[Minimally invasive direct lateral approach debridement, interbody bone grafting, and interbody fusion combined with posterior percutaneous pedicle screw fixation for lumbar spinal tuberculosis].

OBJECTIVE: To investigate the clinical efficacy and superiority of direct lateral interbody fusion combined with posterior percutaneous screw fixation in the treatment of lumbar tuberculosis. METHODS: From June 2013 to August 2016, the clinical data of 83 patients with lumbar tuberculosis were retrospectively analyzed, including 55 males and 28 females, aged from 27 to 72 (49.5±13.5) years. These 83 patients were divided into two groups according to different operation methods, 35 cases in group A were treated with direct lateral interbody fusion combined with posterior percutaneous screw fixation;48 cases in group B were treated with anterior traditional extraperitoneal debridement combined with posterior internal fixation. After operation, regular quadruple antituberculosis drugs were continued for 18 months. The operation time, intraoperative blood loss, hospital stay, bone graft fusion time and complications were compared between the two groups. Visual analogue score (VAS) of lumbar pain, Oswestry Disability Index (ODI), sagittal Cobb angle, erythrocyte sedimentation rate (ESR) and C-reactive protein(CRP) values before and after operation were analyzed. RESULTS: The operation was successfully completed in both groups, and the operation mode was not changed during operation. The operation time, intraoperative blood loss and hospital stay were (149.4±13.3) min, (354.3±69.0) ml, (9.4±1.6) d in group A and(116.8±10.0) min, (721.9±172.3) ml, (11.8±1.7) d in group B, respectively, with significant difference between the two groups (P<0.05). The follow up time was (24.2±5.1) months in group A and (24.0±5.0) months in group B, there was no significant difference between two groups (P>0.05). At the follow-up of 4 months after operation, one patient in group A was found to have enlarged psoas major abscess on the contralateral side, and was cured after secondary operation. No sinus formation, cerebrospinal fluid leakage, internal fixation loosening, fracture or distal junction kyphosis were found during follow-up. The fusion time was (5.1±1.6) months in group A and (5.1± 1.7) months in group B, there was no significant difference between two groups (P>0.05). The VAS, ODI score, sagittal Cobb angle, ESR and CRP value of the lesion segment at the last follow-up of the two groups were significantly improved (P<0.05), but there was no significant difference between two groups (P>0.05). CONCLUSION: The two kinds of operation can obtain satisfactory clinical effect. Direct lateral interbody fusion combined with posterior percutaneous screw fixation can reduce intraoperative blood loss and hospital stay, which is conducive to early rehabilitation of patients.

[One stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers].

OBJECTIVE: To assess the clinical results of one stage temporary atlantoaxial segmental fixation and reduction for Grauer type IIB dens fractures in teenagers. METHODS: From February 2009 to April 2015, 19 teenagers with Grauer type IIB dens fractures not amenable to anteiror screw fixation were enrolled and treated using one stage temporary atlantoaxial segmental fixation and reduction without fusion. There were 14 males and 5 females, aged from 14 to 32 years with an average of (24.6±5.0 ) years. The internal fixation was removed after bone healing confirmed by CT scan. At the last follow-up (at least 1 year after internal fixation removal), dynamic CT was used to assess the atlantoaxial rotation activity. Visual analogue scale (VAS) was recorded before the first operation, before the second operation (removal of internal fixation) and at the last follow-up. Neck Disability Index(NDI) was used to evaluate the efficacy before the second operation (removal of internal fixation) and the last follow-up. RESULTS: After operation, 2 patients developed the symptoms of occipital nerve stimulation such as numbness and pain in the occipitocervical region, and were treated with drugs such as dehydration and neurotrophic drugs, and the symptoms were relieved after 1 to 2 months. All the internal fixations were removed and all the patients were followed up more than 1 year, with time ranging from 18 to 25 months and an average of (21.47±2.41) months. The time of bone fusion after operation was 6 to 10 months with the mean of(8.21±1.27) months. Secondary surgical removal of internal fixation were performed immediately after fracture healing without internal fixation failure. The symptoms of neck pain improved significantly after operation, VAS score decreased from 6.74±0.65 before operation to 0.42±0.51 at the last follow-up after the second operation (removal of internal fixation), with statistically significant differences(P<0.01). The NDI value decreased from (10.58±2.04)% before the second operation (removal of internal fixation) to (3.79±2.23)% at the last follow-up after the second operation (removal of internal fixation), with statistically significant difference(P<0.01). At the last follow-up after the second operation (removal of internal fixation), dynamic CT showed that the unilateral rotation of the atlantoaxial spine reached (15.73±5.57)° to the left, (15.55±5.78)° to the right, and the overall rotation of the atlantoaxial spine was (31.28±10.71)°. CONCLUSIONS: One stage temporary atlantoaxial segmental fixation and reduction for the treatment of Grauer type IIB dens fractures not amenable to anteiror screw fixation in teenagers can avoid the loss of atlantoaxial rotation function caused by atlantoaxial fusion, and to some extent retain the rotation activity of atlanto-axial joint.

Downregulation of Piwil3 suppresses cell proliferation, migration and invasion in gastric cancer.

BACKGROUND: Gastric cancer is one of the most common malignancies worldwide. Recent studies reported that Piwil3 was overexpressed in various cancers, including gastric cancer (GC). This study was intended to investigate its function and mechanism in GC progress. METHODS: Quantitative real time PCR(RT-PCR) and western blotting assays were utilized to measure mRNA and protein expression levels, respectively. SiRNA transfection was performed to suppress the expression of Piwil3. CCK-8 assay, cell invasion and migration assays were used to determine the cell proliferative, cell invasive and migratory ability. RESULTS: The expression of Piwil3 was significantly increased in GC tissues compared with matched normal tissues. The specific siRNA significantly inhibited the protein and mRNA expressions of Piwil3, and effectively inhibited the proliferation and induced G0/G1 phase arrest in GC cells. Downregulation of Piwil3 significantly suppressed the migration and invasion of GC cells. Moreover, the downregulation of Piwil3 also significantly suppressed the tumor volumes in nude mice. Mechanism investigation showed that the downregulation of Piwil3 significantly decreased the mRNA and protein expressions of metastasis-related genes, including RhoC, MTA1, MMP2 and MMP9, and also modulated the phosphorylation levels of JAK2 and STAT3 but not their protein levels. CONCLUSIONS: These findings indicate that overexpression of Piwil3 promotes the proliferation, migration and invasion of GC cells partially through JAK2/STAT3 signal pathway.

Effects of pyruvate-enriched peritoneal dialysis solution on intestinal barrier in peritoneal resuscitation from hemorrhagic shock in rats.

BACKGROUND: To investigate protective effects of pyruvate-enriched peritoneal dialysis solution (P-PDS), compared with lactate-PDS (L-PDS), on the intestinal mucosal barrier in peritoneal resuscitation (PR) from severe hemorrhagic shock (HS) in rats. MATERIALS AND METHODS: Fifty male SD rats were randomly divided into five groups (n = 10): group sham, group control (HS without fluid resuscitation), group intravenous resuscitation (IVR) (HS with IVR only), group L-PDS (HS with i.v. infusion plus PR with L-PDS), and group P-PDS (HS with i.v. infusion plus PR with P-PDS). HS was induced by hemorrhage with mean arterial pressure 40 mm Hg for 60 min. In three groups with fluid rehydration, IVR included shed blood and dl-lactate Ringer solution equal to two times the volume of shed blood during 60 min; in two groups with PR, 20 mL of L-PDS, or P-PDS were infused when i.v. infusion started after HS into the peritoneal cavity in 20 min, respectively. Blood samples were taken for determinations of pH, base excess, PaCO2, PaO2, and D-LA 60 min post fluid resuscitation. After rats were sacrificed, a segment of intestine was harvested for the detection of expressions of intestinal barrier proteins: zonula occludens-1 (ZO-1) and phosphorylated vasodilator-stimulated phosphoprotein (p-VASP) by Western blot and immunohistochemistry. Intestinal morphologic alterations were also observed. RESULTS: Blood pH, base excess, and PaO2 were higher, whereas PaCO2 and D-LA were lower in group P-PDS than in other three HS groups (P < 0.05 and P < 0.01, respectively). Severe acidosis was nearly corrected in group P-PDS. Intestinal barrier proteins ZO-1 and p-VASP were significantly preserved in group P-PDS than in group L-PDS (P < 0.05) although they were improved in group L-PDS in comparison with other two HS groups (P < 0.05 or P < 0.01). Expressions of barrier proteins by Western blotting in group P-PDS were reversed to normal. The score of intestinal epithelial damage index was reduced in group L-PDS, compared with other two HS groups (P < 0.05), however, it was significantly lower in group P-PDS than in group L-PDS (P < 0.05). CONCLUSIONS: Pyruvate was superior to lactate in PDS in the correction of severe acidosis with PR. P-PDS was more preservative of expressions of intestinal ZO-1 and p-VASP and mucosal barrier function, compared with L-PDS in PR from severe HS in rats.

Simple and rapid detection of Salmonella by direct PCR amplification of gene fimW.

This study established a simple method of specifically detecting Salmonella species by amplifying fimW gene, which was involved in regulating Salmonella type I fimbriae expression. A pair of primers was designed to target and discriminate the 68 Salmonella strains of 23 Salmonella serovars available to us from 12 non-Salmonella strains of five different kinds of bacteria by polymerase chain reaction (PCR) amplification. Results showed that specific DNA fragment with an expected size of 477 bp was successfully amplified from all Salmonella serovars, while no target band was detected in non-Salmonella species. The sensitivity of this PCR-amplifying system reached to 1 pg DNA chromosome and 10(2) cfu of Salmonella enteritis strain CMCC(B) 50336. The above results demonstrated the method as a simple, sensitive, and specific way for Salmonella detection.

GATA5 loss-of-function mutations associated with congenital bicuspid aortic valve.

Bicuspid aortic valve (BAV) is the most common form of congenital cardiovascular defect in humans worldwide and is responsible for substantial morbidity and mortality. Accumulating evidence has demonstated that genetic risk factors are involved in the pathogenesis of BAV. However, BAV is genetically heterogeneous and the genetic basis underlying BAV in a large number of patients remains unknown. In the present study, the coding regions and splice junction sites of the GATA5 gene, which codes for a zinc-finger transcription factor crucial for the normal development of the aortic valve, was sequenced initially in 110 unrelated patients with BAV. The available relatives of the mutation carriers and 200 unrelated healthy individuals used as controls were subsequently genotyped for GATA5. The functional effect of the mutations was characterized by using a luciferase reporter assay system. As a result, two novel heterozygous GATA5 mutations, p.Y16D and p.T252P, were identified in two families with autosomal dominant inheritance of BAV, respectively. The variations were absent in 400 control chromosomes and the altered amino acids were completely conserved evolutionarily. Functional assays revealed that the two GATA5 mutants were associated with significantly reduced transcriptional activity compared with their wild-type counterpart. To the best of our knowledge, this is the first study on the association of GATA5 loss-of-function mutations with enhanced susceptibility to BAV, providing novel insight into the molecular mechanism involved in human BAV and suggesting a potential role for the early prophylaxis and personalized treatment of this common congenital heart disease.

Mutation spectrum of GATA4 associated with congenital atrial septal defects.

INTRODUCTION: Congenital atrial septal defect (ASD) is the second commonest form of cardiac developmental anomaly, responsible for substantial morbidity and mortality in affected individuals. Previous studies have implicated genetic defects in the pathogenesis of ASD. However, ASD is largely a genetically heterogeneous disease and the genetic determinants for ASD in the majority of patients remain to be identified. MATERIAL AND METHODS: The entire coding region of GATA4, a gene encoding a zinc-finger transcription factor essential for normal cardiac morphogenesis, was sequenced in 220 unrelated patients with ASD. The available relatives of the patients harboring the identified mutations and 200 unrelated ethnicity-matched control individuals were genotyped. RESULTS: Four heterozygous missense GATA4 mutations, p.P36S, p.H190R, p.S262A, and p.V399G, were identified in four unrelated patients with ASD, respectively. These mutations were neither detected in 200 control individuals nor described in the human SNP database. Alignment of multiple GATA4 protein sequences across species indicated that the affected amino acids were highly conserved evolutionarily. Genetic analysis of the available relatives of the mutation carriers showed that in each family the mutation co-segregated with ASD. CONCLUSIONS: The findings expand the spectrum of mutations in GATA4 linked to ASD and provide new insight into the molecular etiology associated with ASD, suggesting the potential implications for the genetic diagnosis and gene-specific therapy for this prevalent cardiovascular abnormality in humans.

Novel GATA6 mutations associated with congenital ventricular septal defect or tetralogy of fallot.

Congenital heart disease (CHD) is the most common form of developmental malformation and is the leading noninfectious cause of infant mortality. Emerging evidence indicates that genetic defects are involved in the pathogenesis of CHD. Nevertheless, CHD is genetically heterogeneous, and the molecular basis for CHD in a majority of patients remains unknown. In this study, the whole coding region of GATA6, a gene encoding a zinc-finger transcription factor crucial for normal cardiogenesis, was sequenced in 380 unrelated patients with CHD. The relatives of the index patients harboring the identified mutations and 200 unrelated control individuals were subsequently genotyped. The functional effect of the mutations was characterized using a luciferase reporter assay system. As a result, two novel heterozygous GATA6 mutations, p.D404Y and p.E460X, were identified in two families with ventricular septal defect and tetralogy of Fallot, respectively. The mutations co-segregated with CHD in the families with complete penetrance, and were absent in 400 control chromosomes. Functional analysis demonstrated that the mutated GATA6 proteins were associated with significantly decreased transactivational activity in comparison with their wild-type counterpart. These findings provide novel insight into the molecular mechanism implicated in CHD, suggesting potential implications for the early prophylaxis and personalized treatment of CHD.

Novel GATA4 mutations in patients with congenital ventricular septal defects.

BACKGROUND: Ventricular septal defect (VSD) is the most prevalent type of congenital heart disease and is a major cause of substantial morbidity and mortality in infants. Accumulating evidence implicates genetic defects, especially in cardiac transcription factors, in the pathogenesis of VSD. However, VSD is genetically heterogeneous and the genetic determinants for VSD in most patients remain to be identified. MATERIAL/METHODS: A cohort of 230 unrelated patients with congenital VSD was included in the investigation. A total of 200 unrelated ethnically matched healthy individuals were recruited as controls. The entire coding region of GATA4, a gene encoding a zinc-finger transcription factor essential for normal cardiac morphogenesis, was sequenced initially in 230 unrelated VSD patients. The available relatives of the mutation carriers and 200 control subjects were subsequently genotyped for the presence of identified mutations. RESULTS: Four heterozygous missense GATA4 mutations of p.Q55R, p.G96R, p.N197S, and p.K404R were identified in 4 unrelated patients with VSD. These mutations were not detected in 200 control individuals nor described in the human SNP database. Genetic analysis of the relatives of the mutation carriers showed that in each family the mutation co-segregated with VSD. CONCLUSIONS: These findings expand the mutation spectrum of GATA4 linked to VSD and provide new insight into the molecular etiology responsible for VSD, suggesting potential implications for the genetic diagnosis and gene-specific therapy for VSD.

A novel GATA4 loss-of-function mutation associated with congenital ventricular septal defect.

Ventricular septal defect (VSD) is the most prevalent type of congenital heart disease and a major cause for the significantly increased morbidity and mortality among infants. Aggregating evidence indicates that genetic defects are involved in the pathogenesis of congenital VSD. Nevertheless, VSD is genetically heterogeneous, and the genetic determinants for VSD in the majority of patients remain to be identified. In this study, the entire coding region of GATA4, a gene encoding a zinc finger transcription factor essential for normal cardiac morphogenesis, was sequenced in 160 unrelated patients with VSD. The available relatives of the index patient harboring the identified mutation and 200 unrelated control individuals were subsequently genotyped. The disease-causing potential of a sequence alteration was evaluated by MutationTaster, and the functional effect of the mutation was characterized using a luciferase reporter assay system. As a result, a novel heterozygous GATA4 variation, p.R43W, was identified in a proband with VSD, that was absent in control subjects. Genetic analysis of the family members of the variation carrier showed that the substitution co-segregated with VSD. The p.R43W variant was predicted to be a pathogenic mutation, and the functional analysis demonstrated that the GATA4 R43W mutant protein resulted in significantly decreased transcriptional activity compared with its wild-type counterpart. The findings expand the mutational spectrum of GATA4 linked to VSD and provide more insight into the molecular mechanism of VSD.

A novel GATA4 mutation responsible for congenital ventricular septal defects.

Ventricular septal defect (VSD) is the most common type of cardiovascular developmental anomaly and is an important risk factor for the substantially increased morbidity and mortality in newborns. Aggregating evidence implicates genetic defects in the pathogenesis of congenital VSD. However, VSD is genetically heterogeneous and the genetic determinants for VSD in most patients remain to be identified. In this study, the whole coding region of the GATA4 gene, which encodes a zinc-finger transcription factor pivotal to cardiogenesis, was initially sequenced in 210 unrelated patients with VSD. The relatives of the index patient carrying the identified mutation and 200 unrelated ethnically-matched healthy individuals used as controls were subsequently genotyped. The functional effect of the mutant GATA4 was characterized in contrast to its wild-type counterpart using a luciferase reporter assay system. A novel heterozygous GATA4 mutation, p.G296R, was identified in a family with VSD inherited as an autosomal dominant trait. Absent in 200 control individuals, the mutation co-segregated with VSD in the family with 100% penetrance and was completely conserved evolutionarily across species. Functional analysis displayed that the p.G296R mutation of GATA4 was associated with a decreased transcriptional activity. The findings expand the spectrum of mutations in GATA4 linked to VSD and provide more insight into the molecular mechanism involved in VSD. The results of the present study imply the potential implications in the genetic diagnosis and gene-specific therapy of this common malformation in infancy.

Involvement of a novel GATA4 mutation in atrial septal defects.

Atrial septal defect (ASD) is one of the most common types of congenital heart disease and is associated with a significant increase in the morbidity and mortality of affected individuals. Accumulating evidence indicates that genetic defects play important roles in the pathogenesis of congenital ASD. However, ASD is genetically heterogeneous and the genetic determinants for ASD in the majority of the patients remain to be identified. In this study, the entire coding region of GATA4, a gene encoding a zinc-finger transcription factor crucial to embryogenesis, was initially sequenced in 120 unrelated patients with ASD. The available relatives of patients carrying the identified mutation and 200 ethnicity-matched unrelated control individuals were genotyped. The functional characteristics of the GATA4 mutant were compared to its wild-type counterpart using a luciferase reporter assay system. A novel heterozygous missense GATA4 mutation, p.G21V, was identified in 2 unrelated families with ASD, which was not detected in the control population nor reported in the human gene mutation database. Alignment of multiple GATA4 proteins displayed that the affected amino acid residue was highly conserved across species. Functional analysis showed that the p.G21V GATA4 mutation was associated with a decreased transcriptional activity. The findings underscore the pathogenic link between compromised GATA4 function and congenital ASD, providing new insight into the molecular mechanism involved in this common form of congenital cardiovascular anomalies.

Novel NKX2-5 mutations in patients with familial atrial septal defects.

Atrial septal defect (ASD) is a common cardiovascular malformation and an important contributor to substantial morbidity and mortality. Increasing evidence demonstrates that mutated NKX2-5, a gene encoding a homeobox transcription factor crucial to cardiogenesis, is a significant genetic determinant for congenital ASD. Nevertheless, the genetic basis for ASD in a majority of ASD patients remains largely unknown. In the current study, the entire coding region of NKX2-5 was sequenced initially for 58 unrelated probands with familial ASD. The relatives of the probands harboring identified mutations and 200 unrelated control individuals were subsequently genotyped. Three novel heterozygous NKX2-5 mutations (p.P43GfsX59, p.C46 W, and p.S179F) were identified respectively in three families with autosomal dominantly inherited ASD. These mutations, absent in 200 control individuals, cosegregated with ASD in the families that had complete penetrance. The findings expand the spectrum of mutations in NKX2-5 linked to ASD and contribute to genetic counseling, clinical interventions, and prenatal prevention of ASD for individuals with genetic susceptibility.

[Clinical research of Dahuang Fuzi decoction in auxiliary treatment of severe acute pancreatitis: a multi-center observation in 206 patients].

OBJECTIVE: To observe the efficacy of Dahuang Fuzi decoction in patients with severe acute pancreatitis (SAP), and to provide valuable medical evidences for a treatment of SAP with combined traditional Chinese and western medicine. METHODS: A prospective, multi-center, randomized, controlled clinical trial was designed. Two hundred and six adult patients with SAP admitted to intensive care unit (ICU) in three tertiary university teaching hospitals in Dalian from January 2007 to February 2010 were randomly divided into two groups: soapsuds enema control group (control group, n=101) and Dahuang Fuzi decoction enema study group (study group, n=105). The levels of serum amylase, albumin (Alb), D-lactic acid, endotoxin and diamine oxidase (DAO), high-sensitive C-reactive protein (hs-CRP), immunoglobulin (IgG, IgA, IgM), complements (C3, C4), tumour necrosis factor-α (TNF-α), interleukins (IL-6, IL-8) were determined before and after treatment for 2, 4, 7 days. The bowel sound, gastrointestinal function score, the acute physiology and chronic health evaluation II (APACHEII) score and the length of mechanical ventilation (MV), the length of stay in ICU, the mortality rate and average hospital expenses within 28 days were compared. RESULTS: Compared with control group, in the study group the levels of serum amylase, DAO, D-lactic acid and endotoxin were lowered, the Alb was increased, the levels of TNF-α, IL-6, IL-8, hs-CRP were decreased, the function of body immunity was enhanced, intestinal peristalsis was enhanced, gastrointestinal function score and APACHEII score were improved, the length of MV was reduced, the length of stay in ICU was diminished, the 28-day mortality and average hospital expenses were lowered [4 days amylase (U/L): 357.35±137.54 vs. 492.95±189.42, 2 days DAO (kU/L) : 5.20±0.59 vs. 5.45±0.72, 4 days D-lactic acid (mmol/L): 3.31±0.48 vs. 4.15±0.55, 2 days endotoxin (kEU/L): 0.29±0.11 vs. 0.34±0.14, 4 days Alb (g/L): 34.75±3.56 vs. 32.53±3.44, 2 days TNF-α (ng/L): 3.08±0.45 vs. 3.36±1.11, 2 days IL-6 (ng/L): 298.54±67.82 vs. 313.56±73.91, 4 days IL-8 (ng/L): 30.48±8.56 vs. 45.16±10.81, 2 days hs-CRP (mg/L): 32.56±11.83 vs. 40.42±15.10, 4 days IgG (g/L): 7.05±2.56 vs. 9.53±2.94, 2 days IgA (mg/L): 1 600±170 vs. 1 400±140, 4 days IgM (mg/L): 1 310±280 vs. 1 650±290, 4 days C3 (g/L): 1.11±0.09 vs. 1.50±0.15, 4 days C4 (g/L) : 0.32±0.11 vs. 0.41±0.10, 2 days bowel sound (times/min): 1.26±0.45 vs. 1.15±0.41, 2 days gastrointestinal function score: 2.24±0.98 vs. 2.42±1.05, 4 days APACHEII score: 16.4±6.8 vs. 20.1±7.1, the length of MV (days): 6.5±3.1 vs. 10.1±4.6, the length of stay in ICU (days): 11.3±6.3 vs. 13.8±7.5, mortality: 8.6% vs. 16.8%, average hospital expenses (yuan): 72 thousands vs. 86 thousands, P<0.05 or P<0.01]. CONCLUSION: Dahuang Fuzi decoction may enhance the intestinal peristalsis, protect the gastrointestinal barrier function, reduce the bacteria and endotoxin translocation and the releasing of inflammation mediators, protect the function of body immunity, reduce the length of MV, the length of stay in ICU, and lower the 28-day mortality and average hospital expenses, and it can improve the prognosis of patients with SAP.

[Determination of dextran sulfate sodium with ethyl violet by resonance Rayleigh scattering].

In the Britton Robinson buffer medium (pH 9.0-10.5), either dextran sulfate sodium (DSS) or ethyl violet (EV) showed very faint resonance Rayleigh scattering (RRS) spectra. However, when DSS and EV were mixed together, the interaction between DSS and EV by virtue of electrostatic and hydrophobic forces occurred, which greatly enhanced the RRS intensity and a new RRS spectrum for the DSS-EV system appeared with three obvious scattering wavelengths at 348.0, 509.8 and 680.0 nm, respectively. All these RRS peaks increased with the increase in DSS concentration. The maximum scattering wavelength appeared at 509.8 nm; and therefore was selected as the determination wavelength for the system. The RRS intensity was directly proportional to the concentration of DSS in the range of 0.005-2.4 microg x mL(-1), and the detection limit was 3.25 ng x mL(-1). The characteristics of RRS and absorption spectra of the DSS-EV system, the influencing factors, such as solution pH, EV concentration, reaction time, temperature, and ion strength, and the optimum conditions for the reaction were investigated. The influence of foreign substances on the DSS-EV system was also studied. The method was sensitive and selective, and has been applied to the determination of DSS in synthetic samples with satisfactory results. A new method for the determination of trace amounts of DSS based on the RRS method has been developed.

[Effects of ischemic preconditioning on the hypothermic ischemia/reperfusion injury of immature rabbit hearts].

AIM: To study effects of ischemic preconditioning on the hypothermic ischemia/reperfusion injury of immature rabbit hearts. METHODS: The isolated immature rabbit (3-4 weeks) hearts were perfused on Langendorff apparatus. After 30 min perfusing with 37 degrees C K-H perfusate, the hearts in part one were yielded 0, 1, 2 or 3 times of IP respectively before 120 min ischemia at 20 degrees C hypothermia, and the hearts in part two were yielded 0 or 2 times of IP before being arrested by infusion of St. Thomas II crystalloid cardioplegic solution, then the arrested hearts were yielded ischemia for 30, 90 or 120 min at 32 degrees C, 25 degrees C and 2 degrees C hypothermia respectively. Then all the hearts were reperfused for 30 min at 37 degrees C normothermia. Heart rate (HR), left ventricular developed pressure (LVDP), +/- dp/dt(max) were recorded at baseline, preischemic and 1, 3, 5, 10, 20, 30 min after reperfusion. Also contents of ATP and MDA and activity of SOD and Ca(2+) -ATPase of myocardium were measured. RESULTS: At the end of reperfusion, the recovery rate of left ventricular function in IP2 group were significantly higher than that of control group and IP3 group (P < 0.01, P < 0.05), also the IP2 group showed a higher content of ATP and activity of Ca(2+) -ATPase than control group and IP3 group (P < 0.01, P < 0.05). When the ischemic hearts were at different hypothermia accompanied with CCS, the recovery rate of left ventricular function and contents of ATP in SIP1 and SIP2 group were significantly higher than that of SCon 1 group and SCon 2 group respectively (P < 0.01, P < 0.05), the contents of MDA in the two IP groups were lower than that of the two control groups. CONCLUSION: IP can attenuate the hypothermic ischemia/reperfusion injury of immature rabbit hearts, the cardioprotective effects are dependent on the mode of IP and the possible mechanisms may involve the following aspects: decrease the consumption of ATP, inhibit lipid peroxidation and maintain the activity of Ca(2+) -ATPase of cardiac myocyte.