Dipterocarpoidae genomics reveal their demography and adaptations to Asian rainforests

Dipterocarpoideae species form the emergent layer of Asian rainforests. They are the indicator species for Asian rainforest distribution, but they are severely threatened. Here, to understand their adaptation and population decline, we assemble high-quality genomes of seven Dipterocarpoideae species including two autotetraploid species. We estimate the divergence time between Dipterocarpoideae and Malvaceae and within Dipterocarpoideae to be 108.2 (97.8‒118.2) and 88.4 (77.7‒102.9) million years ago, and we identify a whole genome duplication event preceding dipterocarp lineage diversification. We find several genes that showed a signature of selection, likely associated with the adaptation to Asian rainforests. By resequencing of two endangered species, we detect an expansion of effective population size after the last glacial period and a recent sharp decline coinciding with the history of local human activities. Our findings contribute to understanding the diversification and adaptation of dipterocarps and highlight anthropogenic disturbances as a major factor in their endangered status.

[Efficacy observation and compliance analysis of pollen allergen drops in seasonal allergic rhinitis]

To study the efficacy and compliance analysis of pollen allergen drops in the treatment of allergic rhinitis. The method of single-center controlled was used to analyze the dates' results. From July 2021 to September 2021, 80 patients with seasonal allergic rhinitis were referred to the clinic of otorhinolaryngology in First Hospital of Shanxi Medical University.40 patients received sublingual immunotherapy (SLIT group), and the other 40 patients received symptomatic drug treatment as the control group. The total rhinoconjunctivitis symptom score (TRSS), the visual analogue scale(VAS), total medication score (TMS) and combined scores of medication and rhinoconjunctivitis symptoms (CSMRS) of the patient before the start of the treatment and after the first year of the treatment were compared to assess the efficacy of sublingual immunotherapy of Artemisia pollen. Follow the shedding during the study, the safety of the drug and the causes for compliance analysis were analyzed and recorded. The results of comparison with TRSS, VAS, TMS and CSMRS in two groups in the period of pretherapy were as follows: TRSS(12.393±3.023, 12.450±3.029, t=-0.077, P=0.939), VAS(8.357±1.026, 8.400±0.982, t=-0.173, P=0.862), TMS(3.214±0.568, 3.175±0.501, t=0.301, P=0.764), CSMRS (5.286±0.680, 5.253±0.677, t=0.199, P=0.843), there was no significant difference (P>0.05); lower observed symptom scores were got in the post-treatment pollen peak SLIT group compared to the control group, TRSS(3.964±1.551, 7.750±2.169, t=-7.918, P<0.05), VAS(2.893±0.956, 5.175±1.481, t=-8.286, P<0.05), TMS (1.821±0.863, 3.175±0.501, t=-8.163, P<0.05), CSMRS (2.489±0.921, 4.468±0.601, t=-10.723, P<0.05), and the differences between the groups were statistically significant (P<0.05); the SLIT group significantly reduced all symptom scores at the first peak compared to the starting, TRSS(12.393±3.023, 3.964±1.551, t=20.576, P<0.05), VAS (8.357±1.026, 2.893±0.956, t=30.070, P<0.05), TMS (3.214±0.568, 1.821±0.863, t=7.151, P<0.05), CSMRS(5.286±0.680, 2.489±0.921, t=14.533, P<0.05) and there was statistical difference (P<0.05). No significant adverse reactions occured during medication in the SLIT group. A total of 12 cases were shed in the SLIT group, so the compliance rate was 70%. The four reasons were that patients considered the course was long (4 cases, 33%); the drugs were expensive (3 cases, 25%); patients were busy with their work and life (3 cases, 25%); patients were affected by the outbreak (2 cases, 17%). In summary, Artemisia pollen sublingual drops may improve the symptoms of the patients who got allergic rhinitis caused by Artemisia pollen after the treatment for one year. However, due to the lack of sufficient understanding of immunotherapy or the difficulty in adhering to standardized medication, the compliance with sublingual immunotherapy is still poor, the compliance with sublingual immunotherapy needs to be further improved through patient education.

[Research progress in immunomodulation in orthodontic tooth movement]

In the process of orthodontic tooth movement, the secretion of cytokines by immune cells or cell-cell interaction affects the regulation of osteoclast and osteoblast differentiation. Increasingly, studies have focused on the role in the immune system in orthodontic bone remodeling. Based on the biological role of different immune cells or cytokines, this article briefly presents the research progress of immunomodulation in orthodontic tooth movement and future perspective, hopefully providing a deeper and more comprehensive understanding of the biological mechanism in orthodontic tooth movement.

Coupling of Surface Plasmon Modes and Refractive Index Sensitivity of Hollow Silver Nanoprism

Localized surface plasmon (LSP) modes depend strongly on the morphology of nanoparticle and the surrounding dielectric medium. The hollow nanostructure provides a new way to modulate the surface plasmon modes due to the additional cavity surface. In this work, we study systematically the multipolar surface plasmon modes of hollow silver nanoprism (HSN) by simulation of electron energy loss spectroscopy (EELS) spectra based on the boundary element method (BEM). Herein the effects of the cavity size and position are taken into account. The LSP modes of HSNs are compared with those of perfect silver nanoprism (SN). The red-shift behaviors of multipolar modes can be found as increasing the cavity size. Modes A and C have similar red-shift tendency and obey the plasmon ruler equation, which can be explained by dipole-dipole coupling mode. Meanwhile, the degenerate modes will be split by changing the cavity position, and opposite shift tendencies of split degenerate states are observed. These are caused by different coupling nature of degenerate modes. Moreover, high refractive index sensitivity (RIS) can be obtained for HSN by changing the cavity size and position.

[Allergic rhinitis management:environment control and patient education]

Objective:To observe the auxiliary curative effect of combined clostridium and bifidobacterium capsules, live (also called Changlekang) in the treatment of allergic rhinitis by comparing IL-10, transforming growth factor-β1(TGF-β1), the quality of life score and symptom score before and after oral Changlekang.Method:Twenty qualified patients in the study group and 20 qualified patients in the control group were enrolled.The study group was given changlekang, desloratadine citrate disodium tablets and mometasone furoate nasal spray for treatment. After 2 weeks of treatment, Changlekang was still given for maintenance therapy for 6 weeks, and no other two kinds of drugs. The control group was given the desloratadine citrate disodium tablets and mometasone furoate nasal spray for 2 weeks and then quited the clinical trials. The changes of symptom score, quality of life score, serum IL-10, serum TGF-β1 would be statistically analyzed during the treatment.Result:①Before treatment, serum TGF-β1 and IL-10 of normal group was significantly different from the study group and the control group (P< 0.001), and the study group and the control group's were significantly lower than the normal group.②With the increase of treatment time, serum IL-10, TGF-β1 levels of patients in the study group increased gradually. Four point method ocular symptoms score, VAS ocular symptoms score and total score of RQLQ decreased gradually; ③patients in the control group after 2 weeks'treatment, serum IL-10, TGF-β1 was higher than that before treatment (P< 0.001), at the same time all symptom scores, total score of RQLQ were lower than those before treatment (P< 0.001). ④After 2 weeks' treatment, patients in the study group, the serum IL-10 is higher than that of control group (P< 0.001); ⑤Before treatment serum IL-10, TGF-β1 of AR patients might have little correlation with symptom scores, total score of RQLQ on linear (P> 0.05).Conclusion:①serum IL-10, TGF-β1 levels of AR patients may be lower thannormal, and IL-10, TGF-β1 may be involved in the pathogenesis of AR. ②Changlekang may increase the production of serum IL-10, TGF-β1 in AR patients. ③AR patients with desloratadine citrate and mometasone furoate nasal spray treatment combined with Canglekang may promote higher serum IL-10 production than conventional two combination therapy, but there is no more significant improvement in symptoms score and quality of life score. ④Changlekang may improve ocular symptoms and the quality of life in AR patients. ⑤Before treatment serum IL-10, TGF-β1 of AR patients may have little correlation with symptom scores, total score of RQLQ, as a result the level of serum IL-10 and TGF-β1 can not be used to evaluate the severity of AR for the time being.

[Analysis on the spatial-temporal characteristics of hand-foot-mouth disease in Shaanxi province, 2009-2013]

Objective: To study the spatial-temporal dynamical features of hand-foot-mouth disease (HFMD) in Shaanxi Province, so as to provide evidence for the development of relative prevention and control programs on HFMD. Methods: Surveillance data of HFMD was collected from the China Information System for Diseases Control and Prevention from 2009 to 2013. Related data on population and gross domestic product (GDP) was obtained from Shaanxi Statistical Yearbook. Statistical tools as R3.4.1, ArcGIS 10.2 and SaTScan 9.2 software were used to describe the spatial-temporal distribution of the disease. Power-law method on spatial-temporal-multicomponent model was used to analyze the spatial-temporal evolution of the HFMD epidemics in Shaanxi Province. Results: A total of 229 904 cases of HFMD were reported in Shaanxi Province from 2009 to 2013, with an average annual incidence as 122.50 per 100 000. Obvious seasonal characteristics were noticed, with 71.71% of the total cases identified between April and July. Counties with high incidence were mainly distributed in the mid-and east parts of Guanzhong area. Through temporal and spatial scan statistics, we identified that ClassⅠ clustering area was fixed to the central and southeast regions of Shaanxi province which were around Xi'an City between 2009 and 2013, with the relative risk (RR) as 2.24, ranging from 2.18 to 3.08. Results from Power-law analysis showed that the continuous follow-up impact from the previous HFMD epidemics appeared strong in Tongguan, Pucheng districts of Weinan City and Weiyang district of Xi'an, with autoregressive components as 1.14, 0.97 and 0.89, respectively. The risk of HFMD seemed high in Huayin city, Changan and Yanta districts and with the endemic components as 5.08, 4.12 and 4.08, respectively. Impact of the epidemics on nearby districts was largely seen in Lianhu district of Xi'an, Wugong district of Xianyang and Gaoling district of Xi'an with epidemic components as 2.12, 2.08 and 1.77, respectively. The etiological constituents of HFMD were mainly Enterovirus 71 between 2009 and 2012, while HFMD was mainly caused by other entero-viruses, in 2013. Conclusion: Significant spatial-temporal heterogeneity of HFMD was seen in Shaanxi province, which called for specific strategies to be developed in the highly endemic areas.

[Analysis on the factors related to the immediate success rate of radiofrequency catheter ablation on patients with idiopathic right ventricular outflow tract ventricular arrhythmia]

Objective: To analyze the clinical characteristics of patients with idiopathic right ventricular outflow tract (RVOT) ventricular arrhythmias (VA) and factors related to the immediate success rate of radiofrequency ablation. Methods: Patients diagnosed as idiopathic RVOT arrhythmia in Fuwai Hospital from February 2009 to January 2013 were retrospectively screened. Patients with structural heart disease or inherited arrhythmia were excluded. All patients underwent endocardial electrophysiological study and radiofrequency catheter ablation. Baseline clinical and operation records were collected and analyzed. Immediate success rate was defined as no inducible ventricular arrhythmia by isoprinosine and electrophysiological induction at the end of ablation. The origins of idiopathic RVOT were classified as septal, anterior, posterior, free wall site, epicardial and RVOT-aorta root site. Results: A total of 468 patients were finally included, and the age was (40.4±13.3) years old and 60.5%(283/468) patients were female. Immediate radiofrequency success rate was 89.3%(418/468). Patients were divided into ablation success group (n=418) and ablation failure group (n=50). Percent of female patients and patients with interventricular septal origin was significantly higher in the ablation success group than in ablation failure group (261(62.4%) vs. 22 (44.0%) , P=0.01, and 233(55.7%) vs. 18(36.0%), P=0.005), while percent of patients with epicardial origin was significantly lower in the ablation success group than in ablation failure group (17(4.1%) vs. 11(22.0%), P<0.001). Immediate success rate was the highest for patients with the septal origin and the lowest for patients with epicardial origin (92.8%(233/251) vs. 60.7%(17/28), P<0.05). Multivariate analysis showed that the origin site of VAs was the most important independent factor related to the success rate of ablation. Compared with the septal origin patients, patients with RVOT-aorta root and epicardial origin VAs faced with 1.82-fold and 8.26-fold increased risk of failed ablation, respectively (OR=2.82, 95%CI 1.05-7.57, and OR=9.26, 95%CI 3.60-23.86). Sex category was not the independent risk factor for failed ablation(OR=1.76, 95%CI 0.93-3.33, P=0.08) . Conclusions: The immediate success rate of radiofrequency catheter ablation for idiopathic RVOT ventricular arrhythmia is relative high, however, immediate success rate of radiofrequency catheter ablation is relatively low for patients with epicardial and RVOT-aorta root origin arrhythmia and VAs origin is an independent risk factor of immediate ablation success rate.

Association of TUSC3 gene polymorphisms with non-syndromic mental retardation based on nuclear families in the Qinba mountain area of China

TUSC3 interacts with the protein phosphatase 1 and magnesium ion transport system, which plays an important role in learning and memory. Abnormal conditions of learning and memory are common clinical characteristics of mental retardation (MR). However, the association of TUSC3 genetic polymorphisms with MR remains unknown. A total of 456 DNA samples including 174 nuclear families containing MR were collected in the Qinba mountain area of China. The genotypes of eight tag single nucleotide polymorphisms of TUSC3 were evaluated with traditional genetic methods. Family-based association tests, transmission disequilibrium tests (TDTs), and haplotype relative risk (HRR) analyses were performed to investigate the association between genetic variants of the TUSC3 gene and MR. The genetic polymorphisms rs10093881, rs6530893, and rs6994908 were associated with MR (all P values <0.05) based upon the results of single-site TDT and HRR analyses. The haplotype block consisting of rs6530893 and rs6994908, harboring the sixth exon of TUSC3, was also associated with MR (all P values <0.05). This study demonstrated an association between genetic polymorphisms of the TUSC3 gene and MR in the Qinba mountain area, the sixth exon of which might contribute to the risk of MR. However, further studies are needed on the causal mechanisms in this association.

No association between FGD1 gene polymorphisms and intellectual developmental disability in the Qinba mountain area

FGD1 encoding a guanine nucleotide exchange factor, specifically activates Rho GTPase cell division cycle 42 (Cdc42). Dysfunction of FGD1 causes Aarskog-Scott syndrome (MIM #305400), an X-linked disorder that may affect bone and intellectual development. However, the relationship between FGD1 and intellectual developmental disorders (IDD) remains unclear. The purpose of this study was to investigate the genetic association between the FGD1 polymorphism and IDD. Working with families from the Qinba mountain area where the occurrence of IDD is higher than the average in China, we analyzed 456 samples from 130 nuclear families, effectively controlling for stratification and environmental factors. Five SNP loci (rs2230265, rs7881608, rs2239809, rs6614244, and rs2284710) were selected that were well distributed within the FGD1 gene. Genotyping was performed through single-strand conformation polymorphism and restriction fragment length polymorphism. The data were analyzed with transmission disequilibrium tests. In the Qinba mountain area, no significant association was observed between IDD and allele or genotype frequencies, or the haplotype of the 5 SNP loci of the FGD1 gene. The results indicate that FGD1 may not be a monogenetic X-linked factor in IDD. Further studies are required to investigate its role in intellectual development based on its specific interactions with Cdc42 or other partner proteins contributing to IDD.

Molecular cloning and characterization of the pseudorabies virus US1 gene

Using polymerase chain reaction, a 1050-bp sequence of the US1 gene was amplified from the pseudorabies virus (PRV) Becker strain genome; identification of the US1 gene was confirmed by further cloning and sequencing. Bioinformatics analysis indicated that the PRV US1 gene encodes a putative polypeptide with 349 amino acids. The encoded protein, designated PICP22, had a conserved Herpes_IE68 domain, which was found to be closely related with the herpes virus immediate early regulatory protein family and is highly conserved among the counterparts encoded by Herpes_IE68 genes. Multiple nucleic acid sequence and amino acid sequence alignments suggested that the product of PRV US1 has a relatively higher homology with ICP22-like proteins of genus Varicellovirus than with those of other genera of Alphaherpesvirinae. In addition, phylogenetic analysis showed that PRV US1 has a close evolutionary relationship with members of the genus Varicellovirus, especially Equid herpes virus 1 (EHV-1), EHV-4 and EHV-9. Antigen prediction indicated that several potential B-cell epitopes are located in PICP22. Also, subcellular localization analysis demonstrated that PICP22 is predominantly located in the cytoplasm, suggesting that it might function as a cytoplasmic-targeted protein.

Prognostic significance of PUMA in pancreatic ductal adenocarcinoma

OBJECTIVES

To investigate retrospectively whether alterations of p53 upregulated mediator of apoptosis (PUMA) protein levels and somatic mutations of the PUMA gene are characteristic of pancreatic ductal adenocarcinoma (PDAC).

METHODS

Immunohistochemical analyses of PUMA were performed in pancreatic tumour tissue samples, and paired normal pancreatic tissue samples, from patients with PDAC. Apoptosis was detected using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling assay.

RESULTS

A total of 70 patients with PDAC had samples available; 49 cases (70.0%) had high PUMA protein levels. PUMA was not detected in paired normal tissue samples. Significantly higher levels of PUMA protein were detected in low-grade tumours (tumour -node-metastasis stages I and II), compared with higher grade (stage III) tumours. Of the PDAC cases, the mean apoptosis index value for PUMA-positive specimens was significantly higher than that for PUMA-negative specimens. Overall survival was significantly associated with PUMA immunoreactivity.

CONCLUSIONS

High levels of PUMA in PDAC tumour cells suggest that PUMA expression may play a role in pancreatic tumourigenesis.

Investigating the spatial-temporal variation of nitrogen cycling in an urban river in the North China Plain

Urban rivers are essential in retaining nutrients, but little is known about nitrogen cycling in these rivers in semiarid areas. We measured chemical and isotopic compositions of ammonium (NH4(+)-N) and nitrate (NO3(-)-N) to investigate spatial-temporal variation of nitrogen cycling in the Fuhe River in the North China Plain. Nitrogen pollution in the river was mainly induced by extra NH4(+)-N inputs which come from the discharges of urban sewage and effluents of wastewater treatment plants in upstream. NH4(+)-N obtained from decomposing organic matter of sediments can diffuse into the overlying water. Intense nitrification then occurs at the terrestrial-aquatic interface. Due to less vegetation in spring and autumn, loss of NH4(+)-N is mainly caused by nitrification. In contrast, significant NH4(+)-N is absorbed by plants in summer. NO3(-)-N generated from nitrification can be denitrified during the study period. The highest NO3(-)-N loss (about 86.3%) was observed in summer. The contribution of NO3(-)-N loss due to denitrification is 44.6%. The remaining 55.4% is due to plant uptake. The results suggested that nitrogen cycling in the river is related to temperature and dry-wet cycles. And vegetation restoration along the river could benefit the incremental improvements to the aquatic ecosystem.

[MRI analysis of non-traumatic multiple vertebral collapse in aged people]

OBJECTIVE

To evaluate the MRI in the differential diagnosis of acute non-traumatic vertebral collapse.

METHODS

Sixty-eight cases were retrospected. All cases were studied with sagittal T1-weighted MR images, T2-weighted MR images, gadolinium-enhanced T1-weighted MR images, and axial T1-weighted MR images. Twelve of 68 were performed extra coronal T1-weighted MR images and 22 with additional axial gadolinium-enhanced T1-weighted images.

RESULTS

The causes of vertebral collapse were: (1) osteoporosis (n = 31), their images showed retropulsion of bony fragments of collapsed vertebral body which kept the normal signal into the spinal canal as the distinctive sign; (2) metastatic tumor (n = 30), their images showed destructions of pedicles of vertebral and epidural mass as the distinctive sign, and hyperintense or mixed hyperintense signal on T2WI and enhanced T1WI of compressed vertebrae; and (3) multiple myeloma (n = 7), their images showed long T1WI and long T2WI, without destruction of pedicle and epidural mass in compressed vertebrae.

CONCLUSION

MRI is useful to the differentiations of the non-traumatic vertebral collapse in aged.

Effects of salvianolic acid A on oxygen radicals released by rat neutrophils and on neutrophil function

Salvianolic acid A (Sai A) has demonstrated potent antioxidant activity in previous studies. In the present study, the effects of Sai A on oxygen radicals released by rat neutrophils and on neutrophil function were investigated. Superoxide anion assayed by the nitroblue tetrazolium test and hydrogen peroxide detected with redox of scopoletin were scavenged concentration dependently by Sai A in n-formyl-methionyl-leucylphenylalanine (fMLP)- and phorbol myristate acetate (PMA)-stimulated rat neutrophils. Hydroxyl radicals generated in PMA-stimulated neutrophils, measured by HPLC, also were scavenged significantly by Sai A, whereas Sai A showed no significant effects on chemotaxis toward fMLP and phagocytosis of latex beads by rat neutrophils. In addition, the intracellular free calcium and cyclic nucleotide levels of neutrophils, when stimulated by fMLP, were not affected by Sai A. These results suggest that Sai A could significantly scavenge oxygen radicals released by activated neutrophils without affecting their functional ability.

[Effects of 2-(p-dimethylaminostyryl) pyridine methycholide (DSPM-Ci) on ECG, left atrium contractivity and on papillary muscle action potentials]

The effects of DSPM-Cl on ECG in rats, on the dose-effect curve in guinea pig left atria and on the fast action potential (AP), high-K+ depolarized slow action potential (SAP) in guinea pigs papillary muscle were examined electrophysiologically. DSPM-Cl (2 mg.kg-1) showed significant nagative frequency, negative conductivity effect, and prolonged the PP and PR interval. DSPM-CI (30-50 mumol.L-1) was shown to inhibit left atria contractility and shift the concentration-response curve of Iso and CaCl2 to the right with PD2' values of 4.60 and 4.13, respectively. In addition, DSPM-Cl was found to prolong the duration of action potential 90 (APD90) and effective refractory period (ERP), and decrease the maximal upstroke velocity (Vmax) in K(+)-depolarized guinea pigs papillary muscles. The results suggest that, like verpamil, DSPM-Cl might be a calcium antagonist.

Effect of schisanhenol on function and surface shape of rat neutrophils

AIM

To study the regulatory effect of Schisanhenol (Sal) on function of rat neutrophils.

RESULTS

It was found that Sal (1, 10, and 100 mumol.L(-1)) inhibited neutrophil activities such as chemotaxis, phagocytosis, and superoxide anion production in vitro in a concentration-dependent manner. Changes of surface morphology of neutrophils were observed by scanning electron microscopy, showing that the ruffles and pseudopods on neutrophil surface increased under the stimulation by chemotactic peptide N-formyl-Met-Leu-Phe (FMLP). When pretreated with Sal 100 mumol.L(-1), the ruffles and pseudopods disappeared and the surface became smooth. Sal 100 mumol.L(-1) decreased the cytosolic calcium concentration of neutrophils and increased the intracellular cAMP level.

CONCLUSION

These data suggested that Sal could inhibit the function of rat neutrophils through affecting the cytosolic free calcium and cAMP level besides its anti-oxidant activity.

Effects of nicotinamide on cardiac contraction force and slow inward current

The effects of nicotinamide (Nic) on cardiac contraction force and on slow inward current (Isi) in guinea pigs were studied with atrial strips and voltage clamp techniques. Verapamil (Ver), MnCl2, nifedipine (Nif), and propranolol (Pro) depressed markedly the positive inotropic effect induced by Nic in a noncompetitive manner. The pD2 values of Ver, MnCl2, Nif, and Pro were 6.19, 3.41, 5.00, and 6.43, respectively. The action of Nic was reduced by a low Ca2+ Tyrode solution and disappeared in a Ca(2+)-free solution. Nic 33 mmol.L-1 elevated the Isi from 6.5 +/- 1.3 microA to 10.3 +/- 2.2 microA. The results suggest that Nic promotes the Ca2+ influx and its site of action is different from that of both Pro and the calcium antagonists.

[Cardioprotection of 2-[p-(dimethylamino)styryl]pyridine methiodide against ischemic damage and myocardial lipid peroxidation]

Mice were injected ip DSPM 1 or 3 mg.kg-1 3 h prior to a subcutaneous injection of isoproterenol (Iso) 20 mg.kg-1 once daily for 2 d. Iso induced reductions of Se-glutathione peroxidase (Se-GSH-PX), superoxide dismutase (SOD) activities, and an increase of malondialdehyde (MDA) content in myocardium. DSPM 1 or 3 mg.kg-1 significantly abated reduction of Se-GSH-PX activity and decreased MDA production and DSPM 3 mg.kg-1 also abated reduction of SOD activity in the hearts from Iso-treated mice. The changes of above indices were in accordance with those of myocardial ultrastructure and creatine phosphokinase (CPK) concentration in serum. The results indicate that DSPM has a protective effect on myocardial ischemic injury probably by inhibiting oxygen free radicals and subsequent lipid peroxidation.

Improved myocardial protection by antegrade perfusion in combination with coronary sinus occlusion in the presence of left anterior descending artery obstruction

The present study was undertaken to evaluate the improved protection of antegrade aortic root perfusion combined with intermittent coronary sinus occlusion (APCSO) for the 1-hour ischemic myocardium in the presence of left anterior descending artery occlusion, 12 dogs were divided into 2 groups: anteperfusion (AP) alone (n = 6) and APCSO (n = 6). The experimental results showed that APCSO provided a better cardioplegic distribution and a lower hypothermia (15.6 degrees C versus 17.2 degrees C) in the occluded LAD region, compared with AP. After ischemia, cardiac index and left ventricular stroke index recovered excellently in APCSO (128% to 141% and 115% to 158% of preischemic values, respectively), and much worse in AP (69% to 82% and 53% to 73% of preischemic values, respectively). Our study has confirmed that APCSO is superior to AP in myocardial protection in the presence of coronary artery occlusion.

[Anti-lipid peroxidation and protective effects of phenytoin sodium on ischemic myocardium of mice]

Isoproterenol (Iso, 20 mg.kg-1 x d-1 x 2 d) induced widespread and severe myocardial damages at ultrastructural level, decreased the myocardial Se-glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activities, increased the serum creatine phosphokinase (CPK) concentration and myocardial malondialdehyde (MDA) content. Phenytoin sodium (Phe) 15 or 30 mg.kg-1 ip pretreatment diminished the CPK release and MDA production, protected the Se-GSH-Px activity in the Iso-induced damage of mouse heart. The pretreatment with 30 mg.kg-1 abated the reduction of SOD activity. However, Phe 15 mg.kg-1 did not show such an effect. Phe (15 or 30 mg.kg-1) reduced the ultrastructural cardiotoxicity of Iso, and the membrane structure of ischemic myocardium was protected. The protective effects of verapamil pretreatment 3 mg.kg-1 ip were weaker than those of Phe on ultrastructural changes, but biochemical changes were similar to those of Phe. The results suggested that Phe possessed anti-lipid peroxidation and protective effects on ischemic myocardium.

[Effects of 2-[p-(dimethylamino)styryl] pyridine methiodide on conduction and refractory period of atrioventricular node in rat]

The effects of 2-[p-(dimethylamino)styryl] pyridine methiodide (DSPM) on rat ECG and HBE were studied. The P-R and R-R intervals of ECG were lengthened 40.3% and 115.4% respectively, after iv injection of DSPM 2 mg/kg. DSPM (1.5 and 2 mg/kg) affected the A-H interval in a dose-dependent manner with no change in the H-V interval of HBE. DSPM 0.5 mumol/L lengthened the A-H interval of isolated perfused hearts in frequency-dependent manner, with greater prolongation at higher frequency. The effect of verapamil on the A-H interval was less than that of DSPM. Propranolol had no effect on the frequency-dependent delay of atrioventricular node. DSPM 0.5 mumol/L lengthened the functional and effective refractory periods of atrioventricular node by 26.8% and 31% respectively. These phenomena support that DSPM may be a calcium antagonist.

[Effects of 2-[p-(dimethylamino)styryl]pyridine methiodide on contractive response of rabbit aortic strips]

The effects of 2-[p-(dimethylamino) styryl]pyridine methiodide (DSPM) on rabbit aortic contraction induced by high K+, norepinephrine (NE) and Ca2+ were studied. On rabbit thoracic aortic strips, DSPM inhibited the contraction induced by KCl and NE in normal modified Tyrode's solution. DSPM shifted the dose-response relationships of KCl and NE to the right, and depressed their maximal responses; the pD'2 values were 5.09 and 5.16 respectively. After the strip had been exposed to Ca2(+)-free Tyrode's solution for 2 h, the NE-induced responses were further inhibited by DSPM, whereas the KCl-induced responses were not significantly affected. On depolarized vessels, the dose-response relationships of CaCl2 were also shifted to the right and their maximal responses were also depressed by DSPM, suggesting that DSPM is a non-competitive antagonist. The pD'2 value was 6.86. These results suggest that DSPM is a calcium antagonist. It not only inhibited the influx of extracellular calcium, but also has an inhibitory effect on the release of sequestered calcium in the rabbit aortic smooth muscle.

[Effects of 2-[p-(dimethylamino) styryl] pyridine methiodide on action potentials of depolarized papillary muscle cells of guinea pig]

Effects of 2-[p-(dimethylamino) styryl] pyridine methiodide (DSPM), nifedipine (Nif), CaCl2 and isoprenaline (Iso) on action potentials (AP) of guinea pig papillary muscle cells depolarized by high K+ (15.4 mmol/L) were studied by microelectrode technique. DSPM 45 mumols/L decreased the Vmaxf and Vmaxs of phasee O of the AP by 14 and 26%, respectively. APD90 was lengthened by 7%, amplitude of action potentials (APA) was decreased by 3%. The effects of CaCl2 on Vmaxs of phase 0 of the AP of depolarized papillary muscle cells were abolished by DSPM 45 mumols/L, but the effects of Iso were not antagonized. Effects of DSPM on Vmaxs of the AP of depolarized papillary muscle cells and the influence of DSPM to the action of CaCl2 and Iso were similar to those of Nif. It further suggests that DSPM may be a calcium antagonist.

[Effects of 2[p-(dimethylamino)styryl]pyridine methiodide on action potentials of sinoatrial node cells of rabbits]

The effects of 2[p-(dimethyl-amino)styryl]pyridine methiodide (DSPM) on the action potential of dominant pacemaker cells in sinoatrial nodes of rabbits were studied by microelectrode technique. DSPM 45 mumol/L decreased the slope of phase 4, the maximum rate of rise of the action potential and the action potential amplitude by 54% (P less than 0.01), 27% (P less than 0.05) and 13% (P less than 0.05), respectively, and increased the spontaneous sinus cycle length and action potential duration at 90% repolarization by 62 and 26% (P less than 0.01), respectively. These effects of DSPM were similar to that of nifedipine 3.9 mumol/L. The positive chronotropic effect of nicotinamide 33 mmol/L was completedly blocked by DSPM 45 mumol/L while that of isoprenaline 0.11 mumol/L was partially blocked by DSPM 45 mumol/L. The results suggest that DSPM may be a Ca2+ antagonist.

[Effects of 2[p-(dimethylamino)styryl] pyridine methiodide on mouse and rabbit]

The effects of 2[p-(dimethylamino)styryl] pyridine methiodide on mouse and rabbit ECG and on the contraction of isolated rabbit atrial muscles were studied. DSPM produced long-lasting bradycardia and A-V block in a dose-dependent manner, but did not effect intraventricular conduction. DSPM antagonized the positive chronotropic and dromotropic effects of isoprenaline (Iso) in vivo, and antagonized the inotropic effects of Iso and CaCl2 non-competitively in vitro. The pD'2 were 4.49 and 4.52, respectively. It is suggested that DSPM may be a Ca2+ antagonist.