Novel AT2R agonist, β-Pro7Ang III, is cardio- and vaso-protective in diabetic spontaneously hypertensive rats

Stimulation of the angiotensin II type 2 receptor (AT2R) evokes protective effects in various cardiovascular diseases. Thus, this study aimed to investigate the effects of AT2R stimulation, with or without AT1R blockade, in a model of hypertension with concomitant type 1 diabetes mellitus (T1DM). Spontaneously hypertensive rats (SHRs) were given either citrate or a single dose of streptozotocin (STZ; 55 mg/kg, i.p.) to induce diabetes. After 4 weeks of diabetes, animals were administered either a vehicle (saline), AT2R agonist, β-Pro7Ang III (0.1 mg/kg/day via osmotic mini-pump), AT1R blocker, candesartan (2 mg/kg/day via drinking water), or a combination of both for a further 8 weeks. β-Pro7Ang III treatment had no effect on blood pressure, but attenuated the significant increase in cardiac interstitial collagen and protein expression of fibrotic and inflammatory markers, and superoxide levels that was evident in diabetic SHRs. These effects were not observed with candesartan, despite its blood pressure lowering effects. Although β-Pro7Ang III had no effect on aortic fibrosis, it significantly attenuated MCP-1 protein expression and superoxide levels when compared to both the non-diabetic and diabetic SHRs, to a similar extent as candesartan. In both the heart and vasculature, the effects of β-Pro7Ang III in combination with candesartan were similar to those of β-Pro7Ang III alone, and superior to candesartan alone. It was concluded that in hypertension with concomitant diabetes, AT2R stimulation with a novel ligand alone, or in combination with AT1R blockade, improved the cardiac and vascular structural changes that were strongly associated with inflammation and oxidative stress, independent of blood pressure regulation.

[Clinical efficacy of bulleyaconitine A combined with gabapentin on postherpetic neuralgia]

Objective: To investigate the analgesic efficacy and safety of state-dependent sodium channel blocker-bulleyaconitine combined with calcium channel blocker-gabapentin on postherpetic neuralgia (PHN). Methods: A double-blind, randomized, placebo-controlled, parallel-group, multi-center study involving Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Qinghai Provincial People's Hospital, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine Affiliated to Shanghai University of Traditional Chinese Medicine, the Second Affiliated Hospital of Kunming Medical University was performed from September 2018 to December 2019. A total of 75 PHN patients were randomly divided into the experiment group (n=41) and the control group (n=34). On the basis of first-line treatment with gabapentin, the experiment group was given bulleyaconitine A tablets, while the control group was given placebo. The primary outcome was a 50% improvement in the visual analogue scale (VAS), and the effective rate of achieving the primary outcome between the two groups was compared; the Cox regression model was used to analyze the impact of related factors on the disease outcome. Secondary outcomes including scores of pain scales (ID-pain, DN4), Patient Health Questionnaire (PHQ-9), 7-item Generalized Anxiety Disorder (GAD-7) at 1, 2, 3, 4, 8, 12 weeks after treatment were applied to evaluate the efficacy and safety of the combination of bulleyaconitine A tablets with first-line drug in the treatment of PHN. Results: The effective rate was 68.3% (28/41) and the time reached the primary outcome was 28 (7, 84) days in the experiment group, while in the control group, the effective rate was 52.9% (18/34) and the time reached the primary outcome was 56 (14, 84) days. Cox regression analysis indicated that the grouping factor of oral bulleyaconitine A tablets was an independent factor for improving the outcome of PHN (HR=2.063, 95%CI: 1.059-4.018, P<0.05), and the probability of the experiment group reaching the primary outcome was 2.063 times that of the control group (P<0.05). Meanwhile, the outcome probability of the long disease course group (>6 months) was only 0.201 times that of the short disease course group (<6 months) (HR=0.201, 95%CI: 0.073-0.551, P<0.05). There was no statistically significant difference in the trend of VAS between the two groups (P>0.05). The scores of ID-pain, DN4, PHQ-9, and GAD-7 of the two groups were significantly improved compared with those before enrollment (P<0.05), but the differences between the two groups were not statistically significant (all P>0.05). Conclusion: Bulleyaconitine A tablet can promote the therapeutic efficacy of gabapentin, and improve the outcome of PHN in a short period of 3 months.

Antibiotic-chemoattractants enhance neutrophil clearance of Staphylococcus aureus

The pathogen Staphylococcus aureus can readily develop antibiotic resistance and evade the human immune system, which is associated with reduced levels of neutrophil recruitment. Here, we present a class of antibacterial peptides with potential to act both as antibiotics and as neutrophil chemoattractants. The compounds, which we term 'antibiotic-chemoattractants', consist of a formylated peptide (known to act as chemoattractant for neutrophil recruitment) that is covalently linked to the antibiotic vancomycin (known to bind to the bacterial cell wall). We use a combination of in vitro assays, cellular assays, infection-on-a-chip and in vivo mouse models to show that the compounds improve the recruitment, engulfment and killing of S. aureus by neutrophils. Furthermore, optimizing the formyl peptide sequence can enhance neutrophil activity through differential activation of formyl peptide receptors. Thus, we propose antibiotic-chemoattractants as an alternate approach for antibiotic development.

Abstract P405: Cardioprotective Actions Of Nitroxyl Donor Angeli's Salt Are Preserved In The Diabetic Heart And Vasculature In The Face Of Nitric Oxide Resistance

Introduction: The risk of fatal cardiovascular events is increased in patients with type 2 diabetes mellitus (T2DM). A major contributor to poor prognosis is impaired nitric oxide (NO•) signalling at the level of tissue responsiveness, termed NO• resistance. Nitroxyl (HNO) induces positive inotropic and lusitropic effects in healthy and failing hearts.

Hypothesis: We hypothesised that in a rodent model, T2DM will promote, and HNO will circumvent, NO• resistance in the myocardium and coronary vasculature.

Methods: At 8 weeks of age, male Sprague-Dawley rats commenced a high-fat diet. After two weeks, the rats received low-dose streptozotocin (two intraperitoneal injections, 35 mg/kg, over two consecutive days), and continued the diet. Twelve weeks later, hearts were Langendorff-perfused to assess responses to the NO• donor diethylamine NONOate (DEA/NO) and the HNO donor Angeli’s salt.

Results: Inotropic, lusitropic and coronary vasodilator responses to DEA/NO were impaired, and responses to Angeli’s salt were preserved or enhanced, in T2DM hearts compared with non-diabetic hearts.

Conclusions: This is the first evidence that inotropic and lusitropic responses are preserved, and NO• resistance in the coronary vasculature is circumvented, by the HNO donor Angeli’s salt in T2DM. These findings highlight the cardiovascular therapeutic potential of HNO donors, especially in cardiac emergencies such as acute ischaemia or heart failure.

Figure 1. Dose-response curves and maximal responses to DEA/NO or Angeli's salt in diabetic or non-diabetic hearts. (A-C) LV+dP/dt, (D-F) LV-dP/dt and (G-I) coronary flow rate. Data expressed as change from baseline (denoted by Δ), mean ± SEM. Data analysed by two-way RM ANOVA with Sidak's post-hoc test. *P<0.05 vs. non-diabetic. LV, left ventricular; LV+dP/dt, maximal rate of rise in LV pressure; LV-dP/dt, maximal rate of fall in LV pressure.

[Effect of esmolol in septic shock patients with tachycardia: a randomized clinical trial]

Objective: To investigate the effect of esmolol in septic shock patients with tachycardia. Methods: A prospective randomized controlled trial was conducted. Screening septic shock patients that admitted to Department of General Intensive Care Unit of the First Affiliated Hospital of Zhengzhou University from June 2016 to August 2017. After 24 h resuscitation therapy, 100 cases of septic shock patients with tachycardia (heart rate>100 bpm) were divided into esmolol group (n=50) and control group (n=50) with random number table. Patients in esmolol group accepted standard treatment plus esmolol injection with an initial dose of 25 mg/h. Heart rate target is 80 to 100 bpm. Patients in esmolol group continued to use esmolol for 7 days or to the day the patient left the ICU when the heart rate didn't achieve the target. Patients in control group were given standard treatment. Primary outcome was 28 d mortality. Secondary outcomes included heart rate, norepinephrine dosages, lactate level, inflammatory markers in per day during the trial; acute physiology and chronic health evaluation (APACHE Ⅱ) and sequential organ failure assessment (SOFA) on day 1, 3, 5, 7; length of hospital stay, length of mechanical ventilation, medication time of vasoactive agent. The data were compared with t test or rank sum test between the two groups. Results: The 28 d mortality of esmolol group and control group was 62%, 68%, respectively(χ(2)=0.529, P=0.529). Logistic regression analysis showed that primary heart rate (increase of 10 bpm, OR=1.568, 95%CI: 1.039-1.238, P=0.027), primary APACHEⅡ (OR=1.134, 95%CI: 1.026-1.239, P=0.005), integral heart rate (per 10 bpm, OR=2.207, 95%CI: 1.400-3.479, P=0.001) were independent risk factors for 28 d mortality. Compared with control group, the esmolol group had a lower heart rate on day 1-7; but over all, there was no statistically significant difference in heart rate between the two groups (P>0.05). There was no significant difference in total does of norepinephrine, lactate level, inflammatory markers, APACHE Ⅱ, SOFA, length of hospital stay between the two groups (all P>0.05). Conclusion: Tachycardia significantly increases the risk of death in patients with septic shock, esmolol may decrease the mortality by controlling heart rate.

Novel single nucleotide polymorphisms of the bovine methyltransferase 3b gene and their association with meat quality traits in beef cattle

DNA methylation is essential for adipose deposition in mammals. We screened SNPs of the bovine DNA methyltransferase 3b (DNMT3b) gene in Snow Dragon beef, a commercial beef cattle population in China. Nine SNPs were found in the population and three of six novel SNPs were chosen for genotyping and analyzing a possible association with 16 meat quality traits. The frequencies of the alleles and genotypes of the three SNPs in Snow Dragon beef were similar to those in their terminal-paternal breed, Wagyu. Association analysis disclosed that SNP1 was not associated with any of the traits; SNP2 was significantly associated with lean meat color score and chuck short rib score, and SNP3 had a significant effect on dressing percentage and back-fat thickness in the beef population. The individuals with genotype GG for SNP2 had a 25.7% increase in lean meat color score and a 146% increase in chuck short rib score, compared with genotype AA. The cattle with genotype AG for SNP3 had 35.7 and 24% increases in dressing percentage and 28.8 and 29.2% increases in back-fat thickness, compared with genotypes GG and AA, respectively. Genotypic combination analysis revealed significant interactions between SNP1 and SNP2 and between SNP2 and SNP3 for the traits rib-eye area and live weight. We conclude that there is considerable evidence that DNMT3b is a determiner of beef quality traits.

The prevalence and spectrum of alpha and beta thalassaemia in Guangdong Province: implications for the future health burden and population screening

AIM

Thalassaemia is a good candidate disease for control by preventive genetic programmes in developing countries. Accurate population frequency data are needed for planning the control of thalassaemia in the high risk Guangdong Province of southern China.

METHODS

In total, 13397 consecutive samples from five geographical areas of Guangdong Province were analysed for both haematological and molecular parameters.

RESULTS

There was a high prevalence of carriers of alpha thalassaemia (8.53%), beta thalassaemia (2.54%), and both alpha and beta thalassaemia (0.26%). Overall, 11.07% of the population in this area were heterozygous carriers of alpha and beta thalassaemia. The mutation spectrum of alpha and beta thalassaemia and its constitution were fully described in this area. This study reports the true prevalence of silent alpha thalassaemia in the southern China population for the first time. In addition, two novel mutations that give rise to alpha thalassaemia, one deletion resulting in beta thalassaemia, and a rare deletion (--(THAI) allele) previously unreported in mainland China were detected. The frequency of the most common mutation, the Southeast Asian type of deletion (--(SEA), accounting for 48.54% of all alpha thalassaemias) was similar to the total of two alpha(+) thalassaemia deletions (-alpha(3.7) and -alpha(4.2), accounting for 47.49% of alpha thalassaemia).

CONCLUSION

Both alpha and beta thalassaemia are widely distributed in Guangdong Province of China. The knowledge gained in this study will enable the projected number of pregnancies at risk to be estimated and a screening strategy for control of thalassaemia to be designed in this area.

[Selection of high taxol content cell lines of Taxus yunnanensis Cheng et L. K. Fu]

OBJECTIVE

To select high taxol content cell lines of Taxus yunnanensis.

METHOD

Choosing different cell aggregates according to their color, texture, growth rate and secretion of colorful substances, culturing them separately, and further analyzing their growth rates and taxolcontents.

RESULT AND CONCLUSION

Cell lines with higher taxol contents could be obtained by careful selection; those with darker color, lower growth rate and higher ratio of dry cell weight vs. fresh cell weight usually has higher taxol contents.