[Association of fibroblast growth factor 23 with age-related cardiac diastolic function subclinical state in a healthy Chinese population]

Objective: To determine the association of serum fibroblast growth factor-23 concentrations with age-related cardiac diastolic function subclinical state and whether this association differs by sex. Methods: Seven hundred sixteen healthy subjects (aged 35-89 years, 68.4% female) were selected from National Basic Research Program of China (973 Program-China Medical University subsection) between January 2014 and February 2015 and assigned into 4 groups according to sex and age:< 60 years old male and female group, ≥ 60 years old male and female group. Blood biochemical indicators and general clinical data of the subjects were measured. The glomerular filtration rate (eGFR) were estimated using the Modified Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI-ASIA) equation. The fibroblast factor 23 (FGF-23), C-reactive protein (CRP) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). Cardiac structure and function parameters including left atrial diameter (LAD), inter-ventricular septum thickness (IVST), left ventricle posterior wall thickness (LVPWT), left ventricle mass index (LVMI),left atrial mass index (LAVI) and the ratio of peak velocity of early filling to the septal early peak diastolic mitral annulus velocity(E/e') were measured by echocardiography. Association between serum FGF-23 and aging-related diastolic function subclinical status was analyzed by binary Logistic regression analysis. Results: (1) Serum log-transformed FGF-23 levels were significantly higher in males than in females [(2.0±0.3) ng/L vs (1.9±0.4) ng/L, P<0.05]. (2) Cardiac diastolic function gradually decreased with age, and age related cardiac diastolic function decline of female was significantly higher than males[E/e':<60 years old male group (7.6±2.6), ≥ 60 years old male group (8.6±2.7), P<0.01;<60 years old female group (8.3±2.3), ≥ 60 years old female group (9.5±3.1), P<0.01; LAVI:<60 years old female group (14±5) ml/m(2), ≥ 60 years old female group (16±5) ml/m(2), P<0.01]. (3) Serum FGF-23 was significantly positively correlated with age (r=0.089, P<0.05) and LAVI (r=0.084, P<0.05) in total study population while with E/e' (r=0.149, P<0.05) only in males. There was no significant correlation between serum FGF-23 and cardiac diastolic function parameters in females. (4) Binary Logistic regression analysis showed that median and high FGF-23 were independently associated with age-related cardiac diastolic function decline (OR=2.831, 95% CI: 1.144-7.009, P=0.024; OR=2.548, 95% CI: 1.053-6.163, P=0.038) in males. Conclusions: Serum FGF-23 concentrations are associated with age-related cardiac diastolic function subclinical state in a healthy Chinese population. High levels of FGF-23 are independently associated with age-related cardiac diastolic function decline in males.

Leptin and leptin receptor gene polymorphisms are correlated with production performance in the Arctic fox

The polymerase chain reaction-single-strand conformation polymorphism technique was employed to measure mononucleotide diversity in the coding region of the leptin and leptin receptor genes in the Arctic fox. The relationships between specific genetic mutations and reproductive performance in Arctic foxes were determined to im-prove breeding strategies. We found that a leptin gene polymorphism was significantly associated with body weight (P < 0.01), abdominal circumference (P < 0.01), and fur length (P < 0.01). Furthermore, a polymorphism in the leptin receptor gene was associated with carcass weight and guard hair length (P < 0.01). Leptin and leptin receptor gene combinatorial genotypes were significantly associated with abdominal circumference, fur length (P < 0.01), and body weight (P < 0.05). The leptin gene is thus a key gene affecting body weight, abdominal circumference, and fur length in Arctic foxes, whereas variations in the leptin receptor mainly affect carcass weight and guard hair. The marker loci identified in this study can be used to assist in the selection of Arctic foxes for breeding to raise the production performance of this species.

Genetic diversity of the Arctic fox using SRAP markers

Sequence-related amplified polymorphism (SRAP) is a recently developed molecular marker technique that is stable, simple, reliable, and achieves moderate to high numbers of codominant markers. This study is the first to apply SRAP markers in a mammal, namely the Arctic fox. In order to investigate the genetic diversity of the Arctic fox and to provide a reference for use of its germplasm, we analyzed 7 populations of Arctic fox by SRAP. The genetic similarity coefficient, genetic distance, proportion of polymorphic loci, total genetic diversity (Ht), genetic diversity within populations (Hs), and genetic differentiation (Gst) were calculated using the Popgene software package. The results indicated abundant genetic diversity among the different populations of Arctic fox studied in China. The genetic similarity coefficient ranged from 0.1694 to 0.0417, genetic distance ranged from 0.8442 to 0.9592, and the proportion of polymorphic loci was smallest in the TS group. Genetic diversity ranged from 0.2535 to 0.3791, Ht was 0.3770, Hs was 0.3158, Gst was 0.1624, and gene flow (Nm) was estimated at 2.5790. Thus, a high level of genetic diversity and many genetic relationships were found in the populations of Arctic fox evaluated in this study.

Magnetic properties of (Fe50Co50)(1-x)-Gdx thin films with diluted Gd doping

(Fe50Co50)(1-x)-Gdx thin films (30 nm) with x<15% deposited on silicon substrates by magnetron sputtering were investigated by X-ray diffraction, vibrating sample magnetometer, and ferromagnetic resonance. Theoretical fittings of the angular dependent ferromagnetic resonance field of the FeCoGd films have been performed using the Landau-Lifshitz equation It is found that the ferromagnetic resonance experimental data is well fitted by the theory and various magnetic properties have been extracted in accordance. The saturation magnetization decreases from 22750 Oe at x = 0% to 14079 Oe at x = 14% in the FeCo-Gd film, and the perpendicular magnetic anisotropy has changed from an easy film plane to an easy film normal geometry. The gyromagnetic ratio, as well as the Landé g factor, are found increased also with increasing Gd content, i.e. from g = 2.08 at x = 0% to g = 2.29 at x = 14%. An enhancement of the L-S coupling in the presence of a low Gd content has been concluded based on an observable increase from 0.011 at x = 12% up to 0.015 at x = 14% in the Gilbert damping.

Fluoroscopically guided nose tube drainage of mediastinal abscesses in post-operative gastro-oesophageal anastomotic leakage

OBJECTIVE

The aim of this study was to retrospectively evaluate the technical success rates and clinical effectiveness of fluoroscopically guided nose tube drainage of mediastinal abscesses and a nasojejunum feeding tube in post-operative gastro-oesophageal anastomotic leakage (GEAL).

METHODS

From January 2006 to June 2011, 18 cases of post-operative GEAL with mediastinal abscesses after oesophagectomy with intrathoracic oesophagogastric anastomotic procedures for oesophageal and cardiac carcinoma were treated by insertion of a nose drainage tube and nasojejunum feeding tube under fluoroscopic guidance. We evaluated the feasibility of two-tube insertion to facilitate leakage site closure and complete resolution of the abscess, and the patients' nutritional benefit was also evaluated by checking the serum albumin level between pre- and post-enteral feeding via the feeding tube.

RESULTS

The two tubes were placed successfully under fluoroscopic guidance in 18 patients (100%). The procedure time for two-tube insertion ranged from 20 to 40 min (mean 30 min). 17 patients (94%) achieved leakage site closure after two-tube insertion and had a good tolerance of two tubes in the nasal cavity. The serum albumin level was significant, increased from pre-enteral feeding (2.49 ± 0.42 g dl(-1)) to the post-enteral feeding (3.58 ± 0.47 g dl(-1)) via the feeding tube (p<0.001). The duration of follow-up ranged from 1 to 49 months (mean 19 months).

CONCLUSION

The insertion of nose tube drainage and a nasojejunum feeding tube under fluoroscopic guidance is safe, and it provides effective relief from mediastinal abscesses in GEAL after oesophagectomy. Moreover, our findings indicate that two-tube insertion may be used as a selective procedure to treat mediastinal abscesses in post-operative GEAL. Advances in knowledge Directive drainage of mediastinal abscesses in post-operative GEAL may be an effective treatment.

274 POTENTIAL OF BOVINE MARROW STROMAL CELLS CULTURED AT DIFFERENT PASSAGES TO DIFFERENTIATE INTO ADIPOCYTE-LIKE CELLS

Bovine marrow stromal cells (MSC) would serve as a preclinical large-animal model for investigating the use of the adult pluripotent cells MSC for human cell therapies, but the information is limited. In this study, adipocytic differentiation was examined in bovine MSC at different passages (psg) after various adipogenic treatments, as the first step in characterizing the multilineage differentiation potential during an extensive culture. Bovine MSC were cultured from the femurs of 3-month-old Holstein calves using a previously described method with slight modifications (Xiang et al. 2001 Chin. J. Pathophysiol. 17, 598–601). The MSC at psg 2, 5, 10, 15, and 20 (total cell culture periods of 10, 19, 34, 49, and 64 days, respectively, 4 × 103 cells cm–2) were cultured for 2 days post-psg. Previously, we found that most of mouse MSC became adipocyte-like cells after they were cultured with a base medium (DMEM, 4.5 g L–1 glucose, plus 10% FBS) containing horse serum (HS) for 5 weeks. Therefore, the bovine MSC at each psg (70% confluence) were then cultured in the base medium containing 0.1 μm dexamethasone, 0.1 mm 3-isobutyl-1-methylxanthine, 0.2 mm indomethacin, and 10 μg mL–1 insulin [hormonal-mixture (HM) group], the base medium containing 15% HS (HS group), or the base medium (control group) for adipogenic induction. The cells were stained with oil red O after being cultured in the respective medium for 1, 3, or 5 weeks. In this study, all cells containing oil red O-stained lipid droplets (LD) were counted as ‘oil red O-positive (OP) cells’, regardless of the size and number contained. The rate of OP cells in each group was determined as follows. In the dishes, the total number of cells (60 to 100 cells) and OP cell number were counted in a randomly selected microscopic field (200×), and the rate of OP cells was calculated. A total of 10 random fields of view were examined, and the mean value was obtained for each group. Data were analyzed by ANOVA. In the HM group, OP cells were detectable about Day 7 and were clearly visible by 2 weeks. After 5 weeks, OP cell rates were significantly greater (P < 0.05) in the cells at psg 2 and 5 than in those at psg 10, 15, and 20 (71 and 70% v. 66, 63, and 64%). In the HS group, cytoplasmic LD was detectable about Day 10 and the number increased gradually by 3 weeks. After 5 weeks, OP cell rate was significantly greater (P < 0.05) in the cell at psg 2, 5, and 10 than in those at psg 15 and 20 (53, 57, and 51% v. 47 and 39%). Also, the size and number of LD in each cell tended to be lower in the HS group than in the corresponding HM group. In the control group, 4–5% of the cells were OP after 5 weeks. These results suggest that the ability of bovine MSC to differentiate into adipocyte-like cells decreased after long-term culture, and that horse serum was capable of inducing adipocytic differentiation of bovine MSC in vitro, but its efficacy was less than that of the hormonal mixture. Further studies to detect adipocyte-specific markers, such as G3PDH activity and aP2 expression, from these cells are needed for the quantitative analysis of the differentiation.

45 DEVELOPMENT OF BOVINE NUCLEAR TRANSFER EMBRYOS DERIVED FROM ADULT MARROW STROMAL CELLS AND FETAL MUSCLE CELLS

The use of less differentiated cells, such as marrow stromal cells (MSCs), as the nuclear donor may increase the efficiencies of somatic cell cloning in cattle. Healthy offspring was produced from bovine MSCs (Kato et al. 2004 Biol. Reprod. 70, 415–418); however, there is little information that directly compared the post-implantation survival among the clones originated from MSCs and other somatic cells. The objective of this study was to evaluate the developmental potential in vitro and in vivo of bovine NT embryos derived from adult MSCs and fetal muscle cells (FMCs). Primary cell populations of MSCs and FMCs were obtained from the femurs of 8- and 12-months-old Holstein cows (MSC1 and MSC2 groups, respectively) and a Holstein fetus at 8 months of gestation (FMC group), respectively. They were used as donor cells for the NT procedure (Murakami et al. 2005 Cloning Stem Cells 7, 77–81) at passages 1 to 3. Briefly, oocytes collected from cow ovaries were enucleated at 20 h post-in vitro maturation (IVM), and the donor cell was placed into the perivitelline space. The couplets were fused electrically, activated (10 μg mL–1 cycloheximide; 4 h), and cultured in CR1aa medium. Development in vitro of these embryos is summarized in Table 1. Data were analyzed by ANOVA. The fusion rates were higher in the MSC groups than in the FMC group. The rate of cleaved embryos was significantly lower (P < 0.05) in the MSC1 group than in the other groups. However, there were no significant differences among the groups in the rates of development into morulae/blastocysts on Day 6. A total of 8 and 3 fresh good quality Day 6 embryos in the MSC1 and FMC groups, respectively, were nonsurgically transferred to 6 naturally cycling Holstein females 6 days after estrus (3 recipients/group, 1–3 embryos/female). On Day 30 of gestation, none of the recipients were pregnant in the FMC group, while 2 recipients in the MSC1 group were diagnosed as pregnant via ultrasonography; they remained pregnant on Day 80 of gestation. In addition, a total of 4 Day 7 embryos cryopreserved in 1.8 m ethylene glycol plus 0.05 m trehalose were directly transferred to 4 synchronized recipients after thawing (1 embryo/female) in the MSC1 group. Of those, 2 females were pregnant on day 30 of gestation. These results indicate that the developmental potential in vitro of bovine NT embryos derived from adult MSCs was comparable to that of the embryos derived from fetal muscle cells, and that pregnancies were produced after transfer of the fresh and frozen–thawed NT embryos derived from the MSC, but the sample size was small. Further studies with more replicates are needed to evaluate viability in vivo of these cloned embryos for comparative purposes. Table 1.Development in vitro of bovine NT embryos derived from different cell types

Rotation of the pinning direction in the exchange bias training effect in polycrystalline NiFe/FeMn bilayers

For polycrystalline NiFe/FeMn bilayers, we have observed and quantified the rotation of the pinning direction in the exchange bias training and recovery effects. During consecutive hysteresis loops, the rotation of the pinning direction strongly depends on the magnetization reversal mechanism of the ferromagnet layer. The interfacial uncompensated magnetic moment of antiferromagnetic grains may be irreversibly switched and rotated when the magnetization reversal process of the ferromagnet layer is accompanied by domain wall motion and domain rotation, respectively.

Susceptibility to active decompensated cirrhosis is associated with polymorphisms of intercellular adhesion molecule-1 (ICAM-1) in chronic HBV carriers

Intercellular adhesion molecule-1 (ICAM-1) plays an important role in the pathogenesis of viral hepatitis B. Several inflammatory diseases are associated with distinct polymorphisms of the ICAM-1 gene. The aims of this study were to analyse the association of ICAM-1 polymorphisms G241R and K469E with susceptibility to active decompensated cirrhosis in chronic hepatitis B virus (HBV) carriers. The polymorphisms at codons G241R and K469E of ICAM-1 were analysed by sequence-specific primer polymerase chain reaction (PCR-SSP) in 572 unrelated chronic HBV carriers and 157 unrelated healthy HBV non-infected blood donors. There were significantly increased frequencies of R at codon 241 and E at codon 469 in patients with active decompensated cirrhosis (38.3% and 58.3%), compared with patients with chronic hepatitis B (CHB; 21.9% and 46.5%) and chronic asymptomatic HBV carriers (AsC; 12.6% and 40.3%). The frequencies of R241-E469 haplotype and genotypes carrying at least one R241-E469 haplotype were significantly higher in patients with active decompensated cirrhosis than those in patients with CHB (38.3% and 63.3%vs 21.9% and 36.7%), and significantly higher in patients with CHB than those in AsC (21.9% and 36.7%vs 12.6% and 23.3%). The ICAM-1 polymorphisms at codons G241R and E469K were associated with the disease susceptibility, and susceptibility to active decompensated cirrhosis is significantly increased in chronic HBV carriers carrying at least one R241-E469 haplotype.

83 DEVELOPMENT OF BOVINE IN VITRO-PRODUCED BLASTOCYSTS AFTER CRYOPRESERVATION IN CHEMICALLY DEFINED SOLUTIONS AND ONE-STEP DILUTION

Efficient embryo cryopreservartion using a protein-free defined solution would be beneficial for hygienic commercial embryo transport. In addition, one-step rehydration of frozen–thawed embryos could allow direct transfer of cryopreserved embryos after thawing. The objective of this study was to assess the viability in vitro of bovine in vitro-produced (IVP) embryos after freezing and thawing in a base cryoprotective solution [modified synthetic oviduct fluid (mSOF) medium containing 1.8 m ethylene glycol and 0.05 m trehalose] supplemented with various concentrations of polyvinyl alcohol (PVA). The methods used for in vitro embryo production and embryo cryopreservation were modified from those described previously (Murakami et al. 1998 Cryobiology 36, 206–212). Briefly, oocytes collected from cow ovaries were matured, fertilized in vitro for 5 h, and cultured in mSOF containing 0.4% bovine serum albumin (BSA) at 38.5�C in a humidified atmosphere of 5% CO2, 5% O2, and 90% N2 (reduced-O2 atmosphere; Day 0). On Day 3, only cleaved embryos were co-cultured with bovine cumulus cells in mSOF containing 5% fetal bovine serum (FBS) in a humidified atmosphere of 5% CO2 in air. On Day 7, embryos that reached the blastocyst stage were selected and immersed directly into the base cryoprotective solution supplemented with 0.4% BSA (0.4BSA group, the protein-containing control group) or 1.5, 3.0, or 6.0% PVA (1.5PVA, 3PVA, and 6PVA groups, respectively) at room temperature. After exposure to solution, embryo–cryoprotectant solutions were loaded into 0.25-mL plastic straws and cryopreserved by the standard slow freezing method (about 60 to 100 embryos in each group). The frozen straws were placed in air for 10 s, and plunged into a 38.5�C water bath for 10 s; the contents were expelled into a plastic dish. The embryos were then transferred directly to pre-incubated minimum essential medium alpha medium containing 5% FBS and MEM nonessential amino acids solution (mαMEM) for one-step rehydration. These frozen.thawed embryos were washed well and cultured in fresh mαMEM in a reduced-O2 atmosphere for 3 days to examine the developmental potential in vitro. Data were analyzed by ANOVA. The percentage of re-expanded embryos after freezing and thawing was significantly higher (P < 0.05) in 0.4BSA and 1.5PVA groups than in the 3PVA and 6PVA groups (95.4% in 0.4BSA and 90.9% in 1.5PVA v. 73.4% in 3PVA and 57.7% in 6PVA). In addition, there was no significant difference between 0.4BSA and 1.5PVA groups in the percentage of embryos developed into hatched blastocysts (82.0 v. 80.2%), but the percentage decreased with increasing PVA concentration (51.1% in 3PVA and 29.3% in 6PVA, respectively). These results suggest that the biological product BSA added in our standard cryoprotective solution can be replaced with 1.5% PVA to support similar viability of frozen.thawed bovine IVP embryos after one-step dilution. Further studies, including direct transfer of these frozen embryos after thawing, are needed to substantiate these results.

24 DEVELOPMENT OF BOVINE CLONED EMBRYOS PRODUCED BY NUCLEAR TRANSFER OF EMBRYONIC CULTURED CELLS ISOLATED FROM SOMATIC CELL NUCLEAR TRANSFER BLASTOCYSTS

Embryonic stem (ES) cells derived from somatic cell nuclear transfer (NT) bovine embryos would increase the utility of the cow as a large animal model for human cell therapy. They would also be useful for studies of cell differentiation. Such cells exhibit full pluripotency, and cloned offspring were obtained from them following a second NT in mice, indicating that the reprogramming that produced pluripotent ES cells could be reversed (Wakayama et al. 2001 Science 292, 740–743). The objective of this study was to examine if there would be any beneficial effects of using somatic cell NT-derived embryonic cultured cells as donors for cloning in cattle. Cloned embryos were produced from a single cell line of bovine fetal fibroblasts (FF) and adult ear-tip cells (AEC) (passages 1 to 5) by NT, as described previously (Dong et al. 2004 Asian–Aust. J. Anim. Sci. 17, 168–173). NT embryos that reached the blastocyst stage were cultured separately to isolate embryonic cultured cells derived from FF (NT-FF) and AEC (NT-AEC) according to previous methods (Dong et al. 2003 Acta Genet. Sin. 30, 114–118). More than 80% of the generated embryonic cultured cells stained positive for alkaline phosphatase. Embryonic cells cultured for 7 to 35 days were used as the donor cells for NT in the NT-FF and NT-AEC groups. Cloned embryos were produced using individual cell lines of FF, AEC, NT-FF, and NT-AEC (passages 1 to 5, putative cell cycle stage of G0 or G1) as donor cells, and their development in vitro is summarized in Table 1. The FF and AEC groups include data from the initial round of NT. The rates of fusion and embryo development were compared by chi-square analysis. Duncan's multiple range test was used to compare the mean cell numbers of blastocysts. The percentage of embryos that developed into blastocysts was significantly higher (P < 0.05) in the FF group than in the AEC group. Interestingly, we observed that the developmental potential in vitro and the mean cell number of blastocysts tended to be higher in the NT-FF and NT-AEC groups than in the FF and AEC groups. A total of 15 and 6 good quality Day 7 embryos in the NT-FF and NT-AEC groups were nonsurgically transferred to 5 and 3 synchronized recipients (2 to 3 embryos/female), respectively. On Day 30 of gestation, 3 (60%) and 1 (33%) females in the NT-FF and NT-AEC groups, respectively, were diagnosed as pregnant via ultrasonography. One (20%) recipient cow in the NT-FF group remained pregnant at Day 60 of gestation, but lost the pregnancy by Day 90. These results suggest that cloning of bovine embryonic cultured cells generated from fetal and adult somatic cells by NT can produce transferable embryos and initiate pregnancies, although none of the pregnancies has developed beyond the first trimester at this time. Table 1. Development in vitro of bovine NT embryos produced from different donor cell types

Coronary perfusion related changes in myocardial contractile force and systolic ventricular stiffness

OBJECTIVE

The mechanism by which changes in coronary perfusion alter myocardial oxygen consumption (MVO2; Gregg phenomenon) is controversial. This study examined the effect of coronary perfusion on myocardial contractile force and systolic ventricular stiffness in the intact, ejecting heart.

METHODS

During selective perfusion of the left anterior descending coronary artery, coronary blood flow was changed with or without concurrent changes in coronary perfusion pressure in 19 alpha chloralose anaesthetised dogs. Regional myocardial segment length (end diastolic length; end systolic length) and developed force were measured with piezoelectric crystals and with a miniature force transducer, respectively. MVO2 was calculated from coronary flow and arteriovenous O2 difference. The slope of the force-length curve during ejection period (delta F/delta SL) was used as an index of systolic myocardial stiffness.

RESULTS

When coronary perfusion pressure was varied from 60 to 180 mm Hg (protocol 1, n = 11), maximum developed force (Fmax), delta F/delta SL, and MVO2 increased with perfusion pressure while end diastolic length, segmental shortening, and other haemodynamic variables stayed constant. When coronary blood flow was increased at constant perfusion pressure by infusion of either a low dose or a high dose adenosine (protocol 2, n = 8), Fmax, delta F/delta SL, and MVO2 increased while end diastolic length, segmental shortening, and other haemodynamic variables stayed constant. MVO2 and delta F/delta SL increased more steeply with flow in protocol 1.

CONCLUSIONS

(1) Increased coronary blood flow enhances myocardial contractile force, systolic ventricular stiffness, and MVO2 in the intact, ejecting heart. (2) Coronary blood flow induced changes in myocardial contractile force and systolic ventricular stiffness, but not end diastolic length, are probably responsible for coronary blood flow related changes in MVO2.

Coronary pressure-flow autoregulation protects myocardium from pressure-induced changes in oxygen consumption

Pressure-flow autoregulation minimizes changes in coronary blood flow (CBF) when coronary perfusion pressure (CPP) is altered. This investigation determined if autoregulation also minimizes CPP-induced changes in coronary vascular volume (CVV) and CVV-dependent changes in myocardial oxygen consumption (MVO2). In 11 anesthetized dogs, the left anterior descending coronary artery was cannulated, and responses to 20-mmHg changes in CPP were examined over a range of CPP from 60 to 180 mmHg. Changes in CPP had no significant effect on systemic hemodynamics or on left ventricular end-diastolic segment length, end-systolic segment length, or percent segment shortening. In hearts with effective pressure-flow autoregulation [closed-loop gain (GC) > 0.4], CVV increased 0.06%/mmHg change in CPP. For the same hearts, MVO2 increased 0.04%/mmHg change in CPP. In hearts with ineffective autoregulation (GC < 0.4), CVV increased 0.97%/mmHg (P < 0.001 vs. autoregulating hearts), and MVO2 increased 0.41%/mmHg (P < 0.001 vs. autoregulating hearts). MVO2 and CVV were correlated (r = 0.69, P < 0.0001) independently of autoregulatory capability, but only when autoregulation was poor and capacitance was elevated did CPP significantly affect MVO2. We conclude that pressure-flow autoregulation protects myocardium from CPP-induced changes in CVV, which in turn produces changes in oxygen consumption.

Preconditioning with supply-demand imbalance limits infarct size in dog heart

OBJECTIVE

The aim was to examine whether an absolute reduction in energy supply is required for preconditioning against myocardial infarction, and whether an episode of increased adrenergic activity with or without supply-demand imbalance is capable of triggering cardioprotection.

METHODS

41 anaesthetised dogs were subjected to 60 min left circumflex artery occlusion followed by 5 h reperfusion (control group, n = 8). The left stellate cardiac nerve was stimulated for 5 min starting 10 min before coronary occlusion in the stimulation group (STIM group, n = 8). The left circumflex artery flow increase that normally accompanies adrenergic stimulation was prevented by a pneumatic occluder in another group (STIM-R group, n = 8). Infarct size and area at risk were determined by triphenyl tetrazolium chloride staining and Evans blue dye, respectively. Regional myocardial blood flow during ischaemia and during stimulation (STIM-R group) was measured with radioactive microspheres.

RESULTS

In the STIM group, adrenergic stimulation increased the coronary blood flow by approximately twofold from baseline. In the STIM-R group, transmural myocardial blood flow in the flow restricted left circumflex artery region was 64% of the flow to the non-flow-restricted left anterior descending coronary artery region. Haemodynamic variables were not different among the experimental groups except during adrenergic stimulation. Collateral blood flow and area at risk were comparable among the three groups. Infarct size as a percentage of area at risk (%IS/AAR) was significantly smaller in the STIM-R group [7.6(3.2)%] than in the control group [27.9(7.3)%], whereas %IS/AAR in the STIM group [21.7(4.1)%] was not. Furthermore, the regression line between collateral blood flow and %IS/AAR was significantly shifted downward in the STIM-R group, but not in the STIM group.

CONCLUSIONS

(1) Transient energy supply-demand imbalance triggers infarct size limitation; an absolute reduction in energy supply is not required for preconditioning. (2) Increased adrenergic activity without supply-demand imbalance seems unable to trigger appreciable cardioprotection.

Effect of acute trauma on the levels of intracellular cAMP, cGMP and DNA: Studies on endocrinology and metabolism

In this experiment, we used morgrel dogs to study the effect of trauma on the neuro-endocrine and metabolic organs and the effects of hormones on metabolism by determining the levels of intracellular cAMP, cGMP and DNA. From the changes in intracellular nucleotides, we learned that many neuro-endocrine organs and the main metabolic organs are characteristic of predominance in alpha-adrenoreceptor after trauma, thereby leading to high blood sugar.

[The kinetics of plasma coagulation fibrinolysis levels in acute myocardial infarction before and after treatment with intravenous urokinase]

The levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI) and other substances of coagulation-fibrinolysis, such as fibronectin (Fn) and von willebrand factor (vWF) as well as the activity content of antithrombin-III(AT-III) in plasma were determined in 20 patients with acute myocardial infarction (AMI). In 11 of them these measurements were carried out before and after the treatment with urokinase (UK1000 000 IU). The results suggested that the function of coagulation-fibrinolytic system was disturbed in AMI. Thrombolytic treatment with UK could interfere and improve the stabilization of fibrinolytic activity in the body, but these actions last only short time. Some substances of coagulation showed change with UK treatment.