Evidence of serial connection between the plasma volume and two interstitial fluid compartments.

BACKGROUND: Kinetic analysis of fluid volume shifts can identify two interstitial fluid compartments with different turnover rates, but how they are connected to the bloodstream is unknown. METHODS: Retrospective data were retrieved from 217 experiments where 1.5 L of Ringer's solution (mean) had been administered by intravenous infusion over 30 min to awake and anesthetized humans (mean age 40 years). Urinary excretion and hemoglobin-derived plasma dilution served as input variables in a volume kinetic analysis using mixed models software. Possible modes of connection between the two interstitial fluid compartments and the bloodstream were judged by covariance analysis between kinetic rate constants, physiological variables, and time factors. RESULTS: The return flow of already distributed fluid to the plasma via a fast-exchange interstitial compartment was inhibited ongoing infusion of fluid (-38 %), which was probably due to increase of the venous pressure during volume loading. Ongoing infusion also greatly retarded the entrance of fluid to the slow-exchange compartment (-85 %), which suggests that infused Ringer's first had to enter the fast-exchange compartment. A high mean arterial pressure markedly increased the urine output and, to a lesser degree, also the rate of entrance of fluid to the fast-exchange compartment. Moreover, a high blood hemoglobin concentration retarded the rate of entrance of fluid to the fast-exchange compartment. CONCLUSIONS: The fast-exchange but not the slow-exchange interstitial fluid compartment was affected by intravascular events, which suggests that only the fast-exchange compartment is directly connected to the circulating blood.

Higher estimated plasma volume status is associated with increased thrombotic risk and impaired survival in patients with primary myelofibrosis.

Introduction: Blood plasma represents a large reservoir of cytokines and other mediators of inflammation. Higher estimated plasma volume status (ePVS) has been shown to correlate with increased thrombotic risk in polycythemia vera patients, but its clinical and prognostic associations in patients with myelofibrosis are unknown which we aim to evaluate in this study. Materials and methods: We retrospectively analysed a multicentric cohort of 238 patients with primary (PMF) and secondary myelofibrosis (SMF). Estimated plasma volume status was calculated using the Strauss-derived Duarte formula. Overall survival (OS) and time to thrombosis (TTT) considering both arterial and venous thromboses were primary endpoints of interest. Results: Median ePVS was 5.8 dL/g and it did not significantly differ between PMF and SMF patients. Patients with more advanced disease features, more pronounced inflammation and higher comorbidity burden had higher ePVS. Higher ePVS (> 5.6 dL/g) was associated with shorter OS in PMF (unadjusted hazard ratio, HR = 2.8, 95% confidence interval, CI (1.79-4.41), P < 0.001) and SMF (unadjusted HR = 2.55, 95% CI (1.1-5.71), P =0.025) and with shorter TTT in PMF (> 7 dL/g, unadjusted HR = 4.1, 95% CI (1.44-11.59), P = 0.009) patients. Associations with OS diminished in multivariate analyses after adjustments for the dynamic-international-prognostic-scoring-system (DIPSS) and myelofibrosis-secondary-to-PV-and ET-prognostic-model (MYSEC-PM), respectively. Association with TTT remained significant independently of JAK2 mutation, white blood cell count and chronic kidney disease. Conclusions: Myelofibrosis patients with more advanced disease features and more pronounced inflammation have higher ePVS, indicative of expanded plasma volume. Higher ePVS is associated with impaired survival in PMF and SMF and higher thrombotic risk in PMF patients.

Plasma disappearance rate of albumin when infused as a 20% solution.

BACKGROUND: The transcapillary leakage of albumin is increased by inflammation and major surgery, but whether exogenous albumin also disappears faster is unclear. METHODS: An intravenous infusion of 3 mL/kg of 20% albumin was given over 30 min to 70 subjects consisting of 15 healthy volunteers, 15 post-burn patients, 15 patients who underwent surgery with minor bleeding, 10 who underwent surgery with major bleeding (mean, 1.1 L) and 15 postoperative patients. Blood Hb and plasma albumin were measured on 15 occasions over 5 h. The rate of albumin disappearance from the plasma was quantitated with population kinetic methodology and reported as the half-life (T1/2). RESULTS: No differences were observed for T1/2 between volunteers, post-burn patients, patients who underwent surgery with minor bleeding and postoperative patients. The T1/2 averaged 16.2 h, which corresponds to 3.8% of the amount infused per h. Two groups showed plasma concentrations of C-reactive protein of approximately 60 mg/L and still had a similarly long T1/2 for albumin. By contrast, patients undergoing surgery associated with major hemorrhage had a shorter T1/2, corresponding to 15% of the infused albumin per h. In addition, our analyses show that the T1/2 differ greatly depending on whether the calculations consider plasma volume changes and blood losses. CONCLUSION: The disappearance rate of the albumin in 20% preparations was low in volunteers, in patients with moderately severe inflammation, and in postoperative patients.

Revisiting Diagnostic performances of serum erythropoïetin level and JAK2 mutation for polycythemias: analysis of a cohort of 1090 patients with red cell mass measurement.

We assessed the diagnostic performances of erythropoietin and JAK2 mutations in 1,090 patients with suspected polycythemia who were referred for red cell mass (RCM) measurement. In patients with a high haematocrit and/or haemoglobin level, a low erythropoietin level (<=3·3 mUI/ml) and JAK2 mutation showed comparable positive predictive value (PPV) for true polycythemia (RCM>=125%), 92·1% and 90% respectively. A very-low erythropoietin level (<=1·99 mUI/ml) had a PPV of 100% for polycythemia vera (PV) diagnosis. We confirmed the correlations between RCM, erythropoietin and JAK2 variant allelic frequency in PV patients. This study prompts the need to revisit the role of EPO in PV diagnostic criteria.

Plasma and wound fluids from trauma patients suppress neutrophil extracellular respiratory burst.

BACKGROUND: Trauma increases susceptibility to secondary bacterial infections. The events suppressing antimicrobial immunity are unclear. Polymorphonuclear neutrophils (PMNs) migrate toward bacteria using chemotaxis, trap them in extracellular neutrophil extracellular traps, and kill them using respiratory burst (RB). We hypothesized that plasma and wound fluids from trauma patients alter PMN function. METHODS: Volunteer PMNs were incubated in plasma or wound fluids from trauma patients (days 0 and 1, days 2 and 3), and their functions were compared with PMNs incubated in volunteer plasma. Chemotaxis was assessed in transwells. Luminometry assessed total and intracellular RB responses to receptor-dependent and independent stimulants. Neutrophil extracellular trap formation was assessed using elastase assays. The role of tissue necrosis in creating functionally suppressive systemic PMN environments was assessed using a novel pig model where PMNs were incubated in uninjured pig plasma or plasma from pigs undergoing intraperitoneal instillation of liver slurry. RESULTS: Both plasma and wound fluids from trauma patients markedly suppress total PMN RB. Intracellular RB is unchanged, implicating suppression of extracellular RB. Wound fluids are more suppressive than plasma. Biofluids suppressed RB maximally early after injury and their effects decayed with time. Chemotaxis and neutrophil extracellular trap formation were suppressed by biofluids similarly. Lastly, plasma from pigs undergoing abdominal liver slurry instillation suppressed PMN RB, paralleling suppression by human trauma biofluids. CONCLUSION: Trauma plasma and wound fluids suppress RB and other key PMNs antimicrobial functions. Circulating suppressive signals can be derived from injured or necrotic tissue at wound sites, suggesting a key mechanism by which tissue injuries can put the host at risk for infection.

Adaptive changes in single-nephron GFR, tubular morphology, and transport in a pregnant rat nephron: modeling and analysis.

Normal pregnancy is characterized by massive increases in plasma volume and electrolyte retention. Given that the kidneys regulate homeostasis of electrolytes and volume, the organ undergoes major adaptations in morphology, hemodynamics, and transport to achieve the volume and electrolyte retention required in pregnancy. These adaptations are complex, sometimes counterintuitive, and not fully understood. In addition, the demands of the developing fetus and placenta change throughout pregnancy. For example, during late pregnancy, K+ retention and thus enhanced renal K+ reabsorption are required despite many kaliuretic factors. The goal of this study was to unravel how known adaptive changes along the nephrons contribute to the ability of the kidney to meet volume and electrolyte requirements in mid and late pregnancy. We developed computational models of solute and water transport in the superficial nephron of the kidney of a rat in mid and late pregnancy. The midpregnant and late-pregnant rat superficial nephron models predicted that morphological adaptations and increased activity of Na+/H+ exchanger 3 (NHE3) and epithelial Na+ channel are essential for the enhanced Na+ reabsorption observed during pregnancy. Model simulations showed that for sufficient K+ reabsorption, increased activity of H+-K+-ATPase and decreased K+ secretion along the distal segments is required in both mid and late pregnancy. The model results also suggested that certain known sex differences in renal transporter pattern (e.g., the higher NHE3 protein abundance but lower activity in the proximal tubules of virgin female rats compared with male rats) may serve to better prepare females for the increased transport demand in pregnancy.NEW & NOTEWORTHY Normal pregnancy in mammals is generally characterized by massive changes in plasma volume and electrolyte retention. This study provides insights into how the volume and electrolyte requirement in different pregnancy stages are met by coordinated adaptive changes in the kidney. The model results also suggested that certain known sex differences in the renal transporter pattern may serve to better prepare females for the increased transport demand in pregnancy.

Plasma Volume Expansion and Fluid Kinetics of 20% Albumin During General Anesthesia and Surgery Lasting for More Than 5 Hours.

BACKGROUND: Intraoperative administration of crystalloid for plasma volume expansion may be reduced by use of hyperoncotic albumin. However, the degree of plasma volume expansion with administration of 20% albumin is poorly quantitated. We estimated the amount of volume expansion attributable to 20% albumin administration in patients undergoing surgery for more than 5 hours. METHODS: Twenty percent albumin was delivered at 3 mL/kg by intravenous infusion during 30 minutes to 15 patients (mean ± standard deviation [SD] age; 46 ± 15 years) undergoing surgery. Blood samples and urine were collected for 5 hours. Mass balance calculations and volume kinetics were used to estimate plasma volume expansion and capillary leakage of albumin and fluid. RESULTS: Administration of 20% albumin was associated with an increase in plasma volume amounting to 1.7 times the infused volume. After correction for hemorrhage, the median (and 25th to 75th percentiles) intravascular half-life for the administered albumin mass was 20.4 (14.2-34.7) hours. The plasma volume decreased with a half-life of 21.7 (16.1-26.8) hours. Urinary excretion was 3 times greater than the infused volume of albumin, but kinetic analysis suggested that other flows of fluid to and from the plasma occurred more slowly than previously found in volunteers. Hemodynamic support with norepinephrine increased urinary excretion and contracted the plasma volume. CONCLUSIONS: Albumin (20%) increased the plasma volume by 1.7 times the infused volume. Our results do not support that the transcapillary leakage of albumin is accelerated by anesthesia and surgery.

Estimated plasma volume status (ePVS) is a predictor for acute myocardial infarction in-hospital mortality: analysis based on MIMIC-III database.

BACKGROUND: Estimated plasma volume status (ePVS) has been reported that associated with poor prognosis in heart failure patients. However, no researchinvestigated the association of ePVS and prognosis in patients with acute myocardial infarction (AMI). Therefore, we aimed to determine the association between ePVS and in-hospital mortality in AMI patients. METHODS AND RESULTS: We extracted AMI patients data from MIMIC-III database. A generalized additive model and logistic regression model were used to demonstrate the association between ePVS levels and in-hospital mortality in AMI patients. Kaplan-Meier survival analysis was used to pooled the in-hospital mortality between the various group. ROC curve analysis were used to assessed the discrimination of ePVS for predicting in-hospital mortality. 1534 eligible subjects (1004 males and 530 females) with an average age of 67.36 ± 0.36 years old were included in our study finally. 136 patients (73 males and 63 females) died in hospital, with the prevalence of in-hospital mortality was 8.9%. The result of the Kaplan-Meier analysis showed that the high-ePVS group (ePVS ≥ 5.28 mL/g) had significant lower survival possibility in-hospital admission compared with the low-ePVS group (ePVS < 5.28 mL/g). In the unadjusted model, high-level of ePVS was associated with higher OR (1.09; 95% CI 1.06-1.12; P < 0.001) compared with low-level of ePVS. After adjusted the vital signs data, laboratory data, and treatment, high-level of ePVS were also associated with increased OR of in-hospital mortality, 1.06 (95% CI 1.03-1.09; P < 0.001), 1.05 (95% CI 1.01-1.08; P = 0.009), 1.04 (95% CI 1.01-1.07; P = 0.023), respectively. The ROC curve indicated that ePVS has acceptable discrimination for predicting in-hospital mortality. The AUC value was found to be 0.667 (95% CI 0.653-0.681). CONCLUSION: Higher ePVS values, calculated simply from Duarte's formula (based on hemoglobin/hematocrit) was associated with poor prognosis in AMI patients. EPVS is a predictor for predicting in-hospital mortality of AMI, and could help refine risk stratification.

Predictive value of plasma volume status for contrast-induced nephropathy in patients with heart failure undergoing PCI.

AIMS: Contrast-induced nephropathy remains a common complication of coronary procedure and increases poor outcomes, especially in patients with heart failure. Plasma volume expansion relates to worsening prognosis of heart failure. We hypothesized that calculated plasma volume status (PVS) might provide predictive utility for contrast-induced nephropathy in patients with heart failure undergoing elective percutaneous coronary intervention (PCI). METHODS AND RESULTS: We enrolled 441 patients with heart failure undergoing elective PCI from 2012 to 2018. Pre-procedural estimated PVS by the Duarte's formula (Duarte-ePVS) and Kaplan-Hakim formula (KH-ePVS) were calculated for all patients. CIN was defined as an absolute serum creatinine (SCr) increase ≥0.5 mg/dL or a relative increase ≥25% compared with the baseline value within 48 h of contrast medium exposure. We assessed the association between PVS and CIN in patients with heart failure undergoing elective PCI. In 441 patients, 28 (6.3%) patients developed CIN. The median Duarte-ePVS was 4.44 (3.87, 5.13) and the median KH-ePVS was -0.03 (-0.09, 0.05). The best cutoff values for Duarte-ePVS and KH-ePVS to predict CIN were 4.64 (with 78.6% sensitivity and 61.7% specificity) and 0.04 (with 64.5% sensitivity and 75.5% specificity), respectively. After adjusting for potential confounding variables, KH-ePVS > 0.04 [odds ratio (OR) 2.685, 95% confidence interval (CI) 1.012-7.123, P = 0.047] remained significantly associated with CIN whereas Duarte-ePVS was not. CONCLUSIONS: Pre-procedural KH-ePVS is an independent risk factor for CIN in patients with heart failure undergoing elective PCI. The best cutoff point of KH-ePVS for predicting CIN was 0.04.

Carbohydrate hastens hypervolemia achieved through ingestion of aqueous sodium solution in resting euhydrated humans.

PURPOSE: Ingesting beverages containing a high concentration of sodium under euhydrated conditions induces hypervolemia. Because carbohydrate can enhance interstitial fluid absorption via the sodium-glucose cotransporter and insulin-dependent renal sodium reabsorption, adding carbohydrate to high-sodium beverages may augment the hypervolemic response. METHODS: To test this hypothesis, we had nine healthy young males ingest 1087 ± 82 mL (16-17 mL per kg body weight) of water or aqueous solution containing 0.7% NaCl, 0.7% NaCl + 6% dextrin, 0.9% NaCl, or 0.9% NaCl + 6% dextrin under euhydrated conditions. Each drink was divided into six equal volumes and ingested at 10-min intervals. During each trial, participants remained resting for 150 min. Measurements were made at baseline and every 30 min thereafter. RESULTS: Plasma osmolality decreased with water ingestion (P ≤ 0.023), which increased urine volume such that there was no elevation in plasma volume from baseline (P ≥ 0.059). The reduction in plasma osmolality did not occur with ingestion of solution containing 0.7% or 0.9% NaCl (P ≥ 0.051). Consequently, urine volume was 176-288 mL smaller than after water ingestion and resulted in plasma volume expansion at 60 min and later times (P ≤ 0.042). In addition, net fluid balance was 211-329 mL greater than after water ingestion (P ≤ 0.028). Adding 6% dextrin to 0.7% or 0.9% NaCl solution resulted in plasma volume expansion within as little as 30 min (P ≤ 0.026), though the magnitudes of the increases in plasma volume were unaffected (P ≥ 0.148). CONCLUSION: Dextrin mediates an earlier hypervolemic response associated with ingestion of high-sodium solution in resting euhydrated young men. (247/250 words).

Acute effects of estradiol-17ß on plasma volume and uterine cell proliferation in sheep.

Ovarian steroids play an important role in increasing plasma volume in pregnant females and preparing the uterus for implantation. We hypothesized that a short duration of increased estradiol-17ß (E2) would increase plasma volume and uterine cell proliferation in ovariectomized ewes. Adult non-pregnant Romanov ewes (n = 15) were ovariectomized. After ovariectomy, ewes were individually housed and were offered water at ad libitum intake and were fed a pelleted diet at maintenance once daily according to body weight. After at least 30 days post-ovariectomy ewes were fasted and received an implant placed in the axillary region that contained 100 mg of E2 (E2; n = 8) or a sham implant with no E2 (CON, n = 7). After 24 h, ewes were weighed prior to plasma volume measurement procedures. Plasma volume was determined using the Evans blue dye method. Blood samples were taken at 0 (pre dye injection), 5, 10, 15, 20, 25, 30, 40, 50 and 60 min after dye injection. After the final blood collection, ewes were euthanized with an overdose of sodium pentabarbital and uterine weights were recorded. Uterine cross-sections were fixed in formalin for immunohistochemical localization of Ki67 (a marker of proliferating cells) followed by image generation of luminal epithelium and endometrial stroma (5 areas each/tissue section) and analysis to determine the proportion of proliferating cells. Plasma volume tended to be greater in E2 vs CON (2.75 ± 0.11 vs. 2.54 ± 0.12 L, P = 0.07) and uterine weights were greater in E2 vs CON (27.25 ± 2.35 vs. 17.35 ± 2.51 g, P < 0.01). Water intake after implant placement was similar in E2 and CON (3.85 vs. 4.87 ± 0.67 L; P = 0.28). Cell proliferation in the luminal epithelium was greater in E2 vs CON (6.55 vs. 1.2 ± 1.75%, P = 0.02) and stromal cells tended to be greater in E2 vs CON (0.59 vs 0.37 ± 0.06%, P = 0.07). Our results demonstrate that E2-treatment tends to increase plasma volume acutely and increases uterine cell proliferation in ewes.

One-year change in plasma volume and mortality in the Japanese general population: An observational cohort study.

BACKGROUND: Changes in plasma volume, a marker of plasma volume expansion and contraction, are gaining attention in the field of cardiovascular disease because of its role in the prevention and management of heart failure. However, it remains unknown whether a 1-year change in plasma volume is a risk factor for all-cause, cardiovascular, and non-cardiovascular mortality in the general population. METHODS AND RESULTS: We used a nationwide database of 134,291 subjects (age 40-75 years) who participated in the annual "Specific Health Check and Guidance in Japan" check-up for 2 consecutive years between 2008 and 2011. A 1-year change in plasm volume was calculated using the Strauss-Davis-Rosenbaum formula. There were 220 cardiovascular deaths, 1,001 non-cardiovascular deaths including 718 cancer deaths, and 1,221 all-cause deaths during the follow-up period of 3.9 years. All subjects were divided into quintiles based on the 1-year change in plasma volume. Kaplan-Meier analysis demonstrated that the highest 5th quintile had the greatest risk among the five groups. Multivariate Cox proportional hazard regression analysis demonstrated that a 1-year change in plasma volume was an independent risk factor for all-cause, cardiovascular, non-cardiovascular, and cancer deaths. The addition of a 1-year change in plasma volume to cardiovascular risk factors significantly improved the C-statistic, net reclassification, and integrated discrimination indexes. CONCLUSIONS: Here, we have demonstrated for the first time that a 1-year change in plasma volume could be an additional risk factor for all-cause, cardiovascular, and non-cardiovascular (mainly cancer) mortality in the general population.

Blood volume and hemoglobin mass in long-term heart transplant recipients with and without Anemia.

BACKGROUND: In systolic chronic heart failure, a heterogeneous blood volume (BV) regulation can be found with plasma volume expansion in many cases, possibly leading to pseudoanemia. Little is known about the volume status after heart transplantation (HTX). So far, anemia of HTX recipients was solely investigated using hemoglobin-concentration that may be misleading in a clinical context. The objective of the study was whether a difference in plasma volume and red cell volume can be observed in clinically stable heart transplant recipients compared to matched control subjects. Secondary, the aim was to describe anemia in the long-term after HTX based on quantitative data. METHODS: Blood volume and its constituents red cell volume and plasma volume were quantified using an abbreviated carbon monoxide rebreathing method (aCORM) with focus on its primary measure total hemoglobin mass (Hbmass) and coincidental anemia in 36 (7 women) heart transplant recipients. For comparison, a matched control group of 46 (5 women) healthy subjects was selected. RESULTS: Neither Hbmass nor blood volumes were significantly different in HTX patients compared to matched healthy control group subjects. The prevalence of anemia 6.3 ± 4.3 years after transplantation was 19%. Hbmass and red cell volume were significantly lower in anemic HTX patients compared to non-anemic patients while plasma volume was not expanded. Various immunosuppressant regimens did not have an effect on Hbmass, plasma volume or red cell volume. CONCLUSIONS: There was no difference in blood volumes and Hbmass between HTX patients and control subjects. The pathophysiologic blood volume regulation in chronic heart failure does not seem to be longer active in long-term HTX recipients. However, in the long-term after HTX, anemia occurs in a considerable number of patients as true anemia without a clear association with immunosuppression. TRIAL REGISTRATION: German registry for clinical studies, DRKS00006078. Registered 09 May 2014, https://www.drks.de/drks_web/navigate.do?navigationId=trial . HTML&TRIAL_ID=DRKS00006078.

Reduction of estimated fluid volumes following initiation of empagliflozin in patients with type 2 diabetes and cardiovascular disease: a secondary analysis of the placebo-controlled, randomized EMBLEM trial.

BACKGROUNDS/AIM: Sodium glucose co-transporter 2 inhibitors promote osmotic/natriuretic diuresis and reduce excess fluid volume, and this improves cardiovascular outcomes, including hospitalization for heart failure. We sought to assess the effect of empagliflozin on estimated fluid volumes in patients with type 2 diabetes and cardiovascular disease (CVD). METHODS: The study was a post-hoc analysis of the EMBLEM trial (UMIN000024502), an investigator-initiated, multi-center, placebo-controlled, double-blinded, randomized-controlled trial designed primarily to evaluate the effect of 24 weeks of empagliflozin treatment on vascular endothelial function in patients with type 2 diabetes and established CVD. The analysis compared serial changes between empagliflozin (10 mg once daily, n = 52) and placebo (n = 53) in estimated plasma volume (ePV), calculated by the Straus formula and estimated the extracellular volume (eEV), determined by the body surface area, measured at baseline and 4, 12, and 24 weeks after initiation of treatment. Correlations were examined between the changes from baseline to week 24 in each estimated fluid volume parameter and several clinical variables of interest, including N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration. RESULTS: In an analysis using mixed-effects models for repeated measures, relative to placebo empagliflozin reduced ePV by - 2.23% (95% CI - 5.72 to 1.25) at week 4, - 8.07% (- 12.76 to - 3.37) at week 12, and - 5.60% (- 9.87 to - 1.32) at week 24; eEV by - 70.3 mL (95% CI - 136.8 to - 3.8) at week 4, - 135.9 mL (- 209.6 to - 62.3) at week 12, and - 144.4 mL (- 226.3 to - 62.4) at week 24. The effect of empagliflozin on these parameters was mostly consistent across various patient clinical characteristics. The change in log-transformed NT-proBNP was positively correlated with change in ePV (r = 0.351, p = 0.015), but not with change in eEV. CONCLUSIONS: Our data demonstrated that initiation of empagliflozin treatment substantially reduced estimated fluid volume parameters in patients with type 2 diabetes and CVD, and that this effect was maintained for 24 weeks. Given the early beneficial effect of empagliflozin on cardiovascular outcomes seen in similar patient populations, our findings provide an important insight into the key mechanisms underlying the clinical benefit of the drug. Trial registration University Medical Information Network Clinical Trial Registry, number 000024502.

Preoperative histogram parameters of dynamic contrast-enhanced MRI as a potential imaging biomarker for assessing the expression of Ki-67 in prostate cancer.

PURPOSE: To investigate whether preoperative histogram parameters of dynamic contrast-enhanced MRI (DCE-MRI) can assess the expression of Ki-67 in prostate cancer (PCa). MATERIALS AND METHODS: A consecutive series of 76 patients with pathology-proven PCa who underwent routine DCE-MRI scans were retrospectively recruited. Quantitative parameters including the volume transfer constant (Ktrans ), rate contrast (Kep ), extracellular-extravascular volume fraction (Ve ), and plasma volume (Vp ) by outlining the three-dimensional volume of interest (VOI) of all lesions were processed. Then, the histogram analyses of these quantitative parameters were performed. The Spearman rank correlation analysis was used to evaluate the correlation of these parameters and Ki-67 expression of PCa. Receiver operating characteristic (ROC) curve analysis was adopted to evaluate the efficacy of these quantitative histogram parameters in identifying high Ki-67 expression from low Ki-67 expression of PCa. RESULTS: Eighty-eight PCa lesions were enrolled in this study, including 31 lesions with high Ki-67 expression and 57 lesions with low Ki-67 expression. The median, mean, 75th percentile, and 90th percentile derived from Ktrans and Kep had a moderately positive correlation with Ki-67 expression (r = 0.361-0.450, p < 0.05), in which both the median and mean of Ktrans had the highest positive correlation (r = 0.450, p < 0.05). The diagnostic efficacy of the Ktrans median, mean, 75th percentile, and 90th percentile, along with the Kep -based median and mean was assessed by the ROC curve. The area under the curve (AUC) of the mean for Ktrans was the highest (0.826). When the cut-off of the mean for Ktrans was ≥0.47/min, its Youden index, sensitivity, and specificity were 0.625, 0.871, and 0.754, respectively. The AUC of the median of Kep was the lowest (0.772). CONCLUSION: The histogram of DCE-MRI quantitative parameters is correlated with Ki-67 expression, which has the potential to noninvasively assess the expression of Ki-67 with patients of PCa.

Interval-induced metabolic perturbation determines tissue fluid shifts into skeletal muscle.

Intense interval exercise has proven to be as effective as traditional endurance exercise in improving maximal oxygen uptake. Shared by these two exercise regimes is an acute reduction in plasma volume, which is a suggested stimulus behind exercise-induced increases in blood volume and maximal oxygen uptake. This study aimed to link exercise-induced metabolic perturbation with volume shifts into skeletal muscle tissue. Ten healthy subjects (mean age 33 ± 8 years, 5 males and 5 females) performed three 30 s all-out sprints on a cycle ergometer. Upon cessation of exercise magnetic resonance imaging, 31 Phosphorus magnetic resonance spectroscopy and blood samples were used to measure changes in muscle volume, intramuscular energy metabolites and plasma volume. Compared to pre-exercise, muscle volume increased from 1147.1 ± 35.6 ml to 1283.3 ± 11.0 ml 8 min post-exercise. At 30 min post-exercise, muscle volume was still higher than pre-exercise (1147.1 ± 35.6 vs. 1222.2 ± 6.8 ml). Plasma volume decreased by 16 ± 3% immediately post-exercise and recovered back to - 5 ± 6% after 30 min. Principal component analysis of exercise performance, muscle and plasma volume changes as well as changes in intramuscular energy metabolites showed generally strong correlations between metabolic and physiological variables. The strongest predictor for the volume shifts of muscle and plasma was the magnitude of glucose-6-phosphate accumulation post-exercise. Interval training leads to large metabolic and hemodynamic perturbations with accumulation of glucose-6-phosphate as a possible key event in the fluid flux between the vascular compartment and muscle tissue.

Subclinical ketosis risk prediction in dairy cows based on prepartum metabolic indices / [Previsão do risco de cetose subclínica em vacas de leite, baseado nos índices metabólicos pré-parto]

Ketosis can seriously impair cow performance. This study detected changes in prepartum blood metabolic parameters for predicting postpartum ketosis occurrence in dairy cows. Body condition score (BCS) was assessed before and after delivery. Blood samples of 63 cows were collected from 10 days before calving to 10 days after calving to measure metabolic parameters including ß-hydroxybutyric acid (BHBA), non-esterified fatty acid (NEFA), glucose (GLU), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), total protein (TP), albumin (ALB), globulin (GLO), alanine aminotransferase (ALT), and aspartate aminotransferase (AST). There was a postpartum subclinical ketosis incidence of 42.25%. Compared with prepartum, plasma, levels of BHBA, AST, and NEFA significantly increased postpartum, and prepartum AST (R=0.57) and NEFA (R=0.45) showed a significant positive correlation with ketosis postpartum. Plasma GLU level significantly decreased postpartum and was significantly negatively correlated with ketosis (R=-0.21). Receiver operating characteristic curve analysis revealed prepartum BSC < 2.88, and prepartum plasma AST > 68.0 U/L, GLU < 3.97mmol/L, NEFA > 0.27mmol/L, and BHBA > 0.43mmol/L, indicating a high risk of subclinical ketosis postpartum. These levels can be used as risk indicators to predict the occurrence of subclinical ketosis in postpartum cows.(AU)

A cetose pode trazer sérios prejuízos ao desempenho da vaca. Este estudo detectou alterações nos parâmetros metabólicos do sangue pré-parto para prever a cetose pós-parto que ocorre em vacas leiteiras. O escore de condição corporal (ECC) foi avaliado antes e após o parto. Foram coletadas amostras de sangue de 63 vacas entre 10 dias antes e 10 dias após o parto para medir os parâmetros metabólicos, incluindo ácido ß-hidroxibutírico (BHBA), ácido graxo não esterificado (NEFA), glicose (GLU), bilirrubina total (TBIL), bilirrubina direta (DBIL), bilirrubina indireta (IBIL), proteína total (TP), albumina (ALB), globulina (GLO), alanina aminotransferase (ALT) e aspartato aminotransferase (AST). Houve uma incidência de cetose subclínica pós-parto de 42,25%. Em comparação com o pré-parto, o plasma, os níveis de BHBA, AST e NEFA aumentaram significativamente no pós-parto, e AST no pré-parto (R = 0,57) e NEFA (R = 0,45) mostraram uma correlação significativa positiva com cetose pós-parto. O nível plasmático de GLU diminuiu significativamente no pós-parto e foi negativamente correlacionado com a cetose de forma significativa (R = -0,21). A análise da curva característica de operação do receptor revelou BSC pré-parto <2,88 e AST plasmático pré-parto> 68,0 U / L, GLU <3,97mmol / L, NEFA> 0,27mmol / L e BHBA> 0,43mmol / L, indicando um alto risco de cetose subclínica pós-parto. Esses níveis podem ser usados ​​como indicadores de risco para prever a ocorrência de cetose subclínica em vacas no pós-parto.(AU)

Intraoperative Intravascular Effect of Lactated Ringer's Solution and Hyperoncotic Albumin During Hemorrhage in Cystectomy Patients.

BACKGROUND: The intraoperative effect of 20% albumin on plasma volume during surgery involving major blood loss has not been explored extensively due to methodological difficulties. Crystalloids poorly expand the plasma volume, and using a colloid might then be a way to avoid fluid overload. As doubts have been raised about synthetic colloids, albumin solutions are currently used more extensively. This study presents a methodological development showing how plasma volume expansion can be studied in surgical settings with the coinfusion of 20% albumin and lactated Ringer's solution. METHODS: In this single-arm, single-center feasibility study, an intravenous (i.v.) infusion of 3 mL·kg·BW-1 of 20% albumin was administered over 30 minutes to 23 cystectomy patients during the bleeding phase in addition to lactated Ringer's solution to correct blood loss. Blood samples were measured at regular intervals over a period of 300 minutes to estimate the blood volume expansion resulting from simultaneous infusions of lactated Ringer's and 20% albumin solutions, using a regression equation and the area under the volume-time curve method. RESULTS: Mean hemorrhage was 974 mL (standard deviation [SD] ± 381). The regression method showed strong correlation (r2 = 0.58) between blood loss minus blood volume expansion and the independent effects of the infused volume of lactated Ringer's and 20% albumin solutions. The mean plasma volume expansion attributable to the infusion of lactated Ringer's solution amounted to 0.38 (95% confidence interval [CI], 0.31-0.49) of the infused volume; for the 20% albumin, it was 1.94 mL/mL (95% CI, 1.41-2.46 mL/mL) over 5 hours on average (regression method). The mean within-patient change was 0.20 mL/mL (± 0.06 mL/mL) for the lactated Ringer's solution and 2.20 mL/mL (±1.31 mL/mL) for the 20% albumin using the area under the volume-time curve method. CONCLUSIONS: Blood volume expansion averaged 1.9-2.2 times the infused volume of 20% albumin during surgery associated with hemorrhage of around 1000 mL. This effect was long standing and approximately 5 times stronger than for the lactated Ringer's solution. Twenty percent albumin boosts the plasma volume expansion of lactated Ringer's solution to as high as 40% of the infused volume on the average, which is an effect that lasts at least 5 hours.

Effects of different mean arterial pressure targets on plasma volume, ANP and glycocalyx-A randomized trial.

BACKGROUND: Arterial haematocrit (Hct) has been shown to decrease after anaesthesia induction, most probably because of an increased plasma volume (PV). The primary objective was to quantify change in PV if mean arterial pressure (MAP) was kept at baseline level or allowed to decrease to 60 mm Hg. Our secondary objective was to evaluate underlying mechanisms of this response. METHODS: Twenty-four coronary artery bypass patients were randomized to a higher (90 mm Hg, intervention group) or lower (60 mm Hg, control group) MAP by titration of norepinephrine. During the experimental procedure, no fluids were administered. Baseline PV was measured by 125 I-albumin and the change in PV was calculated from the change in Hct. Changes in MAP, plasma 125 I-albumin, colloid osmotic pressure, albumin, Mid Regional-pro Atrial Natriuretic Peptide (MR-proANP) and endothelial glycocalyx components were measured from baseline to 50 minutes after anaesthesia induction. RESULTS: The MAP during the trial was 93 ± 9 mm Hg in the intervention group and 62 ± 5 mm Hg in the control group. PV increased with up to 420 ± 180 mL in the control group and 45 ± 130 mL in the intervention group (P < .001). Albumin and colloid osmotic pressure decreased significantly more in the control group. MR-proANP increased in the control group but no shedding of the glycocalyx layer was detected in either of the groups. CONCLUSION: Allowing mean arterial pressure to fall to 60 mm Hg during anaesthesia induction, increases the plasma volume due to reabsorption of interstitial water, with no ANP-induced degradation of the endothelial glycocalyx.