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Abstract Context Controversy exists regarding if and how body mass index (BMI) impacts antimüllerian hormone (AMH) in women with and without polycystic ovary syndrome (PCOS). Understanding the BMI-AMH relationship has critical implications for clinical interpretation of laboratory values and could illuminate underlying ovarian physiology. Objective To test the hypotheses that (1) BMI is associated with reduced AMH in PCOS and ovulatory controls (OVAs) and (2) the reduction in AMH is not accounted for by dilutional effects. Design/Setting Multicenter cohort. Participants Women aged 25 to 40 years from 2 clinical populations: 640 with PCOS, 921 women as OVAs. Main Outcome Measures Ovarian reserve indices: AMH, antral follicle count (AFC), and AMH to AFC ratio (AMH/AFC) as a marker of per-follicle AMH production. Results In both cohorts, increasing BMI and waist circumference were associated with reductions in AMH and AMH/AFC, after adjusting for age, race, smoking, and site in multivariate regression models. Increasing BMI was associated with reduced AFC in PCOS but not OVAs. Body surface area (BSA), which unlike BMI is strongly proportional to plasma volume, was added to investigate a potential dilutive effect of body size on AMH concentrations. After controlling for BSA, BMI retained independent associations with AMH in both cohorts; BSA no longer associated with AMH. Conclusions In an adjusted analysis, BMI, but not BSA, was associated with reduced AMH; these data do not support a role for hemodilution in mediating the relationship between increased body size and reduced AMH. Decreased AMH production by the follicle unit may be responsible for reduced AMH with increasing BMI.

Earlier research in cats has shown that both cerebral blood volume (CBV) and cerebral blood flow (CBF) can be used to identify layer-dependent fMRI activation with spatial specificity superior to gradient-echo blood-oxygen-level-dependent (BOLD) contrast (Jin and Kim, 2008a). CBF contrast of perfusion fMRI at ultra-high field has not been widely applied in humans to measure laminar activity due to its low sensitivity, while CBV contrast for fMRI using vascular space occupancy (VASO) has been successfully used. However, VASO can be compromised by interference of blood in-flow effects and a temporally limited acquisition window around the blood-nulling time point. Here, we proposed to use DANTE (Delay Alternating with Nutation for Tailored Excitation) pulse trains combined with 3D-EPI to acquire an integrated VASO and perfusion (VAPER) contrast. The signal origin of the VAPER contrast was theoretically evaluated with respect to its CBV and CBF contributions using a four-compartment simulation model. The feasibility of VAPER to measure layer-dependent activity was empirically investigated in human primary motor cortex at 7 ​T. We demonstrated this new tool, with its highly specified functional layer profile, robust reproducibility, and improved sensitivity, to allow investigation of layer-specific cortical functions.

Precise fluid therapy is extremely important during surgeries, as enough circulating blood volume ensures tissue perfusion and cell oxygenation. Yet, extra fluid volume could cause other adverse events, such as heart failure, intestinal swelling, etc. Thus, precise evaluation of the circulating blood volume is essential for maintaining sufficient circulating blood volume and avoiding excessive fluid infusion. This study aimed to evaluate the relationship between SVV and circulating blood volume during intraoperative fluid therapy. SVV was measured by FloTrac/Vigileo in the study. A prospective cohort study was conducted. 103 patients aged from 20 to 60 years old with an ASA Grade I-II and a diagnosis of meningioma less than 3 centimeters planning for selective neurosurgery were randomly divided into the Crystalloid Group and the Colloid Group. After induction, each Patient received 15 ml/kg of Plasma-Lyte-A or 6% hydroxyethyl starch in 30 min followed by continuous infusion at the speed of 0.1 ml/kg during the next 60 min. Hb concentration, Hct, Delta-BV/kg, and Delta-SVV were recorded every 5 minutes. The delta-SVV and Delta-bv/kg were significantly higher in the Crystalloid Group than that of the Colloid Group. There was a strong linear correlation between Delta-SVV and Delta-bv/kg in both Crystalloid Group (Delta-bv / kg = 1.108 Delta-SVV + 0.0712, P < .001) and Colloid Group (Delta-bv / kg = 1.047 Delta-SVV + 0.4153, P < .001). An equation between Delta-bv/kg and Delta-SVV was established (Delta-bv / kg = 1.099 Delta-SVV + 0.1139, P < .001). In conclusion, SVV measured by FloTrac / Vigileo could guile fluid therapy precisely by predicting the blood volume of patients during the intraoperative period, as it has a strong linear correlation with the blood volume of patients who underwent general anesthesia, meaning anesthesiologist could calculate the exact fluid volume for patients' infusion. Further studies with large cohorts and centers would be needed to validate its efficiency.

Objectives To examine with a parallel group study design the performance and physiological responses to a 14-day off-season ‘live high-train low in the heat’ training camp in elite football players. Methods Seventeen professional Australian Rules Football players participated in outdoor football-specific skills (32±1°C, 11.5 h) and indoor strength (23±1°C, 9.3 h) sessions and slept (12 nights) and cycled indoors (4.3 h) in either normal air (NORM, n=8) or normobaric hypoxia (14±1 h/day, FiO2 15.2–14.3%, corresponding to a simulated altitude of 2500–3000 m, hypoxic (HYP), n=9). They completed the Yo-Yo Intermittent Recovery level 2 (Yo-YoIR2) in temperate conditions (23±1°C, normal air) precamp (Pre) and postcamp (Post). Plasma volume (PV) and haemoglobin mass (Hbmass) were measured at similar times and 4 weeks postcamp (4WPost). Sweat sodium concentration ((Na+)sweat) was measured Pre and Post during a heat-response test (44°C). Results Both groups showed very large improvements in Yo-YoIR2 at Post (+44%; 90% CL 38, 50), with no between-group differences in the changes (−1%; −9, 9). Postcamp, large changes in PV (+5.6%; −1.8, 5.6) and (Na+)sweat (−29%; −37, −19) were observed in both groups, while Hbmass only moderately increased in HYP (+2.6%; 0.5, 4.5). At 4WPost, there was a likely slightly greater increase in Hbmass (+4.6%; 0.0, 9.3) and PV (+6%; −5, 18, unclear) in HYP than in NORM. Conclusions The combination of heat and hypoxic exposure during sleep/training might offer a promising ‘conditioning cocktail’ in team sports.

We report a study on twenty-two healthy human subjects of the dynamic relationship between cerebral hemoglobin concentration ([HbT]), measured with near-infrared spectroscopy (NIRS) in the prefrontal cortex, and systemic arterial blood pressure (ABP), measured with finger plethysmography. [HbT] is a measure of local cerebral blood volume (CBV). We induced hemodynamic oscillations at discrete frequencies in the range 0.04-0.20 Hz with cyclic inflation and deflation of pneumatic cuffs wrapped around the subject's thighs. We modeled the transfer function of ABP and [HbT] in terms of effective arterial (K(a)) and venous (K(v)) compliances, and a cerebral autoregulation time constant (τ(AR)). The mean values (± standard errors) of these parameters across the twenty-two subjects were K(a) = 0.01 ± 0.01 μM/mmHg, K(v) = 0.09 ± 0.05 μM/mmHg, and τ(AR) = 2.2 ± 1.3 s. Spatially resolved measurements in a subset of eight subjects reveal a spatial variability of these parameters that may exceed the inter-subject variability at a set location. This study sheds some light onto the role that ABP and cerebral blood flow (CBF) play in the dynamics of [HbT] measured with NIRS, and paves the way for new non-invasive optical studies of cerebral blood flow and cerebral autoregulation.

Objective:To investigate the effects of umbilical cord milking on the need for red blood cell (RBC) transfusion and morbidity in very preterm infants.Patients and Methods:40 singleton infants born between 24 and 28 weeks’ gestation were randomly assigned to receive umbilical cord clamped either immediately (control group, n = 20) or after umbilical cord milking (milked group, n = 20). Primary outcome measures were the probability of not needing transfusion, determined by Kaplan–Meier analysis, and the total number of RBC transfusions. Secondary outcome variables were haemoglobin value and blood pressure at admission.Results:There were no significant differences in gestational age and birth weight between the two groups. The milked group was more likely not to have needed red cell transfusion (p = 0.02) and had a decreased number (mean (SD)) of RBC transfusions (milked group 1.7 (3.0) vs controls 4.0 (4.2); p = 0.02). The initial mean (SD) haemoglobin value was higher in the milked group (165 (14) g/l) than in the controls (141 (16) g/l); p<0.01). Mean (SD) blood pressure at admission was significantly higher in the milked group (34 (9) mm Hg) than in the controls 28 (8) mm Hg; p = 0.03). There was no significant difference in mortality between the groups. The milked group had a shorter duration of ventilation or supplemental oxygen than the control group.Conclusion:Milking the umbilical cord is a safe procedure, reducing the need for RBC transfusions, and the need for circulatory and respiratory support in very preterm infants.

Volume responsiveness can be evaluated by tilting maneuvers such as head‐down tilt (HDT) and passive leg raising (PLR), but the two procedures use different references (HDT the supine position; PLR the semi‐recumbent position). We tested whether the two procedures identify “normovolemia” by evaluating the stroke volume (SV) and cardiac output (CO) responses and whether the peripheral perfusion index (PPI) derived from pulse oximetry provides similar information. In randomized order, 10 healthy men were exposed to both HDT and PLR, and evaluations were made also when the subjects fasted. Central cardiovascular variables were derived by pulse contour analysis and changes in central blood volume assessed by thoracic electrical admittance (TEA). During HDT, SV remained stable (fasted 110 ± 16 vs. 109 ± 16 ml; control 113 ± 16 vs. 111 ± 16 ml, p > 0.05) with no change in CO, TEA, PPI, or SV variation (SVV). In contrast during PLR, SV increased (fasted 108 ± 17 vs. 117 ± 17 ml; control 108 ± 18 vs. 117 ± 18 ml, p < 0.05) followed by an increase in TEA (p < 0.05) and CO increased when subjects fasted (6.7 ± 1.5 vs. 7.1 ± 1.5, p = 0.007) with no change in PPI or SVV. In conclusion, SV has a maximal value for rest in supine men, while PLR restores SV as CBV is reduced in a semi‐recumbent position and the procedure thereby makes healthy volunteers seem fluid responsive. Volume responsiveness can be evaluated by tilting manoeuvres such as head‐down tilt (HDT) and passive leg raising (PLR), but the two procedures use different references (HDT the supine position; PLR the semi‐recumbent position). Stroke volume has a maximal value for rest in supine men, while PLR restores SV as central blood volume is reduced in a semi‐recumbent position and the procedure thereby makes healthy volunteers seem fluid responsive.

ABSTRACT BACKGROUND: Volume expansion and hypertension are widely used for the hemodynamic management of patients with subarachnoid hemorrhage. OBJECTIVE: To investigate the feasibility, adherence, and retention in a trial of volume expansion and blood pressure manipulation to prevent delayed cerebral ischemia. METHODS: A randomized pilot trial using a 2-way factorial design allocating patients within 72 hours of subarachnoid hemorrhage to either normovolemia (NV) or volume expansion (HV) and simultaneously to conventional (CBP) or augmented blood pressure (ABP) for 10 days. The study endpoints were protocol adherence and retention to follow-up. The quality of endpoints for a larger trial were 6-month modified Rankin Scale score, comprehensive neurobehavioral assessment, delayed cerebral ischemia, new stroke, and discharge disposition. RESULTS: Twenty patients were randomized and completed follow-up. The overall difference in daily mean intravenous fluid intake was 2099 mL (95% confidence interval [CI]: 867, 3333), HV vs NV group. The overall mean systolic blood pressure difference was 5 mm Hg (95% CI: −4.65, 14.75), ABP vs CBP group. Adverse events included death (n = 1), delayed cerebral ischemia (n = 1), and pulmonary complications (n = 3). There were no differences in modified Rankin Scale score between HV and NV (difference 0.1; 95% CI: −1.26, 1.46, P = .87) or between ABP and CBP groups (−0.5, 95% CI: −1.78, 0.78, P = .43). Neuropsychological scores were similar between HV vs NV, but tended to be worse in ABP (57 ± 27) vs CBP group (85 ± 21, P = .04). CONCLUSION: This pilot study showed adequate feasibility and excellent retention to follow-up. Given the suggestion of possible worse neurobehavioral outcome with ABP, a larger trial to determine the optimal blood pressure management in this patient population is warranted. (ClinTrials.gov NCT01414894.)

Purpose This study examined the haematological adaptations to high-intensity interval training (HIT), i.e. total haemoglobin mass (tHb-mass), blood volume (BV), and plasma volume (PV), and its effects on VO 2max in well-trained athletes. Methods Twenty-seven male and eight female well-trained (VO 2max 63.7 ± 7.7 ml/min/kg) athletes were randomly assigned to the HIT (HITG, N  = 19) or the control group (CG, N  = 16). Over a 3-week period, the HITG performed 11 HIT sessions, consisting of four 4-min interval bouts at an exercise intensity of 90–95 % of the individual maximal heart rate (HR max ), separated by 4-min active recovery periods. Before and 5 ± 2 days after the intervention, tHb-mass, BV and PV were determined by the CO-rebreathing method. VO 2max was assessed in a laboratory treadmill test. Results tHb-mass (from 753 ± 124 to 760 ± 121 g), BV (from 5.6 ± 0.8 to 5.6 ± 0.9 l) and PV (from 3.2 ± 0.5 to 3.2 ± 0.5 l) remained unchanged after HIT and did not show an interaction (group × time). Within the HITG, VO 2max improved from baseline by +3.5 % ( p  = 0.011), but remained unchanged in the CG. No interaction (group × time) was seen for VO 2max . The HITG showed a significant reduction in HR max compared to the baseline measurement (−2.3 %, p  ≤ 0.001), but HR max remained unchanged in the CG. There was a significant interaction (group × time) for HR max ( p  = 0.006). Also, oxygen pulse significantly increased only in HITG from 22.9 ± 4.4 to 23.9 ± 4.2 ml/beat, with no interaction ( p  = 0.150). Conclusions Eleven HIT sessions added to usual training did neither improve VO 2max nor haematological parameters compared to the CG.

Lung diffusing capacity (DLCO) is influenced by alveolar-capillary membrane conductance ( D M ) and pulmonary capillary blood volume ( V C ), both of which can be impaired in sedentary type 1 diabetes mellitus (T1DM) subjects due to hyperglycemia. We sought to determine if T1DM, and glycemic control, affected DLNO, DLCO, D M , V C and SaO 2 during maximal exercise in aerobically fit T1DM subjects. We recruited 12 T1DM subjects and 18 non-diabetic subjects measuring DLNO, DLCO, D M , and V C along with SaO 2 and cardiac output (Q) at peak exercise. The T1DM subjects had significantly lower DLCO/Q and D M /Q with no difference in Q, DLNO, DLCO, D M , or V C (DLCO/Q = 2.1 ± 0.4 vs. 1.7 ± 0.3, D M /Q = 2.8 ± 0.6 vs. 2.4 ± 0.5, non-diabetic and T1DM, p  < 0.05). In addition, when considering all subjects there was a relationship between DLCO/Q and SaO 2 at peak exercise ( r  = 0.46, p  = 0.01). Within the T1DM group, the optimal glycemic control group (HbA1c <7%, n  = 6) had higher DLNO, DLCO, and D M /Q than the poor glycemic control subjects (HbA1c ≥7%, n  = 6) at peak exercise (DLCO = 38.3 ± 8.0 vs. 28.5 ± 6.9 ml/min/mmHg, DLNO = 120.3 ± 24.3 vs. 89.1 ± 21.0 ml/min/mmHg, D M /Q = 3.8 ± 0.8 vs. 2.7 ± 0.2, optimal vs. poor control, p  < 0.05). There was a negative correlation between HbA1c with DLCO, D M and D M /Q at peak exercise (DLCO: r  = −0.70, p  = 0.01; D M : r  = −0.70, p  = 0.01; D M /Q: r  = −0.68, p  = 0.02). These results demonstrate that there is a reduction in lung diffusing capacity in aerobically fit athletes with T1DM at peak exercise, but suggests that maintaining near-normoglycemia potentially averts lung diffusion impairments.