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1.
Traffic ; 24(3): 146-157, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36479968

RESUMEN

The nucleolus is a common target of viruses and viral proteins, but for many viruses the functional outcomes and significance of this targeting remains unresolved. Recently, the first intranucleolar function of a protein of a cytoplasmically-replicating negative-sense RNA virus (NSV) was identified, with the finding that the matrix (M) protein of Hendra virus (HeV) (genus Henipavirus, family Paramyxoviridae) interacts with Treacle protein within nucleolar subcompartments and mimics a cellular mechanism of the nucleolar DNA-damage response (DDR) to suppress ribosomal RNA (rRNA) synthesis. Whether other viruses utilise this mechanism has not been examined. We report that sub-nucleolar Treacle targeting and modulation is conserved between M proteins of multiple Henipaviruses, including Nipah virus and other potentially zoonotic viruses. Furthermore, this function is also evident for P3 protein of rabies virus, the prototype virus of a different RNA virus family (Rhabdoviridae), with Treacle depletion in cells also found to impact virus production. These data indicate that unrelated proteins of viruses from different families have independently developed nucleolar/Treacle targeting function, but that modulation of Treacle has distinct effects on infection. Thus, subversion of Treacle may be an important process in infection by diverse NSVs, and so could provide novel targets for antiviral approaches with broad specificity.


Asunto(s)
Virus Hendra , Lyssavirus , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , ARN Ribosómico , Lyssavirus/genética , Lyssavirus/metabolismo , Ribosomas/metabolismo , Virus Hendra/genética , Virus Hendra/metabolismo , Factores de Transcripción
2.
Am J Physiol Heart Circ Physiol ; 327(1): H000, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38787381

RESUMEN

Systemic insulin increases muscle sympathetic nerve activity (MSNA) via both central actions within the brainstem and peripheral activation of the arterial baroreflex. Augmented MSNA during hyperinsulinemia likely restrains peripheral vasodilation and contributes to the maintenance of blood pressure (BP). However, in the absence of insulin action within the peripheral vasculature, whether central insulin stimulation increases MSNA and influences peripheral hemodynamics in humans remains unknown. Herein, we hypothesized intranasal insulin administration would increase MSNA and BP in healthy young adults. Participants were assigned to time control [TC, n = 13 (5 females/8 males), 28 ± 1 yr] or 160 IU of intranasal insulin administered over 5 min [n = 15 (5 females/10 males), 26 ± 2 yr]; five (1 female/4 males) participants completed both conditions. MSNA (fibular microneurography), BP (finger photoplethysmography), and leg blood flow (LBF, femoral Doppler ultrasound) were assessed at baseline, and 15 and 30 min following insulin administration. Leg vascular conductance [LVC = (LBF ÷ mean BP) × 100] was calculated. Venous insulin and glucose concentrations remained unchanged throughout (P > 0.05). Following intranasal insulin administration, MSNA (burst frequency; baseline = 100%; minute 15, 121 ± 8%; minute 30, 118 ± 6%; P = 0.009, n = 7) and mean BP (baseline = 100%; minute 15, 103 ± 1%; minute 30, 102 ± 1%; P = 0.003) increased, whereas LVC decreased (baseline = 100%; minute 15, 93 ± 3%; minute 30, 99 ± 3%; P = 0.03). In contrast, MSNA, mean BP, and LVC were unchanged in TC participants (P > 0.05). We provide the first evidence that intranasal insulin administration in healthy young adults acutely increases MSNA and BP and decreases LVC. These results enhance mechanistic understanding of the sympathetic and peripheral hemodynamic response to insulin.NEW & NOTEWORTHY Systemic insulin increases muscle sympathetic nerve activity (MSNA) via central actions within the brainstem and peripheral activation of the arterial baroreflex. In the absence of peripheral insulin action, whether central insulin stimulation increases MSNA and influences peripheral hemodynamics in humans was unknown. We provide the first evidence that intranasal insulin administration increases MSNA and blood pressure and reduces leg vascular conductance. These results enhance mechanistic understanding of the sympathetic and hemodynamic response to insulin.


Asunto(s)
Administración Intranasal , Insulina , Músculo Esquelético , Sistema Nervioso Simpático , Humanos , Masculino , Femenino , Insulina/administración & dosificación , Insulina/sangre , Sistema Nervioso Simpático/efectos de los fármacos , Adulto , Músculo Esquelético/inervación , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Flujo Sanguíneo Regional/efectos de los fármacos , Glucemia/metabolismo , Glucemia/efectos de los fármacos , Voluntarios Sanos , Adulto Joven , Barorreflejo/efectos de los fármacos
3.
Exp Physiol ; 108(5): 692-705, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36951536

RESUMEN

NEW FINDINGS: What is the central question of this study? We sought to establish between-day reproducibility in estimates of middle cerebral artery blood velocity (MCAv) and cerebrovascular reactivity (CVR) in young, healthy male and female adults in tightly controlled experimental conditions. What is the main finding and its importance? Measures of MCAv assessed during morning, afternoon and evening hours are reproducible between days. There is diurnal variation in CVR, with values being highest during the evening compared with the morning. Greater diurnal variation in CVR is associated with more efficient sleep and greater nocturnal blood pressure dipping. These data enhance our understanding of modulators of MCAv and CVR. ABSTRACT: Transcranial Doppler (TCD) is used to assess cerebral blood velocity (CBV) and cerebrovascular reactivity (CVR). Assessments of TCD reproducibility are limited, and few include multiple within-day measurements. We sought to establish reproducibility of CBV and CVR in healthy adults during three time periods (morning, afternoon and evening). We hypothesized that CBV and CVR measured at the same time of day are reproducible between days. We also hypothesized that CBV and CVR exhibit diurnal variation, with measurements being higher in the evening compared with morning/afternoon hours. Twelve adults [six male and six female, 27 years (95% CI, 22-31 years)] completed three measurements (morning, afternoon and evening) on two separate days in controlled conditions (e.g., meals, activity and sleep). Middle cerebral artery blood velocity (MCAv, TCD) was measured continuously at rest and during two CVR tests (end-expiratory apnoea and carbogen inhalation). Intraclass correlation coefficients for resting MCAv showed moderate to good reproducibility, which did not differ between morning, afternoon and evening (0.87, 0.56 and 0.67, respectively; P > 0.05). Intraclass correlation coefficients for peak MCAv during apnoea (0.80, 0.46 and 0.65, respectively; P > 0.05) and minute 2 of carbogen inhalation (0.81, 0.74 and 0.73, respectively; P > 0.05) were also not different from morning compared with afternoon/evening. Time of day had no effect on resting MCAv (F = 0.69, P = 0.51, ƞp 2  = 0.06) or the peak response to apnoea (F = 1.00, P = 0.39, ƞp 2  = 0.08); however, peak MCAv during carbogen breathing exhibited diurnal variation, with highest values in the evening (F = 3.41, P = 0.05, ƞp 2  = 0.24). Measures of CBV and CVR assessed via TCD during morning, afternoon and evening hours are reproducible between days. There is diurnal variation in the MCAv response to carbogen exposure, with CVR being highest during evening compared with morning hours.


Asunto(s)
Apnea , Arteria Cerebral Media , Humanos , Adulto , Masculino , Femenino , Arteria Cerebral Media/fisiología , Reproducibilidad de los Resultados , Dióxido de Carbono , Circulación Cerebrovascular/fisiología , Velocidad del Flujo Sanguíneo/fisiología
4.
Exp Physiol ; 108(12): 1481-1489, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37878751

RESUMEN

The present study evaluated cardiovagal baroreflex sensitivity (BRS) across the menstrual/pill cycle in naturally menstruating women (NAT women) and women using oral hormonal contraceptives (OCP women). In 21 NAT women (23 ± 4 years old) and 22 OCP women (23 ± 3 years old), cardiovagal BRS and circulating concentrations of estradiol and progesterone were evaluated during the lower hormone (early follicular/placebo pill) and higher hormone (late follicular to early luteal/active pill) phases. During the lower hormone phase, cardiovagal BRS up, down and mean gain were lower in NAT women (15.6 ± 8.3, 15.2 ± 6.1 and 15.1 ± 7.1 ms/mmHg) compared with OCP women (24.7 ± 9.4, 22.9 ± 8.0 and 23.0 ± 8.0 ms/mmHg) (P = 0.003, P = 0.002 and P = 0.003, respectively), and higher oestrogen (R2  = 0.15, P = 0.024), but not progesterone (R2  = 0.06, P = 0.18), concentrations were predictive of lower BRS mean gain. During the higher hormone phase, higher progesterone concentrations were predictive of lower BRS mean gain (R2  = 0.12, P = 0.024). A multivariate regression model revealed group (NAT or OCP) to be a significant predictor of cardiovagal BRS mean gain in the lower hormone phase when hormone concentrations were adjusted for (R2  = 0.36, P = 0.0044). The multivariate regression model was not significant during the higher hormone phase (P > 0.05). In summary, cardiovagal BRS is lower in NAT compared with OCP women during the lower hormone phase of the menstrual/pill cycle and might be associated with higher oestrogen concentrations. In contrast, during the higher hormone phase of the menstrual/OCP cycle, higher progesterone concentrations were predictive of lower cardiovagal BRS. NEW FINDINGS: What is the central question of this study? Does cardiovagal baroreflex sensitivity (BRS) differ between naturally menstruating women (NAT women) and women using oral contraceptives (OCP women)? What is the main finding and its importance? The main findings are as follows: (1) NAT women exhibit lower cardiovagal BRS than OCP women during the lower hormone phase of the menstrual or pill cycle; and (2) circulating oestrogen concentrations are significant predictors of cardiovagal BRS during the lower hormone phase, with higher oestrogen concentrations predicting lower BRS. The present data advance our understanding of the effect of endogenous ovarian hormones and OCP use on cardiovascular control mechanisms.


Asunto(s)
Menstruación , Progesterona , Humanos , Femenino , Adulto Joven , Adulto , Barorreflejo , Estradiol , Anticonceptivos Orales , Estrógenos
5.
Am J Physiol Endocrinol Metab ; 322(4): E355-E365, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35187960

RESUMEN

Muscle sympathetic nerve activity (MSNA) increases during hyperinsulinemia, primarily attributed to central nervous system effects. Whether peripheral vasodilation induced by insulin further contributes to increased MSNA via arterial baroreflex-mediated mechanisms requires further investigation. Accordingly, we examined baroreflex modulation of the MSNA response to hyperinsulinemia. We hypothesized that rescuing peripheral resistance with coinfusion of the vasoconstrictor phenylephrine would attenuate the MSNA response to hyperinsulinemia. We further hypothesized that the insulin-mediated increase in MSNA would be recapitulated with another vasodilator (sodium nitroprusside, SNP). In 33 young healthy adults (28 M/5F), MSNA (microneurography) and arterial blood pressure (BP, Finometer/brachial catheter) were measured, and total peripheral resistance (TPR, ModelFlow) and baroreflex sensitivity were calculated at rest and during intravenous infusion of insulin (n = 20) or SNP (n = 13). A subset of participants receiving insulin (n = 7) was coinfused with phenylephrine. Insulin infusion decreased TPR (P = 0.01) and increased MSNA (P < 0.01), with no effect on arterial baroreflex sensitivity or BP (P > 0.05). Coinfusion with phenylephrine returned TPR and MSNA to baseline, with no effect on arterial baroreflex sensitivity (P > 0.05). Similar to insulin, SNP decreased TPR (P < 0.02) and increased MSNA (P < 0.01), with no effect on arterial baroreflex sensitivity (P > 0.12). Acute hyperinsulinemia shifts the baroreflex stimulus-response curve to higher MSNA without changing sensitivity, likely due to insulin's peripheral vasodilatory effects. Results show that peripheral vasodilation induced by insulin contributes to increased MSNA during hyperinsulinemia.NEW & NOTEWORTHY We hypothesized that elevation in muscle sympathetic nervous system activity (MSNA) during hyperinsulinemia is mediated by its peripheral vasodilator effect on the arterial baroreflex. Using three separate protocols in humans, we observed increases in both MSNA and cardiac output during hyperinsulinemia, which we attributed to the baroreflex response to peripheral vasodilation induced by insulin. Results show that peripheral vasodilation induced by insulin contributes to increased MSNA during hyperinsulinemia.


Asunto(s)
Barorreflejo , Hiperinsulinismo , Adulto , Presión Sanguínea , Frecuencia Cardíaca , Humanos , Insulina/farmacología , Músculo Esquelético , Fenilefrina/farmacología , Sistema Nervioso Simpático , Vasodilatadores/farmacología
6.
Am J Physiol Heart Circ Physiol ; 322(6): H1072-H1079, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35486478

RESUMEN

Acute increases in sympathetic nervous system activity (SNA) often elicit peripheral vasoconstriction and increases in blood pressure (BP). Given sympathetic support of BP is modulated by ovarian sex hormones (e.g., estradiol), we sought to examine the effect of menstrual cycle and oral hormonal contraceptive pill (OC) phase on the hemodynamic response to acute increases in SNA. We hypothesized sympathoexcitation via cold pressor test (CPT) would elicit greater peripheral vasoconstriction and increases BP in females with natural menstrual cycles (NC) compared with females taking OC. We further hypothesized that SNA-mediated vasoconstriction would be attenuated during the high estradiol (HE) phase versus the low estradiol (LE) phase of the menstrual/pill cycle. Female NC (n = 11, 25 ± 1 yr) and OC (n = 10, 24 ± 1 yr) participants were studied during the LE (early follicular, placebo pill) and HE (late follicular, active pill) phase of the menstrual/pill cycle. BP (finger photoplethysmography), heart rate (HR, ECG), and forearm blood flow (FBF, venous occlusion plethysmography) were measured during a 5-min baseline and a 2-min CPT. CPT elicited an increase in BP in both groups (time, P < 0.01). During CPT, OC participants exhibited greater and sustained increases in HR compared with NC participants (group × time, P < 0.01). Higher HRs were met with increases in FBF in OC participants during the CPT, which was not observed in NC participants (group × time, P < 0.01). OC participants exhibit greater increases in HR, and paradoxical vasodilation during acute sympathetic activation compared with NC participants. Group differences are unaffected by menstrual/pill phase.NEW & NOTEWORTHY Acute increases in sympathetic nervous system activity often elicit peripheral vasoconstriction and increases in blood pressure (BP). Given sympathetic support of BP is modulated by ovarian sex hormones (e.g., estradiol), we sought to examine the effect of menstrual cycle and oral hormonal contraceptive pill (OC) phase on the hemodynamic response to acute increases in sympathetic nervous system activity via the cold pressor test. We show OC participants exhibit paradoxical vasodilation during acute sympathetic activation compared with participants with natural menstrual cycles; notably, group differences were unaffected by menstrual/pill phase.


Asunto(s)
Anticonceptivos , Hemodinámica , Hipotensión , Sistema Nervioso Simpático , Presión Sanguínea/fisiología , Frío , Anticonceptivos/farmacología , Estradiol/farmacología , Femenino , Humanos , Sistema Nervioso Simpático/fisiología
7.
Am J Physiol Regul Integr Comp Physiol ; 321(6): R903-R911, 2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34668438

RESUMEN

Sex-related differences in respiratory modulation of sympathetic activity have been observed in rodent models of sleep apnea [intermittent hypoxia (IH)]. In light of sex disparities in the respiratory response to acute IH in humans as well as changes in respiratory modulation of muscle sympathetic nerve activity (MSNA) in clinical sleep apnea, we examined sex-related differences in respiratory modulation of MSNA following acute IH. We hypothesized that respiratory modulation of MSNA would be altered in both male and female participants after IH; however, the respiratory patterning of MSNA following IH would be sex specific. Heart rate, MSNA, and respiration were evaluated in healthy male (n = 21, 30 ± 5 yr) and female (n = 10, 28 ± 5 yr) participants during normoxic rest before and after 30 min of IH. Respiratory modulation of MSNA was assessed by fitting polynomials to cross-correlation histograms constructed between sympathetic spikes and respiration. MSNA was elevated after IH in male (20 ± 6 to 24 ± 8 bursts/min) and female (19 ± 8 to 22 ± 10 bursts/min) participants (P < 0.01). Both male and female participants exhibited respiratory modulation of MSNA (P < 0.01); however, the pattern differed by sex. After IH, modulation of MSNA within the breath was reduced in male participants (P = 0.03) but increased in female participants (P = 0.02). Both male and female adults exhibit changes in respiratory patterning of MSNA after acute IH; however, this pattern differs by sex. These data support sex disparities in respiratory modulation of MSNA and may have implications for conditions such as sleep apnea.


Asunto(s)
Hipoxia/fisiopatología , Pulmón/inervación , Músculo Esquelético/inervación , Oxígeno/sangre , Mecánica Respiratoria , Sistema Nervioso Simpático/fisiopatología , Adaptación Fisiológica , Adulto , Biomarcadores/sangre , Femenino , Frecuencia Cardíaca , Humanos , Hipoxia/sangre , Masculino , Factores Sexuales , Factores de Tiempo , Adulto Joven
8.
Am J Physiol Regul Integr Comp Physiol ; 320(6): R771-R779, 2021 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-33851554

RESUMEN

Herein we report in a sample of healthy young men (n = 14) and women (n = 12) that hyperinsulinemia induces time-dependent decreases in total peripheral resistance and its contribution to the maintenance of blood pressure. In the same participants, we observe profound vasodilatory effects of insulin in the lower limb despite concomitant activation of the sympathetic nervous system. We hypothesized that this prominent peripheral vasodilation is possibly due to the ability of the leg vasculature to escape sympathetic vasoconstriction during systemic insulin stimulation. Consistent with this notion, we demonstrate in a subset of healthy men (n = 9) and women (n = 7) that systemic infusion of insulin blunts sympathetically mediated leg vasoconstriction evoked by a cold pressor test, a well-established sympathoexcitatory stimulus. Further substantiating this observation, we show in mouse aortic rings that insulin exposure suppresses epinephrine and norepinephrine-induced vasoconstriction. Notably, we found that such insulin-suppressing effects on catecholamine-induced constriction are diminished following ß-adrenergic receptor blockade. In accordance, we also reveal that insulin augments ß-adrenergic-mediated vasorelaxation in isolated arteries. Collectively, these findings support the idea that sympathetic vasoconstriction can be attenuated during systemic hyperinsulinemia in the leg vasculature of both men and women and that this phenomenon may be in part mediated by potentiation of ß-adrenergic vasodilation neutralizing α-adrenergic vasoconstriction.


Asunto(s)
Adrenérgicos/farmacología , Hiperinsulinismo/tratamiento farmacológico , Sistema Nervioso Simpático/efectos de los fármacos , Vasoconstricción/efectos de los fármacos , Adulto , Presión Sanguínea/efectos de los fármacos , Femenino , Humanos , Masculino , Norepinefrina/farmacología , Flujo Sanguíneo Regional/efectos de los fármacos , Flujo Sanguíneo Regional/fisiología , Sistema Nervioso Simpático/fisiología , Resistencia Vascular/efectos de los fármacos
9.
Exp Physiol ; 106(8): 1689-1698, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-34187092

RESUMEN

NEW FINDINGS: What is the central question of this study? Sympathetically mediated vasoconstriction is preserved during hypoxaemia in humans, but our understanding of vascular control comes from predominantly male cohorts. We tested the hypothesis that young women attenuate sympathetically mediated vasoconstriction during steady-state hypoxaemia, whereas men do not? What is the main finding and its importance? Sympathetically mediated vasoconstriction is preserved or even enhanced during steady-state hypoxia in young men, and the peripheral vascular response to sympathetic activation during hypoxaemia is attenuated in young women. These data advance our understanding of sex-related differences in hypoxic vascular control. ABSTRACT: Activation of the sympathetic nervous system causes vasoconstriction and a reduction in peripheral blood flow. Sympathetically mediated vasoconstriction may be attenuated during systemic hypoxia to maintain oxygen delivery; however, in predominantly male participants sympathetically mediated vasoconstriction is preserved or even enhanced during hypoxaemia. Given the potential for sex-specific differences in hypoxic vascular control, prior results are limited in application. We tested the hypothesis that young women attenuate sympathetically mediated vasoconstriction during steady-state hypoxaemia, whereas men do not. Healthy young men (n = 13, 25 ± 4 years) and women (n = 11, 24 ± 4 years) completed two trials consisting of a 2-min cold pressor test (CPT, a well-established sympathoexcitatory stimulus) during baseline normoxia and steady-state hypoxaemia. Beat-to-beat blood pressure (finger photoplethysmography) and forearm blood flow (venous occlusion plethysmography) were measured continuously. Total and forearm vascular conductance (TVC and FVC, respectfully) were calculated. A change (Δ) in TVC and FVC from steady-state during the last 1 min of CPT was calculated and differences between normoxia and systemic hypoxia were assessed. In men, the reduction in TVC during CPT was greater during hypoxia compared to normoxia (ΔTVC, P = 0.02), whereas ΔTVC did not differ between conditions in women (P = 0.49). In men, ΔFVC did not differ between normoxia and hypoxia (P = 0.92). In women, the reduction in FVC during CPT was attenuated during hypoxia (ΔFVC, P < 0.01). We confirm sympathetically mediated vasoconstriction is preserved or enhanced during hypoxaemia in young men, whereas peripheral vascular responsiveness to sympathetic activation during hypoxaemia is attenuated in young women. The results advance our understanding of sex-related differences in hypoxic vascular control.


Asunto(s)
Hipoxia , Caracteres Sexuales , Presión Sanguínea , Femenino , Antebrazo/irrigación sanguínea , Humanos , Masculino , Flujo Sanguíneo Regional/fisiología , Sistema Nervioso Simpático/fisiología , Vasoconstricción/fisiología
10.
Am J Physiol Heart Circ Physiol ; 319(1): H162-H170, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32502373

RESUMEN

Vasodilatory effects of insulin support the delivery of insulin and glucose to skeletal muscle. Concurrently, insulin exerts central effects that increase sympathetic nervous system activity (SNA), which is required for the acute maintenance of blood pressure (BP). Indeed, in a cohort of young healthy adults, herein we show that intravenous infusion of insulin increases muscle SNA while BP is maintained. We next tested the hypothesis that sympathoexcitation evoked by hyperinsulinemia restrains insulin-stimulated peripheral vasodilation and contributes to sustaining BP. To address this, a separate cohort of participants were subjected to 5-s pulses of neck suction (NS) to simulate carotid hypertension and elicit a reflex-mediated reduction in SNA. NS was conducted before and 60 min following intravenous infusion of insulin. Insulin infusion caused an increase in leg vascular conductance and cardiac output (CO; P < 0.050), with maintenance of BP (P = 0.540). As expected, following NS, decreases in BP were greater in the presence of hyperinsulinemia compared with control (P = 0.045). However, the effect of NS on leg vascular conductance did not differ between insulin and control conditions (P = 0.898). Instead, the greater decreases in BP following NS in the setting of insulin infusion paralleled with greater decreases in CO (P = 0.009). These findings support the idea that during hyperinsulinemia, SNA-mediated increase in CO, rather than restraint of leg vascular conductance, is the principal contributor to the maintenance of BP. Demonstration in isolated arteries that insulin suppresses α-adrenergic vasoconstriction suggests that the observed lack of restraint of leg vascular conductance may be attributed to sympatholytic actions of insulin.NEW & NOTEWORTHY We examined the role of sympathetic activation in restraining vasodilatory responses to hyperinsulinemia and sustaining blood pressure in healthy adults. Data are reported from two separate experimental protocols in humans and one experimental protocol in isolated arteries from mice. Contrary to our hypothesis, the present findings support the idea that during hyperinsulinemia, a sympathetically mediated increase in cardiac output, rather than restraint of peripheral vasodilation, is the principal contributor to the maintenance of systemic blood pressure.


Asunto(s)
Presión Sanguínea , Gasto Cardíaco , Hiperinsulinismo/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Vasodilatación , Adrenérgicos/farmacología , Adulto , Animales , Arterias/efectos de los fármacos , Arterias/fisiología , Femenino , Humanos , Insulina/administración & dosificación , Insulina/farmacología , Pierna/irrigación sanguínea , Masculino , Ratones , Ratones Endogámicos C57BL , Flujo Sanguíneo Regional
11.
Am J Physiol Regul Integr Comp Physiol ; 319(6): R626-R636, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-32966122

RESUMEN

Repetitive hypoxic apneas, similar to those observed in sleep apnea, result in resetting of the sympathetic baroreflex to higher blood pressures (BP). This baroreflex resetting is associated with hypertension in preclinical models of sleep apnea (intermittent hypoxia, IH); however, the majority of understanding comes from males. There are data to suggest that female rats exposed to IH do not develop high BP. Clinical data further support sex differences in the development of hypertension in sleep apnea, but mechanistic data are lacking. Here we examined sex-related differences in the effect of IH on sympathetic control of BP in humans. We hypothesized that after acute IH we would observe a rise in muscle sympathetic nerve activity (MSNA) and arterial BP in young men (n = 30) that would be absent in young women (n = 19). BP and MSNA were measured during normoxic rest before and after 30 min of IH. Baroreflex sensitivity (modified Oxford) was evaluated before and after IH. A rise in mean BP following IH was observed in men (+2.0 ± 0.7 mmHg, P = 0.03), whereas no change was observed in women (-2.7 ± 1.2 mmHg, P = 0.11). The elevation in MSNA following IH was not different between groups (4.7 ± 1.1 vs. 3.8 ± 1.2 bursts/min, P = 0.65). Sympathetic baroreflex sensitivity did not change after IH in either group (P > 0.05). Our results support sex-related differences in the effect of IH on neurovascular control of BP and show that any BP-raising effects of IH are absent in young women. These data enhance our understanding of sex-specific mechanisms that may contribute to BP changes in sleep apnea.


Asunto(s)
Presión Arterial , Barorreflejo , Hipercapnia/fisiopatología , Hipoxia/fisiopatología , Músculo Esquelético/inervación , Síndromes de la Apnea del Sueño/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Adulto , Femenino , Frecuencia Cardíaca , Humanos , Hipercapnia/sangre , Hipoxia/sangre , Masculino , Estudios Prospectivos , Factores Sexuales , Síndromes de la Apnea del Sueño/sangre , Factores de Tiempo
12.
J Virol ; 90(4): 1888-97, 2016 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-26656692

RESUMEN

UNLABELLED: Although avian H5N1 influenza virus has yet to develop the capacity for human-to-human spread, the severity of the rare cases of human infection has warranted intensive follow-up of potentially exposed individuals that may require antiviral prophylaxis. For countries where antiviral drugs are limited, the World Health Organization (WHO) has developed a risk categorization for different levels of exposure to environmental, poultry, or human sources of infection. While these take into account the infection source, they do not account for the likely mode of virus entry that the individual may have experienced from that source and how this could affect the disease outcome. Knowledge of the kinetics and spread of virus after natural routes of exposure may further inform the risk of infection, as well as the likely disease severity. Using the ferret model of H5N1 infection, we compared the commonly used but artificial inoculation method that saturates the total respiratory tract (TRT) with virus to upper respiratory tract (URT) and oral routes of delivery, those likely to be encountered by humans in nature. We show that there was no statistically significant difference in survival rate with the different routes of infection, but the disease characteristics were somewhat different. Following URT infection, viral spread to systemic organs was comparatively delayed and more focal than after TRT infection. By both routes, severe disease was associated with early viremia and central nervous system infection. After oral exposure to the virus, mild infections were common suggesting consumption of virus-contaminated liquids may be associated with seroconversion in the absence of severe disease. IMPORTANCE: Risks for human H5N1 infection include direct contact with infected birds and frequenting contaminated environments. We used H5N1 ferret infection models to show that breathing in the virus was more likely to produce clinical infection than swallowing contaminated liquid. We also showed that virus could spread from the respiratory tract to the brain, which was associated with end-stage disease, and very early viremia provided a marker for this. With upper respiratory tract exposure, infection of the brain was common but hard to detect, suggesting that human neurological infections might be typically undetected at autopsy. However, viral spread to systemic sites was slower after exposure to virus by this route than when virus was additionally delivered to the lungs, providing a better therapeutic window. In addition to exposure history, early parameters of infection, such as viremia, could help prioritize antiviral treatments for patients most at risk of succumbing to infection.


Asunto(s)
Modelos Animales de Enfermedad , Transmisión de Enfermedad Infecciosa , Subtipo H5N1 del Virus de la Influenza A/fisiología , Infecciones por Orthomyxoviridae/patología , Infecciones por Orthomyxoviridae/virología , Animales , Femenino , Hurones , Masculino , Infecciones por Orthomyxoviridae/mortalidad , Infecciones por Orthomyxoviridae/transmisión , Medición de Riesgo , Análisis de Supervivencia
13.
Vet Pathol ; 54(4): 649-660, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28494702

RESUMEN

Newcastle disease is an important disease of poultry caused by virulent strains of Newcastle disease virus (NDV). During the 1998 to 2002 outbreaks of Newcastle disease in Australia, it was observed that the mild clinical signs seen in some chickens infected with NDV did not correlate with the viruses' virulent fusion protein cleavage site motifs or standard pathogenicity indices. The pathogenicity of 2 Australian NDV isolates was evaluated in experimentally challenged chickens based on clinical evaluation, histopathology, immunohistochemistry, and molecular techniques. One of these virus isolates, Meredith/02, was shown to induce only very mild clinical signs with no mortalities in an experimental setting, in contrast to the velogenic Herts 33/56 and Texas GB isolates. This minimal pathogenicity was associated with decreased virus replication and antigen distribution in tissues. This demonstrates that the Australian Meredith/02 NDV, despite possessing a virulent fusion protein cleavage site, did not display a velogenic phenotype.


Asunto(s)
Pollos/virología , Enfermedad de Newcastle/virología , Virus de la Enfermedad de Newcastle/patogenicidad , Enfermedades de las Aves de Corral/virología , Animales , Australia/epidemiología , Brotes de Enfermedades/veterinaria , Enfermedad de Newcastle/epidemiología , Enfermedad de Newcastle/patología , Virus de la Enfermedad de Newcastle/genética , Virus de la Enfermedad de Newcastle/aislamiento & purificación , Enfermedades de las Aves de Corral/epidemiología , Enfermedades de las Aves de Corral/patología , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria
14.
Reproduction ; 150(3): 165-72, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26060317

RESUMEN

In a previous study, 50% calorie restriction in mice from d1.5 to 11.5 of pregnancy resulted in reduced placental weights and areas,relative sparing of labyrinth zone area compared to junctional zone area, and dramatic changes in global gene expression profiles.However, little lasting effect was seen on adult offspring of these pregnancies, with a slight reduction in adiposity in males and some changes in liver gene expression in both sexes. The goals of the present study were to determine whether the placental changes induced by caloric restriction in early pregnancy had permanent, irreversible effects on the placenta, and whether the changes in liver gene expression in adult offspring were present before birth. There were no differences in placental weights or areas, or the areas of individual placental zones near term in mice that had previously been food restricted. Global gene expression profiles at d18.5 were indistinguishable in placentas from control and previously food-restricted mothers. In fetuses from restricted dams at d18.5, liver expression of Gck, a key regulator of glycogen synthesis, was reduced, whereas its expression was increased in livers from adult offspring of restricted dams. Ppara expression was also reduced in fetal livers from restricted dams at d18.5, but not in adult offspring livers. We conclude that alterations in the placenta caused by nutrient restriction in early pregnancy are reversible, and that alterations in gene expression in livers of adult offspring are not a result of changes initiated during pregnancy and maintained through adulthood.


Asunto(s)
Restricción Calórica , Hígado/metabolismo , Placenta/metabolismo , Placenta/patología , Transcriptoma , Animales , Restricción Calórica/efectos adversos , Femenino , Regulación de la Expresión Génica , Quinasas del Centro Germinal , Edad Gestacional , Masculino , Ratones , PPAR alfa/metabolismo , Embarazo , Proteínas Serina-Treonina Quinasas/metabolismo
15.
South Med J ; 108(6): 372-6, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26079465

RESUMEN

OBJECTIVES: The Medical University of South Carolina implemented a patient-centered multidisciplinary breast clinic program (MDBC) in August 2012. In this study, patient satisfaction with the MDBC care delivery model and communication with healthcare providers was examined to inform the refinement of the MDBC program. METHODS: During the first 10 months of the MDBC, patients were asked to complete a 14-question postconsultation telephone survey. A statistical analysis was performed to explore potential associations between age, race, and stage with overall patient satisfaction scores. RESULTS: Overall, patients (N = 52, 56% white, 42% African American, 2% Hispanic; mean age 61 years) rated the quality of care highly (mean 4.7, range [1 = poor to 5 = excellent]) and felt comfortable with their plan of care (mean 1.63, range [1 = extremely comfortable to 5 = not at all comfortable]). No statistically significant differences in overall satisfaction were found by age, race, or stage; however, patient responses were commonly not optimal (ie, either "no" or "yes, but not as much as I would like") when asked if the care team addressed the impact of their diagnosis on personal relationships (40.4%) or emotional health (28.9%). CONCLUSIONS: Patients were highly satisfied with the care they received in the MDBC program. Findings suggest that this model is well suited to a diverse patient population and have highlighted quality improvement targets such as increased emphasis on providers' communication about psychosocial issues.


Asunto(s)
Neoplasias de la Mama/terapia , Atención a la Salud/organización & administración , Satisfacción del Paciente , Calidad de la Atención de Salud , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/psicología , Femenino , Humanos , Persona de Mediana Edad , Modelos Organizacionales , Grupo de Atención al Paciente , Mejoramiento de la Calidad
16.
J Gen Virol ; 95(Pt 6): 1221-1232, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24694397

RESUMEN

West Nile virus (WNV; family Flaviviridae; genus Flavivirus) group members are an important cause of viral meningoencephalitis in some areas of the world. They exhibit marked variation in pathogenicity, with some viral lineages (such as those from North America) causing high prevalence of severe neurological disease, whilst others (such as Australian Kunjin virus) rarely cause disease. The aim of this study was to characterize WNV disease in a mouse model and to elucidate the pathogenetic features that distinguish disease variation. Tenfold dilutions of five WNV strains (New York 1999, MRM16 and three horse isolates of WNV-Kunjin: Boort and two isolates from the 2011 Australian outbreak) were inoculated into mice by the intraperitoneal route. All isolates induced meningoencephalitis in different proportions of infected mice. WNVNY99 was the most pathogenic, the three horse isolates were of intermediate pathogenicity and WNVKUNV-MRM16 was the least, causing mostly asymptomatic disease with seroconversion. Infectivity, but not pathogenicity, was related to challenge dose. Using cluster analysis of the recorded clinical signs, histopathological lesions and antigen distribution scores, the cases could be classified into groups corresponding to disease severity. Metrics that were important in determining pathotype included neurological signs (paralysis and seizures), meningoencephalitis, brain antigen scores and replication in extra-neural tissues. Whereas all mice infected with WNVNY99 had extra-neural antigen, those infected with the WNV-Kunjin viruses only occasionally had antigen outside the nervous system. We conclude that the mouse model could be a useful tool for the assessment of pathotype for WNVs.


Asunto(s)
Fiebre del Nilo Occidental/virología , Virus del Nilo Occidental/patogenicidad , Animales , Antígenos Virales/metabolismo , Sistema Nervioso Central/virología , Modelos Animales de Enfermedad , Femenino , Enfermedades de los Caballos/patología , Enfermedades de los Caballos/virología , Caballos/virología , Humanos , Masculino , Ratones , Especificidad de Órganos , Especificidad de la Especie , Proteínas no Estructurales Virales/inmunología , Proteínas no Estructurales Virales/metabolismo , Virulencia , Replicación Viral , Fiebre del Nilo Occidental/patología , Fiebre del Nilo Occidental/veterinaria , Virus del Nilo Occidental/inmunología , Virus del Nilo Occidental/fisiología
17.
Eur J Immunol ; 43(3): 734-46, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23212959

RESUMEN

Dendritic cell (DC) modification is a potential strategy to induce clinical transplantation tolerance. We compared two DC modification strategies to inhibit allogeneic T-cell proliferation. In the first strategy, murine DCs were transduced with a lentiviral vector expressing CTLA4-KDEL, a fusion protein that prevents surface CD80/86 expression by retaining the co-stimulatory molecules within the ER. In the second approach, DCs were transduced to express the tryptophan-catabolising enzyme IDO. CTLA4-KDEL-expressing DCs induced anergy in alloreactive T cells and generated both CD4(+) CD25(+) and CD4(+) CD25(-) Treg cells (with direct and indirect donor allospecificity and capacity for linked suppression) both in vitro and in vivo. In contrast, T-cell unresponsiveness induced by IDO(+) DCs lacked donor specificity. In the absence of any immunosuppressive treatment, i.v. administration of CTLA4-KDEL-expressing DCs resulted in long-term survival of corneal allografts only when the DCs were capable of indirect presentation of alloantigen. This study demonstrates the therapeutic potential of CTLA4-KDEL-expressing DCs in tolerance induction.


Asunto(s)
Trasplante de Córnea , Células Dendríticas/inmunología , Rechazo de Injerto/inmunología , Inmunomodulación , Tolerancia al Trasplante/inmunología , Traslado Adoptivo , Animales , Antígeno CTLA-4/genética , Antígeno CTLA-4/inmunología , Supervivencia Celular/genética , Supervivencia Celular/inmunología , Anergia Clonal/inmunología , Células Dendríticas/metabolismo , Femenino , Expresión Génica , Vectores Genéticos/genética , Rechazo de Injerto/prevención & control , Supervivencia de Injerto/genética , Supervivencia de Injerto/inmunología , Inmunomodulación/genética , Lentivirus/genética , Activación de Linfocitos/inmunología , Ratones , Oligopéptidos/inmunología , Fenotipo , Señales de Clasificación de Proteína , Linfocitos T/inmunología , Linfocitos T Reguladores/inmunología , Transducción Genética , Trasplante Homólogo
18.
BMC Genomics ; 14: 169, 2013 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-23497009

RESUMEN

BACKGROUND: The pigeon crop is specially adapted to produce milk that is fed to newly hatched young. The process of pigeon milk production begins when the germinal cell layer of the crop rapidly proliferates in response to prolactin, which results in a mass of epithelial cells that are sloughed from the crop and regurgitated to the young. We proposed that the evolution of pigeon milk built upon the ability of avian keratinocytes to accumulate intracellular neutral lipids during the cornification of the epidermis. However, this cornification process in the pigeon crop has not been characterised. RESULTS: We identified the epidermal differentiation complex in the draft pigeon genome scaffold and found that, like the chicken, it contained beta-keratin genes. These beta-keratin genes can be classified, based on sequence similarity, into several clusters including feather, scale and claw keratins. The cornified cells of the pigeon crop express several cornification-associated genes including cornulin, S100-A9 and A16-like, transglutaminase 6-like and the pigeon 'lactating' crop-specific annexin cp35. Beta-keratins play an important role in 'lactating' crop, with several claw and scale keratins up-regulated. Additionally, transglutaminase 5 and differential splice variants of transglutaminase 4 are up-regulated along with S100-A10. CONCLUSIONS: This study of global gene expression in the crop has expanded our knowledge of pigeon milk production, in particular, the mechanism of cornification and lipid production. It is a highly specialised process that utilises the normal keratinocyte cellular processes to produce a targeted nutrient solution for the young at a very high turnover.


Asunto(s)
Columbidae/genética , Perfilación de la Expresión Génica , Leche/fisiología , Triglicéridos/genética , Animales , Apoptosis , Evolución Biológica , Diferenciación Celular , Columbidae/crecimiento & desarrollo , Células Epidérmicas , Epidermis/metabolismo , Queratinocitos/citología , Queratinocitos/metabolismo , Transglutaminasas/genética , Triglicéridos/biosíntesis , beta-Queratinas/genética
19.
J Appl Physiol (1985) ; 135(2): 352-361, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37410902

RESUMEN

Acute exposure to hypoxia promotes both an increase in sympathetic nervous system activity (SNA) and local vasodilation. In rodents, intermittent hypoxia (IH)-mediated increases in SNA are associated with an increase in blood pressure in males but not females; notably, the protective effect of female sex is lost following ovariectomy. These data suggest the vascular response to hypoxia and/or SNA following IH may be sex- and/or hormone specific-although mechanisms are unclear. We hypothesized that hypoxia-mediated vasodilation and SNA-mediated vasoconstriction would be unchanged following acute IH in male adults. We further hypothesized that hypoxic vasodilation would be augmented and SNA-mediated vasoconstriction would be attenuated in female adults following acute IH, with the greatest effect when endogenous estradiol was high. Twelve male (25 ± 1 yr) and 10 female (25 ± 1 yr) participants underwent 30 min of IH. Females were studied in a low (early follicular) and high (late follicular) estradiol state. Preceding and following IH, participants completed two trials [steady-state hypoxia and cold pressor test (CPT)], where forearm blood flow and blood pressure were measured and used to determine forearm vascular conductance (FVC). The FVC response to hypoxia (P = 0.67) and sympathetic activation (P = 0.73) were unchanged following IH in males. There was no effect of IH on hypoxic vasodilation in females, regardless of estradiol state (P = 0.75). In contrast, the vascular response to sympathetic activation was attenuated in females following IH (P = 0.02), independent of estradiol state (P = 0.65). Present data highlight sex-related differences in neurovascular responsiveness following acute IH.NEW & NOTEWORTHY We examined the effects of acute intermittent hypoxia (AIH) on the vascular response to sympathetic activation and acute hypoxia. Present findings show, despite no effect of AIH on the vascular response to hypoxia, the forearm vasoconstrictor response to acute sympathetic activation is attenuated in females following AIH, independent of estradiol state. These data provide mechanistic understanding of potential benefits of AIH, as well as the impact of biological sex.


Asunto(s)
Antebrazo , Hipoxia , Masculino , Femenino , Humanos , Hemodinámica , Presión Sanguínea , Vasodilatación/fisiología , Sistema Nervioso Simpático/fisiología
20.
J Child Adolesc Psychopharmacol ; 33(8): 306-315, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37669021

RESUMEN

Objective: Pediatric anxiety disorders are associated with increased stimulus-driven attention (SDA), the involuntary capture of attention by salient stimuli. Increased SDA is linked to increased activity in the right ventrolateral prefrontal cortex (rVLPFC), especially in the portion corresponding to the ventral attention network (VAN). In this study, we present a small clinical trial using a novel attention training program designed to treat pediatric anxiety by decreasing SDA and activity in the rVLPFC. Methods: Children ages 8-12 with anxiety disorders (n = 18) participated in eight sessions of attention training over a 4-week period. At baseline and after completing training, participants completed clinical anxiety measures and a battery of cognitive tasks designed to measure three different aspects of attention: SDA, goal-oriented attention, and threat bias. A subset of participants (n = 12) underwent baseline and post-training neuroimaging while engaged in an SDA task. Brain analyses focused on activity within the rVLPFC. Results: Parent (p < 0.001)-, child (p < 0.002)-, and clinician-rated (p < 0.02) anxiety improved significantly over the course of training. Training significantly altered SDA [F(1,92) = 8.88, corrected p-value (pcor) < 0.012, uncorrected p-value (puncor) < 0.004]. Anxiety improvement correlated with improvements in goal-directed attention [r(10) = 0.60, pcor < 0.12 puncor < 0.04]. Within an area of the rVLPFC corresponding to the cingulo-opercular network (CON), there was a main effect of training [F(1,20) = 6.75, pcor < 0.16, puncor < 0.02], with decreasing signal across training. There was a significant interaction between training and anxiety on this region's activity [F(1,20) = 9.48, pcor < 0.048, puncor < 0.006]. Post hoc testing revealed that post-training activity within this CON area correlated with residual anxiety [r(10) = 0.68, p < 0.02]. Conclusions: SDA and rVLPFC neural activity may be novel therapeutic targets in pediatric anxiety. After undergoing a training paradigm aimed at modifying this aspect of attention and its underlying neural circuitry, patients showed lower anxiety, changes in SDA and goal-oriented attention, and decreased activity in the CON portion of the rVLPFC.


Asunto(s)
Trastornos de Ansiedad , Entrenamiento Cognitivo , Niño , Humanos , Ansiedad/terapia , Ansiedad/psicología , Trastornos de Ansiedad/terapia , Trastornos de Ansiedad/psicología , Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética , Proyectos Piloto
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