Monte Carlo method applied to the evaluation of the relationship between ejection fraction and its constituent components.

Ventricular function is routinely assessed by applying the clinically accepted metric ejection fraction (EF). The numerical value of EF depends on the interplay between end-systolic volume (ESV) and end-diastolic volume (EDV). The relative impact of the two constitutive components has received little attention. Pediatric cardiologists are interested in EF vs ESV when evaluating various congenital abnormalities. Following successful surgical intervention of Fallot tetralogy, many of these patients receive follow-up, not only during childhood, but also when being adults. Cardiologists diagnosing and treating elderly patients often analyze EF vs EDV, notably for phenotyping heart failure patients. Therefore, we study EF vs ESV as well as EF vs EDV in more detail. We explore the fundamentals of EF while analyzing a Fallot patient group. Three routes were followed, namely nonlinear regression, by implementing a Monte Carlo approach to generate EDV on the basis of known ESV values, and by using a theoretical graphical derivation. Our MRI-based post Fallot repair study includes left (LV) and right ventricular (RV) data (N=124). Using a robust approach we employed nonlinear regression with ESV as an independent variable. EDV was also assessed by Monte Carlo generated values for stroke volume within a physiological range. In all cases ESV emerges as the dominant component of EF, with less (P<;0.0001) impact of EDV. Using three independent routes we demonstrate that values for EF primarily depend on the corresponding ESV. This relationship is nonlinear, and correlation is always better with ESV compared to EDV in these patients, and confirmed in random number modeling studies.

Sex-specific aspects of left and right ventricular volume regulation in patients following tetralogy of Fallot repair.

Ejection fraction (EF) is applied as a clinically relevant metric to assess both left (LV) and right ventricular (RV) function. EF depends on the interplay between end-systolic volume (ESV) and end-diastolic volume (EDV). The role of the two constitutive components is of particular interest for the follow-up study of Fallot patients at risk for RV volume overload. The volume regulation graph (VRG) relates ESV to EDV and has been advanced as a central tool to describe LV and RV function. The method permits additional analysis of the impact of clinically relevant determinants such as sex and age. Following Fallot repair and using MRI we evaluated LV and RV volumes in 124 patients (50 females), who were not taking any medication. Volumes were indexed for body surface area (BSA). The VRG regression lines are similar for both sexes, also when stratified for age (i.e. younger or older than 18 years), and different for LV and RV. However, RV ESV is larger (P=0.039) for adult males, as is RV EDV (P=0.026) in boys, relative to their female counterparts. For LV ESV we also found larger volumes, but only in boys (P=0.023) compared to girls. Average EF (only for RV) is lower in adult men compared to women (P=0.012), and to boys (P=0.007). These findings are partly in contrast with common observations made in individuals without a history of cardiac disease, where (with BSA indexation) LV and RV volumes are similar in children, but consistently larger in adult males. These results highlight the age- and sex-specific volumetric aspects of remodeling following surgery in Fallot patients, and emphasize the pivotal role of ESV size in both RV and LV.

The effects of prophylactic bolus phenylephrine on hypotension during low-dose spinal anesthesia for cesarean section.

BACKGROUND: Continuously infused phenylephrine is frequently used to reduce the incidence of hypotension in women undergoing cesarean section under spinal anesthesia, but less is known about the prophylactic bolus method. We evaluated three prophylactic bolus doses of phenylephrine during low-dose spinal anesthesia for cesarean section. METHODS: One-hundred-and-eighty-four patients were randomized to receive 0.9% saline 2mL (Control Group) or phenylephrine 1.0µg/kg (PHE1 Group), 1.5µg/kg (PHE1.5 Group), or 2.0µg/kg (PHE2 Group) immediately after induction of combined spinal-epidural anesthesia. Maternal blood pressure and heart rate were recorded at 1-min intervals until delivery. Hypotension, defined as systolic blood pressure <80% of baseline, was treated with rescue doses of phenylephrine 100µg at 1-min intervals until hypotension resolved. The incidence of nausea, vomiting, bradycardia, and hypertension, as well as Apgar scores and umbilical blood gases, were recorded. RESULTS: The incidence of hypotension was 71.7% (33/46) in the Control Group, 68.9% (31/45) in the PHE1 Group, 37.0% (17/46) in the PHE1.5 Group and 45.7% (21/46) in the PHE2 Group (P=0.001). The total rescue dose of phenylephrine was greater in the Control Group than those in the PHE1.5 Group (P<0.05) and PHE2 Group (P<0.05). The incidence of hypertension increased as the dose of prophylactic phenylephrine increased (P<0.001) and was highest in the PHE2 group (37%). Other variables did not differ among the four groups. CONCLUSIONS: Under the conditions of this study, prophylactic bolus injection of phenylephrine 1.5µg/kg was a suitable alternative method for reducing the incidence of hypotension during low-dose spinal anesthesia for cesarean section.

Re-categorisation of male lower urinary tract symptoms based on the international prostate symptom score questionnaire.

AIMS: The purpose of this study was to develop a new sub-classification system for male lower urinary tract symptoms (LUTS)-mild, moderate and severe-using the conventional International Prostate Symptoms Score (I-PSS). METHODS: From October 2007 to March 2012, a total of 2234 male patients (≥ 50 years old) presenting with LUTS were enrolled in this study. Patients were sorted according to their I-PSS (ranging from 1 to 35 points) and divided into three groups based on their quality of life (QoL) score. A chi-square automatic interaction detection (CHAID) algorithm, based on adjusted significance testing, was used. The Kappa coefficient was calculated for the agreement of original and new categorisation. RESULTS: Mean total I-PSS and QoL scores were 11.0 and 2.9 respectively. According to the original classification, 838 patients (38.6%) had mild, 1053 (48.5%) had moderate and 282 (13.0%) had severe symptoms. After the CHAID algorithm was applied, the scores were re-categorised as 'mild' (1-6 points), 'moderate' (7-21 points) and 'severe' (22-35 points). The overall model was able to correctly predict whether an I-PSS was associated with mild, moderate or severe symptoms, with 70.1% accuracy. According to this new classification, 704 patients (32.4%) were shown to have mild, 1255 (57.8%) to have moderate and 214 (9.8%) to have severe LUTS. The agreement of conventional and new categorisation is very strong (Kappa coefficient = 0.84). CONCLUSIONS: Conventional categorisation of LUTS by I-PSS needs to be updated and the category of moderate LUTS should be broadened.

Synthesis and reactivity of an efficient 1,2-dehydrocarborane precursor, phenyl[o-(trimethylsilyl)carboranyl]iodonium acetate.

The reaction of [o-(trimethylsilyl)carboranyl]lithium with IPh(OAc)2 in diethyl ether affords an efficient 1,2-dehydro-o-carborane precursor 4: the facile 2 + 4 cycloaddition of 4 with dienes in the presence of the desilylating agent is reported.

Immunostimulatory effects of anionic alkali mineral complex solution Barodon in porcine lymphocytes.

The anionic alkali mineral complex solution, Barodon (Barodon-S.F. Corp., Korea), was evaluated for its effectiveness as a nonspecific immunostimulator in pigs. The effects of Barodon were determined by analysis of feed efficiency, growth rate, and phenotype of leukocyte subpopulations using monoclonal antibodies specific to porcine leukocyte differentiation antigens and flow cytometry (FC). The study was focused to investigate the change in proportion of the CD4+CD8+ double positive T lymphocyte subpopulation (dpp) which exists uniquely in pigs. In addition, the mitogen-stimulated lymphoproliferative response, tissue distribution in lymphoid organs and the adjuvant effect of Barodon on hog cholera vaccine efficiency were determined. The study has revealed the average daily gain rates and feed conversion rates were significantly (p<0.05) improved in either group of pigs fed with 0.05% Barodon-spray feed (Tx-1) or pigs fed with 3% Barodon-fermented feed (Tx-2) in comparison with group of pigs fed with feed containing no Barodon (control). The proportion of cells expressing CD4+ antigen in Barodon-treated group increased from 3 weeks posttreatment and was significantly higher (p<0.05) than that of control at 8 weeks posttreatment. Particularly, the significantly higher proportion was maintained from 8 weeks through 13 weeks posttreatment in Tx-1 group (p<0.05). The proportion of cells expressing CD8+ antigen was significantly higher at 3 weeks posttreatment in Tx-2 (p<0.01). Proportion of MHC class II-expressing cells was significantly higher in Tx-1 and Tx-2 group at 11 weeks and 8 weeks posttreatment (p<0.05), respectively. In addition, the proportion of Non T/Non B (N) cells was also significantly higher in Tx-2 at 3 weeks posttreatment (p<0.01) and maintained to 13 weeks posttreatment (p<0.1). Between Barodon-treated groups, the proportion of MHC class II-expressing cells was observed to be larger in Tx-2 than Tx-1 from 3 weeks to 8 weeks posttreatment (p<0.05). However, there were no significant difference in the proportions of CD2+ cells, B cells, monocytes and granulocytes between Barodon-treated and control group during the experiment. Dual-color FC analysis, study has revealed an increased proportion of dpp present in lymphocytes obtained from peripheral blood (PB) and mesenteric lymph node (MLN) of Barodon-treated group at 8 and 11 weeks posttreatment. The proportion of dpp in PB was 27.5% and 32.1% in Tx-1 and Tx-2, respectively, but only 2.2% in control group at 8 weeks posttreatment. In MLN, the proportion was 45.1% and 52.1% in Tx-1 and Tx-2, respectively, otherwise 16.5% in control group at 8 weeks posttreatment. The mitogen-stimulated activity was significantly higher in Tx-1 than in the control group at 11 weeks posttreatment when cells were stimulated with Con A and PHA, respectively (p<0.01). Also, Con A-, PHA and PWM-stimulated activity was significantly higher in Tx-2 than in the control group at the same time (p<0.05). The tissue distribution of CD4+, CD8+ and CD4+CD8+ dpp in MLN and spleen was significantly larger in Tx-1 and Tx-2 than in the control group (p<0.01). Also, a larger proportion of dpp was observed in Tx-2 than Tx-1 in spleen between Barodon-treated groups (p<0.01). In conclusion, the study has demonstrated that Barodon had an immunostimulatory effect on pigs through proliferation and activation of porcine immune cells, specially CD4+CD8+ dpp lymphocytes.