor profiles will aid the development of hormonal therapies that elicit beneficial effects in specific tissues.

G Protein-Coupled Estrogen Receptor Protects From Angiotensin II-Induced Increases in Pulse Pressure and Oxidative Stress

Our previous work showed that the G protein-coupled estrogen receptor (GPER) is protective in the vasculature and kidneys during angiotensin (Ang) II-dependent hypertension by inhibiting oxidative stress. The goal of the current study was to assess the impact of GPER deletion on sex differences in Ang II-induced hypertension and oxidative stress. Male and female wildtype and GPER knockout mice were implanted with radiotelemetry probes for measurement of baseline blood pressure before infusion of Ang II (700 ng/kg/min) for 2 weeks. Mean arterial pressure was increased to the same extent in all groups, but female wildtype mice were protected from Ang II-induced increases in pulse pressure, aortic wall thickness, and Nox4 mRNA. In vitro studies using vascular smooth muscle cells found that pre-treatment with the GPER agonist G-1 inhibited Ang II-induced ROS and NADP/NADPH. Ang II increased while G-1 decreased Nox4 mRNA and protein. The effects of Ang II were blocked by losartan and Nox4 siRNA, while the effects of G-1 were inhibited by adenylyl cyclase inhibition and mimicked by phosphodiesterase inhibition. We conclude that during conditions of elevated Ang II, GPER via the cAMP pathway suppresses Nox4 transcription to limit ROS production and prevent arterial stiffening. Taken together with our previous work, this study provides insight into how acute estrogen signaling via GPER provides cardiovascular protection during Ang II hypertension and potentially other diseases characterized by increased oxidative stress.

Transabdominal Intrapericardial Approach in Liver Transplantation for Unresectable Primary Hepatic Functioning Paraganglioma With Invasion Into Hepatic Veins and Suprahepatic Vena Cava: A Surgical and Anesthesia Management Challenge

Primary hepatic functional paraganglioma is a rare form of extra-adrenal catecholamine-secreting tumor. Definitive treatment of functioning paraganglioma is challenging because of the critical location of the tumor frequently in close proximity to vital structures and risk of excessive catecholamine release during operative manipulation. We report the multidisciplinary management approach for a case of unresectable primary hepatic functional paraganglioma with invasion into the hepatic veins and suprahepatic vena cava. To our knowledge, this is the first report showing that orthotopic liver transplantation is curative for patients with unresectable primary hepatic paraganglioma. For locally advanced unresectable hepatic paraganglioma that involves the intrapericardial vena cava, a meticulous pre- and intraoperative medical management and transabdominal intrapericardial vascular control of the suprahepatic vena cava during orthotopic liver transplantation allows for complete extirpation of the tumor and achieves optimal outcome.

Impact of a Transplantation Critical Care Model on Short-Term Outcomes Following Liver Transplantation in High Acuity Patients: A Single-Center Experience

BACKGROUND

Orthotopic liver transplantation (OLT) is the definitive treatment for end-stage liver disease (ESLD). Patients with high acuity ESLD are frequently denied life-saving OLT by transplant centers due to reported inferior outcomes. We sought to analyze the impact of a specialized transplant critical care model (TCCM) on patient access to OLT and survival outcomes in high acuity patients.

METHODS

From January 2009 to December 2016, 122 adults were wait-listed at our transplant center with laboratory Model for ESLD ≥35 or Status I. Outcomes in Era I (prior to TCCM) were compared to Era II (TCCM established October 1, 2012).

RESULTS

Era II (TCCM) led to a significant increase in patients' access to OLT. Frequency and need to seek OLT at another center dropped 4-fold in Era II. Compared to Era I, the majority of patients in Era II required intensive care unit management (22% vs 83%, P < .01) and renal replacement therapy (11% vs 70%, P < .01) prior to OLT. Despite a higher acuity of illness in Era II, 1-year patient survival was comparable (89% Era I, 80% Era II, P = .35).

CONCLUSION

Implementation of a specialized TCCM expanded OLT access to high acuity patients, reduced the need to seek higher level of care elsewhere, and achieved excellent short-term post-transplant survival outcomes.

Abstract 113: Female Protection From Arterial Stiffness Diminishes With G Protein-Coupled Estrogen Receptor Deletion or Angiotensin II Hypertension

Arterial stiffness independently predicts cardiovascular mortality, coronary events, and stroke in hypertensive subjects and is exacerbated in women following menopause. Previously, our laboratory indicated that G protein-coupled estrogen receptor (GPER) plays a protective role in the vasculature. Therefore, the current study assessed the impact of sex and GPER on arterial stiffening in control and hypertensive conditions. We hypothesized that genetic deletion of GPER attenuates sex differences in arterial stiffness. Male and female wildtype (wt) and global GPER knockout (ko) mice (n=46) were used between 16-21 weeks of age. Angiotensin II (Ang II) infusion (700 ng/kg/day for two weeks) was used to induce hypertension, and systolic blood pressure (SBP) was measured using tail cuff plethysmography. Local pulse wave velocity (PWV) within the carotid artery was obtained via high frequency ultrasound in both color Doppler and M-mode. Statistical analysis was performed using two-way ANOVA with Sidak’s multiple comparisons test. Baseline SBP was significantly lower in females (P=0.035) but was not impacted by genotype (P=0.78). Baseline PWV was significantly higher in male versus female wt mice (1.29 vs. 0.804 m/s, P=0.003) but was not different in ko mice (1.25 vs. 1.04 m/s, P=0.22). Ang II infusion significantly increased SBP (P<0.001) and PWV (P<0.001) in all groups, removing any impact of sex or genotype. In addition, significant correlations were found between Doppler and M-mode methods for obtaining carotid PWV (r=0.67, P<0.001) and between PWV and ex vivo carotid wall thickness (r=0.70, P=0.004). In contrast, SBP did not correlate with PWV (P=0.77) or carotid wall thickness (P=0.68). In conclusion, we found that GPER deletion did not impact blood pressure either in normotensive or hypertensive conditions. While arteries from female wt mice were less stiff at baseline, genetic deletion of GPER or Ang II infusion removed this protection independent of blood pressure. Moreover, we found that local carotid PWV provides information on vascular status that could not be obtained via blood pressure. This data indicates that GPER plays an important role in female vascular physiology that is absent in pathological conditions.

New insights into arterial stiffening: does sex matter?

This review discusses sexual dimorphism in arterial stiffening, disease pathology interactions, and the influence of sex on mechanisms and pathways. Arterial stiffness predicts cardiovascular mortality independent of blood pressure. Patients with increased arterial stiffness have a 48% higher risk for developing cardiovascular disease. Like other cardiovascular pathologies, arterial stiffness is sexually dimorphic. Young women have lower stiffness than aged-matched men, but this sex difference reverses during normal aging. Estrogen therapy does not attenuate progressive stiffening in postmenopausal women, indicating that currently prescribed drugs do not confer protection. Although remodeling of large arteries is a protective adaptation to higher wall stress, arterial stiffening increases afterload to the left ventricle and transmits higher pulsatile pressure to smaller arteries and target organs. Moreover, an increase in aortic stiffness may precede or exacerbate hypertension, particularly during aging. Additional studies are needed to elucidate the mechanisms by which females are protected from arterial stiffness to provide insight into its mechanisms and, ultimately, therapeutic targets for treating this pathology.

Long- but not short-term estradiol treatment induces renal damage in midlife ovariectomized Long-Evans rats

Clinical recommendations limit menopausal hormone therapy to a few years, yet the impact of a shorter treatment duration on cardiovascular health is unknown. We hypothesized that both short- and long-term estradiol (E2) treatment exerts positive and lasting effects on blood pressure, vascular reactivity, and renal health. This study was designed to mimic midlife menopause, followed by E2 treatment, that either followed or exceeded the current clinical recommendations. Female Long-Evans retired breeders were ovariectomized (OVX) at 11 mo of age and randomized into three groups: 80-day (80d) vehicle (Veh>Veh), 40-day (40d) E2 + 40d vehicle (E2>Veh), and 80d E2 (E2>E2). In comparison to Veh>Veh, both the E2>Veh and E2>E2 groups had lower systolic blood pressure and enhanced mesenteric relaxation in response to estrogen receptor-α stimulation. Despite the reduced blood pressure, E2>E2 induced renal and cardiac hypertrophy, reduced glomerular filtration, and increased proteinuria. Interestingly, kidneys from E2>Veh rats had significantly fewer tubular casts than both of the other groups. In conclusion, long-term E2 lowered blood pressure but exerted detrimental effects on kidney health in midlife OVX Long-Evans rats, whereas short-term E2 lowered blood pressure and reduced renal damage. These findings highlight that the duration of hormone therapy may be an important factor for renal health in aging postmenopausal women.

GPER activation ameliorates aortic remodeling induced by salt-sensitive hypertension

The mRen2 female rat is an estrogen- and salt-sensitive model of hypertension that reflects the higher pressure and salt sensitivity associated with menopause. We previously showed that the G protein-coupled estrogen receptor (GPER) mediates estrogenic effects in this model. The current study hypothesized that GPER protects against vascular injury during salt loading. Intact mRen2 female rats were fed a normal (NS; 0.5% Na(+)) or high-salt diet (HS; 4% Na(+)) for 10 wk, which significantly increased systolic blood pressure (149 ± 5 vs. 224 ± 8 mmHg;P< 0.001). Treatment with the selective GPER agonist G-1 for 2 wk did not alter salt-sensitive hypertension (216 ± 4 mmHg;P> 0.05) or ex vivo vascular responses to angiotensin II or phenylephrine (P> 0.05). However, G-1 significantly attenuated salt-induced aortic remodeling assessed by media-to-lumen ratio (NS: 0.43; HS+veh: 0.89; HS+G-1: 0.61;P< 0.05). Aortic thickening was not accompanied by changes in collagen, elastin, or medial proliferation. However, HS induced increases in medial layer glycosaminoglycans (0.07 vs. 0.42 mm(2);P< 0.001) and lipid peroxidation (0.11 vs. 0.51 mm(2);P< 0.01), both of which were reduced by G-1 (0.20 mm(2)and 0.23 mm(2); both P< 0.05). We conclude that GPER's beneficial actions in the aorta of salt-loaded mRen2 females occur independently of changes in blood pressure and vasoreactivity. GPER-induced attenuation of aortic remodeling was associated with a reduction in oxidative stress and decreased accumulation of glycosaminoglycans. Endogenous activation of GPER may protect females from salt- and pressure-induced vascular damage.

Abstract P043: Estradiol Treatment Duration Significantly Impacts Renal Health in Midlife Ovariectomized Female Long Evans Rats

Current clinical recommendations are that hormone therapy for the treatment of menopausal symptoms be limited to a few years. Our lab previously reported that both transient (40 days) and sustained (80 days) estradiol (E2) treatment initiated immediately after midlife ovariectomy (OVX) in Long Evans rats similarly attenuated OVX-induced increases in blood pressure (BP). This study indicated that the benefits of E2 could be maintained long after treatment cessation. Therefore, the goal of the current study was to determine whether E2 duration similarly protected against renal damage. We hypothesized that both transient and sustained E2 treatment exert positive effects on renal health in midlife OVX Long Evans female rats. Female retired breeders underwent OVX at 11 months of age and received an implant of E2 or vehicle (veh). After 40 days, implants were replaced comprising the following groups: veh>veh (n=9), E2>E2 (n=7), E2>veh (n=10). Animals were placed in metabolic cages at both the 40 and 80 day treatment time points to measure proteinuria, urinary peptides, and creatinine excretion. At the end of the 80 day treatment tissue weights were obtained. Interestingly, kidney hypertrophy was significantly increased in the E2>E2 when analyzed as raw wet weight (veh: 1.0 ± 0.05 g; E2>veh: 0.95 ± 0.02; E2>E2: 1.2 ± 0.04; P<0.0001), or normalized to body weight (veh: 2.5 ± 0.1 mg/gBW; E2>veh: 2.5 ± 0.03; E2>E2: 2.9 ± 0.11; P<0.005). Creatinine excretion was not different between groups (veh: 7.0 ± 0.6 mg/day; E2>veh: 6.4 ± 0.4; E2>E2: 7.6 ± 0.7; P=0.29). However, there was a significant increase in proteinuria measured by the Bradford assay in the E2>E2 group (veh: 2.0 ± 0.8 mg/mgCr; E2>veh: 0.9 ± 0.3; E2>E2: 6.8 ± 2.6; P<0.05). The E2>E2 group also had a significantly lower percentage of urinary peptides (veh: 96 ± 0.8%; E2>veh: 97 ± 0.7%; E2>E2: 79 ± 8.1%; P<0.05), indicating impaired renal function. These results indicate that in midlife OVX Long Evans rats, sustained E2 lowered BP but exerted detrimental effects on kidney function. In contrast, transient E2 treatment lowered BP without renal impairment. Overall, our results indicate that the period of exposure to estradiol may be important for renal health in aging postmenopausal women.

Abstract 079: G Protein-Coupled Estrogen Receptor Deletion Exacerbates Pulse Pressure in Female but not Male Hypertensive Mice

The protective cardiovascular effects of estrogen are mediated by both the classic steroid receptors (ERα/β) and the novel G protein-coupled estrogen receptor (GPER). Our previous work demonstrates a role for GPER in the beneficial effects of estrogen on blood pressure, vascular tone, end organ damage, and aortic remodeling in hypertensive females, due to both direct vasodilatory effects and local regulation of the renin-angiotensin system. Therefore, we hypothesized that genetic deletion of GPER in female mice exacerbates Ang II-induced hypertension and associated tissue damage. Male (M) and female (F) wt and GPER ko mice were implanted with radiotelemetry probes at 11-13 weeks of age to measure baseline blood pressure before infusing Ang II (700 ng/kg/min) for two weeks. MAP (in mmHg) was similar at baseline (F-wt: 108 ± 2, n=4, F-ko: 105 ± 2, n=3, M-wt: 106 ± 4, n=3, and M-ko: 105 ± 0.5, n=3; P = 0.62), and after Ang II (F-wt: 136 ± 11, F-ko: 131 ± 3, M-wt: 148 ± 7, M-ko: 135 ± 5; P=0.51). Pulse pressure was significantly higher in response to Ang II in both sexes (*P<0.0001), and GPER deletion exacerbated this increase in females (30 ± 1 vs 43 ± 4 mmHg, *P<0.05) but not males (37 ± 3 vs. 39 ± 4, P=0.61). Further evaluation of the circadian pattern revealed that pulse pressure was particularly higher in F-ko during the day (28 ± 1 vs. 40 ± 4 mmHg, *P<0.05). Moreover, F-ko mesenteric arteries exhibited enhanced contractility to both receptor-dependent (PGF2α, *P<0.05) and receptor-independent (KCl, *P<0.05) stimulation. Our findings indicate that in females with intact ERα/β signaling, GPER deletion does not alter the initial pressor response to Ang II but exacerbates pulse pressure and resistance artery contractility during hypertension. Pulse pressure is an indirect measure of arterial stiffness and an independent risk factor for adverse cardiovascular events. While pulse pressure increases with aging in both sexes, this increase is markedly exacerbated in women. Our results indicate that loss of endogenous GPER activation due to low circulating estrogen may underlie increased pulse pressure in aging postmenopausal women.

Differences in angiotensin (1-7) between men and women

In experimental animal models of hypertension, angiotensin (1-7) [ANG-(1-7)] is higher in females compared with males; however, it is less clear whether the same applies to humans. Therefore, this study sought to compare circulating concentrations of ANG-(1-7) in apparently healthy men and women under normal physiological conditions. With the use of a cross-sectional experimental design, blood was collected in EDTA anticoagulant from 42 volunteers (21 men and 21 women; and age range, 19-48 yr) for analysis of plasma concentrations of ANG-(1-7) and ANG II. Blood pressure was measured and vascular endothelial function was determined (n = 25) using the brachial artery flow-mediated dilation (FMD) test. As a result, women exhibited a higher circulating concentration of ANG-(1-7) (P = 0.04) compared with men, whereas values of ANG II were similar between groups. Baseline arterial diameter, peak diameter, and shear rate were significantly greater (P < 0.02) in men compared with women. No significant differences in FMD, FMD normalized for shear, or time to peak dilation were observed between men and women. In addition, a positive correlation between ANG-(1-7) and FMD (P = 0.04) and negative association between ANG-(1-7) with ANG II (P = 0.01) were only identified in men, whereas a positive relationship between ANG-(1-7) and diastolic blood pressure (P = 0.03) was observed in women.

IN CONCLUSION

, women exhibit significantly higher plasma concentrations of ANG-(1-7) compared with men. In addition, this study describes a relationship between ANG-(1-7), vascular function, and diastolic blood pressure that appears to be sex dependent.

Chronic ANG II infusion induces sex-specific increases in renal T cells in Sprague-Dawley rats

Recent studies suggest that sex of the animal and T cell impact ANG II hypertension in Rag(-/-) mice, with females being protected relative to males. This study tested the hypothesis that ANG II results in greater increases in proinflammatory T cells and cytokines in males than in females. Male and female Sprague-Dawley (SD) rats, aged 12 wk, were treated with vehicle or ANG II (200 ng·kg(-1)·min(-1)) for 2 wk. Renal CD4(+) T cells and Tregs were comparable between vehicle-treated males and females, although males expressed more Th17 and IL-17(+) T cells and fewer IL-10(+) T cells than females. ANG II resulted in greater increases in CD4(+) T cells, Th17 cells, and IL-17(+) cells in males; Tregs increased only in females. We previously showed that ANG (1-7) antagonizes ANG II-induced increases in blood pressure in females and ANG (1-7) has been suggested to be anti-inflammatory. Renal ANG (1-7) levels were greater in female SD at baseline and following ANG II infusion. Additional rats were treated with ANG II plus the ANG (1-7)-mas receptor antagonist A-779 (48 μg·kg(-1)·h(-1)) to test the hypothesis that greater ANG (1-7) in females results in more Tregs relative to males. Inhibition of ANG (1-7) did not alter renal T cells in either sex. In conclusion, ANG II induces a sex-specific effect on the renal T cell profile. Males have greater increases in proinflammatory T cells, and females have greater increases in anti-inflammatory Tregs; however, sex differences in the renal T cell profile are not mediated by ANG (1-7).

Sirolimus reduces the risk of significant hepatic fibrosis after liver transplantation for hepatitis C virus: a single-center experience

INTRODUCTION

Hepatitis C virus (HCV) recurrence following orthotopic liver transplantation is an expected outcome in all patients transplanted for a primary diagnosis of HCV. HCV recurrence has been shown to be associated with graft fibrosis and graft loss. Recent studies suggest that sirolimus (SRL) therapy may slow or inhibit hepatic fibrosis following liver transplant in patients positive for HCV at the time of transplant.

METHODS

Among 313 patients who underwent orthotopic liver transplantation for HCV between 2000 and 2009, 251 qualified for inclusion in the study. Per protocol liver biopsies were performed on all patients at 1 year following liver transplantation and/or at the time of a clinical diagnosis of HCV recurrence. Biopsies were scored for fibrosis using the Batts-Ludwig staging system (0-4); significant fibrosis was defined as fibrosis ≥ stage 2.

RESULTS

Overall, there was no difference in overall survival or graft loss in the SRL compared with the control group. Multivariate analysis revealed SRL therapy to be associated with decreased odds of significant hepatic fibrosis at year 1 postoperatively and over the study duration.

CONCLUSIONS

This retrospective, single-center study showed sirolimus-based immunosuppression to be associated with a lower risk of significant graft fibrosis, both at year 1 and throughout the study period, following liver transplantation in HCV-infected recipients.

Female spontaneously hypertensive rats are more dependent on ANG (1-7) to mediate effects of low-dose AT1 receptor blockade than males

ANG (1-7) contributes to the blood pressure (BP)-lowering effect of angiotensin receptor blockers (ARBs) in male experimental animals. Females have greater ANG (1-7) concentrations than males; however, the contribution of ANG (1-7) to ARB-mediated decreases in BP in females is unknown. The current study tested the hypothesis that female spontaneously hypertensive rats (SHR) have a larger ANG (1-7) contribution to the BP-lowering effects of the ARB candesartan than male SHR. Twelve-week-old male and female SHR were randomized to receive candesartan (0.5 mg·kg(-1)·day(-1); 7 days), candesartan plus ANG II (200 ng·kg(-1)·min(-1); 7 days), the ANG (1-7) antagonist A-779 (48 μg·kg(-1)·h(-1)) plus candesartan and ANG II. Candesartan decreased basal BP in males and females (baseline vs. candesartan: 142 ± 2 vs. 122 ± 3 and 129 ± 1 vs. 115 ± 1 mmHg, respectively; P < 0.05); however, the decrease was greater in males. ANG II increased BP in males in the presence of candesartan (149 ± 2 mmHg; P < 0.05); candesartan blocked ANG II-induced increases in BP in females (116 ± 1 mmHg). Pretreatment with A-779 abolished candesartan-mediated decreases in BP in females, but not males. A-779 also exacerbated ANG II-induced proteinuria (26 ± 6 vs. 77 ± 11 μg·kg(-1)·day(-1), respectively; P < 0.05) and nephrinuria (20 ± 5 vs. 202 ± 58 μg·kg(-1)·day(-1), respectively; P < 0.05) in candesartan-treated female SHR, with no effect in males. In conclusion, females are more sensitive to the BP-lowering effect of ARBs during ANG II infusion, whereas males are more sensitive under basal conditions. In addition, ANG (1-7) has a greater contribution to ARB-mediated decreases in BP, protein, and nephrin excretion in females relative to males.

Hypertension: what's sex got to do with it?

Hypertension is a complex and multifaceted disease, and there are well established sex differences in many aspects of blood pressure (BP) control. The intent of this review is to highlight recent work examining sex differences in the molecular mechanisms of BP control in hypertension to assess whether the "one-size-fits-all" approach to BP control is appropriate with regard to sex.

Biological implications of extracellular adenosine in hepatic ischemia and reperfusion injury

The purine nucleoside adenosine is clinically employed in the treatment of supraventricular tachycardia. In addition, it has direct coronary vasodilatory effects, and may influence platelet aggregation. Experimental observations mechanistically link extracellular adenosine to cellular adaptation to hypoxia. Adenosine generation has been implicated in several pathophysiologic processes including angiogenesis, tumor defenses and neurodegeneration. In solid organ transplantation, prolonged tissue ischemia and subsequent reperfusion injury may lead to profound graft dysfunction. Importantly, conditions of limited oxygen availability are associated with increased production of extracellular adenosine and subsequent tissue protection. Within the rapidly expanding field of adenosine biology, several enzymatic steps in adenosine production have been characterized and multiple receptor subtypes have been identified. In this review, we briefly examine the biologic steps involved in adenosine generation and chronicle the current state of adenosine signaling in hepatic ischemia and reperfusion injury.

Abstract 254: Chronic Ang II Hypertension Differentially Impacts the Renal T Cell Profile in Males and Females

T cells contribute to angiotensin (Ang) II hypertension in male animal models yet less is known in females. We previously showed that hypertensive female rats have more immuno-suppressive T regulatory cells (Tregs) and males have more pro-inflammatory Th17 cells in their kidneys. This study tested the hypothesis that Ang II results in greater expression of renal Tregs in females and Th17 cells in males. 12 wk old male and female Sprague Dawley rats (SD) were treated with Ang II (200 ng/kg/min) or vehicle for 2 wks; blood pressure (BP) was measured via tail cuff and renal T cell profiles were measured via flow cytometry. Ang II infusion increased BP in both sexes (mmHg: males: 130±2 to 152±2; females: 123±1 to 146±1; p<0.05). Females had lower CD3 + T cell counts at baseline vs. males (p<0.0001). Ang II significantly increased CD3 + T cells in both sexes (p<0.0001). Baseline CD4 + T cell counts were comparable between male and female SD. Ang II infusion increased CD4 + T cells in both sexes (p<0.0001), however, expression remained lower in females (p=0.04). Females had greater expression of Tregs (p<0.0001) at baseline. Ang II infusion increased Treg expression in females (p=0.004), with no effect in males. Males expressed more baseline Th17 cells than females (p<0.001). Though Ang II increased levels in both sexes (p<0.001), females maintained significantly reduced Th17 cell expression vs. males (p<0.001). Therefore, Ang II resulted in female SD having greater renal expression of Tregs and males having greater expression of Th17 cells. In conclusion, sex differences in the T cell profile may contribute to observed sex differences in BP control.

Abstract 513: Impact of Sex and Race on Angiotensin (1-7) in Humans

Approximately 30% of American adults are diagnosed with hypertension; however, only ~50% achieve adequate blood pressure (BP) control with current therapeutic options. Preclinical data demonstrate that a sexual dimorphism exists for angiotensin 1-7 (Ang (1-7)), a vasodilatory peptide that has therapeutic promise in controlling BP. This study sought to determine if 1) sex and race differences in Ang (1-7) are present in normotensives adults, and 2) increases in Ang (1-7) are related to lower BP in hypertensive adults. Blood samples, BP, and flow-mediated dilation (FMD, n=29) were assessed in 45 adults (52% women, 44% African American (AA)). Systolic BP was lower (p=0.013) in women compared to men (111±4 mm Hg vs. 126±4 mm Hg) and higher (p=0.024) in AA compared to Caucasians (C; 125±4 mm Hg vs. 111±4 mm Hg). Diastolic BP was higher (p=0.021) in AA compared to C (77±3 mm Hg vs. 65±4 mm Hg). Overall, Ang (1-7) was highest in C women (44±5 pg/ml) followed by AA women (38±5 pg/ml), C men (33±4 pg/ml), and AA men (30±6 pg/ml). Only within C was a significant correlation between FMD and Ang (1-7) observed (r=0.573;p=0.041). Overall, the change in Ang (1-7) following treatment with candesartan (n=6) was positively associated with the change in FMD (r=0.485) and inversely associated with the change in systolic BP (r=-0.431). These data are the first to identify, in humans, the existence of a sexual and racial dimorphism in Ang (1-7). Our findings support the therapeutic potential of Ang (1-7) to reduce BP and improve endothelial function in hypertensive adults.

Sex differences in angiotensin-converting enzyme modulation of Ang (1-7) levels in normotensive WKY rats

BACKGROUND

Levels of the vasodilatory peptide angiotensin (Ang) (1-7) have been reported to be greater in females than in males, although the molecular mechanism responsible for this is unknown. Angiotensin-converting enzyme (ACE), ACE2, and neprilysin are key enzymes regulating Ang (1-7) formation. We conducted a study to determine the effect of sex on the activities of ACE, ACE2, and neprilysin in the kidneys of normotensive rats. We hypothesized that greater ACE2 or neprilysin activity in females would result in enhanced Ang (1-7) formation as compared with that in males.

METHODS

We measured the enzymatic activities of ACE, ACE2, and neprilysin in the renal cortex and medulla of 12-week-old male and female WKY rats. We treated additional rats with vehicle or enalapril (10 mg/kg/day in drinking water) for 14 days, and measured their Ang II and Ang (1-7) levels.

RESULTS

Renal cortical activity of ACE was greater in female than in male WKY rats (P < 0.05), but the activity of ACE in the renal medulla was not significantly different in the two sexes. Renal cortical and medullary ACE2 and neprilysin activities were comparable in male and female WKY rats. Treatment with enalapril significantly decreased Ang II levels in the renal cortex and medulla of male and female WKY rats as compared with those in vehicle-treated controls (P < 0.05); enalapril did not change the plasma levels of Ang II. Cortical levels of Ang (1-7) were higher in vehicle-treated females than in vehicle-treated males (P < 0.05), and treatment with enalapril decreased Ang (1-7) levels only in females (P < 0.05).

CONCLUSIONS

Our data supports a role for ACE in the formation of renal cortical Ang (1-7) in female WKY rats that is absent in males.

Functional evolution of C(4) pyruvate, orthophosphate dikinase

Pyruvate,orthophosphate dikinase (PPDK) plays a controlling role in the PEP-regeneration phase of the C(4) photosynthetic pathway. Earlier studies have fully documented its biochemical properties and its post-translational regulation by the PPDK regulatory protein (PDRP). However, the question of its evolution into the C(4) pathway has, until recently, received little attention. One assumption concerning this evolution is that changes in catalytic and regulatory properties of PPDK were necessary for the enzyme to fulfil its role in the C(4) pathway. In this study, the functional evolution of PPDK from its ancient origins in the Archaea to its ascension as a photosynthetic enzyme in modern C(4) angiosperms is reviewed. This analysis is accompanied by a comparative investigation into key catalytic and regulatory properties of a C(3) PPDK isoform from Arabidopsis and the C(4) PPDK isoform from Zea mays. From these analyses, it is proposed that PPDK first became functionally seated in C(3) plants as an ancillary glycolytic enzyme and that its transition into a C(4) pathway enzyme involved only minor changes in enzyme properties per se.

Antiviral prophylaxis and recurrence of hepatocellular carcinoma following liver transplantation in patients with hepatitis B

BACKGROUND

Orthotopic liver transplantation (OLT) is a viable treatment option for patients with hepatitis B (HBV) and concomitant hepatocellular carcinoma (HCC). However, cancer recurrence following transplantation approaches 20%. This study sought to identify the clinical and pathological factors associated with post-OLT survival.

METHODS

Univariate and multivariate analyses considered the following variables: combination viral prophylaxis, HBV recurrence, tumor stage, vascular invasion, distribution, nodularity, pre- and post-OLT tumor size, pre-OLT alpha-fetoprotein (AFP), Milan and UCSF criteria, and Asian race.

RESULTS

Cumulatively, HCC recurrence-free survival was 77%, 62%, and 53% at 1, 3, and 5 years, respectively, and was significantly better in patients who were free of viral recurrence post-OLT. Similarly, patients treated with combination prophylaxis had a significantly lower mortality than those who were not.

CONCLUSIONS

Multivariate analysis revealed that AFP>500 ng/mL, presence of vascular invasion by explant, HBV recurrence, and combination prophylaxis were independent predictors of HCC recurrence-free survival.

Split Liver Transplantation

Seventy-five thousand Americans develop organ failure each year. Fifteen percent of those on the list for transplantation die while waiting. Several possible mechanisms to expand the organ pool are being pursued including the use of extended criteria donors, living donation, and split deceased donor transplants. Cadaveric organ splitting results from improved understanding of the surgical anatomy of the liver derived from Couinaud. Early efforts focused on reduced-liver transplantation (RLT) reported by both Bismuth and Broelsch in the mid-1980s. These techniques were soon modified to create both a left lateral segment graft appropriate for a pediatric recipient and a right trisegment for an appropriately sized adult. Techniques of split liver transplantation (SLT) were also modified to create living donor liver transplantation. Pichlmayr and Bismuth reported successful split liver transplantation in 1989 and Emond reported a larger series of nine split procedures in 1990. Broelsch and Busuttil described a technical modification in which the split was performed in situ at the donor institution with surgical division completed in the heart beating cadaveric donor. In situ splitting reduces cold ischemia, simplifies identification of biliary and vascular structures, and reduces reperfusion hemorrhage. However, in situ splits require specialized skills, prolonged operating room time, and increased logistical coordination at the donor institution. At UCLA over 120 in situ splits have been performed and this technique is the default when an optimal donor is available. Split liver transplantation now accounts for 10% of adult transplantations at UCLA and 40% of pediatric transplantations.

Surgical applications of organ preconditioning

In 1986, Murry et al. reported that brief periods of antecedent ischemia in dogs paradoxically reduced (rather than exacerbated) the size of myocardial infarcts created by subsequent prolonged ischemia. This fortuitous discovery, now termed "preconditioning", stimulated further investigation of the inherent adaptive mechanisms present in a variety of tissues and organs. In addition to ischemia, it is now recognized that a protective response can be initiated by multiple means including lipopolysaccharide, heat stress, exercise, adrenergic drugs and even noise. Furthermore, preconditioning protects not only against cell death but also against postischemic contractile dysfunction, stunning and arrhythmias. Despite the preponderance of animal studies demonstrating the benefits of preconditioning, its clinical application has been hampered by clinicians' hesitancy to intentionally subject patients to a noxious stress prior to a planned intervention. However, many of the intracellular signals responsible for the protective effect of preconditioning have been delineated, and pharmacologic manipulation of these signals can accomplish the same benefits. The existence of preconditioning in humans has been demonstrated in vitro and in small clinical trials, and targeted strategies that exploit this endogenous protective mechanism promise to broaden the therapeutic potential of organ preconditioning.

Clinical applications of cardiovascular angiogenesis

Angiogenesis is fundamental to both normal physiologic (wound healing) and pathologic (cancer) processes. Manipulation of divergent angiogenic signals promises effective therapy of atherosclerotic cardiovascular disease. Positive proangiogenic strategies promise collateral circulation to ischemic territories, while negative antiangiogenic strategies starve the fibromuscular proliferation within the atherosclerotic lesion. Indeed, recent phase 1 trials suggest that delivering DNA or recombinant protein to the site of vascular occlusion may stimulate physiologically significant collateral circulation in chronically ischemic myocardium. While symptomatic and functional improvement has been documented, toxicity profiles and effects on long-term patient survival are still unclear. The purposes of this article are as follows: (1) to review the pathophysiologic basis for pro- and antiangiogenic strategies in the treatment of cardiovascular disease, (2) to examine the clinical trials of proangiogenic gene or recombinant protein delivery into ischemic beds, and conversely, (3) to explore antiangiogenic strategies in the prevention and treatment of intimal neovascularization and smooth muscle proliferation within the vessel wall.

Organ preconditioning

The initial discovery of cardiac preconditioning has evolved into an exciting series of practical surgical applications. An enormous amount of evidence demonstrating both the safety and efficacy of ischemic preconditioning is available from animal studies. The challenging premise of intentionally subjecting patients and their organs to transient ischemia has acted as a formidable psychological and ethical impediment to the widespread clinical application of organ preconditioning. A more palatable alternative to ischemic preconditioning now involves approved medications designed to manipulate the cellular machinery mediating ischemic preconditioning. Pharmacologically induced preconditioning seems to confer equal organ protection. The relatively brief (but surgically relevant) window of protection provided by strategies such as ischemic preconditioning or adenosine agonists and potassium-adenosine triphosphate channel openers may, in the future, be extended. We have developed and reported the feasibility of liposomal delivery of heat shock protein to cardiac myocytes with subsequent protection against sepsis-induced dysfunction. Targeted strategies will ultimately broaden the therapeutic potential of organ preconditioning.

Psychosocial outcomes of urban African American adolescents born to teenage mothers

This is a study of psychosocial outcomes of adolescents born to teenage mothers. Adolescents'problem behaviors, psychological well-being, social support, school variables, and sexual behaviors are compared across three groups- those born to mothers 17 or younger, mothers 18-19 years old, and mothers 20 or older. Analyses from two samples of African American adolescents from Maryland (n = 205) and Michigan (n = 570) are reported. The results from both samples indicate that mother's age at birth is unrelated to adolescents' psychosocial outcomes. These two studies add to the limited number of analyses that examine adolescent outcomes for children of teen mothers. The results suggest that efforts to understand social structural determinants of healthy and problematic adolescent development may be more informative than examining the effects of mother's age. They also suggest that teen pregnancy prevention programs may be more effective if they are part of a larger prevention strategy that incorporates social structural change efforts and not only a focus on individual level change.

Vascular cell adhesion molecule--1 expression is obligatory for endotoxin-induced myocardial neutrophil accumulation and contractile dysfunction

BACKGROUND

Sepsis-induced cardiac dysfunction occurs commonly in critically ill patients and is associated with high mortality rates. Neutrophils play a central role in sepsis-induced lung and liver injury; however, the mechanism of sepsis-induced cardiac dysfunction remains unclear. Vascular cell adhesion molecule-1 (VCAM-1) has been implicated in neutrophil-mediated liver injury during endotoxemia and is also expressed in myocardium. The purposes of this study were to examine the temporal relationship of myocardial VCAM-1 expression with neutrophil accumulation during endotoxemia and to determine whether VCAM-1 mediates neutrophil accumulation and cardiac dysfunction during endotoxemia.

METHODS

Mice were subjected to lipopolysaccharide (LPS; 0.5 mg/kg, intraperitoneally). Myocardial VCAM-1 expression and neutrophil accumulation were determined by immunofluorescence staining. Cardiac performance with or without VCAM-1 blocking antibody (5 mg/kg, intravenously) was determined by the Langendorff technique.

RESULTS

LPS caused a time-dependent increase in both myocardial VCAM-1 expression and neutrophil accumulation. At 6 hours after LPS, the immunofluorescent intensity for VCAM-1 increased from 2.5 +/- 0.6 x 10(6) in saline solution controls to 19.9 +/- 3.5 x 10(6) (P <.05, analysis of variance), and neutrophil count increased from 2.4 +/- 1.7/mm(2) in saline solution controls to 13.0 +/- 2.5/mm(2) (P <.05). Left ventricular developed pressure was decreased maximally at 6 hours after LPS compared with saline solution controls (29.1 +/- 1.1 mm Hg vs 53.1 +/- 3.9 mm Hg; P <.05). Treatment with VCAM-1 monoclonal antibody abrogated both myocardial neutrophil accumulation and cardiac dysfunction during endotoxemia.

CONCLUSIONS

LPS-induced myocardial dysfunction is associated with increased expression of VCAM-1 and with neutrophil accumulation. Blockade of VCAM-1 abrogates myocardial neutrophil accumulation and preserves cardiac function during endotoxemia, which supports a role for VCAM-1 as a therapeutic target for myocardial protection during sepsis.

Children's understanding of psychogenic bodily reactions

One hundred twenty-eight children in preschool through fifth grade (range = 4,3-11,4) and 76 adults serving as a comparison group participated in two studies that examined how children reason about psychogenic bodily reactions, that is, ailments or nonconscious physiological responses with origins in the mind (e.g., stress-induced headache). Psychogenic bodily reactions provide an opportunity to study how children integrate knowledge between the domains of bodily response and psychology. In Study 1, participants were asked whether various familiar psychogenic bodily reactions were possible (e.g., can someone get a tummyache from worrying?). In Study 2, participants were presented with a novel domain (hypothetical "aliens" from outer space) and were asked whether various unfamiliar bodily conditions (e.g., toes swelling) could arise from various physical or psychological causes. As predicted, adults typically reported that psychogenic bodily reactions were possible, and that unfamiliar bodily conditions could result from either psychological or physical causes. In contrast, young children typically denied that psychogenic bodily reactions could occur and predicted that unfamiliar bodily conditions resulted from physical causes only. The results support a developmental path: younger children view psychogenic bodily responses as wholly physical, but with age, view them as both physical and psychological phenomena.

The case for beta-adrenergic blockade as prophylaxis against perioperative cardiovascular morbidity and mortality

Perioperative morbidity and mortality are frequently cardiac in origin. Many studies have prospectively attempted to define risk factors for cardiac ischemic events. Although we can now identify high-risk patients, optimal cardioprotective management strategies remain unclear. Treatment with beta-adrenergic antagonists decreases myocardial oxygen consumption and is generally well tolerated. This article reviews the physiologic and clinical basis for using these agents as prophylaxis against cardiovascular events in high-risk surgical patients.

Forging collaborative partnerships to enhance family health: an assessment of strengths and challenges in conducting community-based research

Community-based research has emerged as a vital strategy for developing effective, culturally relevant health interventions. This article describes the strengths and challenges of building a collaborative research partnership based on equality between academic researchers, public health practitioners, and representatives from community-based organizations. The model of collaboration adopted for the Fathers and Sons Project is described and examples of model applications are discussed. Lessons learned in the form of strengths/benefits and potential pitfalls in developing a community-based intervention designed to enhance the health behaviors of African American nonresidential fathers and their sons are provided.

Gender differences in HIV-related sexual risk behavior among urban African American youth: a multivariate approach

Alcohol and other drug (AOD) use during sexual encounters, sexual partner's age, perceived HIV risk and perceived condom effectiveness were studied among 388 sexually active African American youth. Cluster analysis of condom use, number of partners, and frequency of sexual intercourse identified four groups: low risk, monogamy strategy, condom strategy, and high risk. Low-risk youth used condoms consistently and had few partners. High-risk youth used condoms inconsistently with many partners. Monogamy strategy youth used condoms inconsistently but had few partners. Condom strategy youth used condoms consistently with a moderate number of partners. The high-risk group included more males and the monogamy group included more females. High-risk males reported more AOD use during sexual activity than all females, and low-risk or condom strategy males. Females had older partners, rated condoms as less effective and perceived lower HIV/AIDS risk than males. Results suggest differential HIV risk mechanisms by gender. Implications for gender-specific HIV prevention are discussed.

Inhibitory tagging in inhibition of return is affected in schizophrenia: evidence from the stroop task

L. J. Fuentes, A. B. Vivas, and G. W. Humphreys (1999b) showed that stimulus processing is affected when stimuli are presented to locations subject to inhibition of return. They argued that activated representations of stimuli presented at inhibited locations are disconnected from their associated responses through an "inhibitory tagging" mechanism occurring in inhibition of return. In the present research, the authors asked whether such a mechanism is affected in people with schizophrenia. Healthy adults and patients with schizophrenia performed a Stroop task in an inhibition of return paradigm. Healthy adults showed a reduction in the Stroop interference when stimuli were presented at inhibited locations, a result that agrees with the inhibitory tagging mechanism hypothesis and replicates previous findings. However, patients with schizophrenia did not show such a reduction, a result suggesting that they have a deficit in inhibitory processing occurring in inhibition of return.

Resilience among urban African American male adolescents: a study of the protective effects of sociopolitical control on their mental health

Resilience refers to the notion that some people succeed in the face of adversity. In a risk-protective model of resilience, a protective factor interacts with a risk factor to mitigate the occurrence of a negative outcome. This study tested longitudinally the protective effects of sociopolitical control on the link between helplessness and mental health. The study included 172 urban, male, African American adolescents, who were interviewed twice, 6 months apart. Sociopolitical control was defined as the beliefs about one's capabilities and efficacy in social and political systems. Two mental health outcomes were examined--psychological symptoms and self-esteem. Regression analysis to predict psychological symptoms and self-esteem over time were conducted. High levels of sociopolitical control were found to limit the negative consequences of helplessness on mental health. The results suggest that sociopolitical control may help to protect youths from the negative consequences of feelings of helplessness. Implications for prevention strategies are discussed.

Inhibitory processing in visuospatial attention in healthy adults and schizophrenic patients

This study assessed visuospatial attention in healthy adults and medicated schizophrenic patients. Participants performed a visual orientation task in which a peripheral cue was followed. at different intervals, by a target presented either at valid or invalid locations. When the long stimulus onset asynchrony (SOA) was used, participants were presented with either a single peripheral cue (single-cue condition) or two cues, the peripheral cue followed by a central cue (the double-cue condition). Healthy adults showed marginal facilitation effects with the short SOA and similar inhibition of return effects with the long SOA in both single-cue and double-cue conditions. Schizophrenic individuals showed a big facilitation effect with the short SOA and normal inhibition of return with the long SOA in both cue conditions. Results with the short SOA replicated previous findings (Huey, E.D., Wexler, B.E., 1994. Schizophrenia Research 14, 57-63) but, in contrast, we did not observe blunted inhibition of return with the long SOA. An inspection of the differences in the procedures used in both studies may help both to account for the discrepancies and to reveal what processes involved in visuospatial attention are affected in schizophrenia.

Posttraumatic stress disorder in injured adults: etiology by path analysis

OBJECTIVE

Posttraumatic Stress Disorder (PTSD) impairs outcome from injury. We present a path analysis of factors related to the development of PTSD in injured adults.

METHODS

A prospective cohort of 250 patients without severe neurotrauma was evaluated by interview during admission and by mailed self-report 6 months later. Data were gathered from the trauma registry (age, injury mechanism, and Injury Severity Score), social history (gender, income, education, and social support), and survey instruments. Baseline assessment used the Michigan Critical Events Perception Scale (peritraumatic dissociation and subjective threat to life), the Life Experience Survey (stressful exposure history), and the SF36 (general and mental health). PTSD at 6 months was identified with the civilian Mississippi Scale for PTSD. Data are listed as mean +/- SEM or percent (%). Path analysis was conducted by linear regression and significant (p<0.05) variables are shown. Factors are listed with the standardized beta. A negative beta suggests a protective effect.

RESULTS

The 176 patients (72%) who completed the 6-month follow-up were 37.7+/-0.88 years old; 75% were men; and blunt (70%), penetrating (13.5%), and burn (16.4%) mechanisms caused the injuries. Assault was involved in 14.5% of the cases. Average income was $44,300+/-2,700/yr, education was 13.0+/-0.15 years, and Injury Severity Score was 13.9+/-0.50. A total of 42.3% of the patients developed PTSD. The 39.7% of the variance in PTSD explained by the model was due to intentional injury (beta = 0.27), male gender (beta = -0.21), age (beta = -0.20), peritraumatic dissociation (beta = 0.174), baseline mental health (beta = -0.21), and prior life-threatening illness (beta = -0.29). Peritraumatic dissociation was due to the patient's sense of threat to life (beta = -0.47), and threat was related to Injury Severity Score (beta = 0.2), assault(beta = 0.14), education (beta = -0.15), and age (beta = -0.19). Baseline SF36 mental health was related to social support (beta = 0.27) and income (beta = 0.21). Income was contingent on education (beta = 0.21).

CONCLUSION

PTSD occurred in 42.3% of injured adults 6 months after trauma and was related to assault, dissociation, female gender, youth, poor mental health, and prior illness. By modeling PTSD, we may learn more of the etiology, risk stratification, and potentials for the treatment of this common and important morbidity of injury.

Posttraumatic stress disorder after injury: impact on general health outcome and early risk assessment

OBJECTIVE

To evaluate prospectively components of general health outcome after trauma and to report on the further validation of the Michigan Critical Events Perception Scale (MCEPS), an instrument that predicts increased risk for posttraumatic stress disorder (PTSD).

METHODS

Adults without neurologic injury admitted to a Level I trauma center in 1997 were interviewed during hospitalization. Baseline data included demographics, injury mechanism, Injury Severity Score, the Short Form 36 (SF36), and the MCEPS, which measures peri-traumatic dissociation (the sense of depersonalization or derealization during an injury event). Surveys sent by mail and completed 6 months later included the SF36 and civilian Mississippi Scale for PTSD.

RESULTS

A total of 140 patients were interviewed; the 70% (n = 100 patients) who completed the 6-month assessment form the study group. Injuries were categorized as 71% blunt, 13% penetrating, and 16% burn. Mean Injury Severity Score was 13.7+/-0.52. PTSD at 6 months occurred in 42% of the patients and was directly related to MCEPS dissociation (p = 0.001; odds ratio = 3.1; 95% confidence interval, 1.6, 5.9). A stepwise linear regression explains 40% of the variance in 6-month SF36 general health outcome (adjusted R2 = 0.402). The model controls for individual factors related to dissociation, PTSD, and general health outcome. Development of PTSD was independently and inversely related to general health outcome as measured by the SF36 at 6 months (p < 0.001, beta = -0.404). The R2 change of 0.132 for PTSD (vs. 0.082 for 6-month physical function) illustrates that PTSD contributes more to the patient's perceived general health at 6 months than the degree of physical function or injury severity.

CONCLUSIONS

Within hours of injury, the MCEPS identifies patients who are three times more likely to develop PTSD. PTSD compromises self-reported general health outcome in injured adults independent of baseline status, Injury Severity Score, or degree of physical recovery. These data suggest that psychological morbidity is an important part of the patient's perceived general health.

Psychosocial factors and high-risk sexual behavior: race differences among urban adolescents

Adolescence is a period of sexual experimentation. We examined psychosocial predictors of high-risk sexual behavior and condom use. The sample included 824 ninth-graders, most of whom are African American. We conducted separate analyses for whites and African Americans. Predictors included alcohol and substance use, delinquency, prosocial behaviors, and family and peer influences. We found that problem behaviors predicted high-risk sexual behavior, but the effects were stronger for white youth. We also found that friends' behaviors were more predictive than family influences, except for family conflict. In general, the models explained more variance for white youths than for African-American youths. The results suggest that problem behavior theory and social interactions theory may be most relevant for white youth and that other models may be necessary to explain high-risk sexual behavior among African-American youths.

Sexual risk behavior among youth: modeling the influence of prosocial activities and socioeconomic factors

Sexual activity among high-school-aged youths has steadily increased since the 1970s, emerging as a significant public health concern. Yet, patterns of youth sexual risk behavior are shaped by social class, race, and gender. Based on sociological theories of financial deprivation and collective socialization, we develop and test a model of the relationships among neighborhood poverty; family structure and social class position; parental involvement; prosocial activities; race; and gender as they predict youth sexual risk behavior. We employ structural equation modeling to test this model on a cross-sectional sample of 370 sexually active high-school students from a midwestern city; 57 percent (n = 209) are males and 86 percent are African American. We find that family structure indirectly predicts sexual risk behavior through neighborhood poverty, parental involvement, and prosocial activities. In addition, family class position indirectly predicts sexual risk behavior through neighborhood poverty and prosocial activities. We address implications for theory and health promotion.

Psychosocial factors limit outcomes after trauma

BACKGROUND

Psychological morbidity compromises return to work after trauma. We demonstrate this relationship and present methods to identify risks for significant psychological morbidity.

METHODS

Thirty-five adults were evaluated prospectively for return to functional employment after injury using demographic data, validated psychological and health measures, and the Michigan Critical Events Perception Scale. Evaluation was conducted at admission and at 1 and 5 months after injury.

RESULTS

Poor return to work at 5 months was attributable to physical disability (p < 0.05) and psychological disturbance (p < 0.05) in a regression model that controlled for preinjury employment and psychopathologic factors as well as injury severity. A high score on the Impact of Events Scale administered during acute admission predicted development of acute stress disorder at 1 month (p < 0.01, odds ratio (OR) = 9.4) and posttraumatic stress disorder at 5 months (p < 0.05, OR = 6.7). Peritraumatic dissociation on the Michigan Critical Events Perception Scale was predictive for development of acute stress disorder (p < 0.05, OR = 5.8) at 1 month and posttraumatic stress disorder (p < 0.05, OR = 7.5) at 5 months.

CONCLUSION

Psychological morbidity after injury compromises return to work independent of preinjury employment and psychopathologic condition, Injury Severity Score, or ambulation. A high Impact of Events Scale score or peritraumatic dissociation at admission predicts this morbidity.

Validity of adolescents' report of maternal age

Examined the validity of adolescents' reports of their mother's age. Most research on the validity of self-report focuses on personal behaviors such as alcohol and substance use, or response bias due to social desirability. Few studies investigate the validity of adolescents reporting of nonsensitive information. Data from 80 mother-adolescent pairs were collected. The sample included 9th graders from four high school English classes, equal numbers of males and females, and 15% African Americans. The correlation between mothers' reports and youths' reports of mother's age was .99, and 95% of the youth were within a year of their mother's correct age. No race or gender differences were found. These results allow researchers to examine adolescent outcomes for youth born to teen mothers without the expense of also collecting data from their mothers. Results also suggest that adolescents' self-reports of other nonsensitive familial data may also be valid.